Manufacturing method for metal processed product

Abstract

To provide a method for manufacturing a metal processed product that can shorten the manufacturing time, as well as, ensure the desired performance of the metal processed product.SOLUTION: A method for manufacturing a metal processed product includes: a rolling step of, by using a metal body 10 having a groove portion 5 with a bottom portion 4 formed of a first metal body 1, a second metal body 2 arranged opposite the first metal body 1, and a third metal body 3 provided between the first metal body 1 and the second metal body 2, rolling the metal body 10 with a metallic shape-retaining member 6 provided in the groove portion 5; and a shape-retaining member removal step of removing the shape-retaining member 6 after the rolling step.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a metal processed product. [Background technology]

[0002] Methods for manufacturing metal processed products such as shunt resistors and shaped materials for connectors have been disclosed. Many shunt resistors are configured by forming a recess between one electrode and the other, and the accuracy of the recess formation is important to ensure the accuracy of the resistance value. Methods for manufacturing shunt resistors with recesses formed therein have been disclosed, for example, in Patent Document 1 and Patent Document 2.

[0003] The method for manufacturing a shunt resistor described in Patent Document 1 includes a joining step in which a first electrode metal plate made of a copper alloy is laminated on a resistor alloy made of a nickel alloy or the like, and a second electrode metal plate made of an aluminum alloy or the like is laminated on the surface opposite the joining surface of the resistor alloy, and the lamination and joining are performed; and a removal step in which a predetermined area of ​​the first electrode metal surface and a predetermined area of ​​the second electrode metal surface are removed by cutting. The method for manufacturing a shunt resistor described in Patent Document 2 involves brazing a copper plate to at least one surface of a resistive metal plate, removing the oxide film from the surface, and forming a tin-plated film over the entire surface of the copper plate to form an aggregate multilayer plate; cutting the aggregate multilayer plate into strips of a desired width; cutting a predetermined width along the long side from the surface of the strip-shaped multilayer plate on which the tin-plated film is formed, approximately in the center of the short side; removing the tin-plated film, copper plate, brazing material, and at least the diffusion layer between the resistive metal plate and the brazing material by cutting to form a recess; forming a protective film on the bottom of the recess; and cutting the strip-shaped multilayer plate into chips of the desired width. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-57010 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-194316 Summary of the Invention [Problem to be solved by the invention]

[0005] As in the inventions described in Patent Documents 1 and 2, when manufacturing a metal processed product having a recess, the recess is formed by removing a predetermined area by cutting. However, when using a cutting method, it is difficult to adjust the cutting depth, and the cutting process takes time, making it difficult to manufacture a metal processed product such as a shunt resistor that ensures the desired performance in a short time. In addition, metal processed products that do not ensure the desired performance are discarded, which creates the problem of incurring costs.

[0006] An object of the present invention is to provide a method for manufacturing a metal processed product that can shorten the manufacturing time and ensure the desired performance. [Means for solving the problem]

[0007] The method for manufacturing a metal processed product according to the present invention is a method for manufacturing a metal processed product using a metal body having a groove portion whose bottom is formed by a first metal body, a second metal body arranged opposite the first metal body, and a third metal body provided between the first metal body and the second metal body, and is characterized by including a rolling process in which the metal body is rolled with a shape-retaining member provided in the groove portion, and a shape-retaining member removal process in which the shape-retaining member is removed after the rolling process.

[0008] The method for manufacturing a metal processed product according to the present invention is characterized in that the shape-retaining member is made of metal, and in the rolling process, the shape-retaining member is rolled while being inserted into the groove so that the lower surface of the shape-retaining member abuts the bottom of the groove, one side of the shape-retaining member abuts the first metal body, and the other side of the shape-retaining member abuts the second metal body.

[0009] The method for manufacturing a metal processed product according to the present invention is characterized by including, after the shape-retaining member removal process, a heat treatment process in which the rolled metal processed product base material is heat-treated, and a cutting process in which the rolled metal processed product base material is cut to a desired size.

