JP4456523B2 - Brake device for vehicle - Google Patents

Description

  The present invention relates to a brake device for a vehicle.

  In general, as a vehicle brake device, a so-called fluid is provided that includes a pressure regulating valve that regulates and outputs the fluid pressure accumulated in a fluid pressure source to a fluid pressure according to a driver's brake operation, and operates the brake mechanism with the output. A pressure booster type brake device is known. Conventionally, as such a brake device, an accumulator for accumulating a predetermined range of fluid pressure and a fluid pressure accumulated in the accumulator are adjusted to a fluid pressure corresponding to a driver's brake operation and output. The pressure valve, the hydraulic pressure output from the pressure regulating valve is supplied to the auxiliary hydraulic pressure chamber, the piston operates to output the hydraulic pressure, the master cylinder outputs the hydraulic pressure, and the hydraulic pressure output from the master cylinder operates the wheel. There is a thing provided with a caliper which gives braking force to (refer to patent documents 1).

  By the way, the brake device described above includes an electromagnetic valve for further adjusting the hydraulic pressure from the pressure regulating valve and supplying the hydraulic pressure to the auxiliary hydraulic pressure chamber, and an electromagnetic valve for releasing the hydraulic pressure in the auxiliary hydraulic pressure chamber to the reservoir. In addition, by appropriately controlling these solenoid valves, it is possible to arbitrarily set the pressure in the auxiliary hydraulic chamber, that is, the braking force to the wheels.

JP 2002-264895 (paragraphs 0012 to 0020, FIG. 1)

  However, in the brake device described above, when the driver strongly presses the brake pedal when the vehicle is stopped, the hydraulic pressure is higher than necessary (for example, higher than the hydraulic pressure necessary to stop the start due to the creep phenomenon). ) Occurs, causing a problem that a load is applied to the master cylinder and the caliper.

  Therefore, according to the present invention, in the hydraulic booster type brake device, even if the driver strongly depresses the brake pedal when the vehicle is stopped, the vehicle that can reduce the load applied to the brake mechanism such as the master cylinder and the caliper. An object of the present invention is to provide a brake device.

The invention according to claim 1 of the present invention that solves the above-mentioned problems is that the hydraulic pressure source that accumulates the hydraulic pressure while maintaining the hydraulic pressure within a predetermined range, and the hydraulic pressure accumulated in the hydraulic pressure source are supplied to the driver. A pressure regulating valve that regulates and outputs a fluid pressure according to a brake operation, and the fluid pressure source includes a reservoir capable of storing a predetermined amount of fluid, an accumulator for accumulating fluid pressure, And a pump for supplying the accumulator to the accumulator, and a brake device for a vehicle that operates a brake mechanism by the output of the pressure regulating valve, and a stop-related signal detection unit that detects a signal related to the stop of the vehicle; A stop state determining means for determining whether or not the vehicle is in a stopped state based on a signal detected by the stop related signal detecting means, and when the stop state determining means determines that the vehicle is in a stopped state Lower than the predetermined range Until constant is target pressure, the accumulator pressure detecting means for detecting the liquid pressure in the control means for decreasing the fluid pressure outputted from the hydraulic or the pressure regulating valve of the hydraulic pressure source, a pressure accumulator has been hydraulic pressure in the accumulator And the pump is driven when the hydraulic pressure detected by the accumulator pressure detecting means is not more than the lower limit value of the predetermined range, and the pump is stopped when the hydraulic pressure is not less than the upper limit value of the predetermined range. A pump operation control means and a pump operation prohibiting means for prohibiting driving of the pump during the hydraulic pressure reduction control by the hydraulic pressure reduction control means are provided.

  Here, the “brake mechanism” is a disc brake having a structure in which a disc rotor that rotates integrally with an axle is sandwiched between brake pads built in a caliper, and a shoe that is a friction material is pressed against the inner surface of a drum by a wheel cylinder. It refers to a master cylinder or the like that distributes and supplies hydraulic pressure to various brakes such as drum brakes and to each brake provided on each wheel. The “signal related to stopping of the vehicle” is a signal issued when the vehicle stops (for example, a vehicle speed signal indicating 0 km / h, a signal indicating that the shift position of the automatic transmission is at the parking position, This means a signal that is generated when the parking brake is turned on, a signal that changes until the vehicle stops (for example, a negative acceleration generated by a brake operation, a brake depression amount, and the like). Further, the “stop state” means a state where the vehicle is completely stopped, and also includes a state where the vehicle travels at a very small speed of 3 to 5 km / h, for example.

  According to the first aspect of the present invention, when the vehicle is stopped, a signal related to stopping of the vehicle is detected by the stop related signal detecting means, and the signal is output to the stop state determining means. The stop state determining means determines whether or not the vehicle is in a stopped state based on the signal detected by the stop related signal detecting means, and when it is determined that the vehicle is in a stopped state, the signal is reduced in hydraulic pressure. Output to the control means. And when this hydraulic pressure reduction control means receives the above-mentioned signal from the stop state judging means, for example, the hydraulic pressure maintained at a pressure within a predetermined range in the hydraulic pressure source is reduced to a target pressure lower than the predetermined range. Reduce. As a result, even if the driver depresses the brake pedal when the vehicle is stopped, the hydraulic pressure reduced to a low value by the hydraulic pressure reduction control means is supplied from the hydraulic pressure source via the pressure regulating valve to the brake mechanism. Therefore, the load applied to the brake mechanism can be reduced.

According to the invention described in claim 1, in addition to the action, when to lower the hydraulic pressure in the example accumulator by liquid pressure in the control means, the driving of the pump is prohibited by the pump operation prohibition means, hydraulic Interference between the hydraulic pressure reduction control by the reduction control means and the pump control by the pump operation control means can be prevented.

According to the second aspect of the present invention, the hydraulic pressure source that accumulates pressure while maintaining the hydraulic pressure within a predetermined range, and the hydraulic pressure accumulated in the hydraulic pressure source are adjusted to a hydraulic pressure according to the driver's brake operation. A pressure regulating valve that outputs pressure, and the hydraulic pressure source includes a reservoir capable of storing a predetermined amount of liquid, an accumulator for accumulating the hydraulic pressure, and a pump that supplies the liquid in the reservoir to the accumulator And a brake device for a vehicle that operates a brake mechanism with the output of the pressure regulating valve, the stop-related signal detecting means for detecting a signal related to the stop of the vehicle, and the stop-related signal detecting means A stop state determination means for determining whether or not the vehicle is in a stopped state based on the received signal, and when the stop state determination means determines that the vehicle is in a stop state, the stop state is determined to be lower than the predetermined range. Up to the target pressure A liquid pressure in the control means for decreasing the fluid pressure outputted from the hydraulic or the pressure regulating valve, an accumulator pressure detecting means for detecting the hydraulic pressure is accumulated in the accumulator, which is detected by the accumulator pressure detecting means A pump operation control means for driving the pump when the hydraulic pressure is equal to or lower than the lower limit value of the predetermined range, and stopping the pump when the hydraulic pressure is equal to or higher than the upper limit value of the predetermined range; Pressure accumulation range changing means for changing so that the vehicle speed is lower in the low speed state including the stop state than in the high speed state, and the target pressure in the hydraulic pressure lowering control means is the high speed It is set lower than a predetermined range in the state and higher than a lower limit value in the stopped state.

