JP3169372B2 - Pressure control valve for vehicle brake system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control valve used in a vehicle brake device and capable of continuously controlling a brake pressure supplied to a wheel cylinder.

[Conventional technology]

Conventionally, for example, in a proportional electromagnetic pressure regulating valve described in Japanese Patent Application Laid-Open No. 1-178062, an input port leading to a hydraulic pump, an output port leading to a wheel cylinder, and a release port leading to a reservoir are provided in a housing, A spool for switching the communication state of these ports in accordance with the movement of the port is slidably disposed in the housing. The spool is configured to receive the thrust by the linear solenoid disposed in the housing and the hydraulic pressure by the brake oil pressure of the wheel cylinder, and switch the communication state by the resultant force.
With this configuration, the brake hydraulic pressure of the wheel cylinder
Control can be performed in proportion to the amount of electricity input to the linear solenoid.

[Problem to be Solved by the Invention] However, in the above-mentioned conventional example, a brake pressure proportional to the amount of electricity input to the linear solenoid is generated in the wheel cylinder. Therefore, there is a problem that the brake hydraulic pressure is not supplied to the wheel cylinder unless an electric signal is given to the linear solenoid. In other words, if an electrical failure of the linear solenoid (such as a disconnection of the solenoid) or a failure such as a disconnection of the electrical signal transmission system occurs, it becomes impossible to input an electrical signal to the linear solenoid, and normal braking performance is secured. There is a problem that can not be.

The present invention has been made in view of the above points, and continuously controls a brake pressure generated in a wheel cylinder by an input electric signal, and also controls a transmission system of the electric signal such as disconnection. It is an object of the present invention to provide a pressure control valve of a vehicle brake device that can ensure normal braking performance even when a failure occurs.

[Means for solving the problem]

In order to solve the above object, a pressure control valve of a vehicle brake device according to the present invention continuously controls a brake pressure supplied from a pressure source to a wheel cylinder within a range equal to or less than the pressure of the pressure source. A vehicle brake pressure control valve, comprising: a pressure medium flowing out of the wheel cylinder from a first position communicating the pressure source with the wheel cylinder, through a second position holding the brake pressure of the wheel cylinder. A sliding member that slides up to a third position that connects the reservoir that stores the pressure and the wheel cylinder; and a pressure source and the wheel cylinder that are formed on a part of the sliding member and that are connected to the first cylinder. A first flow path communicating at the time of the position, and a second flow formed at a part of the sliding member and communicating the reservoir and the wheel cylinder at the third position. A path, formed on a part of the sliding member, receiving the brake pressure of the wheel cylinder alone without affecting the supply pressure of the pressure source, and applying the sliding member in the direction of the third position. A pressure receiving portion for generating a first urging force, and a second urging force for generating an electromagnetic force when an electric signal is input, and urging the sliding member in the third position direction by the electromagnetic force. An electromagnetic force generating means for generating a force; a biasing means for constantly applying a third biasing force to the sliding member in the first position direction that is greater than a first biasing force generated by the pressure receiving portion; When the moving member is at the first position, the third flow path that connects the wheel cylinder to the reservoir is shut off, and the sliding member slides from the first position to the third position. And valve means for opening the third flow path. The second urging force is changed by a change in a signal, and the sliding member slides so as to balance a force obtained by subtracting the third urging force from the second urging force and the first urging force. And increasing the brake pressure of the wheel cylinder by communicating with the first flow path, or reducing the pressure by communicating with the second flow path and communicating with the third flow path. , And in order to ensure normal braking performance, the state is in the first position when the electromagnetic force is not generated, and the sliding member is in the first position. In some cases, the valve means blocks the third flow path.

[Action]

According to the above configuration, when an electric signal is not input to the electromagnetic force generating means, the force acting on the sliding member is the first urging force by the brake pressure of the wheel cylinder and the third urging force by the urging means. Becomes Here, since the third urging force is set to be larger than the first urging force, the sliding member moves to the first position and communicates the pressure source with the wheel cylinder.

