JP2006249736A - Work device of construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work device of a construction machine for protecting and strengthening a bush joined to an arm tip part so as to rotatably connect a bucket. <P>SOLUTION: In the bush 10 joined to the tip of an arm 1 and rotatably connecting the bucket to the arm, a protective plate 14 for covering an outer peripheral surface is joined to the outer peripheral surface 12a of a part exposed to the bucket side among the bush, and a plurality of belt-like members 16 extending in the peripheral direction of the bush and having a predetermined interval, are joined to an outside surface of the protective plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a working device for a construction machine, and more particularly to a technique for reinforcing an arm tip of a hydraulic excavator that connects buckets for excavating the ground.

In a hydraulic excavator, the bucket is pivotally connected to the tip of the arm, so when excavating the ground with the bucket, the surface of the arm on which the bucket rotates is likely to hit crushed stones and the arm is damaged. There is a problem that it is easy to do.
For this reason, a technique has been developed in which a protective plate is joined by welding to a portion of an arm that is easily hit by crushed stone.

In addition, if the protective plate is damaged, it would be time-consuming to replace the protective plate. Therefore, a plurality of belt-like members are detachably joined to the protective plate by fillet welding, A technique for exchanging only a part of the broken belt-like members among the belt-like members has been developed (see Patent Document 1).
JP 2001-271371 A

By the way, in a hydraulic excavator, a bush is joined to the tip of an arm, and a bucket is rotatably connected via a pin inserted into the bush. The bush is joined to the tip of the arm. Therefore, almost half of the outer peripheral surface is exposed to the bucket side, and there is a problem that, like the above-mentioned arm, crushed stones and the like are easily hit and easily damaged.
Therefore, it is considered that a protective plate is wound around the exposed outer peripheral surface of the bush and joined by welding, thereby protecting the bush from crushed stone or the like.

  However, when excavating the ground with the bucket, the tip of the arm not only hits the crushed stone, but when the bucket rotates around the bush, the tip of the arm, that is, the crushed stone or the like in the gap between the bush and the bucket There is a problem that an excessive load is easily applied to the bush by biting, and this causes a problem that the protection plate is easily damaged and the protection plate must be frequently replaced.

When the replacement frequency of the protective plate is increased in this way, the welding peeling operation and the like increase, and the bush may be easily damaged, which is not preferable.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a construction machine that enhances the protection of a bush joined to an arm tip so as to rotatably connect a bucket. It is in providing the working device.

  To achieve the above object, the construction machine working apparatus according to claim 1 is a construction machine working apparatus having a bucket for excavating the ground and an arm for supporting the bucket, the tip of the arm being And a bush that rotatably connects the bucket to the arm by inserting a pin that supports the bucket, and the outer peripheral surface of the bush is exposed to the bucket side. A protective plate joined so as to cover, and a plurality of strip-like members joined to the outer surface of the protective plate in the circumferential direction of the bush and joined at a predetermined interval.

As a result, the protection plate for protecting the bush that rotatably connects the bucket is reinforced by the plurality of strip members joined to the protection plate, and only the damaged strip member can be replaced. Become.
Further, in the construction machine working apparatus according to claim 2, in claim 1, the plurality of strip-shaped members are arc-shaped square members, and the corners on the outer peripheral side of the arc-shaped square members are chamfered over the entire length. It is characterized by.

In this way, when a plurality of belt-shaped members are formed of arc-shaped square members whose corners are chamfered over the entire length, crushed stones and the like are hardly sandwiched between the strip-shaped members, and even if the bucket rotates, the crushed stones are formed in the gap between the bush and the bucket. It becomes difficult to bite etc.
According to a third aspect of the construction machine working apparatus of the present invention, in the first or second aspect, the plurality of belt-shaped members fill a gap between the outer surface of the protective plate and the bucket that rotates around the bush. The height is set.

Thereby, the clearance gap between a some strip | belt-shaped member and a bucket is made small, and even if a bucket rotates, it becomes difficult to bite a crushed stone etc. in the clearance gap between a bush and a bucket.
According to a fourth aspect of the construction machine working apparatus of the present invention, in any one of the first to third aspects, the plurality of strip members are detachably joined to the outer surface of the protective plate. .

  This makes it easy to replace a damaged belt-like member. For example, by joining the belt-like member to the outer surface of the protective plate by fillet welding, the belt-like member can be easily replaced while securing sufficient strength. It becomes.

According to the construction machine working apparatus of the first aspect, the protection plate for protecting the bush can be reinforced by the plurality of strip-shaped members, and only the damaged strip-shaped member can be replaced on the protection plate.
As a result, it is not necessary to replace the entire protective plate, so that the maintenance can be improved, and the belt-like member is attached and detached on the protective plate. Protection can be strengthened.

