JPH0356218B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention regulates the supply of hydraulic fluid from a source to a motor vehicle brake by means of a regulator assembly according to a skid signal from a skid sensing means, and at least one regulator assembly operating in a bore. The present invention relates to a hydraulic anti-skid brake system for a motor vehicle of the type having an actuating chamber in which a hydraulic pump containing a plunger communicates with a regulator assembly to control re-braking after skid correction.

British Patent A No. 2029914 (Japanese Unexamined Patent Publication No. 55-36187 or Japanese Patent Publication No. 1-27901) and A No. 2069640
In the case of the anti-skid brake device described in Japanese Patent Application Laid-open No. 56-128256 or Japanese Patent Publication No. 1-21024, the adjustment device assembly has a bore, and the deboost piston operates within the bore. and cooperate with the control valve assembly. The control valve assembly is adapted to control communication between the supply fluid and the valve assembly through an expansion chamber defined between the piston and the control valve assembly. The piston is normally held in an inoperative, forward position by the trapped volume of fluid supplied by the pump, in which the valve assembly is fully open and the effective volume of the expansion chamber is minimal. When the squid signal occurs, the fluid entrapment is released, which causes the piston to move to the retracted position, initially closing the valve assembly, isolating the supply from the brake, and then opening the expansion chamber to the active position. The volume can be further increased, thereby allowing brake application pressure to escape. After correction of the skid, the pressure from the pump acts to drive the piston toward its advanced position;
The brakes are first reapplied by pressurizing fluid within the expansion chamber, and later the valve assembly is opened to reestablish communication between the supply fluid and the brakes.

In an anti-static brake system of the type mentioned above, such as UK Patent A 2029914 and UK Patent A 2069640, the initial fluid bleed of the motor vehicle assembly equipment is carried out automatically and the driver is required to open and close the bleed equipment. There is a problem in eliminating the need for operations. Additionally, there is no risk that the bleed device may inadvertently remain stuck in the open position when the volume of trapped fluid supplied by the pump to support the pump, and in particular the piston, in the forward position is bled. It is also desirable to Otherwise, fluid would leak from the device, resulting in the control valve assembly becoming blocked and eventually rendering the pump inoperable.

According to the invention, in a hydraulic brake device of the above-mentioned type, the adjusting device coarse body is provided with a bore;
A deboost piston operates within the bore and cooperates with a control valve assembly to regulate communication between the piston and the control valve assembly between a supply of hydraulic fluid within the bore. There is. The piston is held in an advanced, inoperative position by a confined fluid volume in a space supplied with fluid by a pump, and a bleed device communicates with the space. Friction means are provided to hold the bleed device in the open position during the initial bleed of the device, and the bleed device reaches a predetermined pressure sufficient to overcome the friction means by the fluid pressure on which it is subjected. Sometimes it can be closed automatically.

When assembling the adjustment device, the provision of the friction means makes it possible to place the bleed device in the open position, so that the first bleed of the vehicle assembly device is carried out automatically and the driver There is no need to open and close the bleed device.

The bleed device operates within the bore of the housing;
A spool is provided that can move between a first bleed position where the wall holes of the bore communicate with each other and a second closed position where communication between the wall holes is interrupted. The friction means includes a resilient locking member acting between the bore and the spool, the locking member being positioned in a first position during initial assembly of the adjuster assembly in which the locking member rests on the releasable catch. act to hold the spool in the first bleed position. Thus, when the first bleed of the device is performed and the force containing the pressure in the space acting on the pressure response force on the spool reaches a predetermined pressure, the force acting on the locking member is overcome and the detent to be released. Thereafter, when the spool is driven from the first bleed position to the second bleed position, the locking members are carried by the spool to the second position and are then held together while remaining in the second position.

After the locking member has been conveyed by the spool to the second position, the locking member plays no role in subsequent manual bleeds of the device.

In this connection, the locking member is conveniently provided with an elastic ring provided in an annular groove in the small diameter spool section, the length of which is automatically controlled by the spool in its second section.
It is of sufficient length to return from one position to its first position, allowing manual bleed and ensuring that said return operation is not obstructed by the elastic ring.

