JPS584636A - Brake device - Google Patents

Abstract

PURPOSE:To reduce operating power of a device, by providing a brake control valve, holdable with pressure in accordance with clutch operation, in one channel, and providing an automatic valve, automatically holdable with pressure in accordance with operation of said control valve, in the other channel. CONSTITUTION:One fluid pressure generating chamber of a master cylinder 2 is connected to brake devices 7, 8 through pipes 4, 5 and brake control valve 6, and the other fluid generating chamber is connected to brake devices 12, 13 through pipes 9, 10 and automatic valve 11. The control valve 6 is equipped with a ball shaped valve element 37, and this valve element 37 is not seated to a valve seat 44 under a condition not depressed with a clutch pedal 77 because a small contour part 54 of a plunger 52 is protruded from the valve seat 44, but if the pedal 77 is depressed, a cam shaft 17 is turned through wires 78, 29 to move the plunger 52 rightward, an the valve element 37 can be seated to the valve seat 44. The automatic valve 11 is equipped with a piston 61, operated by pressure in a pressure chamber 64 communicated to the control valve 6, further with a valve 75, shutting off the pipe 9 from the pipe 10 by operation of this piston 61.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake device for a vehicle, etc., and particularly to one equipped with a brake control valve for starting on a climbing road.

Conventionally, this type of device has been equipped with at least two brake systems that supply pressurized fluid from a brake mask cylinder to a brake wheel cylinder through mutually independent piping systems, and one system has a system that detects that there is one uphill road. It is known that the brake wheel cylinder is provided with a brake control valve which can prevent fluid movement towards the brake mask cylinder and which can be opened and closed depending on the clutch device.

In order to make it easier for a vehicle to start on a boarding road, this device reduces the pressure in the brake wheel cylinder in response to a clutch disengagement operation that is performed following a brake engagement operation when stopping on a boarding road. The pressure is maintained so that the vehicle or the like is held in a stopped state even after the brake operation is completed, and furthermore, when starting the vehicle, the pressure is released in response to the clutch connection operation. This makes it possible to make the vehicle safer by performing two operations: depressing the accelerator pedal and gradually returning the rack latch pedal, without operating the handbrake at the same time, when starting on the road. This makes it possible to start the vehicle immediately, and prevent accidents caused by the vehicle or the like moving backwards due to failure to start.

However, in such a device, the brake control valve for maintaining pressure in the wheel cylinder is only installed in one of the multiple systems, so the total brake power required to maintain the stopped state of the vehicle is limited. There is a problem in that if the clutch pedal is not fully engaged after the brake operation is completed, the vehicle or the like may back up, causing an accident.

That is, in recent vehicles, the brake piping system is separated into one including the brake wheel cylinder for the front wheels and the other including the brake wheel cylinder for the rear wheels, so-called front and rear piping systems.
Or, the so-called
In such piping systems, even if pressure is maintained in only one piping system,
Since pressure is supplied to two systems and the pressure at the time of stopping is maintained, the braking force required for stopping is halved.
Eventually, the vehicle etc. will move backwards.

For this reason, the present applicant first installed a brake force control valve that moves under its own weight but has a part in parallel, and made the two balls movable by a single camshaft linked to clutch operation (
Utility Model Application No. 55-21250-Teru) was proposed in an attempt to solve the above problems in a two-system brake system.1. Ta.

According to this proposal, the lack of braking force can be resolved by moving two balls using one camshaft from the valve seat where the balls are seated, against the pressure acting on the balls. Therefore, a considerably large driving force is required for this camshaft, and as a result, the force required to press the clutch pedal is large, making the clutch heavy and making it impossible to operate the clutch quickly.

There is a problem in that the release of brake pressure at the time of starting is delayed, making it impossible to start smoothly.

