JPH021707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air brake device for a vehicle or the like.

The present applicant has developed a technology for maintaining braking force on uphill roads, such as that disclosed in Japanese Utility Model Application Publication No. 55-43905, to air brake devices for vehicles, etc., and has developed this type of device that stores compressed air. an air tank, a brake valve that discharges compressed air from the air tank in response to a driver's operation, an actuator that takes in compressed air from the brake valve to cause brake operation, and the actuator and the brake. The present invention has proposed a holding valve that is provided between the brake valve and the brake valve and closes to prevent pressure release from the actuator to the brake valve side when the vehicle or the like is stopped on an uphill road.

However, since many vehicles equipped with air brake devices are large and heavy, or carry a considerable amount of cargo, braking force is applied to all wheels when the vehicle is stopped. If the holding valve is closed and the braking force applied to a specific wheel among all wheels is maintained, or even if the braking force of all wheels is maintained, the vehicle may stop. In cases such as when the slope of the uphill road you have climbed is steeper than the slope of the road surface immediately before stopping,
This results in insufficient braking force to keep the vehicle in a stopped state on an uphill road, causing problems such as the vehicle backing up on an uphill road.

The present invention was made in view of the above-mentioned problems, and an object of the present invention is to provide an air brake device that can eliminate the lack of braking force when stopped on an uphill road.
In order to achieve this purpose, as the pressure on the brake valve side of the holding valve decreases due to the release of the brake valve after the holding valve is closed, the pressure on the brake valve side of the holding valve and the pressure on the actuator side decrease. A valve device is provided which communicates the air tank and the actuator when a pressure difference occurs.

By doing this, when the driver releases the brake valve operation after the vehicle has stopped on an uphill road and the holding valve has closed, the actuator and the air tank communicate through the valve device and the holding valve closes. The pressure maintained on the actuator side of the valve increases from the pressure discharged from the brake valve in proportion to its operation to the pressure stored in the air reservoir. The braking force maintained on the wheels also increases accordingly.

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

FIG. 1 is a diagram showing an air brake device that is an embodiment of the present invention.

In the figure, 1 indicates the entire air brake device, and this device 1 includes an air tank 3 that stores compressed air from an air compressor 2, and a brake valve 5 that communicates with this air tank 3 via piping 4. The brake valve 5 is connected to a brake actuator (not shown) through a piping 6, a holding valve 7, a piping 8, and a valve device 9 in this order, and is directly connected to a valve device 9 through a piping 10.
has been contacted. Furthermore, the pipe 4 between the brake valve 5 and the air tank 3 is connected directly to the valve device 9 via a branched pipe 11.

To explain the holding valve 7, the holding valve 7 has a main body 14 formed with a stepped hole 15 whose diameter gradually increases in the forward direction of the vehicle, etc., and a hole 16 perpendicular to the stepped hole 15. It has been done. (In Figure 1, 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, and a stepped hole is inserted into the camshaft 17. 15 holes 16
A cam 18 having an eccentrically reduced diameter and having a circular cross section is provided at a portion facing the open end of the cam 1.
Two sealing members 19 and a back-up spring 20 are respectively attached to the same diameter portions sandwiching the piping 8, and a cam chamber 21 constituting a part of the piping system is defined. This cam chamber 21 is connected to the pipe 6 via a connection hole 22.

A recess 23 is provided at the lower end of the camshaft 17 to increase the volume between the camshaft 17 and the closed end of the hole 16, while the upper end of the camshaft 17 has a reduced diameter to increase the volume between the camshaft 17 and the closed end of the hole 16. A connecting portion 24 protrudes outward,
A rotating member 25 having a substantially triangular shape is attached to the connecting portion 24 using a nut 27 and a washer 28 along with a skirt member 26 for keeping out water.

This rotating member 25 has a wire 82 connected to the operating arm 81 of the clutch device 80 connected to one end, and a release spring 83 connected to the vehicle body A at the other end.
Therefore, when looking at the camshaft 17 from above in the figure, the camshaft 17 rotates counterclockwise in response to the clutch disengaging operation, displacing the cam 18 to the right, and vice versa. , the cam 1 is rotated clockwise by the action of the release spring 83 in response to the clutch connection operation.
8 is displaced to the left from the position where it is displaced to the right. The behavior of the camshaft 17 itself is well known as shown in Japanese Utility Model Application No. 55-43905.

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 is guided to slide during rotation.

The sliding device 32 includes a low-friction sliding member 33 made of synthetic resin and having a cylindrical shape with a flange that contacts the camshaft 17.
, a backup 34 and a stopper 35. 36 is waterproof and dustproof boots.

On the other hand, a ball guide 38 having a spherical valve element 37 movable under its own weight is fitted into the large diameter hole portion of the stepped hole 15, and is screwed into the open end of the stepped hole 15. The ball guide 38 is attached to the stepped portion 4 by a washer 41 with a claw 40 disposed between the cover member 39
2 is held in the illustrated position. A large number of axial grooves 43 are formed on the inner surface of the ball 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.

