JP2001323515A - Counterweight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a counterweight, in which a structure is simplified and which can be manufactured at a low cost, by miniaturizing a female screw member installed for fixing to a frame by a bolt and economizing a material for the female screw member while surely preventing intrusion into a tapped hole of cement or the like. SOLUTION: The female screw member 20 is fixed and installed onto the beam placing section 11a of an underside plate 11 constituting the vessel of the counterweight 9 by a welding means, and the bolts 15 are screwed and inserted for fixedly connecting the counterweight 9 onto the frame 3. The tapped holes 20a formed to the female screw member 20 are penetrated, recessed sections 20b having a large diameter are formed at an end section on the side opened into the vessel 10 of the female screw member 20 for closing opening sections to the inside of the vessel 10 of the tapped holes 20a, and elastic plates 21 are secured into the recessed sections 20b, and held under a sealed state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counterweight detachably mounted on a frame of a construction machine.

[0002]

2. Description of the Related Art A construction machine such as a hydraulic excavator or a hydraulic crane has a vehicle which is constructed by mounting an upper revolving structure on a lower traveling structure so as to be revolvable. And a working machine such as a crane. Therefore, FIG. 8 shows the entire configuration of a hydraulic shovel as an example of a construction machine.

In FIG. 1, reference numeral 1 denotes a lower traveling body, and 2 denotes an upper revolving superstructure. The lower traveling body 1 is configured with left and right crawler belts in the illustrated one, but there is also a wheeled traveling body as well as a crawler belt type.

[0004] The upper revolving superstructure 2 is rotatable with respect to the lower traveling superstructure 1 and has a frame 3 as a structure as shown in FIG. A work implement 4 for performing work and a cab 5 on which an operator rides are installed at one end side. The work machine 4 includes a boom 6 connected to the frame 3 so as to be capable of raising and lowering, an arm 7 connected to a tip of the boom 6 so as to be rotatable in a vertical direction,
And a bucket 8 rotatably connected to the tip of the arm 7. Note that another attachment can be attached to the tip of the arm 7 instead of the bucket 8.

When excavating earth and sand by the working machine 4 having the bucket 8, the bucket 8 operates so as to cut into the ground at a position in front of the vehicle. A counter weight 9 is provided at a rear position of the frame 3 in order to balance the rear side of the vehicle so as not to float. The counterweight 9 is detachably mounted on the frame 3. The counterweights 9 are installed on the beams 3a, 3a of the frame 3 projecting rearward as shown in FIG. 9, and are bolted to these two beams 3a. .

Here, for example, the counterweight 9 disclosed in Japanese Patent Application Laid-Open No. 8-284210 has been widely used. The configuration of the known counterweight 9 is shown in FIGS.

The counterweight 9 is formed by filling a hollow container 10 with a heavy object (not shown). This heavy object is composed of, for example, a mixture of massive metal and the like in cement. The weight can be adjusted by the mixing ratio between the metal and the like and the cement, and the whole can be formed into one lump by the action of the cement, so that the inside of the container 10 can be filled substantially without any gap. Therefore, the container 10 constituting the counterweight 9 is a closed container having a predetermined shape.

That is, as shown in FIGS. 10 and 11, the container 10 includes a lower plate 11, an upper plate 12, and a front plate 1.
3 and a rear face plate 14. The rear plate 14 is bent in a substantially arc shape or a shape close to a trapezoid, and these lower plate 11, upper plate 12, front plate 13, and rear plate 14 are
They are connected and fixed to each other by means such as welding. here,
The above-mentioned heavy object is filled from the upper side. Therefore, the upper surface plate 12 is usually divided into a plurality of plates, and is welded after the filling of the heavy object. Further, the lower surface plate 11 is formed with two beam mounting portions 11a mounted on the beam 3a of the frame 3. The beam mounting portion 11a is a recess having a predetermined depth, and the width of the recess substantially matches the width of the beam 3a, and the depth substantially matches the height of the beam 3a. . Further, on the front plate 13, the beam mounting portion 1 is provided.
A notch 13a corresponding to the shape of 1a is provided, and such a notch is not formed in the rear face plate 14. As a result, when viewed from the rear side of the vehicle, the frame 3 of the upper swing body 2 is covered by the rear plate 14 of the counterweight 9.

The counterweight 9 having the above configuration
As shown in FIG. 12, the beam mounting portion 11a of the lower plate 11 of the container 10
And fixed using bolts 15. The bolts 15 are provided at two places for each beam 3a. Here, the beam 3a is formed by the upper and lower plates 16.
a, 16b, and a cylindrical body 16c provided between the two plate bodies 16a, 16b.
Through holes 17a and 17b are formed in the mounting portion of the cylindrical body 16c. Here, the inner diameter of the cylindrical body 16c and the through hole 1
The opening diameters of the bolts 7a and 17b substantially coincide with each other.
5 is slightly larger than the outer diameter of the shaft portion.

