JP2018167312A - Molding equipment and molding method - Google Patents

Abstract

To provide molding equipment and a molding method capable of molding a flange part on an end part side of a metal pipe in an axial direction.SOLUTION: A molding metal mold 13 comprises: a cavity part 120 for forming a pipe body part 150 of a metal pipe 140; and a flange cavity part 121 for forming a flange part 151 for closing a cave V in the metal pipe 140 in an axial direction of the metal pipe 140. The flange prat 151 molded on the flange cavity part 121 closes the cave V in the metal pipe 140 in the axial direction of the metal pipe 140. The flange part 151 formed into the above mentioned shape can function as a flange part 151 on an end part side of the metal pipe 140 in the axial direction. Therefore, by molding the metal pipe 140 by a molding metal mold 13, the pipe body part 150 can be formed, and the flange part 151 on the end part side in the axial direction can be formed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a molding apparatus and a molding method.

  2. Description of the Related Art Conventionally, a molding apparatus is known that performs blow molding by closing a metal pipe with a molding die. For example, the molding apparatus disclosed in Patent Document 1 includes a molding die and a gas supply unit that supplies gas into the metal pipe material. In this molding apparatus, a metal pipe material is placed in a molding die, and the metal pipe material is expanded by supplying gas from the gas supply unit to the metal pipe material with the molding die closed. Mold into a shape corresponding to the shape of the mold.

JP2015-112608A

  In the forming apparatus described above, a flange extending along the axial direction can be formed on the side surface of the metal pipe. On the other hand, as the use forms of metal pipes formed by a forming apparatus are diversified, it is required to form a flange portion for performing welding on the end side in the axial direction of the metal pipe.

  Then, an object of this invention is to provide the shaping | molding apparatus and the shaping | molding method which can form a flange part in the edge part side of the axial direction of a metal pipe.

  A forming apparatus according to the present invention is a forming apparatus for forming a metal pipe by expanding a metal pipe material, and a fluid supply for expanding the metal pipe material by supplying a fluid into the forming mold for forming the metal pipe. A mold for forming a pipe body portion of the metal pipe and a flange for forming a flange portion for closing the cavity in the metal pipe in the axial direction of the metal pipe. A cavity portion.

  According to this molding apparatus, the molding die includes a cavity portion for forming the pipe main body portion of the metal pipe and a flange cavity portion for forming the flange portion. The flange part formed by the flange cavity part closes the cavity in the metal pipe in the axial direction of the metal pipe. The flange portion having such a shape can function as a flange portion on the end side in the axial direction of the metal pipe. Therefore, by forming a metal pipe with a molding die, it is possible to form a pipe main body portion and an axial end portion flange portion. By the above, a flange part can be formed in the axial direction edge part side of a metal pipe.

  In the molding apparatus, the flange cavity portion may be disposed on the end side in the axial direction when the metal pipe material is disposed in the molding die as compared with the cavity portion. Thereby, a flange part can be arrange | positioned at the edge part side in metal pipe material. Therefore, the length in the axial direction occupied by the pipe body portion of the metal pipe material can be increased.

  In the molding apparatus, the flange cavity portion may form a flange portion between a portion of the metal pipe material arranged in the molding die to which a fluid is supplied from the fluid supply portion and the pipe body portion. Thereby, after shaping | molding a metal pipe, by cutting | disconnecting in the position of a flange part, the part left on the pipe main-body part side can be utilized as a flange part formed in the edge part of a metal pipe. On the other hand, the part to which the fluid is supplied from the fluid supply part can be removed from the pipe body part as an unnecessary part.

  In the forming apparatus, the cavity portion includes a first cavity portion that forms the first pipe body portion of the metal pipe, and a second pipe body portion that forms a second pipe body portion at a position different from the first pipe body portion in the axial direction. Two cavity portions, and the flange cavity portion may be disposed between the first cavity portion and the second cavity portion. Thereby, after shaping | molding a metal pipe, the part left on the 1st pipe main-body-part side can be utilized as a flange part by the side of a 1st pipe main-body part by cut | disconnecting in the position of a flange part. On the other hand, the portion left on the second pipe body portion side can be used as a flange portion on the second pipe body portion side.

  A forming method according to the present invention is a forming method for forming a metal pipe by expanding a metal pipe material, and an arrangement step of disposing the metal pipe material in a forming mold for forming the metal pipe, and closing the forming mold. And forming a metal pipe having a shape along the molding die by supplying a fluid into the metal pipe material in a state of expansion, and forming a pipe body portion of the metal pipe in the molding process. And the flange part which obstruct | occludes the cavity in the said metal pipe is formed in the axial direction of a metal pipe.

