Molding system

Abstract

This molding system is provided with: a heating unit for heating a metal tube material; and a molding unit for molding the heated metal tube material, the molding unit being provided with a quenching mechanism for quenching a molded article, and the molded article being conveyed to a cooling mechanism different from the quenching mechanism during quenching by the quenching mechanism.

Description

TECHNICAL FIELD

[0001] The present application relates to a molding system. BACKGROUND

[0002] In the past, as a molding system, the system described in Patent Literature 1 is known. The molding system heats a metal pipe material, and molds the heated metal pipe material using a molding die, so that the shape of the metal pipe material becomes the shape of a molding surface of the molding die. Also, the metal pipe material is quenched while being molded.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2009-220141

[0006] In the heating, molding, and quenching processes described in Patent Literature 1 above, after the metal pipe material is heated to the austenite region, the metal pipe material is molded by being brought into contact with the die, and quenched at a prescribed cooling rate, so that the target mechanical properties and dimensional accuracy are achieved. However, in order to obtain the target mechanical properties and dimensional accuracy, the molded product is removed from the die after reaching the martensite transformation finish temperature (Mf point) or below. Therefore, there is a problem in that the production cycle (Throughput) from the start of molding to the removal of the molded product from the die becomes long, resulting in a longer time for which a single metal pipe material occupies the molding device.

[0007] On the other hand, in order to improve the production efficiency, in the case where the molded product is removed from the die immediately after molding and cooled in air, in the shape of a special-shaped cross section, the cooling rate differs depending on the site, and the cooling rate required for the martensite transformation cannot be obtained, so the target strength cannot be achieved for the entire molded product. Also, the cooling start temperature and the cooling rate of each site of the molded product become uneven, and warping occurs due to the difference in the amount of thermal contraction of each site, so there is a problem in that the target dimensional accuracy cannot be ensured. SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] An embodiment of the present application is achieved in order to solve the above problems, and has an object to provide a molding system in which the production cycle of molding can be shortened while the desired strength of the molded product is obtained.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] The molding system according to one embodiment of the present application includes a heating section that heats a metal pipe material, and a molding section that molds the heated metal pipe material, and a quenching mechanism that quenches a molded product is provided in the molding section, and the molded product is conveyed to a cooling mechanism different from the quenching mechanism during quenching by the quenching mechanism.

[0012] In the molding system, the quenching mechanism that quenches the molded product is provided in the molding section. Therefore, immediately after molding, the molded product is rapidly cooled by the quenching mechanism. Here, the molded product is conveyed to the cooling mechanism different from the quenching mechanism during quenching by the quenching mechanism. Thus, the molded product is rapidly cooled in the cooling mechanism, and quenching is completed. Therefore, the desired strength of the molded product can be obtained by quenching. Moreover, the cooling mechanism is a mechanism different from the quenching mechanism. Therefore, the production cycle until the molded product is taken out of the molding die is shortened, and the molding of the next metal pipe material can be performed in the quenching mechanism of the molding die. Thus, the desired strength of the molded product can be obtained while the molding production cycle is shortened.

[0013] After the metal pipe material is conveyed to the other cooling mechanism, the metal pipe material can be transformed from the martensite start temperature to the martensite finish temperature. Thus, the quenching of the metal pipe material can be completed by the other cooling mechanism.

[0014] The cooling mechanism can be a cooling jig that cools the molded product. At this time, the molded product can be cooled by the cooling mechanism at a place different from the molding die. Therefore, the quenching mechanism and the other cooling mechanism can not be provided in the molding die itself.

[0015] The quenching mechanism and the cooling mechanism can be provided at different positions in the same molding die. At this time, a space for providing the cooling mechanism does not need to be ensured at a place other than the molding die.

[0016] In the molding section, the molding is performed by expanding the metal pipe material by supplying a fluid to the metal pipe material, and in the molding section, the ratio of the cooling time in the cooling mechanism to the cooling time in the molding die can be increased for the case of the metal pipe material having a low blow molding pressure, compared to the case of the metal pipe material having a high blow molding pressure. At this time, shape freezing can be reliably performed even for the metal pipe material having a low blow molding pressure.

