JPH0740337U - Flow control valve for anti-skid control - Google Patents

Abstract

(57) [Abstract] [Purpose] An appropriate pressure increasing speed according to the friction coefficient of the road surface can prevent the extension of the stopping distance on the high μ road surface while eliminating the jerky control feeling on the low μ road surface. Providing flow control valves for skid control. A valve body 19 that opens and closes a flow path that connects between a hydraulic control valve and a wheel cylinder, a spring 20 that urges the valve body 19 in a direction to open the valve body 19, and one of a pressure receiving surface that faces the valve body 20. The master cylinder hydraulic pressure is received on the pressure receiving surface, the wheel cylinder hydraulic pressure is received on the other pressure receiving surface, and when the master cylinder hydraulic pressure is higher than the wheel cylinder hydraulic pressure by the set value or more, the urging force of the spring 20 is resisted. And a piston 18 for operating the valve body 19 in a direction of narrowing the flow path,
The valve body 19 has a first orifice groove 16d and a second orifice groove 16e as a throttle structure that narrows the cross-sectional area of the flow passage in two stages in proportion to the sliding amount of the piston 18, a small diameter first valve portion 19a, and The large-diameter second valve portion 19b is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a flow rate control valve that controls the flow rate of master cylinder liquid supplied to a wheel cylinder in anti-skid control of a vehicle or the like.

[0002]

[Prior art]

 Conventionally, as a flow control valve for anti-skid control, the one described in JP-A-61-282158 is known.

This conventional anti-skid control flow control valve connects between a master cylinder and a hydraulic control valve that opens and closes based on a predetermined condition to increase, maintain, and reduce the wheel cylinder hydraulic pressure. A cut valve, which is provided in the middle of the flow path and opens and closes the flow path that connects between the hydraulic control valve and the master cylinder, and a spring that urges the cut valve to open are opposed to each other. One of the pressure receiving surfaces receives the master cylinder fluid pressure, the other pressure receiving surface receives the wheel cylinder fluid pressure, and if the master cylinder fluid pressure is higher than the wheel cylinder fluid pressure by a preset value or more, The piston that operates the cut valve in the direction that closes the flow path against the urging force of the valve and the master cylinder and the hydraulic control valve that communicate with each other by bypassing the cut valve The structure has a narrowed channel.

That is, in this conventional flow control valve for anti-skid control, when the hydraulic pressure difference before and after the hydraulic control valve is equal to or less than the set value during anti-skid control, a sufficient flow passage cross-sectional area is provided. By ensuring this, an appropriate speed of re-pressurization of the wheel cylinder hydraulic pressure after depressurization is secured, and when the hydraulic pressure difference is equal to or greater than the set value, the flow passage cross-sectional area is reduced to reduce the wheel cylinder pressure after depressurization. It was designed to prevent the rapid re-increase of the hydraulic pressure and thereby improve the accuracy of anti-skid control.

[0005]

[Problems to be solved by the device]

 However, in the conventional flow control valve for anti-skid control, once the cut valve operates as described above, as shown by the chain double-dashed line in FIG. The amount is regulated by the cross-sectional area of the throttle, and the pressure increase rate is uniform under all road surface conditions. Generally, as shown by the dotted line in Fig. 7, the road surface with low friction coefficient ( Since the throttle cross-sectional area is set so that the pressure increase amount will be adjusted to the low μ road surface), the high friction coefficient road surface (hereinafter, high μ road surface) and μ jump (low μ road surface → In a road condition such as a sudden change to a high μ road surface), it takes time to decelerate the vehicle because the required pressure increase rate cannot be obtained.

Contrary to the above, if the throttle cross-sectional area of the cut valve is set so that the pressure increase amount is adjusted to the high μ road surface, the pressure increase speed becomes too fast on the low μ road surface and the control becomes jerky. Becomes

