KR20210118792A - 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, a cut plate (B) is manufactured first by cutting a metal plate having a predetermined thickness into a predetermined shape. Next, a thickness-varied metal plate (TB1) is manufactured by pressing the cut plate (B) with a processing machine (10) comprising a pair of work rolls. Here, one of the pair of work rolls has a radius that varies in a circumferential direction or an axial direction. Accordingly, the thickness-varied metal plate (TB1) manufactured by pressing the cut plate (B) with the processing machine (10) is configured so that the plate thickness varies in two different directions orthogonal to the plate thickness direction. Therefore, the degree of freedom in setting a plate thickness variation for a thickness-varied metal plate can be increased.

Description

Manufacturing method of metal plate with difference in thickness, manufacturing method and processing machine of press parts

The present invention relates to a method for manufacturing a metal plate with a difference in thickness, a method for manufacturing a press part using a metal plate with a difference in thickness, and a processing machine used for manufacturing a metal plate with a difference in thickness.

In the method for manufacturing a steel sheet with a difference in thickness described in Japanese Patent Application Laid-Open No. 2015-033719, at least one of a pair of work rolls included in a two-stage rolling mill is formed so that the radius thereof changes in the circumferential direction. Then, a steel sheet (metal sheet) is inserted between the pair of work rolls and rolled, whereby a steel sheet (metal sheet with a difference in thickness) having a thickness difference in which the sheet thickness is partially changed is manufactured.

However, in the method for manufacturing a steel sheet with a difference in thickness, since the direction in which the sheet thickness of the steel sheet is changed is limited to one direction perpendicular to the sheet thickness direction (the conveyance direction of the steel sheet), the viewpoint of improving the degree of freedom in setting the sheet thickness change There is room for improvement in

This invention provides the manufacturing method of the metal plate with a thickness difference which can improve the setting freedom of the plate|board thickness change in the metal plate with a thickness difference, the manufacturing method of a press part, and a processing machine.

A first aspect of the present invention is a process for manufacturing a cutting plate by cutting a metal plate into a predetermined shape, and a processing machine having a first work roll and a second work roll whose radius is changed in the circumferential and axial directions of a rotation axis. By processing the cut plate by at least one of rolling and forging, it relates to a method for manufacturing a metal plate with a difference in thickness, comprising the steps of: .

According to the first aspect of the present invention, first, a metal plate (eg, a steel plate) is cut into a predetermined shape to produce a cut plate. Next, the cut plate is processed by at least one of rolling and forging by one (single) processing machine having a pair of work rolls (first and second work rolls) to manufacture a metal plate having a different thickness. Here, the radius of the 2nd work roll with which the said processing machine was equipped is changed in the circumferential direction and an axial direction of a rotation axis line. Thereby, the metal plate with a thickness difference manufactured by processing a cutting plate by the said processing machine becomes the structure in which the plate|board thickness was changed in two different directions orthogonal to a plate|board thickness direction. Therefore, according to a 1st aspect, the setting freedom degree of the plate|board thickness change in the metal plate with a thickness difference can be improved.

1st aspect of this invention WHEREIN: The 1st backup roll which is arrange|positioned on the opposite side to the said 2nd work roll across the said 1st work roll, and is in contact with the said 1st work roll, and the said 2nd work roll is interposed A second backup roll disposed on the opposite side to the first work roll and in contact with the second work roll is installed in the processing machine, and when manufacturing a metal plate having the thickness difference, the radius in the first work roll is The second work roll is rotated forward and reverse within a range in which a constant area is in contact with the first backup roll, and a region with a constant radius in the second work roll is in contact with the second backup roll. You may process the said cutting board by rotating a roll forward and reverse.

According to the said 1st aspect, since a pair of backup rolls (1st and 2nd backup roll) are provided in a processing machine, generation|occurrence|production of a so-called crown can be prevented or suppressed. In addition, when a cutting plate is processed by a processing machine, a pair of work rolls rotate forward and reverse within the range in which the area|region with a fixed radius in a pair of work rolls contact|connects a pair of backup rolls. Thereby, since the unstable behavior when the area|region with a changed radius and a pair of backup rolls contact|connects a pair of work rolls does not generate|occur|produce, it can rotate a pair of work rolls stably (smoothly). As a result, the precision of the plate|board thickness change provided to a cutting board by a pair of work rolls becomes favorable.

A second aspect of the present invention provides a step of manufacturing a cut plate by cutting a metal plate into a predetermined shape, and a first work roll comprising a first work roll and a second work roll whose radius is changed in the circumferential or axial direction of a rotation axis. The cutting plate is sequentially processed by at least one of rolling and forging by a second processing machine including a processing machine and a pair of work rolls having different shapes of the first processing machine and the work rolls (first and second work rolls) It has the process of manufacturing the metal plate with the thickness difference by which plate|board thickness was changed in two different directions orthogonal to a plate|board thickness direction by doing this.

According to the second aspect of the present invention, first, a metal plate (eg, a steel plate) is cut into a predetermined shape to produce a cut plate. Next, a first processing machine including a first work roll and a second work roll whose radius is changed in the circumferential or axial direction of the rotation axis, and a pair of work rolls having different shapes from the first processing machine and the work roll The cut plate is processed by at least one of sequential rolling and forging by a second processing machine to manufacture a metal plate having a difference in thickness. Here, the shape of a pair of work rolls is different for each of the said 1st processing machine and a 2nd processing machine. Since a cut plate is processed sequentially by a 1st processing machine and a 2nd processing machine, it becomes possible to manufacture the metal plate with the thickness difference from which the plate|board thickness changed in two different directions orthogonal to a plate|board thickness direction. Therefore, according to a 2nd aspect, the setting freedom degree of the plate|board thickness change in the metal plate with a thickness difference can be improved.

