JP2010269772A - Brake control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately generate liquid pressure corresponding to a required braking force of a wheel with a simpler structure in a brake control device having an electronically controlled brake. <P>SOLUTION: The brake control device 1 includes: wheel cylinders 4FR-4RP for applying a braking force to a wheel by liquid pressure of brake fluid supplied through a flow passage; pumps 60, 61 for supplying the brake fluid to the wheel cylinders 4FR-4RP by means of power and generating hydraulic pressure by pressurizing the supplied brake fluid; an accumulator 63 for storing the pressurized brake fluid and generating hydraulic pressure by supplying the stored brake fluid to the wheel cylinders 4FR-4RP; and a brake ECU 300 for controlling the wheel cylinder pressure to be a target liquid pressure by combining the pumps 60, 61 and the accumulator 63. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a brake control device.

  Conventionally, an electronically controlled brake (ECB) that adjusts the hydraulic pressure supplied to each wheel cylinder by electronically controlling the supply of brake fluid (hydraulic fluid) to the wheel cylinder via the hydraulic fluid circuit Is known (for example, refer to Patent Document 1 or 2).

  In Patent Documents 1 and 2, the brake fluid stored in the reservoir tank is supplied to the wheel cylinder by a pump and pressurized to generate wheel cylinder pressure independently from the operation of the brake operation member by the driver. Are listed.

JP 2000-283055 A JP 9-76890 A

  By the way, in a brake control device equipped with an electronically controlled brake, the hydraulic pressure generated in the wheel cylinder accurately follows the change in the operation amount of the brake operation member, that is, the required change in the braking force of the wheel. Is required. On the other hand, the brake control apparatus described in Patent Document 1 includes a low-pressure pump and a high-pressure pump, and uses these two pumps to adjust the wheel cylinder pressure to a target pressure. That is, the brake control apparatus described in Patent Document 1 improves the followability of the wheel cylinder pressure with respect to the required braking force by combining two pumps having different operating characteristics.

  On the other hand, there is always a demand for lowering the cost of vehicles and improving fuel efficiency, so there is also a demand for further cost reduction and weight reduction for brake control devices equipped with electronically controlled brakes. Therefore, simplification of the structure of the brake control device is required.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a simpler configuration of a hydraulic pressure corresponding to a required braking force of a wheel in a brake control device including an electronically controlled brake. It is to provide a technique that can be generated with high accuracy.

  In order to solve the above problems, a brake control device according to an aspect of the present invention includes a wheel cylinder that applies a braking force to a wheel by hydraulic pressure of hydraulic fluid supplied via a hydraulic fluid flow path, and hydraulic fluid by power. Is supplied to the wheel cylinder, the hydraulic fluid is generated by pressurizing the supplied hydraulic fluid, the hydraulic fluid is stored in a pressurized state, and the stored hydraulic fluid is stored in the wheel cylinder. The hydraulic power in the wheel cylinder is set to a target hydraulic pressure by combining the second power hydraulic pressure source that generates the hydraulic pressure by supplying to the first power hydraulic pressure source and the second power hydraulic pressure source. And a control unit for controlling.

  According to this aspect, the hydraulic pressure corresponding to the required braking force of the wheel can be accurately generated with a simpler configuration.

  In the above aspect, when the difference between the target hydraulic pressure and the current hydraulic pressure is less than or equal to a predetermined threshold value, the control unit generates a hydraulic pressure by the first power hydraulic pressure source, and the difference is the threshold value. The hydraulic pressure may be generated by the first power hydraulic pressure source and the second power hydraulic pressure source. This also makes it possible to accurately generate the hydraulic pressure corresponding to the required wheel braking force.

  In the above aspect, the second power hydraulic pressure source may contain the hydraulic fluid supplied from the first power hydraulic pressure source in a pressurized state. According to this, an increase in the number of parts of the brake control device can be suppressed.

  In the above aspect, the control unit may store the hydraulic pressure in the second power hydraulic pressure source when the brake is not required for the wheel. According to this, the 1st power hydraulic pressure source at the time of non-use can be used effectively.

  In the above aspect, the control unit supplies hydraulic fluid from the first power hydraulic pressure source with an output lower than a maximum output when the hydraulic pressure is generated in the wheel cylinder, and supplies liquid to the second power hydraulic pressure source. Pressure may be stored. According to this, power consumption can be reduced.

  In the above aspect, the first power hydraulic pressure source and the second power hydraulic pressure source are provided in a hydraulic fluid flow path that connects the first power hydraulic pressure source and the second power hydraulic pressure source, and are opened. There may be provided a cut valve that allows the hydraulic fluid to flow between the two. According to this, a stable hydraulic pressure can be generated in the wheel cylinder.

  In the above aspect, the reservoir tank that stores the hydraulic fluid, and the hydraulic fluid stored in the reservoir tank by the operation of the brake operation member by the driver is supplied to the wheel cylinder, and the hydraulic fluid is pressurized by pressurizing the supplied hydraulic fluid. Is provided on the hydraulic fluid flow path connecting the manual hydraulic pressure source and the wheel cylinder, and is closed to shut off the supply of the hydraulic fluid to the wheel cylinder by the manual hydraulic pressure source. A master cut valve, wherein the first power hydraulic pressure source and the second power hydraulic pressure source are provided in parallel with the manual hydraulic pressure source, and the control unit includes the first power hydraulic pressure source or The master cut valve may be closed when hydraulic pressure is generated in the wheel cylinder by the second power hydraulic pressure source. According to this, the brake feeling can be improved by suppressing the displacement of the brake operating member accompanying the change in the hydraulic pressure of the wheel cylinder.

  In the above aspect, a pressure-regulating linear control valve may be provided that is provided on a hydraulic fluid flow path that connects the reservoir tank and the wheel cylinder, and that adjusts the hydraulic pressure generated in the wheel cylinder by the opening of the valve. . According to this, the hydraulic pressure of the wheel cylinder can be adjusted with high accuracy.

  In the above aspect, the pressure-regulating linear control valve is a normally-open control valve that is opened when not energized and whose opening is adjusted by energization control, and operates to connect the reservoir tank and the wheel cylinder A reservoir cut valve may be provided that is provided on the liquid flow path and closes the valve to hold the liquid pressure in the wheel cylinder. According to this, a fail-safe function can be ensured and the reliability of the brake control device can be improved.

  In the above aspect, the working fluid flow downstream side and the upstream side of the pressure regulating linear control valve in the working fluid flow path connecting the reservoir tank and the wheel cylinder are connected without the pressure regulating linear control valve. A pressure reducing flow path, and a pressure reducing valve provided on the pressure reducing flow path and opened to allow the flow of hydraulic fluid between the wheel cylinder and the reservoir tank via the pressure reducing flow path. The controller reduces the hydraulic pressure by increasing the opening of the pressure regulating linear control valve when the difference between the target hydraulic pressure and the current hydraulic pressure is equal to or less than a predetermined threshold value, When the pressure exceeds the threshold value, the hydraulic pressure may be reduced by increasing the opening degree of the pressure regulating linear control valve and opening the pressure reducing valve. According to this, the hydraulic pressure corresponding to the required braking force of the wheel can be generated with high accuracy.

  According to the present invention, in a brake control device provided with an electronically controlled brake, it is possible to accurately generate a hydraulic pressure corresponding to a required wheel braking force with a simpler configuration.

1 is a schematic configuration diagram of a brake control device according to a first embodiment. FIG. 2A is a schematic diagram illustrating a state of the brake control device during normal pressurization, and FIG. 2B is a schematic diagram illustrating a state of the brake control device during normal pressure reduction. FIG. 3A is a schematic diagram showing a state of the brake control device at the time of sudden pressurization, and FIG. 3B is a schematic diagram showing a state of the brake control device at the time of sudden pressure reduction. It is a control flowchart of a brake operation. It is the schematic which shows the state in which the regenerative brake unit was integrated in the brake control apparatus provided with the conventional VSC mechanism. It is a schematic block diagram of the brake control apparatus which concerns on Embodiment 2. It is the schematic which shows the state by which the regenerative brake unit was integrated in the brake control apparatus provided with the conventional ABS mechanism.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a brake control device according to the first embodiment. A brake control device 1 shown in the figure constitutes an electronically controlled brake system (ECB) for a vehicle, and controls braking force applied to four wheels provided in the vehicle. The brake control device 1 according to this embodiment is mounted on, for example, a hybrid vehicle that includes an electric motor and an internal combustion engine as a travel drive source. In such a hybrid vehicle, regenerative braking for braking the vehicle by regenerating kinetic energy of the vehicle into electrical energy and hydraulic braking by the brake control device 1 can be used for braking the vehicle. The vehicle in the present embodiment can execute brake regenerative cooperative control that generates a desired braking force by using both the regenerative braking and the hydraulic braking together.

