JPH04165109A - Miniature cylinder device - Google Patents

Abstract

PURPOSE:To lighten the device in the title by producing a cylinder whose pistons for rotating a rotating stem are arranged on both sides thereof; and producing the rotating stem and the pistons of synthetic resin in compliance with PPS. CONSTITUTION:A rotating stem 20, which is mounted along the through hole axis of the cylinder, whose piston axis is engaged with the groove 25 of a plate-like body 22; and which makes its turning motion by the linear motion of the piston, the cylinder, and the piston are made of PPS synthetic resin. Subsequently, the device in the title is lightweighted, superior in moldability, and able to be produced at low cost with high quality in comparison with that made of Al alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in small cylinder devices used, for example, to open and close valves by air drive.

[Prior art] As shown in FIG. 5 and FIG.
There is a small cylinder device disclosed in Japanese Patent No. 406.

This device consists of aluminum alloy pistons 2, 3 and a rotating stem 4 housed in an aluminum alloy cylinder 1, and has through holes 5, 6 at the top and bottom of the center of the cylinder 1.
A cylindrical rotating stem 4 vertically inserted into the through holes 5 and 6
The top part 4C of the stem protrudes from the cylinder 1 to display the valve opening degree and function as a manual operation shaft.

The rotary stem 4 has two spaces S1 and S2 carved in the radial direction in the axial direction of the stem in two stages, upper and lower, and has a disk-shaped portion 14 between the two spaces S1 and 82. Two sets of grooves 15 having an open outer surface and having a depth from the outside to the inside are provided in the disc-shaped part 14 at circumferentially opposing positions of the disc-shaped part 14. The pistons 2 and 3 have the same shape and have pressure receiving parts 2a and 3a that receive the pressure of the pressure fluid.
and a rod 2b extending from the side of the pressure receiving part toward the center.

3b, and the outer surface of the rod is in sliding contact with the inner surface of the cylinder 1. A pair of brackets are attached to the ends of the rods 2b and 3b.
1, 6, 16, 17, and 17 are integrally provided, and a shaft 18, 19 is passed through the bracket, and the shaft J8.19 has no bearing function and is loosely fitted to allow the roller to rotate. This piston 2.3 is inserted from both open ends of the cylinder 1, and the brackets 16 and 17 are inserted into the space S of the rotating stem 4.
S2, and the shafts 18 and 19 are inserted into the grooves 15 of the stem 4 to be assembled in the cylinder 1, and the central chamber A and the left chamber B
It is divided into the right ventricle C.

The surface of the cylinder 1 has pressure fluid boats PI and P2, the boat p opens directly into the central chamber A in the cylinder 1, and the boat P2 communicates with a passage that runs vertically through the wall of the cylinder. The passage opens at both internal ends of the cylinder 1 and communicates with a left chamber B and a right chamber C, which are separated by a pressure receiving part of a piston.

When pressurized air is supplied from the boat P1, the piston 2,
3 moves linearly in the direction of expansion, and the rotating stem 4 moves from the shafts 18 and 19 of the screws through the stem 15 to the disk-shaped portion 4.
Rotational motion is transmitted to and rotates. When air is supplied from the boat P2, the rotating stem 4 rotates in the opposite direction to the above, and by switching and supplying the two boats PI and P2, the valve connected to the stem 4 is opened and closed. It's turning two.

[Problems to be Solved by the Invention] As described above, the outer surface of the rod slides into contact with the inner surface of the cylinder in response to the reciprocating motion of the pistons 2 and 3, converting it into a rotational motion of the rotary stem 4, thereby rotating the valve shaft of the valve. It rotates, but the whole thing is A.
Since it is made of one alloy, it is heavier than one made of resin, and each part requires cutting, and it is also essential to remove machining particles associated with this.
In particular, the machining accuracy of the inner cylinder required careful attention, making the product expensive as a whole.

The present invention provides a cylinder device that solves the above problems.

[Means for Solving the Problems] The gist of the present invention is that a rotating stem is installed in the center of a cylinder at right angles to the moving direction of the piston, and two stems are connected to the rotating stem on both sides of the cylinder. The inner chamber of the cylinder is divided into a left chamber, a center chamber, and a right chamber by the two pistons, and the linear movement of the piston is controlled by the rotational stem by switching the pressure fluid between the center chamber and the left and right chambers. This cylinder device converts the motion into rotational motion, characterized in that the cylinder, rotating stem, and piston are made of synthetic resin made by PI)S.

