JPS6256605A - Fluid pressure cylinder - Google Patents

Abstract

PURPOSE:To reliably stop a piston at the stroke end by supporting a brake packing formed by uniting a cushion packing and a brake shoe in a body by a support ring mounted on a cylinder in such a manner as to displace. CONSTITUTION:Brake packings 15, 36 are formed by uniting cushion packings 16, 38 and brake shoes 17, 30, 39 in a body. The brake packings 15, 36 are supported in such a manner as to displace by a support ring 18 mounted on a cylinder 1. In this arrangement, in the vicinity of the stroke end of a piston 7, the piston 7 is subjected to shock absorbing force due to cushion pressure, and the brake packings 15, 36 are deformed by the cushion pressure to apply the braking force of the brake shoes 17, 30, 39 to a cushion ring 6, so that the piston 7 can be reliably stopped at the stroke end.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluid pressure cylinder equipped with a brake operated by cushion pressure from a cushion mechanism.

[Prior Art] Near the stroke end of the cylinder, a cushion ring provided on the piston rod is fitted into a cushion packing provided on the cylinder side, thereby closing or restricting the fluid discharge flow path and discharging the fluid into the pressure chamber of the cylinder. A fluid pressure cylinder that temporarily confines fluid to exert a cushioning action is, for example, disclosed in Japanese Utility Model Application No. 58-1.
This is already known as shown in Japanese Patent No. 01008.

The known cushion mechanism including the cushion ring and cushion packing has a simple structure, is small in size, and is inexpensive. The cushion valve has the advantage that the 27917 action can be easily adjusted, but the cushion pressure confined in the pressure chamber by the cushion mechanism near the stroke end of the piston provides a buffering force to the piston, so the load is large. If the inertial force of the piston becomes large due to the piston being moved or its speed increasing, there is a risk that the buffering force to stop the piston will be insufficient and the piston will collide with the cylinder at the end of its stroke.

Also, in order to avoid collision between the piston and cylinder, if the cushioning force of the piston due to the cushion pressure is increased,
The pressure energy of the fluid confined in the cushion mechanism causes the piston to rebound at the end of its stroke.

In order to solve the above-mentioned drawbacks, the present inventors used the cushion pressure generated in the cushion mechanism as a buffering force for stopping the piston, and used the cushion pressure to operate the brake piston.
Proposal 17 (Utility Application No. 130-51900) of a fluid pressure cylinder in which the piston is brought into pressure contact with the piston/row, and the braking force is applied to the piston rod, was able to achieve the intended purpose. However, since the brake piston is used to transmit the cushion pressure to the brake shoes,
There were problems in that the braking mechanism became large and the number of parts increased.

[Problems to be Solved by the Invention] The present invention uses the cushioning pressure generated in the cushion mechanism as a buffering force for stopping the piston, and also uses the cushion pressure to directly actuate the brake shoe, thereby ensuring that the piston is at the end of its stroke. The problem to be solved is to make the braking mechanism compact and inexpensive while also configuring it to stop.

[Means for Solving the Problems] The present invention has a cushion ring provided on the piston rod fitted into a cushion packing provided on the cylinder side at the stroke end of the cylinder, thereby directing discharge fluid into the pressure chamber of the cylinder. In a fluid pressure cylinder that is temporarily enclosed to exhibit a cushioning effect, a brake packing that is an integral part of the cushion packing and a brake shoe is displaceably supported by a support ring provided on the cylinder, and the brake packing is The above problem is solved by making the brake shoe deformable so as to come into pressure contact with the cushion ring by the pressure fluid confined in the pressure chamber.

[Work] Supply high pressure air to one pressure chamber of the cylinder.

When the air in the other pressure chamber is discharged, the piston slides to the air discharge side, and when the cushion ring provided on the piston rod fits into the cushion packing near the stroke end, the pressure chamber is temporarily sealed. , the pressure in the pressure chamber increases to generate cushion pressure, and this cushion pressure applies a buffering force to the piston.

In addition, the cushion pressure presses the brake packing against the support ring, and the brake shoe is displaced in the direction in which it comes into pressure contact with the cushion ring, so both the buffering force due to the cushion pressure and the braking force due to the brake shoe act on the piston. and stops reliably without colliding or bouncing at the end of the stroke.

[Embodiment] FIGS. 1 and 2 show a first embodiment of the present invention, in which a cylinder 1 has a head cover 3 at the end of a cylinder tube 2.
and the rod cover 4 are integrally connected by a tie rod or the like (not shown).

On the other hand, the piston 5 sliding inside the cylinder tube 2 is
It is fixed on the piston rod 7 by suitable means, and cushion rings 6.6 formed with a larger diameter than the piston rod 7 are attached to both sides of the piston.

