JP6186571B2 - Counterweight manufacturing method - Google Patents

Description

  The present invention relates to a counterweight mounted on a work machine such as a hydraulic excavator, a forklift or a handling machine, and more particularly to a counterweight in which a hollow box structure is filled with concrete and a method for manufacturing the same.

  In a work machine such as a hydraulic excavator, a heavy weight counterweight is mounted on the rear side of the vehicle body in order to obtain a weight balance that opposes the work load acting on the work front. Conventionally, this type of counterweight was made of cast metal such as iron because of its high specific gravity and strength, but it is expensive in terms of production cost, such as requiring large-scale production equipment such as a melting furnace. It was. For this reason, the outer weight of the counterweight is made into a hollow box structure to give the whole strength, and the specific gravity as designed by injecting and solidifying concrete containing iron ingots and iron sand as a weight material into the box structure. Currently, many counterweights are used (see, for example, Patent Documents 1 to 4).

  In such concrete-filled counterweights, recycled materials containing a metal component with a large specific gravity can be used as a heavy material mixed with cement, in addition to natural resources such as iron ore and iron sand. For example, small granular scrap materials such as punch scraps, molten metal that has been incinerated as a waste after being melted with high heat and then precipitated using the difference in specific gravity is mixed with cement. In particular, molten metal separated from waste can be supplied inexpensively and stably, and by reusing these as heavyweights for the counterweight, the environmental load is reduced and the resource economy is met.

  A conventional stuffing type counterweight is generally manufactured as follows. First, the outer box structure is processed into a finished product shape on a work machine and finished. After mixing and adjusting the cement and water and a heavy weight material (a relatively high specific gravity aggregate composed mainly of metal) so that it has a specific gravity, the flowing concrete mixed with these is mixed in the box structure while applying vibration. Inject. Thereafter, the concrete is cured and solidified for a predetermined period, thereby completing a counterweight having a predetermined weight.

  JP-A-52-137858   JP-A-53-106172   JP-A-55-128409   JP 2003-41628 A

  It is desirable to use molten metal, which is a waste recycling material, as a concrete weight material for counterweights, leading to a reduction in manufacturing costs. However, it is technically difficult to efficiently divide the molten metal into small lumps, and it is also difficult economically because such work takes time and effort.

  Moreover, in order to set the weight of the weight to the designed predetermined weight, it is necessary to adjust the mixing ratio of the concrete at a ratio corresponding to the specific gravity of the weight material to be mixed. However, when the heavy material used is derived from waste such as molten metal, the specific gravity is not necessarily constant depending on the composition of the metal contained therein. For this reason, the specific gravity of the supplied metal had to be measured one by one, and then the concrete had to be mixed with a composition calculated based on the specific gravity. In particular, when scraps such as iron scrap are mixed, the blending must be determined in consideration of factors such as the market price and supply amount of scrap, which further increases the complexity of such adjustment work. .

  Further, in the conventional counterweight manufacturing method, vibration is applied when concrete is poured into the box structure, so that air is degassed from the aggregate to ensure the specific gravity. However, when such vibration is applied, the aggregate is locally unevenly distributed in the box structure, which may cause variation in the position of the center of gravity of the counterweight. For this reason, it has been difficult to meet the demand for adjusting the position of the center of gravity of the counterweight according to the structure and design of the machine to be mounted.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a counterweight whose cost is reduced by using molten metal, which is a recycled material, as a weight material. Another object of the present invention is to provide a counterweight manufacturing method capable of simplifying the specific gravity adjustment process and reducing the manufacturing cost.

  In order to solve the above-described problems, the present invention is a counterweight used for balancing the weight of a work machine, in which concrete is filled in a hollow box structure, and a metal ingot is formed on a part of the concrete. It is characterized by including.

  The counterweight is preferably a metal casting in which the volume and weight are adjusted in advance by casting the molten metal, which is a precipitate after melting the waste at a high temperature. . For example, the metal ingot is cast with a high-temperature molten metal separated from waste in a sand mold and having a fixed shape. The metal ingot may be obtained by crushing or subdividing a metal lump obtained by solidifying molten metal into a predetermined size with a breaker or the like.

  Further, the metal ingot may be a concrete molded body in which cement is mixed and solidified by molten metal which is a precipitate after melting waste at a high temperature. Furthermore, the concrete aggregate may contain metal particles obtained by quenching molten metal. Furthermore, the concrete molded body may contain a metal by-product containing iron oxide as a main component generated in a steel making process such as rolling, called a mill scale or a hot scarf, as an aggregate.

  Further, the present invention is a method for producing a counterweight used for balancing the weight of a work machine, the step of obtaining a metal ingot by cooling and solidifying molten metal obtained by melting and precipitating waste at a high temperature; A step of placing one or a plurality of the metal ingots in a hollow box structure that forms the exterior of the counterweight, and a flow of mixing cement, heavy material, and water in the box structure in which the metal ingots are placed And a step of curing and solidifying the flowing concrete injected into the box structure.

  In the counterweight manufacturing method, it is preferable that the step of obtaining the metal ingot includes a step of casting a high-temperature molten metal separated from waste with a sand mold and having a certain regularity. Alternatively, the step of obtaining the metal ingot may include a step of crushing a plate-shaped metal lump with a breaker or the like.

