Molding system

Abstract

The forming system includes: a heating unit that heats the metal material by allowing current to flow through it; a forming mold that shapes the heated metal material; and an electroplating unevenness suppression mechanism that suppresses unevenness of the electroplating layer generated in the metal material during the heating process.

Description

Technical Field

[0001] This invention relates to a molding system. Background Technology

[0002] Conventionally, the technology described in Patent Document 1 is known as a forming system. This forming system heats a metal material and shapes the heated metal tube material using a forming mold, thereby shaping the metal tube material to match the shape of the forming surface of the mold. Furthermore, the metal material is quenched simultaneously with the forming process.

[0003] Previous technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-220141 Summary of the Invention

[0006] The technical problem to be solved by the invention

[0007] Here, when the heated metal material is brought into contact with a forming mold for forming, oxide scale sometimes forms on the surface of the metal material due to the heating. Therefore, the surface of the metal material is sometimes electroplated to suppress the formation of this oxide scale. However, when the electroplated layer is heated by electricity, it melts and is affected by the magnetic field generated by the current, sometimes resulting in unevenness in the electroplated layer.

[0008] One embodiment of the present invention was made to solve this problem, and its object is to provide a forming system that can reduce the unevenness of electroplated layers on metal materials.

[0009] means for solving technical problems

[0010] One embodiment of the present invention relates to a molding system comprising a heating section for heating a metal material by passing an electric current through it, a molding die for molding the heated metal material, and an electroplating unevenness suppression mechanism for suppressing unevenness of the electroplated layer generated in the metal material during the heating process.

[0011] In the forming system, the heating unit heats the electroplated metal material by flowing an electric current through it. Therefore, the electroplated layer may sometimes melt due to the heat from the electric heating. To address this, the forming system includes an electroplating layer unevenness suppression mechanism to suppress unevenness of the electroplated layer that occurs in the metal material during the electric heating process. Thus, it is possible to prevent the electroplated layer, which melts due to the electric heating, from becoming uneven. Consequently, unevenness in the electroplated layer of the metal material can be suppressed.

[0012] The electroplating unevenness suppression mechanism can electrically suppress the unevenness of the electroplating layer. In this case, the electroplating unevenness suppression mechanism is electrically adjusted when heated, thereby easily suppressing the unevenness of the electroplating layer.

[0013] The electroplating unevenness suppression mechanism can suppress current changes when heating stops. At this time, in the presence of a magnetic material around the metal, it can suppress the magnitude of the force generated between the metal and the magnetic material due to the rapid change in current.

[0014] The electroplating unevenness suppression mechanism can suppress the current of electric heating. At this time, in the presence of a magnetic body around the metal material, the magnitude of the force generated between the metal material and the magnetic body during electric heating can be suppressed.

[0015] The electroplating unevenness suppression mechanism can mechanically suppress unevenness in the electroplating layer. At this time, the force generated during electric heating due to the relationship between the metal material and the magnetic material present around the metal material can be suppressed according to the structural design.

[0016] The electroplating unevenness suppression mechanism can separate the metal material and the magnetic body by a specified distance during electric heating. At this time, it can suppress the force generated between the magnetic body and the metal material during electric heating.

[0017] The electroplating unevenness suppression mechanism can be composed of a heating unit that heats the metal material outside the forming mold. In this case, the influence of the force generated between the forming mold and the metal material when the electric heating is applied can be suppressed.

[0018] The electroplating unevenness suppression mechanism can be composed of a magnetic shielding component positioned around the metal material during electric heating. This suppresses the forces generated between the molding die and the metal material during electric heating.

[0019] Invention Effects

[0020] According to one embodiment of the present invention, a forming system capable of reducing the unevenness of electroplated layers on metal materials is provided. Attached Figure Description

[0021] Figure 1 This is a block diagram illustrating the structure of the molding system according to an embodiment of the present invention.

[0022] Figure 2 It means Figure 1 A schematic structural diagram of a specific example of the molding system shown.

[0023] Figure 3 It means Figure 1 A schematic structural diagram of a specific example of the molding system shown.

[0024] Figure 4 It means Figure 1 A schematic structural diagram of a specific example of the molding system shown.

[0025] Figure 5 It is a schematic cross-sectional view showing the uneven state of the electroplated layer.

[0026] Figure 6 It is a diagram showing the distribution of the magnetic field generated around a metallic material during electric heating.

[0027] Figure 7 This is a diagram used to illustrate the Lorentz force generated in a flat metallic material.

[0028] Figure 8 It is a schematic diagram used to illustrate the forces generated between a metallic material and a magnetic body.

[0029] Figure 9 These are graphs showing the current and temperature changes.

[0030] Figure 10 This is a diagram used to illustrate the Lorentz force generated in metal tube materials.