The present invention has been made by paying attention to the above-mentioned conventional problems, and an appropriate pressure increasing speed according to a friction coefficient of a road surface eliminates a jerky control feeling on a low μ road surface while increasing a high level. An object of the present invention is to provide a flow control valve for anti-skid control capable of preventing the extension of the stop distance on the μ road surface.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the flow control valve for anti-skid control of the present invention opens and closes based on a predetermined condition in order to increase / hold / reduce the wheel cylinder hydraulic pressure based on the master cylinder hydraulic pressure. A flow control valve for anti-skid control provided in the middle of the flow path connecting the hydraulic pressure control valve and the wheel cylinder, which opens and closes the flow path connecting the hydraulic pressure control valve and the wheel cylinder. The cut valve to be performed, the urging means for urging the cut valve in the opening direction, and the master cylinder hydraulic pressure on one of the opposing pressure receiving surfaces and the wheel cylinder on the other pressure receiving surface. A movable member that receives hydraulic pressure and operates the cut valve in the direction of narrowing the flow passage against the biasing force of the biasing means when the master cylinder hydraulic pressure is higher than the set value by more than the wheel cylinder hydraulic pressure. The a, the said cut-off valve, and a means is provided with a stop structure to narrow the cross-sectional area of the in proportion to the moving amount of the movable member passage in a plurality of stages.

[0009]

[Action]

 As described above, the flow control valve for anti-skid control of the present invention has the feature that the movable member acts against the urging force of the urging means when the master cylinder hydraulic pressure is higher than the set value by more than the wheel cylinder hydraulic pressure. Operate the cut valve in the direction to throttle. Therefore, after that, the wheel cylinder fluid pressure is gradually re-increased through the narrowed flow path, which prevents the wheel cylinder fluid pressure from rapidly re-increasing after decompression. To be done.

Then, the flow passage is narrowed down in a plurality of stages in proportion to the hydraulic pressure difference between the master cylinder hydraulic pressure and the wheel cylinder hydraulic pressure (movable amount of the movable member). That is, on a low μ road surface where the wheel cylinder hydraulic pressure reduction amount is large and the hydraulic pressure difference is large, the throttle amount of the flow passage becomes large and the re-pressure increase is performed gently, which causes a rapid re-pressure increase. While it is possible to eliminate the jerkiness of the control, on the high μ road surface where the wheel cylinder hydraulic pressure reduction amount is small and the hydraulic pressure difference is small, the throttle amount of the flow passage becomes small and a predetermined pressure increase speed is secured. This can prevent extension of the stopping distance.

[0011]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (First Embodiment) FIG. 2 is an overall view showing a normal state in an antiskid brake system using a flow control valve B for antiskid control of a first embodiment of the present invention, in which 1 is a master. Shows a cylinder. This master cylinder 1 generates brake fluid pressure by operating the brake pedal 2.

The brake fluid pressure generated in the master cylinder 1 is transmitted to the wheel cylinder 4 of the brake device via the main flow path 3 so that the wheel is braked.

In the middle of the main flow path 3, a hydraulic pressure control valve for reducing / holding / increasing the brake hydraulic pressure of the wheel cylinder 4 for preventing wheel lock is formed. A valve 5 and a normally open pressure increasing valve 6 are provided. That is, when both valves 5 and 6 are closed, the hydraulic pressure of the wheel cylinder 4 is maintained, and when the pressure increasing valve 6 is closed and the pressure reducing valve 5 is opened, the hydraulic pressure of the wheel cylinder 4 is drained to the reservoir 7 to reduce the pressure. When the pressure reducing valve 5 is closed and the pressure increasing valve 6 is opened, the brake fluid pressure is supplied to the wheel cylinder 4 to increase the pressure. Each valve 5, 6 is an anti-skid controller (not shown). Is controlled based on a predetermined condition. Reference numeral 8 in the figure is a return check valve.

Next, reference numeral 9 in FIG. 1 denotes a hydraulic pump that transfers the brake fluid stored in the reservoir 7 to a main flow path upstream of both valves 5 and 6 (hereinafter referred to as an upstream main flow path) 3a. The damper chamber 10 and the orifice 11 as pulse pressure damping means are provided on the discharge side. In the figure, 9a and 9b are an inlet check valve and an outlet check valve provided on the suction side and the discharge side of the hydraulic pump 9, respectively.

