JP2015167971A - Manufacturing method for molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a molded body which can suppress sparks from occurring between a molded material and an outer mold for electromagnetic molding when performing electromagnetic molding.SOLUTION: The manufacturing method for a molded body performs a step of electromagnetically molding a molded material 100 so as to obtain a molded body 1 by flowing currents to an electromagnetic molding coil 12 arranged in the molded material 100 made of metal materials of a cylindrical body arranged in a cavity 18 of an electromagnetic molding die 11, where at least insulator 19 is formed on a surface of the electromagnetic molding die 11 that contacts the molded body 1 subjected to tube expansion molding by the electromagnetic molding.

Description

  The present invention relates to a method for producing a molded body. More specifically, the present invention relates to a technique for producing a molded body by electromagnetic forming a can or the like.

  A cylindrical body such as a can needs to have a design that is easy to catch the eyes of general consumers, and in addition to the design of the label of the main body, the shape of the can itself is also being studied. For example, Patent Document 1 discloses a technique for embossing a can body. According to this technique, a can, which is a material to be molded, can be sandwiched and embossed by a plurality of rolls having unevenness.

  On the other hand, for example, Patent Documents 2 and 3 disclose techniques for expanding a can body or forming a curved portion using an electromagnetic forming method as a method other than mechanical processing such as roll processing. Has been. According to this technique, since the processing oil is not used unlike the mechanical processing method, the cleaning step of the processing oil can be omitted. Further, it can be processed into a desired shape in a short time such as several milliseconds, and the productivity is excellent.

Special Table 2000-515072 JP-A-9-29370 JP 2006-264769 A

  However, when performing electromagnetic forming in the above-described technique, a high voltage is applied to a material to be molded such as a can. For this reason, dielectric breakdown may occur in the air layer between the material surface of the molding material and the mold, and a spark may be generated between the molding material and the mold to form a spark mark on the molded body.

  Therefore, the main object of the present invention is to provide a method for producing a molded body that suppresses the occurrence of sparks between a material to be molded and an outer mold for electromagnetic forming during electromagnetic forming.

The present invention has been completed as a result of intensive studies by the present inventors in order to solve the above-described problems, and is made of a metallic material made of a cylindrical body disposed in a cavity of an outer mold for electromagnetic forming. Including the step of electromagnetically forming the material to be molded by passing an electric current through an electromagnetically formed coil body inserted in the molding material to obtain a molded body, and Provided is a method for producing a molded body in which at least the surface of the cavity of an outer mold for molding is formed of an insulator.
In this method for manufacturing a molded body, the insulator may be a resin layer.
The outer mold for electromagnetic molding may be provided with a hole penetrating from the cavity toward the outer surface of the outer mold for electromagnetic molding.
Further, a concave portion is formed on at least a part of the surface of the cavity of the outer mold for electromagnetic molding that is in contact with the molded body that is expanded by the electromagnetic molding, and the hole is provided in the concave portion. May be.
In this method of manufacturing a molded body, the electromagnetic forming may be performed by cooling the material to be molded.
Further, in this method for producing a molded body, the gap between the material to be molded and the outer mold for electromagnetic forming may be reduced during the electromagnetic forming.
The material to be molded may be a bottomed cylindrical body.

  ADVANTAGE OF THE INVENTION According to this invention, in the case of electromagnetic forming, the manufacturing method of the molded object which suppressed that a spark generate | occur | produces between a to-be-molded material and the outer mold | type for electromagnetic forming is realizable.

It is a perspective view of the molded object 1 of the 1st Embodiment of this invention. An example of the horizontal cross-sectional shape of the molded object 1 of the embodiment is shown. It is the photograph which copied a part of outer surface of the molded object 1 of the embodiment. It is a perspective view of the molded object 1X after the electromagnetic forming which concerns on related technology. It is the photograph which copied the outer surface of the molded object 1X after the electromagnetic forming which concerns on related technology. It is the schematic of the electromagnetic forming apparatus 10 for manufacturing the molded object 1 of the embodiment. It is a perspective view of the outer mold | type 11 for electromagnetic shaping | molding for manufacturing the molded object 1 of the embodiment. It is a figure for demonstrating the state which is forming the to-be-molded material 100X in order to manufacture the molded object 1X which concerns on related technology. It is a figure for demonstrating the process of manufacturing the molded object 1 of the embodiment. It is a perspective view of the outer mold | type 21 for electromagnetic shaping | molding for manufacturing the molded object 2 of the 2nd Embodiment of this invention. It is a perspective view of the molded object 2 after the electromagnetic forming of the same embodiment. It is a figure for demonstrating the state which is forming the to-be-molded material 102X in order to manufacture the molded object 2X which concerns on related technology. It is a perspective view of the molded object 2X which concerns on related technology. It is a perspective view which shows an example of the molded object 2 of the embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below.

