TWI683707B - Manufacturing method of thickness-varied metal plate, manufacturing method of pressed part, and processing machine - Google Patents

Abstract

In a manufacturing method of a thickness-varied metal plate, first, a cut plate is manufactured by cutting a metal plate having a constant plate thickness into a predetermined shape. Next, the thickness-varied metal plate is manufactured by rolling the cut plate using a processing machine including a pair of work rolls. Here, a radius of one of the pair of work rolls is varied in a circumferential direction and an axial direction. Accordingly, the thickness-varied metal plate manufactured by rolling the cut plate using the processing machine has a plate thickness varied in two different directions orthogonal to a plate thickness direction.

Description

Method for manufacturing variable-thickness metal plate, method for manufacturing pressed parts, and processing machine

[0001] The present invention relates to a method for manufacturing a variable-thickness metal plate, a method for manufacturing a pressed component using the variable-thickness metal plate, and a processing machine for manufacturing a variable-thickness metal plate.

[0002] In the manufacturing method of the variable thickness steel plate described in Japanese Patent Application Publication No. 2015-033719, at least one of a pair of work rolls of a two-stage rolling mill is formed such that its radius changes to the circumference Direction. A steel plate (metal plate) is inserted between the pair of work rolls and rolled, so a variable-thickness steel plate (variable-thickness metal plate) whose plate thickness is partially changed is manufactured.