  As shown in FIG. 1, the brake control device 1 includes a disc brake unit 2FR, 2FL, 2RR, 2RL, a master cylinder 14 (manual hydraulic pressure source), a reservoir tank 16, a stroke simulator unit 18, a hydraulic pressure, An actuator 100 and a brake ECU 300 (control unit) are provided.

  Each of the disc brake units 2FR, 2FL, 2RL, 2RR (hereinafter collectively referred to as “disc brake unit 2” as appropriate) is a right front wheel, a left front wheel, a left rear wheel, and a right rear wheel (all not shown). ). Each disc brake unit 2 includes a brake disc 3FR, 3FL, 3RL, 3RR (hereinafter, collectively referred to as “brake disc 3” as appropriate) and a wheel cylinder 4FR, 4FL, 4RL, 4RR (hereinafter, collectively referred to as “wheel cylinder 4” where appropriate). Each wheel cylinder 4 is connected to the hydraulic actuator 100 via a different hydraulic fluid flow path.

  In each disc brake unit 2, brake fluid (hydraulic fluid) is supplied from the hydraulic actuator 100 to the wheel cylinder 4, and a brake pad (not shown) is pressed against the brake disc 3 that rotates with the wheel by the hydraulic pressure of the brake fluid. It is done. Thereby, a braking force is applied to each wheel. In the present embodiment, the disc brake unit 2 is used, but another braking force applying mechanism such as a drum brake may be used.

  The master cylinder 14 sends the brake fluid toward the wheel cylinder 4 by operating the brake pedal 10 (brake operation member) by the driver. The master cylinder 14 includes a primary chamber 14a, a secondary chamber 14b, a primary piston 14c, a secondary piston 14d, and springs 14e and 14f. The master cylinder 14 is connected to a reservoir tank 16 that stores brake fluid.

  The master cylinder 14 is partitioned into a primary chamber 14a and a secondary chamber 14b by a primary piston 14c and a secondary piston 14d. A push rod extending from the brake pedal 10 is connected to the primary piston 14c. The primary piston 14c presses the push rod so as to return the brake pedal 10 to the initial position side when the brake pedal 10 is not depressed due to the elastic force of the spring 14e. The secondary piston 14d receives the elastic force of the spring 14f and presses the push rod via the spring 14e and the primary piston 14c. When the brake pedal 10 is depressed by the driver, the push rod enters the master cylinder 14, and the primary piston 14c and the secondary piston 14d are pressed. As a result, a pedal stroke as an operation amount of the brake pedal 10 is transmitted to the master cylinder 14, and a master cylinder pressure corresponding to the pedal stroke of the brake pedal 10 is generated in the primary chamber 14a and the secondary chamber 14b.

  On the other hand, when the brake pedal 10 is depressed, the pedal stroke of the brake pedal 10 is input to the stroke sensor 12, and a detection signal corresponding to the pedal stroke is output from the stroke sensor 12. This detection signal is input to the brake ECU 300, and the brake ECU 300 detects the pedal stroke of the brake pedal 10. Here, the stroke sensor 12 is taken as an example of the operation amount sensor for detecting the operation amount of the brake pedal 10, but a pedal force sensor for detecting the pedal force applied to the brake pedal 10 may be used.

  The reservoir tank 16 is connected to each of the primary chamber 14a and the secondary chamber 14b via passages (not shown) when the brake pedal 10 is in the initial position, and supplies brake fluid into the master cylinder 14 or the master cylinder 14 The excess brake fluid is stored.

  A master pipe 202 is connected to the primary chamber 14a of the master cylinder 14, and a master pipe 201 is connected to the secondary chamber 14b. In addition, reservoir pipes 203 and 204 are connected to the reservoir tank 16. These master pipes 201 and 202 and reservoir pipes 203 and 204 are connected to the hydraulic actuator 100, respectively.

  The stroke simulator unit 18 includes a stroke simulator 18a and a simulator cut valve 18b. The stroke simulator 18a is connected to the master pipe 201 via a simulator cut valve 18b. That is, the simulator cut valve 18b is provided in a flow path connecting the master cylinder 14 and the stroke simulator 18a. The simulator cut valve 18b has a solenoid and a spring that are ON / OFF controlled, is opened by an electromagnetic force generated by the solenoid upon receiving a specified control current, and the solenoid is in a non-energized state. This is a normally closed electromagnetic control valve that is in a closed state. When the simulator cut valve 18b is closed, the flow of brake fluid between the master pipe 201 and the stroke simulator 18a is blocked. When the solenoid is energized and the simulator cut valve 18b is opened, the brake fluid can be circulated bidirectionally between the stroke simulator 18a and the master cylinder 14.

  The stroke simulator 18a includes a plurality of pistons and springs, and creates a reaction force according to the depression force of the brake pedal 10 by the driver when the simulator cut valve 18b is opened. As the stroke simulator 18a, it is preferable to employ one having a multistage spring characteristic in order to improve the feeling of brake operation by the driver.

  The hydraulic actuator 100 appropriately adjusts the supply of brake fluid to the wheel cylinder 4 by the master cylinder 14 and a first power hydraulic pressure source and a second power hydraulic pressure source described later. Thereby, the braking force which each wheel cylinder 4 provides to a wheel is adjusted. The hydraulic actuator 100 includes an actuator block in which a plurality of hydraulic fluid channels are formed and a plurality of electromagnetic control valves. The hydraulic fluid channels formed in the actuator block include master channels 205, 206, reservoir channels 207, 208, individual channels 209, 210, 211, 212, pump communication channels 213, 214, Pressure passages 215 and 216, pressure reduction passages 217, 218, 219 and 220, and accumulator communication passages 221 and 222 are included.

  The master channel 205 is connected to the master pipe 201, and the master channel 206 is connected to the master pipe 202. The reservoir channel 207 is connected to the reservoir pipe 203, and the reservoir channel 208 is connected to the reservoir pipe 204. The master channel 205 and the reservoir channel 207 are connected to an individual channel 209 connected to the wheel cylinder 4FR. The master channel 206 and the reservoir channel 208 are connected to an individual channel 212 connected to the wheel cylinder 4RR. The individual flow path 210 connected to the wheel cylinder 4FL is connected to the middle of the individual flow path 209, and the individual flow path 211 connected to the wheel cylinder 4RL is connected to the middle of the individual flow path 212. Thus, each wheel cylinder 4, the master cylinder 14 and the reservoir tank 16 are communicated with each other.

  Here, the master pipes 201 and 202, the master flow paths 205 and 206, and the individual flow paths 209 to 212 constitute a hydraulic fluid flow path that connects the master cylinder 14 and the wheel cylinder 4. The reservoir pipes 203 and 204, the reservoir channels 207 and 208, and the individual channels 209 to 212 constitute a hydraulic fluid channel that connects the reservoir tank 16 and the wheel cylinder 4. In the brake control device 1 according to the present embodiment, the wheel cylinders 4FR, 4FL and the wheel cylinders 4RL, 4RR are connected to the reservoir tank 16 via the separate reservoir pipes 203, 204 and the reservoir channels 207, 208, respectively. Connected with. Therefore, more brake fluid can be supplied to each wheel cylinder 4 than when each wheel cylinder 4 and the reservoir tank 16 are connected by a single flow path. In addition, with the above-described configuration, it is possible to reduce a possibility that a state in which a braking force cannot be applied to all wheels due to a failure of a flow path or a valve or the like can be reduced. As a result, the reliability of the brake control device 1 is improved.

