JPH0645406Y2 - Hydraulically actuated air brake valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a hydraulically actuated air brake valve arranged in a brake circuit of a vehicle or the like.

(Prior Art) As a brake valve of this type, for example, JP-A-54-1 is used.
As disclosed in Japanese Patent No. 59564, an input port that communicates with a compressed air source, an output port that communicates with a brake actuator, an exhaust port that communicates with outside air, and a space provided between the input port and the output port. A normally closed supply valve, an exhaust valve provided between the output port and the exhaust port and normally opened, and a movable body movably arranged to open and close the supply valve and the exhaust valve. And a reaction force chamber formed on one side of the movable body for introducing the pressure of the output port, and a return spring for urging the movable body in a direction in which the supply valve is closed and the exhaust valve is opened. And a spring device that is provided on the other side of the movable body and transmits an input to the movable body is known as a general one.

In the above, a type which is directly actuated by a brake pedal is shown, but recently, in order to operate such a type with a hydraulic pressure generated in a driver-operated master cylinder, the spring device described above is used. A cylinder hole, a piston that is slidably inserted into the cylinder hole and has one end engageable with the spring device, and the other end side of the piston are defined in the cylinder hole. There is a type additionally provided with a cylinder device having a hydraulic chamber communicating with the pressure chamber of a driver-operated master cylinder.

(Problems to be solved by the invention) Even if the movable body is operated by pressing the spring device by the cylinder device as described above, when the movable body is normally in the inoperative position by the return spring, the movable body is directly moved. Alternatively, since the return position is regulated by engaging with an appropriate member via the spring device, simply providing the cylinder device has a problem of impairing the operability as follows.

That is, although the piston of the cylinder device moves according to the pressure difference acting on itself, when the hydraulic pressure is not introduced from the master cylinder into the hydraulic chamber when it is inactive, when acceleration is applied by vibration during traveling of the vehicle, It moves in such a direction as to reduce the volume of the hydraulic chamber so as to form a gap with the spring device. In addition, this tends to hold the piston in its original position due to the sliding resistance of the piston, and at the next brake operation, the piston is engaged with the spring device by the hydraulic pressure introduced into the hydraulic chamber. Until the moving position is reached, the transmission of the operating force from the piston to the movable body via the spring device is disabled, so that there is a problem that the initial operating play is increased.

In view of the above problems, it is an object of the present invention to provide a hydraulically actuated brake valve having improved operability.

(Means for Solving the Problem) In order to achieve the above object, the present invention is provided so as to project into the hydraulic chamber, and when the cylinder device in which the hydraulic pressure is not introduced into the hydraulic chamber is inoperative, A positioning device is provided that engages one end of the piston with the spring device by engaging the other end of the piston.

(Operation) When the master cylinder is not operated by the driver and hydraulic pressure is not introduced from the master cylinder into the hydraulic chamber of the cylinder device, it is attempted to move the piston to the hydraulic chamber side due to vibration while the vehicle is running. Even if the acting force is generated, the piston is prevented from moving toward the hydraulic chamber away from the spring device by the positioning device, and is retained in a position where the piston engages with the spring device without a gap. Therefore, when hydraulic pressure is introduced from the master cylinder into the hydraulic chamber of the cylinder device to operate the brake, the piston receives the hydraulic pressure and immediately starts pressing the spring device, and the operating force is moved via the spring device. It will be transmitted to the body.

(Embodiment) FIG. 1 is a sectional view showing an embodiment of the present invention.

In the drawing, the hydraulically actuated brake valve is indicated by 1 as a whole, and a valve portion A is provided on the lower side of a substrate 2 mounted on a vehicle body (not shown) and a cylinder portion B is provided on the upper side thereof.

The valve portion A has the same function as that of the conventional example except for a part thereof, and therefore will be briefly described.

The valve part A has a main body 5 composed of an upper main body 3 and a lower main body 4 that are connected to each other, has a through hole in the central portion, and has a first side and a right side that communicate with an air reservoir (not shown). The second input ports 6a and 6b are provided on the left side with the first and second output ports 7a and 7b that communicate with a brake chamber (not shown), and the lower end opening of the through hole is common. The exhaust port 8 is formed.