[0003] However, the manufacturing method of the variable thickness steel plate described above is changed only in a direction at right angles to the thickness direction of the plate (only in the feeding direction of the steel plate). Therefore, there is room for improvement from the perspective of allowing greater flexibility to set the thickness variation of the board. [0004] The present invention provides a method of manufacturing a variable-thickness metal plate that allows greater flexibility in setting the plate thickness variation of the variable-thickness metal plate, a method of manufacturing a pressed component, and a processing machine. [0005] The first aspect of the present invention relates to a method of manufacturing a variable-thickness metal plate. The manufacturing method includes: manufacturing a cut by cutting a metal plate having a fixed plate thickness into a predetermined shape Cutting plate; and manufacturing the variable thickness metal plate by processing the cutting plate with at least one of rolling and forging using a processing machine, the plate thickness of which changes in two different directions at right angles to the plate thickness direction Above, the processing machine includes a first work roll and a second work roll, the radius of the second work roll is changed in the circumferential direction and the axis direction of a rotation axis. [0006] According to the first aspect of the present invention, first, the cutting plate is manufactured by cutting a metal plate (eg, steel plate) into a predetermined shape. Next, the variable thickness metal plate is processed by at least one of rolling and forging using the (single) processing machine including the pair of work rolls (the first work roll and the second work roll) Cut the board to make it. Here, the radius of the second work roll of the processing machine is changed in the circumferential direction of the rotation axis and in the axis direction. Therefore, the variable-thickness metal plate manufactured by processing the cutting plate using the processing machine has the plate thickness changed in two different directions at right angles to the plate thickness direction. Therefore, according to the first aspect, greater flexibility is allowed in setting the thickness of the variable-thickness metal plate. [0007] In the first aspect of the present invention, the processing machine may be provided with a first backup roll, which is disposed on the opposite side of the first work roll away from the second work roll and works with the first The roller is in contact, and a second backup roller is disposed on the opposite side of the second work roller away from the first work roller and is in contact with the second work roller. When manufacturing the variable-thickness metal plate, the cutting plate rotates the first work roll within a range where a radius of the first work roll is fixed and in contact with the first support roll Rotate the second work roll in the forward direction and in the opposite direction, and within a range where a fixed radius of the second work roll contacts the second backup roll Treat it in the opposite direction. [0008] According to this first aspect, the processing machine includes the pair of backup rolls (the first backup roll and the second backup roll), so that commonly known crowning can be prevented or suppressed. In addition, in order to process the cutting board with the processing machine, a first work roll is rotated forward in the area where the radius of the first work roll is constant and in contact with the first backup roll In the direction and the opposite direction, and the second work roll is rotated in the forward direction and the opposite direction within the range where the radius of the second work roll is in contact with the second backup roll on. This prevents unstable behavior that may occur when an area of the first work roll or the second work roll with a varying radius contacts the corresponding backup roll, so that the pair of work rolls can be stabilized (smoothly) Turn. Therefore, the pair of work rolls can give the processed board a plate thickness variation with extremely high accuracy. [0009] The second aspect of the present invention relates to a method of manufacturing a variable-thickness metal plate. The manufacturing method includes: manufacturing a cutting plate by cutting a metal plate into a predetermined shape; and by using A first processing machine including a first work roll and a second work roll (the radius of the second work roll varies in a circumferential direction or an axis direction at right angles to a rotation axis), and a first processing machine includes a pair of different The second processing machine for the work rolls of the work rolls (the first work roll and the second work roll) of the first processing machine sequentially processes the cutting plate with at least one of rolling and forging The thickness of the metal plate is changed in two different directions at right angles to the thickness direction of the plate. [0010] According to the second aspect of the present invention, first, the cutting plate is manufactured by cutting a metal plate (eg, steel plate) into a predetermined shape. Next, the variable thickness metal plate is formed by using the first including the first work roll and the second work roll (the radius of which changes in the circumferential direction or the axis direction at right angles to the rotation axis) The processing machine and the second processing machine including a pair of work rolls different in shape from the work rolls of the first processing machine are manufactured by sequentially processing the cut sheet by at least one of rolling and forging. Here, the pair of work rolls of the first processing machine and the pair of work rolls of the second processing machine are different from each other. When the cutting board is processed by the first processing machine and the second processing machine in sequence, the thickness of the board can be changed in two different directions at right angles to the thickness direction of the board. Was made. Therefore, according to the second aspect, greater flexibility is allowed in setting the thickness of the variable-thickness metal plate. [0011] In the second aspect, when the variable-thickness metal plate is manufactured, the direction in which the cutting plate is fed into the first processing machine may be changed to a direction different from the cutting plate The direction being fed into the second processing machine. [0012] According to this second aspect, in order to manufacture the variable-thickness metal plate, the direction in which the cutting plate is fed into the first processing machine may be changed to be different from that in which the cutting plate is fed into the first The direction of the direction inside the processing machine. Therefore, changing the feeding direction can change the direction in which the board thickness of the cutting plate is changed, so that greater flexibility is allowed in setting the change in the board thickness of the variable-thickness metal plate. [0013] In the second aspect, the first processing machine may include a first backup roll that is disposed on the opposite side of the first work roll away from the second work roll and works with the first The roller is in contact, and a second backup roller is disposed on the opposite side of the second work roller away from the first work roller and is in contact with the second work roller. When manufacturing the variable-thickness metal plate, the cutting plate rotates the first work roll by contacting the first support roll within a fixed radius area of the first work roll Rotating the second work roll in the forward direction in the forward direction and the opposite direction, and within a range where a fixed radius area of the second work roll contacts the second backup roll And deal with it in the opposite direction. [0014] According to this second aspect, the first processing machine is provided with the pair of backup rolls (the first backup roll and the second backup roll), so that commonly known crowning can be prevented or suppressed. In addition, in order to process the cutting board with the first processing machine, the first work roll is rotated in the range where the radius of the first work roll is constant and in contact with the first backup roll. In the forward direction and in the opposite direction, and a second work roll is rotated in the forward direction and opposite in the range where the radius of the second work roll is in contact with the second backup roll Direction. This prevents unstable behavior that may occur when an area of the first work roll or the second work roll with a varying radius contacts the corresponding backup roll, so that the pair of work rolls can be stabilized (smoothly) Turn. Therefore, the pair of work rolls can give the cutting board a plate thickness variation with extremely high accuracy. [0015] The third aspect of the present invention relates to a method of manufacturing a pressed component, the manufacturing method including: manufacturing a partially processed by using the manufacturing method of the variable thickness metal plate of the first and second aspects A variable-thickness metal plate; and manufacturing the pressed part by performing cold rolling bending on an untreated portion of the variable-thickness metal plate. [0016] According to the third aspect, the variable-thickness metal plate is manufactured by the method of manufacturing the variable-thickness metal plate in the first and second aspects. Therefore, the third aspect can provide the same operational benefits as the first aspect and the second aspect. Next, a pressed part is manufactured by cold-bending the untreated portion of the variable-thickness metal plate. The yield strength of the processed part of the pressed part has been strengthened by work hardening while the thickness of the plate of the processed part is reduced. Therefore, according to the third aspect, a light-weight pressed part whose strength is partially strengthened can be manufactured.　　 [0017] The fourth aspect of the present invention relates to a processing machine, which includes a first work roll and a second work roll, the radius of which is changed in the circumferential direction and axis direction of a rotation axis.　　 [0018] The processing machine of the fourth aspect including the same configuration as the processing machine described in the first aspect can be applied to the manufacturing method of the variable thickness metal plate of the first aspect. Therefore, the fourth aspect can provide the same operational benefits as the first aspect. [0019] In a fourth aspect, the second work roll may include a second roll body whose radius is fixed in the circumferential direction and the axis direction of the rotation axis, and a second cam, It is detachably mounted on a part of the outer circumferential surface of the second roller body. [0020] According to this fourth aspect, the second work roll whose radius changes in the circumferential direction and the axis direction of the rotation axis is by installing the second cam in the circumferential direction and the radius of the rotation axis The portion of the outer circumferential surface of the second roller body that is fixed in the axial direction is formed. Since the second cam is detachably mounted on the second roller body, the cutting plate can be arbitrarily changed in terms of the thickness of the plate by replacing the second cam. Furthermore, the second cam can be replaced separately during maintenance, which is beneficial to improve maintainability. [0021] In the fourth aspect, the radius of the first work roll may vary in the circumferential direction and axis direction of a rotation axis. [0022] In a fourth aspect, the first work roll may include a first roll body whose radius is fixed in the circumferential direction and the axis direction of the rotation axis, and a first cam, It is detachably mounted on a part of the outer circumferential surface of the first roller body. [0023] As has been discussed above, the manufacturing method of the variable thickness metal plate, the manufacturing method of the pressed part, and the processing machine of the present invention allow a greater variation in setting the plate thickness of the variable thickness metal plate Flexibility.

