JP3273246B2 - Manufacturing method of counterweight for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a counterweight for a construction machine provided at the rear of a main body of various construction machines such as a crawler crane and a pile driver.

[0002]

2. Description of the Related Art Conventionally, as counterweights, there have been used many counterweights which are framed with an iron plate and filled with punches or the like or formed by casting. Because of the problem of visibility, it is desired to reduce the rear radius, so that a stack of iron plates having a higher specific gravity than that described above has been developed.

For example, the counterweight shown in FIG. 4 has two stages of counterweights in which an iron plate is laminated on a counterweight made of a casting or an iron plate frame. This iron plate lamination counterweight is the lowest iron plate 1
And the intermediate iron plate 2 thereon, and the intermediate iron plate 2 and the intermediate iron plate 3 thereon are joined by welding from above, respectively, and the intermediate iron plate 3 and the uppermost iron plate 4 are welded from below. And a plurality of iron plates are vertically stacked, the side surfaces of the stacked iron plates are surrounded by a decorative plate 5, and the decorative plate 5 is welded to the lowermost iron plate 1 and the uppermost iron plate 4 by welding. Being manufactured. The work of welding the decorative plate 5 and the lowest iron plate 1 is performed from below by sneaking under the counterweight, or by inverting the counterweight and setting the welding surface to the upper side.

[0004]

However, since the lower welding while sunk is performed in an unreasonable posture, the workability is poor, there is a concern that the quality of the welded portion is ensured, and the safety is not so good. Is hard to imagine. In addition, although the quality of the welded portion can be ensured in the inverted upper side welding, equipment having a margin for the inverted side is required.

Accordingly, an object of the present invention is to provide a method for manufacturing a counterweight for a construction machine which can be joined by upper welding without inversion, and which is safe and operable.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention is directed to a steel plate which is vertically laminated by welding and encloses the sides of a plurality of iron plates with a decorative plate, and the decorative plate and the lowermost iron plate are surrounded by decorative plates. And a method for manufacturing a counterweight for construction machinery in which the lowermost iron plate and the uppermost iron plate are formed in substantially the same shape, and the intermediate iron plate is formed as the lowermost iron plate and the uppermost iron plate. Is formed in a shape slightly smaller than the iron plate, the lowermost iron plate and the decorative plate are joined by welding from above, and the intermediate iron plate is joined to the upper surface of the lowermost iron plate by welding from above. The iron plate to be laminated on the upper surface of the intermediate iron plate is joined by welding from above and sequentially laminated, and the uppermost iron plate and the upper edge of the decorative plate are joined by welding from above. It is characterized by.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in FIGS. On the lower counterweight 10 made of casting or steel plate,
An upper counterweight 20 on which iron plates are stacked and a middle counterweight 30 on which iron plates are stacked are connected. The upper counterweight 20 has two intermediate iron plates 23 and 24 disposed between the lowermost iron plate 21 and the uppermost iron plate 22, and the left and right side surfaces and the rear side surface of the four stacked iron plates are arranged. Each iron plate is surrounded by a decorative plate 25 having the same specific gravity.

The first intermediate iron plate 23 disposed on the lowermost iron plate 21 is formed in a shape slightly smaller on the front side, both left and right sides and the rear side than the lowermost iron plate 21. The second intermediate iron plate 24 disposed on the upper side is formed to have a shape slightly smaller on the front side than the first iron plate 23, and the uppermost iron plate 22 is substantially the same in outer dimensions as the lowermost iron plate 21. They are formed in the same shape. That is, the uppermost iron plate 22 has the same shape on both the left and right sides and the rear side as the lowermost iron plate 21, and the front side is formed in a shape slightly smaller than the second iron plate 24. Further, the decorative plate 25 is formed with a plate thickness strong enough to support the weight of the entire counterweight 11.

The iron plates 21, 22, 23, 24 and the decorative plate 25 are respectively joined by welding. In this manufacturing process, first, the left and right sides and the rear upper corners of the lowermost iron plate 21 are joined to the decorative plate 25 by welding from above. Subsequently, on the upper surface of the lowest iron plate 21,
The front lower corner portion of the intermediate iron plate 23 is joined by welding from above. Further, the lower front corner of the intermediate iron plate 24 is joined to the upper surface of the intermediate iron plate 23 by welding from above, and the uppermost iron plate 2 is attached to the upper surface of the intermediate iron plate 24.
The front lower corners 2 are joined by welding from the upper side, and the iron plates 21, 22, 23, and 24 are sequentially laminated. And
The upper left corners of the left and right sides and the rear side of the uppermost iron plate 22 and the upper edge of the decorative plate 25 are joined by welding from above.

The work of welding the lowermost iron plate 21 and the uppermost iron plate 22 to the decorative plate 25 is performed sufficiently to maintain the strength of the counterweight 20 to withstand its own weight. , 23, 24 welding work
It is only necessary that they do not move.