  Here, “high speed state, low speed state” refers to a state in which the vehicle is traveling at a speed higher than the predetermined speed at a predetermined speed that is arbitrarily determined, and is the predetermined speed. A state where the vehicle is traveling at a low speed that is lower than the vehicle speed is referred to as a low speed state. The “lower limit value” may be set to a constant value in the low speed state or the high speed state, or may be set to a value that changes in proportion to the speed in the low speed state or the high speed state.

According to the invention described in claim 2, when the vehicles are decelerated from a high speed state to the low speed state, the lower limit that triggers the operation of the pump, and thus be lowered by accumulating range changing means. As a result, even if the hydraulic pressure in the accumulator drops to the lower limit of the predetermined range when the high speed state is reached, the pump is not driven in the low speed state, so the hydraulic pressure in the accumulator is reduced by the hydraulic pressure reduction control. Even if it is lowered, the pump is not driven unnecessarily. That is, when a large braking force is required such as in a high speed state, a high hydraulic pressure is maintained in the accumulator, and when a small braking force such as a low speed state is sufficient, the frequency of driving the pump is decreased to reduce the accumulator. It is possible to achieve a reasonable pressure accumulation according to the required braking energy, such as keeping a low hydraulic pressure inside. In addition, since the frequency of driving the pump is reduced in such a low speed state, noise due to driving of the pump can be suppressed in the low speed state, and power consumption can be suppressed. Furthermore, the target pressure of the hydraulic pressure reduction control is set to be lower than the predetermined range in the high speed state and higher than the lower limit value in the stationary state, so that the hydraulic pressure is reduced to the target pressure by the hydraulic pressure reduction control. Since the driving of the pump is not started during the operation, interference between the hydraulic pressure reduction control by the hydraulic pressure reduction control means and the pump control by the pump operation control means can be suppressed.

According to the third aspect of the present invention, the hydraulic pressure source for accumulating while maintaining the hydraulic pressure within a predetermined range, and the hydraulic pressure accumulated in the hydraulic pressure source are adjusted to the hydraulic pressure according to the driver's brake operation. A pressure regulating valve that outputs pressure, and the hydraulic pressure source includes a reservoir capable of storing a predetermined amount of liquid, an accumulator for accumulating the hydraulic pressure, and a pump that supplies the liquid in the reservoir to the accumulator And a brake device for a vehicle that operates a brake mechanism with the output of the pressure regulating valve, the stop-related signal detecting means for detecting a signal related to the stop of the vehicle, and the stop-related signal detecting means A stop state determination means for determining whether or not the vehicle is in a stopped state based on the received signal, and when the stop state determination means determines that the vehicle is in a stop state, the stop state is determined to be lower than the predetermined range. Up to the target pressure Of the hydraulic or the regulating liquid pressure in the control means for decreasing the fluid pressure output from the valve, and an accumulator pressure detecting means for detecting the hydraulic pressure is accumulated in the accumulator, the hydraulic pressure output from the pressure regulating valve Or an output pressure detecting means for detecting a hydraulic pressure in the brake mechanism, and the hydraulic pressure lowering control means is a normally closed type interposed in a passage connecting the output side of the pressure regulating valve and the reservoir. A first deviation which is a deviation between the target pressure and the hydraulic pressure detected by the output pressure detecting means, and a deviation between the target pressure and the hydraulic pressure detected by the accumulator pressure detecting means. With the control amount calculated based on the second deviation, the normally closed solenoid valve is opened to perform the hydraulic pressure reduction control, and the control amount is set at the initial stage of the hydraulic pressure reduction control. The weight of the first deviation is the second deviation Was determined as larger than the weight in the end, characterized in that it is configured to determine a larger than the weight of the weight of the first deviation of the second deviation.

  Here, the “weight” refers to the degree to which the first deviation or the second deviation contributes to determining the control amount.

According to the third aspect of the present invention , the hydraulic pressure reduction control means is influenced by the first deviation (deviation between the target pressure and the hydraulic pressure detected by the output pressure detection means) in the initial stage of the hydraulic pressure reduction control. Based on the control amount calculated so as to largely reflect, the normally closed electromagnetic valve provided in the passage on the output side of the pressure regulating valve is controlled to open. As a result, the hydraulic pressure on the output side of the pressure regulating valve can be satisfactorily reduced while monitoring the hydraulic pressure value, and the hydraulic pressure in the accumulator is reduced as the hydraulic pressure on the output side of the pressure regulating valve decreases. Can also be gradually reduced. In the initial stage of such a hydraulic pressure reduction control, if the control amount is calculated so that the influence of the second deviation is largely reflected contrary to the above, the pressure regulating valve or the like becomes a resistance and the inside of the accumulator Due to the fact that the hydraulic pressure of the valve is difficult to decrease, a large control amount is maintained for a while from the start of control, thereby excessively reducing the hydraulic pressure on the output side of the pressure regulating valve. However, the present invention can solve such a problem. Further, the hydraulic pressure reduction control means is calculated so that the influence of the second deviation (deviation between the target pressure and the hydraulic pressure detected by the accumulator pressure detection means) is greatly reflected in the final stage of the hydraulic pressure reduction control. Based on the control amount, the normally closed electromagnetic valve provided in the passage on the output side of the pressure regulating valve is controlled to open. As a result, at the end of the control, the hydraulic pressure in the accumulator can be reliably reduced to a desired value.

According to a fourth aspect of the present invention, the hydraulic pressure source for accumulating while maintaining the hydraulic pressure within a predetermined range, and the hydraulic pressure accumulated in the hydraulic pressure source are adjusted to a hydraulic pressure corresponding to a driver's brake operation. A pressure regulating valve that outputs pressure, and the hydraulic pressure source includes a reservoir capable of storing a predetermined amount of liquid, an accumulator for accumulating the hydraulic pressure, and a pump that supplies the liquid in the reservoir to the accumulator And a brake device for a vehicle that operates a brake mechanism with the output of the pressure regulating valve, the stop-related signal detecting means for detecting a signal related to the stop of the vehicle, and the stop-related signal detecting means A stop state determination means for determining whether or not the vehicle is in a stopped state based on the received signal, and when the stop state determination means determines that the vehicle is in a stop state, the stop state is determined to be lower than the predetermined range. Up to the target pressure A liquid pressure in the control means for decreasing the fluid pressure outputted from the hydraulic or the pressure regulating valve, an accumulator pressure detecting means for detecting the hydraulic pressure is accumulated in the accumulator, which is detected by the accumulator pressure detecting means A pump operation control means for driving the pump when a hydraulic pressure is equal to or lower than a lower limit value of the predetermined range, and stopping the pump when the hydraulic pressure is equal to or higher than an upper limit value of the predetermined range; And a hydraulic pressure reduction prohibiting means for prohibiting execution of the hydraulic pressure reduction control by the hydraulic pressure reduction control means during driving of the pump.
According to the invention described in claim 4, when the pump when the liquid pressure in the control unit attempts to perform a liquid pressure in control is being driven, the liquid pressure in inhibiting means, liquid pressure in the control means The hydraulic pressure drop control by is prohibited. Therefore, interference between the hydraulic pressure reduction control by the hydraulic pressure reduction control means and the pump control by the pump operation control means can be prevented.