In said 2nd aspect, when manufacturing the metal plate with the said thickness difference, the conveyance direction of the said cutting plate in the said 1st processing machine is changed to a direction different from the conveying direction of the said cutting board in the said 2nd processing machine, also be

According to the said 2nd aspect, when manufacturing the metal plate with the said thickness difference, the conveyance direction of the cutting plate in the said 1st processing machine is changed to the direction different from the conveying direction of the to-be-processed plate in the said 2nd processing machine. . By this change, since the direction in which a plate|board thickness changes in a cutting board can be changed, it becomes possible to improve further the setting freedom of plate|board thickness change.

Said 2nd aspect WHEREIN: The 1st backup roll which is arrange|positioned on the opposite side to the said 2nd work roll across the said 1st work roll, and is in contact with the said 1st work roll, and the said 2nd work roll between When a second backup roll disposed on the opposite side to the first work roll and in contact with the second work roll is installed in the first processing machine, and a metal plate having the thickness difference is produced, the radius in the first work roll is The second work roll is rotated forward and reverse within a range in which a constant area is in contact with the first backup roll, and a region with a constant radius in the second work roll is in contact with the second backup roll. You may process the said cutting board by rotating a roll forward and reverse.

According to the second aspect, since a pair of backup rolls are provided in the first processing machine, generation of a so-called crown can be prevented or suppressed. In addition, when the cutting board is processed by the said 1st processing machine, within the range which the area|region with a constant radius in a pair of work rolls provided with the said 1st processing machine is in contact with a pair of backup rolls, the said pair of work rolls It is rotated forward and reverse. As a result, unstable behavior when the pair of backup rolls and the area with the changed radius of the pair of work rolls does not come into contact with each other, so that the pair of work rolls can be rotated stably (smoothly). . As a result, the precision of the plate|board thickness change provided to a cutting board by the said pair of work rolls becomes favorable.

A third aspect of the present invention is a method for manufacturing a metal sheet having a thickness difference according to the first or second aspect, a step of manufacturing a metal sheet having a difference in thickness to which a part has been processed; It is related with the manufacturing method of the press part which has the process of performing bending by a press with respect to the site|part to which the process is not given, and manufacturing a press part.

According to the said 3rd aspect, the metal plate with a thickness difference is manufactured by the manufacturing method of the metal plate with a thickness difference of the said 1st aspect or 2nd aspect. Accordingly, effects similar to those of the first aspect and the second aspect are obtained. Next, the bending process by a press is given in cold with respect to the site|part to which the process in the said metal plate with a difference in thickness is not given, and a press component is manufactured. In this press part, in the site|part to which the process was given, the yield strength rises by work hardening, and it is thinned. Therefore, according to a 3rd aspect, the lightweight press part intensified partially can be manufactured.

A 4th aspect of this invention relates to the processing machine provided with a 1st work roll and the 2nd work roll whose radius changed in the circumferential direction and axial direction of a rotation axis line.

Since the said 4th aspect has the structure similar to the processing machine described in the said 1st aspect, it is applicable to the manufacturing method of the metal plate with a thickness difference of the said 1st aspect. Accordingly, effects similar to those in the first aspect are obtained.

In the fourth aspect, the second work roll includes a second roll body having a constant radius in the circumferential direction and the axial direction of the rotation axis, and a second detachably provided on a part of the outer circumferential surface of the second roll body. A cam part may be provided.

According to the fourth aspect, the second cam portion is provided on a part of the outer peripheral surface of the second roll body whose radius is constant in the circumferential direction and the axial direction of the rotation axis, so that the radius is changed in the circumferential direction and the axial direction of the rotation axis. It consists of 2 work rolls. Since the said 2nd cam part is detachable with respect to a 2nd roll main body, an arbitrary plate|board thickness change can be provided to a cutting board by replacement of a 2nd cam part. Moreover, since only the 2nd cam part can be replaced|exchanged at the time of maintenance, it contributes also to the improvement of maintainability.

The said 4th aspect WHEREIN: The radius of the said 1st work roll may change in the circumferential direction of a rotation axis line, and an axial direction.

In the fourth aspect, the first work roll includes a first roll body having a constant radius in the circumferential and axial directions of the rotation axis, and a first cam detachably provided on a part of the outer peripheral surface of the roll body. You may be equipped.

As explained above, in the manufacturing method of the metal plate with a thickness difference, the manufacturing method of a press part, and the processing machine which concern on this invention, the setting freedom degree of the plate|board thickness change in the metal plate with a thickness difference can be improved.

