JP3178387B2 - Construction machine counterweight - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counterweight installed on a construction machine such as a hydraulic shovel or the like, and more particularly to a counterweight which can be divided into two right and left parts.

[0002]

2. Description of the Related Art A hydraulic excavator as an example of a construction machine is for performing operations such as excavation of earth and sand. An upper revolving structure is installed on a lower traveling structure so as to be revolvable. An excavation means is provided in. The excavating means includes a boom provided on the upper swing body so as to be capable of raising and lowering, an arm connected to a tip of the boom so as to be rotatable in a vertical direction, and a front end comprising a bucket rotatably connected to the tip of the arm. It is configured as a working mechanism. Since the front working mechanism excavates earth and sand in a state where the front working mechanism is extended forward, a counterweight is provided at a rear portion of the upper rotating body in order to balance the entire vehicle during this excavation.

[0003] The counterweight comprises a steel container containing a heavy filling such as heavy concrete, the weight of which is set based on the structure of the front working mechanism, particularly the capacity of the bucket. Therefore, in the case of a large-sized hydraulic excavator, the weight of the counterweight is correspondingly increased. The upper revolving structure has a main frame as its structure. The main frame is provided with a pair of left and right structural members, and the boom of the front working mechanism described above is connected to the structural members. The structural member extends to a rear position of the upper rotating body,
The counterweight is generally installed at the rear end of this structural member. The counterweight can be attached to the structural member in a fixed state, but usually, a saddle-shaped recess is provided on the lower surface side of the counterweight, and the saddle-shaped recess is used to mount the counterweight on the structural member. And fixed using bolts. As a result, the counterweight can be attached to and detached from the upper swing body.

[0004]

By the way, among hydraulic excavators, there are large excavators of several hundred tons or more. Such a large-sized hydraulic excavator cannot be transported on land or the like in an assembled state, so that it can be disassembled into several parts and transported. It is natural that the front working mechanism can be separated from the upper revolving unit, and the upper revolving unit can also be divided into three parts, that is, the left and right and the middle part with the main frame as a boundary. Although the counterweight is separated from the upper revolving superstructure, it is extremely heavy, and in some cases it cannot be transported unless it is divided into at least two parts from the viewpoint of weight limitation during road transportation.

[0005] As described above, since the counterweight is mounted on the structural members of the pair of main frames in a horse riding state, it is possible to divide the counterweight into two as left and right divided blocks. By forming a saddle-shaped recess in each of the two divided blocks, each divided block is connected to a structural member. However, due to the overall shape of the divided block, the position of the center of gravity is a position outside the position of the saddle-shaped recess. Therefore, when each of the divided blocks is attached to the structural member, a force acts in a direction inclining outward, and a bending moment acts directly on the structural member, so that the structural member is twisted. Here, the structural member has a box shape, and exhibits extremely high strength in the up-down direction and the left-right direction, but has lower strength in the torsion direction than in these directions. For this reason, if a bending moment is constantly acting on the structural member, there is a risk that the structural member, and eventually the entire main frame, may be deformed for a long time, and there is a problem that the durability is reduced.

The present invention has been made in view of the above points, and an object of the present invention is to provide a structure in which a bending moment is applied to a structural member of a main frame in a state where the counterweight divided into two parts is mounted on the structural member. Is to make it inoperative.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a counterweight of a construction machine fixed to a main frame constituting an upper swing body.
The weight body has a pair of left and right divided blocks in which an overhanging portion is continuously provided, and each of the two divided blocks is mounted on each of the pair of left and right structural members provided on the main frame in a horse riding state. The saddle-shaped concave portion is formed, and the projecting portions of the two divided blocks are arranged on the upper revolving structure in a state of being vertically overlapped at a portion between the two structural members. Things.