According to the invention of any one of claims 1 to 4 , when the vehicle is stopped, the hydraulic pressure supplied to the brake mechanism is reduced by the hydraulic pressure reduction control means. In this brake device, even when the driver strongly depresses the brake pedal when the vehicle is stopped, the load applied to the brake mechanism such as the master cylinder and the caliper can be reduced.

According to the first or fourth aspect of the invention, when one of the pump control and the hydraulic pressure reduction control is executed, the execution of the other is prohibited. Interference between the pressure drop control and the pump control by the pump operation control means can be prevented.

According to the second aspect of the present invention, since the pump driving conditions are switched according to the high speed state or the low speed state, it is possible to achieve a reasonable pressure accumulation according to the required braking energy and to reduce the pump driving frequency. The noise can be reduced by driving the pump, and the power consumption can be reduced. Further, since the pump is not started during the hydraulic pressure reduction control, interference between the hydraulic pressure reduction control by the hydraulic pressure reduction control means and the pump control by the pump operation control means can be suppressed.

According to the third aspect of the invention, since the weighting of the first deviation and the second deviation is changed at the initial stage and the final stage of the hydraulic pressure reduction control, the hydraulic pressure on the output side of the pressure regulating valve at the initial stage of the hydraulic pressure reduction control. Can be prevented, and at the end of the hydraulic pressure reduction control, the hydraulic pressure in the accumulator can be reliably reduced to a desired value.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a schematic configuration diagram illustrating a non-brake operation of the hydraulic brake device according to the present embodiment, and FIG. 2 is a schematic diagram illustrating a normal brake operation of the hydraulic brake device according to the present embodiment. It is a block diagram. FIG. 3 is a configuration diagram of the control device according to the present embodiment, and FIG. 4 is a table showing pump driving conditions.

  As shown in FIG. 1, the hydraulic brake device 1 according to this embodiment includes a hydraulic pressure generation source (hydraulic pressure source) 2 that generates hydraulic pressure P1 and a hydraulic pressure P1 output from the hydraulic pressure generation source 2. The pressure regulating valve 3 for regulating pressure and the hydraulic pressure (master cylinder pressure) for applying braking force to the wheel cylinders 4a, 4b, 4c, 4d of each brake by the hydraulic pressure (output hydraulic pressure) output from the pressure regulating valve 3 A master cylinder 5 for outputting, a brake pedal 6 and a control device 37 are mainly provided.

  The hydraulic pressure generation source 2 includes a motor 7, a pump 10 driven by the motor 7 to pump hydraulic fluid (brake fluid) L from the reservoir 8 through the liquid pipe 9, and hydraulic fluid pumped by the pump 10 within a predetermined pressure range. And a first pressure sensor (accumulator pressure detecting means) 12 for detecting the pressure of the hydraulic pressure P1 output from the accumulator 11. The hydraulic fluid L stored in the reservoir 8 is in an atmospheric pressure state.

  The pressure regulating valve 3 opens at a valve body 14 slidably fitted to one side (right side in the figure) of the hollow cylindrical housing 13 and an end of one side (right side in the figure) of the valve body 14. A pressure regulating valve spool 16 slidably fitted to the bottomed cylindrical portion (the inner peripheral surface of the valve body 14) formed as described above, and a spring 17 for urging the pressure regulating valve spool 16 in the right direction in FIG. It has.

  Large-diameter end portions 14a and 14b that are in sliding contact with the inside of the housing 13 are formed on both ends of the valve body 14, and a small-diameter intermediate portion 14c and an intermediate-diameter intermediate portion 14d are formed between them. The small diameter intermediate portion 14 c is in sliding contact with the small diameter inner peripheral surface 13 a formed on the housing 13.

  An annular high-pressure chamber 18 formed by the large-diameter end portion 14a and the small-diameter intermediate portion 14c of the valve body 14 and the housing 13 includes a liquid passage 13b formed in the housing 13 and a liquid pipe connected to the liquid passage 13b. The accumulator 11 is connected via 19. Further, a low-pressure chamber 20 formed by the outer end surface of the large-diameter end portion 14 a of the valve body 14 and the end surface and inner peripheral surface on one side (right side in the figure) of the housing 13 is a liquid passage 13 c formed in the housing 13. Are connected to the reservoir 8 and the pump 10 via the liquid pipe 9 connected to the liquid passage 13c.

  The pressure regulating valve spool 16 has a shaft portion 16 a at an end portion protruding from the end surface opening portion 13 d of the housing 13, and is provided on the peripheral surface of the shaft portion 16 a that is in sliding contact with the peripheral surface of the end surface opening portion 13 d of the housing 13. Is provided with an annular seal member (not shown). An output hydraulic pressure chamber 15 is formed by the surface of the end portion (left side in the drawing) opposite to the shaft portion 16 a of the pressure regulating valve spool 16 and the inner surface of the valve body 14. Further, the end of the shaft portion 16a of the pressure regulating valve spool 16 is connected to a brake pedal 6 that is rotatably held. When the driver does not depress the brake pedal 6, the brake pedal 6 is not depressed (in FIG. 1). In the state), the large-diameter intermediate portion 16 b of the pressure regulating valve spool 16 is in contact with the end surface in the housing 13 by the urging force of the spring 17. The brake pedal 6 is provided with a known brake operation amount detection sensor 38 that detects an operation amount of the brake pedal 6 (a depression amount of the brake pedal 6).

