JP2576039Y2 - Hydraulic pressure control valve for brake hydraulic pressure control - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure control valve for controlling a brake hydraulic pressure capable of controlling an output hydraulic pressure with respect to a supply hydraulic pressure.

[0002]

2. Description of the Related Art Conventionally, as a hydraulic pressure control valve for controlling brake hydraulic pressure, for example, the one described in Japanese Patent Application Laid-Open No. 4-8767 is known.

This conventional hydraulic pressure control valve for controlling brake hydraulic pressure is incorporated in a brake hydraulic pressure control device for the purpose of controlling the hydraulic pressure supplied to a wheel cylinder with respect to the master cylinder pressure. A spool that regulates the output hydraulic pressure supplied to the wheel cylinder by sliding with the supply hydraulic pressure from the supply source as the hydraulic pressure source, and slides by receiving the master cylinder pressure to press the spool in the output hydraulic pressure increasing direction A solenoid as an actuator for an anti-skid brake system (hereinafter abbreviated as ABS), which is provided in the opposite direction across the spool and presses the spool in the output hydraulic pressure reducing direction; It was equipped with.

[0004]

However, such a conventional hydraulic control valve has a structure in which the master cylinder pressure acts directly on the pilot piston to press the spool, as described above. If the brake pedal is increased while the ABS control for reducing the output hydraulic pressure is being performed, the output hydraulic pressure (wheel cylinder pressure) fluctuates in the increasing direction due to the effect of the master cylinder pressure. There was a problem.

Further, when the brake pedal is suddenly depressed, there is a problem that the output hydraulic pressure overshoots due to the sudden sliding of the pilot piston due to the rapid rise of the master cylinder pressure.

The present invention has been made in view of the above-mentioned conventional problems, and prevents an overshoot of the output hydraulic pressure at the time of sudden braking without reducing the braking force responsiveness in the direction of releasing the brake operation. It is another object of the present invention to provide a hydraulic pressure control valve for controlling brake hydraulic pressure which can suppress fluctuations in output hydraulic pressure due to an increase in the number of steps of a brake pedal during ABS control.

[0007]

In order to achieve the above-mentioned object, in the hydraulic control valve of the present invention, the output hydraulic pressure is controlled by sliding the supply hydraulic pressure from an external hydraulic supply source as a hydraulic pressure source. A spool that regulates pressure, a return spring that urges the spool in a direction to reduce the output hydraulic pressure, a pilot piston that slides by receiving the master cylinder pressure to press the spool in a direction to increase the output hydraulic pressure, and a pilot piston A check valve that is interposed in the master cylinder pressure introduction flow path to prevent the introduction of master cylinder pressure, a constant orifice that bypasses the check valve and communicates with the master cylinder pressure introduction flow path, and is proportional to the control signal. And an actuator that pushes back the pilot piston in a direction to reduce the output hydraulic pressure.

[0008]

According to the hydraulic pressure control valve of the present invention, the spool is pressed and slid in the direction of increasing the output hydraulic pressure in proportion to the master cylinder pressure received by the pilot piston. That is, the spool is arranged at a position where the pressing force of the pilot piston and the urging force of the return spring are balanced, and the output hydraulic pressure is increased in proportion to the received pressure of the pilot piston.

Next, when a control signal is input to the actuator, the actuator acts in the direction of pushing back the pilot piston, whereby the spool is pushed back in the direction of reducing the output hydraulic pressure by the urging force of the return spring. That is, ABS control for reducing the output hydraulic pressure in inverse proportion to the increase in the value of the control signal can be performed.

When the brake pedal is further depressed during the output hydraulic pressure reduction control (at the time of the ABS control) as described above, the check valve is closed by the increase in the master cylinder pressure. Since the increased master cylinder pressure is supplied to the pilot piston while being throttled by the constant orifice, the pilot piston's pressure receiving sensitivity is low, and as a result, the output fluid is increased by increasing the brake pedal depression. Fluctuations in pressure can be reduced.

Further, even in the case of sudden braking, since the increased master cylinder pressure is reduced by the constant orifice, overshoot of the output hydraulic pressure is prevented.

When the brake operation is released, the check valve is opened by reducing the master cylinder pressure.
The braking force can be quickly reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. First Embodiment First, the configuration of the first embodiment will be described.

FIG. 1 is a sectional view showing a hydraulic pressure control valve 7 for controlling brake hydraulic pressure according to a first embodiment of the present invention.
Is a valve body, and a valve hole 11 is formed in the valve body 1. And this valve hole 1
1 includes a hydraulic pressure supply port 11a and a drain port 11b.
Is formed, and an output port 11c is formed at a position between both ports 11a and 11b.

