Jig for molding incremental sheets, apparatus for molding incremental sheets, and molding method thereof.

Abstract

To keep machining accuracy for an edge part of a component that is molded in a sheet material.SOLUTION: An incremental sheet molding device 1 includes: a jig 30 configured by arranging a plurality of columnar bodies; and support parts (241, 242) for causing the jig 30 to abut on a rear surface side of a sheet material 40, which is plastically processed by pressing with a columnar tool 22, and a peripheral edge of a processed shape of the sheet material 40 and positioning an arrangement direction of the columnar bodies of the jig 30 at the peripheral edge.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a technique for incremental sheet forming.

Background Art

[0002] In recent years, incremental sheet forming (ISF) is known, in which a rod-shaped forming tool is rotated while being relatively moved and pressed against a thin sheet material to be plastically processed, for example, so as to draw contour lines to form a target shape. Since ISF does not require a mold compared with conventional press processing methods, there is an advantage that the development period of the mold can be shortened and the manufacturing cost can be saved.

[0003] Patent Document 1 describes an ISF apparatus in which a plurality of locations around a sheet material are clamped by a blank holder via hydraulic cylinders, and the clamping force can be individually adjusted in conjunction with the movement of the tool. According to this ISF apparatus, since each clamping force is individually controlled in conjunction with the movement of the tool, it is possible to apply the necessary inflow and tension at the necessary positions, and as a result, the occurrence of cracks (fractures) and wrinkles is suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In plastic deformation of sheet materials, it is desirable to actively form the edge portion between the central processed shape area and the periphery of the processed shape area. However, in the apparatus described in Patent Document 1, although a support base conforming to the part shape is placed below the sheet material to form the part shape with high precision, no measures are taken for the edge portion. Consequently, the processing of the edge portion is insufficient, and twisting is likely to occur in the formed part, resulting in the problem that sufficient processing accuracy cannot be obtained.

[0006] The present invention has been made in view of the above, and provides an incremental sheet molding apparatus, a method therefor, and an incremental sheet molding jig that molds the edge portion while maintaining processing accuracy by bringing a jig into contact with the back surface of the peripheral edge of the processed shape of the sheet material to be processed. [Means for solving the problem]

[0007] The incremental sheet molding apparatus according to the present invention comprises a jig composed of a plurality of columnar bodies arranged in a row, and a support portion that is located on the back side of the sheet material to be plastically deformed by pressing a tool, and that contacts the jig with the periphery of the processed shape of the sheet material, and positions the jig with the arrangement direction of the columnar bodies aligned with the periphery.

[0008] Furthermore, the incremental sheet forming method according to the present invention comprises the steps of: positioning a jig having a plurality of columnar bodies arranged on the back side of a sheet material to be plastically deformed by pressing a tool, by bringing the jig into contact with the periphery of the processed shape of the sheet material by a support portion, and aligning the direction of the arrangement of the columnar bodies with the periphery; and pressing the tool against the sheet material in the positioned state to perform plastic deformation.

[0009] According to these inventions, the jig is positioned by the support portion, which contacts the periphery of the processed shape of the sheet material, and by aligning the arrangement direction of the multiple columnar bodies with the periphery of the processed shape. This promotes the processing of the part edge, increases the rigidity of the sheet material, and improves dimensional accuracy. Furthermore, since the overall shape of the jig can be appropriately set using multiple columnar bodies, it can be applied as a template for the part shape, taking advantage of the characteristics of moldless molding. In addition, since the insertion position of the columnar bodies relative to the periphery of the processed shape can be adjusted, it is possible to respond to the flow conditions of the sheet material during processing, such as inflow and shrinkage, thereby suppressing the occurrence of cracks and improving molding accuracy.

[0010] Furthermore, in the incremental sheet molding method according to the present invention, the positioning step is performed on the sheet material at a suitable location on the periphery of the processed shape of the sheet material, and on the sheet material in which a recess has been formed in advance on at least one surface. With this configuration, it is possible to respond to the flow conditions of the sheet material during processing, such as inflow and shrinkage, thereby suppressing the occurrence of cracks and improving molding accuracy.

[0011] Furthermore, it is preferable that the columnar bodies have the same shape, as this eliminates the need to consider the arrangement order, making operation and management easier.

[0012] Furthermore, the support portion has a guide that moves the jig in and out in a direction perpendicular to the pushing direction of the tool. This configuration makes it easy to position the tip of the jig in the insertion direction on the periphery of the part shape.