At the end of the manual bleed, the spring assembly is operative to automatically return the spool to the second position, and the spring assembly may include a spring assembly operative to bias the deboost piston to the forward position. desirable.

The spring assembly acts on the inner end of the spool and the manually actuated member acts on the opposite outer end of the spool.

The spring assembly acts upon release of manual force from the manually actuating member to return the spool to its second position so that there is no risk of the device being accidentally left open.

Two embodiments of the invention are illustrated in the accompanying drawings.

The assembly shown in the accompanying drawings comprises a housing 1 with a regulator assembly 2, a hydraulic pump assembly 3 and a hood valve 4. Housing 1
A shaft 5 extending longitudinally from both ends through is connected at one end to the wheel to be braked and at the other end skid sensing means housed in a cylindrical guard 6 carried from the proximal end of the housing 1. (not shown)
is provided.

The foot valve 4 and the skid sensing means may be of any type disclosed in GB A 2029914, and the pump assembly 3 is of the type disclosed in GB A 2029914.
This is the same as disclosed in No. 2069640. Except that the pump 3 is driven in one direction by the eccentric 5a of the shaft 5 and in the opposite direction by the pressure from the foot-operated master cylinder 15 acting on the working piston 3a. There is no need to further explain the above mechanism.

Regulator assembly 2 extends from foot valve 4 and includes a bore 8 within which a deboost piston 9 operates. The piston 9 is normally driven by a spring 12 into an inoperative position against a stop, which stop consists of a closed end wall 10 of a generally cup-shaped sleeve 11, which sleeve 11 extends into a bore remote from the foot valve 4. It is held in the bore 8 by a seal 13 for the end of the 8.

The control valve assembly 14 housed within the sleeve 11 has a bore 8 between the piston 9 and the control valve assembly 14 itself.
The communication between the foot-operated master cylinder 15 and the wheel brakes 16 is regulated via an expansion chamber formed therein.

The control valve assembly 14 includes a continuously operated first valve 1
8 and a second valve 19.

The first valve 18 has an intermediate diameter portion which operates within the bore of the sleeve 11 and a maximum diameter outer portion which operates within the closure body 13.
A first of the stepped piston type, which operates in a blind bore 21 of the piston, whose inner part of smaller diameter carries an annular seal 22 forming the valve head, and whose innermost part of smallest diameter extends into a circular hole 23 in the wall 10; A valve member 20 is provided. The valve head 22 is engageable with a valve seat 29 having a ring in the wall surrounding the circular hole 23. Normally, the valve head 22 is spaced apart from the valve seat 24 by a spring 25 acting between the wall 10 and the shoulder 26 at the stage between the medium diameter and small diameter portions of the piston 20.

The piston 20 has a ball-shaped valve engageable with a valve seat 29 formed by a shoulder provided in the diameter step of a stepped-shaped longitudinally extending open end bore 27 containing a second valve 19 therein. A member 28 is provided.
The ball 28 is usually inserted into the valve seat 2 by means of a search needle 30.
It is biased away from 9. piston 8
The searching needle 30 resists the force of the light compression spring 31.
Collaborate with.

In the normal inoperative position shown, the foot valve 4 is closed so that the piston 9 is held in the forward inoperative position, in which the second valve 19 remains open by the groping needle 30 and the first The valve remains open by spring 25.

When the master cylinder 15 is actuated to apply the brake, hydraulic fluid is supplied to the brake through the radial hole 33 in the wall of the sleeve 11, and is also supplied to the expansion chamber 17 through the first valve 18. Ru. At the same time, fluid can also enter the through bore 27 through the hole 32 in the wall of the piston 20 and flow into the expansion chamber through the opened second valve 19. In this manner, fluid flows to the brake substantially unimpeded.

Fluid from the master cylinder acts on the valve head 22 and the stepped diameter shoulder 26 on the outer end of the wide area piston 20. Master cylinder 15
The pressure acting on the end of the widest area causes the force acting on the piston 20 to be equal to the force of the spring 25 and the pressure acting on the shoulder 26 and the valve head 22. Unrestricted communication will continue until victory is achieved. The first valve 18 is then closed, after which only a small pressure increase occurs due to the fluid passing through the unrestrained passage with the air gap between the valve seats 29.