[0025] Hereinafter, a method of manufacturing a variable-thickness metal plate, a method of manufacturing a pressed component, and a processing machine according to an embodiment of the present invention will be described using FIGS. 1 to 16. The manufacturing method of the variable-thickness metal plate according to this embodiment is a method for manufacturing a variable-thickness metal plate (variable-thickness steel plate), which is used as a vehicle body including, for example, a vehicle The material of the car body member (pressed part) of one part, and the method has a cutting process and a rolling process (processing process). Hereinafter, the manufacturing method of the variable-thickness type metal plate according to this embodiment will be referred to as a manufacturing method of the variable-thickness type steel plate. [0026] In the cutting process, a steel plate (metal plate) having a fixed board thickness is cut into a predetermined shape (in this example, a rectangular shape by press working) or the like ), and a blank material (ie, a cut board, a board to be processed, or a board to be rolled) B as shown in FIGS. 1 and 3 is manufactured. The blank material B is not limited to a rectangular shape, but may be any shape. In addition, the manufacturing method of the variable thickness steel plate according to this embodiment can be used not only on steel plates, but also on other metal plates with plasticity. [0027] Next, in the rolling process, the blank material B is rolled with a rolling machine (processing machine) (the blank material B can be processed by at least one of rolling and forging), a variable thickness type A steel plate TB1 (see FIGS. 1 and 2) or a variable thickness steel plate TB2 (see FIG. 5) can be manufactured. There are two types of this rolling process: the single-step rolling process (single-step processing) shown in FIGS. 1 and 2, and the multi-step rolling process (multi-step processing) shown in FIGS. 3 to 5, And any of these processes can be used. These two rolling processes will be described below.　　 [0028] Single-step rolling process 　　 In the single-step rolling process shown in FIGS. 1 and 2, the blank material B is rolled by a (single) rolling machine 10 to manufacture the variable thickness steel plate TB1. The rolling mill 10 is a two-stage rolling mill and includes a pair of substantially cylindrical work rolls 12 that are arranged parallel to each other with one work roll above the other work roll. The work roll 12 is rotatably supported by a casing (not shown) and is constructed to be driven to be rotated in synchronization with each other by a driving unit (not shown). A specific gap (a gap smaller than the thickness of the board of the blank material B) is provided between the work rolls 12. For convenience of description, FIGS. 1 and 2 show that the work rolls 12 are separated by a distance larger than actual. This also applies to Figures 3 to 5. [0029] As shown in FIGS. 1 and 2, a concave portion (shaped surface) 12A that gives the blank material B a change in the board thickness (variable thickness type shape) is formed on the outer circumferential surface of each work roll 12 (Treated surface). The concave portion 12A may be formed on only one of the work rolls 12. In addition, the shaped surface may be a protrusion instead of a recess 12A. The concave portion 12A is formed to correspond to the target shape of the variable thickness steel plate TB1 to be made by the single-step rolling process. The target shape is a shape corresponding to a change in the plate thickness (variable thickness type shape) required for the pressed part (a body part of a vehicle) to be manufactured using the variable thickness steel plate TB1. [0030] The concave portion 12A is formed only on a portion of the outer circumferential surface of each work roll 12 in the circumferential direction. Therefore, the radius of each work roll 12 in the circumferential region where the recess 12A is provided is smaller than the radius of other circumferential regions where the recess 12A is not provided. The depth of the recess 12A is greater in the central portion of each work roll 12 in the axial direction, and the radius of each work roll 12 is smaller in the deeper area. Therefore, each work roll 12 has a radius varying in the circumferential direction and the axial direction. The work roll 12 is constructed to be driven to rotate synchronously while maintaining a vertically symmetrical rotational position (see FIGS. 1 and 2). The shape of the recess 12A described above is just an example and can be changed as desired. [0031] In the single-step rolling process using the rolling mill 10 configured as described above, the blank material B is inserted between the work rolls 12 of the rolling mill 10 and rolled (see arrows in FIGS. 1 and 2) RM), and the shape of the processing surface of the work roll 12 is thereby imprinted on the blank material B. Therefore, the thickness of the board varies in two different directions (directions of arrows X and Y in FIG. 1) at right angles to a board thickness direction (ie, the direction of arrow Z in FIG. 1) Steel plate TB1 is manufactured. [0032] Multi-step rolling process On the other hand, the multi-step rolling process includes multiple steps (in this example, the first step to the third step) are shown in FIGS. 3 to 5, and the variable thickness formula The steel plate TB2 is used to sequentially roll the blank material B by using a plurality of (three in this example) rolling mills 20, 30, and 40. The rolling mill 20 includes substantially the same configuration as the rolling mill 10, and includes a pair of work rolls 22 including recesses 22A formed on the outer circumferential surface thereof. The rolling mill 30 includes substantially the same configuration as the rolling mill 10, and includes a pair of work rolls 32 including recesses 32A formed on the outer circumferential surface thereof. The rolling mill 40 includes substantially the same configuration as the rolling mill 10, and includes a pair of work rolls 42 including a recess 42A formed on the outer circumferential surface thereof. Conversely, the recess 22A may be formed on only one work roll 22. Conversely, the recess 32A may be formed on only one work roll 32. Conversely, the recess 42A may be formed on only one work roll 42. In addition, the convex portion may be provided on the outer circumferential surface instead of the concave portions 22A, 32A, 42A. The work rolls 22, 32, 42 are different in shape from the work roll 12. In addition, the shapes of the pair of work rolls 22, 32, 42 are also different from each other. [0033] In detail, the rolling mill 20 (see FIG. 3) used in the first step includes the work rolls 22 whose radii are changed in the circumferential direction, respectively. This concave portion 22A is formed on the outer circumferential surface (treatment surface) of each work roll 22. The recess 22A is formed only at a portion of the outer circumferential surface of the work roll 22 in the circumferential direction, and is formed into a constant shape along the axis direction of the work roll 22.　　 [0034] The rolling mill 30 (see FIG. 4) used in the second step includes the work rolls 32 whose radii are changed in the axial direction, respectively. This concave portion 32A is formed on the outer circumferential surface (treatment surface) of each work roll 32. The recess 32A is formed at a central portion of the outer circumferential surface of the work roll 32 in the axial direction, and is formed into a constant shape along the circumferential direction of the work roll 32.　　 [0035] The rolling mill 40 (see FIG. 5) used in the third step includes the work rolls 42 whose radii are changed in the circumferential direction, respectively. The concave portion 42A is formed on the outer circumferential surface (treatment surface) of the work roll 42. The recess 42A is formed only at a portion of the outer circumferential surface of the work roll 42 in the circumferential direction, and is formed into a constant shape along the axis direction of the work roll 42. [0036] In the multi-step rolling process using the rolling mills 20, 30, 40 of the above configuration, first, in the first step shown in FIG. 3, the blank material B is inserted into the rolling mill 20 Between the work rolls 22 and rolled (see arrow RM in FIG. 3 ), the shape on the processing surface of the work rolls 22 is thereby imprinted on the blank material B. Next, in the second step shown in FIG. 4, the blank material B1 that has undergone the first step is inserted between the work rolls 32 of the rolling mill 30 and rolled (see arrow RM in FIG. 4) ), the shapes on the processing surfaces of the work rolls 32 are thereby imprinted on the blank material B1. [0037] Next, in the third step shown in FIG. 5, first, a blank material B2 that has undergone the second step is turned 90 degrees as shown in a plan view (see arrow T in FIG. 5). Then, the blank material B2 is inserted between the work rolls 42 of the rolling mill 40 and rolled (see arrow C and arrow RM in FIG. 5). Therefore, the thickness of the board changes to the variable thickness steel plate TB2 in two different directions (directions of arrow X and arrow Y in FIG. 5) at right angles to the board thickness direction (direction of arrow Z in FIG. 5) (see FIG. 5) Be manufactured. In this embodiment, because the blank material B1 has undergone the second step before the third step, the board thickness changes to the blank material B2 (variable thickness steel plate) in two different directions at right angles to the board thickness direction It was made. Therefore, the third step can be omitted. [0038] In the above-mentioned multi-step rolling process, the blank material B2 is turned 90 degrees as seen in the plan view in the third step, and the direction in which the blank material B2 is fed into the rolling mill 40 is thus changed to one Unlike the blank material B, B1 is fed to the directions in the rolling mills 20, 30. The direction in which the blank material B2 is fed refers to the orientation of the blank material B2 relative to the rolling mill 40 in the plan view while the blank material B2 is rolled by the rolling mill 40. The feeding direction of the blank materials B, B1 refers to the orientation of the blank materials B, B1 relative to the rolling mills 20, 30 in the plan view while the blank materials B, B1 are rolled by the rolling mills 20, 30. The distribution and combination of the rolling process in this multi-step rolling process can be changed arbitrarily.　　