On the other hand, when the electric signal is input to the electromagnetic force generating means, the sliding member receives the second force by the electromagnetic force generating means in addition to the above-mentioned force.
The urging force acts. At this time, the sliding member moves to a position where these three forces are balanced.
When it is out of position, a fluctuation in the brake pressure of the wheel cylinder occurs. The first biasing force fluctuates due to the fluctuation of the brake pressure, and the sliding member moves to the second position, so that the three forces are balanced. That is, since the brake pressure of the wheel cylinder is determined according to the electric signal input to the electromagnetic force generating means, the brake pressure of the wheel cylinder can be continuously controlled by the value of the electric signal.

〔Example〕

Hereinafter, a first embodiment of a pressure control valve according to the present invention will be described with reference to the drawings.

FIG. 1 shows the structure of a pressure control valve according to the present embodiment and the configuration of a hydraulic system for one wheel of an anti-skid control device using the pressure control valve.

In FIG. 1, 1 is a pressure control valve, 23 is a master cylinder, 24 is a brake pedal, 27 is a wheel cylinder of a wheel 34, 30 is a reservoir, and 31 is a pump. Master cylinder
The pipe 23 communicates with the input port 14a of the pressure control valve 1 through a pipe 25, and the wheel cylinder 27 communicates with the output port 14b through a pipe 26. The return port 14c of the pressure control valve 1 is connected to a reservoir 30 by a pipe 29, and the brake fluid stored in the reservoir 30 is
The water is pumped up by the pump 31 and returned to the master cylinder 23 via the pipe 32.

The pressure control valve 1 includes a cup-shaped housing 2 made of a magnetic material, and the housing 2 is mounted on the housing 14 by bolts (not shown). In the housing 2, a resin-molded electromagnetic coil 3, a plate 6 made of a magnetic material, a non-magnetic material cylindrical body 28 brazed to the plate 6, and a magnetic material core 5 are fixed. Further, inside the housing 14, the cylinder 10, the cap 12
A stepped spool 7 (φD ₁ > φD ₂ ) is slidably mounted inside the cylinder 10.

The stepped spool 7 is formed with two slit portions 7a and 7b, and one of the slit portions 7a and 7b is
Through the flow paths 10a and 10b formed in the 10, the input port 14a
And the output port 14b. A pressure chamber 33 is formed at the end of the flow path 10b on the stepped spool 7 side.
The brake pressure of the wheel cylinder 27 is introduced to 33.
A concave portion 7c is formed in the stepped spool 7 so as to face the pressure chamber 33. With the concave portion 7c as a boundary, a diameter φD ₁
Are formed larger than the diameter φD on the left side. The output port 14b and the return port 14c communicate with each other through the flow path 10b, the other slit 7b, the chamber 36 communicating with the slit 7b, and the flow path 12a formed in the cap 12. Room 3
6 communicates with the chamber 35 through a flow path 10c formed in the cylinder 10, and the same pressure always acts on the two chambers 35 and 36.

A spring 8 is attached to the core 5 so as to urge the stepped spool 7 leftward in the figure. A cut valve 11 is inserted into the left end of the stepped spool 7 in the figure, and the communication between the chamber 36 and the flow path 12a is cut off by the pressing force of the spring 8. Further, the cut valve 11 receives the force of the spring 13 from the left side in the drawing (however, the spring force of the spring 13 is set smaller than the spring force of the spring 8), and the cut valve 11 is cut when the stepped spool 7 moves to the right. The valve 11 simultaneously moves to the right while being pressed against the stepped spool 7, so that the chamber 36 communicates with the flow path 12a.

A ring 9 made of a non-magnetic material is fixed to the core 5. When the stepped spool 7 moves rightward in the figure by the electromagnetic force of the electromagnetic coil 3, the ring 9 comes into contact with the ring 9 and comes into contact with the core 5. I try not to. This is the stepped spool 7
If the core 5 comes into contact with the core 5, the stepped spool 7 remains in the core 5 due to residual magnetism even after the electromagnetic force of the electromagnetic coil 3 is extinguished.
This is because it is still bonded to the slab. Further, by forming the cylindrical body 28 from a non-magnetic material, a magnetic path is formed by the electromagnetic coil 3, the core 5, the stepped spool 7, and the plate 6, and the electromagnetic force of the electromagnetic coil 3 is effectively applied to the stepped spool 7. To work. In addition, 15, 16, 17, 18
Is an O-ring, and 19, 20, 21, and 22 are backup rings.

