JP4462061B2 - Electronically controlled hydraulic brake system - Google Patents

Description

  The present invention relates to a hydraulic brake system for a vehicle, and more particularly to a brake system of a type that controls the hydraulic pressure of a wheel cylinder by electronic control.

Electronic control that controls the hydraulic pressure of the wheel cylinder that activates the brake that suppresses the rotation of the wheel to a magnitude corresponding to the operation of the brake operation member of the driver by electronic control based on the hydraulic pressure of the power hydraulic pressure source Hydraulic brake systems are already well known.
In this type of electronically controlled hydraulic brake system, the electronic control unit is normally activated in response to an ON operation of the ignition switch. However, the brake operation may be performed when the ignition switch is OFF. In this case, since the electronic control unit does not operate, the wheel cylinder is operated based on the hydraulic pressure of the master cylinder. Moreover, not all of the wheel cylinders are actuated, and only some of them are often actuated.

Then, since the braking force may be insufficient for the vehicle as a whole, the following Patent Document 1 discloses an electronic control mainly using a computer if the brake operation member is operated even when the ignition switch is off. It has been proposed to allow the device to be activated. In this way, a sufficient braking force can be obtained, but the operational feeling of the brake operation member may be deteriorated. Since the operation of the brake operation member is performed to activate the brake, it is not sufficient to activate the electronic control device, and the brake is activated by the same brake operation that activates the electronic control device. It is necessary to be done. On the other hand, the electronic control device is not in a state where the hydraulic pressure of the wheel cylinder can be controlled immediately after being activated. It is necessary to perform various initial settings at the time of start-up, and it takes a certain time to control the hydraulic pressure, and it takes much more time to perform a self-diagnosis of a failure or the like. For this reason, the electronic control device controls the hydraulic pressure of the wheel cylinder from the middle of the brake operation that caused the electronic control device to start, and the effect of the sudden hydraulic pressure change is transmitted to the brake operation member and sent to the driver. It makes you feel uncomfortable.
For example, in Patent Document 2 below, when the hydraulic pressure of the wheel cylinder is controlled based on the hydraulic pressure of the power hydraulic pressure source, the communication between the master cylinder and the wheel cylinder is blocked by the master cylinder cutoff valve. The normally closed electromagnetic on-off valve allows the brake fluid to flow out from the stroke simulator portion configured as a part of the master cylinder to the reservoir, and the operation reaction force that gradually increases is applied to the brake pedal as the brake operation member. It is described that it is added. In this electronically controlled hydraulic brake system, when the electronic control device is activated in response to a brake operation, the master cylinder shut-off valve is shut off and the normally closed electromagnetic valve is started when hydraulic control of the wheel cylinder is started. Since the on-off valve is opened and the stroke simulator unit is put into a functional state, the brake pedal operation reaction force suddenly decreases, the stepping stroke increases rapidly, and the driver feels uncomfortable.

In order to solve the above-mentioned problem of incongruity, when the electronic control device is activated in response to a brake operation, it is possible to prevent the stroke simulator device such as the stroke simulator unit from being in a functional state as described in the following patent document. 3. However, if the stroke simulator device is kept in a non-functional state and the master cylinder shut-off valve is kept in a shut-off state, it is almost impossible for the brake fluid to flow out from the master cylinder. The operation stroke of the brake operation member is remarkably limited.
Also, in the electronically controlled hydraulic brake system, when the brake operation is performed in the direction in which the brake of the brake operation member is applied, the brake release operation is performed halfway and the brake operation is performed again. The stroke of the second braking operation may be significantly reduced. If the same operation is repeated, the stroke becomes even smaller. When the brake release operation is performed, the master cylinder often allows brake fluid to flow from the reservoir to the pressurization chamber. In such a case, if the above operation is performed, the master cylinder pressurization chamber In other words, the brake fluid may flow into the reservoir, reducing the stroke of the braking operation again. In such a situation, the electronically controlled hydraulic brake system includes a brake operation corresponding activation part, that is, a part that activates the electronic control device according to the brake operation operation of the brake operation member, and the brake operation corresponding activation part. This is particularly likely to occur when the electronic control device is activated by the above, but may occur in other cases.
JP-A-6-127317 JP-A-11-255107 JP 2004-268868 A

If the operation stroke of the brake operation member is limited to be small as described above, it may be impossible to start the drive source of the vehicle.
For example, when a start operation for starting an internal combustion engine as a drive source of a vehicle is performed, if the stop lamp is not lit, in other words, if the brake switch is not in an activated state, the internal combustion engine is started. It is done to prevent them from being let down. This is often the case when the start command device is a push button type. On the other hand, the brake switch is normally activated when the brake operation member is operated for more than the set operation stroke from the origin, and if the operation stroke of the brake operation member is limited to be small, the internal combustion engine Even if this starting operation is performed, the internal combustion engine is not started.
In view of the above circumstances, the present invention has been made with an object of obtaining an electronically controlled hydraulic brake system that does not make it impossible to start a vehicle drive source.

In order to solve the above problems, an electronically controlled hydraulic brake system according to the present invention includes: (a) a master cylinder that generates hydraulic pressure in response to an operation of a brake operation member; and (b) connected to the master cylinder. A plurality of wheel cylinders that operate brakes that respectively suppress rotation of a plurality of wheels of the vehicle; (c) a power hydraulic pressure source that generates hydraulic pressure by power; and (d) at least the master cylinder, wheel cylinder, and power fluid. A switching device provided between the pressure sources and switching at least the three communication states; and (e) a first switching device that communicates at least a part of the plurality of wheel cylinders with the master cylinder. and state, to restrict the outflow of brake fluid from the master cylinder by blocking that of the at least a portion of the master cylinder In state, and an electronic control unit which controls to the second state to control the hydraulic pressure of the power hydraulic fluid pressure said plurality of based on the wheel cylinder pressure source to the size corresponding to the operation the brake operating member, ( f) When a drive source activation command for activating a drive source for running the vehicle is performed, if the operation stroke of the brake operation member is equal to or greater than a set operation stroke, the drive source is permitted to be activated, A drive source activation restricting unit that does not allow activation when smaller than the set operation stroke; and (g) the drive source activation restricting unit does not allow activation of the drive source even though the drive source activation instruction is issued. In this case, the switching device is configured to include an outflow permission unit that controls the switching device to allow the brake fluid to flow out of the master cylinder.

In this electronically controlled hydraulic brake system, the drive source activation restricting section allows the drive source to be activated for some reason, even though the brake source operation command is issued while the brake operation operation of the brake operation member is performed. If not, the flow control unit controls the switching device to allow the brake fluid to flow out of the master cylinder. Therefore, the stroke of the brake operation operation of the brake operation member is increased, the drive source activation restricting unit is allowed to activate the drive source, and the drive source is activated.
In a vehicle equipped with an electronically controlled hydraulic brake system, it is avoided that the drive source cannot be started by restricting the operation stroke of the brake operation member to be small.

Aspects of the Invention

  In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

In each of the following items, the item (1) corresponds to claim 1, the item (3) in claim 2, the item (9) in claim 3, and the outflow allowable part in item (1), Claim 4 is limited to the one that allows the brake fluid to flow out of the master cylinder in accordance with the operation of the outflow allowance command operating member by the driver. A drive source activation impossible detection unit that detects that the activation of the drive source is not actually permitted by the unit, and the brake fluid is discharged from the master cylinder based on the detection of the drive source activation impossible by the drive source activation impossible detection unit. What is limited to what is allowed corresponds to claim 5. The feature described in (2) is added to any one of claims 1, 3 to 5, and the feature described in (4) is added to any one of claims 1 to 6. The above-mentioned feature is added to claim 7, the feature added to claim 7 in (5) is added to claim 8, and the feature added to claim 8 in (6) is added to claim 8. A feature obtained by adding the feature described in the item (7) to any one of the above-described claims 7 to 9 to the item 9 and the feature described in any one of the claims 7 to 10 in the item (8) Each of these corresponds to claim 11 respectively.

