JPS6115344Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a protective cover for the rod of a hydraulic or pneumatic cylinder.

Conventionally, in order to protect the surface of the piston rod b, which protrudes from one end of the cylinder a and performs the telescopic movement, from the adhesion of dust and rust, as shown in Fig. 1, the cylinder device has a piston rod attached to the outer periphery of the piston rod b for the entire length of the telescopic movement stroke. It was covered with a bellows-tubular protective cover c.

However, for example, hydraulic cylinders of cargo loading/unloading machines mounted on cargo ships are rarely used during navigation, and are reduced to a maximum compression state or a state close to it.

In addition, such hydraulic cylinders are particularly susceptible to rust due to exposure to salty atmosphere during navigation due to adhesion of dust and the like during operation.

Therefore, in a hydraulic cylinder used in such a condition, it is not only extremely uneconomical to install a protective cover that covers the entire stroke of the piston rod, but also the overlap of the protective cover at the maximum retracted length. At this time, the rod protrusion L becomes large, which causes the piston rod to become longer, resulting in a problem that the total length of the hydraulic cylinder becomes longer.

In view of the above-mentioned problems, the present invention was developed with the aim of eliminating these drawbacks.The present invention covers only the main length of the piston rod with a protective cover, and isolates the piston rod from the outside air when it is at maximum compression or in a state close to it. The purpose of this invention is to reduce the overlapping margin of the protective cover at the time of maximum compression.

An embodiment of the present invention will now be described with reference to the drawings. FIG. 2 shows the end of the hydraulic cylinder in its most extended state.

A facing member 4 is fixed to the tip of a piston rod 3 which extends and contracts from an end member 2 of the cylinder 1.

A sliding ring 5 made of rubber, synthetic resin, etc. is slidably fitted into the piston rod 3, and a protective cover in the shape of a bellows tube made of neoprene rubber or the like is fitted onto the piston rod 3. 6 is inserted externally and fixed by an annular fastening member 7.

The protective cover 6 protects the piston rod 3 when extended.
The other end is fixed to the outer periphery of a presser plate 8 fixed to the periphery of the shaft hole of the end member 2 by means of an annular fastening member 9. .

Further, the protective cover 6 has several bellows-like ridges, and an elastic ring 1 is formed on the inner periphery of each of the ridges.
0 is fitted, and the annular shape of the protective cover 6 is maintained by the annular ring 10.

In the cylinder rod protective cover having the above structure, when the piston rod 3 is extended as shown in FIG. 2, the sliding ring 5 provided at one end of the protective cover 6 remains in the middle of the piston rod 3. Although the piston rod 3 is exposed, when the piston rod 3 contracts as shown in FIG. Fold in the bellows.

Therefore, when the piston rod 3 is at its maximum length or close to it, the protective cover 6 is closely interposed between the presser plate 8 provided at the end of the cylinder 1 and the opposing member 4, so that the piston rod 3 An airtight space E is formed around the piston rod 3 to isolate the piston rod 3 from the outside air.

That is, if the hydraulic cylinder having the above structure is used in a cargo loading/unloading machine of a cargo ship or the like, it has the effect of protecting the piston rod 3 from salt damage, dirt, and other harmful atmospheres during navigation.

Further, according to the above structure, since the number of bellows on the protective cover 6 is small, the overlapping allowance when folded is small, and the rod protrusion l when the piston rod 3 is at its maximum length is also small. Further, the sliding ring 5 presses the end face 5a of the protective cover 6 into close contact with the stepped portion 4a of the facing member 4 by the elasticity in the expansion direction of the protective cover 6. By molding the material, elasticity in the direction of expansion can be increased.

Next, FIGS. 4 to 6 show other embodiments for bringing the sliding ring and the facing member 4 into airtight contact.

In the embodiment shown in FIG. 4, the sliding ring 11 is made of a permanent magnet, and the opposing member 4 is made of a magnetic material such as iron.
The sliding ring 1 is attached to the stepped portion 4a of the opposing member 4 during contraction.
When 1 collides with each other, they are attracted by the magnet and are securely brought into close contact.

In the embodiment shown in FIG. 5, a compression type coil spring 12 is elastically mounted between a sliding ring 5 and a presser plate 8 fixed to the tip of the cylinder 1 on the inner periphery of a protective cover 6. This is the result of an increased elastic force directed toward .

Furthermore, in the one shown in FIG. 6, the protective cover 13 is formed into a spiral bellows tubular body, and a compression type coil spring 14 is inserted into the inner periphery of the spiral peak. It is elastically biased toward.

In addition, in this configuration, the coil spring 14
It is also possible to provide the protective cover 13 at the spiral troughs or at both the crests and troughs.

As explained above, the protective cover for the rod of the cylinder of the present invention covers a part of the entire stroke of the piston rod, thereby reliably isolating the surface of the rod from the bad atmosphere when the piston rod is retracted, and protecting it from dust, salt damage, etc. At the same time, since the protective cover is short and there is little overlap between the bellows, there is little protrusion of the piston rod when it is at its maximum length, making it possible to shorten the overall length of the cylinder and keeping the opposing member and sliding ring in close contact. Therefore, it has great advantages such as being able to block the intrusion of dust, water, etc.

In the above embodiment, one end of the protective cover was fixed to the cylinder side and the other end was brought into contact with the opposing member, but in the present invention, one end of the protective cover is fixed to the opposing member and the other end is fixed to the opposing member. It may also be configured to abut against the cylinder end.

Furthermore, the same effect can be obtained by loosely fitting the protective cover onto the piston rod so that both ends of the protective cover are in contact with the opposing member and the cylinder end, respectively.

[Brief explanation of the drawing]

The drawings show an embodiment of the protective cover for the rod of the cylinder of the present invention. Figure 1 is a schematic front sectional view of the main part of the conventional device, and Figure 2 is a front sectional view of the main part of the cylinder when it is extended, showing the first embodiment. 3 are front sectional views of the main parts of the cylinder when the cylinder is retracted, and FIGS. 4, 5, and 6 are schematic front sectional views of the main parts of the cylinder, respectively, showing other embodiments. 1...Cylinder, 3...Piston rod, 4...
... Opposing member, 5, 11 ... Sliding ring, 6, 13
... Protective cover, 7, 9 ... Annular fastening member, 10
...Circle, 12, 14...Coil spring.

Claims (1)

[Claims for Utility Model Registration] (1) For a cylinder rod in which the exposed portion of the piston rod is covered with a protective cover only when the piston rod is movably inserted into the cylinder and is in the most retracted state or in a state close to it. In the protective cover, a sliding ring attached to the tip of the protective cover is movably fitted onto the circumferential surface of the piston rod, and a facing member is provided on the piston rod, so that when the piston rod is at its maximum length or in a state close to it, the sliding ring is movably inserted into the circumferential surface of the piston rod. A protective cover for a cylinder rod, characterized in that a member and a sliding ring are brought into close contact with each other. (2) Utility model registration claim 1, characterized in that a bellows-tubular protective cover is elastically biased in the axial direction via a coil spring, and the end face of the protective cover is pressed tightly against the opposing member. Protective cover for the cylinder rods listed. (3) A cylinder rod according to claim 1 of the utility model registration claim, characterized in that a permanent magnet is fixed to the end of the protective cover in the form of a bellows tube, and the cylinder is closely attracted to a facing member made of a magnetic material. protective cover.