JP5136267B2 - Brake control device - Google Patents

Description

  The present invention relates to a brake control device that controls braking force applied to wheels provided in a vehicle.

  2. Description of the Related Art In recent years, many electronically controlled brake systems that control the braking force of each wheel so as to give an optimal braking force to the vehicle according to the traveling state of the vehicle have been adopted as a braking device in the vehicle. In such an electronically controlled brake system, the wheel cylinder pressure of each wheel is monitored by a pressure sensor, and an electromagnetic control valve is installed so that the wheel cylinder pressure becomes the target hydraulic pressure calculated based on the driver's brake pedal operation amount. It controls (refer patent document 1).

In the electronically controlled brake system as described above, a normally open electromagnetic control valve is disposed between the master cylinder and the wheel cylinder. As such a normally open type electromagnetic control valve, Patent Document 2 discloses that a valve body at the tip of a rod is seated on a valve seat against the urging force of a compressed spring by passing a current through a coil. An electromagnetic valve having a structure in which a liquid chamber connected to the master cylinder side and a liquid chamber connected to the wheel cylinder side are separated is disclosed.
JP 2006-199133 A JP 2001-130395 A

  By the way, in the electronically controlled brake system described above, a normally open type solenoid valve is used between the master cylinder and the wheel cylinder. In such a normally open type solenoid valve, the wheel cylinder is caused by the residual pressure of the wheel cylinder. It is necessary to prevent the valve from closing due to the differential pressure even in a situation where the side is at a higher pressure than the master cylinder side. To that end, it is only necessary to increase the load of the compression spring to keep the valve open. However, when the solenoid valve is closed, the drive current required to move the plunger against the load of the compression spring increases. Resulting in. Therefore, there is room for further improvement from the viewpoint of power consumption.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a technique for reducing power consumption in an electromagnetic valve used in a brake control device.

  In order to solve the above problems, a brake control device according to an aspect of the present invention is independent of a manual hydraulic pressure source that pressurizes brake fluid in accordance with an operation amount of a brake operation member by a driver, and a driver's brake operation. A power hydraulic pressure source that accumulates pressure by brake fluid using power, a wheel cylinder that receives a brake fluid from at least one of the manual hydraulic pressure source and the power hydraulic pressure source, and applies a braking force to the wheel; Provided in a path connecting the manual hydraulic pressure source and the wheel cylinder, and when the brake fluid is supplied from the manual hydraulic pressure source to the wheel cylinder, the valve is opened, and from the power hydraulic pressure source to the wheel cylinder And a control valve that is controlled to close when supplying the brake fluid. The control valve is an electromagnetic valve that is provided with a spring that biases the valve body in a direction away from the valve seat, and that closes when the valve body is seated on the valve seat while compressing the spring when energized. The valve chamber in which the valve body is disposed is connected to the flow path on the manual hydraulic pressure source side, and the liquid chamber provided on the opposite side of the valve chamber across the valve seat is the flow path on the wheel cylinder side It is connected to the.

  According to this aspect, for example, there is a problem in the decompression control of the wheel cylinder despite the release of the brake operation, and the liquid chamber connected to the flow path on the wheel cylinder side by the residual pressure of the wheel cylinder is more than the valve chamber. Even in a situation where the pressure is high, the force applied to the valve body is the direction in which the valve body is separated from the valve seat. Therefore, even if the spring load that biases the valve body away from the valve seat is not set to a large value, the non-energized control valve should be open regardless of the residual pressure of the wheel cylinder. Becomes easy. As a result, the brake fluid of the wheel cylinder can be surely flowed to the manual hydraulic pressure source side, and the brake drag due to the residual pressure of the wheel cylinder can be reduced. Further, the spring load can be set small enough that the control valve does not self-close when supplying the brake fluid from the manual hydraulic pressure source to the wheel cylinder without considering the maximum pressure generated by the wheel cylinder. Therefore, when the control valve is closed, the drive current required to overcome the spring load can be reduced, and the power consumption of the brake control device can be reduced.

