JP2513838Y2 - Pneumatic cylinder device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a pneumatic cylinder device that operates by compressed air.

[Prior Art] Usually, in a pneumatic cylinder device, a seal portion is formed on the outer peripheral surface of a piston, and the seal portion seals between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder chamber. .

[Problems to be Solved by the Invention] However, in the pneumatic cylinder device described above, since the seal portion of the piston slides on the inner peripheral surface of the cylinder chamber, the sliding resistance prevents the piston from operating at high speed. Further, the wear of the seal portion prevents the life from being extended.

Further, since it is necessary to form a groove for fitting the seal portion on the outer peripheral surface of the piston, the length of the piston in the axial direction is correspondingly increased, which prevents the piston from being thin and having a short stroke. There is.

An object of the present invention is to provide a pneumatic cylinder device capable of operating the piston at high speed, thinning the cylinder, shortening the length of the cylinder, and extending the life of the cylinder.

[Means for Solving the Problems] A pneumatic cylinder device of the present invention comprises a cylinder tube having a head cover provided at one end and a rod cover provided at the other end, and a rod tube which penetrates the rod cover and slides in the axial direction. A pneumatic cylinder device having a piston rod freely provided and a piston fixed in the piston rod by being positioned in a cylinder chamber to which compressed air formed in the cylinder tube is supplied, the rod cover And an opening of a supply / discharge port provided in each of the head cover and the piston facing the piston,
Between the inner peripheral surface of the cylinder tube and the pitsoon, a gap is formed to allow the leakage of compressed air to the cylinder chambers formed on both sides of the piston, and at the stroke end of the piston, the piston and An elastic seal member is provided which prevents air from leaking from the inner peripheral surface of the cylinder tube to the supply / discharge port and absorbs impact of the piston at the stroke end portion of the piston. .

[Operation] According to the above-mentioned means, when the compressed air is supplied into the cylinder chamber to operate the piston, the piston does not make sliding contact with the inner peripheral surface of the cylinder tube. No resistance is generated, the speed of the piston can be increased, and it is possible to reliably prevent the life of the piston from being obstructed by abrasion of the outer peripheral surface of the piston. Further, since it is not necessary to form a groove or the like for fitting the seal portion on the outer peripheral surface of the piston, the axial length of the piston can be shortened.

In the process of the piston moving to the stroke end,
Part of the compressed air will leak from the gap between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder tube, but at the end of the stroke, the piston comes into contact with the elastic seal member to ensure the compressed air leakage. Can be prevented.

[Embodiment] FIG. 1 is a sectional view showing a pneumatic cylinder device according to an embodiment of the present invention.

The cylinder device of the present embodiment is provided with a cylinder tube 1 having a perfect circular cross section in the radial direction, a rod cover 2 and a head cover 3 which are connected to both ends of the cylinder tube 1, respectively. The cylinder chamber 4 is formed by the coupling.

A piston 5 is provided in the cylinder chamber 4 so as to be displaceable along the axial direction, and a left cylinder chamber 4a and a right cylinder chamber 4b are formed on both end surface sides of the piston 5. The left cylinder chamber 4a communicates with the supply / discharge port 6 formed on the outer peripheral surface of the rod cover 2, and the right cylinder chamber 4a.
4b communicates with the supply / discharge port 7 formed on the outer peripheral surface of the head cover 3, and the openings of the supply / discharge ports 6 and 7 are formed so as to face the piston 5 as shown in the drawing. There is.

The outer peripheral surface of the piston 5 is not provided with a seal portion that is slidably contacted with the inner peripheral surface of the cylinder tube 1, and the compressed air between the inner peripheral surface of the cylinder tube 1 and the outer peripheral surface of the piston 5 is not formed. The piston 5 is structured to be displaced in the cylinder chamber 4 in the axial direction while allowing a slight leakage. That is, the outer peripheral surface of the piston 5 and the cylinder tube 1
A slight gap is formed between the inner peripheral surface and the inner peripheral surface.

From the left end surface of the piston 5, a piston rod 8 is projected along the axial direction, and the piston rod 8 penetrates a bearing 9a and a seal member 9b provided inside the shaft core of the rod cover 2 and projects to the outside. Has been done. Step portions 1a are formed along the circumferential direction on the inner peripheral surface side of the openings at both ends of the cylinder tube 1. An annular seal member 10 made of an elastic material is fitted in each of the step portions 1a,
10 has a quadrangular cross section in the radial direction.

The seal member 10 seals the abutting end surface of the piston 5 when the end surface of the piston 5 abuts, and prevents the compressed air from flowing between the left cylinder chamber 4a and the right cylinder chamber 4b. In addition, the seal member 10 is provided at each of the connecting portions of the cylinder tube 1, the rod cover 2 and the head cover 3 to seal the connecting portions, so that the compressed air in the cylinder chamber 4 is exposed to the outside from the connecting portions. Prevents leaks.

Further, the seal member 10 also has a function of absorbing the impact of the piston 5 by its elastic action when the end surface of the piston 5 is brought into contact.

 Next, the operation of this embodiment will be described.