[0031] Figure 11 This is a schematic diagram representing a magnetic shielding component.

[0032] Figure 12 This is a graph showing the analysis results of the relationship between the distance between the metal tube material and the mold and the Lorentz force.

[0033] Figure 13 This is a graph representing the experimental results.

[0034] Figure 14 This is a graph representing the experimental results.

[0035] Figure 15 This is a graph representing the experimental results.

[0036] Figure 16 This is a graph representing the experimental results.

[0037] Figure 17 This is a graph representing the experimental results.

[0038] Figure 18 It means Figure 1 A schematic structural diagram of a specific example of the molding system shown.

[0039] Figure 19 It means Figure 1 A schematic structural diagram of a specific example of the molding system shown. Detailed Implementation

[0040] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the drawings, the same or corresponding parts are labeled with the same symbols, and repeated descriptions are omitted.

[0041] Figure 1 This is a block diagram illustrating the structure of the molding system 100 according to this embodiment. Furthermore, Figures 2-4 It means Figure 1 A schematic structural diagram of a specific example of the molding system 100 shown.

[0042] The molding system 100 is a system for manufacturing a molded article by heating an electroplated metal material and shaping the heated metal material using a molding die. As the metal material, such as... Figure 2 Tubular metal tube material 40 as shown or such Figure 3 The sheet-like metal material 50 is shown. Examples of metal materials include carbon steel and MnB steel with improved hardenability. In this embodiment, an electroplated metal material is used. An electroplated metal material is a steel material whose surface is covered by an electroplating layer. Details regarding the electroplating layer will be described later.

[0043] like Figure 1 As shown, the molding system 100 includes a heating unit 101, a molding device 103 with a molding mold 102, and an electroplating layer unevenness suppression mechanism 104.

[0044] The heating unit 101 heats the electroplated metal material by allowing an electric current to flow through it. The heating unit 101 includes electrodes for contacting the metal material to allow current to flow through it, and a power source for directing the current to the electrodes. Thus, the metal material heats up due to Joule heating (electric heating) through its own resistance. The forming apparatus 103 is an apparatus for forming the metal material heated by the heating unit 101 using a forming mold 102.

[0045] For example, as the molding device 103, it can be adopted Figure 2 The structure shown. Figure 2 The forming apparatus 103 shown is a device that supplies fluid to the heated metal tube material 40, thereby bringing it into contact with the forming surface of the forming mold for forming and quenching. The forming apparatus 103 includes a heating unit 101.

[0046] like Figure 2As shown, the forming apparatus 103 is an apparatus for forming a hollow metal tube by blow molding. Here, the forming apparatus 103 is mounted on a horizontal plane. The forming apparatus 103 includes a forming mold 102, a drive mechanism 3, a holding part 4, a heating part 101, a fluid supply part 6, a cooling part 7, and a control part 8. Furthermore, in this specification, the metal tube material 40 (metal material) refers to the hollow article before the forming apparatus 103 finishes forming. The metal tube material 40 is a tube material of hardenable steel. Also, sometimes the direction of extension of the metal tube material 40 during forming in the horizontal direction is referred to as the "length direction," and the direction orthogonal to the length direction is referred to as the "width direction."

[0047] The forming mold 102 is a mold for forming the metal tube material 40 into a metal tube, and it has a lower mold 11 and an upper mold 12 that are opposed to each other in the vertical direction. The lower mold 11 and the upper mold 12 are made of steel blocks. The lower mold 11 and the upper mold 12 are respectively provided with recesses for receiving the metal tube material 40. When the lower mold 11 and the upper mold 12 are in close contact with each other (closed mold state), each recess forms a space for forming the target shape of the metal tube material. Therefore, the surface of each recess becomes the forming surface of the forming mold 102. The lower mold 11 is fixed to the base 13 via a mold base or the like. The upper mold 12 is fixed to the sliding member of the drive mechanism 3 via a mold base or the like.

[0048] The drive mechanism 3 is a mechanism that moves at least one of the lower mold 11 and the upper mold 12. Figure 2 In this design, the drive mechanism 3 has a structure that moves only the upper mold 12. The drive mechanism 3 includes: a sliding member 21 that moves the upper mold 12 toward the direction where the lower mold 11 and the upper mold 12 are brought together; a pull-back cylinder 22, which acts as an actuator, generates a force that pulls the sliding member 21 upward; a main cylinder 23, which acts as a drive source, that lowers the sliding member 21 and applies pressure; and a drive source 24 that applies a driving force to the main cylinder 23.