  The master flow paths 205 and 206 have master cut valves 20 and 21 in the middle, respectively. That is, the master cut valves 20 and 21 are provided on the hydraulic fluid flow path that connects the master cylinder 14 and the wheel cylinder 4. The master cut valves 20 and 21 have solenoids and springs that are ON / OFF controlled, and are closed by electromagnetic force generated by the solenoids when supplied with a prescribed control current, and the solenoids are not energized. The normally open electromagnetic control valve is in a valve open state when When the master cut valve 20 is in the open state, the brake fluid can be circulated bidirectionally between the master cylinder 14 and the individual flow paths 209 and 210, and when the master cut valve 21 is in the open state, Brake fluid can be circulated bidirectionally between the master cylinder 14 and the individual flow paths 211 and 212. When a prescribed control current is supplied to the solenoid and the master cut valves 20 and 21 are closed, the flow of brake fluid in the master flow paths 205 and 206 is interrupted. That is, when the master cut valves 20 and 21 are closed, the supply of brake fluid to the wheel cylinder 4 by the master cylinder 14 is shut off.

  Master cylinder pressure sensors 50 and 51 are provided in the master flow paths 205 and 206, respectively, upstream of the brake fluid flow of the master cut valves 20 and 21. The master cylinder pressure sensors 50 and 51 can detect the pressure of the brake fluid in the master passages 205 and 206 on the upstream side of the master cut valves 20 and 21, that is, the master cylinder pressure.

  Reservoir channels 207 and 208 have reservoir cut valves 22 and 23, respectively. That is, the reservoir cut valves 22 and 23 are provided on the hydraulic fluid flow path connecting the reservoir tank 16 and the wheel cylinder 4. The reservoir cut valves 22 and 23 have solenoids and springs that are ON / OFF controlled, and are opened by electromagnetic force generated by the solenoids when supplied with a prescribed control current, and the solenoids are not energized. It is a normally closed electromagnetic control valve that is in a closed state when When the reservoir cut valve 22 is in the closed state, the flow of the brake fluid between the reservoir tank 16 and the individual flow paths 209 and 210 is blocked, and when the reservoir cut valve 23 is in the closed state, the reservoir tank 16 The flow of brake fluid between the individual flow paths 211 and 212 is blocked. Therefore, when the reservoir cut valves 22 and 23 are closed while the hydraulic pressure is generated in the wheel cylinder 4, the hydraulic pressure applied to the wheel cylinder 4 is maintained. When a prescribed control current is supplied to the solenoid and the reservoir cut valve 22 is opened, the brake fluid can be circulated bidirectionally between the reservoir channel 207 and the individual channels 209 and 210. Similarly, when the reservoir cut valve 23 is opened, the brake fluid can be circulated bidirectionally between the reservoir channel 208 and the individual channels 211 and 212.

  The individual flow paths 209 and 212 have pressure-regulating linear control valves 24 and 25 on the upstream side of the brake fluid flow from the connection portions of the individual flow paths 210 and 211, respectively. That is, the pressure regulating linear control valves 24 and 25 are provided on the hydraulic fluid flow path connecting the reservoir tank 16 and each wheel cylinder 4. The pressure-regulating linear control valves 24 and 25 have a linear solenoid and a spring, and are opened when the linear solenoid is in a non-energized state. The valve opens in proportion to the current supplied to the linear solenoid. It is a normally open type electromagnetic control valve whose degree is adjusted. When the pressure regulating linear control valves 24 and 25 are in the open state, the brake fluid can be circulated bidirectionally between the master cylinder 14 or the reservoir tank 16 and the wheel cylinder 4. When a current is applied to the linear solenoid, the valve is closed in proportion to the supplied current, and the flow rate of the brake fluid decreases. Therefore, the flow amount of the brake fluid from each wheel cylinder 4 to the master cylinder 14 or the reservoir tank 16 can be changed by changing the opening degree of the pressure regulating linear control valves 24 and 25. Thereby, the hydraulic pressure generated in each wheel cylinder 4 can be adjusted.

  The pressure regulation linear control valve 24 is provided as a pressure regulation control valve common to the wheel cylinders 4FR and 4FL, and the pressure regulation linear control valve 25 is provided as a pressure regulation control valve common to the wheel cylinders 4RL and 4RR. As described above, if the pressure regulating linear control valves 24 and 25 are made common to the plurality of wheel cylinders 4, the cost can be reduced as compared with the case where the linear control valve is provided for each wheel cylinder 4.

  Here, the reservoir cut valves 22 and 23 are provided on the upstream side of the brake fluid flow with respect to the pressure regulating linear control valves 24 and 25. The pressure regulating linear control valves 24 and 25 are normally open electromagnetic control valves, whereas the reservoir cut valves 22 and 23 are normally closed electromagnetic control valves. According to such a configuration, when the pressure regulating linear control valves 24 and 25 are out of order, the energization to the solenoids of the reservoir cut valves 22 and 23 is turned off, the reservoir cut valves 22 and 23 are closed, and the wheel cylinder Since the hydraulic pressure generated in 4 can be maintained, a fail-safe function can be ensured.

  In addition, when the hydraulic pressure generated in each wheel cylinder 4 by the pressure adjusting linear control valves 24 and 25 is adjusted for a long time, the amount of heat generated by the pressure adjusting linear control valves 24 and 25 is increased by energization for a long time. The control valves 24 and 25 may become hot. On the other hand, according to the above-described configuration, the hydraulic pressure generated in the wheel cylinder 4 can be maintained by turning off the energization to the reservoir cut valves 22 and 23 and closing the reservoir cut valves 22 and 23. It is possible to dissipate the heat generated in the pressure regulation linear control valves 24 and 25 by turning off the energization to the pressure regulation linear control valves 24 and 25 while maintaining the pressure. Therefore, the reliability of the brake control device 1 can be improved.

  The individual flow paths 209 to 212 have holding valves 26, 27, 28, and 29 in the middle. Each of the holding valves 26 to 29 has a solenoid and a spring that are ON / OFF controlled, and both are closed by an electromagnetic force generated by the solenoid when supplied with a prescribed control current, and the solenoid is not turned on. This is a normally open electromagnetic control valve that is opened when energized. The holding valves 26 to 29 that are in the open state can cause the brake fluid to flow in both directions. That is, the brake fluid can flow from the master cylinder 14 and the reservoir tank 16 to the wheel cylinder 4, and conversely, the brake fluid can also flow from the wheel cylinder 4 to the master cylinder 14 and the reservoir tank 16. When the solenoid is energized and the holding valves 26 to 29 are closed, the flow of brake fluid in the individual flow paths 209 to 212 is blocked.

  Pressure-reducing channels 217, 218, 219, and 220 are connected to the individual channels 209 to 212 on the downstream side of the holding valves 26 to 29, respectively. In the middle of the pressure reducing channels 217 to 220, pressure reducing valves 30, 31, 32, and 33 are provided, respectively. Each of the pressure reducing valves 30 to 33 has a solenoid and a spring that are ON / OFF controlled. Each of the pressure reducing valves 30 to 33 is opened by an electromagnetic force generated by the solenoid upon receipt of a specified control current, and the solenoid is not turned on. This is a normally closed electromagnetic control valve that is closed when energized. When the pressure reducing valves 30 to 33 are closed, the flow of brake fluid in the pressure reducing channels 217 to 220 is blocked. When a specified control current is applied to the solenoid and the pressure reducing valves 30 to 33 are opened, the brake fluid is allowed to flow through the pressure reducing flow paths 217 to 220, and the brake fluid flows from the wheel cylinder 4 to the pressure reducing flow. The refrigerant can be returned to the reservoir tank 16 via the paths 217 to 220, the pump communication paths 213 and 214, the reservoir channels 207 and 208, and the reservoir pipes 203 and 204.

  One ends of pump communication paths 213 and 214 are connected to the upstream side of the brake fluid flow from the pressure regulating linear control valves 24 and 25 in the individual flow paths 209 and 212, respectively. The other ends of the pump communication passages 213 and 214 are connected to the suction ports of the pumps 60 and 61. Accordingly, the pumps 60 and 61 and the reservoir tank 16 are connected via the pump communication paths 213 and 214, the individual flow paths 209 and 212, the reservoir flow paths 207 and 208, and the reservoir pipes 203 and 204. The pumps 60 and 61 are driven by a motor 62 to generate power for supplying brake fluid to the wheel cylinder 4. In the present embodiment, the pumps 60 and 61 constitute a first power hydraulic pressure source. The first power hydraulic pressure source can send brake fluid to the wheel cylinder 4 independently of the driver's operation of the brake pedal 10 by power. The pumps 60 and 61 are constituted by a trochoid pump excellent in silence. The pumps 60 and 61 may be constituted by other pumps.

