JP4042301B2 - Counterweight - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a counterweight that is detachably attached to a frame of a construction machine.
[0002]
[Prior art]
Construction machines such as a hydraulic excavator and a hydraulic crane have a vehicle constructed by mounting an upper swinging body on a lower traveling body so that the upper swinging body can turn. The machine is installed. FIG. 8 shows an overall configuration of a hydraulic excavator as an example of a construction machine.
[0003]
In the figure, 1 is a lower traveling body and 2 is an upper turning body. In the illustrated example, the lower traveling body 1 is configured with left and right crawler belts, but there are not only crawler belt-type traveling bodies but also wheel-type traveling bodies.
[0004]
The upper turning body 2 can turn with respect to the lower traveling body 1, and has a frame 3 as a structure as shown in FIG. 9, and the frame 3 performs operations such as excavation of earth and sand. A work room 4 and a driver's cab 5 on which an operator is boarded are installed on one end side. The work machine 4 includes a boom 6 that is connected to the frame 3 so as to be capable of raising and lowering, an arm 7 that is connected to the tip of the boom 6 so as to be rotatable in the vertical direction, and a bucket 8 that is rotatably connected to the tip of the arm 7. It consists of. In addition, it can replace with the bucket 8 and can attach another attachment to the front-end | tip of the arm 7. FIG.
[0005]
When excavating earth and sand with the working machine 4 having the bucket 8, the bucket 8 operates so as to cut into the ground at the front position of the vehicle. A counterweight 9 is provided at the rear position of the frame 3 in order to balance so that the side does not float up. The counterweight 9 is detachably installed on the frame 3. The counterweight 9 is installed in the beams 3a and 3a projecting to the rear side shown in FIG. 9 in the frame 3, and are bolted to these two beams 3a. .
[0006]
Here, as the counterweight 9, for example, the one disclosed in JP-A-8-284210 has been widely used. The structure of this known counterweight 9 is shown in FIGS.
[0007]
The counterweight 9 is composed of a hollow container 10 filled with a heavy object (not shown). This heavy article is composed of, for example, a block metal or the like mixed in cement. The weight can be adjusted by the mixing ratio of the metal or the like and the cement, and the whole can be made into one lump by the action of the cement, and can be filled so that there is substantially no gap inside the container 10. Therefore, the container 10 constituting the counterweight 9 is a sealed container having a predetermined shape.
[0008]
That is, the container 10 is comprised from the lower surface board 11, the upper surface board 12, the front surface board 13, and the rear surface board 14, as shown in FIG.10 and FIG.11. The rear plate 14 is bent in a generally arc shape or a shape close to a trapezoid, and the lower plate 11, the upper plate 12, the front plate 13, and the rear plate 14 are connected and fixed to each other by means such as welding. Yes. Here, the above-mentioned heavy load is filled from the upper side, and therefore the upper surface plate 12 is usually divided into a plurality of plates and welded after filling the heavy load. . The bottom plate 11 is formed with two beam placement portions 11 a that are placed on the beam 3 a in the frame 3. The beam mounting portion 11a is a concave portion having a predetermined depth, and the width dimension of the concave portion substantially coincides with the width dimension of the beam 3a, and the depth substantially coincides with the height dimension of the beam 3a. . Further, the front plate 13 is provided with a notch 13a that matches the shape of the beam mounting portion 11a, and the rear plate 14 is not formed with such a notch. As a result, when viewed from the rear side of the vehicle, the frame 3 in the upper swing body 2 is covered with the rear plate 14 of the counterweight 9.
[0009]
As shown in FIG. 12, the counterweight 9 having the above configuration is installed so that the beam placing portion 11a of the lower surface plate 11 of the container 10 is engaged with the beam 3a of the frame 3, and the bolt 15 It is fixed using. Two bolts 15 are provided for each beam 3a. Here, the beam 3a is composed of upper and lower plate bodies 16a and 16b and a cylinder body 16c laid between the both plate bodies 16a and 16b, and in the mounting portion of the cylinder body 16c on the plate bodies 16a and 16b. Through holes 17a and 17b are formed. Here, the inner diameter of the cylindrical body 16c and the opening diameters of the through holes 17a and 17b substantially coincide with each other and are slightly larger than the outer diameter of the shaft portion of the bolt 15.