[0049] The holding part 4 is a mechanism for holding the metal tube material 40 disposed between the lower mold 11 and the upper mold 12. The holding part 4 includes a lower electrode 26 and an upper electrode 27 that hold the metal tube material 40 at one end along the length of the forming mold 102, and a lower electrode 26 and an upper electrode 27 that hold the metal tube material 40 at the other end along the length of the forming mold 102. The lower electrode 26 and the upper electrode 27 on both sides along the length clamp the metal tube material 40 near its end from the vertical direction, thereby holding the metal tube material 40. Furthermore, grooves with shapes corresponding to the outer peripheral surface shape of the metal tube material 40 are formed on the upper surface of the lower electrode 26 and the lower surface of the upper electrode 27. A drive mechanism (not shown) is provided on the lower electrode 26 and the upper electrode 27, so that the lower electrode 26 and the upper electrode 27 can move independently in the vertical direction.

[0050] The heating unit 101 heats the metal tube material 40. The heating unit 101 is a mechanism that heats the metal tube material 40 by energizing it. The heating unit 101 heats the metal tube material 40 when it is between the lower mold 11 and the upper mold 12 and separated from both molds. The heating unit 101 includes: a lower electrode 26 and an upper electrode 27 on both sides along its length; and a power supply 28 that allows current to flow through these electrodes 26 and 27 to the metal tube material 40.

[0051] Here, the state in which the metal tube material 40 is disposed inside the forming mold 102 refers to the state in which the metal tube material 40 is disposed in the space between the upper mold 12 and the lower mold 11, which are opposite each other. In this state, the metal tube material 40 is opposite the upper mold 12 when it is separated downward relative to the upper mold 12, and opposite the lower mold 11 when it is separated upward relative to the lower mold 11.

[0052] The fluid supply unit 6 is a mechanism for supplying high-pressure fluid into the metal tube material 40 held between the lower mold 11 and the upper mold 12. The fluid supply unit 6 supplies high-pressure fluid to the metal tube material 40, which is heated to a high temperature by the heating unit 101, causing the metal tube material 40 to expand. The fluid supply unit 6 is provided at both ends along the length of the molding die 102. The fluid supply unit 6 includes: a nozzle 31 for supplying fluid into the metal tube material 40 through an opening at one end; a drive mechanism 32 for moving the nozzle 31 forward and backward relative to the opening of the metal tube material 40; and a supply source 33 for supplying high-pressure fluid into the metal tube material 40 via the nozzle 31. During fluid supply and venting, the drive mechanism 32 keeps the nozzle 31 in close contact with the end of the metal tube material 40 to ensure a seal; otherwise, it separates the nozzle 31 from the end of the metal tube material 40. Alternatively, the fluid supply unit 6 can also supply high-pressure air or an inert gas as the fluid. Furthermore, the fluid supply unit 6, the holding unit 4 having a mechanism for moving the metal tube material 40 in the vertical direction, and the heating unit 10 can be provided as the same device.

[0053] The cooling section 7 is a mechanism for cooling the molding die 102. By cooling the molding die 102, the cooling section 7 can rapidly cool the expanded metal tube material 40 when it comes into contact with the molding surface of the molding die 102. The cooling section 7 includes: a flow path 36 formed inside the lower mold 11 and the upper mold 12; and a water circulation mechanism 37 that supplies cooling water to the flow path 36 and circulates it.

[0054] The control unit 8 is a device for controlling the entire molding apparatus 103. The control unit 8 controls the drive mechanism 3, the holding unit 4, the heating unit 101, the fluid supply unit 6, and the cooling unit 7. The control unit 8 repeatedly performs the action of molding the metal tube material 40 using the molding die 102.

[0055] The control unit 8 controls the drive mechanism 3 to lower the upper mold 12 and bring it closer to the lower mold 11, thereby closing the forming mold 102. Meanwhile, the control unit 8 controls the fluid supply unit 6 to seal the openings at both ends of the metal tube material 40 using nozzles 31 and supply fluid. As a result, the softened metal tube material 40 expands and contacts the forming surface of the forming mold 102. Furthermore, the metal tube material 40 is formed into a shape identical to the forming surface of the forming mold 102. Additionally, when forming a flanged metal tube, a portion of the metal tube material 40 is inserted into the gap between the lower mold 11 and the upper mold 12, and then the mold closing process continues, flattening the inserted portion to form the flange. If the metal tube material 40 contacts the forming surface, the forming mold 102, cooled by the cooling unit 7, rapidly cools the metal tube material 40, thereby quenching the metal tube material 40.

[0056] Furthermore, as the molding device 103, it can employ... Figure 3 The structure shown. Figure 3 The forming apparatus 103 shown is an apparatus for forming and quenching a heated flat metal material 50 by contacting the forming surface of the forming mold 102. The forming apparatus 103 includes a heating unit 101.