  The pump 60 is provided as a power hydraulic pressure source common to the wheel cylinder 4FR and the wheel cylinder 4FL, and the pump 61 is provided as a power hydraulic pressure source common to the wheel cylinders 4RL and 4RR. Thus, if the pumps 60 and 61 are made common to the plurality of wheel cylinders 4, the cost can be reduced as compared with the case where a pump is provided for each wheel cylinder 4.

  One ends of pressure-increasing channels 215 and 216 are connected to the discharge ports of the pumps 60 and 61, respectively. The other end of the pressure increasing flow path 215 is connected upstream of the holding valves 26 and 27 of the individual flow paths 209 and 210 and downstream of the pressure regulating linear control valve 24. The other end of the pressure increasing flow path 216 is connected to the upstream side of the holding valves 28 and 29 of the individual flow paths 211 and 212 and to the downstream side of the pressure regulating linear control valve 25. As a result, the brake fluid pumped from the reservoir tank 16 by the pumps 60 and 61 is supplied to the wheel cylinder 4 via the pressure-increasing channels 215 and 216 and the individual channels 209 to 212. Note that the pressure increasing channels 215 and 216 of the present embodiment are connected to the individual channels 209 and 212 via a part of the individual channels 210 and 211, respectively.

  One end of accumulator communication paths 221 and 222 is connected to the middle of the pressure increasing flow paths 215 and 216, respectively. The other ends of the accumulator communication paths 221 and 222 are connected to the accumulator 63. That is, the pumps 60 and 61 and the accumulator 63 are communicated via the accumulator communication paths 221 and 222. The accumulator 63 is supplied with the brake fluid discharged from the pumps 60 and 61, and converts the pressure energy of the brake fluid boosted by the pumps 60 and 61 into the pressure energy of an enclosed gas such as nitrogen and stores the pressure energy. In the accumulator 63, for example, pressure energy of about 14 to 22 MPa is stored. In the present embodiment, the accumulator 63 constitutes a second power hydraulic pressure source. The second power hydraulic pressure source can send the brake fluid pressurized by the pumps 60 and 61 to the wheel cylinder 4 independently from the operation of the brake pedal 10 by the driver.

  The accumulator pressure of the accumulator 63 is maintained within a set range to be maintained by the pumps 60 and 61. The brake ECU 300 estimates the accumulator pressure based on measured values of wheel cylinder pressure sensors 52 and 53 described later. The brake ECU 300 turns on the pumps 60 and 61 to increase the accumulator pressure when the accumulator pressure falls below the lower limit of the set range, and turns off the pumps 60 and 61 when the accumulator pressure exceeds the upper limit of the set range. Finish the pressurization of the accumulator pressure.

  Accumulator cut valves 34 and 35 (cut valves) are provided in the middle of the accumulator communication paths 221 and 222, respectively. The accumulator cut valves 34 and 35 have solenoids and springs that are ON / OFF controlled, and are opened by electromagnetic force generated by the solenoids when supplied with a prescribed control current, and the solenoids are not energized. It is a normally closed electromagnetic control valve that is in a closed state when When the accumulator cut valves 34 and 35 are closed, the flow of the brake fluid in the accumulator communication paths 221 and 222 is blocked. That is, when the accumulator cut valves 34 and 35 are closed, the supply of brake fluid to the accumulator 63 by the pumps 60 and 61 is cut off, and the supply of brake fluid from the accumulator 63 to the wheel cylinder 4 is also cut off. . When a specified control current is applied to the solenoid and the accumulator cut valves 34 and 35 are opened, the brake fluid is allowed to flow through the accumulator communication paths 221 and 222, and the brake fluid from the pumps 60 and 61 to the accumulator 63 is discharged. Supply and supply of the brake fluid from the accumulator 63 to the wheel cylinder 4 are possible.

  When the accumulator cut valves 34 and 35 are closed, the brake fluid discharged from the pumps 60 and 61 does not flow into the accumulator 63, so that the hydraulic pressure generated by the first power hydraulic pressure source is not absorbed by the accumulator 63. Thereby, the stable hydraulic pressure can be generated in the wheel cylinder 4 by the first power hydraulic pressure source.

  In the middle of the accumulator communication paths 221, 222, wheel cylinder pressure sensors 52, 53 are provided. That is, the wheel cylinder pressure sensors 52 and 53 are provided between the pumps 60 and 61 and the accumulator cut valves 34 and 35, and detect the pressure in the accumulator communication paths 221 and 222, that is, the wheel cylinder pressure of the wheel cylinder 4. be able to.

  The brake ECU 300 controls the operation of the stroke simulator unit 18 and the hydraulic actuator 100. The brake ECU 300 is configured as a microprocessor including a CPU, and includes a ROM that stores various programs, a RAM that temporarily stores data, an input / output port, a communication port, and the like in addition to the CPU. The brake ECU 300 can communicate with a host hybrid ECU (not shown) and the like, and based on control signals from the hybrid ECU and signals from various sensors, the simulator cut valve 18b, the pumps 60, 61, Master cut valves 20 and 21, reservoir cut valves 22 and 23, pressure regulating linear control valves 24 and 25, holding valves 26 to 29, pressure reducing valves 30 to 33, and accumulator cut valves 34 and 35 are controlled.

  The brake ECU 300 is connected to a stroke sensor 12, master cylinder pressure sensors 50 and 51, and wheel cylinder pressure sensors 52 and 53. The stroke sensor 12 detects the pedal stroke of the brake pedal 10 and transmits a signal indicating the detected value to the brake ECU 300. Master cylinder pressure sensors 50 and 51 detect the master cylinder pressure and transmit a signal indicating the detected value to brake ECU 300. The detection values of the stroke sensor 12 and the master cylinder pressure sensors 50 and 51 are sequentially given to the brake ECU 300 every predetermined time, and are stored and held in a predetermined storage area of the brake ECU 300.

  In the brake control device 1, when the brake pedal 10 is depressed by the driver, the stroke sensor 12 detects the depression amount, but the brake pedal is also detected from the master cylinder pressure detected by the master cylinder pressure sensors 51 and 52. Ten stepping operation amounts can be obtained. As described above, it is preferable from the viewpoint of fail-safe that the master cylinder pressure is monitored by the master cylinder pressure sensors 50 and 51 on the assumption of the failure of the stroke sensor 12.

  The wheel cylinder pressure sensors 52 and 53 detect the wheel cylinder pressure of the wheel cylinder 4 and transmit a signal indicating the detected value to the brake ECU 300. Here, the brake ECU 300 detects the pressure in the accumulator communication passages 221 and 222 when the accumulator cut valves 34 and 35 are in the open state by the wheel cylinder pressure sensors 52 and 53, thereby adjusting the accumulator pressure of the accumulator 63. Can be estimated. The output values of the wheel cylinder pressure sensors 52 and 53 are also sequentially given to the brake ECU 300 every predetermined time, and stored and held in a predetermined storage area of the brake ECU 300.

  The brake ECU 300 is connected to a stop lamp switch (not shown). The stop lamp switch is turned on when the brake pedal 10 is depressed. As a result, the stop lamp is turned on. When the depression of the brake pedal 10 is released, the stop lamp switch is turned off and the stop lamp is turned off. A signal indicating the lighting state of the stop lamp switch is input from the stop lamp switch to the brake ECU 300 every predetermined time, and is stored and held in a predetermined storage area of the brake ECU 300.

  The brake control device 1 configured as described above can execute brake regeneration cooperative control. The brake control device 1 starts braking upon receiving a braking request. The braking request is generated when a braking force is to be applied to the vehicle, for example, when the driver operates the brake pedal 10. In response to the braking request, the brake ECU 300 calculates a required braking force, and calculates a required hydraulic braking force that is a braking force to be generated by the brake control device 1 by subtracting the regenerative braking force from the required braking force. Here, the effective value of the braking force by regeneration is supplied from the hybrid ECU to the brake control device 1. Then, the brake ECU 300 calculates the target hydraulic pressure of each wheel cylinder 4 based on the calculated required hydraulic braking force. The brake ECU 300 controls the driving of the pumps 60 and 61 and the supply of the brake fluid by the accumulator 63 so that the wheel cylinder pressure becomes the target hydraulic pressure, and supplies it to the pressure regulating linear control valves 24 and 25 by the feedback control law. Determine the value of the control current.