This valve seat assembly 44 includes a seat member 45 made of rubber.
The seat member 45 is made up of a supporting member 46 that is connected to the seat member 45 by unevenness. By fitting the wall of the ball guide 38 into a groove 47 formed on the outer periphery of the seat member 45, the ball guide 38 can be attached to the ball guide 38. Installed in one piece. The seat member 45 has an annular protrusion (not shown) formed on the outer periphery for sealing the space between the seat member 45 and the inner surface of the intermediate diameter portion of the stepped hole 15.
An inner hole 48 is bored therein, and a plate portion 50 that can come into contact with the stepped portion 49 of the stepped hole 15 is formed.

A plunger 52 is movably inserted into the small diameter portion of the stepped hole 15 with a light spring 51 stretched between it and the support member 46 of the valve seat assembly 44. It is brought into contact with the cam 18 by the tension of 51. Further, the plunger 52 has a large number of axial grooves 53 formed on its outer periphery, and a valve seat assembly 44 on the left end side.
A small diameter portion 54 is formed that penetrates through the ball guide 38 and protrudes into the ball guide 38 to be able to come into contact with the valve element 37.

Note that the stepped hole 1 into which the ball guide 38 is inserted is
The inside of 5 is connected to piping 8 through a connection hole 55 formed in main body 14 .

The valve device 9 includes a main body 58 in which a hole 57 having an increased diameter portion 57a is formed in the center thereof, and a spool 59 is provided in the hole 57, and a spring 60 is inserted between the spool 59 and the bottom of the hole 57.
A and 60b are stretched out and movably inserted.
The space formed on the right end side of the hole 57 is an input chamber 61 that communicates with the piping 10, and the space formed on the left end side of the hole 57 is used as an input chamber 61 that communicates with the piping 10. 8 and a relay room 63 that communicates with the brake actuator. Furthermore,
A space within the diameter-increasing portion 57a of the hole 57 is a supply chamber 64 communicating with the piping 11. Each room 61,6
3 and 64 are hermetically divided by sealing members 65 and 66, and when the left sealing member 65 is located in the increased diameter portion 57a as the spool 59 moves to the right, it meets the inner wall of the hole 57. The sealing engagement is released, allowing communication between the relay chamber 61 and the supply chamber 64. 6
7 and 68 are protrusions provided on the spool 59;
It limits the amount of movement of the spool 59 in the left and right direction, and normally the tension of the spring 60b is
The tension of spool 59 is set as a predetermined value larger than the tension of a.
is urged to a position where the protrusion 67 contacts the bottom of the hole 57.

The clutch device 80 is of a type that presses the clutch disk against the flywheel and the pressure plate, and the clutch device 80 is of a type that presses the clutch disk against the flywheel and the pressure plate. wire 85
The arm 81 connected to the point d swings clockwise around point d, and the clutch is disconnected.
When you remove your foot from the clutch pedal 84, the arm 81
The clutch is connected by swinging counterclockwise, and is well known in the art.

In addition, in the figure, 71 indicates an O-ring, b a wire connection portion, d a swing center, and 72 a brake pedal.

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, since the clutch is completely connected, the cam shaft 17 is moved by the biasing force of the release spring 83 so that the cam 18 is positioned relatively to the left, and the small diameter portion 54 of the plunger 52 moves beyond the inner hole 48. It is in the illustrated position protruding into the ball guide 38 . Therefore, since the valve element 37 is remote from the valve seat assembly 44 and is not braked, the spool 59 will have the protrusion 67 aligned with the hole 57.
is in contact with the left bottom part of the housing, and is located at a position that blocks the supply chamber 64 and the relay chamber 63.

In this condition, while driving on an uphill road, a railroad crossing,
When the driver depresses the brake pedal 72 for a signal, etc., compressed air is discharged from the brake valve 4 to the piping 6 side until the pressure reaches a pressure proportional to the pedal force, and a part of this discharged compressed air is transferred to the valve device. Air is supplied to the input chamber 61 of No. 9, and the remaining portions are the cam chamber 21,
Groove 53, inner hole 48, inside ball guide 38, piping 8
Air is supplied to the relay room 63 through the
Air is supplied to the brake actuator via this relay chamber 63, and the brake is applied. At this time, the spool 59 does not move because it receives substantially the same pressure on the left and right equal pressure receiving areas.

Thereafter, when the vehicle or the like is sufficiently decelerated, the driver depresses the clutch pedal 84 while keeping the brake pedal 72 depressed. Then, the clutch is disconnected, the cam shaft 17 rotates counterclockwise when viewed from above, and the cam 18 is displaced to the right. In response to the displacement of the cam 18, the plunger 52 is displaced to the right while contacting the cam 18 due to the biasing force of the spring 51, and moves to a position where its small diameter portion 54 is retracted into the inner hole 48, and the valve element 37 is moved under its own weight. is seated on the valve seat assembly 44 by.

In this state, when the vehicle or the like comes to a complete stop and the driver removes his/her foot from the brake pedal 72 while still depressing the clutch pedal 84, the piping 6 side with the contact area between the valve element 37 and the valve seat assembly 44 as the boundary The pressure on the pipe 8 side is released, but the pressure on the piping 8 side is maintained as it is.

