JP5756418B2 - Brake hydraulic pressure control device for vehicles - Google Patents

Description

  The present invention relates to a vehicle brake hydraulic pressure control device.

  As a vehicle brake fluid pressure control device, a base on which a fluid path for connecting a master cylinder and a wheel cylinder is formed, a state in which brake fluid pressure acting on the wheel cylinder is increased, a state in which pressure is reduced, and a state in which pressure is maintained The control means for switching to the control means, the reservoir for storing the brake fluid released from the control means, the pump for sucking the brake fluid stored in the reservoir, and the suction fluid that leads to the output fluid path that connects the master cylinder and the control means And a suction valve provided on the road.

  In the above-described vehicular brake hydraulic pressure control device, when the brake operator is operated, the intake valve is closed, and the brake hydraulic pressure is transmitted from the master cylinder to the wheel cylinder via the control means. Perform control and anti-lock brake control. Further, when the behavior stabilization control is executed, the suction valve is opened, the brake fluid in the suction fluid passage is sucked into the pump, and flows into the wheel cylinder side.

As shown in FIG. 6, there is a normally-open intake valve 4 that opens and closes in conjunction with the piston 50 of the reservoir 5 as an intake valve used in the above-described vehicle brake hydraulic pressure control device. In the intake valve 4, the contact member 55 protruding from the piston 50 is in contact with the valve body 41 housed in the valve body housing hole 15 through the communication liquid passage 44a (see, for example, Patent Document 1). ).
The piston 50 strokes toward the opening 10a side of the reservoir hole 10 by the brake fluid pressure transmitted to the upstream fluid passage C1 of the suction fluid passage C and the reservoir chamber 12 along with the operation of the brake operator, and the valve When the body 41 moves to the reservoir hole 10 side and the valve body 41 seals the communication liquid path 44a, the suction valve 4 is closed.

Japanese Patent Laid-Open No. 6-8810

  In the suction valve 4 shown in FIG. 6, the upstream liquid is passed through between the valve body 41 and the communication liquid path 44 a until the valve body 41 seals the communication liquid path 44 a after the operation of the brake operator is started. Since brake fluid flows into the reservoir chamber 12 from the path C1, an invalid stroke is generated in the brake operator.

  In addition, when the brake operator is not operated, the valve body 41 is arranged in the vicinity of the communication liquid path 44a, and the movement amount of the valve body 41 when the valve is closed is reduced, thereby reducing the brake. The invalid stroke of the operator can be reduced. However, in the behavior stabilization control, when the brake fluid pressure is increased by the pump, if the interval between the valve body 41 and the communication fluid passage 44a is small, the interval becomes the resistance of the brake fluid. There is a problem that the responsiveness when boosting is reduced.

  It is an object of the present invention to provide a vehicle brake hydraulic pressure control device that can reduce the invalid stroke of a brake operator while ensuring responsiveness when the brake hydraulic pressure is increased by a pump.

In order to solve the above-mentioned problems, the present invention switches between a base body in which a fluid passage for connecting a master cylinder and a wheel cylinder is formed, and a state in which the brake fluid pressure acting on the wheel cylinder is at least increased and reduced. The control means, a reservoir for storing brake fluid released from the control means, a pump for sucking the brake fluid stored in the reservoir, and an output fluid path for communicating the master cylinder and the control means. A brake fluid pressure control device for a vehicle including an intake valve provided in the intake fluid passage.
The reservoir includes a bottomed reservoir hole formed in the base, a first piston movably accommodated in the reservoir hole, a second piston movably provided with respect to the first piston, An elastic member for the first piston that biases the first piston toward the bottom surface of the reservoir hole.
The intake valve includes a valve body accommodation hole formed in the base body and a valve body housed in the valve body accommodation hole.
Further, the base is formed with a communication liquid path having one end opened on the valve seat surface of the valve body housing hole and the other end opened on the bottom surface of the reservoir hole, and the second piston is formed by the communication liquid path. Through the valve body.
When the brake fluid pressure is applied to the first piston and the second piston in accordance with the operation of the brake operator, the second piston is configured to stroke in advance of the first piston. ing.

  In this configuration, in accordance with the operation of the brake operator, the second piston strokes ahead of the first piston, and the valve body moves in the valve closing direction. At this time, since only the second piston strokes greatly, the volume change in the reservoir hole can be reduced. As described above, since the volume change in the reservoir hole is small with respect to the movement amount of the valve body in the valve closing direction, the invalid stroke of the brake operator can be reduced.

  In addition, since the volume change in the reservoir hole when the valve body moves can be reduced, the brake fluid pressure can be reduced by the pump even when the distance between the valve body and the communication fluid path is set to be equal to that of the conventional suction valve. The ineffective stroke of the brake operator can be reduced while ensuring the response when boosting the pressure.

In the present invention, the valve body can be configured so as to seal the communication liquid path only by the stroke of the second piston, but in this configuration, the behavior is stable with the suction valve closed. When the control is performed, it is difficult to open the valve body away from the communication liquid path.
Therefore, it is preferable that the communication fluid path is sealed by the valve body by the stroke of the first piston after the second piston has made a full stroke with respect to the first piston.
In this configuration, when the suction valve is opened, the valve body is pushed away in the direction away from the communication liquid path by the elastic force of the elastic member for the first piston, so that the suction valve is opened quickly. And the response when the brake fluid pressure is increased by the pump can be increased.

