JP2002054171A - Working attachment for construction machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long-wearing working attachment for construction machinery, excellent in abrasion resistance. SOLUTION: A bucket 1 is formed by means of a steel plate undergoing build-up welding with the addition of tungsten carbide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of work attachments such as buckets mounted on construction machines such as hydraulic excavators.

[0002]

2. Description of the Related Art Generally, construction equipment such as a hydraulic excavator is equipped with a work attachment such as a bucket, a ripper, a fork, and a blade, and the work attachment is in direct contact with earth and sand, rock, or the like. , Gradually wears out with use. Conventionally, for example, when a work attachment is a bucket, a double structure in which a thinner steel plate (for example, about 6 mm) is laminated on a main steel plate (for example, a steel plate having a thickness of about 10 to 20 mm) to provide wear resistance and the like. Is improving. In this case, when the wear is advanced and the bearing can no longer be used, it is replaced with a new one. For example, in the case of a bucket, the replacement life is said to be about 1500 hours under normal conditions. .

[0003]

The life of the work attachment is greatly affected by the working conditions. For example, in recent years, construction equipment rentals have become widespread, but construction equipment rented in this manner is often used under severe conditions, so the work attachments are subject to severe wear and their service lives tend to be short. . Therefore, the emergence of a work attachment with excellent wear resistance that can be used for a long time even under such severe conditions is desired.
Here, there was a problem to be solved by the present invention. Furthermore, in the case of the above-mentioned bucket, if the wear progresses, not only the main steel material but also the thin steel sheet forming the bucket shape is damaged, so that there is a problem that it cannot be repaired and reused in practice. There are also problems to be solved by the present invention.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention has been made with the object of solving these problems. It was formed using a welded steel plate. And by doing this,
The strength of the work attachment is increased, the wear resistance is improved, and a longer life can be achieved. In this one,
Tungsten carbide is added to the steel plate of the work attachment worn out by use, and the welded plate is welded, and the welded steel plate is reused to form the work attachment, thereby further extending the life of the work attachment. ,
It can contribute to recycling. In addition, by welding a steel plate to the wear portion of the work attachment and further applying build-up welding to the steel plate to which tungsten carbide is added, it is possible to repair the wear portion with increased strength, and further work attachment Can contribute to longer life and recycling.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a bucket mounted as a work attachment to a hydraulic excavator. The bucket 1 has an R-shaped bottom surface 2, side surfaces 3 erected on both right and left sides of the bottom surface 2, Each part made of a steel plate such as a top surface portion 4 extending from the upper end of the bottom portion 2 is integrally welded, and the bucket 1 is further attached to the top surface portion 4 on the arm (not shown) side. A connecting bracket 5 for swingably connecting is protruded, and a plurality of claws 6 are attached to the front end of the bottom surface 2.

The bottom portion 2 is formed by arranging a plurality of steel plates 2a oriented in the left-right direction in a series and integrally welding them. The outer surface of the steel plates 2a is required to have abrasion resistance. , A build-up weld to which tungsten carbide (WC) is added is applied to substantially the entire surface, and a build-up portion 7 is formed so as to rise from the steel plate 2a. In addition, the parts of the left and right side plates 3 where wear resistance is required,
Overlay portion 7 to which tungsten carbide is added is formed.

Here, in the present embodiment, a plate thickness of 20 mm
The thickness of the overlaid portion 7 is set to 5 mm with respect to the steel plate of No. 5, but the overlaid portion 7 to which the tungsten carbide is added is HB600 to 10 in a Vickers hardness test.
It is more than 00, and it is confirmed that it has excellent hardness. Then, the bucket 1 formed by using the steel plate on which the overlaid portion 7 is formed as a solid material can be used for more than 7000 hours under a normal operation, and is at least 4 to 4 hours larger than the conventional bucket. It has been confirmed that it has a lifespan exceeding 5 times.