  The pressure regulating valve spool 16 includes a communication passage 16c formed along the longitudinal direction from the center of the end surface on the output hydraulic pressure chamber 15 side, a small diameter intermediate portion 16d formed on the outer peripheral surface, and a region around the small diameter intermediate portion 16d. And a communication path 16e communicating with the communication path 16c. The valve body 14 is formed with a communication passage 14e that communicates from its inner peripheral surface toward the high pressure chamber 18 and a communication passage 14f that communicates from its inner peripheral surface toward the low pressure chamber 20. During non-brake operation (state of FIG. 1), the communication passage 14e of the valve body 14 is blocked by the outer peripheral surface of the pressure regulating valve spool 16, and the communication passage 14f is a region around the small diameter intermediate portion 16d of the pressure regulating valve spool 16. It is comprised so that it may communicate with. As a result, the hydraulic pressure P <b> 1 from the accumulator 11 is blocked by the pressure regulating valve 3 and is not transmitted to the master cylinder 5. When the brake is operated (the state shown in FIG. 2), the communication passage 14 e of the valve body 14 is communicated with a region around the small diameter intermediate portion 16 d of the pressure regulating valve spool 16, and the communication passage 14 f is formed on the outer peripheral surface of the pressure regulating valve spool 16. It is configured to be blocked. Thus, the hydraulic pressure P1 from the accumulator 11 is transmitted to the master cylinder 5 via the communication passages 16e and 16c of the pressure regulating valve spool 16, the output hydraulic pressure chamber 15, and the like. Note that the hydraulic pressure exiting through the pressure regulating valve 3 in this way is balanced by the depression amount of the brake pedal 6 (brake operating force), the hydraulic pressure in the output hydraulic pressure chamber 15 and the biasing force of the spring 17. The pressure is appropriately adjusted to a predetermined pressure value.

  A communication passage 14g is formed in the middle-diameter intermediate portion 14d of the valve body 14 to communicate the annular output chamber 21 and the output hydraulic pressure chamber 15 formed on the outer side (housing 13 side).

  The master cylinder 5 is configured integrally with the housing 13 on the other side (the left side in the figure) in the housing 13, and is slidably fitted to the inner periphery of the housing 13, respectively. And springs 23a and 23b for urging the first and second pistons 22a and 22b in the right direction of FIG. An annular seal member (not shown) is provided on each peripheral surface of the first and second pistons 22a and 22b that are in sliding contact with the inner periphery of the housing 13.

  A first master cylinder hydraulic chamber 24 is formed between the first piston 22a and the second piston 22b, and between the second piston 22b and the end face (left side in the figure) in the housing 13, A second master cylinder hydraulic chamber 25 is formed. Further, an auxiliary hydraulic chamber 26 is formed between the first piston 22a and the end face of the valve body 14.

  The first and second master cylinder hydraulic chambers 24 and 25 are provided in each wheel via liquid passages 13e and 13f formed in the housing 13 and liquid pipes 27 and 28 connected to the liquid passages 13e and 13f, respectively. The wheel cylinders 4a, 4b, 4c and 4d are connected. The first and second master cylinder hydraulic pressure chambers 24 and 25 are connected to the reservoir 8 via liquid passages 13g and 13h formed in the housing 13 and liquid pipes 29 and 30 connected to the liquid passages 13g and 13h, respectively. It is connected to the. The fluid passages 13g and 13h communicate with the first and second master cylinder hydraulic pressure chambers 24 and 25, respectively, when the brake is not operated (see FIG. 1), and when the brake is operated (see FIG. 2). Each of the first and second pistons 22a and 22b is closed by the outermost peripheral surfaces.

  The auxiliary hydraulic pressure chamber 26 of the master cylinder 5 and the output chamber 21 of the pressure regulating valve 3 communicate with each other via an output liquid pipe 31 that connects the liquid passages 13 i and 13 j formed in the housing 13. The output liquid pipe 31 is provided with a second pressure sensor (output pressure detection means) 32. The high pressure chamber 18 of the pressure regulating valve 3 communicates with the output liquid pipe 31 via a first branch liquid pipe 33 connected to a liquid passage 13 k formed in the housing 13. The first branch liquid pipe 33 is provided with a normally closed first electromagnetic on-off valve 34. The low pressure chamber 20 of the pressure regulating valve 3 communicates with the output liquid pipe 31 via a second branch liquid pipe 35 connected to a liquid passage 13 m formed in the housing 13. The second branch liquid pipe 35 is provided with a normally closed second electromagnetic on-off valve (normally closed electromagnetic valve) 36.

  The control unit (ECU) 37 is a first normally closed one based on pressure information input from the first and second pressure sensors 12, 32, brake operation amount information input from the brake operation amount detection sensor 38, and the like. , The opening / closing control of the second electromagnetic opening / closing valves 34, 36 and the operation control of the pump 10 (specifically, the motor 7) are performed. In the following description, among the functions of the control device 37, only functions related to control when the vehicle is stopped, which is a feature of the present invention, will be described in detail, and other functions (for example, control during automatic braking) will be described. Etc.) will be omitted. In the following description, since the hydraulic pressure detected by the second pressure sensor 32 (the hydraulic pressure output from the pressure regulating valve 3) is equivalent to the master cylinder pressure output from the master cylinder 5, the master cylinder It will be described as pressure.

  As shown in FIG. 3, the control device 37 includes a control start determination unit 37A, a stop state determination unit 37B, a hydraulic pressure decrease prohibiting unit 37C, an electromagnetic valve control unit (hydraulic pressure decrease control unit) 37D, and a pump operation. Control means 37E and pressure accumulation range changing means 37F are provided.

  Based on the signal detected by the second pressure sensor 32, the control start determination unit 37A determines whether or not the master cylinder pressure indicated by the signal is equal to or higher than the start threshold value (see FIG. 6) for hydraulic pressure reduction control. It has a function. When the control start determination unit 37A determines that the master cylinder pressure is equal to or higher than the start threshold value, the control start determination unit 37A outputs a start signal indicating that to the stop state determination unit 37B.

  When the stop state determination unit 37B receives the start signal output from the control start determination unit 37A, whether the vehicle is stopped based on the vehicle speed signal detected by the vehicle speed sensor (stop related signal detection unit) CS. It has a function to determine whether or not. Specifically, when the vehicle speed signal detected by the vehicle speed sensor CS is a signal representing 0 km / h, the stop state determination means 37B determines that the vehicle is in a stop state, and indicates a stop signal indicating that. Is output to the hydraulic pressure decrease prohibiting means 37C, and in other cases, it is determined that the vehicle is not in a stopped state, and the stop signal is not output to the hydraulic pressure decrease prohibiting means 37C. In this embodiment, the state where the vehicle speed is 0 km / h is set as the stop state, but the present invention is not limited to this, and the vehicle speed is stopped at a very small speed of about 3 to 5 km / h. It may be set as a state.

  When the hydraulic pressure decrease prohibiting means 37C receives the stop signal output from the stop state determining means 37B, the hydraulic pressure decrease prohibiting means 37C refers to the signal output from the pump operation control means 37E, and the pump 10 is not operating based on this signal. It has a function to determine whether or not. When the hydraulic pressure reduction prohibiting unit 37C determines that the pump 10 is not operating, the hydraulic pressure decrease prohibiting unit 37C transmits a permission signal for permitting the electromagnetic valve control unit 37D to execute the control of the second electromagnetic switching valve 36. In addition to outputting, when it is determined that the pump is operating, it has a function of prohibiting the hydraulic pressure reduction control by the electromagnetic valve control means 37D by not outputting the above-mentioned permission signal.