  Another aspect of the present invention is also a brake control device. This device includes a manual hydraulic pressure source that pressurizes the brake fluid in accordance with the amount of operation of the brake operation member by the driver, and a power hydraulic pressure source that accumulates pressure by the brake fluid using power independent of the driver's brake operation. A wheel cylinder that receives a brake fluid from at least one of the manual hydraulic pressure source and the power hydraulic pressure source to apply a braking force to a wheel, and connects the manual hydraulic pressure source and the wheel cylinder, A manual hydraulic pressure transmission path configured to be able to supply brake fluid from the manual hydraulic pressure source to the wheel cylinder, the power hydraulic pressure source and the wheel cylinder are connected, and the power hydraulic pressure source A hydraulic power transmission path configured to be able to supply brake fluid to the wheel cylinder; A wheel cylinder, a reservoir for storing brake fluid, and the power hydraulic pressure source are connected, and a brake fluid discharged from the wheel cylinder can be recovered by the reservoir, and a manual hydraulic pressure transmission path Provided when the brake fluid is supplied from the manual hydraulic pressure source to the wheel cylinder, the valve is opened, and when the brake fluid is supplied from the power hydraulic pressure source to the wheel cylinder, the valve is closed. A first control valve that is provided, and a second control valve that is provided in the power hydraulic pressure transmission path and is controlled to open when supplying brake fluid from the power hydraulic pressure source to the wheel cylinder, Provided on the downstream side of the wheel cylinder, and brake fluid from the wheel cylinder to the recovery path. And a third control valve which is controlled to open to when discharging the. The first control valve is a solenoid valve that is provided with a spring that biases the valve body in a direction away from the valve seat, and closes when the valve body is seated on the valve seat while compressing the spring when energized. A valve chamber in which the valve body is disposed is connected to a flow path on a manual hydraulic pressure source side, and a liquid chamber provided on the opposite side of the valve chamber across the valve seat is on the wheel cylinder side. It is connected to the flow path.

  According to this aspect, for example, the brake fluid is not discharged from the wheel cylinder to the recovery path in spite of the failure of the third control valve and the brake operation is released, and the wheel cylinder side flow is caused by the residual pressure of the wheel cylinder. Even in a situation where the liquid chamber of the first control valve connected to the passage is at a higher pressure than the valve chamber, the force applied to the valve body is the direction in which the valve body separates from the valve seat. For this reason, even if the spring load that biases the valve body away from the valve seat is not set large, the first control valve in the non-energized state is opened regardless of the residual pressure of the wheel cylinder. Easy to do. As a result, the brake fluid of the wheel cylinder can be surely flowed to the manual hydraulic pressure source side, and the brake drag due to the residual pressure of the wheel cylinder can be reduced. Further, without considering the maximum pressure generated by the wheel cylinder, when the brake fluid is supplied from the manual hydraulic pressure source to the wheel cylinder, the spring load can be set so small that the first control valve does not self-close. Therefore, when the first control valve is closed, the driving current necessary to overcome the spring load can be reduced, and the power consumption of the brake control device can be reduced.

  You may further provide the control means which controls opening and closing with the energization amount to the said solenoid valve. The control means may determine the energization amount based on a differential pressure between a first hydraulic pressure generated by the manual hydraulic pressure source and a second hydraulic pressure generated by the wheel cylinder. . This makes it possible to close the valve with a small energization amount, for example, when the differential pressure is small, compared to the case of controlling the opening and closing of the first control valve with the energization amount as a fixed value regardless of the differential pressure, The power consumption of the brake control device can be further reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the power consumption in the solenoid valve used for a brake control apparatus can be reduced.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

(First embodiment)
[Schematic configuration of brake control device]
FIG. 1 is a system diagram showing a brake control device 10 according to the present embodiment. A brake control device 10 shown in FIG. 1 constitutes an electronically controlled brake system for a vehicle, and optimally brakes the four wheels of the vehicle according to the operation of a brake pedal 12 as a brake operation member by a driver. Set. That is, the brake control device 10 can control the braking force applied to the wheels provided on the vehicle.

  The brake pedal 12 is connected to a master cylinder 14 that sends out brake fluid as a working fluid (working fluid) in response to a depression operation by a driver. The brake pedal 12 is provided with a stroke sensor 46 for detecting the depression stroke.

  A stroke simulator 24 that creates a reaction force according to the operating force of the brake pedal 12 by the driver is connected to one output port 14 a of the master cylinder 14. A simulator cut valve 23 is provided in the middle of the flow path connecting the master cylinder 14 and the stroke simulator 24. The simulator cut valve 23 is a normally closed electromagnetic on-off valve that is closed when not energized and is switched to an open state when the operation of the brake pedal 12 by the driver is detected.

