JPH10184612A - Hydraulic cylinder refuse elimination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic cylinder refuse elimination device capable of preventing damage to a packing and to a tube inner wall of a hydraulic cylinder owing to the inclusion of metallic refuse such as an iron powder in the hydraulic cylinder, and resolving pressure-proof failure of the hydraulic cylinder due to the above-mentioned damage, and smoothly operating a circuit without obstructing the flow of pressure oil. SOLUTION: A piston 4 with an extensible rod 41 encircled with a tube 2 is slidably provided in a hydraulic cylinder 1. In this case, a magnetic plug 52 is detachably provided facing into a connection passage 23 formed in the tube 2. The magnetic plug 52 is screwed through a mounting hole 51 formed in a direction almost perpendicular to the connection passage 23. In addition, the magnetic plug 52 is provided in the proximity of a connection part between the connection passage 23 and a connection tube connected thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust removing device for a hydraulic cylinder for removing dust such as iron powder present in a hydraulic circuit.

[0002]

2. Description of the Related Art Conventionally, in a hydraulic circuit equipped with a hydraulic cylinder, the cause of the pressure resistance failure of the hydraulic cylinder is caused by welding spatter, iron powder such as cutting chips and burrs mixed in the piping work, or internal gear pump. Damage to the inner wall of the hydraulic cylinder tube and damage to the packing due to wear pieces and the like are involved.

[0003] Conventionally, as a general dust removing device for removing dust in a fluid passage, Japanese Utility Model Publication No. 61-19 / 1986.
As disclosed in Japanese Unexamined Patent Application Publication No. 809 and 5-45366, a removing device provided with a magnet in a fluid passage is provided, and the removing device is used to remove dust.

[0004]

However, in the above-mentioned prior art, since the removing device is provided in the fluid passage, there is a problem that the removing device acts as a resistance and hinders the flow of the fluid in the fluid passage. In particular, in the case of supplying hydraulic oil such as a hydraulic circuit, a problem that excessive pressure rises in the passage and smooth operation cannot be expected is remarkable.

[0005]

According to a first aspect of the present invention, there is provided a dust removing device for a hydraulic cylinder, wherein a piston having a telescopic rod is slidably provided in the tube. A plug with a magnet is detachably provided facing the connection path thus formed.

According to a second aspect of the present invention, there is provided a dust removing device for a hydraulic cylinder, wherein the plug with magnet is screwed into a mounting hole formed in a direction substantially orthogonal to the connection passage. .

According to a third aspect of the present invention, there is provided a dust removing device for a hydraulic cylinder, comprising: a connecting passage formed in the tube; A plug with a magnet is detachably provided in the vicinity of a connection portion with a connection pipe connected to a connection passage.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the entire structure of a dust removing device for a hydraulic cylinder according to the present invention.

In FIG. 1, reference numeral 1 denotes a hydraulic cylinder. The hydraulic cylinder 1 is provided with a piston 4 having a telescopic rod 41 slidably provided in a tube 2 constituting a cylinder body.

A connecting passage 21 is formed at the center of one end of the tube 2 on the left end side in the figure.
Is connected to the connection pipe 31.

A tube 2 on the right end side in FIG.
The center of the other end is formed with a through hole 22 of an extendable rod 41, and the extendable rod 41 is slidably disposed in the through hole 22 via a seal (not shown) or the like.

A hook-shaped connection passage 23 is formed at the other end of the tube 2.
Is connected.

FIG. 3 shows an example of a hydraulic circuit in the case where the above-mentioned hydraulic cylinder 1 is used for a dump vehicle that tilts a packing box upward.

In this hydraulic circuit, the discharge side of the pump P is communicated with the piston chamber side 1a of the hydraulic cylinder 1 via the control valve V, the bypass pipe 33, and the connection pipe 31.
The rod-side chamber 1b of the hydraulic cylinder 1 is connected to the oil reservoir T through the connection pipe 32.

Then, by switching the control valve V to the left position, the hydraulic oil from the pump P is supplied to the piston side chamber 1a of the hydraulic cylinder 1 through the bypass pipe 33 to extend the telescopic rod 41 of the hydraulic cylinder 1, By tilting the packing box upward and switching the control valve V to the right position, the pressure oil in the piston side chamber 1a of the hydraulic cylinder 1 is returned to the oil reservoir T by the weight of the packing box or the like, and the packing box is returned to its original horizontal position. Prone to the position.

Here, a dust removing device 5 is provided in the hydraulic cylinder 1 used as described above.

The dust removing device 5 includes a plug 52 having a magnet 53 (see FIG. 2) in a mounting hole 51 formed outside the other end of the tube 2 and in a direction substantially perpendicular to the connection passage 23. Is screwed.