The wheel 34 is provided with a wheel speed sensor 37 that generates a pulse signal in accordance with the rotation speed of the wheel 34. Further, the brake pedal 38 is provided with a brake switch 38 which is turned ON only when the brake pedal 24 is depressed. These output signals are sent to an electronic control unit (ECU) 3
The ECU 39 calculates the wheel speed, the locking tendency of the wheels, and the like based on these signals, and outputs a drive signal to the electromagnetic coil 3 of the pressure control valve 1 to adjust the brake pressure of the wheel cylinder 27. I do.

 Next, the operation of this embodiment will be described with reference to FIG.

(I) During normal braking During normal braking, no electromagnetic force is generated by the electromagnetic coil 3 and the stepped spool 7 and the cut valve 11
Is pressed leftward in the figure by the spring 8,
The flow path 12a leading to the return port 14c is shut off.
At this time, the brake pressure of the master cylinder 23 generated when the brake pedal 24 is depressed
Input port 14a, flow path 10a, slit portion 7a of stepped spool 7
Through the passage 10b, the output port 14b, and the pipe 26 to the wheel cylinder 27. In this case, the other slit portion of the stepped spool 7
Although 7b is not in direct communication with the pressure chamber 33, the brake fluid leaks through the clearance for sliding the stepped spool 7 with respect to the cylinder 10. Therefore, the pressure inside the pressure control valve 1 is equal to the brake pressure of the wheel cylinder 27. However, at this time, the flow path 12a leading to the reservoir 30 is surely shut off by the cut valve 11, so that the brake fluid does not leak to the reservoir 30.

(Ii) At the time of anti-skid control When the locking tendency of the wheels 34 is increased by the braking operation during traveling, the anti-skid control is started, and the brake pressure of the wheel cylinder 27 is adjusted by the pressure control valve 1. When adjusting the brake pressure of the wheel cylinder 27,
The electromagnetic coil 3 is excited, and the stepped spool 7 moves rightward in the figure by the electromagnetic attraction force Fc. With the movement of the stepped spool 7, the cut valve 11 also moves rightward by being pushed by the spring 13, and the flow path 1 communicates with the return port 14c.
2a becomes open. As a result, the chamber 36 communicates with the reservoir 30, the pressure in the chamber 36 and the chamber 35 communicating with the chamber 36 via the flow path 10c becomes zero, and the brake pressure of the wheel cylinder 27 can be reduced.

At this time, the brake pressure of the wheel cylinder 27 (that is, the pressure of the pressure chamber 33) is adjusted as follows.

Stepped spool 7, and the boundary of the recess 7c facing the pressure chamber 33, the right side of the diameter [phi] D ₁ is larger than the diameter [phi] D ₂ on the left side. Therefore, the cross-sectional area difference A = (D ₁ ² −D ₂ ² ) · π
Since the pressure introduced into the pressure chamber 33 (ie, the brake pressure Pw / c of the wheel cylinder 27) acts on / 4, the stepped spool 7 applies a force Fp = Pw / c due to the brake pressure Pw / c of the wheel cylinder 27.・ Take A rightward in the figure. Further, the stepped spool 7 receives the electromagnetic force Fc generated by the electromagnetic coil 3 rightward in the drawing, and the resultant force Fs of the springs 8 and 13 (= spring 8)
(The spring force of the spring 13) is received leftward in the drawing. The spool 7 moves so that these three forces Fp, Fc, Fs become Fp + Fc = Fs, and the brake pressure Pw of the wheel cylinder 27 is increased.
/ c is uniquely determined with respect to the electromagnetic force Fc as in the following equation (1).

Pw / c = (Fs−Fc) / A (1) The stepped spool 7 automatically moves so as to maintain the balance of the equation (1). The operation at this time is shown in FIG. 2 (a). ,
This will be described with reference to (b) and (c).

2 (a), 2 (b) and 2 (c) are enlarged views of the vicinity of the pressure chamber 33 of the pressure control valve 1, and FIG. 2 (a) shows that the brake pressure Pw / c is expressed by the equation (1). (B) when the brake pressure Pw / c in the equation (1) is high, and FIG. 2 (c) when the brake pressure Pw / c in the equation (1) is low. The position of the stepped spool 7 is shown.

That is, when the brake pressure Pw / c satisfies the formula (1), the pressure chamber 33 communicating with the wheel cylinder 27 is directly connected to either of the slits 7a and 7b of the spool 7 as shown in FIG. As a result, the brake pressure Pw / c is kept constant. At this time, although a small amount of brake fluid actually flows through the clearance between the stepped spool 7 and the cylinder 10, the pressure in the pressure chamber 33 is kept constant, and apparently no brake fluid flows. Can be considered.

