JPS61236905A - Pneumatic actuator - Google Patents

Abstract

PURPOSE:To obtain an actuator which is resistant to external wounds by covering the outer periphery of a tubular body by a braided reinforcing structure and further covering with the intrusion part intruding into the stitches of the braided reinforcing structure. CONSTITUTION:The outer periphery of a tubular body 1 made of rubber or rubber elastic material is covered with a braided reinforcing structure 2 made of organic or inorganic high tension fiber. Further, the braided reinforcing structure 2 is covered with a covering member 10 which is made of rubber or rubber elastic material and is relatively thin and has the intrusion part intruding into the stitches of the braided reinforcing structure 2. The both edge opened ports of the tubular body 1, braided reinforcing structure 2, and the covering member 10 are sealing joined, and a connecting hole 4 which communicates to the inside vacant space 6 of the tubular body 1 is formed. With such constitution, an actuator resisting to external wounds can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air bag type pneumatic actuator that expands and deforms in diameter by introducing pressurized fluid and generates a contraction force in the axial direction.

(Prior Art) An airbag-type two-speed-matic actuator that expands radially and generates a contraction force axially by introducing a pressurized fluid, such as compressed air, into the internal cavity of a tubular body. Compared to actuators that perform reciprocating motion using hydraulic cylinders or electric motors, the weight of the device itself is lighter (
It has many features such as no problems such as environmental pollution caused by leakage of hydraulic oil or fire caused by sparks.

As such an actuator, for example, one having the structure shown in FIG. 3 is disclosed in Japanese Patent Publication No. 52-40378. 1 is a tubular body, 2 is a braided reinforcement structure on its outer periphery, and 3 is a closing member at both ends. The tubular body 1 is made of rubber, a rubber-like elastic material, or a material equivalent thereto in consideration of air impermeability. The braided reinforcement structure 2 has a braided structure in which the braiding angle θ reaches a so-called resting angle (54''44') when the tubular body 1 is expanded to its maximum diameter due to internal pressure filling, and is made of organic or inorganic high tensile strength material. Fibers such as aromatic polyamide fibers (Kevlar: trade name) and twisted or untwisted bundles of filaments such as ultrafine metal wires are suitable.

Such an actuator A causes an enlargement of the braiding angle of the braided reinforcing structure 2 when a control pressure is applied to the internal cavity 6 of the tubular body 1 via a fitting 5 attached to at least one connecting hole 4 of the closure member 3; In other words, the expansion diameter of the tubular body 1 due to pantograph movement and the contraction in the axial direction resulting from this,
That is, the distance between the connecting bottle holes 7 formed in the closing member 3 is reduced. In addition, code 8 indicates caulking/caulking at both ends.
Cap, 9 indicates indentation.

(Problems to be Solved by the Invention) In this known pneumatic actuator, the tubular body 1 and the braided reinforcing structure 2 are separate bodies, and the contact surface between the tubular body 1 and the braided reinforcing structure 2 and/or Alternatively, the contractile force generated by the actuator can be improved by applying a mold release agent such as fluororesin or molybdenum disulfide to the braided reinforcement structure to minimize the deformation resistance during the pantograph movement of the braided reinforcement structure 2. It was designed to achieve this goal.

For this reason, if pressurized fluid is repeatedly supplied and discharged from the actuator to repeatedly expand and contract the diameter, the braided reinforcement structure 2 may partially or completely break down, and when pressurized fluid is introduced, Since the tubular body locally protrudes and expands in the radial direction from the loosely knitted portion, the loosely knitted body further progresses, making it impossible to function satisfactorily as an actuator.

Further, since the tubular body made of rubber or a rubber-like elastic body is repeatedly subjected to local deformation at the part where the knitting is broken, there is also a problem that the tubular body breaks early. In particular, various problems caused by this knitting failure were noticeable when monofilaments, which have higher tensile strength than multifilaments, were used as the braided reinforcement structure.

An object of the present invention is to provide a pneumatic actuator that prevents the braided reinforcement structure from failing and has a long life.

(Means for Solving the Problems) To achieve this objective, the pneumatic of the present invention. The actuator consists of a tubular body made of rubber or a rubber-like elastic material, the outer periphery of which is covered with a braided reinforcing structure of organic or inorganic high-tensile fibers, and a relatively thin rubber having an intrusion part that penetrates into the mesh of the braided structure. Alternatively, the braided reinforcement structure is covered with a covering member made of a rubber-like elastic material, and these tubular bodies,
The braided reinforcing structure and the openings at both ends of the covering member are sealed together, and at least one of the closing members is provided with a connecting hole that communicates with the internal cavity of the tubular body.

(Function) When pressurized fluid is introduced into the internal cavity of the tubular body through the connection hole provided in the closing member, the braided reinforcement structure resists the intrusion of the covering member made of rubber or rubber-like material that enters the weave. As a result, the tubular body expands in diameter and generates a contraction force in the axial direction.

That is, the &I group reinforcing structure performs pantograph motion while elastically deforming the intrusion portion of the covering member.

On the other hand, if the pressurized fluid is discharged from the internal cavity of the tubular body, the braided reinforcing structure whose braiding angle has been expanded due to the pantograph movement will have its braiding angle reduced as the tubular body contracts and expands. On the other hand, the intrusion portion of the covering member that is elastically deformed during the pantograph movement of the braided reinforcement structure also returns to its initial shape as the tubular diameter contracts and expands. At this time, since the covering member is restored while contacting the braided reinforcing structure, the braided reinforcing structure returns to the initial braided angle without causing any bending.

Note that the covering member exerts deformation resistance when the braided reinforcement structure performs pantograph movement, but the deformation resistance of the intrusion part is sufficiently small compared to the deformation resistance of the tubular body, and the breakage of the braided reinforcement structure is caused by the actuator. The deformation resistance is not a problem when compared with the influence on the material.

