JP4667824B2 - Manufacturing method of can body - Google Patents

Description

The present invention relates to the production how the can body to form a can body embossed the body of the cans substrate and bottomed cylindrical.

As is well known, in so-called cans and bottle cans filled with soft drinks, etc., various patterns etc. are attached to the torso in order to urge consumers to purchase, etc. Product discriminating power is given. Conventionally, for example, painting or embossing is known as means for applying such a pattern or the like.
The latter embossing includes, for example, a first rotating body and a second rotating body that are rotatably supported around rotation axes parallel to each other as shown in Patent Document 1 below. The inner surface of the bottomed cylindrical can base is disposed, and after the second rotating body is disposed outside the can base, the first and second rotating bodies are brought close to each other, and the outer peripheral surface of each rotating body A method of embossing the body portion of the can base body to form a can body by rotating the first and second rotating bodies around their rotational axes while sandwiching the body portion of the can base body. Are known. As the can base, for example, there is a DI can formed by drawing and ironing a metal plate. In addition, when the first rotating body is inserted inside the can base, the outer periphery of the first rotating body is guided along the inner peripheral surface of the can base, thereby guiding the can base in the radial direction (hereinafter referred to as “guide”). Therefore, the difference between the inner diameter of the can base and the outer diameter of the first rotating body is small, and is generally about 0.8 mm.
By the way, in recent years, in order to impart further product discriminating power to cans and the like, it is required that the body portion of the can base be provided with a convex embossing projecting radially outward with respect to the outer peripheral surface thereof.
Special Table 2000-515072

  However, in the prior art, in addition to the small gap between the outer peripheral surface of the first rotating body and the inner peripheral surface of the can base, the convex embossing (hereinafter simply referred to as “convex processing portion”) is applied to the body portion. In order to apply, since it is necessary to form the 1st convex part made convex in radial direction outward on the outer peripheral surface of the said 1st rotary body, the said clearance gap becomes still smaller by the protrusion height of this convex part. Accordingly, when the first rotating body is inserted into the inside of the can base, the first convex portion of the rotating body may collide with the opening end of the can base, and the convex processing portion is formed. Later, when the first rotating body is extracted from the inside of the can base, the convex portion of the rotating body may be caught on the inner peripheral surface of the convex processing portion, and it is difficult to form such a convex processing portion. There was a problem that there was. Furthermore, since the first convex portion as the outermost diameter portion of the first rotating body functions as a guide portion that guides the inner peripheral surface of the can base, the first occupying the entire outer peripheral surface of the first rotating body. When the ratio of one convex part is small, the said guide function cannot fully be exhibited.

  Here, as a means for forming the convex processed portion while providing the first rotating body with the guide function, a first concave portion that is recessed radially inward is formed on the outer peripheral surface of the first rotary body. In addition, the first convex portion is formed on the bottom surface of the concave portion, and the second convex portion is formed on the outer peripheral surface of the second rotating body so as to protrude radially outward at a portion corresponding to the first concave portion. And forming a second recess recessed inward in the radial direction at a portion corresponding to the first protrusion of the protrusion, and sandwiching the body portion by these rotating bodies, thereby allowing the first recess and The body corresponding to the second convex portion is recessed inward in the radial direction to form a concave processed portion, and the convex processed portion is formed in a portion corresponding to the first convex portion and the second concave portion. Can be considered.

  However, in this case, since both the convex and concave portions are formed in the body portion, the proportion of the plastic deformation portion in the whole body portion increases, and the buckling strength of the resulting can body decreases. When the coating film formed on the inner and outer peripheral surfaces of the body portion is torn, or when a plurality of can bodies are collectively transported on a transport conveyor, there is a problem that so-called blocking occurs. Further, similarly to the above, there is a problem that the above-mentioned catch is likely to occur when the first rotating body is extracted from the can base.

The present invention has been made in consideration of such circumstances, and cans can be satisfactorily subjected to a convex embossing projecting radially outward with respect to the outer peripheral surface of the body of the can base. an object of the present invention is to provide a manufacturing how the body.

