JP2006015357A - Die for manufacturing polyhedral periphery wall can, method for manufacturing the same die, and method for manufacturing polyhedral periphery wall can using the same die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die for manufacturing a polyhedral periphery wall can, which die can produce the polyhedral periphery wall can having the excellent external appearance and the pressure resistance by making the beginning and the end of the polyhedral periphery coincide with each other and by eliminating the deviation of pitches. <P>SOLUTION: The die is used to manufacture the polyhedral periphery wall can having the polyhedral periphery formed on at least a part of the can barrel 3. The die comprises an inner die 1 having a polyhedron 4 of the peripheral repetition smaller than the peripheral repetition of a unit surface 6 composing the polyhedral periphery by N (N is a natural number), and an outer die which has a similar figure to the inner die 1 and has a polyhedron 5 composed of envelope lines achieved by turning a reference die larger than the inner die 1 by the dimension t corresponding to the thickness of the can barrel 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mold used for manufacturing a circumferential polyhedral wall can, a method for manufacturing the mold, and a method for manufacturing a circumferential polyhedral wall can using the mold, and in particular, forming a circumferential polyhedron on a can body. Mold for manufacturing a circumferential polyhedral wall can, which can eliminate the positional deviation of the circumferential polyhedron formed around the can body wall and match the start point and the end point with high accuracy. And a method for producing a circumferential polyhedral wall can excellent in appearance and pressure resistance using this mold.

A so-called circumferential polyhedral wall can in which a polyhedral shape is formed on the side wall of the can body is known. And this circumferential polyhedral wall can, first of all, even when the material is thinned, it has a great resistance to the cooling process after content filling sterilization or subsequent deformation under reduced pressure, etc. Secondly, the slip when gripping the can is small, and thirdly, it has a lot of excellent points, such as having a novel design as a can, so it attracts the attention of consumers (for example, (See Patent Documents 1 and 2 by the applicant of the present application).
Japanese Patent Laid-Open No. 4-300038 Japanese Patent No. 2705684

FIG. 6 is a diagram showing an example of the above-described circumferential polyhedral wall can, FIG. 6 (a) is a side view of the circumferential polyhedral wall can, and FIG. 6 (b) is a diagram of the circumferential polyhedral wall can of FIG. It is the top view cut in the -X direction.
This circumferential polyhedral wall can is used for canning, and is formed by winding a can lid 10 around a can body 3 having one end opening of a two-piece can such as a drawn can or a squeezed can. The circumferential polyhedral wall can can also be applied to a three-piece can (see FIG. 9) formed by winding the top and bottom can lids 10 and 10 on both ends of the can body 3 which is open at both ends.
The circumferential polyhedral wall is composed of a large number of structural unit surfaces 6, and each structural unit surface 6 halves the phase of the adjacent structural unit surface 6 in the can axis direction (vertical direction in FIG. 6A). They are staggered.
Each adjacent structural unit surface 6 shares a boundary ridge line 7 and a crossing portion 8 where the boundary ridge lines 7 intersect, and the boundary ridge line 7 and the crossing portion 8 described above are relatively in comparison to the structural unit surface 6. It is convex on the outside of the can.

  Further, adjacent individual structural unit surfaces 6 have a shape bent at ridge lines connecting the four vertices a, b, c, and d located at the crossing portion 8 respectively. Therefore, when the can body 3 is cut in, for example, the XX direction along the ridge line connecting the vertices b and d, the cross-sectional shape is as shown in FIG. It becomes a regular polygon.

FIG. 7 is a schematic view for explaining a method of manufacturing the above-described circumferential polyhedral wall can. In FIG. 7, for convenience of explanation, the shapes of the inner mold and the outer mold are simplified.
The circumferential polyhedral wall can is manufactured using a mold having an inner mold 101 inserted into the inside of the can body 3 and an outer mold 102 disposed on the outside of the can body 3 so as to face the inner mold 101. be able to.