[0057] The molding apparatus 103 includes a molding die 102 for molding a metal material 50 to form a molded article. The molding die 102 includes an upper mold 62 that contacts the upper surface of the metal material 50 and a lower mold 63 that contacts the lower surface of the metal material 50. The molding surface (lower surface) of the upper mold 62 and the molding surface (upper surface) of the lower mold 63 can be formed, for example, into a shape corresponding to a top hat. The molding apparatus 103 includes a drive unit (not shown) for moving at least one of the upper mold 62 and the lower mold 63. The molding apparatus 103 uses the molding surfaces of the upper mold 62 and the lower mold 63 to clamp the metal material 50, thereby molding the metal material 50 into the shape of a molded article. Furthermore, the structure of the molding die 102 is not limited to a structure with molds (e.g., upper mold 62 and lower mold 63) facing each other in the vertical direction; molds facing each other in the horizontal direction can also be configured. Moreover, the number of molds constituting the molding die 102 is not limited to two; it can be divided into three or more.

[0058] The heating unit 101 heats the metal material 50 disposed inside the molding die 102. Here, with... Figure 2 Similarly, the state in which the metal material 50 is disposed inside the molding die 102 refers to the state in which the metal material 50 is disposed in the space between the upper mold 62 and the lower mold 63 relative to each other.

[0059] The heating unit 101 heats the metal material 50 by allowing an electric current to flow through it. Specifically, the heating unit 101 includes a pair of electrodes 70A and 70B and a power supply 71. Electrodes 70A and 70B are components used to contact the metal material 50, allowing an electric current to flow through it. Thus, the metal material 50 heats up due to its own resistance via Joule heating (electric heating). The power supply 71 is connected to electrodes 70A and 70B, allowing current to flow through these electrodes to the metal material 50.

[0060] exist Figure 3In the example shown, electrodes 70A and 70B are in contact with the ends of the metal material 50 along its length. The arrangement of electrodes 70A and 70B in contact with the metal material 50 is not particularly limited. Furthermore, electrodes 70A and 70B can function to hold the metal material 50, but additional holding mechanisms besides electrodes 70A and 70B may also be provided. Moreover, the structure of electrodes 70A and 70B on the molding apparatus 103 is not particularly limited. For example, electrodes 70A and 70B can be mounted on the molding mold 102. In this case, electrodes 70A and 70B can be removed from the molding mold 102 when the heating ends and the upper mold 62 and lower mold 63 are closed. Alternatively, electrodes 70A and 70B can be configured to be positioned separately from the molding mold 102 so that the closing of the upper mold 62 and lower mold 63 does not interfere with electrodes 70A and 70B. Furthermore, it is also possible to configure the electrodes 70A and 70B to have actuators (not shown) provided on them so that the electrodes 70A and 70B can move relative to the molding die 102.

[0061] like Figure 3 As shown, the molding system 100 includes a control unit 80. The control unit 80 is a device for controlling the entire molding system 100. The control unit 80 is electrically connected to the power supply 71 of the heating unit 101. The control unit 80 sends a control signal to the power supply 71 to control the timing of heating by the heating unit 101 and adjust the magnitude of the current, thereby controlling the heating temperature.

[0062] Furthermore, as the molding system 100, it can employ... Figure 4 The structure shown. In Figure 4 In the molding system 100 shown, the heating unit 101 and the molding device 103 are configured as separate units. Therefore, the heating unit 101 can heat the metal tube material 40 outside the molding die 102. At this time, the heating unit 101 heats the metal tube material 40 to point A3 or higher (i.e., 800°C or higher). The state where the heating unit 101 heats outside the molding die 102 means that the heating is performed outside the space opposite to the molds 12 and 11. Figure 4 In the example shown, the heating element 101 is located at a different position from the molding apparatus 103. Furthermore, the metal tube material 40 heated by the heating element 101 is transferred to the molding apparatus 103 via a handling device such as a robotic arm (not shown). Other structures of the molding apparatus 103 are similar to... Figure 2 The molding apparatus 103 shown is the same. Additionally, in... Figure 3 In the forming system 100 that forms a flat metal material 50 as shown, a structure in which the heating unit 101 heats the outside of the forming mold 102 can also be adopted.

[0063] Or, such as Figure 18As shown, the heating unit 101 can perform heating in two stages. First, the heating unit 101 heats the outside of the molding die 102. Figure 18 (See the left figure). At this time, the heating unit 101 heats the metal tube material 40 to above 500°C and below point A3 (i.e., below 800°C). Then, the metal tube material 40 and the heating unit 101 are transported together into the molding die 102 using a conveying device. Figure 18 (Central view). Next, the heating unit 101 heats the metal tube material 40 within the forming mold 102 ( Figure 18 (See the right figure). At this time, the heating unit 101 heats the metal tube material 40 to point A3 or higher (i.e., 800°C or higher). Alternatively, the initial heating outside the forming mold 102 can be performed using a boiler or similar device. This helps to suppress the decrease in tube deformation resistance caused by the tube's temperature drop during transport, thus minimizing the reduction in forming freedom. Furthermore, when the metal tube material 40 is heated inside the forming mold 102, since the metal tube material 40 has already been heated externally, uneven electroplating can be suppressed while forming the tube.

