JP2015123934A - Brake hydraulic pressure generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake hydraulic pressure generator having a down-sized base substrate to which a master cylinder and a stroke simulator are incorporated.SOLUTION: A brake hydraulic pressure generator 1A includes: a master cylinder 20; a main hydraulic passage 11a extending from the master cylinder 20 to a wheel brake; a slave cylinder 40; a communication passage 14a extending from the slave cylinder 40 to the main hydraulic passage 11a; and a master cut valve 15a for opening and closing the main hydraulic passage 11a. The slave cylinder 40 is able to raise a pressure in the wheel brake side of the main hydraulic passage 11a. In a cylinder hole 21 of the master cylinder 20, an opening-side pressure chamber 21d and a bottom-side pressure chamber 21c are formed. To the bottom-side pressure chamber 21c is connected an outflow passage 13 that has a second on-off valve 17a for opening and closing the outflow passage 13.

Description

  The present invention relates to a brake fluid pressure generator used in a vehicle brake system.

  The brake fluid pressure generating device that generates the brake fluid pressure includes a master cylinder that generates the brake fluid pressure by operating the brake pedal, a slave cylinder that generates the brake fluid pressure by driving the motor, and a reaction to the brake pedal. Some have a stroke simulator that applies force (see, for example, Patent Document 1).

JP2012-106637A

  In the conventional brake fluid pressure generating device described above, the cylinder hole of the master cylinder and the cylinder hole of the stroke simulator are provided separately, so that there is a problem that the base body in which the master cylinder and the stroke simulator are incorporated is enlarged.

  An object of the present invention is to provide a brake fluid pressure generating device that can solve the above-described problems and can reduce the size of a base body in which a master cylinder and a stroke simulator are incorporated.

  In order to solve the above problems, a brake fluid pressure generating device according to the present invention includes a master cylinder that generates brake fluid pressure by operating a brake operator, a main fluid pressure path that leads from the master cylinder to a wheel brake, and the brake operation. A slave cylinder that generates brake fluid pressure by driving an electric actuator according to the operation amount of the child, a communication passage that leads from the slave cylinder to the main fluid pressure passage, and a master cut valve that opens and closes the main fluid pressure passage And. The slave cylinder can boost the wheel brake side of the main hydraulic pressure path with respect to the master cut valve. In the cylinder hole of the master cylinder, two pistons are accommodated and a first pressure chamber and a second pressure chamber are formed. An outflow path is connected to the second pressure chamber, and an on / off valve for the outflow path that opens and closes the outflow path is provided.

In the present invention, when the master cut valve is closed and the on-off valve for the outflow passage is opened, the brake fluid pressure generated in the master cylinder is transmitted to the wheel brakes when input to both pistons from the brake operator. Instead, the brake fluid pressure generated in the slave cylinder is transmitted to the wheel brake. At this time, both pistons can move in the cylinder hole while allowing the brake fluid in the second pressure chamber to flow into the outflow path. Thereby, since the brake operator can be stroked, it is possible to give the driver the feeling of operation of the brake operator.
In other words, in the present invention, the second pressure chamber of the master cylinder plays the role of a stroke simulator. Thus, in the present invention, the stroke simulator is provided in the cylinder hole of the master cylinder, and the master cylinder and the stroke simulator are integrated.

In the brake fluid pressure generating device described above, the brake fluid pressure generator includes a first brake system that communicates with at least one of the wheel brakes and a second brake system that communicates with the remaining wheel brakes. A first main hydraulic pressure path provided in the first brake system and leading from the first pressure chamber to the wheel brake, and a second main pressure path provided in the second brake system and leading from the second pressure chamber to the wheel brake. When having a hydraulic pressure path, the master cut valve may be provided in each of the first main hydraulic pressure path and the second main hydraulic pressure path.
In this configuration, when the brake operator is operated in a state where the master cut valve is opened, the brake fluid pressure generated in the first pressure chamber and the second pressure chamber can be transmitted to different wheel brakes.

  In the above-described brake fluid pressure generating device, the on-off valve for the outflow passage may be constituted by a linear solenoid valve. In this configuration, since the brake fluid pressure in the second pressure chamber can be adjusted by adjusting the valve opening pressure of the on-off valve, the operation reaction force applied to the brake operator can be adjusted.

  In the brake hydraulic pressure generator described above, a piston is accommodated in the cylinder hole of the slave cylinder and a pressure chamber is formed, and the communication path leads from the slave cylinder to the first main hydraulic pressure path. You may comprise so that it may have a 1st serial path and the 2nd communicating path which leads to a said 2nd main hydraulic pressure path from the said slave cylinder. In addition, it is desirable to provide a communication passage opening / closing valve in the first series passage or the second communication passage.

  In the above-described brake fluid pressure generating device, the second pressure chamber may accommodate an elastic member that applies a pseudo operation reaction force to the brake operator. In this configuration, the operation reaction force can be efficiently applied to the brake operator by the elastic member.

  In this configuration, when the master cut valve is closed and the open / close valve for the communication path is closed and one communication path is closed, the brake fluid pressure is transmitted from the slave cylinder to the wheel brake through the other communication path. The Therefore, it is possible to increase the pressure of one of the two hydraulic paths independently by the single piston type slave cylinder.