The middle counterweight 30 also has two intermediate iron plates 33 and 34 disposed between the lowermost iron plate 31 and the uppermost iron plate 32, and all side surfaces of the four iron plates are stacked. Is surrounded by a decorative plate 35 having the same specific gravity as each iron plate. The lowermost iron plate 31 and the uppermost iron plate 32 are formed in the same shape, and the intermediate iron plates 33 and 34 are the lowermost iron plate 31.
Further, the front side, the left and right sides, and the rear side of the uppermost iron plate 32 are formed in a slightly smaller shape.

The intermediate iron plate 33 has a lowermost iron plate 3
Oval holes 33a for welding and joining to one upper surface are formed at two places. The intermediate iron plate 34 has an oval hole 34 for welding to the upper surface of the intermediate iron plate 33.
a are formed at two positions with a diameter larger than the hole 33a at a position overlapping with the hole 33a. Further, in the uppermost iron plate 32, elliptical holes 32a for welding and joining to the upper surface of the intermediate iron plate 34 are formed at two positions at positions overlapping with the holes 34a and having a diameter larger than the holes 34a. I have. When the holes are formed so as not to overlap with each other, the diameter of each hole may be the same.

The middle counterweight 30 is formed by welding the front side, left and right sides, and the rear side of the lowermost iron plate 31 to the decorative plate 35 by welding from above, and attaching the intermediate iron plate 33 to the upper surface of the lowermost iron plate 31. The periphery of each hole 33a is joined by welding from the upper side, and the periphery of each hole 34a of the intermediate iron plate 34 is joined to the upper surface of the intermediate iron plate 33 by welding from the upper side. Each hole 32a of the upper iron plate 32 is joined by welding from the upper side, and a blocking plate 36 is welded to the upper surface of each hole 32a to close each hole 32a, and the front side, the left and right sides, and It is manufactured by joining the rear side to the decorative plate 35 by welding from above.

Thus, each iron plate 21, 22, 23, 2
4 and the decorative plate 25, and the iron plates 31, 32, 33 and 34 and the decorative plate 35 are all joined by upper welding.
Welding can be performed without working in an unreasonable position and without reversing, safe and workable, and the quality of the welded parts can be secured.
In addition, since the product is formed of an iron plate and a decorative plate of the same specific gravity, the finished product is easy to manage, and since the specific gravity is heavier than that of a steel plate frame filled with punch cass or a cast product,
It is possible to reduce the size and to make the rear radius smaller than these. In addition, since the superimposed portion around each iron plate is covered with the decorative plate 16, the appearance is as good as the appearance of the iron plate frame filled with punch fins or the like.

In the above embodiment, four iron plates are stacked, but the number of iron plates is not limited to this.

[0016]

As described above, according to the method for manufacturing a counterweight for construction equipment of the present invention, the lowermost iron plate and the uppermost iron plate of a plurality of iron plates vertically stacked by welding are substantially identical. In addition to forming the intermediate iron plate into a shape slightly smaller than the lowermost iron plate and the uppermost iron plate, the decorative plate surrounding the side surfaces of the stacked iron plates and the lowermost iron plate are placed on the upper side. From the top, the middle iron plate is joined to the top surface of the lowest iron plate by welding from above, and the iron plate laminated on top of the middle iron plate is joined by welding from the top and laminated sequentially. The uppermost iron plate and the upper edge of the decorative plate are joined by welding from the upper side, so all welding work is performed on the upper side. Is often The quality can be ensured. Further, by forming the iron plate and the decorative plate having the same specific gravity, the finished product can be easily managed. Furthermore, since the specific gravity is higher than those made of an iron plate frame filled with punch cass or the like or cast products, the size can be reduced and the rear radius can be made smaller than those. In addition, since the overlapping portions of the iron plates are covered with a decorative plate, the appearance is as good as the appearance of an iron plate frame filled with punch cass and the like.

[Brief description of the drawings]

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

FIG. 2 is a partial cross-sectional front view of the counterweight of the embodiment.

FIG. 3 is a plan view of the same.

FIG. 4 is a sectional side view of a conventional counterweight.

[Explanation of symbols]

20: upper counterweight, 21, 31: lowest iron plate, 22, 32: highest iron plate, 23, 24, 33, 3
4: Middle iron plate, 25, 35: decorative plate, 30: middle counterweight

Claims (1)

(57) [Claims] 1. A counterweight for a construction machine in which side surfaces of a plurality of iron plates vertically stacked by welding are surrounded by decorative plates, and the decorative plates are welded to a lowermost iron plate and an uppermost iron plate. In the manufacturing method, the lowermost iron plate and the uppermost iron plate are formed in substantially the same shape, and the intermediate iron plate is formed in a shape slightly smaller than the lowermost iron plate and the uppermost iron plate. The iron plate and the decorative plate are joined by welding from above, the intermediate iron plate is joined to the lowermost iron plate upper surface by welding from above, and the iron plate laminated thereon is attached to the upper surface of the intermediate iron plate. A method for manufacturing a counterweight for a construction machine, comprising joining by welding from the upper side and sequentially stacking, and joining the uppermost iron plate and the upper edge of the decorative plate by welding from the upper side.