The features, advantages and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings in which like elements are denoted by like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view for demonstrating the single rolling process in the manufacturing method of the metal plate (steel plate with a difference in thickness) which concerns on embodiment of this invention.
2 is a side view for explaining a single rolling process.
It is a perspective view for demonstrating the 1st process of the multiple rolling process in the manufacturing method of the steel plate with a thickness difference which concerns on embodiment of this invention.
It is a perspective view for demonstrating the 2nd process of the multiple rolling process in the manufacturing method of the steel plate with a thickness difference which concerns on embodiment of this invention.
It is a perspective view for demonstrating the 3rd process of the multiple rolling process in the manufacturing method of the steel plate with a thickness difference which concerns on embodiment of this invention.
6 is a perspective view of a material to be rolled (steel sheet with a difference in thickness) subjected to rolling processing by the method for manufacturing a steel sheet having a thickness difference in the related art.
7 is a plan view for explaining an example of blank processing on a steel sheet with a difference in thickness subjected to rolling processing by a method for manufacturing a steel sheet with a difference in thickness in the related art.
It is a perspective view for demonstrating an example of the blank processing in the cutting process which concerns on embodiment of this invention.
9 is a perspective view of a blank material cut in combination by blank processing according to an embodiment of the present invention.
10 is a perspective view showing an image at the time of rolling processing of the blank material according to the present embodiment.
It is a side view which shows the modified example of the processing machine which concerns on embodiment of this invention.
It is a front view of the center pillar reinforcement manufactured using the steel plate with a thickness difference manufactured by the manufacturing method of the steel plate with a thickness difference which concerns on embodiment of this invention as a material.
13 is a cross-sectional view taken along line XIII-XIII of FIG. 12 .
14 is a perspective view of the center pillar reinforcement.
15 is a front view of a front pillar lower part manufactured using, as a material, a steel sheet with a difference in thickness manufactured by the method for manufacturing a steel sheet with a difference in thickness according to an embodiment of the present invention.
It is a perspective view of the front floor manufactured using the steel plate with a thickness difference manufactured by the manufacturing method of the steel plate with a thickness difference which concerns on embodiment of this invention as a material.

Hereinafter, the manufacturing method of the metal plate with a thickness difference which concerns on embodiment of this invention, the manufacturing method of a press component, and a processing machine are demonstrated using FIG.1-16. The method for manufacturing a metal sheet with a difference in thickness according to the present embodiment is for manufacturing a steel sheet with a difference in thickness (metal sheet with a difference in thickness) that can be used as a material of, for example, a vehicle body component (pressed component) constituting an automobile body. It is a method, and has a cutting process and a rolling process (processing process). Hereinafter, the manufacturing method of the metal plate with a thickness difference which concerns on this embodiment is called "the manufacturing method of the steel plate with a thickness difference."

In the above-described cutting step, a steel sheet (metal sheet) having a predetermined thickness is cut into a predetermined shape (here, a rectangular shape) by means such as press working, and the blank material shown in Figs. A sheet to be rolled) (B) is manufactured. In addition, the shape of the blank material B is not limited to a rectangular shape, It can be set as arbitrary shapes. In addition, the manufacturing method of the steel plate with a thickness difference which concerns on this embodiment is applicable with respect to the metal plate which has plasticity as well as a steel plate.

Next, in the rolling process, the blank material B is rolled by a rolling mill (processing machine) (it may be processed by at least one of rolling and forging (pressurization)), and the steel sheet TB1 having a difference in thickness (FIGS. 1 and FIG. 2) or a steel plate TB2 (see FIG. 5) having a different thickness is manufactured. In this rolling process, there are two types: the single rolling process (single processing process) shown in FIGS. 1 and 2, and the multiple rolling process (multiple processing process) shown in FIGS. are hired Hereinafter, the said two types of rolling processes are demonstrated.

(Independent rolling process)

In the single rolling process shown in FIGS. 1 and 2 , the blank material B is rolled by one (single) rolling mill 10 to manufacture a steel sheet TB1 having a difference in thickness. This rolling mill 10 is a two-stage rolling mill, and is provided with a pair of substantially cylindrical work rolls 12 arranged in the upper and lower two stages in a mutually parallel attitude|position. These work rolls 12 are rotatably supported by a housing (not shown), and are rotationally driven in synchronization with each other by a driving device (not shown). Between the work rolls 12, a prescribed gap (a gap narrower than the plate thickness of the blank material B) is set. In addition, in FIG.1 and FIG.2, for convenience of description, the work roll 12 is spaced apart from reality, and is shown. This point is the same also in FIGS.

1 and 2, in the outer peripheral surface (processing surface) of the work roll 12, a recess (forming surface) for imparting a plate thickness change (a shape with a difference in thickness) with respect to the blank material B. (12A) is formed. This recessed part 12A may be formed in only one side of the work roll 12. As shown in FIG. In addition, the shaping|molding surface may not be the recessed part 12A, but a convex part may be sufficient. This recessed part 12A is shape|molded in the shape corresponding to the target shape of the steel plate TB1 with a thickness difference manufactured by a single rolling process. And, the above-mentioned target shape is a shape corresponding to the plate thickness change (shape with a difference in thickness) required for a press part (automobile body component) manufactured using the steel plate TB1 with a difference in thickness.

The concave portion 12A described above is formed only in a portion of the peripheral surface of the pair of work rolls 12 in the circumferential direction. For this reason, the radius of each work roll 12 is reduced in the area|region of the circumferential direction in which the recessed part 12A was set compared with the area|region of the circumferential direction in which the recessed part 12A is not set. Moreover, in the recessed part 12A, the depth of the recessed part in the axial direction center part of each work roll 12 is deepened, and the radius of each work roll 12 is further reduced in the said deepening area|region. As a result, each work roll 12 has a configuration in which the radius is changed in both the circumferential direction and the axial direction. These work rolls 12 are configured to be rotationally driven in synchronization so as to always maintain a vertically symmetrical rotational posture (refer to arrows R in FIGS. 1 and 2 ). In addition, the shape of the said recessed part 12A is a simple example, and can be changed suitably.