The inner mold 101 has a polyhedron 104 composed of ridges corresponding to the apexes and ridge lines of the structural unit surface 6 constituting the polyhedral wall of the can body 3. The number of polyhedrons 104 formed on the inner mold 101 is N (N is 1, 2, 3,...) Than the number of repetitions in the circumferential direction of the unit constituting surface 6 constituting the circumferential polyhedron formed on the can body 3. .. (natural number) The number of repetitions is small.
The outer mold 102 has a polyhedron 105 constituted by valleys that mesh with the protrusions constituting the polyhedron 104 of the inner mold 101. The inner mold 101 and the outer mold 102 are arranged so that the corresponding ridges and valleys mesh with each other, and the side wall of the can body 3 is sandwiched between the inner mold 101 and the outer mold 102. By rotating at the same peripheral speed in the reverse direction, a circumferential polyhedral wall can be formed.

  Thus, since the circumferential polyhedron of the can body 3 is formed by rolling each other in a state where the inner mold 101 and the outer mold 102 are engaged, the circumferential shape of the polyhedron 105 of the outer mold 102 is It is necessary to use the envelope obtained by rolling the inner mold 101 as a reference. In the techniques described in Patent Documents 1 and 2, when the outer mold 102 and the inner mold 101 are moved relative to each other, the circumferential shape of the polyhedron 105 of the outer mold 102 is moved from the center of the inner mold 101 to the outer shape. The shape is obtained by subtracting the can body thickness t from the envelope (indicated by the broken line III in the figure) at the position where the perpendicular to the mold 102 and the surface of the inner mold 101 intersect.

However, when the inner polyhedral body 101 and the outer mold 102 are actually used to form a circumferential polyhedron over the entire circumference of the side wall of the can body 3, the starting point of the apex of the circumferential polyhedron formed on the can body 3 is It does not match the end point, it becomes double, the circumferential polyhedral wall can is scratched, the ridgeline of the circumferential polyhedron can no longer appear clearly, and the appearance of the circumferential polyhedral wall can body is impaired Problems arise.
Further, the circumferential polyhedron is intended to improve the strength (pressure resistance) of the can body 3 even with a thin plate due to its geometric structure, but there is a shift in the ridge line between the constituent unit surfaces 6 constituting each of the polyhedrons. When this occurs, there arises a problem that the pressure strength is reduced.

  The present invention has been made in view of the above problems, and when the circumferential polyhedron is formed on the side wall of the can body, the start point and the end point of the circumferential polyhedron can be made to coincide with each other with high accuracy, Providing a mold for manufacturing a circumferential polyhedral wall can that can obtain a circumferential polyhedral wall can having excellent appearance and pressure resistance by clearly raising the ridge line without attaching a ridgeline, and further It aims at providing the manufacturing method of a type | mold, and the manufacturing method of the circumferential polyhedral wall can using this metal mold | die.

In solving the above-mentioned problems, the inventors of the present invention have found that the problems in the prior art are that the shape of the polyhedron 105 of the outer mold 102 and the circumferential polyhedron (configuration) are formed when the circumferential polyhedron is formed on the can body. It was noted that there was a difference between the actual envelope shape drawn by unit surface 6).
That is, in FIG. 7, the envelope III obtained by rolling the inner mold 101 is indicated by a dotted line, but when the envelope III and the inner mold 101 are engaged with each other without sandwiching the can body 3, It becomes an ideal meshing state in which both hardly slip.
The outer mold 102 described in Patent Documents 1 and 2 has a shape obtained by subtracting the dimension t corresponding to the thickness of the can body from the envelope III in FIG. In FIG. 7, the shape of the outer mold 102 is indicated by a solid line, and this shape is hereinafter referred to as “pseudo envelope I”.

Since the shape (pseudo-envelope I) of the outer mold 102 is smaller than the envelope III, an ideal meshing state with the inner mold 101 is not achieved when the can body 3 is not sandwiched.
Next, the state when the can body 3 is sandwiched between the outer mold 102 and the inner mold 101 will be examined with reference to FIG.
As shown in FIG. 8A, when the can body 3 is sandwiched between the inner mold 101 and the outer mold 102 and a circumferential polyhedron is formed on the side surface, the circumference of the structural unit surface 6 on the outer surface side of the can body 3 The length L1 is larger than the circumferential length L0 of the polyhedron 104 of the inner mold 101 (Ll> L0).
Here, when an envelope II (shown by a two-dot chain line in FIG. 8) based on the structural unit surface 6 of the can body 3 is drawn, the envelope II ideally meshes with the structural unit surface 6 of the can body 3. It is an envelope. However, when this envelope II is compared with the pseudo-envelope I of the outer mold 102, there is a shape shift between the two. That is, if the circumference of the arc portion of the envelope II is L2 and the circumference of the arc portion of the pseudo envelope I is L3, the circumference L3 of the outer mold 102 is smaller than the circumference L2 of the envelope II. (L3 <L2).