An anti-skid control flow control valve B is provided in the middle of a main flow path 3b downstream of the valves 5 and 6 (hereinafter referred to as a downstream main flow path) 3b. As shown in detail in FIG. 1, the flow rate control valve B includes a valve unit U, a valve body 13 having a housing hole 12 for housing the valve unit U, and a valve unit housed in the housing hole 12. The valve unit U includes a housing 15, a holder 16, a plug 17, a piston 18, a valve element 19, a spring 20, and a check seal 21. Have

More specifically, the housing 15 has a piston sliding hole 15a formed at the axial center thereof, and a cylindrical portion 15b concentric with the piston sliding hole 15a formed at one end thereof. Further, an annular locking portion 15c is formed so as to project on the outer peripheral surface of the end portion on the side opposite to the tubular portion 15b. The tubular portion 15b is formed with an outer diameter that allows it to be tightly fitted in the large diameter portion 12a of the accommodation hole 12.

The holder 16 has a first communication hole 16a formed at the axial center thereof and communicating with the downstream main flow path 3b, and has one end fitted to the inner peripheral side of the cylindrical portion 15b of the housing 15. A tubular portion 16b forming the first pressure receiving chamber D is formed between the tubular portion 16b and the tubular portion 15b. A second communication hole 16c is formed in the base of the cylindrical portion 16b so as to penetrate the side wall thereof in the radial direction.

A small-diameter valve opening 16f and a large-diameter valve opening 16g are formed at the opening of the first communication hole 16a on the first pressure-receiving chamber D side, and the opening end surface of the small-diameter valve opening 16f and the large-diameter opening are formed. A plurality of first orifice grooves 16d and a second orifice groove 16e, which form a throttle in the scope of claims, are formed in the opening end surface of the valve port 16g in the radial direction. The total cross-sectional area of the second orifice groove 16e is smaller than the total cross-sectional area of the first orifice groove 16d.

The plug 17 is fitted to the outer periphery of an annular locking portion 15c formed at the end of the housing 15 opposite to the tubular portion 15b, and the tip portion thereof is caulked inward. Forms a cylindrical connecting portion 17a that is integrated with the housing 15, and a hollow portion 17b that constitutes the second pressure receiving chamber E and a second pressure receiving chamber E are provided on the upstream main surface on the surface facing the end surface of the housing 15. A radial groove forming a third communication hole 17c for communicating with the flow path 3a is formed. A seal ring 22 is attached to the outer periphery of the plug 17 to seal the gap with the large diameter portion 12a of the accommodation hole 12.

The piston 18 constitutes a movable member within the scope of the claims, and one side thereof is slidably inserted in a piston sliding hole 15 a of the housing 15 while being sealed by a seal ring 23. One end surface receives the hydraulic pressure in the first pressure receiving chamber D (the hydraulic pressure on the downstream main flow path 3 side), and the other end surface receives the hydraulic pressure in the second pressure receiving chamber E (upstream side). The hydraulic pressure on the main channel 3a side is received. Further, on the outer periphery of the middle portion of the piston 18, an annular locking flange portion 18a that restricts sliding in the direction of the plug 17 is formed.

The valve body 19 is integrally formed at the end of the piston 18 on the holder 16 side, and has a large-diameter second valve portion 19b formed in a substantially hemispherical shape on the tip end surface thereof. A small-diameter first valve portion 19a is formed in the central portion of the tip end so as to be able to move back and forth in the axial direction. The small-diameter first valve portion 19a is urged by a spring 19c in a direction projecting outward from the large-diameter second valve portion 19b. Has been done.

The valve body 19 slides in the direction of the holder 16 of the piston 18 so that the small-diameter first valve portion 19 a is first communicated with the first communicating hole of the holder 16 as shown in FIG. 1B. The small-diameter valve opening 16f of 16a is abutted and closed, thereby narrowing the flow path to the total cross-sectional area of the first orifice groove 16d, and finally, as shown in (c) of FIG. The large-diameter second valve portion 19b abuts and closes the large-diameter valve opening 16g, whereby the flow path is further throttled to the total cross-sectional area of the second orifice groove 16e.

That is, the small diameter valve opening 16f and the large diameter valve opening 16g, the first orifice groove 16d and the second orifice groove 16e, the small diameter first valve portion 19a and the large diameter second valve portion 19b, The aperture structure of the range is constructed.

The spring 20 is interposed in a compressed state between the opening end surface of the first communication hole 16a and the locking flange portion 18a of the piston 18 in the first pressure receiving chamber D, and is repulsed by the repulsive force. The urging means constitutes a urging means for urging the piston 18 in a direction to open the first communication hole 16a.