[0010]
The bolt 15 is screwed into a female screw member 18 mounted inside the container 10 constituting the counterweight 9. The female screw member 18 is made of a metal block having a predetermined size, and is fixed to the inner surface side of the beam mounting portion 11a of the lower surface plate 11 by welding means. The female screw member 18 is provided with a screw hole 18a for screwing the bolt 15, and a through hole 11b for screw insertion is formed at a position corresponding to the screw hole 18a of the lower surface plate 11. .
[0011]
Therefore, the counterweight 9 is mounted such that the beam placement portion 11 a of the lower surface plate 11 of the container 10 straddles the beam 3 a in the frame 3. Then, the bolt 15 is inserted into the screw hole 18a of the female screw member 18 through the through hole 17a of the plate body 16a constituting the beam 3a, the cylindrical body 16c, the through hole 17b of the plate body 16b, and the screw hole 18a of the lower surface plate 11 sequentially. By screwing, the counterweight 9 is fixedly connected to the beam 3 a of the frame 3.
[0012]
Here, the operation of installing or removing the counterweight 9 on the frame 3 is performed by suspending it with a crane. Therefore, the top plate 12 constituting the counterweight 9 has, for example, two through holes 12a, and a female screw member for detachably attaching hooks for engaging the crane to these through holes. 19 is fixedly provided by welding means.
[0013]
Thus, as described above, the counterweight 9 is composed of a container 10 filled with a heavy object, and this heavy object is generally composed of metal and cement. . Then, since cement is poured into a fluidized state, the cement poured in this way must be prevented from leaking outside. For this reason, at the time of filling a heavy object, at least a part of the upper surface plate 12 is opened, but the joint between the lower surface plate 11, the front surface plate 13, and the rear surface plate 14 is completely adhered by welding, and no gap is generated. Assembled. At least the lower surface plate 11 is provided with a female screw member 18. If cement or the like enters the screw hole 18a of the female screw member 18, the bolt 15 cannot be screwed. Therefore, the female screw member 18 is fixed to the lower surface plate 11 by welding means or the like so that no gap is generated therebetween.
[0014]
[Problems to be solved by the invention]
In order to prevent foreign matters such as cement from entering the screw hole 18a, the female screw member 18 must be formed with a bag-like screw hole, that is, an incomplete screw portion. Accordingly, the female screw member 18 is required to have a size larger than the required length dimension of the screw hole 18a into which the bolt 15 is screwed. That is, as shown in FIG. 12, when the dimension in the height direction of the female screw member 18 is L, the length of the screw hole 18 a into which the bolt 15 is screwed is set at a middle position from the lower surface side of the female screw member 18. it is the dimension L _1. 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, the length of L ₂ shown in the figure is not particularly involved in the original function as the female screw member.
[0015]
From the above, the female screw member has to use a member that is considerably larger than the required dimension in order to have its original function, and the waste of material becomes extremely large. In addition, since an incomplete screw is formed, it is troublesome to remove the chips after the thread groove processing, and considerable effort is required to completely remove the chips. There are also problems.
[0016]
The present invention has been made in view of the above points, and an object of the present invention is to reduce the size of a female screw member provided for fixing to a frame with a bolt, thereby saving the material. An object of the present invention is to provide a counterweight that can reliably prevent cement and the like from entering a screw hole, and that has a simple structure and can be manufactured at low cost.
[0017]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention is a counterweight in which a hollow container is filled with a heavy object, and a lower surface portion can be fixed to a vehicle body frame with a bolt, A female screw member having a threaded hole therethrough is fixedly provided on the lower surface portion , and a through hole for allowing the bolt to pass through is provided in the lower surface portion at least at a position where the screw hole is provided. The screw hole is provided at the end opposite to the opening side of the screw hole to the through hole, and the seal member is provided between the plug member and the periphery of the screw hole. It is a feature.
[0018]
Here, the plug member constitutes a closing means for closing the threaded hole penetrating the plug member, and it is conceivable that the elastic plate is fixed in a state of being elastically deformed or fixed by a welding means. , since it is intended to close the screw hole constitutes the closure means by a plug member screwed into the screw hole, and configured to provide a seal member between the periphery of the screw member and the screw hole.