Here, when the electromagnetic force Fc is increased, the balance of Expression (1) is lost, and the stepped spool 7 moves rightward as shown in FIG. Then, the slit portion 7b communicates with the pressure chamber 33, and the brake fluid in the pressure chamber 33 flows through the slit portion 7b, the chamber 36, and the flow path 12
a, it is discharged to the reservoir 30 through the return port 14c and the pipe 29. Therefore, the brake pressure Pw acting on the pressure chamber 33
/ c is decompressed. As a result, the brake pressure Pw / c decreases, and the force for pushing the stepped spool 7 rightward decreases, so that the stepped spool 7 gradually moves leftward. When the brake pressure Pw / c is reduced until the equation (1) is satisfied, the brake returns to the position shown in FIG. 2A and holds the pressure.

Conversely, if the electromagnetic force Fc is reduced, the stepped spool 7
As shown in FIG. 2 (c), the slit 7a communicates with the pressure chamber 33 in order to move to the left as shown in FIG. As a result, the brake fluid of the master cylinder 23 passes through the slit portion 7a and passes through the pressure chamber 33.
And the brake pressure Pw / c acting on the pressure chamber 33 increases. Since the force for pushing the stepped spool 7 rightward increases due to the increase in the brake pressure Pw / c, the stepped spool 7 gradually moves rightward. When the brake pressure Pw / c is increased until the equation (1) is satisfied, the stepped spool 7 returns to the position shown in FIG. 2A and holds the pressure.

As described above, the brake pressure Pw / c acting on the wheel cylinder 27 can be controlled by the electromagnetic force Fc. Therefore, at the time of anti-skid control, as the locking tendency of the wheel 34 increases, the electromagnetic force Fc increases to decrease the wheel cylinder pressure Pw / c, and conversely, as the locking tendency decreases, the electromagnetic force Fc decreases to decrease the wheel cylinder pressure. Pressure Pw
Control to increase / c. With such control,
The slip ratio of the wheels 34 can be maintained properly.

In this embodiment, the electromagnetic force Fc is controlled by the value of the current flowing through the electromagnetic coil 3. Also, during the anti-lock control, the pump 31 is always driven to
Is returned to the master cylinder 23 side.

In the present embodiment, by performing the above control, the wheels 34
And the brake pressure Pw / c is continuously controlled, so that it is possible to reduce the generation of sound due to a sudden change in pressure and the shock transmitted to the brake pedal. Further, in this embodiment, a cut valve 11 is provided to prevent the brake fluid leaking from the clearance between the stepped spool 7 and the cylinder 10 from leaking into the reservoir 30. The cut valve 11 reliably shuts off the flow path 12 a leading to the reservoir 30 by the spring force of the spring 8 when the electromagnetic coil 3 is not operated (when not energized).

That is, the brake fluid is supplied to the reservoir 30 during normal braking.
Therefore, the brake pressure is not reduced during normal braking, that is, the performance of the normal brake is not reduced. Further, since the brake fluid is discharged to the reservoir 30 by the cut valve 11 only during the antilock control, the pump 31 may be driven only during the antilock control.

Further, in the present embodiment, the relationship between the electromagnetic force Fc and the brake pressure Pw / c of the wheel cylinder 27 is such that when the electromagnetic force Fc is zero as shown in FIG. This is equal to the cylinder pressure, and the brake pressure Pw / c decreases as the electromagnetic force Fc increases. For this reason, even if the electric system of the electromagnetic coil 3 fails and cannot generate electromagnetic force,
Since the brake pressure of 23 acts on the wheel cylinder 27, there is no obstacle to the normal brake.

Next, a second embodiment of the present invention will be described with reference to FIG.

The pressure control valve shown in FIG. 4 is different from the pressure control valve shown in FIG. 1 in that the spool 7 is divided into a spool 7S and an armature 7A, and a cut valve 11 'is arranged between the spool 7S and the spool 7S inside the core 5'. It is downsized by arranging it in a space. In this pressure control valve, when the armature 7A moves rightward due to electromagnetic attraction,
The cut valve 11 'in contact with 7A also moves to the right,
The flow path 12'a leading to the return port opens. With the movement of the armature 7A and the cut valve 11 ', the spool 7S in contact with the cut valve 11' also moves rightward, and the brake pressure of the wheel cylinder is adjusted as in the first embodiment.