  In the above-described vehicular brake hydraulic pressure control device, an elastic member for the second piston that urges the second piston toward the bottom surface side of the reservoir hole is interposed between the first piston and the second piston. In this case, by setting the spring constant of the elastic member for the second piston to be smaller than the spring constant of the elastic member for the first piston, the second piston is moved along with the operation of the brake operator. The stroke can be made prior to the first piston.

In the vehicle brake hydraulic pressure control device described above, a reservoir formed between the bottom surface of the reservoir hole and the first piston and the second piston in a state where the valve body seals the communication fluid path. When the chamber becomes negative pressure, the first piston and the second piston are stroked toward the bottom surface side of the reservoir hole, and the valve body is pushed by the second piston and separated from the communication liquid path. It is preferable.
In this configuration, when the behavior stabilization control is executed with the intake valve closed, the intake valve can be reliably opened.

In the above-described vehicle brake hydraulic pressure control device, when the second piston is accommodated in the accommodating portion formed in the first piston, the second piston can be stabilized with respect to the first piston. .
Moreover, when the said accommodating part is a recessed part formed in said 1st piston, a 2nd piston can be stabilized with a simple structure with respect to a 1st piston. Furthermore, since the size of the first piston in the radial direction can be sufficiently secured, the slidability of the first piston with respect to the reservoir hole can be maintained equivalent to the piston of the conventional reservoir.

  In the vehicular brake fluid pressure control device according to the present invention, when the brake operator is operated, the volume change in the reservoir hole becomes small with respect to the movement amount of the valve body in the valve closing direction. The ineffective stroke of the brake operator can be reduced while ensuring the responsiveness when increasing the pressure.

1 is a hydraulic circuit diagram of a vehicle brake hydraulic pressure control apparatus according to an embodiment. It is a figure showing an intake valve and a reservoir of this embodiment, and is a sectional view in a state where the intake valve is opened. It is the figure which showed the intake valve and reservoir of this embodiment, and is sectional drawing of the state which the 2nd piston made full stroke. It is a figure showing an intake valve and a reservoir of this embodiment, and is a sectional view in a state where the intake valve is closed. It is the figure which showed the suction valve and reservoir of this embodiment, and is sectional drawing of the state in which the reservoir chamber became the negative pressure. It is sectional drawing which showed the conventional suction valve and the reservoir | reserver.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
The vehicle brake hydraulic pressure control apparatus according to the present embodiment is used in a four-wheeled vehicle or the like, and embodies the hydraulic circuit shown in FIG.

  As shown in FIG. 1, the vehicle brake hydraulic pressure control device U includes a brake output system K1 for braking two wheel brakes FR, RL out of the four wheel brakes FR, RL, FL, RR, and the rest. And a brake output system K2 for braking the two wheel brakes FL, RR.

  The vehicle brake hydraulic pressure control device U has a base body 100 on which a fluid path for connecting a master cylinder M, which is a hydraulic pressure source, and a wheel cylinder W of each wheel brake FR, RL, FL, RR is formed. doing. The base body 100 is a substantially rectangular parallelepiped metal part, and various electric parts, a motor 200, a control device (not shown), and the like are attached to the surface of the base body 100.

  In the vehicle brake hydraulic pressure control device U, independent antilock brake control of each wheel is possible by the control valve means V provided for each wheel brake FR, RL, FL, RR. Further, in the vehicle brake hydraulic pressure control device U, behavior stabilization control is possible by the cooperation of the regulator R, the suction valve 4 and the pump 6 provided in each brake output system K1, K2.

  The brake output system K1 is for braking the right front and left rear wheels, and is a system extending from the inlet port 21 to the outlet ports 22R and 22L. A pipe H1 leading to the output port M2 of the master cylinder M is connected to the inlet port 21, and a pipe H2 leading to the wheel cylinder W of the wheel brakes FR, RL is connected to the outlet ports 22R, 22L.

The brake output system K2 is for braking the left front and right rear wheels, and is a system from the inlet port 23 to the outlet ports 24L and 24R.
A pipe H3 reaching the output port M1 of the master cylinder M, which is the same hydraulic pressure source as the brake output system K1, is connected to the inlet port 23, and the wheel cylinders W of the wheel brakes FL and RR are connected to the outlet ports 24L and 24R. A pipe H4 leading to is connected.
Since the brake output system K2 has substantially the same configuration as the brake output system K1, in the following description, the brake output system K1 will be described in detail, and the brake output system K2 will be described as appropriate.

  The master cylinder M is a tandem type, and a brake pedal BP that is a brake operator is connected to the master cylinder M. That is, the four wheel brakes FR, RL, FL, and RR can be braked by applying a pedal force to one brake pedal BP.

  The brake output system K1 includes a regulator R as a regulator valve, a control valve means V, a suction valve 4, a reservoir 5, a pump 6, an orifice 6a, a damper chamber 7, a hydraulic pressure source side brake hydraulic pressure sensor 8, and a wheel side brake fluid. A pressure sensor 9 is provided.

