JPH0743455Y2 - Fluid pressure cylinder with cushion mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a fluid pressure cylinder having a cushion mechanism.

[Prior Art] Near the stroke end of the piston, a cushion ring provided on the side surface of the piston fits into a cushion packing attached to the inner peripheral surface of a recess provided in the cover to temporarily raise the fluid pressure in the pressure chamber. A fluid pressure cylinder having a cushion mechanism that decelerates the piston by this fluid pressure and stops it in a buffered manner is already known, without particular exemplification.

However, the fluid pressure cylinder having the above-described known cushion mechanism has a problem that the total length of the fluid pressure cylinder becomes long because the cushion ring and the recess are provided on the axial side surface of the piston.

[Problem to be Solved by the Invention] An object to be solved by the present invention is to make a fluid pressure cylinder having a cushion mechanism compact and short in length.

[Means for Solving the Problem] In order to solve the above problems, a fluid pressure cylinder having a cushion mechanism of the present invention is a cylinder having cylinder holes and at least one guide hole installed in parallel to each other, and the cylinder hole. And a piston rod that reciprocates in a guide hole, a piston rod and a guide rod, and a plate that connects the piston rod and the guide rod so that they can move integrally outside the cylinder, and a pair of pressure chambers partitioned by the piston from the port provided in the cylinder. A fluid pressure cylinder for supplying / discharging pressure fluid pressure to / from the piston and moving the piston and the plate integrally, wherein one of the guide hole and the guide rod is a cushion ring, and the other is a cushion ring. Near the end of the piston stroke, which is attached to the axial recess and the inner peripheral surface of the recess. With a cushion packing that is in sliding contact with the outer peripheral surface of the cushion ring,
At least one pressure chamber partitioned by the piston is
It is characterized in that the piston rod, the plate, and the flow path provided in the guide rod communicate with the guide hole, and the port and the guide hole communicate with the main flow path and a bypass flow path having a flow rate adjusting valve.

In order to solve the same problem, a seal ring is attached to the inner peripheral surface of the recess of the fluid cylinder, and a check valve for allowing only the inflow of fluid into the recess is provided in the main passage.

[Operation and effect of device] When a pressure fluid is supplied from one port to one pressure chamber, the piston strokes, and the fluid in the other pressure chamber passes through the passages provided in the piston rod, the plate and the guide rod to the outside from the port. Is discharged.

When the cushion ring fits into the cushion packing near the end of the stroke of the piston, the fluid pressure in the pressure chamber on the discharge side temporarily rises, and the piston is decelerated by this fluid pressure rise and stops in a buffer manner.

In this case, the cushion ring and the cushion packing that move relative to each other are provided in the guide hole provided in parallel with the cylinder hole and the guide rod that slides in the guide hole, and the cushion mechanism is installed in parallel with the piston rod. The total length of the fluid pressure cylinder having the mechanism is shortened, and it can be made compact.

Further, since at least one of the pressure chambers communicates with the guide hole by the flow path provided in the piston rod, the plate and the guide rod, even if the cylinder hole and the guide hole are arranged side by side, the fluid in the pressure chamber is temporarily removed. Can be contained.

[Embodiment] The drawings show an embodiment of the present invention, in which a body 1 of a fluid pressure cylinder having this cushion mechanism is provided with cylinder holes 2 and guide holes 3a and 3b which are parallel to each other, and these holes are end plates 4 Is closed by.

On the plate 6, one ends of a piston rod 7 and guide rods 8a and 8b which closely penetrate an opening formed in the body 1 are attached so as to be integrally movable, and the other end of the piston rod 7 is
A piston 9 that closely slides in the cylinder hole 2 is fixed by an appropriate means, and the other ends of the guide rods 8a and 8b can slide in the axial direction by side bushes 10 and 10 provided in the guide holes 3a and 3b. Supported by.

The end plate 4 includes a cushion ring 12a that is substantially concentric with the guide hole 3a and projects in the axial direction, and a cushion ring 12b attached to the tip of a support member 13 that is substantially concentric with the guide hole 3b and projects in the axial direction. The length between the base end of the cushion ring 12b whose front end faces the end plate side and the base of the support member 13 is substantially equal to the stroke of the piston 9.

The guide rods 8a and 8b have cushion rings 12a and 12b at the tips.
Has axial recesses 14a, 14b in which are loosely fitted, and cushion packings 15, 15 which are in sliding contact with the outer peripheral surfaces of the cushion rings 12a, 12b are mounted on the inner peripheral surfaces near the openings of these recesses. In the cushion packings 15 and 15, one side of the V-shaped cross section is fixed to the inner peripheral surfaces of the recesses 14a and 14b, and when the cushion rings 12a and 12b are fitted, the other side of the V-shaped is cushioned by the fluid pressure in the recesses. Pressure contact with the outer peripheral surface of
It is configured to function as a check valve.

