JP2000063083A - Counterweight device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately carry out positioning between layered respective weights. SOLUTION: On the upper face of a lower weight 8, fitting projection parts 10, 11 are arranged at a lateral interval, while on the lower face of an intermediate weight 12, a circular hole 14 and an oblong hole 15 are arranged at a lateral interval. The circular hole 14 is fitted around the fitting projection part 10 of the lower weight 8 while keeping slight clearances in the longitudinal direction and in the lateral direction. The oblong hole 15 is fitted around the fitting projection part 11 while keeping a slight clearance in the longitudinal direction and a sufficient clearance in the lateral direction. In this way, the fitting projection parts 10, 11 on the lower weight 8 side and the circular hole 14 and the oblong hole 15 on the intermediate weight 12 side can be surely fitted to each other, and consequently, positioning between the lower weight 8 and the intermediate weight 12 can be carried out with high precision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counterweight device for a construction machine mounted on a construction machine such as a hydraulic crane or a hydraulic excavator to balance the weight of an upper swing body.

[0002]

2. Description of the Related Art Generally, a hydraulic crane used for transporting materials from the ground to a high place at a construction site such as a high-rise building has an undercarriage and an upper revolving frame having a revolving frame rotatably mounted on the undercarriage. Body, a boom provided so as to be able to undulate on the front side of the revolving frame of the upper revolving structure, a working device having a hanging hook, etc., and a working device including a hanging load is provided on the rear side of the revolving frame. A counterweight is installed to balance the weight.

As the counterweight, there is known a laminated type counterweight composed of a plurality of layers of weights which are stacked on the rear side of the revolving frame.
In this type of laminated counterweight, the counterweight, which is a heavy item, is disassembled into layers and conveyed to the work site, and for example, the weights of the layers are stacked and assembled on the revolving frame according to the weight of the suspended load. (For example, Japanese Utility Model Laid-Open No. 59-15690, Japanese Utility Model Publication 3-127)
689 publication).

Here, each weight constituting the above-mentioned laminated type counterweight is provided with a bolt insertion hole penetrating upward and downward, and each weight is formed by a bolt inserted into the bolt insertion hole of each stacked weight. Is concluded.

Then, one of the upper and lower abutting surfaces of each of the weights to be stacked is provided with a fitting convex portion in the left and right directions separately from each other, and the other abutting surface is provided with a left engaging surface. , A fitting recess is provided which is spaced rightward and fitted into the fitting projection, and when the weights are stacked, the fitting projection fits into the fitting recess, thereby It is configured so that the bolt insertion holes provided in the weight can be aligned with each other.

By the way, since the above-mentioned fitting convex portion and fitting concave portion are generally formed integrally with the weight by casting, due to thermal contraction of the cast weight, the intervals between the fitting convex portions and the fitting In many cases, the distance between the recesses is different.

On the other hand, in general, the inner diameter of the fitting recess is made larger than the outer diameter of the fitting projection by about 20 to 30 mm, so that the intervals between the fitting projections and the fitting recesses are provisionally set. Even if the interval is different, the fitting protrusion can be reliably fitted into the fitting recess.

[0008]

However, as described above, the inner diameter of the fitting recess is 20 to 3 larger than the outer diameter of the fitting projection.
If it is made larger by about 0 mm, when the fitting concave portion is fitted to the fitting convex portion, the bolt insertion hole of the lower weight and the bolt insertion hole of the upper weight are accurately aligned. I can't do it.

Therefore, for example, with the upper weight slightly hoisted by using an auxiliary crane or the like, the operator manually aligns the bolt insertion hole of the upper weight with the bolt insertion hole of the lower weight. However, there is a problem that this alignment work is very complicated.

Further, when there is a large gap between the fitting convex portion and the fitting concave portion, it is possible to prevent the weights from being displaced in the horizontal direction when the hydraulic crane performs a turning operation or the like. It cannot be prevented by fitting the fitting convex portion and the fitting concave portion. Therefore, it is necessary to increase the number of bolts for fastening each weight, which causes a problem of increasing the number of parts.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a counterweight device for a construction machine capable of accurately aligning the stacked weights. There is.

[0012]

In order to solve the above-mentioned problems, the present invention is a laminate which is provided on the rear side of a revolving structure and has one or more layers in which weights are stacked in the upward and downward directions. The mold counterweight and the weights forming the laminated counterweight are aligned with each other,
A fitting convex portion provided on one of the upper and lower abutting surfaces of the weights and spaced apart in the left and right directions, and the other of the upper and lower abutting surfaces of the weights. It is applied to the counterweight device of a construction machine, which is provided on the abutting surface of the above-mentioned abutting member so as to be spaced apart in the left and right directions and has a fitting concave portion that fits into each of the fitting convex portions.

