JPH0735127Y2 - Fluid actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a fluid actuator, and more particularly to a fluid actuator for controlling the opening degree of a valve in a stepwise manner.

b. Prior Art FIG. 3 conceptually shows an exhaust brake system using the above fluid actuator.

In this exhaust brake system, the valve 1 is controlled in two stages of a fully closed position and a substantially fully closed position in order to perform a warm-up action.

In this exhaust brake system, the negative pressure actuator 2
A negative pressure circuit 6 for interposing a positioning spring 5 between the diaphragm 3 and the rod 4 and applying a two-stage pressure to the actuator 2 is provided. The negative pressure circuit 6 branches the pipeline 8 from the vacuum pump 7 into pipelines 8a and 8b, and interposes a pressure adjusting valve 9 in one of the pipelines 8b and electromagnetically connects the pipelines 8a and 8b. It connects to the pipeline 11 via the switching valve 10, and the pipeline 11 is connected to the pressure chamber 12 of the actuator 2. The diaphragm 3 of the actuator 2 is biased rightward in FIG. 3 by the spring 13, and the tip of the rod 4 is connected to the lever 14 of the valve 1.

In the exhaust brake system, the valve 1 is fully opened in the normal traveling state as shown in FIG. In this state, the pressure chamber 12 of the actuator 2 is opened to the atmosphere via the switching valve 10, and the actuator 2
Is unloaded. Therefore, the lever of valve 1
14 is the urging force of the spring 13 in FIG.
It is located on the right.

When the switching valve 10 is moved to the right in order to perform the exhaust brake action, the pressure chamber 12 of the actuator 2 is communicated with the vacuum pump 7 via the pipe line 8a. Then, the pressure in the pressure chamber 12 of the actuator 2 is reduced, and accordingly, the diaphragm 3 is moved to the left in FIG. At this time, the displacement of the diaphragm 3 is transmitted to the rod 4 and moves the rod 4 leftward in FIG. When the rod 4 moves the stroke S ₁ , the spring receiver 15 contacts the inner wall 12 a of the pressure chamber 12. This position is the almost fully closed position A of the valve 1. When rod 4 reaches this position, it remains in that position until the pressure in pressure chamber 12 is large enough to deflect spring 5. Pressure chamber
When the pressure in 12 further decreases, the diaphragm 3 is further moved to the left in FIG. 3, and the rod 4 is also moved accordingly. Then, when the rod 4 moves an appropriate amount S ₃ within the stroke S ₂ , the lever 14 contacts the stopper 16 shown in FIG. 5, and the rod 4 is stopped there. That is, the lever 14 also moves by the stroke S ₃ , is stopped at point C in FIG. 3, and the valve 1 is fully closed.

The warm-up action is performed by moving the switching valve 10 to the left in FIG. In this state, the pressure chamber 12 of the actuator 2 is communicated with the vacuum pump 7 via the conduit 8b. Therefore, the air in the pressure chamber 12 is
Is sucked by the vacuum pump 7 via the. by the way,
When the pressure in the pressure chamber 12 drops to a constant pressure, the pressure regulating valve 9 shuts off the conduit 8b and disconnects the pressure chamber 12 from the vacuum pump 7. As a result, the pressure chamber 12 is kept at a constant pressure. Kept in. The pressure at this time is the pressure between points A and B in the graph of FIG. Therefore, the lever 14 is stopped at the point A, and the valve 1 is in the almost fully closed position. In this state, the exhaust pipe 17 is slightly opened, the exhaust gas of the engine is discharged to the outside, the engine stop is avoided, and the warm-up is performed.

c. Problems to be Solved by the Invention By the way, in such an exhaust brake system, it is necessary to adjust the substantially fully closed position of the valve 1 for each vehicle and according to the environment in which the vehicle is used.

Therefore, in this exhaust brake system, as shown in FIG. 3 and FIG. 5, the rod 4 is divided into two, they are connected by a turnbuckle 18, and the length of the rod 4 is changed to warm the valve 1. I was adjusting the machine position.
That is, when the rod 4 is lengthened, the diaphragm 3 is positioned at the position moved to the left in FIG. This means that the stroke S ₁ becomes smaller, and as a result, the rotation amount of the valve 1 also becomes smaller. In FIG. 5, reference numeral 19 is a stopper for setting the fully closed position of the valve 1.