[Function] P i) S synthetic resin has excellent injection moldability, has a low thermal shrinkage rate, and can be molded into a specified shape without dimensional shrinkage or deformation after injection molding. Also, since it is lightweight and has little frictional resistance, there is little sliding resistance between the piston and cylinder, and because it is lightweight, it has good responsiveness to pressure fluid. Furthermore, PPS is oil,
It has a 4N property that is stable against water, chemicals, etc., and can be installed almost without restriction in the location where the valve is installed.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a perspective view of the rotating stem 20 of the first embodiment, which is made of PPS synthetic resin and is located at the center of the cylinder as described in the prior art section, and extends from the upper and lower surfaces of the cylinder. The rotary stem 2o is mounted along the shaft of a through hole drilled in the rotary stem 2o, and is connected to the valve shaft of a valve or the like through square holes 21 formed at the upper and lower ends of the rotating stem 2o, and is driven. A disk-like body 22 shown in FIG. 2.3 is provided in the central portion in the axial direction, and the disk-like body 22 is made of steel and formed by cutting or press working, and has holes 23.
A pair of grooves 25 and 25 are provided in a direction perpendicular to the hole 23 and facing each other. Holes 23.23 are filled with upper and lower spaces S, S when the PPS synthetic resin that forms the whole is injection molded.
The resin of the beams 24, 24, 24, 24 forming the beam 2 flows and is integrally bonded and molded.

FIG. 4 is a perspective view showing the piston 30, in which two pistons 30 having the same shape as described in the prior art section are mounted on both sides of a cylinder made of PPS synthetic resin. The piston 30 is formed by injection molding PPS synthetic resin, and has a pressure receiving part 31 that receives the pressure of the pressure fluid.
An O-ring 32 is attached to the outer periphery of the cylinder so that it slides in a sealed manner against the inner wall of the cylinder. Reference numeral 33 denotes a rod extending from the side to the center of the pressure receiving part 31. A pair of brackets 34, 34 are formed at the ends of the rod 33 and protrude inwardly, and bearings 35, 35 are fitted into the brackets 34, 34. and this bearing 3
A steel shaft 36 is rotatably inserted through the shaft 5.

The rotating stem 20 and piston 30 formed in this way fit the brackets 34, 34 of the piston 30 into the spaces S, S2 above and below the rotating stem 20, and the grooves 25 of the plate-shaped body 22
．． 25 is fitted with the shaft 36 inserted through the bracket, and the PP
It is assembled into a cylinder made of S synthetic resin. Since the groove 25 and the shaft 36 connecting the rotating stem 20 and the piston 30 are made of steel, they have excellent wear resistance and deformation resistance, and have low frictional resistance, which greatly improves the life of the connecting engagement part. Since the entire body is made of PPS synthetic resin, it is light, the piston moves easily within the cylinder, and the response to pressure fluid is good.

In addition, this PPS synthetic resin has excellent injection moldability and a low heat shrinkage rate, so it can greatly improve the roundness and surface roughness when injection molding the cylinder, rotating stem 20, and piston 30, and prevent waviness and molding. There is no distortion, so the sliding resistance between the piston and cylinder is small, and the tightness of the O-ring 32 attached to the outer periphery of the piston 30 is uniform, so there is no one-sided wear of the O-ring 32, and the sliding torque of the piston is reduced. The lifespan of opening/closing cycles has been greatly improved.

This PPS synthetic resin contains 40% glass fiber in PPS, and carbon may be added as appropriate. This PPS synthetic resin has excellent injection moldability, so even if there are variations in wall thickness, there will be no quality problems such as cracking, shrinkage, or distortion. It is a material that is stable even when installing a valve, and there are almost no restrictions on the location where the valve can be installed.Also, it is lighter than conventional AI alloys.
Easy to handle due to quantity.

[Effects] As explained above, the small cylinder device of the present invention is lightweight, has good responsiveness, has low frictional resistance between the piston and cylinder, has a long opening/closing life, and has excellent moldability, making it possible to produce a high-quality cylinder device at a low cost. Can be manufactured.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a rotating stem showing an embodiment of the present invention;
FIG. 2 is a plan view showing the plate-like body shown in FIG. 1, FIG. 3 is a front view of FIG. 2, FIG. 4 is a perspective view of a piston showing an embodiment of the present invention, and FIG. FIG. 6 is an exploded perspective view showing the prior art, and FIG. 6 is an assembled sectional view showing the prior art. 20... Rotating stem, 22... Disc-shaped body, 23...
Hole', 24...Beam, 25...Groove, 30...Piston, 31...Pressure receiving part, 33...Rod, 34...
Bracket, 35... bearing, 36... shaft

Claims (1)

[Claims] 1) A rotating stem is installed in the center of the cylinder perpendicular to the direction of movement of the piston, and two pistons connected to the rotating stem are installed on both sides of the cylinder,
The inner chamber of the cylinder is divided into a left chamber, a central chamber, and
In a cylinder device that is divided into a right chamber and converts linear motion of a piston into rotational motion of a rotating stem by switching pressure fluid to a central chamber and left and right chambers, the cylinder, rotating stem, and piston are connected to a PPS. A cylinder device characterized by being manufactured from synthetic resin.