  When the solenoid valve control unit 37D receives the permission signal output from the hydraulic pressure decrease prohibiting unit 37C, the solenoid valve control unit 37D refers to the signals output from the first and second pressure sensors 12 and 32, and based on these signals. By controlling the second electromagnetic opening / closing valve 36, the hydraulic pressure P2 output from the pressure regulating valve 3 (see FIG. 2) is reduced. Here, before describing the function of the electromagnetic valve control unit 37D in detail, the pump operation control unit 37E and the pressure accumulation range changing unit 37F for outputting or deriving information necessary for the control of the electromagnetic valve control unit 37D will be described. It will be done first. In the present embodiment, the solenoid valve control means 37D and the second solenoid on-off valve 36 correspond to “hydraulic pressure drop control means” in the claims.

  The pump operation control unit 37E drives the pump 10 when the hydraulic pressure detected by the first pressure sensor 12 (hereinafter also referred to as “accumulator pressure”) is equal to or lower than the lower limit value of the predetermined range, and the predetermined range. It has a function of stopping the pump 10 when it becomes equal to or greater than the upper limit value. When the pump 10 is driven, the pump operation control means 37E outputs an ON signal indicating that to the hydraulic pressure decrease prohibiting means 37C, and when the pump 10 is stopped, an OFF signal indicating that fact. Is output to the hydraulic pressure decrease prohibiting means 37C. The predetermined range is appropriately set by a pressure accumulation range changing unit 37F described later.

  The pressure accumulation range changing unit 37F has a function of determining whether the vehicle is in a low speed state or a high speed state based on a vehicle speed signal detected by the vehicle speed sensor CS, and sets a predetermined range according to the determination result. In addition, it has a function of outputting data indicating the set predetermined range to the pump operation control means 37E. Specifically, as shown in FIG. 4, the pressure accumulation range changing unit 37F sets the lower limit value to 135 bar (13.5 MPa) and sets the upper limit value to 145 bar (14) when it is determined that the vehicle is in a low speed state. A predetermined range with a lower limit value of 175 bar (17.5 MPa) and an upper limit value of 190 bar (19.0 MPa) when it is determined that the vehicle is in a high speed state. Is set.

  The predetermined range is not limited to the numerical values as in the present embodiment, and can be set as appropriate. Specifically, it is only necessary that at least the lower limit value of the lower limit value and the upper limit value of the predetermined range is set to be lower in the low speed state than in the high speed state. That is, in the present embodiment, the upper limit value in the low speed state may be set to 190 bar instead of 145 bar. However, when the upper limit value in the low speed state is set to a low value of 145 bar as in the present embodiment, it is possible to suppress unnecessary driving of the pump 10, thereby preventing noise by driving and suppressing power consumption. Therefore, it is desirable to set as in this embodiment. The determination of whether the vehicle is in a low speed state or a high speed state can be made by determining whether the vehicle speed is equal to or higher than a predetermined value, but a predetermined value indicating a boundary between the low speed state and the high speed state. It goes without saying that can be arbitrarily set. Further, in the present embodiment, the lower limit value and the upper limit value are fixed to the above-described values in the low speed state and the high speed state, but the present invention is not limited to this, and the lower limit value and the upper limit value in the low speed state and the high speed state are set. It is good also as a value which changes suitably in proportion to speed, respectively.

  Next, details of the operation of the control device 37 and the function of the electromagnetic valve control means 37D will be described with reference to FIGS. 3, 5, and 6. FIG. In the drawings to be referred to, FIG. 5 is a flowchart showing the operation of the control device according to the present embodiment, and FIG. 6 shows a graph showing the hydraulic pressure fluctuation during the hydraulic pressure reduction control, a graph and a function for calculating the control amount. It is explanatory drawing shown.

  As shown in FIGS. 3 and 5, first, based on the signal detected by the second pressure sensor 32, the control start determination unit 37A determines that the master cylinder pressure indicated by the signal is the threshold value for starting the hydraulic pressure reduction control (see FIG. 3). 6) or not (step S1). If it is determined in step S1 that the master cylinder pressure is equal to or higher than the start threshold (Yes), it is determined whether or not the vehicle is stopped (stopped state) by the stop state determination unit 37B (step S1). S2).

  If it is determined in step S2 that the vehicle is stopped (Yes), it is determined by the hydraulic pressure decrease prohibiting means 37C whether or not the pump 10 is not operating (step S3). If it is determined in step S3 that the valve is not operating (Yes), the accumulator pressure (PACC) sent from the first pressure sensor 12 is first set to the target pressure (PRACC) by the electromagnetic valve control means 37D. It is determined whether or not it is higher (step S4). Here, the target pressure is set to a value lower than the lower limit value (175 bar) of the predetermined range in the high speed state shown in FIG. 4 and higher than the lower limit value (135 bar) of the predetermined range in the low speed state.

  When it is determined in step S4 that the accumulator pressure is higher than the target pressure (Yes), the solenoid valve control means 37D calculates a control amount by each function shown in FIG. 6 (step S5), and the control amount Based on the above, the second electromagnetic on-off valve 36 is controlled to open / close (step S6). And after step S6, it returns to step S2 and the above-mentioned process (step S2-S6) is performed again. In addition, when it is determined No in steps S1 to S4, the hydraulic pressure reduction control (steps S2 to S6) is temporarily terminated or when the hydraulic pressure reduction control is not executed (determined No in step S1). (When it is done), the state is maintained (step S7), and the process returns to START again.

The calculation of the control amount in step S5 described above is performed as follows.
As shown in FIG. 6, the control amount K is calculated by adding the value obtained by multiplying the evaluation function J by the proportional control gain Kp and the value obtained by multiplying the integral value of the evaluation function J by the integral control gain Ki. . The evaluation function J is a value obtained by multiplying an accumulator pressure deviation (second deviation) ERRA, which is a deviation between the target pressure PRACC and the accumulator pressure PACC, by the accumulator pressure feedback specific gravity WA, the target pressure PRACC, and the master cylinder pressure PMC. Is calculated by adding a master cylinder pressure feedback specific gravity WM to a master cylinder pressure deviation (first deviation) ERRM that is a deviation of Then, the master cylinder pressure feedback specific gravity WM and the accumulator pressure feedback specific gravity WA are the accumulator pressure feedback when the master cylinder pressure feedback specific gravity WM is “1 (large)” at the start of the hydraulic pressure reduction control (at the time of START shown in the graph). The specific gravity WA is set to “0 (small)”, and this relationship is set to gradually reverse as the control proceeds. Thereby, in the initial stage of the hydraulic pressure reduction control (until the specific gravity WA and WM are switched), the weight of the master cylinder pressure deviation ERRM is weighted so as to be larger than the weight of the accumulator pressure deviation ERRA. The function J and the control amount K are calculated. Further, in the final stage of the hydraulic pressure reduction control (after the specific gravity WA and WM are switched), the evaluation function J is weighted so that the weight of the accumulator pressure deviation ERRA is larger than the weight of the master cylinder pressure deviation ERRM. The control amount K is calculated.