[0064] Furthermore, it is also possible to adopt Figure 19 The structure shown. Figure 19 The heating element 101 shown undergoes two stages of heating, followed by natural air cooling after the first heating. First, the heating element 101 heats the outside of the molding die 102. Figure 19 (See the left figure). At this time, the heating unit 101 heats the metal tube material 40 to above 500°C and below point A3 (i.e., below 800°C). Then, the metal tube material 40 is removed from the heating unit 101 and allowed to air cool naturally. Figure 19 (Central view). Next, the metal tube material 40 is placed in the heating section 101 provided in the forming mold 102, and the heating section 101 heats the metal tube material 40 within the forming mold 102. Figure 19 (See the right figure). At this time, the heating unit 101 heats the metal tube material 40 to point A3 or higher (i.e., 800°C or higher). Alternatively, the initial heating outside the forming mold 102 can be performed using a boiler or the like. This suppresses the deformation resistance of the tube caused by the temperature drop due to natural heat dissipation. Furthermore, when the metal tube material 40 is heated inside the forming mold 102, since the metal tube material 40 has already been heated externally, uneven electroplating can be suppressed while the tube is formed.

[0065] Return to Figure 1 The electroplating unevenness suppression mechanism 104 is a mechanism for suppressing unevenness of the electroplated layer generated in the metal material during electrical heating. Here, the unevenness of the electroplated layer in the metal material will be explained. Figures 2-4In the apparatus shown, the metal material can be quenched simultaneously with forming. However, to achieve sufficient quenching, the metal material needs to be heated to a temperature above the Ac3 point during electroplating to induce an austenitic phase transformation. Therefore, when the metal material is heated to this high temperature, an oxide scale may form on its surface. To suppress this oxide scale formation, the surface of the metal material is electroplated with an electroplating material. Examples of electroplating materials include AlSi electroplating. Here, when AlSi is used as the electroplating material, aluminum has a melting point of 652°C, which is lower than the target heating temperature above the Ac3 point (i.e., 900–1000°C). Therefore, the electroplated layer on the metal surface may melt during electroplating. According to the magnetic field generated by the current and Fleming's left-hand law based on the current, a strong attractive force acts on the molten electroplated layer, resulting in a phenomenon of molten electroplated layer movement (pinch effect) (i.e., the so-called unevenness of the molten electroplated layer). If the thickness of the electroplated layer on a metal material becomes uneven depending on the location, it will lead to the exposure of the iron in the base material, resulting in a reduced oxide scale suppression effect. When using electroplated metal materials, there is a problem of uneven molten electroplated layers. For example, during heating, the aluminum plating reacts with the iron in the base material, and the alloying reaction between iron and aluminum progresses, for example, forming intermetallic compounds (FeAl3) with melting and boiling points above 1000°C. If the heating rate is slow, the alloying reaction proceeds before reaching the melting point of aluminum (652°C), thus preventing the aluminum from melting. However, if the heating rate is fast, the melting point temperature of aluminum (652°C) is reached before the alloying reaction is fully completed, and part of the aluminum plating will melt, resulting in the aforementioned unevenness. Therefore, the electroplating unevenness suppression mechanism 104 suppresses the generation of such uneven electroplating layers, thereby ensuring the uniformity of the thickness of the electroplated layer on the metal material.

[0066] For example, Figure 5 (a) is a schematic cross-sectional view showing that an electroplated layer 52 is uniformly formed on the surface of the base material 51 of the flat metal material 50. Figure 5 (b) is a schematic cross-sectional view showing the state of the electroplated layer 52 formed on the surface of the base material 51 of the flat metal material 50, which is biased toward a specified position. Figure 5 (c) is a schematic cross-sectional view showing that an electroplated layer 42 is uniformly formed on the surface of the base material 41 of the tubular metal tube material 40. Figure 5 (d) is a schematic cross-sectional view showing the state of the electroplating 42 formed on the surface of the base material 41 of the tubular metal tube material 40, which is biased towards a predetermined location. In the absence of an electroplating unevenness suppression mechanism 104 in the forming system, the following will occur: Figure 5 The unevenness of the electroplated layer is shown in (b) and (d). To address this, the unevenness suppression mechanism 104 suppresses the unevenness of the electroplated layer, thereby, as... Figure 5 As shown in (a) and (c), an electroplated layer 52 of uniform thickness can be formed.