(1) a master cylinder that generates hydraulic pressure in response to an operation of a brake operation member;
A plurality of wheel cylinders that are connected to the master cylinder and actuate brakes that respectively suppress rotation of a plurality of wheels of the vehicle;
A power hydraulic pressure source that generates hydraulic pressure by power,
A switching device provided between at least the master cylinder, the wheel cylinder and the power hydraulic pressure source, and switching at least the three communication states;
The switching device includes a first state in which at least a part of the plurality of wheel cylinders communicates with the master cylinder, and at least a part of the switching apparatus is shut off from the master cylinder. With the brake fluid outflow restricted from the master cylinder, An electronic control unit that controls the hydraulic pressure of the plurality of wheel cylinders to a second state that controls the hydraulic pressure of the plurality of wheel cylinders according to the operation of the brake operation member based on the hydraulic pressure of the power hydraulic pressure source;
The vehicle For running When the drive source start command for starting the drive source is issued, if the operation stroke of the brake operation member is equal to or greater than the set operation stroke, the drive source is allowed to start, and if the drive source is less than the set operation stroke A drive source activation restricting section that does not allow activation, and
Despite the drive source start command being issued An outflow permission unit that controls the switching device to allow the brake fluid to flow out of the master cylinder when the drive source activation restriction unit does not allow the drive source to be activated;
An electronically controlled hydraulic brake system comprising:
The drive source activation command may be issued based on the operation of the drive source activation operation member by the driver, or may be a drive command from an automatic activation device that automatically activates the drive source. In addition, the outflow allowance unit can allow outflow according to the operation of the outflow allowance command operation member by the driver, but the drive source activation restricting unit detects that the drive source activation is not permitted. The drive source activation impossibility detection unit is preferably included, and the drive source activation impossibility detection unit detects, for example, drive source activation prohibition itself by the drive source activation restriction unit, or a drive source activation instruction and It is possible to detect both that the operation stroke of the brake operation member does not reach the set operation stroke, or it is possible to detect both the drive source activation command and the drive source inactivation. Furthermore, the outflow permission unit may be provided in the electronic control device, or may be provided separately from the electronic control device.
(2) The electronically controlled hydraulic brake according to (1), including a brake operation corresponding activation unit that activates the electronic control device in accordance with a brake operation operation that is an operation in a direction in which the brake of the brake operation member is applied. system.
Even if the drive source activation command is issued while the brake operation of the brake operation member is being performed, the situation where the drive source is not activated is, as mentioned above, the electronically controlled hydraulic brake system is activated corresponding to the brake operation. This mode is particularly effective because it is likely to occur when the electronic control device is activated by the brake operation corresponding activation unit.
The electronically controlled hydraulic brake system is usually provided with an activation unit that activates the electronic control device in response to an ON operation of a drive source activation device such as an ignition switch. In contrast, the brake operation corresponding activation part can also be referred to as a second activation part or a secondary activation part. However, the presence of the main activation part is not essential. For example, the electronic control device is activated by the brake operation corresponding activation unit regardless of the state of the drive source activation device, and automatically operates when a certain period of time has elapsed without being activated even if activated once. It is also possible to stop the operation.
(3) After the brake action operation that causes the electronic control device to be activated by the brake operation corresponding activation unit, the brake release operation is performed halfway and the brake action operation is performed again. When the drive source activation restricting unit does not allow the drive source to be activated when it is performed once or more times, the switching device is controlled so as to allow the brake fluid to flow out of the master cylinder. (2) The electronically controlled hydraulic brake system according to the item.
When the electronic control device is activated by a single brake operation operation of the brake operation member, the above operation (referred to as a pumping operation) is performed even if the drive source activation restriction unit does not allow the activation of the drive source. If this is performed once or twice or more times, the drive source activation restricting unit may not allow the drive source to be activated, and the feature of this section is to avoid the occurrence of the situation. It is valid.
(4) The switching device includes an outflow allowance valve device that allows the brake fluid to flow out of the master cylinder to other than the wheel cylinder, and the outflow allowance portion controls the brake from the master cylinder under the control of the outflow allowance valve device. The electronically controlled hydraulic brake system according to any one of (1) to (3), further including an outflow permissible valve device controller that allows outflow of liquid.
If the outflow allowance valve device is allowed to flow out of the brake fluid from the master cylinder to other than the wheel cylinder by the outflow allowance valve device control unit, the state in which the drive source activation restricting unit is not permitted to start the drive source is solved. The
(5) The electronically controlled hydraulic brake system includes a reservoir that stores brake fluid, the outflow allowable valve device includes a reservoir communication valve device that communicates the master cylinder with the reservoir, and the outflow allowable valve device control unit includes: An electronically controlled hydraulic brake according to (4), further comprising a reservoir communicating valve device controller that allows the brake fluid to flow from the master cylinder to the reservoir by communicating the master cylinder with the reservoir via the reservoir communicating valve device; system.
If the master cylinder communicates with the reservoir, the stroke of the brake operation operation of the brake operation member increases, and the state in which the activation of the drive source is not permitted by the drive source activation restriction unit is solved.
(6) The reservoir communication valve device is
A master cylinder shut-off valve that is provided between the master cylinder and at least one of the plurality of hole cylinders and is capable of switching between a communicating state for communicating the two and a shut-off state for shutting off;
A pressure reducing valve provided between the at least one wheel cylinder and the reservoir and capable of switching between a communication state in which the two communicate with each other and a shut-off state in which the both are disconnected;
The reservoir communication valve control unit includes:
When the drive source is not permitted to be activated by the drive source activation restricting unit, the master cylinder shut-off valve and the pressure reducing valve are both in communication, and the pressure is reduced to allow the brake fluid to flow from the master cylinder to the reservoir via both. The electronically controlled hydraulic brake system as set forth in (5), which includes a valve-routed flow allowance section.
According to the feature of this section, the reservoir communication valve device can be configured by the master cylinder shut-off valve and the pressure reducing valve provided for different purposes, and the cost of the device can be reduced as compared with the case where the dedicated reservoir communication valve device is provided. Reduction can be achieved.
The master cylinder shut-off valve may be provided between the master cylinder and one wheel cylinder, or may be provided between the master cylinder and two or more wheel cylinders. The pressure reducing valve may be provided between the reservoir and one wheel cylinder, or may be provided between the reservoir and two or more wheel cylinders.
(7) The switching device is As the outflow allowable valve device A non-functional state that includes a stroke simulator control valve and prevents the brake fluid from flowing out of the master cylinder to other than the plurality of wheel cylinders, and allows the brake operation member to increase the operation stroke of the brake operation member. Including a stroke simulator device that is in a functional state to apply a reaction force that increases with The outflow allowable valve device controller Is controlled by the stroke simulator control valve from the master cylinder. To the stroke simulator device The electronically controlled hydraulic brake system according to any one of (4) to (6), further including a stroke simulator control valve control unit that allows the brake fluid to flow out.
The stroke simulator device is provided between the stroke simulator and the master cylinder and communicates with the stroke simulator for increasing the hydraulic pressure of the master cylinder while containing the brake fluid discharged from the pressurizing chamber of the master cylinder. It is often considered to include a stroke simulator control valve that controls shutoff, but is not essential. For example, a stroke simulator unit configured as a part of the master cylinder and a stroke simulator control valve for controlling communication and blocking between the simulator chamber and the reservoir may be included. For example, as described in Patent Document 2, the stroke simulator section can be formed by forming a simulator chamber partitioned by a pressurizing chamber and a simulator piston in the housing of the master cylinder. If the brake fluid is allowed to flow out of the simulator chamber, the simulator piston can be moved, and even if the brake fluid does not flow out from the pressurizing chamber itself, the pressurizing piston can be operated and operated on the brake operation member. Strokes can be generated. Here, the outflow of brake fluid from the simulator chamber is also regarded as outflow from the master cylinder.
In any case, the stroke simulator device is disabled when the master cylinder and at least one of the plurality of wheel cylinders communicate with each other, but functions when the master cylinder is disconnected from all wheel cylinders. State.
If the stroke simulator device is in a functional state, the brake fluid can flow out from the master cylinder, so that the stroke of the brake operation increases. In the electronically controlled hydraulic brake system of this section, the stroke simulator control valve functions as an outflow allowable valve device.
(8) The spillable valve device includes a flow rate control device capable of controlling a flow rate of the brake fluid by controlling a supply current, and the spillable valve device controller is connected to the master cylinder via the spillable valve device. A flow rate gradual change control unit that gradually changes the flow rate of the brake fluid by the control of the flow rate control device in at least one of starting and stopping the outflow of the brake fluid (4) to (7) The electronically controlled hydraulic brake system according to any one of the items.
When the brake fluid flow from the master cylinder is started through the flow allowance valve device, if the flow rate of the brake fluid is gradually increased, a sudden stroke increase of the brake operating member is avoided, and the brake fluid from the master cylinder is prevented from flowing. If the flow rate of the brake fluid is gradually reduced when the outflow is stopped, a sudden stop of the brake operation member is avoided, and the brake operation feeling is improved.
The flow rate control device can also be used as an outflow allowable valve device. For example, the outflow allowable valve device includes a linear valve whose opening degree changes according to the supply current. According to the linear valve, it is possible to perform both allowance / non-acceptance of brake fluid outflow and flow control in the outflow permitted state.
(9) In the case where the outflow permission unit is not permitted to start the drive source by the drive source start restricting unit even though the brake operation member is operated with an operation force equal to or greater than a set operation force, The electronically controlled hydraulic brake system according to any one of (1) to (8), wherein control is performed to allow the brake fluid to flow out of the master cylinder.
By adopting the feature of this section, it is possible to allow the brake fluid to flow out from the master cylinder only when it is really necessary.
(10) The electronic control according to any one of (1) to (9), wherein the drive source activation restriction unit includes a brake operation detection device that detects that the brake operation member has been operated for a set operation stroke or more. Hydraulic brake system.
(11) The brake operation detecting device includes a brake switch that changes an output signal between a state where the brake operation member is operated from the original position for a set operation stroke or more and a state where the brake operation member is not operated for a set operation stroke or more. The electronically controlled hydraulic brake system according to the item.
(12) The master cylinder is
A housing and a pressure piston that cooperate with each other to form a pressure chamber;
A check device that allows the flow of brake fluid from the reservoir to the pressurizing chamber when retreating the pressurizing piston to increase the volume of the pressurizing chamber, and prevents reverse flow of the brake fluid when the pressurizing piston moves forward When
An electronically controlled hydraulic brake system according to any one of (1) to (11).
In the case where the master cylinder has the above configuration, the stroke of the brake action operation due to the pumping operation is likely to be reduced, and thus the present invention is particularly effective.
(13) The electronically controlled hydraulic brake system according to any one of (1) to (12), wherein the drive source activation operation member is a push button.
(14) The electronically controlled hydraulic brake system according to any one of (1) to (13), wherein the drive source is an internal combustion engine.
(15) Provided separately from the outflow allowance portion as the first outflow allowance portion, and from the master cylinder in accordance with the brake action operation that causes the electronic control device to be activated by the brake operation corresponding activation portion, The state according to any one of (2) to (14), further including a second outflow permission unit that controls the switching device in a state in which the outflow to at least one of the wheel cylinders is permitted.
Electronically controlled hydraulic brake system.
In the electronically controlled hydraulic brake system, even when the electronic control device is activated in response to the operation of the brake operation member, the state in which the hydraulic pressure of the wheel cylinder can be immediately controlled, that is, the switching device can be controlled normally. It does n’t mean. Therefore, in this system, when the electronic control device is started, first, the switching device is allowed to flow out from the master cylinder to at least one of the plurality of wheel cylinders by the second outflow allowance unit. It was. When there are a plurality of wheel cylinders connected to the master cylinder, if at least one of the wheel cylinders is prohibited from being shut off from the master cylinder, the function of the stroke simulator device is performed on the at least one wheel cylinder. The brake operation member can be operated. As described above, an appropriate operation stroke can be generated while satisfactorily avoiding the driver from feeling a sense of discomfort due to a sudden change in hydraulic pressure during the brake operation.
Thus, if the second outflow permitting part allows the brake fluid to flow out, it is possible to prevent a situation in which the drive source activation restricting part does not allow the drive source to be activated. But doing so is not essential. The operation stroke of the brake operation member by allowing the brake fluid to flow out by the second outflow permitting portion is set to be smaller than the operation stroke necessary for starting the drive source by the drive source start restricting portion. It is not impossible to do. In addition, even when the second drainage permitting portion allows the brake fluid to flow out, the drive source activation restricting portion normally prevents the drive source from being allowed to start, so that the drive source activation restriction is prevented. There is a case where the driving source is not permitted to be activated by the unit. For example, the pumping operation described in the above section (3) is an example, and the brake operation detection device such as the brake switch described in the above section (11) is out of the allowable range. Is another example.
As described above, even if the second spillable portion is provided, the drive source is activated by the action of the first spillable portion even if the drive source activation restricting portion does not allow the drive source to be activated for various reasons. Can be activated.
Of the plurality of wheel cylinders that do not allow the function of the stroke simulator device as described above, the electronic control unit can be in a state where it can perform hydraulic pressure control based on the hydraulic pressure of the power hydraulic pressure source. In this case, the hydraulic pressure control can be started immediately, and by doing so, a shortage of braking force as a whole vehicle can be avoided well.
In an electronically controlled hydraulic brake system, at the time of failure of an electronic control unit, at least some wheel cylinders are often made operable by the hydraulic pressure of the master cylinder. That is, usually, the master cylinder and at least some of the plurality of wheel cylinders are often kept in communication. In this case, when the electronic control device is activated by the brake operation corresponding activation unit, at least in the first half of the brake operation, control of the switching device by the electronic control device is prohibited. obtain. In this case, the second outflow permission unit can be referred to as a control prohibition unit.
(16) The electronic control device causes the switching device to shut off the at least one wheel cylinder from the master cylinder until the second outflow permission unit reaches an operation amount of the brake operation member reaching a second set operation amount. The electronically controlled hydraulic brake system according to (15), further including a shut-off prohibiting unit that prohibits the shut-off and permits the shut-off when the second set operation amount is exceeded.
The operation stroke of the brake operation member can be considered as the operation amount, and the operation force can be considered as the operation amount. In any case, if blocking of at least one wheel cylinder from the master cylinder is prohibited until the operation amount reaches the second set operation amount, the brake fluid from the master cylinder to at least one of the plurality of wheel cylinders The outflow is allowed, and an appropriate stroke operation of the brake operation member becomes possible.
If an operation stroke is employed as the operation amount, it is possible to particularly reliably ensure the operation stroke of the brake operation member when the electronic control device is activated by the brake operation corresponding activation unit.
If the wheel cylinder is allowed to be shut off from the master cylinder, the brake fluid outflow from the master cylinder is restricted and the operation stroke of the brake operation member is restricted, but the operation amount of the brake operation member is the second set operation amount. Even if the brake operation member is further operated thereafter, the amount is often small, and even if the operation stroke is limited, the driver does not feel uncomfortable.
After the wheel cylinder is allowed to be shut off from the master cylinder, it is desirable, but not essential, that the hydraulic pressure of the wheel cylinder be increased based on the hydraulic pressure of the power hydraulic pressure source as in the next section. When the electronic control unit is activated in response to the operation of the brake operation member, the vehicle is stopped and the braking force of the entire vehicle generated by the operation of the brake operation member is often small, and is cut off from the master cylinder. This is because it is normal that the hydraulic pressure of the wheel cylinder that has been made does not have to increase thereafter.
Note that the “second set operation amount” refers to the set operation stroke in the above item (1) as a “first set operation amount” and is referred to as a “second set operation amount” in contrast thereto. .
(17) The electronic control unit causes the switching device to switch the hydraulic pressure of the at least one wheel cylinder until the second outflow permission unit reaches an operation amount of the brake operation member reaching the second set operation amount. The electronic control hydraulic pressure according to (16), including a hydraulic pressure control prohibiting unit that prohibits the control of the power based on the hydraulic pressure of the power hydraulic pressure source and allows the hydraulic pressure source to exceed the second set operation amount. Brake system.
The control of the hydraulic pressure of the at least one wheel cylinder allowed by the hydraulic pressure control prohibition unit may be the same control as the control in the second state, but may be a different control. In the latter case, for example, the hydraulic pressure of at least one wheel cylinder is the same as the control in the second state in that the hydraulic pressure is set to correspond to the operation amount of the brake operation member. It is possible to make the control different in relation to the pressure.
If the hydraulic pressure of the at least one wheel cylinder is controlled based on the hydraulic pressure of the power hydraulic pressure source, the hydraulic pressure of the wheel cylinder functioning as a stroke simulator can be further increased after the function is finished. It becomes possible, and if necessary, it can be made higher than the hydraulic pressure of the master cylinder, and the braking force of the entire vehicle can be increased.
(18) When the hydraulic pressure of the at least one wheel cylinder is allowed to be controlled by the hydraulic pressure control prohibiting unit and then the operation amount of the brake operation member is reduced to a third setting operation amount, the electronic control An apparatus causes the switching device to shut off the at least one wheel cylinder from the master cylinder, and to control a hydraulic pressure of the at least one wheel cylinder based on a hydraulic pressure of the power hydraulic pressure source. A reprohibition department to ban again,
An asymptotic control unit that asymptotically approaches the actual hydraulic pressure of the wheel cylinder to the actual hydraulic pressure of the master cylinder before the re-inhibition by the re-inhibition unit;
The electronically controlled hydraulic brake system as described in (17).
When the second outflow permission unit includes the hydraulic pressure control prohibition unit, the driver may feel uncomfortable during the brake release operation. The reason is presumed as follows. When the brake release operation is performed quickly, the master cylinder pressure rapidly decreases accordingly, but the wheel cylinder pressure has a decrease delay due to the control delay, and the wheel cylinder and the master cylinder are communicated with each other. In this case, there is a hydraulic pressure difference between the two, and it is presumed that the influence of this hydraulic pressure difference is transmitted to the brake operation member and makes the driver feel uncomfortable. On the other hand, if the asymptotic control unit is provided, before the reinhibition by the reinhibition unit, that is, before the master cylinder and the wheel cylinder are communicated, the actual hydraulic pressure of the wheel cylinder is changed to the actual liquid pressure of the master cylinder. Since the pressure is gradually approached, it is possible to prevent the driver from feeling uncomfortable at the time of re-inhibition, or to reduce the uncomfortable feeling.
