JPS6217404A - Rotary actuator - Google Patents

Abstract

PURPOSE:To increase output torque by forming ribs for connecting piston portions parallel to and independently from each other and mounting a pin parallel to an output shaft between both ribs. CONSTITUTION:Two ribs 2 for connecting two piston portions 2a, 2b are formed parallel to and independently from each other, a pin 11 parallel to an output shaft 8 is mounted between both ribs 2d, and a finger portion engaged with the pin 11 of a connecting portion 10 is extended to the space between the ribs. In this arrangement, both the output shaft 8 and the pin 11 are eccentric from the central axis of a piston, and the eccentricity of the shaft and the pin can be enlarged more than that well-known, so that the connecting arm can be lengthened and output torque can be increased.

Description

[Detailed description of the invention] 1. The present invention is a rotary actuator that converts reciprocating motion of a piston due to fluid pressure into rotational motion of a shaft, and outputs the converted motion, for example,
The present invention relates to an actuator that can be used as a swing actuator for automatically opening and closing a valve, operating a 90° rotation mechanism, etc.

The rotary actuators of the Jt type described above are known, for example, from Japanese Patent Application Laid-Open No. 58-24605.

In a known rotary actuator, two piston parts are integrally connected by two ribs, a hollow part is formed between both ribs, and a trunnion pin is fitted into a bifurcated clevis formed integrally with the rib. The tip of the yoke fixed to the output shaft is engaged with the trunnion pin.

Both of the two ribs have a shape corresponding to a part of a cylindrical surface along the wall surface of the cylinder case, and the yoke is movable within the range inside the cylindrical surface of both ribs.

In the conventional rotary actuator, the range of motion is inside the cylindrical rib forming the piston in the cylinder case, so the length of the yoke, that is, the connecting member, is limited. In other words, the distance between the output shaft center and the trunnion bin center cannot be long, and the transmitted torque is limited.

The present invention solves the above-mentioned conventional problems by utilizing a piston composed of two piston parts and two ribs connecting both piston parts, and in this case, the ribs are aligned with the axis. Formed as parallel ribs that are independent from each other, a pin parallel to the output shaft is installed between both ribs, and a finger portion of the connecting member that engages with the pin is formed so as to extend into a space between both ribs. Achieved by

Since the two ribs are independent of each other, the space between the two ribs is open in the radial direction up to the wall surface of the cylinder case. Therefore, the leg portion of the connecting portion extending to the space between the two ribs can utilize the entire inner wall surface of the cylinder case as a range of movement.

The range of motion of the tip in the radial direction is not obstructed by ribs, unlike in the past.

The reciprocating motion of the piston is transmitted to the fingers of the yoke as a continuous member via a pin arranged between both ribs, and the yoke moved by the pin rotates the output shaft.

The length of the fingers of the yoke can be made as long as possible to near the inner wall of the cylinder case, and at this time, if the pin is installed as close to the inner wall of the cylinder case as possible, the length between the center of the output shaft and the center of the bottle can be increased. It can be made larger than conventional rotary actuators.

1 serving■ The details of the present invention will be explained with reference to embodiments shown in the drawings.

In FIGS. 1 to 4, a rotary actuator 1 includes a cylinder part including a piston 2 and a cylinder case 3 that reciprocally accommodates the piston 2, and is integrally formed with the cylinder case 3 and arranged to face each other. The output shaft part 9 includes an output shaft 8 rotatably supported by the first support part 4 and the second support part 5 via a metal 6.7.

The piston 2 has a piston portion 2a of 2 frlJ,
2b, and a bridge portion 2C that connects both piston portions.

The bridge portion 2c is formed as two mutually independent ribs 2d extending parallel to the piston axis. Both of the two ribs 2d are present in approximately half of one side outward from the center in the diametrical direction of the piston parts 2a and 2b in the width direction, and the other half has a space between the piston parts 2a and 2b. Become. There is a space between the two ribs 2d from the center of the piston portion to the inner wall surface of the cylinder case 3 in the diametrical direction.

The output shaft 8 is disposed in the remaining half of the space where the rib 2d does not exist, and is supported at a position offset from the piston center axis of the cylinder case 3. Therefore, even if the piston 2 reciprocates, the rib 2d does not come into contact with the output shaft 8.

A pin 11 whose end is supported by each of the two ribs 2d (the ribs are shown through in the figure) is provided to connect both ribs, and the pin 11 extends parallel to the output shaft 8. .

A connecting arm 10 as a connecting member is fixedly attached by inserting a hole 10a at one end into the output shaft 8, and a connecting arm 10, which serves as a connecting member, is fixedly attached to the output shaft 8 by inserting a hole 10a at one end thereof. It has a finger portion 10b extending into the space. The connecting arm 10 is formed as a thin plate-like member having a thickness that can be inserted into the space between the two lips 2d, and is formed in a fork shape.