By the way, the above-mentioned build-up welding is performed while weaving is performed using a build-up welding wire (not shown). In this case, an arc between the base material steel plate and the welding wire is used. Build-up welding is performed while adding tungsten carbide powder into a molten pool formed by arc heat generated from the welding. The details of the overlay welding are described in Japanese Patent Application Laid-Open No. 2000-141037, which was invented by the inventor of the present invention and previously filed, and will not be described here.

On the other hand, the bucket 1 gradually wears out over a long period of use, but when the wear has progressed, the bucket 1 is dismantled into a steel plate, and a build-up welding in which tungsten carbide is added to the steel plate. And the bucket 1 is formed again. By performing such repair, the life of the bucket 1 is further extended. Further, for example, when the steel plate 2a constituting the bottom surface portion 2 of the bucket 1 is worn out so as not to be used for the bottom surface portion 2 again, the other portion (for example, the wear of the bucket side plate portion 3 is welded). Less part)
, Or as a reinforcing plate, it is possible to achieve approximately 100% recycling.

[0010] In the structure constructed as described above, the bucket 1 is formed by using a steel plate which is weld-added with tungsten carbide added thereto. As a result, the strength of the bucket 1 is measured, and the bucket 1 is resistant. Abrasion is significantly improved,
Even when used under severe conditions, a long life can be achieved. Moreover, in this case, when the wear of the bucket 1 has advanced, the bucket 1 is dismantled to a steel plate,
The bucket 1 can be formed again by building-up welding in which tungsten carbide is added to the steel sheet, which can contribute to a longer life and recycling of the bucket 1.

Further, the present invention can be applied to a case where a work attachment worn due to use is repaired. For example, the claw 6 of the bucket 1 is formed by attaching a chip 9 to the front end of the bottom part 2 via an adapter 8.
The part indicated by hatching wears. Therefore, a steel sheet 10 (preferably a high-tensile steel sheet excellent in abrasion resistance to which manganese (Mn), chromium (Cr), carbon (C), etc. is added) is applied to the portion that has been worn away. Welding 1
0a, and furthermore, the steel plate 10 and the weld 10a are reinforced by overlay welding with tungsten carbide (WC) added thereto. In this case, build-up welding may be performed on the entire surface of the steel sheet 10, but as shown in FIG. 5, build-up welding is performed only on a portion where the wear is severe, such as the front end and side edges. Alternatively, build-up welding may be performed on an appropriate portion according to the shape and use of the chip. It has been confirmed that the chip 9 repaired in this way has increased strength and has at least twice the life of a conventional chip. Further, such repair of the chip 9 can be performed several times repeatedly, which can contribute to further prolonging the life and recycling.

It should be noted that the present invention is not limited to the present embodiment, but can be applied not only to buckets but also to various work attachments such as dozers. In addition, the steel plate weld-added with tungsten carbide is used for the wear resistance of the undercarriage of track-type construction machinery, the tip of the back reamer method, the excavated teeth of screws, crusher teeth, tractor tips, shredder teeth, etc. Can be widely used in parts where is required.

[Brief description of the drawings]

FIG. 1 is a side view of a bucket.

FIG. 2 is a front view of a bucket.

FIG. 3 is a view taken in the direction of arrow A in FIG. 1;

FIGS. 4A, 4B, and 4C are a plan view, a side view, and a bottom view of a claw portion.

FIGS. 5A, 5B, and 5C are a plan view, a side view, and a bottom view of the claw portion after chip repair.

[Explanation of symbols]

 1 Bucket 7 Overlay 9 Chip 10 Steel Plate

Claims (3)

[Claims] 1. A work attachment for a construction machine, wherein the work attachment is formed using a steel plate weld-added with tungsten carbide. 2. The work attachment according to claim 1, wherein tungsten carbide is added to the steel plate of the work attachment worn by use, and the welded plate is welded, and the welded steel plate is reused to form the work attachment. A work attachment for a construction machine, characterized by the following. 3. The work attachment for a construction machine according to claim 1, wherein a steel plate is welded to a wear portion of the work attachment, and furthermore, the steel plate is subjected to build-up welding with addition of tungsten carbide.