<First Embodiment>

  First, the molded object 1 of the 1st Embodiment of this invention is demonstrated. FIG. 1 is a perspective view of a molded body 1 of the present embodiment. FIG. 2 shows an example of a horizontal cross-sectional shape (cross-sectional shape along line AA in FIG. 1) of the molded body 1 of the present embodiment.

[Molded body 1]
The molded body 1 of this embodiment is obtained by expanding and molding a material to be molded 100 (see FIG. 7 described later) by electromagnetic forming. That is, the molded body 1 refers to a material to be molded 100 that has been expanded by electromagnetic forming, and the material to be molded 100 refers to a material before the molded body 1 is electromagnetically molded. As shown in FIG. 1, the shape of the molded body 1 of the present embodiment is not particularly limited as long as it is a cylindrical body. For example, it has a cylindrical shape. The cross-sectional shape of the AA line in FIG. 1 (cross-sectional shape parallel to the XY plane) can be a circle as shown in FIG. 2A, for example. In addition to this, as shown in FIG. 2b, it may be oval, as shown in FIG. 2c, it may be a substantially triangular shape with rounded corners, or as shown in FIG. 2d. In addition, a concave shape may be formed on each side of a substantially rectangular shape with rounded corners. In addition, the molding material 100 for obtaining the molded body 1 of the present embodiment is preferably a bottomed cylindrical body in order to prevent loss of overcurrent during electromagnetic molding and reduce the amount of energy input, for example. .

  The molding material 100 for obtaining the molded body 1 of the present embodiment is made of a metal material. Although it does not specifically limit as a metal material which comprises the to-be-molded material 100, For example, a light alloy material is mentioned, Specifically, aluminum, aluminum alloy (3004, 3104, 5201, 5182, 6022 etc.) etc. are mentioned. It is done. Note that a resin film (paint film, film laminate) of about several μm to several tens of μm may be formed on the surface of the molded body 1. Moreover, phosphoric acid chromate treatment, zirconium phosphate treatment, or the like may be performed as a base treatment of the resin film.

  FIG. 3 is a photograph showing a part of the outer surface of the molded body 1 of the present embodiment. As shown in FIG. 3, the molded body 1 of the present embodiment is manufactured by expanding the molding material 100 by electromagnetic molding by a manufacturing method described later, thereby suppressing the occurrence of sparks on the outer surface, It has an outer surface with a good appearance. On the other hand, FIG. 4 is a perspective view of a molded body 1X according to the related art. FIG. 5 is a photograph showing a part of the outer surface of the molded body 1X according to the related art. As shown in FIGS. 4 and 5, in the molded body 1 </ b> X according to the related art, a spark mark x is easily generated on the outer surface. In addition, defects such as dents and wrinkles may occur in the molded body 1X due to air remaining between the molding material 100X and the electromagnetic molding outer mold 111 (see FIG. 8 described later) during manufacturing.

[Method for Manufacturing Molded Body 1]
Next, the manufacturing method of the molded object 1 of this embodiment is demonstrated. Since the molded body 1 of the present embodiment is manufactured by the manufacturing method described below, it is possible to suppress the occurrence of defects such as spark marks x, wrinkles, and recesses on the outer surface as described above.

  FIG. 6 is a schematic view of an electromagnetic forming apparatus 10 for manufacturing the formed body 1 of the present embodiment. In the electromagnetic forming apparatus 10, the surface of a cavity 18 (see FIG. 7 to be described later) that comes into contact with the formed body 1 expanded by electromagnetic forming is formed of at least an insulator 19 in the outer mold 11 for electromagnetic forming. It has the feature in being.

  As shown in FIG. 6, in this electromagnetic forming apparatus 10, the capacitor 14 is discharged by turning on the switch 13. As a result, a large current is instantaneously passed through the electromagnetic forming coil body 12, and an induced current is generated in the molding material 100 by the magnetic flux generated from the electromagnetic forming coil body 12, and due to the interaction between this induced current and the electromagnetic field, A force (electromagnetic force) for expanding the material to be molded 100 works. In FIG. 6, reference numeral 15 denotes a power source of the charging circuit, and reference numeral 16 denotes a charging switch.