  According to this shaping | molding method, the effect | action and effect similar to the above-mentioned shaping | molding apparatus can be acquired.

  According to this invention, a flange part can be formed in the edge part side of the axial direction of a metal pipe.

It is a schematic block diagram which shows the shaping | molding apparatus which concerns on embodiment of this invention. It is an enlarged view of the periphery of the electrode, (a) is a diagram showing a state in which the electrode holds the metal pipe material, (b) is a diagram showing a state in which the seal member is pressed against the electrode, (c) is a front view of the electrode It is. It is a schematic sectional drawing which shows the mode of the shaping die just before closing a flange cavity part. It is a schematic sectional drawing which shows the mode of the molding die of the state which obstruct | occluded the flange cavity part. (A) is sectional drawing of the shaping die along the Va-Va line of FIG. 3, (b) is sectional drawing of the shaping die along the Vb-Vb line of FIG. It is a schematic sectional drawing of the shaping die of the shaping | molding apparatus which concerns on a modification. It is a schematic diagram which shows the metal pipe after shaping | molding.

  Hereinafter, preferred embodiments of a molding apparatus according to the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same part or an equivalent part, and the overlapping description is abbreviate | omitted.

<Configuration of molding equipment>
FIG. 1 is a schematic configuration diagram of a molding apparatus according to the present embodiment. As shown in FIG. 1, a molding apparatus 10 for molding a metal pipe includes a molding die 13 including an upper die 12 and a lower die 11, and a drive mechanism 80 that moves at least one of the upper die 12 and the lower die 11. The pipe holding mechanism 30 that holds the metal pipe material 14 disposed between the upper mold 12 and the lower mold 11, and the heating mechanism 50 that energizes and heats the metal pipe material 14 held by the pipe holding mechanism 30. A gas supply part 60 for supplying high-pressure gas (gas) into the heated metal pipe material 14 held between the upper mold 12 and the lower mold 11 and the metal pipe material held by the pipe holding mechanism 30 14 includes a pair of gas supply mechanisms (fluid supply units) 40 and 40 for supplying gas from the gas supply unit 60 and a water circulation mechanism 72 for forcibly cooling the molding die 13 with water. mechanism 0 driving, driving of the pipe holding mechanism 30 is configured to include the driving of the heating mechanism 50, and a control unit 70 for controlling each of the gas supply of the gas supply unit 60, a.

  The lower mold 11 which is one of the molding dies 13 is fixed to the base 15. The lower mold 11 is composed of a large steel block, and includes, for example, a rectangular cavity (concave portion) 16 on the upper surface thereof. A cooling water passage 19 is formed in the lower mold 11 and is provided with a thermocouple 21 inserted from below at a substantially central position. The thermocouple 21 is supported by a spring 22 so as to be movable up and down.

  Further, a space 11a is provided in the vicinity of the left and right ends (left and right ends in FIG. 1) of the lower mold 11, and electrodes 17 and 18 (lower portions), which will be described later, which are movable parts of the pipe holding mechanism 30, are provided in the space 11a. Side electrodes) and the like are arranged so as to be movable up and down. Then, by placing the metal pipe material 14 on the lower electrodes 17 and 18, the lower electrodes 17 and 18 are in contact with the metal pipe material 14 disposed between the upper mold 12 and the lower mold 11. To do. Thus, the lower electrodes 17 and 18 are electrically connected to the metal pipe material 14.

  An insulating material 91 for preventing energization is provided between the lower mold 11 and the lower electrode 17 and under the lower electrode 17, and between the lower mold 11 and the lower electrode 18 and under the lower electrode 18. Each is provided. Each insulating material 91 is fixed to an advance / retreat rod 95 which is a movable portion of an actuator (not shown) constituting the pipe holding mechanism 30. This actuator is for moving the lower electrodes 17, 18 and the like up and down, and the fixed portion of the actuator is held on the base 15 side together with the lower mold 11.

  The upper mold 12, which is the other of the molding dies 13, is fixed to a later-described slide 81 that constitutes the drive mechanism 80. The upper mold 12 is composed of a large steel block, and has a cooling water passage 25 formed therein, and is provided with, for example, a rectangular cavity (recess) 24 on the lower surface thereof. The cavity 24 is provided at a position facing the cavity 16 of the lower mold 11.