  In another aspect of the method for producing the counterweight, a step of obtaining a metal ingot whose weight and volume are adjusted in advance by cooling and solidifying molten metal obtained by melting and precipitating waste at a high temperature; Injecting a flow of concrete mixed with cement, heavy material and water into a hollow box structure forming the outer shell, and then placing one or more metal ingots in the box structure; Curing and solidifying the fluid concrete poured into the box structure.

  The counterweight manufacturing method may further include a step of reinjecting the concrete into the box structure after the metal ingot is installed at a predetermined position in the middle of the box structure. .

  The counterweight manufacturing method may further include a step of applying vibration when the fluid concrete is poured into the box structure.

  According to the counterweight of the present invention and the manufacturing method thereof, the recycled material can be used as the weight material to be filled in the box structure forming the exterior of the counterweight, and the specific gravity adjustment process is simplified to reduce the manufacturing cost. Can be reduced.

FIG. 1 is a side view showing a hydraulic excavator as an example of a work machine on which a counterweight is mounted. FIG. 2 is a perspective view showing a state in which a metal ingot is installed in the counterweight box structure. Drawing 3 is a figure showing the example of the metal casting which is a metal ingot.

  As a preferred embodiment of the counterweight according to the present invention, a counterweight 10 mounted on a rear portion of a main body of a hydraulic excavator will be described.

  FIG. 1 is a side view showing a hydraulic excavator 1 that is an example of a work machine on which a counterweight 10 is mounted. The excavator 1 includes an upper swing body 2 and a lower traveling body 3 which are main bodies, and the upper swing body 2 is installed on the lower traveling body 3 via a swing device 4. In addition, although the crawler type lower traveling body 3 is shown in FIG. 1, it may be a wheel type lower traveling body having a tire.

  The upper swing body 2 is provided with a cabinet 7 as a cab and a work front 5 for performing work such as excavation. The work front 5 includes a boom 5a attached to the upper swing body 2 by a boom cylinder 6a so as to be raised and lowered, an arm 5b rotatably attached to an end of the boom 5a by an arm cylinder 6b, and an end of the arm 5b. It has an articulated link structure having a bucket 5c rotatably attached by a bucket cylinder 6c.

  In the main body of the upper swing body 2, a hydraulic pump that supplies high-pressure oil to various actuators such as the above-described working system cylinder and traveling system motor, a control valve that controls the hydraulic system, and an engine that is a power source that drives the hydraulic pump Power unit including etc. is installed.

  In order to obtain a weight balance against the work load acting on the work front 5, a heavy weight counterweight 10 is mounted on the main body of the upper swing body 2. The counterweight 10 has a structure in which heavy concrete is filled in a hollow box structure 11 made of iron. The box structure 11 forming the exterior of the counterweight 10 is processed into a shape with a design so as to constitute a part of the rear side of the excavator 1 in appearance.

  The counterweight 10 according to the present embodiment includes a metal casting 21 whose weight and volume are adjusted in advance, which is an aspect of the metal ingot 20, in a part of the heavy concrete filled in the box structure 11. . FIG. 2 is a perspective view showing a state in which the metal casting 21 is installed on the box structure 11 of the counterweight 10. In order to understand the invention, in FIG. 2, the illustration of the heavy concrete (heavy material other than the metal ingot) in the box structure 11 to be filled in the finished counterweight is omitted.

  The metal casting 21 is a small piece of metal obtained by, for example, casting a molten metal precipitated by using a difference in specific gravity after melting incineration ash of waste with high heat. In particular, molten metal separated from waste can be obtained inexpensively and stably, and reusing them for the counterweight 10 not only contributes to cost reduction but also may be effective in effective use of resources. It is.

  Moreover, it is preferable that the metal casting 21 is cast with a certain shape by injecting a high-temperature molten metal separated from the waste into a sand mold and solidifying it. According to this, it is possible to easily obtain a metal casting 21 having an arbitrary shape and volume suitable for the specification of the counterweight to be manufactured. In addition, such a casting operation can be performed on the site near the incinerator of the waste disposal site, and there is an advantage that a process of heating and melting the slag once cooled is not necessary.

  The metal ingot 20 may be obtained by crushing or subdividing a metal lump obtained by accumulating high-temperature molten metal separated from waste and solidifying into a plate shape into a predetermined size using a breaker or the like. A large mass of molten metal having a relatively high specific gravity can be easily obtained simply by pouring molten metal (metal) into a ground dug shallow in a place near the incinerator and cooling it naturally. Thereby, the acceptance cost of the metal ingot 20 as a recycled material can be further reduced.

  Moreover, the other aspect of the metal ingot 20 may be a concrete molded body in which a molten metal, which is a precipitate after melting waste at a high temperature, is used as an aggregate and cement is mixed and solidified. The weight material of the concrete molding may include metal particles obtained by quenching molten metal separated from waste. Moreover, you may use the metal by-product which has as a main component the iron oxide produced in the steelmaking processes, such as rolling called a mill scale or a hot scarf, as a heavy material.