  FIG. 7 is a perspective view of an example of the electromagnetic forming outer mold 11 for manufacturing the molded body 1 by expanding the molding material 100 by electromagnetic forming. As shown in FIG. 7, the outer mold 11 for electromagnetic forming has a cavity 18 formed inside a main body portion 17. In the cavity 18, a molding material 100 made of a cylindrical metal material can be arranged in the direction of the arrow F <b> 1, and the molding material 100 can be provided with an electromagnetic molding coil body 12 capable of flowing a current. It can be inserted in the direction of arrow F2.

  As described above, the surface of the cavity 18 that comes into contact with the molded body 1 obtained by expanding the molded material 100 by tube forming by electromagnetic molding is formed of the insulator 19. In order to prevent discharge between the main body portions 17 of the outer mold 11 for electromagnetic forming, it is preferable that the insulator 19 is also formed at a portion where the plurality of main body portions 17 are joined. Further, the entire outer mold 11 for electromagnetic forming may be formed not only by the surface of the cavity 18 but also by the insulator 19 as a whole.

  Next, before describing a specific process of electromagnetically forming the molding material 100 for obtaining the molded body 1 of the present embodiment by the electromagnetic molding apparatus 10, first, to obtain the molded body 1X according to the related art. A method for electromagnetically forming the workpiece 100X will be described.

  FIG. 8 is a diagram for explaining a state in which the molding material 100X is subjected to pipe expansion molding by electromagnetic molding and a molded body 1X according to related technology is manufactured. When the molding material 100X is electromagnetically molded, an insulator is formed on the surface of the cavity 118 of the main body 117 in the outer mold 111 for electromagnetic molding, which comes into contact with the molded body 1X that has been expanded by electromagnetic molding. Not. Therefore, when the molding material 100X is electromagnetically molded, dielectric breakdown occurs in the air layer between the outer surface of the molding material 100X and the electromagnetic molding outer mold 111, and the gap between the molding material 100X and the electromagnetic molding outer mold 111 occurs. Sparks. Thereby, a spark mark x is formed on the outer surface of the molded body 1X obtained from the molding material 100X.

  On the other hand, in the manufacturing method of the molded object 1 of this embodiment by the electromagnetic molding apparatus 10, it can suppress that a spark trace generate | occur | produces in the molded object 1. FIG. FIG. 9 is a diagram for explaining a process of manufacturing the molded body 1. First, as shown in FIG. 9 a, the molding material 100 is disposed in the cavity 18 of the electromagnetic molding outer mold 11 described above, and the electromagnetic forming coil body 12 is inserted into the molding material 100.

  Next, as shown in FIG. 9b, a discharge is made from the capacitor 14 (see FIG. 6) of the electromagnetic forming apparatus 10, and the molding material 100 is expanded to the surface side of the cavity 18 of the main body 17 (in the direction of arrow F3). The At this time, since the surface of the cavity 18 of the main body portion 17 that comes into contact with the molded body 1 that is expanded by electromagnetic molding is formed of the insulator 19, the molding material 100 and the outer mold 11 for electromagnetic molding 11 It is possible to suppress the occurrence of sparks between them.

  The insulator 19 may be made of a material that does not cause dielectric breakdown during electromagnetic forming, and can be formed using a resin, ceramic, or the like, but is preferably a resin layer. Examples of the resin constituting the resin layer include epoxy resins, urethane resins, PP resins, nylon resins, and the like, which are properly used depending on the application in order to improve elasticity, machinability, tube expansion accuracy, durability, and the like. be able to.

  Since the insulator 19 is a resin layer, the resin layer has a certain elasticity, so that damage due to cracking of the mold can be prevented, and a mold can be manufactured at a lower cost. Further, only the surface portion of the cavity 18 may be formed of the insulator 19, or the entire electromagnetic forming outer mold 11 may be formed of the insulator 19.

  Further, as will be described in detail in a second embodiment to be described later, even though the electromagnetic forming outer mold 11 is provided with a hole 26 penetrating from the cavity 18 toward the outer surface of the electromagnetic forming outer mold 11. Good. Thus, by providing the hole 26 in the electromagnetic forming outer mold 11, the gas existing between the molded body 1 and the insulator 19 is discharged from the hole 26 to the outside of the electromagnetic forming outer mold 11. Is done. Therefore, although electromagnetic forming is performed in a very short time, air remains between the formed body 1 and the outer mold 11 for electromagnetic forming, and defects such as wrinkles and recesses are generated in the formed body 1. Can be prevented.

  Further, although not particularly limited, it is preferable to perform the electromagnetic forming while cooling the molding material 100. Thereby, while being able to reduce the input energy at the time of shaping | molding, since the thermal damage of the electromagnetic forming coil body 12 can be reduced, the some molded object 1 can be shape | molded continuously, and the molded object 1 The mass productivity is improved.