[0017] Effects of Invention

[0018] According to one embodiment of the present application, a molding system that can shorten a molding production cycle while ensuring the dimensional accuracy of a molded product is provided. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1is a block diagram showing the structure of a molding system according to an embodiment of the present application.

[0020] Figure 2 is a schematic configuration diagram of a specific example of the molding system shown in Figure 1

[0021] Figure 3 is a schematic configuration diagram of a specific example of the molding system shown in Figure 1

[0022] Figure 4 is a schematic configuration diagram of a specific example of the molding system shown in Figure 1

[0023] Figure 5 is a diagram showing a specific example of a cooling jig.

[0024] Figure 6 is a diagram showing a specific example of a cooling jig.

[0025] Figure 7 is a CCT graph showing the cooling process in each step.

[0026] Figure 8 is a diagram showing a molding die of the molding system shown in the modification example.

[0027] Figure 9 is a diagram showing an example of another molded article.

[0028] Figure 10 shows the relationship between the temperature of the flat portion of the molded article after gas blow molding and the blow holding time in the molding die under different blow molding pressures.

[0029] Figure 11 (a) of FIG. 7 is a graph showing the relationship between the cooling method and the time of the molded article in the comparative example and the embodiment, Figure 11 (b) of FIG. 7 is a graph showing the time ratio of cooling by the molding die and the time ratio of cooling by the cooling mechanism when based on the total cooling time. DETAILED DESCRIPTION

[0030] Hereinafter, a preferred embodiment of the present application will be described with reference to the accompanying drawings. In each drawing, the same reference numerals are assigned to the same parts or equivalent parts, and repeated description will be omitted.

[0031] Figure 1 is a block diagram showing the structure of a molding system 100 according to the present embodiment. Also, Figures 2 to 4 is a schematic configuration diagram of a specific example of the molding system 100 shown in Figure 1

[0032] ​​​​The forming system 100 is a system that heats a metal material and shapes the heated metal material using a forming mold, thereby producing a molded article 140 (see reference). Figure 4 As a metallic material, it employs, for example... Figure 2 The tubular metal tube material 40 shown or such Figure 3 The plate-shaped metal material 50 shown. For example, carbon steel or MnB steel with improved hardenability may be used as the metal material.

[0033] like Figure 1 As shown, the molding system 100 includes a heating unit 101, a molding device 103 (molding unit) with a molding die 102, and a cooling mechanism 104.

[0034] The heating unit 101 heats the metal material by allowing an electric current to flow through it. The heating unit 101 includes electrodes for contacting the metal material and allowing an electric current to flow through them, and a power source for allowing the current to flow through the electrodes. Thus, the metal material itself generates heat due to Joule heating (electric heating) by utilizing its own resistance. The forming apparatus 103 is an apparatus that uses a forming mold 102 to form the metal material heated by the heating unit 101.

[0035] 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 performs forming and quenching by supplying fluid to a heated metal tube material 40, causing it to contact the forming surface of a forming mold. The forming apparatus 103 includes a heating unit 101.

[0036] like Figure 2 As shown, the forming apparatus 103 is an apparatus for forming a hollow metal tube by blow molding. Here, the forming apparatus 103 is arranged 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 refers to the hollow workpiece before forming is completed in the forming apparatus 103. The metal tube material 40 is a hardenable steel tube. In the horizontal direction, the direction in which the metal tube material 40 extends during forming is sometimes referred to as the "length direction," and the direction orthogonal to the length direction is referred to as the "width direction."

[0037] The molding die 102 is a die that molds a metal pipe from the metal pipe material 40, and has a lower side die 11 and an upper side die 12 that face each other in the vertical direction. The lower side die 11 and the upper side die 12 are composed of steel blocks. The lower side die 11 and the upper side die 12 each have a recessed portion for receiving the metal pipe material 40. The lower side die 11 and the upper side die 12 form a space for molding the metal pipe material into a target shape by the respective recessed portions in a state of being in close contact with each other (a die closing state). Thus, the surfaces of the respective recessed portions become molding surfaces of the molding die 102. The lower side die 11 is fixed to the base 13 via a die holder or the like. The upper side die 12 is fixed to the slide of the drive mechanism 3 via a die holder or the like.