  In the brake fluid pressure generating device described above, the master cut valve is a three-way valve, and can communicate the master cylinder side and the wheel brake side, and block the communication path side and the wheel brake side. . Moreover, the said master cut valve can interrupt | block the said master cylinder side and the said wheel brake side, and can connect the said communicating path side and the said wheel brake side. Thus, when the master cut valve is a three-way valve, the hydraulic circuit of the brake hydraulic pressure generator can be simplified.

  In the present invention, since the stroke simulator is provided in the cylinder hole of the master cylinder and the master cylinder and the stroke simulator are integrated, the base on which the master cylinder and the stroke simulator are assembled can be reduced in size.

1 is a hydraulic circuit diagram showing a vehicle brake system using a brake hydraulic pressure generator according to a first embodiment. It is a hydraulic-pressure circuit diagram of the hydraulic-pressure control apparatus of the brake system for vehicles of a first embodiment. It is a figure which shows the relationship between the operation amount of a brake pedal, and pressure. It is the hydraulic circuit diagram which showed the time of starting of the brake hydraulic pressure generator of 1st embodiment. It is a modification of the brake hydraulic pressure generator of 1st embodiment, and is a hydraulic circuit figure of composition which connected an outflow way to an opening side pressure room. It is the hydraulic circuit diagram which showed the brake system for vehicles using the brake hydraulic pressure generator of 2nd embodiment. It is the hydraulic circuit diagram which showed the modification of the brake hydraulic pressure generator of 2nd embodiment.

Each embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
In the description of each embodiment, the same constituent elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[First embodiment]
In the first embodiment, a case where the brake fluid pressure generating device of the present invention is applied to the vehicle brake system A shown in FIG. 1 will be described as an example.

  As shown in FIG. 1, the vehicle brake system A includes a by-wire brake system that operates when a prime mover (such as an engine or an electric motor) is started, and a hydraulic system that operates when the prime mover is stopped. It is equipped with both brake systems.

The vehicle brake system A supports a brake fluid pressure generating device 1A that generates a brake fluid pressure in accordance with an operation amount of a brake pedal P (“brake operator” in claims), and stabilization of vehicle behavior. And a hydraulic pressure control device 2.
The vehicle brake system A can be mounted not only on a vehicle that uses only an engine (internal combustion engine) as a power source, but also on a hybrid vehicle that uses a motor together, an electric vehicle that uses only a motor as a power source, and a fuel cell vehicle. .

  The brake fluid pressure generator 1A generates brake fluid pressure by driving a base body 10, a master cylinder 20 that is operated by operating the brake pedal P, and a motor 44 (electric actuator) according to the amount of operation of the brake pedal P. A slave cylinder 40 and an electronic control unit 50 are provided.

The base body 10 is a metal part mounted on a vehicle, and has two cylinder holes 21 and 41 and a plurality of hydraulic pressure paths 11a, 11b, 13, 14a, and 14b. Various components such as a reservoir 26 and a motor 44 are attached to the base 10.
In the base body 10, a first brake system K1 and a second brake system K2 are provided. The first brake system K1 is provided with a first main hydraulic pressure passage 11a that leads from the master cylinder 20 to one of the wheel brakes FL, RR, and the second brake system K2 includes from the master cylinder 20 to the other wheel brake RL, A second main hydraulic pressure passage 11b leading to the FR is provided. In addition, an outflow passage 13 and two communication passages 14 a and 14 b are formed in the base 10.

  The master cylinder 20 has two first pistons 22 and 23 (secondary pistons and primary pistons) inserted into a bottomed cylindrical first cylinder hole 21 and three elastic members accommodated in the first cylinder hole 21. Members 24a, 24b, and 25.

A bottom-side pressure chamber 21c (a “second pressure chamber” in the claims) is formed between the bottom surface 21a of the first cylinder hole 21 and the first piston 22 (secondary piston) on the bottom surface 21a side. Yes. First elastic members 24a and 24b made of coil springs are accommodated in the bottom pressure chamber 21c.
The first elastic members 24a and 24b push the first piston 22 moved to the bottom surface 21a side back to the opening 21b side and apply an operation reaction force to the brake pedal P. That is, the bottom side pressure chamber 21c also has a role as a pressure chamber for the stroke simulator.

An opening-side pressure chamber 21d (“first pressure chamber” in the claims) is formed between the first piston 22 on the bottom surface 21a side and the second piston 23 (primary piston) on the opening 21b side. Yes. A second elastic member 25 made of a coil spring is accommodated in the opening-side pressure chamber 21d.
The 2nd elastic member 25 pushes back the 2nd piston 23 which moved to the bottom face 21a side to the opening part 21b side.

The rod P1 of the brake pedal P is inserted into the first cylinder hole 21 through the opening 21b. The tip of the rod P1 is connected to the second piston 23 on the opening 21b side. Thereby, the 2nd piston 23 by the side of the opening part 21b is connected with the brake pedal P via the rod P1.
Both the first pistons 22 and 23 receive the depression force of the brake pedal P, slide in the first cylinder hole 21 toward the bottom surface 21a, and apply brake fluid in the bottom pressure chamber 21c and the opening pressure chamber 21d. Press.