First, in the state shown in FIG. 1 in which the left end surface of the piston is in contact with the left seal member 10, when compressed air is supplied to the left cylinder chamber 4a through the supply / discharge port 6, the piston 5 is caused by the action of the compressed air. It is displaced to the right, and the right end face of the piston 5 is brought into contact with the right seal member 10.

When the piston 5 is displaced, the left cylinder chamber 4a
The right cylinder chamber 4b and the right cylinder chamber 4b communicate with each other through a slight gap between the outer periphery of the piston 5 and the inner periphery of the cylinder tube 1, so that the compressed air in the left cylinder chamber 4a is communicated with the right cylinder chamber 4a.
Although a small amount is discharged to 4b, this gap is sealed by the right end surface of the piston 5 coming into contact with the right seal member 10, and the communication state between the left cylinder chamber 4a and the right cylinder chamber 4b is cut off.

In this shut-off state, when a control valve (not shown) is switched to supply compressed air to the right cylinder chamber 4b through the supply / discharge port 7, the piston 5 is displaced to the left by the action of the compressed air, and the fluid in the left cylinder chamber 4a The pressure is discharged from the supply / discharge port 6, and the left end surface of the piston 5 is brought into contact with the left seal member 10.

Even when the piston 5 is displaced to the left side, the left cylinder chamber 4a and the right cylinder chamber 4b communicate with each other through the gap between the outer circumference of the piston 5 and the inner circumference of the cylinder tube 1. The left end face of the is brought into contact with the left seal member 10 to be sealed, and the communication state thereof is cut off.

The piston 5 does not have a seal portion that is slidably contacted with the inner peripheral surface of the cylinder chamber 4 during its operation, and the entire outer peripheral surface of the piston 5 and the inner peripheral surface of the cylinder chamber 4 are not in close contact with each other. As a result, sliding resistance is not generated on the outer peripheral surface side of the piston 5, so that high-speed operation of the piston 5 can be achieved, and wear of the seal portion on the outer peripheral surface side of the piston 5 prevents a long life from being obstructed. Can be prevented.

Further, since it is not necessary to form a groove or the like for fitting the seal portion on the outer peripheral surface of the piston 5, the axial length of the piston 5 can be shortened, and the piston 5 can be made thin and have a short stroke. Can be realized.

Further, the seal member 10 is interposed between the cylinder tube 1, the rod cover 2 and the head cover 3 to seal the joint portion, and the seal member 10 also has a function of absorbing the impact of the piston 5. Because
The pneumatic cylinder device can be downsized and simplified, the number of parts can be reduced, the cost can be reduced, the service life can be extended, and noise can be prevented.

The present invention has been specifically described above based on the embodiments.
The present invention is not limited to the above embodiment, and can be variously modified without departing from the gist thereof.

For example, although the illustrated pneumatic cylinder device is a double-acting cylinder device, it may be a single-acting cylinder device. In the case of such a single-acting type cylinder device, the seal member 10 is not provided on both end sides of the cylinder chamber 4 as in the present embodiment, but the seal member 10 is provided only on one end side of the cylinder chamber 4. It is possible to Further, the seal member 10 is not limited to the rectangular cross section in the radial direction,
It is also possible to use an elliptic diameter or double O-rings.

[Effects of the Invention] According to the structure of the cylinder device of the present invention, the following effects can be obtained.

(1). Since the outer peripheral surface of the piston does not have a seal portion that is in sliding contact with the inner peripheral surface of the cylinder chamber, sliding resistance does not occur on the outer peripheral surface side of the piston, so high-speed operation of the piston can be achieved. It is possible to reliably prevent the life of the piston from being obstructed by wear of the seal portion on the outer peripheral surface side of the piston.

(2). Since it is unnecessary to form a groove or the like for fitting the seal portion on the outer peripheral surface of the piston, the axial length of the piston can be shortened.

(3). Due to the effect of (2) described above, the piston can be made thinner and the length of the cylinder can be shortened.

[Brief description of drawings]

FIG. 1 is a sectional view showing a cylinder device according to an embodiment of the present invention. 1 ... Cylinder tube, 1a ... Step, 2 ... Rod cover, 3 ... Head cover, 4 ... Cylinder chamber, 4a ...
Left cylinder chamber, 4b ... Right cylinder chamber, 5 ... Piston, 6,7 ... Supply / discharge port, 8 ... Piston rod, 9a ...
… Bearing, 9b …… Seal member, 10 …… Seal member.

Claims (1)

(57) [Scope of utility model registration request] 1. A cylinder tube having a head cover at one end and a rod cover at the other end, a piston rod penetrating through the rod cover and slidable in the axial direction, and the cylinder tube. A pneumatic cylinder device having a piston fixed inside the cylinder chamber formed therein and supplied with compressed air, the piston being fixed to the rod cover and the head cover. The opening is formed so as to face the piston, and a gap is formed between the inner peripheral surface of the cylinder tube and the piston to allow the compressed air to leak to the cylinder chambers formed on both sides of the piston. , At the stroke end of the piston, from between the piston and the inner peripheral surface of the cylinder tube to the supply / discharge port Thereby preventing the leakage of air, the pneumatic cylinder apparatus characterized by comprising an elastic sealing member to absorb the impact of the piston at the stroke end of said piston.