  A space 12a is provided in the vicinity of the left and right ends (left and right ends in FIG. 1) of the upper mold 12 in the same manner as the lower mold 11, and a movable portion of the pipe holding mechanism 30 will be described later in the space 12a. Electrodes 17 and 18 (upper electrodes) and the like are arranged so as to be movable up and down. Then, in a state where the metal pipe material 14 is placed on the lower electrodes 17 and 18, the upper electrodes 17 and 18 are arranged between the upper mold 12 and the lower mold 11 by moving downward. Contact the metal pipe material 14. Thereby, the upper electrodes 17 and 18 are electrically connected to the metal pipe material 14.

  Insulating materials 101 for preventing energization are provided between the upper mold 12 and the upper electrode 17 and above the upper electrode 17, and between the upper mold 12 and the upper electrode 18 and above the upper electrode 18, respectively. Yes. Each insulating material 101 is fixed to an advance / retreat rod 96 which is a movable portion of an actuator constituting the pipe holding mechanism 30. This actuator is for moving the upper electrodes 17, 18 and the like up and down, and the fixed portion of the actuator is held on the slide 81 side of the drive mechanism 80 together with the upper mold 12.

  In the right part of the pipe holding mechanism 30, a semicircular arc-shaped groove 18a corresponding to the outer peripheral surface of the metal pipe material 14 is formed on each of the surfaces where the electrodes 18, 18 face each other (see FIG. 2). The metal pipe material 14 can be placed so as to fit into the concave groove 18a. In the right portion of the pipe holding mechanism 30, a semicircular arc-shaped groove corresponding to the outer peripheral surface of the metal pipe material 14 is formed on the exposed surface where the insulating materials 91 and 101 face each other, like the groove 18a. ing. Further, a tapered concave surface 18b is formed on the front surface of the electrode 18 (the surface in the outer direction of the mold). Therefore, when the metal pipe material 14 is sandwiched from above and below by the right side portion of the pipe holding mechanism 30, the outer periphery of the right end portion of the metal pipe material 14 can be surrounded so as to be in close contact over the entire circumference. ing.

  In the left part of the pipe holding mechanism 30, a semicircular arc-shaped groove 17a corresponding to the outer peripheral surface of the metal pipe material 14 is formed on each of the surfaces where the electrodes 17 and 17 face each other (see FIG. 2). The metal pipe material 14 can be placed so as to fit into the concave groove 17a. In the left portion of the pipe holding mechanism 30, a semicircular arc-shaped groove corresponding to the outer peripheral surface of the metal pipe material 14 is formed on the exposed surface where the insulating materials 91 and 101 face each other, like the groove 18a. ing. In addition, a tapered concave surface 17b is formed on the front surface of the electrode 17 (surface in the outer direction of the mold). Therefore, when the metal pipe material 14 is sandwiched from above and below by the left portion of the pipe holding mechanism 30, the outer periphery of the left end portion of the metal pipe material 14 can be surrounded so as to be in close contact over the entire circumference. ing.

  As shown in FIG. 1, the drive mechanism 80 includes a slide 81 that moves the upper mold 12 so that the upper mold 12 and the lower mold 11 are aligned with each other, and a shaft 82 that generates a driving force for moving the slide 81. And a connecting rod 83 for transmitting the driving force generated by the shaft 82 to the slide 81. The shaft 82 extends in the left-right direction above the slide 81 and is rotatably supported. An eccentric crank 82a that protrudes from the left and right ends and extends in the left-right direction at a position away from the axis. Have. The eccentric crank 82 a and a rotating shaft 81 a provided in the upper part of the slide 81 and extending in the left-right direction are connected by a connecting rod 83. In the drive mechanism 80, the height of the eccentric crank 82a is changed by controlling the rotation of the shaft 82 by the control unit 70, and the change in the position of the eccentric crank 82a is transmitted to the slide 81 via the connecting rod 83. Thus, the vertical movement of the slide 81 can be controlled. Here, the swinging (rotating motion) of the connecting rod 83 that occurs when the position change of the eccentric crank 82a is transmitted to the slide 81 is absorbed by the rotating shaft 81a. The shaft 82 rotates or stops according to the driving of a motor or the like controlled by the control unit 70, for example.

  The heating mechanism 50 includes a power supply unit 55 and a bus bar 52 that electrically connects the power supply unit 55 and the electrodes 17 and 18. The power supply unit 55 includes a direct current power source and a switch, and can energize the metal pipe material 14 via the bus bar 52 and the electrodes 17 and 18 in a state where the electrodes 17 and 18 are electrically connected to the metal pipe material 14. Has been. The bus bar 52 is connected to the lower electrodes 17 and 18 here.

