Successive forming method

Abstract

A successive molding method for molding a metal plate W into a three-dimensional shape by pressing a rod-shaped tool T against the metal plate W and moving the rod-shaped tool T, the rod-shaped tool T being disposed on one side of the metal plate W and a heating device H1 being disposed on the other side of the metal plate W, a local movement range of a rod-shaped tool (T) on a metal plate (W) is determined on the basis of a preset movement path and movement speed of the rod-shaped tool (T), heating is performed for a constant period of time from the inside of the local movement range, and the metal plate (W) is molded using the rod-shaped tool (T). The metal plate W is molded while heating corresponding to a local movement range continuous with respect to the previous local movement range is performed in order, thereby heating and annealing the portion plastically deformed by the rod-like tool T in the molding step. The residual stress generated on the metal plate W is removed to improve the shape freezing property of the molded article.

Description

Technical Field

[0001] The present invention relates to a sequential forming method for forming a metal plate into a three-dimensional shape by using a rod-shaped tool, and in particular to a sequential forming method and a sequential forming device for annealing a forming portion of the metal plate. Background Art

[0002] As a current sequential forming method, there is a method described in Patent Document 1, for example. The sequential forming method described in Patent Document 1 uses a rod-shaped tool having a laser irradiator as a heating unit. The rod-shaped tool has a laser irradiator on the front side of its moving direction. In the sequential forming method, when the rod-shaped tool is pressed against a metal plate and moved, a laser is irradiated to the front side of the rod-shaped tool to heat the metal plate, and the heated portion is pressed by the rod-shaped tool to cause plastic deformation, thereby releasing and reducing the residual stress of the metal plate.

[0003] Patent Document 1: Japanese Patent No. 3959455 Summary of the invention

[0004] However, in the above-mentioned sequential forming method, the rod-shaped tool moves multiple circles in a contour line to form the metal plate. In contrast, in the current sequential forming method, the rod-shaped tool and the laser irradiator move as a whole, so in order to always irradiate the laser to the front side of the rod-shaped tool, it is difficult to ensure the laser propagation path from the outside toward the laser irradiator. In addition, in the current sequential forming method, the part before forming based on the rod-shaped tool is heated, so it may not be possible to remove the residual stress after forming, and it is difficult to improve the shape freezing of the molded product. In addition, in order to fully heat, it is necessary to reduce the moving speed of the rod-shaped tool, but the productivity is greatly reduced, so it is not realistic.

[0005] The present invention is proposed in view of the above-mentioned current situation, and its purpose is to provide the following sequential forming method and sequential forming device, that is, to heat the metal plate from the back side during the forming process, thereby annealing the part that has been plastically deformed by the rod-shaped tool, removing the residual stress generated in the metal plate, and improving the shape freezing property of the formed product.

[0006] The sequential forming method of the present invention is characterized in that the front end of a rod-shaped tool is pressed against a metal plate and moved to form the metal plate into a three-dimensional shape, wherein the following components are used: a rod-shaped tool disposed on one main surface side of the metal plate; and a heating device disposed on the other main surface side of the metal plate to heat the metal plate. The sequential forming method is characterized in that a local moving range of the rod-shaped tool on the metal plate is determined based on a predetermined moving path and moving speed of the rod-shaped tool, the local moving range is heated from the inside for a constant time, and the metal plate is formed by the rod-shaped tool, and then the metal plate is formed while heating corresponding to the next local moving range that is continuous with the previous local moving range is performed in sequence along the moving path of the rod-shaped tool.

[0007] The sequential forming device of the present invention is used for the above-mentioned sequential forming method. The sequential forming device comprises: a rod-shaped tool, which is arranged on one main surface side of a metal plate; a heating device, which is arranged on the other main surface side of the metal plate; a tool driving device, which drives the rod-shaped tool in at least three orthogonal axial directions; and a main control device, which controls the tool driving device. Moreover, the sequential forming device is characterized in that the heating device can heat each of a plurality of local moving ranges divided into a moving path of the rod-shaped tool from the inner side thereof, and the main control device has a function of controlling the heating device based on the driving data of the rod-shaped tool.