[0010] The method for manufacturing a metal processed product according to the present invention is characterized in that the first metal body constitutes a first electrode, the second metal body constitutes a second electrode, and the third metal body constitutes a resistive metal body, and the metal processed product is used as a resistor.

[0011] The method for manufacturing a metal processed product according to the present invention is characterized in that the shape-retaining member is made of any of materials having work hardening similar to that of the third metal body, such as stainless steel, iron alloy, or copper alloy.

[0012] The manufacturing method of the metal processed product according to the present invention is characterized in that the sum of the thickness of the third metal body constituting the groove portion and the thickness of the shape-retaining member is the same as the thickness of the first metal body and the thickness of the second metal body. [Effects of the Invention]

[0013] The method for manufacturing a metal processed product according to the present invention produces a metal processed product having grooves by rolling a metal body with a shape-retaining member provided in the grooves of the metal body and then removing the shape-retaining member after rolling. Because the shape-retaining member can be easily removed, production can be completed in a short time. Furthermore, after the shape-retaining member is removed, the grooves maintain their desired shape and the groove surface has minimal irregularities, ensuring the performance of the metal processed product. Therefore, the method for manufacturing a metal processed product according to the present invention can produce the desired metal processed product with high precision and reduce waste. [Brief explanation of the drawings]

[0014] [Figure 1] 1A and 1B are diagrams for explaining the metal body (resistor body) manufacturing process of the method for manufacturing a metal processed product according to the first embodiment of the present invention, in which (a) is an oblique view of the resistor body, and (b) is a side view of the resistor body. [Figure 2]1A and 1B are diagrams showing a state in which a shape-retaining member is provided in a groove of a resistor body in a method for manufacturing a metal processed product according to a first embodiment of the present invention, where FIG. 1A is a perspective view and FIG. 1B is a side view. [Figure 3] 1A to 1C are diagrams for explaining the rolling step of the method for manufacturing a metal processed product according to the first embodiment of the present invention, in which (a) is a perspective view, (b) is a front view, and (c) is a side view. [Figure 4] 1A and 1B are diagrams for explaining the shape-retaining member removal process of the manufacturing method of a metal processed product according to the first embodiment of the present invention, in which (a) is an oblique view of the removal stage, and (b) is an oblique view of the shape-retaining member after it has been removed. [Figure 5] 1A and 1B are diagrams showing a shunt resistor (metal processed product) manufactured by a method for manufacturing a metal processed product according to a first embodiment of the present invention, in which (a) is a perspective view and (b) is a front view. [Figure 6] 10A and 10B are diagrams for explaining the manufacture of a connector by the cutting process of the method for manufacturing a metal processed product according to the second embodiment of the present invention, where (a) shows the state before cutting and (b) shows the state after cutting. DETAILED DESCRIPTION OF THE INVENTION

[0015] The method for manufacturing a metal processed product according to the present invention is for manufacturing a metal processed product using a metal body having a first metal body, a second metal body arranged opposite the first metal body, and a groove having a bottom formed by a third metal body provided between the first and second metal bodies. This method for manufacturing a metal processed product includes a rolling step in which the metal body is rolled with a shape-retaining member provided in the groove, and a shape-retaining member removal step in which the shape-retaining member is removed after the rolling step. The first metal body, the second metal body, and the third metal body may be the same or different metal bodies, and this method for manufacturing a metal processed product is used for manufacturing metal processed products used in shunt resistors, connector profiles, power transistor components, lead frame components, LEDs, terminals, etc.

[0016] [First embodiment] In this embodiment, the metal processed product is a shunt resistor, and a method for manufacturing the metal processed product will be described with reference to FIGS. 1 to 5. FIG.