  The master cylinder 14 is connected to a reservoir tank 26 for accommodating brake fluid. The reservoir tank 26 is provided with a liquid level detecting device that detects the liquid level of the brake fluid in the reservoir tank 26. The master cylinder 14 functions as a manual hydraulic pressure source that can pressurize the stored brake fluid in accordance with the amount of operation of the brake pedal 12 by the driver.

  A brake hydraulic pressure control pipe 16 for the left front wheel is connected to one output port 14 a of the master cylinder 14. The brake hydraulic control pipe 16 is connected to a wheel cylinder 20FL for the left front wheel that applies a braking force to the left front wheel (not shown). A brake hydraulic control pipe 18 for the right front wheel is connected to the other output port 14b of the master cylinder 14, and the brake hydraulic control pipe 18 applies a braking force to the right front wheel (not shown). Is connected to the wheel cylinder 20FR. In the present embodiment, the brake hydraulic control pipes 16 and 18 function as a manual hydraulic pressure transmission path.

  A left solenoid valve 22FL as a master cut valve is provided in the middle of the brake hydraulic control pipe 16 for the left front wheel, and a right valve as a master cut valve is also provided in the middle of the brake hydraulic control pipe 18 for the right front wheel. A solenoid valve 22FR is provided. These left solenoid valve 22FL and right solenoid valve 22FR are both normally open solenoid valves that are open when not energized and switched to closed when energized. The left solenoid valve 22FL and the right solenoid valve 22FR are normally switched to the closed state when the operation of the brake pedal 12 by the driver is detected. Hereinafter, the right solenoid valve 22FR and the left solenoid valve 22FL are collectively referred to as “solenoid valve 22” as appropriate.

  A left master pressure sensor 48FL for detecting the master cylinder pressure on the left front wheel side is provided in the middle of the brake hydraulic control pipe 16 for the left front wheel. A right master pressure sensor 48FR for measuring the master cylinder pressure on the right front wheel side is provided. In the brake control device 10, when the brake pedal 12 is depressed by the driver, the stroke sensor 46 detects the depression operation amount. The master detected by the left master pressure sensor 48FL and the right master pressure sensor 48FR. The depressing operation force (depressing force) of the brake pedal 12 can also be obtained from the cylinder pressure. As described above, it is preferable from the viewpoint of fail-safe that the master cylinder pressure is monitored by the two pressure sensors 48FL and 48FR assuming the failure of the stroke sensor 46. Hereinafter, the left master pressure sensor 48FL and the right master pressure sensor 48FR are collectively referred to as a master cylinder pressure sensor 48 as appropriate.

  On the other hand, one end of a hydraulic supply / discharge pipe 28 is connected to the reservoir tank 26, and a suction port of an oil pump 34 driven by a motor 32 is connected to the other end of the hydraulic supply / discharge pipe 28. . The discharge port of the oil pump 34 is connected to a high pressure pipe 30, and an accumulator 50 and a relief valve 53 are connected to the high pressure pipe 30. In the present embodiment, a reciprocating pump having two or more pistons (not shown) that are reciprocally moved by the motor 32 is employed as the oil pump 34. Further, as the accumulator 50, an accumulator 50 that converts the pressure energy of the brake fluid into the pressure energy of an enclosed gas such as nitrogen is stored.

  The accumulator 50 stores the brake fluid whose pressure has been increased to, for example, about 14 to 22 MPa by the oil pump 34 that functions as power independent of the driver's brake operation. Further, the valve outlet of the relief valve 53 is connected to the hydraulic supply / discharge pipe 28. When the pressure of the brake fluid in the accumulator 50 is abnormally increased to about 25 MPa, for example, the relief valve 53 is opened and the high pressure brake is opened. The fluid is returned to the hydraulic supply / discharge pipe 28. Further, the high-pressure pipe 30 is provided with an accumulator pressure sensor 51 that detects the outlet pressure of the accumulator 50, that is, the pressure of the brake fluid in the accumulator 50.

  The high pressure pipe 30 functioning as a power hydraulic pressure transmission path is connected to the right front wheel wheel cylinder 20FR, the left front wheel wheel cylinder 20FL, and the right rear wheel wheel cylinder via the pressure increasing valves 40FR, 40FL, 40RR, and 40RL. 20RR and a wheel cylinder 20RL for the left rear wheel. Hereinafter, the wheel cylinders 20FR to 20RL will be collectively referred to as “wheel cylinders 20”, and the pressure increase valves 40FR to 40RL will be appropriately collectively referred to as “pressure increase valves 40”. Each of the pressure increasing valves 40 is a normally closed electromagnetic flow control valve (linear valve) that is closed when not energized and is used to increase the pressure of the wheel cylinder 20 as necessary.