  In addition, by changing the weighting with time as described above, as shown in the graph of FIG. 6, the master cylinder pressure PMC is prevented from excessively decreasing immediately after the start of the hydraulic pressure reduction control (START), and the hydraulic pressure reduction control is performed. At the end of (END), the accumulator pressure PACC can be reliably settled to the target pressure PRACC. Here, “too much lowering of the master cylinder pressure PMC” refers to a phenomenon in which the master cylinder pressure PMC is excessively reduced, and this phenomenon occurs when, for example, the control amount is calculated based only on the accumulator pressure deviation ERRA. Occur. That is, in this case, since the narrow flow path in the pressure regulating valve 3 becomes a resistance (orifice) and the hydraulic pressure in the accumulator 11 is difficult to decrease, it has been a while since the start of control. Since a large control amount is maintained, the hydraulic pressure (master cylinder pressure PMC) in the auxiliary hydraulic pressure chamber 26 where no resistance is interposed between the second electromagnetic on-off valve 36 is excessively reduced. Become. For this reason, when the control for changing the weighting with the passage of time as in the present embodiment is performed, good fluid pressure reduction control is realized.

  In order to change the weighting with time, for example, the timer may be started when it is determined Yes in step S1, and the timer may be stopped when the process proceeds to step S7. According to this, while the processing of steps S2 to S6 is repeatedly performed, the specific gravity WA and WM can be derived from the graph of FIG. 6 by referring to the timer value at that time as appropriate in step S5. .

  Next, the operation of the hydraulic brake device 1 will be described. In the following description, general operations will be briefly described before describing the operation of the hydraulic brake device 1 when the vehicle stops, which is a feature of the present invention.

<Non-brake operation>
As shown in FIG. 1, when the brake pedal 6 is not depressed, the control device 37 controls the drive of the pump 10 (specifically, the motor 7) based on the detection signal detected by the first pressure sensor 12. As a result, the hydraulic fluid (brake fluid) L is appropriately supplied from the reservoir 8 to the accumulator 11 through the fluid pipe 9, and a predetermined fluid pressure (135 to 145 bar or 175 to 190 bar) is accumulated therein. The hydraulic pressure P1 output from the accumulator 11 is supplied to the high pressure chamber 18 of the pressure regulating valve 3 through the liquid pipe 19 and the liquid passage 13b.

  In this situation, the communication passage 14e is blocked by the outer peripheral surface of the pressure regulating valve spool 16 urged by the spring 17 in the right direction in the figure, and the output hydraulic pressure chamber 15 has communication passages 16c and 16e and a small diameter intermediate portion 16d. , The fluid pressure P1 is not output from the high pressure chamber 18 to the output fluid pressure chamber 15. Therefore, no hydraulic pressure is generated in the output hydraulic pressure chamber 15 during non-braking operation.

<During normal brake operation>
During normal brake operation (when the vehicle is running), as shown in FIG. 2, when the brake pedal 6 is depressed by the driver, the pressure regulating valve spool 16 is urged by the spring 17 according to the depression amount. Accordingly, the output fluid pressure chamber 15 moves to the back side (left side in FIG. 2). In this situation, the hydraulic pressure P1 is output from the high pressure chamber 18 to the output hydraulic pressure chamber 15 through the communication path 14e, the small diameter intermediate portion 16d, the communication path 16e, and the communication path 16c. As a result, in the output hydraulic pressure chamber 15, the input hydraulic pressure P <b> 1 is adjusted to a hydraulic pressure (output hydraulic pressure) P <b> 2 corresponding to the depression amount of the brake pedal 6.

  The regulated fluid pressure P2 is output to the auxiliary fluid pressure chamber 26 via the communication passage 14g, the output chamber 21, the fluid passage 13i, the output fluid pipe 31, and the fluid passage 13j. The first master 22a slides to the back side (left side in FIG. 2) of the housing 13 against the urging force of the spring 23a by the hydraulic pressure P2 input into the auxiliary hydraulic pressure chamber 26, and thereby the first master. A hydraulic pressure P 3 is generated in the cylinder hydraulic pressure chamber 24. Further, due to the hydraulic pressure (master cylinder pressure) P3 generated in the first master cylinder hydraulic pressure chamber 24, the second piston 22b is moved to the back side (left side in FIG. 2) of the housing 13 against the urging force by the spring 23b. By sliding, a hydraulic pressure (master cylinder pressure) P <b> 4 is generated in the second master cylinder hydraulic pressure chamber 25.

  As a result, the hydraulic pressures P3 and P4 generated in the first and second master cylinder hydraulic pressure chambers 24 and 25 are supplied to the respective wheel cylinders 4a, 4b and 4c via the respective liquid passages 13e and 13f and the respective liquid pipes 27 and 28. , 4d, a predetermined braking force is obtained.

  In this way, during normal brake operation, the hydraulic pressure P2 adjusted according to the depression amount of the brake pedal 6 is output from the output hydraulic pressure chamber 15 of the pressure adjustment valve 3 to the auxiliary hydraulic pressure chamber 26 of the master cylinder 5. Thus, a predetermined large braking force can be obtained with a light depression force.

  When the depression of the brake pedal 6 is released from the brake operating state, the pressure regulating valve spool 16 slides to the right in FIG. 2 by the hydraulic pressure of the output hydraulic pressure chamber 15 and the urging force of the spring 17. The hydraulic pressure P1 output from the high pressure chamber 18 to the output hydraulic pressure chamber 15 is shut off. In this situation, the output hydraulic pressure chamber 15 communicates with the reservoir 8 via the communication passages 16c and 16e, the small diameter intermediate portion 16d, the communication passage 14f, the low pressure chamber 20, the liquid passage 13c, and the liquid pipe 9. The hydraulic fluid in the pressure chamber 15 and the auxiliary hydraulic chamber 26 becomes atmospheric pressure.

  Further, the first and second pistons 22a and 22b also slide to the valve body 14 side (right side in FIG. 2) by the urging force of the springs 23a and 23b, and return to the position at the time of non-brake operation shown in FIG. In this situation, the first and second master cylinder hydraulic chambers 24 and 25 communicate with the reservoir 8 via the liquid passages 13g and 13h and the liquid pipes 29 and 30, respectively, and the first and second master cylinder hydraulic chambers. The hydraulic fluid in 24 and 25 becomes atmospheric pressure.

<When operating the brake while the vehicle is stopped>
As shown in FIG. 7, when a braking operation is performed while the vehicle is stopped, the control device 37 (particularly, the electromagnetic valve control means 37D) appropriately opens the second electromagnetic opening / closing valve 36 as described above. By controlling the valve, the hydraulic pressure P2 regulated by the pressure regulating valve 3 and output to the master cylinder 5 is passed through the second branch liquid pipe 35, the liquid passage 13m, the low pressure chamber 20, the liquid passage 13c, and the liquid pipe 9. And absorbed by the reservoir 8. Therefore, an increase in the hydraulic pressure in the auxiliary hydraulic chamber 26 of the master cylinder 5 and the first and second master cylinder hydraulic chambers 24 and 25 is suppressed, and the load on each of the wheel cylinders 4a to 4d is reduced. Can do.

