JPS5836882Y2 - Cushion mechanism of fluid pressure cylinder - Google Patents

Description

[Detailed description of the invention] The invention provides a cushion plate that is held at a distance necessary for cushioning action from the piston and has a plurality of throttle holes, and a cover of the cylinder that can come into contact with the cushion plate. This invention relates to a cushion mechanism for a fluid pressure cylinder having a plurality of passages connected to supply/discharge ports opened on the end face and an annular groove connecting the open ends of the passages.

Conventionally, this type of cushion mechanism law was filed in 1988-1388.
As shown in FIGS. 1 to 3, the piston 4 is slidably fitted into the cylinder tube 1, and the piston 4 and the cover 3 are attached to the right side of the piston 4 to form a cylinder. A cylinder chamber 13 is formed at the end face 3a of the cover 3 in order to obtain the necessary discharge flow rate.
It is connected to the supply/discharge port 11 through a plurality of passages 10, 10, .

A cylinder chamber 14 is formed on the left side of the piston 4 by the piston 4 and the cover 2 having the connecting member 15, and the supply/discharge port 12 is connected to the cylinder chamber 14.

A piston rod 5 is attached to the piston 4 with a lock nut 6.
This piston rod 5 (/'
i It extends to the outside through the cover 3, and has a connecting member 16 at its tip.

Further, a stepped portion 5a is formed on the piston rod 5 at a distance necessary for a cushioning action from the piston 4, and the narrow diameter portion formed by the stepped portion 5a can come into contact with the end surface 3a of the cover 3. The cushion plate 7 is rotatably inserted.

This cushion plate 7 has a plurality of aperture holes so as to be connected to a plurality of passages 10, 10, . 8, 8... are provided, and these aperture holes 8, 8...
By changing the number of ..., the effectiveness of the cushion can be changed.

A spring 9 is interposed between the cushion plate 7 and the piston 4, and the spring 9 always keeps the cushion plate 7 on the stepped portion 5.
It is intended to press toward a, and to maintain the distance necessary for a cushioning effect.

As shown in FIG. 3, the end surface 3a of the cover 3 is provided with an annular groove 18 that connects a plurality of passages 10, 10..., and the cushion plate 7 and the end surface 3a of the cover 3 are in contact with each other. The plurality of throttle holes 8, 8... communicate with the passages 10, 10, no matter where they are located.

In the fluid pressure cylinder having such a configuration, when pressure fluid is supplied into the cylinder chamber 14 through the housing supply/discharge port 12, the piston 4 is pushed toward the right side in the figure by the pressure fluid.

At this time, the pressure fluid in the cylinder chamber 13 on the right side of the piston 4 is supplied to the supply/discharge port 1 from the plurality of passages 10, 10...
1 and the force pushing the piston 4 leftward in the figure has been released, so the piston 4 is pushed rightward and continues to move to the position where it comes into contact with the end surface 3a of the cover 3.

Thereafter, the piston 4 moves to position 1 where the cushion plate 7 and the end surface 3a of the cover 3 are in contact with each other as shown in FIG. 2, and the piston 4 and the cushion plate I form a pressure chamber 17. By moving to the right, the pressure fluid in the pressure chamber 17 flows through the plurality of throttle holes 8, 8...
The piston 4 is narrowed down and discharged through the annular groove 18, the passages 1o, 10, .

However, in such a conventional cushion mechanism, when the throttle hole provided in the cushion plate and the passage opening in the cover coincide, the pressure fluid is ejected from the throttle hole to the passage at high speed. A high-speed region and a low-speed region are formed in the vicinity, and negative pressure occurs near the high-speed region, and cavitation occurs due to the negative pressure state.

The degree to which cavitation occurs varies depending on the load acting on the device used by the cushion mechanism, the ejection distance of the pressurized fluid, etc., and the frequency and sound generated also change.

Furthermore, there is a problem in that this frequency and sound resonate with other equipment or structures to which the equipment is attached, causing abnormal vibrations and sounds.

This is because the flow direction of the pressure fluid ejected from the throttle hole of the cushion plate is the same as the direction of the passage leading the pressure fluid to the supply/discharge port.

The present invention was developed in view of the above-mentioned problems, and the generation of cavitation is suppressed by making the direction in which the pressure fluid is ejected from the throttle hole of the cushion plate different from the direction of the passage communicating with the supply/discharge port. The technical challenge is to reduce the vibration and noise caused by this cavitation.

A means for solving this technical problem is to tilt the throttle hole so that when the cushion plate and the end surface of the cover abut, the pressure fluid squeezed by the throttle hole collides with the inner wall or groove of the passage. It is.

By adopting such a means, even if the throttle hole of the cushion plate and the passage overlap, the throttle hole is provided at an angle, so the pressurized fluid ejected from the throttle hole will immediately collide with the inner wall of the passage. do.

Therefore, the high-speed region of the ejected pressure fluid is reduced, suppressing the occurrence of cavitation, and reducing vibration and noise caused by this cavitation.