  In order to solve such problems and achieve the above object, a method for manufacturing a can body according to the present invention includes a first rotating body and a second rotating body that are rotatably supported around rotation axes parallel to each other. The first rotating body is disposed inside the bottomed cylindrical can base, and after the second rotating body is disposed outside the can base, the first and second rotating bodies are brought close to each other. The body of the can base is sandwiched between the outer peripheral surfaces of these rotating bodies, and in this state, the first and second rotating bodies are rotated about their rotation axes, so that the body of the can base is A method for manufacturing a can body that is embossed to form a can body, wherein an outer peripheral surface of the first rotating body is formed with a first recess that is recessed inward in the radial direction. A first convex portion that is convex outward in the radial direction is formed, and on the outer peripheral surface of the second rotating body, A second convex portion that is convex outward in the radial direction is formed in a portion corresponding to the first concave portion, and a portion corresponding to the first convex portion of the second convex portion is concave inward in the radial direction. When the body portion is sandwiched by the outer peripheral surfaces of the first and second rotating bodies, the body portion is directed radially inward from the outer peripheral surface side by the second convex portion. In this state, at least a part of the amount of deformation in this direction is pressed so as to be elastically deformed, and the inner peripheral surface side corresponding thereto is entered into the first concave portion, and the first convex portion is When the nipping by the outer peripheral surfaces of the first and second rotating bodies is released after being fitted into the second depression through the trunk, the first depression and the first are caused by the elastic restoring force of the trunk. The body part corresponding to the two convex parts is restored and moved radially outward, and is paired with the first convex part and the second concave part. A body portion outer peripheral surface of the part, from the first recess and the body portion outer peripheral surface other than the portion corresponding to the second convex portion, characterized in that is positioned radially outward.

  According to the method for manufacturing a can body according to the present invention, the sandwiching of the body portion by the first and second rotating bodies is released, and the first recess and the second protrusion are caused by an elastic restoring force of the body portion. Since the barrel corresponding to the portion is restored and moved radially outward, it is possible to easily and reliably form the convex processed portion protruding radially outward on the outer peripheral surface of the barrel of the can base by embossing. . That is, since the gap is formed between the inner peripheral surface of the convex processing portion and the first convex portion by the restoration movement, when the first rotating body is extracted from the can base, the first convex portion is It is possible to suppress the catching on the inner peripheral surface of the convex processed portion.

  Here, it is desirable that the outermost diameter surface of the first convex portion is located radially inward from the surface of the non-formed portion of the first concave portion. In this case, the outer diameter of the first rotating body does not increase due to the formation of the first convex portion for forming the convex portion on the body portion. Therefore, when the first rotating body is inserted inside the can base during the embossing, it is possible to avoid the first rotating body from colliding with the opening end of the can base. Furthermore, at the time of the insertion, not the first convex portion but the non-formed portion of the first concave portion functions as a guide portion that guides the inner peripheral surface of the can base. Therefore, even when the ratio of the first convex portion in the entire outer peripheral surface of the first rotating body is small, the guiding function of the first rotating body can be sufficiently exhibited.

  In addition, when the sandwiching of the body portion by the first and second rotating bodies is released, the elastic restoring force causes the first inner surface corresponding to the first concave portion and the second convex portion to be the first inner surface. It is desirable to restore and move a portion excluding a portion corresponding to one convex portion and the second concave portion from the outermost surface in the radial direction of the first convex portion outward in the radial direction. In this case, when the first rotating body is extracted from the can base after embossing, it is possible to reliably suppress the first convex portion from being caught on the inner peripheral surface of the convex processed portion.

According to the can body manufactured by the method for manufacturing a can body according to the present invention, the convex processed portion protrudes radially outward with respect to the outer peripheral surface of the body portion. Can be provided. In addition, since the convex processing portion is formed by the restoring movement, it becomes possible to limit the plastic deformation portion to the convex processing portion, the reduction of the buckling strength of the can body, and the inner and outer surfaces of the can main body. It is possible to prevent the coating film formed on the surface from being torn and to suppress the occurrence of so-called blocking when a plurality of can bodies are placed on a conveyor and collectively transported. can do.

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a schematic configuration of a can body manufacturing apparatus for carrying out the can body manufacturing method shown as one embodiment of the present invention.
As shown in FIG. 1, the can body manufacturing apparatus 10 presses the barrel portion of the can base 50 in the radial direction to form a convex processing portion that protrudes radially outward with respect to the outer circumferential surface of the barrel portion. A mold part 11, a support part 12 that is disposed below the mold part 11 and supports the can base 50 so as to be movable toward and away from the mold part 11 and rotatable, and the mold part 11 and the support part 12. The control part 13 which controls the drive of this is provided.