First and second input ports 6a, 6b and first and second output ports 7
Between the a and 7b, the valve bodies 9a and 9b are respectively the valve springs 10a and 10b.
And the lower part of the piston 12 and the relay piston 13 as movable bodies which are arranged so as to be seated on the supply valve seats 11a and 11b formed in the main body 5 and which are arranged to face the respective valve bodies 9a and 9b. The exhaust valve seats 14a, 14b are formed so that they can be seated on the respective valve bodies 9a, 9b, the reaction chamber 15 below the piston 12, the relay chamber 16 above the large diameter portion of the relay piston 13, Reaction chamber 17 on the lower side
Are distinguished from each other. Each valve body 9a, 9b and supply valve seat 11a, 1
1b means first and second air supply valves 18a and 18b, respectively, and respective valve bodies 9
a and 9b and the exhaust valve seats 14a and 14b are the first and second exhaust valves 19
Form a and 19b respectively. The reaction force chamber 15 is the first output port.
When the first exhaust valve 19a is opened while always communicating with 7a, the inner hole 21 of the shaft portion 20 of the relay piston 13 and each valve element 9a,
When the first air supply valve 18a is opened through the inner hole of 9b and the first air supply valve 18a is opened, the first input port 6a can communicate with each other, and the relay chamber 16 is
Through the small hole 22, the first output port 7a and the reaction force chamber 15 are constantly communicated with each other, the reaction chamber 17 is always communicated with the second output port 7b, and the valve body is opened when the second exhaust valve 19b is opened. Through the inner hole of 9b to the exhaust port 8,
When the second air supply valve 18b is opened, it communicates with the second input port 6b.

The shaft portion 20 of the relay piston 13 penetrates the valve body 9a and enters the reaction force chamber.
It extends to 15 and engages with the shaft member 25 inserted into the inner hole 24 of the shaft portion 23 of the piston 12, so that even if the large diameter portion is pressed by the operating spring 26, it does not move further downward. It is supported.

The piston 12 is biased upward by a return spring 27 arranged below, and a spring device 28 is provided on the upper surface side of the piston 12.
Is provided. The spring device 28 is provided between the piston 12 and the spring seat 31 that fixes the sleeve 29 by screwing the nut 30 to the sleeve 29 fitted to the shaft portion 23 and at the same time. Spring 32 and a second spring 33 having a small diameter are concentrically arranged with respect to the shaft portion 23, and the first spring 32 is loaded and the second spring 33 is unloaded. When the first spring 32 is stretched and compressed by the spring receiver 34 by a predetermined amount, the spring receiver 34 engages with the spring receiver 35 and the second spring is engaged.
I made it possible to compress 33.

Above the spring seat 31 is a return spring for the relay piston 13.
36 is stretched between a spring receiver 37 engaging with the shaft member 25.

In contrast to the valve section A, the cylinder section B is as follows.

A cylinder body 41 having a cylinder hole 40 coaxial with the valve portion A is fixed to the substrate 2 with its opening facing the spring seat 31, and the cylinder hole 40 has a first spring 32 The plunger 42 in the shape of a cup is brought into contact with only the spring receiver 34 downward, and the piston 44 defining the hydraulic chamber 43 is inserted upward so that the upper end of the plunger 42 serves as a spherical surface portion 45. It is adapted to abut the piston 44. In the cylinder portion B, the hydraulic chamber 43 is connected to a master cylinder (not shown) by a connecting portion 46 formed in the cylinder body 41, and an air bleeder device 47 is provided.

The cylinder bore 40 has a positioning device 50 for the piston 44.
This device 50 has a stepped hole 52 having a small diameter portion 51 on the cylinder hole 40 side, a lower screw portion 53 screwed to the small diameter portion 51, and an upper screw portion 54 having a stepped hole. 52 is loosely fitted, and the screw portion 53,
A seal part 55 formed between 54 is tightly fitted in the stepped hole 52 via a seal material 56 to dispose an adjuster 57.
The screw portion (54) has a lock nut (58) screwed in until it comes into contact with the cylinder body (41). In addition, in the figure, a
Indicates a lip-type seal, and b indicates an O-ring.

The operation of such an embodiment will be described below.

Now, screw the adjuster 57 into place, and then use the lock nut 58 to prevent the adjuster 57 from loosening.
The screw 44 of the adjuster 57 causes the upper end to come into contact with the lower end of the adjuster 57 and move downward, whereby the plunger 42 also comes into contact with the lower end, so that it moves downward together with the plunger 42,
Finally, it abuts the spring bearing 34 via the plunger 42.
At this time, if the adjuster 57 is pushed down further, the piston
The piston 44 and the plunger 42 push the piston 12 downward against the tension of the return spring 27 to move the piston 12, and the valve body 9a and the discharge valve seat 14
decrease the distance from a. At the same time, the downward movement of the piston 12 also moves the relay piston 13 downward, so that the gap between the valve body 9b and the discharge valve seat 14b is also reduced. At this time, since the preload of the spring device 28 is sufficiently large, it is not further compressed by a pressing force to compress the return spring 27, and the tension of the actuating spring 26 is lower than the tension of the return spring 36. Since it is also small, there is no effect.

In this way, the piston 44 is
The valve device 9 and the gap between the spring device 28 and
It is also possible to adjust the gap amount between the a and 9b and the discharge valve seats 14a and 14b.

The operation of the entire brake valve 1 will be briefly described as follows.