The feature of the configuration adopted by the invention of claim 1 is that the fitting concave portion located in one of the left and right directions among the fitting concave portions is a fitting convex portion fitted into the fitting concave portion. Is formed as a circular hole that fits with a slight gap in the front, rear, left, and right directions, and the fitting recess located on the other of the left and right directions is a fitting projection that is fitted to this. There is a slight gap in the front and rear directions between the and, and it is formed as a long hole that fits with a sufficient gap in the left and right directions.

With this configuration, the space between the fitting protrusions provided on one of the upper and lower abutting surfaces of the weights to be stacked and the distance between the engaging convex portions on the other abutting surface. Even if the distance between the fitting recesses is different, one of the fitting recesses has a circular hole located in one of the left and right directions, and one of the fitting recesses has a slight gap in the front and rear directions and in the left and right directions. With the fitting convex portion fitted, it is possible to reliably fit the oblong hole located on the other left or right direction of each fitting concave portion to the other fitting convex portion.

In this case, since the slotted holes are fitted in the fitting projections with a slight gap in the front and rear directions, the stacked weights are displaced from each other in the front and rear directions and the left and right directions. This can be prevented, and the alignment between the weights can be performed accurately.

According to the second aspect of the present invention, the inner diameter of the circular hole located in one of the left and right directions among the fitting recesses and the elongated hole located in the other of the left and right directions among the fitting recesses. What is the minor axis of
In consideration of an error in casting the weight, the size is set to reduce rattling in the fitted state with the fitting convex portion.

With this structure, the fitting protrusions provided on one of the upper and lower abutting surfaces of the weights to be stacked are provided on the other abutting surface. The fitting recesses can be securely fitted, and rattling between the stacked weights can be suppressed.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a counterweight device for a construction machine according to the present invention will be described below with reference to FIGS.

In FIG. 1, 1 is a lower traveling body, 2 is an upper revolving body mounted on the lower traveling body 1 so as to be rotatable,
The upper revolving structure 2 includes a revolving frame 3, a driver's cab 4 provided on the revolving frame 3, a machine room 5, a laminated counterweight 7 described later, and the like.

Here, on the front side of the revolving frame 3, a working device 6 for hanging work is provided so that it can be lifted and lowered. The rear side of the swivel frame 3 is shown in FIG. 2 and FIG.
As shown in FIG. 5, the stacking type counter weights 7 are bifurcated weight supporting portions 3A, 3A.

Reference numeral 7 denotes a laminated counterweight disposed on the rear side of the revolving frame 3, and the laminated counterweight 7 includes a lower layer weight 8 mounted on the weight supporting portion 3A of the revolving frame 3 and the lower layer. The weight 8 is composed of middle layer weights 12 and 18 and an upper layer weight 24, which will be described later, stacked on the weight 8, and balances the weight with the working device 6 provided on the front side of the revolving frame 3.

Here, as shown in FIGS. 2 and 3, the lower layer weight 8 includes an upper surface 8A, a lower surface 8B, a front surface 8C, a curved rear surface 8D, and left and right side surfaces 8E, 8E. It has a semi-cylindrical shape that is long in the direction, and each fitting protrusion 1 described later
It is integrally formed with 0 and 11 by casting. The lower layer weight 8 is fastened to the weight supporting portion 3A of the revolving frame 3 by a bolt (not shown) or the like.

Numerals 9 and 9 are bolt insertion holes formed in the lower layer weight 8 so as to be separated from each other in the left and right directions.
Are formed so as to extend upward and downward from the upper surface 8A toward the lower surface 8B.

Numerals 10 and 11 are two fitting protrusions which are integrally formed on the upper surface (abutting surface) 8A of the lower layer weight 8 and are spaced apart in the left and right directions. The fitting protrusion 10 has an outer diameter d1 ( For example, d1 =
85 mm), and the fitting protrusion 11 has an outer diameter d2.
It has a columnar shape (for example, d2 = 85 mm).
Then, the fitting protrusions 10 and 11 have a space p (for example, p
= 2500 mm ± 7 mm), they are separated in the left and right directions.

