JP2001032328A - Counterweight supporting structure of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the counterweight supporting structure of a construction machine in which the accuracy of a supporting surface supporting a counterweight as a counterweight supporting section for an upper frame is improved and cost such as material cost is reduced. SOLUTION: A counterweight supporting section is formed at the rear end of an upper frame. The counterweight supporting section has a vertical plate extended from the upper frame, a bottom plate 64 welded to the lower end face of the vertical plate, a back plate 62 welded to the upper end face of the vertical plate, a plurality of pipe members 1 welded to the back plate 62 and the bottom plate 64 while being projected from the top face of the back plate 62 and being fixed and counterweight supporting surfaces 4 formed to each of the upper end faces of a plurality of the pipe members 1 at that time. A counterweight 53 is supported so as to be abutted against the counterweight supporting surfaces 4 and so as not to be abutted against the top face of the back plate 62.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counterweight support structure for a construction machine such as a hydraulic shovel.

[0002]

2. Description of the Related Art A conventional counterweight support structure for a construction machine will be described in detail with reference to the drawings. FIG. 4 is a side view showing a general hydraulic excavator provided with a counterweight. FIG. 5 is a perspective view showing a frame structure of an upper swing body provided in the hydraulic excavator shown in FIG.

[0003] In the figure, reference numeral 50 denotes a hydraulic excavator.
1, an upper revolving body 52 rotatably connected to an upper part of the lower traveling body 51, and an attachment 57 connected to a front portion of the upper revolving body 52 so as to be vertically rotatable. A driver's cab 56 is provided at a front portion of the upper swing body 52, and a counterweight 53 having a weight that balances with the attachment 57 is provided at a rear end portion. Further, a prime mover and the like are disposed on the upper revolving structure 52 and between the counter weight 53 and the cab 56 and are covered with a guard 55. The counterweight 53, the driver's cab 56, the engine and the like are mounted on an upper frame 54 arranged on the lower surface of the upper swing body 52. The upper frame 54 has a center section 58 disposed in the front-rear direction of the center, and side decks 59 and 60 provided to protrude left and right of the center section 58. The center section 58 includes a bottom plate 64 disposed on the lower surface, and the bottom plate 64.
A pair of standing plates 61 are provided upright on the upper surfaces of the pair of standing plates with a space therebetween, and a back plate 62 is disposed substantially vertically on each of the rear upper surfaces of the pair of standing plates 61. The center section 58 has an attachment connection portion 63 for connecting the attachment 57 at a front portion thereof, and a counter weight support portion 65 for connecting and supporting the counter weight 53 at a rear end portion. .

Next, the above-described counterweight support structure 6
5 will be described in detail. FIG. 6 is a first conventional example showing the portion A in FIG. On the upper and lower sides of the standing plate 61,
2 and the bottom plate 64 are disposed substantially horizontally and welded,
A strength member having an I section is formed. Both ends of a bracket 66 having a U-shape in cross section are welded to one side surface of the standing plate 61, and the upper end and the lower end of the bracket 66 are connected to the lower surface of the back plate 62 and the bottom plate 64. By being welded and connected to the upper surface, a strength structure having a closed cross section composed of the standing plate 61, the back plate 62, the bottom plate 64, and the bracket 66 is formed. Bolt holes 67 for passing bolts for connecting and fixing the counterweight are provided above and below the closed cross-section structure. In this case, the mounting surface on the counter weight side comes into contact with and is supported by the upper surface of the back plate 62. According to this configuration, the strength structure having the I-section and the closed-section can have a strength capable of supporting the counterweight.

FIG. 7 is a second conventional example showing the portion A in FIG. Above and below the standing plate 61, a back plate 62 and a bottom plate 64 are disposed substantially horizontally and welded to each other to form an I-section strength member. A part of the back plate 62 is cut out so as to form a surface along one side surface of the upright plate 61. A block 68 made of a steel material is provided in the notch.
It is fitted and welded. This block 68
A pair of bolt holes 69 are formed between the upper and lower portions, so that bolts for connecting and fixing the counterweight pass through from below. In this case, the mounting surface on the counterweight side comes into contact with and is supported by the upper surface of the block 68.

[0006]

Generally, the outer surface of the counterweight is used so as to be a part of the outer surface of the upper swing body. In this case, it is not necessary to separately prepare a guard at the rear end of the upper revolving structure, so that the number of parts can be reduced. However, when the counterweight is used as a part of the outer surface, the support of the counterweight is mainly performed by the counterweight support of the upper frame. The accuracy of the mounting position of the upper revolving body becomes low, and it becomes difficult to adjust the position of the upper revolving structure with a guard or the like that forms another outer surface, thereby causing the appearance of the outer surface of the upper revolving body to be remarkably deteriorated. For example, in the counterweight support structure shown in FIG. 6, a bracket and an upright plate are welded to the lower surface of the back plate. However, there is a problem that the mounting accuracy of the counter weight is low. For this reason, in order to improve the mounting accuracy of the counterweight, the mounting position of the counterweight has been adjusted by interposing a plurality of shims having different thicknesses.