Here, in order to fix the two divided blocks, it is preferable that the overhanging portions between the weight body and the structural members and the overhanging portions that are overlapped with each other are respectively connected by bolts. . As for the shape of the two divided blocks, the weight main body has the same shape, the overhang portion has the same shape, one overhang portion is from the upper side of the weight main body portion, and the other overhang portion is the same as the weight main body portion. It is preferable to adopt a configuration projecting from the lower side.
The weight of the left and right divided blocks may be the same, but one of the divided blocks may be heavier than the other, for example, due to the mounting position of the front working mechanism. For this purpose, it is possible to change the volume of the left and right divided blocks or to change the specific gravity of the packing material contained in each divided block.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. First, FIGS. 1 and 2 show the overall configuration of a hydraulic shovel. In the drawing, reference numeral 1 denotes a lower traveling body having a pair of left and right crawler tracks 1R and 1L. An upper revolving body 3 is pivotally connected to a traveling body frame 1a of the lower traveling body 1 via a revolving device 2. I have. The upper swing body 3 is provided with a driver's cab 4 for an operator to board and operate the machine, and a front working mechanism 5 as digging means for performing work such as digging of earth and sand. . The front working mechanism 5 includes a boom 5a provided on the frame 3a of the upper revolving unit 3 so as to be capable of raising and lowering, an arm 5b rotatably connected to the tip of the boom 5a in a vertical direction, and a rotating arm at the tip of the arm 5b. And a bucket 5c movably provided. Each of these front working mechanisms 5 is driven by a hydraulic cylinder,
The crawler belts 1R and 1L constituting the lower traveling body 1 are driven by a hydraulic motor, and the turning device 2 is also driven by a hydraulic motor. The hydraulic actuator including the hydraulic cylinder and the hydraulic motor is driven by pressure oil supplied from a hydraulic pump installed in a machine room 6 provided in the upper swing body 3. Therefore, equipment such as a hydraulic pump, an engine for driving the hydraulic pump, and a direction switching valve are provided in the machine room 6. Further, the fuel tank and the hydraulic oil tank are also installed in the area where the machine room 6 is provided.

As is apparent from FIG. 3, the frame 3a of the upper swing body 3 constitutes a main frame 7 which is a single unit by connecting a pair of structural members 7R and 7L to each other by a connecting member (not shown). Machine room beds 8R and 8L are provided on both left and right sides of the main frame 7, respectively. The structural members 7 constituting these main frames 7
The R, 7L and the machine room beds 8R, 8L each have a box structure. In particular, the structural members 7R, 7L are connected to a boom 5a of the front working mechanism 5 at a tip thereof to receive excavation resistance and the like. Therefore, it has extremely high strength. A space between the main frame 7 and the machine room beds 8R and 8L is separably connected to a screw seat 9 fixedly provided using a bolt-nut. On the mainframe 7,
The tank 10 is installed, and an upper turning wheel constituting the turning device 2 is mounted. Also, machine room bed 8
Devices such as an engine and a hydraulic pump are mounted on R and 8L, respectively.

As described above, the structure that the upper swing body 3 can be divided into three parts is to enable transportation. In the case of a hydraulic excavator weighing several hundred tons or more, it cannot be transported in an assembled state at the time of land transport, due to its size and weight, regardless of whether it is transported by sea on a ship. Therefore, the boom 5a, the arm 5b, and the bucket 5c that constitute the front working mechanism 5
And the left and right crawler tracks 1R.
1L and the frame 1a are separated. Further, a turning device 2 for connecting the frame 1a and the upper revolving unit 3 in the lower traveling unit 1 is also configured to be separable into the frame 1a side and the upper revolving unit 3 side. Furthermore, the machine room beds 8R and 8L of the upper swing body 3 and the machine room 6
Can also be separated.

As described above, the hydraulic excavator is for performing operations such as excavation of earth and sand, and this operation is performed by the front working mechanism 5. When a large amount of earth and sand is excavated in a state where the boom 5a and the arm 5b in the front working mechanism 5 are extended forward, the center of gravity moves forward,
The rear side of the vehicle may rise and become unstable. Therefore, in order to stably hold the entire vehicle when the front working mechanism 5 is operated, the counterweight 11 is provided. The counterweight 11 is fixedly provided at the rear ends of the structural members 7R and 7L on the frame 3a of the upper swing body 3. As described above, since the counterweight 11 is for balancing the operation of the front working mechanism 5, the weight is set based on the structure of the front working mechanism 5, especially the capacity of the bucket 5c.

The counterweight 11 is made up of structural members 7R, 7
L is detachably attached to the upper revolving unit 3 during transportation.
Separated from In a large hydraulic excavator, the capacity of the bucket 5c is extremely large, and therefore, the weight of the counterweight 11 is also large, and some of the counterweight 11 cannot be transported by itself.

From the above, as is apparent from FIGS. 3 to 6, the weight of each unit of transportation is reduced by dividing the counterweight 11 into two parts on the left and right sides, thereby enabling the transportation. Thus, as shown in FIGS. 3 and 4, the counterweight 11 is composed of a pair of left and right divided blocks 12R and 12L. These two divided blocks 12R and 12L are formed by filling a steel container with a heavy filler, for example, heavy concrete or iron lump. Divided blocks 12R, 12
L is composed of weight body portions 13R, 13L and overhang portions 14R, 14L, respectively. The weight main bodies 13R and 13L have a shape obtained by roughly dividing the counterweight 11 into two right and left parts, and the projecting part 14R projects below the weight main body 13R toward the divided block 12L. In addition, the overhanging portion 14L is provided on the upper side of the weight main body 13L in the divided block 1
It protrudes toward the 2R side. These overhangs 14
The thickness dimensions of R and 14L are substantially the same, and the weight main bodies 13R and 13L are
In order to secure a space for accommodating 4R, a part is cut off in a concave shape. A recess having a predetermined height from the lower surface side is formed in each of the weight body portions 13R and 13L.
2R and 12L are replaced with the structural members 7R and 7L of the main frame 7.
The saddle-shaped recessed portions 15R and 15L are respectively mounted on the rear end portions in a riding state.