[0038] The drive mechanism 3 is a mechanism that moves at least one of the lower side die 11 and the upper side die 12. In the present embodiment, the drive mechanism 3 has a structure that moves only the upper side die 12. The drive mechanism 3 has a slide 21 that moves the upper side die 12 to bring the lower side die 11 and the upper side die 12 closer to each other, a return cylinder 22 that functions as an actuator that generates a force to pull the slide 21 upward, a main cylinder 23 that functions as a drive source that applies a downward pressure to the slide 21, and a drive source 24 that imparts a driving force to the main cylinder 23. Figure 2

[0039] The holding portion 4 is a mechanism that holds the metal pipe material 40 disposed between the lower side die 11 and the upper side die 12. The holding portion 4 has a lower side electrode 26 and an upper side electrode 27 that hold the metal pipe material 40 on one end side in the length direction of the molding die 102, and a lower side electrode 26 and an upper side electrode 27 that hold the metal pipe material 40 on the other end side in the length direction of the molding die 102. The lower side electrodes 26 and the upper side electrodes 27 on both length direction sides hold the metal pipe material 40 by sandwiching the vicinity of the end portion of the metal pipe material 40 from the vertical direction. Further, on the upper surface of the lower side electrode 26 and the lower surface of the upper side electrode 27, a groove portion having a shape corresponding to the outer peripheral surface of the metal pipe material 40 is formed. The lower side electrodes 26 and the upper side electrodes 27 are provided with a not-shown drive mechanism, and can be independently moved in the vertical direction, respectively.

[0040] The heating portion 101 heats the metal pipe material 40. The heating portion 101 is a mechanism that heats the metal pipe material 40 by applying electric current thereto. The heating portion 101 heats the metal pipe material 40 in a state where the metal pipe material 40 is separated from the lower side die 11 and the upper side die 12. The heating portion 101 has the lower side electrodes 26 and the upper side electrodes 27 on both length direction sides described above, and a power source 28 that causes electric current to flow through the metal pipe material 40 via these electrodes 26, 27.

[0041] ​Here, the state in which the metal pipe material 40 is arranged inside the molding die 102 means a state in which the metal pipe material 40 is arranged in a space between the upper side die 12 and the lower side die 11 with respect to the upper side die 12 and the lower side die 11 that face each other. In this state, the metal pipe material 40 faces the upper side die 12 in a state in which the metal pipe material 40 is separated downward with respect to the upper side die 12, and faces the lower side die 11 in a state in which the metal pipe material 40 is separated upward with respect to the lower side die 11.

[0042] The fluid supply part 6 is a mechanism for supplying a high-pressure fluid to the inside of the metal pipe material 40 held between the lower side die 11 and the upper side die 12. The fluid supply part 6 supplies a high-pressure fluid to the metal pipe material 40 that is in a high-temperature state by being heated by the heating part 101, to expand the metal pipe material 40. The fluid supply part 6 is provided at both end sides in the length direction of the molding die 102. The fluid supply part 6 has a nozzle 31 that supplies a fluid to the inside of the metal pipe material 40 from an opening part of an end portion of the metal pipe material 40, a drive mechanism 32 that moves the nozzle 31 in and out with respect to the opening part of the metal pipe material 40, and a supply source 33 that supplies a fluid at a high pressure to the inside of the metal pipe material 40 via the nozzle 31. The drive mechanism 32 brings the nozzle 31 into close contact with the end portion of the metal pipe material 40 in a state in which sealing is ensured at the time of supplying the fluid and at the time of exhausting, and separates the nozzle 31 from the end portion of the metal pipe material 40 at other times. In addition, the fluid supply part 6 can supply a gas such as high-pressure air or an inert gas as the fluid. Furthermore, the fluid supply part 6 can be configured as the same device as the holding part 4 that has a mechanism for moving the metal pipe material 40 in the up-and-down direction and the heating part 101.

[0043] The cooling part 7 is a mechanism that cools the molding die 102. The cooling part 7 is capable of rapidly cooling the metal pipe material 40 when the expanded metal pipe material 40 comes into contact with the molding surface of the molding die 102, by cooling the molding die 102. The cooling part 7 has a flow path 36 formed in the inside of the lower side die 11 and the upper side die 12, and a water circulation mechanism 37 that supplies cooling water to the flow path 36 to circulate the cooling water.

