JP2005054977A - Anti-rotation cylinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent rotary motion of a rod when a piston and a rod of a hydraulic cylinder reciprocate with high accuracy and at a low cost. <P>SOLUTION: A guide rod penetrating the piston is installed on the members at both ends of a cylinder tube, and the piston is moved along the guide rod. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an anti-rotation cylinder that prevents rotational movement that occurs when a piston rod of a fluid pressure cylinder reciprocates.

FIG. 1 is a schematic cross-sectional view showing one form of a conventional anti-rotation cylinder. The operation and action of the conventional anti-rotation cylinder will be described with reference to this figure.

A front bonnet 2 is fixedly installed at one end of the cylinder tube 1 (right side in the figure). A supply / discharge hole 3 is mounted on a side surface of the front bonnet, and a seal member 4 having a polygonal cross section and a bearing 5 having a polygonal cross section are mounted at the center. A rear bonnet 6 is fixedly installed at the other end (the left side in the figure) of the cylinder tube 1. A supply / discharge hole 7 is provided on the side surface of the rear bonnet, and a nut and washer receiving portion 6a, which will be described later, is provided in the center.

A piston 8 and a piston rod 9 having a polygonal cross section are installed inside the anti-rotation cylinder 50, and a small diameter portion 9a of the piston rod is fastened and fixed to the piston by a nut 10 and a washer 11, and the small diameter portion is hermetically sealed. An O-ring 12 to be maintained is mounted. A pair of seal members 13 facing outward are mounted on the outer periphery of the piston 8. The tip 9b of the piston rod 9 penetrates the bearing 5 and the seal member 4 and projects outside the front bonnet.

A space formed by the piston 8 and the front bonnet 2 is a pressure chamber 14, and a space formed by the piston and the rear bonnet 6 is a pressure chamber 15.

In such an anti-rotation cylinder 50, when a fluid is first introduced into the pressure chamber 15 from the intake / exhaust hole 7 of the rear bonnet 6 and the piston 8 is pressurized, the piston 8 moves along the inner wall of the cylinder tube 1 in the right direction in the figure. It moves and stops in contact with the front bonnet 2. As the piston 8 moves, the fluid in the pressure chamber 14 is discharged from the supply / discharge hole 3 to the outside.

Next, when a fluid is introduced into the pressure chamber 14 from the supply / exhaust hole 3 of the front bonnet 2 to pressurize the piston 8, the piston 8 moves in the left direction along the inner wall of the cylinder tube 1, and the rear bonnet 6. Stops in contact with. As the piston 8 moves, the fluid in the pressure chamber 15 is discharged from the supply / discharge hole 7 to complete the reciprocating operation of the rotation prevention cylinder 50.

The problem to be solved is that the prevention of rotation of a rod having a polygonal cross section has the disadvantage that the rotation angle caused by the allowable gap with the bearing is large because the diagonal distance of the rod cross section is small and the rotation prevention accuracy is low. Furthermore, the center portion of the front bonnet having a square cross section, the piston rod having a polygonal cross section, and the bearing having a polygonal cross section are difficult to process, resulting in a high cost factor. Further, the sealing member having a polygonal cross section has a problem in sealing performance.

The present invention has been devised under such circumstances, and its purpose is to increase the rod rotation prevention accuracy, adopt an inexpensive round piston rod, bearing and seal member, This eliminates the disadvantages and eliminates the high cost problem.

In the anti-rotation cylinder that introduces fluid into the cylinder and reciprocates the pressurized piston along the inner wall of the cylinder tube to extract the output from the piston rod, a guide is provided between the cylinder tube and the piston rod. The rod is arranged in parallel with the piston rod.

The guide rod passes through a guide hole provided in the piston, and both ends thereof are fixedly installed on the front bonnet and the rear bonnet. The guide holes are configured to be attached with outwardly facing seal members.

A bearing through which the piston rod penetrates and a seal member that keeps the airtightness of the front bonnet and the piston lock at the center of the front bonnet are installed.