[0039] Heat treatment Next, heat treatment for variable thickness steel plates TB1, TB2 will be described. In this embodiment, the variable-thickness steel plates TB1 and TB2 manufactured by the above rolling process (single-step rolling process or multi-step rolling process) are shaped into one by being bent in the subsequent stamping process The predetermined shape. However, work hardening occurs in the rolled portions of the variable-thickness steel plates TB1 and TB2, which represents a situation that is difficult for plastic forming to be implemented later. Therefore, this embodiment is based on the premise that a heat treatment is performed on the variable-thickness steel sheets TB1, TB2 that have undergone the rolling treatment. [0040] In detail, for example, the stamping process after the rolling process is a hot stamping process. During the hot stamping process, before the stamping process, the variable thickness steel plates TB1, TB2 are heated to a predetermined temperature by high-frequency induction heating or the like. During this heating, work hardening due to rolling (thickness change processing) is eliminated. [0041] For example, in the example where the stamping process after the rolling process is a cold stamping process, an annealing process for annealing the variable-thickness steel sheets TB1 and TB2 is additionally performed before the cold stamping process. This work hardening is eliminated in this annealing process. Therefore, although the number of treatments is increased due to the addition of annealing treatment, the annealing treatment allows the variable thickness steel sheets TB1, TB2 to be used like ordinary cold stamped parts. [0042] The variable-thickness steel sheets TB1, TB2 according to this embodiment are not limited to the variable-thickness steel sheets subjected to the above heat treatment. That is, the strength of the variable-thickness steel sheets TB1, TB2 according to this embodiment can be partially strengthened by maintaining work hardening conditions and making good use of the strengthened yield strength. Therefore, compared to strengthening the strength by increasing the plate thickness of the variable thickness steel plate, the variable thickness steel plate of the present invention can achieve a reduction in thickness and weight.　　 [0043] Operation and benefits 　　 Next, the operation and benefits of this embodiment will be described. [0044] According to the manufacturing method of the variable-thickness steel plate of this embodiment, during the blanking process, the blank material B is manufactured by cutting a steel plate having a fixed plate thickness into a predetermined shape. Next, this rolling process is implemented. The rolling process is the single-step rolling process or the multi-step rolling process. When the rolling process is the single-step rolling process, the variable thickness steel plate TB1 is manufactured by rolling the blank material B with a single rolling mill 10 including the pair of work rolls 12. Here, each work roll 12 of the rolling mill 10 has a radius that changes in the circumferential direction and the axis direction. Therefore, the variable-thickness steel plate TB1 manufactured by rolling the blank material B using the rolling mill 10 has the plate thickness changed in two different directions at right angles to the plate thickness direction. Therefore, this manufacturing method is better than the manufacturing method of the variable-thickness steel plate (which is hereinafter simply referred to as the manufacturing method of the variable-thickness steel plate of the prior art) contained in the section [Technical Field of the Invention] in setting the board thickness Allow greater flexibility. [0045] On the other hand, when the rolling process is a multi-step rolling process, the variable thickness steel plate TB2 is obtained by sequentially rolling the blank material B with a plurality of rolling mills 20, 30, 40 In manufacturing, the rolling mills include work rolls 22, 32, 42 respectively, and their radii change in the circumferential direction and the axis direction. Here, the pairs of work rolls 22, 32, 42 of the plurality of rolling mills 20, 30, 40 are different from each other in shape. As the blank material B is sequentially rolled by the plurality of rolling mills 20, 30, 40, the variable-thickness steel plate TB2 whose plate thickness is changed in two different directions at right angles to the plate thickness direction is manufactured come out. Therefore, this manufacturing method allows greater flexibility in setting the change in the thickness of the plate compared to the manufacturing method of the variable thickness steel plate of the prior art. As described above, according to this embodiment, regardless of whether the rolling process is a single-step rolling process or a multi-step rolling process, the board thickness changes in two different directions at right angles to the board thickness direction ( The variable thickness steel plate TB1 or TB2 can be manufactured in any direction in a plane at right angles to the thickness direction of the board). Therefore, the thickness of the body member made of the variable thickness steel plate TB1 or TB2 can be changed in any direction, such as the up and down direction of the vehicle or the front and rear direction of the vehicle. Therefore, the strength and rigidity required by the vehicle body can be ensured, and the weight of the vehicle body can still be reduced, thereby improving the fuel efficiency and sports performance of the vehicle. [0047] In the single-step rolling process, the variable-thickness steel plate TB1 is simply manufactured by rolling the blank material B using the single-rolling mill 10. Therefore, this process simplifies the manufacturing process and contributes to cost reduction. On the other hand, in the multi-step rolling process, the variable thickness steel plate TB2 is manufactured by sequentially rolling the blank material B using a plurality of rolling mills 20, 30, and 40. Therefore, the processing force required to roll the blank material B can be dispersed among the rolling mills 20, 30, and 40. Therefore, the durability of the rolling mills 20, 30, 40 can be more easily ensured. [0048] In addition, in the multi-step rolling process, the blank material B is fed into one of the plurality of rolling mills 20, 30, 40, the direction of the rolling mill 40 is changed to a direction, which is different from This blank material B is fed into the direction of the other rolling mills 20, 30. Changing the feeding direction in this way can change the direction in which the board thickness of the blank material B is changed, so that greater flexibility can be allowed when setting the board thickness change, and the variable thickness steel plate TB2 can be given a complicated shape. [0049] In this embodiment, rolling (thickness change processing) is performed on the blank material B (cutting plate) that can be cut into an arbitrary shape. Therefore, the direction in which the blank material B is fed into each rolling mill (that is, the direction in which the thickness of the board given to the blank material B changes) can be arbitrarily set, and is not limited to the above example of the multi-step rolling process . Therefore, the complicated variable-thickness shapes required for car body members and the like can be easily handled.　　 [0050] Furthermore, in this embodiment, rolling is performed on the blank material B as described above, which can improve the material productivity compared to the prior art variable thickness steel plate manufacturing method. In detail, in the manufacturing method of the prior-art variable-thickness steel plate shown in FIG. 6, rolling (thickness change processing) is performed when the steel plate S is wound on a payoff reel R1 and wound up. The machine (take-up reel) R2 is implemented on a steel plate (metal plate) S (which is a material to be rolled) that can be rolled, and then the steel plate S is shown in FIG. 6 The blank lines L1, L2 are cut. After that, a cut steel plate SB (see FIG. 7) is cut into a shape P of parts to be manufactured (see FIGS. 6 and 7). Therefore, the combination process cannot be performed unless the board thickness distribution is symmetrical with respect to the part P. [0051] More specifically, in the case where the rolling is performed on the steel sheet S being wound on the uncoiler R1 and the winder R2, for example, the shaded area in FIGS. 6 and 7 constitutes a The thick plate portion S1 with a larger board thickness, and the other areas constitute the thin plate portion S2 with a smaller board thickness. A plurality of thick plate portions S1 and thin plate portions S2 are formed at regular intervals. Therefore, if the arrangement of the thick plate portion S1 is asymmetric with respect to the part shape P as shown in FIGS. 6 and 7, only one portion can be cut from one steel plate SB, so that a large amount of scrap SC (the The steel plate SB is produced outside the part shape P). Therefore, depending on the shape of the part, the material productivity is extremely low and the manufacturing cost is high. [0052] In contrast, in this embodiment, the blank material B is manufactured by cutting the steel plate before rolling, and rolling is performed on the blank material B. Therefore, as shown in FIGS. 8 and 9, in order to manufacture the blank material B, a plurality of blank materials B may be cut out from the steel plate SB before being rolled (commonly referred to as combined cutting). After that, the blank material B that has been cut out is rolled (see FIG. 10). Therefore, the amount of scrap SC generated can be greatly reduced and the material productivity is significantly improved, so that the manufacturing cost can be reduced. Fig. 10 shows the first step of the multi-step rolling process. [0053] Furthermore, in this embodiment, the variable-thickness steel plates TB1, TB2 are manufactured by rolling using a rolling mill (roller), as compared to forging using a general press machine to manufacture the variable-thickness steel plates, This can significantly reduce the processing power required. In detail, for example, when a general press is used, a processing force of several tons to several thousands tons is required. Conversely, when a rolling mill is used, the thickness change processing, for example, uses less than one-tenth of the processing force required by a punching machine. Alternatively, the blank material B may be heated before being rolled by the roller press. Therefore, the processing force can be further reduced, and the blank material B can be given a more complicated variable thickness shape.　　 [0054] Variations of the rolling mill 10 Next, variations of the rolling mills 10, 20, 30, and 40 according to this embodiment will be described using FIG. Like the rolling mill 10, the rolling mill 50 of this modification includes a pair of work rolls 52. However, each work roll 52 includes a cylindrical roll body 54 whose radius is fixed in the circumferential direction and the axial direction, and a cam 56 which is detachably mounted on one of an outer circumferential surface of the roll body 54 section. When viewed from the axial direction of the roller body 54, each cam 56 has a substantially semi-circular arc shape. The cam 56 has a shape giving the blank material B a thickness change (variable thickness type shape). [0055] The rolling mill 50 further includes a pair of backup rolls 58 that support the pair of work rolls 52 from the upper and lower sides. The support rollers 58 are arranged such that the work rollers 52 are positioned between them and face each other. The support rollers 58 are arranged parallel to the pair of work rollers 52. Each backup roller 58 is in contact with a side of the roller body 54 of the corresponding one of the work rollers 52 where the cam 56 is not installed. While the blank material B is being rolled by the pair of work rolls 52, the backup rolls 58 prevent or suppress the elastic deformation of the pair of work rolls 52 due to excessive reaction from the blank material B (workpiece) ( Skew). Therefore, commonly known as crowning can be prevented or suppressed. [0056] In order to use the rolling mill 50 to roll the blank material B, each work roll 52 is rotated like a pendulum in a forward direction and an opposite direction within a range, within which A radius of the work roll 52 is a fixed area (in this example, an area on the outer circumferential surface of the roll body 54 where the cam 56 is not installed) and a corresponding one of the support rolls 58 is in contact ( (See arrows SW1 and SW2 in FIG. 11). [0057] Therefore, when the rolling mill 50 performs rolling on the blank material B, it is absolutely necessary that the work rolls 52 are continuously rotated during rolling. As with the rolling mill 50, a half-split structure of the cam 56 (processing member) of the pair of work rolls 52 can be employed by rotating the pair of work rolls 52 forward like a pendulum Roll in the opposite direction. This can prevent unstable behavior that occurs when an area of the work roll 52 having a varying radius comes into contact with the pair of backup rolls 58 so that the pair of work rolls 52 can be stably (smoothly) rotated. Therefore, the pair of work rolls 52 can give the blank material B a plate thickness variation with extremely high accuracy. [0058] In detail, in FIG. 5 of JP 2015-033719 A, which discloses the manufacturing method of the variable-thickness steel plate, a configuration is shown in which the support rollers 33, 34 (the cross-sectional shape of which is different from the cylindrical shape Work rolls 31, 32) are provided to the work rolls 31, 32, and when the work rolls 31, 32 are moved up and down along the shape of the support rolls 33, 34, a variable thickness type shape is given to a roll Rolled material. However, according to this configuration, the rotation of the work rolls 31, 32 and the backup rolls 33, 34 is momentarily unstable when these rolls contact each other at the corners (ends) of the areas where the backup rolls 33, 34 have a radius r4. For this reason, it will be difficult to stably give a variable thickness shape to a material to be rolled. In this regard, according to this variation, a variable thickness shape can be stably given to the blank material B through the steady rotation of the pair of work rolls 52. [0059] In the rolling mill 50, the work roll 52 whose radius changes in the circumferential direction and in the axial direction is fixed in the circumferential direction and in the axial direction by installing the cam 56 in the radius The roller body 54 is formed on a part of the outer circumferential surface. Since the cam 56 is detachably mounted on the roller body 54, the thickness of the blank material B can be given an arbitrary change by replacing the cam 56. Furthermore, the cam 56 can be replaced separately during maintenance, which contributes to improving maintainability.　　 [0060] Example 　　 Next, an example of a vehicle body member (frame member) made of a variable thickness steel plate according to this embodiment will be described with reference to FIGS. 12 to 16. Arrows FR, UP, and OUT, which are marked as necessary in FIGS. 12 to 16, respectively mark the front side of the vehicle, the upper side of the vehicle, and the outer side in the vehicle width direction.　　 [0061] FIGS. 12 to 14 show a central pillar reinforcement 60 manufactured using a variable thickness steel plate according to this embodiment. The central pillar reinforcement 60 has: a side wall 60A; a front wall 60B and a rear wall 60C, which extend from the front and rear sides of the front wall 60A toward the vehicle width direction inside; and a front flange 60D and A rear flange 60E, which extends toward the opposite side from the ends of the front wall 60B and the rear wall 60C on the inner side in the vehicle width direction, respectively. [0062] In the central pillar reinforcement 60, a thick plate portion 62 (see the hatched area in FIGS. 12 to 14) is provided on the upper portion of the side wall 60A, the front wall 60B, and the rear wall 60C, while the others Some have a smaller board thickness. More specifically, the center pillar reinforcement 60 is formed such that the thickness of the plate gradually decreases toward the upper/lower upward sides of the vehicle of the thick plate portion 62, and the plate thickness of the front wall 60B and the rear wall 60C The level at which the thick plate portion 62 is provided gradually decreases toward the front flange 60D and the rear flange 60E (see arrows A1 to A3 in FIGS. 13 and 14). Therefore, the strength of the upper portion of the center pillar reinforcement 60 that protects the vehicle cabin is strengthened, and the lower portion of the center pillar reinforcement 60 that absorbs energy in the event of a lateral collision of the vehicle, etc., and does not require strong front and rear flanges 60D, 60E are reduced in thickness and weight.　　 [0063] Similarly, FIG. 15 shows a front pillar lower part 70 made of a variable thickness steel plate according to this embodiment. The front pillar lower member 70 has: a side wall 70A; a front wall 70B and a rear wall 70C, which extend from the front side and the rear side of the front wall 70A toward the inside in the vehicle width direction; and a front flange 70D and A rear flange 70E, which extends toward the opposite side from the ends of the front wall 70B and the rear wall 70C on the inner side in the vehicle width direction, respectively. In the front pillar lower part 70, a thick plate portion 72 (see the hatched area in FIG. 15) is provided in the upper/lower upward middle portion of the side wall 70A, the front wall 70B and the rear wall 70C, while the others Some have a smaller board thickness. The front pillar lower member 70 is formed so that the thickness of the board gradually decreases toward both sides of the thick plate portion 72 above/below the vehicle, and the board thickness of the front wall 70B and the rear wall 70C is provided with the The level of the thick plate portion 72 gradually decreases toward the front flange 70D and the rear flange 70E. The front pillar lower part 70 can provide the same functional benefits as the central pillar reinforcement 60. [0064] On the other hand, FIG. 16 shows a front floor member 80 made of a variable-thickness steel plate according to this embodiment. In the front floor member 80, a floor tunnel 80A, which is provided at the central portion in the vehicle direction, which protrudes toward the upper side of the vehicle, and each side of the floor tunnel 80A, which is provided on both sides in the vehicle width direction A left floor portion 80B and a right floor portion 80C are formed into a substantially flat board shape. In the front floor member 80, the middle portions of the left floor portion 80B and the right floor portion 80C in the front/rear direction of the vehicle (see the hatched area in FIG. 16) constitute a thin plate portion 82, which has a plate thickness greater than that of other portions Small board thickness. [0065] The front floor member 80 corresponds to a stamping member in the present invention, and cold stamping is performed on the variable thickness steel plate TB1 or the variable thickness steel plate TB2 without performing heat treatment (for example, annealing) Processing to manufacture. Therefore, in the thin plate portion 82 (that is, the portion rolled by the manufacturing method of the variable-thickness steel plate according to this embodiment), the work hardening condition is maintained after the thickness is reduced. The yield strength of the thin plate portion 82 has been strengthened due to work hardening. According to the front floor member 80, the middle portions of the left floor portion 80B and the right floor portion 80C in the vehicle front/rear direction that tend to lack strength are strengthened by work hardening, and at the same time, the thickness of the middle portion is Decrease. Therefore, the strength of the front floor member 80 is locally strengthened and its weight is reduced.　　 [0066] The present invention is extremely versatile, because many vehicle body members in which work hardening is locally formed as described above are expected to have advantageous effects. The board thickness of a vehicle body member (frame member) is typically set according to the part where it is required to be strong, so that the board thickness of other parts that it is not required to be strong usually has an excessive board thickness. However, using the variable thickness steel plate of the present invention can remove this excessive plate thickness. Therefore, the present invention is a technology that can be widely applied to frame components to reduce the weight of a vehicle.　　 [0067] The present invention has been described above by showing the embodiment and some examples, but the present invention can be implemented with many variations, which are achieved within the scope of the gist of the present invention. It should be understood that the scope of the rights of the present invention is not limited to the above embodiments.