[0013] Furthermore, the guides are arranged on a plane perpendicular to the pushing direction of the tool, and in four mutually perpendicular directions. This configuration allows for the placement of jigs in each of the four directions of the sheet material's plane, facilitating the machining of the part edges around the entire perimeter, thereby increasing the rigidity and improving the dimensional accuracy of the sheet material.

[0014] Furthermore, the columnar body has an uneven surface that contacts the periphery of the processed shape of the sheet material. With this configuration, by adopting an uneven surface that contacts the periphery of the processed shape, the edge processing can be changed from a simple straight line to a wavy or bent shape, and as a result, twisting that occurs during molding is effectively suppressed.

[0015] Furthermore, the support portion includes spacers interposed between any of the arranged columnar bodies. This configuration takes advantage of the feature of using multiple columnar bodies and increases its versatility as a template for various purposes.

[0016] Furthermore, the incremental sheet molding jig according to the present invention has a plurality of columnar bodies that abut against the back side of the sheet material to be plastically processed by pressing a tool, and the columnar bodies are stacked in the thickness direction along the periphery of the processed shape. According to the present invention, since the jig is composed of a plurality of columnar bodies, a jig that is easy to construct and easy to operate is provided. [Effects of the Invention]

[0017] According to the present invention, it is possible to maintain processing accuracy for the edge portions of parts formed from sheet material. [Brief explanation of the drawing]

[0018] [Figure 1] This is an overall configuration diagram showing an example of an incremental sheet molding apparatus according to the present invention. [Figure 2] This figure shows an example of the mechanism of an incremental sheet molding apparatus according to the present invention, where (A) is a plan view, (B) is a side cross-sectional view of (A) along A-A', and (C) is a side cross-sectional view of (A) along B-B'. [Figure 3] This is a side cross-sectional view illustrating the procedure for plastic deformation using tools, and mainly showing the support state of the edge portion of the sheet material. [Figure 4] This is a schematic perspective view of a conventional sheet material support mechanism (C-Backing-Plate) used as a comparative example in the test. [Figure 5]A chart showing the test results, where (A) and (B) show the results of the comparative examples, (D) and (E) show the results of the examples, and (C) and (F) show the cross-sectional profiles along the processing directions (X, Y) of the comparative examples and examples. [Figure 6] A diagram showing another embodiment. (A) is a plan view showing the arrangement state of the jigs when the periphery of the molded part is not straight. (B) shows a state where the upper end face shape of each plate-like body that abuts against the back surface of the periphery of the molded part is formed in a concave-convex shape, such as a hemispherical shape or a semi-cylindrical shape, instead of a plane, and the upper diagram is shown upside down in the drawing, but shows a state where the boundary (Upper edge) between the molded part and the periphery of the sheet material after processing is formed in a waveform. [Figure 7] A diagram showing still another embodiment. (A) is a schematic side view showing a configuration in which the jig is moved in and out in the vertical direction, and (B) is a plan view showing an example of the arrangement state of each columnar body of the jig in the horizontal plane. [Figure 8] A diagram showing a modified example in which a concave portion is formed in a part of the surface of the sheet material. (A) is a schematic view in which a concave portion including a depression or a groove is formed so as to correspond to the gap portion of the jig, and (B) is a schematic view in which a long hole is formed in the same location.

Embodiments for Carrying out the Invention

[0019] FIG. 1 is an overall configuration diagram showing an example of an incremental sheet forming apparatus 1 according to the present invention. FIG. 2 is a diagram showing an example of the mechanism part of the incremental sheet forming apparatus 1. (A) is a plan view, (B) is a side cross-sectional view taken along the A - A' side of (A), and (C) is a side cross-sectional view taken along the B - B' side of (A).

[0020] As shown in FIG. 1, the incremental sheet forming apparatus 1 includes a processing unit 20 controlled by a control unit 10. The control unit 10 includes a processing control unit 11 having a processor for controlling the processing operation by the processing unit 20, and a storage unit 12 for storing necessary data. Note that the control unit 10 may include an input operation unit provided with a touch key, a touch panel, etc. as necessary, and a display unit for displaying operation contents and operation information.

