JPH1122704A - Spring return type actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spring return type actuator to eliminate a need for a receiver tank heretofore used, and hold compressed air from an air source by a spring chamber and other body chamber. SOLUTION: An actuator is provided with a cylinder chamber 1 and a spring chamber 5, and the spring of the spring chamber 5 is compressed or expanded according to reciprocation motion of a piston 2 and a piston rod 3 through injection or discharge of compressed air in the cylinder chamber 1, and an output shaft 11 is rotated through reciprocation motion of the piston rod 3. In a so formed spring return type actuator, an air source 12 is connected to the spring chamber 5, and connected to a cylinder chamber 1 from the spring chamber 5 through a solenoid valve 15 or a manually-operated valve 16. The spring chamber 5 or the spring chamber 5 and the body chamber are utilized as an air tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spring return type actuator, and more particularly, to an actuator which has conventionally been connected from an air source to a cylinder chamber via a receiver tank, and which does not require a receiver tank.

[0002]

2. Description of the Related Art A conventional spring return type actuator will be described with reference to FIG. In FIG. 3, reference numeral 1 denotes a cylinder chamber having a piston 2 and a piston rod 3 joined to the piston 2 and having a supply / exhaust port 4 for compressed air. A spring chamber 5 has a spring 6 and a spring retainer 7. Numeral 8 is a conversion unit between linear motion and rotational motion, which is composed of a pin 9 on the piston rod 3 and an arm 10 engaged with the pin 9, and rotates the output shaft 11 by the linear motion of the piston rod 3. Output shaft 11
The valve and the like engaged with the actuator are driven.

In the cylinder chamber 1, an air source 12 is provided with a check valve 1
8 and connected to the compressed air supply / exhaust port 4 via a receiver tank 19 and a solenoid valve 20. When compressed air is supplied to the cylinder chamber 1, the output shaft 1 is moved by the pin 9 and the arm 10 from the piston 2 via the piston rod 3.
1 shows a state where it has rotated. When returning, release compressed air,
The pressure of the spring 6 returns the piston 2 to its original position.

[0004]

When the air source 12 is cut off due to a power failure or the like in the above-described configuration, compressed air from the air source 12 cannot be obtained. Is used. FIG. 3 shows a case where the receiver tank 19 is used. However, providing the receiver tank 19 has disadvantages in that the equipment cost is increased and a space for installation is required.

An object of the present invention is to provide an actuator which does not require the above-mentioned receiver tank.

[0006]

SUMMARY OF THE INVENTION To achieve the above object, the present invention is an actuator having a cylinder chamber and a spring chamber, and injects or discharges compressed air into and out of the cylinder chamber to reciprocate a piston and a piston rod. In a spring return type actuator in which an output shaft is rotated by reciprocating motion of a piston rod that compresses or expands a spring in a spring chamber in accordance with movement, an air source is connected to the spring chamber, and an electromagnetic valve is connected from the spring chamber. Alternatively, it is a spring return type actuator which is connected to a cylinder chamber via a manual valve and uses the spring chamber or the spring chamber and the body chamber as an air tank.

(Operation) In the present invention, an air source is connected to the spring chamber, and the spring chamber is connected to the cylinder chamber via an electromagnetic valve or a manual valve, and the spring chamber or the spring chamber and the body chamber are used as an air tank. This eliminates the need for a conventional receiver tank. The spring chamber includes only the spring and the spring retainer, and can sufficiently hold the compressed air. Further, if a body chamber including a piston rod and a conversion part between linear motion and rotary motion is used in addition to the spring chamber, considerable compressed air can be held.
Since the piston and the piston rod are sealed by an O-ring, no leakage of compressed air occurs.

The required pressure can be set by the pressure-intensifying valve from the operating pressure of the actuator, the volume of the space, the number of times of operation, etc., and smooth operation can be performed. When the air source is cut off due to a power failure or the like, the air source can be operated by the spring chamber or the air stored in the spring chamber and the body chamber.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A spring return type actuator of the present invention normally injects compressed air into a cylinder chamber to make a forward movement of a piston and a piston rod, and compresses a spring in a spring chamber via a spring retainer. The compressed air is discharged, the piston rod is moved backward by the spring force of the spring, and the output shaft is driven.

[0010]

1 is a side sectional view of a spring return type actuator according to the present invention, showing a case where a cylinder is returned by a spring force of a spring. FIG. 2 shows a state in which the piston is driven by using the compressed air in the spring chamber and the body chamber. 1 is a cylinder chamber and 2 is a piston. 3 is a piston rod and 4 is a supply / exhaust port. Reference numeral 5 denotes a spring chamber in which a spring 6 is loaded. 7 is a spring retainer. Numeral 8 is a conversion unit between linear motion and rotational motion, which is composed of a pin 9 on the piston rod 3 and an arm 10 engaged with the pin 9, and rotates the output shaft 11 by the linear motion of the piston rod 3. A valve or the like engaged with the output shaft 11 is driven. The converter 8 for converting the linear motion into the rotary motion forms a body chamber between the cylinder chamber 1 and the spring chamber 5.

Reference numeral 12 denotes an air source, 13 denotes a pressure increasing valve, and 14 denotes a pressure reducing valve. The required pressure can be set based on the operating pressure of the actuator, the volume of the space, the number of operations, and the like. In some cases, the pressure increasing valve 13 and the pressure reducing valve 14 are not used.
FIG. 2 shows a state in which compressed air is supplied to the cylinder chamber by the solenoid valve 15 or the manual valve 16 using air in the spring chamber and the body chamber. Therefore, even if there is no supply of compressed air from the air source at the time of a power failure or the like, it can be driven. 1
Reference numeral 7 denotes an O-ring that seals between the piston 2 and the piston rod 3 so that a complete seal can be obtained even when compressed air is held in the spring chamber or the spring chamber and the body chamber.

[0012]

According to the present invention, the compressed air from the air source can be held in the spring chamber and the body chamber, and the necessary pressure is adjusted based on the operating pressure of the actuator, the volume of the space portion, the number of times of operation, and the like. Can be sent to
It can operate smoothly. Also, even if the air from the air source is cut off due to a power outage or the like, air can be supplied to the cylinder chamber through a solenoid valve or a manual valve by the air held in the spring chamber or the body chamber. There was no need to install a receiver tank, etc., and the piping system was simplified, and a compact spring-return actuator could be provided.

[Brief description of the drawings]

FIG. 1 is a side sectional view and system diagram of a spring return type actuator of the present invention.

FIG. 2 is a side sectional view showing driving of the actuator.

FIG. 3 is a side sectional view and a system diagram showing a conventional actuator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder chamber 2 Piston 3 Piston rod 4 Supply / exhaust port 5 Spring chamber 6 Spring 7 Spring retainer 12 Air source 15 Solenoid valve 16 Manual valve

Claims (1)

[Claims] An actuator having a cylinder chamber and a spring chamber, wherein the spring in the spring chamber is compressed or expanded in response to injecting or discharging compressed air into and out of the cylinder chamber to make the piston and the piston rod move back and forth. In a spring return type actuator configured to rotate an output shaft by reciprocating motion of a piston rod, an air source is connected to a spring chamber, and the spring chamber is connected to a cylinder chamber via an electromagnetic valve or a manual valve,
A spring return type actuator, wherein a spring chamber or a spring chamber and a body chamber are used as an air tank.