The bolt 15 is adapted to be screwed into a female screw member 18 mounted inside the container 10 constituting the counterweight 9. The female screw member 18 is formed of a metal block having a predetermined size, and is fixed to the inner surface side of the beam mounting portion 11a on the lower surface plate 11 by welding means. The female screw member 18 is provided with a screw hole 18a into which the bolt 15 is screwed.
A through hole 11b for screw insertion is formed at a position corresponding to one screw hole 18a.

Therefore, the counterweight 9 is constructed such that the beam mounting portion 11a of the lower plate 11 of the container 10 is
Is mounted so as to straddle the beam 3a. Then, the bolt 15 is connected to the female screw member 18 through the through hole 17a of the plate 16a, the inside of the cylindrical body 16c, the through hole 17b of the plate 16b, and the screw hole 18a of the lower plate 11 in order.
The counterweight 9 is fixedly connected to the beam 3a of the frame 3 by screwing into the screw hole 18a.

Here, the counterweight 9 is connected to the frame 3
The work of installing and removing the cranes is performed by hanging them with a crane. Therefore,
For example, two holes 12a are formed in the upper surface plate 12 constituting the counterweight 9, and a female screw member 19 for detachably attaching a hook for engaging with a crane to these through holes is formed. It is provided fixedly by welding means.

As described above, the counterweight 9 is made of a container 10 filled with a heavy material, which is usually made of metal and cement. Things. Then, since the cement is poured in a fluidized state, it is necessary to prevent the cement thus poured from leaking to the outside. For this reason, when filling heavy objects, the upper plate 12
At least a part is opened, but the joint between the lower plate 11 and the front plate 13 and the rear plate 14 is completely adhered by welding so that no gap is formed. At least the lower surface plate 11 is provided with a female screw member 18. If cement or the like enters the screw hole 18 a of the female screw member 18, the bolt 15 cannot be screwed. Therefore, the female screw member 18 is fixed to the lower plate 11 by welding means or the like so that no gap is formed therebetween.

[0014]

In order to prevent foreign matter such as cement from entering the inside of the screw hole 18a, the female screw member 18 must be formed with a bag-shaped screw hole, that is, an incomplete screw portion. Must. Therefore, this female screw member 1
8 needs to be larger than the required length of the screw hole 18a into which the bolt 15 is inserted. That is, FIG.
As shown in the figure, the height dimension of the female screw member 18 is L
That when, and the length of the screw hole 18a of the bolt 15 is screwed is the dimension L ₁ position halfway from the lower surface of the female screw member 18. This dimension L ₁ is constitutes a interference of the bolt 15, thus in order to provide sufficient connection strength, it is necessary to predetermined length. However, then the length of L ₂ shown in the previous figures are not particularly involved in the original function as a female screw member.

[0015] From the above, in order for the female screw member to have its original function, it is necessary to use a member that is considerably larger than the required size, and waste of material becomes extremely large. In addition, since incomplete threads are formed, it is troublesome to remove chips after thread groove processing, and it takes considerable time to completely remove chips. There are also problems.

The present invention has been made in view of the above points, and has as its object to reduce the size of a female screw member provided for fixing to a frame with bolts.
It is an object of the present invention to provide a counterweight which can save the material and can surely prevent cement or the like from entering a screw hole, and thus can be manufactured at a low cost with a simple structure.

[0017]

In order to achieve the above-mentioned object, the present invention provides a counterweight in which a hollow container is filled with a heavy object, and a lower surface portion of which can be fixed to a vehicle body frame by bolts. In the container, a female screw member having a screw hole therethrough is provided fixedly to the lower surface plate, and the bolt is inserted into a position where at least the screw hole is provided in the lower surface plate. In addition, a through-hole for the screw hole is formed, and an end of the screw hole on the side opposite to the opening side to the through-hole is closed by a closing means.

Here, as a specific configuration of the closing means, a large-diameter concave portion is formed at the end of the screw hole of the female screw member, and the elastic plate is elastically deformed in the concave portion. Then, it is possible to adopt a configuration in which the fastening is performed in a substantially tightly fitted state. It is also possible to use a closing plate for closing the end of the screw hole, and fix the closing plate to the end face of the female screw member by welding means. Further, since the screw hole is closed, the closing means may be configured by a plug member screwed into the screw hole. In this case, it is desirable to provide a seal member between the screw member and the periphery of the screw hole.

