JP5262918B2 - Vehicle braking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle braking device capable of reducing cost while achieving a further proper pressure adjustment. <P>SOLUTION: This vehicle braking device 1 includes a master cylinder 2 for generating operational hydraulic pressure from basic hydraulic pressure in response to operation of a pedal, a pump 3 for boosting the operational hydraulic pressure, a pressure adjusting valve 4 for generating control hydraulic pressure by adjusting the boosted operational hydraulic pressure, supply means 6 and 7 for supplying the operational hydraulic pressure or the control hydraulic pressure to a wheel cylinder 5 as supply hydraulic pressure, and a control means 10a for controlling the control hydraulic pressure in target control hydraulic pressure by controlling a closing unit time TC by setting an opening unit time of the pressure adjusting valve 4 to a variation period TQ of a deliver flow rate of the pump 3. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a vehicle braking device that brakes a vehicle by combining a pedal force brake based on an operation of a pedal and an increased pump-up brake.

  Conventionally, as a suitable vehicle braking device applied to a vehicle, an operating hydraulic pressure is generated from a basic hydraulic pressure by a master cylinder based on a pedal operation, and the operating hydraulic pressure is not increased and supplied as it is to a wheel cylinder as a supply hydraulic pressure. The wheel cylinder pushes the piston of the wheel brake device from the cylinder and presses the pad against the wheel disk to execute the braking operation, and the control hydraulic pressure is increased by the pump and the differential pressure valve to generate the control hydraulic pressure. Supply it to the wheel cylinder as a supply hydraulic pressure, and push out the piston of the brake device of the wheel from the cylinder by the wheel cylinder and press the pad against the disk of the wheel to appropriately select the pump-up brake that executes the braking operation, for example, Patent Document 1 or Patent Document 2 has been proposed

  Such selection of pedal force brakes and pump-up brakes is intended to increase the degree of freedom in selecting braking force and to realize vehicle attitude control, as well as to hybrid vehicles, electric vehicles, and fuel cell vehicles. In a vehicle that uses a regenerative brake, such as when the braking force by the regenerative brake is sufficient, the pedal force brake is selected, and the braking force by the regenerative brake cannot be obtained sufficiently by the failure of the battery, inverter, or control circuit. In addition, the pump up brake is selected and the mechanical brake is used to compensate for the insufficient braking force of the regenerative brake.

JP 2005-255017 A JP 2006-21745 A

  However, in such a vehicle braking device shown in Patent Document 1 or Patent Document 2, the control hydraulic pressure pressurized by the pump 51 shown in FIG. 5 is arranged between the master cylinder 52 and the wheel cylinder 53. In order to adjust the pressure based on the duty ratio control of 54, a damper and an accumulator are disposed between the pump 51 and the pressure adjusting valve 54 in order to realize stable pressure adjustment, or against the rotation of the motor. It becomes necessary to employ a pump having a plurality of pistons or a gear-type pump with a small fluctuation in the discharge flow rate, resulting in an increase in the number of parts and an increase in cost of the pump itself.

  For the purpose of suppressing such an increase in cost, as shown in FIG. 5, it is possible to omit the provision of a damper, an accumulator or the like between the pump 51 and the pressure regulating valve 54, and an inexpensive single piston system. It is also possible to adopt a pump of this type.

  However, compared with the case where the discharge flow rate of the gear pump type pump shown in FIG. 6 is relatively stable regardless of the passage of time, the discharge flow rate of the inexpensive single piston type pump is sine as shown in FIG. Only the upper half of the wave or cosine wave has a waveform that is periodically repeated, and the fluctuation is large.

  For this reason, in the case where coordination of the fluctuation cycle of the discharge capacity of the pump 51 and the timing of the duty ratio control of the pressure regulating valve 54 as shown in FIG. 8 is not taken into consideration, the outlet of the pump 51 and the downstream side of the pressure regulating valve 54 9 is generally small and does not have a sufficient pressure accumulating function. Therefore, the hydraulic pressure discharged by the pump 51 is effectively transmitted to the pressure regulating valve 54 as shown in FIG. However, there is a problem that it is difficult to control the control oil pressure with a desired pressure increase gradient, that is, to increase the pressure of the control oil pressure appropriately and adjust the pressure.