  Further, the gap between the molding material 100 and the electromagnetic forming outer mold 11 may be reduced during the electromagnetic forming. Thereby, the air remaining between the electromagnetic forming outer mold 11 and the molding material 100 can be more reliably excluded.

  As described above in detail, in the electromagnetic forming outer mold 11 for manufacturing the formed body 1 of the present embodiment, the surface of the cavity 18 in contact with the formed body 1 obtained by expanding the molding material 100 by electromagnetic forming is formed. The insulator 19 is formed. Therefore, it can suppress that a spark generate | occur | produces between the to-be-molded material 100 and the outer mold | type 11 for electromagnetic forming. Further, in the case where the specific hole 26 is provided in the electromagnetic forming outer mold 11, although the electromagnetic forming itself is performed in a very short time, the air is formed between the material to be molded 100 and the electromagnetic forming outer mold 11. It is also possible to prevent defects such as wrinkles and recesses from occurring in the molded body 1. The molded body 1 of the present embodiment produced in this way has a good outer surface without spark marks, and is excellent in aesthetics even if the outer surface is designed by printing a label thereafter. Become.

<Second Embodiment>
Next, the molded object 2 of the 2nd Embodiment of this invention is demonstrated. The molded body 2 of the present embodiment is also obtained by expanding the molding material by electromagnetic molding. FIG. 10 is a perspective view of the electromagnetic forming outer mold 21 for manufacturing the molded body 2 of the present embodiment. In contrast to the molded body 1 of the first embodiment of the present invention described above, the molded body 2 of the present embodiment has a bead 3 formed on the outer surface (see FIG. 11 described later). More specifically, in the molded body 2 of the present embodiment, a concave portion (bead-forming concave portion) 25 is provided on the surface of the cavity 28 of the electromagnetic molding outer mold 21 used in the production, and the concave portion. A hole 26 penetrating from 25 to the outer surface of the main body 27 is provided.

  FIG. 11 is a perspective view of the molded body 2 after being electromagnetically molded by the electromagnetic molding outer mold 21. The molded body 2 expanded by electromagnetic molding enters the concave portion 25 of the electromagnetic molding outer mold 21 shown in FIG. 10, and the beads 3 are formed on the outer surface of the molded body 2. At this time, since the hole 26 is provided from the concave portion 25 of the electromagnetic molding outer mold 21 toward the outer surface of the electromagnetic molding outer mold 21, no air remains in the bead 3, and the bead of the molded body 2. It is possible to prevent defects such as wrinkles and recesses from being formed on the 3.

  Here, the process of manufacturing the molded body 2X according to the related art will be described with reference to FIGS. FIG. 12 is a diagram for explaining a state in which the material to be molded 102X is electromagnetically molded in order to obtain the molded body 2X according to the related art. FIG. 13 is a perspective view of the molded body 2X after electromagnetic forming according to the related art.

  As shown in FIG. 12 a, first, a material to be molded 102 </ b> X for manufacturing the related-art molded body 2 </ b> X is placed in the cavity 128 of the electromagnetic molding outer mold 121. Next, in the same manner as the molding material 1 of the first embodiment and the molding material 2 of the second embodiment, an electric current is applied to an electromagnetic forming coil body (not shown) inserted into the molding material 102X. By flowing, the molded body 2X is manufactured by electromagnetic forming and pipe expansion (see FIG. 12b).

  At this time, the material to be molded 102X is expanded by electromagnetic forming at a high speed and is in close contact with the main body 127 of the outer mold 121 for electromagnetic forming. Then, the air existing between the material to be molded 102 and the main body 127 flows in the direction of the arrow F4 and is trapped and collected in the concave portion 125 without being completely removed outside the outer mold 121 for electromagnetic forming. . Therefore, as shown in FIG. 13, defects Y such as dents and wrinkles due to the trapped air are generated in the bead 3X of the electromagnetically molded body 2X.

  On the other hand, as shown in FIG. 10, the molded body 2 of the present embodiment uses an electromagnetic molding outer mold 21 provided with a hole 26 penetrating from the concave portion 25 toward the outer surface of the main body portion 27. Manufactured. Therefore, when the molded body 2 obtained by expanding the material to be molded by electromagnetic forming comes into close contact with the main body 27 of the electromagnetic forming outer mold 21, the air remaining in the concave portion 25 passes through the holes 26 for electromagnetic forming. It is pushed out of the outer mold 21 and discharged.

