Tongue manufacturing method

Abstract

To provide a tongue manufacturing method for a manufacturing device in which a rolling process is automated.SOLUTION: This tongue manufacturing method uses a blank rolling device 1 provided with a first holding conveyance machine 17 that holds a blank metal plate 8 and moves and a roll rolling machine 3. The roll rolling machine 3 includes an upper roll 18 and a lower roll 19 disposed to face the upper roll 18. The first holding conveyance machine 17 conveys the blank metal plate 8 between the upper roll 18 and the lower roll 19. The blank metal plate 8 is held between the upper roll 18 and the lower roll 19. The first holding conveyance machine 17 reciprocates, and the upper roll 18 and the lower roll 19 rotate to roll the blank metal plate 8.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing tongs for holding and removing an object to be held, such as food or ingredients. [Background technology]

[0002] Conventionally, the applicant of the present application has manufactured tongs as described in Patent Document 1, but in the manufacturing process, rolling is performed to thin the elastic curved portion 5. In the rolling process, the part that will become the elastic curved portion 5 is passed between two rotatably arranged upper and lower rolls multiple times to thin the part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4022924 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in order to thin the elastic curved portion (5) to a predetermined thickness, it was necessary to pass the elastic curved portion (5) between the rolls arranged above and below several to several tens of times to manufacture one tongue, so when manufacturing a large number of tongues, manual rolling took a very long time.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to solve the above problems and to provide a method for manufacturing tongues using a manufacturing device that automates the rolling process. [Means for solving the problem]

[0006] The tongs manufacturing method of the present invention is a tongs manufacturing method using a material rolling device equipped with a holding and conveying machine that holds and moves a raw metal plate, and a roll rolling machine, wherein the roll rolling machine has an upper roll and a lower roll arranged opposite the upper roll, and the holding and conveying machine conveys the raw metal plate into the gap between the upper roll and the lower roll, the raw metal plate is sandwiched between the upper roll and the lower roll, and the raw metal plate is rolled by the holding and conveying machine reciprocating and the upper roll and the lower roll rotating. Effect of the Invention

[0007] According to the present invention, the rolling process of the bent portion of the tongue can be performed automatically, and the time required for the rolling process can be shortened compared to manual work. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a front view of the material rolling device according to the embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view taken along line AA in FIG. 1. [Diagram 3] FIG. 2 is a diagram showing a raw metal sheet, an upper roll, and a lower roll immediately before rolling in one embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing a raw metal sheet, an upper roll, and a lower roll during rolling in one embodiment of the present invention. [Diagram 5] FIG. 1A is a diagram showing a raw metal plate, an upper roll, and a lower roll with the first holding and conveying machine moved to the front side in one embodiment of the present invention; FIG. 1B is a diagram showing a raw metal plate, an upper roll, and a lower roll with the first holding and conveying machine moved to the rear side. [Figure 6] FIG. 2 is a diagram illustrating a control device according to an embodiment of the present invention. [Figure 7] FIG. 11 is a diagram showing rolling conditions 1 / 2 of a display screen in one embodiment of the present invention. [Figure 8] FIG. 13 is a diagram showing rolling conditions 2 / 2 on a display screen in one embodiment of the present invention. [Figure 9]FIG. 2 is a diagram showing a display unit in one embodiment of the present invention. [Figure 10] FIG. 2 is a diagram showing a manufacturing process chart of the tongs in one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, common parts in all of these drawings are given common reference numerals. In addition, all of the configurations described below are not necessarily essential requirements of the present invention.

[0010] 1 and 2 show an embodiment of a material rolling apparatus 1 used in the method for manufacturing tongues according to the present invention. The material rolling apparatus 1 includes a material supplying machine 2, a rolling mill 3, a press cutter 4, a conveying device 5 including a plurality of conveying machines, and a control device 6.

[0011] The finished product, tongs 7 (see FIG. 10), is manufactured by rolling a raw metal plate 8, which is a long and narrow rectangular metal plate, using a raw material rolling device 1, and then going through processes such as cutting, pressing, bending, polishing, and cleaning. This embodiment is a method for manufacturing tongs 7 made entirely of stainless steel, and stainless steel with a thickness of 2.2 mm is used as the raw metal plate 8.