  A reservoir 26 is connected to the first cylinder hole 21. The reservoir 26 is a container that stores brake fluid, and is attached to the upper surface of the base body 10.

The slave cylinder 40 includes a second piston 42 inserted into a bottomed cylindrical second cylinder hole 41, an elastic member 43 accommodated in the second cylinder hole 41, a motor 44, a drive transmission unit 45, It has.
A pressure chamber 41 b is formed between the bottom surface 41 a of the second cylinder hole 41 and the second piston 42. An elastic member 43 made of a coil spring is accommodated in the pressure chamber 41b.

  The motor 44 is an electric servo motor that is driven and controlled by the electronic control unit 50. A drive gear 44b, which is a spur gear, is attached to the output shaft 44a of the motor 44. The drive gear 44b meshes with the driven gear 45c of the drive transmission unit 45 via the gear 44c.

The drive transmission unit 45 converts the rotational driving force of the output shaft 44a of the motor 44 into a linear axial force.
The drive transmission unit 45 includes a rod 45a that is in contact with the second piston 42, a cylindrical nut member 45b that surrounds the rod 45a, and a driven gear 45c that is a spur gear formed on the entire circumference of the nut member 45b. And.

  A spiral thread groove is formed on the outer peripheral surface of the rod 45a. A plurality of balls 45d are rotatably accommodated in the thread groove, and the nut member 45b is screwed to each ball 45d. Thus, the ball screw mechanism is provided between the nut member 45b and the rod 45a.

  When the output shaft 44a rotates, the rotational driving force is input to the nut member 45b via the drive gear 44b, the gear 44c, and the driven gear 45c. Then, a linear axial force is applied to the rod 45a by the ball screw mechanism provided between the nut member 45b and the rod 45a, and the rod 45a moves forward and backward.

  The tip of the rod 45a is in contact with the second piston 42. When the rod 45a moves to the second piston 42 side, the second piston 42 receives an input from the rod 45a and slides in the second cylinder hole 41 to the bottom surface 41a side, and brake fluid in the pressure chamber 41b. Pressurize.

Next, each hydraulic pressure path formed in the substrate 10 will be described.
The two main hydraulic pressure paths 11 a and 11 b are hydraulic pressure paths starting from the first cylinder hole 21 of the master cylinder 20.
The first main hydraulic pressure passage 11 a communicates with the opening side pressure chamber 21 d of the master cylinder 20. Further, the second main hydraulic pressure path 11 b communicates with the bottom surface side pressure chamber 21 c of the master cylinder 20. Pipes Ha and Hb leading to the hydraulic pressure control device 2 are connected to the two output ports 19 and 19 which are the end points of both the main hydraulic pressure paths 11a and 11b.

The first series passage 14 a and the second communication passage 14 b are hydraulic pressure paths starting from the second cylinder hole 41 of the slave cylinder 40. The two communication passages 14a and 14b merge with the common hydraulic pressure path 46 before the second cylinder hole 41, and are connected to the second cylinder hole 41 as one liquid path.
The first series passage 14a communicates with the first main hydraulic pressure passage 11a. The second communication passage 14b communicates with the second main hydraulic pressure passage 11b.

In the first main hydraulic pressure passage 11a, a connection portion with the first series passage 14a is provided with a first switching valve 15a (a “master cut valve” in the claims) that is a two-position three-port three-way valve. It has been.
The first switching valve 15a is a solenoid valve, and at the first position (initial state) when not energized, the upstream side (master cylinder 20 side) and the downstream side (output port 19 side) of the first main hydraulic pressure passage 11a. The first main hydraulic pressure passage 11a and the first series passage 14a are shut off while communicating with one wheel brake FL, RR).
Further, the first switching valve 15a, in the second position at the time of energization, shuts off the upstream side and the downstream side of the first main hydraulic pressure passage 11a, and the first series passage 14a and the first main hydraulic pressure passage 11a. It communicates with the downstream side.

Similarly to the first main hydraulic pressure passage 11a, the second main hydraulic pressure passage 11b is connected to the second communication passage 14b at the second switching valve 15b (“master” in the claims). A cut valve ") is provided.
The second switching valve 15b is a solenoid valve, and in the first position (initial state) when not energized, the upstream side (master cylinder 20 side) and the downstream side (output port 19 side) of the second main hydraulic pressure passage 11b. The second main hydraulic pressure passage 11b and the second communication passage 14b are cut off while communicating with the other wheel brakes RL, FR).
Further, the second switching valve 15b, in the second position during energization, blocks the second communication path 14b and the second main hydraulic pressure path while blocking the upstream side and the downstream side of the second main hydraulic pressure path 11b. It communicates with the downstream side of 11b.

  The first series passage 14a is provided with a first on-off valve 16 that is a normally-open electromagnetic valve. The first on-off valve 16 opens and closes the first series passage 14a.

The outflow path 13 is a hydraulic pressure path starting from the first cylinder hole 21 of the master cylinder 20 and communicates with the bottom side pressure chamber 21c. Further, the outflow path 13 communicates with the reservoir 26.
The outflow path 13 is provided with a second on-off valve 17a that is a normally closed electromagnetic valve. The second on-off valve 17a opens and closes the outflow passage 13.