In the independent rolling process using the rolling mill 10 of the said structure, the blank material B is inserted and rolled between the work rolls 12 in the said rolling machine 10 (refer arrow RM in FIGS. 1 and 2). ), the shape of the work surface of the work roll 12 is transferred to the blank material B. Thereby, the steel sheet TB1 (FIG. 1 and FIG. 2) with a thickness difference in which the sheet thickness is changed in two different directions (arrow X direction and arrow Y direction in FIG. 1) orthogonal to the sheet thickness direction (arrow Z direction in FIG. 1) see) is prepared.

(Multiple rolling process)

On the other hand, the multiple rolling process is comprised by the some process (here 1st process thru|or 3rd process) shown in FIGS. 40), the blank material B is sequentially rolled to manufacture a steel plate TB2 with a difference in thickness. This rolling mill 20 has a structure fundamentally similar to the rolling mill 10 mentioned above, and is equipped with the pair of work rolls 22 in which the recessed part 22A was formed in the outer peripheral surface. This rolling mill 30 has the structure fundamentally similar to the rolling mill 10 mentioned above, and is provided with the pair of work rolls 32 in which the recessed part 32A was formed in the outer peripheral surface. This rolling mill 40 has the structure fundamentally similar to the rolling mill 10 mentioned above, and is provided with the pair of work rolls 42 in which the recessed part 42A was formed in the outer peripheral surface. The recessed portion 22A may be formed only on one side of the work roll 22 . The recessed portion 32A may be formed on only one side of the work roll 32 . The recessed portion 42A may be formed on only one side of the work roll 42 . In addition, the outer peripheral surface may be provided with the convex part instead of the recessed parts 22A, 32A, and 42A. However, these work rolls 22, 32, 42 differ in shape from the work roll 12 mentioned above. In addition, these pair of work rolls 22, 32, 42 differ in shape from each other.

Specifically, the rolling mill 20 (refer FIG. 3) used for a 1st process is equipped with the work roll 22 whose radius changed in the circumferential direction. A recessed portion 22A is formed on an outer peripheral surface (processed surface) of the work roll 22 . This recessed part 22A is formed only in a part of the circumferential direction in the outer peripheral surface of the work roll 22, and is formed in a fixed shape along the axial direction of the work roll 22. As shown in FIG.

On the other hand, the rolling mill 30 (refer FIG. 4) used for a 2nd process is equipped with the work roll 32 in which the radius was changed in the axial direction. A recessed portion 32A is formed on an outer peripheral surface (processed surface) of the work roll 32 . This recessed part 32A is formed in the central part of the axial direction in the outer peripheral surface of the work roll 32, and is formed in a fixed shape along the circumferential direction of the work roll 32. As shown in FIG.

On the other hand, the rolling mill 40 (refer FIG. 5) used for a 3rd process is equipped with the work roll 42 whose radius changed in the circumferential direction. A recessed portion 42A is formed on an outer peripheral surface (processed surface) of the work roll 42 . This recessed part 42A is formed only in a part of the circumferential direction in the outer peripheral surface of the work roll 42, and is formed in a fixed shape along the axial direction of the work roll 42. As shown in FIG.

In the multiple rolling process using the rolling mills 20, 30, 40 of the said structure, first, in the 1st process shown in FIG. 3 WHEREIN: A blank material (B) between the work rolls 22 in the rolling mill 20. is inserted and rolled (refer to arrow RM of FIG. 3), and the shape of the work surface of the work roll 22 is transcribe|transferred to the blank material B. Next, in the second step shown in FIG. 4 , the blank material B1 after the first step is inserted between the work rolls 32 in the rolling mill 30 and rolled (refer to the arrow RM in FIG. 4 ), The shape of the work surface of the work roll 32 is transcribe|transferred to the blank material B1.

Next, in the 3rd process shown in FIG. 5, first, the blank material B2 after a 2nd process is rotated 90 degree|times in planar view (refer arrow T in FIG. 5). Then, the blank material B is inserted between the work rolls 42 in the rolling mill 40 and is rolled (refer arrow C and arrow RM of FIG. 5). Thereby, the steel plate TB2 (refer to FIG. 5) with a thickness difference in which the plate thickness is changed in two different directions (arrow X direction and arrow Y direction in FIG. 5) orthogonal to the plate thickness direction (arrow Z direction in FIG. 5) It is made up of a composition. In addition, in this embodiment, by passing the 2nd process before the 3rd process, the blank material B2 (steel plate with a difference in thickness) in which the plate|board thickness was changed in two different directions orthogonal to the plate-thickness direction is manufactured. has been For this reason, it is good also as a structure in which the 3rd process was abbreviate|omitted.

In the above-described plurality of rolling processes, when the blank material B is rotated 90 degrees in plan view in the third step, the feeding direction of the blank material B2 in the rolling mill 40 is to the rolling mills 20 and 30 . It has a structure changed in the direction different from the conveyance direction of the blank materials B and B1 in this. In addition, the above-mentioned "transfer direction of the blank material B2" is a plane-viewed direction of the blank material B with respect to the rolling mill 40 at the time of rolling of the blank material B2 by the rolling mill 40. In other words, the "transfer direction of the blank materials B and B1" described above is the blank material ( It refers to the direction seen from the plane of B, B1). In addition, the distribution and combination of rolling in a multiple rolling process can be changed freely.

