JP2016036843A - Method and apparatus for manufacturing bottle can with screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve enhancement of dimension stability of a screw and operability of re-sealing thereof.SOLUTION: A screw formation process includes: a screw molding start work which moves an inner element 64A and an outer element 64B in a direction such that a clearance between the inner element 64A and the outer element 64 is reduced in the state in which a circumferential direction of the inner element 64A and the outer element 64B is located at a predetermined start position and a cylindrical part 18 (screw molding planned part) is inserted between the inner element 64A and the outer element 64B; a screw molding work which forms a screw 6 on the cylindrical part 18 in such a manner that the cylindrical part 18 is sandwiched between the inner element 64A and the outer element 64B, and in the sandwiched state, the inner element 64A and the outer element 64B are rotated around an axis O of an intermediate molding 19 while being rolled; and a screw molding completion work which moves the inner element 64A and the outer element 64B in a direction such that the clearance therebetween is increased after the screw 6 is formed, and returns the circumferential direction of the inner element 64A and the outer element 64B to the start position.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a bottled can having a screw to which a cap is screwed.

As a container filled with contents such as a beverage, a bottle-shaped can (bottle can) made of an aluminum alloy, in which a cap is screwed to a cap portion having a screw portion, is known.
In this bottle can, as disclosed in Patent Document 1, an aluminum alloy plate is formed into a cylindrical body in which a bottom plate portion and a cylindrical side portion are integrated by drawing and ironing (DI molding), and the opening The diameter of the portion is reduced to form a shoulder portion, and a cylindrical portion having an enlarged diameter for screw forming is formed in a portion above the neck portion having a small diameter formed at the upper end of the shoulder portion. It is manufactured by applying a thread forming process to the part and performing a curl forming process to the opening end part.

  In this bottle can manufacturing process, the screw portion sandwiches the cylindrical portion between the core inserted into the cylindrical portion and the outer core disposed outside the cylindrical portion, and the core and outer core can be It is formed by rolling while revolving around the axis. The threaded portion is usually a right-handed screw. In order to form the right-handed screw, a right-handed thread-like convex portion is formed on the core, and a left-handed thread-like convex portion is formed on the outer core.

  A bottle can having this type of threaded portion can be sealed with a cap again after opening. However, unlike a bottle container, since it is a metal bottle can, there exists a problem that the dimension of a screw part is not stabilized. For this reason, when the dimension of a screw part varies, the malfunction which the torque at the time of a sealing operation again may arise.

  In this regard, in Patent Document 1, when a right-hand thread is formed in a threaded portion, a thread-forming tool having a core and an outer core is clockwise when viewed from the opening end of the intermediate molded body toward the bottom, that is, a screw When the mountain is formed from the upper side to the lower side, the material is attracted and bent without sufficient tension, spring back occurs, and the height of the mountain part tends to be higher than the target. Pay attention. For this reason, in the method described in Patent Document 1, the screw forming tool is formed counterclockwise, that is, the screw thread is formed from below to above. As a result, the threaded portion can be formed so that the material is stretched from the lower end side of the cylindrical portion (the base portion) toward the opening end portion, and bending can be performed in a state where sufficient tension is applied to the material of the threaded portion. Therefore, the shape of the threaded portion can easily follow the shape of the core, and the dimensions of the threaded portion can be stably formed. Therefore, the threaded bottle can described in Patent Document 1 describes that the sealing operation can be easily performed again.

International Publication No. 2013/146470

  However, although the dimensional stability of the thread portion has been improved by the method described in Patent Document 1, it is still insufficient and dimensional variations still occur. For this reason, the malfunction which the torque at the time of a sealing operation becomes high has arisen, and the further improvement is calculated | required.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a manufacturing method and a manufacturing apparatus for a bottled can with a thread, in which the dimensional stability of the threaded portion is good and the sealing operability is improved again. And

The threaded part of the bottle can sandwiches the threaded part forming part (cylindrical part) of the intermediate molded body before the thread forming process between the core and the outer part, and these core and outer part are connected to the axis of the can. Since it is formed by rolling while rotating around, a part of the screw part is overlapped so that the screw part is reliably formed without leaving a gap around the entire circumference of the part to be formed. One or more rounds are processed. For this reason, every time molding of the threaded portion is repeated, the molding end position in the circumferential direction of the core and the outer core and the molding start position (direction of the core and outer core) gradually shift in the circumferential direction. As a result, the overlap formation position (twice processing position) of the screw portion is formed differently for each bottle can. Also, depending on the difference in the molding start position of the screw part, the core and outer core and the material of the thread part molding scheduled part may cause slipping during molding. In this case, it overlaps with the first molding. In this case, the thread portion may be distorted and formed due to a deviation from the second forming. And if the thread part is distorted, the torque when sealing the opened bottled can with bottles again will increase, causing the consumer to misunderstand that the bottle is closed even though it is not completely closed. As a result, there was a risk of causing leakage of the contents.
As described above, the present inventor has caused variation in the circumferential dimension of the threaded portion by forming the overlapped position of the threaded portion in the circumferential direction for each bottle can. In view of the above, the following solution was adopted.

  The method for manufacturing a threaded bottle can according to the present invention includes a core having a right-handed convex portion on the outer periphery for forming a screw portion in a thread portion forming planned portion of an intermediate molded body before forming the screw portion, Using a screw forming tool comprising a right thread-like convex part and a corresponding outer thread having a left-hand thread-like convex part on the outer periphery, and having a thread part forming step of forming the thread part in the thread part forming planned part, In the thread portion forming step, the circumferential direction of the core and the outer core is arranged at a predetermined start position, and the thread portion forming planned portion is inserted between the core and the outer core. In this state, a thread part forming start operation for moving the core and the outer element in a direction to narrow the interval between the core and the outer element, and the thread part forming schedule by the core and the outer element The intermediate component while rolling the core and the outer core in the sandwiched state. By rotating around the axis of the body, the thread portion forming operation for forming the thread portion in the thread portion forming planned portion, and after forming the thread portion, the core and the outer core are spaced from each other. It has a screw part forming end operation for moving in the expanding direction and returning the circumferential direction of the core and the outer core to the start position.