Next, a third embodiment of the present invention will be described with reference to FIG.

The pressure control valve shown in FIG. 5 is different from the pressure control valve 1 shown in FIG. 1 in that a spool 7 is connected to a spool 107S and an armature 107A.
And the pressure of the wheel cylinder is spool 107S
To act on one end of the
The spring force by 108 and 113 is applied to the spool 107S and the armature 107.
It is configured to act on A in one direction.

With such a configuration, the pressure control valve according to the present embodiment can reduce the size of the electromagnetic coil 3 and improve the reliability of the brake device, and can further facilitate the processing and manufacture of the pressure control valve. Become.

Hereinafter, the configuration and operation of the pressure control valve according to the present embodiment will be described in detail.

A pressure receiving portion 107T is disposed at one end of the spool 107S, and one end of the pressure receiving portion 107T is exposed to a flow path 116 formed by the housing 114 and the cylinder 110. The brake pressure of the wheel cylinder 27 is introduced into the flow passage 116 through the output port 114b and the pipe 26, and the pressure receiving portion 107T receives a force in the right direction in the drawing by the brake pressure. The force received by the pressure receiving portion 107T acts on the spool 107S, and the spool 107S is urged rightward in the drawing. The spool 107S has
A spring force by the spring 108 acts in a direction opposite to the force from the pressure receiving portion 107T. The spring force of the spring 108 is set larger than the urging force of the brake pressure acting on the spool 107S via the pressure receiving portion 107T, and the spool 107S is normally pressed leftward in the drawing. In such a state, the master cylinder 23 and the wheel cylinder 27 are connected to the pipe 25, the input port 114a, and the spool 107S.
The slits 107a, the flow paths 115 and 116, the output port push 114b, and the pipe 26 communicate with each other to perform a normal braking operation.

Inside the spool 107S, a slit 107b of the spool is provided.
The flow path 109 is formed so as to communicate with the communication hole 136 via the communication hole 136. This flow path 109 communicates with the chamber 135, and also communicates with the flow path 113 which communicates with the return port 114c when the cut valve 111 is opened. The cut valve 111 has a valve body fixed to the armature 107A, and a valve seat 112 is press-fitted into a part of the flow path 113. Reference numeral 120 denotes a rotation stopper, one of which is press-fitted into the cylinder 110, and the other is inserted into the armature 107A with a predetermined clearance so as not to hinder sliding of the armature 107A. The rotation stopper 120 prevents the valve element 111 of the cut valve 111 from being displaced from the valve seat 112 when the armature 107A moves by receiving the electromagnetic force of the electromagnetic coil 103 and moves. .

The spool 107S penetrates through the inside of the armature 107A, and the stepped portion of the end of the spool 107S that contacts the spring 108 is engaged with a part of the armature 107.
Thereby, the electromagnetic coil 103 is excited, and when the armature 107A moves rightward in the drawing due to the electromagnetic attraction force, the armature 107A and the spool 107S move integrally. However, since the urging force of the spring 113 acts on the armature 107A in the left direction in the figure, when the electromagnetic coil 103 is not excited, the armature 107A is pressed to the left direction in the figure.

With this configuration, when the electromagnetic coil 103 is excited, the resultant force of the electromagnetic attraction force of the electromagnetic coil 103 and the urging force of the brake pressure of the wheel cylinder 27 is set at a position where the resultant force balances the urging force of the springs 108 and 113.
A and the spool 107S move. At this time, the spool 107
If the two slits 107a and 107b of S and the flow path 115 are not blocked, the brake pressure of the wheel cylinder 27 is increased or decreased. This change in the brake pressure causes the spool 107S to move, and finally the two slit portions 107a, 107b and the flow path 115 are both shut off (actually, the same amount of brake fluid flows in and out). Stabilizes in position. Therefore, similarly to the first embodiment, the brake pressure of the wheel cylinder 27 is uniquely determined with respect to the electromagnetic force of the electromagnetic coil 103, and can be continuously controlled.