  In the heating mechanism 50, the direct current output from the power supply unit 55 is transmitted by the bus bar 52 and input to the electrode 17. The direct current passes through the metal pipe material 14 and is input to the electrode 18. The direct current C is transmitted by the bus bar 52 and input to the power supply unit 55.

  Returning to FIG. 1, each of the pair of gas supply mechanisms 40 is connected to a cylinder unit 42, a cylinder rod 43 that moves forward and backward in accordance with the operation of the cylinder unit 42, and a tip of the cylinder rod 43 on the pipe holding mechanism 30 side. And a sealing member 44. The cylinder unit 42 is mounted and fixed on the block 41. A tapered surface 45 is formed at the tip of the seal member 44 so as to be tapered, and is configured to fit the tapered concave surfaces 17b, 18b of the electrodes 17, 18 (see FIG. 2). The seal member 44 extends from the cylinder unit 42 toward the tip, and as shown in detail in FIGS. 2A and 2B, a gas passage through which the high-pressure gas supplied from the gas supply unit 60 flows. 46 is provided.

  The gas supply unit 60 includes a gas source 61, an accumulator 62 that stores the gas supplied by the gas source 61, a first tube 63 that extends from the accumulator 62 to the cylinder unit 42 of the gas supply mechanism 40, A pressure control valve 64 and a switching valve 65 provided in one tube 63; a second tube 67 extending from the accumulator 62 to a gas passage 46 formed in the seal member 44; The pressure control valve 68 and the check valve 69 are provided. The pressure control valve 64 serves to supply the cylinder unit 42 with a gas having an operating pressure adapted to the pressing force of the seal member 44 against the metal pipe material 14. The check valve 69 serves to prevent the high pressure gas from flowing back in the second tube 67. The pressure control valve 68 provided in the second tube 67 serves to supply a gas having an operating pressure for expanding the metal pipe material 14 to the gas passage 46 of the seal member 44 under the control of the control unit 70. Fulfill.

  The control unit 70 can supply a gas having a desired operating pressure into the metal pipe material 14 by controlling the pressure control valve 68 of the gas supply unit 60. Moreover, the control part 70 acquires temperature information from the thermocouple 21 by information being transmitted from (A) shown in FIG. 1, and controls the drive mechanism 80, the power supply part 55, and the like.

  The water circulation mechanism 72 includes a water tank 73 that stores water, a water pump 74 that pumps up and pressurizes the water stored in the water tank 73 and sends the water to the cooling water passage 19 of the lower mold 11 and the cooling water passage 25 of the upper mold 12. It consists of a pipe 75. Although omitted, a cooling tower for lowering the water temperature and a filter for purifying water may be interposed in the pipe 75.

<Metal pipe forming method using forming equipment>
Next, a method for forming a metal pipe using the forming apparatus 10 will be described. First, a cylindrical metal pipe material 14 of a hardenable steel type is prepared. The metal pipe material 14 is placed (input) on the electrodes 17 and 18 provided on the lower mold 11 side using, for example, a robot arm or the like. Since the grooves 17a and 18a are formed in the electrodes 17 and 18, the metal pipe material 14 is positioned by the grooves 17a and 18a.

  Next, the control unit 70 controls the drive mechanism 80 and the pipe holding mechanism 30 to cause the pipe holding mechanism 30 to hold the metal pipe material 14. Specifically, the upper die 12 and the upper electrodes 17 and 18 held on the slide 81 side by the driving mechanism 80 move to the lower die 11 side, and the upper electrode 17 and the upper electrode 17 included in the pipe holding mechanism 30 are moved. By actuating an actuator that allows the 18 and the like and the lower electrodes 17 and 18 to move forward and backward, the vicinity of both ends of the metal pipe material 14 is sandwiched by the pipe holding mechanism 30 from above and below. This clamping is caused to closely adhere to the entire circumference of the metal pipe material 14 near both ends due to the presence of the concave grooves 17a and 18a formed in the electrodes 17 and 18 and the concave grooves formed in the insulating materials 91 and 101. It will be clamped in such a manner.

  At this time, as shown in FIG. 2A, the end of the metal pipe material 14 on the electrode 18 side has a groove 18 a and a taper concave surface 18 b of the electrode 18 in the extending direction of the metal pipe material 14. It protrudes to the seal member 44 side from the boundary. Similarly, the end of the metal pipe material 14 on the electrode 17 side protrudes more toward the seal member 44 than the boundary between the concave groove 17a and the tapered concave surface 17b of the electrode 17 in the extending direction of the metal pipe material 14. The lower surfaces of the upper electrodes 17 and 18 and the upper surfaces of the lower electrodes 17 and 18 are in contact with each other. However, the configuration is not limited to the configuration in which the metal pipe material 14 is in close contact with the entire periphery of the both ends, and a configuration in which the electrodes 17 and 18 are in contact with part of the metal pipe material 14 in the circumferential direction may be employed.