  The two pressure sensors 18a and 18b detect the magnitude of the brake fluid pressure. Information acquired by both pressure sensors 18 a and 18 b is output to the electronic control unit 50.

The first pressure sensor 18 a is disposed upstream of the first switching valve 15 a and detects the brake fluid pressure generated in the master cylinder 20.
The second pressure sensor 18b is disposed on the downstream side of the second switching valve 15b, and the second switching valve 15b communicates the second communication path 14b with the downstream side of the second main hydraulic pressure path 11b. When it is, the brake fluid pressure generated in the slave cylinder 40 is detected.

  The stroke sensor ST is a sensor that detects the position of the rod P1 of the brake pedal P. The electronic control unit 50 detects the amount of depression of the brake pedal P based on information from the stroke sensor ST.

  The electronic control unit 50 operates the motor 44 and controls both the switching valves 15a and 15b based on information obtained from various sensors such as the pressure sensors 18a and 18b and the stroke sensor ST, a program stored in advance, and the like. The switching and the opening / closing of both opening / closing valves 16, 17a are controlled.

  The hydraulic pressure control device 2 performs various hydraulic pressure controls such as anti-lock brake control and behavior stabilization control by appropriately controlling the brake hydraulic pressure applied to each wheel cylinder W of the wheel brakes FL, RR, RL, FR. The structure which can be performed is provided and is connected to each wheel cylinder W via piping.

  As shown in FIG. 1, the hydraulic control device 2 is disposed between the brake hydraulic pressure generating device 1 and the wheel brakes FL, RR, RL, FR. The pipes Ha and Hb connected to the output port 19 of the base body 10 are connected to the inlet port 121 of the hydraulic pressure control device 2 as shown in FIGS. 1 and 2. The wheel brakes FL, RR, RL, FR are connected to the outlet port 122 of the hydraulic pressure control device 2 through pipes, respectively. In a normal state, the brake fluid pressure output from the brake fluid pressure generator 1 through the main fluid pressure passages 11a and 11b corresponding to the depression force of the brake pedal P is the wheel brakes FL, RR, RL, and FR. Applied to the cylinder W.

  Here, the hydraulic path 81 leading to the pipe Ha from the first brake system K1 communicates with the wheel brake FL on the left side of the front wheel and the wheel brake RR on the right side of the rear wheel. Further, the hydraulic pressure path 82 leading to the pipe Hb from the second brake system K2 leads to the wheel brake FR on the right side of the front wheel and the wheel brake RL on the left side of the rear wheel. In the following, the system including the hydraulic path 81 is referred to as “first hydraulic system 120a”, and the system including the hydraulic path 82 is referred to as “second hydraulic system 120b”.

  The hydraulic control device 2 is provided with two control valve means V corresponding to each wheel brake FL, RR in the first system 120a. Similarly, each wheel brake RL, Two control valve means V are provided corresponding to the FR. Further, the hydraulic pressure control device 2 is provided with a reservoir 5, a pump 6, an orifice 9, a pressure regulating valve (regulator) R, and a suction valve 8 in each of the first system 120a and the second system 120b. The hydraulic pressure control device 2 is provided with a common motor 6a for driving the pump 6 of the first system 120a and the pump 6 of the second system 120b.

  The control valve means V is a valve that controls the flow of hydraulic pressure from the brake hydraulic pressure generator 1 or the pump 6 to the wheel brakes FL, RR, RL, FR (specifically, the wheel cylinder W). The pressure can be increased, held or decreased. Therefore, the control valve means V includes an inlet valve 3, an outlet valve 4, and a check valve 3a.

  The inlet valve 3 is a fluid pressure path from the fluid pressure paths 81, 82 to the wheel brakes FL, RR, RL, FR (upstream of the wheel brakes FL, RR, RL, FR, hereinafter referred to as “wheel fluid pressure path”). This is a normally open proportional solenoid valve. Therefore, the differential pressure upstream and downstream of the inlet valve 3 can be adjusted according to the value of the drive current flowing through the inlet valve 3. The inlet valve 3 is normally open, thereby allowing the brake fluid pressure to be applied from the brake fluid pressure generator 1 to the wheel brakes FL, RR, RL, FR. Further, the inlet valve 3 is blocked by the control of a control unit (not shown) when the wheel is about to lock, thereby blocking the brake hydraulic pressure applied to each wheel brake FL, RR, RL, FR. The control unit is provided on a base body or the like constituting the hydraulic pressure control device 2.

  The outlet valve 4 is provided between each wheel brake FL, RR, RL, FR and each reservoir 5 (from the hydraulic pressure path closer to the wheel cylinder W than the inlet valve 3 to the reservoir 5, the pump 6 and the hydraulic pressure path 81 (82). This is a normally-closed solenoid valve arranged on the fluid pressure path leading to Although the outlet valve 4 is normally closed, the hydraulic pressure applied to each wheel brake FL, RR, RL, FR is applied to each reservoir 5 by being released by the control unit when the wheel is about to lock. Let it go.