(Example) The pneumatic actuator of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a preferred embodiment of the present invention. Note that parts in the figure that are equivalent to those shown in FIG. 3 are designated by the same reference numerals.

1 is a tubular body, 2 is a braided reinforcement structure on its outer periphery, 3 is a closing member at both ends, and 4 is a connecting hole provided in one of the closing members, which communicates with an internal cavity 6 of the tubular body 1. 5 is a fitting attached to the connection hole 4 for connection to a conduit containing an operating pressure source, for example an air compressor. 7 is a connecting pin hole, 8 is a caulking cap, and 9 is an impression when caulking is performed.

The two outer peripheries of the braided reinforcement structure are covered with a covering member 10 made of rubber or rubber-like elastic material, as shown in FIG. 2(a). This situation is partially cut and developed in FIG. 2(b). In this embodiment, the braided reinforcing structure 2 is made of monofilament, such as nylon or polyester fiber, which has a small coefficient of friction, a smooth surface, and little elongation.

In order to provide this braided reinforced structure 2 with a coating member that covers its outer periphery, a release agent is applied to the outer circumferential surface of the braided reinforced structure and the tubular body 1.
For example, a fluororesin or silicone resin is pre-applied, and then a covering member of unvulcanized rubber or rubber-like elastic material is applied to the outer surface of the braided reinforcing structure 2. And some of this covering material! It is pressed so as to penetrate into the stitches of the &U reinforcement structure 2, and then heated and vulcanized. In addition, this vulcanization work is
Although it is advantageous for the work to be performed simultaneously with the tubular body 1, it may be performed separately from the vulcanization work of the tubular body.

The cross-sectional view of the actuator after vulcanization is shown in the second figure.
Shown in Figure (c). Reference numeral 10a indicates an intrusion portion of the covering member 10 that has intruded into the stitches of the braided reinforcement structure 2. As mentioned above, since a mold release agent is applied in advance to the outer peripheral surfaces of the tubular body 1 and the braided reinforcement structure 2, the covering member 10 does not adhere to the tubular body 19 and the braided reinforcement structure 2. There isn't.

When pressurized fluid is introduced from an air compressor (not shown) into the internal cavity 6 of the tubular body 1 of the actuator configured in this way, the braided reinforcement structure performs a pantograph movement, and the tubular body expands and deforms in the axial direction. Generates contractile force. At this time, the covering member 10 also expands radially outward due to the expansion and diameter deformation of the tubular body. On the other hand, the intrusion portion 10a of the covering member is elastically deformed in accordance with the pantograph movement of the &W\tJi reinforcing structure 2, that is, the deformation of the stitch portion.

After the actuator has performed a predetermined movement, when the compressed air is discharged from the internal cavity 6, the diameter of the covering member 10 is also reduced as the diameter of the tubular body 1 is reduced, and the braided reinforcing structure 2 is expanded in response to this movement. The braid angle that was created is also reduced. At this time, the intruding portion that has invaded the stitches of the braided reinforcement structure is restored based on the release of the elastic energy stored during the deformation, and the engaged braided reinforcement structure is returned to the initial braid angle. therefore,
No knitting occurs in the braided reinforcement structure.

Furthermore, since the covering member also functions as a protective cover that protects the braided reinforcing structure and the tubular body, an actuator that is resistant to external damage is obtained. Furthermore, by forming the covering member from a material with excellent weather resistance, it is possible to eliminate as much as possible the adverse effects of ultraviolet rays on the tubular body and the braided reinforcement structure.

(Effects of the Invention) As detailed above, in the pneumatic actuator of the present invention, the outer periphery of the tubular body is covered with a braided reinforcement structure, and the rubber or rubber-shaped Since the tubular body is covered with a covering member made of an elastic material, the braided reinforcement structure will not break even if pressurized fluid is repeatedly supplied and discharged from the tubular body. Therefore, not only multifilaments but also monofilaments, which have higher tensile strength than multifilaments, can be used as the braided reinforcing structure, in which case the performance and service life of the actuator will be significantly improved. Moreover, the covering member is
To obtain an actuator that is resistant to external damage because it also functions as a protective cover that protects the actuator from external external damage.

[Brief explanation of the drawing]

FIG. 1 is a partially cross-sectional front view of the pneumatic actuator of the present invention; FIG. 2(a) is a schematic diagram of the actuator shown in FIG. Figure (b) is an explanatory diagram showing the actuator's braided reinforcement structure and covering member shown in Figure 1 developed, and Figure 2 (
c) is a vertical sectional view showing a part of the actuator shown in FIG. 1, and FIG. 3 is a front view showing a known pneumatic actuator in partial section. 1 - Tubular body 2 - Braided reinforcement structure 3... - Closing member 4 - Connection hole 5 - Fitting 6 - Internal cavity 7 Series of connecting pin holes 8 -
・Caulking cap 9・-Indentation 10・−・
- Covering member 10a - Intrusion part

Claims (1)

[Claims] 1. It has a tubular body made of rubber or rubber-like elastic material, a braided reinforcing structure made of organic or inorganic high-tensile fibers that covers the outer periphery of the tubular body, and an intrusion part that covers the outer periphery of the braided reinforcing structure and enters into the stitches of the braided reinforcing structure. A covering member made of rubber or a rubber-like elastic material, and a closing member sealingly joining the tubular body, the braided reinforcing structure, and the openings at both ends of the covering member, and at least one of the closing members is provided in the internal cavity of the tubular body. A pneumatic actuator having a communicating hole and generating a contractile force in the axial direction by supplying and discharging pressurized fluid into an internal cavity.