[0012] The material supplying machine 2 is provided with a stocker 11 for stocking the material metal plates 8. The stocker 11 has a plurality of regulating bars 12 for regulating the horizontal movement of the material metal plates 8, and a bottom receiving portion 13 for placing the material metal plates 8. The material metal plates 8 are arranged between the plurality of regulating bars 12 and are stocked in a state where multiple sheets are stacked one on top of the other.

[0013] The raw metal plates 8 stocked in the raw material supplying machine 2 are taken out by a first suction conveying machine 14 constituting the conveying device 5. The first suction conveying machine 14 adsorbs the uppermost raw metal plate 8 stored in the stocker 11, lifts it upward, and takes it out of the stocker 11.

[0014] A non-contact type first displacement sensor 15 is provided between the material supplying machine 2 and the rolling mill 3. The first suction conveying machine 14 conveys the material metal plate 8 in the horizontal direction, and the first displacement sensor 15 detects the thickness of the material metal plate 8 as the material metal plate 8 passes by. By inspecting the thickness of the material metal plate 8, it is checked whether the material metal plate 8 is conveyed in a state where multiple pieces are erroneously stuck together. If the detection result of the first displacement sensor 15 determines that there are multiple material metal plates 8, the conveying by the first suction conveying machine 14 is stopped. At this time, an alarm means (not shown) is used to alarm the error information by turning on a lamp or by sound or image. If the detection result of the first displacement sensor 15 determines that there is only one material metal plate 8, the first suction conveying machine 14 delivers the material metal plate 8 to the center positioning machine 16. The center positioning machine 16 positions the center position of the material metal plate 8 in the left-right direction by clamping the material metal plate 8 from the left-right direction. In the subsequent steps, the raw metal plate 8 is transferred while its center in the left-right direction is maintained. The raw metal plate 8 whose center in the left-right direction has been determined is delivered from the centering device 16 to the first suction conveying device 14. The first suction conveying device 14, which has received the raw metal plate 8, delivers it to the first holding conveying device 17 which constitutes the conveying device 5.

[0015] The roll rolling machine 3 has an upper roll 18, a lower roll 19, an upper roll drive unit 20, a lower roll drive unit 21, a second non-contact displacement sensor 22 that detects the thickness of the raw metal sheet 8, an image sensor 23 that detects the external shape of the raw metal sheet 8, an upper roll maintenance unit 24, and a lower roll maintenance unit 25.

[0016] When the first holding and conveying machine 17 receives the raw metal plate 8 from the first suction conveying machine 14, it firmly holds the left and right end portions of the raw metal plate 8 and conveys the raw metal plate 8 into the gap S between the upper roll 18 and the lower roll 19.

[0017] As shown in FIG. 5, the upper roll 18 and the lower roll 19 have a perfect circular shape when viewed from the axial direction. Also, as shown in FIG. 3 and FIG. 4, the upper roll 18 and the lower roll 19 have rolling surfaces 26, 27 in contact with the base metal sheet 8 that have a slightly outwardly convex arc shape when viewed from a direction perpendicular to the axial direction. The upper roll 18 and the lower roll 19 have the same shape, and the rotation axis 28 (center axis) of the upper roll 18 and the rotation axis 29 (center axis) of the lower roll 19 are located on a virtual straight line L1 (see FIG. 5) extending vertically. Also, the widthwise center P1 of the upper roll 18 and the widthwise center P2 of the lower roll 19 are located on a virtual straight line L2 extending vertically. That is, the upper roll 18 and the lower roll 19 are located at the same positions in the front-rear and left-right directions, and are different only in the up-down direction.

[0018] The upper roll 18 can be rotated around a rotation shaft 28 by a drive motor (not shown) provided in the upper roll drive unit 20. Similarly, the lower roll 19 can be rotated around a rotation shaft 29 by a drive motor (not shown) provided in the lower roll drive unit 21. The upper roll 18 can be moved in the vertical direction by a moving device 30. The lower roll 19 in this embodiment does not have a moving device and does not move in the vertical direction, but it may be equipped with a moving device like the upper roll 18 and be movable in the vertical direction. By moving the upper roll 18 by the moving device 30, the interval T between the upper roll 18 and the lower roll 19 can be adjusted to any length.