  The check valve 3a is connected to each inlet valve 3 in parallel. This check valve 3a is a valve that allows only inflow of brake fluid from each wheel brake FL, RR, RL, FR side to the brake fluid pressure generating device 1 side (master cylinder 20 side). Even when the inlet valve 3 is closed when there is no brake fluid input from the brake fluid pressure generator 1 (when the input of the brake pedal P is released), the check valve 3 a , RR, RL, FR side allows the brake fluid to flow from the brake fluid pressure generator 1 side.

The reservoir 5 has a function of storing brake fluid that is released when each outlet valve 4 is opened. Further, between the reservoir 5 and the pump 6, a check valve 5a that allows only the flow of brake fluid from the reservoir 5 side to the pump 6 side is interposed.
The pump 6 has a function of sucking the brake fluid stored in the reservoir 5 and returning the brake fluid to the brake fluid pressure generating device 1 side through the orifice 7a. As a result, the brake fluid absorbed by the reservoir 5 can be returned to the brake fluid pressure generating device 1 side, and the brake fluid pressure is generated regardless of whether the brake pedal P is operated, for example, and the wheel brakes FL, RR are generated. , RL, FR can generate braking force. Note that the amount of brake fluid discharged by the pump 6 depends on the rotational speed of the motor 6a.
The orifice 9 attenuates the pulsation of the pressure of the brake fluid discharged from the pump 6.

  The pressure regulating valve R allows the flow of brake fluid from the hydraulic pressure path 81 (82) to the wheel hydraulic pressure path side at normal times and increases the pressure on the wheel cylinder W side by the brake hydraulic pressure generated by the pump 6. While blocking this flow, it has a function of adjusting the pressure on the wheel hydraulic pressure side to a set value or less, and includes a switching valve 7 and a check valve 7a.

The switching valve 7 is a normally open proportional solenoid valve interposed between the hydraulic pressure path 81 (82) leading to the brake hydraulic pressure generating device 1 and the wheel hydraulic pressure path. Although details are not shown, the valve body of the switching valve 7 is urged in the valve closing direction by an electromagnetic force corresponding to the applied current, and the pressure of the wheel hydraulic pressure path is the pressure of the hydraulic pressure path 81 (82). When the pressure is higher than a predetermined value (this predetermined value is due to the applied current), the brake fluid escapes from the wheel hydraulic pressure path toward the hydraulic pressure path 81 (82), so that the wheel hydraulic pressure side The pressure (the brake fluid pressure in the wheel brakes FL, FR, RL, RR) is adjusted to a predetermined pressure. That is, the valve closing force is arbitrarily changed in accordance with the value of the drive current (indicated current value) input to the switching valve 7, whereby the differential pressure upstream and downstream of the switching valve 7 is adjusted, and the wheel hydraulic pressure path The pressure can be adjusted below the set value.
The check valve 7a is connected to each switching valve 7 in parallel. The check valve 7a is a one-way valve that allows the flow of brake fluid from the hydraulic pressure path 81 (82) to the wheel hydraulic pressure path.

The suction valve 8 is a normally closed electromagnetic valve provided in a fluid pressure path (hereinafter referred to as “suction fluid pressure path”) from the fluid pressure path 81 (82) to the pump 6, and opens the suction fluid pressure path. The state to be switched and the state to be blocked are switched. The suction valve 8 is opened by the control of the control unit when the hydraulic pressure in each wheel brake FL, FR, RL, RR is increased by the pump 6, for example.
The pressure sensor 80 detects the brake fluid pressure in the fluid pressure path 81 (82), and the detection result is input to the control unit.

  In such a hydraulic pressure control device 2, the brake fluid pressure (acting on the wheel cylinders W of the wheel brakes FL, RR, RL, FR) is controlled by controlling the opening / closing states of the inlet valve 3 and the outlet valve 4 by the control unit. Caliper hydraulic pressure) is adjusted. For example, in a normal state where the inlet valve 3 is open and the outlet valve 4 is closed, if the brake pedal P is depressed, the hydraulic pressure from the brake hydraulic pressure generator 1 is transmitted to the wheel cylinder W as it is and the pressure is increased. . Further, when the inlet valve 3 is closed and the outlet valve 4 is opened, the brake fluid flows out from the wheel cylinder W to the reservoir 5 side, and the caliper hydraulic pressure is reduced to be in a reduced pressure state. In a state where both the inlet valve 3 and the outlet valve 4 are closed, the caliper hydraulic pressure is held and a holding state is established.

Next, an outline of the operation of the vehicle brake system A will be described.
In the vehicle brake system A, as shown in FIG. 4, when the stroke sensor ST detects that the brake pedal P is operated, the electronic control unit 50 switches both the switching valves 15a and 15b. In addition, when the ignition switch of a vehicle is turned ON, the electronic control apparatus 50 may switch both switching valve 15a, 15b.
Accordingly, the upstream side and the downstream side of the first main hydraulic pressure passage 11a are blocked, and the first series passage 14a and the downstream side of the first main hydraulic pressure passage 11a communicate with each other. Further, the upstream side and the downstream side of the second main hydraulic pressure path 11b are blocked, and the second communication path 14b and the downstream side of the second main hydraulic pressure path 11b communicate with each other.