[0067] Figure 6 In diagram (a), the distribution of the magnetic field generated around the plate-shaped metal material 50 during electric heating is shown. At this time, as... Figure 7 As shown in (a), if a current flows in one direction along the metal material 50, a magnetic field is generated in the metal material 50, and its distribution is as follows. Figure 7 As shown in (b). Figure 7 The upper section of (b) schematically shows the orientation and magnitude of the magnetic field generated in the metallic material 50. Figure 7 The lower section of (b) shows a graph of the magnetic field of the metallic material 50. In the metallic material 50 undergoing electric heating, this magnetic field distribution is generated simultaneously with the flow of current, thus resulting in a Lorentz force based on Fleming's left-hand law. Figure 7 The upper section of (c) schematically illustrates the orientation and magnitude of the Lorentz force generated in the metallic material 50. Figure 7 The lower section of (c) shows a graph of the Lorentz force on metallic material 50. (See diagram below.) Figure 7 As shown in (c), the direction of the Lorentz force is from the positive side of the metal material 50 in the X direction to the negative side in the X direction, and from the negative side of the metal material 50 in the X direction to the positive side in the X direction (reference). Figure 7 (c) Therefore, if the electroplated layer melts during heating, the molten electroplated layer will be biased towards the center in the X direction.

[0068] To address this, the electroplating unevenness suppression mechanism 104 electrically suppresses the unevenness of the electroplating layer. Electrically suppressing the unevenness of the electroplating layer means suppressing the unevenness by controlling the flow of current supplied from the heating unit 101 to the metal material 50. Specifically, the electroplating unevenness suppression mechanism 104 can suppress the current supplied by the heating element. Furthermore, this electrically suppressed unevenness of the electroplating layer can be applied to… Figures 2-4 In any type of molding system 100. When the unevenness of the electroplating layer is electrically suppressed by the electroplating layer unevenness suppression mechanism 104, the electroplating layer unevenness suppression mechanism 104 is composed of a heating part 101 and control parts 8, 80 that control the heating part 101. For example, Figure 9The diagram shows a current curve CG1 when the electroplating unevenness suppression mechanism 104 performs current control to suppress unevenness in the electroplating layer, and a temperature change curve TG1 when this current control is performed. Additionally, curves CG2 and TG2 are curves when no current control for suppressing unevenness in the electroplating layer is performed. As shown in curve CG1, the electroplating unevenness suppression mechanism 104 suppresses the current to a lower current than that shown in curve CG2 of the comparative example, and allows the current to flow. Thus, when the electroplating unevenness suppression mechanism 104 performs current control to suppress the current, Figure 7 The magnetic field shown in (b) will decrease, resulting in a bias towards Figure 7 The Lorentz force at the center, as shown in (c), decreases. Therefore, unevenness in the electroplated layer can be suppressed. Furthermore, regarding curve CG1, the heating time increases accordingly due to current suppression. The electroplating unevenness suppression mechanism 104 is not particularly limited; however, the current for heating can be suppressed to the range of 4kA to 10kA. If the current exceeds this range, the suppression effect will be lower; if it is less than this range, the heating time will become excessively long. Additionally, the heating current without current suppression is in the range of 9kA to 18kA.

[0069] Furthermore, when the magnetic material (i.e., the molding die 102) is present near the metal material 50, heating will produce [something] when the current is applied. Figure 8 The induced current is shown in (a). Therefore, a repulsive force is generated in the metallic material 50. On the other hand, at the end of the heating process, a repulsive force is generated. Figure 8 The induced current is shown in (b). Therefore, an attractive force is generated in the metallic material 50. Under the influence of this repulsive or attractive force, unevenness in the electroplated layer occurs. To address this, as a method of electrically suppressing unevenness in the electroplated layer, the electroplated layer unevenness suppression mechanism 104 can suppress current changes when the heating is stopped. For example, as... Figure 9 As shown in section "A", when the heating is stopped, the electroplating unevenness suppression mechanism 104 does not abruptly stop the current (refer to the imaginary line) but slowly reduces the current, thereby decreasing the current in a way that resembles a curve. In this way, by suppressing the current change when the heating stops, unevenness in the electroplating layer is suppressed. Figure 8 The attraction shown in (b) can suppress unevenness of the electroplated layer. In addition, although not particularly limited, the unevenness suppression mechanism 104 can, for example, vary the current within a range from the initial current value to about half of the current value.