The mold part 11 includes a first rotating body 20 and a second rotating body 21 supported so as to be rotatable around rotation axes parallel to each other, and the rotating bodies 20 and 21 each having a rotation direction opposite to each other, and And a first drive unit 14 that rotates in synchronization. Both the first and second rotating bodies 20 and 21 are made of, for example, metal, preferably urethane.
The support unit 12 includes a chuck 31 configured to hold the bottom surface of the can base 50 or the can body 52, a slide unit 32 that supports the chuck 31 so as to be close to and away from the mold unit 11, and the chuck 31. And a motor unit 33 that is rotatably supported around the can axis.

Here, in the present embodiment, as shown in FIG. 2, a first recess 20a that is recessed toward the radially inner side is formed on the outer peripheral surface of the first rotating body 20, and the first recess 20a. A first convex portion 20b is formed on the bottom surface of the first convex portion 20b so as to protrude outward in the radial direction. In the illustrated example, the depth of the first recess 20a is made larger than the protrusion height of the first protrusion 20b, and the outer diameter of the non-formed portion 20c of the first recess 20a is the largest on the outer peripheral surface of the first rotating body 20. ing. Moreover, the 1st convex part 20b is formed in the axial direction center part of the 1st recessed part 20a.
On the outer peripheral surface of the second rotating body 21, as shown in FIG. 2, a second convex portion 21a that is convex radially outward is formed at a portion corresponding to the first concave portion 20a. A second concave portion 21b that is concave inward in the radial direction is formed in a portion corresponding to the first convex portion 20b in the portion 21a.

  In the above configuration, the size of the first concave portion 20a in plan view from the radially outer side of the first rotating body 20 is larger than the size of the second convex portion 21a in plan view from the radially outer side of the second rotating body 21. The size of the first convex portion 20b in plan view from the outside in the radial direction of the first rotating body 20 is made smaller than the size in plan view of the second concave portion 21b from the outside in the radial direction of the second rotating body 21. ing. That is, when the first and second rotating bodies 20 and 21 approach and separate from each other, the second convex portion 21a of the second rotating body 21 is inserted into and removed from the first concave portion 20a of the first rotating body 20, and the second rotation. The first convex portion 20b of the first rotating body 20 is inserted into and removed from the second concave portion 21b of the body 21.

  Here, on the outer peripheral surface of the first rotating body 20, the non-formed portion 20c of the first recess 20a and the first recess 20a are, as shown in FIG. 2, a first convex curved surface portion that is convex outward in the radial direction. It is smoothly connected via 20d. Moreover, the 1st recessed part 20a and the 1st convex part 20b are smoothly connected via the 1st concave curved surface part 20e dented in radial direction inward. And the 1st recessed part 20a is made into the taper shape which inclined gradually toward radial inward from the 1st convex curved surface part 20d to the 1st concave curved surface part 20e. That is, the 1st recessed part 20a is made into the shape of a mortar, and becomes the structure by which the 1st convex part 20b was formed in the deepest part of this mortar.

  The curvature radius R1 of the first convex curved surface portion 20d is 14 mm or more and 160 mm or less, and the curvature radius R2 of the first concave curved surface portion 20e is 14 mm or more and 160 mm or less. Further, the distance L in the axial direction between the first convex curved surface portion 20d and the first concave curved surface portion 20e is 7 mm or more and 25 mm or less, and the deepest position in the first concave portion 20a (the portion located on the most radially inward side). And the non-formed portion 20c in the radial direction, that is, the depth A of the first recess 20a is 0.4 mm or more and 1.4 mm or less.

Next, a method of forming a convex processed portion on the body portion of the can base 50 by using the can body manufacturing apparatus configured as described above will be described.
When the can base 50 is conveyed to the can body manufacturing apparatus 10, first, the bottom surface of the can base 50 is held by the chuck 31, and then the motor unit 33 is rotationally driven. By rotating around the can axis, the can base 50 is positioned around the can axis.

