JPH0546444B2 - - Google Patents

Description

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

(Prior art and its problems) Pneumatic actuators, which expand in the radial direction and contract in the longitudinal direction by introducing pressurized fluid, are lighter in weight and move more smoothly than devices that use electric motors or hydraulic cylinders. It has many excellent features not found in conventional actuators, such as the ability to perform positioning reliably. As such an actuator, for example, the one shown in FIG. 3 is known from Japanese Patent Publication No. 52-40378. In the figure, 1 is a tubular body, 2 is a braided reinforcement structure around its outer periphery, 3 is a closing member at both ends, and 4 is a caulking cap.

The tubular body 1 is preferably made of rubber or a rubber-like elastic material in terms of its air impermeability and flexibility, but equivalent materials such as various plastic materials may be substituted.

The braided reinforcement structure 2 has a braided structure that reaches a so-called rest angle (54° 44') when the tubular body 1 is expanded to its maximum diameter due to internal pressure filling.
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 suitable.

One of the closure members 3 is bored, at least on one side, into a connecting hole 8 which communicates with the internal cavity 7 of the tubular body 1 via a hole 6 formed in the lengthwise direction of the nipple 5, in which a fitting 9 is mounted. Although not shown, an operating pressure source, such as an air compressor, is connected to the fitting 9 through a conduit including a flow rate control valve, and a control pressure is applied to the internal cavity 7 of the tubular body 1, thereby increasing the braided reinforcement structure 2. The enlargement of the braid angle, that is, the pantograph movement, causes the expanded diameter of the tubular body 1 and the resulting contraction in the axial direction, that is, the distance between the connecting pin holes 10 of the closing member 3 is reduced.

When such a pneumatic actuator is used as a drive device, it is common to use a set of at least two pneumatic actuators because the pneumatic actuator generates a contractile force. As such a drive device, for example, the one shown in FIG. 4 can be considered. That is, two pneumatic actuators 20
a and 20b are connected to a pulley 12 rotatably supported by a support member 11 using a chain or wire 14, respectively, and the actuator is actuated via fittings 9a and 9b connected to an operating pressure source. By supplying pressurized fluid into the internal cavity, the pulley 12 is rotated as shown by arrow A in the figure.

For this reason, it is necessary to devise a method for attaching the closing member and the wire, which tends to increase the size of the closing member. This means that the effective length of the actuator is small relative to the overall size of the actuator, and the output is small. Furthermore, the weight of the base portion relative to the actuator becomes large, and the lightweight characteristic of the pneumatic actuator is impaired.

(Object of the Invention) An object of the present invention is to solve the above-mentioned problems and to provide a pneumatic actuator as a lightweight drive means with a large effective length.

(Structure of the Invention) To achieve this object, the pneumatic actuator of the present invention comprises tubular bodies made of rubber or rubber-like elastic material spaced apart in the longitudinal direction, and an organic or A braided reinforcing structure using inorganic high tensile strength fibers as a tensile reinforcing element, and a closing member that seals and joins the openings at both ends of each tubular body together with the braided reinforcing structure and has a connecting hole on at least one side. Become.

(Function) Therefore, according to the pneumatic actuator of the present invention, pressurized fluid is introduced from the operating pressure source into the internal cavity of one of the tubular bodies through the connecting hole to generate a contraction force in the axial direction, If the pressurized fluid is discharged from the other tubular body through the connection hole, the tubular bodies placed apart from each other are connected by the braided reinforcement structure, so the direction of the tubular body into which the pressurized fluid is introduced is will be moved to. Therefore, the pulley can be driven by winding or abutting the connecting portion of the braided reinforcing structure around the pulley, as shown in FIG. 4, for example. Moreover, the closing member that seals and joins the opposing ends of the tubular body does not need to be devised to connect with a chain or wire that engages with a driven part such as a pulley, and simply connects the tubular body and the braided reinforcement structure. Since all that is required is sealing and bonding, the structure is compact and simple.

(Example) A pneumatic actuator according to the present invention will be described in detail below with reference to the drawings. For the sake of simplicity, the same reference numerals as in FIGS. 3 and 4 have the same functions.

FIG. 1 shows a pneumatic actuator 20 showing one embodiment of the present invention, and as is clear from FIG. 1, it is comprised of driving parts 30a, 30b and a connecting part 30c. The driving parts 30a and 30b each include a tubular body 1, a braided reinforcing structure 2 that reinforces the outer periphery of the tubular body 1, a closing member 3 on the pressurized fluid introduction side that seals one opening of the tubular body together with the braided reinforcing structure, and a closing member 3 that seals one opening of the tubular body. A braided reinforcement structure 2 located spaced apart from member 3
and a closing member 3 for sealing the other opening of the tubular body.
a, 3b. The closing member 3 has a connecting hole 8 for supplying and discharging pressurized fluid into the internal cavity 7 of the tubular body 1.
and attach fitting 9. Therefore, the pressurized fluid supplied by the operating pressure source (not shown) is
It is fed into the internal cavity 7 through a communication hole formed in the nipple 5 of the closure member 3. The reference numeral 4 designates a caulking cap that cooperates with the closing member 3.