When the piston is pressurized and reciprocates along the inner wall of the cylinder tube, rotation of the piston is prevented by the action of the guide rod penetrating the piston. Further, since the distance from the central axis of the piston rod to the central axis of the guide rod is set large, the rotation angle becomes small and the rotation prevention accuracy becomes high. Furthermore, since the piston rod having a round cross section, the bearing having a round cross section and the sealing member having a round cross section can employ inexpensive commercial products, the problem of high sealing performance and high cost can be solved.

FIG. 2 is a sectional view showing an embodiment of the rotation preventing cylinder of the present invention.

A front bonnet 2 is installed and fixed to one end (right side of the figure) of the cylinder tube 1.
The supply / discharge hole 3 is provided on the side surface of the front bonnet 2, and a bearing 17 through which the piston rod 16 passes and a seal member 18 that keeps the airtightness of the front bonnet 2 and the piston rod 16 are mounted in the center. A rear bonnet 6 is fixedly installed at the other end (the left side in the figure) of the cylinder tube 1. A supply / discharge hole 7 is provided on the side surface of the rear bonnet, and a nut and washer receiving portion 6a, which will be described later, is provided in the center.

The piston 8 and the piston rod 16 are installed inside the anti-rotation cylinder 70, and the outwardly facing seal members 13 are mounted on the outer periphery of the piston. The small diameter portion 16 a of the piston rod is inserted into the center portion of the piston, and is fastened and fixed by the nut 10 and the washer 11. An O-ring 12 that keeps airtightness with the piston is attached to the small diameter portion 16a of the piston rod. The tip 16 b of the piston rod penetrates the bearing 17 and the seal member 18 and protrudes to the outside of the front bonnet 2.

A guide hole 8a is provided at a predetermined position of the piston, and seal members 19 facing each other are attached. Two guide rods 20 penetrating the guide hole are installed in parallel with the piston rod 16 and both ends thereof are inserted and fixed to the front bonnet 2 and the rear bonnet 6 respectively.

A space formed by the piston 8 and the front bonnet 2 is referred to as a pressure chamber 14, and a space formed by the piston 8 and the rear bonnet 6 is referred to as a pressure chamber 15.

The operation and action of the anti-rotation cylinder of the present invention will be described below with reference to FIG.

First, the fluid is introduced into the pressure chamber 15 from the supply / discharge hole 7 of the rear bonnet 6. The pressurized piston 8 moves to the right in the figure, and comes into contact with the front bonnet 2 and stops. As the piston moves, the fluid in the pressure chamber 14 is discharged from the supply / discharge hole 3 to the outside.

Since the piston is prevented from rotating by the action of the guide rod 20, the piston rod 16 fixed to the piston also does not rotate. Further, since the distance from the center of the piston rod to the center of the guide rod is set large, the rotation angle becomes small, and the accuracy of rotation prevention, which is the main point of the present invention, becomes high.

Next, fluid is introduced into the pressure chamber 14 from the supply / discharge hole 3 of the front bonnet 2. The pressurized piston moves to the left in the figure, and comes into contact with the rear bonnet 6 and stops. As the piston moves, the fluid in the pressure chamber 15 is discharged from the supply / discharge hole 7 to the outside.

Since the piston is prevented from rotating by the action of the guide rod 20, the piston rod 16 fixed to the piston is also prevented from rotating, which is the main point of the present invention. The anti-rotation accuracy of reciprocating movement is equivalent.

It is a schematic sectional drawing of the rotation prevention cylinder of a prior art. It is a schematic sectional drawing of the rotation prevention cylinder of this invention.

Explanation of symbols

1 cylinder tube 2 front bonnet 4 seal member 5 bearing 6 rear bonnet 8 piston 8a guide hole 9 piston rod 14 pressure chamber 15 pressure chamber 16 piston rod 19 seal member 20 guide rod

Claims (3)

Introducing a fluid into the cylinder, reciprocating the pressurized piston along the inner wall of the cylinder tube, and installing a guide rod that penetrates the piston in the cylinder that extracts the output from the piston rod. Anti-rotation cylinder features. Anti-rotation cylinder, characterized in that the guide rod is placed on the bonnet installed on the cylinder tube. Anti-rotation cylinder characterized by an airtight seal member installed between the piston and guide rod

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