  In view of the above problems, an object of the present invention is to provide a vehicle braking device that can reduce costs while realizing more appropriate pressure regulation.

In order to solve the above problem, the vehicle braking device according to the present invention is:
A master cylinder that generates operating oil pressure from the basic oil pressure in response to pedal operation;
A pump for increasing the operating oil pressure;
A pressure regulating valve that regulates the increased operation hydraulic pressure to generate a control hydraulic pressure;
Supply means for supplying the operation hydraulic pressure or the control hydraulic pressure to a wheel cylinder as supply hydraulic pressure;
Control means for controlling the control hydraulic pressure to the target control hydraulic pressure by setting the opening unit time of the pressure regulating valve to the fluctuation period of the discharge flow rate of the pump and controlling the closing unit time.

  The supply means is appropriately constituted by a hydraulic pipe, a holding valve, and a pressure reducing valve.

  According to the vehicle braking device of the present invention, the opening unit time of the pressure regulating valve is basically fixed by setting it so as to coincide with a reference cycle that is a fluctuation cycle of the discharge flow rate of the pump. By matching the time and the fluctuation period, the pump is, for example, an inexpensive single piston system, and even when the fluctuation during the fluctuation period is large, the discharge generated by the pump during the fluctuation period, that is, one period. With the flow rate, the flow rate that passes through the pressure regulating valve is constant for each fluctuation period, and the fluctuation of the discharge flow rate can be absorbed by the opening operation of the pressure regulating valve in the opening unit time.

  For this reason, the hydraulic piping capacity between the discharge port of the pump and the holding valve located downstream of the pressure regulating valve is generally small and does not have a sufficient pressure accumulating function, and a damper, an accumulator, etc. It is possible to control the control hydraulic pressure with a desired pressure-increasing gradient even under the condition that there are no parts having a separate pressure accumulating function, and it is possible to appropriately increase and regulate the control hydraulic pressure. be able to.

Here, in the vehicle braking device,
The master cylinder, the pump, the pressure regulating valve, and a supply system for supplying the operation hydraulic pressure or the control hydraulic pressure to the wheel cylinder as a supply hydraulic pressure includes a plurality of systems.
The control means switches between the selection of one of the multiple systems and the selection of the multiple systems,
After the control means switches the selection from the single system to the multiple system, the target control oil pressure is less than or equal to a predetermined oil pressure for the target control oil pressure and the target pressure increase gradient of the supply oil pressure used for executing the control, When the target pressure increase gradient is equal to or lower than a predetermined pressure increase gradient, the control means preferably changes the target control oil pressure from a reference pressure to a low reference pressure lower than the reference pressure.

  Specifically, the control means reduces the duty ratio by increasing the closing unit time of the pressure regulating valve, and changes the target control hydraulic pressure from the reference pressure to the low reference pressure. The reference pressure is an initial value of the target control oil pressure.

  According to the vehicle braking device, under conditions where both the target control hydraulic pressure and the target pressure increase gradient are low, the duty for reducing the pump pressure is reduced by increasing the closing unit time and decreasing the duty ratio. Power consumption can be reduced and operating noise can be reduced.

Furthermore, in the vehicle braking device,
When the target control oil pressure is greater than a predetermined oil pressure, or when the target pressure increase gradient is greater than a predetermined pressure increase gradient, the control means returns the target control oil pressure to a reference pressure, and sets the opening unit time to the discharge flow rate of the pump. It is preferable to make it larger than the fluctuation period.

  Specifically, the control means returns the target control hydraulic pressure to the reference pressure by shortening the closing unit time of the pressure regulating valve.

  According to the vehicle braking device, under a condition where either the target control hydraulic pressure or the target pressure increase gradient is high, the close unit time is shortened to increase the duty ratio, and the control hydraulic pressure is increased to a desired pressure increase gradient. Control can be realized, and the control hydraulic pressure can be appropriately increased and regulated.

  In addition, after the selection of the multiple systems is continuously performed by the control means and the control means once makes the opening unit time larger than the fluctuation period of the discharge flow rate of the pump, the control means It is preferable that the target control hydraulic pressure is maintained at the reference value and the open unit time is maintained.

