JP2506968Y2 - Fluid pressure cylinder with movable cushion valve - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure cylinder with a movable cushion valve.

[0002]

2. Description of the Related Art A cushion valve is fixed to one side or both sides of a piston, and during the stroke of the piston, the cushion valve is fitted into a cushion packing attached to a recess opening of the cover, whereby the piston and the cover are partitioned.
A fluid pressure cylinder with a cushion valve that temporarily confines the fluid discharged from the pressure chamber to raise the pressure and decelerates the piston by this fluid pressure to stop the stroke at the stroke end is well known, without particular exemplification. In the above-described known fluid pressure cylinder, it is necessary to lengthen the cushion stroke in order to increase the cushion function. However, if the cushion stroke is lengthened, the axial length of the cover becomes longer, and therefore the total length of the fluid pressure cylinder becomes longer. There is a problem that it becomes big.

As a solution to this problem, a fluid pressure cylinder with a movable cushion valve is proposed, in which a cushion valve is slidably mounted on a rod and the cushion valve is biased by a spring in a direction to separate it from the piston. (For example, see Japanese Utility Model Laid-Open No. 54-34892). In the above proposed fluid pressure cylinder, the cushion valve is slidably attached to the rod, so that the cushion function can be increased without increasing the total length of the fluid pressure cylinder. There is a new problem that the life of the cushion mechanism is short because the seal between them is a sliding seal and is easily worn.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid pressure cylinder with a movable cushion valve, which is small in size and has a long cushion mechanism life.

[0005]

In order to solve the above problems, a fluid pressure cylinder with a movable cushion valve according to the present invention comprises:
Cylinder tube and head covers on both sides in the axial direction
And a rod cover, a piston and a rod that reciprocate in the cylinder, a head side cushion valve and a rod side cushion valve that are slidably mounted on both sides of the piston with respect to the rod, and these cushion valves. Springs for urging each of the head cover and rod cover away from the piston .
A cushion packing mounted near the opening of the recess is provided to allow the cushion to move during the stroke of the piston and rod.
The valve to the cushion packing, and
Of the pressure chamber partitioned by the head cover and rod cover
Temporarily contain the exhaust fluid and use this containment fluid pressure.
In a fluid pressure cylinder with a movable cushion valve for decelerating a piston, the head-side cushion valve is cup-shaped with the head cover side closed, and the rod cover abuts against the rod-side cushion valve. It is characterized by having a seat packing that seals between the valve and the rod.

[0006]

[Operation] When the piston and rod stroke toward the head side, the head side cushion valve is fitted into the cushion packing, and the fluid discharged from the pressure chamber on the head side is temporarily contained and increases in pressure. It is decelerated to a buffer stop at the stroke end. When the piston and the rod make a stroke toward the rod side, the rod-side cushion valve fits into the cushion packing, so that the piston is decelerated and stops at the stroke end in the same manner as at the head side.

In these cases, between the cushion valve on the head side and the rod is the cup-shaped head side cushion valve itself, and between the rod side cushion valve and the rod on the rod side is the seat packing of the rod side cushion valve. The seals are respectively sealed by abutting with each other, and unlike the sliding seals, the wear is small, so that the life of the cushion mechanism can be extended.

[0008]

1 and 2 show an embodiment of the present invention, in which a cylinder 1 has a cylinder tube 2 and a head cover 3 and a rod cover 4 at both axial ends thereof, which are connected by tie rods 5 ,. They are connected together. One end of the piston 7 that reciprocates airtightly in the cylinder tube 2 is in contact with the stepped portion 8a of the rod 8 and is attached to the rod 8 so as to be integrally movable by a tubular nut 9 screwed to the tip of the rod 8. Has been. The head side cushion valve 10 slidably mounted on the tubular nut 9 has a head cover 3
It has a cup-like shape with its side closed and is urged in a direction away from the piston 7 by a spring 11 that is contracted between it and the rod 8, and engaging portions 9a and 10a provided on the tubular nut 9 and the cushion valve 10 are provided. By the engagement of, the protrusion from the rod 8 is prevented. On the other hand, the rod-side cushion valve 12 slidably mounted on the rod cover 4 side of the piston 7 has a spring 13 compressed between the piston 7 and the spring 13.
Is urged in the direction away from the piston by the expanded diameter portion 8b of the rod 8 and the engagement portion 12a of the cushion valve 12 to prevent the rod 8 from protruding toward the rod cover 4 side.