In the following description, the liquid path from the inlet port 21 to the regulator R is referred to as “output liquid path A”, and the flow path from the regulator R to the outlet ports 22R and 22L is referred to as “wheel liquid path B”. A flow path from the output liquid path A to the pump 6 is referred to as “suction liquid path C”, and a flow path from the pump 6 to the wheel liquid path B is referred to as “discharge liquid path D”. Furthermore, the flow path from the wheel liquid path B to the suction liquid path C is referred to as “open path E”.
Further, “upstream side” means the master cylinder M side, and “downstream side” means the wheel cylinder W side.

  The regulator R has a function of switching between a state of permitting and shutting off the flow of brake fluid in the output fluid passage A, and a brake of the wheel fluid passage B when the flow of brake fluid in the output fluid passage A is shut off. It has a function of adjusting the hydraulic pressure below a predetermined value, and includes a cut valve 1 and a check valve 1a.

  The cut valve 1 is a normally open linear solenoid valve interposed between the output fluid path A and the wheel fluid path B, and allows the brake fluid to flow from the output fluid path A to the wheel fluid path B. The state to perform and the state to interrupt | block are switched. That is, the cut valve 1 has a configuration capable of adjusting the valve opening pressure by controlling energization to the solenoid.

Since the cut valve 1 is normally open, the brake fluid discharged from the pump 6 to the discharge fluid passage D and flowing into the wheel fluid passage B is allowed to return to the suction fluid passage C.
Further, when the brake pedal BP is depressed and the brake fluid pressure is applied to the wheel cylinder W, the cut valve 1 is closed by the control of a control device (not shown), and the brake fluid pressure applied to the regulator R from the output fluid path A The brake fluid pressure in the wheel fluid passage B can be appropriately opened and adjusted to the suction fluid passage C according to the balance with the force for closing the valve.

  The check valve 1a is connected to the cut valve 1 in parallel. The check valve 1a is a one-way valve that allows the flow of brake fluid from the output fluid path A to the wheel fluid path B.

  One control valve means V is provided for each of the wheel brakes FR and RL. The control valve means V is in a state in which the wheel liquid path B is opened and the open path E is cut off, in a state in which the wheel liquid path B is cut off and the open path E is opened, and in which the wheel liquid path B and the open path E are cut off And has an inlet valve 2, a check valve 2 a and an outlet valve 3.

The inlet valve 2 is a normally-open electromagnetic valve provided in the wheel fluid passage B, and allows the brake fluid to flow from the upstream side to the downstream side when in the valve-open state, and is in the valve-closed state. Shut off.
The inlet valve 2 is closed when the electromagnetic coil is excited based on a command from a control device (not shown), and is opened when the electromagnetic coil is demagnetized.

  The check valve 2 a is a valve that allows only the inflow of brake fluid from the downstream side to the upstream side, and is connected in parallel to each inlet valve 2.

The outlet valve 3 is a normally closed electromagnetic valve interposed between the wheel fluid passage B and the release passage E, and brake fluid from the wheel cylinder W side to the reservoir 5 side when in the closed state. Block inflow and allow when valve is open.
The outlet valve 3 opens when the electromagnetic coil is excited based on a command from a control device (not shown), and closes when the electromagnetic coil is demagnetized.

  The reservoir 5 is provided in the suction fluid passage C, and has a function of temporarily storing the brake fluid released to the release passage E when each outlet valve 3 is opened.

The suction valve 4 is a normally-open mechanical valve provided in the suction fluid passage C, and switches between a state in which the suction fluid passage C is opened and a state in which the suction fluid passage C is shut off.
The suction valve 4 is configured to open and close in conjunction with the pistons 51 and 52 (see FIG. 2) in the reservoir 5.

The pump 6 is interposed between the suction liquid path C and the discharge liquid path D, is driven by the rotational force of the motor 200, sucks the brake liquid stored in the reservoir 5, and discharges it to the discharge liquid path D. To do. Thereby, the brake fluid pressure generated by depressing the brake pedal BP can be increased.
When the cut valve 1 is closed and the suction valve 4 is open, the pump 6 uses the brake fluid stored in the master cylinder M, the output fluid path A, the suction fluid path C, and the reservoir 5. Suction and discharge to discharge liquid path D. Accordingly, the brake fluid pressure can be applied to the wheel cylinder W even when the brake pedal BP is not depressed.

  The damper chamber 7 and the orifice 6a attenuate the pulsation of the brake fluid discharged from the pump 6 by the cooperative action.

The hydraulic pressure source side brake hydraulic pressure sensor 8 measures the brake hydraulic pressure in the output hydraulic path A, that is, the magnitude of the brake hydraulic pressure in the master cylinder M.
As described above, the master cylinder M is a tandem type, and the brake fluid pressures in the brake output systems K1 and K2 are the same. Therefore, the hydraulic pressure source side brake fluid pressure sensor 8 is provided only in one brake output system K1. Is arranged.
The value of the brake fluid pressure measured by the fluid pressure source side brake fluid pressure sensor 8 is taken in by a control device (not shown) as needed, and behavior stabilization control is executed based on the magnitude of the measured brake fluid pressure. Is done.

The wheel side brake hydraulic pressure sensor 9 measures the magnitude of the brake hydraulic pressure acting on the wheel cylinder W of the wheel brake FR.
The value of the brake fluid pressure measured by the wheel side brake fluid pressure sensor 9 is taken in by a control device (not shown) as needed, and antilock brake control, behavior stabilization control, etc. based on the measured brake fluid pressure. Is executed.