When the skid signal is received, the foot valve 4 opens to release the trapped fluid volume in the bore 8 so that the piston 9 can retract against the force of the spring 12. Since the pressure at which the skid signal is generated is higher than the pressure at which the first valve 18 is closed,
First, the second valve 19 can be closed. As a result, the communication between the master cylinder 15 and the brake 16 is cut off, the piston 9 continues to retreat, and the effective volume of the expansion chamber 17 continues to increase, thus releasing the pressure acting on the brake 16. I can do it.
When the foot valve 4 is opened, the pump 3 becomes unbalanced and fluid is pumped through the foot valve 4 from the returning reservoir 32 into the bore 8 in a closed circuit. Since communication between the piston 3a and the master cylinder 15 is not restricted, the pump 3 can operate freely.

When the skid signal ends, foot valve 4 closes, isolating bore 8 from reservoir 32, and then
Pump 3 operates to increase the pressure within bore 8,
As a result, the piston 9 is driven to its inoperative retracted position. By first moving the piston 9 in this direction, the trapped fluid volume in the expansion chamber 17 is pressurized and used again for the brake 16, and by subsequent movement, the second valve 19 is opened. , fluid can flow unrestricted from the master cylinder to the expansion chamber 17 through the gap between the ball 28 and the valve seat 29. In this way, the first valve 18 closes at a predetermined pressure, regardless of the movement of the piston 9. Second
In the valve 19, the piston 9 is connected to the stopper 1 of the sleeve 11.
When it moves away from 0, it closes, and when it moves in the direction of this stopper 10, it opens. When the pressure from the master cylinder 15 drops below a predetermined pressure, the first valve 18 reopens and the fluid flows between the master cylinder 15 and the brake 16.
can flow freely and unrestricted between them.

Bleeding of the space 40, which traps fluid therein and normally serves to hold the piston 9 in the advanced position, can be effected by the action of a bleed device 41, which is shown in detail in FIG.

As shown in FIG. 2, the housing 1 is provided with a stepped bore 42 whose inner end portion 43 of largest diameter communicates with a space 40. As shown in FIG. A differently contoured spool 44 operates within the bore 42. The spring acts through an abutment plate 45 on the inner end of the spool 44 at its largest diameter and drives the spool 44 into a relatively outwardly advanced position. In this position the outer end of the spool 44 cooperates with a stop consisting of a closure 46 screwed into the outer end of the bore 42.

Spool 43 carries first and second axially spaced seals 47, 48. A first seal 47 is permanently disposed within a portion 49 of the bore 42 of the smallest diameter, and a second seal 47 carried by the largest diameter portion varies in diameter between the largest diameter portion 43 and the intermediate diameter portion 51. Shoulder part 5 of step part
radial passage 52 cooperating with 0 and reaching the foot valve 4
from the bleed passage 53 that reaches the atmosphere.
A bleed passage 53 is disposed between the two seals 47, 48 and extends from the intermediate bore portion 51.
Shoulder 50 is beveled or has a radius of curvature to facilitate sealing fit of second seal 48 within intermediate diameter portion 51 . This inoperative position of spool 44 is shown at the bottom of FIG.

A finger-shaped piece or button 54 is disposed between the seal 46 and the outer end of the spool 44 .
A retaining ring or spring clip 55 in an annular groove 56 at 4 frictionally engages the portion of bore 42 of minimum diameter.

At the top of FIG. 2, spool 44 is shown in its initially assembled position, with seal 48
is displaced from shoulder 50 into bore portion 43 and spaced apart from the wall of bore portion 43 so that fluid flow between passages 52 and 53 is free. Spool 44 is held in this position by a retaining ring 55 which acts as a releasable catch.

When the device is first fully bled, the hydraulic pressure acting on spool 40 acts on the diameter of spool 44 defined by seal 48. This pressure, acting in conjunction with the force of spring 12, automatically drives spool 44 to the position shown at the bottom of FIG. 48 engages shoulder 50 and engages intermediate diameter bore portion 49 to open passageway 52.
and 53 from each other.

The retaining ring 55 remains in the forward position shown in the lower part of FIG. 2, and the manual bleed can be performed by simply pressing the finger piece 54 inward and displacing the spool 44 in the axial direction against the force of the spring. It can be carried out.