The accommodation hole 12 of the valve body 13 is formed with a first port 12b at the bottom thereof, which communicates the first communication hole 16a with the downstream main flow path 3b on the wheel cylinder 4 side, and an intermediate portion thereof. The diameter portion 12c is formed with a second port 12d for communicating the second communication hole 16c with the downstream main flow passage 3b on both valves 5, 6 side, and the large diameter portion 12a is provided with a third communication hole 17c. A third port 12e that communicates is formed, and the third port 12e communicates with the upstream main flow channel 3a via the pilot flow channel 24. An annular flow passage 12f that connects the first port 12b and the second port 12d (that is, the downstream main flow passage 3b) is formed between the holder 16 and the accommodation hole 12.

The check seal 21 is mounted in an annular groove formed on the outer periphery of the holder 16, and the outer peripheral check valve portion 21 a is in contact with the inner peripheral surface of the small diameter portion 12 g of the accommodating hole 12. The fluid flow in the flow path 12f is allowed from the first port 12b (wheel cylinder 4) to the second port 12d (both valves 5 and 6), but is prevented from flowing in the opposite direction. .

The fixing nut 14 fixes the valve unit U by being screwed into the opening of the accommodation hole 12 in the valve body.

Next, the operation of the embodiment will be described. a) During normal brake operation As shown in FIG. 2, when the brake pedal 2 is stepped on, brake fluid pressure is generated in the master cylinder 1. This brake fluid pressure flows from the upstream main flow passage 3a to the pressure increasing valve 6 and And through the flow rate control valve B of the downstream main flow path 3b, and is transmitted to the wheel cylinder 4 to brake the wheel. That is, normally, the pressure reducing valve 5 is closed and the pressure increasing valve 6 is opened, and the flow rate control valve B, as shown in FIG. 1, has the first communication hole formed by the valve body 19 by the urging force of the spring 20. Since the closed state of 16a is released and the downflow side main flow path 3b is opened, the brake fluid pressure is transmitted to the wheel cylinder 4 via the main flow path 3.

Therefore, since the main flow path 3 is not provided with the orifice, the brake fluid pressure is smoothly transmitted, and a high braking response is obtained. It should be noted that decompression by releasing the operation of the brake pedal 2 is also smoothly performed by the main flow path 3, and similarly a high braking release response is obtained.

B) At the time of anti-skid control When the brake pedal 2 is operated as described above and the wheels are likely to lock, anti-skid control is performed. That is, as shown in FIG. 3, both valves 5 and 6 are operated to perform pressure reduction / holding / increase to optimally control the brake fluid pressure of the wheel cylinder 4. First, both valves 5 and 6 are controlled. At the start of the operation, the pressure increasing valve 6 is closed and the pressure reducing valve 5 is opened to reduce the brake fluid pressure in the wheel cylinder 4.

Therefore, in this state, in the flow rate control valve B, the hydraulic pressure on the second pressure receiving chamber E side (master cylinder hydraulic pressure) remains, and the hydraulic pressure on the first pressure receiving chamber D side (wheel cylinder hydraulic pressure) decreases. Therefore, a hydraulic pressure difference is generated between both pressure receiving surfaces of the piston 18, and when the hydraulic pressure difference exceeds a set value, the piston 18 starts sliding against the urging force of the spring 20, and first, When the pressure difference reaches a predetermined value, the small-diameter first valve portion 19a abuts and closes the small-diameter valve opening 16f of the first communication hole 16a, as shown in (b) of FIG. When the flow passage is throttled to the total cross-sectional area of the orifice groove 16d and the hydraulic pressure difference further increases to reach a predetermined value, the large diameter second valve portion 19b has a large diameter as shown in (c) of FIG. It abuts the valve opening 16g and closes it. The flow path is narrowed down to the total cross-sectional area of the groove 16e.

FIG. 5 shows the pressure increase amount characteristic of the wheel cylinder hydraulic pressure with respect to the hydraulic pressure difference between the master cylinder hydraulic pressure and the wheel cylinder hydraulic pressure at the time of re-pressurization. In this figure, the solid line shows the flow control valve B. Characteristics when not operating (when the first communication hole 16a is fully open), 1-dotted line is the characteristic when only the small diameter valve opening 16f is closed (when narrowing down to the total cross-sectional area of the first orifice groove 16d), the dotted line is the small diameter valve The characteristics when the opening 16f and the large-diameter valve opening 16g are closed (when the total cross-sectional area of the second orifice groove 16e is narrowed) are shown, and the two-dot chain line shows the characteristics of the embodiment of the present invention. In this way, the narrowing of the flow path is performed stepwise according to the hydraulic pressure difference.