  For example, the pressure increasing valve 40 is controlled to open when supplying brake fluid from the accumulator 50 to the wheel cylinder 20. A disc brake unit is provided for each wheel of the vehicle (not shown), and each disc brake unit generates a braking force by pressing the brake pad against the disc by the action of the wheel cylinder 20.

  Further, the wheel cylinder 20FR for the right front wheel and the wheel cylinder 20FL for the left front wheel are connected to the hydraulic supply / discharge pipe 28 via the pressure reducing valve 42FR or 42FL, respectively. The pressure reducing valves 42FR and 42FL are normally closed electromagnetic flow control valves (linear valves) used for pressure reduction of the wheel cylinders 20FR and 20FL as necessary. On the other hand, the wheel cylinder 20RR for the right rear wheel and the wheel cylinder 20RL for the left rear wheel are connected to the hydraulic supply / discharge pipe 28 via a pressure reducing valve 42RR or 42RL which is a normally open electromagnetic flow control valve. . Hereinafter, the pressure reducing valves 42FR to 42RL are collectively referred to as “pressure reducing valve 42” as appropriate. For example, the pressure reducing valve 42 is controlled to open when the brake fluid is discharged from the wheel cylinder 20 to the hydraulic supply / discharge pipe 28. The hydraulic supply / discharge pipe 28 functions as a recovery path configured so that the brake fluid discharged from the wheel cylinder 20 can be recovered by the reservoir tank 26.

  Further, as shown in FIG. 1, the brake control device 10 according to the present embodiment corresponds to the vicinity of the wheel cylinders 20FR to 20RL for the right front wheel, the left front wheel, the right rear wheel, and the left rear wheel, respectively. Wheel cylinder pressure sensors 44FR, 44FL, 44RR and 44RL for detecting the wheel cylinder pressure acting on the wheel cylinder 20 are provided. Hereinafter, the wheel cylinder pressure sensors 44FR to 44RL are collectively referred to as “wheel cylinder pressure sensor 44” as appropriate. The wheel cylinder pressure sensor 44 functions as a pressure detection unit that detects the pressure of the brake fluid acting on the wheel cylinder 20.

  The right solenoid valve 22FR and the left solenoid valve 22FL, the pressure increasing valves 40FR to 40RL, the pressure reducing valves 42FR to 42RL, the oil pump 34, the accumulator 50, and the like constitute the hydraulic actuator 80 of the brake control device 10. The hydraulic actuator 80 is controlled by an electronic control unit (hereinafter referred to as “ECU”) 200.

  The ECU 200 is a nonvolatile memory such as a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for data storage and program execution, and a backup RAM that can retain stored contents even when the engine is stopped. An A / D converter for converting an analog signal input from a memory, an input / output interface, various sensors, and the like into a digital signal and taking it in, a timer for timing, and the like are provided.

  The ECU 200 is electrically connected to various actuators including the hydraulic valves 80 such as the electromagnetic valves 22FR and 22FL, the simulator cut valve 23, the pressure increasing valves 40FR to 40RL, and the pressure reducing valves 42FR to 42RL.

  The ECU 200 is electrically connected to various sensors / switches that output signals for use in control. That is, a signal indicating the wheel cylinder pressure in the wheel cylinders 20FR to 20RL is input to the ECU 200 from the wheel cylinder pressure sensors 44FR to 44RL.

  Further, a signal indicating the pedal stroke of the brake pedal 12 is input from the stroke sensor 46 to the ECU 200, and signals indicating the master cylinder pressure are input from the right master pressure sensor 48FR and the left master pressure sensor 48FL, and from the accumulator pressure sensor 51. A signal indicating the accumulator pressure is input.

  Further, the ECU 200 receives a signal indicating the fluid level of the brake fluid from the fluid level detecting device provided in the reservoir tank 26. The ECU 200 is connected to a warning lamp 54 for notifying the driver of a decrease in the liquid level of the reservoir tank 26.