The present invention was made in view of the problems on paper, and aims to provide a brake device that can start on a boarding road with a light operation, and in order to achieve this purpose,
In the other system, in response to the operation of the brake control valve,
An automatic valve is provided that can prevent fluid movement from the brake wheel cylinder of the other system toward the brake mask cylinder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The brake device of the present invention will be explained in detail below based on illustrated examples.

FIG. 1 is an overall view of a brake device according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG.

In Fig. 1.2, the brake device is generally designated by l, and the device 1 includes a brake tandem master cylinder 2 which has two independent hydraulic pressure generating chambers (not shown) formed inside. have.

This mask cylinder 2 is attached to the vehicle body A and is actuated by a brake pedal 3 which is swingably attached to the vehicle body A, and one hydraulic pressure generating chamber is connected to a pipe 4.
．． 5 and a brake control valve 6 to the brake wheel cylinders (not shown) of the brake device 7 for the right front wheel and the brake device 8 for the left rear wheel, and the other hydraulic pressure generating chamber is connected to the piping 9. It is connected to brake wheel cylinders (not shown) of a brake device 12 for the front left wheel and a brake device 13 for the rear right wheel via an automatic valve 11 provided integrally with the lO and brake control valve 6.

Particularly, the brake control valve 6 will be explained with reference to FIG. 2. The brake control valve 6 has a stepped hole 15 in the main body 14 whose diameter gradually increases in the direction of forward movement of the vehicle, and the stepped hole 15. A perpendicular hole 16 is drilled therein. (In Fig. 1.2, the forward direction of the vehicle, etc. is assumed to be to the left when facing the figure.) A camshaft 17 is rotatably inserted into the hole 16. An eccentrically reduced diameter cam 18 is provided at a portion of the stepped hole 15 opposite to the open end of the hole 16, and two
A cam chamber 21, which constitutes a part of the piping system, is partitioned. This cam chamber 21 is connected to the piping 4 through a connecting hole 22. A recess 23 is provided in the lower end of the camshaft 17, which increases the volume between the camshaft 17 and the closed end of the hole 16.
The upper end of the camshaft 17 is formed into a connecting portion 24 that has a reduced diameter and projects outward from the hole 16 .

A rotating member 25 having a substantially triangular shape is provided at the junction portion 24.
However, along with the water-shielding skirt member 26, the nut 27
and washer 28 for installation.

Referring to FIG. 1, this rotating member 25 is connected to a wire 29 at one end (detailed shape and structure are not shown).
Shown schematically. ), in response to the swinging of the clutch actuating arm 30, it can rotate together with the camshaft 17 by or against the tension of a release spring 31 stretched between it and the vehicle body A on the other end side. .

Further, the camshaft 17 is prevented from coming out of the hole 16 by a sliding device 32 provided at the open end of the hole 16, and the sliding device 32 is guided to slide when rotating. , a low-friction sliding member 33 made of synthetic resin and having a flanged cylindrical shape that contacts the camshaft 17, a back upper 34, and a stopper 3.
It consists of 5. 36 is waterproof and dustproof boots.

On the other hand, a ball guide 38 having an automatically movable spherical valve element 37 inside is fitted into the large diameter hole of the five-stepped hole 15, and a lid 39 is screwed onto the stepped hole 15. A washer 41 with an elastic piece 40 provided between the lid 39 and the ball guide 38 holds it in the illustrated position where it abuts against the stepped portion 42 .

A large number of axial grooves 43 are formed on the inner surface of the pole guide 38, and a valve seat assembly 44 on which the valve element 37 can be seated is fitted at the end of the stepped portion 42. There is.

This valve seat assembly 44 consists of a seat member 45 made of rubber and a support member 46 that is connected to the seat member 45 by unevenness. By fitting the ball guide 38
((4). The seat member 45 has an inner diameter 1
A round protrusion (not shown) is formed on the outer periphery to seal the space between the support member 46 and the support member 46, and an inner hole 48 is formed in the supporting member 46, and a stepped hole 150 and a stepped portion 49 are formed in the support member 46. A plate portion 50 is formed which can come into contact with.