  Since the inner mold 101 and the outer mold 102 rotate with each other while meshing like a gear, on the axis line connecting the rotation centers of the inner mold 101 and the outer mold 102, the protrusions of the inner mold 101 and the valleys of the outer mold 102 Match. However, since the pseudo envelope I of the outer mold 102 does not coincide with either the envelope III of the inner mold 101 or the envelope II of the structural unit surface 6 of the can body 3, the can body 3 is composed of the polyhedron 105 of the outer mold 102. It will be processed while sliding against. As a result, the starting point and the end point of the apex of the structural unit surface 6 of the can body 3 do not coincide with each other, the surface of the can body 3 is wrinkled, or the ridgeline does not appear clearly. It is expected that

  Based on this examination result, the inventor of the present invention makes the shape of the outer mold 102 the same as the envelope II, that is, ideally with the inner mold 101 as shown in FIG. An outer envelope having a shape larger than the meshing envelope III and the pseudo-envelope I of the outer mold 102 described in Patent Documents 1 and 2, and substantially matching the envelope II based on the structural unit surface 6 of the can body 3 It has been found that the above problems can be solved at once by using a mold.

Specifically, as described in claim 1, the mold is used for manufacturing a circumferential polyhedral wall can in which a circumferential polyhedron is formed on at least a part of a can body, and the circumferential polyhedron is configured. An inner mold having a polyhedron having a number of repetitions N (N is a natural number) smaller than the number of repetitions in the circumferential direction of the polyhedron, and a shape similar to the inner mold and corresponding to the thickness of the can body The mold has a configuration including an outer mold having a polyhedron made of an envelope obtained by rotating a reference mold larger than the mold.
According to this configuration, since the circumference of the envelope of the outer mold matches the circumference of the structural unit surface of the circumferential polyhedral wall, when forming the circumferential polyhedron on the side wall of the can body, the polyhedron and the outer mold Are ideally meshed, the start point and the end point are made to coincide with each other with high accuracy, and the pitch does not shift.
The outer mold may be a so-called rack as long as the circumferential polyhedron can be formed on the can body wall by meshing with the inner mold and relatively moving. Moreover, as described in claim 2, a polyhedron may be repeatedly formed in a circumferential direction of a circumferential surface or a circular arc surface.

Said metal mold | die can be manufactured using the electric discharge machining method which forms the said to-be-processed object in a predetermined shape by producing an electric discharge between an electrode and a to-be-processed object.
Specifically, as described in claim 3, an electrode larger than the inner mold is prepared by an amount similar to the inner mold inserted into the can body and corresponding to the thickness of the can body. Then, while moving the outer mold base material close to the electrode at a synchronized speed, electric discharge is generated between the electrode and the outer mold base material, and the outer mold base material is subjected to the electric discharge machining. The outer mold may be formed by forming a polyhedron having an envelope based on the electrode surface of the electrode.

Further, as described in claim 4, when the outer mold base material has an arc-shaped peripheral surface, the electrode and the outer mold base material are rotated at the same peripheral speed in opposite directions. It can be manufactured by repeatedly forming a polyhedron in the circumferential direction of the peripheral surface of the outer mold base material.
The manufacturing method of the circumferential polyhedral wall can of the present invention is the manufacturing method of the circumferential polyhedral wall can in which the circumferential polyhedron is formed on at least a part of the can body as described in claim 5. An inner mold having a polyhedron having a number of repetitions N (N is a natural number) smaller than the number of repetitions in the circumferential direction of the polyhedron that constitutes the inner surface, and a shape similar to the inner mold and corresponding to the thickness of the can body A mold comprising an outer mold having a polyhedron composed of an envelope obtained by rotating a reference mold larger than the inner mold is prepared, the inner mold is inserted into the can body, and the outer mold is The inner mold and the outer mold are synchronized with each other by placing the inner mold and the outer mold so as to sandwich the side wall of the can barrel between the inner mold and the outer mold. A method of forming a circumferential polyhedron on the can body while relatively moving at a speed. A.