  The electronic control unit 50 opens the second on-off valve 17a. As a result, the brake fluid in the bottom pressure chamber 21 c of the master cylinder 20 can flow out to the reservoir 26 through the outflow path 13.

  Both the first pistons 22 and 23 receive the depression force of the brake pedal P, slide in the first cylinder hole 21 toward the bottom surface 21a, and apply brake fluid in the bottom pressure chamber 21c and the opening pressure chamber 21d. Press. Since the upstream side and the downstream side of both main hydraulic pressure paths 11a and 11b are blocked, the brake hydraulic pressure generated in the master cylinder 20 is not transmitted to the wheel cylinder W.

Further, when the brake fluid in the bottom pressure chamber 21c is pressurized, the brake fluid flows out from the bottom pressure chamber 21c to the outflow passage 13. The first pistons 22 and 23 move toward the bottom surface 21a against the urging force of the first elastic members 24a and 24b while causing the brake fluid in the bottom surface side pressure chamber 21c to flow out to the outflow passage 13.
Thereby, since the brake pedal P strokes, the operation feeling of the brake pedal P can be given to the driver. Further, the first pistons 22 and 23 are urged toward the opening 21b by the first elastic members 24a and 24b, and the first pistons 22 and 23 are simulated against the brake pedal P. The operational reaction force is given.

When the depression of the brake pedal P is detected by the stroke sensor ST, the motor 44 of the slave cylinder 40 is driven, and the second piston 42 moves to the bottom surface 41a side, so that the brake fluid in the pressure chamber 41b is discharged. Pressurized.
The electronic control unit 50 determines the brake fluid pressure output from the slave cylinder 40 (the brake fluid pressure detected by the second pressure sensor 18b) and the brake fluid pressure output from the master cylinder 20 (the operation amount of the brake pedal P). And the number of revolutions of the motor 44 is controlled based on the comparison result. In this way, the brake fluid pressure generator 1A generates brake fluid pressure according to the amount of operation of the brake pedal P.

  The brake fluid pressure generated by the brake fluid pressure generating device 1A is transmitted to each wheel cylinder W via the fluid pressure control device 2, and each wheel cylinder W is activated to apply a braking force to each wheel.

Next, in a state where the brake pedal P is depressed and the motor 44 of the slave cylinder 40 is driven, the electronic control unit 50 determines that the brake fluid pressure detected by the second pressure sensor 18 is the operation of the brake pedal P. It is determined whether or not the brake fluid pressure has increased to the amount (detected by the stroke sensor ST) (whether or not it has increased to a preprogrammed determination value) (see FIG. 3).
When the brake fluid in either the first main hydraulic pressure passage 11a or the second main hydraulic pressure passage 11b decreases, the electronic control device 50 determines that the brake hydraulic pressure detected by the second pressure sensor 18 is the brake pedal P. It is determined that the brake fluid pressure does not increase corresponding to the operation amount, and the first on-off valve 16 is closed (stroke control based on the operation amount of the brake pedal P). Accordingly, the first main hydraulic pressure path 11a and the slave cylinder 40 are disconnected, and the slave cylinder 40 is connected only to the downstream side of the second main hydraulic pressure path 11b.

  After closing the first opening / closing valve 16, the electronic control unit 50 increases (recovers) the brake fluid pressure on the downstream side of the second main hydraulic pressure passage 11b to the brake fluid pressure corresponding to the operation amount of the brake pedal P. ), The pressure increase control of the slave cylinder 40 is continued while the first on-off valve 16 is closed. That is, the electronic control unit 50 determines that the brake fluid is decreasing on the downstream side of the first main hydraulic pressure passage 11a, and increases the brake fluid pressure on the downstream side of the second main hydraulic pressure passage 11b by the slave cylinder 40. Let As a result, the wheel cylinder W communicating with the second main hydraulic pressure passage 11b is boosted, and a braking force is applied to the wheel. The first main hydraulic pressure path 11a and the slave cylinder 40 are continuously disconnected.

  On the other hand, if the electronic control unit 50 determines that the brake hydraulic pressure on the downstream side of the second main hydraulic pressure passage 11b has not recovered after closing the first on-off valve 16, the first on-off valve 16 While opening the valve (returning to the initial state), the motor 44 is stopped and the first switching valve 15a is switched to connect the upstream side and the downstream side of the first main hydraulic pressure passage 11a. Further, the second on-off valve 17a is closed (returned to the initial state) to stop the brake fluid from flowing from the master cylinder 20 to the outflow passage 13. That is, the electronic control unit 50 determines that the brake fluid is decreasing on the downstream side of the second main hydraulic pressure passage 11b, and increases the brake hydraulic pressure in the first main hydraulic pressure passage 11a by the master cylinder 20. As a result, the wheel cylinder W communicating with the first main hydraulic pressure passage 11a is boosted, and a braking force is applied to the wheel. The second main hydraulic pressure passage 11b is continuously cut off from the upstream side and the downstream side by the second switching valve 15b. Thereby, the brake hydraulic pressure generated in the master cylinder 20 is not applied to the downstream side of the second main hydraulic pressure passage 11b.

