Molding device

Abstract

This molding device comprises: a heating unit for heating a metal material; a molding die for molding the heated metal material; and a temperature adjustment mechanism for adjusting the temperature of at least a part of a non-quenching portion of the molding die, to form a non-quenched region in a molded product after molding the metal material. The temperature adjustment mechanism includes: a heating mechanism for forming the non-quenched region in the molded product by heating the non-quenching portion of the molding die during molding by the molding die; and a cooling mechanism for cooling the non-quenching portion of the molding die at a timing after the non-quenched region is formed in the molded product.

Description

Molding equipment

[0001] The present disclosure relates to a molding apparatus.

[0002] Conventionally, molding devices for molding heated metal materials have been known. For example, Patent Document 1 below discloses a molding device including a mold having a pair of lower and upper molds, a gas supply unit that supplies gas into a metal pipe material held between the molds, and a heating unit that heats the metal pipe material by electrical heating. This molding device also includes a cooling unit that flows water through a flow path formed in the mold to cool the heated metal pipe during molding. This allows the molding device to perform quench molding by bringing the cooled mold into contact with the metal pipe material.

[0003] Japanese Patent Application Laid-Open No. 2009-220141

[0004] In the heating, forming, and quenching processes described in the aforementioned Patent Document 1, the formed product is quenched. Here, a non-quenched portion may be formed in at least a portion of the formed product. In this case, the forming die is heated so that the cooling rate is slowed down to a temperature at which quenching will not occur when the metal material contacts the forming die. To suppress temperature variations in the forming die and ensure forming accuracy in the next forming, it is necessary to adjust the temperature of the forming die by, for example, dissipating heat into the atmosphere before the next forming. However, the time lost for such temperature adjustment results in a problem of reduced production efficiency.

[0005] Therefore, an object of the present disclosure is to provide a molding apparatus that can improve production efficiency.

[0006] A molding apparatus according to one aspect of the present disclosure includes a heating section that heats a metal material, a molding die that molds the heated metal material, and a temperature adjustment mechanism that adjusts the temperature of at least a portion of the non-hardened portion of the molding die to form a non-hardened region in a molded product after molding of the metal material. The temperature adjustment mechanism includes a heating mechanism that heats the non-hardened portion of the molding die to form a non-hardened region in the molded product during molding with the molding die, and a cooling mechanism that cools the non-hardened portion of the molding die at a timing after the non-hardened region is formed in the molded product.

[0007] This molding apparatus includes a temperature adjustment mechanism that adjusts the temperature of at least a portion of a non-hardened portion of the molding die to form a non-hardened region in a molded product after molding of the metal material. Therefore, the molding apparatus can form a non-hardened portion in at least a portion of the molded product, which has reduced strength due to not being hardened. The temperature adjustment mechanism includes a heating mechanism that heats the non-hardened portion of the molding die to form a non-hardened region in the molded product during molding using the molding die. By heating the non-hardened portion with the heating mechanism, the cooling rate can be slowed when the heated metal material comes into contact with the non-hardened portion, preventing hardening of the non-hardened region. Furthermore, the temperature adjustment mechanism includes a cooling mechanism that cools the non-hardened portion of the molding die after the non-hardened region is formed in the molded product. By cooling the non-hardened portion that has become hot with the cooling mechanism, the target mold temperature can be quickly reached for starting the next molding. This reduces the time lost in temperature adjustment for the next molding. As a result, the production efficiency of the molding apparatus can be improved.

[0008] The cooling mechanism may cool the non-hardened portion of the forming die at a timing after the bainite transformation is complete in the formed part. Once the bainite transformation is complete in the non-hardened region of the formed part, lowering the temperature of the forming die thereafter does not affect the state of the non-hardened region. Therefore, this can be used as an appropriate timing for the cooling mechanism to start cooling.

[0009] The heating mechanism and the cooling mechanism may be provided inside the molding die, in which case the heating mechanism and the cooling mechanism can quickly adjust the temperature of the molding die.

[0010] According to the present disclosure, a molding device capable of improving production efficiency can be provided.