[0019] When the upper roll 18 is lowered by the moving device 30, the raw metal sheet 8 arranged in the gap S between the upper roll 18 and the lower roll 19 is sandwiched between the upper roll 18 and the lower roll 19. In this state, the first holding and conveying machine 17 reciprocates in the front-rear direction multiple times, and the upper roll 18 and the lower roll 19 rotate, so that the central portion of the raw metal sheet 8 in the left-right direction (longitudinal direction) is rolled. The rotation of the upper roll 18 and the lower roll 19 is synchronized, and they start and stop rotating at the same time. They also rotate at the same speed and in the same rotation range (rotation angle). The reciprocating movement of the first holding and conveying machine 17 and the rotation of the upper roll 18 and the lower roll 19 are also synchronized, and when the first holding and conveying machine 17 moves in the traveling direction (forward direction), the upper roll 18 rotates clockwise and the lower roll 19 rotates counterclockwise in the side view shown in FIG. 5(A). On the other hand, when the first holding and conveying machine 17 moves backward (rearward), in the side view shown in FIG. 5(B), the upper roll 18 rotates counterclockwise and the lower roll 19 rotates clockwise. The rolled portion 8A of the raw metal sheet 8 gradually extends to the left and right to form an extension portion 8B, and gradually becomes thinner. Therefore, as the reciprocating motion of the first holding and conveying machine 17 increases, the upper roll 18 gradually descends, and the interval T between the upper roll 18 and the lower roll 19 gradually narrows. When the preset number of reciprocating motions is completed, the upper roll 18 ascends.

[0020] During rolling processing, the number of times and the speed of reciprocating movements of the first holding and conveying machine 17, the spacing T of the gap S between the upper roll 18 and the lower roll 19, and the amount of rotation (rotation angle) and rotation speed of the upper roll 18 and the lower roll 19 can be set by the operation panel 36 of the control device 6 described later.

[0021] When the first rolling process is completed, the raw metal plate 8 is conveyed while being held by the first holding and conveying machine 17, and passes the second displacement sensor 22 and the image sensor .

[0022] The second displacement sensor 22 detects the thickness of the rolled portion 8A of the raw metal sheet 8 rolled by the upper roll 18 and the lower roll 19. If the detection result of the second displacement sensor 22 indicates that the rolled portion 8A has a predetermined thickness, it is conveyed to the image sensor 23, and if the thickness is other than the predetermined thickness, the conveyance of the raw metal sheet 8 by the first holding conveyor 17 is stopped. At this time, a notification means (not shown) lights up a lamp or notifies error information by sound or image.

[0023] The image sensor 23 detects the outer shape of the rolled raw metal plate 8. If it is determined from the detection result of the image sensor 23 that the outer shape of the raw metal plate 8 is not a predetermined shape, the transport of the raw metal plate 8 by the first holding and conveying machine 17 is stopped. At this time, a notification means (not shown) notifies error information by turning on a lamp or by sound or image. If it is determined that the outer shape of the raw metal plate 8 is a predetermined shape, the raw metal plate 8 is transported by the first holding and conveying machine 17 and proceeds to the next process.

[0024] The upper roll maintenance unit 24 periodically oils, wipes, and polishes the rolling surface 29 of the upper roll 18. That is, the maintenance is automatically performed to maintain the rolling surface 29 of the upper roll 18 in a normal state. Similarly, the lower roll maintenance unit 25 periodically oils, wipes, and polishes the rolling surface 30 of the lower roll 19, and automatically performs maintenance to maintain the rolling surface 30 of the lower roll 19 in a normal state. After the raw metal sheet 8 that has been rolled is transported by the first holding and transporting device 17, the upper roll 18 and the lower roll 19 rotate a predetermined amount, so that the positions of the rolling surfaces 26, 27 that come into contact with the raw metal sheet 8 (rolling portion 8A) during the next rolling process are changed. This prevents the rolling surfaces 26, 27 from being worn unevenly in parts due to long-term use. In this embodiment, the positions of the rolled surface parts 26, 27 in contact with the raw metal sheet 8 are changed every time, but the positions of the rolled surface parts 26, 27 in contact with the raw metal sheet 8 may be changed every predetermined number of times. When changing the positions, the upper roll 18 and the lower roll 19 may be changed by the same amount or by different amounts.

[0025] The press cutter 4 cuts off a predetermined amount of the extension portion 8B that extends in the left and right directions of the rolled portion 8A after the first rolling process is performed by the roll rolling machine 3. The second suction conveyor 31 constituting the conveying device 5 receives the material metal plate 8 that has been subjected to the first rolling process from the first holding conveyor 17. The second suction conveyor 31 conveys the material metal plate 8 toward the press cutter 4 and hands it over to the second holding conveyor 32. The second holding conveyor 32, which firmly holds the material metal plate 8, conveys the material metal plate 8 to the cutting position of the press cutter 4 and stops there. Thereafter, the cutter 33 of the press cutter 4 descends and cuts off a predetermined amount of the left and right extension portions 8B.