As shown in FIG. 2, the plug 52 has the magnet 53 fitted substantially at the center of the distal end on the connection passage 23 side. More specifically, a fitting hole 521 is formed substantially at the center of the distal end portion of the plug 52, and the magnet 5 is inserted deep into the fitting hole 521.
3 and the peripheral edge 522 of the tip end of the insertion hole 521.
Is crimped inward, so that the magnet 53 is inserted into the insertion hole 521.
It is held so that it does not come out of.

A male screw 54 is formed on the outer peripheral surface of the tip of the plug 52, and the male screw 54 is inserted into the mounting hole 51.
By screwing into the female screw formed in the
Is placed within. At this time, the plug 52 provided with the magnet 53
Is located at a position slightly retracted in the mounting hole 51 without protruding into the connection passage 23.

As the magnet 53, for example, a samarium-cobalt magnet is used, and the surface magnetic velocity density is preferably 3000 gauss.

Reference numeral 55 in FIG. 2 denotes a mounting portion for interposing a seal.

By providing the dust removing device 5 in the hydraulic cylinder 1 as described above, the metallic dust passing through the connection passage 23 is magnetized and held by the magnet, and the dust existing in the circuit is removed from the circuit. You.

The dust includes welding spatter, iron powder such as cutting chips and burrs, and debris inside the gear pump, which are mixed during piping work, and the dust is removed by a dust removing device.

As a result, it is possible to prevent damage to the inner wall of the tube of the hydraulic cylinder 1 and damage to various packings provided in the hydraulic cylinder 1 caused by the above-mentioned dust entering the hydraulic cylinder 1. Defects can be eliminated. Moreover, since the dust removal device 5 is disposed at a position retracted from the connection passage 23, the circuit can be smoothly operated without obstructing the flow of the pressure oil.

The replacement of the plug 52 is usually performed at the same time as the replacement of the hydraulic oil in the hydraulic circuit, and this replacement is usually performed in units of several years. That is, once the plug 52 is disposed, it is not removed for several years until the replacement time. It should be noted that the replacement is not limited to the above replacement time, and may be replaced, for example, by regular maintenance.

In this embodiment, a hydraulic cylinder for a dump vehicle for tilting a cargo box has been described as an example. However, the present invention is not limited to this and can be applied to all hydraulic cylinders. .

Further, the mounting portion and the mounting number of the plug 52 are not limited to the present embodiment. For example, the plug 52 may be provided in both of the two connection passages 21 and 23 formed in the hydraulic cylinder. The same effect as described above can be obtained by providing the connection part near the connection part with the connection pipe 31 or the connection part between the connection passage 23 and the connection pipe 32.

[0029]

As described above, according to the present invention, the plug with magnet is provided near the connection passage of the hydraulic cylinder or near the connection between the connection passage and the connection pipe connected to the connection passage. The metal dust passing through the connection passage and the vicinity of the connection portion is magnetically attached and held by a magnet provided on the plug, and the dust existing in the circuit is removed from the circuit. This can prevent damage to the inner wall of the tube of the hydraulic cylinder and damage to the packing caused by mixing of the dust into the hydraulic cylinder, and can eliminate the pressure failure of the hydraulic cylinder caused by the damage. In addition, since the dust removing device is disposed at a position retracted from the connection passage, the circuit can be smoothly operated without obstructing the flow of the pressure oil.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the entire configuration of a dust removing device for a hydraulic cylinder according to the present invention.

FIG. 2 shows a plug with a magnet, and FIG.
FIG. 2B is a plan view.

FIG. 3 is a diagram illustrating an example of a hydraulic circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic cylinder 2 Tube 23 Connection passage 32 Connection pipe 4 Piston 41 Telescopic rod 5 Dust removal device 51 Mounting hole 52 Plug 53 Magnet

Claims (3)

[Claims] 1. A hydraulic cylinder in which a piston having a telescopic rod is slidably provided in a tube, wherein a magnet-equipped plug is detachably provided facing a connection passage formed in the tube. Dust removal device for hydraulic cylinders. 2. The dust removing device for a hydraulic cylinder according to claim 1, wherein the magnet-equipped plug is screwed into a mounting hole formed in a direction substantially orthogonal to the connection passage. 3. A hydraulic cylinder in which a piston having a telescopic rod is slidably provided in a tube, the hydraulic cylinder being provided near a connecting portion between a connecting passage formed in the tube and a connecting pipe connected to the connecting passage. A dust removing device for a hydraulic cylinder, wherein a plug with a magnet is detachably provided facing the surface.