The asymptotic control unit may be configured to always make the actual hydraulic pressure of the hall cylinder asymptotic to the actual hydraulic pressure of the master cylinder while the operation amount of the brake operation member is reduced to the third set operation amount. It is also possible to adopt an aspect in which asymptotics are made only in the vicinity of the set operation amount.
Here, the “actual hydraulic pressure of the master cylinder” includes the master cylinder pressure when the operation amount of the brake operation member reaches the second set operation amount and at least one wheel cylinder is disconnected from the master cylinder, The master cylinder pressure is included.
(19) The switching device is
One or more master cylinder shut-off valves provided between the master cylinder and at least some of the plurality of wheel cylinders, and shut off communication between the at least some wheel cylinders and the master cylinder;
When at least one of the one or more master cylinder shut-off valves is open, the master cylinder shuts off from the master cylinder to a non-functional state that prevents the brake fluid from flowing out of the plurality of wheel cylinders. A stroke simulator device that is allowed to operate in a state in which the valve is closed, and is in a functional state in which a reaction force that increases with an increase in the operation stroke of the brake operation member is applied to the brake operation member;
And at least one of the one or more master cylinder shut-off valves is in a shut-off state when the second simulator is allowed to flow out brake fluid from the master cylinder. The electronically controlled hydraulic brake system according to item (15), including a shut-off prohibiting unit that prohibits the above.
If the second outflow permitting portion includes a shut-off prohibiting portion that prohibits the master cylinder shut-off valve from closing in a non-functional state of the stroke simulator device, the brake fluid outflow from the master cylinder (at least of the plurality of wheel cylinders) Can be tolerated).
(20) The switching device is provided between each of the plurality of wheel cylinders, the reservoir, and the power hydraulic pressure source, and at least allows the brake fluid to flow into the wheel cylinders from the power hydraulic pressure source. A hydraulic control valve device that is switchable between a state and a state that allows brake fluid to flow out from each wheel cylinder to the reservoir, wherein the second outflow permitting portion is configured such that the shut-off prohibiting portion is the one or more masters. The electronic control unit according to (19), further comprising a hydraulic pressure control prohibiting unit that prohibits control of the hydraulic pressure of the at least one wheel cylinder by the hydraulic pressure control valve device in a state in which at least one of the cylinder cutoff valves is prohibited from closing. Control hydraulic brake system.
The hydraulic pressure control valve device for each of the plurality of wheel cylinders can be constituted by, for example, one directional switching valve or a combination of two on-off valves. In any case, when the master cylinder shut-off valve is prohibited from being shut off by the shut-off prohibiting portion and the brake fluid is allowed to flow out from the master cylinder to the at least one wheel cylinder, the hydraulic control valve device also controls the hydraulic pressure. It is desirable that the operation is prohibited by the prohibition unit so that the brake fluid from the power hydraulic pressure source does not flow into the same wheel cylinder.
In addition to the above two states, it is desirable that the hydraulic control valve device be in a state in which, for example, inflow of brake fluid into the wheel cylinder and outflow from the wheel cylinder are not allowed.
(21) The second outflow allowing portion operates from the master cylinder, a wheel cylinder that operates a brake that suppresses rotation of the left wheel among the plurality of wheels, and a wheel that operates a brake that suppresses rotation of the right wheel. The electronically controlled hydraulic brake system according to any one of (15) to (20), wherein the brake fluid is allowed to flow out to any one of the cylinders.
For the other wheel cylinder, the hydraulic pressure can be controlled by the electronic control device from the beginning of the operation of the brake operation member, and the brake fluid flows from the master cylinder to the wheel cylinder for the left and right wheels. A large braking force can be obtained as compared with the case where it is allowed.
(22) The second outflow permitting portion permits outflow of brake fluid from the master cylinder to a wheel cylinder that operates a brake that suppresses rotation of a front wheel among the plurality of wheels. Item 15. The electronically controlled hydraulic brake system according to any one of Items (21) to (21).
In a mode in which this item is subordinate to item (21), either a wheel cylinder that operates a brake that suppresses rotation of the left front wheel or a wheel cylinder that operates a brake that suppresses rotation of the right front wheel is operated from the master cylinder. The brake fluid is allowed to flow out.
The characteristics of the items (21) and (22) are also applicable to the electronically controlled hydraulic brake system described in any of the items (23) to (34).
(23) a master cylinder that generates hydraulic pressure in response to an operation of the brake operation member;
A plurality of wheel cylinders that are connected to the master cylinder and actuate brakes that respectively suppress rotation of a plurality of wheels of the vehicle;
A power hydraulic pressure source that generates hydraulic pressure by power,
A reservoir for storing brake fluid;
1 is provided between the master cylinder and at least some of the plurality of wheel cylinders, and is switchable between a communication state in which at least some of the wheel cylinders communicate with the master cylinder and a cutoff state in which the master cylinder is cut off. Two or more master cylinder shut-off valves;
In the at least one communication state of the one or more master cylinder shut-off valves, the master cylinder shut-off valve is in a non-functional state that prevents the flow of brake fluid from the master cylinder to other than the plurality of wheel cylinders. A stroke simulator device that is in a functional state of allowing the reaction force to increase with an increase in the operation stroke of the brake operation member on the brake operation member while allowing the outflow in the closed state;
A state provided between each of the plurality of wheel cylinders and the power hydraulic pressure source and the reservoir, at least allowing a brake fluid to flow into each wheel cylinder from the power hydraulic pressure source; A plurality of hydraulic control valve devices each switchable to a state allowing the outflow of brake fluid to the reservoir;
The one or more master cylinder shut-off valves, the stroke simulator device, and the plurality of hydraulic pressure control valve devices are connected, and at least one of the one or more master cylinder shut-off valves is in the communication state and A first state in which the stroke simulator device is in the non-functional state; and the one or more master cylinder shut-off valves are in the shut-off state; the stroke simulator device is in the functional state; and the plurality of hydraulic pressure control valves An electronic control device capable of taking a second state of controlling the device to control the hydraulic pressure of the plurality of wheel cylinders to a magnitude corresponding to the operation amount of the brake operation member;
When a drive source start command for starting the drive source of the vehicle is issued, if the operation stroke of the brake operation member is equal to or greater than a set operation stroke, the drive source is allowed to start and is smaller than the set operation stroke Includes a drive source activation regulating unit that does not allow activation, and
A first outflow permitting unit that allows the brake fluid to flow out of the master cylinder when the drive source activation restricting unit does not permit the activation of the drive source;
Including electronically controlled hydraulic brake system.
According to the electronically controlled hydraulic brake system of this section, for example, the effect described in the effect of the invention can be obtained.
The first outflow permission unit may be provided in the electronic control device, or may be provided separately from the electronic control device.
(24) The electronic control unit may further take a third state in which the master cylinder shut-off valve is in the shut-off state and the stroke simulator device is in the non-functional state, and the first outflow permitting portion is the drive The electronic control unit according to item (23), wherein when the activation of the drive source is not permitted by the source activation restriction unit, the electronic control unit is controlled from the third state to a state in which the brake fluid is allowed to flow out from the master cylinder. Control hydraulic brake system.
For example, as in the electronically controlled hydraulic brake system described in Patent Document 3, when the electronic control device is activated in response to a brake operation, the master cylinder shut-off valve is shut off and the stroke simulator device is If this section is applied to a system in which the electronic control device takes the third state without being in the functional state, the drive source can be activated.
(25) A brake operation corresponding activation unit that activates the electronic control device in accordance with an operation of the brake operation member;
A non-functional state holding unit that keeps the stroke simulator device in the non-functional state during the operation of the brake operation member that caused the electronic control device start by the brake operation corresponding start unit,
Until the operation amount of the brake operation member that caused the electronic control device activation by the brake operation corresponding activation unit reaches a second setting operation amount different from the setting operation stroke as the first setting operation amount, Prohibiting switching of at least one master cylinder shut-off valve to at least one shut-off state and control of at least one of the plurality of hydraulic control valve devices corresponding to at least one master cylinder shut-off valve A second outflow permitting portion that allows outflow of brake fluid from the master cylinder to at least one of the at least some wheel cylinders;
When the operation amount of the brake operation member exceeds the second set operation amount, the electronic control device makes the master cylinder shut-off valve in a shut-off state, makes the stroke simulator device in a non-functional state, and An operation amount corresponding control unit that controls the hydraulic pressure of at least one wheel cylinder to a size corresponding to at least the operation amount of the brake operation member;
The electronically controlled hydraulic brake system according to (23) or (24).
The operation amount correspondence control unit switches at least one of the at least one master cylinder shut-off valve to a shut-off state and controls the hydraulic pressure control device to set the hydraulic pressure of the at least one wheel cylinder to the operation amount of the brake operation member. Control to the corresponding size.
With respect to the at least one wheel cylinder, it is possible to prevent the hydraulic pressure control by the hydraulic pressure control device from being performed even after the operating amount reaches the second set operating amount. The hydraulic pressure control is performed by the operation amount corresponding control unit. Even if the hydraulic pressure control based on the hydraulic pressure of the power hydraulic pressure source is not performed, the at least one wheel cylinder is operated by the hydraulic pressure of the master cylinder, but the hydraulic pressure control based on the hydraulic pressure of the power hydraulic pressure source is not performed. If performed, it becomes possible to apply a larger hydraulic pressure to the wheel cylinder.
When there are a plurality of wheel cylinders connected to the master cylinder, if switching to the shut-off state of the master cylinder shut-off valve corresponding to at least one of them and control of the hydraulic pressure control device are prohibited, at least Stroke simulator on one wheel cylinder
The function of the device can be fulfilled, and the brake operation member can be operated.
It is possible that some of the plurality of wheel cylinders are connected to the master cylinder and others are not connected to the master cylinder. Even when the operation amount of the operation member does not reach the second set operation amount, it can be controlled by the hydraulic control valve device, and it is desirable.
The second outflow permission unit and the non-functional state holding unit may be provided in the electronic control device, or at least one of them may be provided separately from the electronic control device. For example, it is provided in the middle of a connection line that connects an electronic control unit and a master cylinder shut-off valve, hydraulic control valve device, stroke simulator device (stroke simulator control valve), etc., and controls the supply of drive current from the former to the latter A circuit that performs this is an example of the latter.
(26) The electronic control unit is
When the hydraulic pressure of the at least one wheel cylinder is controlled by the operation amount corresponding control unit and the operation amount of the brake operation member is reduced to a third set operation amount, the electronically controlled hydraulic brake system is A prohibition state return unit for returning to a prohibited state in which switching of the at least one master cylinder cutoff valve to the cutoff state and control of the hydraulic control valve device corresponding to the master cylinder cutoff valve are prohibited;
An asymptotic control unit that ascends the actual hydraulic pressure of the at least one hole cylinder to the hydraulic pressure of the master cylinder before returning to the prohibited state by the prohibited state return unit;
The electronically controlled hydraulic brake system according to item (25).
When the electronically controlled hydraulic brake system is returned to the prohibited state by the prohibited state return unit, the at least one master cylinder shut-off valve is in the communication state. At that time, if there is a hydraulic pressure difference between the master cylinder side and the wheel cylinder side of the master cylinder shut-off valve, the influence of the hydraulic pressure change when the hydraulic pressure difference is eliminated is transmitted to the brake operation member, making the driver feel uncomfortable. However, if an asymptotic control unit is provided, the hydraulic pressure difference is reduced before the at least one master cylinder shut-off valve is brought into a communication state, so that the sense of incongruity is eliminated or reduced. .
(27) The second set operation amount is the third set operation amount, and
The asymptotic control unit includes a shut-off master cylinder pressure storage unit that stores a shut-off master cylinder pressure that is a hydraulic pressure of the master cylinder when the operation amount of the brake operation member reaches the second set operation amount. The actual hydraulic pressure of the at least one wheel cylinder asymptotically approaches the master cylinder pressure at the time of shut-off while the operation amount once exceeds the second set operation amount and then decreased to the second set operation amount. The electronically controlled hydraulic brake system according to item (26).
“Once the second set operation amount is exceeded and then reduced to the second set operation amount” means “from when the operation amount starts to decrease until the second set operation amount is reached” However, it may be “at least during that period”. The next item is an example of the latter.
When the operation amount is reduced to the second set operation amount, if the wheel cylinder pressure is the master cylinder pressure when shut off by the control by the asymptotic control unit in this section, the master cylinder shut-off valve Since there is almost no hydraulic pressure difference between the wheel cylinder and the master cylinder, adverse effects on the brake operating member at the time of communication, the occurrence of abnormal noise, and the like are favorably avoided.
The features of this section and (28) can also be applied to the electronically controlled hydraulic brake system described in sections (15) to (22).
(28) The asymptotic control unit, after the operation amount once exceeds the fourth setting operation amount larger than the third setting operation amount, is decreased to the fourth setting operation amount and then to the third setting operation amount The electronically controlled hydraulic brake system as set forth in (27), wherein an actual hydraulic pressure of the at least one wheel cylinder is made asymptotic to the shut-off master cylinder pressure while being reduced.
(29) The third setting after the asymptotic control unit is decreased to the fourth setting operation amount after the operation amount once exceeds the fourth setting operation amount larger than the second and third setting operation amounts. The electronically controlled hydraulic brake system as set forth in (26), wherein the actual hydraulic pressure of the at least one hole cylinder is made asymptotic to the actual hydraulic pressure of the master cylinder while being reduced to an operation amount.
The asymptotic control unit in this section, when the operation amount is once decreased after exceeding the fourth setting operation amount larger than the second and third setting operation amounts, is reduced to the fourth setting operation amount after the third setting operation amount. While being reduced to the set operation amount, the actual hydraulic pressure of the at least one hole cylinder is made asymptotic to the actual hydraulic pressure of the master cylinder. When the operation amount is decreased without exceeding the fourth set operation amount, the asymptotic control unit can be disabled or can be operated.
The second set operation amount and the third set operation amount can be the same size or different sizes.
(30) The asymptotic control unit includes an actual hydraulic pressure of the at least one wheel cylinder and an actual hydraulic pressure of the master cylinder when the operation amount of the brake operation member is reduced to the fourth set operation amount. The electronically controlled hydraulic brake system according to (29), further including a control gain changing unit that changes a control gain of the operation amount corresponding control unit to a larger value as a difference between the two is larger.
If the control gain of the hydraulic pressure control device itself is increased, the problem caused by the control delay of the wheel cylinder pressure can be solved, but another problem arises that the control accuracy of the wheel cylinder pressure may be lowered. On the other hand, the control gain changing unit has a difference between the actual hydraulic pressure of the at least one wheel cylinder and the actual hydraulic pressure of the at least one wheel cylinder when the operating amount of the brake operating member is reduced to the fourth set operating amount. Since the control gain of the control unit corresponding to the operation amount is changed to a larger value as the value increases, the brake gain operation speed increases, and the control delay increases as the control delay of the wheel cylinder pressure increases. It is possible to reduce or eliminate the uncomfortable feeling at the time of the brake release operation while avoiding the deterioration of the control accuracy.
(31) The asymptotic control unit sets a target hydraulic pressure determined by the operation amount corresponding control unit as the operation amount is decreased from the fourth setting operation amount to the third setting operation amount. The electronically controlled hydraulic brake system according to (29) or (30), which includes a target hydraulic pressure correcting unit that corrects the actual hydraulic pressure so as to approach the actual hydraulic pressure.
The electronic control device normally controls the fluid pressure of the at least one wheel cylinder to a target fluid pressure determined by the operation amount corresponding control unit, and between the fourth set operation amount and the third set operation amount, The target hydraulic pressure corrected by the pressure correction unit is controlled.
(32) The operation stroke corresponding control in which the operation amount corresponding control unit controls the hydraulic pressure of the at least one wheel cylinder based on an operation stroke as an operation amount of the brake operation member and a predetermined control rule. The electronically controlled hydraulic brake system according to any one of (25) to (31), including a section.
The operation stroke of the brake operation member itself may be detected, and the operation stroke is acquired by detecting an amount proportional to the operation stroke of the brake operation member, such as an input rod stroke for inputting the operation force of the brake operation member to the master cylinder. May be. As the predetermined rule, it is preferable that the hydraulic pressure of the at least one wheel cylinder is increased from the master cylinder hydraulic pressure at the start of control with a predetermined gradient with respect to an increase in operation stroke. However, it is not limited to this.
When the hydraulic pressure of the at least one wheel cylinder is controlled by the operation amount corresponding control unit, the master cylinder shut-off valve corresponding to the wheel cylinder is shut off, and the stroke simulator device is disabled. The stroke of the pressurizing piston is based on the elastic deformation of the constituent members, and the operation stroke of the brake operation member is also limited to be small. In order to alleviate this problem, it is also possible to provide a mechanical stroke simulator between the brake operating member and the pressurizing piston of the master cylinder separately from the stroke simulator device.
(33) The operation force corresponding control in which the operation amount corresponding control unit controls the hydraulic pressure of the at least one wheel cylinder based on the operation force as the operation amount of the brake operation member and a predetermined control rule. The electronically controlled hydraulic brake system according to any one of (25) to (32), including a section.
When this term depends on the term (32), both the operation stroke correspondence control unit and the operation force correspondence control unit are provided. For example, this is an effective mode in the case where either one is selectively operated according to the situation or one is a fail-safe portion for the other.
The operating force applied to the brake operating member itself may be detected, or may be acquired by detecting an amount proportional to the operating force, such as the hydraulic pressure of the master cylinder.
When the hydraulic pressure of the at least one wheel cylinder is controlled by the operation amount corresponding control unit, the operation stroke of the brake operation member is limited to be relatively small as described above. If the above-described mechanical stroke simulator is provided, the operation stroke after permitting the start of control can be increased to some extent, but there is a limit. Therefore, in the operation stroke response control unit, it is necessary to control the at least one wheel cylinder pressure in response to a minute change in the operation stroke, and it is relatively difficult to increase the control accuracy. If the operation force corresponding control unit is employed, the control accuracy of the at least one wheel cylinder pressure can be easily increased.
(34) A brake operation corresponding activation unit that activates the electronic control device in accordance with a brake operation operation that is an operation in a direction in which the brake of the brake operation member is applied.
An automatic stop unit that automatically stops the electronic control unit when a predetermined condition is satisfied;
The electronically controlled hydraulic brake system according to any one of (1) to (33).
The automatic stop unit may automatically stop the electronic control device when a predetermined condition is satisfied while the ignition switch is off, regardless of whether the ignition switch is on or off. The electronic control device may be automatically stopped when a predetermined condition is satisfied. In addition, the “predetermined condition” is a condition indicating that it is unlikely that the hydraulic brake needs to be activated in the near future, or that at least a large braking force needs to be generated. For example, (a) the set time or more has passed since the ignition switch was turned off, and (b) the state where the brake operation operation is not performed continues for the set time or more. , (C) Inactive state of the brake for more than the set time (difference from (b) in a system where the hydraulic brake may be automatically activated), (d) Electronic control (E) the parking brake is in the active state, (f) the transmission shift lever is in the neutral positive position. At least one such that the tio down or parking position, or can be combinations of two or more thereof.