  At the end of thread part forming operation, the orientation of the core and the outer core is returned to the predetermined start position, and the orientation of the core and the outer core is arranged at the predetermined start position before starting the formation of the screw part. Therefore, it is possible to always start forming the threaded portion from a predetermined start position. That is, each time the molding of the threaded portion is repeated for different intermediate molded bodies, the molding of the threaded portion is started in a state where the directions of the core and the outer core are returned and aligned at a predetermined start position. For this reason, since the molding start position of the threaded portion of each intermediate molded body does not shift, the overlap forming position of the threaded portion can be formed at the same position in the circumferential direction in different intermediate molded bodies. Therefore, since the threaded portion can be formed without causing a variation in the circumferential dimension for each individual intermediate molded body, the dimensional stability of the threaded portion can be achieved. In addition, since the molding of the threaded portion is started from a predetermined starting position in the circumferential direction, the molding can be performed with a certain reproducibility. Sealing operability can be improved.

  An apparatus for manufacturing a threaded bottle can according to the present invention includes a core having a right-handed convex portion on the outer periphery for forming a screw portion on a thread portion forming planned portion of an intermediate molded body before forming the screw portion, A threaded portion forming mechanism comprising a right threaded convex portion and a corresponding outer thread having a left threaded convex portion on the outer periphery, wherein the threaded portion forming mechanism is configured such that the core and the outer core are the threaded portion. A mechanism for forming the threaded portion with respect to the outer periphery of the threaded portion forming planned portion by rotating around the axis of the intermediate formed body while sandwiching the forming planned portion, wherein the core and the outer It is characterized by comprising start position return means for arranging the circumferential direction at a predetermined start position before the start of the formation of the threaded portion.

  Alignment of the core and outer core at a predetermined start position, and starting molding of the threaded portion from a predetermined start position in the circumferential direction, variation in the circumferential dimension of each individual intermediate molded body The threaded portion can be formed without causing the above. Therefore, since the molding can be performed with a certain reproducibility, the dimensional stability of the threaded portion can be achieved, the variation of the screw distortion can be reduced, and the seal operability can be improved again. be able to.

In the manufacturing apparatus of the threaded bottle can of the present invention, a support member that rotates around the axis of the intermediate formed body simultaneously with the outer member is provided, and the start position return means includes an inner magnet attached to the outer child member. And a magnet mechanism having an outer magnet attached to the support member and facing a magnetic pole attracting the inner magnet at the start position.
By utilizing the attracting and repulsion between the inner magnet and the outer magnet, the outer core at a position shifted from the starting position can be returned to the starting position, and the core can also be returned to the starting position.

In the apparatus for manufacturing a threaded bottle can of the present invention, a support member that rotates around the axis of the intermediate molded body simultaneously with the outer member is provided, and the start position return means connects the outer member and the support member. It is good to be comprised by the expansion-contraction spring which carries out.
Using the restoring force of the expansion spring, the outer core arranged in a direction shifted from the start position can be returned to the start position, and the core can also be returned to the start position accordingly.

  According to the present invention, it is possible to stabilize the size of the thread portion of each threaded bottle can, so that the sealing operation can be facilitated.

It is a front view which shows the upper half of the bottle can in 1st Embodiment of this invention. It is sectional drawing which shows the initial stage of the manufacturing process of a bottle can in order of (a)-(c). It is a front view near the cylindrical part of an intermediate fabrication object. It is a front view which shows a bottle can manufacturing apparatus schematically. It is an arrow line view which follows the AA line of FIG. It is sectional drawing which shows a screw forming tool. It is an arrow line view of the direction which goes to the bottom part from the opening end which follows the DD line | wire of FIG. It is an arrow line view of the direction which goes to an opening end from the bottom part in alignment with the EE line of FIG. It is a front view of the core of a screw forming tool. It is the longitudinal cross-sectional view of the intermediate molded object which shows the state which has arrange | positioned the core and outer core of a screw forming tool via the cylindrical part of the intermediate molded object, and follows the can axial direction of a thread part. It is a longitudinal cross-sectional view of the intermediate molded object which shows the state which pinched | interposed the cylindrical part of the intermediate molded object between the core and the outer core. It is a perspective view of the starting position return means using a magnet mechanism. FIG. 13 is a F arrow view of the start position return means shown in FIG. 12. It is sectional drawing which shows a curl part shaping | molding tool. It is sectional drawing which shows the relationship between the bottle can and cap of one Embodiment which concerns on this invention, the state where the left half screwed the cap to the bottle can, and the right half covered the bottle can before re-screwing Each state is shown. It is sectional drawing which shows the screw forming tool of the bottle can manufacturing apparatus of 2nd Embodiment. It is an arrow line view of the direction which goes to an opening end from the bottom part in alignment with the GG line of FIG. It is a perspective view of the starting position return means using an expansion spring. It is a H arrow line view of the starting position return means shown in FIG.