  Further, although not shown, ECU 200 receives a signal indicating the wheel speed of each wheel from a wheel speed sensor installed for each wheel, a signal indicating a yaw rate from the yaw rate sensor, and a steering wheel sensor from the steering angle sensor. A signal indicating the steering angle is input.

  In the brake control device 10 configured as described above, when the brake pedal 12 is depressed by the driver, the ECU 200 calculates the target deceleration of the vehicle from the pedal stroke representing the depression amount of the brake pedal 12 and the master cylinder pressure. Then, a target hydraulic pressure that is a target value of the wheel cylinder pressure of each wheel is obtained in accordance with the calculated target deceleration. Then, the ECU 200 controls the pressure increasing valve 40 and the pressure reducing valve 42 so that the wheel cylinder pressure of each wheel becomes the target hydraulic pressure.

  On the other hand, the electromagnetic valves 22FR and 22FL are closed at this time, and the simulator cut valve 23 is opened. Therefore, the brake fluid sent from the master cylinder 14 by the depression of the brake pedal 12 by the driver flows into the stroke simulator 24 through the simulator cut valve 23.

  When the accumulator pressure is less than the lower limit value of the preset control range, the oil pump 34 is driven by the ECU 200 to increase the accumulator pressure. When the accumulator pressure enters the control range, the drive of the oil pump 34 is stopped. Is done.

(Schematic configuration of solenoid valve)
Next, a schematic configuration of the electromagnetic valve used in the present embodiment will be described. FIG. 2 is a cross-sectional view schematically showing a cross section of a normally open solenoid valve used as a master cut valve of the present embodiment.

  As shown in FIG. 2, the solenoid valves 22FL and 22FR that are normally open switching solenoid valves include a valve seat 140, a valve body 142, a rod 143, a plunger 144 that is a movable member, and a sleeve that also serves as a fixed member. 145, a spring 146, a valve chamber 147, and a solenoid 149. The spring 146 provided in the valve chamber 147 biases the ball-shaped valve body 142 in the direction of separating from the valve seat 140. When a current is supplied to the solenoid 149 during energization, an electromagnetic driving force acts in a direction in which the plunger 144 is attracted by the sleeve 145, that is, in a direction in which the valve body 142 approaches the valve seat 140. The valve body 142 is closed by being seated on the valve seat 140 while compressing the spring 146. On the other hand, in a state where no current is supplied to the solenoid 149, the valve element 142 is separated from the valve seat 140 by the biasing force of the spring 146, and the electromagnetic valve is opened.

  The solenoid valves 22FL and 22FR are respectively provided in brake hydraulic control pipes 16 and 18 that constitute a path connecting the master cylinder 14 and the wheel cylinder 20, and supply brake fluid from the master cylinder 14 to the wheel cylinder 20. When the brake fluid is supplied to the wheel cylinder 20 from the accumulator 50, the valve is controlled to be closed.

  In the brake control device 10 configured as described above, when the device is in a normal state, when the driver depresses the brake pedal 12, the electromagnetic valve 22 is closed, and the accumulator 50 is operated according to the stroke amount of the brake pedal 12. The high-pressure brake fluid is supplied to the wheel cylinder 20 through the pressure increasing valve 40 opened. The wheel cylinder 20 receives the supply of brake fluid and applies braking force to the wheels. Thereafter, when the driver releases the depression of the brake pedal 12, the pressure reducing valve 42 is opened, and the brake fluid in the wheel cylinder 20 is collected in the reservoir tank 26 via the hydraulic supply / discharge pipe 28. The pressure is reduced.

  Incidentally, in the brake control device 10, in a situation where the pressure reducing valve 42 fails and does not open, the brake fluid cannot be discharged from the pressure reducing valve 42 to the hydraulic supply / discharge pipe 28 even if the operation of the brake pedal 12 is released. . As it is, the brake drag due to the residual pressure of the wheel cylinder 20 becomes a problem. However, when the operation of the brake pedal 12 is released in the brake control device 10, the electromagnetic valve 22 is opened. Normally, the wheel cylinder pressure is higher than the master cylinder pressure, so that the high-pressure brake fluid on the wheel cylinder side can be returned to the reservoir tank 26 by causing the brake hydraulic control pipes 16 and 18 to flow backward.