[0021] The memory unit 12 includes a control program memory unit 121 that stores the control program, and a processing information memory unit 122 that stores the attributes of the sheet material 40 to be processed, processing conditions such as the shape of the molded part, etc. The control program executes rotational control and movement control in three axes of the tool 22 that performs plastic forming. The processor of the processing control unit 11 reads the control program from the memory unit 12 and executes it, thereby generating control information to drive the tool 22 as described later, and outputs it to the drive unit 221.

[0022] Next, the processing unit 20 will be described. The processing unit 20 includes a mechanism for supporting the jig 30 and the sheet material 40, and a mechanism for processing the sheet material 40.

[0023] The support mechanism comprises a housing 21, a base 23 installed inside the housing 21, and a lower template 241, a blank holder 242, and a press plate 243, all made of metal, which are positioned on the base 23 and function as support parts that clamp the jig 30 and the sheet material 40 in the vertical direction. It also includes fasteners 25 that fasten these together to position the jig 30 and the sheet material 40. Furthermore, as shown in Figure 2(C), the support mechanism includes clamping members 261 that clamp the jig 30 at both the left and right ends, and fasteners 26 that attach the jig 30 to the press plate 243 via the clamping members 261. In this embodiment, the lower template 241, the blank holder 242, the press plate 243, and the top frame 231 of the base 23 are formed as a frame consisting of a square annular frame on a horizontal plane, so as to prevent interference with the parts that are formed in the Z-axis direction of the sheet material 40, as will be described later.

[0024] The machining mechanism comprises a tool 22, a moving mechanism 220 to which sliders for moving the tool 22 in the left-right (X) and front-back (Y) directions are assembled, and which has a known lifting mechanism in the up-down (Z) direction (the direction in which the tool 22 is pushed in), and a drive unit 221 for transmitting driving force to each motor, which is the drive source for the moving mechanism 220.

[0025] The housing 21 is provided as needed and mainly houses the main parts of the processing section 20. The base 23 has, for example, a rectangular parallelepiped shape and is constructed by assembling each side with a frame, and has a top frame 231 at the top.

[0026] Next, the jig 30 will be described. In Figure 1, jigs 31 and 32 are arranged in the left-right direction X, and in the front-back direction Y, jigs 33 and 34 are arranged as shown in Figure 2(A). Hereafter, when simply referring to a jig, it will be written as jig 30, and when specifying the arrangement position, it will be written as jig 31, ...34. In this embodiment, jig 30 is composed of multiple columnar bodies, or plate-like bodies, of the same shape, and functions as an edge jig by stacking multiple plate-like bodies. More specifically, jig 30 is manufactured from a hard material and has a rectangular parallelepiped shape with one long side. The dimensions of jig 30 can be, for example, a long side dimension of several centimeters to several tens of centimeters, a height dimension of several centimeters, and a thickness dimension of several millimeters to several centimeters. The preferred dimensions can be selected according to the size of the sheet material 40 and the required accuracy, and it is also possible to use sizes exceeding the above depending on the application. The jig 30 is used by being inserted between the lower template 241 and the blank holder 242. More specifically, the jig 30 is inserted horizontally from the outside, perpendicular to the frames of the lower template 241 and the blank holder 242 in its longitudinal direction.

[0027] As shown in Figure 2, the fasteners 25 are provided at the four corners in a plan view, and as shown in Figures 2(B) and (C), the top frame 231 and the retaining plate 243 are fastened together by screwing bolts into fastening holes 251 that penetrate from the top frame 231 to the retaining plate 243.

[0028] Furthermore, although not shown in Figure 1, as shown in Figure 2(C), the multiple plate-like bodies constituting the jig 32 are stacked in the thickness direction (left-right direction in Figure 2(C)) and are clamped at both ends in the thickness direction by the clamping members 261. The clamping members 261 have clamping surfaces of the required thickness (depth direction of the paper in Figure 2(C)), and both clamping surfaces face each other and are fixed in position while clamped by fasteners 26, for example, bolts, screwed in through corresponding elongated holes 2431 on the upper surface of the retaining plate 243.

[0029] Figure 3 is a side cross-sectional view illustrating the procedure for plastic deformation using a tool, and mainly showing the support state of the edge portion of the sheet material 40. Figure 3 shows the insertion dimension of the jig 30. In Figure 3, the tip of the jig 30 in the insertion direction is inserted to a position corresponding to the upper edge, which is the boundary between the processed shape of the sheet material 40 and the peripheral edge 40c. The insertion dimension may reach the position of the component edge, or it may be set to a position that is an appropriate dimension λ in front of the boundary position, taking into account the inflow of peripheral edge 40c during processing. The insertion operation of the jig 30 may be manual, or it may be automatic or semi-automatic by applying a mechanism such as a hydraulic cylinder. With the jig 30 inserted, operations are performed on the fasteners 26 and 25.