[0044] Thus, the quenching mechanism 105 that quenches the molded product 140 is provided on the molding die 102. The quenching mechanism 105 is constituted by the molding surface of the molding die 102 and the cooling part 7.

[0045] The control part 8 is a device that controls the entire molding device 103. The control part 8 controls the drive mechanism 3, the holding part 4, the heating part 101, the fluid supply part 6, and the cooling part 7. The control part 8 repeatedly performs an operation of molding the metal pipe material 40 by the molding die 102.

[0046] The control section 8 controls the drive mechanism 3 to lower the upper mold 12 to approach the lower mold 11, thereby performing mold closing of the molding mold 102. On the other hand, the control section 8 controls the fluid supply section 6 to seal the opening portions of both ends of the metal pipe material 40 with the nozzles 31 and to supply the fluid. Thereby, the metal pipe material 40 that is heated and softened expands to contact the molding surface of the molding mold 102. Then, the metal pipe material 40 is molded along the shape of the molding surface of the molding mold 102. In addition, when a metal pipe with a flange is formed, after a part of the metal pipe material 40 is made to enter the gap between the lower mold 11 and the upper mold 12, further mold closing is performed, thereby flattening the entered part to form a flange portion. When the metal pipe material 40 contacts the molding surface, quenching of the metal pipe material 40 is performed by the molding mold 102 that is cooled by the cooling section 7.

[0047] Also, as the molding device 103, a structure as shown in FIG. 6 can be adopted. Figure 3 Figure 3 The molding device 103 shown in FIG. 6 is a device that performs molding and quenching by bringing the heated flat metal material 50 into contact with the molding surface of the molding mold 102. This molding device 103 is provided with the heating section 101.

[0048] The molding device 103 is provided with the molding mold 102 that molds the metal material 50 to form a molded product. The molding mold 102 is provided with the upper mold 62 that contacts the upper surface of the metal material 50 and the 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 in a shape corresponding to, for example, a cap shape or the like. The molding device 103 is provided with a drive section (not shown) that moves at least one of the upper mold 62 and the lower mold 63. The molding device 103 molds the metal material 50 into the shape of the molded product by sandwiching the metal material 50 with the molding surface of the upper mold 62 and the molding surface of the lower mold 63. In addition, the structure of the molding mold 102 is not limited to the structure in which the upper mold 62 and the lower mold 63 are disposed in a facing manner in the vertical direction, but the molds can be disposed in a facing manner in the horizontal direction. Also, the number of molds that constitute the molding mold 102 is not limited to two, but can be divided into three or more.

[0049] The heating section 101 heats the metal material 50 disposed inside the molding mold 102. Here, the state in which the metal material 50 is disposed inside the molding mold 102 means the state in which the metal material 50 is disposed in the space between the upper mold 62 and the lower mold 63 that face each other. Figure 2

[0050] ​​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 to allow an electric current to flow through it. As a result, the metal material 50 heats up due to Joule heating (electric heating) due to its own resistance. The power supply 71 is connected to electrodes 70A and 70B and allows an electric current to flow through these electrodes 70A and 70B through the metal material 50.

[0051] exist Figure 3 In the example shown, electrodes 70A and 70B are in contact with the ends of the metal material 50 along its length. There is no particular limitation on the arrangement of electrodes 70A and 70B relative to the metal material 50. Furthermore, electrodes 70A and 70B may function to hold the metal material 50, but other holding mechanisms besides electrodes 70A and 70B may also be provided. There is no particular limitation on the structural arrangement of electrodes 70A and 70B relative to the molding apparatus 103. For example, electrodes 70A and 70B may be mounted on the molding die 102. In this case, electrodes 70A and 70B can be removed from the molding die 102 when the heating is completed and the upper die 62 and lower die 63 are closed. Alternatively, electrodes 70A and 70B may be configured such that they do not interfere with the molding die 102 even when the upper die 62 and lower die 63 are closed. Furthermore, it is also possible to configure the electrodes 70A and 70B to have actuators (not shown) provided in them, and the electrodes 70A and 70B to be movable relative to the molding die 102.

[0052] 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 controls the timing of heating by the heating unit 101 by sending control signals to the power supply 71, and adjusts the magnitude of the current, thereby controlling the heating temperature.