[0068] B ‧‧‧ blank material TB1 ‧ ‧ ‧ variable thickness steel plate TB 2 ‧ ‧ ‧ variable thickness steel plate 10 ‧ ‧ ‧ roll mill 12 ‧ ‧ work roll 12A ‧ ‧ concave part 20 ‧ ‧ ‧ 30 ‧‧Rolling machine 40‧‧‧Rolling machine 22‧‧‧Work roll 22A‧‧‧Concave part 32‧‧‧Work roll 32A‧‧‧Concave part 42‧‧‧Working roll 42A‧‧‧Concave part B2‧‧‧Blank material B1 ‧‧‧Blank material S‧‧‧Steel plate R1‧‧‧Uncoiler R2‧‧‧Rewinder L1‧‧‧Blank line L2‧‧‧Blank line S1‧‧‧Thick plate part S2‧‧‧Thin plate part SB ‧‧‧Steel plate SC‧‧‧Scrap P‧‧‧Part shape 50‧‧‧Roll mill 52‧‧‧Work roll 54‧‧‧Roll main body 56‧‧‧Cam 58‧‧‧Back roller 60‧‧‧Central column Reinforcement 60A‧‧‧Side wall 60B‧‧‧Front wall 60C‧ Rear wall 60D‧‧‧Front flange 62‧‧‧Thick plate part 60E‧‧‧Front flange 70‧‧‧Front pillar lower part 70A‧ ‧‧Side wall 70B‧‧‧Front wall 70C‧‧‧Back wall 70D‧‧‧Front flange 72‧‧‧Thick plate part 70E‧‧‧Flange 80‧‧‧Front floor piece 80A‧‧‧Floor tunnel 80B ‧‧‧Left floor part 80C‧‧‧Right floor part 82‧‧‧Thin plate part