  The motor 200 is a common power source for the pump 6 of the brake output system K1 and the pump 6 of the brake output system K2, and operates based on a command from a control device (not shown).

  Based on outputs from the hydraulic pressure source side brake hydraulic pressure sensor 8, the wheel side brake hydraulic pressure sensor 9, and a wheel speed sensor (not shown), the control device includes a cut valve 1 of the regulator R, an inlet valve 2 of the control valve means V, and The opening / closing of the outlet valve 3 and the operation of the motor 200 are controlled.

  Next, normal brake control, antilock brake control, and behavior stabilization control realized by the control device will be described with reference to the hydraulic circuit of FIG. In the present embodiment, a front-wheel drive vehicle having front wheels as drive wheels will be described as an example.

(Normal brake control)
During normal brake control in which each wheel is not likely to lock, the plurality of solenoid valves are demagnetized by the control device. That is, in normal brake control, the cut valve 1 and the inlet valve 2 are opened, and the outlet valve 3 is closed. Further, the suction valve 4 is in an open state.

  When the driver depresses the brake pedal BP in such a state, the brake fluid pressure generated due to the depression force is transmitted to the wheel cylinders W of the wheel brakes FR, RL, FL, RR as they are. The wheel is braked. At this time, the intake valve 4 is closed by the brake fluid pressure generated by depressing the brake pedal BP.

(Anti-lock brake control)
The anti-lock brake control is executed when the wheel is likely to fall into the locked state, and the control valve means V corresponding to the wheel brakes FR, RL, FL, RR of the wheel likely to fall into the locked state is provided. This is realized by controlling and appropriately selecting a state in which the brake fluid pressure acting on the wheel cylinder W is reduced, increased or kept constant.
Note that whether to select pressure reduction, pressure increase, or holding is determined by the control device based on a wheel speed obtained from a wheel speed sensor (not shown).

If the wheel is about to enter the locked state while the brake pedal BP is being depressed, anti-lock brake control is started by the control device.
In the following, the operation at the time of anti-lock brake control will be described on the assumption that the right front wheel (wheel braked by the wheel brake FR) is about to enter the locked state.

When it is determined by the control device that the brake fluid pressure acting on the wheel cylinder W of the wheel brake FR should be reduced, the wheel fluid path B is blocked by the control valve means V corresponding to the wheel brake FR, The open path E is opened.
Specifically, the inlet valve 2 is excited to be closed, and the outlet valve 3 is excited to be opened. The intake valve 4 is closed by the brake fluid pressure generated by depressing the brake pedal BP.
As a result, the brake fluid in the wheel fluid passage B communicating with the wheel cylinder W flows into the reservoir 5 through the release passage E, and the brake fluid pressure acting on the wheel cylinder W is reduced.

  When the antilock brake control is executed, the motor 200 is driven to operate the pump 6, and the brake fluid stored in the reservoir 5 is returned to the wheel fluid passage B via the discharge fluid passage D.

Further, when it is determined by the control device that the brake fluid pressure acting on the wheel cylinder W of the wheel brake FR should be kept constant, the control valve means V corresponding to the wheel brake FR causes the wheel fluid path B and Each open path E is blocked.
Specifically, the inlet valve 2 is excited to be closed, and the outlet valve 3 is demagnetized to be closed.
If it does in this way, brake fluid will be confine | sealed in the flow path closed by the wheel cylinder W, the inlet valve 2, and the outlet valve 3, and the brake fluid pressure which was acting on the wheel cylinder W will be kept constant.

Further, when the control device determines that the brake fluid pressure acting on the wheel cylinder W of the wheel brake FR should be increased, the wheel fluid passage B is opened by the control valve means V corresponding to the wheel brake FR. Then, the open path E is blocked.
Specifically, the inlet valve 2 is demagnetized and opened, and the outlet valve 3 is demagnetized and closed.
In this way, the brake fluid pressure generated due to the depression force of the brake pedal BP acts directly on the wheel cylinder W, and the brake fluid pressure acting on the wheel cylinder W is increased.

(Behavior stabilization control)
The behavior stabilization control is for preventing the disturbance of behavior caused by changes in driving conditions, etc., and the behavior stabilization control such as skid control and traction control is started by the control device according to the state of the vehicle. The
In the following description, it is assumed that the right front wheel (the wheel braked by the wheel brake FR) is braked to stabilize the vehicle behavior when the brake pedal BP is not depressed.

When the control device determines that the front right wheel should be braked in a state where the brake pedal BP is not depressed, the cut valve 1 is energized to be closed, and the control valve corresponding to the wheel brake FR is used. In the control valve means V other than the means V, the inlet valve 2 is excited to be closed, and the motor 200 is operated to drive the pump 6.
In this way, the brake fluid stored in the master cylinder M, the output fluid path A, and the suction fluid path C is connected to the wheel cylinder W of the wheel brake FR via the pump 6 and the discharge fluid path D. It flows into only the fluid passage B, the brake fluid pressure acts on the wheel cylinder W, and the right front wheel is braked.

  Next, the structure of the intake valve 4 and the reservoir 5 in the vehicle brake hydraulic pressure control device U of the present embodiment will be described in detail.