(heat treatment)

Next, the heat treatment of the steel plates TB1 and TB2 having the thickness difference will be described. In the present embodiment, the steel sheets TB1 and TB2 having different thicknesses manufactured through the above-described rolling process (single rolling process or multiple rolling process) are subjected to bending in the subsequent pressing process, and are formed into a predetermined shape. do. However, in the steel sheets TB1 and TB2 having these thickness differences, since work hardening has occurred in the portion subjected to rolling processing, plastic working thereafter becomes difficult as it is. For this reason, this embodiment presupposes heat-processing with respect to the steel plates TB1, TB2 with a thickness difference after a rolling process.

Specifically, for example, the pressing process after the rolling process becomes a hot pressing process. In this hot pressing process, before press working, steel plates TB1 and TB2 with a thickness difference are heated to predetermined temperature by means, such as high frequency dielectric heating, for example. At the time of this heating, it has a structure in which work hardening by rolling processing (processing with a difference in thickness) is removed.

Moreover, for example, when the pressing process after a rolling process becomes a cold pressing process, before a cold pressing process, the annealing process of annealing the steel plates TB1 and TB2 with a thickness difference is added. In this annealing process, it has a structure in which said work hardening is removed. In this way, although the number of processes increases by adding an annealing process, use as a normal cold-pressed part becomes possible.

However, the steel sheets TB1 and TB2 with a difference in thickness according to the present embodiment are not limited to the above-described heat treatment. That is, in the steel sheets TB1 and TB2 having a difference in thickness according to the present embodiment, the strength can be partially increased by using the increase in yield strength in the state where work hardening is maintained as it is. As a result, compared with the case where the thickness of the whole steel plate with a thickness difference is increased for strength increase, for example, it becomes possible to achieve thickness reduction and weight reduction of the steel plate with a thickness difference.

(action and effect)

Next, the operation and effect of the present embodiment will be described.

According to the manufacturing method of the steel plate with a thickness difference which concerns on this embodiment, in a cutting process, the steel plate of a fixed plate thickness is cut|disconnected into a predetermined shape, and the blank material B is manufactured. Next, it transfers to a rolling process. This rolling process turns into either a single rolling process and a multiple rolling process. When the rolling process is a single rolling process, the blank material B is rolled by the single rolling mill 10 provided with a pair of work rolls 12, and the steel plate TB1 with a thickness difference is manufactured. Here, each work roll 12 with which the said rolling mill 10 was equipped has the structure in which the radius changed in the circumferential direction and the axial direction. Thereby, the steel plate TB1 with a thickness difference produced by rolling the blank material B by the rolling mill 10 becomes the structure in which the plate|board thickness was changed in two different directions orthogonal to the plate|board thickness direction. Therefore, compared with the manufacturing method of a steel sheet with a thickness difference described in the column of the background art (hereinafter simply referred to as "a method for manufacturing a steel sheet with a thickness difference in the related art"), it is possible to improve the degree of freedom in setting the sheet thickness change.

On the other hand, when the rolling process is a multiple rolling process, the blank material B is used by a plurality of rolling mills 20, 30, 40 each provided with work rolls 22, 32, 42 whose radii are changed in the circumferential or axial direction. ) are sequentially rolled to manufacture a metal plate TB2 having a difference in thickness. Here, in the plurality of rolling mills 20 , 30 , 40 , the shape of the pair of work rolls 22 , 32 , 42 is different for each. Since the blank material B is sequentially rolled by these plurality of rolling mills 20, 30, 40, it is possible to manufacture a steel sheet TB2 having a thickness difference in which the sheet thickness is changed in two different directions orthogonal to the sheet thickness direction. becomes Therefore, compared with the conventional manufacturing method of a steel plate with a thickness difference, the setting freedom of plate thickness change can be improved.

As described above, in the present embodiment, in the case where the rolling process is any of the single rolling process and the plurality of rolling processes, the plate thickness in two different directions (arbitrary directions in the plane orthogonal to the plate thickness direction) orthogonal to the plate thickness direction. A steel plate (TB1 or TB2) having a different thickness can be manufactured. This makes it possible to change the thickness of the body component parts manufactured using the steel plates TB1 or TB2 with different thicknesses in free directions such as the vehicle vertical direction and the vehicle front-rear direction, so that the strength and rigidity required for the vehicle body It becomes possible to achieve weight reduction of the vehicle body while securing the

In addition, in a single rolling process, since the steel plate TB1 with a thickness difference is manufactured only by rolling the blank material B with the single rolling mill 10, a manufacturing process is simplified, and it contributes to cost reduction. On the other hand, in the multiple rolling process, the blank material (B) is sequentially rolled by a plurality of rolling mills (20, 30, 40) to produce a steel sheet (TB2) with a difference in thickness, so the working force for rolling the blank material (B) can be dispersed in each rolling mill (20, 30, 40). Thereby, it becomes easy to ensure the durability of each rolling mill 20, 30, 40.

In addition, in the multiple rolling process, the conveyance direction of the blank material B in one rolling mill 40 among the plurality of rolling mills 20, 30, 40 is the blank material in the other rolling mills 20, 30 ( It is changed in a direction different from the conveying direction of B). By this change, since the direction in which the plate thickness changes in the blank material B can be changed, it becomes possible to further improve the degree of freedom in setting the plate thickness change, and provides a complicated shape to the steel plate TB2 with a difference in thickness. can do.