[0017] 1(a) and 1(b), a method for manufacturing a shunt resistor (metal workpiece) according to this embodiment uses a metal body (resistor body) 10 having a first metal body (first electrode) 1, a second metal body (second electrode) 2 disposed opposite the first metal body 1, and a groove 5 provided between the first metal body 1 and the second metal body 2 and having a bottom 4 formed by a third metal body (resistive metal body) 3. The method for manufacturing this shunt resistor includes a metal body (resistor body) fabrication step for fabricating the resistor body 10 having the groove 5, a rolling step for providing a shape-retaining member 6 in the groove 5 and rolling the resistor body 10 with this shape-retaining member 6 provided, a shape-retaining member removal step for removing the shape-retaining member 6 after the rolling step, a heat treatment step for heat-treating the rolled resistor body 10 after the shape-retaining member removal step, and a cutting step for cutting to a desired size. The first metal body 1, the second metal body 2, and the third metal body 3 are rectangular parallelepiped, long metal bodies of the same size. The sizes of these metal bodies can be changed as needed depending on the purpose. 1(a) and 1(b) as a reference, the short side direction is the left-right direction X, the long side direction is the front-back direction Y, and the height direction is the up-down direction Z.

[0018] Each step of the method for manufacturing the shunt resistor according to this embodiment will be described below.

[0019] [Metal body manufacturing process] In the metal body fabrication process, a resistor body 10 is fabricated using multiple metals. In the resistor body 10, a plate-shaped resistive metal body 3 is sandwiched between a first electrode 1 and a second electrode 2, and is welded to the side surfaces of the first electrode 1 and the second electrode 2, respectively. This welding is performed by, for example, electron beam welding. The thickness of the resistive metal body 3 in the vertical direction Z is smaller than the thicknesses of the first electrode 1 and the second electrode 2. Therefore, a groove 5 with a rectangular cross section is formed between the first electrode 1 and the second electrode 2, with the top surface of the resistive metal body 3 as its bottom 4 (FIG. 1(b)).

[0020] For example, pure copper is used for the first electrode 1 and the second electrode 2, and for example, a copper alloy (86% copper, 12% manganese, 2% nickel), a nickel alloy (57% or more nickel, containing chromium, iron, and manganese), nichrome, etc. is used for the resistive metal body 3. Note that the first electrode 1, second electrode 2, and resistive metal body 3 are not limited to the above metals and can be selected appropriately.

[0021] [Rolling process] After the resistor body 10 is fabricated, as shown in FIGS. 2(a) and 2(b), a metallic shape-retaining member 6 is provided in the groove 5. The lower surface of the shape-retaining member 6 contacts the bottom of the groove 5, one side of the shape-retaining member 6 contacts the first electrode 1, and the other side of the shape-retaining member 6 contacts the second electrode 2. This shape-retaining member 6 functions as a dummy material to maintain the desired shape of the groove 5 after the rolling process. The shape-retaining member 6 has the same size as the groove 5, and the sum of the thickness T3 of the resistive metal body 3 constituting the groove 5 and the thickness T6 of the shape-retaining member 6 is the same as the thickness T1 of the first electrode 1 and the thickness T2 of the second electrode 2 (FIG. 2(b)). Therefore, with the shape-retaining member 6 inserted in the groove 5, the upper surface of the resistor body 10 becomes substantially flat. The shape-retaining member 6 can be made of a material that has work hardening similar to that of the resistive metal body 3, such as stainless steel, iron alloy, or copper alloy, and is appropriately selected in accordance with the metals of the first electrode 1, second electrode 2, and resistive metal body 3. In this embodiment, the shape-retaining member 6 is made of stainless steel. Since the resistive metal element 3 becomes hardened by rolling, the work hardening similar to that of the resistive metal element 3 means the property of becoming hardened by rolling in the same manner as the resistive metal element 3.

[0022] As shown in Figures 3(a) and 3(b), the rolling process is performed using a rolling device equipped with upper and lower rollers 20, and the resistor body 10 is pressed from the vertical direction Z at room temperature while the shape-retaining member 6 is inserted into the groove portion 5. During this process, the upper roller 20 simultaneously presses the first electrode 1, the second electrode 2, and the shape-retaining member 6. After the rolling process, the rolled resistor body 10 (hereinafter also referred to as resistor base material 11) is obtained as shown in Figure 3(c).