As shown in FIG. 2, the reservoir 5 is provided so as to be movable with respect to the reservoir hole 10 formed in the base body 100, the first piston 51 movably accommodated in the reservoir hole 10, and the first piston 51. The second piston 52 is provided.
Further, a first elastic member 53 for the first piston 51 that biases the first piston 51 toward the bottom surface 11 of the reservoir hole 10 and a second piston that biases the second piston 52 toward the bottom surface 11 of the reservoir hole 10. And a second elastic member 54 for 52.

The reservoir hole 10 is a bottomed cylindrical hole that opens to the surface 100 a of the base body 100. The opening 10 a of the reservoir hole 10 is closed by a plate-like lid member 110 attached to the surface 100 a of the base body 100. Further, a spring support portion 110 a is projected from the inner surface of the lid member 110 at a position corresponding to the central portion of the reservoir hole 10.
In addition, a valve body accommodation hole 15 to be described later is opened at the center of the bottom surface 11 of the reservoir hole 10, and a downstream fluid passage C <b> 2 of the suction fluid passage C is opened near the outer peripheral edge of the bottom surface 11.

  The first piston 51 is a metal part having a circular cross section disposed concentrically with the central axis of the reservoir hole 10, and the outer diameter of the first piston 51 is smaller than the inner diameter of the reservoir hole 10. A reservoir chamber 12 is defined between the first piston 51 and the bottom surface 11 of the reservoir hole 10.

The first piston 51 is fitted with a seal member 51d which is an annular rubber part. The inner peripheral edge of the seal member 51d is fitted in a seal groove 51c formed on the outer peripheral surface of the first piston 51.
The outer peripheral edge of the seal member 51 d contacts the inner peripheral surface of the reservoir hole 10, so that the space between the outer peripheral surface of the first piston 51 and the inner peripheral surface of the reservoir hole 10 is liquid-tightly sealed. The first piston 51 is slidable in the axial direction with respect to the inner peripheral surface of the reservoir hole 10.

  In the first piston 51, an accommodating portion 51e, which is a cylindrical recess, is formed at the center of the tip surface 51a (the upper surface in FIG. 2). Furthermore, a spring receiving portion 51g, which is a cylindrical recess, is formed at the center of the bottom surface 51f of the housing portion 51e.

  The second piston 52 is a metal part having a circular cross section disposed concentrically with the central axis of the first piston 51, and is accommodated in the accommodating portion 51e. The front end surface 52a (the upper surface in FIG. 2) of the second piston 52 and the front end surface 51a of the first piston 51 are arranged on the same plane.

The second piston 52 is fitted with a seal member 52d which is an annular rubber part. The inner peripheral edge of the seal member 52d is fitted in a seal groove 52c formed on the outer peripheral surface of the second piston 52.
The outer peripheral edge portion of the seal member 52d is in contact with the inner peripheral surface of the accommodating portion 51e, so that the space between the outer peripheral surface of the second piston 52 and the inner peripheral surface of the accommodating portion 51e is liquid-tightly sealed. The second piston 52 is slidable in the axial direction with respect to the inner peripheral surface of the housing portion 51e.

  A contact member 55, which is a bar-shaped metal part, projects from the center of the front end surface 52a of the second piston 52. The base end portion 55 b of the contact member 55 is fitted in a mounting hole 52 e formed in the center portion of the front end surface 52 a of the second piston 52, and the front end portion 55 a is opened in the bottom surface 11 of the reservoir hole 10. It is inserted into the hole 15.

The first elastic member 53 is a coil spring interposed between the first piston 51 and the lid member 110.
The distal end portion 53 a of the first elastic member 53 is in contact with the proximal end surface 51 b (the lower surface in FIG. 2) of the first piston 51. Further, the base end portion 53 b of the first elastic member 53 is in contact with the inner surface of the lid member 110. The spring support portion 110 a of the lid member 110 is inserted into the proximal end opening of the first elastic member 53, and the first elastic member 53 is positioned at the central portion of the reservoir hole 10.

The second elastic member 54 is a coil spring interposed between the first piston 51 and the second piston 52.
The distal end portion 54 a of the second elastic member 54 is in contact with the proximal end surface 52 b (the lower surface in FIG. 2) of the second piston 52. Further, the base end portion 54b of the second elastic member 54 is in contact with the bottom surface 51h of the spring receiving portion 51g. When the base end portion 54b of the second elastic member 54 enters the spring receiving portion 51g, the second elastic member 54 is positioned at the center of the housing portion 51e.

The suction valve 4 includes a valve body housing hole 15 formed in the base body 100 and a valve body 41 housed in the valve body housing hole 15.
A third elastic member 43 for the valve body 41 that biases the valve body 41 toward the reservoir hole 10 is provided in the valve body accommodation hole 15.

The valve body accommodation hole 15 is a bottomed cylindrical hole that opens to the bottom surface 11 of the reservoir hole 10. The central axis of the valve body accommodating hole 15 and the central axis of the reservoir hole 10 are arranged on the same axis.
Further, an upstream liquid path C1 of the suction liquid path C is opened at the center of the bottom surface 16 of the valve body accommodation hole 15.