According to a sixth aspect of the present invention, in the case where the outer polyhedron is repeatedly formed in the circumferential direction, the inner mold and the outer mold are rotated in the opposite directions at the same peripheral speed while the can is This is a method for forming a circumferential polyhedron on the body.
According to these methods, the outer mold is formed so as to have an envelope polyhedron obtained by rotating the reference shape larger than the inner mold by an amount corresponding to the thickness of the can body, so that the outer mold The circumference of the arc of the envelope of the envelope and the circumference of the arc of the envelope drawn by the structural unit plane can be made to coincide with each other, eliminating the pitch deviation of the circumferential polyhedron and the deviation of the start and end points. it can.

According to the present invention, even when the circumferential polyhedron is formed over the entire circumference of the can body, no slip occurs between the can body and the outer mold, and the start point and the end point of the apex of the circumferential polyhedron can be matched. Therefore, a three-dimensional pattern with excellent appearance can be formed on the can body, and scratches and cracks are not generated on the outer surface of the can body.
Further, since the ridge line between the structural unit surfaces does not shift, the pressure-resistant strength of the circumferential polyhedral wall can is not reduced.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.
1 and 2 relate to an embodiment of the present invention. FIG. 1 is a schematic view showing a state where a circumferential polyhedron is formed on a side wall of a can body by an inner mold and an outer mold, and FIG. It is an enlarged view of the processing part of the can body by an outer type | mold.
In FIGS. 1 and 2, the shapes of the inner mold and the outer mold are simplified for convenience of illustration and explanation. In the following description, the same parts and members as those in the conventional example are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIGS. 1 and 2, the basic shapes of the inner mold 1 and the outer mold 2 inserted into the can body 3 in this embodiment are the conventional inner mold 101 and outer mold shown in FIGS. 102.
In this embodiment, the peripheral length L2 of the envelope-shaped polyhedron 5 formed on the peripheral surface of the outer mold 2 is the peripheral length of the structural unit surface 6 formed on the side wall of the can body 3 as shown in FIG. The length is almost the same as L1. That is, the outer mold 2 has substantially the same shape as the envelope II examined with reference to FIG.

Such an outer mold 2 can be formed by a method as shown in FIG.
That is, a reference electrode 11 is prepared which is similar to the inner mold 1 and is larger than the inner mold 1 by a dimension t corresponding to the thickness of the can body 3. Then, the electrode 11 is used to perform electric discharge machining on the outer peripheral surface of the outer mold base 12 having a circular cross section.
Specifically, the electrode 11 is brought close to the outer mold base material 12, and the outer mold electrode 11 and the outer mold base material 12 are connected to each other while intermittent discharge is generated between the electrode 11 and the outer mold base material 12. Electric discharge machining is performed by rotating in the opposite directions at the same peripheral speed.
Thereby, a polyhedron 5 having an envelope corresponding to the electrode surface 11 a of the electrode 11 is formed on the peripheral surface of the outer mold base material 12. Since the circumferential length of the electrode surface 11a of the electrode 11 substantially coincides with the circumferential length (L1) of the circumferential polyhedron formed on the side wall of the can body 3, the circumferential length of the arc portion of the envelope is the circumferential shape. It almost coincides with the perimeter of the polyhedron.