[0030] According to this, the following effects can be expected. Specifically, since the jig 30 can be positioned to correspond to the part edge of the sheet material 40, the processing of the part edge can be accelerated, resulting in increased rigidity and improved dimensional accuracy. In addition, since the insertion dimensions of the jig 30 can be adjusted to match the shape of the part edge, it can be applied as a template, making it possible to take advantage of the characteristics of moldless molding. Furthermore, by predicting the movement of the sheet material 40 during processing and adjusting the insertion dimensions accordingly, cracking can be prevented and moldability can be improved.

[0031] Returning to Figure 1, the tool 22 is supported by the moving mechanism 220 so as to be movable in the XYZ directions. The tool 22 has a cylindrical shape extending in the Z-axis direction and is rotatably mounted around its axis by a motor (not shown). The tool 22 may be non-rotatable, but in this embodiment, it rotates at a predetermined rotational speed in response to a rotation signal from the tool rotation drive unit 223 during machining.

[0032] Meanwhile, the tool position control unit 111 moves the tool 22 along a predetermined path, for example, sequentially along contour lines (Tool path: see Figure 3), at a predetermined speed, according to the shape of the part to be molded. With each rotation, it sequentially switches to position information that pushes the tool in the Z-axis direction by a predetermined dimension (Step size: see Figure 3). The position information is calculated by the tool position control unit 111 based on machining information. The calculated position information is converted into drive signals for each axis by the XYZ axis drive unit 222 and output to the movement mechanism unit 220, thereby controlling the movement of the tool 22.

[0033] In the above configuration, the following describes a test conducted to determine whether there was a significant difference in processing results between the example using a jig and the comparative example without a jig. The example used the sheet material support structure shown in Figures 1 and 2. The comparative example used a conventional sheet material support mechanism (C-Backing-Plate) shown in the schematic perspective view of Figure 4. Figure 5 is a table showing the test results, where (A) and (B) show the results for the comparative example, (D) and (E) show the results for the example, and (C) and (F) show the cross-sectional profiles of the comparative example and the example along the processing direction (X, Y). The purpose of the test was to verify whether there was a significant difference in processing accuracy in the Z direction between the example and the comparative example.

[0034] The sheet material support mechanism shown in Figure 4 as a comparative example comprises a base 23' of the same size as the base 23 in Figure 1, a top backing plate 241' of the base 23', and a frame blank holder 242' stacked on the top backing plate 241'. Bolt holes 25' are formed at multiple corresponding positions on the frame of the top backing plate 241' and the blank holder 242'. The sheet material 40 can be sandwiched between the top backing plate 241' and the blank holder 242' and fastened with bolts to prepare it for processing. The base 23' with the sheet material 40 fastened was placed inside the housing 21 in Figure 1, and processing was performed under the same conditions as in the embodiment.

[0035] The comparative example and the embodiment were molded parts of the same shape, and were subjected to clamped L-shaped plastic deformation. Both sheet materials were made of aluminum, with dimensions of 240 mm x 240 mm and a thickness of 0.5 mm. The processing conditions were as follows: the tool was cylindrical with a diameter of 10 mm and a hemispherical tip. The tool feed rate was 1000 mm / min and the tool rotation speed was 0.0 rpm. In the embodiment, the dimension λ of the jig facing the periphery of the shaped part relative to the upper edge was 0.0 mm, while in the comparative example it was 4.0 mm.

[0036] After the processing tests in the comparative example and the example were completed, the processing state of both processed sheet materials was measured (Keyence VR-5000, manufactured by Keyence). Figure 5 shows the processing results. In Figure 5, (A) and (D) show the distribution of Z displacement, and (B) and (E) show the shape error of the Z displacement. Also, (C) and (F) in Figure 5 show the cross-sectional profiles along sections D1-F1 and D2-F2. Section D1-F1 along AA represents the X-axis direction, and section D2-F2 along B-B represents the Y-axis direction.

