JPS6035763Y2 - Dust cover internal pressure adjustment device for reciprocating cylinders - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a dust cover internal pressure adjusting device for a reciprocating cylinder.

Conventionally, a reciprocating cylinder device is known in which dust covers 9 as shown in FIG. 1 are disposed at both ends of a cylinder 1.

A piston rod 3 extends through the cylinder 1, and a piston 5 is fixed to the piston rod 3 so as to slide in a sealed manner on the inner peripheral surface of the cylinder 1.

Moreover, piston rons 1 are provided on the inner circumferential surface of both axial ends of the cylinder 1.
A sealing member 7 that seals and slides on the three circumferential surfaces is arranged.

As a result, the inside of the cylinder 1 has two mutually independent first chambers 1.
The piston rod 3 is partitioned into a second chamber 5 and a second chamber 17, and the piston rod 3 is caused to reciprocate by applying fluid pressure to both chambers.

Further, dust covers 9 are disposed at both ends of the cylinder 1 in order to prevent dust from entering the cylinder 1.

One end of the dust cover 9 is fitted onto the outer circumferential surface of the cylinder 1, and the other end is fixed onto the circumferential surface of the piston rod 3.

Furthermore, when the piston rod 3 reciprocates, the volume within one dust cover increases and the volume within the other dust cover decreases, so in order to compensate for this volume change,
A communication pipe 11 is provided for communicating the interiors of both dust covers with each other.

In a cylinder device with such a structure, the dust cover 9
As the piston rod 3 reciprocates, the air present inside the cylinder 1 is sucked into the cylinder 1 through the seal member 7, and as a result, the inside of the dust cover 9 becomes negative pressure, causing the dust cover 9 to move excessively toward the piston rod 3. There was a risk that the dust cover 9 would be deformed and damaged by friction due to the piston rod 3.

Conversely, if the pressure inside the dust cover 9 increases due to a rise in temperature, etc., the dust cover is pulled outward excessively,
There has been a problem in that leakage or damage may occur at the fitting portion between the dust cover 9 and the cylinder 1 or the piston rod 3.

The present invention eliminates the above-mentioned drawbacks of the conventional products. By providing a communication means that allows the inside of the dust cover or the inside of the communication pipe to communicate with the atmosphere, when a positive or negative pressure state occurs inside the dust cover, the air is released through the communication means. Since the dust cover is discharged or supplied, the dust cover is not excessively deformed.

Next, an embodiment of the present invention will be explained based on FIG.

In the figure, a protrusion 19 is formed in the middle of the conventional communication pipe 11 shown in FIG. , a communication means 13 is disposed, which is covered by an umbrella-shaped portion 21 and includes an orifice 23 that communicates the inside of the communication pipe 11 with the atmosphere side.

In this embodiment, the communication means 13 is provided in the communication pipe 11, but it may also be provided in the dust cover 9, or it may be an orifice or the like provided between the fitting surface of the dust cover 9 and the cylinder 1 or the piston rod 3. good.

In the present invention, the communication means is provided as described above, and the inside of the dust cover or the inside of the communication pipe is communicated with the atmosphere, so that the inside of the dust cover is not in a high or low pressure state compared to the atmospheric pressure, and as a result, This prevents the dust cover from being prematurely worn and damaged.

[Brief explanation of the drawing]

FIG. 1 is a diagram relating to a reciprocating cylinder device according to the prior art, and FIG. 2 is a diagram showing an embodiment of the present invention. 1... Cylinder, 3... Piston rod, 5... Piston, 7... Tool member,
9...Dust cover, 11...Communication pipe,
13...Communication means, 15...First chamber, 17...Second chamber, 19...Output, 21...・Umbrella-shaped part, 23...
Orifice.

Claims (1)

[Scope of utility model registration request] A cylinder 1, a piston rod 3 extending through the cylinder 1, a piston 5 fixed to the piston rod 3 and sliding in a sealed manner with the inner surface of the cylinder 1, an inner circumferential surface of the cylinder 1 sandwiching the piston 5. 2 placed in
a pair of dust covers 9.9 arranged at both ends of the cylinder 1 with one end fixed to the cylinder 1 side and the other end held on the outer peripheral surface of the piston rod 3; and both dust covers 9. , 9, and is provided with a communication means 13 that allows the inside of the dust cover 9.9 or the inside of the communication pipe 11 to communicate with the atmosphere side. Device.