The container may be provided with another female screw member in addition to the above-mentioned fixing portion to the vehicle body frame.
For example, to attach and detach the counterweight, the crane is hung by a crane, and a hook engaging member with which a hook of the crane is engaged may be mounted on the upper surface. The hook engaging member is mounted so as to be screwed into the upper part of the counterweight. Therefore, the female screw member is also mounted on the upper surface part for this purpose, and this female screw member is also provided with a threaded hole that forms a complete screw as described above, and the end of the screw hole is closed by closing means. It can be configured to occlude.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, members that are the same as or equivalent to those of the above-described related art are described using the same reference numerals, and detailed descriptions thereof are omitted.

First, in FIG. 1, reference numeral 20 denotes a female screw member, and the female screw member 20 is provided by being fixed to a beam mounting portion 11a of a lower plate 11 constituting the container 10 of the counterweight 9 by welding means. Thus, the counterweight 9 is fixedly connected to the frame 3.
Here, the female screw member 20 is connected to the container 1 on the lower plate 11.
0, and a screw hole 20a facing the through hole 11b formed in the lower plate 11 is provided.

The screw hole 20a is provided so as to penetrate the female screw member 20, unlike the prior art. That is, both ends of the female screw member 20 are open, one end of which is in communication with the through hole 11 b of the lower plate 11, and the other end is opened toward the inside of the container 10. However, if the heavy material is welded to the lower plate 11 in this state, a fluid such as cement, which is a component of the heavy material, enters the screw hole 20a.

Therefore, in order to close the opening of the screw hole 20a to the inside of the container 10, as shown in FIG. 2 and FIG. A recess 20b having a diameter is formed. And this recess 2
An elastic plate 21 constituting a closing means is mounted in Ob. The elastic plate 21 is formed of a spring-like thin disk, and has a concave curved surface shape whose central portion protrudes in one direction.
0 is slightly larger than the inner diameter of the recess 20b. Therefore, the elastic plate 21 is mounted so as to be engaged with the inner peripheral wall of the concave portion 20 b in a state of being elastically deformed and in close contact with the inner peripheral wall, and swells out from the end face of the female screw member 20.

Therefore, when the elastic plate 21 is mounted, the outer peripheral surface of the elastic plate 21 is urged so as to be pressed against the inner peripheral wall of the concave portion 20b, so that the elastic plate 21 is fitted into the concave portion 20b. The screw hole 20a is stably held and the screw hole 20a is sealed in a closed state. In particular, when a fluid such as cement is pressed against the elastic plate 21, a pressing force acts in a direction in which the elastic plate 21 is flattened, and the sealing property is further improved. For this reason, not only fluid such as cement but also moist air containing cement and the like does not enter, so that adhesion of foreign matter to the screw hole 20a can be completely prevented.

As described above, the female screw member 20 has a thickness (height) dimension substantially equivalent to the depth of the concave portion 20b in addition to the screw length of the bolt 15, and the depth of the concave portion 20b. The height may be shallow enough to hold the elastic plate 21. Therefore, it is possible to significantly reduce the thickness of the female screw member 20, specifically compared to the female screw member of the related art described above, it is possible to shorten the length corresponding substantially to that dimension L ₂ minutes. As a result, the material of the female screw member 20 can be minimized, and the material can be saved. A screw hole 20a provided in the female screw member 20 is provided.
Is a completely threaded portion that penetrates the female screw member 20, so that chips generated when performing the thread forming process can be easily removed, and the processability of the screw is improved.

As a second embodiment of the closing means, as shown in FIGS. 4 and 5, an end portion of a female screw member 30 provided with a screw hole 30a is provided with an outer portion which is sufficiently larger than the diameter of the screw hole 30a. A closing disc 31 can be used as a closing means having a diameter. The closing disk 31 is fixed to the end face of the female screw member 30 by welding means, whereby the end of the screw hole 30a formed of a completely threaded portion is sealed.

Further, as a third embodiment of the closing means, as shown in FIG. 6, a plug member 41 as a closing means is screwed into an end of a female screw member 40 provided with a screw hole 40a. May be configured. The plug member 41 is a screw hole 4
0a may be closed and held so as not to fall out of the screw hole 40a.
The length of the threaded portion to the head may be very small. The outer diameter of the head of the plug member 41 is not sufficiently larger than the diameter of the screw hole 40a, and the sealing member 42 is interposed between the head and the end face of the female screw member 40, whereby the screw hole 40a is formed. The sealing performance of the device is further improved.

As described above, even with the constructions of the second and third embodiments, the dimensions of the female screw member can be reduced, and the workability of the screw hole can be improved.

As described above, the counterweight 9 is provided with a female screw member for fixing the frame 3 to the frame 3 with the bolts 15. The counterweight 9 is further lifted on the upper surface of the container 10 by a crane. As shown in FIG. 7, a hook engaging member 50 that engages with a hook of a crane is configured to be detachably attached to the frame 3 in order to be attached to or detached from the frame 3. is there. The hook engaging member may be provided integrally with the container 10 and cannot be attached or detached. However, the hook engaging member 50 is attached only when the counterweight 9 is attached / detached. It is preferable in appearance that the plug 51 provided with the seal member 51a is mounted.