The support member 4 of the valve seat assembly 44 is attached to the small diameter part of the stepped hole 15.
A plunger 52 is movably inserted with a light spring 51 stretched between it and the right side of the plunger 52.
It is brought into contact with the cam 18 by the tension of the spring 51. In addition, the plunger 52 has a number of axial grooves 53 formed on its outer periphery, and protrudes into the ball guide 3B through the valve seat assembly 44 on the left end side so that it can come into contact with the valve element 37. A small diameter portion 54 is formed.

The automatic valve 11 provided integrally with the brake control valve 6 has a stepped hole 55 formed in the main body 14 parallel to the service hole 15, and this stepped hole 55 has a small-diameter hole 57 and a large-diameter hole 58 formed with a stepped portion 56 interposed therebetween, which gradually increase in diameter toward the right.

The stepped hole 55 has a large diameter part 59 in the small diameter hole 67, and a large diameter part 59 in the small diameter hole 67, and a large diameter part 59 in the small diameter hole 67.
A differential piston 61 with a small diameter portion 60 fitted in the small diameter hole 5 is movably inserted into the end of the small diameter hole 5], and is connected to the pipe 5 through the connecting hole 62 and into the stepped hole 15 through the hole 63. A first pressure chamber 64 is defined which communicates with each other, and a connection part 65 for the piping 10 is formed on the open end side of the large diameter hole 58 and is screwed onto the open end. A second pressure chamber 68 is defined, which communicates with the pipe 10, and also communicates with the large diameter hole 58 and the pipe 9 via the connecting portion 6.
11. A banding member 70 sandwiched between two rings 69 is fitted on the outer periphery of the diameter portion 60 of the differential piston 61.
The space between the small diameter part 60 and the large diameter hole 58 is sealed, and a rubber valve member 71 is attached to the end of the small diameter part 60 with a spring receiver 72.
The differential piston 61 is biased to the right by a light valve spring 73 disposed between the differential piston 61 and the valve spring 73.

A seat surface 74 is formed on the end face of the plug 66 facing the valve member 71, and the communication between the piping 10 and the second pressure chamber 68 can be disconnected by the seat surface 4 and the valve member 71. Naben 7
5 are configured. Also.

The open end of the glove 66 with respect to the @2 pressure chamber 68 is provided with a throttle passage 76 that functions as described below.

In addition, in Fig. 1.2, 77 is a clutch pedal;
78 is the clutch pedal 7f and the clutch actuating arm 30
Clutch wire installed at the connection.

79Fi engine, 80 has 5 transmift system 81
Fi each shows a clutch device including the arm 30 mentioned above. Note that the clutch device 81 shown schematically for ease of explanation is a flywheel 82 that rotates together with the engine 79. Pressure plate 83. A block 84 that moves on the axis in response to the swing of the arm 30. It has a diamond slam spring 85 disposed between the plate 83 and the block 84, and a latch disk 86 which is electrically distributed between the wheel 82 and the plate 83 and can be frictionally engaged with both. are doing. Incidentally, since the latch device 81 like this is widely known, a detailed explanation will be omitted.

In addition, in FIG. 1.2, the members indicated by ``hot'' are sealing members that are appropriately selected and used depending on the mounting location.

The member indicated by b is the backup ring for the sealing member a, the point indicated by d is the center of rocking or rotation of the pedal, etc., and the point indicated by e is the connection part between the pedal etc. and the wire. Each location is indicated.

The functions of the device 1 will be described below.

Assume that the driver of the vehicle is not operating the brake or clutch and is driving the vehicle at an appropriate speed.