  As a result, in the brake control device 1, the brake fluid is supplied from the reservoir tank 16 or the accumulator 63 to each wheel cylinder 4 and braking force is applied to the wheels. Further, the brake fluid is discharged from each wheel cylinder 4 through the pressure regulating linear control valves 24 and 25 as necessary, and the braking force applied to the wheels is adjusted. In the present embodiment, a wheel cylinder pressure control system is configured including the pumps 60 and 61, the accumulator 63, the pressure regulating linear control valves 24 and 25, and the like, and so-called brake-by-wire braking force control is performed by the wheel cylinder pressure control system. Is done. The wheel cylinder pressure control system is provided in parallel to the brake fluid supply path from the master cylinder 14 to the wheel cylinder 4. That is, the pumps 60 and 61 as the first power hydraulic pressure source and the accumulator 63 as the second power hydraulic pressure source are provided in parallel with the master cylinder 14 as the manual hydraulic pressure source. The brake control device 1 according to the present embodiment can naturally control the braking force by the wheel cylinder pressure control system even when the required braking force is provided only by the hydraulic braking force without using the regenerative braking force. .

  When brake-by-wire braking force control is performed, the brake ECU 300 closes the master cut valves 20 and 21 and opens the simulator cut valve 18b. This is because the brake fluid sent from the master cylinder 14 in accordance with the operation of the brake pedal 10 by the driver is supplied not to the wheel cylinder 4 but to the stroke simulator unit 18. During the brake regeneration cooperative control, a differential pressure corresponding to the magnitude of the regenerative braking force acts between the upstream and downstream of the master cut valves 20 and 21.

  When the required braking force is generated only by the hydraulic braking force in the brake-by-wire braking force control, the brake ECU 300 controls the master cylinder pressure as the target hydraulic pressure of the wheel cylinder pressure. Therefore, in this case, it is not always necessary to supply the brake fluid to the wheel cylinder 4 by the wheel cylinder pressure control system. This is because the required braking force can be naturally generated if the master cylinder pressure pressurized by the driver's operation of the brake pedal 10 is introduced into the wheel cylinder 4 as it is.

  Next, the brake operation of the brake control device 1 according to the present embodiment will be described separately for normal pressure increase / decrease time and sudden pressure increase / decrease time with reference to FIGS. 2 (A) to 3 (B). FIG. 2A is a schematic diagram illustrating a state of the brake control device during normal pressurization. FIG. 2B is a schematic diagram illustrating a state of the brake control device during normal pressure reduction. FIG. 3A is a schematic diagram illustrating a state of the brake control device during rapid pressurization. FIG. 3B is a schematic diagram showing a state of the brake control device at the time of sudden pressure reduction. 2 (A) to 3 (B), the main flow of the brake fluid is indicated by a thick line.

  Here, the time of normal pressure increase / decrease refers to a case where the difference between the target hydraulic pressure of each wheel cylinder 4 calculated from the required hydraulic braking force and the current hydraulic pressure is equal to or less than a predetermined threshold value. In the case of sudden pressure increase / decrease, the difference between the target hydraulic pressure of the wheel cylinder 4 and the current hydraulic pressure exceeds the threshold value, and the fluctuation range of the hydraulic pressure per unit time is larger than that during normal pressure increase / decrease. Say. The threshold value for separating the normal pressure increase / decrease from the sudden pressure increase / decrease can be appropriately set based on the experiment or simulation by the designer, and the threshold value is stored and held in a predetermined storage area of the brake ECU 300. .

  When the amount of depression of the brake pedal 10 changes and the detection signal of the stroke sensor 12 at that time is input to the brake ECU 300, the brake ECU 300 calculates a required braking force corresponding to the amount of depression of the brake pedal 10, The required hydraulic braking force is calculated by subtracting the regenerative braking force from the power. Then, the brake ECU 300 calculates the target hydraulic pressure of each wheel cylinder 4 based on the calculated required hydraulic braking force, and determines whether the control to be performed by comparing the target hydraulic pressure with the current hydraulic pressure is pressurization. And the difference between the target hydraulic pressure and the current hydraulic pressure is compared with a predetermined threshold value to determine whether it is normal pressure increase or decrease.

(Brake operation during normal pressure increase / decrease)
In the case of normal pressurization, the brake ECU 300 opens the simulator cut valve 18b and closes the master cut valves 20, 21 as shown in FIG. As a result, the supply of brake fluid from the master cylinder 14 to the wheel cylinder 4 is interrupted, and the brake fluid delivered from the master cylinder 14 is supplied to the stroke simulator 18a. The brake ECU 300 controls the motor 62 to drive the pumps 60 and 61 and opens the reservoir cut valves 22 and 23 and the holding valves 26 to 29 so that the pressure reducing valves 30 to 33, the accumulator cut valve 34, 35 is closed. As a result, the brake fluid stored in the reservoir tank 16 passes through the reservoir pipes 203 and 204, the reservoir channels 207 and 208, the pump communication channels 213 and 214, the pressure increasing channels 215 and 216, and the individual channels 209 to 212. To be supplied to each wheel cylinder 4. When the brake fluid is supplied to the wheel cylinder 4 by the pumps 60 and 61 in this way, the supplied brake fluid is pressurized, thereby generating a hydraulic pressure in each wheel cylinder 4.

  The brake ECU 300 adjusts the opening degree of the pressure regulating linear control valves 24 and 25 based on the detection results of the wheel cylinder pressure sensors 52 and 53. As a result, the brake fluid supplied to the wheel cylinder 4 is returned to the reservoir tank 16 according to the opening degree of the pressure regulating linear control valves 24 and 25, and the hydraulic pressure of each wheel cylinder 4 is adjusted to the target hydraulic pressure. Is done. The brake ECU 300 drives the pumps 60 and 61 by adjusting the opening amounts of the pressure regulating linear control valves 24 and 25 and adjusting the energization amount to the motor 62 based on the detection results of the wheel cylinder pressure sensors 52 and 53. You may make it adjust the hydraulic pressure of each wheel cylinder 4 by controlling quantity.

  On the other hand, in the case of normal pressure reduction, the brake ECU 300 stops driving the pumps 60 and 61 as shown in FIG. 2 (B) and adjusts the pressure linearly based on the detection results of the wheel cylinder pressure sensors 52 and 53. The opening degree of the control valves 24 and 25 is increased. As a result, the brake fluid supplied to each wheel cylinder 4 is supplied to the individual flow paths 209 to 212, the reservoir flow paths 207 and 208, and the reservoir pipes 203 and 204 due to the differential pressure between the upstream and downstream pressure control linear control valves 24 and 25. Circulates to the reservoir tank 16 via. As a result, the hydraulic pressure in each wheel cylinder 4 is reduced.

(Brake operation during sudden pressure reduction)
In the case of rapid pressurization, as shown in FIG. 3 (A), the brake ECU 300 opens the simulator cut valve 18b and closes the master cut valves 20, 21 to be sent from the master cylinder 14. The brake fluid is supplied to the stroke simulator 18a. The brake ECU 300 drives the pumps 60 and 61, opens the reservoir cut valves 22 and 23, and the holding valves 26 to 29, and closes the pressure reducing valves 30 to 33. As a result, the brake fluid of the reservoir tank 16 passes through the reservoir pipes 203 and 204, the reservoir passages 207 and 208, the pump communication passages 213 and 214, the pressure increase passages 215 and 216, and the individual passages 209 to 212. It is supplied to the cylinder 4. In addition, the brake ECU 300 opens the accumulator cut valves 34 and 35. As a result, the brake fluid stored in the accumulator 63 in a pressurized state is supplied to each wheel cylinder 4 via the accumulator communication paths 221, 222, the pressure-increasing flow paths 215, 216, and the individual flow paths 209-212. Thus, hydraulic pressure is generated in each wheel cylinder 4 by supplying brake fluid to each wheel cylinder 4 by the pumps 60 and 61 and the accumulator 63.

  In addition, the brake ECU 300 adjusts the opening degree of the pressure regulating linear control valves 24 and 25 in the same manner as during normal pressurization, and returns the brake fluid supplied to each wheel cylinder 4 to the reservoir tank 16, so that each wheel cylinder The hydraulic pressure of 4 is adjusted to the target hydraulic pressure. The brake ECU 300 may adjust the hydraulic pressures of the wheel cylinders 4 by adjusting the opening amounts of the pressure regulating linear control valves 24 and 25 and controlling the driving amounts of the pumps 60 and 61.

