JPH0640968Y2 - Fluid pressure actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a fluid pressure actuator used for a transmission for an automobile or the like.

[Prior Art] A gear actuator in which a synchronous clutch of a gear transmission is operated by a fluid pressure actuator has already been put into practical use. Especially, in the case of using pressurized air for fluid pressure, the piston rod is almost constant and at a considerably high operating speed. Due to the operation, the stepwise operation of the synchronous clutch may be overloaded, which may cause squealing of gears and further wear of the sliding portion.

This point will be described in detail with respect to the case of the pin type synchronous clutch.As shown in FIGS. 5 and 6, the synchronous clutch has a transmission gear 26 supported on the input shaft of the transmission, a spline 26a is formed, and a spline 26a is formed. Synchronous disk 27 with conical surface
Is fixedly supported. On the other hand, the sleeve 31 is supported on the output shaft 25 by the spline 30 having the same diameter as the spline 26a so as to be slidable in the axial direction, and the sleeve 31 supports the synchronization pin 29 and the guide pin 33. The guide pin 33 is held in a neutral position by the locking ball 32, while the synchronizing pin 29 has a synchronizing ring 28, which is frictionally engageable with the synchronizing disc 27, supported at the end thereof, and a pin hole 35 (see FIG. 6) of the sleeve 31. ) Central part 29
b is thin, and conical surfaces 29a are formed between the two ends. Conical surfaces 35a are also formed at both ends of the pin hole 35.

In the above-mentioned synchronizing clutch, when the sleeve 31 is pushed to the left, for example, the guide pin 33 causes the left synchronizing ring to move.
28 is pressed against the synchronous disk 27, and the rotation of the input shaft is transmitted to the sleeve 31 via the synchronous disk 27 and the synchronous ring 28 (first stage).

At this time, the synchronization pin 29 is eccentric with respect to the pin hole 35. Further, when the sleeve 31 is pressed to the left, the conical surface 29a of the synchronization pin 29 engages with the conical surface 35a of the pin hole 35, the synchronization ring 28 comes into close contact with the synchronization disk 27, and the rotational speeds of both are synchronized. (Second stage).

Thus, when the rotation speeds of the synchronization disk 27 and the synchronization ring 28 become the same, there is no resistance between the sleeve 31 and the synchronization pin 29, and the sleeve 31 slides on the conical surface 29a of the synchronization pin 29 and advances to the left end side. At the same time, guide pin 33 and guide pin
The locking ball 32 that holds 33 in the neutral position is disengaged, and the spline 30 of the sleeve 31 meshes with the spline 26a to achieve rotational coupling between the input shaft and the output shaft 25 (third stage).

Corresponding to the stepwise operation of the synchronous clutch as described above, the actuator that drives the sleeve 31 is also required to operate fast in the first stage, slow in the second stage, and fast in the third stage.

Japanese Utility Model Laid-Open No. 60-73905 discloses an actuator in which the operating speed automatically decreases at the end of the stroke, which is described above in which the operating speed of the piston is switched between high speed and low speed according to the operating section. It does not meet the requirements.

[Problems to be Solved by the Invention] In view of the above problems, an object of the present invention is that the cylinder has a simple shape, is easy to machine and assemble, and has a high speed /
It is to provide a fluid pressure actuator that can be switched to a low speed.

[Means for Solving the Problem] In order to achieve the above object, the structure of the present invention is such that a piston 22 is inserted into a cylinder 20 having a uniform inner diameter and the first and second end chambers 1 are inserted.
The rod 10, which is divided into 2 and 21 and is coupled to the piston 22, is projected from the second end chamber 21 to the outside, and at least one annular groove 19 is provided on the circumferential surface of the piston 22. The piston 22 is provided with axial passages 18 and 13 communicating with the end chamber 12, and the annular groove is provided when the piston 22 is located at the process end on the first end chamber side.
A port 16 communicating with 19 is provided in the central peripheral wall of the cylinder 20, and the port 15 provided in the end wall of the first end chamber 12 and the port 16 of the central peripheral wall are communicated with each other through a passage having a throttle 8.
Port 17 on the end wall of end chamber 21 and the port on the central peripheral wall
One of 16 is selectively connected to the fluid pressure source by the switching valve 4.

[Operation] The piston 22 receives the fluid pressure intermittently supplied to the first end chamber 12 through the port 16 on the peripheral wall of the central portion of the cylinder 20, the annular grooves 19 and 14 of the piston 22, and the passages 18 and 13 of the piston 22. , Is moved forward by the fluid pressure supplied from the port 15 of the end wall of the first end chamber 12 of the cylinder 20 through the passage having the throttle 8, but the annular groove 19 of the piston 22 is formed in the central wall of the cylinder 20. Port of 16
When the piston 22 is in communication, the operating speed of the piston 22 increases, and the peripheral surface of the piston 22 causes
When is closed, the operation speed of the piston 22 becomes slow. In this way, control can be obtained in which the operating speed of the piston 22 is switched between high speed and low speed according to the operating section.

[Embodiment of the Invention] As shown in FIG. 1, an actuator 9 has a piston 22 fitted inside a cylinder 20 to define a first end chamber 12 and a second end chamber 21. The rod 10 connected to the piston 22 is projected from the second end chamber 21 to the outside, and the reciprocating movement of the rod 10 connects / disconnects the synchronous clutch. A port 15 is provided on the end wall of the first end chamber 12, and is connected to the switching valve 4 via the opening / closing valve 5. Similarly, the port 17 of the second end chamber 21 is connected to the opening / closing valve 7
And is connected to the switching valve 4.