  Embodiments of the claimable invention will be described below with reference to the drawings. In addition to the following examples, the claimable invention can be practiced in various modifications based on the knowledge of those skilled in the art, including the aspects described in the above [Aspect of the Invention] section. .

  FIG. 1 conceptually illustrates an electronically controlled hydraulic brake system for a vehicle that is an embodiment of the claimable invention. This electronically controlled hydraulic brake system includes a brake pedal 10 serving as a brake operating member, a master cylinder 12, wheel cylinders 14, 16, 18, 20, a brake actuator 22, a reservoir 24, a stroke simulator device 26, and an electronic control device 28 (FIG. 2). See).

  As shown in FIG. 1, the master cylinder 12 includes a housing 200 and pressurizing pistons 204 and 206 fitted into a cylinder bore 202 of the housing 200 so as to be liquid-tight and slidable. The brake pedal 10 is linked to the pressurizing piston 206 via the input rod 208, and when the brake pedal 10 is depressed, the pressurizing pistons 204 and 206 are advanced. Each of the pressurizing pistons 204 and 206 cooperates with the housing 200 to form pressurizing chambers 210 and 212 in front of each other, and the pressurizing chambers 210 and 212 are respectively connected to the first connection provided in the housing 200. Ports 214 and 216 are connected to wheel cylinders 14 and 16 for operating brakes that suppress the rotation of the left and right front wheels 38 and 40, respectively.

  The pressurizing pistons 204 and 206 are urged in the backward direction in which the volumes of the pressurizing chambers 210 and 212 increase by return springs 220 and 222 accommodated in the pressurizing chambers 210 and 212, respectively. The rearward movement limits of the pressure pistons 210 and 212 due to the biasing of the springs 220 and 222 are defined by pins 224 and 226 provided on the housing 200, respectively. Each of the pins 224 and 226 is provided so as to extend in the radial direction of the cylinder bore 202, and the pressurizing pistons 204 and 206 can be moved relative to the pins 224 and 226 in the axial direction, respectively.

  The pressurizing pistons 204 and 206 hold liquid tightness with the housing 200 by cup seals 228 and 230, which are a kind of seal members, and form pressurizing chambers 210 and 212, respectively. The reservoir 24 stores brake fluid at atmospheric pressure. The housing 200 is provided with second connection ports 232 and 234 on the rear side of the cup seals 228 and 230 of the pressurizing pistons 204 and 206 in a state of being moved to the retracted end position, and is connected to the reservoir 24. Yes. The cup seals 228 and 230 are provided between the reservoir 24 and the pressurizing chambers 210 and 212, respectively, and allow the brake fluid to flow from the reservoir 24 toward the pressurizing chambers 210 and 212. The reverse flow is prevented, the flow of brake fluid from the reservoir 24 to the pressurization chambers 210 and 212 is allowed when the pressurizing pistons 204 and 206 are retracted, and the reverse direction of the brake fluid when the pressurizing pistons 204 and 206 are advanced. Block the flow of In the present embodiment, the cup seals 228 and 230 constitute a check device.

  On-off valves 240 and 242 are provided in the pressurizing pistons 204 and 206, respectively. The on-off valves 240 and 242 are provided between the second connection ports 232 and 234 and the pressurizing chambers 210 and 212, bypassing the cup seals 228 and 230, respectively. 248, 250. The valve elements 244 and 246 are respectively provided in the pressurizing pistons 204 and 206 so as to be axially movable relative to valve holes 252 and 254 that communicate the second connection ports 232 and 234 with the pressurizing chambers 210 and 212. In addition to being fitted, the springs 260 and 262 disposed between the valve holding portions 256 and 258 are urged rearward (in the direction of seating on the valve seats 248 and 250). The valve holding portions 256 and 258 are provided with communication passages 264 and 266 that allow the pressurization chambers 210 and 212 and the on-off valves 240 and 242 to communicate with each other.

  The valve elements 244 and 246 come into contact with the pins 224 and 226 at the retracted ends of the pressurizing pistons 204 and 206, so that the valve elements 244 and 246 are separated from the valve seats 248 and 250, and the on-off valves 240 and 242 are opened. State. Thereby, the pressurizing chambers 210 and 212 are communicated with the second connection ports 232 and 234 via the communication passages 264 and 266 and the valve holes 252 and 254, and are communicated with the reservoir 24. When the brake pedal 10 is depressed, the valve elements 244 and 246 are separated from the pins 224 and 226 by the advance of the pressurizing pistons 204 and 206. In a state where the pressurizing pistons 204 and 206 are moved forward by a set distance or more, the valve elements 244 and 246 are seated on the valve seats 248 and 250 by the biasing of the springs 260 and 262, and the on-off valves 240 and 242 are closed. Thus, the communication between the pressurizing chambers 210 and 212 and the second connection ports 232 and 234 is blocked. In this embodiment, the on-off valves 240 and 242 constitute a shut-off device, and the pressurization chambers 210 and 212 are shut off from the reservoir 24 by the shut-off. , 206 is generated according to the force applied to it, and supplied to the wheel cylinders 14,16. Hereinafter, the wheel cylinders 14 and 16 are referred to as front cylinders 14 and 16 as necessary.

  The stroke simulator device 26 is connected to one pressurizing chamber 210 of the master cylinder 12. In this embodiment, the stroke simulator device 26 includes a stroke simulator 42 and a stroke simulator control valve (hereinafter abbreviated as a simulator control valve) 44. The stroke simulator 42 is configured to increase the hydraulic pressure of the master cylinder 12 while containing the brake fluid discharged from the pressurizing chamber 210. In this embodiment, the simulator control valve 44 is constituted by a normally closed electromagnetic on-off valve, which is provided between the stroke simulator 42 and the pressurizing chamber 210 and is always closed to block communication between the two. However, it is opened by supplying current to the solenoid to allow both to communicate.

The brake actuator 22 will be described.
The brake actuator 22 controls the hydraulic pressures of the wheel cylinders 18 and 20 that activate the brakes that suppress the rotation of the wheel cylinders 14 and 16 and the left rear wheel 46 and the right rear wheel 48, respectively. Hereinafter, the wheel cylinders 18 and 20 are referred to as rear cylinders 18 and 20 as necessary. As shown in FIG. 1, the brake actuator 22 includes two master cylinder shutoff valves 56 and 58, a power hydraulic pressure source 60, four hydraulic pressure control valve devices 62, two master cylinder pressure sensors 64, and four wheel cylinder pressures. A sensor 66 is provided. These components of the brake actuator 22 are integrally assembled to a box-shaped main body member (not shown).

  The power hydraulic pressure source 60 includes a pump 70 that pumps the brake fluid from the reservoir 24 through the reservoir passage 68, a pump motor 72 that drives the pump 70, an accumulator 74 that stores the brake fluid discharged from the pump 70 under pressure, And a relief valve 76 that regulates the discharge pressure of the pump 70 to a set value or less, and generates hydraulic pressure by power.

  The four wheel cylinders 14, 16, 18, and 20 are connected to the power hydraulic pressure source 60 through each of the four hydraulic pressure control valve devices 62. The four hydraulic pressure control valve devices 62 include linear pressure-increasing valves 80, 82, 84, 86 for controlling the inflow of brake fluid from the pump 70 or the accumulator 74 to the wheel cylinders 14, 16, 18, 20, respectively. 14, 16, 18, 20 includes linear pressure reducing valves 90, 92, 94, 96 that control the outflow of the brake fluid to the reservoir 24, and the pump 70, the accumulator 74, and the linear pressure increasing valves 80 to 86 are increased. The linear pressure reducing valves 90 to 96 and the reservoir 24 are connected by a pressure reducing passage 100 and a reservoir passage 68. For each of the four wheel cylinders 14, 16, 18, 20, a hydraulic pressure control valve device 62 including one linear pressure increasing valve and one linear pressure reducing valve is provided, and the hydraulic pressure is controlled independently of each other. Yes, the four sets of linear pressure increasing valves and linear pressure reducing valves are connected to the wheel cylinders 14, 16, 18, 20 by the wheel cylinder passages 102, 104, 106, 108, respectively. Each of the four hydraulic pressure control devices 62 is provided between each of the wheel cylinders 14, 16, 18, and 20 and the power hydraulic pressure source 60 and the reservoir 24.

  A hydraulic pressure source hydraulic pressure sensor 110 is provided between the pump 70 and the linear pressure increasing valves 80 to 86 to detect the hydraulic pressure of the power hydraulic pressure source 60, and the hydraulic pressures of the wheel cylinders 14, 16, 18, and 20 are detected. It is detected by the wheel cylinder pressure sensor 66. The master cylinder shut-off valves 56 and 58 are provided between the two pressurizing chambers 210 and 212 of the master cylinder 12 and the front cylinders 14 and 16, respectively. The master cylinder pressure sensor 64 is provided between the pressure chambers 212 and 212, and the hydraulic pressures generated in the pressure chambers 210 and 212 are detected. The master cylinder shut-off valves 56 and 58 are normally open electromagnetic on-off valves in this embodiment, and are always opened and switched to a communication state in which the pressurizing chambers 210 and 212 and the front cylinders 14 and 16 are communicated. However, it is closed by supplying a current to the solenoid and switched to a shut-off state in which the pressurizing chambers 210 and 212 and the front cylinders 14 and 16 are shut off. In the stroke simulator device 26, during normal braking, the master cylinder shut-off valves 56 and 58 are opened, and the simulator control valve 44 is closed in a state in which the master cylinder shut-off valve 56 and 58 are switched to the communication state. When the master cylinder shutoff valves 56 and 58 are closed and switched to the shutoff state, the simulator control valve 44 is opened from the master cylinder 12 to the parts other than the front cylinders 14 and 16. The brake fluid is allowed to flow into the brake pedal 10 while the brake fluid discharged from the pressurizing chamber 210 of the master cylinder 12 is accommodated in the stroke simulator 42, and increases as the stepping stroke increases. It becomes a functional state to act.

  The linear valve is an electromagnetic control valve having a predetermined relationship between the hydraulic pressure difference between the upstream side and the downstream side and the supply current, and the valve opening pressure can be changed according to the increase or decrease of the supply current. A type of electromagnetic on-off valve. Therefore, the linear pressure increasing valves 80 to 86 and the linear pressure reducing valves 90 to 96 can control the wheel cylinder pressure to an arbitrary height by controlling the supply current, and can continuously change the wheel cylinder pressure. In the electronically controlled hydraulic brake system, the linear pressure increasing valves 80 to 86 are all normally closed valves, the linear pressure reducing valves 90 and 92 provided for the front cylinders 14 and 16 are respectively normally closed valves, and the rear cylinder 50 , 52 are normally open valves, respectively. Therefore, the linear pressure increasing valves 80 to 86 are closed when no current is supplied to the solenoid, and opened when the current is supplied, and the brake fluid from the power hydraulic pressure source 60 to the wheel cylinders 14, 16, 18, 20 is opened. Allowed to flow in and increases the wheel cylinder pressure. The linear pressure reducing valves 90 and 92 are closed when no current is supplied to the solenoid, switched to a shut-off state that shuts off the front cylinders 14 and 16 and the reservoir 24, and opened when current is supplied. The brake fluid is allowed to flow out from the wheel cylinders 14 and 16 to the reservoir 24, and is switched to a communication state in which the front cylinders 14 and 16 are communicated with the reservoir 24, thereby reducing the wheel cylinder pressure. The linear pressure reducing valves 94 and 96 are opened and communicated when no current is supplied to the solenoid, permitting the brake fluid to flow from the front cylinders 18 and 20 to the reservoir 24, and reducing the wheel cylinder pressure. If the current is supplied to the cylinder, the valve is closed and switched to the shut-off state, and the brake fluid from the wheel cylinders 18 and 20 is prevented from flowing out. The linear pressure reducing valves 94 and 96 are also opened by decreasing the supply current. Each of the four hydraulic pressure control valve devices 62 is configured to allow the brake fluid to flow from the power hydraulic pressure source 60 to each wheel cylinder by combining the control of the linear pressure increasing valve and the control of the linear pressure reducing valve, and each wheel. Switching between a state in which the brake fluid is allowed to flow from the cylinder 24 to the reservoir 24 and a state in which the brake fluid is not allowed to flow from the power hydraulic pressure source 60 to the wheel cylinder or from the wheel cylinder to the reservoir 24 is possible. It is.

  In this embodiment, the switching device includes a stroke simulator device 26, master cylinder shut-off valves 56 and 58, and a hydraulic pressure control valve device 62, and the communication state of the master cylinder 12, the front cylinders 14 and 16, and the power hydraulic pressure source 60 is switched. In the state where the communication between the master cylinder 12 and the front cylinders 14, 16 is cut off, the hydraulic pressure control valve device 62 reduces the hydraulic pressure of the front cylinders 14, 16 based on the hydraulic pressure of the power hydraulic pressure source 60. Control the size according to the amount. The state in which the master cylinder shut-off valves 56 and 58 are in communication and the stroke simulator device 26 is in a non-functional state is the first state, and the master cylinder shut-off valves 56 and 58 are shut off and in the stroke simulator device. 26 is in a functional state, and a plurality of hydraulic pressure control valve devices 62 are controlled to control the hydraulic pressure of the wheel cylinders 14, 16, 18, 20 to a magnitude corresponding to the depression amount of the brake pedal 10. Is the second state.

  The electronically controlled hydraulic brake system is controlled based on a command from the electronic control unit 28. As shown in FIG. 2, the electronic control device 28 includes a control unit including a computer 152 and an input / output unit 154, and a plurality of drive circuits 156. The computer 152 includes a CPU 160, a ROM 162, a RAM 164 and a bus for connecting them. In the input / output unit 154, in addition to the master cylinder pressure sensor 64 and the like, various sensors such as a brake switch 170 and a stroke sensor 172 are input. And solenoids such as the linear pressure increasing valves 80 to 86 and the linear pressure reducing valves 90 to 96 are connected to the output side.

  The brake switch 170 is a kind of brake operation detection device, detects that the brake pedal 10 has been depressed more than the set depression stroke from the original position, and is turned on when the brake pedal 10 is depressed more than the set depression stroke from the original position. If it is, an ON signal is output, and an OFF signal is output in an OFF state where the pedal is not depressed for a set depression stroke or more. The original position is defined by, for example, a stopper (not shown). The stroke sensor 172 detects a depression stroke that is the depression amount of the brake pedal 10. The stepping amount is a type of operation amount, the stepping stroke is a type of operation stroke, and the stroke sensor 172 is an aspect of a brake operation member operation stroke detection device that is a type of brake operation member operation amount detection device, A pedal depression stroke detection device as a pedal depression amount detection device is configured. In the electronically controlled hydraulic brake system, the depression force of the brake pedal 10 is acquired based on the detection of the hydraulic pressure of the master cylinder 12. The stepping force is an aspect of the operation force that is a kind of the operation amount, and the portion that acquires the stepping force based on the master cylinder pressure of the master cylinder pressure sensor 64 and the electronic control unit 28 is the brake operation member operation force detection device. A pedal depression force detection device as a kind of pedal depression amount detection device is configured. Two master cylinder pressure sensors 64 are provided, and two master cylinder pressures can be obtained. For example, the stepping force may be acquired based on either one, for example, the larger master cylinder pressure. Two average values may be used as the master cylinder pressure, and the stepping force may be acquired.

  In the electronically controlled hydraulic brake system, when the brake pedal 10 is depressed and the brake switch 170 is turned on, the brake lamp 176 is turned on and the power supply circuits 178 and 180 are driven. The drive current is supplied to the computer 152 and the drive circuit 156 from the power supply circuit 180. The power supply circuit 180 is also driven when an ignition switch 182 serving as a drive source drive operation member is turned on. Even if the ignition switch 182 is not turned on, the electronic control device 28 can be operated when the brake pedal 10 is depressed. Thus, the electronic control device 28 is activated when the brake pedal 10 is depressed. This is called a rapid start. When the power supply circuit 180 is driven by either the brake switch 170 or the ignition switch 182, the supply of drive current to the computer 152 and the drive circuit 156 is continued until the ignition switch 182 is switched off.