[0011] 2(a) is a schematic configuration diagram showing a molding device according to an embodiment of the present disclosure; FIG. 2(a) is a schematic side view showing a thermal expansion unit; FIG. 2(b) is a cross-sectional view showing the state when a nozzle seals a metal pipe material; FIG. 2(b) is a schematic cross-sectional view showing a temperature adjustment section of a molding die; FIG. 2(b) is a schematic view showing a metal pipe after molding; and FIG. 2(b) is a graph showing the molding time and the change in the state of a metal pipe material. FIG. 2(a) is a graph showing the timing of temperature adjustment of a temperature adjustment mechanism of a molding device according to an embodiment, and FIG. 2(b) is a graph showing the timing of temperature adjustment of a temperature adjustment mechanism of a molding device according to a comparative example.

[0012] Hereinafter, preferred embodiments of a molding apparatus according to the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and duplicated explanations will be omitted.

[0013] FIG. 1 is a schematic diagram of a molding apparatus 1 according to this embodiment. As shown in FIG. 1, the molding apparatus 1 is an apparatus for molding a metal pipe having a hollow shape by blow molding. In this embodiment, the molding apparatus 1 is installed on a horizontal surface. The molding apparatus 1 includes a molding die 2, a drive mechanism 3, a holding unit 4, a heating unit 5, a fluid supply unit 6, a temperature adjustment unit 7, and a control unit 8. In this specification, a metal pipe material 40 (metal material) refers to a hollow article before molding is completed in the molding apparatus 1. The metal pipe material 40 is a pipe material made of a steel type that can be hardened. In addition, among the horizontal directions, the direction in which the metal pipe material 40 extends during molding may be referred to as the "longitudinal direction," and the direction perpendicular to the longitudinal direction may be referred to as the "width direction."

[0014] The forming die 2 is a die for forming a formed product 140 (see FIG. 4 ) from a metal pipe material 40, and includes a lower die 11 and an upper die 12 that face each other in the vertical direction. The lower die 11 and the upper die 12 are made of steel blocks. Each of the lower die 11 and the upper die 12 has a recess for accommodating the metal pipe material 40. When the lower die 11 and the upper die 12 are in close contact with each other (closed state), each recess forms a space of the target shape for forming the metal pipe material. Therefore, the surface of each recess becomes the forming surface of the forming die 2. The lower die 11 is fixed to a base 13 via a die holder or the like. The upper die 12 is fixed to a slide of the drive mechanism 3 via a die holder or the like.

[0015] The metal pipe material 40 has a quenched region E1 with high strength and a non-quenched region E2 with low strength. Therefore, the forming die 2 performs rapid cooling to increase the cooling rate in the quenched region E1 of the metal pipe material 40, and performs slow cooling to slow the cooling rate in the non-quenched region E2 of the metal pipe material 40. The upper die 12 and the lower die 11 have quenching portions 12A, 11A that quench the quenched region E1, and non-quenching portions 12B, 11B that prevent quenching in the non-quenched region E2. In this embodiment, the non-quenched region E2 is provided at approximately the center of the formed product 140 (metal pipe material 40), and the quenched regions E1 are provided to sandwich the non-quenched region E2 in the longitudinal direction. Therefore, the upper mold 12 and the lower mold 11 have non-hardened portions 12B, 11B at their central positions and hardened portions 12A, 11A that sandwich the non-hardened region E2 in the longitudinal direction. As a result, as shown in Figure 4, the non-hardened region E2 (hatched portion) of the molded product 140 after molding becomes a part with low strength, and the hardened region E1 becomes a part with high strength.

[0016] The drive mechanism 3 is a mechanism that moves at least one of the lower mold 11 and the upper mold 12. In Fig. 1, the drive mechanism 3 is configured to move only the upper mold 12. The drive mechanism 3 includes a slide 21 that moves the upper mold 12 so that the lower mold 11 and the upper mold 12 are aligned with each other, a pull-back cylinder 22 as an actuator that generates a force that pulls the slide 21 upward, a main cylinder 23 as a drive source that pressurizes the slide 21 downward, and a drive source 24 that applies a drive force to the main cylinder 23.