[0053] 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 apparatus 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, that is, above 800°C. The state where the heating unit 101 heats outside the molding die 102 means that the heating is performed outside the space between the molds 12 and 11. Figure 4In the example shown, the heating section 101 is provided at a position different from the molding device 103. Also, the metal pipe material 40 heated by the heating section 101 is set on the molding device 103 by a conveyance device such as a robot not shown. The other structure of the molding device 103 is the same as that of the molding device 103 shown in Figure 2 In the example shown, the heating section 101 is provided at a position different from the molding device 103. Also, the metal pipe material 40 heated by the heating section 101 is set on the molding device 103 by a conveyance device such as a robot not shown. The other structure of the molding device 103 is the same as that of the molding device 103 shown in Figure 3 In the example shown, the heating section 101 is provided at a position different from the molding device 103. Also, the metal pipe material 40 heated by the heating section 101 is set on the molding device 103 by a conveyance device such as a robot not shown. The other structure of the molding device 103 is the same as that of the molding device 103 shown in

[0054] Returning to Figure 1 , the cooling mechanism 104 is a mechanism that cools the molded product 140. As shown in Figure 4 , the cooling mechanism 104 is provided at a position different from the quenching mechanism 105. In the present embodiment, the cooling mechanism 104 is provided at a position different from the molding die 102, and is provided outside the molding die 102. The molded product 140 is conveyed to the cooling mechanism 104 different from the quenching mechanism 105 during quenching by the quenching mechanism 105.

[0055] The cooling mechanism 104 can be a jig 110 that cools the molded product 140. The cooling mechanism 104 has an upper jig 111 and a lower jig 112 that accommodate the molded product 140 after molding. The upper jig 111 and the lower jig 112 cool the molded product 140 by gripping the molded product 140 and absorbing heat from the molded product 140 at the portion in contact with the molded product 140.

[0056] Referring to Figure 5 and Figure 6 , a specific example of the jig 110 for cooling will be described. As shown in Figure 5 (a) and Figure 6 (a), the jig 110 has a mold-like member as the upper jig 111 and the lower jig 112, the mold-like member having a contact surface 117 corresponding to the outer peripheral surface of the molded product 140. A cooling circuit 116 through which a refrigerant flows is provided inside the upper jig 111 and the lower jig 112. The cooling circuit 116 is provided so as to be buried inside the mold, and extends in the length direction along the periphery of the contact surface 117. Thus, the upper jig 111 and the lower jig 112 cool the molded product 140 by bringing the contact surface 117 cooled by the cooling circuit 116 into contact with the molded product 140.

[0057] As shown in Figure 5 (b) and Figure 6 (b), the jig 110 has a member composed of a plurality of ribs 118 as the upper jig 111 and the lower jig 112. As shown in Figure 6As shown in (b), in the upper-side clamp 111 and the lower-side clamp 112, a plurality of fins 118 are arranged in a lattice shape, and an inner space 119 corresponding to the molded product 140 is formed. Thus, the upper-side clamp 111 and the lower-side clamp 112 contact each fin 118 with the molded product 140 in the inner space 119, and the heat is dissipated by each fin 118, thereby cooling the molded product 140. In addition, between the fins 118, the cooling of the molded product 140 can be promoted by directly injecting a cooling medium (water or the like).

[0058] Reference Figure 7 The cooling processes of each process are shown in a CCT graph. The curve G1 shows the relationship between the temperature and the time in a case where only the molding device 103 is used and the molded product 140 is cooled to the Mf point in the molding die 102 after molding. In the process of the curve G1, since the molded product 140 is cooled in the molding die 102, the time of each molded product 140 occupying the molding device 103 becomes long. The curve G2 shows the relationship between the temperature and the time in a case where the molded product 140 is taken out of the molding die 102 after molding and is naturally cooled in the air. At this time, since the cooling speed of the molded product 140 in the air is slow, the martensite structure cannot be obtained, and the transformation-induced deformation occurs.