Then, the clutch disc 86 frictionally engages with the flyhole 82 and the pressure plate 83 under the action of the maximum load of the diamond 7 ram spring 85, resulting in a so-called clutch connected state. By being biased to the position shown by tension, the plunger 52 is moved to the left by the cam 18 to a position where the small diameter portion 54 of the armpit plunger 52 projects beyond the valve seat assembly 44 and into the interior of the pole guide 38. However, as a vehicle or the like travels on the road, the valve element 37 is unable to sit on the valve seat assembly 44 even if it attempts to do so. In addition, since the brake is not applied, no pressure is generated inside each piping system, and no pressure is received from the differential piston 61Fi or the interpressure chambers 64, 68, so the valve spring 73 When the driver is driving on a boarding road in such a state that the valve 75 is in the open position, for example, when approaching a hoof clipping and the driver depresses the brake pedal 3 to apply the brake, the mask cylinder opens. 2 to piping 4,
9, pressure is generated in each piping system, and the pressure fluid is supplied to the wheel cylinder of each brake device, so the brakes begin to be applied. At this time, the brake device 7,
For 8, piping 4. Cam chamber 21. Groove 53 of plunger 52. Bore 48 of valve seat assembly 44. Ball guide 38
Inside, hole 63. First pressure chamber 64. The brake device 12.13 is connected via the piping 5 to the piping 9, the second pressure chamber 68. Pressure liquid is supplied independently from each mask cylinder 2 via the piping 1o.

When pressure is transmitted into each pressure chamber 64, 68, the differential piston 61 must be such that the acting force applied to the large pressure receiving area on the left end side is greater than the acting force applied to the vehicle receiver EE area on the right end side. , the differential piston 61 tries to move to the right.
Since the stepped portion of the stepped hole 55 engages with the ring 69, there is no acting force in the right direction that overcomes the acting force that the sealing member 70 receives on the pressure receiving area on the right side.
The differential piston 61 is located at the illustrated position where it engages with the stepped portion of the differential piston 61. (It is assumed that the pressures generated in the two hydraulic pressure generating chambers of the mask cylinder 2 are substantially equal.) After that, when the vehicle etc. is sufficiently decelerated, the driver depresses the brake pedal 3 and clutches the brake pedal. Depress pedal 77 deeply. Then, the clutch pedal 770 swings (or rotates) around point d.

Hereinafter, this will be simply referred to as oscillation. ), the clutch wire 78
The clutch actuating arm 30 swings clockwise around point d via the clutch device 81.
As the block 84 moves to the left, the diamond 7 ram spring 85 bends about point d, deforming the pressure plate 83 away from the flywheel 82, and causing the clutch disc 86's brake disc 86 and flywheel 82 to move away from the flywheel 82. The frictional engagement with the clutch is completely released, and the clutch becomes in a disengaged state. On the other hand, at the same time, due to the swinging of the clutch actuating arm 3o, the wire 2
9, the rotary member 25 of the brake control valve 6 is
In FIG. 1, it rotates counterclockwise against the biasing force of the release spring 31. The rotation of the rotation member 25 causes the camshaft 17 to rotate.

As the cam 18 and the plunger 52 slide and the cam 18 is displaced, the plunger 52 is moved by the biasing force of the spring 51.
moves to the right, and finally the valve element 37 touches the valve seat assembly 44.
In this state, when the vehicle etc. comes to a complete stop and the driver removes his/her foot from the brake pedal 3, the valve element 3
Although the pressure on the piping 4 side is released from the contact area between the valve seat assembly 7 and the valve seat assembly 44, the pressure on the piping 5M is maintained as it is.

4, in which the pressure inside the second pressure chamber 68 decreases as the pressure decreases;
Since the pressure is maintained in the first pressure chamber 64, when the pressure in the second pressure chamber 68 decreases to some extent, the differential piston 61 moves toward the left end side of the first pressure chamber 64.
The rightward moving force received by the pressure inside the @2 pressure chamber 68 on the right end side is the leftward moving force due to the pressure inside @2 pressure chamber 68 being directly received, and the acting force due to the hydraulic pressure acting on the right side of the sealing member 70. The differential piston/6! is inserted through the ring 69. (The biasing force of the valve spring 73 is small, so it will be ignored in this explanation.)
The explanation will also ignore sliding resistance. ), the differential piston 61 moves to the right and closes the valve 75.

