JPH05599B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an elastic contractile body used in an air bag type actuator, which is mainly used as an actuator for a robot and utilizes an axial contractile force based on an expanded diameter as an operating force. be.

[Prior art]

This type of conventional elastic contracting body generally consists of an inner cylinder as a tubular member made of an elastic material such as rubber, and a reinforcing layer with a braided structure that covers the outer periphery of this inner cylinder, sealing both ends and applying pressure to the internal space. When applied, the reinforcing layer expands in the radial direction and contracts in the axial direction due to the pantograph movement of the reinforcing layer. Furthermore, the reinforcing layer is not joined to the inner cylinder in order to prevent the generation of resistance against changes in the diameter of the inner cylinder.

By the way, in the case of an elastic contracting body with such a structure, when both ends of the elastic contracting body are closed and pressure is applied to the internal space, the diameter changes by 2 to 3 times and the axial length becomes 20 to 40 mm. %, but when it changes to its maximum diameter, the maximum stress acts on the reinforcing layer, and in order to suppress the change in the inner cylinder, the fibers or cords of the reinforcing layer sink into the inner cylinder, which is an elastic body, and the inner cylinder tightens. This shortens the life of the inner cylinder and, by extension, the life of the elastic contractile body.

[Purpose of the invention]

An object of the present invention is to solve the problems with the conventional elastic contraction body, and to obtain an elastic contraction body which has the same functions as the conventional elastic contraction body and has excellent durability.

[Structure of the invention]

To achieve this object, the elastic contractile body of the present invention consists of an inner cylinder made of an elastic body, and a reinforcing layer of a braided structure that covers the outer periphery of the inner cylinder in an unbonded state. In an elastic contracting body that expands in the radial direction and contracts in the axial direction due to the pantograph movement of the reinforcing layer when pressure is applied to the space, the protection is made by knitting fibers in fine stockinette between the inner cylinder and the reinforcing layer. The invention is characterized in that a layer is provided to prevent damage caused by the reinforcing layer biting into the inner cylinder due to the expansion.

〔Example〕

The elastic contractile body of the present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a diagram showing the structure of an embodiment of the present invention, in which 1 is an inner cylinder made of an elastic material, and rubber or a rubber-like elastic material is useful in terms of air impermeability and flexibility. However, equivalent materials such as various plastics may be substituted. The braided reinforcing layer 2 covering the outer periphery is made of a tensile strength reinforcing element, and is made of organic or inorganic high tensile strength fibers, such as aromatic polyamide fibers (Kevlar: trade name), twisted or untwisted bundles of filaments such as ultrafine metal wires. etc. are applicable. The protective layer 3 provided between the inner tube 1 and the reinforcing layer 2 is made by knitting fibers similar to those of the reinforcing layer 2 in a stretchable manner such as stockinette knitting, and using even thinner yarns with a density of 100.
%, so that the inner cylinder 1 and the reinforcing layer 2 do not come into contact with each other even when stretched 2 to 3 times, and do not create resistance when the diameter changes.

With this structure, the inner cylinder of this elastic contraction body does not come into direct contact with the reinforcing layer, so the inner cylinder is not damaged by the reinforcing layer, and the life of the inner cylinder is extended.
As a result, it becomes possible to dramatically improve the lifespan of the elastic contractile body.

FIG. 2 shows an embodiment in which the elastic contractile body of the present invention is applied to a pneumatic actuator. The inner cylinder 1, the reinforcing layer 2, and the protective layer 3 have the same structure as the embodiment shown in FIG. The closing member 5 includes nipples 6 that are tightly attached to the openings at both ends of the elastic contracting body 4, preferably using an adhesive, for sealing, and a flange 7 that controls positioning.
and an eye or clevis end 8 provided with a connecting pin hole, and an annular protrusion 9 may be provided on the outer periphery of the nipple 6 to prevent it from coming off, forming a gentle taper toward the tip with a steep taper in the opposite direction. good. One side of the closing member 5 is provided with a connecting hole 11 which communicates with the inner cavity of the elastic contraction body 4 through a central hole 10, and a fitting 12 is attached thereto. The caulking cap 13 is engaged with the flange 7 and covers the outer periphery of the end of the elastic contracting body 4, and is made of a cylindrical metal part with a flare 14 formed at the end, and is locally pressed in the radial direction toward the nipple 6 to close it. The member 5 is sealed and bonded to the elastic shrinkable body 4. 15 is an indentation made by a caulking tool.

Next, the operation of this pneumatic actuator will be explained. When an operating pressure source (not shown), such as an air compressor, is connected to the fitting 12 and a conduit containing a three-way valve and a controlled pressure is applied to the internal cavity of the elastic contracting body 4, the braid angle of the braided reinforcing layer 2 changes. Due to the expansion of θ, that is, the pantograph movement, the diameter of the elastic contracting body 4 expands as shown by the two-dot chain line, and this causes contraction in the axial direction, that is, the distance between the connecting pin holes of the closing member 5 decreases. The contraction force at this time moves a member or device connected to the actuator.

When the control pressure is released, the air in the internal cavity of the elastic contracting body 4 is dissipated into the atmosphere through a three-way valve (not shown), and the elastic contracting body 4 is compressed as the braid angle θ of the braided reinforcing layer 2 decreases. It is restored and expanded to return to its original state.

Such a pneumatic actuator can, for example, be connected by a pin between articulated actuating arms of a robot by means of the eyes or clevis ends 8 of the closing member 5 at both ends, thereby allowing bending, extension, and articulation between the actuating arms. can.

〔Effect of the invention〕

As detailed above, the elastic contractile body of the present invention has a structure in which a protective layer is provided between the inner cylinder made of an elastic body and the reinforcing layer of the braided structure that covers the outer periphery of this inner cylinder. The elastic contracting body, which breaks after a very small number of expansions and contractions, approaches the original number of fatigue failures of the elastic body that forms the inner cylinder, extending its life to several million times of expansion and contraction, making it simple and inexpensive. This has the advantage of providing a long-life pneumatic actuator with a simple structure.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the structure of an embodiment of the elastic contracting body of the present invention, and FIG. 2 is a partially sectional front view showing an example of application of the elastic contracting body of the present invention to a pneumatic actuator. 1... Inner cylinder, 2... Reinforcement layer, 3... Protective layer, 4
...Elastic contraction body, 5... Closing member, 6... Nipple, 7... Flange, 8... Clevis end, 9...
Annular protrusion, 10... Central hole, 11... Connection hole, 1
2...fitting, 13...caulking camp, 14...flare, 15...indentation.

Claims (1)

[Claims] 1. An inner cylinder made of an elastic body, and a reinforcing layer of a braided structure that covers the outer periphery of the inner cylinder in a non-bonded state, and both ends of which are sealed and pressure is applied to the internal space. In the elastic contractible body that contracts in the axial direction as the reinforcing layer expands in the radial direction due to the pantograph movement of the reinforcing layer, a protective layer made of fine knitted fibers is provided between the inner cylinder and the reinforcing layer. Contracted body.