[0026] The raw metal sheet 8 from which the left and right extension portions 8B have been cut off by the cutting machine 33 is transferred from the second holding conveyor 32 to the second suction conveyor 31. The second suction conveyor 31 conveys the raw metal sheet 8 in the direction of the rolling machine 3 and transfers it to the first holding conveyor 17. The first holding conveyor 17 conveys the raw metal sheet 8 to the gap S between the upper roll 18 and the lower roll 19. The upper roll 18 descends, the raw metal sheet 8 is sandwiched between the upper roll 18 and the lower roll 19, and the first holding conveyor 17 reciprocates multiple times in the front-rear direction, so that the rolled portion 8A of the raw metal sheet 8 is subjected to a second rolling process.

[0027] The raw metal plate 8 that has been subjected to the second rolling process is conveyed while being held by the first holding and conveying machine 17, and passes through the second displacement sensor 22 and the image sensor 23. If the detection result of the second displacement sensor 22 indicates that the rolled portion 8A of the raw metal plate 8 has a predetermined thickness, the raw metal plate 8 is conveyed to the image sensor 23, and if the thickness is other than the predetermined thickness, the conveyance of the raw metal plate 8 by the first holding and conveying machine 17 is stopped, and error information is notified by the notification means (not shown). If the detection result of the image sensor 23 indicates that the outer shape of the raw metal plate 8 is not the predetermined shape, the conveyance of the raw metal plate 8 by the first holding and conveying machine 17 is stopped, and error information is notified by the notification means (not shown). If the outer shape of the raw metal plate 8 is determined to be the predetermined shape, the raw metal plate 8 is conveyed by the first holding and conveying machine 17, and proceeds to the next process.

[0028] The raw metal plate 8 is transferred from the first holding conveyor 17 to the second suction conveyor 31. The second suction conveyor 31 transfers the raw metal plate 8 to the second holding conveyor 32, which conveys the raw metal plate 8 beyond the press-cut machine 4 and transfers it to the third suction conveyor 34. The third suction conveyor 34 stores the raw metal plate 8 in a storage box 36 placed on a conveyor device 35 constituting the conveying device 5. When a predetermined number of raw metal plates 8 are stored in the storage box 36, the storage box 36 is transported by the conveyor device 35 to a predetermined location.

[0029] As shown in Figures 2 and 6, the control device 6 is provided with an operation panel 37 for performing various settings such as turning on / off the power supply of the material rolling device 1, adjusting the distance T of the gap S between the upper roll 18 and the lower roll 19 of the rolling mill 3, the rotation speed and rotation range (rotation angle) of the upper roll 18 and the lower roll 19, and the number of reciprocating movements of the first holding and conveying device 17 during rolling. Therefore, by performing various settings according to the thickness, size, etc. of the material metal plate 8, it is possible to roll various types of tongs 7. In other words, the same material rolling device 1 can roll tongs 7 of various sizes and thicknesses.

[0030] The display screen 38 displays various settings as shown in Fig. 7 and Fig. 8. For example, the display screen 38 displays product type information such as a display H1 of a product type number, which is the product name of the tongs 7 to be manufactured, a display H2 of the length in the longitudinal direction of the raw metal sheet 8, a display H3 of the width in the lateral direction of the raw metal sheet 8, and a display H4 of the thickness of the raw metal sheet 8, as shown in Fig. 7, a display H5 of a rolling target value, a display H6 of a first rolling speed, a display H7 of a second rolling speed, a display H8 of the position of the upper roll 18 that rises and falls, a display H9 of the number of movements during rolling processing, and a display H10 of the rotation angles of the upper roll 18 and the lower roll 19, as shown in Fig. 8, a display H11 of the number of times oiling is performed by the upper roll maintenance unit 24 and the lower roll maintenance unit 25, a display H12 of the number of times polishing is performed, a display H13 of the position of the rolling center relative to the set reference position, a display H14 of an abnormal value of the crack width detected by the image sensor 23, and a display H15 of an abnormal value of the crack depth detected by the image sensor 23, and other rolling conditions. In addition, when the display H9 shows "2", it indicates one round trip, and when it shows "4", it indicates two round trips.

