JPH0796139B2 - Circular polyhedral wall can manufacturing method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a circumferential polyhedron wall can, and more particularly, to a cooling process after filling and sterilizing contents or preservation even after the material is thinned. TECHNICAL FIELD The present invention relates to a method and an apparatus for producing a peripheral polyhedral wall can having excellent resistance to vacuum deformation and the like with excellent productivity.

[0002]

2. Description of the Related Art Conventionally, as a material for a can for canning, a metal plate has been mainly used in view of gas barrier property, heat resistance, pressure resistance, etc. A so-called three-piece can or metal plate formed by joining opposite end edges by means such as welding, bonding or soldering to form a side canned can body and winding both ends of the can body with the top and bottom lids. A so-called two-piece can in which a bottomed can body is subjected to drawing / deep drawing or further ironing and a lid is wound around the upper end of the bottomed can body is widely used.

In these canned cans, many efforts have been made to make the material thickness as thin as possible for the purpose of reducing the material cost of the can and reducing the weight of the can itself. However, if the material thickness is reduced,
The mechanical strength of the can body naturally lowers, and in particular, during the cooling process after the content filling and sterilization, or during the subsequent storage or transportation, the can body is significantly deformed (deformed) due to the reduced pressure inside. Further, in the case of a canned product, collision between cans may be unavoidable during handling or transportation, but the collision may cause deformation of the can body.

When such a deformation occurs in the can body of a can for canning, not only the appearance of the product is deteriorated and the commercial value is impaired, but also pinholes, cracks, peeling, etc. are formed in the inner and outer protective coating layers of the metal plate. There is a possibility that coating defects may occur, causing problems such as corrosion, metal elution, or leakage due to pitting corrosion. Conventionally, as a means for reinforcing the can body member, it is known to form a bead in the circumferential direction and a bead in the can height direction (can axis direction) on the can body member.

The Applicant has previously found that a circumferential polyhedral wall is formed on at least a part of the can body, and the polyhedral wall is a constituent unit surface,
Boundary ridges where the constituent unit surfaces are in contact with each other and intersections where the boundary ridges intersect with each other, and the boundary ridges and the intersecting portions are convex to the outside of the can relative to the constituent unit surfaces, and are adjacent to the constituent unit surface. We proposed a can for cans in which the aligned can axial directions are arranged with a phase difference.

Further, this circumferential polyhedron wall can uses an inner die having projections corresponding to the vertices and ridges of the polyhedron on the surface and an outer die having projections corresponding to the valleys of the polyhedron on the surface. It has also been proposed that the outer mold is engaged with the can body before lid-wrapping to form a polyhedron.

[0007]

The circumferential polyhedron wall has a unique reinforcing structure, so that the deformation strength by external pressure (or internal decompression) is remarkably improved, and a unique three-dimensional effect based on the polyhedron is obtained. It has the feature that it can be easily grasped by the can body when drinking the contents of the can, etc., but it is difficult to process at the boundary ridge line where the constituent unit areas contact each other and the intersection where the boundary ridge lines intersect. The coating is vulnerable to damage during processing due to its harshness, and it is never easy to form polyhedral walls with high production rates and high yields.

Accordingly, it is an object of the present invention to provide a method and an apparatus capable of producing a peripheral polyhedral wall can without damaging the coating film on the can body and at a high production speed and productivity. is there.

Another object of the present invention is to allow the inner and outer molds for forming a polyhedron to be smoothly meshed in a constantly synchronized state, and moreover, supplying a can barrel to a molding zone, polyhedron wall molding and molding. It is an object of the present invention to provide a device in which all operations such as discharging the can body from the area are continuously and automatically performed.

[0010]

According to the present invention, in a method of manufacturing a can in which a circumferential polyhedron wall is formed on at least a part of the can body, an inner mold having a can body side wall inserted into the can body is used. The outer mold is sandwiched between the outer mold and the outer mold arranged outside the can body, and has a polyhedral shape having a number of repetitions that is at least one less than the number of repetitions of the circumferential surface of the polyhedral wall on which the inner mold is to be molded. Is the same as the number of repetitions of the surface in the circumferential direction of the polyhedron wall to be formed and the shape obtained by subtracting almost the thickness of the can body from the envelope at the position where the vertical line from the center of the inner mold to the outer mold intersects the surface of the inner mold. The method for manufacturing a circumferential polyhedral wall can is characterized in that the inner mold and the outer mold are synchronously moved relative to each other to perform molding.