The head cover 3 and the rod cover 4 have four parts 11 bored from the piston 5 side at their centers, and this recessed part 11
A brake packing 15 is arranged on the mouth side of the recess 11.
The bottom side of is formed to have a larger diameter than the cushion ring 6,
It is connected to a boat 14 for supplying and discharging high-pressure air.

The brake packing 15 includes a cushion packing 16 on the piston 5 side, and a plurality of brake shoes 17 integrally attached behind the cushion packing 16 in the radial direction. --, the brake packing 1
5 is supported by the inner edge of a support ring 18 fitted and fixed in the recess 11 and a stopper 19 fixed to a groove on the inner periphery of the recess 11, and the periphery is inclined toward the piston 5 side. It is loosely fitted into the inside so that the diameter can be reduced.

The cushion packing 16 is made of an elastic material such as rubber, has an annular groove extending toward the piston 5 side, and the cushion ring 6 described above is closely inserted into the center hole. The packing 16 and the cushion ring 6 constitute a cushion mechanism in the pressure chamber 20 of the cylinder 1. On the other hand, the brake shoe 17. - The fist has an arcuate braking surface 22 as shown in FIG. 3, and the braking surface 22. The inner diameter of the imaginary circle formed by ... is a slightly larger diameter than the cushion ring 6 in the non-braking state shown in FIG. A braking surface 22 is formed to press against the cushion ring 6 to apply braking force. The above brake shoe 17. ... is formed of a metallic material made by sintering metal powder, a cermet made by sintering porcelain material and metal powder, etc., but these materials may be lined only on the braking surface 22, or the brake shoe 17 ．．・
- Instead, the cushion ring 6 can also be formed of the above-mentioned material.

Although not shown, the brake shoes 17,
The contact surface 23 to the support ring 1B is the support ring 18
It may also be an arcuate surface that matches the curvature of the inner edge.

Furthermore, a communication hole 24 is bored in the covers 3 and 4 to communicate the pressure chamber 20 of the cylinder 1 with the bow 14.
(See FIG. 2), the communication hole 24 is provided with a cushion valve 25 whose flow rate can be adjusted by restricting it.

As shown in FIG. 1, the rod cover 4 has a rod hole 26 formed therethrough, and the piston rod 7 has the above-mentioned brake packing 15. It is led out of the cylinder 1 through the support ring 18 and the rod hole 26 in an airtight manner.

In FIG. 1, the reference numeral 27 is a piston backing that seals between the piston 5 and the cylinder tube 2, and the reference numeral 28 is a wear ring, both of which are attached to a groove formed on the outer periphery of the piston 5.

Next, the operation of the first embodiment will be explained.

In FIG. 1, high pressure air is supplied to the pressure chamber 20 on the head side by a switching valve (not shown), and the pressure chamber 20 on the rod side is supplied with high pressure air.
0 air is released to the atmosphere through the brake packing 15 on the rod side, the gap between the support ring 18 and the piston rod 7, and the port 14, and the piston 5 is driven by the high pressure air supplied to the pressure chamber 20 on the head side. Fig. 1 shows the state in which it is sliding to the left. When the cushion ring 6 fits into the cushion packing 16 of the brake packing 15 due to the sliding of the piston 5, a pressure chamber acts on the cushion packing 16. The internal and external peripheral parts of the cushion packing 16 are sealed by the fluid pressure inside the cushion packing 16, and the pressure chamber 20 on the rod side is temporarily in a sealed state, so that the internal pressure rapidly increases. This increased internal pressure in the pressure chamber 20 acts on the piston 5 as a cushion pressure, and also acts on the brake packing 15, causing it to be absorbed by the support ring 18.
The brake shoe 17 attached to the cook and packing 1B presses against the brake shoe 17. - The jar rotates using the inner edge of the support ring 18 as a fulcrum, and is displaced from the illustrated tilted state to the upright direction.

This displacement causes the brake shoe 17. Since the inner diameter of Φ· is reduced, the braking surface 22. ... applies a braking force to the cushion ring 6 by pressing against the outer peripheral surface of the cushion ring 8, and due to the buffering force and this braking force, the piston 5 collides with the cover at the end of the stroke, or the elastic energy of the cushion pressure Stops reliably without bouncing back.

The air confined in the pressure chamber 20 on the rod side passes through the communication hole 24 and the cushion valve 25 and gradually flows into the boat 1.
4 and the cushion pressure decreases, the brake packing 15 returns to its original state due to the elastic restoring force of the cushion packing 16, and the brake shoe 17
．． The braking action caused by -- is canceled.

By switching the switching valve (not shown), high pressure air is supplied to the pressure chamber 20 on the rod side, and air on the head side is transferred to the boat 1.
4 to the atmosphere, high pressure air is supplied from the rod side boat 14 to the rod side pressure chamber 20, and the piston 5 slides to the right. The following operations are similar to those described above.