On the other hand, the counterweight support structure shown in FIG. 7 has a support surface formed on the upper surface of the block. In this case, this block only welds the side surface to the cutout portion of the back plate after the welding of the upright plate and the back plate. There is no worry about the influence, and there is no worry about distortion of this support surface. However, since this block is a lump of steel, there is a problem that the material cost is high, the cost is high, and it is difficult to process.

The present invention has been made in view of such circumstances, and has been made to improve the precision of a support surface for supporting a counterweight, and to reduce costs such as material costs. It is an object of the present invention to provide a counterweight support structure for a construction machine.

[0009]

According to a first aspect of the present invention, in a construction machine having a counterweight support at a rear end of an upper frame, the counterweight support extends from the upper frame. A standing plate, a bottom plate welded to a lower end surface of the standing plate, a back plate welded to an upper end surface of the standing plate, and a back plate welded to the back plate and the bottom plate, and protruding from an upper surface of the back plate. And a plurality of pipe members fixedly mounted on the upper and lower surfaces of the plurality of pipe members. The counter weights are in contact with the counter weight support surfaces, and the back plate It is characterized by being supported so as not to contact the upper surface.

[0010] In this case, the portion that contacts the lower surface of the counterweight is limited to the counterweight support surface formed on the upper surface of each of the plurality of pipe members. The counterweight can be accurately supported without being affected by the welding strain of the I-section strength member, and the cost can be reduced by an inexpensive pipe member.

According to a second aspect of the present invention, in the counterweight support structure for a construction machine according to the first aspect, each of the plurality of pipe members is vertically slidable between upper and lower portions of the back plate and the bottom plate. Wherein the welding of the plurality of pipe members to the back plate and the bottom plate is performed in a state where the counterweight support surfaces formed on the upper surfaces of the plurality of pipe members are located on substantially the same plane. Is what you do.

In this case, by adjusting the slide position of each of the plurality of pipe members, it is possible to easily secure the counterweight support surface, so that there is no need for secondary work such as shim adjustment and the like, and the efficiency of assembly work is reduced. Leads to improvement.

[0013] The invention according to claim 3 is the invention according to claim 1 or 2.
In the counterweight support structure of the construction machine described in the above,
The plurality of counterweight support surfaces are obtained by machining after welding the plurality of pipe members to the back plate and the bottom plate.

According to this structure, after welding the plurality of pipe members to the back plate and the bottom plate, the upper surfaces of the plurality of pipe members are collectively machined, so that the counterweight support surface can be easily obtained. There is no need for secondary work such as shim adjustment, which leads to further improvement in assembly work efficiency.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a counterweight support structure for a construction machine according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a detailed view of a main part showing a structure of a counterweight support according to the present invention, and FIG. 2 is a detailed sectional view of a main part showing a connection state between the counterweight support and the counterweight according to the present invention. The components having the same configuration as the prior art are denoted by the same reference numerals, and description thereof will be omitted. Although the counterweight support is originally composed of a pair of left and right sides, only one side will be described here for convenience of description.

At the upper and lower ends of the standing plate 61, a back plate 62 and a bottom plate 64 are welded substantially horizontally to the standing plate 61, and a strength member having an I section is formed. The back plate 62 and the bottom plate 64
Are provided with two pairs of pipe holes 2 at positions facing each other in the vertical direction. In each of the two pairs of pipe holes 2 located in the vertical direction relative to the back plate 62 and the bottom plate 64, a pipe 1 as a pair of pipe members having a bolt hole 3 for passing a bolt 5 therein is vertically movable. Has been fitted. This pipe 1 has a counterweight 53 on its upper surface.
The pipe 1 is arranged such that the counterweight support surface 4 projects from the upper surface of the back plate 62. The pipe 1 is welded to the back plate 62 and the bottom plate 64. More specifically, the upper and lower surfaces of the back plate 62 and the circumferential side surfaces of the pipe 1 are welded (8 and 9 in the drawing), respectively, while being inserted into the pipe holes of the back plate 62. The amount of protrusion of the pipe 1 with respect to the upper surface of the back plate 62 is preferably set so that at least the upper end of the pipe 1 does not melt off during welding. According to this, since the supporting area of the counterweight supporting surface 4 formed on the upper surface of the pipe 1 can be sufficiently ensured, there is no concern that the supporting strength of the counterweight 53 is reduced. On the other hand, on the bottom plate 64 side where the pipe 1 is inserted, the lower portion of the pipe 1 is inserted only into a part of the upper portion of the pipe hole 2 formed in the bottom plate 64, and the upper surface of the bottom plate 64 and the circumferential side surface of the pipe 1 and the pipe hole The inner wall 2 and the lower surface of the pipe 1 are welded (see FIGS. 6 and 7). Here, by setting the lower surface of the pipe 1 above the lower surface 64 a of the bottom plate 64, the bolt head 5 a projects below the lower surface 64 a of the bottom plate 64 when the bolt 5 is inserted from below into the bolt hole 3 of the pipe 1. And the bolt 5 can be protected. The bolt 5 is inserted from below into the bolt hole 3, is screwed to a bolt screwing portion 53 a of the counterweight 53, and is connected to the counterweight 53.