[0031] The control device 6 is provided with a display unit 39 that displays an image captured by the image sensor 23, so that the operator can check the shape of the raw metal plate 8. As shown in FIG. 9, the display unit 39 displays the rolled portion 8A, the extended portion 8B, and a part of the portion that will become the handle 7C of the raw metal plate 8. The display unit 39 also displays the work width, which is the length in the short direction of the portion that will become the handle 7C of the raw metal plate 8, the shift width in the front-rear direction from the reference position, the crack width that has occurred in the raw metal plate 8, and the crack depth, which is the depth of the crack that has occurred in the raw metal plate 8. In FIG. 7, the work width is displayed as 22.341 mm, the shift width is displayed as 0.338 mm, the crack width is displayed as 0.000 mm, and the crack depth is displayed as none. If any of the work width, the shift width, and the crack width deviates from the preset value, the transport of the raw metal plate 8 by the first holding and transporting machine 17 is stopped, and error information is notified. At this time, the shape of the raw metal plate 8 displayed on the display unit 39 can be visually confirmed.

[0032] As shown in Fig. 10, the entire manufacturing process of the tongs 7 is roughly as follows, and in the material rolling device 1, steps 1 to 3 are carried out. Steps 1 to 3 are fully automated. The material metal plate 8 contained in the container 35 is transported to a cutting device (not shown) which carries out step 4. Step 1: A first rolling process is performed on the central portion in the longitudinal direction of a raw metal plate 8. Step 2: The left and right extending portions 8B of the rolled portion 8A are cut off by a predetermined amount. Step 3: The rolled portion 8A of the raw metal plate 8 is subjected to a second rolling process. Step 4: The raw metal plate 8 is cut into a provisional shape of the tongs 7. Step 5: One of the clamping portions 7A is subjected to rolling. Step 6: One of the clamping portions 7A is cut by a press to form the outer shape. Step 7: The other clamping portion 7B is subjected to rolling. Step 8: The other clamping portion 7B is cut by a press to form the outer shape. Step 9: Press the handle 7C. Step 10: Sand the entire surface. Step 11: Wash the whole thing. Step 12: One of the clamping portions 7A is subjected to a press working to be curved. Step 13: The other clamping portion 7B is subjected to a press working to be curved. Step 14: The rolled portion 8A is folded by a press to form a folded portion 7D. Step 15: The clamping portions 7A and 7B are polished. Step 16: The whole is washed and the tongs 7 are completed. Step 17: The tongs 7 are packaged.

[0033] As described above, the method for manufacturing the tongs 7 of this embodiment is a method for manufacturing the tongs 7 using the material rolling device 1 equipped with the first holding and conveying machine 17 that holds and moves the raw metal plate 8 and the rolling machine 3. The rolling machine 3 has an upper roll 18 and a lower roll 19 arranged opposite to the upper roll 18. The first holding and conveying machine 17 conveys the raw metal plate 8 to the gap S between the upper roll 18 and the lower roll 19, and the raw metal plate 8 is sandwiched between the upper roll 18 and the lower roll 19. The first holding and conveying machine 17 reciprocates and the upper roll 18 and the lower roll 19 rotate, thereby rolling the raw metal plate 8. This allows the rolling process to be automatically performed on the portion that will become the bent portion 7D of the tongs 7. As a result, the working time can be significantly reduced compared to the case of performing the rolling process manually.

[0034] In the method for manufacturing the tongs 7 of this embodiment, the upper roll 18 has a perfect circle shape when viewed from the direction of the rotation shaft 28, the lower roll 19 has a perfect circle shape when viewed from the direction of the rotation shaft 29, the rolling surface portion 26 of the upper roll 18 has a slightly outwardly convex arc shape when viewed from the direction perpendicular to the rotation shaft 28, and the rolling surface portion 27 of the lower roll 19 has a slightly outwardly convex arc shape when viewed from the direction perpendicular to the rotation shaft 29. Therefore, the rolling process can be performed so that the longitudinal center portion of the rolling portion 8A of the material metal plate 8 is the thinnest and gradually becomes thicker toward the portion that becomes the handle 7C of the tongs 7. This allows an appropriate elastic force to be generated when the clamping portions 7A and 7B of the tongs 7 are opened and closed.