[0019]
The container may be provided with another female screw member in addition to the above-described fixing portion to the vehicle body frame. For example, in order to attach and detach the counterweight, the counterweight is suspended from a crane. A hook engaging member that engages with a hook in the crane may be attached to the upper surface portion. This hook engaging member is mounted so as to be screwed into the upper portion of the counterweight. Therefore, for this purpose, the female screw member is mounted on the upper surface portion. The female screw member is also provided with a threaded hole that forms a complete screw similar to that described above, and the end of this screw hole is closed by a closing means. It can be configured to be occluded.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or equivalent members as those of the above-described conventional technology will be described using the same reference numerals, and detailed description thereof will be omitted.
[0021]
First, in FIG. 1, reference numeral 20 denotes a female screw member, and this female screw member 20 is fixed to the beam mounting portion 11 a of the lower surface plate 11 constituting the container 10 of the counterweight 9 by welding means. This is for fixedly connecting the weight 9 to the frame 3. Here, the female screw member 20 is provided inside the container 10 in the lower surface plate 11, and a screw hole 20 a facing the through hole 11 b formed in the lower surface plate 11 is provided.
[0022]
Thus, unlike the prior art, the screw hole 20a is provided so as to penetrate the female screw member 20. That is, both ends of the female screw member 20 are open, one end side thereof communicates with the through hole 11 b of the lower surface plate 11, and the other end opens toward the inside of the container 10. However, if welding is performed on the lower surface plate 11 in this state and a heavy object is filled, a fluid such as cement that is a component of the heavy object enters the screw hole 20a.
[0023]
Therefore, in order to close the opening portion of the screw hole 20a to the inside of the container 10, as shown in FIGS. 2 and 3, a large-diameter concave portion is formed at the end of the female screw member 20 on the side opened to the inside of the container 10. 20b is formed. And it is set as the structure which mounts the closure means in this recessed part 20b . As a reference example of the closing means, for example, the elastic plate 21 can be used. That is, the elastic plate 21 is formed of a thin disc having spring properties, and has a concave curved surface shape with a central portion protruding in one direction, and an outer diameter thereof is that of the concave portion 20b of the female screw member 20. It is slightly larger than the inner diameter. Accordingly, the elastic plate 21 is mounted so as to be brought into close contact with the inner peripheral wall of the recess 20b in an elastically deformed state, and bulges from the end face of the female screw member 20.
[0024]
Accordingly, when the elastic plate 21 is mounted, the outer peripheral surface of the elastic plate 21 is urged so as to be in pressure contact with the inner peripheral wall of the recess 20b. As a result, the elastic plate 21 is stably fitted in the recess 20b. The screw hole 20a is sealed in a sealed 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 performance is further improved. For this reason, not only fluid such as cement but also moist air containing cement or the like is prevented from entering, and adhesion of foreign matter in the screw hole 20a can be completely prevented.
[0025]
As described above, the female screw member 20 has a thickness (height) dimension substantially corresponding to the depth of the concave portion 20b in addition to the screwing length of the bolt 15, and the depth of the concave portion 20b is elastic. It may be shallow enough to hold the plate 21. Therefore, the thickness dimension of the female screw member 20 can be remarkably shortened. Specifically, as compared with the above-described conventional female screw member, it is possible to shorten the length corresponding to the dimension L ₂ . As a result, the material of the female screw member 20 can be minimized, and the material can be saved. Further, since the screw hole 20a provided in the female screw member 20 is a complete screw portion that penetrates the female screw member 20, it is possible to easily eliminate chips generated when processing to form a screw. Also, the workability of the screw is improved.
[0026]
As other reference examples of the closing means, as shown in FIGS. 4 and 5, an outer diameter sufficiently larger than the diameter of the screw hole 30a is provided at the end of the female screw member 30 provided with the screw hole 30a. It is using the obstruction | occlusion disc 31 as an obstruction | occlusion means to have. The closing disc 31 is fixed to the end face of the female screw member 30 by welding means, whereby the end portion of the screw hole 30a constituted by the complete screw portion is sealed.
[0027]
Accordingly, as the embodiment of the closure means, as shown in FIG. 6, which was composed of the plug member 41 as closure means screwing so the end portion of the female screw member 40 provided with a screw hole 40a There is . Since the plug member 41 only needs to close the end portion of the screw hole 40a and be held so as not to drop out of the screw hole 40a, the length of the screwed portion to the screw hole 40a is very small. good. The outer diameter of the head of the plug member 41 is made sufficiently larger than the diameter of the screw hole 40a, and the seal member 42 is interposed between the head and the end surface of the female screw member 40, whereby the screw hole 40a. The hermeticity is further improved.