FIG. 4 is a diagram for explaining a method for determining the peripheral length L0 of the polyhedron 4 of the inner mold 1 and the peripheral length of the electrode surface 11a of the electrode 11 (corresponding to the peripheral length L1). FIG. FIG. 4B is a partial cross-sectional view of the can body 3 when the structural unit surface 6 is formed.
As shown in FIG. 4A, the material forming the can body 3 has a neutral line J that does not expand or contract even if it is bent or a circumferential polyhedron is formed.
The total length Lj of the neutral line J in the circumferential direction of the can body 3 is Dp as the inner diameter of the can body 3 and t as the wall thickness of the can body 3.
Lj = (Dp + t) π (1)
It can be expressed as

On the other hand, when a circumferential polyhedron having N repetitions in the circumferential direction (N is a natural number) is formed on the side wall of the can body 3, the length Lk of the neutral line J in the arbitrary k-th structural unit surface 6 is as shown in FIG. As shown in (b)
Lk = Lj / N (2)
It can be expressed as
Further, when the circumferential polyhedron having N repetitions is formed on the side wall of the can body 3, the material forming the can body 3 is formed as shown in FIG. The inner side is in close contact with the polyhedron 4 of the inner mold 1, and the outer side of the can body 3 is stretched in the circumferential direction.

Also at this time, since the total length Lj in the circumferential direction of the neutral line J does not change, the apex angle of an isosceles triangle having one constituent unit surface 6 as a base and an apex at the center of the can body 3 is α (α = 2π / N), the circumferential length L0 inside the can body and the circumferential length L1 outside the can body of the unit constituting surface 6 are respectively
L0 = Lk−t · tan (α / 2) (3)
L1 = Lk + t · tan (α / 2) (4)
It can be expressed as
Therefore, the circumference of the polyhedron 4 of the inner mold 1 can be obtained as L0, and the circumference of the electrode surface 11a in the electrode 11 for forming the outer mold 2 can be obtained as L1.

  The inner mold 1 and the outer mold 2 formed as described above are separated from each other by a distance t corresponding to the thickness of the can body 3 so that the corresponding protrusions and valleys mesh with each other. Arrange. Then, the inner mold 1 is inserted into the can body 3, the side wall of the can body 3 is sandwiched between the inner mold 1 and the outer mold 2, and the inner mold 1 and the outer mold 2 are synchronized with each other at the peripheral speeds in opposite directions. A circumferential polyhedron is formed on the side wall of the can body 3 while rotating.

  FIG. 5 illustrates a procedure for performing circumferential polyhedron processing on the can body 3 with a rotary molding apparatus using the inner mold 1 and the outer mold 2 having the above-described configuration. In addition, since this shaping | molding apparatus is well-known, description is abbreviate | omitted about the detail of each part.

The can body 3 is inserted into the inner mold from the position indicated by (1) in FIG.
The cam member 140 is disposed outside the inner mold 1 over a range slightly wider than the range of the turret positions (3) to (9). The cam member 140 pushes the outer periphery of the can body 3 by shifting the outer mold 2 toward the inner mold 1 with a cam roller (not shown). As a result, the inner wall of the can body 3 on the side in contact with the outer mold 2 is pressed against the inner mold 1 in the range of the turret positions (4) to (8).

In the range of turret positions (4) to (8), the peripheral surface polyhedron processing is performed on the can body 3 while the inner mold 1 and the outer mold 2 are rotated synchronously. When the can body 3 is sent to the turret position (9), the cam roller 140 (not shown) is released from the cam member 140 and the can body 3 comes out of the inner mold 1.
In this way, circumferential polyhedron processing is performed on the side wall of the can body 3. The can body 3 that has been processed is unloaded from the molding apparatus at the discharge position A.

Although preferred embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments.
For example, the outer mold 2 is formed by processing a circular outer mold base material 12 and has a configuration in which a polyhedron 5 is repeatedly formed on the circumference, but is linearly formed on the outer mold base material on the rack. It is good also as a structure which formed the polyhedron repeatedly.
1 to 3, for convenience of illustration and explanation, the number of corners of the outer mold 2 is the same as the number of corners of the inner mold 1 (octagons), but the circumference of the envelope of the outer mold 2 is a circumferential polyhedron. The number of corners of the outer mold 2 may be N (N is a natural number of 1, 2, 3...) Or less than the number of corners of the inner mold 1. .

  The method of the present invention is suitable for the case where the circumferential polyhedron is formed over the entire circumference of the side wall of the can body, but can also be applied to the case where the circumferential polyhedron is formed on a part of the side wall of the can body. Moreover, the can in which the circumferential polyhedron is formed according to the present invention can be applied not only to foods and beverages but also to industrial products such as pharmaceuticals and oils.