Reference numeral 12 is a middle-layer weight stacked on the lower-layer weight 8. The middle-layer weight 12 has a semi-cylindrical shape similar to that of the lower-layer weight 8 and has circular holes 14, elongated holes 15 and fitting projections described later. The parts 16 and 17 are integrally formed by casting.

Reference numerals 13 and 13 denote bolt insertion holes formed in the middle-layer weight 12 so as to be separated from each other in the left and right directions. Each bolt insertion hole 13 is formed from the upper surface 12A to the lower surface 12 of the middle-layer weight 12.
It is formed so as to extend upward and downward toward B and communicates with each bolt insertion hole 9 of the lower layer weight 8.

Reference numeral 14 denotes the lower surface (abutting surface) of the intermediate weight 12.
12B is a circular hole as a fitting concave portion, and 15 is a long hole as a fitting concave portion provided on the lower surface 12B of the middle-layer weight 12 together with the circular hole 14, and as shown in FIG.
And the long hole 15 have a space P (for example, P = 2500 mm ±
7mm) and left and right separated, lower layer weight 8
It is fitted to the fitting convex portions 10 and 11 provided on the.

Here, the inner diameter D1 of the circular hole 14 is slightly larger than the outer diameter d1 of the fitting convex portion 10 of the lower layer weight 8 fitted therein, and is set to D1> d1 + (2 to 3 mm), for example. Has been done. Therefore, the circular hole 14 is defined by the middle weight 1
2 has an inner diameter dimension D1 which takes into account an error due to heat shrinkage during casting and which reduces rattling when the fitting protrusion 10 of the lower layer weight 8 is fitted to the fitting protrusion 10 On the other hand, the front and rear directions are fitted with a slight gap in the left and right directions.

On the other hand, the minor diameter D2 in the front and rear directions of the elongated hole 15
Is slightly larger than the outer diameter d2 of the fitting protrusion 11 of the lower layer weight 8 fitted to this, for example, D2> d2 + (2
Is set to 3 mm). The left and right major axes L of the elongated holes 15 are sufficiently larger than the outer diameter d2 of the fitting projection 11, and are set to L> d2 + 30 mm, for example. Therefore, the long hole 15 has a short diameter dimension in consideration of an error due to heat shrinkage or the like during the casting of the middle-layer weight 12, and reduces rattling when the fitting convex portion 11 of the lower-layer weight 8 is fitted therein. D2 is provided, and the fitting convex portion 11 is fitted with a slight gap in the front and rear directions and a sufficient gap in the left and right directions.

When the intermediate layer weight 12 is stacked on the lower layer weight 8, the fitting convex portion 1 of the lower layer weight 8 is stacked.
By fitting the circular holes 14 and the elongated holes 15 of the middle layer weight 12 into the holes 0 and 11, the bolt insertion holes 9 of the lower layer weight 8 and the bolt insertion holes 13 of the middle layer weight 12 can be aligned with each other. Has become.

Reference numerals 16 and 17 denote the upper surface 12 of the intermediate weight 12.
Each of the fitting protrusions 1 is formed by two fitting protrusions formed integrally with A.
Reference numerals 6 and 17 are configured in the same manner as the above-described fitting convex portions 10 and 11.

Reference numeral 18 denotes a second-stage middle-layer weight stacked on the middle-layer weight 12. The middle-layer weight 18 has a semi-cylindrical shape similar to that of the lower-layer weight 8 and has a circular hole 20, an elongated hole 21 and a hole 21 which will be described later. Together with the fitting convex portions 22 and 23, they are integrally formed by casting.

Reference numerals 19 and 19 denote bolt insertion holes formed in the middle-layer weight 18 so as to be separated from each other in the left and right directions. Each bolt insertion hole 19 is formed from the upper surface 18A to the lower surface 18 of the middle-layer weight 18.
It is formed so as to extend upward and downward toward B and communicates with each bolt insertion hole 13 of the middle weight 12.

Reference numeral 20 denotes a circular hole as a fitting concave portion provided on the lower surface 18B of the middle layer weight 18, 21 denotes a long hole as a fitting concave portion provided on the lower surface 18B of the middle layer weight 18 together with the circular hole 20, which is a circular hole. 20 is configured similarly to the circular hole 14 described above, and the elongated hole 21 is configured similar to the elongated hole 15 described above.

Then, when stacking the middle-layer weight 18 on the middle-layer weight 12, the circular holes 20 and the long holes 21 of the middle-layer weight 18 are fitted into the fitting projections 16 and 17 of the middle-layer weight 12 so that the middle-layer weight 18 is fitted. The bolt insertion holes 13 of the weight 12 and the bolt insertion holes 19 of the middle-layer weight 18 can be aligned with each other.