Hereinafter, an embodiment of the present invention will be described.
The bottle can 1 is made of a thin metal plate of aluminum or an aluminum alloy. As shown in FIG. 1, a shoulder portion 3 that gradually decreases in diameter toward the upper side and a shoulder portion 3 of the shoulder portion 3. A cylindrical small-diameter neck portion 4 extending upward from the upper end and a base portion 5 are formed at the upper end of the neck portion 4. The base portion 5 includes a screw portion 6 formed on the outer periphery, a jaw portion 7 formed below the screw portion 6 and fixing the skirt end portion of the cap, and a curl portion 8 formed above the screw portion 6. Have.

  In order to manufacture the bottle can 1, first, the aluminum plate material is punched and drawn to form a relatively large diameter and shallow cup 10 as shown in FIG. The cylindrical body 11 having a predetermined height is formed as shown in FIG. 2B by performing the drawing process and the ironing process (DI process), and the upper ends thereof are trimmed and trimmed. By this DI processing, the bottom of the cylindrical body 11 is formed into a bottom shape as the final bottle can 1.

  Next, the bottle can 1 is manufactured by the screwed bottle can manufacturing apparatus 20 (hereinafter simply referred to as a bottle can manufacturing apparatus) shown in FIGS. 4 and 5. Next, the bottle can manufacturing apparatus 20 will be described. In addition, this bottle can manufacturing apparatus 20 is for processing the cylindrical body 11 formed as described above into a bottle can 1 having a final shape, and the shape of the can changes as the processing progresses. However, below, when the shape of a can is not specifically limited between this cylinder 11 and the bottle can 1, it demonstrates as the intermediate molded object 19. FIG.

  The bottle can manufacturing apparatus 20 includes a work holding unit 30 that holds a plurality of intermediate molded bodies 19, a tool holding section 40 that holds a plurality of molding tools 42 that perform various molding processes on the intermediate molded bodies 19, and both holdings. And a drive unit 22 for driving the units 30 and 40. The work holding side of the work holding unit 30 that holds the intermediate molded body 19 and the tool holding side of the tool holding unit 40 that holds the forming tool 42 are arranged to face each other.

  The work holding unit 30 has a configuration in which a plurality of holding devices 32 holding the intermediate molded body 19 are arranged in an annular shape along the circumferential direction on the surface of the disk 31 supported by the support shaft 21 that faces the tool holding unit 40. Has been. The disk 31 is intermittently rotated around the support shaft 21 by the drive unit 22, whereby the intermediate molded bodies 19 supplied from the supply unit 33 via the supply side star wheel 34 are one by one in the holding device 32. It is held and conveyed in the circumferential direction of the disk 31. The intermediate molded body 19 is molded by each molding tool 42 of the tool holding unit 40 during conveyance by the disk 31 and then sequentially discharged to the discharge unit 36 through the discharge-side star wheel 35 as a molded bottle can 1. .

Here, the holding device 32 includes a pad portion 37 that contacts the bottom surface of the intermediate molded body 19 and a ring portion 38 having an air chuck or the like that can hold the outer peripheral surface of the bottom portion (see FIG. 6). The intermediate molded body 19 is held by gripping a portion of the molded body 19 that extends from the bottom to the lower portion of the barrel in the can axis direction. In FIG. 4, some of the plurality of holding devices 32 provided on the entire circumference of the disk 31 are illustrated, and the remaining holding devices 32 are not shown.
In addition, the intermediate molded body 19 is supplied with the cylindrical body 11 formed by DI molding to the supply unit 33, but is sequentially deformed by processing, and the discharge unit 36 becomes the final-shaped bottle can 1.

  In the tool holding unit 40, a plurality of various forming tools 42 are arranged in an annular shape along the circumferential direction on the surface of the disk 41 supported by the support shaft 23 that faces the work holding unit 30, and the disk 41 is supported by the drive unit 22. The shaft 23 is configured to advance and retreat in the axial direction. The support shaft 23 is provided coaxially inside the support shaft 21.

  The tool holding portion 40 includes a plurality of shoulder necking molds for reducing the diameter of the opening of the intermediate molded body 19 (neck-in processing), and reducing the diameter after partially reducing the diameter of the reduced diameter opening. A mold for forming a cylindrical portion 18 to be described later, a neck necking mold for forming a tapered portion 17 and an open end 16 above the cylindrical portion 18, a screw forming tool for forming the screw portion 6, and a curl A plurality of forming tools 42 for performing processing corresponding to each processing step, such as a curl forming tool for forming the portion 8, are provided. These forming tools 42 are arranged in a ring on the disk 41 in the circumferential direction in the order of the processes.

  The intermittent rotation stop position of the work holder 30 (disk 31) with the axis of the support shaft 21 as the center of rotation is determined by the can axis of each intermediate molded body 19 with the opening facing the tool holder 40 side. It is set so as to coincide with the central axis of 42 respectively. And by the intermittent rotation of the disk 31 by the drive part 22, each intermediate molded body 19 is rotationally moved to a position facing each molding tool 42 for the next process, and the next stage processing is performed.

  That is, when the tool holding unit 40 moves forward and the workpiece holding unit 30 and the tool holding unit 40 approach each other, each molding tool 42 performs processing according to each process on the intermediate molded body 19, and both the holding units 30. , 40 are spaced apart from each other, the workpiece holding unit 30 is rotated so that the molding tool 42 in the next process faces each intermediate molded body 19. In this way, by repeating the operations in which the holding portions 30 and 40 approach each other to perform processing, and separate and rotate, the shoulder portion 3, the screw portion 6 and the like are formed in the intermediate molded body 19, and the bottle can 1 Is formed.

  Each of these forming tools 42 processes each intermediate formed body 19 held by the work holding part 30 separately when the tool holding part 40 advances to the left in FIG. 4 toward the work holding part 30. Apply. In the following, these forming tools will be described using reference numeral 42 when a specific tool is not limited.