At this time, the pressure inside the pipe 1O decreases slightly by the time the valve 75 closes, but since the pipe 1O and the second pressure chamber 68 are connected through the throttle passage 76, Since this is done in such a way that the pressure does not drop excessively due to the curvature effect, it is automatically held in the pipe 10 after all.

Therefore, since the pressure is maintained in the wheel cylinder of each brake device 7, 8, 12, 13, the same pressure remains in the brake device 12.
Since the slightly reduced pressure is maintained in 3, the total braking force is slightly smaller than the total braking force when the vehicle is stopped on the slope, but enough braking force is obtained to keep the vehicle stopped on the slope. be able to.

Through the operations up to this point, the vehicle or the like is maintained in a stopped state with the clutch pedal 77 being depressed, the clutch being engaged and disengaged, and the brake being applied.

Next, a case where the driver starts the vehicle will be described.

Now, as described above, when starting the vehicle from a stopped state by depressing only the clutch pedal 77 #i
First, the driver depresses the accelerator pedal (not shown) and gradually returns the clutch pedal 77 to the inoperative position (return position) while increasing the rotational speed of the engine 79 slightly. Then, the clutch actuating arm 30 swings in the opposite direction to when the clutch is engaged, and the clutch disc 86 receives a portion of the maximum load of the diaphragm spring 85 and frictionally engages with the flywheel 82 and pressure plate 83. This is a so-called half-clutch state. Further, in the brake control valve 6, the rotating member 25 rotates clockwise due to the urging force of the release spring 31, and the cam 18 is accordingly displaced to move the plunger 52, and the small diameter portion of the plunger 52 is rotated. By bringing the valve element 37 into contact with the valve element 37 and separating the valve element 37 from the valve seat assembly 44, the pressure within the pipe 5 is released to about 2 degrees in the mask cylinder. As the pressure in the pipe 5 decreases, the differential piston 61 balances its movement force in the left and right direction, thereby reducing the pressure in the pipe IO.

As a result, driving force is transmitted to the wheels (driving wheels) from the engine 79 via the clutch device 81, and the pressure in each wheel cylinder decreases, causing the braking force applied to the wheels to gradually decrease. As a result, the vehicles finally start and fall asleep on the boarding road.

When the clutch pedal 77 is completely released after the vehicle has started, the clutch is fully engaged, and the pressure in each wheel cylinder is also released, resulting in a normal running state.

According to the above-described embodiment, in the system including the pipes 4 and 5, a device is provided that allows the valve element 37 to be seated and removed from the valve seat assembly 44 in conjunction with clutch operation, and the pipes 9 and 10 are
In a system including this, it is configured to detect that pressure is confined within the piping 5, in other words, in response to actuation of the brake control valve 6, pressure is also confined within the piping 10. Therefore, by confining the brake pressure to two systems, it is possible to secure sufficient braking force for stopping on the boarding road, and when starting, the operating force required to disengage the valve element 37 is reduced. It's nice to have it, so you can minimize its operating power. Furthermore, by reducing the operating force, the brake can be released quickly when starting, and when the clutch is in a partially engaged state, the braking force can be reduced to an appropriate level, allowing smooth starting. Be able to do it.

In addition, in the automatic valve 11, in order to open and close the valve 75, the differential piston 61 is moved by the difference in the biasing force or moving force in the left and right direction acting on the differential piston 61. Then, since the differential piston 61 is moved by comparing the pressure contained in the pipe 5 and the internal pressure of the mask cylinder 2 on the pipe 9 side, the operating state of the brake control valve 6 and the mask cylinder The automatic valve 11 and the brake control valve 6 work together to reliably maintain the stop on the uphill road, and also to prevent The brake can be released reliably, and the reliability of the device is excellent.