  In the vehicle including the electronically controlled hydraulic brake system, the ignition switch 182 is a push button. To drive the power supply circuit 180, the ignition switch 182 only needs to be pressed and turned on. In order to start the engine 190, the ignition switch 182 needs to be pressed and switched to the on state while the brake pedal 10 is depressed more than the set depression stroke. This set stepping stroke is referred to as an engine start allowable stroke. The engine 190 and the engine control device 192 constitute an engine system 194. The engine control device 192 is mainly composed of a computer 196, and the computer 196 is connected to the input / output unit 154 of the computer 152. The power supply circuit 180 also supplies current to the engine system 194.

  The ROM 162 includes a main routine (not shown), an electric braking control routine, an antilock control routine, a traction control routine, a vehicle stability control routine, a rapid start determination routine and a wheel cylinder pressure control shown in the flowcharts of FIGS. Various programs such as a routine, a rapid start wheel cylinder pressure control routine, and an electronic control unit automatic stop determination routine are stored. These routines are repeatedly executed every predetermined time. The electronic control device 28 takes the first state and the second state by executing the wheel cylinder pressure control routine.

  In this electronically controlled hydraulic brake system, the electronic control unit 28 uses the detection signals of various sensors such as the master cylinder pressure sensor 64 when any control is performed by operating the brake actuator 22 such as electric braking control. Based on this, the vehicle state is acquired, and on the basis thereof, the target hydraulic pressure is determined for each of the four wheel cylinders 14, 16, 18, and 20, and the linear pressure increasing valves 80 to 86 and the linear pressure increase valves are obtained so as to obtain the target hydraulic pressure. The current supplied to each solenoid of the pressure reducing valves 90 to 96 is determined, and the supply is controlled. By supplying the determined current, the hydraulic pressure control valve device 62 is operated, and the brake is operated while the hydraulic pressures of the wheel cylinders 14, 16, 18, and 20 are controlled to the target hydraulic pressure. When the wheel cylinder pressure is controlled by the operation of the linear pressure increasing valves 80 to 86 and the linear pressure reducing valves 90 and 92, the master cylinder cutoff valves 56 and 58 are closed. When the wheel cylinder pressure is electrically controlled based on the depression of the brake pedal 10, the simulator control valve 44 is opened and the stroke simulator device 26 is put into a functional state except during a rapid start described later. The brake fluid is discharged from the pressurizing chamber 210 to the stroke simulator 42, and an operational feeling corresponding to the pedal effort is given to the driver.

  In the electronically controlled hydraulic brake system, when the electronic control device 28 is activated by rapid start, the hydraulic pressure of the rear cylinders 18 and 20 is controlled by the hydraulic control valve device 62, but the front cylinders 14 and 16 are controlled. As for the hydraulic pressure control valve device 62 until the stepping stroke of the brake pedal 10 becomes equal to or greater than the set stepping stroke which is the set operation stroke, the hydraulic pressure control valve device 62 is inoperative and is based on the driver's stepping operation on the brake pedal 10. The hydraulic pressure is generated. During this time, the master cylinder shut-off valves 56 and 58 are kept open, the simulator control valve 44 is kept closed and in a non-functional state, and the front cylinders 14 and 16 are communicated with the master cylinder 12. The brake fluid in the pressurizing chambers 210 and 212 of the master cylinder 12 is allowed to flow out to the front cylinders 14 and 16. Therefore, the depression stroke of the brake pedal 10 by the driver is not limited, and an appropriate depression stroke can be generated. When the depression stroke becomes equal to or greater than the set depression stroke, the hydraulic pressure of the front cylinders 14 and 16 is controlled by the hydraulic pressure control valve device 62 to a magnitude corresponding to the depression of the brake pedal 10. Therefore, the master cylinder shut-off valves 56 and 58 are closed, the front cylinders 14 and 16 are shut off from the master cylinder 12, and the outflow of brake fluid from the pressurizing chambers 210 and 212 to the front cylinders 14 and 16 is prohibited. The stroke simulator device 26 is in a non-functional state while the depression of the brake pedal 10 that caused the rapid start is continued, and while ensuring the braking force by controlling the front cylinder pressure by the hydraulic pressure control valve device 62, It is avoided that the pressurizing chamber 210 is communicated with the stroke simulator 42 in a state where hydraulic pressure is generated by depressing the brake pedal 10 and the driver feels uncomfortable. Until the depression stroke reaches the set depression stroke, it is the first half of the depression operation of the brake pedal 10. In this electronically controlled hydraulic brake system, the brake fluid flows from the master cylinder 12 to the front cylinders 14, 16 in the first depression. Is acceptable. This set stroke is referred to as a hydraulic pressure control allowable stroke. Since the hydraulic pressure control is prohibited in a state where the stepping stroke is smaller than the set stepping stroke, the set stroke is also a hydraulic pressure control prohibiting stroke.

The engine start allowable stroke is a first set operation amount, and the hydraulic pressure control allowable stroke is a second set operation amount. In this embodiment, the hydraulic control allowable stroke is set larger than the engine start allowable stroke. In the electronically controlled hydraulic brake system, as described above, the brake fluid is allowed to flow out from the master cylinder 12 to the front cylinders 14 and 16 during the rapid start of the brake pedal 10 as described above. During this time, the depression of the brake pedal 10 is not limited, and normally the depression stroke exceeds the engine activation allowable stroke, so that the driver can activate the engine 190 by operating the ignition switch 182.
If the brake switch is turned on at a rapid start and the electronic control unit can control the solenoid valve, the master cylinder shut-off valve is immediately closed and the stroke simulator device is only disabled. For example, even if the engine start allowable stroke is obtained once, the engine start operation is not performed in that state, and if the pumping operation is performed by depressing the brake pedal halfway and then depressing again, the master cylinder The stroke simulator and the wheel cylinder are not communicated with each other, the depression of the brake pedal is remarkably restricted, and the engine start allowable stroke cannot be obtained. On the other hand, in this electronically controlled hydraulic brake system, since the depression of the brake pedal 10 is allowed until the hydraulic control allowable stroke, the engine 190 cannot be started at all.

  However, even in this electronically controlled hydraulic brake system, it is not without the possibility that the depression stroke of the brake pedal 10 will be significantly limited at the time of rapid start. For example, when the brake pedal 10 is depressed beyond the allowable hydraulic pressure control stroke, the brake release operation is quickly performed halfway, and then the pumping operation that is depressed again is performed one or more times. The stroke at the time of depression may become remarkably small. As illustrated in FIG. 9, the depression of the brake pedal 10 is released from the state where the pedal stroke exceeds the hydraulic pressure control allowable stroke and the hydraulic pressure of the front cylinders 14, 16 is controlled by the hydraulic pressure control valve device 62. When the stroke is smaller than the hydraulic pressure control allowable stroke, the master cylinder shut-off valves 56 and 58 are opened and the front cylinders 14 and 16 are communicated with the pressurizing chambers 210 and 212. Due to the delay in returning the brake fluid to 210 and 212, the pressurizing chambers 210 and 212 become weak negative pressure, and the master cylinder pressure decreases to weak negative pressure as shown by the solid line in FIG. , 212 is supplied with brake fluid from the reservoir 24 via cup seals 228, 230. Therefore, as indicated by the broken line in FIG. 9, the front cylinder pressure gradually decreases. If much of the brake fluid remains contained in the front cylinders 14 and 16, and the brake pedal 10 is depressed again in this state, the brake fluid is less likely to flow out from the pressurizing chambers 210 and 212 to the front cylinders 14 and 16, The pedal stroke is limited small. This tendency increases as the speed of the pumping operation increases and the number of times increases. Although the above description has been given of the case where the pumping operation is performed after stepping over the allowable hydraulic pressure control stroke for ease of illustration, the pumping operation is performed within a range not exceeding the allowable hydraulic pressure control stroke. A similar situation may occur in some cases.

  Therefore, in order to obtain a pedal stroke that exceeds the engine start allowable stroke, a larger pedaling force is required than when the pedal stroke is not limited, and the master cylinder pressure and the front cylinder pressure increase as shown by dotted lines in FIG. However, if the master cylinder pressure is relatively small, the pedal stroke is limited to be smaller than the engine start allowable stroke STEG, and the engine 190 may not be started. Therefore, in this electronically controlled hydraulic brake system, the engine start brake fluid outflow allowable condition is that the pedal stroke is smaller than the engine start allowable stroke STEG even though the master cylinder pressure is larger than the set pressure PMEG. Is established, the linear pressure reducing valve 90 is opened, the brake fluid flows out from the master cylinder 12 to the reservoir 24 through the master cylinder shut-off valve 56 and the linear pressure reducing valve 90, thereby enabling the brake pedal 10 to be depressed, An engine start allowable stroke is secured. At this time, the supply current to the solenoid of the linear pressure reducing valve 90 is gradually increased and gradually decreased, and the flow rate of the brake fluid flowing out from the master cylinder 12 is gradually increased and gradually decreased. It is done.

First, the control of the wheel cylinder pressure at the time of rapid start will be described based on the flowcharts shown in FIGS.
The rapid start determination routine shown in FIG. 3 will be described. When the electronic control device 28 is started by supplying current from the power supply circuit 180 by depressing the brake pedal 10 or by turning on the ignition switch 182, a rapid start determination routine is executed, and step 1 (hereinafter “step 1”) is performed. , Abbreviated as S1), it is determined whether or not the flag F is set. The flag F stores that it has been determined whether or not a rapid start has been performed. For example, the flag F is reset in the initial setting, the determination result of S1 is NO, S2 is executed, and the flag F is Set. Next, S3 is executed, and it is determined whether or not the ignition switch 182 is switched on. If the ignition switch 182 is off, the determination result in S3 is NO, S4 is executed, and it is stored that the electronic control unit 28 has been activated by rapid start. For example, a rapid start execution flag provided in the RAM 164 is set. On the other hand, when S3 is executed, if the ignition switch 182 is switched to the ON state, the determination result of S3 is YES, S4 is skipped, and the execution of the routine ends. For this reason, the rapid start execution flag is not set and remains reset.

  Regardless of what causes the electronic control device 28 to be activated by setting the flag F, the next time S1 is executed, the determination result is YES and S2 to S4 are skipped. The rapid start determination routine is repeatedly executed from when the electronic control unit 28 is activated until it stops, but whether or not the rapid start has been performed is determined only once when the electronic control unit 28 is activated. It is. Therefore, for example, in this electronically controlled hydraulic brake system, the drive current is supplied to the electronic control unit 28 for a set time even after the ignition switch 182 is switched to the OFF state, and the brake pedal 10 is depressed. Although it is provided, it is avoided that the rapid start is determined when the brake pedal 10 is depressed. Even if the electronic control device 28 is started by turning on the ignition switch 182 and then the brake pedal 10 is depressed with the ignition switch 182 turned off, the flag F is set and S3 is executed. The rapid start is not performed even if the brake pedal 10 is depressed in a state where the ignition switch 182 is turned off.

  The wheel cylinder pressure control routine shown in FIG. 4 is started by either turning on the power when the ignition switch 182 is turned on or turning on the power when the brake pedal 10 is depressed. In S11, a rapid start is performed. It is determined whether or not it has been received. This determination is made based on whether or not a rapid start is stored. If the electronic control unit 28 is not a rapid start but is activated by turning on the ignition switch 182, the determination result in S11 is NO. At step S16, normal braking control is performed.

  The normal braking control is control in a state where the electronic control device 28 is activated, the initial setting is completed, and various electromagnetic valves and the like are controlled based on the depression of the brake pedal 10 to control the hydraulic pressure. The target hydraulic pressure is set for each of the four wheel cylinders 14, 16, 18, and 20 based on the amount of stepping, for example, the stepping force, and the linear pressure increasing valves 80 to 86 and the linear pressure reducing valves are obtained so as to obtain the target hydraulic pressure. In this control, the supply currents to the solenoids 90 to 96 are set, and the four hydraulic control valve devices 62 are operated. In the normal braking control, it is determined whether or not the brake pedal 10 is depressed. When the brake pedal 10 is depressed, the target hydraulic pressure is set and the braking control is performed. At this time, the master cylinder shut-off valves 56 and 58 are closed, the simulator control valve 44 is opened, and the stroke simulator device 26 is put into a functional state. When the brake pedal 10 is not depressed, the braking control is not performed, and when the braking control is already performed, the control end process is performed.

  If a rapid start is performed and the execution of the rapid start is stored in the rapid start determination routine, the determination result of S11 is YES, S12 is executed, and it is determined whether the engine 190 has failed to start. . The failure to start the engine means that the engine 190 was not started even though the brake pedal 10 was depressed and the ignition switch 182 was turned on. As described later, the engine control device 192 determines whether or not the engine 190 has failed to start. Here, the determination result is read. If the start of the engine 190 has not failed, the determination result in S12 is NO, S13 is executed, and wheel cylinder pressure control at the rapid start is performed.

  The wheel cylinder pressure control at the rapid start will be described based on the flowchart shown in FIG. In S21 of the wheel cylinder pressure control routine, the hydraulic pressure control of the rear cylinders 18 and 20 is performed. Since the rear cylinders 18 and 20 are not connected to the master cylinder 12 and the hydraulic pressure thereof is controlled only by the hydraulic pressure control valve device 62, the brake pedal 10 is depressed and the brake pedal 10 is depressed in the same manner as during normal braking. Be controlled.

  Next, S22 is executed, and it is determined whether or not the pedal stroke that is the depression stroke of the brake pedal 10 is equal to or greater than the hydraulic pressure control allowable stroke ST0 that is the set depression stroke. The pedal stroke is acquired based on the detection signal of the stroke sensor 172, and it is determined whether or not the current pedal stroke, which is the acquired pedal stroke, is greater than or equal to the hydraulic pressure control allowable stroke ST0. In S22, both the pedal stroke acquired at the time of execution of S22 this time and the pedal stroke acquired at the time of the previous execution of S22 are stored. Each time a new pedal stroke is acquired in S22, the pedal stroke stored as the previous pedal stroke (the pedal stroke acquired during the previous execution of S22) of the two currently stored pedal strokes is The pedal stroke erased and stored as the current pedal stroke (the pedal stroke acquired at the time of the previous execution of S22) is set as the previous pedal stroke, and the pedal stroke newly acquired at S22 is set as the current pedal stroke. It is memorized.

  At the beginning of the depression of the brake pedal 10, the pedal stroke is smaller than the hydraulic pressure control allowable stroke ST0, the determination result in S22 is NO, S23 is executed, and a command to open the master cylinder shut-off valves 56, 58 is output. Is done. Thereby, if the master cylinder shut-off valves 56 and 58 are closed, they are opened, and if they are opened, they are kept open. At the beginning of the depression of the brake pedal 10, the normally open master cylinder shut-off valves 56 and 58 are opened and remain open. In S23, the hydraulic pressure control valve device 62 performs hydraulic pressure control termination processing. For example, the current supply to the solenoids of the linear pressure increasing valves 80 and 82 and the linear pressure reducing valves 90 and 92 is cut off, and the normal state is restored. However, nothing is performed if the hydraulic control is not performed by the hydraulic control valve device 62. In a state where the pedal stroke is smaller than the hydraulic pressure control allowable stroke ST0, the master cylinder cutoff valves 56 and 58 are opened and the hydraulic pressure control valve device 62 is not controlled, so that the master cylinder cutoff valves 56 and 58 are brought into the cutoff state. Switching and the control of the hydraulic control valve device 62 provided for the front cylinders 14 and 16 corresponding to the master cylinder shut-off valves 56 and 58 are prohibited. After the determination result in S22 is NO, it is determined whether or not the previous value of the pedal stroke is equal to or greater than the hydraulic pressure control allowable stroke ST0. If the hydraulic pressure control allowable stroke ST0 is equal to or greater, the master cylinder is shut off. The valves 56 and 58 are opened and the hydraulic pressure control valve device 62 performs a hydraulic pressure control end process. When the hydraulic pressure control allowable stroke ST0 is smaller, the master cylinder cutoff valves 56 and 58 are simply opened. You may do it.

