JPH0558911U - Fluid pressure actuator - Google Patents

Abstract

(57) [Summary] [Purpose] In a pneumatic cylinder, eliminate wear of magnets, prevent generation of magnetic powder, and purify clean rooms. In a pneumatic cylinder, a magnet 9 manufactured in the order of molding, coating and magnetizing is used, and the magnet 9 is fixed to an outer peripheral groove 10 between the pistons 5a and 5b by adhesion. A constant clearance is formed between the cylinder tube 1 and the inner peripheral surface of the cylinder tube 1.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a fluid pressure actuator, and more particularly to a technique effective when applied to a magnet for a magnetically sensitive position sensor provided in a driving body such as a piston.

[0002]

[Prior Art]

 In this type of pneumatic cylinder, a magnetically sensitive position sensor is arranged on the outer peripheral surface of the cylinder tube corresponding to the stroke end, and the position sensor is installed in the outer peripheral groove of the piston that reciprocates by air pressure inside the cylinder tube. It has a structure with a magnet that magnetically senses.

[0003]

[Problems to be solved by the device]

 However, in the structure of the conventional pneumatic cylinder described above, since the clearance between the outer peripheral surface of the magnet and the inner peripheral surface of the cylinder tube is small, the magnet comes into contact with the inner peripheral surface of the cylinder tube and wears, causing There was a problem that powder was generated and scattered in the clean room.

Further, since the magnet is provided in the outer peripheral groove of the piston in a loosely fitted state, the magnet is loosened, and the magnet is worn to generate magnetic powder, which is scattered in the clean room. was there.

An object of the present invention is to provide a fluid pressure actuator capable of eliminating wear of a magnet, preventing generation of magnetic powder, and cleaning a clean room.

The above and other objects and novel features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

[0007]

[Means for Solving the Problems]

 The following is a brief description of the outline of the typical invention disclosed in the present application.

The fluid pressure actuator of the present invention is disposed on the outer peripheral surface of the actuator body at the position corresponding to the stroke end and the magnet provided on the driving body that reciprocates in the actuator body by fluid pressure. A magnetic sensitive type position sensor that detects the position of the driving body in response to magnetism is provided.A magnet is fixed to the driving body by adhesion, and the magnet is fixed between the outer peripheral surface of the magnet and the inner peripheral surface of the actuator body. The structure has a certain clearance.

In this case, as the magnet, a structure in which a magnet manufactured in the order of molding, coating and magnetization is used can be used.

[0010]

[Action]

 According to the fluid pressure actuator of the present invention, the magnet is fixed to the driving body by adhesion, and a certain clearance is formed between the outer peripheral surface of the magnet and the inner peripheral surface of the actuator body. You can eliminate hits and rattling.

Therefore, it is possible to eliminate wear of the magnet, prevent the generation of magnetic powder, and purify the clean room.

In this case, since the magnet is manufactured by molding, coating, and magnetizing in this order, the magnetic powder is not adsorbed on the surface during coating, which causes the generation of magnetic powder. Can be further prevented and the clean room can be further cleaned.

[0013]

【Example】

 FIG. 1 is a sectional view showing a fluid pressure actuator according to an embodiment of the present invention, and FIG. 2 is a sectional view showing an essential part of the fluid pressure actuator of FIG.

The fluid pressure actuator in this embodiment is applied to a pneumatic cylinder. In this pneumatic cylinder, the cylinder tube 1, the head cover 2, and the rod cover 3 form a cylinder chamber 4 therein, and a piston 5 is slidably provided in the cylinder chamber 4 and the piston (driving body) 5 The piston rod 6 fixed to pierces the rod cover 3 and extends to the rod side.

Further, the cylinder chamber 4 is partitioned into first and second cylinder chambers 4 a and 4 b by a piston 5, and the first and second cylinder chambers 4 a and 4 b are formed in the rod cover 3 and the head cover 2. The first and second supply / discharge ports 7a and 7b are connected to each other.

A magnetically sensitive position sensor 8 is arranged on the outer peripheral surface of the cylinder tube 1 at a position corresponding to the end of the stroke, and a magnet 9 for magnetically sensing the position sensor 8 for switching is provided. 5 is provided.