As described above, after the small-diameter valve opening 16f or the small-diameter valve opening 16f and the large-diameter valve opening 16g are closed, the brake fluid pressure of the wheel cylinder 4 is changed to an annular shape by opening the check seal 21. The pressure is smoothly discharged from the pressure reducing valve 5 to the reservoir 7 via the flow path 12f, whereby the pressure is smoothly reduced.

After that, when the brake fluid pressure of the wheel cylinder 4 becomes insufficient due to the pressure reducing operation as described above, the pressure reducing valve 5 is closed while the pressure increasing valve 6 is opened as shown in FIG. The brake fluid pressure of No. 4 is re-incremented. At the start of this re-increase, the piston 18 operates as described above in accordance with the fluid pressure difference between the master cylinder fluid pressure and the wheel cylinder fluid pressure at that time. Since the first communication hole 16a is gradually narrowed by the valve body 19 (see (b) or (c) in FIG. 1), the brake fluid pressure passing through the pressure increasing valve 6 is , Which is gently transmitted to the wheel cylinder 4, whereby it is possible to obtain a slowly increasing pressure characteristic according to the hydraulic pressure difference.

That is, on a low μ road surface where the wheel cylinder hydraulic pressure reduction amount is large and the hydraulic pressure difference is large, the throttle amount of the flow passage is increased and the re-pressurization is gently performed. While it is possible to eliminate the tingling control feeling due to pressure, on a high μ road surface where the wheel cylinder pressure reduction amount is small and the hydraulic pressure difference is small, the throttle amount of the flow passage is reduced and a prescribed pressure increase speed is secured. As a result, extension of the stop distance can be prevented.

As described above, the effects listed below are obtained in this embodiment. During normal brake operation, smooth circulation of brake fluid pressure can be obtained to ensure high damping response and high brake release response, and high decompression response during anti-skid control. It is possible to obtain the slow boosting characteristic while ensuring the above.

With an appropriate pressure increasing speed according to the friction coefficient of the road surface, it is possible to prevent the extension of the stopping distance on the high μ road surface while eliminating the jerky control feeling on the low μ road surface.

(Second Embodiment) FIG. 6 is a sectional view showing a main part of a flow control valve B for anti-skid control according to a second embodiment of the present invention. As shown in FIG. The diaphragm structure for narrowing the cross-sectional area of the flow path in a plurality of steps is different from that of the first embodiment, and the other configurations are the same as those of the first embodiment. Will be omitted, and only the differences will be described.

That is, in the flow control valve B of this embodiment, the valve body 19 has a cylindrical large-diameter second valve portion 19e and a small-diameter first valve portion at the tip as shown in FIG. 19d is formed in a stepped shape, and a first annular orifice 16h is formed at the opening of the first communication hole 16a axially opposed to this with the outer peripheral surface of the small diameter first valve portion 19d. At the same time, a common valve port 16k is formed between the outer peripheral surface of the large-diameter second valve portion 19e and a second annular orifice 16j having a larger throttle amount than the first annular orifice 16h.

Therefore, in this embodiment as well, the piston 18 is actuated by the two valve portions 19d and 19e of the valve body 19 as described above according to the hydraulic pressure difference between the master cylinder hydraulic pressure and the wheel cylinder hydraulic pressure. Since the first communication hole 16a is gradually narrowed down (see (b) and (c) in FIG. 6), the same action and effect as those of the first embodiment can be obtained.

Although the embodiment of the present invention has been described above with reference to the drawings, the specific configuration is not limited to this embodiment.

For example, in the first embodiment, the throttle is composed of the orifice groove, but it may be composed of the orifice hole. Further, the orifice groove and the orifice hole can be formed on the valve body side.

Further, in the embodiment, the movable member is composed of the piston, but it may be composed of a diaphragm, a bellows or the like.