  At this time, a force based on a differential pressure between the wheel cylinder pressure and the master cylinder pressure is applied to the valve body 142 of the electromagnetic valve 22. Therefore, if the flow path 150 communicating with the liquid chamber 154 on the valve seat 140 side is connected to the master cylinder side, and the flow path 152 communicating with the valve chamber 147 is connected to the wheel cylinder side, the above-mentioned differential pressure is assumed. The spring 146 must be compressed with a load sufficient to overcome the above. Since the maximum wheel cylinder pressure that can be generated in the brake control device 10 is considerably larger than the master cylinder pressure, the solenoid valve 22 must be opened unless the load of the compressed spring 146 is increased. Even in the state, the rod 143 cannot be pushed back. Increasing the load of the spring 146 solves such a problem. On the other hand, when the valve is closed normally, an excessive current is required to overcome the large load of the compressed spring 146, and the power consumption is reduced. From this point of view, further improvements are needed.

  Therefore, in the solenoid valve 22 according to the present embodiment, the flow path 152 communicating with the valve chamber 147 in which the valve body 142 is disposed is connected to the master cylinder side, and the valve chamber 147 is sandwiched between the valve seat 140 and the solenoid valve 22. A flow path 150 communicating with a liquid chamber 154 provided on the opposite side is connected to the wheel cylinder side.

  As a result, there is a malfunction in the pressure reduction control of the wheel cylinder 20, for example, the pressure reduction valve 42, despite the release of the operation of the brake pedal 12, and the liquid connected to the flow path on the wheel cylinder side due to the residual pressure of the wheel cylinder 20. Even in a situation where the chamber 154 has a higher pressure than the valve chamber 147, the force applied to the valve body 142 is in the direction in which the valve body 142 is separated from the valve seat 140. Therefore, even if the load of the spring 146 that biases the valve body 142 in the direction away from the valve seat 140 is not set large, the solenoid valve 22 when not energized is opened regardless of the residual pressure of the wheel cylinder 20. It becomes easy to be in a valve state.

  As a result, the brake fluid of the wheel cylinder 20 can be reliably passed to the master cylinder 14 side, and the brake drag due to the residual pressure of the wheel cylinder 20 can be reduced. Further, without considering the maximum pressure generated by the wheel cylinder 20, the load of the spring 146 can be set so small that the electromagnetic valve 22 does not self-close when supplying brake fluid from the master cylinder 14 to the wheel cylinder 20. Therefore, when the electromagnetic valves 22FL and 22FR are closed, the driving current required to overcome the load of the spring 146 can be reduced, and the power consumption of the brake control device 10 can be reduced.

  Note that the lower limit of the load of the spring 146 is that the brake fluid supplied from the master cylinder 14 in the brake control device 10 in the braking mode in which the brake fluid is supplied from the master cylinder 14 to the wheel cylinder 20 instead of from the accumulator 50. What is necessary is just to set to such an extent that the solenoid valve 22 does not self-close by the pressure of. In the electromagnetic valve 22 according to the present embodiment, the brake fluid supplied from the master cylinder 14 flows into the valve chamber 147 in a direction perpendicular to the moving direction of the valve body 142. It is difficult for the force to move to the position to work, and in that respect, it is difficult to self-close.

  In addition, the ECU 200 according to the present embodiment controls opening and closing according to the amount of current supplied to the electromagnetic valve 22. The ECU 200 acquires information on the master cylinder pressure generated in the master cylinder 14 from the master cylinder pressure sensor 48, and information on the wheel cylinder pressure generated in the wheel cylinder 20 from the wheel cylinder pressure sensor 44, and the master cylinder pressure. The energization amount is controlled based on the differential pressure between the pressure and the wheel cylinder pressure. Thereby, compared with the case where the opening / closing of the solenoid valve 22 is controlled with the energization amount as a fixed value regardless of the differential pressure, for example, when the differential pressure is small, the solenoid valve 22 can be closed with a small energization amount. Thus, the power consumption of the brake control device 10 can be further reduced.

  As described above, the present invention has been described with reference to the above-described embodiment. However, the present invention is not limited to the above-described embodiment, and the present invention can be appropriately combined or replaced with the configuration of the embodiment. It is included in the present invention. In addition, it is possible to appropriately change the combination and order of the processes in the embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to the embodiment. The described embodiments can also be included in the scope of the present invention.