  The concrete molded body is manufactured as follows, for example. First, as a metal component (weight material) to be contained in a concrete molded body, a molten metal mass or metal particle separated from waste is prepared, and its specific gravity is measured. The target specific gravity is determined based on the volume and weight of the molded body to be manufactured, and the weight mixing ratio of the cement and the metal component is determined based on the measured specific gravity of the metal component and the known specific gravity of cement and water.

  After weighing the metal component and cement as materials, they are mixed with water at the determined blending ratio. The flow concrete obtained in this way is poured into a formwork assembled with a wooden board, etc., and cured and solidified for a predetermined period of time. Is done.

  The counterweight 10 according to the present embodiment having such a configuration is manufactured as follows.

  First, the metal ingot 20 is prepared by cooling and solidifying molten metal obtained by melting and precipitating waste at a high temperature. The metal ingot 20 is, for example, a metal casting 21 or a concrete molded body whose weight and volume are adjusted in advance. As described above, the metal casting 21 is cast with a constant size and shape by injecting and solidifying a high-temperature molten metal (molten metal) separated from waste into a sand mold. Moreover, a concrete molding is shape | molded by a cement and water into a predetermined dimension shape by making a molten metal into an aggregate. The metal ingot 20 used for manufacturing the counterweight 10 is preferably a metal casting 20 in terms of cost and ease of manufacturing, but instead, a plate-like molten metal lump is made to a predetermined size. What was obtained by crushing or subdividing may be sufficient, and the concrete molding mentioned above may be sufficient.

  Subsequently, one or more metal ingots 20 are placed on the bottom surface in the hollow box structure 11 that forms the exterior of the counterweight 10. At this time, when the design center of gravity position of the counterweight 10 is slightly deviated left and right with respect to the center, for example, the entire center of gravity may be adjusted by shifting the installation position of the metal casting 21 accordingly. Further, when the position of the center of gravity of the counterweight 10 is further rearward or higher, the center of gravity of the counterweight 10 is easily adjusted to the designed position by appropriately adjusting the position where the metal ingot 20 is placed. be able to.

  Then, the flow concrete which mixed the weight material and water and adjusted specific gravity is inject | poured in the box structure 11 in which the metal ingot 20 was set | placed. The concrete poured into the box structure 11 may include a mass of molten metal separated from waste similar to the metal ingot 20 or a granular material thereof as a weight material. Moreover, you may mix iron scrap materials, gravel, etc., such as punch scraps, into the flowable concrete inject | poured in the box structure 11. FIG. Furthermore, a metal by-product containing iron oxide as a main component, which is called a mill scale or a hot scarf and produced in a steelmaking process such as rolling, may be mixed into the concrete as a weight material.

  When pouring concrete into the box structure 11, vibration is applied. Thereby, the packing density of the heavy concrete after solidification can be raised by defoaming the bubble mixed with the lump of molten metal and the granular material from the concrete and leveling the surface. Finally, the counterweight 10 is manufactured by curing and solidifying the flowing concrete injected into the box structure 11.

  As another method for manufacturing the counterweight 10, a flowing concrete mixed with cement, a heavy material and water is poured into the box structure 11, and then a metal ingot 20 is placed in the box structure 11. One or a plurality may be placed. Moreover, after the metal ingot 20 is installed at a predetermined position in the middle of the box structure 11, a step of reinjecting the concrete may be included.

FIG. 3 is a view showing an example of a metal casting 21 that is a metal ingot manufactured in an experiment. The prototype metal casting 21 has a rectangular parallelepiped shape, and the dimensions of each side are 585 mm in length, 150 mm in width, and 370 mm in height (volume 3.25 × 10 ⁻² m ³ ). Since the weight of the metal casting per piece was 217 kg, a specific gravity of 6.7 was obtained. Here, the specific gravity refers to a ratio with respect to a reference density of 1 ton / m ³ .

  The counterweight of the embodiment is for mounting a 120-ton class hydraulic excavator. The prototype counterweight had a total weight of 15.6 tons filled with concrete.

  The embodiments described above are merely examples for explaining the invention, and these aspects are not to be construed as limiting the scope of the invention. The counterweight according to the present invention may be mounted on a forklift, a handling machine, or other work machine in addition to a hydraulic excavator, and is widely used not only in a vehicle system machine but also in a crane or other industrial machine.

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 2 Upper turning body 3 Lower traveling body 4 Turning apparatus 5a Boom 5b Arm 5c Bucket 6a Boom cylinder 6b Arm cylinder 6c Bucket cylinder 7 Cabinet (operating room)
10 Counterweight 11 Box structure 20 Metal ingot 21 Metal casting (an example of a metal ingot)

Claims (1)

A counterweight manufacturing method used for balancing the weight of a work machine,
A step of obtaining a metal ingot by cooling and solidifying molten metal obtained by melting and precipitating waste at a high temperature;
Placing one or more of the metal ingots in a hollow box structure forming the exterior of the counterweight;
Injecting a flowing concrete mixed with cement, heavy material and water into the box structure in which the metal ingot is placed;
Curing and solidifying the flowing concrete poured into the box structure.

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