According to the present invention, cavitation can be suppressed by changing the state of the negative pressure generated by causing the pressure fluid ejected from the throttle hole to collide with the inner wall of the groove or passage during the cushioning action, and the vibration caused by this cavitation.
Sound can be reduced.

In addition, because the present invention has an inclined aperture hole, it is possible to suppress the occurrence of cavitation no matter where the aperture hole is located. However, the aperture hole can be provided in any position, and the aperture hole can be located at any position during assembly, which has the unique effect of simplifying assembly.

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 4 is a schematic view of a conventional fluid pressure cylinder and a cushion mechanism according to an embodiment of the present invention, Fig. 5 is a sectional view taken along line B-B of Fig. 4, and Fig. 6 is a cushion of Fig. 4. FIG. 7 is an enlarged view of the main part during operation, and is a sectional view of the main part, taken along C--C in FIG.
A cross-sectional view of C is shown.

The buttons and portions in FIG. 4 indicated by the same reference numerals as in FIG. 1 are the same in structure as explained based on FIG. 1, and detailed explanations thereof will be omitted.

4 to 7, which are different from FIG. 1, the throttle hole 19 provided in the cushion plate 7 is located at the position where the throttle hole 19 and the passage 10 coincide.
The annular groove 18 is inclined at 45 degrees in the tangential direction of the annular groove 18 so that the pressure fluid throttled by the passage 10 collides with the inner wall 10a of the passage 10. It is designed to communicate with 18.

In order to prevent rotational force from acting on the cushion plate 7 by tilting the aperture hole 19 at 45 degrees in the cushion plate 7, as shown in FIG. The holes 19 are provided on opposite sides and inclined at 45 degrees in the same direction so that the rotational forces cancel each other out.

When the piston 4 moves at 1 where the cushion plate I and the end surface 3a of the cover 3 come into contact with each other due to the pressure fluid in the cylinder chamber 14 as described above, the piston 4 and the cushion plate 7 are brought into contact with each other as shown in FIG. As the piston 4 moves to the right, the pressure fluid in the pressure chamber 17 is throttled by the throttle hole 19 and ejected from the throttle hole 19 at a high speed, and is ejected onto the inner wall 10a of the passage 10. Collision occurs (see Figure 7).

Therefore, since the state of negative pressure generated near the high speed range can be changed, cavitation can be suppressed and vibrations and sounds generated by cavitation can be reduced.

Further, as shown in FIG. 7, when the piston 4 moves and the cushion plate 7 comes into contact with the end surface 3a of the cover 3, the cushion plate I rotates around the piston rod 5 and moves to the position of the throttle hole 19. Even when the pressure fluid moves to the position 19a, the pressure fluid is ejected from the throttle hole 19a at high speed and collides with both the annular groove 18 and the inner wall 10a of the passage 10, so the pressure fluid occurs near the high speed region as described above. The state of negative pressure can be changed to suppress cavitation and reduce vibration and sound.

In the above description, the plurality of aperture holes 19 provided in the cushion plate 7
, 19... and a plurality of passages 10, 10... that open in the end surface 3a of the cover 3 have been explained by taking up only one location where they coincide, but the other locations are the same as described above. .

Also, the throttle hole 19°19... and the passage 10, 10...
I explained when they match, but the aperture holes 19, 19...
・When the passages 10, 10... do not match, that is, when the throttle holes 19, 19... communicate with the passages 10, 10... through the annular groove 18, cavitation occurs regardless. Can provide a cushioning effect.

Depending on the shape of the cover, the direction and angle of the throttle hole mentioned above can be set to any direction and angle at which the pressure fluid ejected from the throttle hole collides with an obstacle such as an inner wall or an annular groove of a passage opening at the end face of the cover. The aperture hole is not limited to the aperture hole shown in the first embodiment.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a cylinder with a conventional cushion mechanism, Fig. 2 is an enlarged view of the main part of Fig. 1 when the cushion is in action, and Fig. 3 is a sectional view taken along line A-A in Fig. 1. Figure 4 is a schematic diagram of the cylinder shown in Figure 1 provided with the cushion mechanism of the present invention;
Fig. 5 is a BB sectional view of Fig. 4, Fig. 6 is an enlarged view of the main part showing the cushion action in Fig. 4, and Fig. 1 is C-C of Fig. 6.
FIG. 3... Cover 3a... End J 7.
...Cushion board, 8, 19, 19a...
・Aperture hole, 10... Passage, 10a...
Inner wall, 18... annular groove.

Claims (1)

[Scope of utility model registration request] A cushion plate is provided which is held at a distance necessary for cushioning action from the piston and has a plurality of throttle holes, and a plurality of passages connected to the supply and discharge ports are provided on the end face of the cylinder cover that can come into contact with the cushion plate. In the cushion mechanism of the fluid pressure cylinder, which is provided with an annular groove connecting the open end of the passage, when the cushion plate and the end surface of the cover abut, the pressure fluid squeezed by the throttle hole is A cushion mechanism for a fluid pressure cylinder, characterized in that the throttle hole is inclined so as to collide with an inner wall or groove of a passage.