JP3554837B2 - Reusing method of rejected slab material, holding member and balancer by the method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for reusing a rejected slab material in which a rejected slab material whose component is not guaranteed is reused in a slab material manufactured in the middle of a manufacturing process of a rolled steel material manufactured by a continuous casting method, an ingot method, or the like. And a holding member and a balancer according to the method.
[0002]
[Prior art]
Conventionally, in an industrial machine, a balancer is installed to prevent occurrence of imbalance due to rotation or movement of a structure inside the machine during operation, and in a work vehicle, a heavy machine is lifted by a work machine, In order to balance and stably work when moving, a counterweight for mounting a steel material is often mounted inside the machine body opposite to the working machine. Members such as the counterweight and the balancer (hereinafter collectively referred to as a balancer) are generally manufactured by processing from a rolled steel material or from a cast product.
[0003]
[Problems to be solved by the invention]
However, the above conventional manufacturing method has the following problems.
(1) The material of a balancer for an industrial machine or a work vehicle and a holding member for holding the balancer does not require mechanical strength or durability, and the density of the material is within a substantially constant range. If the difference between the calculated weight value calculated from the external weight and the calculated weight value is small, it can be used. However, rolled steel materials sold on the market can be used as mechanical structural members requiring mechanical strength and durability in terms of the structure and performance of the machine. Therefore, when a rolled steel material is used as the material of the balancer and its holding member, a material of excessive quality is used, and there is a problem that the material cost is high and the manufacturing cost is high. In addition, when purchasing a rolled steel material having a thickness suitable for a desired purpose or specifications, an order is usually made by order production. It is necessary to purchase more than a few, and therefore, there is a problem that wasteful stock increases each time a design change is made, or a delivery time is long, and it is very difficult to respond to the design change.
(2) Further, the method of processing the counterweight, balancer, or its holding member from a cast product has a problem that the cost of a mold for casting is high, so that the manufacturing cost is high and the production delivery time is long. In addition, when changing the design, it is necessary to change the thickness and shape of the material, which requires a redesign of the mold, which increases production costs and delivery time. There is also the problem of chipping.
[0004]
The present invention focuses on the problems of the prior art described above, and aims to make it possible to manufacture a balancer and its holding member at a low cost. Specifically, a rejected slab material produced in the middle of a manufacturing process of a rolled steel material It is an object of the present invention to provide a method of reusing the above, and a holding member and a balancer by the method.
[0005]
Means for Solving the Problems, Functions and Effects
Of the slabs manufactured in the middle of the manufacturing process of rolled steel manufactured by the continuous casting method, ingot making method, etc., of the rejected slabs whose components are not guaranteed by inspection of the composition, etc. Usually occurs at a rate of about 1 to 2%. Such some rejected slab materials are generally evaluated only as waste, and are often re-charged into a blast furnace and used again after re-melting. Alternatively, a part thereof may be sold as slab scrap at a price considerably lower than the price of the rolled steel material whose composition is guaranteed, for example, about 30 to 50% of the price of the rolled steel material.
The rejected slab material is a slab material manufactured in the middle of a rolled steel material manufacturing process, which has been determined to be a rejected product by component inspection, has passed the shape inspection, and has a specific gravity substantially equivalent to the passed product. However, since some of the components were out of the predetermined standard range in the composition component inspection, they were classified as rejected products. Therefore, this rejected slab material cannot be used as a mechanical structural member requiring mechanical strength and durability, but it is only necessary to have a predetermined weight and a weight holding function without requiring it. It can be used as a material for members.
In order to achieve the above object, the present invention is to reuse the rejected slab material as a material for construction machines and industrial machines, for example, counterweights, balancers and their holding members, and thereby, at low cost. It is possible to provide a counterweight, a balancer, and a holding member thereof that can be manufactured and can easily cope with a design change.
[0006]
In order to achieve the above object, the first invention is a slab material manufactured in the middle of a manufacturing process of a rolled steel material by a casting method such as a continuous casting method or an ingot-making method, and a composition component inspection of the slab material is determined to be out of a predetermined standard. This is a method of recycling the rejected slab material, in which the rejected slab material is cut into strips and then reused as a member that does not require mechanical strength.