  In a state where the slave cylinder 40 does not operate (for example, when electric power cannot be obtained), the first switching valve 15a and the second switching valve 15b are opened as shown in FIG. 17a is closed. Accordingly, the upstream side and the downstream side of the first main hydraulic pressure passage 11a and the second main hydraulic pressure passage 11b communicate with each other, and the brake hydraulic pressure generated in the bottom pressure chamber 21c and the opening pressure chamber 21d of the master cylinder 20 is generated. Are transmitted to different wheel cylinders W.

  In the brake fluid pressure generating apparatus 1A as described above, as shown in FIG. 4, in a state where both the switching valves 15a and 15b are closed and the second on-off valve 17a is opened, the brake pedal P is connected to the master cylinder 20. When input to both pistons 22, 23, both pistons 22, 23 move in the first cylinder hole 21 while causing the brake fluid in the bottom side pressure chamber 21 c to flow out to the outflow path 13. Thereby, since the brake pedal P strokes, the operation feeling of the brake pedal P can be given to the driver. Further, a pseudo operation reaction force is applied to the brake pedal P by the first elastic members 24a and 24b.

Thus, in the brake fluid pressure generating device 1A, the bottom surface side pressure chamber 21c of the master cylinder 20 serves as a stroke simulator. Further, in a state where the slave cylinder 40 is not operated, the brake fluid pressure generated in the bottom side pressure chamber 21c is transmitted to the one wheel cylinder W, so that it also has a function as the tandem piston type master cylinder 20. .
That is, in the brake fluid pressure generating apparatus 1A, a stroke simulator is provided in the first cylinder hole 21 of the master cylinder 20, and the master cylinder 20 and the stroke simulator are integrated. Therefore, the base 10 on which the master cylinder 20 and the stroke simulator are assembled can be reduced in size.

  In the brake fluid pressure generating device 1A, the operation reaction force is efficiently applied to the brake pedal P by using the urging forces of the first elastic members 24a and 24b.

  Further, in the brake fluid pressure generating device 1A, as shown in FIG. 1, the bottom-side pressure chamber 21c and the opening-side pressure chamber are opened by opening both the switching valves 15a and 15b and closing the second on-off valve 17a. The brake hydraulic pressure generated at 21d can be transmitted to different wheel cylinders W.

  Further, when the brake pedal P is depressed and the motor 44 of the slave cylinder 40 is driven, when the brake fluid in either the first main hydraulic pressure passage 11a or the second main hydraulic pressure passage 11b decreases, The first on-off valve 16 is closed. Thus, the single piston type slave cylinder 40 can independently increase the pressure of one system of the two systems. And based on the fluctuation | variation of the brake hydraulic pressure of both the main hydraulic pressure paths 11a and 11b after closing the 1st on-off valve 16, in either the 1st main hydraulic pressure path 11a or the 2nd main hydraulic pressure path 11b It can be determined whether the brake fluid is decreasing.

  Moreover, in the brake fluid pressure generating apparatus 1A, since the single piston type slave cylinder 40 is used, the slave cylinder 40 can be reduced in size.

  Further, in the brake hydraulic pressure generating device 1A, since both the switching valves 15a and 15b are three-way valves, the hydraulic pressure circuit of the brake hydraulic pressure generating device 1A can be simplified.

As mentioned above, although 1st embodiment of this invention was described, this invention is not limited to said 1st embodiment, In the range which does not deviate from the meaning, it can change suitably.
In the brake hydraulic pressure generator 1A of the first embodiment, as shown in FIG. 1, the outflow path 13 is connected to the bottom pressure chamber 21c of the master cylinder 20, but as shown in FIG. May be connected to the opening-side pressure chamber 21d. In this configuration, two second elastic members 25a and 25b are accommodated in the opening-side pressure chamber 21d, and the opening-side pressure chamber 21d serves as a stroke simulator. That is, the opening-side pressure chamber 21d becomes the “second pressure chamber” in the claims.

  In the brake fluid pressure generating device 1A, the switching valves 15a and 15b are three-way valves, but a switching valve that is a normally open electromagnetic valve is provided in the main hydraulic pressure path, and is downstream of the switching valve in the main hydraulic pressure path. A communication path may be connected to the side. In this configuration, the upstream side and the downstream side of the main hydraulic pressure path are blocked by closing the switching valve. The brake fluid pressure generated in the slave cylinder can be transmitted to the wheel cylinder through the communication passage and the downstream side of the main fluid pressure passage.

  In the brake fluid pressure generator 1A, the single piston type slave cylinder 40 is used. However, a tandem piston type slave in which two pistons are accommodated in the second cylinder hole 41 and two pressure chambers are formed. A cylinder may be used. In this case, the first series passage 14a and the second communication passage 14b are connected to different pressure chambers.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
As shown in FIG. 6, the brake hydraulic pressure generator 1 </ b> B of the second embodiment is different from the brake hydraulic pressure generator 1 </ b> A (see FIG. 1) of the first embodiment that the second on-off valve 17 b is a linear solenoid valve. Is different.
The second on-off valve 17b of the second embodiment can adjust the valve opening pressure by controlling energization to the solenoid.