  Thus, at the time of rapid pressurization, the brake ECU 300 combines the generation of the hydraulic pressure on the wheel cylinder 4 by the pumps 60 and 61 and the generation of the hydraulic pressure on the wheel cylinder 4 by the accumulator 63 to combine the hydraulic pressure of the wheel cylinder 4. Is adjusted to the target hydraulic pressure. Specifically, the brake ECU 300 supplies the brake fluid by the pumps 60 and 61 to generate the hydraulic pressure in each wheel cylinder 4, and supplies the brake fluid by the accumulator 63 to generate the hydraulic pressure in each wheel cylinder 4. Let Therefore, the amount of increase in the hydraulic pressure per unit time can be increased compared with the case where the hydraulic pressure is generated only by the pumps 60 and 61, and thus the hydraulic pressure of each wheel cylinder 4 can reach the target hydraulic pressure in a short time. be able to. The brake ECU 300 may adjust the hydraulic pressure of the wheel cylinder 4 by generating the hydraulic pressure by the accumulator 63 instead of generating the hydraulic pressure by the pumps 60 and 61.

  On the other hand, in the case of sudden pressure reduction, as shown in FIG. 3B, the brake ECU 300 stops driving the pumps 60 and 61 and adjusts the pressure regulation linear based on the detection results of the wheel cylinder pressure sensors 52 and 53. The opening degree of the control valves 24 and 25 is increased. As a result, the brake fluid supplied to each wheel cylinder 4 is supplied to the individual flow paths 209 to 212, the reservoir flow paths 207 and 208, and the reservoir pipes 203 and 204 due to the differential pressure between the upstream and downstream pressure control linear control valves 24 and 25. Circulates to the reservoir tank 16 via. In addition, the brake ECU 300 opens the pressure reducing valves 30 to 33. As a result, the brake fluid supplied to each wheel cylinder 4 is subjected to pressure reducing flow paths 217 to 220, pump communication paths 213 and 214, reservoir flow paths 207 and 208, due to the pressure difference between the upstream and downstream pressure reducing valves 30 to 33. It returns to the reservoir tank 16 via the reservoir pipes 203 and 204. As a result, the hydraulic pressure in each wheel cylinder 4 is reduced.

  Thus, at the time of sudden pressure reduction, the brake ECU 300 stops driving the pumps 60 and 61, opens the pressure regulating linear control valves 24 and 25, and supplies the brake fluid to the reservoir tank 16 via the individual flow paths 209 to 212. At the same time, the pressure reducing valves 30 to 33 are opened, and the brake fluid is returned to the reservoir tank 16 through the pressure reducing channels 217 to 220. Therefore, compared with the case where only the brake fluid is recirculated by opening the pressure regulating linear control valves 24 and 25, the amount of decrease in the hydraulic pressure per unit time can be increased, and therefore the hydraulic pressure of each wheel cylinder 4 is shortened. The target hydraulic pressure can be reached in time.

  When an abnormality occurs in the brake ECU 300 or each electromagnetic control valve of the hydraulic actuator 100, the energization of the motor 62 and each electromagnetic control valve is all turned off. As a result, as shown in FIG. 1, the simulator cut valve 18b, the reservoir cut valves 22, 23, the pressure reducing valves 30-33, and the accumulator cut valves 34, 35 are closed, and the master cut valves 20, 21, The pressure linear control valves 24 and 25 and the holding valves 26 to 29 are opened. As a result, the master cylinder pressure generated in the master cylinder 14 due to the depression of the brake pedal 10 is directly transmitted to each wheel cylinder 4, whereby a braking force can be applied to the wheel.

  Subsequently, a control flow of the brake operation in the brake control device 1 will be described. FIG. 4 is a control flowchart of the brake operation. This flow is executed by the brake ECU 300, and is repeatedly executed at a predetermined timing when the ignition switch is turned ON, for example.

  As shown in FIG. 4, when the control flow of the brake operation is started, it is first determined whether or not the amount of depression of the brake pedal 10 has changed (step 1: hereinafter abbreviated as S1. The same applies to other steps). If the depression amount of the brake pedal 10 has not changed (S1_No), the determination is repeated until the depression amount of the brake pedal 10 changes. If the amount of depression of the brake pedal 10 has changed (S1_Yes), the target hydraulic pressure is calculated, and the calculated target hydraulic pressure is compared with the current hydraulic pressure (S2). Then, it is determined from the comparison between the target hydraulic pressure and the current hydraulic pressure whether the control to be performed is the pressurization control (S3). When the control to be performed is pressurization (S3_Yes), the difference between the target hydraulic pressure and the current hydraulic pressure is compared with a predetermined threshold value (S4). From the comparison, it is determined whether or not the control to be performed is the rapid pressurization control (S5).

  If the control to be performed is rapid pressurization (S5_Yes), supply of brake fluid by the pumps 60 and 61 and supply of brake fluid by the accumulator 63, that is, application by the first power hydraulic pressure source and the second power hydraulic pressure source. The pressure is executed (S6), and the control ends. When the control to be performed is not rapid pressurization (S5_No), it is determined that the control to be performed is normal pressurization (S7), and the brake fluid is supplied by the pumps 60 and 61, that is, by the first power hydraulic pressure source. Pressurization is executed (S8), and the control ends.

  On the other hand, if the control to be performed is not pressurization (S3_No), it is determined that the control to be performed is depressurization (S9), and the difference between the target hydraulic pressure and the current hydraulic pressure is compared with a predetermined threshold value. (S10). Then, it is determined from the comparison whether or not the control to be performed is the rapid pressure reduction control (S11). When the control to be performed is rapid pressure reduction (S11_Yes), pressure reduction is performed by opening the pressure regulating linear control valves 24 and 25 and opening the pressure reducing valves 30 to 33 (S12), and the control is finished. When the control to be performed is not rapid pressure reduction (S11_No), it is determined that the control to be performed is normal pressure reduction (S13), and the pressure reduction to open the pressure regulating linear control valves 24 and 25 is executed (S14). Control ends.

  Accumulation of pressure in the accumulator 63 is performed as follows. That is, when the brake ECU 300 detects from the signal of the stroke sensor 12 that the brake pedal 10 is not operated, the brake ECU 300 drives the pumps 60 and 61 and opens the reservoir cut valves 22 and 23 and the accumulator cut valves 34 and 35. As a state, brake fluid is supplied from the pumps 60 and 61 to the accumulator 63. As a result, pressure energy is stored in the accumulator 63. At this time, the brake ECU 300 supplies the brake fluid by the pumps 60 and 62 at an output lower than the maximum output when the wheel cylinder 4 generates the hydraulic pressure, and stores the hydraulic pressure in the accumulator 63. The holding valves 26 to 29 are closed so that no hydraulic pressure is generated in the wheel cylinder 4.

  Thus, in this embodiment, since the hydraulic pressure is stored in the accumulator 63 by the pumps 60 and 61, it is not necessary to provide a pump for storing pressure in the accumulator 63, and an increase in the number of parts can be suppressed. Further, when the braking request to the wheel is not issued, or when the braking force is not applied to the wheel, the hydraulic pressure is stored in the accumulator 63 by the pumps 60 and 61. The pumps 60 and 61 at the time of use can be used effectively. Further, since the hydraulic pressure is stored in the accumulator 63 with an output lower than the maximum output of the pumps 60 and 61 when the hydraulic pressure is generated in the wheel cylinder 4, the electric power consumed by the stored pressure in the accumulator 63 can be reduced. it can.

  Further, as shown in FIG. 5, the brake control device 1 according to the present embodiment can be formed using a brake control device having a conventionally known vehicle stability control (VSC) mechanism. . FIG. 5 is a schematic view showing a state in which a regenerative brake unit is incorporated in a brake control device having a conventional VSC mechanism. That is, accumulator communication paths 221 and 222 are added to the VSC unit included in the conventional brake control device to form the VSC unit 100b. And, between the VSC unit 100b and the master cylinder 14, a regenerative brake unit 100a including master cut valves 20, 21, reservoir cut valves 22, 23, accumulator cut valves 34, 35, and an accumulator 63 is incorporated. Corresponding flow paths are connected to each other to form the brake control device 1 according to the present embodiment.