At this time, as the pressure on the piping 6 side is released from the brake valve 5 to the atmosphere, the pressure in the input chamber 61 decreases, but the pressure in the relay chamber 63 is maintained as it is. The acting force that urges the spool 59 to the right gradually increases, and finally,
The spool 59 moves through the protrusion 68 to a position where it abuts the right bottom of the hole 57, thereby communicating the relay chamber 63 and the supply chamber 64.

Therefore, compressed air from the air tank 3 is directly supplied to the relay chamber 63, and the pressure supplied to the brake actuator varies from the pressure proportional to the previous pedal force to the pressure inside the air tank 3. Therefore, the braking force obtained by operating the brake actuator increases, and the vehicle or the like is given sufficient braking force to stop on an uphill road.

Through the operations up to this point, the clutch pedal has been depressed, the clutch has been disconnected, and the brake has been applied to maintain a stopped state.

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

Now, as mentioned above, in order to start the vehicle from a stopped state by depressing only the clutch pedal 84, the driver first depresses the accelerator pedal (not shown) to slightly increase the engine speed. While doing so, gradually return the clutch pedal to the inoperative position (return position). Then, the clutch enters a so-called half-clutch state, and the driving force is gradually transmitted to the wheels, and the camshaft 17 is rotated clockwise when viewed from above by the biasing force of the release spring, and the cam 18 is displaced to the left. The small diameter portion 5 of the plunger 52
The plunger 52 is moved so that the valve element 4 protrudes into the ball guide 38, whereby the valve element 37 is separated from the valve seat assembly 44, and the pressure on the piping 8 side is gradually released, and the braking force is gradually reduced. . At this time, the relay chamber 63 and the supply chamber 64 communicate with each other via a groove 62, but by making the passage area of this groove 62 relatively small, it is possible to connect the relay chamber 64 to the relay chamber 63. The pressure increase or holding effect due to air supply can be made smaller than the effect of releasing the pressure in the relay chamber 63 via the holding valve 7, and therefore, after the start of the clutch connecting operation, The pressure in the relay chamber 63 gradually decreases, and finally, due to the tension difference between the springs 60a and 60b, the spool 59
moves to the left and cuts off communication between the relay chamber 63 and the supply chamber 64.

By reducing the braking force on the wheels and increasing the driving force, the vehicle or the like starts on an uphill road, and then when the foot is removed from the clutch pedal, the vehicle returns to a normal running state.

According to the above embodiment, the following effects are achieved.

Since the pressure supplied to the brake actuator at the time of stopping is the pressure on the air tank 3 side, sufficient braking force can be obtained. Therefore, the stopped state of the vehicle, etc. on the uphill road is reliably maintained, and the vehicle, etc. does not move backward.

At the time of starting, when the holding valve 7 is switched to pressure release, the pressure on the piping 8 side will not drop suddenly and in a short time because air will continue to be supplied from the supply chamber 64 to the relay chamber 63 for a while. , there will be no shortage of braking force until the clutch is in a half-clutch state.

As mentioned above, various useful effects can be obtained according to the above-mentioned embodiments, but the present invention can be implemented without being limited to the above-mentioned examples.

That is, in the illustrated example, the valve device 9 is operated by directly detecting the pressure difference, but after both the operation of the brake valve 5 and the operation of the clutch device 80 are detected, the brake valve 5 changes to non-operation. In other words, it may be activated by detecting the cause of the differential pressure across the holding valve, and the specific example of the holding valve itself is similar to that shown in the illustration. Instead of a wire type, use a valve that opens and closes using hydraulic pressure from the clutch master cylinder, and install a holding valve in each multi-system piping system.
Providing a valve device for at least one holding valve, providing a holding valve for a trailer of a tractor-trailer, and for this holding valve, or
For example, a holding valve may be provided for both the tractor and trailer, and a valve device may be provided for each holding valve on the trailer side, and modifications other than these examples are also possible.

As is clear from the above, according to the present invention, as the pressure on the brake valve side of the holding valve decreases due to the release of the brake valve after the holding valve is closed, the pressure on the brake valve side of the holding valve and the operation increase. When a pressure difference occurs between the air tank and the actuator, the actuator side pressure that is maintained is increased to the air tank pressure by providing a valve device that connects the air tank and the actuator.
It is possible to obtain an air brake device capable of resolving insufficient braking force that causes a vehicle to back up on an uphill road.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an air brake device that is an embodiment of the present invention. 1...Air brake device, 3...Air tank, 5...
...Brake valve, 7...Holding valve, 9...Valve device.

Claims (1)

[Claims] 1. An air tank that stores compressed air, a brake valve that discharges compressed air from the air tank in response to a driver's operation, an actuator that takes in compressed air from the brake valve to cause brake operation, and A holding valve provided between the actuator and the brake valve and closed to prevent pressure release from the actuator to the brake valve side when the vehicle or the like stops on an uphill road. In the brake device, as the brake valve side pressure of the holding valve decreases due to the release of the brake valve after the holding valve is closed, a pressure difference is generated between the brake valve side pressure of the holding valve and the actuator side pressure. and,
An air brake device comprising a valve device that communicates the air tank and the actuator.