  According to the vehicle braking device, the selection of the multiple systems is continuously executed, the target control hydraulic pressure is temporarily returned to the reference pressure, and the opening unit time is determined from the fluctuation cycle of the discharge flow rate of the pump. After the change, the target control hydraulic pressure and the opening unit time are maintained as they are, and the control hydraulic pressure is changed according to the asynchronous period of the fluctuation timing of the opening timing of the holding valve and the discharge flow rate of the pump. Variations in the boost gradient can be reduced.

  According to the vehicle braking device of the present invention, it is possible to reduce costs while realizing more appropriate pressure regulation.

It is a mimetic diagram showing one embodiment of a vehicle braking device concerning the present invention. It is a schematic diagram which shows the control content of one Embodiment of the vehicle braking device which concerns on this invention. It is a schematic diagram which shows the control content of one Embodiment of the vehicle braking device which concerns on this invention. It is a flowchart which shows the control content of the vehicle braking device which concerns on this invention. It is a schematic diagram which shows the form of the conventional vehicle braking device. It is a schematic diagram which shows the fluctuation | variation of the discharge flow rate of the pump of the conventional vehicle braking device. It is a schematic diagram which shows the fluctuation | variation of the discharge flow rate of the pump of the vehicle braking device which concerns on this invention. It is a time chart which shows the control content of the conventional vehicle braking device. It is a schematic diagram which shows the pressure | voltage rise gradient by the control content of the conventional vehicle braking device.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic view mainly showing a hydraulic system of one embodiment of a vehicle braking apparatus according to the present invention. FIG. 2 is a time chart showing the relative relationship between the opening / closing operation of the pressure regulating valve and the fluctuation cycle of the pump discharge flow rate in one embodiment of the vehicle braking apparatus according to the present invention. FIG. 3 is a schematic diagram showing the control contents of one embodiment of the vehicle braking apparatus according to the present invention.

  As shown in FIG. 1, it has the hydraulic piping system of system # 1 and system # 2 of the vehicle braking device 1, and for each system, a master cylinder 2, a pump 3, a pressure regulating valve 4, and a wheel cylinder 5 The holding valve 6, the pressure reducing valve 7, the reservoir 8, the motor 9, and the brake ECU 10 (Electronic Control Unit) are configured.

  The brake ECU 10 includes, for example, a CPU, a ROM, a RAM, a data bus connecting them, and an input / output interface. The CPU performs predetermined processing according to a program stored in the ROM, and constitutes the control means 10a.

  As shown in FIG. 1, the master cylinder 2 is operated by a brake pedal, and is driven by a booster connected to a negative pressure generation pipe that generates negative pressure using a negative pressure of an engine (not shown). The pedaling force input by the driver to the pedal is boosted, and the operating hydraulic pressure is generated from the basic hydraulic pressure in the reservoir attached to the master cylinder 2 based on the boosted pedaling force. It is. Operating hydraulic pressure is provided to the inlets of the system 1 and the system 2 of the vehicle braking device 1.

  In the vehicle, the system # 1 hydraulically brakes the right front wheel FR and the left rear wheel RL, for example, and the system # 2 hydraulically brakes the left front wheel FL and the right rear wheel RR, and only the parts to be controlled are different. Since both configurations are the same, only system # 1 will be described.

  The hydraulic pipe is first branched at the branch point A from the inlet toward the downstream side, and the differential pressure valve 4 is arranged on the downstream side after branching from the branch point A of the hydraulic pipe to the left side. A branch point B is provided, and a holding valve 6 for the right front wheel FR is provided on one downstream side of the branch point B, and a holding valve 6 for the left rear wheel RL is provided on the other side. On the other hand, the hydraulic piping branched to the right side from the branch point A upstream of the differential pressure valve 4 is connected to the discharge port of the pump 3 without the damper and the accumulator, and the reservoir 8 and the suction port of the pump 3 are connected to each other by the hydraulic piping. Is done.