Therefore, the rod 4 needs to have a length that is at least the stroke L of the rod 4 plus the length of the turnbuckle 18, and the actuator 2 becomes large.

Then, the objective of this invention is providing the actuator which aimed at miniaturization.

d. Means for Solving the Problems In the fluid actuator of the present invention, the pressure sensitive member having the output rod is urged to one side by the first spring, and the pressure sensitive member is separated from the housing by a constant distance. When the pressure sensitive member is actuated by the fluid pressure while the second spring is arranged by applying a set load in advance and the pressure sensitive member increases, the pressure sensitive member first moves to the first Actuated against the biasing force of the spring of the second spring, after the second spring abuts the housing, remains there until the second spring is deflected, after which the biasing of the first and second springs. In a fluid actuator operated against a force, the output rod is extended into the housing, and the extension is slidably moved on the bottom surface of a disc-shaped spring receiver. The second spring is provided between the spring receiver and the pressure sensitive member, and a pipe joint is disposed in the housing on the extension of the output rod. A stopper having a passage that communicates the passage of the pipe joint with the inside of the housing is arranged on the circumference so as to be able to move forward and backward, and a flange is formed at the tip of the stopper, and when the first spring is bent, The flange is in contact with the open end of the spring receiver.

e. Action In the fluid actuator of the present invention, the amount of movement of the first stage of the pressure sensitive member is set by adjusting the amount of protrusion of the stopper. That is, as the pressure acting on the pressure sensitive member increases, the pressure sensitive member first moves while bending the first spring through the spring receiver until the second spring comes into contact with the stopper. Movement of the second
The second step operation in which the first spring and the second spring are further moved while being flexed after a quiescent period until the second spring is flexed after the spring comes into contact with the stopper. However, by adjusting the protrusion amount of the stopper, the distance between the stopper and the spring receiver is adjusted, and thus the operation amount of the first stage of the pressure sensitive member is set.

f. Embodiment FIGS. 1 and 2 show an example in which the fluid actuator according to the present invention is used to drive an exhaust valve.

In the housing 21 of the fluid actuator 20, a diaphragm 22 is arranged as a pressure sensitive member. The diaphragm 22 includes an output rod 23, and the output rod 23 extends from the housing 21 to the outside. A guide rod 24 extending in a direction opposite to the output rod 23 is planted in the diaphragm 22. This rod
24 has a collar at the end. A bottom surface of a plate-shaped spring receiver 25 is loosely fitted to the guide rod 24. The spring receiver 25 is prevented from falling off the guide rod 24 by the collar. A second spring 27 is arranged between the diaphragm 22, the housing 21, and the spring receiver 25. this house,
Especially, an appropriate set load is applied to the second spring 27.

Further, the housing 21 of the fluid actuator 20 includes
The pipe joint 28 is fixed. At one end of the pipe joint 28, a negative pressure circuit similar to the conventional negative pressure circuit 10 shown in FIG.
29 pipes 29a are connected. The pipe joint 28 has a female screw portion 28a on the inner circumference of the other end portion, and one end of a stopper 30 is screwed into the female screw portion 28a. This stopper 30
Has a passage 30a inside and a slotted groove 30b on the end face for receiving the tip of a driver. This stopper 30
Has a flange portion 30c at the other end. The flange portion 30c serves as a stopper surface 3 that receives the spring receiver 25.
It forms 0d.

The fluid actuator 20 is installed in the exhaust pipe 32 by fixing the housing 21 to the bracket 31 and fixing the bracket 31 to the exhaust pipe 32. Further, the output rod 23 of the fluid actuator 20 is connected to the lever 35 of the exhaust valve 34 via the connection fitting 33.

The fluid actuator 20 operates as follows and controls the valve 34 of the exhaust brake system.

In this exhaust brake device, when the actuator 20 is in the non-operating state, the lever 35 has an adjusting bolt arranged on the bracket 31.
It touches the tip of 36. The adjusting bolt 36 positions the exhaust valve 34 at the fully open position.