Next, a method for manufacturing the bottle can 1 will be described in the order of steps while explaining the detailed configuration of the bottle can manufacturing apparatus 20.
The upper portion of the cylindrical body 11 formed up to the state shown in FIG. 2B by drawing and ironing (DI molding) of a thin plate such as an aluminum alloy is reduced in diameter as shown in FIG. After the formation, as shown in FIG. 3, the intermediate molded body 19 is manufactured before the small diameter portion 12 is subjected to reduction diameter and diameter expansion processing and screw processing.

  Specifically, first, the diameter of the opening of the cylindrical body 11 is gradually reduced by die necking while sequentially using a plurality of forming tools 42 arranged in the circumferential direction of the tool holding portion 40, and FIG. As shown, a shoulder portion 3 and a cylindrical small diameter portion 12 extending upward from the shoulder portion 3 are formed to form a stepped molded body 13. The forming tool 42 used to form the shoulder 3 and the small diameter portion 12 is provided with a plurality of the same basic configurations except that the diameters before and after processing are different. Are processed sequentially while transferring. A series of forming tools 42 for forming the shoulder portion 3 and the small diameter portion 12 is referred to as a shoulder necking die.

  Next, with respect to the small diameter portion 12, the diameter expansion processing and the diameter reduction processing are repeated, and as shown in FIG. 3, an opening end portion 16 whose diameter is reduced toward the upper end and a taper portion 17 connected thereto are formed. Then, an intermediate molded body 19 is formed. Then, due to the processing of the opening end portion 16 and the taper portion 17, the portion that has not been processed below becomes the cylindrical portion 18. The cylindrical portion 18 is formed to have a thickness of 0.25 to 0.4 mm.

  A forming tool for forming the tapered portion 17 and the reduced opening end portion 16 on the distal end side of the cylindrical portion 18 is referred to as a mouth necking die. Further, the can upper portion forming mechanism is constituted by the various forming tools 42 such as the above-mentioned shoulder necking type and the driving unit 22 for driving them.

  In this series of manufacturing steps, as shown in FIG. 3, the intermediate molded body 19 includes an open end portion 16 formed in a straight shape having a dimension from the upper end necessary for forming the curled portion 8, and The tapered end 17 gradually increases in diameter downward from the lower end of the open end 16, and the cylindrical portion 18 is formed at the lower end of the tapered portion 17. The cylindrical portion 18 is formed in a straight cylindrical shape, and a jaw portion 7 having an outer diameter larger than that of the cylindrical portion 18 is provided at the lower end portion of the cylindrical portion 18. A diameter-reduced neck portion 4 and a shoulder portion 3 whose diameter is increased from the lower end of the neck portion 4 are continuously formed at the lower end of the jaw portion 7.

  In the intermediate molded body 19, the outer diameter D1 of the opening end portion 16 is set smaller than the thread root diameter D2 of the screw portion 6 to be molded. Further, the outer diameter D3 of the cylindrical portion 18 is set to an intermediate diameter between the thread diameter D4 and the valley diameter D2. For example, when the thread diameter D4 is 37 mm, the thread valley diameter D2 is 36.3 mm, and the distance between the first and second stages of the screw is 2.5 mm to 4.5 mm, the outer diameter D3 of the cylindrical portion 18 Is set to 36.5 mm to 36.8 mm. The tapered portion 17 that communicates between the cylindrical portion 18 and the opening end portion 16 has an inclination angle θ of 10 ° to 30 ° with respect to the can axis direction, and a length H along the can axis direction of 2.0 to 2.0. Set to 6.0 mm.

Next, the screw part 6 is formed using the screw forming tool shown in FIGS.
A screw forming tool 42C for forming the threaded portion 6 includes a first housing 61 attached to the disk 41, and a second housing 62 attached to the first housing 61 so as to be movable forward and backward as indicated by an arrow B in FIG. And have. The entire screw forming tool 42C is rotationally driven by the drive unit 22 as indicated by an arrow C around the rotation axis 51.

  The second housing 62 is biased and held on the distal end side (downward in FIG. 6) with respect to the first housing 61 by a biasing member (not shown), and the inner periphery of the cylindrical portion 18 of the intermediate molded body 19 is inside thereof. A core 64A that is in contact with the surface and an outer core 64B that is in contact with the outer peripheral surface are provided.

  As shown in FIG. 9, the core 64 </ b> A has a right-handed uneven shape (a screw-forming convex part 91 and a screw-forming part) for forming a right-handed screw part 6 on the outer peripheral surface of the substantially cylindrical tip part. Recess 93) and is supported so as to be rotatable about a shaft 65 (axis 65a).

As shown in FIG. 10, the outer element 64 </ b> B has a left-handed uneven shape (a screw-forming convex part 92 and a screw-forming part) for forming a right-handed screw part 6 on the outer peripheral surface of the substantially cylindrical tip part. Recess 94) and is supported so as to be rotatable about a shaft 66 (axis 66a).
The screw forming convex portions 91 and 92 and the screw forming concave portions 93 and 94 formed on the outer peripheral surfaces of the core 64A and the outer core 64B are respectively formed in a spiral shape and a shape corresponding to each other. Yes.

  The shaft 65 of the core 64A is rotatably accommodated in a block body 67 that also serves as a gear box. The block body 67 is supported in the second housing 62 so as to be swingable around the support shaft 69 in a direction perpendicular to the shaft 65. The shaft 66 of the outer element 64B is rotatably accommodated in a block body 68 that also serves as a gear box. The block body 68 is supported in the second housing 62 so as to be swingable around the support shaft 70 in a direction perpendicular to the shaft 66.