[0044]

[Effect of device]

 As described above, in the flow control valve for anti-skid control of the present invention, the cut valve that opens and closes the flow path that connects between the hydraulic pressure control valve and the wheel cylinder, and the cut valve is opened. Of the master cylinder fluid pressure on one of the opposing pressure receiving surfaces and the wheel cylinder fluid pressure on the other pressure receiving surface. When the cylinder fluid pressure is higher than a set value, the cut valve has a movable member that operates in a direction to narrow the flow path against the urging force of the urging means. By adopting a structure with a throttle structure that narrows down the cross-sectional area of the flow path in multiple stages in proportion to the amount of movement, an appropriate pressure increase speed can be obtained according to the friction coefficient of the road surface. Jerky control on the road While eliminating the effect is obtained that is as an extension of the stopping distance in the high μ road surface can and child prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing details of a flow control valve of a first embodiment of the present invention, in which (a) is a flow control valve (cut valve).
State of non-operation of, (b) is the first throttle stage by operation,
(C) shows the 2nd throttle stage by operation, respectively.

FIG. 2 is an overall view showing a normal state of an anti-skid brake system using a flow control valve for anti-skid control of a first embodiment of the present invention.

FIG. 3 is an overall view showing a pressure reducing operation state in an anti-skid brake system using the anti-skid control flow control valve of the first embodiment of the present invention.

FIG. 4 is an overall view showing a re-pressurizing operation state after decompression in the anti-skid brake system using the anti-skid control flow control valve of the first embodiment of the present invention.

FIG. 5 is a characteristic diagram of a wheel cylinder hydraulic pressure increase amount with respect to a hydraulic pressure difference between a master cylinder hydraulic pressure and a wheel cylinder hydraulic pressure in an anti-skid brake system using a flow control valve for anti-skid control of the first embodiment of the present invention. Is.

FIG. 6 is a cross-sectional view showing a main part of a flow control valve of a second embodiment of the present invention, in which (a) is a flow control valve (cut valve).
State of non-operation of, (b) is the first throttle stage by operation,
(C) shows the 2nd throttle stage by operation, respectively.

FIG. 7 is a characteristic diagram of a wheel cylinder hydraulic pressure increase amount with respect to a hydraulic pressure difference between a master cylinder hydraulic pressure and a wheel cylinder hydraulic pressure in an anti-skid brake system using a conventional anti-skid control flow control valve.

[Explanation of symbols]

 B Flow rate control valve 1 Master cylinder 3b Downstream main flow path (flow path) 4 Wheel cylinder 5 Pressure reducing valve (hydraulic pressure control valve) 6 Pressure increasing valve (hydraulic pressure control valve) 16a First communication hole (cut valve) 16d No. 1 Orifice Groove (Throttle Structure) 16e Second Orifice Groove (Throttle Structure) 16f Small Diameter Valve Port (Throttle Structure) 16g Large Diameter Valve Port (Throttle Structure) 18 Piston (Movable Member) 19 Valve Body (Cut Valve) 19a Small Diameter First Valve part (throttle structure) 19b Large diameter second valve part (throttle structure) 20 Spring (biasing member) 16h Annular first orifice (throttle structure) 16j Annular second orifice (throttle structure) 16k Common valve port (throttle structure) 19d Small diameter first valve section (throttle structure) 19e Large diameter second valve section (throttle structure)

Claims (1)

[Scope of utility model registration request] 1. A flow path connecting a hydraulic pressure control valve and a wheel cylinder, which opens and closes based on a predetermined condition to increase / hold / depress the wheel cylinder hydraulic pressure based on the master cylinder hydraulic pressure. A flow control valve for anti-skid control provided on the way, wherein a cut valve that opens and closes a flow path that connects between the hydraulic pressure control valve and the wheel cylinder, and urges the cut valve to open. The master cylinder hydraulic pressure is received on the biasing means and one of the opposing pressure receiving surfaces, the wheel cylinder hydraulic pressure is received on the other pressure receiving surface, and the master cylinder hydraulic pressure is the set value from the wheel cylinder hydraulic pressure. And a movable member that operates the cut valve in a direction of narrowing the flow path against the urging force of the urging means when the pressure is higher than the above, and the cut valve includes the movable member in proportion to the movable amount of the movable member. Disconnection of flow path Antiskid control flow control valve, characterized in that it comprises a diaphragm structure to narrow the product in a plurality of steps.