The head cover 3 and the rod cover 4 are
Cushion packings 18a and 18b having recesses 16a and 16b communicating with the pressure chambers 15a and 15b and the ports 17a and 17b, and the cushion valves 10 and 12 tightly fitted in the openings of the recesses on the pressure chamber side. Is installed. Further, the covers 3 and 4 are formed with flow paths 22a and 22b in which variable throttles 20a and 20b and check valves 21a and 21b are provided in parallel for communicating the pressure chambers 15a and 15b with the ports 17a and 17b. A seat packing 23 is attached to the bottom of the recess 16b so that the tip of the rod-side cushion valve 12 abuts and seals between the cushion valve 12 and the rod 8.

In the above embodiment , the pressure chamber 1 is connected to the port 17a.
When compressed air is supplied to the 5a, stroke leftward piston 7 and rod 8 in the figure, when the cushion valve 12 is fitted to the cushion seal 18b, the exhaust air of the pressure chamber 15b is boosted encapsulated temporarily, this The piston 7 is decelerated by the fluid pressure . When the piston 7 and the rod 8 travel further, the cushion valve 12 comes into contact with the seat packing 23 and the cushion valve 12 and the rod 8
A seal is made between and (see FIG. 2). Seal in pressure chamber 15b
The air taken in passes through the throttle channel 22b and the port 17
Since it is gradually discharged from b, the piston 7 and the rod 8 stop the cushioning at the stroke end while compressing the spring 13 . When compressed air is supplied to the pressure chamber 15b from the port 17b, the piston 7 and the rod 8 stroke rightward in the figure. Since the cushioning action and the like after the head side cushion valve 10 is tightly fitted in the cushion packing 18a are the same as those on the rod side, detailed description thereof will be omitted. In this case, the head side cushion valve 10 and the rod 8
The gap is sealed by the cup-shaped head side cushion valve 10 itself. Therefore, the rod 8 and the cushion
Even if a sliding seal portion is not provided between the valves 10 and 12,
The air contained in the pressure chambers 15a and 15b is recessed by the recess 16
There is no leakage to a and 16b.

In the above embodiment , the cushion function can be enhanced without increasing the length of the cylinder 1. Further, since there is no sliding seal portion between the cushion valves 10 and 12 and the rod 8, wear of the seal portion is small, so that the life of the cushion mechanism can be extended.

[0012]

EFFECTS OF THE INVENTION The present invention has a long life of the seal member because there is no sliding seal portion that easily wears between the cushion valve slidably mounted on the rod and the rod. Can be long.

[Brief description of drawings]

1 is a half section longitudinal sectional view of an embodiment.

FIG. 2 is an explanatory diagram of a sealed state on a rod side.

[Explanation of Codes] 1 Cylinder 3 Head cover 4 Rod cover 7 Piston 8 Rod 10, 12 Cushion valve 11, 13 Spring 15a, 15b Pressure chamber 18a, 18b Cushion packing 23 Seat packing

Claims (1)

(57) [Scope of utility model registration request] 1. A cylinder tube and its axially opposite sides
A cylinder having a head cover and a rod cover, a piston and a rod that reciprocate in the cylinder, a head side cushion valve and a rod side cushion valve that are slidably mounted on both sides of the piston with respect to the rod, and these cushions. The spring for urging the valve away from the piston and the head cover and rod cover
A cushion packing attached near the opening of the recess formed in the bar, and the straw of the piston and rod.
The cushion valve into the cushion packing while
The piston, head cover and rod cover
Temporarily contain the discharge fluid of the pressure chamber
The fluid pressure cylinder with a movable cushion valve to decelerate the piston by the fluid pressure put, the head-side cushion valve, the head cover side is a closed cup, the rod cover, the cushion valve by the abutment of the rod-side cushion valve A fluid pressure cylinder with a movable cushion valve, comprising a seat packing that seals between the rod and the rod.