According to the construction machine working apparatus of claim 2, by forming a plurality of band-shaped members with arc-shaped square members whose corners are chamfered over the entire length, crushed stones or the like can be hardly sandwiched between the band-shaped members, and the bucket Even if it rotates, it can be made difficult to bite crushed stone or the like into the gap between the bush and the bucket.
Thereby, it is possible to prevent an excessive load from being applied to the bush, and it is possible to reduce the damage to the belt-like member and reduce the replacement frequency of the belt-like member.

According to the construction machine working apparatus of the third aspect, the gaps between the plurality of belt-like members and the bucket can be reduced, and even if the bucket rotates, it is difficult to bite crushed stone or the like into the gap between the bush and the bucket.
Accordingly, it is possible to prevent an excessive load from being applied to the bush, and it is possible to reduce the damage of the belt-like member and reduce the replacement frequency of the belt-like member.

  According to the construction machine working apparatus of the fourth aspect, the damaged belt-like member can be easily replaced. In this case, for example, by joining the belt-shaped member to the outer surface of the protective plate by fillet welding, the belt-shaped member can be easily replaced while securing a sufficient strength in the belt-shaped member.

Hereinafter, an embodiment of a working device for a construction machine according to the present invention will be described by taking a case where the construction machine is a hydraulic excavator as an example.
In general, a hydraulic excavator is roughly constituted by a lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a front attachment (working device) that is provided on the upper revolving body so as to be able to move up and down. Has been. The front attachment includes a boom that can be raised and lowered on the front side of the upper swing body, an arm that can be pivoted on the tip side of the boom, and a pivot that can pivot on the tip side of the arm. It is comprised with the provided bucket.

FIG. 1 is a view showing an arm 1 and a bucket 2 of a front attachment according to the present invention.
As shown in the figure, the arm 1 and the bucket 2 are connected by inserting a pin 20 that supports the bucket 2 into a bush 10 joined to the tip of the arm 1. Thereby, although a detailed description is omitted, the bucket 2 is rotatable with respect to the arm 1 as indicated by an arrow in the figure. In addition, the broken line in a figure has shown the rotation limit position, respectively, and the bucket 2 can rotate within the said rotation limit position range.

2 is a detailed view of the bush 10 joined to the tip of the arm 1 as seen from the direction of arrow A in FIG. 1, and FIG. 3 is a view of the bush 10 as seen from the direction of arrow B in FIG. Hereinafter, the configuration of the bush 10 according to the present invention will be described with reference to FIGS.
As shown in FIGS. 2 and 3, the bush 10 is welded and fixed to the tip of the arm 1 so that substantially half of the outer peripheral surface 12 is exposed to the bucket 2 side.

And the protection plate 14 which consists of a steel plate avoids the greasing hole 13 along the outer peripheral shape of the said exposed part 12a in the substantially half part of the outer peripheral surface 12 exposed to the bucket 2 side, ie, the exposed part 12a. Thus, it is joined by welding or the like.
A plurality of strip-like members 16 are disposed on the outer surface of the protection plate 14 so as to extend in the circumferential direction of the bush 10. Specifically, the plurality of belt-like members 16 are joined to the outer surface of the protective plate 14 by, for example, fillet welding with a predetermined interval.

The band-shaped member 16 is made of, for example, a square steel material formed in an arc shape, and both ends are formed in a tapered shape, and a pair of corner portions 16a and 16a on the outer peripheral side of the arc-shaped square steel material are chamfered over the entire length. Has been. Here, the corner portions 16a, 16a are chamfered, for example, but may be chamfered.
FIG. 4 is a detailed view of the bush 10 schematically shown in FIG. 3 including the pin 20 and the bucket 2. In addition, the broken line in a figure shows each rotation limit position corresponding to FIG.

  As shown in the figure, the rear end portion 2a of the bucket 2 is close to the bush 10 and rotates along the bush 10, but in detail, the protection plate 14 and the belt-like member 16 It is provided within the rotation range of the end 2 a and is provided so as to fill a gap between the bush 10 and the rear end 2 a of the bucket 2. In other words, the belt-like member 16 is formed so as to fill the gap between the protective plate 14 and the rear end portion 2a of the bucket 2, that is, the gap between the belt-like member 16 and the rear end portion 2a. The height is set so that there is almost no loss.