[0037] As shown in Figures 5(A) and (D), the central L-shaped lettering area had an indentation dimension of -12.30 mm to -14.77 mm, according to the gauge, and there was no difference even when including the peripheral dimensions of -0.03 mm to -2.43 mm. On the other hand, the width of the sloped area in the Z direction along the outer periphery of the lettering area was slightly wider in (A) and the slope was gentler compared to (D). Furthermore, in the comparative example of (A), the slope of the inner area of ​​the L-shaped bend around the lettering area (the area including the intersection of the line segment shown A-A and the line segment shown B-B) changed more smoothly in the range of -2.43 mm to -12.30 mm compared to (D), and was gentler.

[0038] Next, as shown in Figures 5(B) and (E), the gauge scale in (B) is about an order of magnitude larger. Furthermore, in the comparison example in (B), there is a shape error of 10.00 mm in Z displacement, particularly in the region bent inward in the L-shape (the region including the intersection of the line segment shown A-A and the line segment shown B-B). This is a large molding error compared to the 0.5 mm in (E), indicating that the processing accuracy is considerably lower.

[0039] In Figures 5(C) and (F), the solid lines represent the target shape, (1) shows the shape formed in the comparative example, and (2) shows the shape formed in the embodiment. For both (C) and (F), the comparative example shape (1) has a gentler slope at the periphery, and in particular, the slope at the periphery on the side of the region bent inward of the L-shape (the region including the intersection of the line segments A-A and B-B) was significantly gentler compared to the embodiment shape (2). Thus, it was found that the embodiment had higher machining accuracy in the Z direction, mainly at the part edges, compared to the comparative example.

[0040] Other embodiments will be described below with reference to Figures 6 to 8.

[0041] Figure 6(A) is a plan view showing the arrangement of the plate-shaped bodies constituting the jig 30, with their insertion dimensions adjusted to follow the shape of the upper edge, when the upper edge of the part shape is not straight. By constructing the jig 30 from a collection of plate-shaped bodies of the required thickness, it can be applied to shapes other than straight upper edges, thus providing high versatility as a template.

[0042] Figure 6(B) shows a side view of the jig 30 from the insertion direction in the lower diagram, and an inverted perspective view of the sheet material 40 in the upper diagram. The lower diagram shows a case where the shape of the upper end surface 30t of each plate-like body of the jig 30 that abuts the periphery of the molded part is formed to be uneven, for example, hemispherical or semi-cylindrical, instead of being flat. The upper diagram shows a case where the boundary (upper edge) between the molded part and the periphery of the processed sheet material 40 is formed in a wave shape corresponding to the upper end surface 30t of each plate-like body. By changing the upper edge from a simple straight line to a wave shape or a bent shape, twisting that occurs during molding can be suppressed even more effectively.

[0043] Figure 7 shows yet another embodiment, where (A) is a schematic side view of a jig 30A configured to move up and down (lift and lower), and (B) is a plan view showing an example of the arrangement of each columnar body 301A of the jig in a horizontal plane. Note that the jig 30A may be a plate-shaped body, but a columnar shape is used here. Also, in Figure 7(A), the jig 30A may be configured to be raised and lowered manually and fixed in position, but an automatic or semi-automatic mechanism may be used here. For example, the hydraulic cylinder 30B may be configured such that each columnar body 301A of the jig 30A has a lifting rod, and the lifting and lowering of each columnar body 301A is performed in response to a drive signal from a hydraulic controller. Figure 7(B) shows a configuration in which the jig 30A is arranged in a ring-shaped rectangle on all four sides, and each is arranged in multiple rows (3 rows in Figure 7(B)), and the rows and columnar bodies 301A that come into contact with (rise) the sheet material 40 can be controlled according to the size of the upper edge. In Figure 7(B), each square in the jig 30A represents one columnar body 301A. Alternatively, the columnar bodies 301A may be arranged in a single row, and a structure or moving mechanism that allows them to move horizontally according to the position and size of the upper edge may be adopted.

[0044] Figure 8 shows a modified example in which a recess is formed on a part of the surface of the sheet material. However, Figure 8 is only intended to show the positional relationship between the recesses 401 and 402 of the sheet materials 40A and 40B and the gap in the jig 30 for clarity, and is not necessarily entirely accurate. The gap is provided to ensure the flow of material during processing and according to the shape of the part edge. Figure 8(A) shows a recess 401 formed in which a long indentation or groove is formed in the direction along the upper edge to correspond to the gap in the jig 30. The recess 401 may be formed on at least one of the front and back surfaces of the sheet material 40A. The spacer 30s ensures the gap in the jig 30. Figure 8(B) shows a recess 402 formed in the same location, consisting of an elongated hole or the like. By pre-forming the recesses 401 and 402 using the gap before use, the flow of the sheet material during processing is promoted, twisting is prevented, and molding accuracy is maintained.