  A branch point C is provided on the downstream side of the leftmost holding valve 6 in FIG. 1 of the system # 1, and the wheel cylinder 5 of the right front wheel FR communicates with one hydraulic pipe downstream of the branch point C. The downstream of the branch point C of the piping is communicated with the reservoir 8 via the pressure reducing valve 7. Similarly, a branch point D is provided on the downstream side of the holding valve 6 on the right side of the system 1 in FIG. 1, and the wheel cylinder 5 of the left rear wheel RL is communicated with one hydraulic pipe downstream of the branch point D. The downstream of the branch point D of the other pipe is communicated with the reservoir 8 via the pressure reducing valve 7.

  The pump 3 is a single piston type pump and is rotated by the driving force of the motor 9. The differential pressure valve 4 is constituted by a linear solenoid valve, and the opening unit time TO and the closing unit time TC are controlled based on a command from the control means 10a of the brake ECU 10.

  The pump 3 is rotated by driving the motor 9 based on a command from the control means 10a of the brake ECU 10 to increase the operating oil pressure, and the pressure regulating valve 4 adjusts the increased operating oil pressure to generate the control oil pressure. To do. The holding valve 6 and the pressure reducing valve 7 are appropriately opened and closed based on a command from the control means 10a to constitute supply means for supplying the control hydraulic pressure to the wheel cylinder 5 as the supply hydraulic pressure, and the holding valve 6 is closed to reduce the pressure. When the valve 7 is opened, the supply hydraulic pressure supplied to the wheel cylinder 5 is discharged to the reservoir 8, and the discharged supply hydraulic pressure flows back to the master cylinder 2 via the reservoir 8.

  As shown in FIG. 2, the control means 10a of the brake ECU 10 executes a setting process for setting the opening unit time TO of the pressure regulating valve 4 so as to coincide with the fluctuation cycle TQ of the discharge flow rate Q of the pump 3, that is, the reference cycle TB. Thus, the control hydraulic pressure is controlled to the target control hydraulic pressure by controlling the closing unit time TC.

  The control means 10a of the brake ECU 10 includes a master cylinder 2, a pump 3, a pressure regulating valve 4, and a holding valve 6 and a pressure reducing valve 7 constituting supply means for supplying control hydraulic pressure to the wheel cylinder 5 as supply hydraulic pressure, respectively. Selection of either one of the multiple systems including system # 1 and system # 2 and selection of the multiple systems are switched according to the required deceleration based on the pedal stroke required for the entire vehicle.

  After switching the selection from the single system to the multiple systems, the control means 10a performs threshold determination on the target control oil pressure and the target pressure increase gradient of the supply oil pressure used to execute the braking control that realizes the required deceleration. That is, the control means 10a reduces the duty ratio by increasing the closing unit time TC of the pressure regulating valve 4 when the target control oil pressure is equal to or less than the predetermined oil pressure and the target pressure increase gradient is equal to or less than the predetermined pressure increase gradient. A change process for changing the control oil pressure from the reference pressure PB to a low reference pressure A_Mpa lower than the reference pressure PB is executed.

  When the target control oil pressure is larger than the predetermined oil pressure or the target pressure increase gradient is larger than the predetermined pressure increase gradient, the control means 10a increases the duty ratio by shortening the closing unit time TC and makes the reference control oil pressure the reference. Returning to the pressure PB, a re-change process is performed in which the opening unit time TO is set to B_msec, which is larger than the fluctuation period TQ of the discharge flow rate of the pump 3.

  Further, selection of multiple systems including both system # 1 and system # 2 is continuously performed by the control means 10a across the control cycle, and the control means 10a once pumps the open unit time TO as described above. After setting B_msec, which is larger than the fluctuation period TQ of the discharge flow rate, the control means 10a performs a holding process of holding the target control hydraulic pressure at the reference value PB and holding the open unit time TO at B_msec.

  That is, when the control means 10a switches the selection from the single system to the multiple systems and then executes the selection of the multiple systems continuously, the target control of the supply hydraulic pressure used for executing the braking control for realizing the required deceleration is performed. The threshold value determination is not performed for the oil pressure and the target pressure increase gradient, and the control unit 10a increases the closing unit time TC of the pressure regulating valve 4 even when the target control oil pressure is equal to or lower than the predetermined pressure and the target pressure increase gradient is equal to or lower than the predetermined pressure increase gradient. Thus, the duty ratio is lowered, and the change process for changing the target control hydraulic pressure from the reference pressure PB to the low reference pressure A_Mpa lower than the reference pressure PB is not executed.