As described above, the embodiments described above have various effects, but the present invention is not limited to the embodiments described above, but can be implemented.

FIG. 3 shows another embodiment of the invention. In addition, in the one shown in FIG. Portions or parts having substantially the same functions, structures, and shapes as those in FIG. 2 are given the same symbols as those in FIGS. 1 and 2, and the explanation thereof will be omitted, and particularly differences will be described.

In FIG. 3, two liquid connection parts 90 and 91 are formed by directly communicating with the stepped hole 15, and an automatic valve 11' is directly attached to the open end of the stepped hole 15 with bolts or the like (not shown). This is what I did.

The automatic valve 11' has a main body 95 formed with upper and lower liquid connecting portions 92, 93 communicating with inner holes 94, respectively.

The inner hole 94 is a stepped hole whose diameter gradually increases toward the left with a stepped portion 96 interposed therebetween.The left end of the inner hole 94 is closed by a lid 97, and the right end is It communicates with the inside of the stepped hole 15 by. Further, a substantially axial differential piston 99 is inserted into the inner hole 94 so as to be movable, and between a left end recess 100 of the differential piston 99 and a recess 101 of the lid 97. The piston 99 is biased to the right by a light spring 102 arranged.

A lip seal type sealing member 10 is provided on the left side outer periphery of the differential piston 99 to seal between the inner hole 94 and the piston 99.
3 is disposed adjacent to the stepped portion 96 through the inner lip 105 of the sealing member 103.
A small hole 106 that can be displaced from side to side is formed in a cylindrical portion forming a recess 100 of the differential piston 99. A through hole 107 opened in the inner hole 94 on the right side of the sealing member 103
A part of the inner hole 94 is communicated with a hydraulic pressure generating chamber (not shown) of the mask cylinder through the through hole 107.

The connecting portions 90 and 92 are connected to the brake wheel cylinder of the front wheel brake system, and the connecting portions 91 and 93 are connected to that of the rear wheel, respectively, by an X piping system similar to the piping system shown in Figs. 1 and 2. Connected.

The operation of this embodiment is as follows.

When the brake is applied, the pressure of one system is transmitted from the small hole 98 into the inner hole 94, the differential piston 99 receives a movement force to the left, and the pressure of the other system is transmitted from the through hole 107 to the inner hole 94. The pressure of the other system is transmitted into the bore 94 and is further transmitted through the small bore 106 and into the large diameter bore of the bore 94 deforming the inner lip 105, thereby causing the differential piston 99 to move. receives a force that moves it to the right. When the brake is applied, the forces of movement in the left and right directions on the differential piston 99 are balanced, and the differential piston 99 is in a position where the small hole 1116 is aligned with the inner lip 105. .

Next, the clutch is operated to seal the pressure in the stepped hole 15 and release the brake.

Then, the pressure between the sealing member 103 and the sealing member a in the inner hole 94 decreases, and along with this, the pressure in the inner hole 94 on the left side of the sealing member 103 also gradually decreases due to the narrowing effect of the small hole 106. The force that tries to move the differential piston 99 to the left increases, and the small hole 106 of the differential piston 99
is moved until it is located to the left of the inner lip 105. Although this causes a slight pressure drop in the other system,
Pressure is contained.

When starting, the differential piston 99 moves to the right due to the pressure drop in the stepped hole 15, and the small hole 106 is located on the right side of the inner lip 105, and the pressure in the other system is reduced to 10 g.
released through.

According to the above-described embodiment, in addition to the same effects as the previous embodiment, the following effects are also obtained.

That is, in this embodiment, even when the differential piston 99 moves to the left, it is possible to deform the inner IJ and piston 105 to supply pressurized fluid from the mask cylinder side to the wheel cylinder side. Therefore, even if the system on the stepped hole 15 side is vented first during the air venting operation when installed on an actual vehicle, the system on the inner hole 94 side can be vented easily.