Here, in the pressure control valve 1 according to the first embodiment, when the communication between the chamber 36 and the flow path 12a is cut off, the cut valve 11 exerts a force to the left in the drawing by the brake pressure introduced into the chamber 36. Receive. This is because the flow path .2a communicates with the reservoir, and the portion facing the flow path 12a receives substantially no force, whereas the cut valve 11 has a force on the side in contact with the spool 7. This is because the brake pressure introduced into the chamber 36 acts on the entire surface. Therefore, the spring force of the spring 13 needs to be strong enough to move the cut valve 11 reliably even when high-pressure brake fluid is introduced into the chamber 13. For this reason, the spring force of the spring 8 urging the spool 7 must be correspondingly increased. However, if the spring force of the spring 8 is increased,
A large electromagnetic force is required to move the spool 7 overcoming the spring force, resulting in an increase in the size of the electromagnetic coil 3 or an increase in power consumption in the electromagnetic coil 3.

On the other hand, in the present embodiment, the spring 108
Is only required to be greater than the urging force applied to the spool 107S by the brake pressure of the wheel cylinder 27, and it is not necessary to increase the spring force so much. The spring 113 only needs to be able to simply press the armature 107A to the left in the drawing, so that the spring force may be small even at all. Therefore, spool 107S
Also, since the electromagnetic force for moving the armature 107A may be small, the size of the electromagnetic coil can be reduced, or
Power consumption can be reduced.

Further, according to the present embodiment, even if the spring 108 is damaged, for example, the armature 107A is still pressed to the left by the spring 113, so that the cut valve 111 does not open. Further, even when the spring 113 is broken or when both the spring 108 and the spring 113 are broken, the armature 1
The cut valve is kept closed by the back pressure of 07A. This is because the flow path 113 communicates with the reservoir 30 and the force applied to the valve body facing the flow path 113 is almost zero, while the armature 107A has its entire surface in contact with the spring 113. The reason is that the brake pressure introduced into the chamber 135 acts on the chamber 135.

As described above, in the pressure control valve according to the present embodiment, the cut valve 111 is not opened except when the electromagnetic force of the electromagnetic coil 103 acts. That is, the brake fluid is supplied to the reservoir 30 due to the damage of the springs 108 and 113.
It is possible to reliably prevent the oil from flowing out to the vehicle, and it is possible to improve the reliability of the brake device.

Further, the pressure control valve 1 of the first embodiment is configured such that the right and left diameters are made different from each other with respect to the concave portion 7c of the spool 7, and the brake pressure of the wheel cylinder 27 is received by the difference in cross-sectional area. I have. For this reason, the space in which the spool 7 of the cylinder 10 slides also matches the shape of the spool 7,
It is necessary to make the diameter different. However,
It is difficult to coaxially process and manufacture portions of the spool 7 and the cylinder 10 having different diameters.

On the other hand, in this embodiment, since the spool 107S and the pressure receiving portion 107T are configured separately,
Production can be facilitated.

FIG. 6 shows a configuration of a hydraulic system of an anti-skid control device when a pressure control valve according to the present invention is applied to a vehicle having a hydro booster as a fourth embodiment of the present invention.

In FIG. 6, reference numeral 50 denotes a brake pressure generator provided with a hydro booster 52. Reference numeral 40 denotes an electromagnetic switching valve for switching connection between a port 40a communicating with the pressure control valve, a port 40b communicating with the master cylinder 53, and a port 40c communicating with the hydro booster 52. During anti-skid control,
The electromagnetic switching valve 40 connects the hydraulic booster 52 to the pressure control valve, and supplies the brake fluid necessary for regulating the wheel cylinder pressure from the hydraulic booster 52. Here, the supply pressure from the hydro booster 52 is
The pressure has been adjusted to the equivalent of the brake pressure. The brake fluid discharged from the pressure control valve is returned to the reservoir 54 of the pressure generating unit 50 via the pipe 63.

As described above, the pressure control valve according to the present invention can be used not only for the recirculation type (closed loop type) anti-skid control device as in the first embodiment but also for the open loop type anti-skid control device. . In particular, when the pressure control valve according to the present invention is used in an open loop type anti-skid control device, pressure pulsation does not occur, which is very effective in reducing operation noise and pedal kickback.

In the above embodiment, the control of the electromagnetic force Fc is controlled by the current value applied to the electromagnetic coil. However, the drive signal of the electromagnetic coil is a duty signal as shown in FIG. 8, and its duty ratio t / T (for example, The electromagnetic force Fc can be controlled by controlling 1 msec <T <100 msec).