[0017] The holding unit 4 is a mechanism for holding the metal pipe material 40 disposed between the lower mold 11 and the upper mold 12. The holding unit 4 includes a lower electrode 26 and an upper electrode 27 that hold the metal pipe material 40 at one end of the molding die 2 in the longitudinal direction, and a lower electrode 26 and an upper electrode 27 that hold the metal pipe material 40 at the other end of the molding die 2 in the longitudinal direction. The lower electrode 26 and the upper electrode 27 on both sides in the longitudinal direction hold the metal pipe material 40 by sandwiching the vicinity of the end of the metal pipe material 40 from above and below. Grooves having a shape corresponding to the outer peripheral surface of the metal pipe material 40 are formed on the upper surface of the lower electrode 26 and the lower surface of the upper electrode 27. The lower electrode 26 and the upper electrode 27 are provided with drive mechanisms (not shown) that allow them to move independently in the vertical direction.

[0018] The heating unit 5 heats the metal pipe material 40. The heating unit 5 is a mechanism that heats the metal pipe material 40 by passing electricity through the metal pipe material 40. The heating unit 5 heats the metal pipe material 40 between the lower mold 11 and the upper mold 12, while the metal pipe material 40 is spaced apart from the lower mold 11 and the upper mold 12. The heating unit 5 includes the lower electrode 26 and the upper electrode 27 on both sides of the longitudinal direction, and a power source 28 that applies current to the metal pipe material 40 via these electrodes 26, 27. The heating unit may be arranged in a pre-process of the molding device 1 and may be an external heating unit.

[0019] The fluid supply unit 6 is a mechanism for supplying high-pressure fluid into the metal pipe 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 pipe material 40, which has been heated by the heating unit 5 to a high temperature, thereby expanding the metal pipe material 40. The fluid supply unit 6 is provided on both longitudinal ends of the molding die 2. The fluid supply unit 6 includes a nozzle 31 that supplies fluid into the metal pipe material 40 from an opening at the end of the metal pipe material 40, a drive mechanism 32 that moves the nozzle 31 back and forth relative to the opening of the metal pipe material 40, and a supply source 33 that supplies high-pressure fluid into the metal pipe material 40 through the nozzle 31. The drive mechanism 32 brings the nozzle 31 into close contact with the end of the metal pipe material 40 while ensuring a seal during fluid supply and exhaust, and moves the nozzle 31 away from the end of the metal pipe material 40 at other times. The fluid supply unit 6 may supply a gas such as high-pressure air or an inert gas as the fluid. Furthermore, the fluid supply unit 6 may be integrated into the same device as the holding unit 4 having a mechanism for moving the metal pipe material 40 in the vertical direction, and the heating unit 5 .

[0020] The components of the holding unit 4, the heating unit 5, and the fluid supply unit 6 may be configured as a unitized thermal expansion unit 150. Fig. 2(a) is a schematic side view showing the thermal expansion unit 150. Fig. 2(b) is a cross-sectional view showing the state when the nozzle 31 seals the metal pipe material 40.

[0021] 2( a), the thermal expansion unit 150 includes the above-mentioned lower electrode 26 and upper electrode 27, an electrode mounting unit 151 on which the electrodes 26, 27 are mounted, the above-mentioned nozzle 31 and drive mechanism 32, a lifting unit 152, and a unit base 153. The electrode mounting unit 151 includes a lifting frame 154 and electrode frames 156, 157. The electrode frames 156, 157 function as part of a drive mechanism 60 that supports and moves the electrodes 26, 27. The drive mechanism 32 drives the nozzle 31, and moves it up and down together with the electrode mounting unit 151. The drive mechanism 32 includes a piston 61 that holds the nozzle 31 and a cylinder 62 that drives the piston. The lifting unit 152 includes a lifting frame base 64 attached to the upper surface of the unit base 153, and a lifting actuator 66 that applies lifting and lowering motion to the lifting frame 154 of the electrode mounting unit 151 via the lifting frame base 64. The lifting frame base 64 has guide portions 64a and 64b that guide the lifting and lowering motion of the lifting frame 154 relative to the unit base 153. The lifting unit 152 functions as part of the drive mechanism 60 of the holding part 4. The thermal expansion unit 150 has multiple unit bases 153 with different inclination angles of their upper surfaces, and by replacing these, it is possible to change and adjust the inclination angles of the lower electrode 26, upper electrode 27, nozzle 31, electrode mounting unit 151, drive mechanism 32, and lifting unit 152 all at once.