The distance between the two fingers is the pin 1 installed between the two lips 2d.
1 or the ring 12 fitted on the pin 11 is set so that it slides smoothly with almost no play.

The entire connecting arm 10 can be integrally molded from sintered metal.

When molded from sintered metal, the fork-shaped fingers can be formed with precise tolerances of 1/100 inch or less between the two surfaces, and no special machining is required.

The spacing between the finger parts 10b is set to 1 by precision forming with sintered metal.
Since it can be formed with a precise tolerance of /100 tm or less, there is almost no play between the pin 11 and the pin 11. In addition, since the pin 11 or ring 12 has a cylindrical surface, the height can be increased even by machining.

It is possible to obtain high accuracy.

The space between the two lips 2d is completely open in the radial direction, and there is no part where the fingers Job of the connecting arm 10 collide. Therefore, the dimensions of the finger portions 10b of the connecting arm 10 can be set to be long enough to prevent the tip of the finger portions 10b from coming into contact with the inner wall surface of the cylinder case 3 when rotating around the output shaft 8. Pin 11 in contact with finger portion 10b
(Indirectly, the ring 12 can be interposed) If the position is selected as close to the inner wall surface of the cylinder case 3 as possible, the distance from the center of the output shaft 8 to the center of the pin 11 can be set to be long. I can do it.

Since the center of the output shaft 8 and the center of the pin 11 are arranged at positions offset in the direction opposite to U with respect to the piston center axis, the connecting arm 10 can fully and effectively utilize the space between the inner wall surfaces of the cylinder case 3. I can do it. Therefore, compared to the diameter of the cylinder case 3, the effective length of the connecting arm 10 (the distance from the center of the output shaft to the center of the bottle) can be made larger than in the past.

If the length between the center of the output shaft and the center of the pin 11 can be increased, the torque transmitted to the output shaft 8 due to the reciprocating motion of the piston 2 can be increased. In other words, it is possible to provide a rotary actuator with a large output torque.

A sealing member 2e is fitted in the piston portions 2a, 2b to seal the space between the piston portions 2a and 2b and the inner wall surface of the cylinder case 3. Although an O-ring may be used as the sealing member, it is preferable to provide a lip seal. In other words, if the lip portion is arranged as shown in the figure so that it contacts the piston portions 2a, 2b and the cylinder case 3 at an outer position, air from the space between the piston portions 2a and 2b will not leak to the outside. However, it is possible to prevent it from flowing into the space between the piston parts 2a and 2b from the outside.

As a result, the air pressure in the space between the piston parts 2a and 2b)
: The problem that occurs in the case of O-rings, where sliding resistance at the seal portion increases due to tampering, can be avoided. There are various types of lip backings, such as U-shaped, Y-shaped, Y-shaped, etc.

The output shaft 8 is secured to the support 4. by means of a stop ring 13.14.
This is to prevent tax deductions from 5.

Both ends of the cylinder case 3 are sealed by flanges 15.16, and the piston portion 2a is attached to the flanges 15.16.
Alternatively, a joint screw 17 is screwed into contact with 2b to determine the limit position of movement of the piston, and the adjustment screw can be fixed in position with a nut 18.

Cylinder case 3, first support i4 and second support grS5
The main body is constituted by flange 1!5.16. Second
The support part 5 has a pedestal part 5 that protrudes from the cylinder case 3.
a is formed, and the interior surrounded by the rectangular outline of the pedestal portion 5a is formed as a recessed portion 5b. The output shaft 8 is in the fourth part 5b.
Eyes 820 indicating the rotation angle of the output shaft 8 by the pointer 19 attached to the shaft are integrally formed as protrusions at predetermined angular intervals.

It is convenient that the height of the scale 20 is equal to or less than the height of the outline of the pedestal portion 5a.

Connecting end 8A of square cross section of output shaft 8 to square hole of pointer 19
It has a structure in which it is inserted into the body and fixed with a stop ring 21. Generally, by rotating the output shaft 8 by 90 degrees,
It opens and closes valves connected to the output shaft 8, switches, etc. The pointer 19 can be used to point to the scale on the right side or the scale on the left side of the plane orthogonal to the cylinder axis. For example, if the output shaft 8 is switched from the closed position to the open position by clockwise rotation while pointing to the scale on the right side, the output shaft 8 is switched from open to closed by counterclockwise rotation. In this state, if you change the position of the pointer 19 so that it points to the scale on the left, the output shaft can be used as a scale so that it switches from open to closed when rotated clockwise and from closed to open when rotated counterclockwise. can.

For this purpose, it is recommended to write open/close symbols at opposite positions in a plane perpendicular to the cylinder axis. In FIG. 1, "open" is indicated by the symbol "0" and "closed" is indicated by the symbol rSJ. There is an advantage that the pointer 19 can be adapted to 1Mff1 by simply changing the attachment state of the pointer 19 according to the opening/closing direction of the member attached to the output shaft 8.