  Hereinafter, the control content of the vehicle braking device 1 of a present Example is demonstrated using a flowchart and a map. FIG. 4 is a flowchart showing the control contents of the vehicle braking apparatus 1 according to the present invention.

  In step S1 shown in FIG. 4, the control means 10a of the brake ECU 10 determines whether or not the system # 1 is selected and controlled in the current control cycle. Proceed, if negative, proceed to step S5.

  In step S2, the control means 10a determines whether or not the system # 1 is selected and controlled in the previous control cycle. If the determination is affirmative, the process proceeds to step S3. If the determination is negative, the control means 10a proceeds to step S3. Skip to step S4.

  In step S3, the control unit 10a adds +1 to the number of driving of the pump 3, and in step S4, the control unit 10a calculates target control hydraulic pressures tag_pWC1R and tag_pWC1L calculated from the required deceleration and stored in the RAM. The target boost gradients tag_dpWC1R and tag_dpWC1L are read.

  If it is determined negative in step S1, the process proceeds to step S5, and the control means 10a determines whether the system # 1 is selected and controlled in the previous control cycle. If there is, proceed to step S6, and if not, skip step S6 and proceed to step S7.

  In step S6, the control means 10a adds −1 to the drive number of the pump 3, and in step S7, the control means 10a calculates target control hydraulic pressures tag_pWC1R and tag_pWC1L calculated from the required deceleration and stored in the RAM. Then, the target boost gradients tag_dpWC1R and tag_dpWC1L are reset.

  In step 8, the control means 10a of the brake ECU 10 determines whether or not the system # 2 is selected and controlled in the current control cycle. If the result is affirmative, the process proceeds to step S9. If there is, the process proceeds to step S12.

  In step S9, the control means 10a determines whether or not the system # 2 is selected and controlled in the previous control cycle. If the determination is affirmative, the process proceeds to step S10. If the determination is negative, the control means 10a proceeds to step S10. Skip to step S11.

  In step S10, the control means 10a adds +1 to the drive number of the pump 3, and in step S11, the control means 10a calculates the target control hydraulic pressure tag_pWC2R, tag_pWC2L calculated from the required deceleration and stored in the RAM, The target boost gradients tag_dpWC2R and tag_dpWC2L are read.

  If it is determined negative in step S8, the process proceeds to step S12, and the control means 10a determines whether or not the system # 2 is selected and controlled in the previous control cycle. If there is, proceed to step S13, and if not, skip step S13 and proceed to step S14.

  In step S13, the control means 10a adds −1 to the drive number of the pump 3, and in step S14, the control means 10a calculates target control hydraulic pressures tag_pWC2R and tag_pWC2L calculated from the required deceleration and stored in the RAM. Then, the target boost slopes tag_dpWC2R and tag_dpWC2L are reset.

  In step S15, the control means 10a determines whether or not the pump drive number set in steps S3, S6, S10, and S13 is 2. If the determination is affirmative, the process proceeds to step S16. If the determination is negative, step S20 is performed. Proceed. In step S20, the control means 10a executes a setting process for setting the target control hydraulic pressure to the reference pressure PB and setting the open unit time TO to the reference cycle TB that is the fluctuation cycle TQ.

  In step S16, the control means 10a determines whether or not the open unit time TO of the holding valve 4 of the target system # 1 and / or system # 2 has been changed to B_msec in the previous control cycle. If there is, a holding process that proceeds to return is executed, and if not, the process proceeds to step S17.

  In step S17, the target control hydraulic pressures tag_pWC1R, tag_pWC1L, tag_pWC2R, tag_pWC2L are all equal to or lower than the predetermined hydraulic pressure, and the target pressure increase gradients tag_dpWC1R, tag_dpWC1L, tag_dpWC2R, and all are determined to be positive Cag. In the case, the process proceeds to step S18, and in the case of negative, the process proceeds to step S19.

  In step S18, the control means 10a executes a change process for changing the target control oil pressure to A_Mpa. In step S19, the control means 10a returns the target control oil pressure to the reference pressure PB and changes the open unit time TO to B_msec. Execute re-change processing. The processing from step S1 to step S20 is repeatedly executed by the control means 10a every control cycle.