[0022] The nozzle 31 is a cylindrical member into which the end of the metal pipe material 40 can be inserted. The nozzle 31 is supported by a drive mechanism 32 so that the center line of the nozzle 31 coincides with the reference line SL1. The inner diameter of the supply port 31a at the end of the nozzle 31 on the metal pipe material 40 side is approximately equal to the outer diameter of the metal pipe material 40 after expansion molding. In this state, the nozzle 31 supplies high-pressure fluid from an internal flow path 63 to the metal pipe material 40. An example of the high-pressure fluid is gas.

[0023] Returning to FIG. 1 , the temperature adjustment unit 7 is a mechanism for adjusting the temperature of the molding die 2. The temperature adjustment unit 7 cools the molding die 2 in the quenching sections 12A and 11A, thereby enabling the metal pipe material 40 to be rapidly cooled and quenched when it comes into contact with the molding surface of the molding die 2. Furthermore, the temperature adjustment unit 7 adjusts the temperature of the molding die 2 in the non-quenching sections 12B and 11B, thereby enabling the metal pipe material 40 to be adjusted to a temperature at which quenching does not occur when it comes into contact with the molding surface of the molding die 2. The temperature adjustment unit 7 includes flow paths formed inside the lower die 11 and the upper die 12, a supply mechanism 37 that supplies and circulates a temperature adjustment medium to the flow paths, and a control unit 8 that controls the supply mechanism 37. A more detailed configuration of the temperature adjustment unit 7 will be described later.

[0024] The control unit 8 is a device that controls the entire molding device 1. The control unit 8 controls the drive mechanism 3, the holding unit 4, the heating unit 5, the fluid supply unit 6, and the supply mechanism 37. The control unit 8 repeatedly performs the operation of molding the metal pipe material 40 in the molding die 2.

[0025] Specifically, the control unit 8 controls the timing of transfer from a transfer device such as a robot arm to place the metal pipe material 40 between the open lower and upper dies 11 and 12. Alternatively, the control unit 8 may have an operator manually place the metal pipe material 40 between the lower and upper dies 11 and 12. The control unit 8 also controls the actuators of the holding unit 4 to support the metal pipe material 40 with the lower electrodes 26 on both longitudinal sides, and then lower the upper electrode 27 to sandwich the metal pipe material 40. The control unit 8 also controls the heating unit 5 to electrically heat the metal pipe material 40. As a result, an axial current flows through the metal pipe material 40, and the metal pipe material 40 itself generates heat through Joule heat due to its own electrical resistance.

[0026] The control unit 8 controls the drive mechanism 3 to lower the upper die 12 and bring it close to the lower die 11, thereby closing the molding die 2. Meanwhile, the control unit 8 controls the fluid supply unit 6 to seal the openings at both ends of the metal pipe material 40 with the nozzle 31 and supply fluid. As a result, the metal pipe material 40, softened by heating, expands and comes into contact with the molding surface of the molding die 2. The metal pipe material 40 is then molded to conform to the shape of the molding surface of the molding die 2. When a metal pipe with a flange is formed, a portion of the metal pipe material 40 is inserted into the gap between the lower die 11 and the upper die 12, and then the mold is closed to crush the inserted portion and form a flange portion. When the quenched region E1 of the metal pipe material 40 comes into contact with the molding surface, the metal pipe material 40 is quenched by the molding die 2, which is cooled by the temperature adjustment unit 7.

[0027] The temperature adjustment unit 7 will be described in more detail with reference to FIG. 3 . The temperature adjustment unit 7 includes cooling mechanisms 70A and 80A and temperature adjustment mechanisms 70B and 80B. The cooling mechanism 70A is provided inside the upper mold 12 and cools the molding surface of the mold 12. The cooling mechanism 80A is provided inside the lower mold 11 and cools the molding surface of the mold 11. The cooling mechanism 70A has flow paths 71 provided in the quenching portions 12A on both sides of the mold 12. The flow paths 71 cool the molding surfaces of the quenching portions 12A by flowing cooling water from the supply mechanism 37. The cooling mechanism 80A also has flow paths 81 provided in the quenching portions 11A on both sides of the mold 11. The flow paths 81 cool the molding surfaces of the quenching portions 11A by flowing cooling water from the supply mechanism 37.

