JPH0343903Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a brake operation control valve device that is optimal for use in brake equipment for vehicles, etc., and in particular, the valve device that is suitable for the inlet connected to the pressure source side and the brake actuator side. a movable body movably arranged in a hole communicating the inlet and the outlet; a preload spring that biases the movable body to one side with a predetermined biasing force; a pressure-receiving part that is provided on the body and moves the movable body to the other side against the biasing force of the preload spring when the outlet side pressure reaches a predetermined pressure or more;
The present invention relates to a brake operation control valve device in which the inlet and the outlet communicate with each other via a throttle passage when the movable body is on the one side, and freely communicate with each other when the movable body is on the other side.

[Conventional technology and its problems]

For example, this type of device is
The one disclosed in No. 19452 is known.
In this device, when the pressure on the outlet side is above a predetermined pressure, the inlet side and the outlet side freely communicate with each other, and when the pressure on the outlet side is below a predetermined pressure, the inlet side and the outlet side communicate with each other through a throttle passage. As a result, the supply speed of pressure fluid to the brake actuator is slowed down at the beginning of the brake operation to obtain the desired effect. However, when braking suddenly, the throttling effect becomes large and the delay in braking becomes noticeable. This can lead to dangerous driving situations.

In order to prevent this, it is conceivable to make the aperture variable, but the variable mechanism becomes quite complicated. It is desirable to solve this problem with a simple mechanism.

[Problem that the invention attempts to solve]

The present invention was created in view of the above problems, and the technical problem is to detect the degree of sudden braking by the increase in pressure on the inlet side, and to establish communication between the front and rear of the throttle in response to this, and to solve this problem. The object of the present invention is to provide a brake operation control valve device that does the following.

[Means] The above object is to provide a second movable body that receives the pressure on the inlet side and is movable when the pressure reaches a predetermined level or more in the configuration described at the beginning, and to move according to the movement of the second movable body. This is achieved by a brake operation control valve device in which a check valve allowing free communication between the inlet and the outlet is arranged with the direction from the outlet to the inlet being the forward direction.

〔Example〕

Hereinafter, a brake operation control valve device according to an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, the brake operation control valve device of this embodiment is indicated as 1 as a whole, and a stepped hole 3 is formed in the upper part of a main body 2, and the opening end thereof is connected to a cover body 4 with a seal ring 5 interposed therebetween. is blocked by. An output connection hole 6 is formed in the lid 4, and is connected to a brake actuator, such as an air-over-hydraulic booster, via a pipe (not shown).

A stepped piston 7 fitted with seal rings 9 and 10 is slidably fitted into the stepped hole 3, and defines an input chamber 13 and an output chamber 15 on both sides thereof. Also, an air chamber 1 is provided between the seal rings 9 and 10.
2 is defined, which communicates with the atmosphere via a through hole 11.

A valve body 16 is disposed between the lid body 4 and the stepped piston 7 and is biased toward the lid body 4 by a spring 17, and the stepped piston 7 is biased toward the valve body 16 by a spring 8. , is in contact with the valve body 16 in the normal illustrated state. A small diameter through hole is provided in the center of the valve body 16.
That is, a throttle hole 16a is formed, and a through hole 14 is formed in the stepped piston 7 in the axial direction in alignment with this. The input chamber 13 on the right side of the stepped piston 7 is constantly in throttle communication with the output chamber 15 on the left side via the through hole 14, the throttle hole 16a, and the groove 19 formed in the end surface of the lid body 4.

The open end of the hole 20 formed in the lower part of the main body 2 is closed by a lid 21 with a seal ring 23 interposed therebetween. An input connection hole 22 is formed in the lid 21, and is connected to a compressed air source via a pipe (not shown), for example, a relay valve. The relay valve has a well-known configuration, although not shown, and supplies compressed air from a compressed air source to the input connection hole 22 as an output in response to an input from a brake valve operated by a brake pedal.

A second stepped piston 27 is fitted with a seal ring 28 in the hole 20 so as to be slidable therein.
It is biased to the right by a spring 31 and is in contact with the lid body 21 in the normal state shown.

Input side communication chambers 34 are provided on both sides of the stepped piston 27.
and an output side communication chamber 32 are formed, which are connected to the above-mentioned input chamber 13 through diagonal through holes 26 and 33, respectively.
and is in constant communication with the output chamber 15. On the other hand, the input side communication chamber 34 is constantly in communication with the input connection hole 22 through the radial through hole 25 and the axial through hole 24 formed in the lid body 21 and through the input connection holes 22 and 24 described above. ing. Further, the output side communication chamber 32 is always in communication with the above-mentioned output connection hole 6 via the diagonal passage hole 33, the output chamber 15, and the diagonal passage hole 18 formed in the lid body 4.