In addition, in this embodiment, since rolling processing (processing with a difference in thickness) is performed with respect to the blank material B (cut plate) which can be cut into arbitrary shapes, it is not limited to the example of the multiple rolling process mentioned above, Each The feeding direction of the blank material B in the rolling mill (that is, the direction in which a plate thickness change is applied to the blank material B) can be freely set. Thereby, it is possible to easily process a shape having a complex thickness difference required for a vehicle body component or the like.

Moreover, in this embodiment, since rolling is performed with respect to the blank material B as mentioned above, compared with the manufacturing method of the steel plate with a thickness difference in the related art, it becomes possible to improve the yield of material. That is, in the method for manufacturing a steel sheet having a difference in thickness of the related art, as shown in FIG. 6 , a steel sheet (metal strip) S as a rolled material is wound on a payoff reel R1 and a take-up reel R2. , after performing rolling processing (processing with a difference in thickness) on the steel sheet S, the steel sheet S is cut along the blank lines L1 and L2 shown in FIG. 6 . Then, the cut|disconnected steel plate SB (refer FIG. 7) is cut|disconnected to the shape P (refer FIG. 6 and FIG. 7) of the component to be manufactured. For this reason, when plate|board thickness distribution is not symmetrical with respect to the component shape P, combination processing cannot be performed.

That is, when rolling is performed with respect to the steel plate S wound on the payoff reel R1 and the take-up reel R2, for example, in FIGS. It becomes part S1, and a location other than that turns into thin plate part S2 with a thin plate|board thickness. Then, a plurality of the thick plate portion (S1) and the thin plate portion (S2) are formed at equal pitch. For this reason, when the arrangement of the thick plate part S1 with respect to the part shape P is not symmetrical as shown in FIGS. 6 and 7 , only one part can be cut out from one steel plate SB. It becomes impossible, and the scrap SC (the part outside the component shape P in the steel plate SB) generate|occur|produces in large quantity. For this reason, depending on the shape of a part, a material yield becomes very bad, and manufacturing cost becomes high.

On the other hand, in this embodiment, a steel plate is cut|disconnected before a rolling process, the blank material B is manufactured, and rolling is performed with respect to the said blank material B. For this reason, as shown in FIGS. 8 and 9, at the time of manufacturing the blank material B, a plurality of blank materials B can be cut out from the steel sheet SB before rolling (so-called combined cutting). . And the blank material B cut out after that is rolling-processed (refer FIG. 10). For this reason, it becomes possible to reduce the generation amount of the scrap SC significantly, and since the yield of a material improves significantly, manufacturing cost can be reduced. In addition, in FIG. 10, the 1st process of a multiple rolling process is shown.

In addition, in this embodiment, since the steel sheets TB1 and TB2 with a difference in thickness are manufactured by forging with a rolling mill (roll), compared with the case where steel sheets with a difference in thickness are manufactured by forging with a normal press machine, processing power can be significantly reduced. That is, as described above, when a normal press machine is used, for example, a processing force of tens of thousands of tons is required, but when a rolling machine is used, for example, processing with a difference in thickness with a processing force of 1/10 or less of a press machine can be done Moreover, it is good also as a structure which heats the blank material B before the rolling process by a rolling mill. Thereby, while being able to further reduce said processing force, it becomes possible to provide the shape with a more complicated thickness difference with respect to the blank material (B).

(Modified example of the rolling mill 10)

Next, the modified example of the rolling mills 10, 20, 30, 40 which concerns on this embodiment is demonstrated using FIG. This rolling mill 50 is provided with a pair of work rolls 52 similarly to the rolling mill 10 mentioned above. However, these work rolls 52 include a cylindrical roll main body 54 having a constant radius in the circumferential and axial directions, and a cam portion 56 detachably provided on a part of the outer peripheral surface of the roll main body 54 . are each provided. Each cam portion 56 is formed in a substantially semicircular arc shape in the axial direction of the roll main body 54 . A shape for imparting a plate thickness change (a shape with a difference in thickness) to the blank material B is formed in these cam portions 56 .

Moreover, this rolling mill 50 is equipped with the pair of backup rolls 58 which support the pair of work rolls 52 from both upper and lower sides. The backup roll 58 is arrange|positioned on the mutually opposite side with the work roll 52 interposed therebetween, and the backup roll 58 is arrange|positioned parallel to the pair of work roll 52. As shown in FIG. These backup rolls 58 are in contact with the surface on which the cam part 56 in each roll main body 54 of the pair of work rolls 52 is not provided. In these backup rolls 58, when the blank material B is rolled by the pair of work rolls 52, the pair of work rolls 52 have excessive reaction force from the blank material B (workpiece). Prevents or suppresses elastic deformation (bending) by Accordingly, it is possible to prevent or suppress the occurrence of a so-called crown.

In addition, when rolling the blank material B using this rolling mill 50, the area|region in the work roll 52 with a constant radius (here, the cam part 56 among the outer peripheral surfaces of the roll main body 54 is not provided. area) in which the work roll 52 is rotated forward and reverse like a pendulum within a range in which the back-up roll 58 is in contact (refer to arrows SW1 and SW2 in FIG. 11).

That is, in this rolling mill 50, since a rolling process is performed with respect to the blank material B, it is not necessarily required that a pair of work roll 52 rotates continuously at the time of a rolling process. Therefore, as in the above-described rolling mill 50, the cam portion 56 (processing portion) of the pair of work rolls 52 is divided into halves, and the pair of work rolls 52 are rotated forward and reverse like a pendulum. It becomes possible to perform a rolling process. As a result, unstable behavior when the area of the work roll 52 with a changed radius and the backup roll 58 comes into contact does not occur, so that the pair of work rolls 52 can be rotated stably (smoothly). have. As a result, the precision of the plate|board thickness change provided to the blank material B by the pair of work rolls 52 becomes favorable.

