JP2560190Y2 - Piston rod protection device for fluid cylinder device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for protecting a piston rod in a fluid cylinder device. In particular, the present invention is suitable for application to a hydraulic cylinder device used for a construction machine such as a power shovel, but is not limited to this application.

[0002]

2. Description of the Related Art Construction machines such as power shovels are often used for scooping up debris such as rocks.
In such an operation, rock falls on the hydraulic cylinder. The surface of the piston rod of the hydraulic cylinder is hard chrome plated to improve the adhesion with the seal provided on the cylinder. As a result, the seal is damaged.

In order to solve this problem, it has been proposed to provide a protection plate outside the cylinder device. For example, Japanese Utility Model Publication No. 3-46247 discloses a plate-like protector in which a plate-like guide rail is attached to the outside of a cylinder of a fluid cylinder device so as to extend in the longitudinal direction of the cylinder, and one end is fixed to a piston rod. A protection device for a fluid cylinder device configured to be guided by the guide rail is disclosed. In this protection device, the protector moves along the guide rail as the cylinder device expands and contracts to protect the piston rod protruding from the cylinder.

In the structure shown in FIG. 8 of Japanese Utility Model Publication No. 3-46247, both side edges of the protector are bent into a U-shape to form a guide groove, and the guide groove is formed on both side edges of the guide rail. Engages. In this structure, since rattling occurs between the guide groove of the protector and the guide rail, chattering noise is generated, which is not preferable. Japanese Utility Model Publication No. 3-46247 discloses a structure for solving this problem in FIG. In the structure shown in FIG. 4, guide shoes are attached to the inner surfaces of both sides of the plate-like protector, and both side edges of the guide rail are slidably engaged with the guide shoe grooves without rattling.

[0005]

In the structure disclosed in FIG. 4 of Japanese Utility Model Publication No. 3-46247, in order to prevent abrasion due to sliding between the plate-shaped guide rail and the guide shoe,
It is necessary to apply a lubricant such as grease. The applied lubricant adheres to the guide rail and is exposed outside the protector as the cylinder device expands and contracts. Since the part to which the guide rail is attached is relatively exposed to earth and sand, the earth and sand easily adhere to the lubricant on the guide rail, causing wear of the guide shoe and the guide rail.

The present invention solves the above-mentioned problems of the conventional piston rod protection device in the cylinder device, and can guide the protection plate for protecting the piston rod without rattling, and can suppress wear. It is an object to provide a piston rod protection device.

[0007]

According to the present invention, there is provided a cylinder, a piston slidably disposed in the cylinder, and one end fixed to the piston and extending from the cylinder to the outside. In a fluid cylinder device comprising a piston rod provided so as to protrude, a protection plate having one end fixed near an outer end of the piston rod and extending in the longitudinal direction of the cylinder along the side of the piston rod and the cylinder. The guide plate is fixed to the outside of the cylinder between the cylinder and the protection plate, and the protection plate is guided by the guide plate in the longitudinal direction of the cylinder.

In particular, the present invention provides a protective device having such a structure, wherein at least one pair of guided rollers is disposed near both sides of the protective plate on the side of the protective plate facing the cylinder, and the guided roller is disposed. It is always engaged with both side edges of the guide plate. The guided roller is rotatably supported by a spacer attached to the protection plate, and a lubricant is applied between the spacer and the guided roller.

[0009]

The cylinder device of the present invention having the above configuration is
It is attached to a machine such as a power shovel so that the protection plate faces the side where rocks and earth fall. According to the above configuration of the present invention, the protection plate moves along the side of the cylinder as the cylinder device expands and contracts. Therefore, the piston rod of the cylinder device is always covered with the protection plate, and there is no risk of hitting falling rocks or earth and sand. As the protection plate moves along the side of the cylinder, the rollers provided on the protection plate roll along both edges of the guide plate. Therefore, the protection plate can move smoothly. Further, since the roller can be mounted so as to engage with the guide plate without rattling, there is no danger of generating chattering noise or the like. Further, in a preferred aspect of the present invention, the roller is supported on the protective plate via the spacer, and the lubricant is applied between the roller and the spacer, so that the movement of the roller is smoother and the lubricant is protected. Since it is not exposed on the front side of the plate, there is no danger of earth and sand adhering to this lubricant.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a cylinder device 1 includes a cylinder 2
And a piston 3 slidably disposed in the cylinder in the longitudinal direction. The piston 3 is provided with a piston rod 4. One end of the piston rod 4 is fixed to the piston 3, and the other end protrudes from the cylinder 2 in the longitudinal direction. An end cap 5 is attached to the end of the cylinder 2, and the piston rod 4 extends through the end cap 5 in the longitudinal direction. The end cap 5 is provided with a seal 6 that contacts the outer peripheral surface of the piston rod 4.