  A gear 71 is provided on the support shaft 69 of the block body 67, and a gear 72 is provided on the support shaft 70 of the block body 68. The gear 71 and the gear 72 are meshed with each other. In addition, a gear 73 is provided on the shaft 65 of the core 64A, and a gear 74 is also provided on the shaft 66 of the outer core 64B, and these gears 71 to 74 are in mesh with each other.

  Specifically, the gear 73 of the core 64A, the gear 71 in the block body 67 that accommodates the core 64A, the gear 72 in the other block body 68, and the outer core 64B that is accommodated in the block body 68 are shown. The gears mesh with each other in the order of the gear 74. As a result, the core 64A and the outer core 64B rotate in synchronization. The block bodies 67 and 68 swing in the direction orthogonal to the shafts 65 and 66 around the respective support shafts 69 and 70 while maintaining the meshed state of the gears 71 and 72 of the both block bodies 67 and 68. I can move.

  The rotation of the core 64A and the outer core 64B synchronized with each other is, for example, the number of rotations of the outer core 64B such that the core 64A is rotated once, twice, or three times with respect to one rotation of the outer core 64B. In contrast, the rotational speed of the core 64A is set to an integral multiple.

Further, as shown by arrows in FIG. 8, the core 64A and the outer core 64B are counterclockwise (counterclockwise) when viewed from the lower end side of the screw forming tool 42C, and the outer core 64B is The screw forming tool 42 </ b> C having the core 64 </ b> A and the outer core 64 </ b> B is revolved clockwise (clockwise) around the rotation axis 51 by the second housing 62 while rotating clockwise (clockwise). In other words, when viewed from the opening end of the intermediate molded body 19 toward the bottom, the core 64A rotates clockwise, the outer core 64B rotates counterclockwise, and the screw forming tool 42C including the core 64A and the outer core 64B. Revolves around the rotation axis 51 counterclockwise.
These gears 71 to 74 constitute a screw tool rotating mechanism.

  An auxiliary block 81 is connected to the block 67 that supports the core 64 </ b> A by a shaft 82. The auxiliary block 81 is supported in the second housing 62 so as to be movable in a direction orthogonal to the shaft 65 of the core 64A and the shaft 66 of the outer core 64B. A cam roller 83 is rotatably supported on the outer side of the auxiliary block 81 by a shaft 85 that is orthogonal to the advancing / retreating direction of the second housing 62. The cam roller 84 is rotatably supported by a shaft 85 orthogonal to the advancing / retreating direction of the second housing 62 on the outer side of the block body 68 that supports the outer element 64B.

  These cam rollers 83 and 84 are in contact with cam surfaces 86 and 87 on the inner surface of the first housing 61, respectively. The cam rollers 83 and 84 move in the radial direction of the second housing 62 in accordance with a change in the relative position between the first housing 61 and the second housing 62 by the drive unit 22. When these cam rollers 83 and 84 are pushed inward of the second housing 62 by the cam surfaces 86 and 87 on the inner surface of the first housing 61 as indicated by arrows in FIG. 7, the core 64A and the outer core 64B approach each other. Thus, the wall of the cylindrical portion 18 of the intermediate molded body 19 can be sandwiched and deformed between the irregularities of the outer peripheral surfaces.

  The cam rollers 83 and 84, the cam surfaces 86 and 87 of the first housing 61, and the drive unit 22 constitute a screw tool clamping mechanism. And the screw part formation mechanism is comprised by the screw tool rotation mechanism mentioned above and this screw tool clamping mechanism.

  In addition, a ring member 88 having a cylindrical surface 88a along the body portion 2 of the intermediate molded body 19 is rotatably provided at the tip of the second housing 62 via a cover member 63 (supporting member in the present invention). . The elastic member 39 is attached to the ring member 88, and the ring member 88 is pressed against the intermediate formed body 19 via the elastic member 39 when the screw forming tool 42 </ b> C advances with respect to the intermediate formed body 19. It is supposed to be.

  On the other hand, a stopper member 89 is provided on the work holding unit 30 side. When the tool holding portion 40 (screw forming tool 42C) advances with respect to the intermediate molded body 19, the ring member 88 comes into contact with the stopper member 89, whereby the most advanced position of the second housing 62 is set to the intermediate molded body 19. Becomes constant. Further, when the second housing 62 rotates around the rotation axis 51, the cover member 63 rotates integrally with the second housing 62, but the ring member 88 provided rotatably on the cover member 63 is provided with a stopper member. The intermediate molded body 19 is held in a stationary state by coming into contact with 89.

Further, the screw forming tool 42C has a start position returning means for arranging the circumferential direction of the core 64A and the outer core 64B at a predetermined start position before starting the formation of the screw portion 6 on the intermediate formed body 19. 45 is provided.
As shown in FIG. 6, the start position return means 45 is attached to the inner magnet 46A attached to the outer peripheral surface of the shaft 66 of the outer core 64B and the inner peripheral surface of the insertion hole of the cover member 63 that passes through the shaft 66. And a magnet mechanism having an outer magnet 46B. The inner magnet 46A and the outer magnet 46B have a predetermined start position where the molding of the screw portion 6 is started by the core 64A and the outer core 64B (the first portion where the cylindrical portion 18 is sandwiched between the core 64A and the outer core 64B). 8 and 12, the magnetic poles attracting each other are arranged in a facing direction. Specifically, as shown in FIG. 13B, in the state where the core 64A and the outer core 64B are arranged at the start position, the orientation of the core 64A and the outer core 64B is the N pole of the inner magnet 46A. The (positive electrode) and the south pole (negative electrode) of the outer magnet 46B are arranged to face each other.