[0007]
According to the first invention, after the rejected slab material is cut into strips having a predetermined thickness, it is reused as a member not requiring strength, for example, a counterweight, a balancer and a holding member for construction machines and industrial machines. . In order to cut the rejected slab material into strips, a gas cutting machine such as an eye tracer and an NC gas cutting device which are generally widely used can be used. The target member can be easily obtained by using the plate material cut in a strip shape as it is or by processing it into a desired size and shape by gas cutting or the like. Therefore, a member that does not require strength can be manufactured at a very low cost as compared with manufacturing a rolled steel material or a cast product by processing, and it is possible to easily cope with a design change without increasing costs. .
[0008]
An outline of a method of reusing the rejected slab material will be described.
First, the rejected slab material is cut in the width direction or the longitudinal direction of the rejected slab material by an eye tracer or a gas cutting machine such as an NC gas cutting device to produce a flat bar-shaped plate material. The number of torches used for this cutting is N1 (N1 ≧ 2), and the torch interval is set to the thickness of the flat bar plate to be manufactured. By this first cutting, (N1-1) flat bar-shaped plate members are manufactured. Next, in the second cutting, N2 (N2 ≧ 2) of the flat bar-shaped plate members are arranged on a cutting liner of a gas cutting machine, and N2 flat bar-shaped plate members are simultaneously cut by N2 torches. .
In this manner, (N1-1) flat bar-shaped plate members are manufactured by the first cutting, and then, N2 materials are simultaneously cut by the second cutting with the number n2 of torches, and the required member is cut. Is hereinafter referred to as a double cutting method.
[0009]
Generally, cutting a thick plate requires a long cutting time and a high manufacturing cost. However, two or more materials (flat bar-shaped plate materials) and members to be manufactured by one cut are manufactured, and the manufacturing time per member is reduced, and the purchase price of rejected slab materials as materials is reduced. Since it is very inexpensive, the manufacturing cost can be reduced as compared with a conventional method of processing a rolled steel material or a method of manufacturing from a cast product. Also, when it is necessary to change the thickness of the material for the design change of the member to be manufactured, when performing the first cutting of the rejected slab material, set the torch interval to the thickness of the member to be manufactured. It can be easily handled by cutting the rejected slab material in the width direction or the longitudinal direction.
[0010]
According to a second aspect of the present invention, there is provided a holding member that holds a heavy object by being attached to a structure such as a work vehicle or an industrial machine. This is a holding member in which a plate material obtained by cutting a material into a strip shape is processed into a desired size and shape.
[0011]
According to the second invention, the holding member that is attached to the structure and holds the heavy object is formed by cutting the rejected slab material into a strip shape using the reusing method of the rejected slab material into a desired size and shape. Process and produce. The holding member only needs to be a member that does not deform even when the counterweight or the balancer is held above the holding member, and does not particularly require strength. Therefore, the holding member can be manufactured at a very low cost by the method of reusing the rejected slab material, utilizing the low price and the shape and dimension stability, which are the characteristics of the rejected slab material.
[0012]
A third invention is a balancer to be attached to a structure such as a work vehicle or an industrial machine. In the process of using the method for reusing a rejected slab material according to claim 1, the rejected slab material is cut into strips. It is a balancer obtained by processing a plate material into a desired size and shape.
[0013]
According to the third aspect of the present invention, the balancer to be attached to the structure is manufactured by processing the plate material obtained by cutting the rejected slab material into strips into a desired size and shape using the method for reusing the rejected slab material. . A balancer installed for the purpose of balancing the weight of the body structure itself when the body structure moves or transports a heavy object does not require any special mechanical strength, and it is sufficient if the weight is heavy, so a value with a large specific gravity Material is suitable. Therefore, taking advantage of the low price, the shape and dimension stability, and the specific gravity stability (specific gravity is around 7.80) which are the characteristics of the rejected slab material, the balancer can be re-used by reusing the rejected slab material. Inexpensively.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment according to the present invention will be described below with reference to FIGS.
First, a basic procedure of a method for recycling a failed slab material according to the present invention will be described with reference to FIGS.
FIG. 1 is an explanatory view of an example of a manufacturing process of a standard rolled steel material and a process of generating a rejected slab material according to the present invention. Here, the manufacturing process number is indicated by adding S.