It is a systematic diagram which shows the brake control apparatus which concerns on this Embodiment. It is sectional drawing which shows typically the cross section of the normally open type solenoid valve used as a master cut valve of this Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Brake control apparatus, 12 Brake pedal, 14 Master cylinder, 16 Brake hydraulic control pipe, 18 Brake hydraulic control pipe, 20 Wheel cylinder, 22 Solenoid valve, 23 Simulator cut valve, 24 Stroke simulator, 26 Reservoir tank, 28 Hydraulic supply / discharge Pipe, 30 high pressure pipe, 32 motor, 34 oil pump, 40 pressure increasing valve, 42 pressure reducing valve, 44 wheel cylinder pressure sensor, 46 stroke sensor, 48 master cylinder pressure sensor, 50 accumulator, 51 accumulator pressure sensor, 80 hydraulic actuator, 140 Valve seat, 142 Valve body, 143 Rod, 144 Plunger, 145 Sleeve, 146 Spring, 147 Valve chamber, 149 Solenoid, 150 Flow path, 152 Flow path, 154 liquid chamber, 200 ECU.

Claims (2)

A manual hydraulic pressure source that pressurizes the brake fluid according to the amount of operation of the brake operation member by the driver;
A power hydraulic pressure source that accumulates pressure by brake fluid using power independent of the driver's brake operation;
A wheel cylinder that applies a brake fluid from at least one of the manual hydraulic pressure source and the power hydraulic pressure source to apply a braking force to the wheel;
Provided in a path connecting the manual hydraulic pressure source and the wheel cylinder, and when the brake fluid is supplied from the manual hydraulic pressure source to the wheel cylinder, the valve is opened, and from the power hydraulic pressure source to the wheel cylinder An open / close control valve that is controlled to close when supplying brake fluid to
The open / close control valve is provided with a spring that biases the valve body in a direction away from the valve seat, and is an electromagnetic valve that closes when the valve body is seated on the valve seat while compressing the spring when energized. The valve chamber in which the valve body is arranged is connected to the flow path on the manual hydraulic pressure source side, and the liquid chamber provided on the opposite side of the valve chamber across the valve seat is the flow on the wheel cylinder side. Connected to the road,
And further comprising a control means for controlling opening and closing according to the energization amount to the electromagnetic valve,
The control means determines the energization amount based on a differential pressure between a first hydraulic pressure generated by the manual hydraulic pressure source and a second hydraulic pressure generated by the wheel cylinder. Brake control device. A manual hydraulic pressure source that pressurizes the brake fluid according to the amount of operation of the brake operation member by the driver;
A power hydraulic pressure source that accumulates pressure by brake fluid using power independent of the driver's brake operation;
A wheel cylinder that applies a brake fluid from at least one of the manual hydraulic pressure source and the power hydraulic pressure source to apply a braking force to the wheel;
A manual hydraulic pressure transmission path configured to connect the manual hydraulic pressure source and the wheel cylinder, and to supply brake fluid from the manual hydraulic pressure source to the wheel cylinder;
A power hydraulic pressure transmission path configured to connect the power hydraulic pressure source and the wheel cylinder and to be able to supply brake fluid from the power hydraulic pressure source to the wheel cylinder;
A recovery path configured to connect the wheel cylinder, a reservoir for accommodating brake fluid, and the power hydraulic pressure source, and to recover the brake fluid discharged from the wheel cylinder by the reservoir;
When supplying brake fluid from the manual hydraulic pressure source to the wheel cylinder, the valve is opened and when supplying brake fluid from the power hydraulic pressure source to the wheel cylinder. A first open / close control valve that is controlled to close ;
A second control valve provided in the power hydraulic pressure transmission path and controlled to open when supplying brake fluid from the power hydraulic pressure source to the wheel cylinder;
A third control valve provided on the downstream side of the wheel cylinder and controlled to open when the brake fluid is discharged from the wheel cylinder to the recovery path;
The open / close first control valve is provided with a spring that urges the valve body in a direction separating the valve body from the valve seat, and the valve body closes when the valve body is seated on the valve seat while compressing the spring when energized. The valve chamber in which the valve body is arranged is connected to the flow path on the manual hydraulic pressure source side, and the liquid chamber provided on the opposite side of the valve chamber across the valve seat is on the wheel cylinder side Connected to the flow path of
And further comprising a control means for controlling opening and closing according to the energization amount to the electromagnetic valve,
The control means determines the energization amount based on a differential pressure between a first hydraulic pressure generated by the manual hydraulic pressure source and a second hydraulic pressure generated by the wheel cylinder. Brake control device.

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