  According to the vehicle braking device 1 of the present embodiment realized by the control contents described above, the following operational effects can be obtained. That is, the opening unit time TO of the pressure regulating valve 4 is basically fixed by setting it so as to coincide with the fluctuation cycle TQ = reference cycle TB of the discharge flow rate Q of the pump 3, and the opening unit time TO and the fluctuation cycle TQ are matched. Thus, the pump 3 is configured by an inexpensive single piston system as in this embodiment, and even when the fluctuation in the fluctuation period TQ is large as shown in the lower part of FIG. As the discharge flow rate Q generated by 3 propagates through the hydraulic piping, the flow rate passing through the pressure regulating valve 4 is changed regardless of the correlation between the phase of the flow rate Q and the phase of opening and closing of the pressure regulating valve 4 for each fluctuation period TQ. As a constant, the fluctuation of the discharge flow rate Q can be absorbed by the opening operation of the pressure regulating valve 4 in the opening unit time TO.

  In other words, the hydraulic piping capacity between the discharge port of the pump 3 and the pressure regulating valve 4 and the holding valve 6 located downstream of the pressure regulating valve 4 is limited in terms of mounting on the vehicle and is generally small and may have a sufficient pressure accumulating function. However, according to the vehicle braking device 1 shown in the present embodiment, the hydraulic piping between the pump 3 and the pressure regulating valve 4 and the holding valve 6 is not provided with a damper or an accumulator even under such a constraint condition. The control oil pressure can be controlled with a desired pressure increase gradient, and the control oil pressure can be appropriately increased and regulated.

  Further, in the vehicle braking apparatus 1 of the present embodiment, the control means 10a sets the closing unit time TC of the pressure regulating valve 4 when the target control oil pressure is equal to or lower than the predetermined oil pressure and the target pressure increase gradient is equal to or less than the predetermined pressure increase gradient. Since the duty ratio is lowered by increasing the target pressure and the target control oil pressure is changed from the reference pressure PB to the low reference pressure A_Mpa lower than the reference pressure PB, the closing unit time TC is set under the condition that both the target control oil pressure and the target pressure increase gradient are low. The duty ratio can be lowered to reduce the load on the motor 9 related to the pressure increase of the pump 3, thereby reducing the power consumption and the operating noise.

  In addition, in the vehicle braking apparatus 1 of the present embodiment, the control means 10a shortens the closing unit time TC when the target control oil pressure is greater than the predetermined oil pressure or the target pressure increase gradient is greater than the predetermined pressure increase gradient. As a result, the duty ratio is increased to return the target control hydraulic pressure to the reference pressure PB, and the opening unit time TO is set to B_msec, which is larger than the reference cycle TB which is the fluctuation cycle TQ of the discharge flow rate of the pump 3. Under a condition where any one of the target pressure increase gradients is relatively high, the control hydraulic pressure can be controlled at a desired pressure increase gradient by shortening the closing unit time TC and increasing the duty ratio. The pressure can be increased and adjusted appropriately.

  In addition, selection of multiple systems including both system # 1 and system # 2 is continuously performed by the control unit 10a across the control cycle, and the control unit 10a temporarily sets the open unit time TO as described above. After setting B_msec larger than the fluctuation period TQ of the discharge flow rate of the pump 3, the control means 10a holds the target control hydraulic pressure at the reference value PB and holds the opening unit time TO at B_msec longer than the reference period TB. The selection of multiple systems is continuously executed, the target control hydraulic pressure is once returned to the reference pressure PB, and the opening unit time TO is larger than the reference cycle TB which is the fluctuation cycle TQ of the discharge flow rate Q of the pump 3. After the change to B_msec, since both the target control hydraulic pressure and the opening unit time TO are held as they are across the control cycle, the holding valve 4 Operation timing and asynchronous fluctuation period TQ of discharged flow rate Q of the pump 3 is generated, the step-up gradients of the control hydraulic pressure can as much as possible to reduce that variation.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions are made to the above-described embodiments without departing from the scope of the present invention. be able to.