Hereinafter, an example of the control will be described with reference to the flowchart of FIG.

The flowchart shown in FIG.
s) and for each wheel.

In step 200, the wheel speed Vw is calculated based on the detection signal from the wheel speed sensor 37. In step 210, the wheel acceleration Vw is calculated based on the wheel speed Vw calculated in step 200. In step 220, the vehicle speed Vb is calculated from the wheel speed Vw calculated in step 200. In step 225, based on the vehicle speed Vb calculated in step 220, a reference speed Vs for determining the tendency to lock the wheels is calculated by the following equation.

In _{Vs = K 3 · Vb-K} 4 step 230, the wheel speed Vw computed at step 200-220, using the wheel acceleration Vw and the reference speed Vs, a lock parameters W showing the locking tendency of the wheels by the following formula Calculate.

W = K1 (Vw−Vs) + K2 · Vw In step 235, the absolute value of the lock parameter W calculated in step 230 is compared with a predetermined value A, and the absolute value of the lock parameter W is larger than the predetermined value A. In some cases, the value of the target hydraulic pressure change amount ΔP is calculated by the following equation.

ΔP = K ₅ · W On the other hand, when the absolute value of the lock parameter W is smaller than the predetermined value A, the value of the target oil pressure change amount ΔP is set to zero.
In step 240, using the target hydraulic pressure change amount ΔP calculated in step 230, the wheel cylinder
Calculate the target hydraulic pressure P0 of the 27 brake pressures.

P0 = P0 _(n-1) + [Delta] P Note that P0 _(n-1) is the previously calculated target oil pressure.

In step 250, the drive duty ratio of the drive signal applied to the electromagnetic coil is calculated based on the target oil pressure P0 calculated in step 240. In step 260, it is determined whether or not the target oil pressure P0 calculated this time is equal to the target oil pressure P0 _(n-1) calculated last time. At this time, if it is determined that the two target oil pressures are equal, it means that the absolute value of the lock parameter W calculated in step 230 is smaller than the predetermined value A, that is, the tendency to lock the wheels is small. In this case, the process proceeds to step 270, and the duty cycle T of the drive duty ratio is set to the first duty cycle TH. If it is determined in step 260 that the target hydraulic pressures are different from each other, it means that the locking tendency of the wheels is large, and the process proceeds to step 280, where the duty cycle T of the drive duty ratio is changed to the second duty cycle TC. And Here, the first duty cycle TH is equal to the second duty cycle TC.
It is set shorter than. Thus, when the locking tendency is small and it is not necessary to change the value of the target oil pressure P0, the duty frequency is set high, so that the spool (and the armature) is driven stably by the average current. Therefore, the flow rate of the brake fluid flowing through the clearance between the spool and the cylinder is reduced, and the amount of the brake fluid discharged to the reservoir can be reduced.
When the locking tendency is large and the value of the target oil pressure P0 needs to be changed, the duty frequency is set low, so that the spool (and the armature) is driven while slightly vibrating. Therefore, when the target hydraulic pressure P0 changes, the hysteresis at the time of driving the spool (and the armature) can be reduced. That is, when the spool (and the armature) moves, the resistance is received, and the resistance becomes the largest when the movement of the spool (and the armature) starts. Therefore, when it is necessary to change the target hydraulic pressure P0, the spool (and the armature) is always driven while slightly vibrating. As a result, the resistance can be reduced, so that the hysteresis at the time of driving the spool (and the armature) can be reduced.

In step 290, a drive signal to be given to the electromagnetic coil is output based on the drive duty ratio calculated in step 250 and the duty cycle T set in steps 270 and 280.

Further, in the above-described embodiment, the example in which the pressure control valve of the present invention is applied to the anti-skid control device has been described. However, the pressure control valve of the present invention is not limited to the anti-skid control device, but may be a traction control device or a normal brake. It is also very effective for the distribution of braking force.