[0008] Effects of the Invention

[0009] The sequential forming method and sequential forming device of the present invention, by adopting the above-mentioned structure, can heat the metal plate from the inside during the forming process, thereby annealing the range that has been plastically deformed by the rod-shaped tool, removing the residual stress generated in the metal plate, and improving the shape freezing property of the formed product. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is an explanatory diagram showing an example of a sequential molding apparatus that can be applied to the sequential molding method according to the first embodiment of the present invention.

[0011] Figure 2 It is a plan view showing the relationship between the moving path of the rod-shaped tool of the metal plate and the heating range of the heating device.

[0012] Figure 3 It is a side view showing the projection range of the rod-shaped tool on the metal plate.

[0013] Figure 4 This is a graph showing the relationship between time and temperature when a metal plate is heated.

[0014] Figure 5It is an explanatory diagram showing another example of the heating device in the second embodiment of the sequential molding method according to the present invention.

[0015] Figure 6 It is a plan view showing still another example of the heating device in the third embodiment of the sequential molding method according to the present invention.

[0016] Figure 7 yes Figure 6 A side view of the heating device is shown.

[0017] Figure 8 yes Figure 6 An oblique view of the nozzle shown.

[0018] Fig. 9 It is a plan view showing still another example of the heating device in the fourth embodiment of the sequential molding method according to the present invention.

[0019] Fig.10 yes Figure 8 A side view of the heating device is shown.

[0020] Fig.11 yes Figure 8 An oblique view of the nozzle shown. DETAILED DESCRIPTION

[0021] <First embodiment>

[0022] Figure 1 1 is a diagram showing an example of a sequential forming device that can be applied to the sequential forming method according to the present invention in the first embodiment. The sequential forming device shown in the figure includes: a rod-shaped tool T, which is arranged on one main surface side of the metal plate W (the upper surface side in the figure); and a heating device H1, which is arranged on the other main surface side of the metal plate W (the lower surface side in the figure).

[0023] In addition, the sequential forming device includes: a tool driving device 1 that drives the rod-shaped tool T in at least three orthogonal axial directions; and a main control device 2 that controls the tool driving device 1. The heating device H1 can heat each of the plurality of local moving ranges divided into the moving path of the rod-shaped tool T from the inner side. In addition, the main control device 2 has a function of controlling the heating device H1 based on the driving data of the rod-shaped tool T.

[0024] The metal plate W is a flat plate as a blank of a molded product. The metal plate W is held around by a clamp 3 during successive molding. The clamp 3 has a fixed lower frame 3A and an upper frame 3B that can be raised and lowered relative to the lower frame 3A and firmly clamps the metal plate W around between the lower frame 3A and the upper frame 3B.

[0025] The rod-shaped tool T is a well-known structure in which the front end portion at the bottom is kept in a posture with the axis along the vertical direction in the illustrated example and has an appropriate shape such as a spherical surface, and is driven in three orthogonal axial directions by a tool driving device 1. A multi-axis control type working robot, an NC machine tool, etc. can be used for the tool driving device 1. The tool driving device 1 can move the mounted rod-shaped tool T in the X and Y directions as horizontal directions and the Z direction as a vertical direction. In addition, the rod-shaped tool T can also be rotated around each axis.

[0026] The heating device H1 is preferably a device that heats the metal plate W in a non-contact manner. The heating device H1 of this embodiment is a device that heats the metal plate W by irradiating the laser L. That is, the heating device H1 includes: a laser oscillator 11; a laser scanner 12 that scans the laser L toward the metal plate W; and an optical fiber 13 that transmits the laser from the laser oscillator 11 to the laser scanner 12.

[0027] The laser scanner 12 can scan the other main surface (lower surface) of the metal plate W with the laser L at high speed in an arbitrarily set range. Thus, the heating device H can heat each of the arbitrarily set ranges, i.e., the plurality of local moving ranges into which the moving path of the rod-shaped tool T is divided, from the inner side thereof.

[0028] The main control device 2 is a computer, and all movement paths, movement speeds, and pressing amounts on the metal sheet W from the forming start point to the forming end point are input in advance as driving data of the rod-shaped tool T for forming the metal sheet W into a formed product.