The hydraulic pressure supply port 11a is connected to an external hydraulic pressure supply source 6, and the drain port 11b is
The output port 11c is connected to the drain tank T via the drain side connection port 1b and is at atmospheric pressure.
Is the wheel cylinder 3 of the brake device for each wheel
It is connected to the.

The valve spool 4 is slidably housed in the valve hole 11. The valve spool 4 has an annular communication groove 4a for communicating between the hydraulic pressure supply port 11a and the output port 11c, and the output port 1
An annular communication groove 4b is formed to allow communication between the drain communication port 1c and the drain port 11b, and the two annular communication grooves 4a, 4b are formed.
A throttle land 4c is formed between the output ports 11c so as to overlap with the output port 11c.
Are formed between the variable apertures s and t.

That is, when the valve spool 4 slides to the left in the drawing, the variable throttle s is shut off and the variable throttle t is opened, so that the hydraulic pressure at the output port 11c changes in a direction to increase. When the valve spool 4 slides rightward in the drawing, contrary to the above, the variable throttle s is opened and the variable throttle t is shut off. As a result, the output hydraulic pressure of the output port 11c changes in a decreasing direction.

An ABS solenoid 5 for sliding the valve spool 4 is provided at an outer peripheral position of a right end portion of the valve spool 4 in the drawing by an attraction force generated by energization, and the ABS solenoid 5 is energized. Then, the valve spool 4 is slid rightward in the drawing, and the output port 11 is
The output hydraulic pressure of c is reduced.

Each of the solenoids 5 includes a solenoid body B, a coil K, and a plunger 54.

The solenoid body portion B includes a base 51 fixed to an end face of the valve body 1 by bolts 60b,
An intermediate cylinder 56 fitted and fixed to the base 51;
It consists of a suction member 58 fitted to the intermediate cylinder 56.

The coil section K is composed of a coil 53 for generating a magnetic field, a hobbin 55 made of a non-magnetic material around which the coil 53 is wound, and a coil casing 52 for covering the outer periphery of the hobbin 55. . The coil portion K is detachably mounted on the outer periphery of the solenoid body portion B, and is replaceably attached by a fastening nut 59 screwed to an outer periphery of an end portion of the suction member 58.

In the center of the base 51, a valve hole 1 is provided.
A through hole 57 forming a plunger chamber 62 having a diameter larger than that of
The plunger portion 54 is slidably received in the through hole 57 via the bush 100. The right end surface of the valve spool 4 in the drawing is in contact with the end surface of the plunger portion 54.

The attraction member 58, the coil casing 52, the base 51, the bush 100, and the plunger portion 54 are each made of a magnetic material, and a magnetic loop is formed by these members. It has become. A magnetic leakage portion 61 having a triangular cross section for generating a force for attracting the plunger portion 54 is formed on the inner end surface of the suction member 58.

On the other hand, a back chamber cover 17 forming a back chamber 17a on the end face of the valve spool 4 is fixedly mounted on the left end face of the valve body 1 with bolts 60a. A return spring 4d is interposed in a compressed state between the valve spool 4 and the end face of the valve spool 4 and presses and biases the valve spool 4 rightward in the drawing by the repulsive force. Therefore, when there is no input of the master cylinder pressure, the valve spool 4 is pressed rightward in the drawing, and the output hydraulic pressure of the output port 11c is in the atmospheric pressure state.

A stopper pin 80 is provided in the axial center portion of the inner end face of the back chamber cover 17 so as to protrude toward the end face of the valve spool 4, while the valve spool 4 facing the stopper pin 80 is provided. A piston slide hole 63 communicating with the output port 11c is formed at the axial center of the end face, and a cylindrical reaction force piston 64 is slidably provided in the piston slide hole 63.

On the other hand, a pilot chamber 66 into which a cylindrical pilot piston 65 is slidably inserted is formed at the axial center of the inner end surface of the suction member 58.
A master cylinder pressure introduction port 67 is formed on the outer end face of the master cylinder pressure introduction port 69, and a master cylinder pressure introduction channel 69 communicating between the master cylinder pressure introduction port 67 and the pilot chamber 66.
Is provided with a check valve 30 that allows only the flow from the pilot chamber 66 side.

As shown in an enlarged view of a main part of FIG. 1, the check valve 30 has a valve port 30a communicating between the pilot chamber 66 and the flow path 69, and a spring 30b for connecting the valve port 30a to the master cylinder pressure. The ball valve 30c is urged in the closing direction from the introduction port 67 side.
Reference numeral 70 denotes a ferrule mounted in the master cylinder pressure inlet 67. One end of the spring 30b is supported at the tip end of the ferrule 70.

The valve port 30 with which the ball valve 30c contacts
A constant orifice 31 is formed at the opening edge of “a” so as to constantly communicate between the flow path 69 and the pilot chamber 66.

The master cylinder pressure inlet 67
Are connected to the master cylinder 2.