Reference numerals 22 and 23 denote the upper surface 18 of the intermediate weight 18.
Each of the fitting protrusions 2 is formed by two fitting protrusions formed integrally with A.
The reference numerals 2 and 23 have the same configuration as the above-described fitting protrusions 10 and 11.

Reference numeral 24 denotes an upper layer weight stacked on the intermediate layer weight 18. The upper layer weight 24 has a semi-cylindrical shape similar to that of the lower layer weight 8 and is integrally formed with a circular hole 26 and an elongated hole 27 described later by casting. Has been formed.

Numerals 25 and 25 are bolt insertion holes formed in the upper layer weight 24 so as to be separated from each other in the left and right directions. Each bolt insertion hole 25 is formed from the upper surface 24A to the lower surface 24 of the upper layer weight 24.
It is formed so as to extend upward and downward toward B and communicates with each bolt insertion hole 19 of the middle weight 18.

Reference numeral 26 is a circular hole as a fitting recess provided in the lower surface 24B of the upper layer weight 24, and 27 is an elongated hole as a fitting recess provided in the lower surface 24B of the upper layer weight 24 together with the circular hole 26. 26 is configured similarly to the circular hole 14 described above, and the elongated hole 27 is configured similar to the elongated hole 15 described above.

Then, when stacking the upper layer weight 24 on the intermediate layer weight 18, by fitting the circular holes 26 and the elongated holes 27 of the upper layer weight 24 into the fitting convex portions 22 and 23 of the intermediate layer weight 18, The bolt insertion holes 19 of the weight 18 and the bolt insertion holes 25 of the upper layer weight 24 can be aligned with each other.

Reference numerals 28 and 28 denote the bolt insertion holes 25 of the upper layer weight 24 to the bolt insertion holes 1 of the intermediate layer weight 18.
9, bolts inserted into the bolt insertion holes 13 of the middle layer weight 12 and the bolt insertion holes 9 of the lower layer weight 8,
Each bolt 28 has nuts 29, 29 screwed on the lower end side thereof, so that the weights 8, 12, 18, 2 stacked are laminated.
4 is to be concluded.

The counterweight device according to the present embodiment has the above-mentioned structure, and the operation of assembling the laminated counterweight 7 on the rear side of the revolving frame 3 will be described below.

First, the lower layer weight 8 is lifted by an auxiliary crane (not shown) or the like, and the lower layer weight 8 is fastened to the weight supporting portion 3A of the revolving frame 3 by using bolts (not shown) or the like.

Next, the middle-layer weight 12 hoisted by the crane is lowered toward the lower-layer weight 8, and the fitting convex portions 10 and 11 of the lower-layer weight 8 are fitted with the circular holes 14 and the elongated holes 15 of the middle-layer weight 12. As a result, the middle-layer weight 12 is stacked on the lower-layer weight 8.

Here, the lower layer weight 8 and the intermediate layer weight 1
Since 2 is formed by casting, the actual spacing p (p = 2) between the fitting protrusions 10 and 11 provided on the lower layer weight 8 is set.
500 mm ± 7 mm) and the actual distance P (P = 2500) between the circular hole 14 and the long hole 15 provided in the middle-layer weight 12.
mm ± 7mm), maximum 14m in left and right direction
An error of m may occur.

However, in the present embodiment, the major axis L of the elongated hole 15 in the left and right directions is formed larger than the outer diameter d2 of the fitting convex portion 11 by 30 mm.

For this reason, a provisional error of 14 mm occurs between the interval p between the fitting protrusions 10 and 11 on the lower layer weight 8 side and the interval P between the circular hole 14 and the elongated hole 15 on the intermediate layer weight 12 side. Even if it occurs, the lower weight 8 as shown in FIG.
The circular hole 1 of the middle-layer weight 12 is formed in each of the fitting convex portions 10 and 11 of
4. The middle-layer weights 12 can be stacked while securely fitting the long holes 15.

In this case, the inner diameter D1 of the circular hole 14 provided in the middle layer weight 12 is the outer diameter of the fitting convex portion 10 provided in the lower layer weight 8 in consideration of an error due to heat shrinkage during casting of the middle layer weight 12. It is set to be larger than d1 by 2 to 3 mm, and the short diameter D2 in the front and rear directions of the elongated hole 15 is 2 to 3 larger than the outer diameter d2 of the fitting convex portion 11 provided on the lower layer weight 8.
It is set larger by mm.