In the valve body housing hole 15, a cylindrical member 44 is fitted into an end of the reservoir hole 10 on the bottom surface 11 side.
The cylindrical member 44 is a metal part in which the communication liquid path 44a penetrates in the axial direction. The valve body accommodation hole 15 and the reservoir chamber 12 communicate with each other through the communication liquid path 44a.
A valve seat surface 44b whose diameter increases in a funnel shape toward the bottom surface 16 side of the valve body housing hole 15 is formed on the distal end surface of the cylindrical member 44, and a communication liquid path 44a is formed at the center of the valve seat surface 44b. It is open.
A contact member 55 projecting from the tip end surface 52a of the second piston 52 is inserted into the communication liquid passage 44a, and the brake pedal BP (see FIG. 1) is not depressed (state shown in FIG. 2). , The tip end portion 55 a of the contact member 55 is in contact with the valve body 41.

  The valve body 41 is a spherical metal component housed in the valve body housing hole 15. The diameter of the valve body 41 is formed larger than the inner diameter of the communication liquid passage 44a. And when the valve body 41 contact | abuts to the valve seat surface 44b, the opening part of the communicating liquid path 44a is sealed, and the suction valve 4 will be in a valve closing state (refer FIG. 4).

The third elastic member 43 is a coil spring interposed between the bottom surface 16 of the valve body accommodation hole 15 and the valve body 41.
The third elastic member 43 has a function of urging the valve body 41 toward the reservoir hole 10 so as to surely contact the valve seat surface 44b. Further, the third elastic member 43 has a function of stabilizing the valve body 41 at the center portion of the valve body housing hole 15, and in particular, can stabilize the valve body 41 that is not in contact with the valve seat surface 44b. it can.

  In the suction valve 4 and the reservoir 5 of the present embodiment, the spring constant of the second elastic member 54 is set larger than the spring constant of the third elastic member 43 and smaller than the spring constant of the first elastic member 53. Has been.

Therefore, as shown in FIG. 2, when the brake pedal BP (see FIG. 1) is not depressed, the force (F4, F5) of the first elastic member 53 and the second elastic member 54 is added ( F4 + F5) is larger than the elastic force (F2) of the third elastic member, so the first piston 51 and the second piston 52 are pushed into the bottom surface 11 side of the reservoir hole 10, and the third elastic member 43 is most compressed. It will be in the state.
In this state, the valve element 41 is opened largely apart from the valve seat surface 44b, and the reservoir chamber 12 is formed between the pistons 51 and 52 and the bottom surface 11 of the reservoir hole 10, and the upstream liquid passage C1 is formed. It communicates with the downstream liquid passage C <b> 2 via the valve body accommodation hole 15 and the reservoir chamber 12.

Further, as shown in FIG. 3, when the brake fluid pressure is transmitted to the valve body accommodating hole 15 and the reservoir chamber 12 in accordance with the operation of the brake pedal BP (see FIG. 1), the first piston 51 and the second piston The force (F2 + F8) obtained by adding the force (F8) for pushing 52 to the opening 10a side of the reservoir hole 10 and the elastic force (F2) of the third elastic member 43 is the first elastic member 53 and the second elasticity. It becomes larger than the total force (F4 + F5) of the elastic force (F5, F4) of the member 54.
At this time, since the spring constant of the second elastic member 54 is much smaller than the spring constant of the first elastic member 53, only the second piston 52 precedes the first piston 51 and the opening 10 a of the reservoir hole 10. Stroke to the side.

  As shown in FIG. 2, the stroke amount L1 until the valve element 41 contacts the valve seat surface 44b is set larger than the stroke amount L2 until the second piston 52 contacts the bottom surface 51f of the housing portion 51e. Has been. As a result, as shown in FIG. 3, even when the second piston 52 is in contact with the bottom surface 51f of the housing portion 51e (the second piston 52 is in a full stroke), the valve element 41 is in contact with the valve seat surface 44b. It is configured not to.

When the brake fluid pressure in the upstream fluid passage C1 and the reservoir chamber 12 further increases after the second piston 52 has made a full stroke, the force that pushes the pistons 51 and 52 and the resilience of the third elastic member 43 are increased. The combined force (F2 + F8) is further greater than the combined force (F4 + F5) of the elastic forces of the first elastic member 53 and the second elastic member 54 described above.
As a result, the first piston 51 strokes toward the opening 10a side of the reservoir hole 10, the second piston 52 strokes in conjunction with the first piston 51, and the valve body 41 moves toward the communication liquid path 44a. As a result, as shown in FIG. 4, the valve body 41 abuts on the valve seat surface 44b to seal the communication liquid path 44a.

  Further, in a state where the valve body 41 seals the communication fluid path 44a, the brake fluid pressure transmitted to the valve body housing hole 15 in accordance with the operation of the brake pedal BP (see FIG. 1) causes the valve body 41 to communicate with the communication fluid path. 44a side pushing force (F1), the brake fluid pressure of the reservoir chamber 12 pushes the first piston 51 and the second piston 52 toward the opening 10a side of the reservoir hole 10 (F8), and the third elastic member 43 The total force (F1 + F2 + F8) of the elastic force (F2) is the elastic force (F5, F4) of the first elastic member 53 and the second elastic member 54, and the brake fluid pressure in the reservoir chamber 12 is the valve body 41. Is larger than the force (F4 + F5 + F7) obtained by adding the force (F7) that pushes the valve body accommodating hole 15 toward the bottom surface 16 side, the state where the valve body 41 seals the communication liquid path 44a is maintained.