As shown in the lower part of FIG. 2, since the retaining ring 55 has already been displaced, the spool 44 is held in a position displaced in the middle during the bleed after assembly described above.
The spring automatically returns the spool 44 to the position shown and the seal 48 isolates the two passages 52 and 53 from each other. During manual bleed, retaining ring 55 remains in the forward position.

In the bleed device 41 shown in FIG. 3, a retaining ring 55 and a groove 56 are provided behind and in the middle of the seal 47, and the finger-like pieces 54 are omitted.

In the illustrated retracted bleed position of spool 44, retaining ring 55 engages beveled shoulder 56 at a diametric step between bore portions 51 and 49. This increases the frictional grip of the retaining ring 55, and the retaining ring 55 is designed to lose at the predetermined pressure. Thereafter, the retaining ring 55 is moved forward together with the spool 44 to the forward position shown by the dotted line.

The spool 44 has a blind bore 6 extending in the longitudinal direction.
0 is provided in the bore 60, and in the bore 60,
The throttle valve and piston assembly 61, which is the subject of publication No. 248469, is activated.

The structure and operation of the bleed device shown in Figure 3 are as follows.
It is the same as that in the figure, and corresponding parts are indicated by corresponding symbols.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an adjusting device and skid sensing assembly for a hydraulic anti-skid brake system suitable for a motorcycle or light passenger car or light truck, FIG. 2 is a longitudinal cross-sectional view of a bleed device, and FIG. 3 is a separate FIG. 3 is a longitudinal sectional view of the bleed device of FIG. Explanation of main symbols, 1...Housing, 2...Adjusting device assembly, 3...Hydraulic pump assembly, 4...Foot valve, 5...Shaft, 6...Cylindrical guard, 8...Bore, 9...
Deboost piston, 10... Closing end wall, 11... Sleeve, 13... Sealing body, 14... Control valve assembly, 1
5... Foot-operated master cylinder, 16... Wheel brake, 18... First valve, 19... Second valve, 22... Annular seal, valve head.

Claims (1)

Claims: 1. The supply of working fluid from a source 15 to a motor vehicle brake 16 is regulated by a regulator assembly 2 in accordance with a skid signal from a skid sensing means, the at least one valve sliding within a bore. A hydraulic pump 3 with one plunger 3a communicates with said regulator assembly and comprises an actuating chamber for regulating brake re-action after skid correction, said regulator assembly having a bore 1 in which A deboost piston 9 slides, the deboost piston cooperating with a control valve assembly 14, the control valve assembly being in the bore between the deboost piston and the control valve assembly. For motor vehicles, the communication between a source of fluid and the brake is regulated, and the deboost piston 9 is held in an inactive advance device by fluid confined in a space 40 supplied by the pump. In the hydraulic anti-static brake system, a bleed device 41 communicates with said space 40, said bleed device 41 having a spool 44 which is freely movable axially between an open position and a closed position, friction means 55 for holding the bleed device in the open position during bleed, pressure sensitive means cooperating with the bleed device and responsive to fluid pressure;
The spool 44 is pushed from the open position to the closed position, and the pressure sensitive means automatically overcomes the friction means 55 and pushes the spool to the closed position when the fluid pressure reaches a predetermined pressure. A hydraulic anti-static brake device that is characterized by: 2. The spool 44 slides within the second bore 42 of the housing and has a first bleed position where the holes 52 and 53 in the wall of the bore communicate, and a second closed position where the communication between the holes is blocked. and said friction means 55 comprises a resilient locking member acting between said second bore and said spool, said resilient locking member being movable during initial assembly of said adjuster assembly. disposed in the first position and acting as a releasable stop in the first position to retain the spool in the first bleed position;
Thereby, when an initial bleed is performed and the force due to the pressure in the space acting on the pressure sensitive surface of the spool reaches a predetermined value, the force of the locking member is defeated and the stopper is released. , thereafter the locking member is carried on the spool and moves to the second position as the spool is pushed from the first bleed position to a second position; 2. A hydraulic anti-skid brake system as claimed in claim 1, wherein is held at said second position.