Therefore, as compared with the case where the inner diameter of the fitting concave portion is formed to be larger than the outer diameter of the fitting convex portion by about 20 to 30 mm as in the prior art, for example, the middle layer weight 12 is provided in front of the lower layer weight 8. The positional deviation between the rear direction and the left and right directions can be limited to the range of the above-mentioned dimensional difference of 2 to 3 mm. Therefore, the bolt insertion holes 9 of the lower layer weight 8 and the bolt insertion holes 13 of the intermediate layer weight 12 can be reliably aligned by simply stacking the intermediate layer weights 12.

Further, even if the dimension T1 from the front surface 8C of the lower layer weight 8 to the fitting convex portion 10 and the dimension T2 from the front surface 8C of the lower layer weight 8 to the fitting convex portion 11 are different, The middle-weight 12 is attached to the fitting protrusion 10.
By rotating the middle-layer weight 12 around the fitting convex portion 10 with the circular hole 14 of FIG. 6 fitted, the oblong hole 15 of the middle-layer weight 12 can be surely fitted to the fitting convex portion 11. Therefore, the middle layer weight 12 can be stacked on the lower layer weight 8.

Thus, after stacking the middle-layer weight 12 on the lower-layer weight 8, the middle-layer weight 18 hung by the crane is stacked on the middle-layer weight 12. Also in this case, the circular hole 20 and the elongated hole 21 of the middle layer weight 18 are formed in the fitting convex portions 16 and 17 of the middle layer weight 12 in the same manner as described above.
By fitting, the bolt insertion holes 13 of the middle layer weight 12 and the bolt insertion holes 19 of the middle layer weight 18 can be surely aligned with each other.

Further, the upper layer weight 24 lifted by the crane is stacked on the intermediate layer weight 18. Also in this case, as in the case described above, the circular holes 26 and the elongated holes 27 of the upper layer weight 24 are formed in the fitting convex portions 22 and 23 of the intermediate layer weight 18, respectively.
By mating with each other, the bolt insertion holes 19 of the middle layer weight 18 and the bolt insertion holes 25 of the upper layer weight 24 can be surely aligned with each other.

Then, the lower layer weight 8 and the intermediate layer weight 1
2. After stacking the intermediate layer weight 18 and the upper layer weight 24 in order, from the bolt insertion holes 25 of the upper layer weight 24 to the bolt insertion holes 19 of the intermediate layer weight 18, the bolt insertion holes 13 of the intermediate layer weight 12 and the lower layer weight 8 respectively. The bolt 28 is inserted into each bolt insertion hole 9. Then, by screwing the nut 29 on the lower end side of the bolt 28,
The stacked weights 8, 12, 18, 24 can be fastened by the bolts 28, and the stacked counterweight 7 can be assembled on the rear side of the revolving frame 3.

In this case, the fitting convex portion 11 of the lower layer weight 8
And the long hole 15 of the middle layer weight 12, the fitting convex portion 17 of the middle layer weight 12 and the long hole 21 of the middle layer weight 18, the fitting convex portion 23 of the middle layer weight 18 and the long hole 27 of the upper layer weight 24.
Are fitted with a slight gap of about 2 to 3 mm in the front and rear directions, respectively. For this reason, when the upper swing body 2 swings, each weight 8, 12, 18, 24
It is possible to prevent the positions from being displaced from each other.
Therefore, it is not necessary to increase the number of fastening bolts 28 in order to suppress the positional deviation of the weights 8, 12, 18, 24, and it is possible to contribute to the reduction of the number of parts.

In the above-described embodiment, the case where the fitting convex portion is provided on the upper surface side of each weight and the fitting concave portion is provided on the lower surface side is given as an example, but the present invention is not limited to this. The fitting recess may be provided on the upper surface side of each weight, and the fitting projection may be provided on the lower surface side.

Further, in the above-mentioned embodiment, the hydraulic crane was explained as an example of the construction machine, but the present invention is not limited to this, and other construction machines equipped with counterweights such as hydraulic excavators, for example. Can also be applied to.