Further, as shown in FIG. 5, when the reservoir chamber 12 becomes negative pressure in a state where the valve body 41 seals the communication liquid path 44 a, the first elastic member 53 and the second elastic member 54 are elastic. The force (F3 + F4 + F5), which is the sum of the force (F5, F4) and the force (F3) by which the first piston 51 and the second piston 52 are attracted to the bottom surface 11 side of the reservoir hole 10 by negative pressure, 15 is a sum of the brake fluid pressure (F1) in 15, the elastic force (F2) of the third elastic member 43, and the force (F6) that the valve element 41 is pressed against the valve seat surface 44b by the negative pressure ( The spring constants of the elastic members 53, 54, 43 are set so as to be larger than (F1 + F2 + F6).
Thus, since the spring constant of each elastic member 53, 54, 43 is set, when the reservoir chamber 12 becomes negative pressure with the suction valve 4 closed, the first piston 51 and the second piston The piston 52 strokes toward the bottom surface 11 of the reservoir hole 10, and the valve body 41 is pushed by the contact member 55 and is separated from the valve seat surface 44a.

  Next, the operation of the intake valve 4 and the reservoir 5 when normal brake control, antilock brake control, and behavior stabilization control are executed in the vehicle brake hydraulic pressure control device U of the present embodiment will be described.

(Normal brake control)
As shown in FIG. 2, when the intake valve 4 is opened, the brake pedal BP (see FIG. 1) is depressed, and the brake fluid pressure generated in the reservoir chamber 12 is applied to the first piston 51 and the second piston 52. When it acts, the second piston 52 strokes ahead of the first piston 51 as shown in FIG. Furthermore, after the second piston 52 has made a full stroke, as shown in FIG. 4, the first piston 51 makes a stroke, and the valve body 41 seals the communication liquid passage 44a, so that the intake valve 4 is in a closed state. Become.

(Anti-lock brake control)
When the brake pedal BP (see FIG. 1) is depressed and the intake valve 4 is closed as shown in FIG. 4, the anti-lock brake control is executed and the brake hydraulic pressure acting on the wheel cylinder W shown in FIG. When the pressure is reduced, the brake fluid in the wheel fluid passage B flows from the open passage E through the downstream fluid passage C2 into the reservoir chamber 12 shown in FIG. As a result, the first piston 51 strokes toward the opening 10 a side of the reservoir hole 10, and the brake fluid is stored in the reservoir chamber 12.

(Behavior stabilization control)
As shown in FIG. 2, when the behavior stabilization control is executed in a state where the intake valve 4 is opened and the pump 6 (see FIG. 1) is operated, the brake fluid in the upstream fluid path C <b> 1 passes through the intake valve 4. As a result, the brake fluid in the reservoir chamber 12 and the downstream fluid passage C2 is sucked into the pump 6, and the brake fluid is discharged from the pump 6 into the discharge fluid passage D (see FIG. 1).

When the brake pedal BP (see FIG. 1) is depressed and the suction valve 4 is closed as shown in FIG. 5, the behavior stabilization control is executed, and the pump 6 (see FIG. 1) is activated. 12 and the brake fluid in the downstream fluid passage C2 are sucked into the pump 6, and the reservoir chamber 12 becomes negative pressure.
When the reservoir chamber 12 becomes negative pressure, the first piston 51 and the second piston 52 are brought into contact with the bottom surface 11 of the reservoir hole 10 by the elastic force (F5, F4) of the first elastic member 53 and the second elastic member 54 and the negative pressure. The force (F3 + F4 + F5), which is the sum of the force (F3) attracted to the side, is generated by the brake fluid pressure (F1) of the valve body housing hole 15, the elastic force (F2) of the third elastic member 43, and the negative pressure. Since the spring constants of the elastic members 53, 54, and 43 are set to be larger than the force (F1 + F2 + F6) obtained by adding the force (F6) that the valve body 41 is pressed against the valve seat surface 44b, the first The one piston 51 and the second piston 52 are stroked toward the bottom surface 11 of the reservoir hole 10, the valve body 41 is pushed by the contact member 55 and separated from the valve seat surface 44a, and the intake valve 4 is opened. .

As a result, the brake fluid in the upstream fluid passage C1 is sucked into the reservoir chamber 12 and the downstream fluid passage C2 via the suction valve 4, and the brake fluid in the reservoir chamber 12 and the downstream fluid passage C2 is sucked into the pump 6. 6 is discharged into the discharge liquid passage D (see FIG. 1).
In the suction valve 4 of the present embodiment, the force (F3) that the first piston 51 and the second piston 52 are attracted to the bottom surface 11 side of the reservoir hole 10 by the negative pressure and the elastic force (F4) of the second elastic member 54. Since the valve element 41 is pushed out in a direction away from the communication liquid path 44a with the force applied by the elastic force (F5) of the first elastic member 53, the suction valve 4 can be reliably opened.

  In the vehicle brake hydraulic pressure control device U as described above, as shown in FIG. 3, the second piston 52 strokes ahead of the first piston 51 as the brake pedal BP (see FIG. 1) is depressed. The valve body 41 moves in the valve closing direction in conjunction with the second piston 52. At this time, after the second piston 52 has made a full stroke, the first piston 51 makes a stroke, but since the second piston 52 makes a full stroke and the first piston 51 hardly makes a stroke, the volume change in the reservoir hole 10 is reduced. can do. Thus, since the volume change in the reservoir hole 10 becomes small with respect to the movement amount of the valve body 41 in the valve closing direction, the invalid stroke of the brake pedal BP can be made small.