First, iron ore, limestone, coke, and the like are charged into a blast furnace to produce hot metal (S1). The molten iron is transferred to a converter by a mixed iron wheel, refined in the converter to form molten steel (S2). This molten steel is charged into a continuous casting facility (S3) to produce a slab material (S4). Alternatively, there is a case where slab material is manufactured (S4) after smelting molten steel refined in a converter in an upper and lower ingot casting ingot facility and passing through a soaking roll through a soaking furnace (S5). . The slab material is inspected for its components and shape, and is sorted into acceptable and rejected products. The slab material that passed the shape inspection and had a specific gravity of about 7.80, but was discriminated as a rejected product because a part of the components was out of the specified range in the composition component inspection, was regarded as a rejected slab material. (S6). The slab material that has passed this inspection process is heat-treated through the steps of rough rolling and finish rolling, and after further cutting the product, after being passed a material test, inspection of mechanical properties and appearance, etc., is shipped as a steel product. (S7).
[0015]
The rejected slab material is usually evaluated mostly as scrap and re-used in the blast furnace for re-melting and used, or a part is sold as slab scrap at 30 to 50% of the product price of rolled steel. I have. In the present invention, among such slab materials, the rejected slab material determined to be rejected by the component inspection is low in price, the shape and dimensions are stable, and the specific gravity is 7.80. Focusing on the fact that it is stable in the vicinity, it is reused for members that do not require strength in construction machines and industrial machines.
[0016]
FIG. 2 shows an example of the shape and dimensions of the rejected slab material. Here, the dimensions of the rejected slab material are plate thickness T1: 245 mm, length L: 1500 mm, width B: 1600 mm.
FIG. 3 shows an example of a member W (such as a counterweight) which does not require strength and which does not hinder the use of a rejected slab material. 75 mm, length L1: 1545 mm, width b: 225 mm.
[0017]
Next, as a first embodiment, a method of manufacturing the member W shown in FIG. 3 from the rejected slab material shown in FIG. 2 will be described with reference to FIGS.
In the first cutting shown in FIG. 4, a predetermined number (for example, three) of torches J1, J2, and J3 are used, and a plate thickness t1 (here, 75 mm) of a member W for manufacturing an interval D between the torches. Set to. The three torches J1, J2, J3 are cut in parallel in the direction of the arrow shown. By this stripping, two flat bar-shaped materials having a thickness t1 of 75 mm, a length L1 of 1600 mm, and a width b of 245 mm are simultaneously manufactured.
Here, the discarded material P shown in FIG. 4 is to be discarded after cutting, and the width of the discarded material has a predetermined width (here, 20 mm). Usually, the structure of the material in the waste material width portion (end face portion) may not be uniform, and this may cause deformation such as bending or twisting of the flat bar-like material including the waste material width portion after cutting and cutting. Sometimes. For this reason, the flat bar-shaped material used as the member W does not include the end face portion, thereby preventing the material from being deformed. In addition, it is necessary to allow for a kerf width serving as a cutting allowance of the torch. In general, in the case of an NC gas cutting machine, the kerf width may be about 2 mm.
In the embodiment of FIG. 4, the number of the stripping torches is three. However, as the number of the torches increases, the productivity of the flat bar-shaped material increases, and the manufacturing cost of the first cutting can be reduced. .
[0018]
Next, referring to FIG. 5, a second cutting for manufacturing a member W that does not require the strength of the construction machine and the industrial machine from the flat bar-shaped material Q will be described.
A predetermined number (here, for example, four) of flat bar-shaped materials Q produced by the first cutting are arranged on a cutting liner of a gas cutting machine. In the second cutting, the material is cut simultaneously with a predetermined number (here, four) capable of cutting the number of torches simultaneously. In FIG. 5, the movement trajectory of the torch is programmed in the NC controller, and the torch moves while cutting in a predetermined cutting direction (for example, the direction of an arrow in the figure) from the cutting start position K1 on, for example, a dashed line in the figure. I do. As a result, four rectangular members having a thickness t1 of 75 mm, a length L1 of 1545 mm, and a width b of 225 mm can be manufactured at the same time. In order to make the external dimensions of the member the same as those described above, it is natural to set the movement trajectory of the torch in consideration of the kerf width serving as the cutting allowance of the torch.
[0019]
Next, a second embodiment will be described with reference to FIG. In the present embodiment, a method of manufacturing a flat bar-shaped material using the rejected slab material shown in FIG. 2 and manufacturing two or more members, not limited to a rectangle, from the single material, will be described. .