More specifically, the inner lip 105 functions like a check valve that allows fluid to move from the master cylinder side to the wheel cylinder side, but prohibits the reverse movement, and prevents the brake fluid from flowing backward during air bleeding. , (liquid movement toward the mask cylinder side), air can be removed quickly and easily.

Further, by operating the clutch following the brake operation, preparations can be made to contain the pressure in each unit, but even if even higher pressure is generated in the brake piping system after this preparation is completed, the valve element 37 will move due to the pressure difference. and inner lip 10
By deforming 5, the high pressure can also be transmitted to the wheel cylinder side, without impairing braking performance.

Furthermore, even when only normal brake operation is performed and no clutch operation is performed, the left and right pressure receiving areas of the differential piston 99 are made equal, so that brake pressure is not unnecessarily confined to the other system. Brake performance will not be impaired.

As described above, the second embodiment also provides various effects.

As is clear from the above, according to one aspect of the present invention, one system is provided with a brake control valve that can maintain pressure in response to clutch operation, and the other system is automatically supplied with pressure in response to the operation of this brake control valve. By providing an automatic valve that can be held, a brake device can be obtained that reduces the force required for operation and operation, thereby allowing smooth starting on a climbing road.

Although various things have been described above, it goes without saying that the present invention is not limited to the illustrated examples and can be implemented.

That is, the configuration of the brake control valve itself can be changed from that shown in the figure, for example, as shown in Japanese Utility Model Application Publication No. 55-16930, a reciprocating camshaft is used instead of a rotary camshaft. Alternatively, as shown in Japanese Utility Model Application Publication No. 55-33822, a clutch that utilizes the hydraulic pressure of a hydraulic clutch may be used.

In the example shown in FIG. 3, the sealing area of the piston 99 by the sealing member 103 is made equal to that by the sealing member 1, but the former is made slightly smaller than the latter to prevent pressure drop when maintaining the stop. Of course, it is also possible to do so. On the other hand, the former should be made slightly larger than the latter within a range that does not adversely affect stopping on the uphill road, in other words, within a range that does not cause insufficient braking force. ), during normal brake operation, the brakes of the other system may be released preferentially. Furthermore, in the illustrated example, the pressure drop on the wheel cylinder side is prevented by the throttling effect of the throttling passage 76 or the small hole 106, but even if a small passage with a throttling effect is not provided, the presence of piping resistance will prevent the pressure from decreasing. If sufficient pressure remains on the wheel cylinder side to ensure stopping, there is no need to provide a small passage as described above, and if piping resistance etc. is extremely small, or if the time required to move the differential piston is If the area is large, restrictive small passages may be provided to the extent necessary.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing an embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along line A-A, and FIG. 3 is a cross-sectional view showing another embodiment. 1... Brake device 2... Tandem master cylinder 6... Brake control valve 9, 10... Piping 11
... Automatic valve patent applicant - Japan Air Brake Co., Ltd. procedural amendment (
Spontaneous) April 1, 1980 1, Indication of the case Patent Application No. 99878 of 1988 2, Name of the invention Brake device 3, Address of the person making the amendment 1-46 Wakihama Kaigan-dori, Special Ward, Kobe City <Telephone Kobe (
078) 231-4131〉4.Date of notice of reasons for refusal Drawing/contents of amendment a Replace drawing 3 with the attached drawing.

Claims (1)

[Claims] At least two brake systems are provided for supplying pressurized fluid from the brake mask cylinder to the brake wheel cylinder by mutually independent piping systems, one system having:
In a brake device that is equipped with a brake control valve that can detect that the road is uphill and prevent the movement of fluid from the brake wheel cylinder to the brake mask cylinder, and that can be opened and closed depending on the clutch device, one A brake device comprising an automatic valve capable of blocking fluid movement from the brake wheel cylinder of the other system toward the brake mask cylinder in response to the operation of the brake control valve.