〔The invention's effect〕

As described above, according to the pressure control valve of the vehicle brake device of the present invention, the brake pressure generated in the wheel cylinder can be continuously controlled by the input electric signal, and the electric signal transmission system and the like can be controlled. Even if an electrical failure such as disconnection occurs, normal braking performance can be ensured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention, and FIG.
FIGS. 3 (a), 3 (b) and 3 (c) are explanatory views for explaining the operation of the pressure control valve shown in FIG. 1, and FIG. 3 is an electromagnetic force Fc of the pressure control valve shown in FIG. FIG. 4 is a characteristic diagram showing a relationship with pressure, FIG. 4 is a configuration diagram showing a configuration of a second embodiment of the present invention, FIG. 5 is a configuration diagram showing a configuration of a third embodiment of the present invention, and FIG. FIG. 7 is a configuration diagram showing a configuration of a fourth embodiment of the present invention, FIG. 7 is a flowchart showing an example of control when the pressure control valve according to the present invention is duty-driven, and FIG. 8 is a waveform diagram showing a drive signal for duty driving. . 1 ... Pressure control valve, 3 ... Electromagnetic coil, 7 ... Spool, 8 ...
... Spring, 10 ... Cylinder, 11 ... Check valve, 1
3… Spring, 14a… Input port, 14b… Output port, 14c… Return port, 23… Master cylinder, 24…
... brake pedal, 27 ... wheel cylinder, 30 ... reservoir, 31 ... pump, 33 ... pressure chamber.

Continuation of the front page (72) Inventor Hideo Wakata 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (72) Inventor Masahiko 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Nihon Denso Co., Ltd. (72 ) Inventor Takahiro Goto 1-1 1-1 Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-64-12189 (JP, A) JP-A-1-103562 (JP, A) JP-A 3-199790 (JP, A)

Claims (4)

(57) [Claims] 1. A vehicle brake pressure control valve for continuously controlling a brake pressure supplied from a pressure source to a wheel cylinder within a range equal to or lower than a pressure of the pressure source. From a first position communicating with the wheel cylinder to a third position communicating the reservoir that stores the pressure medium flowing out of the wheel cylinder through a second position that holds the brake pressure of the wheel cylinder, and a third position that communicates with the wheel cylinder. A first sliding member which is formed on a part of the first sliding member and which communicates the pressure source with the wheel cylinder at the first position;
A flow path, a second flow path formed in a part of the sliding member, which communicates the reservoir and the wheel cylinder at the third position, and a second flow path formed in a part of the sliding member, A pressure receiving portion that generates a first biasing force that biases the sliding member in the direction of the third position by receiving only the brake pressure of the wheel cylinder without being affected by the supply pressure of the source; When input, an electromagnetic force is generated, and the electromagnetic force is used to urge the sliding member in the third position direction.
Electromagnetic force generating means for generating an urging force, and urging means for constantly applying a third urging force larger than the first urging force generated by the pressure receiving portion to the sliding member in the first position direction. When the sliding member is at the first position, a third flow path that connects the wheel cylinder to the reservoir is shut off, and the sliding member moves from the first position to the third position. Valve means for opening the third flow path when slid, wherein the second urging force is changed by the change of the electric signal, and the third urging force is subtracted from the second urging force. In order to balance the force and the first urging force, the sliding member slides, and the brake pressure of the wheel cylinder is increased by communicating with the first flow path. The pressure is reduced by communicating with the third flow path. And controlling the pressure to a value corresponding to the electric signal, and in order to ensure normal braking performance, in a state where the electromagnetic force is not generated, the state is the first position; and When in the first position,
A pressure control valve for a vehicle brake device, wherein the valve means blocks the third flow path. 2. The pressure generating source according to claim 2, wherein:
A switching member including the first flow path and the second flow path for switching a communication state between a wheel cylinder and a reservoir,
An action member that receives the electromagnetic force generated by the electromagnetic force generation means is formed separately, and when the action member receives the electromagnetic force, the action member urges the switching member and integrally forms the switching member. 2. The pressure control valve according to claim 1, wherein the pressure control valve slides in a third position direction. 3. The system according to claim 1, wherein a target hydraulic pressure of a brake pressure applied to said wheel cylinder is calculated, and a drive duty ratio of a drive signal to said electromagnetic force generating means is controlled according to a change in said target hydraulic pressure. A pressure control valve for a vehicle brake device according to claim 2. 4. The vehicle according to claim 3, wherein the calculation of the target oil pressure is performed based on a target oil pressure change amount based on a parameter relating to a wheel speed, and is executed based on the target oil pressure change amount. Pressure control valve for brake equipment.