  For example, when the selection is switched from a single system of system # 1 or system # 2 to a multiple system including system # 1 and system # 2, the total hydraulic piping capacity borne by the motor 9 driving the pump 3 increases. For this reason, the fluctuation period TQ of the discharge flow rate Q of the pump 3 becomes longer. On the contrary, when the selection is switched from the multiple system to the single system, the total hydraulic pressure borne by the motor 9 driving the pump 3 is increased. Since the pipe capacity is reduced, the fluctuation period TQ of the discharge flow rate of the pump 3 is shortened. The fluctuation cycle TQ before and after the switching of the selection can be obtained in advance by experiment or simulation, etc., and the fluctuation cycle TQ obtained by the control means 10a is stored, and each time the switching is performed, the open unit time TO is determined as a single system. It is good also as changing according to the fluctuation period TQ corresponding to each fluctuation period TQ or multiple systems.

  Furthermore, when a flow rate sensor or a pressure sensor for detecting the discharge flow rate of the pump 3 can be provided on the hydraulic piping, the fluctuation period TQ of the discharge flow rate Q is detected in real time, and the opening unit time of the pressure regulating valve 4 is determined. Feedback control can also be performed by the control means 10a of the brake ECU 10 so that TO coincides with the fluctuation cycle TQ.

  The present invention relates to a vehicle braking device, and more appropriately controls the pressure regulation by a pressure regulating valve, and the pump has a large temporal variation in the discharge flow rate at a lower price, for example, as a single piston type pump and Eliminates the need to add components that complement pressure accumulation performance such as dampers and accumulators to the hydraulic piping between the pressure regulating valve, and the hydraulic piping between the pump and pressure regulating valve is large to ensure pressure accumulation performance Can be abolished. For this reason, according to the present invention, the unit price of the parts constituting the vehicle braking device can be reduced, the number of parts can be reduced, and the hydraulic piping capacity can be reduced, so that the cost of the entire vehicle can be reduced. it can. Therefore, the present invention is useful when applied to various vehicles such as passenger cars, trucks, and buses.

DESCRIPTION OF SYMBOLS 1 Vehicle braking device 2 Master cylinder 3 Pump 4 Pressure regulating valve 5 Wheel cylinder 6 Holding valve 7 Pressure reducing valve 8 Reservoir 9 Motor 10 Brake ECU
10a Control means

Claims (4)

  A master cylinder that generates an operation oil pressure from a basic oil pressure in response to an operation of the pedal, a pump that increases the operation oil pressure, a pressure adjustment valve that adjusts the increased operation oil pressure to generate a control oil pressure, and the operation Supply means for supplying the hydraulic pressure or the control hydraulic pressure to the wheel cylinder as a supply hydraulic pressure, and setting the opening unit time of the pressure regulating valve to the fluctuation period of the discharge flow rate of the pump and controlling the closing unit time to target the control hydraulic pressure A vehicle braking device comprising control means for controlling to control oil pressure.   The master cylinder, the pump, the pressure regulating valve, and a supply unit that supplies the operation hydraulic pressure or the control hydraulic pressure as a supply hydraulic pressure to a wheel cylinder include a plurality of systems, and the control unit is any one of the multiple systems. Switching between the selection of the single system and the selection of the multiple system, and after the control means switches the selection from the single system to the multiple system, the target control hydraulic pressure and target of the supply hydraulic pressure used for executing the control Regarding the pressure increase gradient, when the target control oil pressure is equal to or less than a predetermined oil pressure and the target pressure increase gradient is equal to or less than the predetermined pressure increase gradient, the control means changes the target control oil pressure from a reference pressure to a low reference pressure lower than the reference pressure. The vehicle braking device according to claim 1, wherein the vehicle braking device is changed.   When the target control oil pressure is greater than a predetermined oil pressure, or when the target pressure increase gradient is greater than a predetermined pressure increase gradient, the control means returns the target control oil pressure to a reference pressure, and sets the opening unit time to the discharge flow rate of the pump. The vehicle braking device according to claim 2, wherein the vehicle braking device is longer than the fluctuation period of the vehicle.   After the selection of the multiple systems is continuously performed by the control means, and the control means once makes the opening unit time larger than the fluctuation cycle of the discharge flow rate of the pump, the control means performs the target control. 4. The vehicle braking device according to claim 3, wherein hydraulic pressure is maintained at the reference value and the opening unit time is maintained.

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