Ports 17a and 17b for supplying and exhausting compressed air opened in the end plate 4
The main flow paths 18a, 18b and the bypass flow paths 20a, 20b opening at the tip end of the cushion ring 12a and the base end of the cushion ring 12b via the needle valves 19, 19 constituting the flow rate adjusting valve, the guide hole 3a. , 3b, and the pressure chambers 21a, 21b, which are defined by the piston 9 and are divided by the flow paths 22a, 22b, form the recesses 14a,
It communicates with the bottom of 14b.

In the first embodiment, when the piston 9 and the plate 6 are at the end of the downward stroke, the switching valve (not shown) is switched and compressed air is supplied from the port 17a in the state shown in FIG. Path 18a, guide hole 3a, and flow path 2
2a is supplied to the pressure chamber 21a, and at the same time, the air in the pressure chamber 21b is discharged from the port 17b through the flow passage 22b, the guide hole 3b and the main flow passage 18b. Move.

When the piston 9 and the plate 6 approach the end of the upward stroke, the cushion packing 15 contacts the outer peripheral surface of the cushion ring 12b, the communication between the pressure chamber 21b and the recess 14b and the main flow path 18b is cut off, and the air is contained. 2 (see FIG. 2), the fluid pressure temporarily rises, the piston 9 and the plate 6 are decelerated by this fluid pressure, and the air in the pressure chamber 21b has the bypass valve 20b having the needle valve 19.
When the piston 9 and the plate 6 are gradually stopped at the stroke end position, the cushioning action can be adjusted by adjusting the opening degree of the needle valve 19.

When the switching valve is switched and compressed air is supplied from the port 17b to the pressure chamber 21b, the piston 9 and the plate 6 move downward in the drawing. Since the movements of the piston 9 and the plate 6 in this case are the same as those in the upward movement, detailed description thereof will be omitted.

Although not shown, a cushion ring may be provided at the tip of the guide rods 8a, 8b, and a recess into which the cushion ring is loosely fitted may be provided in the guide holes 3a, 3b. It may be provided on only one of the guide rods.

The cushion packing 15 in the first embodiment has a function of sealing the fluid in the pressure chambers 21a, 21b and the recesses 14a, 14b and a check valve function, but separates the seat function and the check valve function. be able to.

FIG. 3 shows a second embodiment of the present invention in which the sealing function and the check valve function are separated, and the end plate 26 of the second embodiment connects the ports 17a, 17b with the guide holes 3a, 3b. Main flow path 18a,
A check valve 27 that allows only the fluid to flow from the port into the guide hole is installed in 18b (both one is shown in the drawing), and a seal ring 28 that replaces the cushion packing is installed on the inner peripheral surface of the recess.

The other structure and operation of the second embodiment are the same as those of the first embodiment except that the seal ring 28 has a recess sealing function and the check valve 27 has a backflow prevention function.

[Brief description of drawings]

The drawings show an embodiment of the present invention, and FIGS. 1 and 2 are vertical sectional front views of the first embodiment showing different states, and FIG. 3 is a vertical sectional view showing an essential part of the second embodiment. 2 ... Cylinder hole, 3a, 3b ... Guide hole, 6 ... Plate, 7 ... Piston rod, 8a, 8b ... Guide rod,
9 ... Piston, 12a, 12b ... Cushion ring, 14a, 1
4b …… Concave, 15 …… Cushion packing, 17a, 17b ……
Port, 18a, 18b ... Main flow path, 19 ... Needle valve, 20a, 2
0b …… Bypass passage, 21a, 21b …… Pressure chamber, 27 …… Check valve, 28 …… Seal ring.

Claims (2)

[Scope of utility model registration request] 1. A cylinder having a cylinder hole and at least one guide hole installed in parallel with each other, a piston reciprocating through the cylinder hole and the guide hole, a piston rod and a guide rod, and a piston rod and a guide rod. It is a fluid pressure cylinder that has a plate that is integrally movable outside and that supplies and discharges pressure fluid from a port provided in the cylinder to a pair of pressure chambers defined by the piston to move the piston and the plate integrally. One of the guide hole and the guide rod forms a cushion ring, and the other of the guide hole and the guide rod is mounted on the inner peripheral surface of the concave portion in the axial direction in which the cushion ring is loosely fitted, and near the end of the stroke of the piston. And a cushion packing that makes sliding contact with the outer peripheral surface of the Kutomo 1-way pressure chamber of,
A flow path provided in the piston rod, the plate and the guide rod communicates with a guide hole, and the port and the guide hole communicate with a main flow path and a bypass flow path having a flow rate adjusting valve. A fluid pressure cylinder having a cushion mechanism. 2. The fluid pressure cylinder according to claim 1, wherein a seal ring is attached to the inner peripheral surface of the recess, and a check valve is provided in the main flow passage to allow only fluid to flow into the recess. Fluid pressure cylinder having the above cushion mechanism.