[0035] Furthermore, in the method for manufacturing tongs 7 of this embodiment, the material rolling apparatus 1 is equipped with a control device 6 that controls the first holding and conveying machine 17 and the rolling mill 3, and the control device 6 sets the number of reciprocating movements, speed, and moving distance of the first holding and conveying machine 17, and the rotation speed, number of rotations, and rotation angle of the upper roll 18 and the lower roll 19. Therefore, by setting the control device 6 according to the thickness of the material metal plate 8 and the shape of the tongs 7 as a finished product, it is possible to appropriately perform rolling processing on the material metal plate 8 of various types of tongs 7.

[0036] In the method for manufacturing the tongs 7 according to the present embodiment, the base metal sheet 8 is in contact with the upper roll 18 and the lower roll 19 while the first holding and conveying device 17 is reciprocating. Therefore, both sides of the base metal sheet 8 can be uniformly rolled.

[0037] Furthermore, the method for manufacturing tongs 7 of this embodiment includes an image sensor 23 for detecting the shape of the base metal sheet 8, and the shape of the base metal sheet 8 is detected by the image sensor 23 after the rolling process. Therefore, it is possible to confirm the shape of the base metal sheet 8 after the rolling process and to judge whether the rolling process has been performed appropriately.

[0038] Moreover, in the method for manufacturing the tongs 7 of this embodiment, the interval T between the upper roll 18 and the lower roll 19 changes while the first holding and conveying device 17 is reciprocating. Therefore, the base metal sheet 8 is gradually thinned by the rolling process, and by narrowing the interval T between the upper roll 18 and the lower roll 19, the rolled portion 8A of the base metal sheet 8 can be rolled to a desired thickness.

[0039] In addition, in the method for manufacturing the tongs 7 of this embodiment, the rolling mill 3 includes a moving device 30 that moves the upper roll 18 toward and away from the lower roll 19. Therefore, the interval T of the gap S between the upper roll 18 and the lower roll 19 can be adjusted.

[0040] The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, when manufacturing thin tongs 7, the bent portion may be rolled only once because the material metal plate 8 is thin. In this case, it is not necessary to cut off the left and right extensions 8B of the rolled portion by the press cutter 4. [Explanation of symbols]

[0041] 1. Material rolling equipment 3 Roll Mill 6. Control device 8. Metal plate 17 First holding conveyor (holding conveyor) 18 Upper roll 19 Lower roll 26 Rolled surface 27 Rolled surface S Gap

Claims

1. A method for manufacturing tongs using a material rolling device including a holding and conveying machine for holding and moving a material metal plate and a rolling machine, The rolling mill has an upper roll and a lower roll arranged opposite to the upper roll, the holding and conveying machine conveys the base metal plate to a gap between the upper roll and the lower roll, The base metal plate is sandwiched between the upper roll and the lower roll, A method for manufacturing tongs, characterized in that the material metal plate is rolled by the holding and conveying machine reciprocating and the upper roll and the lower roll rotating.

2. The upper roll has a perfect circular shape when viewed from the direction of the rotation axis, The lower roll has a perfect circular shape when viewed from the direction of the rotation axis, The rolling surface portion of the upper roll has an arc shape that is slightly convex outward when viewed from a direction perpendicular to the rotation axis direction, The method for manufacturing tongues according to claim 1, characterized in that the rolling surface portion of the lower roll has an arc shape that is slightly convex outward when viewed from a direction perpendicular to the rotation axis direction.

3. The material rolling device includes a control device for controlling the holding and conveying machine and the rolling machine, The method for manufacturing tongs as described in claim 1, characterized in that the control device sets the number of reciprocating movements, speed, and moving distance of the holding and conveying device, and the rotational speed, number of rotations, and rotation angle of the upper roll and the lower roll.

4. 2. The method for manufacturing tongues according to claim 1, wherein the metal plate is in contact with the upper roll and the lower roll while the holding and conveying machine is reciprocating.

5. An image sensor is provided to detect the shape of the base metal plate, 2. The method for manufacturing tongues according to claim 1, wherein the shape of the raw metal plate is detected by the image sensor after the rolling process.

6. The method for manufacturing tongs according to claim 1, wherein the distance between the upper roll and the lower roll changes while the holding and conveying device is reciprocating.

7. The method for manufacturing tongues according to claim 1, characterized in that the rolling machine is provided with a moving device for moving the upper roll in a direction toward and away from the lower roll.

Images