According to the above, the following effects can be obtained in the present embodiment.
Even if the driver strongly presses the brake pedal 6 when the vehicle is stopped, the hydraulic pressure P2 output to the master cylinder 5 by the control device 37 is reduced, so that the master cylinder 5 and the wheel cylinders 4a to 4d Such a load can be reduced.
When the pump 10 is driven during the execution of the hydraulic pressure reduction control, the execution of the hydraulic pressure reduction control is prohibited (FIG. 5; Steps S3 and S7), so that interference between the pump control and the hydraulic pressure reduction control is prevented. can do.

Since the driving conditions of the pump 10 are switched according to the high speed state and the low speed state, it is possible to achieve a reasonable pressure accumulation according to the required braking energy, and to reduce the driving frequency of the pump 10 to reduce noise due to the driving of the pump 10. And power consumption can be reduced.
Since the weighting of the master cylinder pressure deviation ERRM and the accumulator pressure deviation ERRA is changed in the initial and final stages of the hydraulic pressure reduction control, an excessive reduction in the hydraulic pressure on the output side of the pressure regulating valve 3 is prevented in the initial stage of the hydraulic pressure reduction control. In addition, the hydraulic pressure in the accumulator 11 can be reliably reduced to the target pressure PRACC at the end of the hydraulic pressure reduction control.

In addition, this invention is implemented in various forms, without being limited to the said embodiment.
In the present embodiment, when the pump control is started during the hydraulic pressure reduction control, the hydraulic pressure reduction control is terminated (FIG. 5; Steps S3 and S7). However, the present invention is not limited to this, and the hydraulic pressure is controlled. A pump operation prohibiting unit that prohibits driving of the pump 10 may be provided during the decrease control. Specifically, as shown in FIG. 8, when it is determined in step S3 in this embodiment that the pump 10 is driven (No), the pump 10 is stopped (step S8), and then step S4. What is necessary is just to comprise a flow so that a process may be advanced. According to this, since the driving of the pump 10 is prohibited during the hydraulic pressure reduction control, the interference between the hydraulic pressure reduction control and the pump control is prevented, and the master cylinder pressure and the accumulator pressure are quickly increased. Can be reduced.

  In the present embodiment, in order to reduce the pressure of the auxiliary hydraulic pressure chamber 26, the hydraulic pressure P2 output from the pressure regulating valve 3 is absorbed by the reservoir 8 by the opening / closing control of the second electromagnetic opening / closing valve 36. Is not limited to this. For example, a pipe for returning the liquid in the liquid pipe 19 disposed between the accumulator 11 and the housing 13 in the present embodiment (see FIG. 2) to the reservoir 8 is provided, and a normally closed electromagnetic opening and closing is provided in this pipe. A valve may be provided and the hydraulic pressure P1 of the hydraulic pressure generating source 2 may be reduced by appropriately controlling the normally closed electromagnetic on-off valve. In this case, the fluid pressure in the auxiliary fluid pressure chamber 26 is also the fluid passage 13j, the output fluid pipe 31, the fluid passage 13i, the output chamber 21, the communication passage 14g, the output fluid pressure chamber 15, the communication passages 16c and 16e, and the small diameter intermediate portion. It will be absorbed into the reservoir 8 through the periphery of 16d, the communication passage 14e, the high pressure chamber 18, the liquid passage 13b, the liquid pipe 19, and a newly provided pipe. Even with such a structure, the load on the master cylinder 5 or the like can be reduced by a brake operation while the vehicle is stopped, as in this embodiment.

  In the present embodiment, in order to detect the hydraulic pressure P2 output from the pressure regulating valve 3, the output pressure pipe 31 is provided with the second pressure sensor 32 that is an output pressure detection means. However, the present invention is not limited to this. For example, the liquid pipe 27 and the liquid pipe 28 may be provided. In this case, the hydraulic pressure P3 or hydraulic pressure P4 in the brake mechanism (master cylinder 5 or wheel cylinders 4a to 4d) is detected, but the hydraulic pressures P3 and P4 are equivalent to the hydraulic pressure P2. Therefore, the hydraulic pressure reduction control in the present embodiment can be performed similarly.

  In the present embodiment, the second electromagnetic on-off valve 36 is employed as the normally closed electromagnetic valve, but the present invention is not limited to this, and an electromagnetic proportional valve, for example, may be employed. In the present embodiment, nothing is provided in the output liquid pipe 31, but the present invention is not limited to this. For example, a normally open electromagnetic on-off valve or an electromagnetic proportional valve may be provided. According to this, for example, the hydraulic pressure P2 coming out from the pressure regulating valve 3 can be further regulated by the electromagnetic proportional valve.

  In the present embodiment, it is determined by monitoring the master cylinder pressure whether or not to enter the hydraulic pressure reduction control (FIG. 5; steps S2 to S6) (step S1), but the present invention is not limited to this. For example, the determination may be made by monitoring a signal from the brake operation amount detection sensor 38. Further, the processing in steps S1 and S3 in the present embodiment may be omitted. Even in this case, the hydraulic pressure reduction control corresponding to the brake operation while the vehicle is stopped can be performed.

It is a schematic block diagram which shows the time of non-brake operation of the hydraulic brake device which concerns on this embodiment. It is a schematic block diagram which shows the time of normal brake operation of the hydraulic brake device which concerns on this embodiment. It is a block diagram of the control apparatus which concerns on this embodiment. It is a table | surface which shows the drive conditions of a pump. It is a flowchart which shows operation | movement of the control apparatus which concerns on this embodiment. It is explanatory drawing which shows the graph and function for calculating the graph which shows the hydraulic pressure fluctuation | variation during hydraulic pressure fall control, and control amount. It is a schematic block diagram which shows the effect | action of a hydraulic brake device when brake operation is performed while a vehicle stops. It is a flowchart which shows the function of the solenoid valve control means and pump operation | movement prohibition means which concern on other embodiment.