It is the schematic which shows a mode that a circumferential polyhedron is shape | molded by the inner mold | type and an outer mold | type on the can body wall concerning one Embodiment of this invention. It is an enlarged view of the processing part of the can body by an inner type | mold and an outer type | mold. It is the schematic explaining the shaping | molding method of an outer mold | type. FIG. 4A is a diagram for explaining a method of determining the perimeter of the inner polyhedron and the perimeter of the electrode surface of the electrode. FIG. 4A is a partial cross-sectional view of the can body before forming the perimeter polyhedron, FIG. ) Shows a partial cross-sectional view of the can body when a circumferential polyhedron is formed. It is a figure explaining the procedure which performs a circumferential polyhedron process to a can body with a rotary-type shaping | molding apparatus using an inner type | mold and an outer type | mold. FIG. 6A is a side view of a circumferential polyhedral wall can, and FIG. 6B is a side view of the circumferential polyhedral wall can of FIG. It is the figure cut in the X direction. It is the schematic explaining the manufacturing method of the circumferential polyhedral wall can described in patent document 1,2. FIG. 8A is a diagram for explaining a problem in the prior art, and FIG. 8B is a diagram for explaining the principle of the present invention. It is a figure which shows another example of a circumferential polyhedral wall can (3-piece can).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner type | mold 2 Outer type | mold 3 Can body 4, 5 Polyhedron 6 Structural unit surface 7 Ridge line 8 Crossing part 10 Can lid 11 Electrode 11a Electrode surface 12 Outer mold base material

Claims (6)

A mold used for manufacturing a circumferential polyhedral wall can in which a circumferential polyhedron is formed on at least a part of the can body,
An inner mold having a polyhedron having a number of repetitions N (N is a natural number) less than the number of repetitions in the circumferential direction of the polyhedron constituting the circumferential polyhedron;
An outer mold having a polyhedron consisting of an envelope obtained by rotating a reference mold larger than the inner mold by a dimension similar to the inner mold and corresponding to the thickness of the can body,
A mold for manufacturing a circumferential polyhedral wall can. 2. The mold for manufacturing a circumferential polyhedral wall can according to claim 1, wherein the outer polyhedron is repeatedly formed in a circumferential direction. A method for producing a mold for producing a circumferential polyhedral wall can according to claim 1 or 2,
Prepare an electrode larger than the inner mold by a dimension similar to the inner mold inserted into the can body and corresponding to the thickness of the can body,
While moving the outer mold base material close to this electrode at a synchronized speed, an electric discharge is generated between the electrode and the outer mold base material, and the outer mold base material is subjected to the electric discharge machining. Forming a polyhedron consisting of an envelope based on the electrode surface of the electrode to be the outer mold,
The manufacturing method of the metal mold | die for circumferential polyhedral wall can characterized by these. When the workpiece has an arcuate circumferential surface, the polyhedron is formed in the circumferential direction of the circumferential surface of the workpiece while rotating the electrode and the workpiece at the same circumferential speed in opposite directions. It forms repeatedly, The manufacturing method of the metal mold | die for circumferential polyhedral wall cans of Claim 3 characterized by the above-mentioned. In the method for producing a circumferential polyhedral wall can in which a circumferential polyhedron is formed on at least a part of the can body,
An inner mold having a polyhedron having a number of repetitions N (N is a natural number) less than the number of repetitions in the circumferential direction of the polyhedron constituting the circumferential polyhedron, and a similar shape to the inner mold, and the thickness of the can body Preparing a mold composed of an outer mold having a polyhedron composed of an envelope obtained by rotating a reference mold larger than the inner mold by a corresponding dimension;
The inner mold is inserted into the can body, the outer mold is disposed outside the can body, and the inner mold and the outer mold are sandwiched between the inner mold and the outer mold. Meshing the mold and forming a circumferential polyhedron on the can body while relatively moving the inner mold and the outer mold at a synchronized speed;
A method for producing a circumferential polyhedral wall can characterized by the above. When the outer polyhedron is repeatedly formed in the circumferential direction, the outer polyhedron is formed in the can body while rotating the inner die and the outer die in opposite directions at the same peripheral speed. A method for producing a circumferential polyhedral wall can according to claim 5.

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