  In the brake fluid pressure generator 1B of the second embodiment, the flow rate of the brake fluid flowing out from the bottom side pressure chamber 21c to the outflow passage 13 is adjusted by adjusting the valve opening pressure of the second on-off valve 17b, and the bottom surface The brake fluid pressure in the side pressure chamber 21c is adjusted. Thereby, the operation reaction force given to the brake pedal P can be adjusted.

Specifically, in the initial state where the upstream side and the downstream side of the first main hydraulic pressure path 11a and the second main hydraulic pressure path 11b are blocked and the stroke amount of the brake pedal P is small, the electronic control unit 50 is The energization amount to the second on-off valve 17b is increased to reduce the valve opening pressure of the second on-off valve 17b. In this state, since the flow resistance of the brake fluid of the second on-off valve 17b is reduced, the operation reaction force applied to the brake pedal P is reduced.
When the stroke amount of the brake pedal P increases, the electronic control unit 50 decreases the energization amount to the second on-off valve 17b and increases the valve opening pressure of the second on-off valve 17b. That is, by restricting the flow path of the second on-off valve 17b so as to close the second on-off valve 17b, the flow resistance of the brake fluid of the second on-off valve 17b increases, and therefore is applied to the brake pedal P. The reaction force increases.

  In the brake fluid pressure generator 1B of the second embodiment, as shown in FIG. 7, a normally open linear solenoid valve can be used as the second on-off valve 17b. In this case, the valve opening pressure of the second on-off valve 17b when not energized is set large, and the flow of the brake fluid of the second on-off valve 17b when not energized is reduced.

  In the brake fluid pressure generating device 1B, as shown in FIG. 6, the outflow path 13 is connected to the bottom pressure chamber 21c of the master cylinder 20, but the outflow path 13 is connected to the opening pressure chamber 21d. Also good.

1A Brake fluid pressure generator (first embodiment)
1B Brake hydraulic pressure generator (second embodiment)
2 Hydraulic pressure control device 10 Base 11a First main hydraulic pressure path 11b Second main hydraulic pressure path 13 Outflow path 14a First series path 14b Second communication path 15a First switching valve (master cut valve)
15b Second switching valve (master cut valve)
16 1st on-off valve 17a 2nd on-off valve (1st embodiment)
17b Second on-off valve (second embodiment)
20 master cylinder 21 first cylinder hole 21c bottom side pressure chamber 21d opening side pressure chamber 22, 23 first piston 24 first elastic member (second embodiment)
24a, 24b first elastic member (first embodiment)
25 Second elastic member 26 Reservoir 40 Slave cylinder 41 Second cylinder hole 41c Pressure chamber 42 Second piston 43 Elastic member 44 Motor (electric actuator)
44a Output shaft 45 Drive transmission unit 50 Electronic control unit A Vehicle brake system P Brake pedal P1 Rod ST Stroke sensor W Wheel cylinder

Claims (6)

A master cylinder that generates brake fluid pressure by operating the brake operator;
A main hydraulic path leading from the master cylinder to the wheel brake;
A slave cylinder that generates a brake fluid pressure by driving an electric actuator according to an operation amount of the brake operator;
A communication path leading from the slave cylinder to the main hydraulic pressure path;
A master cut valve for opening and closing the main hydraulic pressure path,
The slave cylinder is capable of increasing the pressure on the wheel brake side from the master cut valve of the main hydraulic pressure path,
In the cylinder hole of the master cylinder, two pistons are accommodated and a first pressure chamber and a second pressure chamber are formed,
An outflow path is connected to the second pressure chamber;
A brake fluid pressure generating device, wherein an on-off valve for an outflow passage for opening and closing the outflow passage is provided. A first brake system that communicates with at least one of the wheel brakes and a second brake system that communicates with the remaining wheel brakes.
As the main hydraulic pressure path,
A first main hydraulic pressure path provided in the first brake system and leading from the first pressure chamber to the wheel brake;
A second main hydraulic pressure path provided in the second brake system and leading from the second pressure chamber to the wheel brake;
The brake hydraulic pressure generator according to claim 1, wherein the master cut valve is provided in each of the first main hydraulic pressure path and the second main hydraulic pressure path.   The brake hydraulic pressure generator according to claim 1 or 2, wherein the on-off valve for the outflow passage is a linear solenoid valve. In the cylinder hole of the slave cylinder, a piston is accommodated and a pressure chamber is formed,
As the communication path,
A first series passage from the slave cylinder to the first main hydraulic passage;
A second communication path that leads from the slave cylinder to the second main hydraulic pressure path,
The brake hydraulic pressure generator according to claim 2 or 3, wherein an opening / closing valve for a communication path is provided in the first series path or the second communication path.   The brake according to any one of claims 1 to 4, wherein the second pressure chamber contains an elastic member that applies a pseudo operation reaction force to the brake operator. Hydraulic pressure generator. The master cut valve is a three-way valve,
A state in which the master cylinder side and the wheel brake side are communicated, and the communication path side and the wheel brake side are blocked;
6. The device according to claim 1, wherein the master cylinder side and the wheel brake side are blocked, and the state where the communication path side and the wheel brake side are communicated can be switched. The brake fluid pressure generator according to one item.

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