[0059] In contrast, the curve G3 is a process related to the present embodiment, and shows the relationship between the temperature and the time in a case where the molded product 140 is carried and cooled by the cooling mechanism 104 after molding. When the molded product 140 is cooled by the quenching mechanism 105 of the molding die 102, the curve G3 describes a similar trajectory (PT1) to the curve G1. During the carrying process of the molded product 140, the curve G3 describes a similar trajectory (PT2) to the curve G2. When the molded product 140 is cooled by the cooling mechanism 104, the curve G3 describes a trajectory (PT3) in which the temperature sharply decreases at a similar slope to the curve G1. The molded product 140 is sharply cooled and frozen to the Mf point by the cooling mechanism 104, thereby obtaining the martensite structure, and the deformation is also suppressed. Also, since the molded product 140 is taken out after molding in the molding die 102, the time of each molded product 140 occupying the molding device 103 becomes short, thereby improving the production efficiency. In other words, in the present embodiment, the molded product 140 is carried to another cooling mechanism 104 at the middle of the cooling by the quenching mechanism 105, and is cooled from the start temperature of the martensite transformation to the end temperature of the martensite transformation by the other cooling mechanism. Thus, the martensite structure can be obtained even at the middle of the quenching, while the production efficiency is improved.

[0060] Next, the effects of the molding system 100 related to the present embodiment will be described.

[0061] In the molding system 100, a quenching mechanism 105 for quenching the molded article 140 is provided on the molding apparatus 103. Therefore, after molding, the molded article 140 is immediately and rapidly cooled in the quenching mechanism 105. During the quenching process in the quenching mechanism 105, the molded article 140 is transferred to a cooling mechanism 104, which is different from the quenching mechanism 105. Thereby, the molded article 140 is rapidly cooled in the cooling mechanism 104, thus completing the quenching. Therefore, the desired strength of the molded article 140 can be obtained by quenching. Furthermore, the cooling mechanism 104 is a different mechanism from the quenching mechanism 105. Therefore, the production cycle from the start of molding to the removal of the molded article 140 from the molding die 102 is shortened, and the next metal tube material 40 can be molded in the quenching mechanism 105 of the molding die 102. Thus, the desired strength of the molded article 140 can be obtained while shortening the molding production cycle.

[0062] After the metal tube material 40 is transferred to another cooling unit 104, it can be cooled from the martensitic transformation start temperature to the martensitic transformation end temperature. Thus, the quenching of the metal tube material 40 can be completed by the other cooling unit 104.

[0063] The cooling mechanism 104 can be a cooling fixture for cooling the molded article 140. In this case, the molded article 140 can be cooled by the cooling mechanism 104 at a location different from the molding die 102. Therefore, it is unnecessary to... Figure 8 Thus, a quenching mechanism 105 and another cooling mechanism 104 are provided on the forming mold 102 itself.

[0064] Here, on Figure 9 The molded article 140 shown is described below. Figure 9 The molded article 140 shown includes a tube body portion 141 and a pair of flange portions 142. The tube body portion 141 has flat portions 141a and 141b and side portions 141c and 141d. The flange portions 142 are formed by flattening a portion of the metal tube material 40. For this molded article 140, compared with the temperatures of the measuring points P3 and P5 of the flat portions 141a and 141b, the cooling rate of the measuring points P2 and P4, which are the R portions, is slower. In order to make the temperature the same as that of the measuring points P3 and P5, the cooling of the measuring points P2 and P4 is about 1.5 seconds slower than that of the measuring points P3 and P5. Figure 10indicates the relationship between the temperature of the flat portions 141a, 141b of the molded article 140 after gas blow molding and the blow-molding holding time in the molding die at different blow-molding pressures. From the graph, it is known that in the case of a higher blow-molding pressure (25 MPa), the temperature is below 200°C regardless of the holding time, but in the case of a lower blow-molding pressure, the temperature does not decrease to below 200°C if the holding time is short. Therefore, depending on the shape of the molded article 140 or the molding conditions, if the cooling is ended without sufficient cooling, warping can occur due to the difference in the amount of thermal shrinkage.