[0070] Next, the unevenness of the electroplating layer on the metal tube material 40 will be explained. Figure 6Figure (b) shows the magnetic field distribution when the metal tube material 40 is electrically heated. The shape of the metal tube material 40 is point-symmetric, therefore the surrounding magnetic field is also symmetrically distributed. Consequently, the magnetic field in the direction perpendicular to the material surface is zero (see reference). Figure 10 Therefore, the gravitational force in the tangential direction is also zero (see reference (b)). Figure 10 In (c) of this study, the unevenness of the molten electroplated layer is suppressed. To this end, as shown in [examples omitted]... Figure 6 As shown in (c), if a magnetic material such as the forming mold 102 is present near the metal tube material 40 during heating, the uniformity of the magnetic field distribution will be disrupted. This results in a magnetic field perpendicular to the material surface. Consequently, an attractive force is generated in the tangential direction within the metal tube material 40 (see reference). Figure 12 This can lead to uneven electroplating. To address this unevenness, the electroplating unevenness suppression mechanism 104 can mechanically suppress it. Mechanically suppressing unevenness means suppressing it by adjusting the structure. In this case, the electroplating unevenness suppression mechanism 104 separates the metal tube material 40, which is heated by electricity, from the magnetic body (forming mold 102) by a predetermined distance or more. In this case, the electroplating unevenness suppression mechanism 104 is composed of a heating section 101 that positions the metal tube material 40 during heating. Alternatively, the electroplating unevenness suppression mechanism 104 is composed of a heating section 101 that heats the metal material outside the forming mold 102. In this case, the electroplating unevenness suppression mechanism 104 consists of an externally located heating section 101 (see reference). Figure 4 The electroplating unevenness suppression mechanism 104 can be composed of a magnetic shielding member disposed around the metal material when heated by electricity. Furthermore, this mechanical electroplating unevenness suppression mechanism 104 can be applied to a forming system 100 for a flat metal material 50.

[0071] When the uneven electroplating layer suppression mechanism 104 separates the metal tube material 40 from the magnetic body (forming mold 102) by a predetermined distance or more, it can separate them by a distance of 20 mm or more. For example, Figure 12 As shown in (b), the Lorentz force in the tangential direction increases at a distance of 20 mm, but increasing this distance further suppresses the Lorentz force. Additionally, Figure 12 The experiment shown yielded the following results: the outer diameter of the metal tube material 40 was set to 60 mm, the plate thickness to 1 mm, the tube length to 1000 mm, and the current to 9000 A. The Lorentz force acting on each unit area was analyzed for four cases: the distance from the tube surface to the mold was 20 mm, 50 mm, 100 mm, and there was no mold.

[0072] like Figure 11As shown, the magnetic shielding member 105 constituting the electroplating unevenness suppression mechanism 104 is configured to cover the periphery of the metal tube material 40 when electrically heated. The magnetic shielding member 105 is composed of two semi-circular parts, which are combined when electrically heated to cover the metal tube material 40. Furthermore, during molding, the magnetic shielding member 105 retracts from the periphery of the metal tube material 40.

[0073] Next, refer to Figures 13-17 This experiment describes an evaluation of the electroplating unevenness suppression effect of the electroplating unevenness suppression mechanism 104. In this experiment, the AlSi electroplating thickness per unit area mass of "Usibor (registered trademark)" (150 g / m²) was measured. 2 A 1.2mm thick metal tube material 40 was used. Measurements were taken of heating both inside and outside the molding die 102. Heating temperatures were set to 900°C, 1000°C, 1100°C, and 1200°C for both internal and external heating. For internal heating, the heating rate was controlled at 15°C / sec and 150°C / sec (the current value for the target heating rate was first determined, and experiments were conducted under constant current conditions). For internal heating, the upper die was moved to a position unaffected by the magnetic field. Measurements were taken at two positions for the lower die: a lifting position (lower die lifting position) of 45mm and 70mm based on the lifting position of the heating unit 101. At the lifting position of 45mm, the distance between the metal tube material 40 and the die was 15mm; at the lifting position of 70mm, the distance was 40mm.

[0074] exist Figure 13 The image shows observations of the appearance under various conditions. For example... Figure 13 As shown, when the lower mold is at a lifting position of 45 mm and the heating rate is 150 °C / sec, thicker portions of the electroplated layer were observed on both sides adjacent to the weld seam. This indicates that unevenness in the electroplated layer was confirmed. Compared to this result, under other conditions, the thickness of the electroplated layer is more dispersed, demonstrating that unevenness in the electroplated layer is suppressed. In particular, external heating further reduces unevenness. Therefore, it can be confirmed that increasing the distance between molds or applying external heating can suppress unevenness in the electroplated layer.

[0075] Figures 14-16 This is a graph showing the circumferential distribution of the surface height of the metal tube material 40 under various conditions. From... Figure 14 Images (a) and (b) confirm the correlation between the distance between the metal tube material 40 and the mold and the unevenness of the electroplating layer. Figure 14In (a) and (b), a greater distance can suppress the unevenness of the electroplated layer. Therefore, it can be confirmed that the greater the distance between the metal tube material 40 and the surrounding magnetic body (mold, etc.), the more the unevenness of the electroplated layer can be reduced.