[0028] The temperature adjustment mechanism 70B is provided inside the upper mold 12 and adjusts the temperature of the molding surface of the mold 12. The temperature adjustment mechanism 80B is provided inside the lower mold 11 and adjusts the temperature of the molding surface of the mold 11. The temperature adjustment mechanisms 70B, 80B adjust the temperature of non-hardened portions 12B, 11B of the molding mold 2, thereby forming a non-hardened region E2 in the molded product 140 after molding of the metal pipe material 40.

[0029] Here, the non-hardening portion 12B, 11B includes a heated mold block 12Ba, 11Ba on the molding surface side and a normal mold block 12Bb, 11Bb on the opposite side. The normal mold block 12Bb, 11Bb is a block that connects the hardening portions 12A, 11A on both sides. The temperature adjustment mechanism 70B, 80B has flow paths 72, 82 provided in the normal mold block 12Bb, 11Bb. The flow paths 72, 82 are supplied with cooling water similar to the flow paths 71, 81 of the hardening portion 12A, 11A. The heated mold block 12Ba, 11Ba is a block that has a higher temperature than the hardening portion 12A, 11A. A heat insulating member 75 (or an air gap) is provided between the hardening portion 12A, 11A and the heated mold block 12Ba, 11Ba.

[0030] The temperature adjustment mechanisms 70B and 80B include heating mechanisms 79 and 89 and cooling mechanisms 73 and 83. The heating mechanisms 79 and 89 and the cooling mechanisms 73 and 83 are provided inside the molding die 2.

[0031] The heating mechanisms 79, 89 heat the non-hardening portions 12B, 11B of the molding die 2 to form a non-hardening region E2 in the molded product 140 during molding with the molding die 2. By partially heating the non-hardening portions 12B, 11B, the temperature adjustment mechanisms 70B, 80B can control the cooling rate of the molded product 140 to slow down when it comes into contact with the molding surface of the molding die 2. The heating mechanisms 79, 89 are configured with induction heaters provided inside the heating die blocks 12Ba, 11Ba. The induction heaters heat the surrounding heating die blocks 12Ba, 11Ba by inductively heating them. However, heaters may also be used as the heating mechanisms 79, 89.

[0032] The cooling mechanisms 73, 83 are mechanisms that cool the non-hardened portions 12B, 11B of the molding die 2 at a timing after the non-hardened region E2 is formed in the molded product 140. The cooling mechanisms 73, 83 are composed of flow paths provided in the non-hardened portions 12B, 11B on both sides of the heated mold blocks 12Ba, 11Ba. The flow paths cool the molding surfaces of the non-hardened portions 13A, 13B by flowing cooling water from the supply mechanism 37.

[0033] Next, referring to FIG. 5, the change in the state of the metal pipe material 40 over the forming time will be described. Graph G1 shows the change in state of the metal pipe material 40 formed in the quenching units 12A and 11A having the cooling mechanisms 70A and 80A. As shown in graph G1, the metal of the metal pipe material 40 in contact with the quenching units 12A and 11A is rapidly cooled and its temperature drops to the martensitic transformation region. As a result, the formed product 140 is quenched, and a quenched region E1 is formed.

[0034] Graph G2 shows the change in state of the metal pipe material 40 being formed in the non-quenched portions 12B, 11B having the temperature adjustment mechanisms 70B, 80B. Graph G2a of graph G2, which occurs before timing P1, shows the state in which the heating mechanisms 79, 89 are heating the non-quenched portions 12B, 11B. Graph G2b of graph G2, which occurs after timing P1, shows the state in which the heating mechanisms 79, 89 stop heating and the cooling mechanisms 73, 83 are cooling the non-quenched portions 12B, 11B. As shown in graph G2a, the metal of the metal pipe material 40 in contact with the non-quenched portions 12B, 11B is cooled at a slower cooling rate than in graph G1. Therefore, the metal of the metal pipe material 40 transitions to the bainite transformation region rather than the martensitic transformation region. As a result, the bainite transformation is completed in the formed product 140, and the non-quenched region E2 is formed. Here, the cooling mechanisms 73, 83 cool the non-hardened portions 12B, 11B of the molding die 2 at timing P1, which is after the bainite transformation is complete in the molded product 140. As a result, the temperature of the molded product 140 drops sharply, as shown in graph G2b. Timing P1 may be set in advance to be the time estimated for the completion of the bainite transformation. Graph G2c shows the temperature behavior when the cooling mechanisms 73, 83 do not cool the non-hardened portions 12B, 11B at timing P1. As shown in graph G2c, when active cooling is not performed, the cooling rate is slow and it takes time for the temperature to drop.