[0065] In this regard, in the case where there is a portion of the molded article 140 where the cooling speed is slow, such as Figure 9 , or the blow-molding pressure cannot be increased due to limitations of the manufacturing conditions, by using the cooling mechanism 104 of the molding system 100 according to the present embodiment, the occupancy time of the molding device 103 can be shortened, and warping due to the difference in the amount of thermal shrinkage can be suppressed by sufficiently cooling. For example, Figure 11 (a) is a graph showing the relationship between the cooling method and the time for the molded article for the comparative example in which cooling is performed only by the molding die 102 and the embodiment in which cooling is performed by the molding die 102 and the cooling mechanism 104. Here, the time required for the molded article to cool to the target temperature (for example, 200°C) after molding is shown. In the comparative example, the entire cooling process is performed only by the molding die 102, which takes time tl (for example, 40 seconds). In contrast, in the embodiment, cooling by the molding die 102 is performed in a shorter time t2 (for example, 30 seconds) than tl, and the molded article is taken out of the molding die 102. At this time, the molded article has not cooled to the target temperature. Then, cooling is performed by the cooling mechanism 104 for time t3 until the target temperature is reached.

[0066] Here, depending on the shape of the molded article 140 that is molded, the blow-molding pressure in the molding device 103 can not be increased due to limitations of the manufacturing conditions. In the case of a lower blow-molding pressure, as shown in the above-described Figure 10 , it takes time to reduce the temperature of the molded article to the desired temperature. Therefore, in the molding device 103, the ratio of the cooling time in the cooling mechanism 104 to the cooling time in the molding die 102 can be increased in the case of a metal pipe material 40 of which the blow-molding pressure is low, relative to the case of a metal pipe material 40 of which the blow-molding pressure is high. At this time, the shape can be reliably frozen even for a metal pipe material 40 of which the blow-molding pressure is low. Specifically, Figure 11 (b) is a graph showing the proportion of the cooling time by the molding die 102 and the proportion of the cooling time by the cooling mechanism 104 when the entire cooling time is taken as a basis. As Figure 11As shown in (b), the ratio of cooling time in the cooling mechanism 104 to cooling time in the molding die 102 is higher when the "blow pressure" is lower than when the "blow pressure" is higher.

[0067] This invention is not limited to the embodiments described above. For example, Figures 2 to 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.

[0068] For example, such as Figure 8 As shown, the quenching mechanism 105 and the cooling mechanism 104 can be installed at different locations within the same forming mold 102. In this case, it is not necessary to ensure space for the cooling mechanism 104 outside the forming mold 102. Specifically, as... Figure 8 As shown in (a), a forming surface 55 of a quenching mechanism 105 and a contact surface 117 of a cooling mechanism 104 are formed in a forming mold 102. When the forming in the quenching mechanism 105 is completed (see reference...), Figure 8 If (a) is reached, the molded article 140 is then conveyed to the adjacent cooling mechanism 104 (see reference 104). Figure 8 (b)). Then, the mold is closed, and the molded article 140 is clamped by the mold 12 and the mold 11 and cooled by the cooling mechanism 104. Figure 8 (c)).

[0069] In addition, in this embodiment, metal materials such as metal plates can also be used, besides metal pipe materials.

[0070] Symbol Explanation

[0071] 100-Forming system, 101-Heating section, 102-Forming mold, 103-Forming device (forming section), 104-Cooling mechanism, 105-Quenching mechanism, 110-Clamping fixture.

Claims

1. A molding system comprising: a heating section that heats a metal pipe material; and a molding section that molds the heated metal pipe material using a molding die, wherein a quenching mechanism that quenches a molded product is provided in the molding section, and wherein the molded product is conveyed to a cooling mechanism different from the quenching mechanism during quenching by the quenching mechanism.

2. The molding system according to claim 1, wherein the metal pipe material is cooled from a martensitic transformation start temperature to a martensitic transformation finish temperature after being conveyed to the cooling mechanism.

3. The molding system according to claim 1, wherein the cooling mechanism is a cooling jig that cools the molded product.

4. The molding system according to claim 1, wherein the quenching mechanism and the cooling mechanism are provided at different positions in the same molding die.

5. The molding system according to claim 1, wherein the molding is performed by expanding the metal pipe material by supplying a fluid to the metal pipe material in the molding section, and wherein, in the molding section, a ratio of a cooling time in the cooling mechanism to a cooling time in the molding die is increased for the metal pipe material having a lower blow molding pressure than for the metal pipe material having a higher blow molding pressure. ​ ​ ​ ​ ​ ​ ​ ​ ​

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