Three flat bar-shaped materials produced by the first cutting are placed on a cutting liner of a gas cutting machine. In the second cutting, three materials are cut simultaneously with three torches. 6, the torch moves from the cutting start position K2 while cutting in a predetermined direction (for example, the direction of the arrow in the figure) from the cutting start position K2 according to the program of the NC controller. Here, two members are manufactured from one flat bar-shaped material. Therefore, for example, three rectangular members 1 and three deformed members 2 can be manufactured at the same time.
[0020]
The method for reusing a rejected slab material according to the present invention provides a method for manufacturing a member that does not require mechanical strength by twice cutting a rejected slab material using an NC gas cutting machine or the like. . Generally, the cutting of a thick plate takes a long cutting time and increases the manufacturing cost. As shown in the first and second embodiments of the present invention, the manufacturing time per member is reduced by manufacturing two or more members as a material and a product by one cutting, and Since the purchase price of the rejected slab material is low, the manufacturing cost can be reduced as compared with the conventional method of processing from a rolled steel material or the method of manufacturing from a cast product.
As described above, the recycle method of the rejected slab material by the double cutting method reduces the material yield of the manufactured member with respect to the initially purchased rejected slab material, and cuts the material twice. Although the production time is longer, there is a slight increase in the production cost. However, even if these increases are taken into account, the production cost is significantly larger than the conventional method of manufacturing from a rolled steel material or a cast product (for example, 15 to 15). A reduction of about 25%) can be expected.
[0021]
Next, as a third embodiment, a holding member for holding a heavy object attached to a structure will be described with reference to FIGS.
7 is a plan view of a main part of a counterweight of the construction machine, and FIG. 8 is a sectional view taken along line XX of FIG.
As shown in FIG. 8, a member 6 is fixed by welding or the like between a lower portion of the outer frame 4 of the vehicle body structure 3 and a lower plate 5 forming a part of the bottom of the vehicle body structure 3. A member 7 is disposed on the upper portion of the member 6 and is fastened from the lower surface of the member 6 by a bolt 8 or the like.
[0022]
The member 6 holds the member 7 (here, a counterweight) on its upper surface, and may be made of any material that does not deform even when the member 7 is held, and does not particularly require strength. When a steel plate for a mechanical structure is used for the outer frame 4 and the lower plate 5 of the vehicle body structure 3, the member 6 is fixed to the outer frame 4 and the lower plate 5 by welding or the like to form an integral structure. Is done. Alternatively, when a reinforced plastic plate is used for the outer frame 4, the member 6 is provided with holes for taps and bolts 8 for fastening the reinforced plastic plate.
In the third embodiment of the present invention, the member 6 for holding the member 7 is manufactured by a method for reusing a rejected slab material, and this member is referred to as a holding member H.
[0023]
FIG. 9 shows the shape and dimensions of the holding member H fixed to the P portion. As the holding member H, first, a flat bar-shaped material having a plate thickness t1 of 180 mm, a length L1 of 1600 mm, and a width b of 245 mm (not shown) is manufactured by the first cutting of the method for reusing a failed slab material. . Next, the holding member H having the shape and dimensions shown in FIG. 9 is manufactured by the second cutting.
In this way, the holding member H is manufactured by utilizing the low cost and the shape and dimension stability, which are characteristics of the rejected slab material. Since the specific gravity of the holding member H manufactured by the method of reusing the rejected slab material is near 7.80, the weight of the holding member H can be calculated by the outer dimensions and the specific gravity. The difference between the calculated value and the actual weight is small and can be used as a part of the necessary balance material of the vehicle body structure itself. Moreover, the rejected slab material is a material that can easily be tapped and the holes for the bolts 8 can be easily formed, so that the outer frame 4 of the vehicle body structure 3 and the steel plate for the mechanical structure of the lower plate 5 can be easily fixed by welding. Can be. Thus, the manufacturing cost can be reduced, and the rejected slab material can be used effectively.
[0024]
Next, a fourth embodiment will be described. This embodiment is an example in which the member 7 disposed on the upper surface of the member 6 is manufactured by a method of reusing a rejected slab material. This member 7 is used when the vehicle body structure moves or transports a heavy object. The balancer G balances the weight of the vehicle body structure itself. For this reason, the member 7 does not need any particular mechanical strength, and it suffices to have a heavy weight, so that a material having a large specific gravity is suitable.