When the switching valve of the negative pressure circuit 29 is switched to the low pressure side and the pressure in the negative pressure chamber 21a of the actuator 20 decreases, the diaphragm 22 is operated against the urging force of the first spring 26. When the diaphragm 22 is operated in this manner and the spring receiver 25 contacts the stopper surface 30d of the stopper 30, the diaphragm 22 is stopped there. That is, the negative pressure chamber
The negative pressure in 21a is not large enough to deflect the second spring 27 and actuate the diaphragm 22. In this state, the exhaust valve 34 is maintained in a substantially fully closed position, so that the engine is warmed up.

When the switching valve of the negative pressure circuit 29 is switched to the lowest pressure side in the fully opened state of the exhaust valve 34, the diaphragm 22 is operated, that is, the spring receiver 25 contacts the stopper 30, and
Then, after being temporarily stopped, the second spring 27 is bent and further actuated. When the exhaust valve 34 is fully closed, the diaphragm 22 has the lever 35
It is stopped by coming into contact with the head of the bolt 37 installed at 31. In this state, the exhaust brake action is performed.

By the way, when it is desired to set the exhaust valve 34 to a substantially fully closed position, that is, the warmed-up position, for example, to a slightly opened position,
Insert the tip of the screwdriver into the slit groove 30b of the stopper 30 and rotate the stopper 30 to move the stopper 30 into the housing.
It should be projected into 21. Then, the distance between the spring receiver 25 and the stopper 30 becomes shorter, which shortens the stroke of the first stage of the output rod 23, and the exhaust valve
34 will be stopped at a position that is more open than the warm-up position.

Although the diaphragm 22 is shown as the pressure sensitive member in the above embodiment, the actuator of the present invention may employ a piston.

g. Effect of the Invention As described above, in the fluid actuator according to the present invention, since the stop position of the first stage of the output rod is set by the stopper arranged in the housing, the output rod can be short, which results in The fluid actuator can be made compact.

In the fluid actuator according to the present invention, the second spring is used, and the spring can perform stable two-step control without the pressure sensitive member being affected by the pressure fluctuation of the negative pressure chamber. The stroke amount in one step can be arbitrarily adjusted, and a seal member is not required between the stopper and a member supporting the stopper.

[Brief description of drawings]

1 and 2 show an example in which the fluid actuator according to the present invention is applied to an exhaust brake device.
The figure is a front sectional view thereof, FIG. 2 is a side view thereof, FIG. 3 is a conceptual diagram showing a conventional exhaust brake device, FIG. 4 is a diagram showing characteristics of the actuator, and FIG. It is the side view which showed the fluid actuator. 20 …… Fluid actuator, 21 …… Housing, 21a…
… Negative pressure chamber, 22 …… Diaphragm, 23 …… Output rod, 24
...... Guide rod, 25 ...... Spring holder, 26 ...... First
Spring, 27 …… second spring, 28 …… pipe fitting, 28a …… female screw part, 29 …… negative pressure circuit, 30 …… stopper, 30a …… passage, 30b …… slit groove, 30c… … Flange part, 30d …… Stopper face, 31 …… Bracket, 32 …… Exhaust pipe, 33 …… Connecting metal fitting, 34 …… Exhaust valve, 35 …… Lever, 36,37 …… Bolt.

Claims (1)

[Scope of utility model registration request] 1. A pressure-sensitive member having an output rod is urged to one side by a first spring, the pressure-sensitive member is kept at a constant distance from a housing, and a set load is applied in advance to the pressure-sensitive member. When the second spring is provided and the pressure sensitive member is operated by the negative pressure of the negative pressure chamber, the pressure sensitive member first resists the urging force of the first spring as the pressure increases. Are actuated, and after the second spring abuts the housing, the second spring
In a fluid actuator that remains there until it is deflected and is then acted against the biasing forces of the first and second springs, extending the output rod into the negative pressure chamber of the housing, the extension The bottom surface of a disc-shaped spring receiver having a sufficient depth for slidingly engaging the second spring between the spring receiver and the pressure-sensitive member to extend the output rod. A pipe joint is arranged in the above housing, and a stopper having a passage for communicating the passage of the pipe joint with the inside of the housing is arranged on the inner periphery of the pipe joint so as to be movable back and forth, and the tip of the stopper is provided. A fluid actuator, wherein a flange is formed on the first spring, and when the first spring is bent, the flange comes into contact with the open end of the spring receiver.