Therefore, the divided blocks 12R and 12L are
First, the saddle-shaped concave portion 15R of the divided block 12R is mounted so as to be fitted to the structural member 7R, and then the divided block 12L is mounted so that the saddle-shaped concave portion 15L is fitted to the structural member 7L. Since the divided blocks 12R and 12L weigh approximately half the weight of the counterweight 12, each of the divided blocks 12R and 12L can be easily and smoothly mounted on the upper swing body 3.

In the mounted state, as shown in FIG. 5, not only the opposing vertical surfaces of both divided blocks 12R and 12L are joined but also the overhanging portion 1R over the overhanging portion 13R.
The 3L horizontal surface will be in contact. As shown in FIGS. 5 and 6, a plurality of bushes 16 penetrating in the vertical direction are provided at portions of the weight main bodies 13R, 13L of the divided blocks 12R, 12L, and the structural members 7R, The upper and lower plates of 7L have bolt insertion holes 17,
A through bolt 18 is inserted through the bush 16 into the bolt insertion hole 17, and a nut 19 is screwed into a lower end of the through bolt 18. In addition, overhang part 1
4R and 14L also have bushes 20 at a plurality of locations, respectively.
The bolts 21 are inserted through the bushes 20, 20 provided in the 4 L, and the nuts 22 are screwed into the lower ends thereof, and the nuts 19, 22 are tightened respectively. The divided counterweight 11 is fixedly attached to the upper swing body 3.

In order to prevent the bolt heads of the through bolts 18, 21 from protruding from the upper surface of the counterweight 11, recesses 23 are provided at the mounting portions of the through bolts 18, 21 on the upper surfaces of the divided blocks 12 R, 12 L. A cover 24 is attached to the recess 23. Therefore, by attaching the cover 24, the upper surface of the counterweight 11 is almost completely flat.

The above-mentioned two divided blocks 12R, 12R
L is attached to the upper revolving unit 3, and is passed through the bolts 18 to the structural members 7 </ b> R and 7 </ b> L.
Further, both divided blocks 12R and 12L are connected to each other by through bolts 21. In this mounting state, the two divided blocks 12R and 12L have a dimensional relationship such that no gap is formed between the divided blocks 12R and 12L.
The 13L vertical surfaces are joined to each other, and
The horizontal surfaces of R and 14L come into contact with each other, and the vertical surface on the rear end side of the overhanging portion 14L located on the upper side is joined to the inner vertical surface of the weight body 13R.

Here, the divided blocks 12R and 12L are
Since there is a difference in the distance from the saddle-shaped recesses 15R and 15L to both ends, as shown in FIG.
Center-of-gravity positions G ₁ and G _{2 of} 2R and 12L respectively
Will be located outside the connection to the structural members 7R, 7L. However, since the overhang portions 14R and 14L are provided, the positions of the centers of gravity G ₁ and G ₂ can be set to positions somewhat close to the saddle-shaped recessed portions 15R and 15L. When the divided blocks 12R and 12L are completely independent of each other, these barycentric positions G ₁ and G
_As shown by an arrow in FIG. ₂ , as shown by an arrow in FIG. However, both divided blocks 12R, 12L
Is absorbed by the horizontal surfaces of the projecting portions 15R, 15L and the vertical surfaces of the weight main portions 14R, 14L so that the mutual pressing force is increased,
In this direction, the two divided blocks 12R and 12L exhibit the same function as the one-piece, and the structural member 7
A load from above only acts substantially on R and 7L. Here, the structural members 7R and 7L constituting the main frame 7 have a box structure, and the strength is extremely high in the vertical direction, and a load in the bending direction, which is inferior in strength to this direction, does not act. 7R, 7L
Is improved, and its deformation, damage and the like are prevented.