  Subsequently, the control unit 70 heats the metal pipe material 14 by controlling the heating mechanism 50. Specifically, the control unit 70 controls the power supply unit 55 of the heating mechanism 50 to supply power. Then, the electric power transmitted to the lower electrodes 17 and 18 via the bus bar 52 is supplied to the upper electrodes 17 and 18 and the metal pipe material 14 sandwiching the metal pipe material 14 and exists in the metal pipe material 14. Due to the resistance, the metal pipe material 14 itself generates heat due to Joule heat. That is, the metal pipe material 14 is in an electrically heated state.

  Subsequently, the molding die 13 is closed with respect to the heated metal pipe material 14 by the control of the drive mechanism 80 by the control unit 70. As a result, the cavity 16 of the lower mold 11 and the cavity 24 of the upper mold 12 are combined, and the metal pipe material 14 is disposed and sealed in the cavity portion between the lower mold 11 and the upper mold 12.

  Thereafter, the cylinder unit 42 of the gas supply mechanism 40 is operated to advance the seal member 44 to seal both ends of the metal pipe material 14. At this time, as shown in FIG. 2 (b), the seal member 44 is pressed against the end portion of the metal pipe material 14 on the electrode 18 side, so that the boundary between the concave groove 18a and the tapered concave surface 18b of the electrode 18 is exceeded. A portion protruding toward the seal member 44 is deformed in a funnel shape so as to follow the tapered concave surface 18b. Similarly, when the seal member 44 is pressed against the end portion of the metal pipe material 14 on the electrode 17 side, a portion protruding to the seal member 44 side from the boundary between the groove 17a and the tapered concave surface 17b of the electrode 17 is It deforms into a funnel shape along the tapered concave surface 17b. After the sealing is completed, high-pressure gas is blown into the metal pipe material 14, and the metal pipe material 14 softened by heating is formed so as to follow the shape of the cavity portion.

  Since the metal pipe material 14 is heated to a high temperature (around 950 ° C.) and softened, the gas supplied into the metal pipe material 14 is thermally expanded. For this reason, for example, the supplied gas is compressed air, and the metal pipe material 14 at 950 ° C. can be easily expanded by the thermally expanded compressed air.

  The outer peripheral surface of the metal pipe material 14 swelled by blow molding is brought into contact with the cavity 16 of the lower mold 11 and rapidly cooled, and at the same time is brought into contact with the cavity 24 of the upper mold 12 to rapidly cool (the upper mold 12 and the lower mold 11 are Since the heat capacity is large and the temperature is controlled at a low temperature, if the metal pipe material 14 comes into contact, the heat of the pipe surface is taken away to the mold side at once, and quenching is performed. Such a cooling method is called mold contact cooling or mold cooling. Immediately after being quenched, austenite transforms to martensite (hereinafter, austenite transforms to martensite is referred to as martensite transformation). In the second half of the cooling, the cooling rate was reduced, so that martensite was transformed into another structure (truthite, sorbite, etc.) by recuperation. Therefore, it is not necessary to perform a separate tempering process. In the present embodiment, cooling may be performed by supplying a cooling medium into the cavity 24, for example, instead of or in addition to mold cooling. For example, the metal pipe material 14 is brought into contact with the mold (upper mold 12 and lower mold 11) until the temperature at which martensitic transformation begins, and then the mold is opened and the cooling medium (cooling gas) is used as the metal pipe material. The martensitic transformation may be generated by spraying on 14.

  As described above, blow molding is performed on the metal pipe material 14, and then cooling is performed to perform mold opening, thereby obtaining a metal pipe having a substantially rectangular cylindrical main body, for example.

  Next, with reference to FIGS. 3 to 5, characteristic portions of the molding apparatus 10 according to the present embodiment will be described. The metal pipe 140 molded by the molding apparatus 10 according to this embodiment includes a pipe body 150 formed in a desired shape in the axial direction of the metal pipe 140 and a cavity V in the metal pipe 140 in the axial direction. The flange part 151 to close | close and the side part flange part 152 formed along the axial direction in the side part of the metal pipe 140 are provided (refer FIG. 7). In order to mold the metal pipe 140 having such a shape, as shown in FIGS. 3, 4, and 5, the molding die 13 includes a cavity part 120, a flange cavity part 121, and a side flange cavity part 123. (See FIG. 5).