The other end of each tubular body 1 is provided with a closing member 3a,
3b, and a sealing ring 15 to connect the tubular body 1 and the braided reinforcing structure 2 to the closure members 3a, 3.
Each sticks to b. Therefore, when pressurized fluid is supplied into the internal cavity 7, the tubular body 1 expands in diameter and contracts in the axial direction.

By the way, the braided reinforcing structure 2 reinforcing the outer periphery of each tubular body 1 extends beyond the closing members 3a and 3b to form a connecting portion 30c. Therefore, if the connecting portion 30c is wound around the pulley 12 shown by the two-dot chain line, for example,
The pulley 12 can be rotated around its axis in response to the pressure difference between the pressurized fluids acting on each tubular body.

In addition, the braided reinforcement structure 2 performs pantograph movement in the portion related to the tubular body 1 as described above and allows the expansion diameter deformation of the tubular body, but the connecting portion 3
At 0c, almost no pantograph movement occurs, so the displacement in the axial direction caused by the expansion diameter deformation of the tubular body is reliably transmitted. Further, in this embodiment, a ring-shaped member is used to attach the tubular body 1 and the braided reinforcement structure 2 to the closing members 3a and 3b, respectively, but a band-shaped member may also be used.
Alternatively, a caulking cap 4 can also be used,
The present invention is not limited to this embodiment. Further, the connecting portion 30c may have not only a braided structure but also a structure in which tensile strength reinforcing elements are twisted.

FIG. 2 shows another embodiment of the invention. In this embodiment, at least a portion of the connecting portion 30c is covered with a covering material 16 made of rubber or a rubber-like elastic material. The other parts are the same as those in the embodiment shown in FIG. 1, so their explanation will be omitted.

In this embodiment, since the connecting portion is covered with the covering material 16, even if the connecting portion 10c comes into contact with a driven member, such as a pulley, the organic or inorganic high-tensile fibers that make up the braided reinforcement structure are easily damaged. The life of the actuator is improved without any problems.

(Effects) As detailed above, the pneumatics and
In the actuator, tubular bodies made of rubber or rubber-like elastic material spaced apart in the longitudinal direction are reinforced with a braided reinforcement structure using organic or inorganic high-tensile fibers as tensile reinforcement elements, and connected to each other, and the openings of each tubular body are connected to each other. Since the ends are sealed and joined with the closing member, there is no need to connect them using chains, wires, etc. as in conventional actuators, and there is no problem in attaching the closing member to the chain, etc. do not have. Therefore, since the dimensions of the closing member can be made compact, the weight of the actuator itself can be reduced, and the effective length of the actuator can be increased. Furthermore, since there is no need to separately attach a chain or the like, there are many advantages such as, for example, attachment to a driven member such as a pulley becomes much easier.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view of one embodiment of the pneumatic actuator of the present invention, FIG. 2 is a partially sectional front view of another embodiment of the present invention, and FIG. 3 is a conventional FIG. 4 is a schematic diagram showing an example of a drive device using a conventional pneumatic actuator. 1... Tubular body, 2... Braided reinforcement structure, 3, 3
a, 3b... Closing member, 4... Caulking cap,
5... Nipple, 6... Hole, 7... Internal cavity, 8
... Connection hole, 9, 9a, 9b ... Fitting, 10 ... Connection pin hole, 11 ... Supporting member, 1
2...Pulley, 14...Chain, 15...Sealing ring, 16...Coating material, 20, 20a, 20b
...Pneumatic actuator, 30a, 3
0b...drive section, 30c...coupling section.

Claims (1)

[Scope of Claims] 1 Tubular bodies made of rubber or rubber-like elastic material spaced apart in the longitudinal direction, and organic or inorganic high tensile strength fibers that reinforce the outer periphery of these tubular bodies and connect them to each other as tensile reinforcement elements. It comprises a braided reinforcing structure, and a closing member that seals and joins the openings at both ends of each tubular body together with the braided reinforcing structure and has a connecting hole on at least one side, and expands and deforms in diameter by supplying and discharging pressurized fluid. A pneumatic actuator characterized by generating a contraction force in a direction. 2. The pneumatic actuator according to claim 1, wherein at least a portion of the connecting portion of the braided reinforcement structure that connects the tubular bodies to each other is provided with a covering material of rubber or rubber-like elastic material.