JP2993506B2 - Actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an actuator that operates by the energy of a fluid.

(Prior Art) Conventionally, hydraulic and pneumatic cylinders, hydraulic and pneumatic motors, and the like have been widely used as actuators operated by the energy of a fluid.

Since these actuators generally have a sliding portion (for example, between a piston and a cylinder), the working fluid is easily leaked,
There were drawbacks that smooth operation and precise positioning were difficult due to sliding friction.

On the other hand, conventionally, a pneumatic actuator utilizing elastic deformation of rubber has been devised. For example, trade name Pneumatic Finger, Pat, DEPS 2426086-C3, US 39815
There is something like 28.

As shown in FIGS. 8 and 9, this main structure has a semi-cylindrical elastic member 91 made of rubber, and a bellows portion 92 is provided on a part of the elastic member 91 in the axial direction. Have been.
A port for sending air into one end of the elastic body 91
93 are provided. Accordingly, when the pressure in the elastic body 91 is increased by sending the air pressure P from the port 93, the bellows portion 92 is expanded and the entire elastic body 91 is elastically deformed as shown in FIG. For this reason, the elastic body 9
By adjusting the pressure in 1, the position amounts A and V and the operating force F of the tip shown in FIG. 8 can be controlled and can be used as an actuator. Therefore, unlike the conventional cylinder, the working fluid can be operated smoothly without leakage of the working fluid.

However, when a thin and small robot arm is configured by using the actuator as it is, a space for a bellows portion is required to realize multiple degrees of freedom.
Extremely small diameter was not possible.

(Problem to be Solved by the Invention) As described above, an actuator utilizing deformation of an elastic body provided with a bellows portion can operate smoothly without leakage of working fluid unlike a cylinder. However, the diameter is increased by the amount required for the bellows, and it is not suitable for use as a robot arm because the diameter cannot be reduced.

Therefore, an object of the present invention is to provide an actuator that can operate smoothly, can be easily reduced in diameter, and has a simple structure.

[Configuration of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention comprises a first member that is elastically deformable and a second member that is less elastically deformable than the first member. Integrating the first member and the second member so as to form a cylindrical body having a non-circular cross-section as a whole and being arranged side by side in the axial direction, and adjusting the pressure inside the cylindrical body. Thus, the actuator performs a bending operation.

(Operation) According to the above, by adjusting the pressure inside the cylindrical body, the first member constituting the cylindrical body has directivity in the bending direction due to its cross-sectional shape. Perform a bending operation in the direction. As described above, since the bending operation can be performed without providing the bellows portion, an actuator having a simple structure in which the operation is smooth and the diameter can be easily reduced is realized.

Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an actuator showing a first embodiment of the present invention and a perspective view showing an operation. The actuator 1 has lower flexibility than a first member made of rubber or the like, and a tubular elastic body 2 having a substantially rectangular cross section, an upper cover 3, a lower cover 4, a tube 5, and a tubular elastic body. The reinforcing member 6 is a second member made of a member (a metal plate, a plastic, or the like) that hardly undergoes elastic deformation. The reinforcing member 6 is large enough to completely cover the bottom surface of the tubular elastic body 2 and is firmly fixed to the bottom surface. The upper lid 3 and the lower lid 4 are fixed near both ends of the cylindrical elastic body 2, thereby forming a hollow pressure chamber 7 inside the actuator 1. The pressure chamber 7 is filled with a fluid (here, air), but the fluid is communicated with the outside only by the tube 5.
There is no leakage of fluid from the connection between the upper lid 3, the lower lid 4 and the cylindrical elastic body 2.

With the actuator 1 configured as described above,
Here, by changing the pressure in the pressure chamber 7 through the tube 5 by an external pressure control device (not shown),
The actuator 1 can be bent by an arbitrary amount. FIG. 1 (c) shows the bending operation of the actuator 1 when the pressure in the pressure chamber 7 is increased by a dotted line. Since the first member is formed in a substantially rectangular cross section, the actuator 1 has a characteristic that it is easily curved in the long side direction. Further, the bottom surface of the actuator 1, that is, the side covered with the reinforcing member 6, is less likely to be elastically deformed than other portions. Therefore, the entire actuator 1 bends toward the reinforcing member 6. When the pressure in the pressure chamber 7 is reduced to the original pressure, the actuator 1 is restored to the original shape.