[0029] The main control device 2 has a function of controlling the heating device H1 based on the above-mentioned driving data of the rod-shaped tool T. Specifically, the laser scanner 12 is mainly controlled in the following manner, that is, based on the moving path and moving speed of the rod-shaped tool T, the local moving range of the rod-shaped tool T on the metal plate W is determined, and the laser L is scanned on the back side of the local moving range, and heating is performed at a constant time.

[0030] Next, the sequential molding method will be described together with the operation of the sequential molding device. Figure 1 As shown, the front end of the rod-shaped tool T is pressed against the metal plate W held by the fixture 3 and moved. Specifically, after the rod-shaped tool T is moved along the circular path, the rod-shaped tool T is displaced inward and downward at a predetermined pitch (pitch feeding), and the movement along the next circular path and the pitch feeding are repeated. Thus, in the sequential forming method, the rod-shaped tool T is moved in a contour line shape, and the metal plate W is formed by gradually pressing down the bottom, and finally a three-dimensional formed product is obtained.

[0031] In the sequential forming method according to the present invention, when sequential forming is performed as described above, the local moving range of the rod-shaped tool T on the metal plate W is determined based on the moving path and moving speed of the rod-shaped tool T which are set in advance, and the local moving range is heated from the back for a constant time, and the metal plate W is formed by the rod-shaped tool T. In the sequential forming method, the metal plate W is formed while sequentially heating corresponding to the next local moving range which is continuous with the previous local moving range.

[0032] In the sequential molding method of this embodiment, as Figure 2 As shown in FIG. 1 , the circumferential path P shown by the solid line is determined as the local moving range of the rod-shaped tool T on the metal plate W, as shown in FIG. Figure 2 As shown by the dotted line A in FIG. 1 , heating is performed from the inner side at a constant time for the local moving range. That is, based on the driving data of the rod-shaped tool T of the main control device 2, as shown in FIG. Figure 1 As shown, the laser scanner 12 is controlled so that the laser L scans the inner side of the local moving range and heats at a constant time. The laser L repeatedly scans in one direction at a high speed. In addition, the scanning speed of the laser L is significantly higher than the moving speed of the rod-shaped tool T.

[0033] At this time, in the sequential forming method, as a more preferred embodiment, when heating is performed from the inner side at a constant time with respect to the local moving range of the rod-shaped tool T on the metal plate W, as shown in FIG. Figure 3 As shown, heating is started from the projection range in the axial direction of the rod-shaped tool T. When the thickness of the metal plate W is t (mm), the heating time of the metal plate W is set to be greater than or equal to 2.4×t (minutes).

[0034] Here, regarding the sequential forming using the sequential forming apparatus, for example, at the time point when the rod-shaped tool T is moved a constant distance, the range on the metal sheet W that is plastically deformed by the rod-shaped tool T can be heated from the inner side for a constant time. In contrast, in the sequential forming method, the local moving range is determined, heating is started from the projection range of the rod-shaped tool T in the axial direction, and the metal sheet W is formed by the rod-shaped tool T.

[0035] Therefore, in the above-mentioned sequential forming method, preheating is performed from the inner side of the unformed range where the rod-shaped tool T has not passed, and during this period, the rod-shaped tool T continues to move. Therefore, as a result, the entire range subjected to plastic deformation by the rod-shaped tool T is heated from its inner side for a constant time.

[0036] In addition, in the sequential molding method of this embodiment, the heating device H1 is used to repeatedly scan the laser L in one direction, so Figure 4 The temperature indicated by the middle dotted line fluctuates up and down, but if the temperature fluctuation range as shown in the figure exceeds the target temperature, annealing can be performed sufficiently.

[0037] In addition, the heating time of the metal plate W was set to be greater than or equal to 2.4×t (minutes), and the heating holding time required for annealing in the field of heat treatment was set to 1 hour per 1 inch of plate thickness, and the unit of plate thickness was converted to millimeters. In addition, the following experiment was conducted, that is, the steel plate was heated at 510°C by electromagnetic induction heating, and the heating time was changed in units of 1 minute within the range of 1 minute to 8 minutes. As a result, it was found that it is preferable to set the heating time to be greater than or equal to 2.4×t (minutes).