  Further, since the volume change in the reservoir hole 10 when the valve body 41 moves can be reduced, even when the interval between the valve body 41 and the communication liquid path 44a is set to be equal to that of the conventional suction valve, The invalid stroke of the brake pedal BP can be reduced while ensuring the response when the brake fluid pressure is increased by the pump 6 (see FIG. 1).

  In the vehicular brake hydraulic pressure control device U, as shown in FIG. 2, the second piston 52 is housed in the housing portion 51 e that is a recess formed in the first piston 51, and therefore the second piston 52 is placed in the first piston 52. The piston 51 can be stabilized with a simple configuration. Further, since the size of the first piston 51 in the radial direction can be sufficiently secured, the slidability of the first piston 51 with respect to the reservoir hole 10 can be maintained equal to the piston of the conventional reservoir.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
For example, in this embodiment, as shown in FIG. 4, after the second piston 52 has made a full stroke, the valve body 41 seals the communication liquid passage 44a by the first piston 51 making a stroke. When the brake pedal BP (see FIG. 1) is depressed and the suction valve 4 is closed, the behavior of the behavior stabilization control is executed so that the suction member 4 can be opened. , 54, 43, and the pressure receiving area of each piston 51, 52, and only the second piston 52 is stroked so that the valve body 41 seals the communication liquid passage 44a. Also good.

  In the present embodiment, as shown in FIG. 2, the second piston 52 is accommodated in the accommodating portion 51 e that is a recess formed in the first piston 51, but the front end surface 51 a of the first piston 51 is flat. The second piston 52 and the first piston 51 may be arranged side by side in the axial direction of the reservoir hole 10.

  Moreover, in this embodiment, although each elastic member 53,54,43 is comprised by the coil spring, the structure is not limited, For example, you may use a leaf | plate spring and a disc spring.

  Moreover, in this embodiment, although the 1st piston 51 and the 2nd piston 52 are formed with the metal, the structure is not limited, For example, you may use resin.

2 Inlet valve 3 Outlet valve 4 Suction valve 5 Reservoir 6 Pump 10 Reservoir hole 12 Reservoir chamber 15 Valve body accommodation hole 41 Valve body 43 Third elastic member 44a Communication fluid passage 44b Valve seat surface 51 First piston 51e Accommodation part 51g Receiving part 52 Second piston 53 First elastic member 54 Second elastic member 55 Contact member 100 Base A Output fluid passage B Wheel fluid passage BP Brake pedal C Suction fluid passage C1 Upstream fluid passage C2 Downstream fluid passage E Open passage FR, FL, RR, RL Wheel brake K1, K2 Brake output system M Master cylinder U Brake fluid pressure control device for vehicle V Control valve means W Wheel cylinder

Claims (6)

A base body on which a liquid path for connecting the master cylinder and the wheel cylinder is formed;
Control means for switching to at least a state of increasing and reducing a brake fluid pressure acting on the wheel cylinder;
A reservoir for storing brake fluid released from the control means;
A pump for sucking the brake fluid stored in the reservoir;
A brake hydraulic pressure control device for a vehicle, comprising: a suction valve provided in an suction fluid path that communicates with an output fluid path that communicates the master cylinder and the control means;
The reservoir is
A bottomed reservoir hole formed in the substrate;
A first piston movably accommodated in the reservoir hole;
A second piston movably provided with respect to the first piston;
An elastic member for the first piston that urges the first piston toward the bottom surface side of the reservoir hole,
The intake valve is
A valve body accommodation hole formed in the base;
A valve body housed in the valve body housing hole,
The base is formed with a communication liquid path having one end opened on the valve seat surface of the valve body housing hole and the other end opened on the bottom surface of the reservoir hole,
The second piston is in contact with the valve body through the communication liquid path,
When the brake fluid pressure is applied to the first piston and the second piston in accordance with the operation of the brake operator, the second piston is configured to stroke in advance of the first piston. A brake fluid pressure control device for a vehicle.   After the second piston has made a full stroke with respect to the first piston, the valve body is configured to seal the communication liquid path by the first piston making a stroke. The brake fluid pressure control device for a vehicle according to claim 1. Between the first piston and the second piston, an elastic member for the second piston that urges the second piston toward the bottom surface side of the reservoir hole is interposed,
3. The vehicular brake hydraulic pressure control device according to claim 2, wherein a spring constant of the elastic member for the second piston is set smaller than a spring constant of the elastic member for the first piston.   In a state where the valve body seals the communication liquid path, when the reservoir chamber formed between the bottom surface of the reservoir hole and the first piston and the second piston becomes negative pressure, the first piston 4. The vehicle brake fluid according to claim 3, wherein the second piston strokes toward a bottom surface side of the reservoir hole, and the valve body is pushed by the second piston and separated from the communication fluid path. Pressure control device.   5. The vehicular brake hydraulic pressure control device according to claim 1, wherein the second piston is housed in a housing portion formed in the first piston. 6.   The vehicular brake hydraulic pressure control device according to claim 5, wherein the housing portion is a recess formed in the first piston.

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