For this purpose, a through hole 12a is formed in the top plate 12 of the container 10 constituting the counterweight 9, and a female screw member 52 is fixed to the through hole 12a by welding means. Here, the female screw member 52 is provided in a state where the surface thereof substantially coincides with the surface of the upper plate 12, and
It protrudes toward the inside. The female screw member 52 may be any one of the first to third embodiments described above,
For example, the configuration may be substantially the same as that of the female screw member 20 according to the first embodiment. That is, the female screw member 5
2 has a screw hole 52 which constitutes a completely threaded portion therethrough.
a is provided, a concave portion 52b is provided on an end face located inside the container 10, and a thin closing disc-shaped elastic plate 53 having spring property is provided in the concave portion 52b so as to be engaged.

As described above, the female screw member 52 to which the hook engaging member 50 is removably mounted is also formed with the screw hole 52a having a completely threaded portion, so that the female screw member 52 can be miniaturized and the screw can be machined. The subsequent work of removing chips is facilitated. In addition, although the screw hole 52a is provided so as to penetrate, the end is closed by a closing means made of an elastic plate 53 or the like, so that rainwater or the like can be prevented from entering the inside of the container 10. As a result, it is possible to prevent rust or the like from being generated and deteriorated on the inner surface of the container 10.

[0032]

Since the counterweight of the present invention is constructed as described above, the female screw member provided for fixing the bolt to the frame can be reduced in size, the material can be saved, and cement and the like can be saved. Can be reliably prevented from entering the screw hole, and thus the structure is simple and the manufacturing can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a counterweight according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a female screw member in the counterweight of FIG. 1;

FIG. 3 is a right side view of FIG. 2;

FIG. 4 is a cross-sectional view of a female screw member of a counterweight according to a second embodiment of the present invention.

FIG. 5 is a right side view of FIG.

FIG. 6 is a sectional view of a female screw member of a counterweight according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a state in which a female screw member for mounting a hook engaging member as a female screw member in the counterweight according to the present invention is mounted.

FIG. 8 is a front view of a hydraulic shovel as an example of a construction machine to which a counterweight is attached.

FIG. 9 is an external view of a frame on which a counterweight is mounted.

FIG. 10 is a front view showing a container constituting a counterweight according to the related art, with a part thereof cut away.

FIG. 11 is a sectional view taken along line XX of FIG. 10;

FIG. 12 is a sectional view of a female screw member provided on the counterweight of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper revolving structure 3 Frame 3a Beam 9 Counterweight 10 Container 11 Lower plate 11a Beam mounting part 11b Through hole 12 Top plate 12a Through hole 13 Front plate 14 Rear plate 15 Bolts 20, 30, 40, 52 Female screw Member 20a, 30a, 40a, 52a Screw hole 20b, 52b Recess 21, 53 Elastic plate 31 Closing disk 41 Plug member 42 Seal member 50 Hook engaging member

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Koji Tahara 650, Kandate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. (72) Inventor Yoshiyoshi Nakayama 650, Kandamachi, Tsuchiura-shi, Ibaraki F-term (reference) 2D015 FA01 3F205 AA05 BA01 GA01 GA02

Claims (6)

[Claims] 1. A hollow container filled with a heavy material,
In the counterweight, a lower surface portion of which can be fixed to a vehicle body frame by a bolt, a female screw member having a threaded through hole is provided in the container so as to be fixed to the lower surface plate. At least a hole for inserting the bolt is provided at a position where the screw hole is provided, and an end of the screw hole on the side opposite to the opening side of the through hole is sealed by a closing means. A counterweight characterized by the following. 2. The female screw member according to claim 1, wherein a large-diameter concave portion is formed at an end of the screw hole, and the closing means is constituted by an elastic plate fastened tightly to the concave portion. The counterweight according to claim 1. 3. The closing means is a closing plate for closing an end of the screw hole, and the closing plate is fixed to an end face of the female screw member by welding means. Counterweight. 4. The counterweight according to claim 1, wherein said closing means is a plug member screwed into said screw hole. 5. The counterweight according to claim 4, wherein a seal member is provided between the plug member and the periphery of the screw hole. 6. A plurality of through holes are formed in an upper surface of the container,
These through holes are provided to penetrate the screw holes,
A female screw member having an internal end of the screw hole closed by closing means is fixedly provided, and a hook engaging member to which a hook for hanging by a crane is engaged. The counterweight according to claim 1, wherein the counterweight is detachably screwed.