[0038] Moreover, in the above-mentioned sequential forming method, it also depends on the pitch feed amount of the rod-shaped tool T and the size of the spot diameter of the laser L. However, heating including pre-heating can also be performed not only on the inner side of the range subjected to plastic deformation by the rod-shaped tool T, but also in its vicinity, that is, the subsequent circumferential path and the pitch feed path which are the unformed range.

[0039] Furthermore, in the above-mentioned sequential forming method, as described above, the metal sheet W is formed by moving the rod-shaped tool T to the forming end point while sequentially performing heating corresponding to the next partial moving range (for example, the next circumferential path) that is continuous with the previous partial moving range. At this time, in the above-mentioned sequential forming method, when the heating of the previous partial moving range does not exceed a constant time, the scanning range of the laser L is expanded for the previous partial moving range plus the next partial moving range, and at the time point when the heating of the previous partial moving range exceeds the constant time, the scanning range of the laser L is set to the next partial moving range. Thus, the heating of the previous partial moving range is terminated.

[0040] Therefore, in the sequential forming method and the sequential forming device described in the above embodiment, the metal plate is heated from the back during the forming process, thereby annealing the range that is plastically deformed by the rod-shaped tool, removing the residual stress generated in the metal plate, and improving the shape freezing of the molded product. In addition, in the sequential forming method and the sequential forming device, the metal plate W is placed in the middle and the rod-shaped tool T and the heating device are arranged, so there is no need to worry about hindering the free movement of the rod-shaped tool T.

[0041] In addition, in the above-mentioned sequential forming method, heating is started from the projection range of the axial direction of the rod-shaped tool T, and the metal sheet W is formed by the rod-shaped tool T, so that preheating can be performed from the inner side of the unformed range that the rod-shaped tool T does not pass. As a result, the plastic deformation range of the metal sheet W can be effectively heated and annealed, and residual stress can be fully removed, which helps to improve the shape freezing property.

[0042] Furthermore, in the above-mentioned sequential forming method, the heating time of the metal plate W is set to be greater than or equal to 2.4×t (minutes), so that the plastic deformation range of the metal plate W can be effectively heated and annealed, which can help to fully remove residual stress and further improve shape freezing.

[0043] Furthermore, in the above-mentioned sequential forming method, the metal plate W is formed by holding the periphery of the metal plate W with the clamp 3, so that the metal plate W can be sequentially formed by a relatively simple device without using a forming die or the like. In the above-mentioned sequential forming method, the shape freezing property of the molded product is maintained well, so it is also easy to remove the molded product from the clamp 3.

[0044] Furthermore, in the above-mentioned sequential forming method, the heating device H1 is a device for heating the metal plate W in a non-contact manner, and in particular, a device for heating the metal plate W by irradiating the laser L, so the scanning range of the laser L can be freely set based on the driving data of the rod-shaped tool T, and the heating can be concentrated on the required range. In addition, in the above-mentioned sequential forming method, the metal plate W is formed in a downwardly extending manner, but the metal plate W can be heated even if the height position of the laser scanner 12 is not changed.

[0045] Figures 5 to 11 This is a diagram for explaining a sequential molding apparatus applicable to the sequential molding method according to the present invention in the second to fourth embodiments. In each of the following embodiments, the same reference numerals are given to the same components as those in the first embodiment, and detailed description thereof is omitted.

[0046] <Second embodiment>

[0047] The sequential forming method according to the present invention utilizes a device that heats the metal plate W in a non-contact manner as the heating device H2. Figure 5 In the sequential forming device shown, the heating device H2 is an electromagnetic induction heating device, and detailed illustration is omitted, but the surface of the metal plate W opposite to the other main surface (the upper surface in the figure) has a structure with multiple heating parts that can work independently, which can heat the metal plate W locally.