[0035] Next, the timing of temperature adjustment by the temperature adjustment mechanisms 70B and 80B will be described in more detail with reference to FIG. 6( a). The "Non-Quenched Section" graph in FIG. 6( a) shows the temperature adjustment state of the non-quenched sections 12B and 11B. "Mold Heating" indicates a state in which the non-quenched sections 12B and 11B are heated by the heating mechanisms 79 and 89. "Hold" indicates a state in which neither heating nor cooling is performed. "Mold Cooling" indicates a state in which the non-quenched sections 12B and 11B are cooled by the cooling mechanisms 73 and 83. The "Press" graph in FIG. 6( a) shows the pressing state of the molding die 2. "Pipe Clamp" indicates a state in which molding is possible using the molding die 2. "Press Standby" indicates a state in which the molding die 2 is open. The "Electrical Heating Current" graph in FIG. 6( a) shows the electrical heating state of the metal pipe material in the heating section 5. "Electrical Heating ON" indicates a state in which electrical heating is performed, and "Electrical Heating OFF" indicates a state in which electrical heating is stopped. The "Non-Quenched Section Temperature" graph shows the temperature of the non-quenched sections 12B and 11B.

[0036] As shown in FIG. 6A, while the forming die 2 is open, the heating mechanisms 79, 89 heat the non-hardened portions 12B, 11B (time t1). When the temperature of the non-hardened portions 12B, 11B reaches the target die temperature before the start of forming, the heating mechanisms 79, 89 stop heating (time t2). Next, the heating unit 5 electrically heats the metal pipe material 40. When the metal pipe material 40 reaches the target temperature, the electrical heating stops, and the forming die 2 moves to the forming position and begins forming (time t3). During forming, the temperature of the forming die 2 also increases due to contact between the heated metal pipe material 40 and the forming die 2. After the time required for the bainite transformation to be completed has elapsed, the cooling mechanisms 73, 83 start cooling the non-hardened portions 12B, 11B (time t4). After a predetermined time has elapsed, the forming die 2 is opened to remove the formed product 140 (time t5). After further time has passed, the heating mechanisms 79 and 89 heat the non-hardened portions 12B and 11B (time t6). This completes one molding cycle. The time T1 between times t3 and t5 is the cooling time for the non-hardened portions 12B and 11B by the cooling mechanisms 73 and 83.

[0037] Next, the operation and effects of the molding device 1 according to this embodiment will be described.

[0038] First, referring to FIG. 6(b), a comparative example molding apparatus will be described. The comparative example molding apparatus has a structure in which the cooling mechanisms 73, 83 are removed from the temperature adjustment mechanisms 70B, 80B of the molding apparatus 1 shown in FIG. 3. In other words, the non-quenched sections 12B, 11B only have heating mechanisms. FIG. 6(b) is a graph showing the timing of temperature adjustment by the temperature adjustment mechanism of the comparative example molding apparatus. As shown in FIG. 6(b), while the molding die 2 is open, the heating mechanisms 79, 89 heat the non-quenched sections 12B, 11B (time t1). When the temperature of the non-quenched sections 12B, 11B reaches the target mold temperature before molding begins, the heating mechanisms 79, 89 stop heating (time t2). Next, the heating unit 5 electrically heats the metal pipe material 40. When the metal pipe material 40 reaches the target temperature, electrical heating is stopped, and the molding die 2 moves to the molding position to begin molding the metal pipe material 40 (time t3). Next, the metal pipe material 40 is molded, and after a predetermined time has elapsed, the molding die 2 is opened to remove the molded product 140 (time t4). After further time has elapsed, the heating mechanisms 79 and 89 heat the non-hardened portions 12B and 11B (time t5). This completes one molding cycle. In the molding device according to the comparative example, the press standby time T2 determines the cooling time of the non-hardened portions 12B and 11B of the molding die 2. The non-hardened portions 12B and 11B are cooled by heat radiation rather than by a cooling mechanism, and therefore the cooling rate is slow (see graph G2c in FIG. 5). This lengthens the press standby time T2. As a result, the time per molding cycle is longer.