  Next, S24 is executed to determine whether or not the depression of the brake pedal 10 has been released. This determination is made based on, for example, whether or not the brake switch 170 is off. If the depression is not released, the determination result in S24 is NO and the execution of the routine is terminated.

  As long as the brake pedal 10 is depressed, S11, S21 to S24 are repeatedly executed until the pedal stroke becomes equal to or greater than the hydraulic pressure control allowable stroke ST0. If the pedal stroke becomes equal to or greater than the hydraulic pressure control allowable stroke ST0, the determination result in S22 is YES, S26 is executed, and it is determined whether the previous value of the pedal stroke is smaller than the hydraulic pressure control allowable stroke ST0. The previous value of the pedal stroke is the pedal stroke stored as the previous pedal stroke of the two pedal strokes stored in S22. In S22, the determination result in S22 is YES during the operation of the brake pedal 10. It is determined whether or not the current pedal stroke that has become the pedal stroke that is equal to or greater than the hydraulic pressure control allowable stroke ST0 for the first time. The action operation is an operation for increasing the amount of depression of the brake pedal 10 and operating the brake.

  If the previous value of the pedal stroke is smaller than the hydraulic control allowable stroke which is the set stroke, the current pedal stroke in which the determination result in S22 is YES is equal to or greater than the hydraulic control allowable stroke for the first time. The determination result is YES, S27 is executed, and the hydraulic pressure of the master cylinder 12, for example, the hydraulic pressure of the pressurizing chamber 210 is stored in the RAM 164. An average value of the hydraulic pressures in the pressurizing chambers 210 and 212 may be set as the master cylinder pressure, and one of the hydraulic pressures may be set as the master cylinder pressure. The hydraulic pressure in the master cylinder 12 is referred to as a master cylinder pressure PM0 when shut off, which is the master cylinder pressure when the master cylinder is shut off. This is because, as will be described below, when the pedal stroke reaches the hydraulic pressure control allowable stroke ST0, the master cylinder shut-off valves 56 and 58 are closed and the front cylinders 14 and 16 are shut off from the master cylinder 12.

  During the operation of the brake pedal 10, once the pedal stroke becomes equal to or greater than the hydraulic pressure control allowable stroke ST0, the previous pedal stroke also exceeds the hydraulic pressure control allowable stroke ST0, and the determination result of S26 is NO and S28 is determined. The hydraulic pressure of the front cylinders 14 and 16 is controlled by the hydraulic pressure control valve device 62. While the master cylinder shut-off valves 56 and 58 are closed, the target hydraulic pressure is set for the front cylinders 14 and 16, and the hydraulic pressure control valve device 62 provided for the front cylinders 14 and 16 is obtained so as to obtain the target hydraulic pressure. The supply currents to the solenoids of the linear pressure increasing valves 80 and 82 and the linear pressure reducing valves 90 and 92 are set.

  In the present embodiment, the target hydraulic pressure is set based on the master cylinder pressure and the master cylinder pressure at the start of control. The master cylinder pressure at the start of control is the master cylinder pressure PM0 at the time of shut-off previously stored in S27, and the target hydraulic pressure is increased from the master cylinder pressure PM0 at the time of shut-off as shown in FIG. On the other hand, it is set to be increased at a predetermined gradient. In this embodiment, this gradient is the same as the control gradient of the wheel cylinder pressure by the hydraulic pressure control valve device 62 in the normal braking control. Therefore, the hydraulic pressures of the front cylinders 14 and 16 are lower than the hydraulic pressures of the rear cylinders 18 and 20 controlled by the hydraulic pressure control valve device 62 from the beginning of the depression of the brake pedal 10, but are increased with the same gradient. Thus, the hydraulic pressure is controlled to be higher than the hydraulic pressure generated only by depressing the brake pedal 10, and a large braking force is obtained.

  While the hydraulic pressure of the front cylinders 14 and 16 is controlled by the hydraulic pressure control valve device 62, the master cylinder shut-off valves 56 and 58 are operated and closed to shut off the communication between the master cylinder 12 and the wheel cylinders 14 and 16. However, the simulator control valve 44 is not operated, is closed and remains in a non-functional state, and the pressurizing chamber 210 of the master cylinder 12 is not communicated with the stroke simulator 42. The brake fluid outflow from the pressurizing chamber 210 to the stroke simulator 42 is prohibited, and the driver's stepping on the brake pedal 10 is permitted by elastic deformation of the components such as the fluid passages 34 and 36, and the pedal stroke is Although limited to a small amount, the pedal force is generated in the same manner as when brake fluid is allowed to flow from the master cylinder 12 to the front cylinders 14 and 16 or the stroke simulator 42, and the front cylinder pressure is controlled with high accuracy.

  As described above, in the electronically controlled hydraulic brake system, when the brake pedal 10 is depressed at the rapid start, the master cylinder shutoff valves 56 and 58 are not shut off until the pedal stroke reaches the hydraulic control allowable stroke ST0. In addition, the stroke simulator device 26 remains in a non-functional state, and the outflow of the brake fluid from the master cylinder 12 to the wheel cylinders 14 and 16 is permitted, thereby allowing the brake pedal 10 to be depressed. Accordingly, the wheel cylinders 14 and 16 are disconnected from the master cylinder 12 during the stepping, and the driver feels uncomfortable with the stepping operation as in the case where the master cylinder 12 is connected to the stroke simulator 42 and the hydraulic pressure changes suddenly. Never hold. When the pedal stroke reaches the hydraulic pressure control allowable stroke ST0, the master cylinder shut-off valves 56 and 58 are closed, the brake fluid from the master cylinder 12 to the front cylinders 14 and 16 is not allowed to flow, and the stepping stroke is limited to be small. However, at that time, the brake pedal 10 is already stepped on the hydraulic pressure control allowable stroke ST0, and the driver rarely feels uncomfortable.

  When the driver releases the brake pedal 10 and releases the brake operation, the pedal stroke decreases. Also during this time, while the pedal stroke is equal to or greater than the hydraulic pressure control allowable stroke ST0, the hydraulic pressure of the front cylinders 14 and 16 is reduced while being controlled by the hydraulic pressure control valve device 62.

  If the pedal stroke becomes smaller than the hydraulic pressure control allowable stroke ST0, the determination result in S22 is NO, S23 is executed, the master cylinder shutoff valves 56 and 58 are opened, and the hydraulic pressure control valve device 62 Control termination processing is performed. As a result, the wheel cylinders 14 and 16 are communicated with the pressurizing chambers 210 and 212, and thereafter, the wheel cylinder pressure is reduced as the pedal stroke is reduced.

  When the pedal stroke is reduced, the master cylinder pressure is restored to a state in which there is no elastic deformation of the structural members that are elastically deformed during the operation until the pedal stroke is equal to or less than the hydraulic pressure control allowable stroke ST0. When the master cylinder shutoff valves 56 and 58 are opened when the pedal stroke becomes smaller than the hydraulic control allowable stroke ST0 and the master cylinder shutoff valves 56 and 58 are opened, the master cylinder pressure is the shutoff master cylinder pressure PM0. The target hydraulic pressure of the front cylinders 14 and 16 is also the master cylinder pressure PM0 when shut off. This is because the target hydraulic pressure is set so as to increase / decrease at a set gradient with respect to the increase / decrease of the master cylinder pressure from the shut-off master cylinder pressure PM0. Thereafter, as the brake pedal 10 is released, the front cylinder pressure and the master cylinder pressure are reduced while the front cylinders 14 and 16 and the pressurizing chambers 210 and 212 are in communication with each other.

  If the depression of the brake pedal 10 is released, the determination result in S24 is YES, S25 is executed, and the memory that the rapid start has been performed is erased from the RAM 164. Therefore, the next time S11 is executed, the determination result is NO and S16 is executed. Even if the electronic control unit 28 is activated by the depression of the brake pedal 10 and the wheel cylinder pressure control at the rapid start is performed, if the depression of the brake pedal 10 is released, the next time the brake pedal 10 is depressed, The electronic control device 28 is in a state in which the hydraulic pressure can be controlled from the beginning of the depression, and there is no problem even if the wheel cylinder pressure control at the rapid start is not performed.

  In this electronically controlled hydraulic brake system, the electronic control device shown in FIG. 6 is activated both when the electronic control device 28 is activated by depressing the brake pedal 10 and when the ignition switch 182 is activated. An automatic stop determination routine is executed. This routine is configured to stop the electronic control unit 28 when the ignition switch 182 is turned off and the brake pedal 10 is not depressed for a set time. These are automatic stop conditions for the electronic control unit 28. When this condition is satisfied, it may be considered that the driver does not intend to perform braking, and the current supply to the electronic control unit 28 is stopped and there is no problem.

  Therefore, it is determined in S31 of the electronic control unit automatic stop determination routine whether or not the ignition switch 182 is in an OFF state, whether or not the brake pedal 10 is depressed in S32, and the set time has elapsed in S33. It is determined whether or not. If the ignition switch 182 is turned off and the brake pedal 10 is not depressed for a set time, the determination results of S31, S32, and S33 are YES, S34 is executed, and the electronic control unit 28 is executed. Current supply is cut off and stopped. Further, the flag F is reset.

  Even when the electronic control device 28 is activated by a rapid start, if the brake pedal 10 is depressed, the electronic control device 28 is kept activated and the wheel cylinder pressure is controlled. However, if the electronic control device 28 is activated but the ignition switch 182 is not turned on and the depression of the brake pedal 10 remains released, the electronic control device 28 can be automatically stopped when the stop condition is satisfied. . If the brake pedal 10 is depressed in this state, the electronic control unit 28 is rapidly started, and wheel cylinder pressure control at the time of rapid start is performed.

The engine startup will be described.
In the engine control device 192, when the engine system 194 is powered on, an engine start routine shown in FIG. 7 is executed. In S61 of the engine activation routine, it is determined whether or not the engine 190 is activated. If the engine 190 is activated, the determination result in S61 is YES and the execution of the routine ends. On the other hand, if the engine 190 has not been started, the determination result in S61 is NO, S62 is executed, and it is determined whether or not the ignition switch 182 has been turned on. If the ignition switch 182 is not turned on, the determination result in S62 is NO and the execution of the routine ends.

  If the ignition switch 182 is turned on, the determination result in S62 is YES, S63 is executed, and it is determined whether the brake switch 170 outputs an on signal. In this embodiment, the pedal stroke when the output signal of the brake switch 170 changes from the off signal to the on signal is the engine start allowable stroke STEG. If the brake switch 170 outputs the on signal, the brake pedal 10 Means that the pedal stroke exceeds the engine start allowable stroke STEG, the engine may be started, the determination result in S63 is YES, S64 is executed, and an engine start command is output. The Activation of the engine 190 is permitted. If it is stored that the engine has failed to start, it is deleted. The engine start failure is stored, for example, by setting an engine start failure flag provided in the RAM of the computer 196. Here, the engine start failure flag is reset. On the other hand, if the brake switch 170 outputs an OFF signal, the determination result in S63 is NO, S65 is executed, the engine start failure flag is set, and the engine start failure is stored. The engine 190 is not permitted to start and is not permitted.

  The determination in S12 of the wheel cylinder pressure control routine is performed based on the determination of success or failure of engine start in the engine start routine. If the engine start has failed and the engine start failure flag is set, the determination result in S12 is YES and S14 is executed to determine whether the engine start brake fluid outflow permission condition is satisfied. The In this embodiment, this condition is that the master cylinder pressure PM is larger than the brake fluid outflow allowable set pressure PMEG and the pedal stroke is smaller than the engine start allowable stroke STEG. The latter condition is that the determination result of S12 is Since the condition is satisfied when the answer is YES, only the determination of whether the master cylinder pressure PM is greater than the brake fluid outflow allowable set pressure PMEG is actually performed.

  If the engine start brake fluid outflow allowable condition is satisfied, the determination result in S14 is YES, S15 is executed, and the linear pressure reducing valve 90 provided for the front cylinder 14 is opened. In a state where the engine has failed to start, since the pedal stroke is smaller than the engine start allowable stroke and smaller than the hydraulic control allowable stroke ST0, the master cylinder shut-off valves 56 and 58 are opened and are in communication with each other. Brake fluid flows from the pressurizing chamber 210 to the reservoir 24 through the master cylinder shut-off valve 56 and the linear pressure reducing valve 90. According to the linear valve, it is possible to perform both allowance / non-acceptance of brake fluid outflow and flow control in the outflow permitted state. In this embodiment, the linear pressure reducing valve 90 is set in advance as shown in FIG. And the supply current to the solenoid is gradually increased and decreased. The brake fluid outflow amount from the master cylinder 12 is gradually increased and the depression speed of the brake pedal 10 is gradually increased and then gradually decreased, so that sudden depression and sudden stop are avoided. . The linear pressure reducing valve 90 is a normally closed valve. When the linear pressure reducing valve 90 is opened, the valve element moves against the urging force of the spring as the urging means and is separated from the valve seat. Since a set load is applied to the spring, the current necessary to overcome the set load (strictly, a current slightly smaller than that) is supplied all at once, and then the supply current gradually increases. The linear pressure reducing valve 90 is gradually opened and gradually closed. After the supply current is gradually reduced and the linear pressure reducing valve 90 is just closed, the supply current is reduced at once. The current supply time of the linear pressure reducing valve 90 takes into account the increasing and decreasing gradients of the brake fluid outflow amount, and a sufficient amount of brake fluid flows out so that the pedal stroke of the brake pedal 10 exceeds the engine start allowable stroke STEG. It is set to a sufficient length. In FIG. 10, it is assumed that the pedal stroke from the start of re-depression when the depressing of the brake pedal 10 is loosened and depressed again is illustrated.

  In S15, a current is supplied to the solenoid of the linear pressure reducing valve 90, and the linear pressure reducing valve 90 is gradually opened and brought into a communication state by being increased with a set gradient. The outflow amount of the brake fluid is gradually increased. As a result, the brake pedal 10 can be depressed, and the pedal stroke exceeds the engine start allowable stroke ST0. Then, if the set time elapses after the linear pressure reducing valve 90 starts to open, the supply current is gradually decreased with the set gradient, the linear pressure reducing valve 90 is closed, and the brake fluid flows from the pressurizing chamber 210 to the reservoir 24. Is stopped, and the brake pedal 10 is returned to a state where the brake fluid is supplied from the pressurizing chamber 210 to the front cylinder 14.