Through bolts 18 and 21 are mounted to fix the two divided blocks 12R and 12L to the structural members 7R and 7L. When a force in the shear direction acts on the through bolts 18 and 21, these through bolts 18 and 21 are attached. There is a risk of deformation or breakage of the wires 18 and 21. As described above, the positions of the centers of gravity of the divided blocks 12R and 12L and the respective structural members 7
Since the force in the direction of inclination generated due to the difference in position between the connecting portions of R and 7L is received by the pressing force of the divided blocks 12R and 12L on the vertical plane and the horizontal plane, the through-blocking force is applied. No particular shearing force acts on the bolts 18, 21. Further, since the two divided blocks 12R and 12L are connected to the free ends of the structural members 7R and 7L, the entire counterweight 11 composed of the two divided blocks 12R and 12L is inclined in the direction shown by the arrow in FIG. And The two divided blocks 12R and 12L are overhanging portions 15
Since the horizontal planes of R and 15L, the vertical surface on the rear end side of the overhanging portion 15L located above and the inner vertical surface of the weight main body 13R are in close contact with each other, the counterweight 11 is divided into two divided blocks 12R. , 12L, they work in this direction as well as one-piece. Therefore, the counter weight 11 is 2
Despite the division, the divided blocks 12R and 12L substantially function as an integral body in a direction in which stress may act due to such division. , 21 are also improved in durability.

When the hydraulic excavator is disassembled, the counterweight 11 is also divided into two divided blocks 12R and 12L having substantially the same weight, so that when the heavy counterweight 11 is transported by land transportation. ,
The weight can be kept within the range of the weight limit on the road, and the vehicle can be transported by simple transportation means. In addition, since the length is substantially reduced to half in terms of size, it can be stored compactly not only during transportation but also during storage.

Here, the weights of the two divided blocks 12R and 12L constituting the counterweight 11 may be the same, and the internal specific gravity of one of the divided blocks may be changed so as to be heavier than the other. It can also be formed. Also, for example, due to the connection position of the front working mechanism and the like, a pair of structural members is not provided at a position equidistant from the center line of the vehicle, but is provided at a position deviated leftward or rightward. In this case, the two divided blocks may have different shapes and weights.

[0023]

As described above, according to the present invention, when the counterweight is divided into two parts, each divided block is provided with a saddle-shaped concave part which is mounted on each of the structural members in a horse riding state. In addition, since the overhanging parts that are vertically overlapped at the position between the two structural members are connected continuously, when disassembling and transporting the hydraulic excavator, the heavy counterweight can also be divided, so that It is possible to reduce the weight of an object constituting one unit, and it is possible to prevent a bending moment or the like from acting on a structural member due to a deviation between the position of the center of gravity of the divided block and the position of connection to the structural member at the time of mounting. And so on.

[Brief description of the drawings]

FIG. 1 is an external view of a hydraulic excavator as an example of a construction machine equipped with a counterweight according to an embodiment of the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is an exploded perspective view showing a rear part of an upper swing body of the hydraulic excavator in an exploded state.

FIG. 4 is a diagram schematically showing a state in which divided blocks constituting a counterweight are joined.

FIG. 5 is a cross-sectional view showing a state where the counterweight is attached to the main frame.

FIG. 6 is a sectional view taken along line XX of FIG. 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lower traveling body 3 Upper revolving superstructure 5 Front working mechanism 7 Main frame 7R, 7L Structural member 11 Counter weight 12R, 12L Split weight 13R, 13
L Weight body 14R, 14L Overhang 15R, 15
L Saddle-shaped recess 18, 21 Bolt 19, 22
nut

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E02F 9/18

Claims (5)

(57) [Claims] 1. A counterweight for a construction machine fixed to a main frame constituting an upper revolving structure, comprising a pair of left and right divided blocks in which an overhanging portion is continuously connected to a weight main body, and each of the two divided blocks is provided. A saddle-shaped recessed portion to be mounted in a riding state is formed on each of the pair of left and right structural members provided on the main frame on the weight main body, and the overhanging portions of both divided blocks are vertically moved at a portion between these two structural members. A counterweight for a construction machine, wherein the counterweight is installed on the upper swing body in a state of being superimposed on the counterweight. 2. The structure according to claim 1, wherein each of the two divided blocks is configured to mutually connect between the weight body and the structural member and between the both overhangs with bolts. Construction equipment counterweight. 3. The two divided blocks have the same weight main body portion and the same overhang portion, and one overhang portion is formed from the upper side of the weight main body portion.
The counterweight of a construction machine according to claim 1, wherein the other overhanging portion is configured to overhang from a lower side of the weight body. 4. The counterweight of a construction machine according to claim 3, wherein the two divided blocks have the same weight. 5. The counterweight of a construction machine according to claim 1, wherein the two divided blocks have different weights by storing packing materials having different specific gravities.