  In this case, the hydraulic actuator 100 includes a regenerative brake unit 100a and a VSC unit 100b. Conventional brake control devices having an ECB mechanism generally have one power hydraulic pressure source. A pressure regulating linear control valve is provided in the flow path connecting the power hydraulic pressure source and the wheel cylinder, and this pressure regulating linear control valve is always subjected to high pressure from the power hydraulic pressure source, and the pressure regulating linear control valve The hydraulic pressure of the wheel cylinder was adjusted with a large differential pressure between upstream and downstream. For this reason, the conventional pressure regulating linear control valve requires high pressure resistance and a highly accurate pressure regulating function. On the other hand, since the brake control device 1 according to the present embodiment includes two power hydraulic pressure sources, the hydraulic pressure generated by each power hydraulic pressure source can be reduced. High pressure from the accumulator 63 is received by the accumulator cut valves 34 and 35. Therefore, the pressure-regulating linear control valves 24 and 25 can adjust the pressure of each wheel cylinder 4 without receiving a higher pressure than in the past and with a small differential pressure between the upstream and downstream sides. Therefore, the pressure regulation linear control valves 24 and 25 do not need to have a high pressure resistance and a highly accurate pressure regulation function as required in a conventional ECB mechanism. Therefore, the pressure regulation linear control valve provided in the conventional VSC unit can be used for the pressure regulation linear control valves 24 and 25 of the brake control device 1.

  Further, in the configuration in which the hydraulic pressure is generated in the wheel cylinder only by the pump, it is necessary to increase the size of the pump or to provide a plurality of pumps in order to apply a high pressure to the wheel cylinder. On the other hand, in the brake control apparatus 1, since the pumps 60 and 61 and the accumulator 63 are combined to generate the hydraulic pressure in the wheel cylinder 4, it is not necessary to increase the size of the pump or to provide a plurality of pumps. Therefore, the pump provided in the conventional VSC unit can be used for the pumps 60 and 61 of the brake control device 1. For these reasons, the brake control device 1 according to the present embodiment can be formed using a conventional VSC mechanism.

  Thus, the brake control device 1 according to the present embodiment can be configured using a conventional brake control device that does not have an ECB mechanism. Therefore, the addition of an ECB mechanism to a vehicle equipped with a brake control device that does not have an ECB mechanism can be realized at a lower cost than when the installed brake control device is replaced with a brake control device with an ECB mechanism, In addition, the amount of waste generated can be reduced. In addition, the configuration of the brake control device 1 according to the present embodiment can reduce the scale of the change applied to the conventional brake control device, so that the ECB can be easily applied to a brake control device that does not have an ECB mechanism. Mechanisms can be added. The wheel cylinder pressure sensor 54 and the reservoirs 64 and 65 provided in the conventional VSC unit are unnecessary in the brake control device 1 according to the present embodiment and can be discarded. From the viewpoint of minimizing the changes to be made, these are left mounted in this embodiment.

  Summarizing the operational effects of the configuration described above, the brake control device 1 according to the present embodiment combines the first power hydraulic pressure source including the pumps 60 and 61 and the second power hydraulic pressure source including the accumulator 63. Then, the wheel cylinder pressure is adjusted so as to be the target hydraulic pressure. Specifically, the brake control device 1 normally generates a hydraulic pressure in the wheel cylinder 4 by the first power hydraulic pressure source, and the difference between the target hydraulic pressure and the current hydraulic pressure exceeds a predetermined threshold value. In this case, hydraulic pressure is generated in the wheel cylinder 4 by the first power hydraulic pressure source and the second power hydraulic pressure source. Therefore, according to the brake control device 1 according to the present embodiment, the hydraulic pressure corresponding to the required braking force of the wheel can be accurately generated in the brake control device including the electronically controlled brake.

  Further, in the configuration in which the hydraulic pressure is generated in the wheel cylinder only by the pump, it is necessary to provide a large pump or a plurality of pumps in order to apply a high pressure to the wheel cylinder. A configuration for accurately adjusting the accumulator pressure is required. On the other hand, the brake control device 1 is configured to apply a high pressure by combining the pumps 60 and 61 and the accumulator 63, and the hydraulic pressure generated by each of the pumps 60 and 61 and the accumulator 63 can be kept low. Therefore, the brake control device 1 can be configured more simply. Moreover, since the number of installed pumps can be reduced, the silence of the brake control device 1 can be improved.

  Further, in the brake control device 1 according to the present embodiment, the accumulator 63 is accumulated by the pumps 60 and 61 as the first power hydraulic pressure source, so there is no need to provide a pressure accumulating pump for the accumulator 63. The increase in points can be suppressed. Further, since the hydraulic pressure is stored in the accumulator 63 by the pumps 60 and 61 when no braking force is applied to the wheels, the pumps 60 and 61 when not in use can be used effectively. Further, since the hydraulic pressure is stored in the accumulator 63 with an output lower than the maximum output of the pumps 60 and 61 when the hydraulic pressure is generated in the wheel cylinder 4, the electric power consumed by the stored pressure in the accumulator 63 can be reduced. it can.

  In addition, the brake control device 1 includes accumulator cut valves 34 and 35 in the accumulator communication paths 221 and 222 that connect the pumps 60 and 61 and the wheel cylinder 4 and the accumulator 63. Accordingly, when the brake fluid is supplied to the wheel cylinder 4 by the pumps 60 and 61, the inflow of the brake fluid from the pumps 60 and 61 to the accumulator 63 can be avoided by closing the accumulator cut valves 34 and 35. As a result, a stable hydraulic pressure can be generated in the wheel cylinder 4.

  In addition, the brake control device 1 adjusts the pressure on the flow path connecting the reservoir tank 16 and the wheel cylinder 4, specifically, upstream of the connection portions of the individual flow paths 210 and 211 in the individual flow paths 209 and 212. Linear control valves 24 and 25 are provided. Thereby, the hydraulic pressure of the wheel cylinder 4 can be adjusted with high accuracy. Further, since the accumulator cut valves 34 and 35 are subjected to high pressure from the accumulator 63, it is not necessary to give the pressure regulating linear control valves 24 and 25 higher pressure resistance than the conventional ECB configuration. Further, since the pressure regulating linear control valves 24 and 25 can adjust the wheel cylinder pressure with a small differential pressure, the occurrence of pulsation can be suppressed, and as a result, the generation of abnormal noise and vibration can be suppressed. Can do.

  Further, the brake control device 1 includes master cut valves 20 and 21 on the flow path connecting the master cylinder 14 and the wheel cylinder 4, specifically, the master flow paths 205 and 206, and the pumps 60 and 61 or the accumulator 63. When the hydraulic pressure is generated in the wheel cylinder 4, the master cut valves 20, 21 are closed. Thereby, it is possible to avoid the displacement of the brake pedal 10 caused by the brake fluid flowing into or out of the master cylinder 14 with the fluctuation of the wheel cylinder pressure, and the brake feeling can be improved. Moreover, the fluid pressure of the brake fluid can be reduced to an atmospheric pressure equivalent.

  Further, the brake control device 1 includes reservoir cut valves 22 and 23 on the upstream side of the pressure regulation linear control valves 24 and 25. Thereby, even if it is a case where the pressure regulation linear control valves 24 and 25 fail, since the hydraulic pressure which generate | occur | produced in the wheel cylinder 4 can be hold | maintained, a fail safe function is securable. In addition, while maintaining the hydraulic pressure generated in the wheel cylinder 4, the energization of the pressure regulating linear control valves 24, 25 can be turned off to dissipate the heat generated in the pressure regulating linear control valves 24, 25. Therefore, the reliability of the brake control device 1 can be improved.

  In addition, the brake control device 1 includes a pressure reducing flow path 217 to 220 that connects the downstream side and the upstream side of the pressure regulating linear control valves 24 and 25 without the pressure regulating linear control valves 24 and 25, and a pressure reducing flow path. Pressure reducing valves 30 to 33 provided in the paths 217 to 220 are provided. In normal times, the hydraulic pressure is reduced by adjusting the opening degree of the pressure regulating linear control valves 24 and 25, and is adjusted when the difference between the target hydraulic pressure and the current hydraulic pressure exceeds a predetermined threshold value. In addition to adjusting the opening degree of the pressure linear control valves 24 and 25, the hydraulic pressure is reduced by opening the pressure reducing valves 30 to 33. Thereby, the hydraulic pressure corresponding to the required braking force of the wheel can be generated with high accuracy.