  The cavity part 120 is a cavity for forming the pipe body part 150 of the metal pipe 140. In the pipe main body 150, the pipe main body 150 of the metal pipe 140 has a desired cross-sectional shape in the axial direction (see FIG. 5), and has a cavity V therein. Therefore, the cavity part 120 has a cross-sectional shape corresponding to a desired cross-sectional shape of the metal pipe 140 in the axial direction.

  The side flange cavity portion 123 is a cavity for forming the side flange portion 152 of the metal pipe 140. The side flange portion 152 is formed by being sandwiched between the surface of the side flange cavity portion 123 of the lower die 11 and the surface of the side flange cavity portion 123 of the upper die 12 without any gap (FIG. 5B). reference).

  An example of the configuration of the cavity 120 and the side flange cavity 123 will be described with reference to FIG. The cavity 120 is configured by combining a recess 120A formed in the lower mold 11 and a recess 120B formed in the upper mold 12. The recess 120A of the lower mold 11 is recessed in a rectangular shape downward from the upper surface of the lower mold 11, and includes a bottom surface 120Aa and side surfaces 120Ab and 120Ac formed on both sides in the width direction of the bottom surface 120Aa. . The recess 120B of the upper mold 12 is recessed in a rectangular shape upward from the lower surface of the lower mold 11, and includes an upper surface 120Ba and side surfaces 120Bb and 120Bc formed on both sides of the upper surface 120Ba in the width direction. . The recess 120A and the recess 120B have symmetrical shapes in the vertical direction. When the lower mold 11 and the upper mold 12 are closed, the bottom surface 120Aa and the side surfaces 120Ab and 120Ac of the recess 120A and the upper surface 120Ba and the side surfaces 120Bb and 120Bc of the recess 120B are combined to form a rectangular cross-sectional shape. In order to form, the pipe main-body part 150 of the metal pipe 140 is formed in a rectangular cross section (see FIG. 5B). However, the shape of the pipe body 150 is not particularly limited, and any shape can be adopted. Further, the shape of the cavity portion 120 is appropriately changed according to the shape of the pipe main body portion 150.

  The side flange cavity portion 123 is configured by combining a pair of clamping surfaces 123A formed on the lower mold 11 and a pair of clamping surfaces 123B formed on the upper mold 12. One clamping surface 123A extends from the upper end of the side surface 120Ab of the lower mold 11 to the outside in the width direction. The other clamping surface 123A extends from the upper end of the side surface 120Ac of the lower mold 11 to the outside in the width direction. One clamping surface 123B extends from the lower end of the side surface 120Bb of the upper mold 12 to the outside in the width direction. The other clamping surface 123B extends from the upper end of the side surface 120Bc of the upper mold 12 to the outside in the width direction. The pair of clamping surfaces 123A and the pair of clamping surfaces 123B are opposed to each other in the vertical direction. In a state where the lower mold 11 and the upper mold 12 are closed, the pair of clamping surfaces 123A and the pair of clamping surfaces 123B are combined to sandwich and crush the side portions on both sides of the metal pipe 140, thereby forming a flat side flange. A portion 152 is formed (see FIG. 5B).

  As shown in FIGS. 3 and 4, the flange cavity portion 121 is a cavity for forming the flange portion 151. The flange cavity portion 121 is configured by combining a protruding portion 121A formed on the lower mold 11 and a protruding portion 121B formed on the upper mold 12. The protrusion 121A protrudes upward from the bottom surface 120Aa of the recess 120A of the lower mold 11. The flange portion 151 closes the cavity V in the pipe main body portion 150 over the entire region in the width direction. Therefore, the protrusion 121A is formed over the entire region in the width direction of the recess 120A (see FIG. 5). The protrusion 121A shown in FIGS. 3 and 4 has a truncated cone section, but the shape is not particularly limited. For example, the protrusion 121A may be rectangular or curved. Note that the lower surface of the protruding portion 121A is formed at the same position in the vertical direction as the clamping surface 123B of the side flange cavity portion 123. The protrusion 121B and the upper surface 120Ba of the recess 120B of the upper mold 12 protrude downward. The protrusion 121B has a vertically symmetrical configuration with the protrusion 121A. That is, the protruding portion 121A and the protruding portion 121B face each other in the vertical direction.

  In a state where the lower mold 11 and the upper mold 12 are closed, the protruding portion 121A and the protruding portion 121B are combined so that the portion corresponding to the pipe main body portion 150 of the metal pipe 140 is sandwiched and crushed. Thereby, the flat flange part 151 is formed (refer FIG. 4). The flange portion 151 and the side flange portion 152 are provided so as to form a continuous flat plate.