Explanation of symbols

1 Hydraulic brake device 2 Hydraulic pressure source (hydraulic pressure source)
3 Pressure regulating valve 4a, 4b, 4c, 4d Wheel cylinder (brake mechanism)
5 Master cylinder (brake mechanism)
6 Brake pedal 8 Reservoir 10 Pump 11 Accumulator 12 First pressure sensor (Accumulator pressure detecting means)
32 Second pressure sensor (output pressure detection means)
34 1st electromagnetic on-off valve 36 2nd electromagnetic on-off valve (normally closed solenoid valve, hydraulic pressure drop control means)
37 Control Device 37A Control Start Judgment Unit 37B Stopping State Judgment Unit 37C Fluid Pressure Decrease Inhibiting Unit 37D Solenoid Valve Control Unit (Liquid Pressure Decrease Control Unit)
37E Pump operation control means 37F Accumulated pressure range changing means 38 Brake operation amount detection sensor CS Vehicle speed sensor (stop-related signal detection means)
ERRM Master cylinder pressure deviation ERRA Accumulator pressure deviation P1 Hydraulic pressure P2 Hydraulic pressure PMC Master cylinder pressure PACC Accumulator pressure PRACC Target pressure WA Accumulator pressure feedback specific gravity WM Master cylinder pressure feedback specific gravity

Claims (4)

A hydraulic pressure source for accumulating pressure while maintaining the hydraulic pressure within a predetermined range;
A pressure regulating valve that regulates and outputs the hydraulic pressure accumulated in the hydraulic pressure source to a hydraulic pressure corresponding to a driver's brake operation;
The fluid pressure source has a reservoir capable of storing a predetermined amount of fluid, an accumulator for accumulating fluid pressure, and a pump for supplying the fluid in the reservoir to the accumulator,
A brake device for a vehicle that operates a brake mechanism by the output of the pressure regulating valve ,
A stop-related signal detecting means for detecting a signal related to the stop of the vehicle;
Based on the signal detected by the stop related signal detection means, a stop state determination means for determining whether or not the vehicle is in a stop state;
When it is determined by the stop state determination means that the vehicle is in a stop state, the hydraulic pressure of the hydraulic pressure source or the hydraulic pressure output from the pressure regulating valve is reduced to a target pressure set lower than the predetermined range. Hydraulic pressure drop control means ;
Accumulator pressure detecting means for detecting the hydraulic pressure accumulated in the accumulator;
A pump operation that drives the pump when the hydraulic pressure detected by the accumulator pressure detecting means is less than or equal to the lower limit value of the predetermined range, and stops the pump when the hydraulic pressure is greater than or equal to the upper limit value of the predetermined range. Control means;
A vehicle brake device comprising: a pump operation prohibiting unit that prohibits driving of the pump during the hydraulic pressure decrease control by the hydraulic pressure decrease control unit. A hydraulic pressure source for accumulating pressure while maintaining the hydraulic pressure within a predetermined range;
A pressure regulating valve that regulates and outputs the hydraulic pressure accumulated in the hydraulic pressure source to a hydraulic pressure corresponding to a driver's brake operation;
The fluid pressure source has a reservoir capable of storing a predetermined amount of fluid, an accumulator for accumulating fluid pressure, and a pump for supplying the fluid in the reservoir to the accumulator,
A brake device for a vehicle that operates a brake mechanism by the output of the pressure regulating valve,
A stop-related signal detecting means for detecting a signal related to the stop of the vehicle;
Based on the signal detected by the stop related signal detection means, a stop state determination means for determining whether or not the vehicle is in a stop state;
When it is determined by the stop state determination means that the vehicle is in a stop state, the hydraulic pressure of the hydraulic pressure source or the hydraulic pressure output from the pressure regulating valve is reduced to a target pressure set lower than the predetermined range. Hydraulic pressure drop control means;
Accumulator pressure detecting means for detecting the hydraulic pressure accumulated in the accumulator;
A pump operation that drives the pump when the hydraulic pressure detected by the accumulator pressure detecting means is less than or equal to the lower limit value of the predetermined range, and stops the pump when the hydraulic pressure is greater than or equal to the upper limit value of the predetermined range. Control means;
Pressure accumulation range changing means for changing the lower limit value so that the vehicle speed is lower in the low speed state including the stop state than in the high speed state,
The target pressure in the liquid pressure drop control means, the high-speed state below a predetermined range when the, vehicles braking devices you characterized in that it is set higher than the lower limit value when the vehicle stop state. A hydraulic pressure source for accumulating pressure while maintaining the hydraulic pressure within a predetermined range;
A pressure regulating valve that regulates and outputs the hydraulic pressure accumulated in the hydraulic pressure source to a hydraulic pressure corresponding to a driver's brake operation;
The fluid pressure source has a reservoir capable of storing a predetermined amount of fluid, an accumulator for accumulating fluid pressure, and a pump for supplying the fluid in the reservoir to the accumulator,
A brake device for a vehicle that operates a brake mechanism by the output of the pressure regulating valve,
A stop-related signal detecting means for detecting a signal related to the stop of the vehicle;
Based on the signal detected by the stop related signal detection means, a stop state determination means for determining whether or not the vehicle is in a stop state;
When it is determined by the stop state determination means that the vehicle is in a stop state, the hydraulic pressure of the hydraulic pressure source or the hydraulic pressure output from the pressure regulating valve is reduced to a target pressure set lower than the predetermined range. Hydraulic pressure drop control means;
Accumulator pressure detecting means for detecting the hydraulic pressure accumulated in the accumulator;
Output pressure detecting means for detecting the hydraulic pressure output from the pressure regulating valve or the hydraulic pressure in the brake mechanism, and
The hydraulic pressure drop control means includes
A normally closed solenoid valve interposed in a passage connecting the output side of the pressure regulating valve and the reservoir;
A first deviation which is a deviation between the target pressure and the hydraulic pressure detected by the output pressure detecting means, and a second deviation which is a deviation between the target pressure and the hydraulic pressure detected by the accumulator pressure detecting means. With the control amount calculated based on the valve, the normally closed solenoid valve is opened to execute the hydraulic pressure reduction control,
The control amount is determined so that the weight of the first deviation is larger than the weight of the second deviation at the initial stage of the hydraulic pressure reduction control, and the weight of the second deviation is set as the first deviation at the end stage. vehicles brake system characterized in that it is configured to determine a larger than the weight of the. A hydraulic pressure source for accumulating pressure while maintaining the hydraulic pressure within a predetermined range;
A pressure regulating valve that regulates and outputs the hydraulic pressure accumulated in the hydraulic pressure source to a hydraulic pressure corresponding to a driver's brake operation;
The fluid pressure source has a reservoir capable of storing a predetermined amount of fluid, an accumulator for accumulating fluid pressure, and a pump for supplying the fluid in the reservoir to the accumulator,
A brake device for a vehicle that operates a brake mechanism by the output of the pressure regulating valve,
A stop-related signal detecting means for detecting a signal related to the stop of the vehicle;
Based on the signal detected by the stop related signal detection means, a stop state determination means for determining whether or not the vehicle is in a stop state;
When it is determined by the stop state determination means that the vehicle is in a stop state, the hydraulic pressure of the hydraulic pressure source or the hydraulic pressure output from the pressure regulating valve is reduced to a target pressure set lower than the predetermined range. Hydraulic pressure drop control means;
Accumulator pressure detecting means for detecting the hydraulic pressure accumulated in the accumulator;
A pump operation that drives the pump when the hydraulic pressure detected by the accumulator pressure detecting means is less than or equal to the lower limit value of the predetermined range, and stops the pump when the hydraulic pressure is greater than or equal to the upper limit value of the predetermined range. Control means;
Wherein during operation of the pump by the pump actuation control means, the liquid pressure lowering control means vehicles brake system you comprising: the liquid pressure in inhibiting means for inhibiting the execution of the liquid pressure in the control, the by .

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