[0023] [Shape-retaining material removal process] After the rolling process, a shape-retaining member removal process is performed. In this shape-retaining member removal process, the shape-retaining member 6 is removed from the groove portion 5 of the resistor base material 11, as shown in FIG. 4(a). The shape-retaining member 6 is removed by hand or by machine along the front-rear direction Y of the resistor base material 11. After the shape-retaining member 6 is removed, the desired shape of the groove portion 5 is maintained between the first electrode 1 and the second electrode 2 in the resistor base material 11, as shown in FIG. 4(b).

[0024] [Heat treatment process] In the heat treatment process, the resistor base material 11 is heat treated to adjust the strength and other properties to the desired level. By performing the heat treatment, the metal structure constituting the first electrode 1, the second electrode 2, and the resistive metal body 3 can be made uniform. The heat treatment process can also be performed after the cutting process described below.

[0025] [Cutting process] In the cutting step, the resistor base material 11 is cut to a desired size by a cutting machine to obtain the chip-type shunt resistor 100 shown in FIGS. 5(a) and 5(b).

[0026] Next, the effects of the method for manufacturing a shunt resistor (metal processed product) according to this embodiment will be described.

[0027] In the method for manufacturing a shunt resistor according to this embodiment, rolling is performed with the shape-retaining members 6 inserted in the grooves 5, and then the shape-retaining members 6 are removed, so that the grooves 5 maintain the desired shape in the resistor base material 11 after rolling. Furthermore, the bottoms 4 of the grooves 5 after the shape-retaining members 6 are removed have extremely small irregularities compared to when recesses are formed by cutting, and there is no variation in the resistance value of the resistive metal body 3, ensuring the desired resistance value. Therefore, the method for manufacturing a shunt resistor can manufacture a shunt resistor 100 that ensures the desired performance.

[0028] In the conventional manufacturing method of shunt resistors that involves a cutting process, a certain number of resistors that do not exhibit the desired resistance value are generated and are discarded. The method for manufacturing a shunt resistor according to this embodiment can stably produce shunt resistors exhibiting the desired resistance value, thereby reducing the amount of shunt resistors that are discarded and significantly reducing costs.

[0029] In the manufacturing method of the shunt resistor according to this embodiment, the grooves 5 can be easily formed by removing the shape-retaining member 6 after the rolling step. The work of removing the shape-retaining member 6 can be completed in a short time, and the manufacturing time can be shorter than in conventional manufacturing methods that involve a cutting step.

[0030] Furthermore, the shunt resistor 100 manufactured by the method for manufacturing a shunt resistor according to this embodiment has extremely small irregularities on the bottom 4 of the groove 5, and is highly aesthetically pleasing.

[0031] [Second embodiment] In this embodiment, the metal processed product is a metal connector, and a method for manufacturing the metal processed product will be described. The metal body manufacturing process, rolling process, and shape-retaining member removal process of the metal processed product manufacturing method of this embodiment are performed in the same manner as the method for manufacturing a metal processed product according to the first embodiment. The metal body 12 produced in the metal body production step is made of, for example, a copper alloy. In the method for producing a metal processed product of this embodiment, the first metal body 1, the second metal body 2, and the third metal body 3 constituting the metal body 12 are made of copper or phosphor bronze.

[0032] After the shape-retaining member removal step, a cutting step is performed to cut the cut portions L shown in FIG. 6(a). Specifically, the left side portion of the first metal body 1, the right side portion of the second metal body 2, and the center portion of the third metal body 3 are each cut along the front-rear direction Y. This results in the production of a connector 200 composed of the first metal body 1 and the third metal body 3, and a connector 200 composed of the second metal body 2 and the third metal body 3, as shown in FIG. 6(b). These connectors 200 are formed with an L-shaped cross section. The size of the connector 200 and the metals that make it up are determined appropriately depending on the application, etc.