  The flange cavity portion 121 is between the pipe main body portion 150 and the portions 14a and 14b to which gas is supplied from the seal member 44 of the gas supply mechanism 40 in the metal pipe material 14 disposed in the molding die 13. Each flange portion 151 is formed. That is, the one flange cavity portion 121 is provided at a position on the one end portion 13a side in the extending direction of the metal pipe material 14 to be arranged and at a position separated from the end portion 13a. The other flange cavity portion 121 is provided at a position on the other end portion 13b side in the extending direction of the metal pipe material 14 to be arranged and at a position separated from the end portion 13b.

  Next, a procedure for molding the pipe body 150, the flange 151, and the side flange 152 by the molding die 13 will be described in detail. First, as shown in FIGS. 3 and 5A, the lower mold 11 and the upper mold 12 are maintained in a state where they are not completely closed. In this state, the gas supply mechanism 40 performs primary blow. At this time, since the flange portion 151 does not completely close the metal pipe material 14 in the axial direction, the gas can pass through the cavity V. Next, the gas supply mechanism 40 performs secondary blowing while closing the lower mold 11 and the upper mold 12. Finally, as shown in FIGS. 4 and 5B, the lower mold 11 and the upper mold 12 are completely closed, and the pipe main body 150, the flange 151, and the side flange 152 are formed. As shown in the upper part of FIG. 7A, the metal pipe 140 immediately after being taken out from the molding die 13 is in a state where the portions 14a and 14b to which the gas is supplied remain on both end sides in the longitudinal direction. Therefore, by cutting along the cut line CL at the position of the flange portion 151 on both ends, the metal pipe 140 having the flange portions 151 on the both ends in the longitudinal direction as shown in the lower part of FIG. Can be obtained.

  Next, operations and effects of the molding apparatus 10 and the molding method according to the present embodiment will be described.

  According to the molding apparatus 10 according to the present embodiment, the molding die 13 includes a cavity part 120 for forming the pipe body part 150 of the metal pipe 140, a flange cavity part 121 for forming the flange part 151, Is provided. The flange portion 151 formed by the flange cavity portion 121 closes the cavity V in the metal pipe 140 in the axial direction of the metal pipe 140. The flange portion 151 having such a shape can function as the flange portion 151 on the end side in the axial direction of the metal pipe 140. Therefore, by forming the metal pipe 140 with the molding die 13, it is possible to form the pipe main body portion 150 and the flange portion 151 on the end portion side in the axial direction. As described above, the flange portion 151 can be formed on the end portion side of the metal pipe 140 in the axial direction.

  In the molding apparatus 10, the flange cavity portion 121 may be disposed on the end portion side in the axial direction when the metal pipe material 14 is disposed in the molding die 13 as compared with the cavity portion 120. Thereby, the flange part 151 can be arrange | positioned at the edge part side in the metal pipe material 14. FIG. Therefore, the length in the axial direction occupied by the pipe body 150 of the metal pipe material 14 can be increased.

  In the molding apparatus 10, the flange cavity portion 121 is between the pipe main body 150 and the portions 14 a and 14 b to which the gas is supplied from the gas supply mechanism 40 in the metal pipe material 14 disposed in the molding die 13. The flange portion 151 is formed. As a result, after the metal pipe 140 is formed, cutting is performed at the position of the flange portion 151, so that the portion remaining on the pipe body portion 150 side is used as the flange portion 151 formed at the end portion of the metal pipe 140. it can. On the other hand, the portions 14a and 14b to which the gas is supplied from the gas supply mechanism 40 can be removed from the pipe body 150 as unnecessary portions.

  The forming method according to the present embodiment is a forming method for forming the metal pipe 140 by expanding the metal pipe material 14, and an arrangement step for disposing the metal pipe material 14 in a forming die 13 for forming the metal pipe 140. And forming a metal pipe 140 having a shape along the molding die 13 by supplying a gas into the metal pipe material 14 and expanding the metal pipe material 14 with the molding die 13 closed. Then, the pipe main-body part 150 of the metal pipe 140 is formed, and the flange part 151 that closes the cavity V in the metal pipe 140 is formed in the axial direction of the metal pipe 140.

  According to this shaping | molding method, the effect | action and effect similar to the above-mentioned shaping | molding apparatus 10 can be acquired.

  The present invention is not limited to the embodiment described above.

