JP2000046014A - Pneumatic actuator with built-in position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect both of the linear movement and the rotary movement by using a bearing to be fitted on a shaft as a rotary shaft of an actuator to be rotated by the operation of the compressed air and a rotary shaft of a rotating position detector. SOLUTION: When the compressed air is supplied from a pipeline port P1, a shaft 2 is extruded by a bearing 5, and when the compressed air is supplied from a pipeline port P2, the shaft 2 is pulled into the bearing 5 and a cylinder 1. A linear position detector 4 for potentiometer is built in the shaft 2 so that the position on the straight line corresponding to the position of the shaft 2 can be detected. In the case of a valve type oscillating actuator 6, when the compressed air is supplied from a pipeline port P3, the bearing 5 is rotated right as a rotary shaft of an oscillation type actuator 6, and when the compressed air is supplied from a pipeline port P4, the bearing 5 is rotated left. Rotating position at this stage can be detected as an angle data by a rotating position detector 9. With this structure, wiring for outputting the detection data can be saved.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic actuator having a built-in position detector, and more particularly, to a compact built-in position detector for detecting the linear position and the rotational position of a pneumatic actuator performing linear motion and rotational motion. It is about a pneumatic actuator.

2. Description of the Related Art FIG. 7 shows a linear air cylinder incorporating a linear position detector. Piston 10
There is a shaft 102 having a built-in linear position detector 103 such as a potentiometer, for example.
As shown in FIG. 8, there is a type in which a rotational position detector sensor 202 is attached to the oscillating type actuator 201 so as to be fully closed and fully opened with a positioner 203 interposed therebetween. There is no one equipped with only a detection sensor.

As described above, in the prior art, one of linear motion and rotational motion is output. In an actuator which performs linear motion while rotating, linear motion and rotational motion are output. It is impossible to detect both of the positions with a combination of existing products.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention has been developed in order to detect both positions when a shaft connected to a piston of an actuator performs a linear motion while performing a rotary motion. A shaft integrated with a piston of an actuator that performs a linear motion by the operation of a linear position detector built-in, the outer periphery of the shaft is formed in a non-circular cross section such as a hexagon or an ellipse, and a bearing for internally fitting the shaft, An actuator that performs rotational movement by the operation of compressed air and a pneumatic actuator with a built-in position detector that is used as a rotation axis of a rotational position detector.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on a specific embodiment shown in the accompanying drawings. This actuator is used for, for example, a robot arm. A piston 3 integrated with a shaft 2 is slidably provided in a cylinder 1. The axis of the cylinder 1, that is, the shaft 2
The linear position detector 4 of the potentiometer is disposed at a position which is also the axis of the axis. The principle of the linear position detector 4 is that, as shown in FIG. 3, the voltage applied between the terminals (1) and (3) is divided in proportion to the position of the shaft 2 and output from the terminal (2). Is done. The outer periphery of the shaft 2 is formed in a non-circular cross section such as a hexagon or an ellipse so as to transmit a rotational movement. A bearing 5 in which the shaft 2 is fitted is disposed on the tip side of the cylinder 1. As shown in FIGS. 1 and 4, the bearing 5 is used as a rotation axis of the swing actuator 6, and the rotational force of the swing actuator 6 is transmitted from the bearing 5 to the shaft 2. 4 and 5, the inner surface of the bearing 5 is formed so as to be fitted with the shaft 2 having a non-circular cross section such as a hexagon or an ellipse. In the swing actuator 6, the bearing 5 is swingably provided in a housing 7, and a vane 8 inscribed in the housing 7 extends from the bearing 5. Also,
As shown in FIG. 5, a rotational position detector 9 is externally fitted and fixed to the bearing 5. The rotational position detector 9 and the housing 7 are screwed to the cylinder 1 by inserting a bolt, for example. As shown in FIG. 6, the principle of the rotational position detector 9 is that the voltage applied between the terminal (1) and the terminal (3) is divided in proportion to the position of the wiper 10, and the voltage is applied from the terminal (2). Is output. The signal detected by the rotational position detector 9 is led out to an amplifier 11 provided at the base end of the cylinder 1 via a wiring 12. In FIG. 1, when compressed air is supplied from a pipe port P1, the shaft 2 is pushed out from a bearing 5, and when compressed air is supplied from a pipe port P2,
The shaft 2 is drawn into the bearing 5 and the cylinder 1. A linear position detector 4 of a potentiometer is built in the shaft 2 so that a linear position corresponding to the position of the shaft 2 can be detected. In the case of the valve-type swing actuator 6 as shown in FIG. 4, when compressed air is supplied from the pipe port P3, the bearing 5 rotates clockwise as a rotation axis of the swing actuator 6, and compressed air is supplied from the pipe port P4. Then, the bearing 5 rotates left. The same applies to the case where the swing actuator is an actuator that performs continuous rotation. The rotational position at that time is detected by the rotational position detector 6 as, for example, angle data. As shown in FIG. 1, by using the amplifier 7 of the detector as the linear position detector 6 and the rotational position detector 9, it is possible to reduce the number of wires for outputting the detection data.

As described above, according to the present invention, a linear position detector is built in a shaft integrated with a piston of an actuator which performs a linear motion by the operation of compressed air, and the outer periphery of the shaft is formed as a hexagon or an ellipse. Formed in a non-circular cross-section, the bearing for internally fitting the shaft is an actuator that performs rotational motion by the operation of compressed air and a pneumatic actuator with a built-in position detector that uses the rotation axis of the rotational position detector as a smaller space. It has become possible to detect the linear position and the rotation angle.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a specific embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a diagram illustrating the principle of a linear position detector.

FIG. 4 is a sectional view taken along line IV-IV of FIG.

FIG. 5 is a sectional view taken along line VV of FIG. 1;

FIG. 6 is a diagram illustrating the principle of a rotational position detector.

FIG. 7 is a sectional view of a conventional linear air cylinder incorporating a conventional linear position detector.

FIG. 8 is a perspective view of an example in which a rotational position detection sensor is attached to a conventional swing type actuator via a positioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder 2 ... Shaft 3 ... Piston 4 ... Linear position detector 5 ... Bearing 6 ... Oscillating cylinder 7 ... Housing 8 ... Vane 9 ... Rotational position detector 10 ... Wiper 11 ... Amplifier P1, P2, P3, P4 ... Piping port

Claims (1)

[Claims] 1. A shaft integrated with a piston of an actuator which performs a linear motion by the operation of compressed air, a linear position detector is built in, and the outer periphery of the shaft is formed in a non-circular cross section such as a hexagon or an ellipse. And a pneumatic actuator with a built-in position detector, in which a bearing that fits inside is used as a rotary shaft of a rotary position detector and an actuator that performs a rotational motion by the operation of compressed air.