A valve spring 30 and a valve element 34' biased to the left by the valve spring 30 are disposed in the stepped inner hole 29 of the second stepped piston 27. In the normal state shown, the valve element 34' comes into contact with the stepped portion 29a of the stepped inner hole 29,
The flow of compressed air from the input side communication chamber 34 side to the output side communication chamber 32 side is blocked, but the reverse is allowed. That is, the valve body 34', the spring 30, the stepped portion 29
A constitutes a check valve. Stepped piston 27
The pressure-receiving areas on both sides of the stepped piston 27 are the same, but when sudden braking is applied, the flow path resistance of the above-mentioned throttle hole 16a increases, and the leftward pressing force due to the differential pressure on both sides of the stepped piston 27 is increased by the force of the spring 31. When the force becomes larger than the force, the stepped piston 27 moves to the left, comes into contact with the end wall 2a of the hole 20, and stops. Valve body 34' is spring 30
However, when the shaft portion 35 comes into contact with the end wall 2a, the valve body 34' is separated from the stepped portion 29a of the inner hole 29, and the input side communication chamber 34
and the output side communication chamber 32 are in free communication. In addition,
A groove 27a is formed at the end of the stepped piston 27, so that even if the stepped piston 27 contacts the end wall 2a, the flow resistance is sufficiently small.

The embodiment of the present invention is constructed as described above. Next, this effect will be explained.

First, a case in which normal brake operation is performed will be described. That is, a case will be described in which the brake pedal (not shown) is not suddenly depressed and the supply speed of compressed air to the input connection hole 22 is not very high.

Compressed air flows from the input connection hole 22 to the through holes 24, 2.
5, input side communication room 34, through hole 26, input room 13,
It flows into the output chamber 15 through the through hole 14, the throttle hole 16a, and the groove 19 of the lid 4. From here, diagonal hole 1
8. The compressed air is supplied through the output connection hole 6 into a compressed air chamber of an air-over-hydraulic booster (not shown). However, since the supply is through the throttle hole 16a, the supply speed is low, and this makes it difficult to achieve the desired effect, for example, by creating a shock at the joint between the air servo section and the master cylinder section of the air-over hydraulic booster. can be avoided.

Since the stepped piston 7 receives pressure from the output chamber 15 at its large diameter portion, the rightward pressing force of the stepped piston 7 due to the pressure inside the output chamber 15 is reduced by the pressure inside the input chamber 13. When the pressure rises enough to overcome the sum of the leftward pressing force of the spring 8 and the spring force of the spring 8, the stepped piston 7 moves to the right and the valve body 16
and the stepped piston 7 are separated. As a result, the axial passage hole 14 of the stepped piston 7 is in free communication with the output chamber 15. The compressed air, whose supply speed has been reduced until now through the throttle hole 16a, can now be supplied to the output chamber 15 at a much higher speed. The brake fluid pressure at the wheels increases rapidly and the brakes are applied quickly.

Compressed air is also supplied from the output chamber 15 through the diagonal passage hole 33 to the output side communication chamber 32, but the pressure rises at approximately the same speed as the pressure in the input side communication chamber 34, and the difference between the two sides of the stepped piston 27 increases. Since the pressure is not large enough to overcome the spring force of spring 31, stepped piston 27 remains stationary in the state shown. Therefore, the flow from the input side communication chamber 34 to the output side communication chamber 32 is blocked.

If the above is shown graphically, the pressure in the output chamber 15 or the brake fluid pressure in the wheels changes over time as shown by the solid line A in FIG. In other words, if the brake pedal is depressed at time t ₀ , approximately time t ₂
Until then, the pressure rises slowly due to the action of the throttle hole 16a, after which it rises sharply until about time _t3 , and then remains constant.