The present embodiment is characterized in that the magnet 9 is improved.

That is, the piston 5 is formed by connecting two pistons 5a and 5b, and a magnet 9 is fixed to the outer peripheral groove 10 between the two pistons 5a and 5b by adhesion. A constant clearance L is formed between the inner peripheral surface of the tube 1.

Further, the magnet 9 used is one manufactured in a clean environment in the order of molding, coating and magnetization in order to prevent magnetic powder from adhering to the surface during coating. ing.

Reference numeral 11 is a piston packing, 12 is a rod packing, and 13 is a bush.

Next, the operation of this embodiment will be described.

Although the piston 5 is reciprocated by the air pressure in the cylinder chambers 4a and 4b, and the position sensor 8 is magnetically sensitive by the magnet 9, the position of the stroke end of the piston 5 can be detected. In the example, the magnet 9 is fixed to the outer peripheral groove 10 between the pistons 5a and 5b by adhesion, and a constant clearance L is formed between the outer peripheral surface of the magnet 9 and the inner peripheral surface of the cylinder tube 1. Therefore, it is possible to eliminate the hit and play of the magnet 9.

Therefore, the wear of the magnet 9 can be eliminated, the generation of magnetic powder can be prevented, and the clean room can be cleaned.

In this case, as the magnet 9, the magnet 9 manufactured under a clean environment in the order of molding, coating and magnetizing is used, so that the magnetic powder is not generated on the surface during coating. Since it does not adsorb, the generation of magnetic powder can be further prevented, and the clean room can be further cleaned.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above-described embodiment, the case where the magnet is provided in the piston of the pneumatic cylinder has been described, but the present invention is not limited to this, and the present invention can be applied to the case where the magnet is provided in the vane of the oscillating actuator. it can.

In the above description, the invention made by the present inventor was mainly described in the field of application of a fluid pressure actuator such as a pneumatic cylinder that operates by pneumatic pressure, but the invention is not limited to this, and a hydraulic cylinder that operates by hydraulic pressure. It can also be applied to fluid pressure actuators such as.

[0028]

[Effect of the device]

 The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) The magnet is fixed to the driving body by adhesion, and a certain clearance is formed between the outer peripheral surface of the magnet and the inner peripheral surface of the actuator body. Can be eliminated.

(2) Due to the effect of the above (1), it is possible to eliminate wear of the magnet, prevent generation of magnetic powder, and clean the clean room.

(3). In the case of (1) above, since the magnet is a magnet manufactured in the order of molding, coating and magnetization, the magnetic powder is adsorbed on the surface during coating. Therefore, it is possible to further prevent the generation of magnetic powder and further purify the clean room.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a fluid pressure actuator that is an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main part of the fluid pressure actuator of FIG.

[Explanation of symbols]

 1 Cylinder Tube 2 Head Cover 3 Rod Cover 4 Cylinder Chamber 4a First Cylinder Chamber 4b Second Cylinder Chamber 5 Piston (Drive) 5a Piston 5b Piston 6 Piston Rod 7a First Supply / Discharge Port 7b Second Supply / Discharge Port 8 Position Sensor 9 Magnet 10 Outer Groove 11 Piston Packing 12 Rod Packing 13 Bushing L Clearance

Claims (3)

[Scope of utility model registration request] 1. A magnet provided on a driving body that reciprocates in an actuator body by fluid pressure, and a magnet disposed on an outer peripheral surface of the actuator body at a position corresponding to a stroke end portion of the driving body in response to magnetism from the magnet. A magnetically sensitive position sensor for detecting a position, a magnet is fixed to the driving body by adhesion, and a constant clearance is formed between the outer peripheral surface of the magnet and the inner peripheral surface of the actuator body. Fluid pressure actuator. 2. The fluid pressure actuator according to claim 1, wherein a magnet manufactured in the order of molding, coating and magnetization is used as the magnet. 3. The fluid pressure actuator according to claim 1, wherein the magnet is a magnet manufactured in a clean environment in the order of molding, coating and magnetization.