  Thereby, defects, such as a wrinkle and a recessed part, do not arise in the bead 3 of the molded object 2, but the molded object 2 has the outstanding beauty | look. Furthermore, the electromagnetic forming outer mold 21 for manufacturing the molded body 2 of the present embodiment is similar to the electromagnetic forming outer mold 11 for manufacturing the molded body 1 of the first embodiment described above, after the electromagnetic forming. The surface of the cavity 28 that comes into contact with the insulator 19 is covered with an insulator 19. Therefore, in the molded object 2, it can suppress that a spark trace generate | occur | produces on the whole outer surface.

  Further, the hole 26 may be provided at a position other than the concave portion 25 on the surface of the cavity 28, and in this case as well, on the outer surface other than the bead 3, similarly to the molded body 1 of the first embodiment. It is also possible to prevent the occurrence of defects such as wrinkles and recesses.

  The molded body 2 after the electromagnetic molding according to the present embodiment is not limited to the shape as shown in FIG. 11, and can be a material to be molded with various beads. FIG. 14 is a perspective view showing an example of another molded body 2 of the present embodiment.

  For example, one or a plurality of ring-shaped parallel beads may be formed by winding the side surface of the cylindrical shaped body 2 (see FIG. 14a). Further, in the shaped body 2 having a constricted center position on the side surface, one or a plurality of dimples in a substantially hemisphere may be arranged at a position close to the bottom surface (see FIG. 14b). Further, a bead may be formed so as to be wound around the side surface while being inclined with respect to the bottom surface (see FIG. 14c). One or more beads may be arranged on the side surface of the cylinder in a direction perpendicular to the bottom surface (see FIG. 14d).

  A plurality of dimples having different sizes may be formed on the side surface of the cylinder (see FIG. 14e). Moreover, the convex part of the shape like the footprint of animals, such as a dog and a cat, may be formed in the side surface of a cylinder (refer FIG. 14f). Moreover, the convex part which carried out the shape of a human hand may be formed in the side surface of a cylinder (refer FIG. 14g). Moreover, the convex part of the shape imitating a meteor may be formed in the side surface of a cylinder (FIG. 14h). As described above, various beads can be formed by appropriately adjusting the shape of the hole 26 provided in the electromagnetic forming outer mold 21.

  The configuration and effects other than the configuration and effects described in the present embodiment are the same as those in the first embodiment described above.

  As described in detail above, in the electromagnetic molding outer mold 21 for manufacturing the molded body 2 of the present embodiment, the surface of the cavity 28 in contact with the molded body 2 is formed of the insulator 19, and the surface has a concave shape. A portion 25 is provided, and a hole 26 penetrating from the concave portion 25 toward the outer surface of the main body portion 27 is provided. Therefore, it can suppress that a spark generate | occur | produces between a to-be-molded material and the outer mold | type 21 for electromagnetic forming, and that defects, such as a wrinkle and a recessed part, generate | occur | produce on the bead surface of the molded object 2 after electromagnetic forming. Can be prevented. In this way, in the molded body 2 of the present embodiment, beads having various shapes with excellent aesthetics can be formed.

DESCRIPTION OF SYMBOLS 1, 2 Forming body 3 Bead 10, 20 Electromagnetic forming apparatus 11, 21 Outer mold for electromagnetic forming 12 Electromagnetic forming coil body 17, 27 Main body part 18, 28 Cavity 19 Insulator 25 Concave part 26 Hole 100 Molding material

Claims (7)

A molded body is formed by electromagnetically molding the molding material by passing an electric current through an electromagnetic molding coil body inserted into the molding material made of a cylindrical metal material disposed in the cavity of the outer mold for electromagnetic molding. Including the steps of:
The manufacturing method of the molded object by which the surface of the said cavity of the said outer mold for electromagnetic forming which contact | connects the said molded object expanded by the said electromagnetic forming is formed with the insulator.   The method for producing a molded body according to claim 1, wherein the insulator is a resin layer.   The method for manufacturing a molded body according to claim 1 or 2, wherein the outer mold for electromagnetic molding is provided with a hole penetrating from the cavity toward an outer surface of the outer mold for electromagnetic molding. A concave portion is formed on at least a part of the surface of the cavity of the outer mold for electromagnetic molding that comes into contact with the molded body that has been expanded by the electromagnetic molding,
The manufacturing method of the molded object of Claim 3 with which the said hole is provided in the said recessed part.   The manufacturing method of the molded object of any one of Claims 1-4 which cool the said to-be-molded material and perform the said electromagnetic shaping | molding.   The manufacturing method of the molded object of any one of Claims 1-5 which pressure-reduces the clearance gap between the said to-be-molded material and the said outer mold for electromagnetic forming, while performing the said electromagnetic forming. The method for producing a molded body according to any one of claims 1 to 6, wherein the molding target is a bottomed cylindrical body.