[0024] The features, benefits, and technical and industrial importance of the exemplary embodiments of the present invention are described below with reference to the accompanying drawings, in which the same element symbols denote the same elements, and among them: 　　 FIG. 1 is a perspective view, It illustrates a single-step rolling process in a method of manufacturing a variable-thickness metal plate (variable-thickness steel plate) according to an embodiment of the present invention; FIG. 2 is a side view of the single-step rolling process; FIG. 3 is a A perspective view illustrating the first step of the multi-step rolling process in the manufacturing method of the variable thickness steel plate according to the embodiment of the present invention; FIG. 4 is a perspective view illustrating the embodiment of the variable thickness steel plate according to the embodiment of the present invention The second step of the multi-step rolling process in the manufacturing method; FIG. 5 is a perspective view illustrating the third step of the multi-step rolling process in the manufacturing method of the variable-thickness steel plate according to the embodiment of the present invention; 　　 FIG. 6 Is a perspective view illustrating an example of a material (variable thickness steel plate) that has been rolled by the manufacturing method of a variable thickness steel plate of the prior art; FIG. 7 is a plan view whose illustration is implemented in An example of blanking on the variable-thickness steel plate that has been rolled by the manufacturing method of the prior-art variable-thickness steel plate; FIG. 8 is a perspective view illustrating an example of the cutting process according to an embodiment of the present invention Examples of punching; 　　 FIG. 9 is a perspective view illustrating the combination-cut punching material combined by punching according to an embodiment of the present invention; 　　 FIG. 10 is a perspective view showing a roll being rolled according to the present invention Image of rolled blanks; 　　 FIG. 11 is a side view showing a modified example of a processing machine according to an embodiment of the present invention; 　　 FIG. 12 is manufactured using a method of manufacturing a variable thickness steel plate according to an embodiment of the present invention The front view of the central pillar reinforcement manufactured by using the variable thickness steel plate as the material; 　　 FIG. 13 is a cross-sectional view taken along XIII-XIII of FIG. 12; 　　 FIG. 14 is a perspective view of the central pillar reinforcement; 　　 FIG. 15 is used A front view of a lower part of a front pillar manufactured by using a variable thickness steel plate manufactured by a method of manufacturing a variable thickness steel plate according to an embodiment of the present invention as a material; and FIG. 16 is a variable thickness steel plate according to an embodiment of the present invention A perspective view of a front floor member manufactured by using a variable-thickness steel plate manufactured by the manufacturing method as a material.