[0057]

As described above in detail, according to the first aspect of the invention, one of the upper and lower abutting surfaces of the weights to be stacked is fitted to one of the abutting surfaces so as to be leftward and rightwardly spaced apart. And a fitting recess is provided on the other abutting surface so as to be spaced apart left and right, and the fitting recess located in one of the left and right directions of each fitting recess is fitted to this. Formed as a circular hole that fits with a slight gap in the front, rear and left and right directions between the fitting convex part,
The fitting recess located on the other side in the left and right directions has a slight gap in the front and rear directions with the fitting projection that is fitted to this, and a sufficient clearance in the left and right directions. Since it is formed as a long hole to be fitted, even if the distance between the fitting convex portions and the distance between the fitting concave portions are different, for example, one of the circular holes located to the left or right of the fitting concave portions In the state of being fitted in the fitting convex portion of No. 2, the elongated hole located in the other of the fitting concave portions in the left and right directions can be surely fitted in the other fitting convex portion. In this case, since the elongated holes are fitted in the fitting convex portion with a slight gap in the front and rear directions, it is possible to prevent the stacked weights from being displaced in the front and rear directions and the left and right directions. The weights can be accurately aligned.

Further, it is possible to prevent the weights stacked by fitting the fitting convex portion and the fitting concave portion from being displaced in the front and rear directions and the left and right directions at the time of turning of the turning body. Therefore, it is not necessary to increase the number of bolts for fastening each weight, which can contribute to a reduction in the number of parts.

Further, even if the intervals between the fitting recesses and the intervals between the fitting protrusions are different, the fitting protrusions and the fitting recesses can be securely fitted to each other, so that the weight is provided. It is not necessary to require strict dimensional accuracy for the intervals of the fitting protrusions and the intervals of the fitting recesses, and the manufacturability of the weight can be improved.

According to the second aspect of the present invention, the inner diameter of the circular hole located in one of the left and right directions of the fitting recesses and the other of the fitting recesses in the other of the left and right directions. The minor diameter of the long hole is set to a size that reduces rattling in the fitting state with the fitting convex portion in consideration of an error during casting of the weight. Even when the intervals of the fitting convex portions and the intervals of the fitting concave portions are different, each fitting convex portion provided on one of the abutting surfaces of the upper and lower abutting surfaces of the weights to be stacked, The fitting recesses provided on the other abutting surface can be reliably fitted. In addition, since the rattling between the fitting concave portion and the fitting convex portion can be reduced in the state where the fitting convex portions and the fitting concave portions are fitted to each other, the alignment between the stacked weights can be accurately performed. It can be carried out.

[Brief description of drawings]

FIG. 1 is a front view showing a hydraulic crane provided with a counterweight device according to an embodiment of the present invention.

2 is a partially cutaway left side view showing the laminated counterweight in FIG. 1. FIG.

FIG. 3 is a transverse sectional view showing the lower layer weight as seen from the direction of arrows III-III in FIG. 2.

FIG. 4 is a transverse cross-sectional view showing an intermediate layer weight as seen from the direction of arrows IV-IV in FIG. 2.

FIG. 5 is a transverse cross-sectional view at the same position as in FIG. 3, showing a state in which the fitting concave portion of the middle layer weight is fitted to the fitting convex portion of the lower layer weight.

[Explanation of symbols]

2 Upper revolving structure 7 Stacked counterweight 8 Lower layer weight 10,11,16,17,22,23 Fitting convex part 12,18 Middle weight 14, 20, 26 circular hole (fitting recess) 15, 21, 27 oblong hole (fitting recess) 24 Upper weight

Claims (2)

[Claims] 1. A laminated type counter weight, which is provided on the rear side of a revolving structure and is formed by stacking weights in an upper and lower direction and arranging one layer or a plurality of layers, and each weight forming the laminated type counter weight. In order to align with each other, one of the upper and lower abutting surfaces of each of the weights is fitted with a fitting convex portion which is spaced apart in the left and right directions, and the upper and lower of the weights. In the counterweight device for a construction machine, which is provided on the other abutting surface of the abutting surfaces and is spaced apart in the left and right directions, and includes a fitting concave portion that fits into each of the fitting convex portions. The fitting recess located on one of the left and right sides of the recess is a circular hole that fits between the fitting projection fitted to the recess with a slight gap in the front and rear directions and in the left and right directions. And the fitting recesses located on the other side in the left and right directions are Before between the convex portion, is rearwardly have a slight clearance, left, counterweight device for a construction machine characterized by being formed as a long hole that fits with sufficient clearance in the right direction. 2. The inner diameter of a circular hole located in one of the left and right directions of the fitting recesses and the minor diameter of an elongated hole located in the other of the fitting recesses in the left and right directions. The counterweight device for a construction machine according to claim 1, wherein the weight is set so that rattling is reduced in a fitted state with the fitting convex portion in consideration of an error during casting of the weight.