[0048] In the sequential forming method, the bottom of the metal plate W is gradually pressed down to form the metal plate W. In contrast, the heating device H2 may be configured to be movable up and down in order to maintain a constant interval with the bottom of the metal plate W, although it depends on the forming amount of the metal plate W. In addition, the heating device H2 is formed into a concave and convex upper surface shape corresponding to the forming shape of the metal plate W, and a heating portion may be arranged on the upper surface thereof. However, if a plurality of heating portions are arranged in a coplanar shape and a structure is configured to move the entire device up and down, various forming shapes can be handled.

[0049] Similar to the aforementioned embodiment, the sequential forming method using the sequential forming device determines the local moving range of the rod-shaped tool T on the metal plate W based on the predetermined moving path and moving speed of the rod-shaped tool T, heats the local moving range from the inside at a constant time, and forms the metal plate W using the rod-shaped tool T. Then, the metal plate W is formed while sequentially heating the next local moving range that is continuous with the previous local moving range.

[0050] At this time, the heating device H2 operates the heating part corresponding to the inner side of the local moving range of the rod-shaped tool T, heats the local moving range from the inner side, and starts and stops the corresponding heating part in sequence as the local moving range is updated.

[0051] Therefore, regarding the above-mentioned sequential forming method and sequential forming device, the metal plate W is heated from the inner side during the forming process, thereby annealing the range that has been plastically deformed by the rod-shaped tool T, removing the residual stress generated in the metal plate W, and improving the shape freezing property of the formed product.

[0052] <Third embodiment>

[0053] Figure 6 to Figure 8 This is a diagram for explaining still another example of a sequential molding apparatus that can be applied to the sequential molding method according to the third embodiment of the present invention. Figure 6 The sequential forming device shown in the figure is structured such that the heating device H3 is provided with a plurality of heaters 14 on the other main surface side of the metal plate W. Figure 7 and Figure 8 As shown, the heater 14 has a nozzle 17 for spraying hot air heated by the heater 15 at the front end of a pipe 16 having the heater 15 in the middle.

[0054] In the sequential forming method, as described in the previous embodiment, after the rod-shaped tool (T) is moved along the circular path, the rod-shaped tool is displaced inward and downward and moved along the next circular path. That is, in the sequential forming method, the metal sheet W is formed in the following manner, that is, while the rod-shaped tool is moved in a contour shape, the bottom of the metal sheet W is gradually pressed down.

[0055] In contrast, in the example of the heating device H3 shown in the figure, a heater 14 having a square nozzle 17 is arranged in the center, and four heaters 14 having slit-shaped nozzles 17 are arranged around it. In this case, each nozzle 17 is arranged to form four sides of a quadrilateral. In addition, the heating device H3 is arranged in such a way that four heaters 14 are set as one group so that the nozzles 17 of the multiple groups of heaters 14 are formed in a contour shape. Therefore, each heater 14 has a nozzle 17 whose slit becomes longer as it goes to the outside.

[0056] In the sequential forming method using the sequential forming device having the above-mentioned heating device H3, the local moving range of the rod-shaped tool on the metal plate W is determined in the same manner as in the previous embodiment. With respect to the heating device H3, the heater 14 corresponding to the inner side of the local moving range of the rod-shaped tool T is operated, and hot air is supplied to the inner side of the local moving range for heating. As the local moving range is updated, the corresponding heater 14 is started and stopped in sequence.

[0057] Therefore, regarding the above-mentioned sequential forming method and sequential forming device, the metal plate W is heated from the inner side during the forming process, thereby annealing the range that has been plastically deformed by the rod-shaped tool, removing the residual stress generated in the metal plate W, and improving the shape freezing property of the formed product.

[0058] The heating device H3 of the sequential forming device of the above embodiment may be configured to change the height of each heater 14 in accordance with the forming shape of the metal plate W, and each heater 14 may be moved up and down individually or all heaters 14 may be moved up and down together.

[0059] <Fourth embodiment>

[0060] Figures 9 to 11 This is a diagram for explaining still another example of a sequential molding apparatus that can be applied to the sequential molding method according to the fourth embodiment of the present invention. Fig. 9 The sequential forming device shown in the figure is structured such that a heating device H4 has a plurality of heaters 14 arranged vertically and horizontally on the other main surface side of the metal plate W. Fig.10 and Fig.11As shown, each heater 14 has a square nozzle 17 for spraying hot air heated by the heater 15 at the tip of a pipe 16 having the heater 15 in the middle, and the nozzles 17 are arranged vertically and horizontally.