Next, the mounting structure of the pipe 1 will be described. Pipe 1 used to support counterweight 53
Since there are a plurality of pipes, the counterweight support surfaces 4 of these pipes 1 need to be arranged on the same plane. For this reason, in the present invention, the positioning of the counterweight support surface 4 is previously performed by adjusting the slide of the pipe 1 in the vertical direction, and after adjustment, the counterweight support surface 4 is welded to the back plate 62 and the bottom plate 64. In this case, since the pipe 1 is finally welded, there is no risk of distortion or the like occurring on the counterweight support surface on the upper surface of the pipe 1. Further, the I-section formed by the standing plate 61, the back plate 62, and the bottom plate 64 and the pair of pipes 1 can provide sufficient strength to support the counterweight 53. If the machining of the plurality of counterweight support surfaces 4 is performed after the plurality of pipes 1 are welded, the accuracy of the counterweight support surface 4 is further improved. Leads to.

Next, another embodiment of a counterweight support structure for a construction machine according to the present invention will be described with reference to FIG.
FIG. 3 is a main part detailed view showing another embodiment of the counterweight support structure according to the present invention. The same components as those in the above-described embodiment are denoted by the same reference numerals.

At the upper and lower ends of the standing plate 61, a back plate 62 and a bottom plate 64 are welded substantially horizontally to the standing plate 61 to form an I-section strength member. The standing plate 61 is divided into a plurality of parts in the front-rear direction, and a plurality of pipes 20 having bolt holes 21 are respectively inserted between the divided standing plates 61 so as to be vertically rotatable, similarly to the above-described embodiment. It is welded with its head protruding above the upper surface of the back plate 62.
This also allows a plurality of slide-adjustable pipes 20.
As a result, the accuracy of the surface in contact with the counterweight can be obtained, the connection and position adjustment of the counterweight can be easily performed, and the I-section composed of the upright plate 61, the back plate 62, and the bottom plate 64 and the plurality of pipes 20 provide Sufficient strength to support the counterweight can be obtained.

[0020]

According to the first aspect of the present invention, the portion contacting the lower surface of the counterweight is limited to the counterweight support surface formed on the upper surface of each of the plurality of pipe members. The counterweight can be accurately supported without being affected by the welding strain of the I-section strength member composed of the standing plate, the bottom plate, and the back plate, and the cost can be reduced by using an inexpensive pipe member. it can.

According to the second aspect of the present invention, by adjusting the sliding position of each of the plurality of pipe members, it is possible to easily secure the counterweight support surface, so that secondary operations such as shim adjustment are required. Is gone,
This leads to improved assembly work efficiency.

According to the third aspect of the invention, after welding the plurality of pipe members to the back plate and the bottom plate, the upper surfaces of the plurality of pipe members are collectively machined to easily obtain the counterweight support surface. Therefore, there is no need for secondary work such as shim adjustment, which leads to further improvement in assembly work efficiency.

[Brief description of the drawings]

FIG. 1 is a detailed view of a main part showing a structure of a counterweight support according to the present invention.

FIG. 2 is a detailed sectional view of a main part showing a connection state between the counterweight support and the counterweight according to the present invention.

FIG. 3 is a main part detailed view showing another embodiment of the counterweight support structure according to the present invention.

FIG. 4 is a side view showing a general hydraulic excavator provided with a counterweight.

5 is a perspective view showing a frame structure of an upper swing body provided in the hydraulic excavator shown in FIG.

FIG. 6 is a first conventional example showing a portion A in FIG. 5;

FIG. 7 is a second conventional example showing the portion A in FIG.

[Explanation of symbols]

 1: Pipe 3: Bolt hole 4: Counter weight support surface 5: Bolt 53: Counter weight 54: Upper frame 57: Attachment 61: Standing plate 62: Back plate 64: Bottom plate 65: Counter weight support

Claims (3)

[Claims] 1. A construction machine having a counterweight support at the rear end of an upper frame, wherein the counterweight support is welded to a standing plate extending from the upper frame and to a lower end surface of the standing plate. A bottom plate, a back plate welded to the upper end surface of the upright plate, a plurality of pipe members welded to the back plate and the bottom plate, and protruding and fixed from the upper surface of the back plate; A counterweight support surface formed on each of the upper end surfaces of the pipe members, wherein the counterweight is supported so as to abut the counterweight support surface and not to abut on the upper surface of the back plate. And counterweight support structure for construction machinery. 2. Each of the plurality of pipe members is configured to be vertically slidable between upper and lower sides of the back plate and the bottom plate, and the welding of the plurality of pipe members to the back plate and the bottom plate is performed by the plurality of pipe members. 2. The counterweight support structure for a construction machine according to claim 1, wherein the counterweight support surface formed on the upper surface of the pipe member is positioned substantially on the same plane. 3. The plurality of counter weight support surfaces,
3. The counterweight support structure for a construction machine according to claim 1, wherein the counterweight support structure is obtained by machining after welding the plurality of pipe members to the back plate and the bottom plate.