[0033] In the method for manufacturing a metal processed product according to this embodiment, by cutting the third metal body 3 portion of the metal body 12 after removing the shape-retaining member 6 along the front-rear direction Y, when different types of metals are used for the first metal body 1 and the third metal body 3, it is possible to manufacture a connector (metal processed product) 200 having different types of metal at the end portions. On the other hand, when the same type of metal is used for the first metal body 1, the second metal body 2, and the third metal body 3, it is possible to manufacture a connector 200 having the same type of metal at the end portions. In this way, not only can a metal processed product having a concave groove like the shunt resistor 100 shown in the first embodiment be manufactured, but also a metal processed product having a groove 5 and an L-shaped cross section can be manufactured. Furthermore, by adjusting the sizes of the first metal body 1, the second metal body 2, etc. and the cutting position of the third metal body 3, it is possible to manufacture connectors 200 of various sizes, and this method for manufacturing a metal processed product allows for easy size adjustment.

[0034] Although the present embodiment has been described above, it is possible to select and / or change the configurations given in the above embodiment to other configurations as appropriate without departing from the spirit of the present invention.

[0035] In this embodiment, a shunt resistor and a connector have been exemplified to describe a method for manufacturing a metal processed product, but the method for manufacturing a metal processed product of the present invention can be applied to metal processed products in which grooves or steps are formed. It can also be used to manufacture metal processed products in which multiple grooves are formed, not just one. The manufacturing method of the present invention can also be used when grooves are formed not only on the top side but also on the bottom side (both sides) or side surfaces. In the method for manufacturing a metal processed product of the present invention, the heat treatment step is not essential, and after the shape-retaining member removal step, the cutting step may be performed without the heat treatment step.

[0036] In this embodiment, the third metal body is sandwiched between the first metal body and the second metal body, but the first metal body and the second metal body may be welded to the upper surface of the third metal body. Furthermore, the cross-sectional shape of the grooves to be formed is not limited to rectangular, and for example, triangular grooves may be formed.

[0037] The method for manufacturing a metal processed product according to the present invention has been described above. This manufacturing method can be used for the production of a wide variety of products in small quantities, and can produce desired metal processed products at low cost. [Explanation of symbols]

[0038] 1 First metal body (first electrode) 2 Second metal body (second electrode) 3 Third metal body (resistance metal body) 4 Bottom 5 Groove 6 Shape retention member 10 Metal body (resistor body) 11 Resistor base material 12 Metal body 20. Laura 100 Shunt resistor (metalwork) 200 Connectors (metal processed products) L cutting section T1, T2, T3, T6 thickness X Left / right direction Y Front-to-rear direction Z vertical direction

Claims

1. A method for manufacturing a metal processed product using a metal body having a first metal body, a second metal body arranged opposite to the first metal body, and a groove portion having a bottom formed by a third metal body provided between the first metal body and the second metal body, a rolling step of rolling the metal body in a state where a shape-retaining member is provided in the groove portion; A shape-retaining member removing step of removing the shape-retaining member after the rolling step, A method for manufacturing a metal processed product, comprising:

2. The shape-retaining member is made of metal, In the rolling step, the shape-retaining member is rolled while being inserted into the groove so that the lower surface of the shape-retaining member abuts against the bottom of the groove, one side surface of the shape-retaining member abuts against the first metal body, and the other side surface of the shape-retaining member abuts against the second metal body. The method for manufacturing a metal processed product according to claim 1 .

3. After the shape-retaining member removing step, a heat treatment step of heat-treating the rolled metal workpiece base material, and a cutting step of cutting the rolled metal workpiece base material to a desired size are included.

3. The method for manufacturing a metal processed product according to claim 1 or 2.

4. the first metal body constitutes a first electrode, the second metal body constitutes a second electrode, and the third metal body constitutes a resistive metal body, and the metal processed product is used for a resistor; 3. The method for manufacturing a metal processed product according to claim 1 or 2.

5. The shape-retaining member is made of a material having work hardening similar to that of the third metal body, such as stainless steel, an iron alloy, or a copper alloy.

3. The method for manufacturing a metal processed product according to claim 1 or 2.

6. The sum of the thickness of the third metal body constituting the groove portion and the thickness of the shape-retaining member is the same as the thickness of the first metal body and the thickness of the second metal body. The method for manufacturing a metal processed product according to claim 1 .

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