A guide plate 7 is disposed outside the cylinder 2 so as to extend in the longitudinal direction along the side of the cylinder 2. As shown in FIG. 2, near the closed end of the cylinder 2,
A band 8 having a boss 9 is attached. One end of the above-described guide plate 7 is attached to the boss 9 with a bolt 10. At the opposite end of the cylinder 2, the other end of the guide plate 7 is attached to a boss 11 implanted in the cylinder by a bolt (not shown).

Referring to FIG. 1, a protection plate 12 is disposed outside the guide plate 7. The protection plate 12 has one end fixed to an end of the piston rod 4 projecting from the cylinder 2. The other end of the protection plate 12 is guided to the guide plate 7 by the guide mechanism 13. The guide mechanism 13 includes the cylinder 2
And a pair of rollers 14 arranged adjacent to both side edges of the protection plate on the side facing. As shown in FIG. 2, a spacer 15 having a substantially T-shaped cross section having a flange 15a is provided at each side edge of the protection plate, and a roller 14 is disposed between the flange 15a and the washer 16 of the spacer 15. You. A mounting bolt 17 is mounted so as to pass through the spacer 15 and the washer 16 from the protection plate 12, and a nut 17 a is engaged with an end of the bolt 17.
With this structure, the roller 14 is attached to the protection plate.

A groove 14a is formed around the roller 14. Both side edges of the guide plate 7 fit into the groove 14a without play. A lubricant such as grease is applied between the roller 14 and the spacer 15 and between the roller 14 and the washer 16. In the structure described above, when the cylinder device 1 expands and contracts, the piston rod 4
Get in and out of Since the protection plate 12 has one end attached to the piston rod 4, the protection plate 12 moves in the longitudinal direction of the cylinder device 1 according to the movement of the piston rod 4.
At this time, the other end of the protection plate is guided by the guide plate 7. As the protection plate 12 moves, the roller 14 moves along both side edges of the guide plate 7 while rotating. Therefore, the movement of the protection plate 12 is performed smoothly.

FIG. 3 shows a cylinder device 1 according to an embodiment of the present invention.
1 is attached to a power shovel 18. The cylinder device 1 is a boom 1 of a power shovel 18.
8a. This attachment is performed such that the protection plate 12 of the cylinder device 1 faces the operation area 19 of the shovel 18b. Therefore, the excavator 1 during work
The rock 20 falling from the bump 8 hits the protection plate and does not damage the piston rod 4 covered by the protection plate. Also, since the roller 14 becomes a shadow of the protection plate, the roller 14
Is not exposed to the working area. Therefore, there is no problem that earth and sand adhere to the lubricant.

[0015]

According to the structure of the present invention, the protection plate is smoothly guided by the loose play between the roller 14 and the guide plate 7, and there is no danger of chattering when the machine is running. Further, since the protection plate is guided by the rolling of the roller, there is no sliding portion and there is no problem of wear. further,
In the aspect of the present invention in which the roller is supported by the spacer and the lubricant is applied between the roller and the spacer, the lubricant is not exposed to the earth and sand, and the smooth rotation of the roller is guaranteed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cylinder device showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along line II of FIG. 1;

FIG. 3 is a side view showing a state in which the cylinder device according to the embodiment of the present invention is mounted on a power shovel.

[Explanation of symbols]

1 is a cylinder device, 2 is a cylinder, 3 is a piston, 4 is a piston rod, 7 is a guide plate, 12 is a protection plate, 14 is a roller, 15 is a spacer, and 16 is a washer.

Claims (1)

(57) [Scope of request for utility model registration] And 1. A cylinder consists of a slidably arranged piston in the cylinder, a piston rod that is provided so that one end is fixed to the piston extends out to the outside from the cylinder, the piston rod A protection plate having one end fixed near the outer end thereof and extending in the longitudinal direction of the cylinder along the side of the piston rod and the cylinder, and fixed to the outside of the cylinder between the cylinder and the protection plate Provided in the piston rod protection device of the fluid cylinder device, wherein the protection plate is guided by the guide plate in the longitudinal direction of the cylinder. At least one pair of guided rollers is disposed near both sides of the protection plate, and the guided rollers are always on both side edges of the guide plate. Tokigakarigo to have, the guided roller
Is rotatable on the spacer attached to the protection plate.
Supported between the spacer and the guided roller.
A piston rod protection device for a fluid cylinder device, wherein a lubricant is applied .