When pressure is supplied to the hydraulic chamber 43 from a master cylinder (not shown), the piston 44 moves to the piston via the plunger 42.
12 is moved downward, the first exhaust valve 19a is closed, and the first exhaust valve 19a is closed.
The air supply valve 18a is opened, and at the same time, the relay piston 13 also moves downward, so the second exhaust valve 19b is closed and the second exhaust valve 19b is closed.
The air supply valve 18b is opened. Then, first, the pressure in the reaction force chamber 15 is discharged from the first output port 7a and simultaneously supplied to the relay chamber 16 to press the relay piston 13 downward, and further acts on the piston 12 to supply the pressure. The air valve 18a is pressed in the direction to close it. Therefore, the piston 12 continues to open the air supply valve 18a until the input received from the spring device 28 and the reaction force received from the reaction force chamber 15 are balanced, and when balanced, the exhaust valve 1
9a and the air supply valve 18a are both closed, and the spring device 28 is further compressed from the pre-compression state according to the input force and the reaction force. Further, the relay piston 13 also raises the pressure of the reaction force chamber 17 so that the input received from the relay chamber 16 and the reaction force received from the reaction force chamber 17 are balanced, and when balanced, the air supply valve 18b and the exhaust valve 19b. Both are closed. The pressure of the output ports 7a and 7b obtained by such an operation is an air pressure proportional to the pressure supplied to the hydraulic chamber 43.

When the pressure supplied to the hydraulic chamber 43 is high, the spring device 28
Therefore, the compression amount of the first spring 32 increases, so that the second spring 32
33 also acts, and in this case, the spring constant changes due to the combination of the two springs 32, 33, so that the change of the output with respect to the change of the input becomes large compared to the case where the second spring 33 does not act. Output will be obtained.

When the pressure in the hydraulic chamber 43 is released, the spring device 28 loses the input, so that the piston 12 returns to the posture defined by the spring seat 31, and the piston 12 is tensioned by the return spring 27 to cause the spring device 28 and the plunger 42 to move. , And returns to the position where it abuts the adjuster 57 via the piston 44, and further, the relay piston 13 moves upward by the return spring 36 as the piston 12 moves upward, so that each air supply valve 18a , 18b closed and each exhaust valve 19a, 1
Since the valve 9b is opened, the pressure in each of the counter pressure chambers 15 and 17 and the pressure in the relay chamber 16 are exhausted to the outside air from the exhaust port 8 and the operation is completed.

In the present embodiment, by rotating the adjuster 57, the piston 44 is pushed down in the drawing to move the piston 44 to the plunger 42.
Since the piston 44 can be engaged with the spring device 28 via the plunger 42 without a gap, it is possible to reliably prevent the occurrence of the initial operation play as described above.

Then, by increasing the screwing amount of the adjuster 57, it is possible to adjust the gap amount between the valve bodies 9a, 9b and the discharge valve seats 14a, 14b, and adjust the valve gap to improve the operability of the valve. The secondary effect of being able to improve can be acquired.

Further, since the positioning device 50 uses members such as the adjuster 57 and the lock nut 58, the configuration is simple and does not become unnecessarily complicated.

[Effect of device]

As is apparent from the above description, according to the present invention, the positioning device provided so as to project into the hydraulic chamber of the cylinder device prevents the piston from moving toward the hydraulic chamber when it is inoperative, and Since the return position of is stably regulated to the position to be engaged with the spring device, it is possible to reliably prevent a situation in which the piston is separated from the spring device and an initial operation play is generated at the time of brake operation, It is possible to immediately maintain a state in which the operating force corresponding to the hydraulic pressure introduced into the hydraulic chamber can be transmitted from the piston to the movable body via the spring device, and thus it is possible to improve the operational response and reliability of the valve.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention. 1 ... Brake valve responding to hydraulic pressure, 28 ... Spring device, 44
...... Piston, 50 …… Positioning device, B …… Cylinder part.

Claims (1)

[Scope of utility model registration request] 1. An input port that communicates with a compressed air source, an output port that communicates with a brake actuator, an exhaust port that communicates with the outside air, and a normal time provided between the input port and the output port. A supply valve which is closed, an exhaust valve which is provided between the output port and the exhaust port and which is normally opened, and a movable body which is movably arranged to open and close the supply valve and the exhaust valve, A reaction force chamber that is formed on one side of a movable body and into which the pressure of the output port is introduced; a return spring that urges the movable body in a direction of closing the supply valve and opening the exhaust valve; A spring device provided on the other side of the movable body for transmitting an operating force to the movable body, and a cylinder device provided on the opposite side of the spring device to the movable body, wherein the cylinder device includes a cylinder hole, A piston slidably inserted into the cylinder hole and one end of which is engageable with the spring device. A hydraulic pressure chamber which is defined in the cylinder hole at the other end side of the piston and communicates with a pressure chamber of a master cylinder operated by a driver, and a hydraulic pressure is introduced into the hydraulic pressure chamber to cause the piston to move. In a hydraulically responsive air brake valve in which the movable body can be moved through the spring device by being moved to the spring device side, the hydraulic brake type air brake valve is provided so as to project into the hydraulic chamber, and the hydraulic pressure is applied to the hydraulic chamber. A hydraulically responsive air brake valve having a positioning device for engaging one end of the piston with the spring device by engaging the other end of the piston when the cylinder device is not activated.