A mounting seat 22 is formed on the side of the cylinder case 30,
A solenoid valve or the like is attached to the mounting seat 22.

The mounting seat 22 is formed with an opening 23.23, which is connected to the flange 1 by a passageway 24.25 formed in the cylinder case 3, as shown in FIG.
It communicates with the left and right chambers of the piston parts 2a and 2b, respectively, through the space on the 5.16 side.

Figures 1 to 4 show a double-acting rotary actuator that operates by alternately switching the flow paths 24 and 25 to the suction side and the discharge side by the switching operation of a solenoid valve mounted directly or indirectly on the mounting seat 22. As a modification, as shown in FIGS. 5 and 6, a single-acting rotary actuator 1' may be formed by fixing a wing cartridge 26 to the cylinder case 3 instead of one of the flanges, for example, the flange 15. I can do it.

The spring cartridge 26 includes a cartridge case 27, a sleeve-shaped spring receiver 28 supported in the cartridge case 27, a spring guide 29 slidably attached to the spring receiver, and a spring fixed to the spring guide 29. The receiver has a disk 30 and a spring 31 stretched between the spring receiver 28 and the disk 30. When the spring receiver is fixed to the cylinder case 3, the disk 30 is connected to the piston 2. (2a in the figure).

When fluid is supplied by the action of the electromagnetic valve attached to the mounting seat 22, the piston 2 is pushed to the left in the figure against the force of the spring 31. The amount of movement of the piston is adjusted by the screwing amount of an adjustment screw 32 screwed into the cartridge case 27.

When the fluid is discharged by switching the solenoid valve, the piston 2 returns to its initial position by the force of the spring 31. Although no particular explanation is given for each rotary actuator listed in (a), (b), important parts are equipped with known sealing members to prevent fluid leakage.
The following measures have been taken.

The output shaft 8 of the low reactor actuator 1, 1' is equipped with a device such as a positioner that controls the rotational position of the rotary actuator, or a switch such as a rotary switch that outputs an electrical signal by rotating the output shaft of the rotary actuator. etc. may be installed. The casing of such a device can be directly fe-fastened to the tapped hole of the pedestal ff15a.

In this case, the shaft of the device is connected to the output shaft 8 via a coupling.
Alternatively, a square hole is formed in the shaft end of the device, and the square hole is inserted into the end of the output shaft, which has a square cross section, for connection. This allows the device to be assembled as an integral structure with the rotary actuator.

The device can be assembled to the rotary actuator using a bracket instead of being directly attached to the pedestal 5a.

According to the present invention, both the output shaft and the pin to which the connecting member connects are eccentric with respect to the piston center axis, and the amount of eccentricity of both can be made larger than that of known systems. In this case, the cylinder case has a normal cylindrical shape and no special treatment is required. Therefore, it has become possible to increase the length of the connecting arm and increase the output torque. It became possible to make the cylinder case more compact for products with the same output.

If the backing of the piston part is lip backing, the sliding resistance due to leakage will be small and the output efficiency will be high.

[Brief explanation of drawings]

Fig. 1 is a plan view of a low reactor actuator according to the present invention, Fig. 2 is a partially cutaway front view, Fig. 3 is a plan cross-sectional view, Fig. 4 is a front longitudinal sectional view, and Fig. 5 is a separate view. FIG. 6 is a partially cutaway plan view showing a single-acting rotary actuator according to an embodiment of the present invention, and FIG. 6 is a front vertical sectional view. 1.1'...Rotary actuator 2...Piston, 2a, 2b...Piston part 2c...
Bridge 2d...Rib 3...Cylinder case 8...Output shaft 10...Connection arm (connection part) 10a...Hole 10b...Finger 11...
Bin Figure 1 Figure 2

Claims (1)

[Scope of Claims] A piston, a cylinder case that reciprocates the piston, and an output shaft that is rotatably supported by the cylinder case and extends in a direction perpendicular to the axis of the cylinder case. In the rotary actuator, the piston includes a connecting member that connects the piston and the output shaft and converts reciprocating linear motion of the piston into reciprocating rotational motion of the output shaft, the piston comprising two piston parts and a bridge that connects both piston parts. The bridge is formed by two parallel ribs extending parallel to the piston axis and spaced apart from each other with the piston axis in between, the ribs extending in the width direction of the piston. The output shaft is arranged eccentrically with respect to the piston axis in a range where the rib does not exist, and one end is fixed to the output shaft. The connecting member extends into the space between the two ribs.
A rotary actuator having two finger portions, a pin having both ends supported by the ribs and extending between the two ribs in parallel to the output shaft is engaged between the two fingers. .