  In this way, when the brake fluid flows from the master cylinder 12 to the reservoir 24 and the pedal stroke increases and exceeds the engine start allowable stroke ST0, the brake switch 170 is turned on, and the determination result in S63 of the engine start routine becomes YES. S64 is executed and the engine 190 is started. In addition, the memory of engine start failure is reset. Therefore, when S12 is executed next time, the determination result is NO and S13 is executed, and the wheel cylinder pressure control at the rapid start is performed. If the depression of the brake pedal 10 is released, the determination result in S11 is NO and S16 is executed. The pressurizing pistons 204 and 206 return to the retracted end position, the on-off valves 240 and 242 are opened, and the brake fluid in the front cylinders 14 and 16 returns to the reservoir 24 through the pressurizing chambers 210 and 212.

  Even when the pumping operation is performed in a range where the depression stroke of the brake pedal 10 does not exceed the allowable hydraulic pressure control stroke, the pedal stroke is limited to a small value, and even if the engine 190 is started, the allowable engine startup stroke is obtained. In this case as well, if the determination result in S12 of the wheel cylinder pressure control routine is YES, and if the determination result in S14 is YES, S15 is executed, and the master cylinder 12 The brake fluid flows out from the pressurizing chamber 210 to the reservoir 24 through the master cylinder shutoff valve 56 and the linear pressure reducing valve 90, and the depression of the brake pedal 10 is not limited to a small amount, and the engine start allowable stroke is obtained. Can be activated. By replenishing the brake fluid from the reservoir 24 to the pressurizing chambers 210 and 212 by repeating the pumping operation, the amount of the brake fluid stored in the front cylinders 14 and 16 becomes larger than when the pumping operation is not performed. Brake fluid is unlikely to flow out from the pressurizing chambers 210 and 212 to the front cylinders 14 and 16, and in order to obtain a pedal stroke that exceeds the engine start allowable stroke, a larger pedaling force is required than when the pedal stroke is not limited. is there. When the brake pedal 10 returned to the middle of the original position is depressed again, the master cylinder pressure and the front cylinder pressure are increased as shown by the dotted lines in FIG. 9, and the faster the pumping operation, the higher the number of times, However, if the master cylinder pressure exceeds the brake fluid outflow allowable set pressure, the brake fluid is caused to flow out of the pressurizing chamber 210 due to the communication with the reservoir 24, and the engine start allowable stroke is increased. It will be obtained.

As is apparent from the above description, in this embodiment, the brake switch 170 is turned on based on the depression of the brake pedal 10, and the power supply circuit 180 is thus in a state of supplying drive current to the computer 152 and the like. Constitutes a brake operation corresponding activation part, the part for executing S22, S23 of the electronic control unit 28 constitutes a hydraulic pressure control prohibiting part as a second outflow permission part, and the part for executing S22, S23, S26, S28 Constitutes a blocking prohibition portion and a hydraulic pressure control prohibition portion as the outflow permission portion. A state in which the brake fluid is allowed to flow out from the master cylinder 12 to the wheel cylinders 14 and 16 by the second outflow permitting portion is a brake fluid outflow permitting state at the time of activation of the brake operation corresponding electronic control device. In addition, during the wheel cylinder pressure control at the rapid start, the normally closed simulator control valve 44 is not switched to the open state, but remains closed, and the configuration of the electronic control unit 28 that keeps the stroke simulator device 26 in a non-functional state is nonfunctional. A state holding unit is configured. Furthermore, the part that executes S28 of the electronic control device 28 constitutes a stepping force correspondence control unit that is an operation force correspondence control unit as the operation amount correspondence control unit, and the part that executes S31 to S34 constitutes an automatic stop unit. Yes. Further, the RAM 164 constitutes a shut-off master cylinder pressure storage unit. Furthermore, the part which performs S22 and S26 of the electronic control apparatus 28 comprises the 2nd setting operation amount arrival detection part which detects that the depression stroke of the brake pedal 10 reached the setting depression stroke.
Further, the brake switch 170 constitutes a drive source activation restricting portion, the master cylinder shut-off valves 56 and 58 and the linear pressure reducing valve 90 constitute a reservoir communication valve device as an outflow allowable valve device, and a portion for executing S12 of the computer 152 Constitutes a drive source activation impossibility detection unit, a portion for executing S14 constitutes a drive source activation intention confirmation unit or a brake fluid outflow allowance confirmation unit, and a portion for executing S15 is an outflow allowance valve as a first outflow allowance unit It constitutes an outlet allowing part via a pressure reducing valve, which is a reservoir communication valve control unit as a device control unit. A state where the brake fluid outflow from the master cylinder 12 is permitted by the first outflow permitting portion is a brake fluid outflow permitting state at the time of drive source activation restriction. In the present embodiment, in addition to the first and second states, the electronic control device takes a brake fluid discharge allowable state at the time of brake operation corresponding electronic control device activation and a brake fluid outflow allowable state at the time of drive source activation restriction. These can also be referred to as the fourth state and the fifth state, respectively.
The linear pressure reducing valve 90 can also control the flow rate by controlling the supply current to the solenoid, constitutes a flow rate control device, and the flow rate control device also serves as an outflow allowable valve device. A portion that gradually increases and decreases the supply current to the solenoid of the pressure reducing valve 90 and gradually increases and decreases the flow rate of the brake fluid flowing out from the master cylinder 12 constitutes a flow rate gradual change control unit.
In addition, the part that executes S62 and S63 of the engine control device 192 constitutes an engine start success / failure determination part, and the part that executes S65 and the part that stores the success or failure of engine start of the computer 196 constitutes an engine start success / failure storage part. ing.

Another embodiment of the claimable invention will be described with reference to FIGS.
In the electronically controlled hydraulic brake system according to the present embodiment, when the depression of the brake pedal 10 is released at the rapid start, the actual hydraulic pressure of the front cylinders 14 and 16 is controlled asymptotically to the master cylinder pressure PM0 when shut off. Done. The other configurations are the same as those of the embodiment shown in FIGS. 1 to 10, and the same reference numerals are given to the components having the same functions to show the corresponding relationship, and the description thereof is omitted.

  When the depression of the brake pedal 10 is released while the front cylinder pressure is controlled by the hydraulic pressure control valve device 62 at the rapid start, the driver may feel uncomfortable. The reason for this is that when the brake release operation is performed quickly, the master cylinder pressure decreases rapidly, but the pedal stroke reaches the set stroke due to the decrease delay caused by the control delay of the wheel cylinder pressure. Thus, when the master cylinder shut-off valves 56 and 58 are opened, it is assumed that the front cylinder pressure is larger than the master cylinder pressure, and the influence of this hydraulic pressure difference is transmitted to the brake pedal 10. If there is no delay, the front cylinder pressure is lowered as shown by a thick dotted line in FIG. 12, but is lowered as shown by a two-dot chain line due to the lowering delay, and when the master cylinder shut-off valves 56 and 58 are opened, The front cylinder pressure becomes larger than the master cylinder pressure when shut off.

  Therefore, in the electronically controlled hydraulic brake system of the present embodiment, when the depression of the brake pedal 10 is released, the operation is continued until the master cylinder pressure is reduced to the set master cylinder pressure PM1 that is larger than the master cylinder pressure PM0 when shut off. As in the operation, the target hydraulic pressure is set based on the master cylinder pressure at the time of shutoff and a preset gradient. After the target hydraulic pressure is reduced to the set master cylinder pressure PM1, as shown by the broken line in FIG. The target hydraulic pressure is set so that the actual hydraulic pressure of the cylinders 14 and 16 gradually approaches the master cylinder pressure when shut off.

The control of the wheel cylinder pressure at the rapid start will be described based on the flowchart shown in FIG. Also in this system, the wheel cylinder pressure control routine of the above embodiment is executed, and the control routine shown in FIG. 11 is executed as the control of S13 of the wheel cylinder pressure control routine. In the rapid start wheel cylinder pressure control routine of this embodiment, the description of the same parts as those of the control of the above embodiment is omitted.
If the electronic control unit 28 is activated by a rapid start and the depression stroke of the brake pedal 10 becomes equal to or greater than the hydraulic pressure control allowable stroke ST0 and the previous value of the pedal stroke also exceeds the hydraulic pressure control allowable straw ST0, the steps after S51 Is executed.

  During the operation of the brake pedal 16, once the pedal stroke exceeds the hydraulic pressure control allowable stroke, the previous pedal stroke also exceeds the hydraulic pressure control allowable stroke, the determination result of S26 becomes NO, and S51 is executed. The In S51, it is determined whether or not the depression of the brake pedal 10 is an action operation for operating the brake. This determination is made based on, for example, whether the master cylinder pressure has increased. The determination is made based on whether or not the stepping force is increasing. When S51 is executed, for example, the detection value of the master cylinder pressure sensor 64 that detects the hydraulic pressure in the pressurizing chamber 210 is read and stored. Here, the master cylinder pressure acquired by the previous execution of S51 and the master cylinder pressure acquired by the current execution of S51 are stored in the same manner as the storage of the two successive pedal strokes in S22. It is determined whether or not the master cylinder pressure is greater than the previous master cylinder pressure. The master cylinder pressure is obtained by two master cylinder pressure sensors 64. For example, the average value of the two master cylinder pressures is set as the current master cylinder pressure. One of the two master cylinder pressures may be the current master cylinder pressure. If the current master cylinder pressure is larger than the previous master cylinder pressure, the brake pedal 10 is being operated, the determination result in S51 is YES, S28 is executed, and the target hydraulic pressure in the front cylinders 14 and 16 is executed. Is set.

  When the driver releases the brake pedal 10 and releases the brake operation, the pedal stroke decreases. Also during this time, while the pedal stroke is equal to or larger than the hydraulic pressure control allowable stroke ST0, the hydraulic pressures of the wheel cylinders 14 and 16 are reduced while being controlled by the hydraulic pressure control valve device 62 by executing S28 and S53. At the time of brake release operation, the current master cylinder pressure becomes smaller than the previous master cylinder pressure, the determination result in S51 is NO, S52 is executed, and whether or not the master cylinder pressure has decreased to the set master cylinder pressure PM1. Determined. The set master cylinder pressure PM1 is set by applying a set pressure to the master cylinder pressure PM0 when shut off. If the master cylinder pressure PM does not decrease beyond the set master cylinder pressure PM1, the determination result in S52 is NO and S28 is executed, and the target hydraulic pressure of the front cylinders 14 and 16 is set in the same manner as during the operation. Is done.

If the master cylinder pressure PM becomes smaller than the set master cylinder pressure PM1, the determination result in S52 is YES, S53 is executed, and the actual hydraulic pressure of the front cylinders 14 and 16 approaches the master cylinder pressure PM0 when shut off. A target hydraulic pressure Pref is set. The target hydraulic pressure Pref is set according to the following formula in this embodiment.
Pref = α · Pref0 + (1−α) · PM0
α = (PM−PM0) / (PM1−PM0)
In this embodiment, Pref0 is a target hydraulic pressure set in the same manner as in the operation operation, and PM is an actual master cylinder pressure. Therefore, when the master cylinder pressure PM becomes smaller than the set master cylinder pressure PM1, the coefficient α becomes larger than 0 and smaller than 1, and the target hydraulic pressure Pref is set as the target hydraulic pressure set in the same manner as in the operation operation. It is set on the basis of both Pref0 and master cylinder pressure PM0 when shut off.

  While the depressing operation of the brake pedal 10 is performed, the determination result in S52 is YES due to a decrease in the master cylinder pressure, and S53 is executed. Even when S53 is executed, the master cylinder shutoff valves 56 and 58 remain closed. As the actual master cylinder pressure PM approaches the shut-off master cylinder pressure PM0, the coefficient α decreases, the target fluid pressure Pref approaches the shut-off master cylinder pressure PM0, and the pedal stroke decreases to the fluid pressure control allowable stroke ST0. When the master cylinder shut-off valves 56 and 58 are opened, the actual master cylinder pressure PM becomes equal to the shut-off master cylinder pressure PM0, and the target hydraulic pressure Pref is set to the shut-off master cylinder pressure PM0. In the electronically controlled hydraulic brake system, as described above, the target hydraulic pressure is set so that the hydraulic pressure increases from the master cylinder pressure PM0 when shut off at a set gradient and decreases at the same set gradient as when increased. As the actual master cylinder pressure PM decreases, the target hydraulic pressure approaches the shut-off master cylinder pressure PM0. However, by setting the coefficient α, the target hydraulic pressure decrease gradient is increased, and the graph of FIG. As shown, the decrease delay is absorbed and the actual front cylinder pressure is brought close to the master cylinder pressure when shut off. Therefore, when the master cylinder shut-off valves 56 and 58 are opened, the hydraulic pressure difference between the hydraulic pressures of the front cylinders 14 and 16 and the hydraulic pressure of the master cylinder 12 is small. There is little outbreak. Although the illustration is omitted in FIG. 13 due to the quick release operation of the brake pedal 10, after the master cylinder shut-off valves 56 and 58 are opened, the master cylinder pressure rapidly decreases as shown in FIG. The front cylinder pressure decreases slowly.

  If the pedal stroke becomes smaller than the hydraulic pressure control allowable stroke ST0, the determination result in S22 is NO, S23 is executed, the master cylinder shutoff valves 56 and 58 are opened, and the control by the hydraulic pressure control valve device 62 is performed. The end process is performed. S23 and S24 are executed until the depression of the brake pedal 10 is released, and the front cylinders 14 and 16 are disconnected from the master cylinder 12, and the control of the front cylinder pressure by the hydraulic pressure control valve device 62 is again prohibited.

  Thus, in the electronically controlled hydraulic brake system, the hydraulic control allowable stroke ST0 is the third set operation amount, and the third set operation amount and the second set operation amount are the same. Further, at the time of brake release operation, the master cylinder pressure is lowered with the same gradient as that at the time of operation by restoring elastic deformation of components such as the liquid passage until the master cylinder shut-off valves 56 and 58 are opened. The master cylinder pressure when the pedal stroke is reduced to the hydraulic pressure control allowable stroke ST0 becomes the master cylinder pressure PM0 when shut off. The master cylinder pressure PM0 when shut off is also the third set operation amount and is set to the master cylinder pressure PM0 when shut off. The master cylinder pressure PM1 to which pressure is applied is the fourth set operation amount.

  When the brake release operation is performed without the master cylinder pressure exceeding the set master cylinder pressure PM1, S28 is not executed, only S53 is executed, and the front cylinder pressure is made asymptotic to the master cylinder pressure PM0 when shut off. It is done.

  Also in this electronically controlled hydraulic brake system, the wheel cylinder pressure control routine is executed in the same manner as in the above-described system, and when the engine start fails and the engine start brake fluid outflow allowable condition is satisfied, the linear pressure reducing valve 90 is opened. As a result, the brake fluid flows from the master cylinder 12 to the reservoir 24 through the master cylinder shut-off valve 56 and the linear pressure reducing valve 90. As shown in the graph of FIG. 14, when the depression of the brake pedal 10 is loosened, if the pedal stroke becomes equal to or less than the hydraulic pressure control allowable stroke ST0, the master cylinder pressure rapidly decreases and becomes negative. The cylinder pressure is gradually reduced. Then, when the brake pedal 10 is depressed again without releasing the depression, the master cylinder pressure and the front cylinder pressure are increased as shown by thin dotted lines in FIG. 14, but if the master cylinder pressure is relatively small, The pedal stroke is limited to be smaller than the engine start allowable stroke STEG. As a result, the linear pressure reducing valve 90 is opened if the engine start brake fluid outflow allowable condition that the pedal stroke is smaller than the engine start allowable stroke STEG and the master cylinder pressure exceeds the brake fluid outflow allowable set pressure PMEG is satisfied. By the outflow of the brake fluid from the master cylinder 12 to the reservoir 24, the driver can further depress the brake pedal 10 to start the engine 190.