Hereinafter, the operation and effect of the construction machine working device according to the present invention configured as described above will be described.
As described above, the protective plate 14 is joined to the exposed portion 12 a of the bush 10 along the exposed portion 12 a, and a plurality of strip-like members 16 are provided on the protective plate 14. Thus, the protection plate 14 can be sufficiently reinforced, and the protection of the bush 10 can be strengthened compared to the case of the protection plate 14 alone, and crushed stones and the like fly to the bush 10 side while excavating the ground with the bucket 2. Even if it can be done, crushed stone or the like can be received by the plurality of strip-shaped members 16 and damage to the bush 10 can be reliably suppressed.

Further, even if the belt-like member 16 is greatly damaged by crushed stone or the like, only the damaged belt-like member 16 can be individually replaced without replacing all of the plurality of belt-like members 16, thereby improving the maintainability. Can be achieved.
Further, when replacing the belt-shaped member 16, the belt-shaped member 16 is attached / detached on the protective plate 14, that is, welding peeling work and welding work are performed, so that the bush 10 itself is not damaged by the attachment / detachment work. The bush 10 can be sufficiently protected.

Furthermore, since the band-shaped member 16 is fillet welded to the outer surface of the protective plate 14, it is easy to peel off the welding while maintaining a constant welding strength, and the band-shaped member 16 ensures sufficient strength. However, it is possible to further improve the maintainability.
Further, when the belt-shaped member 16 is made of, for example, a square steel material formed in an arc shape and the pair of corner portions 16a and 16a are chamfered over the entire length, the belt-shaped member 16 adjacent to crushed stones or the like while excavating the ground with the bucket 2 is used. Even if it enters between 16, the crushed stone and the like will be repelled well at the chamfered portion, and the crushed stone and the like will not easily be sandwiched between the belt-like members 16 and 16. From this, when the bucket 2 rotates, it can be made difficult to bite crushed stone or the like into the gap between the bush 10 and the rear end portion 2a of the bucket 2, and an excessive load can be prevented from being applied to the bush 10. Damage to the belt-like member 16 can be reduced and the replacement frequency of the belt-like member 16 can be reduced.

Further, since the belt-like member 16 is provided on the outer surface of the protective plate 14 so that the gap between the belt-like member 16 and the rear end 2a is almost eliminated, the bucket 2 is rotated. When moved, even a relatively small crushed stone can be made difficult to bite into the gap between the bush 10 and the rear end 2a of the bucket 2.
As a result, it is possible to prevent an excessive load from being applied to the bush 10 and reduce the damage to the belt-like member 16 and reduce the replacement frequency of the belt-like member 16.

This is the end of the description of the embodiment of the present invention, but the embodiment is not limited to the above.
For example, in the above-described embodiment, the case where the construction machine is a hydraulic excavator has been described as an example. Can be suitably applied.
Moreover, in the said embodiment, although the strip | belt-shaped member 16 was made into the square steel material shape | molded, for example in the arc shape, the strip | belt-shaped member 16 may be the strip | belt-shaped plate member etc. which cut the steel plate long.

  In the above embodiment, the pair of corners 16a, 16a of the belt-like member 16 are chamfered over the entire length, but a certain degree of effect can be obtained even when chamfering is not performed.

It is a figure which shows the arm and bucket of a front attachment which concern on this invention. FIG. 2 is a detailed view of a bush joined to the tip of an arm as viewed from the direction of arrow A in FIG. 1. It is the figure which looked at the bush from the arrow B direction of FIG. It is detail drawing of the bush shown including the bucket in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Arm 2 Bucket 2a Rear end part 10 Bush 12 Outer peripheral surface 12a Exposed part 14 Protective plate 16 Band-shaped member (square member)
16a Corner 20 pin

Claims (4)

A working device for a construction machine having a bucket for excavating the ground and an arm for supporting the bucket,
A bushing joined to the tip of the arm and rotatably connecting the bucket to the arm by inserting a pin that supports the bucket;
A protective plate joined to cover the outer peripheral surface of the bush on the outer peripheral surface of the portion exposed on the bucket side;
A plurality of band-shaped members that extend in the circumferential direction of the bush and are joined to the outer surface of the protective plate at a predetermined interval;
A construction machine working apparatus characterized by comprising:   The working device for a construction machine according to claim 1, wherein the plurality of belt-shaped members are arc-shaped square members, and the corners on the outer peripheral side of the arc-shaped square members are chamfered over the entire length.   The height of the plurality of belt-shaped members is set so as to fill a gap between the outer surface of the protection plate and the bucket rotating around the bush. Construction equipment work equipment.   The work device for a construction machine according to any one of claims 1 to 3, wherein the plurality of belt-like members are detachably joined to the outer surface of the protective plate.

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