A stopper pin 42 having a protruding portion abutting on the pilot piston 65 is press-fitted and fixed to the axial center of the end surface of the plunger portion 54 facing the inner end surface of the pilot piston 65.

The back chamber 17a and the plunger chamber 62
Are connected to each other through orifices 12, 12 for preventing damping of the valve spool 4, and are connected to a reservoir tank T via a drain-side connection port 1b.

A drive current from a brake controller 13 is applied to the coil 53 of the solenoid 5, and detection signals from a vehicle speed sensor 18 and a wheel rotation sensor 19 are input to the brake controller 13. You.

Next, the operation of the embodiment will be described.

(A) Non-braking When the brake pedal is not depressed, the master cylinder pressure of the master cylinder 2 at each wheel becomes 0. Therefore, the return spring 4d is set by the hydraulic pressure control valve 7 for controlling the brake hydraulic pressure. The valve spool 4 is pressed and slid in the right direction in the drawing by the force, and the output hydraulic pressure of the output port 11c is O.

Accordingly, the hydraulic pressure supplied to each wheel cylinder 3 is also O, and the brake device is inactive.

(B) During normal braking When the brake pedal is depressed, the master cylinder pressure of the master cylinder 2 rises in accordance with the depressing force. From the pressure introduction port 67 to the flow path 69, the constant orifice 31
The pilot piston 65 receives pressure via the valve port 30a, and presses and slides the pilot piston 65 leftward in the drawing. This pressing force causes the valve spool 4 to resist the set force of the return spring 4d. It is pressed and slid in the left direction of the drawing.
By increasing the output hydraulic pressure of 1c, the supply hydraulic pressure to each wheel cylinder 3 increases.

On the other hand, the output hydraulic pressure of the output port 11c is received by a reaction force piston 64,
Is pressed and slid to the left in the drawing. When the sliding of the reaction force piston 64 is regulated by the stopper pin 80,
The pressure receiving reaction force of the reaction force piston 64 acts on the valve spool 4 as a feedback force, whereby the valve spool 4 is pushed back to the right in the drawing.

That is, the valve spool 4 applies a pressing force of the pilot piston 65 and a pressure receiving reaction force of the reaction force piston 64 +
It is arranged at a position where the set force of the return spring 4d is balanced. In this case, since the pressure receiving cross-sectional area of the pilot piston 65 is larger than the reaction force piston 64, the output hydraulic pressure (W / W) with respect to the master cylinder pressure (M / CYL pressure) as shown in the boosting function characteristic of FIG. / CYL pressure) is increased by the pressure receiving cross-sectional area ratio of the pistons 65 and 64, whereby the master cylinder pressure for the wheel cylinder 3 is increased to a predetermined magnification (about 9 times in the embodiment).
The boosting function (hydraulic pressure booster function) for boosting the depression force of the brake pedal is exerted, and a strong braking force can be obtained.

(C) At the time of sudden braking When the brake pedal is suddenly depressed, the master cylinder 2
The master cylinder pressure rises rapidly, but in the direction of increasing the master cylinder pressure, the check valve 30 is closed, so that the master cylinder pressure is reduced to the pilot chamber 66 by the constant orifice 31 to the pilot chamber 66. Since this is introduced, overshooting of the output hydraulic pressure due to rapid sliding of the pilot piston 65 can be prevented.

When the depressing operation of the brake pedal is released, the master cylinder pressure sharply decreases, but the check valve 30 is opened in the direction of decreasing the master cylinder pressure.
The pilot piston 65 is quickly slid to the right in the drawing due to the set force, so that the braking state of the wheels can be immediately released.

(D) ABS operation During sudden braking or braking on a low μ road such as a snowy road, the frictional resistance of the tire against the road surface becomes smaller than the braking frictional resistance of the wheel by the braking device, causing the tire to slip. Then, the wheels are locked.

Therefore, in the brake controller 13,
The vehicle speed detected by the vehicle speed sensor 18 and the wheel rotation sensor 1
When the slip state of the tire is detected from the wheel rotation speed detected in step 9, a drive current is applied to the ABS solenoid 5 of the brake hydraulic pressure control valve 7 in accordance with the slip amount.

As described above, when the current is applied to the ABS solenoid 5, the suction member 58 and the coil casing 5
2, the base 51, the bush 100, and the plunger portion 54, a magnetic loop is formed, and the plunger portion 54 is moved rightward in the drawing to the magnetic leakage portion 61 having a triangular cross section formed on the inner end surface of the attraction member 58. A suction force for sliding is generated, whereby the valve spool 4 is pushed back to the right in the drawing by the set force of the return spring 4d.