[0039] In contrast, the molding apparatus 1 according to the present embodiment includes temperature adjustment mechanisms 70B and 80B that adjust the temperature of at least a portion of the non-hardened portions 12B and 11B of the molding die 2 to form a non-hardened region E2 in the molded product 140 after molding of the metal pipe material 40. Therefore, the molding apparatus 1 can form the non-hardened portions 12B and 11B, which have reduced strength due to not being hardened, in at least a portion of the molded product 140. The temperature adjustment mechanisms 70B and 80B include heating mechanisms 79 and 89 that heat the non-hardened portions 12B and 11B of the molding die 2 to form the non-hardened region E2 in the molded product 140 during molding using the molding die 2. By using the heating mechanisms 79 and 89 to heat the non-hardened portions 12B and 11B, the cooling rate can be slowed down when the heated metal pipe material 40 comes into contact with the non-hardened portions 12B and 11B, preventing quenching in the non-hardened region E2. Furthermore, the temperature adjustment mechanisms 70B, 80B have cooling mechanisms 73, 83 that cool the non-hardened portions 12B, 11B of the molding die 2 after the non-hardened region E2 is formed in the molded product 140. The cooling mechanisms 73, 83 cool the non-hardened portions 12B, 11B, which have reached a high temperature, allowing the target mold temperature to be quickly reached for starting the next molding (see FIG. 6(a)). This reduces the time lost in adjusting the temperature for the next molding. As a result, the production efficiency of the molding device 1 can be improved.

[0040] The cooling mechanisms 73, 83 may cool the non-hardened portions 12B, 11B of the forming die 2 at a timing after the bainite transformation is completed in the formed product 140. Once the bainite transformation is completed in the non-hardened region E2 of the formed product 140, thereafter lowering the temperature of the forming die 2 does not affect the state of the non-hardened region E2. Therefore, this can be adopted as an appropriate timing for the cooling mechanisms 73, 83 to start cooling.

[0041] The heating mechanisms 79, 89 and the cooling mechanisms 73, 83 may be provided inside the molding die 2. In this case, the heating mechanisms 79, 89 and the cooling mechanisms 73, 83 can quickly adjust the temperature of the molding die 2.

[0042] The present disclosure is not limited to the above-described embodiments.

[0043] For example, the shape of the metal pipe after molding is not particularly limited, and it may be a metal pipe with a flange or a metal pipe without a flange.

[0044] The forming device may be a hot stamping forming device that heats and quenches a metal material. In this case, the metal material is a plate material. However, other forming devices may also be used.

[0045] The heating and cooling mechanisms may be provided outside the mold.

[0046] 1...molding device, 2...molding die, 11, 12...die, 11B, 12B...non-hardened portion, 40...metal pipe material (metal material), 70B, 80B...temperature adjustment mechanism, 73, 83...cooling mechanism, 79, 89...heating mechanism, 140...molded product, E1...hardened area, E2...non-hardened area.

Claims

1. A molding device comprising: a heating unit which heats a metallic material; a molding die which molds the heated metallic material; and a temperature adjustment mechanism which adjusts the temperature of at least a portion of a non-hardened portion of the molding die to form a non-hardened region in a molded product after molding of the metallic material, wherein the temperature adjustment mechanism has: a heating mechanism which heats the non-hardened portion of the molding die to form the non-hardened region in the molded product during molding with the molding die; and a cooling mechanism which cools the non-hardened portion of the molding die at a timing after the non-hardened region is formed in the molded product.

2. A molding device as described in claim 1, wherein the cooling mechanism cools the non-hardened portion of the molding die at a timing after bainite transformation is completed in the molded product.

3. The molding apparatus according to claim 1, wherein the heating mechanism and the cooling mechanism are provided within the molding die.

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