  The magnetic force attracted and repelled between the inner magnet 46A and the outer magnet 46B is sufficiently higher than the frictional force when the cylindrical portion 18 is sandwiched between the core 64A and the outer core 64B and the screw portion 6 is formed. Small. For this reason, the core 64A and the outer core 64B can be smoothly rotated without being affected by the magnetic force between the inner magnet 46A and the outer magnet 46B when the threaded portion 6 is formed.

  On the other hand, after the threaded portion 6 is formed, the core 64A and the outer core 64B are swung in a direction that increases the distance between them, and the contact between the core 64A and the outer core 64B and the cylindrical portion 18 is released. Since the resistance due to the frictional force between the core 64A and the outer core 64B and the cylindrical portion 18 is eliminated, the inner magnet 46A and the outer magnet 46B repel or attract each other, so that the N pole of the inner magnet 46A and the outer magnet 36B The outer element 64B rotates around the axis 66 (axis 66a) until the arrangement (start position) opposite to the S pole. At this time, since the rotation of the outer core 64B and the core 64A is synchronized by the gears 71 to 74, the core 64A also rotates around the shaft 65 along with the rotation of the outer core 64B. The direction of the child 64B returns to a predetermined start position. As a result, when the core 64A and the outer core 64B are stopped in a direction deviated from the direction of the start position, that is, as shown in FIG. 13A, the inner magnet 46A and the outer magnet 46B are deviated from the attracting direction. Even if it is stopped, the circumferential direction of the core 64A and the outer core 64B starts as shown in FIG. 13B every time the threaded portion 6 is repeatedly formed by the start position return means 45. Return to position and align.

Next, the detailed configuration of the core 64A and the outer core 64B of the screw forming tool 42C, and the screw portion forming step of forming the screw portion 6 in the cylindrical portion 18 of the intermediate formed body 19 using the screw forming tool 42C. Details will be described.
On the outer peripheral surfaces of the core 64A and the outer core 64B, as shown in FIGS. 9 and 10, a cylindrical portion 18 of the intermediate molded body 19 (a portion to be formed with a screw portion in the present invention) has a right-handed shape. Screw forming convex portions 91 and 92 and screw forming concave portions 93 and 94 for forming the screw portion 6 are respectively formed in a spiral shape and a shape corresponding to each other. The core 64A and the outer core 64B approach each other as described above, sandwich the cylindrical portion 18 of the intermediate molded body 19 between the concavo-convex portions, and rotate around the axis O of the intermediate molded body 19. Thus, the screw part 6 is formed in the cylindrical part 18. The screw forming convex portion 91 of the core 64A is formed in a right-hand thread shape (hereinafter, referred to as a right screw-shaped convex portion 91), and the screw forming convex portion 92 of the outer core 64B is formed in a left-hand thread shape (hereinafter, referred to as a right-hand thread). Left-handed convex portion 92).

  FIG. 10 shows a state in which the core 64A and the outer core 64B face each other through the wall of the cylindrical portion 18, and the core 64A and the outer core 64B start as shown in FIG. 13 (b). The position return means 45 is placed in a predetermined start position. FIG. 11 shows a state where the core 64A and the outer core 64B are close to each other and sandwich the cylindrical portion 18 therebetween. For the sake of convenience, in FIG. 10, the core 64 </ b> A is shown in front view, and the outer core 64 </ b> B is shown in half in front view, and the remaining half is not shown. In FIG. 11, only the outline is shown for the core 64A and the outer core 64B. Then, the core 64A and the outer core 64B approach from the state shown in FIG. 10, and the cylindrical portion 18 is sandwiched to perform screw forming.

  First, in the thread portion forming start operation, the circumferential direction of the core 64A and the outer core 64B is arranged at a predetermined start position where the triangular marks P1 and P2 face each other as shown in FIG. 13B. State. In this state, when the screw forming tool 42C is advanced with respect to the intermediate molded body 19, the cylindrical surface 88a of the ring member 88 is first fitted into the can body 2 from the shoulder 3 of the intermediate molded body 19, and then the ring The member 88 comes into contact with the stopper member 89, and the cylindrical portion 18 of the intermediate molded body 19 is inserted between the core 64A and the outer core 64B. When the screw forming tool 42C further advances, the axial interval between the first housing 61 and the second housing 62 is narrowed. At this time, as shown by the arrows in FIG. 7 by the cam surfaces 86 and 87 of the first housing 61, the cam rollers 83 and 84 are pushed, and accordingly, the core 64A and the outer core 64B arranged at predetermined start positions are moved. Move in the direction of narrowing the distance between each other.

Then, the core 64A and the outer core 64B move further, the core 64A comes into contact with the inner peripheral surface of the cylindrical portion 18, and the outer core 64B comes into contact with the outer peripheral surface of the cylindrical portion 18. The cylindrical portion 18 is sandwiched between the core 64A and the outer core 64B. In this sandwiched state, the entire screw forming tool 42C (the first housing 61 and the second housing 62) is rotationally driven around the rotation axis 51 as indicated by the arrow C, whereby the core 64A and the outer core 64B. Rotates around the cylindrical portion 18, and the thread portion forming operation is performed as shown in FIG.
That is, the right-handed concave / convex shape of the core 64A (the screw-forming convex portion 91 and the screw-forming concave portion 93) and the left-hand screw-like concave / convex shape of the outer core 64B (the screw-forming convex portion 92 and the screw-forming concave portion 94). ), The core 64A and the outer core 64B rotate (revolve) around the rotation axis 51, and the core 64A is rotated by the inner periphery of the cylindrical portion 18 by friction. Along the axis 65a along the axis (rotation), and the outer core 64B rolls around the axis 66a along the outer peripheral surface of the cylinder 18 (rotation), so that the screw portion on the cylinder 18 6 is formed. The threaded portion 6 is partially overlapped, and the cylindrical portion 18 is processed one or more times.