(Embodiment 2)
In the brake control device 1 according to the second embodiment, the pressure-regulating linear control valves 24 and 25 are provided in the reservoir flow paths 207 and 208, and the pump communication paths 213 and 214 are upstream of the reservoir cut valves 22 and 23. It is different from the first embodiment in that it is connected to the paths 207 and 208. Hereinafter, this embodiment will be described. The other configuration of the brake control device 1, the brake operation, and its control flow are basically the same as those in the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  FIG. 6 is a schematic configuration diagram of a brake control device according to the second embodiment. As shown in FIG. 6, the brake control device 1 includes a disc brake unit 2, a master cylinder 14, a reservoir tank 16, a stroke simulator unit 18, a hydraulic actuator 100, and a brake ECU 300. Pressure regulating linear control valves 24 and 25 are provided on the downstream side of the brake fluid flow with respect to the reservoir cut valves 22 and 23 in the reservoir channels 207 and 208, respectively. In addition, one ends of pump communication paths 213 and 214 are connected to the upstream sides of the reservoir cut valves 22 and 23 in the reservoir flow paths 207 and 208, respectively. Even with such a configuration, a brake operation similar to that of the first embodiment can be performed.

  Further, as shown in FIG. 7, the brake control device 1 according to the present embodiment can be formed using a brake control device having a conventionally known ABS (Anti-lock Brake System) mechanism. FIG. 7 is a schematic view showing a state in which a regenerative brake unit is incorporated in a brake control device having a conventional ABS mechanism. That is, the accumulator communication paths 221 and 222 are added to the ABS unit included in the brake control device having a conventionally known ABS mechanism to form the ABS unit 100c. And, between the ABS unit 100c and the master cylinder 14, master cut valves 20, 21, reservoir cut valves 22, 23, pressure regulating linear control valves 24, 25, accumulator cut valves 34, 35, and an accumulator 63 were provided. The regenerative brake unit 100a is incorporated and the corresponding flow paths are connected to each other to form the brake control device 1 according to the present embodiment.

  In this case, the hydraulic actuator 100 includes a regenerative brake unit 100a and an ABS unit 100c. Here, in the configuration in which the hydraulic pressure is generated in the wheel cylinder only by the pump, it is necessary to increase the size of the pump or to provide a plurality of pumps in order to apply a high pressure to the wheel cylinder. On the other hand, in the brake control apparatus 1, since the pumps 60 and 61 and the accumulator 63 are combined to generate the hydraulic pressure in the wheel cylinder 4, it is not necessary to increase the size of the pump or to provide a plurality of pumps. Therefore, the pump provided in the conventional ABS unit can be used for the pumps 60 and 61 of the brake control device 1. Thereby, the brake control apparatus 1 which concerns on this embodiment can be formed using the conventional ABS mechanism.

  Thus, the brake control device 1 according to the present embodiment can be configured using a conventional brake control device that does not have an ECB mechanism. Therefore, the addition of an ECB mechanism to a vehicle equipped with a brake control device that does not have an ECB mechanism can be realized at a lower cost, and the amount of waste generated can be reduced. In addition, the configuration of the brake control device 1 according to the present embodiment can reduce the scale of the change applied to the conventional brake control device, so that the ECB can be easily applied to a brake control device that does not have an ECB mechanism. Mechanisms can be added. The wheel cylinder pressure sensor 54 and the reservoirs 64 and 65 provided in the conventional ABS unit are unnecessary in the brake control device 1 according to the present embodiment and can be discarded. From the viewpoint of minimizing the changes to be made, these are left mounted in this embodiment.

  The brake control device 1 having the above-described configuration can achieve the same effects as those of the first embodiment.

  The present invention is not limited to the above-described embodiment, and an appropriate combination of the elements of the embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to the embodiments based on the knowledge of those skilled in the art, and the embodiments to which such modifications are added can be included in the scope of the present invention. . The configuration shown in each figure is for explaining an example, and any configuration that can achieve the same function can be changed as appropriate, and the same effect can be obtained.

  1 Brake control device, 4, 4FR, 4FL, 4RL, 4RR Wheel cylinder, 14 Master cylinder, 16 Reservoir tank, 20, 21 Master cut valve, 22, 23 Reservoir cut valve, 24, 25 Pressure regulation linear control valve, 30, 31, 32, 33 Pressure reducing valve, 34, 35 Accumulator cut valve, 60, 61 Pump, 63 Accumulator, 217, 218, 219, 220 Pressure reducing flow path, 300 Brake ECU.

Claims (10)

A wheel cylinder that applies braking force to the wheel by the hydraulic pressure of the hydraulic fluid supplied through the hydraulic fluid flow path;
A first power hydraulic pressure source that supplies hydraulic fluid to the wheel cylinder by power and generates hydraulic pressure by pressurizing the supplied hydraulic fluid;
A second power hydraulic pressure source for storing hydraulic fluid in a pressurized state and generating hydraulic pressure by supplying the stored hydraulic fluid to the wheel cylinder;
A controller that controls the hydraulic pressure in the wheel cylinder so as to be a target hydraulic pressure by combining the first hydraulic power source and the second hydraulic power source;
A brake control device comprising:   When the difference between the target hydraulic pressure and the current hydraulic pressure is less than or equal to a predetermined threshold, the control unit generates a hydraulic pressure by the first power hydraulic pressure source, and the difference exceeds the threshold The brake control device according to claim 1, wherein hydraulic pressure is generated by a first power hydraulic pressure source and a second power hydraulic pressure source.   The brake control device according to claim 1 or 2, wherein the second power hydraulic pressure source stores the hydraulic fluid supplied from the first power hydraulic pressure source in a pressurized state.   4. The brake control device according to claim 3, wherein the control unit stores hydraulic pressure in a second power hydraulic pressure source when the brake is not required for the wheel. 5.   The control unit supplies hydraulic fluid from the first power hydraulic pressure source at an output lower than a maximum output when the hydraulic pressure is generated in the wheel cylinder, and stores the hydraulic pressure in the second power hydraulic pressure source. The brake control device according to claim 3 or 4, characterized by the above-mentioned.   Provided in a hydraulic fluid flow path connecting the first power hydraulic pressure source and the second power hydraulic pressure source, and opened between the first power hydraulic pressure source and the second power hydraulic pressure source. The brake control device according to any one of claims 3 to 5, further comprising a cut valve that allows the flow of the hydraulic fluid. A reservoir tank for storing hydraulic fluid;
A manual hydraulic pressure source for supplying hydraulic fluid stored in the reservoir tank to the wheel cylinder by operating a brake operation member by a driver, and generating hydraulic pressure by pressurizing the supplied hydraulic fluid;
A master cut valve provided on a hydraulic fluid flow path connecting the manual hydraulic pressure source and the wheel cylinder, and closing to shut off the supply of the hydraulic fluid to the wheel cylinder by the manual hydraulic pressure source,
The first power hydraulic pressure source and the second power hydraulic pressure source are provided in parallel with the manual hydraulic pressure source,
The control unit closes the master cut valve when hydraulic pressure is generated in the wheel cylinder by the first power hydraulic pressure source or the second power hydraulic pressure source. The brake control device according to any one of 6.   A pressure-regulating linear control valve is provided on a hydraulic fluid flow path connecting the reservoir tank and the wheel cylinder, and adjusts a hydraulic pressure generated in the wheel cylinder by an opening degree of the valve. Item 8. The brake control device according to item 7. The pressure-regulating linear control valve is a normally open control valve whose opening is adjusted by energization control in a valve open state when not energized,
9. The brake control according to claim 8, further comprising a reservoir cut valve provided on a hydraulic fluid flow path connecting the reservoir tank and the wheel cylinder to close the valve cylinder and hold the hydraulic pressure in the wheel cylinder. apparatus. Pressure reducing flow path connecting the hydraulic fluid flow downstream side and upstream side of the pressure regulating linear control valve in the hydraulic fluid flow path connecting the reservoir tank and the wheel cylinder without the pressure regulating linear control valve. When,
A pressure reducing valve that is provided on the pressure reducing flow path and opens to permit the flow of hydraulic fluid between the wheel cylinder and the reservoir tank via the pressure reducing flow path;
The control unit reduces the hydraulic pressure by increasing the opening degree of the pressure regulating linear control valve when the difference between the target hydraulic pressure and the current hydraulic pressure is equal to or less than a predetermined threshold, and the difference is 10. The brake control device according to claim 8, wherein when the threshold value is exceeded, the hydraulic pressure is reduced by increasing the opening degree of the pressure regulating linear control valve and opening the pressure reducing valve.

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