That is, in Fig. 5 of Japanese Patent Application Laid-Open No. 2015-033719, which discloses a method for manufacturing a steel sheet having a difference in thickness, backup rolls 33 and 34 having a cross-sectional shape are arranged with respect to the cylindrical work rolls 31 and 32, , a configuration in which the work rolls 31 and 32 move up and down along the shape of the backup rolls 33 and 34 to give a shape with a difference in thickness is shown. However, in this configuration, when the work rolls 31 and 32 and the backup rolls 33 and 34 come into contact at the corner (end) of the area of the radius r4 in the backup rolls 33 and 34, the There are moments when the rotation becomes very unstable. For this reason, it is estimated that it is difficult to provide the shape with a stable thickness difference with respect to a to-be-rolled material. In this respect, in this modified example, it becomes possible to provide the shape with a stable thickness difference with respect to the blank material B by a pair of work roll 52 stable rotation.

Further, in this rolling mill 50, the cam portion 56 is provided on a part of the outer peripheral surface of the roll body 54 whose radius is constant in the circumferential direction and the axial direction, whereby the radius is changed in the circumferential direction and the axial direction ( 52) is composed. Since the cam portion 56 described above is detachable from the roll main body 54 , an arbitrary plate thickness change can be imparted to the blank material B by replacing the cam portion 56 . Moreover, since only the cam part 56 can be replaced|exchanged at the time of maintenance, it also contributes to the improvement of maintainability.

(Example)

Next, an example of a vehicle body component (vehicle frame member) manufactured using the steel plate with a difference in thickness according to the present embodiment will be described with reference to FIGS. 12 to 16 . In addition, arrow FR suitably shown in FIGS. 12-16 has shown the vehicle front, arrow UP has shown vehicle upper side, and arrow OUT has shown the vehicle width direction outer side.

12 to 14, the center pillar reinforcement 60 manufactured using the steel plate with a difference in thickness according to this embodiment is shown. The center pillar reinforcement 60 includes a side wall 60A, a front wall 60B and a rear wall 60C extending inward from the front and rear sides of the side wall 60A in the vehicle width direction, a front wall 60B and The rear wall 60C has a front flange 60D and a rear flange 60E extending in opposite sides from an inner end in the vehicle width direction.

In this center pillar reinforcement 60, the back plate part 62 on the upper side of the side wall 60A, the front wall 60B, and the rear wall 60C (refer the area|region where the dot was taken in FIGS. 12-14). is set, and portions other than that are formed with a thin plate. In detail, in this center pillar reinforcement 60, the plate thickness gradually decreases as the rear plate part 62 goes toward both sides of the vehicle in the vertical direction, and at the height at which the rear plate part 62 is set, the front wall It is formed so that the plate|board thickness of 60B and the rear wall 60C may decrease gradually toward the front flange 60D side and the rear flange 60E side (refer arrows A1 to A3 in FIGS. 13 and 14). As a result, in the center pillar reinforcement 60, the strength of the upper side supporting the cabin is improved, while the lower side that absorbs energy in the event of a side collision of a vehicle or the like, or the front and rear flanges that do not require strength (60D, 60E) is thinned and the weight is reduced.

Similarly, FIG. 15 shows the front pillar lower part 70 manufactured using the steel plate with a difference in thickness according to this embodiment. The front pillar lower portion 70 includes a side wall 70A, a front wall 70B and a rear wall 70C, and a front wall 70B and a rear wall extending inward in the vehicle width direction from the front and rear sides of the side wall 70A. The barrier 70C has a front flange 70D and a rear flange 70E extending to opposite sides from an inner end in the vehicle width direction. In this front pillar lower part 70, a back plate part 72 (refer to the area|region where a dot was taken in FIG. 15) is set in the vertical direction middle part of the side wall 70A, the front wall 70B, and the back wall 70C. and the other parts are formed of a thin plate. In the front pillar lower part 70, the plate thickness of the rear plate part 72 is formed to decrease gradually toward both sides of the vehicle in the vertical direction, and at the height at which the rear plate part 72 is set, the front wall 70B and It is formed so that the plate|board thickness of 70 C of rear walls may gradually decrease toward the front flange 70D side and the rear flange 70E side. Also in this front pillar lower part 70, the same effect as that of the center pillar reinforcement 60 mentioned above is acquired.

On the other hand, in FIG. 16, the front floor 80 manufactured using the steel plate with a thickness difference concerning this embodiment is shown. As for the front floor 80, the floor tunnel part 80A provided in the center part in the vehicle width direction is expanded toward the vehicle upper side, and the left floor part 80B and the right side which are located on both sides of the vehicle width direction of the floor tunnel part 80A. The floor part 80C is formed in the substantially flat shape. In this front floor 80, the middle portion in the vehicle front-rear direction of the left floor portion 80B and the right floor portion 80C (refer to the dotted area in Fig. 16) is a thin portion 82 thinner than the other portions. has been

This front floor 80 corresponds to the "press part" in the present invention, and cold press working without heat treatment such as annealing to the steel sheet TB1 with the thickness difference or the steel sheet TB2 with the thickness difference. It is manufactured by carrying out For this reason, the said thin part 82, ie, the site|part to which the rolling process was performed by the manufacturing method of the steel plate with a thickness difference concerning this embodiment is thinned and work-hardened as it is. In this thin part 82, the yield strength is rising by work hardening. In this floor tunnel portion 80A, the strength of the middle portion in the vehicle front-rear direction of the left floor portion 80B and the right floor portion 80C, which tends to be insufficient in strength, is improved by work hardening, and the portion is reduced in thickness. It has a lightweight structure while being locally strengthened.