When the pressure on the brake pedal is released to release the brake, the input connection hole 22 is communicated with the atmosphere, and the compressed air from the air-over hydraulic booster is passed through the output connection hole 6, the through hole 18, the output chamber 15, and the axial direction. Through hole 14, input chamber 13, diagonal through hole 2
6. Air is exhausted from the input connection hole 22 through the input side communication chamber 34 and the through holes 25 and 24. The compressed air from the output chamber 15 further passes through the diagonal passage hole 33, opens the valve body 34, and is exhausted from the input connection hole 22. When the pressure decreases so that the sum of the extraction force of the compressed air in the input chamber 13 and the spring force of the spring 8 to the stepped piston 7 becomes greater than the extraction force of the compressed air in the output chamber 15, the stepped piston 7 moves to the left. The air moves and comes into contact with the valve body 16 as shown in the figure, cutting off free communication on both sides, and thereafter, the air is exhausted to the input chamber 13 side through the throttle hole 16a. Note that as long as the pressure in the output communication chamber 32 on the second stepped piston 27 side overcomes the spring force of the valve spring 30 (this spring force may be sufficiently small), the valve body 34' is opened. , and are exhausted to the input connection hole 22 side. Therefore, the brake can be released quickly.

Next, a case will be described in which emergency braking (sudden braking) is performed. That is, a case will be described in which the brake pedal is suddenly depressed and the supply speed of compressed air to the input connection hole 22 is extremely high.

In this case, the pressure in the input chamber 13 rises rapidly, but the pressure rise rate in the output chamber 15 is slow due to the throttle hole 16a. Therefore, even if the pressure in the input chamber 13 becomes sufficiently high, the stepped piston 7 does not move. On the other hand, in the lower stepped piston 27, the pressure in the input side communication chamber 34 increases rapidly, but the pressure in the output side communication chamber 3
Since the rate of pressure rise at point 2 is slow, a large pressure difference is generated and the pressure moves quickly to the left. As a result, the valve body 3
4' is separated from the stepped portion 29a of the inner hole 29, and both communication chambers 34 and 32 are in free communication. Therefore, the compressed air from the input connection hole 22 is transferred to the input side communication chamber 34, the inner hole 29 of the stepped piston 27, the output side communication chamber 32,
It is supplied to the air-over hydraulic booster through the diagonal passage hole 33, the output chamber 15, the diagonal passage hole 18, and the output connection hole 6. On the other hand, the pressure in the outlet chamber 15 rises rapidly due to the introduction of compressed air from the diagonal passage hole 33, and the resulting rightward pressing force of the stepped piston 7 is combined with the leftward pressing force due to the pressure in the input chamber 13 and the spring 8. When the stepped piston 7 moves to the right and separates from the valve body 16, the compressed air is no longer output even if it passes through the input chamber 13 and the axial hole 14. It flows into chamber 15. In this way, sudden braking can be applied as desired.

If the above is shown in a graph, the pressure in the output chamber 15 or the brake fluid pressure in the wheels changes with time, as shown by the chain line B in FIG. That is, if the brake pedal is suddenly depressed at time t ₀ , the pressure immediately increases rapidly as desired and reaches a constant value approximately at time t ₁ .

When loosening the brake, the brake can be quickly loosened in the same manner as the normal brake operation described above. Note that during braking, the stepped piston 27 moves back to the illustrated position before the pressure reaches a constant level.

Although the embodiments of the present invention have been described above, the present invention is of course not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the embodiments described above, the first stepped piston and related parts may be replaced with conventionally known structures.

Furthermore, although the above embodiments have been described as being applied to an air-over-hydraulic booster, the present invention is not limited thereto and can be applied to general brake actuators.

[Effect of idea]

As described above, according to the brake operation control valve device of the present invention, there is no braking delay during sudden braking despite having the throttle passage.
Furthermore, the brake can be released more quickly.

[Brief explanation of drawings]

FIG. 1 is a sectional side view of a brake operation control valve device according to an embodiment of the present invention, and FIG. 2 is a graph showing the operation of the device. In the drawings, 1... Brake operation control valve device, 27... Second stepped piston, 30... Valve spring, 34'... Valve body.

Claims (1)

[Scope of utility model registration request] an inlet connected to a pressure source side, an outlet connected to a brake actuator side, and a movable body movably disposed within a hole communicating the inlet and the outlet;
a preload spring that biases the movable body toward one side with a predetermined biasing force; and a preload spring provided on the movable body that resists the biasing force of the preload spring when the outlet side pressure reaches a predetermined pressure or higher. and a pressure-receiving part that moves the movable body to the other side, so that when the movable body is on the one side, the inlet and the outlet communicate with each other via a throttle passage, and when the movable body is on the other side, they communicate freely. In the brake operation control valve device, a second movable body is provided which receives the pressure on the inlet side and is movable when the pressure reaches a predetermined level, and the inlet and the outlet are controlled according to the movement of the second movable body. A brake operation control valve device comprising a freely communicating check valve arranged with the direction from the outlet to the inlet as the forward direction.