[0076] from Figure 15 Figures (a), (b), and (c) confirm the correlation between the heating temperature based on electroplating and the unevenness of the electroplated layer. No differences in electroplated layer unevenness due to different heating temperatures were observed in any of the graphs. Therefore, it can be concluded that the unevenness of the electroplated layer arises during electroplating, and the final temperature has a relatively small influence.

[0077] from Figure 16 In (a) and (b), the correlation between the heating rate and the unevenness of the electroplated layer can be confirmed. Figure 16 The unevenness of the electroplated layer in (b) is reduced, indicating that a slower heating rate is more effective in suppressing unevenness. It can be assumed that a smaller current leads to a smaller Lorentz force, and similarly to boiler heating, the alloying-promoting effect during the heating process plays a role.

[0078] Figure 17 This is a bar graph showing the maximum height of electroplating unevenness under various conditions. The graph confirms that increasing the distance between the metal tube material 40 and the mold significantly reduces electroplating unevenness.

[0079] Next, the effects of the molding system 100 according to this embodiment will be explained.

[0080] The molding system 100 according to this embodiment includes: a heating unit 101 that heats the metal material by passing an electric current through it; a molding die 102 that shapes the heated metal material; and an electroplating unevenness suppression mechanism 104 that suppresses the unevenness of the electroplating layer generated in the metal material during heating.

[0081] In the forming system 100, the heating unit 101 heats the electroplated metal material by flowing an electric current through it. Therefore, the electroplated layer may sometimes melt due to the heat from the electric heating. To address this, the forming system 100 includes an electroplating layer unevenness suppression mechanism 104 to suppress unevenness of the electroplated layer that occurs in the metal material during electric heating. Therefore, it is possible to suppress the unevenness of the electroplated layer that has melted due to electric heating. Thus, unevenness of the electroplated layer on the metal material can be suppressed.

[0082] The electroplating unevenness suppression mechanism 104 can electrically suppress the unevenness of the electroplating layer. At this time, the electroplating unevenness suppression mechanism 104 is electrically adjusted when heated by electricity, thereby easily suppressing the unevenness of the electroplating layer.

[0083] The electroplating unevenness suppression mechanism 104 can suppress current changes when the heating stops. At this time, in the presence of a magnetic body around the metal material, it can suppress the magnitude of the force generated between the metal material and the magnetic body that accompanies the rapid change in current.

[0084] The electroplating unevenness suppression mechanism 104 can suppress the current of electric heating. At this time, when there is a magnetic body around the metal material, the magnitude of the force generated between the metal material and the magnetic body during electric heating can be suppressed.

[0085] The electroplating unevenness suppression mechanism 104 can mechanically suppress the unevenness of the electroplating layer. At this time, it is possible to suppress the force generated when heating due to the relationship between the metal material and the magnetic body present around the metal material, according to the structural design.

[0086] The electroplating unevenness suppression mechanism 104 can separate the metal material and the magnetic body by a predetermined distance during electric heating. At this time, it can suppress the force generated between the magnetic body and the metal material during electric heating.

[0087] The electroplating unevenness suppression mechanism 104 can be composed of a heating section 101 that heats the metal material outside the forming mold. In this case, the influence of the force generated between the forming mold and the metal material when the electric heating is applied can be suppressed.

[0088] The electroplating unevenness suppression mechanism 104 can be composed of a magnetic shield 105 disposed around the metal material when electrically heated. In this case, it is possible to suppress the force generated between the molding die and the metal material when electrically heated.

[0089] This invention is not limited to the embodiments described above. For example, Figures 2-4 The molding apparatus described is merely one example; as long as it does not depart from the spirit of the invention, the molding apparatus may have any structure.

[0090] Symbol Explanation

[0091] 100- Molding system, 101- Heating section, 102- Molding mold, 104- Electroplating unevenness suppression mechanism, 105- Magnetic shielding component.

Claims

1. A molding system, characterized in that, have: The heating element heats the electroplated metal material by allowing an electric current to flow through it. A forming mold, wherein the forming mold is a magnetic body, is used to form the heated metal material; and An electroplating unevenness suppression mechanism suppresses unevenness in the electroplated layer that occurs during electrical heating in the metal material. The electroplating unevenness suppression mechanism ensures that the metal material is separated from the mold by a specified distance when the power is applied for heating, and the specified distance is greater than 20mm.

2. A molding system, characterized in that, have: The heating element heats the electroplated metal material by allowing an electric current to flow through it. A forming mold, wherein the forming mold is a magnetic body, is used to form the heated metal material; and An electroplating unevenness suppression mechanism suppresses unevenness in the electroplated layer that occurs during electrical heating in the metal material. The uneven electroplating layer suppression mechanism is composed of a heating part that heats the metal material outside the forming mold.

3. The molding system according to claim 1 or 2, characterized in that, The electroplating unevenness suppression mechanism mechanically suppresses the unevenness of the electroplating layer.

Images