[0045] As shown in Figure 8, multiple recesses 401 and 402 for adjusting the inflow and deformation of the sheet materials 40A and 40B during processing are arranged and formed, for example, along the perimeter of the sheet surfaces of the sheet materials 40A and 40B. However, a configuration for adjusting the inflow and deformation of the sheet material 40 during processing can also be appropriately adopted. For example, multiple protrusions that are elongated in the circumferential direction may be formed along the perimeter of the sheet surface of the sheet material 40. The protrusions may be formed on at least one side of the front and back surfaces of the sheet material 40.

[0046] In the above embodiment, the example showed a lower template 241, a blank holder 242, and a press plate 243 as the support part, but it may also be supported by the lower template 241 and the blank holder 242. Also, although the example was described in which the jig 30 is configured in all four directions, it may be configured in one place, two opposing places, etc., depending on the application, and is not limited to a rectangular shape. Furthermore, the plate-like bodies that make up the jigs 30, 30A are not particularly limited in shape as long as they are columnar tools that enable forming, such as those with a hemispherical, ellipsoidal, or flat tip (with a rounded corner on the periphery) tip shape. In addition, the pushing operation of the tool 22 into the sheet material 40 may include a relative pushing operation. Also, since a forming angle may occur depending on the shape of the part, the jig 30 may be inserted in a direction perpendicular to the pushing direction of the tool 22, including a direction that is substantially perpendicular to the pushing direction. [Explanation of Symbols]

[0047] 1. Incremental sheet molding apparatus 20 Processing Department 22 Tools 241 Lower template (support section, guide, one of the first or second frame sections) 242 Blank holder (support section, guide, other half of the first and second frame) 243 Retaining plate (support part) 25 Fasteners 26 Fasteners 30, 30A, 31, 32, 33, 34 Jig 30t uneven upper surface 40, 40A, 40B sheet material 401,402 recess

Claims

1. A jig composed of multiple columnar bodies arranged in a row, The back side of the sheet material to be plastically deformed by pressing a tool, and the jig is positioned by contacting the periphery of the processed shape of the sheet material and aligning the arrangement direction of the columnar body with the periphery, The support portion is an incremental sheet molding apparatus having a guide that moves the jig in a direction perpendicular to the pushing direction of the tool.

2. The incremental sheet molding apparatus according to claim 1, wherein the columnar bodies have the same shape.

3. The incremental sheet molding apparatus according to claim 1, wherein the guide is arranged on a plane perpendicular to the pushing direction of the tool and in four directions perpendicular to each other.

4. A jig comprising a plurality of columnar bodies arranged in a row, The back side of the sheet material to be plastically deformed by pressing a tool, and the jig is positioned by contacting the periphery of the processed shape of the sheet material and aligning the arrangement direction of the columnar body with the periphery, The support portion is an incremental sheet molding apparatus comprising spacers interposed between any of the arranged columnar bodies.

5. The incremental sheet molding apparatus according to claim 4, wherein the columnar bodies have the same shape.

6. The incremental sheet molding apparatus according to claim 4, wherein the columnar body has an uneven shape on the surface that contacts the peripheral edge of the processed shape of the sheet material.

7. The back side of a sheet material to be plastically deformed by pressing a tool, the steps include: positioning a jig having a plurality of columnar bodies arranged in it, bringing the jig into contact with the periphery of the processed shape of the sheet material by a support portion, and aligning the direction of the arrangement of the columnar bodies with the periphery; The process includes the step of pressing the tool against the sheet material in a positioning state to perform plastic deformation, The positioning step is performed on the sheet material at a suitable location on the periphery of the processed shape of the sheet material, and the sheet material has a recess pre-formed on at least one surface, in an incremental sheet molding method.

8. The incremental sheet molding method according to claim 7, wherein the columnar bodies have the same shape.

9. The incremental sheet molding method according to claim 7, wherein the columnar body has an uneven shape on the surface that contacts the peripheral edge of the processed shape of the sheet material.

10. An incremental sheet molding jig having a plurality of columnar bodies, which abut against the back side of a sheet material that is plastically deformed by pressing a tool, and which are arranged in a stacked manner in the thickness direction along the periphery of the processed shape.

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