JPS596247Y2 - Cushion device for fluid pressure cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cushion device for a fluid pressure cylinder.

Conventionally, as shown in FIG. 1, a cushion device for a hydraulic cylinder is provided with holes 8 and 9 in which cylinder force bars 2 and 3 receive cushion plungers 6 and 7 that slide on the inner periphery of a cushion ring. Annular grooves 10 and 11 are provided near the openings of the holes to provide the cushion rings 4 and 5.
The cushion device has a complicated structure and is expensive to manufacture. If the cylinder tube 14 is fixed by welding 15, it becomes difficult to attach or replace the cushion ring 5 even when the piston 16 is pulled out, and the tapered portion 17 at the tip of the cushion plunger 6 or 7 becomes difficult to attach or replace. or 18 is cushion ring 4
5, that is, immediately before the cushion plunger contacts the inner periphery of the cushion ring, the pressure in the cushion pressure generating part that is closed by the cushion ring and piston packing becomes quite high, so the cushion ring is moved inside the cushion ring. It was compressed and deformed on the circumferential side and collided with the cushion plunger, often resulting in early breakage.

The purpose of the present invention is to simplify the structure of the cushion device, reduce manufacturing costs, make it easy to attach and replace the cushion ring, and improve the durability of the cushion ring.

Therefore, in the present invention, a fluid inlet/outlet port is provided near the end of the cylinder tube, and a cushion ring that closely contacts the inner surface of the cylinder tube is attached to an annular groove formed near the end of the piston. When the fluid pressure on the piston center side is higher than on the piston end side, a fluid passage is formed through which the fluid passes through the annular groove,
The cushion ring is shaped so that the fluid passage is closed when the fluid pressure on the piston end side is higher than that on the piston center side, and the arrangement of the fluid inlet/output port, the cushion ring, and the piston packing corresponds to the stroke of the piston. At the ends, the cushion ring is located closer to the cylinder tube end than the fluid inlet/outlet port, and the piston packing is located closer to the center of the cylinder tube than the fluid inlet/outlet port.

Next, the present invention will be explained in detail.

One embodiment of the present invention is shown in FIG. 2, in which fluid inlet and outlet ports 12 and 13 are provided near the end of the cylinder tube 14, and an annular groove 2 is formed near the end of the piston
1 and 22 are fitted with cushion rings 24 and 25 that are in close contact with the inner surface 23 of the cylinder tube, and as shown in FIG. 4, when the fluid pressure on the piston center side 29 of the cushion rings 25 is higher than on the piston end side 27 A fluid passage 30 passing through the annular groove 22 is formed, and when the fluid pressure on the piston end side 27 of the cushion ring 25 is higher than that on the piston center side 29, the fluid passage 30 passes through the annular groove 22 as shown in FIGS. The arrangement of the fluid inlet/outlet port 13, the cushion ring 25, and the piston packing 34 is such that the cushion ring 25 closes the fluid inlet/outlet port 13 at the stroke end of the piston 36, as shown in FIG. The piston packing 34 is located closer to the cylinder end 33 than the fluid inlet/outlet port 13.
It is located on the center side 35 of the cylinder tube.

As an example, the cushion ring 25 shown in FIGS. 9 and 10 has a plurality of radial grooves 40 formed on one side of a flat annular plate and a cut arrow portion 39.

As another example, the cushion ring 41 shown in FIGS. 11 and 12 is a flat annular plate with a cutout 39, and when used, the cushion ring 41 shown in FIGS. 7 and 8 has an annular groove. A fluid passage 42 consisting of a hole communicating between the bottom of the cylinder 22 and the cylinder chamber 38 is provided.

As yet another example, the cushion ring 43 shown in FIGS. 13 and 14 is made from a spirally wound flat annular plate, and in use, the cushion ring 43 shown in FIGS.
As shown in FIGS. and 8, a fluid passage 42 is provided in the annular groove.

Next, the operation of the cushion device of the present invention will be explained.

In FIG. 2, when pressure fluid is supplied from the fluid inlet/outlet port 12 to one cylinder chamber 37 in the cylinder tube and the piston 36 moves to the right, the fluid in the other cylinder chamber 38 in the cylinder tube 14 is After the fluid is discharged from the fluid inlet/outlet port 13, the piston 36 approaches near the right end in FIG. 2, and the cushion ring 25 passes through the fluid inlet/outlet port 13 in FIGS. 13, the fluid in the other cylinder chamber 38 in the cylinder tube 14 and the fluid inlet/outlet port 13 are blocked by the cushion ring 25, so that the fluid in the other cylinder chamber 38 is as shown in FIG. and a gap in the notch 39 of the cushion ring 25, as shown in FIG. ) and is gradually discharged from the fluid inlet/outlet port 13, creating a cushioning effect that suppresses the speed of the piston 36.

Next, when fluid is supplied from the fluid inlet/outlet port 13 and the piston 36 moves to the left, the cushion ring 25 moves to the right as shown in FIGS. 4 and 6, and the cushion ring 25 moves to the right side of the mounting groove. In this state, fluid can freely flow into the cylinder chamber 38 from the inner periphery of the cushion ring 25 through the radial groove 40, so the piston 36 can be moved quickly and smoothly to the left.

As described above, according to the cushion device of the present invention, since the cushion ring slides on the inner surface of the cylinder tube, there is no need to provide a cushion plunger, and it is only necessary to form a cushion ring mounting groove near the end of the piston. .

Furthermore, since there is no need for a hole for the cushion plunger to be inserted, an effective cushioning effect can be provided with an extremely simple device, and manufacturing costs are reduced, resulting in great benefits in terms of design and manufacturing.

[Brief explanation of drawings]

FIG. 1 shows an example of a conventional cushion device for a fluid pressure cylinder, FIGS. 2 to 8 show a cushion device for a fluid pressure cylinder according to the present invention, and FIGS. 9 to 14 show a cushion ring. It is something. 1 to 4 and 7 to 8 are partial longitudinal cross-sectional views,
Figures 5 and 6 are partially enlarged views of Figures 3 and 4, Figures 9, 11 and 13 are front views of the cushion ring, and Figures 10, 12 and 14 are FIG. 3 is a cross-sectional view of the cushion ring. 12. 13 is a fluid inlet/outlet port, 14 is a cylinder tube, 16, 36 is a piston, 21. 22 is an annular groove;
24. 25 is a cushion ring, 30 is a fluid passage, 3
9 is a notch, and 40 is a radial groove.

Claims (3)

[Scope of utility model registration request] (1) A fluid inlet/outlet port that opens into the cylinder tube is provided slightly inside the closed end of the cylinder tube, and a cylinder chamber that is closed by the piston end surface is formed between the port and the closed end of the cylinder tube. At the same time, a cushion ring and a piston packing that closely slide on the inner surface of the cylinder tube are placed in an annular groove formed on the outer periphery of the piston so as to be located outside and inside the opening position of the port, respectively, when the piston is at the stroke end. and the cushion ring is installed in the annular groove with a margin for movement in the axial direction, and when it abuts the axially outer side surface of the annular groove, communicates the closed cylinder chamber with the port via the annular groove. A cushion device for a fluid pressure cylinder, characterized in that the cushion device is configured to cut off communication between the closed cylinder chamber and the port when it comes into contact with the inner side surface of the annular groove. (2) The cushion device according to claim 1, wherein the cushion ring has a radial groove on the outer end surface in the axial direction. (3) The cushion ring has substantially flat both end surfaces, and a hole is formed at the end of the piston to communicate the bottom of the annular groove in which the cushion ring is installed with the closed cylinder chamber. A cushion device according to claim 1 of the utility model registration claim.