That is, the pressing force of the pilot piston 65 generated by the brake operation, the pressure receiving reaction force of the reaction force piston 64 + the set force of the return spring 4d + the suction force,
The valve spool 4 is disposed at a position where the pressure is balanced, that is, the valve spool 4 is pushed back to the right in the drawing by the suction force, whereby the output hydraulic pressure (supply hydraulic pressure to the wheel cylinder 3) decreases. As the braking force of the wheel decreases, the slip amount of the wheel decreases.

Then, in the brake controller 13,
The detected slip amount is constantly compared with a preset appropriate slip amount (braking force), and the increase / decrease control of the current value applied to the ABS solenoid 5 is controlled so that the detected slip amount becomes an appropriate slip amount. Is performed. That is, FIG.
The master cylinder pressure (M /
The output fluid pressure (W / CYL pressure) characteristics with respect to the CYL pressure can be changed.

At the time of the ABS control, as described above, the master cylinder pressure supplied to the master cylinder pressure inlet 67 is supplied to the pilot chamber 66 while being throttled by the constant orifice 31. It is possible to suppress a change in the output hydraulic pressure due to an increased depression of the brake pedal during control.

As described above, in the present embodiment, the following effects can be obtained.

The throttle action of the constant orifice 31 prevents overshooting of the output hydraulic pressure at the time of sudden braking, and suppresses fluctuations in the output hydraulic pressure due to increased brake pedal depression during ABS control. .

When the brake operation is released, the check valve 30 is opened, and the braking force can be quickly reduced.

Since the hydraulic pressure booster mechanism that exerts a boost function is compactly incorporated in the hydraulic pressure control valve 7, the brake hydraulic pressure control system as a whole can be reduced in weight and size, and the mountability on the vehicle is improved. Get higher.

(Second Embodiment) Next, a hydraulic pressure control valve 7 for controlling brake hydraulic pressure according to a second embodiment will be described. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only different check valve portions will be described.

FIG. 3 is an enlarged sectional view showing the check valve 30 in the hydraulic pressure control valve 7 for controlling brake hydraulic pressure according to the second embodiment of the present invention. As shown in FIG. Ball valve 30c from right side of piston
The pressing pin 65a is formed to protrude toward the direction,
A constant orifice 32 is cut out on the ball valve 30c side.

Therefore, in this embodiment, when the master cylinder pressure is zero, the push pin 65a pushes the ball valve 30c by the pilot piston 65 sliding rightward in the drawing by the set force of the return spring 4d. Valve port 30
a to open the pilot chamber 6 via the valve port 30a at the start of the braking operation.
6, which has the effect of increasing the response of the braking force rise to the braking operation in addition to the effect of the first embodiment.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and even if there is a design change or the like within a range not departing from the gist of the present invention. Included in the invention.

For example, in the embodiment, the solenoid is used as the actuator, but other actuators such as a force motor and a rotary DC conversion type motor can be used.

[0056]

As described above, in the hydraulic pressure control valve of the present invention, a check is provided in the middle of the master cylinder pressure introduction flow passage for the pilot piston to prevent the introduction of the master cylinder pressure. By providing a valve and a constant orifice that bypasses the check valve and communicates with the master cylinder pressure introduction flow path, without reducing the braking force responsiveness in the brake operation release direction,
An effect is obtained that overshooting of the output hydraulic pressure at the time of sudden braking can be prevented, and fluctuation of the output hydraulic pressure due to an increase in the number of steps of the brake pedal during the ABS control can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a hydraulic pressure control valve for controlling brake hydraulic pressure according to a first embodiment of the present invention;

FIG. 2 is a hydraulic pressure characteristic diagram of an embodiment hydraulic pressure control valve.

FIG. 3 is an enlarged sectional view of a main part of a hydraulic pressure control valve for controlling brake hydraulic pressure according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 4 Valve spool 4d Return spring 5 ABS solenoid (actuator) 6 External hydraulic pressure supply source 7 Hydraulic pressure control valve 30 Check valve 31 Constant orifice 32 Constant orifice 65 Pilot piston

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16K 31/12-31/165 F16K 31/36-31/42 B60T 8/40 F16K 31/06 385

Claims (1)

(57) [Scope of request for utility model registration] 1. A spool for adjusting an output hydraulic pressure by sliding the supply hydraulic pressure from an external hydraulic pressure supply source as a hydraulic pressure source, a return spring for urging the spool in a direction to reduce the output hydraulic pressure, A pilot piston that slides by receiving the master cylinder pressure and presses the spool in the direction to increase the output hydraulic pressure, and is interposed in the master cylinder pressure introduction flow passage for the pilot piston and prevents the introduction of the master cylinder pressure A check valve that bypasses the check valve, a constant orifice that communicates with the master cylinder pressure introduction flow path by bypassing the check valve, and an actuator that pushes back the pilot piston in a direction to reduce the output hydraulic pressure in proportion to the control signal. Characteristic hydraulic control valve.