In the above embodiment, the cushion mechanism and the brake mechanism are provided on both the head side and the rod side of the cylinder, but they may be provided on either the head side or the rod side if necessary.

FIG. 4 shows another example of the configuration of the brake shoe in the first embodiment. This brake shoe 30 has a hollow truncated cone shape, has a slit 31 in the generatrix direction, and the inner surface of the center hole is connected to the braking surface 30. It is said that

When the conical surface of the brake shoe 30 is pressed against the inner edge of the support ring 18, the brake shoe 30 is displaced in a direction in which the diameter is reduced by the slit 31, and the braking surface 32 is pressed against the outer periphery of the cushion ring 6.

FIG. 5 shows a second embodiment of the present invention, in which a recess 35 is formed in a rod cover 34, and a support ring 37 of a brake packing 38 is fitted into the inner wall of the recess 35. has been done.

The brake packing 36 is made by integrally combining a hollow cylindrical cushion packing 38 made of an elastic material such as rubber and a hollow cylindrical brake shoe 38 shown in FIG. 6A or B on the inner surface thereof. These are fitted into a support ring 37, and the cushion packing 38 has an annular shoulder portion 40 on the inner edge on the piston 5 side into which the cushion ring 6 is tightly fitted, and an annular groove 41 that is open on the piston 5 side. It is formed.

6A and 6B show an example of the configuration of the brake shoe 33 in the second embodiment, and the brake shoe 39 in FIG.
2 Axial slot from both ends of the cylinder to near the other end 7) 3
9a are formed alternately, and the brake shoe 39 in FIG. 6B has a slit 7) 39b extending over the entire length in the axial direction.

Further, in the brake packing 36, the cushion pressure formed by fitting the cushion ring 6 into the shoulder portion 40 of the third day of the cushion packing acts in the concave groove 41, thereby causing the inner part of the cushion packing 38 to move in the diameter reducing direction. The brake shoe 39 is brought into pressure contact with the cushion ring 6 by displacement, but the rest is the same as the first embodiment.

Note that the above-mentioned cushion mechanism and brake mechanism can also be provided on the rod side of the cylinder.

The other configurations and operations of the second embodiment are the same as those of the first embodiment, so detailed explanation thereof will be omitted.

[Effects of the Invention] In the present invention, near the stroke end of the piston, the piston receives a buffering force due to the cushion pressure, and the cushion pressure deforms the brake packing to apply the braking force by the brake shoe to the cushion ring. Even when the load on the piston is large and the speed is high, it not only prevents the piston from colliding with the cylinder, but also prevents the piston from bouncing back due to the elastic energy of the fluid generated by the cushion pressure, and prevents the piston from reaching the end of the stroke. It can be stopped reliably.

Furthermore, since the cushion pressure is applied directly to the brake packing supported by the support ring, the braking mechanism can be made compact and inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of the first embodiment of the present invention, FIG. 2 is a top end view of the same, and FIG. 3 is a perspective view of the brake shoe shown in FIG. 1.
FIG. 4 is a perspective view showing another example of the configuration of the knee,
FIG. 5 is a vertical sectional view of the main part of the second embodiment of the present invention, and FIG. 6A
, B are perspective views of the brake shoe of the second embodiment. 1 φΦ cylinder. 8--Cushion ring, 7-Piston rod, 15.38--Brake packing. 111.38-・Cushion packing, 17.30.
39. Brake shoe, 18. 37. Support ring, 20. Pressure chamber. Fig. 2 Fig. 3 Fig. 1 Fig. 6 A Fig. 6 B Fig. 5 Hand fF, Light amendment (self-motivated) Commissioner of the Japan Patent Office Black 1) Akio Yu 1, Indication of the case 1985 Patent Application No. 194285 No. 2, Name of the invention Fluid pressure cylinder 3, Relationship with the case of the person making the amendment Patent applicant address 1-18-4 Shinbashi, Minato-ku, Tokyo Name Susumu Omura, President and CEO of NMC Corporation 4, Agent 〒 160 Phone (343) 875
5 Address: 1-9-12 Nishi-Shinjuku, Shinjuku-ku, Tokyo
Issue 6, Figures 1 and 5 of the drawings to be amended, Figure 7, and contents of the amendments Figures 1 and 5 of the drawings will be amended as shown in the attached sheet.

Claims (1)

[Claims] 1. At the stroke end of the cylinder, a cushion ring provided on the piston rod is fitted into a cushion packing provided on the cylinder side, thereby temporarily sealing the discharged fluid in the pressure chamber of the cylinder, In a fluid pressure cylinder designed to exhibit a cushioning effect, a brake packing that is an integral part of the cushion packing and a brake shoe is movably supported by a support ring provided on the cylinder, and the brake packing is placed in the pressure chamber. A fluid pressure cylinder characterized in that a brake shoe can be deformed so as to come into pressure contact with a cushion ring by sealed pressure fluid.