If such an actuator 1 is used, the diameter can be sufficiently reduced as compared with a conventional one in which a bellows portion is provided to realize a bending operation, and the operation is performed smoothly. Of course, the structure is simple. Further, as described above, since the amount of bending can be freely set only by changing the pressure, an arbitrary amount of bending can be achieved freely.

 Hereinafter, the same portions are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 2 is a sectional view of an actuator showing a second embodiment of the present invention. This embodiment has the same components as the first embodiment, but the cross-sectional shape, that is, the shape of the tubular elastic body 12 is substantially semicircular in cross-section. different. With such an actuator 11, unnecessary expansion due to pressure acting on the corners of the cylindrical elastic body can be prevented, and an efficient bending operation is realized.

FIG. 3 is a sectional view of an actuator showing a third embodiment of the present invention. The present embodiment has the same shape as the second embodiment, but the cylindrical elastic body 22 is formed of an anisotropic elastic material, and the present actuator 21 differs from the actuator 11 in this point. Here, as the anisotropic elastic material, a spirally wound aramid fiber (trademark) 28 coated with silicon rubber, which is an elastic material, is used. They are arranged to be in the axial direction. Such an actuator 21
Then, unnecessary expansion of the tubular elastic body can be prevented as much as possible, and a very efficient bending operation is realized.

FIG. 4 is a sectional view of an actuator showing a fourth embodiment of the present invention. In this embodiment, the reinforcing member 6 is not used unlike the previous embodiments, and only the portion related to the bottom surface of the tubular elastic body 32 is anisotropic. This method uses the same material as that of the third embodiment described above, but differs from the third embodiment in that the direction in which the longitudinal elastic modulus is large is the axial direction of the actuator 31. With such an actuator 31, since the elastic modulus of the bottom surface is larger than that of the other portions, the three actuators 1, 1
A bending operation similar to that of 1, 21 is realized.

FIG. 5 is a sectional view and a perspective view of an actuator showing a fifth embodiment of the present invention. In the present embodiment, the aramid fibers are arranged on the top and bottom surfaces of the tubular elastic body 52 so that the actuator 51 is bent substantially in an S shape, and the actuator according to the fourth embodiment is connected upside down. It has a structure close to. By doing so, the actuator 51 changes into a complicated shape instantly.

In the above embodiments, the actuator is formed by fixing and integrating the cylindrical elastic body and the upper lid and the lower lid. However, the material of the cylindrical elastic body, the upper lid, and the lower lid may be the same. It may be different.

FIG. 6 is a side sectional view showing a modification of the actuator of the present invention. As described above, when the actuator 61 is manufactured, the actuator 61 is molded in a state of being curved upward in the drawing in advance as shown in FIG. By doing so, the actuator 61 can be bent in both directions. Of course, in this case, another structure may be used.

FIG. 7 is a side view showing an actuator of the present invention applied as a hand part of a robot. As shown in this figure, if the hand-held actuator 81 is configured by fixing the actuator 71 to a holding portion 80 made of a hard member such as a metal having a substantially L-shaped cross section, a grasping operation of an object can be realized. it can. Further, if the contact surface with the object is formed of a relatively soft member, the object will not be given an excessive force. In this application example, it is of course possible to use the other actuators described above.

〔The invention's effect〕

As described above, according to the present invention, an actuator having a simple structure, which operates smoothly and can be easily reduced in diameter, is realized.

[Brief description of the drawings]

1 to 6 are views showing an actuator of the present invention,
FIG. 7 is a view showing an example in which the actuator of the present invention is applied to a hand portion of a robot, and FIGS. 8 and 9 are views showing a conventional actuator. 1,11,21,31,51,61,71 ... actuator, 2,12,22,32,52 ... cylindrical elastic body (cylindrical body, first member), 6 ... reinforcing member (second member) 7) Pressure chamber, 28 Aramid fiber (second in combination with cylindrical elastic body)
Of the member),

Claims (1)

(57) [Claims] A first member that is elastically deformable; and a second member that is less elastically deformable than the first member, wherein the first member and the second member are in an axial direction. And are integrated so as to form a cylindrical body as a whole, and the cross-sectional shape of the first member is perpendicular to the length of the surface on which the second member is disposed. The length of the first direction is adjusted by adjusting the pressure inside the cylindrical body.
An actuator for bending the member in a direction in which the second member is arranged.