[0028]
By constructing as described above , the complete thread portion makes it easy to eliminate chips generated during processing to form the screw, improves the workability of the screw hole, and the dimensions of the female screw member. Shortening is achieved.
[0029]
By the way, as described above, the counterweight 9 is provided with the female screw member for fixing to the frame 3 with the bolts 15, but the counterweight 9 is further lifted on the upper surface portion of the container 10 by the crane and attached to the frame 3. In some cases, a hook engaging member 50 that engages with a hook of a crane is detachably attached as shown in FIG. The hook engaging member may be provided integrally with the container 10 and cannot be attached / detached. However, the hook engaging member 50 is attached only when the counterweight 9 is attached / detached. It is preferable in terms of appearance that the plug 51 provided with the seal member 51a is mounted.
[0030]
For this purpose, a through hole 12a is formed in the upper surface 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 so that the surface thereof substantially coincides with the surface of the upper surface plate 12, and protrudes toward the inside of the container 10. The female screw member 52 can have substantially the same configuration as the female screw member 20 in any of the first to third embodiments described above, for example, the first embodiment. That is, the female screw member 52 is provided with a screw hole 52a that constitutes a complete screw portion that penetrates the female screw member 52, and a concave portion 52b is provided on an end surface located on the inner side of the container 10, and the concave portion 52b has a spring property. A thin closing disc-like elastic plate 53 is provided to be engaged.
[0031]
In this way, the female screw member 52 to which the hook engaging member 50 is detachably attached also forms the screw hole 52a which is a complete screw portion, whereby the female screw member 52 can be reduced in size and cut after the screw is processed. Powder removal work becomes easy. Moreover, although the screw hole 52a is provided so as to penetrate therethrough, the end portion is closed by the closing means including the elastic plate 53 and the like, so that rainwater and the like can be prevented from entering the inside of the container 10. As a result, it is possible to prevent the inner surface of the container 10 from being deteriorated due to rust or the like.
[0032]
【The invention's effect】
Since the counterweight of the present invention is configured as described above, it is possible to reduce the size of the female screw member provided for fixing to the frame with bolts, and to save the material, and cement or the like enters the screw hole. It is possible to surely prevent this, and the effect is that the structure is simple and can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a sectional view of a counterweight showing an example of means for closing a screw hole when a screw hole penetrating a female screw member is used.
2 is a cross-sectional view of a female screw member in the counterweight of FIG. 1. FIG.
FIG. 3 is a right side view of FIG. 2;
FIG. 4 is a cross-sectional view of a female screw member provided with another example of a means for closing a threaded hole that passes therethrough .
FIG. 5 is a right side view of FIG. 4;
6 is a cross-sectional view of a female screw member in counterweight showing the form of implementation of the present invention.
FIG. 7 is a cross-sectional view of a state where a female thread member for mounting a hook engaging member as a female thread member in the counterweight according to the present invention is mounted.
FIG. 8 is a front view of a hydraulic excavator as an example of a construction machine to which a counterweight is attached.
FIG. 9 is an external view of a frame to which a counterweight is attached.
FIG. 10 is a front view showing a container constituting a counterweight according to the prior art with a part broken away.
11 is a sectional view taken along line XX in FIG.
12 is a cross-sectional view of a female screw member provided on the counterweight of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper revolving body 3 Frame 3a Beam 9 Counterweight 10 Container 11 Lower surface plate 11a Beam mounting part 11b Through hole 12 Upper surface plate 12a Through hole 13 Front surface plate 14 Rear surface plate 15 Bolt 20, 30, 40, 52 Female screw Member 20a, 30a, 40a, 52a Screw hole 20b, 52b Recess

Claims (1)

In the counterweight, which is filled with heavy objects in a hollow container, and the lower surface part can be fixed to the body frame with bolts,
Inside the container, a female screw member having a threaded hole therethrough is provided fixed to the lower surface portion ,
And in this lower surface part , a through hole for allowing the bolt to pass through is provided at least at a position where a screw hole is provided,
Furthermore, a plug member is screwed into the end opposite to the opening side to the through hole of the screw hole ,
A counterweight , wherein a sealing member is provided between the stopper member and the periphery of the screw hole .

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