10‧‧‧Rolling mill

12‧‧‧Work roller

12A‧‧‧recess

TB1‧‧‧ variable thickness steel plate

B‧‧‧ Blank material

Claims (8)

A manufacturing method of a variable-thickness metal plate, the manufacturing method comprising: manufacturing a cutting plate by cutting a metal plate into a predetermined shape; and at least one of rolling and forging by using a processing machine The processing of the cutting plate to produce a variable thickness metal plate, its plate thickness changes in two different directions at right angles to the plate thickness direction, the processing machine includes a first work roll and a second work roll , The second work roll has a shaping surface, wherein the radius in the area of the shaping surface of the second work roll changes in the circumferential direction and axis direction of a rotation axis and the shaping surface is a concave portion Or a protruding portion, wherein the processing machine includes a first support roll, which is disposed on the opposite side of the first work roll away from the second work roll and is in contact with the first work roll, and a second support Roller, which is arranged on the opposite side of the second work roll away from the first work roll and is in contact with the second work roll, and when manufacturing the variable-thickness metal plate, the cutting plate is made by Turning the first work roll in the forward direction and the opposite direction within a range of a fixed radius area of the first work roll contacting the first support roll, and in the second work The second work roll is rotated in a forward direction and an opposite direction to be processed within a range where a fixed radius area of the roll contacts the second backup roll. A manufacturing method of variable thickness metal plate, the manufacturing method includes: Manufacturing a cutting plate by cutting a metal plate into a predetermined shape; and by using a first work roll and a second work roll (the second work roll has a shaping surface, in which (A radius of the area of the shaping surface of the second work roll changes in the circumferential direction or axis direction of a rotation axis and the shaping surface is a concave or convex portion), and a first processing machine including a The second processing machine for work rolls (the shape of which is different from the first work roll and the second work roll of the first processing machine) sequentially processes the cut plate by at least one of rolling and forging to manufacture A variable thickness metal plate whose thickness varies in two different directions at right angles to the thickness direction of the plate, wherein, when the variable thickness metal plate is manufactured, the cutting plate is fed into the first processing machine The inner direction is changed to a direction different from the direction in which the cutting board is fed into the second processing machine. A method for manufacturing a variable-thickness metal sheet as claimed in item 2 of the patent scope, wherein the first processing machine includes a first backup roll, which is disposed on the opposite side of the first work roll away from the second work roll And is in contact with the first work roll, and a second backup roll, which is disposed on the opposite side of the second work roll away from the first work roll and is in contact with the second work roll, and when the change is made In the case of a thick-type metal plate, the cutting plate rotates the first work roll forward in a range where a radius of the first work roll is fixed and in contact with the first support roll Direction and the opposite direction, and a fixed radius area of the second work roll and The second work roll is rotated in the forward direction and the opposite direction within the range where the second backup roll is in contact. A method of manufacturing a pressed component, the method comprising: manufacturing a partially-processed variable-thickness metal plate by using the variable-thickness metal plate manufacturing method according to any one of claims 1 to 3; And the pressed part is manufactured by performing cold rolling bending on the untreated portion of the variable thickness metal plate that has been partially processed. A processing machine for manufacturing a variable-thickness metal plate, the processing machine including: a first work roll; and a second work roll having a shaped surface, wherein the shaped surface of the second work roll The radius in the area of is changed in the circumferential direction and axis direction of a rotation axis and the shaping surface is a concave portion or a convex portion, wherein the processing machine includes a first support roller, which is provided in the first work The roller is on the opposite side of the second work roll away from and in contact with the first work roll, and a second backup roll is disposed on the opposite side of the second work roll away from the first work roll and is The second work roll is in contact, and when the variable thickness metal plate is manufactured, the cutting plate is in contact with the first backup roll through a fixed radius area of the first work roll Rotate the first work roll in the forward direction and the opposite direction Upwards, and within a range where a fixed radius area of the second work roll contacts the second backup roll, the second work roll is rotated in the forward direction and the opposite direction to be processed. A processing machine as claimed in item 5 of the patent application, wherein the second work roll includes a second roll body whose radius is fixed in the circumferential direction of the rotation axis and the axis direction, and a first Two cams, which are detachably mounted on a part of the outer circumferential surface of the second roller body. For example, the processing machine of claim 5 or 6, wherein the radius of the first work roll varies in the circumferential direction and axis direction of a rotation axis. A processing machine as claimed in item 7 of the patent application, wherein the first work roll includes a first roll body whose radius is fixed in the circumferential direction of the rotation axis and the axis direction, and a first A cam is detachably mounted on a part of the outer circumferential surface of the first roller body.

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