[0025]
FIG. 10 is a detailed view of a portion P in FIG. 7 and is a plan view showing five balancers G disposed on the upper surface of the holding member H. FIG. 11 shows a cut shape and dimensions of the balancer G of FIG. As shown in these figures, the balancer G was manufactured by a flat bar having a thickness t1 of 200 mm, a length L1 of 1600 mm, and a width b of 245 mm by the first cutting of the method for reusing a failed slab material. Produce the material. Next, by the second cutting, the balancers G having the indicated dimensions, each having a rectangular shape or a trapezoidal shape shown in FIG. 11, are manufactured. At this time, the two balancers G of the vehicle body structure 3 are cut from one flat bar-shaped material. In addition, at the time of the second cutting shown in FIG. 11, it is natural that the position of the torch is set in consideration of a kerf width of about 2 mm serving as a cutting allowance of the torch.
[0026]
The balancer G manufactured in this way makes use of the characteristics of the rejected slab material, such as low cost, stable shape and dimensions, and specific gravity of about 7.80.
Therefore, the manufacturing cost of the balancer G is reduced, and the uniformity of the material and the specific gravity required for the heavy object as the balancer are near 7.80. The weight of the balancer G can be calculated. The difference between the calculated value and the actual weight is small, and the required weight balance of the vehicle body structure itself can be accurately obtained.
[0027]
As described above, according to the present invention, according to the component inspection of the slab material, the rejected slab material out of the standard range, the counterweight such as the material related to the mechanical strength of the work vehicle or industrial machine, It can be reused as a heavy object such as a balancer and its holding member. At this time, the rejected slab material is cut into strips to produce a flat bar-shaped plate having a desired thickness, and if necessary, the flat bar-shaped plate is further cut into members having a predetermined size and shape. Heavy objects such as counterweights and balancers and their holding members can be manufactured by simple processing steps. Therefore, due to the low cost of the rejected slab material, it is possible to manufacture a heavy object such as a counterweight and a balancer and a holding member for the heavy object. In addition, when there is a change in design such as plate thickness, it is only necessary to change the cutting interval when cutting into strips. The production cost can be greatly reduced as compared with the case where an order is placed.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an example of a manufacturing process of a standard rolled steel material and a process of generating a rejected slab material.
FIG. 2 shows an example of the shape and dimensions of a rejected slab material.
FIG. 3 shows an example of a member that does not hinder the use of a rejected slab material.
FIG. 4 is an explanatory diagram of a first cutting according to the first embodiment of the present invention.
FIG. 5 is an explanatory diagram of a second cutting according to the first embodiment of the present invention.
FIG. 6 is an explanatory view of a method of manufacturing two or more members in a modified form according to the second embodiment of the present invention.
FIG. 7 is a plan view of a main part of the vehicle body structure.
FIG. 8 is a sectional view taken along line XX of FIG. 7;
FIG. 9 shows the shape and dimensions of the holding member H.
FIG. 10 is a detailed view of a portion P in FIG. 7;
FIG. 11 shows the shape and dimensions of the balancer G.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rectangular member, 2 ... deformed member, 3 ... Car body structure, 4 ... Outer frame, 5 ... Lower plate, 6, 7 ... Member, 8 ... Bolt, S1: Hot metal, S2 ... Molten steel, S3 ... Continuous casting, S4: Slab material, S5: Upper and lower cast steel ingot, S6: Rejected slab material, S7: Steel material, H: Holding member, G: Balancer.

Claims (3)

It is a method of reusing a rejected slab material that has been out of a predetermined standard by a composition component inspection among slab materials manufactured in the middle of a manufacturing process of a rolled steel material by a casting method such as a continuous casting method or an ingot casting method. ,
A method for reusing a rejected slab material, comprising cutting the rejected slab material into strips and reusing it as a member that does not require mechanical strength. A holding member that holds a heavy object by being attached to a structure such as a work vehicle or an industrial machine,
A holding member, wherein a plate material obtained by cutting the rejected slab material into a strip is processed into a desired size and shape in a process of using the rejected slab material recycling method according to claim 1. A balancer attached to a structure such as a work vehicle or an industrial machine,
2. A balancer, wherein a plate material obtained by cutting the rejected slab material into strips is processed into a desired size and shape in a process of using the rejected slab material recycling method according to claim 1.

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