  For example, instead of the one shown in FIG. 3, a molding die 13 shown in FIG. 6 may be adopted. In the molding die 13 shown in FIG. 6, the cavity portion is different from the first cavity portion 160 forming the first pipe body portion 150 </ b> A of the metal pipe 140 in a position different from the first pipe body portion 150 </ b> A in the axial direction. And a second cavity 170 that forms the second pipe body 150B. The lower mold 11 includes a concave portion 160 </ b> A of the first cavity portion 160 and a concave portion 170 </ b> A of the second cavity portion 170. The upper mold 12 includes a concave portion 160B of the first cavity portion 160 and a concave portion 170B of the second cavity portion 170. Further, the flange cavity portion 121 is disposed between the first cavity portion 160 and the second cavity portion 170. The flange cavity portion 121 is provided at the center position of the molding die 13. A metal pipe 140 as shown in the upper part of FIG. 7B is obtained by molding using such a molding die 13. By cutting along the cut line CL at the position of the flange portion 151 at the center position, as shown in the lower part of FIG. 7B, two metal pipes having a flange portion 151 at one end in the longitudinal direction. 140A and 140B can be obtained. In addition, the position in the axial direction of the flange cavity part 121 is not specifically limited, You may change suitably.

  The cavity part of the molding die shown in FIG. 6 has a second cavity at a position different from the first pipe body part 150A in the axial direction and the first cavity part 160 forming the first pipe body part 150A of the metal pipe 140. A second cavity portion 170 that forms the pipe main body portion 150 </ b> B, and the flange cavity portion 121 is disposed between the first cavity portion 160 and the second cavity portion 170. Thus, after the metal pipe 140 is formed, the portion remaining on the first pipe body 150A side is cut at the position of the flange 151, so that the flange 151 on the first pipe body 150A side is left. Available as On the other hand, the portion left on the second pipe body 150B side can be used as the flange 151 on the second pipe body 150B side.

  In the above-described embodiment, the current heating is performed using the electrodes 17 and 18, but a metal pipe material heated in advance may be set in a molding die.

  In the above-described embodiment, the gas supply mechanism is employed as the fluid supply unit. However, the fluid is not limited to gas, and liquid may be supplied.

  The position and quantity of the flange portion are not particularly limited. For example, the flange portions as shown in FIGS. 3 and 4 may be provided only on one side in the axial direction instead of being provided at both ends of the metal pipe. Moreover, as shown in FIG. 6, it may replace with the form which uses the axial direction center vicinity of a metal pipe as a flange part, and the form which uses the position away from the center as a flange part may be sufficient. Moreover, as shown in FIG. 6, it may replace with the form which divides | segments a metal pipe into two after shaping | molding completion, and the form divided | segmented into 3 or more may be sufficient. However, in this case, it is necessary to form at least as many flange portions as the “number of divisions−1”.

  DESCRIPTION OF SYMBOLS 10 ... Molding apparatus, 13 ... Mold, 14 ... Metal pipe material, 40 ... Gas supply mechanism (fluid supply part), 120 ... Cavity part, 121 ... Flange cavity part, 140 ... Metal pipe, 150 ... Pipe main-body part, 150A ... 1st pipe main-body part, 150B ... 2nd pipe main-body part, 151 ... Flange part, 160 ... 1st cavity part, 170 ... 2nd cavity part.

Claims (5)

A forming apparatus for forming a metal pipe by expanding a metal pipe material,
A molding die for molding the metal pipe;
A fluid supply part for supplying and expanding a fluid into the metal pipe material,
The molding die is
A cavity for forming a pipe body of the metal pipe;
A molding apparatus comprising: a flange cavity portion for forming a flange portion that closes a cavity in the metal pipe in the axial direction of the metal pipe.   The molding apparatus according to claim 1, wherein the flange cavity portion is disposed closer to an end portion in the axial direction when the metal pipe material is disposed in the molding die than the cavity portion.   The flange cavity portion forms the flange portion between the pipe body portion and a portion of the metal pipe material arranged in the molding die to which a fluid is supplied from the fluid supply portion. The molding apparatus according to claim 2. The cavity portion is
A first cavity part forming a first pipe body part of the metal pipe;
A second cavity part that forms a second pipe body part at a position different from the first pipe body part in the axial direction,
The molding apparatus according to claim 1, wherein the flange cavity portion is disposed between the first cavity portion and the second cavity portion. A forming method for forming a metal pipe by expanding a metal pipe material,
An arrangement step of arranging the metal pipe material in a molding die for molding the metal pipe;
Forming the metal pipe having a shape along the molding die by supplying a fluid into the metal pipe material and expanding the metal pipe material with the molding die closed; and
In the molding step,
A forming method for forming a pipe body portion of the metal pipe and forming a flange portion for closing a cavity in the metal pipe in an axial direction of the metal pipe.

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