And after forming the screw part 6, in the screw part shaping | molding completion | finish operation | work, the core 64A and the outer core 64B move to the direction which expands a mutual space | interval. At this time, since the outer core 64B is rotated around the cylindrical portion 18 one or more times, the orientation of the core 64A and the outer core 64B is indicated by triangular marks P1, as shown in FIG. P2 is in a position shifted from the position facing each other.
However, since the core 64 </ b> A and the outer core 64 </ b> B are in a state where the resistance due to friction caused by contact with the cylindrical portion 18 is released, an inner magnet 46 </ b> A attached to the shaft 66 is provided in the cover member 63. FIG. 13B shows a position where the outer core 64B rotates around the axis 66a and attracts the inner magnet 46A and the outer magnet 46B to each other by attracting or repelling with the outer magnet 46B. Return to the start position. At this time, since the rotation of the outer core 64B and the core 64A is synchronized by the gears 71 to 74, the core 64A also rotates together with the rotation of the outer core 64B, so that the outer core 64B and the core 64A are , The triangle marks P1 and P2 return to the facing start position.

  In this way, at the time of the thread portion forming completion operation, the orientation of the core 64A and the outer core 64B is returned to the predetermined start position by the start position return means 45 constituted by the inner magnet 46A and the outer magnet 46B. Before processing the threaded portion 6 in the next intermediate molded body 19, the orientation of the core 64A and the outer core 64B can be arranged at a predetermined start position. For this reason, each time the molding of the threaded portion 6 is repeated for different intermediate molded bodies 19, the molding of the threaded portion 6 is started with the orientation of the core 64A and the outer core 64B aligned at the predetermined start positions. Can do. Thereby, the molding start position of the screw portion 6 is not shifted for each intermediate molded body 19, and molding can be started from the same position. In the plurality of intermediate molded bodies 19, the overlap forming position of the screw portion 6 is set. They can be formed at the same position in the circumferential direction.

  Therefore, the threaded portion 6 can be formed without causing a variation in the circumferential dimension for each individual intermediate molded body 19, and the dimensional stability of the threaded portion 6 can be achieved. In addition, since the molding of the threaded portion 6 is started from a predetermined start position in the circumferential direction, the molding can be performed with a certain reproducibility. The seal operability can be improved.

  After the screw forming process in this manner, the diameter of the opening end portion 16 is further reduced, and the curled portion 8 is formed by curling the opening end portion 16 having the reduced diameter. Manufactured. As shown in FIG. 14, the molding tool 42D for forming the curled portion 8 includes a rounding die 97 that rounds the opening end 16 of the intermediate molded body 19 while turning it back, and the rounded opening end in the radial direction. There are crushing dies 98 that crush in the direction, and each is formed in a roll shape, and is molded while rotating around the intermediate molded body 19. In this case, since the curling process is performed after the thread forming process, the thread end can be formed with the rigidity of the opening end portion 16 being low.

  On the other hand, the cap 111 that covers the bottle can 1 has a circular top plate portion 112 and a cylindrical skirt portion 113. The cap 111 is put on the cap part 5 of the bottle can 1, and then the skirt part 113 is formed by a capping roll so as to follow the screw part 6 and the jaw part 7 of the cap part 5, thereby forming a screw thread on the skirt part 113. 114 is formed and is screwed to the base portion 5. Further, by winding the lower end 115 of the skirt 113 around the jaw 7, the cap 111 and the bottle can 1 are fixed to each other as shown in the left half of FIG.

  Then, when the cap 111 is rotated so as to loosen from the screwed state shown in the left half of FIG. 15, the slit 116 formed in the skirt portion 113 breaks between the lower end portion 115 and the upper portion, The lower end portion 115 is left on the jaw portion 7 in a band shape, and the upper portion of the cap 111 can be removed from the base portion 5. Further, when the removed cap 111 is put on the base part 5 for sealing again, the lowermost end of the thread 114 on the inner peripheral surface of the cap 111 is on the tapered part 17 of the base part 5 as shown in the right half of FIG. Go down while sliding.

  The threaded portion 6 of the bottle can 1 is molded with a certain reproducibility starting from a predetermined starting position in the circumferential direction, so that the dimensional stability of the threaded portion 6 is stabilized. It is intended for sex. For this reason, the variation of the screw distortion is reduced, and the sealing operation can be smoothly performed again in the plurality of bottle cans 1 without any difference.

FIGS. 16-19 has shown the screw forming tool 42C of the manufacturing apparatus of the screwed bottle can of 2nd Embodiment of this invention.
In the manufacturing apparatus 20 of the first embodiment, as shown in FIG. 6, the start position return means 45 is constituted by a magnet mechanism composed of an inner magnet 46A and an outer magnet 46B, but in the second embodiment, FIG. As shown, the start position return means 47 is constituted by an expansion spring 48 that connects the outer element 64 </ b> B and the cover member 63.
In the second embodiment, the same constituent elements as those of the manufacturing apparatus of the first embodiment are used except for the starting position return means 47. Therefore, in each drawing, common elements to the first embodiment are used. The same reference numerals are given and the description is omitted.