[0061] In the sequential forming method using the sequential forming device having the above-mentioned heating device H4, the local moving range of the rod-shaped tool on the metal plate W is determined in the same manner as in the previous embodiment, and in the heating device H4, the heater 14 corresponding to the inner side of the local moving range of the rod-shaped tool T is operated, and the local moving range is heated from its inner side using hot air, and the corresponding heater 14 is started and stopped in sequence as the local moving range is updated.

[0062] Therefore, regarding the above-mentioned sequential forming method and sequential forming device, the metal plate W is heated from the inner side during the forming process, thereby annealing the range that has been plastically deformed by the rod-shaped tool, removing the residual stress generated in the metal plate W, and improving the shape freezing property of the formed product.

[0063] In addition, the heating device H4 of the sequential forming device of the above embodiment can be formed into a structure that changes the height of each heater 14 according to the forming shape of the metal plate W, or each heater 14 can be moved up and down separately, or all heaters 14 can be moved up and down together.

[0064] In addition, in the aforementioned second embodiment (refer to Figure 5 ), the detailed structure of the heating part of the heating device H2 is not shown in the figure, but it can also replace Figure 6 and Figure 8 The nozzle 17 shown is provided with a heating portion for electromagnetic induction heating.

[0065] The structure of the sequential forming method and the sequential forming device according to the present invention is not limited to the above-mentioned embodiments, and can be appropriately changed within the scope of the present invention. In each embodiment, the case where the metal plate W is kept horizontal is shown as an example, but in the sequential forming (die casting) without using a forming mold, the metal plate W can also be kept in a vertical state or an inclined state for forming.

[0066] Description of the label

[0067] 1 Tool drive

[0068] 2 Main control device

[0069] H1~H4 Heating device

[0070] T Stick Tool

[0071] W Metal Plate

Claims

1. A sequential forming method for forming a metal plate into a three-dimensional shape by pressing a tip of a rod-shaped tool against a metal plate and moving the tool, wherein: The metal plate is heated by the rod-shaped tool disposed on one main surface side of the metal plate and a heating device disposed on the other main surface side of the metal plate. Based on the preset moving path and moving speed of the rod-shaped tool, a local moving range of the rod-shaped tool on the metal plate is determined, the local moving range is heated from the inner side for a constant time, and the metal plate is formed by the rod-shaped tool. Then, the metal plate is formed while heating corresponding to the next partial movement range that is continuous with the previous partial movement range is performed in sequence.

2. The sequential forming method according to claim 1, characterized in that: When heating is performed from the back for a constant time with respect to the local moving range of the rod-shaped tool on the metal plate, heating is started from the projection range of the rod-shaped tool in the axial direction.

3. The sequential forming method according to claim 1, characterized in that: When the thickness of the metal plate is t (mm), the heating time of the metal plate is greater than or equal to 2.4×t (minutes).

4. The sequential forming method according to claim 1, characterized in that: The molding is performed while maintaining the circumference of the metal plate.

5. The sequential forming method according to claim 1, characterized in that: The heating device is a device for heating the metal plate in a non-contact manner.

6. The sequential forming method according to claim 5, characterized in that: The heating device is a device that heats the metal plate by irradiating the metal plate with laser light.

7. The sequential forming method according to claim 5, characterized in that: The heating device is a device that heats the metal plate by blowing hot air.

8. A sequential forming device, used in the sequential forming method according to claim 1, characterized in that: The successive molding device comprises: The rod-shaped tool is arranged on one main surface side of the metal plate; The heating device is arranged on the other main surface side of the metal plate; A tool driving device that drives the rod-shaped tool in at least three orthogonal axial directions; and a main control device, which controls the tool drive device, The heating device can heat each of the plurality of local moving ranges divided into the moving path of the rod-shaped tool from the inner side thereof. The main control device has a function of controlling the heating device based on the driving data of the rod-shaped tool.

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