  As is apparent from the above description, in this embodiment, the part that executes S22 and S23 of the electronic control unit 28 constitutes the re-inhibition part or the prohibition state return part, and the part that executes S27 is the master cylinder when shut off. The pressure storage unit is configured, and the asymptotic control unit is configured together with the portion that executes S53. Moreover, the part which performs S22 of the electronic control apparatus 28 comprises the 3rd setting operation amount arrival detection part, and the part which performs S52 comprises the 4th setting operation amount arrival detection part.

  In addition, when the operation stroke of the brake operation member is insufficient and the engine fails to start, the brake fluid is allowed to flow out from the master cylinder to the stroke simulator device, and the engine is started by depressing the brake pedal. Also good. In this case, for example, if the stroke simulator device includes a stroke simulator and a simulator control valve as in the above embodiment, the simulator control valve is opened to allow the brake fluid to flow out from the master cylinder to the stroke simulator. If the simulator control valve is an electromagnetic on-off valve that can be switched between an open state that is opened when current is supplied to the solenoid and an open state that is closed when supply is stopped, the simulator control valve need only be opened for a set time. It is desirable to adjust the flow rate by performing duty control so that the moving speed of the valve is accelerated and decelerated so that it is gradually opened or closed. The simulator control valve may be a linear valve and the flow rate may be adjusted. The simulator control valve constitutes an outflow allowable valve device, controls the simulator control valve of the electronic control device, and the portion that allows the brake fluid to flow out from the master cylinder to the stroke simulator constitutes the stroke simulator control valve device control unit.

  Further, the control at the rapid start may be performed entirely based on the operation stroke of the brake operation member from the start to the release of the operation of the brake operation member, or may be performed based on the entire operation force. In these cases, the second, third, and fourth set operation amounts can be set only by the operation stroke or the operation force, respectively.

  In addition, it is not indispensable to control the hydraulic pressure of the wheel cylinder based on the hydraulic pressure of the power hydraulic pressure source after the operating amount of the brake operating member reaches the set operating amount at the rapid start. The wheel cylinder is kept in communication with the master cylinder until the operation of the operation member is released, and the brake is activated by supplying the hydraulic pressure generated in the master cylinder by the operation of the brake operation member by the driver to the wheel cylinder. It may be allowed to be made.

  Further, in each of the above embodiments, the hydraulic pressure control at the rapid start is performed for all the front cylinders, but only a part of the front cylinders are performed, and the remaining front cylinders are the same as the rear cylinders. Alternatively, the hydraulic pressure may be controlled by a hydraulic pressure control valve device. It is not indispensable to perform the hydraulic pressure control at the rapid start for all the wheel cylinders connected to the pressurizing chamber of the master cylinder, and only a part may be performed. In this case, for example, in each of the above embodiments, the rear cylinder pressure control is performed in S21 of the wheel cylinder pressure control routine, and the master cylinder shut-off valve corresponding to one of the left and right front cylinders is closed to control the hydraulic pressure. The valve device 62 controls the hydraulic pressure of one front cylinder to a magnitude corresponding to the depression force of the brake pedal 10. In S23, the master cylinder cutoff valve corresponding to the other front cylinder is opened and closed in S28. Regardless of which of the left and right front cylinders is controlled by the hydraulic control valve device 62, the stroke simulator device is kept in a non-functional state during the depression of the brake pedal that causes the electronic control device to start. .

  Further, when releasing the operation of the brake operation member, control may be performed so that the hydraulic pressure of the wheel cylinder gradually approaches the hydraulic pressure of the master cylinder from the beginning of the release.

  Furthermore, the target hydraulic pressure of the wheel cylinder during normal braking control may be set based on the operation stroke of the brake operation member, or may be set based on the operation stroke and the operation force. In the former case, if the wheel cylinder pressure is controlled based on the hydraulic pressure of the power hydraulic pressure source after the operating amount of the brake operating member exceeds the first set operating amount at the rapid start, the target fluid of the wheel cylinder pressure The pressure is set based on the operation stroke. In the latter case, the pressure may be set based on both the operation stroke and the operation force, or may be set based on the operation force.

  Further, the stroke simulator and the simulator control valve may be provided for each of the two pressurizing chambers of the master cylinder. Also in this case, the stroke simulator device is kept in a non-functional state during the operation of the brake operation member that causes the electronic control device activation by the brake operation corresponding activation unit.

  In each of the above embodiments, the check device and shut-off device for the master cylinder are each constituted by a cup seal and an on-off valve provided on the pressurizing piston. However, the cup provided with the check device on the pressurizing piston is provided. It may be configured by a seal, and the blocking device may be configured by a port formed in the housing. The port connects the pressurizing chamber and the reservoir in a state where the pressurizing piston is located at the retracted end, and the pressurizing chamber is defined in relation to the cup seal in a state where the pressurizing piston moves forward a set distance or more from the retracted end. It is located on the opposite side (the rear side from the cup seal), and is provided at a position that blocks communication between the pressurizing chamber and the reservoir.

  Furthermore, when the wheel cylinder that operates the brake that suppresses the rotation of the rear wheel is connected to the master cylinder, the second outflow permitting portion causes the brake fluid to flow out from the master cylinder to the wheel cylinder of the rear wheel brake. It may be allowed.

  Further, the electronic control unit may execute an engine start routine shown in FIG. In this case, the part which performs S62 and S63 of the electronic control unit constitutes a drive source activation impossibility detecting unit.

  Further, in S12 of the wheel cylinder pressure control routine, it is determined whether or not the ignition switch is turned on and whether or not the brake switch is turned on, and whether or not the drive source cannot be started is determined. It may be detected.

  Further, in an electronically controlled hydraulic brake system in which the master cylinder has two pressurizing chambers, each of which is connected to the front cylinder, the linear pressure reducing valve is opened to allow the brake fluid to flow out from the master cylinder to the reservoir. In this case, the linear pressure reducing valve provided for the front cylinder of the right front wheel brake may be opened, or the linear pressure reducing valves provided for the front cylinders of the left and right front wheel brakes may be opened together.

  Further, the claimable invention can be applied to an electronically controlled hydraulic brake system in which the connection between the master cylinder and the wheel cylinder is made in another manner. For example, a plurality of master cylinders, for example, one of the two pressurizing chambers is connected to a wheel cylinder that operates each brake on the left and right front wheels, and the other is connected to a wheel cylinder that operates each brake on the left and right rear wheels Electronic control where hydraulic brake system or one of the two pressurizing chambers is connected to the wheel cylinder of each brake of the left front wheel and right rear wheel, and the other is connected to the wheel cylinder of each brake of the right front wheel and left rear wheel The claimable invention can be applied to a hydraulic brake system. In these cases, for one of the systems, even at the rapid start, the wheel cylinder is disconnected from the master cylinder by starting the operation of the brake operation member, and the hydraulic pressure is controlled based on the hydraulic pressure of the power hydraulic pressure source. Thus, a high braking force can be obtained. One of the two systems performs hydraulic pressure control during rapid start, and the other performs hydraulic pressure control during normal braking. Further, the control at the time of rapid start may be performed for both wheel cylinders of two brakes belonging to one of the two systems, or only one of them may be performed.

1 is a circuit diagram showing an electronically controlled hydraulic brake system that is an embodiment of the claimable invention; FIG. It is a block diagram which shows notionally the electronic control apparatus of the said electronically controlled hydraulic brake system. It is a flowchart which shows the rapid start determination routine memorize | stored in ROM of the computer which comprises the main body of an electronic controller. It is a flowchart which shows the wheel cylinder pressure control routine memorize | stored in ROM of the said computer. It is a flowchart which shows the wheel cylinder pressure control routine at the time of the rapid start memorize | stored in ROM of the said computer. It is a flowchart which shows the electronic controller automatic stop determination routine memorize | stored in ROM of the said computer. It is a flowchart which shows the engine starting routine memorize | stored in ROM of the computer of the engine control apparatus of the vehicle provided with the said electronically controlled hydraulic brake system. It is a graph which shows the relationship between the brake pedal depression amount when the wheel cylinder pressure control at the time of rapid start is performed by the said wheel cylinder pressure control routine, and the target hydraulic pressure of a wheel cylinder. It is a graph explaining the outflow of the brake fluid from a master cylinder when engine starting fails. It is a graph which shows the change with respect to time of the electric current and pedal stroke which are supplied to a linear pressure-reduction valve for the outflow of the brake fluid from the said master cylinder. It is a flowchart which shows the wheel cylinder pressure control routine at the time of a rapid start memorize | stored in ROM of the computer which comprises the main body of the electronic controller of the electronically controlled hydraulic brake system which is another Example of claimable invention. FIG. 12 is a graph showing changes with time in front cylinder pressure and master cylinder pressure when wheel cylinder pressure control is performed by the rapid start wheel cylinder pressure control routine shown in FIG. 11. 12 is a graph showing a relationship between a brake pedal depression amount, a front cylinder pressure, and a master cylinder pressure when wheel cylinder pressure control is performed by the rapid start wheel cylinder pressure control routine shown in FIG. 12 is a graph for explaining the outflow of brake fluid from a master cylinder when engine start-up fails when wheel cylinder pressure control at a rapid start is performed based on the flowchart shown in FIG. 11.

Explanation of symbols

  10: Brake pedal 12: Master cylinder 14, 16: Front cylinder 26: Stroke simulator device 28: Electronic control device 42: Stroke simulator 44: Stroke simulator control valve 56, 58: Master cylinder shutoff valve 60: Power hydraulic pressure source 62: Fluid pressure control valve device 80, 82, 84, 86: Linear pressure increasing valve 90, 92, 94, 96: Linear pressure reducing valve 182: Ignition switch

Claims (11)

A master cylinder that generates hydraulic pressure in response to the operation of the brake operating member;
A plurality of wheel cylinders that are connected to the master cylinder and actuate brakes that respectively suppress rotation of a plurality of wheels of the vehicle;
A power hydraulic pressure source that generates hydraulic pressure by power,
A switching device provided between at least the master cylinder, the wheel cylinder and the power hydraulic pressure source, and switching at least the three communication states;
The switching device includes a first state in which at least a part of the plurality of wheel cylinders communicates with the master cylinder, and a brake from the master cylinder by disconnecting at least a part of the switching device from the master cylinder. In a state where the outflow of liquid is restricted, the hydraulic pressure of the plurality of wheel cylinders is controlled to a second state in which the hydraulic pressure of the plurality of wheel cylinders is controlled to a magnitude corresponding to the operation of the brake operation member based on the hydraulic pressure of the power hydraulic pressure source. An electronic control unit;
When a drive source activation command for activating a drive source for driving the vehicle is issued, if the operation stroke of the brake operation member is equal to or greater than a set operation stroke, the drive source is permitted to be activated and a setting operation is performed. A drive source activation restricting section that does not allow activation when the stroke is smaller than the stroke;
When the drive source activation restriction unit does not allow the drive source to be activated even though the drive source activation command has been issued , the switching device is controlled to a state in which the brake fluid is allowed to flow out of the master cylinder. An electronically controlled hydraulic brake system characterized by comprising an outflow allowing portion. Wherein said brake operating corresponding activation unit that activates in response to the braking action operation is an operation of the direction which applies the brake of the brake operating member said electronic control unit, the outflow allowable portion, electrons by the brake operation corresponding starting unit After the brake operation that caused the control device to start, when the brake release operation is performed halfway and the brake operation operation is performed again one or more times, the drive source activation restriction unit drives the drive 2. The electronically controlled hydraulic brake system according to claim 1 , wherein when the activation of the source is not permitted, the switching device is controlled to allow the brake fluid to flow out of the master cylinder. 3. In the case where the outflow permission portion is not permitted to start the drive source by the drive source start restricting portion even though the brake operation member is operated with an operation force equal to or greater than a set operation force, electronically controlled hydraulic brake system according to claim 1, characterized in that to control the state of allowing the outflow of the brake fluid. 2. The electronically controlled hydraulic brake system according to claim 1, wherein the outflow permission unit allows the brake fluid to flow out of the master cylinder in accordance with an operation of an outflow permission command operation member by a driver. The outflow permission unit includes a drive source activation impossibility detection unit that detects that the drive source activation restriction unit does not actually permit activation of the drive source, and the drive source activation impossibility detection unit detects the drive source activation impossibility. 2. The electronically controlled hydraulic brake system according to claim 1, wherein the brake fluid is allowed to flow out of the master cylinder based on The brake operation corresponding start part which starts the said electronic control apparatus according to the brake action operation which is the operation of the direction which makes the said brake of the said brake operation member act is given, The Claim 1 or 3 thru | or 5 characterized by the above-mentioned. Electronically controlled hydraulic brake system as described in The switching device includes an outflow allowance valve device that allows an outflow of brake fluid from the master cylinder to a portion other than the wheel cylinder, and the outflow allowance portion controls the outflow of the brake fluid from the master cylinder under the control of the outflow allowance valve device. The electronically controlled hydraulic brake system according to any one of claims 1 to 6 , further comprising an outflow allowable valve device controller that allows The electronically controlled hydraulic brake system includes a reservoir for storing brake fluid, the outflow allowable valve device includes a reservoir communication valve device for communicating the master cylinder with the reservoir, and the outflow allowable valve device control unit includes the reservoir. 8. An electronically controlled hydraulic pressure according to claim 7 , further comprising a reservoir communication valve device controller that allows the brake fluid to flow from the master cylinder to the reservoir by communicating the master cylinder with the reservoir via the communication valve device. Brake system. The reservoir communication valve device comprises:
A master cylinder shut-off valve that is provided between the master cylinder and at least one of the plurality of hole cylinders and is capable of switching between a communicating state for communicating the two and a shut-off state for shutting off;
A pressure reducing valve that is provided between the at least one wheel cylinder and the reservoir and is capable of switching between a communicating state and a shut-off state that shuts off both, and the reservoir communicating valve device control unit includes:
When the drive source is not permitted to be activated by the drive source activation restricting unit, the master cylinder shut-off valve and the pressure reducing valve are both in communication, and the pressure is reduced to allow the brake fluid to flow from the master cylinder to the reservoir via both. 9. The electronically controlled hydraulic brake system according to claim 8 , further comprising a valve-routed flow allowance section. The switching device includes a stroke simulator control valve as the outflow allowance valve device, and a non-functional state that prevents outflow of brake fluid from the master cylinder to other than the plurality of wheel cylinders, and allows outflow and the brake operation. A stroke simulator device in a functional state in which a reaction force that increases with an increase in the operation stroke of the brake operation member is applied to the member, and the outflow allowable valve device control unit controls the master cylinder by controlling the stroke simulator control valve. The electronically controlled hydraulic brake system according to any one of claims 7 to 9 , further comprising a stroke simulator control valve control section that allows a brake fluid to flow out from the brake simulator to the stroke simulator device . The spillable valve device includes a flow rate control device capable of controlling a flow rate of brake fluid by controlling a supply current, and the spillable valve device controller is configured to supply brake fluid from the master cylinder via the spillable valve device. at least one of the time of stopping the outflow and when to start the flow of claims 7 to 10, characterized in that it comprises a flow graded control unit for graded the flow rate of brake fluid by the control of the flow control device The electronically controlled hydraulic brake system according to any one of the above.

Images