  Then, the can base 50 is moved forward in the can axis direction toward the mold portion 11 through the slide portion 32 of the support portion 12, and the first rotating body 20 is inserted inside the can base 50, so that FIG. As shown in FIG. 2, the first rotating body 20 is disposed inside the can base 50 and the second rotating body 21 is disposed outside the can base 50. Next, the first and second rotating bodies 20 and 21 are brought close to each other, the body portion of the can base 50 is sandwiched between the outer peripheral surfaces of the rotating bodies 20 and 21, and the first and second rotating bodies 20 are in this state. , 21 is rotated around these rotational axes to emboss the barrel portion of the can base 50 to form the convex portion. Then, after the first and second rotating bodies 20 and 21 are separated from each other, the support portion 12 is separated from the mold portion 11, and the first rotating body 20 is extracted from the inside of the can main body 52.

  Here, when the body portion is sandwiched between the outer peripheral surfaces of the first and second rotating bodies 20 and 21, the body portion is directed radially inward from the outer peripheral surface side by the second convex portion 21a in this direction. The first convex portion is pressed in such a manner that at least a part of all the deformation amounts is elastically deformed and the inner peripheral surface side corresponding to this is made to enter the first concave portion 20a as shown in FIG. 20b is inserted into the second recess 21b through the body portion. That is, of the body portion of the can base 50, portions corresponding to the first convex portion 20a excluding the first convex portion 20b and the second convex portion 21a excluding the second concave portion 21b (hereinafter referred to as “peripheral portions of the convex processing portion”). )), Depending on the tapered shape of the first convex curved surface portion 20d and the first concave portion 20a, the generated strain is limited to the deformation within the elastic limit, and the peripheral portion of the convex processing portion is plastically deformed. Is avoided. On the other hand, the portion corresponding to each of the first convex portion 20b and the second concave portion 21b in the trunk portion is plastically deformed because the first convex portion 20b is fitted into the second concave portion 21b via the trunk portion. It is deformed to the region and plastically deforms.

  Accordingly, when the sandwiching of the body portion by the first and second rotating bodies 20 and 21 is released, the first recess portion 20a and the second protrusion portion 21a are caused by the elastic restoring force of the body portion as shown in FIG. Corresponding to the first convex portion 20b and the second concave portion 21b, the outer peripheral surface of the portion corresponding to the first convex portion 20b and the second concave portion 21b corresponds to the first concave portion 20a and the second convex portion 21a. It will be located radially outward from the outer peripheral surface of the body part (non-forming parts 20c, 21c) other than the part to be formed, and the convex processed part is formed. Furthermore, in this embodiment, the part except the part corresponding to each of the 1st convex part 20b and the 2nd recessed part 21b among the internal peripheral surfaces of the trunk | drum corresponding to each of the 1st recessed part 20a and the 2nd convex part 21a is made into the 1st convex. The part 20b is restored and moved radially outward from the outermost surface in the radial direction.

  As described above, according to the method for manufacturing a can body according to the present embodiment, when the sandwiching of the trunk portion by the first and second rotating bodies 20 and 21 is released, the elastic restoring force of the trunk portion is used. Since the barrel corresponding to the first concave portion 20a and the second convex portion 21a is restored and moved radially outward, the convex portion protruding radially outward on the outer peripheral surface of the barrel base of the can base 50 is embossed. It can be easily and reliably formed. That is, since the gap is formed between the inner peripheral surface of the convex processing portion in the body portion and the first convex portion 20b by the restoration movement, when the first rotating body 20 is extracted from the can base body 50, It becomes possible to suppress the 1 convex part 20b from being caught on the inner peripheral surface of the convex processed part.

  Moreover, since the depth of the 1st recessed part 20a is made larger than the protrusion height of the 1st convex part 20b, the outermost diameter surface of the 1st convex part 20b is radial direction from the surface of the non-formation part 20c of the 1st recessed part 20a. The outer diameter of the first rotating body 20 is not increased by forming the first convex portion 20b for forming the convex processed portion on the body portion because it is located inside. Accordingly, when the first rotating body 20 is inserted inside the can base 50, it is possible to avoid the first rotating body 20 from colliding with the opening end of the can base 50. Further, at the time of the insertion, not the first convex portion 20b but the non-formed portion 20c of the first concave portion 20a functions as a guide portion for guiding the inner peripheral surface of the can base 50. Therefore, even when the ratio of the first convex portion 20b in the entire outer peripheral surface of the first rotating body 20 is small, the guiding function of the first rotating body 20 can be sufficiently exhibited.