In addition, as described above, the vehicle body component parts that can be expected to have an effect by applying work hardening locally span a wide range, so the versatility of the present invention is very large. In addition, in general, since the plate thickness is set in accordance with the part that requires strength, the plate thickness of the part that does not require strength is often unnecessarily thick for body components (vehicle skeleton parts). By using the steel sheet having a thickness difference according to the invention as a material, unnecessary sheet thickness can be eliminated. Accordingly, the present invention is a technique that can be widely applied to vehicle frame parts in order to reduce the weight of a vehicle.

As mentioned above, although embodiment and some Example were shown and this invention was demonstrated, this invention can be implemented with various changes in the range which does not deviate from the summary. It goes without saying that the scope of the present invention is not limited to the above embodiments.

Claims (7)

A method for manufacturing a metal plate with a difference in thickness,
Cutting the metal plate into a predetermined shape to produce a cutting plate (B),
The cutting plate B is cut by a processing machine 50 having a first work roll whose radius is changed in the circumferential and axial directions of the rotation axis, and a second work roll whose radius is changed in the circumferential and axial direction of the rotation axis. By processing by at least one of rolling and forging, producing a metal plate TB1 having a thickness difference in which the plate thickness is changed in two different directions orthogonal to the plate thickness direction,
A first backup roll disposed on the opposite side to the second work roll with the first work roll interposed therebetween and in contact with the first work roll, and on the opposite side to the first work roll with the second work roll interposed therebetween and installing a second backup roll in contact with the second work roll in the processing machine 50,
When manufacturing the metal plate TB1 having the thickness difference, the first work roll is rotated forward and reverse within a range in which a region with a constant radius in the first work roll is in contact with the first backup roll, and the second work roll The manufacturing method of the metal plate with a thickness difference which rotates the said 2nd work roll forward and reverse within the range in which the area|region with a constant radius in a roll contact|connects the said 2nd backup roll, and processes the said cutting board (B). A method for manufacturing a metal plate with a difference in thickness,
Cutting the metal plate into a predetermined shape to produce a cutting plate (B),
A first processing machine 20 including a first work roll whose radius is changed in the circumferential direction and axial direction of the rotation axis, and a second work roll whose radius is changed in the circumferential or axial direction of the rotation axis, and the first processing machine By processing the cutting plate B by at least one of sequential rolling and forging by a second processing machine 30 having a pair of work rolls having different shapes from the first and second work rolls, the thickness direction and Comprising manufacturing a metal plate (TB2) having a thickness difference in which the plate thickness is changed in two different orthogonal directions,
A first backup roll disposed on the opposite side to the second work roll with the first work roll interposed therebetween and in contact with the first work roll, and on the opposite side to the first work roll with the second work roll interposed therebetween and installing a second backup roll in contact with the second work roll in the first processing machine 20,
When manufacturing the metal plate TB2 having the thickness difference, the first work roll is rotated forward and reverse within a range in which a region with a constant radius in the first work roll is in contact with the first backup roll, and the second work roll The manufacturing method of the metal plate with a thickness difference which rotates a said 2nd work roll forward and reverse within the range which the area|region with a constant radius in a roll contacts with a said 2nd backup roll, and processes the said cutting plate. 3. The method of claim 2,
When manufacturing the metal plate TB2 with the said thickness difference, the conveyance direction of the said cutting plate in the said 1st processing machine 20 is different from the conveying direction of the said cutting plate in the said 2nd processing machine 30. The manufacturing method of the metal plate with a thickness difference which changes to . A method for manufacturing a press part,
Manufacturing the metal plates (TB1, TB2, 82) with a difference in thickness to which a part was processed by the manufacturing method according to any one of claims 1 to 3;
A press comprising manufacturing a press part by performing bending by a press in cold with respect to a portion not subjected to processing in the metal plates (TB1, TB2, 82) having a difference in thickness to which the processing has been applied to the part The manufacturing method of the part. It is a processing machine that manufactures metal plates with different thicknesses,
a first work roll whose radius is changed in the circumferential direction and the axial direction of the rotation axis;
a second work roll whose radius is changed in the circumferential direction and the axial direction of the rotation axis;
a first backup roll disposed on the opposite side to the second work roll with the first work roll interposed therebetween and in contact with the first work roll; and
and a second backup roll disposed on the opposite side to the first work roll with the second work roll interposed therebetween and in contact with the second work roll,
A region with a constant radius in the first work roll rotates the first work roll forward and reverse within a range in contact with the first backup roll, and the area with a constant radius in the second work roll is the second backup A processing machine configured to produce a metal plate (TB1) having a thickness difference by processing the cut plate (B) by rotating the second work roll forward and reverse within a range in contact with the roll. 6. The method of claim 5,
The second work roll is provided with a second roll body having a constant radius in the circumferential direction and the axial direction of the rotation axis, and a second cam part detachably provided on a part of the outer peripheral surface of the second roll body. . 7. The method of claim 5 or 6,
A processing machine, wherein the first work roll includes a first roll body having a constant radius in a circumferential direction and an axial direction of a rotation axis, and a first cam part detachably provided on a part of an outer peripheral surface of the roll body.

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