  Also in the second embodiment, after the cylindrical portion 18 (screw portion forming planned portion) is sandwiched between the core 64A and the outer core 64B in the screw portion forming operation and the screw portion 6 is formed, the outer portion 64B is Since the circumference of the cylindrical portion 18 is rotated one or more times, the orientation of the core 64A and the outer core 64B is indicated by triangular marks P1 and P2 as shown in FIG. Stops at a position deviated from the start position shown in FIG. In this state, the expansion / contraction spring 48 is pulled and extended more than when the orientation of the core 64A and the outer core 64B is arranged at the predetermined start position. For this reason, in the screw part forming completion operation, the core 64A and the outer core 64B are moved in a direction in which the interval between the core 64A and the outer core 64B is increased, and friction caused by contact between the cylindrical portion 18, the core 64A and the outer core 64B. When the resistance is released, the expansion spring 48 connecting the outer element 64B and the cover member 63 contracts to return to the original length (restoring force). As a result, the outer element 64B rotates around the axis 66a and returns to the position where the expansion spring 48 becomes the shortest, that is, the start position shown in FIG. At this time, since the rotation of the outer core 64B and the core 64A is synchronized by the gears 71 to 74, the core 64A also rotates together with the rotation of the outer core 64B, so that the outer core 64B and the core 64A are , The triangle marks P1 and P2 return to the facing start position.

As described above, also in the second embodiment using the start position return means 47 using the expansion spring 48, the outer element 64B arranged in a direction shifted from the start position is used by using the restoring force of the expansion spring 48. The core 64A can be returned to the start position along with the return to the predetermined start position. For this reason, whenever it repeats shaping | molding of the screw part 6, the shaping | molding start position of the screw part 6 does not shift | deviate, but shaping | molding can be started from the same position.
Therefore, the threaded portion 6 can be formed without causing a variation in the circumferential dimension for each individual intermediate molded body 19, and the dimensional stability of the threaded portion 6 can be achieved. In addition, since the molding of the threaded portion 6 is started from a predetermined start position in the circumferential direction, the molding can be performed with a certain reproducibility. The seal operability can be improved.

  In addition, this invention is not limited to the thing of the structure of the said embodiment, In a detailed structure, it is possible to add a various change in the range which does not deviate from the meaning of this invention.

DESCRIPTION OF SYMBOLS 1 Bottle can 2 Body | body part 3 Shoulder part 4 Neck part 5 Cap part 6 Screw part 7 Jaw part 8 Curl part 10 Cup 11 Cylindrical body 12 Small diameter part 13 Stepped molding 14 Large diameter part 15 Reduced diameter part 16 Open end part 17 Taper Part 18 Cylindrical part (Scheduled part formation part)
DESCRIPTION OF SYMBOLS 19 Intermediate molded object 20 Bottle can manufacturing apparatus 22 Drive part 30 Work holding part 32 Holding apparatus 39 Elastic member 40 Tool holding part 42,42A-42D Molding tool 45 Start position return means 46A Inner magnet 46B Outer magnet 47 Start position return means 48 Telescopic spring 51 Rotation axis 61 First housing 62 Second housing 63 Cover member (support member)
64A Core 64B Outer core 67, 68 Block body 69, 70 Support shaft 71-74 Gear 81 Auxiliary block body 83, 84 Cam roller 86, 87 Cam surface 91 Right thread-shaped convex part (screw forming convex part)
92 Left-hand threaded convex part (screw-forming convex part)
93, 94 Recessed portion 97 for thread formation Rounding die 98 Crushing die 111 Cap 112 Top plate portion 113 Skirt portion 114 Thread 115 Lower end portion 116 Slit

Claims (4)

A core having a right-hand thread-like convex part on the outer periphery for forming a screw part in a thread-part molding intended part of the intermediate molded body before forming the thread part, and a left-hand-like convex part corresponding to the right-hand thread convex part A thread forming step of forming the threaded portion in the threaded portion forming planned portion using a thread forming tool including an outer core having a portion on the outer periphery;
The thread part forming step includes:
In the state where the circumferential direction of the core and the outer core is arranged at a predetermined start position, and the threaded portion forming portion is inserted between the core and the outer core, A thread part forming start operation for moving the core and the outer core in a direction to narrow the interval between the outer cores;
By sandwiching the thread portion molding planned portion between the core and the outer core, while rotating the core and the outer core in the sandwiched state, by rotating around the axis of the intermediate molded body, A threaded portion forming operation for forming the threaded portion in the threaded portion forming planned portion;
After forming the threaded portion, the threaded portion moves the core and the outer core in a direction that increases the distance between them, and returns the circumferential direction of the core and the outer core to the start position. A method for producing a threaded bottle can, comprising: a molding finishing operation. A core having a right-hand thread-like convex part on the outer periphery for forming a screw part in a thread-part molding intended part of the intermediate molded body before forming the thread part, and a left-hand-like convex part corresponding to the right-hand thread convex part A screw portion forming mechanism including an outer element having a portion on the outer periphery,
The screw part forming mechanism is configured such that the core and the outer core rotate with respect to the outer periphery of the thread part forming planned part by rotating around the axis of the intermediate molded body while sandwiching the thread part forming planned part. A mechanism for forming the threaded portion,
An apparatus for producing a threaded bottle can, comprising: a start position returning means for arranging the circumferential direction of the core and the outer core at a predetermined start position before the formation of the threaded portion. A support member that rotates around the axis of the intermediate molded body simultaneously with the outer core,
The start position return means is configured by a magnet mechanism having an inner magnet attached to the outer element and an outer magnet attached to the support member and facing a magnetic pole attracting the inner magnet at the start position. The manufacturing apparatus of the bottled can with a screw according to claim 2 characterized by things. A support member that rotates around the axis of the intermediate molded body simultaneously with the outer core,
The said starting position return means is comprised by the expansion-contraction spring which connects the said outer core and the said supporting member, The manufacturing apparatus of the bottled can with a screw of Claim 2 characterized by the above-mentioned.

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