  Further, when the sandwiching of the body portion by the first and second rotating bodies 20 and 21 is released, due to the elastic restoring force, among the body inner peripheral surfaces corresponding to the first recessed portion 20a and the second projecting portion 21a, respectively. Since the portion excluding the portion corresponding to the first convex portion 20b and the second concave portion 21b is restored and moved radially outward from the radially outermost surface of the first convex portion 20b, the first rotating body 20 is embossed. It is possible to reliably suppress the first convex portion 20b from being caught on the inner peripheral surface of the convex processing portion of the body portion when the base body 50 is extracted from the can base 50.

  Moreover, since the said convex process part protrudes radially outward with respect to a trunk | drum outer peripheral surface, the can main body formed in this way can be provided with merchandise discrimination power. In addition, since the convex processing portion is formed by the restoring movement, it becomes possible to limit the plastic deformation portion to the convex processing portion, the reduction of the buckling strength of the can body, and the inner and outer surfaces of the can main body. It is possible to prevent the coating film formed on the surface from being torn and to suppress the occurrence of so-called blocking when a plurality of can bodies are placed on a conveyor and collectively transported. can do.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, only when the body portion corresponding to the first concave portion 20a and the second convex portion 21a is completely restored by the restoring force when the sandwiching of the body portion by the first and second rotating bodies 20 and 21 is released. In addition, the present invention can also be applied to a case where a part of the deformation amount due to the rotating bodies 20 and 21 is plastic deformation. Moreover, the 1st convex part 20b is not restricted to the case where it forms in the deepest part of the 1st recessed part 20a made into mortar shape, You may form on the said inclined taper surface.

The barrel portion of the can body, to provide a manufacturing how the can body a convex embossing protruding radially outwardly with respect to the outer peripheral surface can be favorably performed.

It is the schematic which shows the whole structure of the manufacturing apparatus of the can main body for enforcing the manufacturing method of the can main body shown as one Embodiment of this invention. FIG. 3 is a first process diagram when the method for manufacturing a can body shown as an embodiment of the present invention is implemented, and is a partially enlarged cross-sectional view of the first and second rotating bodies shown in FIG. 1. FIG. 6 is a second process diagram when the method for manufacturing a can body shown as an embodiment of the present invention is implemented, and is a partially enlarged cross-sectional view of the first and second rotating bodies shown in FIG. 2. FIG. 4 is a third process diagram when the method for manufacturing a can body shown as an embodiment of the present invention is implemented, and is a partially enlarged cross-sectional view of the first and second rotating bodies shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 1st rotary body 20a 1st recessed part 20b 1st convex part 21 2nd rotary body 21a 2nd convex part 21b 2nd recessed part 50 Can base | substrate 52 Can main body

Claims (1)

A first rotating body and a second rotating body that are rotatably supported about rotation axes parallel to each other are provided, the first rotating body is disposed inside a bottomed cylindrical can base, and the second rotation After the body is arranged outside the can base, the first and second rotating bodies are brought close to each other, and the body of the can base is sandwiched between the outer peripheral surfaces of the rotating bodies, and in this state, the first, A method of manufacturing a can body by forming a can body by embossing the body portion of the can base by rotating the second rotating body around these rotation axes,
On the outer peripheral surface of the first rotating body, a first recess is formed that is recessed radially inward, and a first protrusion that is protruded radially outward is formed in the first recess,
On the outer peripheral surface of the second rotating body, a second convex portion that is convex radially outward is formed at a portion corresponding to the first concave portion, and the first convex portion of the second convex portion A second recess recessed inward in the radial direction is formed in the corresponding part,
When the body portion is sandwiched between the outer peripheral surfaces of the first and second rotating bodies, the body portion is directed radially inward from the outer peripheral surface side by the second convex portion, and all deformation amounts in this direction are reduced. At least a portion of the second concave portion is pressed so as to be elastically deformed, and the second convex portion is inserted into the first concave portion via the trunk portion in a state in which the inner peripheral surface side corresponding to this is pushed into the first concave portion. Inserted into
Thereafter, when the pinching by the outer peripheral surfaces of the first and second rotating bodies is released, the body corresponding to the first recess and the second protrusion is radially outwardly moved by the elastic restoring force of the body. The body outer peripheral surface of the portion corresponding to the first convex portion and the second concave portion is radially moved from the outer peripheral surface of the trunk portion other than the portion corresponding to the first concave portion and the second convex portion. A method for producing a can body, characterized in that the can body is located outward.

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