According to the present invention, the port 16 is provided on the peripheral wall of the central portion of the cylinder 20, and is connected to the switching valve 4 via the opening / closing valve 6. To be precise, the port 16 of the central peripheral wall is arranged at a position where the port 16 communicates with the annular groove 19 when the piston 22 is located at the stroke end on the side of the first end chamber. The throttle 8 is inserted and connected to the passage communicating between the port 15 and the port 16.

On the other hand, the annular groove 14, 19 is provided in the piston 22, the annular groove 14,
The chamber formed by 19 passes through passages (holes) 13, 18
Is communicated to the end chamber 12. The switching valve 4 opens and closes the fluid pressure source P.
A state in which the tanks R (5, 6) and the tank R (in the case of pressurized air, simply open to the atmosphere) are connected to the open / close valve 7;
Switch to the opposite state.

Next, the operation of the fluid pressure actuator according to the present invention will be described. In the state shown in FIG. 1, the piston 22 is at the leftmost position and the synchronous clutch is cut off. At the time of shifting to a low speed stage where the problem described at the beginning poses a problem, the opening / closing valve 5 is closed and the opening / closing valves 6 and 7 are opened.

Pressurized air from the fluid pressure source passes through the switching valve 4 and the open / close valve 6 and becomes a port.
16 enters the inside of the annular groove 19, and at the same time, enters the first end chamber 12 from the port 15 via the throttle 8. In this case, the pressurized air that has entered the annular groove 19 passes through the passage 18, the annular groove 14, and the passage 13 and then flows into the first air.
The piston 22 is pushed to the right at a high speed (normal operating speed) because it enters the end chamber 12 of. At this time, the air in the second end chamber 21 is discharged to the atmosphere through the port 17, the opening / closing valve 7, and the switching valve 4.

As shown in FIG.
When is closed, the operation speed of the piston 22 decreases due to the action of the diaphragm 8. Furthermore, as shown in FIG.
When the port 16 is opened by 14, the operating speed of the piston 22 increases again. As shown in FIG. 4, when the port 16 is closed by the peripheral surface of the piston 22, the operating speed of the piston 22 decreases again.

Therefore, in the synchronous clutch shown in FIG. 5, from the neutral position of the sleeve 31 to the first stage in which the synchronous ring 28 makes frictional contact with the synchronous disk 27, the piston 22 is quickly activated as shown in FIG. In the second step of bringing the synchronizing ring 28 into close contact with the synchronizing disk 27 for synchronization, the piston 22 is caused to operate in a loose manner as shown in FIG. 2, and the spline 30 of the sleeve 31 is meshed with the spline 26a of the speed change gear. Then, as shown in FIG. 3, if the piston 22 is actuated quickly, the operation of the synchronous clutch can be performed smoothly and a quick connecting operation can be achieved.

When the open / close valve 5 is opened, the piston 22 moves forward in the entire operation section (full stroke) at a normal operation speed. Further, when the switching valve 4 is switched and the open / close valves 5, 6, 7 are opened, the pressurized fluid Is the second
Is supplied to the end chamber 21 of the piston, and the piston 22 moves back at the normal operating speed.

[Advantage of the Invention] As described above, the present invention partitions the first and second end chambers by inserting the piston into the cylinder having a uniform inner diameter, and connects the rod connected to the piston to the outside from the second end chamber. Providing at least one annular groove on the circumferential surface of the piston, and providing the piston with an axial passage that connects the annular groove to the first end chamber, and the piston is located at the stroke end on the first end chamber side. At the time of opening, a port communicating with the annular groove is provided in the central peripheral wall of the cylinder, and the port provided in the end wall of the first end chamber and the port of the central peripheral wall communicate with each other by a passage having a throttle, Since one of the port provided on the end wall of the end chamber and the port on the peripheral wall of the central portion is made to selectively communicate with the fluid pressure source by the switching valve, the following effects are obtained.

(A) Since the operating speed of the piston can be switched between high speed and low speed according to the operating section in relation to the operating section of the actuator, for example, the operating speed of the synchronous clutch of the gear transmission is controlled according to its operating stage. Therefore, smooth and quick operation can be achieved without any stress between the operation members, and gear noise and wear of the sliding portion can be prevented.

(B) Since a stroke sensor and a complicated electronic control circuit are not required, an inexpensive and reliable actuator can be provided.

(C) Since the cylinder is a straight cylinder and the piston is provided with the annular groove and the passage (hole), the cylinder and the piston can be easily processed and assembled.

(D) Even if the port of the peripheral wall of the cylinder is closed by the peripheral surface of the piston, the pressure receiving area does not change, so the pushing force (driving force) of the actuator is not greatly reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a schematic configuration of a fluid pressure actuator according to the present invention, FIGS. 2 to 4 are side sectional views showing respective operating states of the fluid pressure actuator, and FIG. 5 is a fluid pressure actuator according to the present invention. FIG. 6 is a side cross-sectional view of a pin-type synchronous clutch adopting the above-mentioned FIG. 8: throttle, 12: end chamber, 13, 18: passage, 14, 19: annular groove, 15, 16, 1
7: Port, 20: Cylinder, 22: Piston

Claims (1)

[Scope of utility model registration request] 1. A piston having a uniform inner diameter fitted with a piston to define first and second end chambers, and a rod connected to the piston is projected from the second end chamber to the outside, and at least a peripheral surface of the piston is provided. One annular groove is provided, and the piston is provided with an axial passage that connects the annular groove to the first end chamber.
A port that communicates with the annular groove when located at the end of the end chamber of the cylinder is provided in the peripheral wall of the central portion of the cylinder, and the port provided in the end wall of the first end chamber and the port of the central peripheral wall are throttled. A fluid pressure actuator, wherein the fluid pressure actuator is characterized in that it is communicated by a passage provided therein, and one of a port provided on an end wall of the second end chamber and a port of a central peripheral wall is selectively communicated with a fluid pressure source by a switching valve.