In the present invention, it is desirable to rotate the can body to be molded at a speed synchronized with the inner mold prior to sandwiching the can body to be molded.
It is desirable to engage with the inner mold via an elastic member such as rubber so that they cannot rotate relative to each other.

According to the present invention, further, in a can manufacturing apparatus in which a circumferential polyhedral wall is formed on at least a part of a can body, the number of repetitions is at least one less than the number of repetitions of the polyhedral wall to be molded in the cylinder direction. An inner mold having a number of polyhedron shapes; a rotating member in which a plurality of the inner molds are arranged circumferentially so as to be able to rotate and revolve; and an inside of a can body that is sequentially provided along a moving path of the inner mold of the rotating member. It consists of an insertion mechanism into the mold, an outer mold for molding the polyhedron wall, and a discharge mechanism from the inner mold of the can body. The outer mold for molding the polyhedron wall is the normal from the center of the inner mold to the outer mold and the inner mold surface. And a mold surface having at least the same number of repetitions as the number of repetitions of the circumferential surface of the polyhedron wall to be molded. A manufacturing apparatus is provided.

A preferred apparatus of the present invention comprises a second rotating member which is coaxial with the rotating member and is axially spaced apart, and which rotates in synchronization with the rotating member; A can body holding mechanism arranged coaxially and slidably in the axial direction,
And a can body position control mechanism for moving the can body holding mechanism from the can body supply position to the molding position of the outer mold, fixing the can body at this molding position, and moving from the molding position to the can body discharging position. .

[0014]

According to the present invention, the side wall of the can body is sandwiched between the inner mold inserted in the can body and the outer mold arranged outside the can body to form the peripheral polyhedron wall. A polyhedral shape having a surface repetition number that is at least one less than the surface repetition number in the circumferential direction of the polyhedral wall to be molded, and at least the same surface repetition number as the circumferential surface repetition number of the polyhedral wall to be molded. Having a number is the first feature.

In the polyhedral wall can to which the present invention is applied, a polyhedral wall is formed circumferentially on the can body, and the polyhedral wall is generally a structural unit surface and a boundary ridge line between the structural unit surfaces. And a crossing portion where the boundary ridge lines intersect with each other,
The boundary ridgeline and the intersecting portion are relatively convex to the outside of the can as compared with the constituent unit surface, and in this polyhedron wall, adjacent can axial direction arrangements of the constituent unit surfaces are arranged with a phase difference. ing.

In the present invention, the inner die is provided with a polyhedral shape corresponding to the inner surface of the polyhedral wall structure. When the polyhedral shape is n, the number of surface repetitions in the circumferential direction of the polyhedral wall,

[Mathematical formula-see original document] m = n- [alpha], where [alpha] is an integer such as 1 or 2, and m is the number of face repetitions of the inner polyhedron shape. That is, the polyhedron has a surface repetition number satisfying

By doing so, when the inner mold rotates one rotation and α / n rotation relative to the outer mold, a predetermined circumferential polyhedron wall, that is, a polyhedron wall having a surface repetition number of n is formed on the can body. Since it is possible to form and the diameter of the inner mold can be made smaller than the minimum inner diameter of the can body before and after molding, it is easy to insert the inner mold into the can body and remove it from the can body after molding. Can be done.

In the present invention, the above-mentioned inner mold and outer mold are synchronously moved relative to each other to form the polyhedral wall on the can body. However, the polyhedron shape of the outer mold is divided into the outer mold and the inner mold. The second feature is that the shape is obtained by subtracting almost the thickness of the can body from the envelope at the position where the perpendicular line from the center of the inner mold to the outer mold and the surface of the inner mold intersect when moved relatively.

In FIG. 1 for explaining the envelope, the inner mold is shown in a triangular cross section and the outer mold 2 is shown in a straight line for simplification. The center P of the inner die 1 is at a constant distance from the straight line 1 of the outer die, and this distance is the radius r of the circumscribed circle of the inner die 1.
be equivalent to. The inner mold 1 moves leftward in FIG. 1 while rotating in the arrow direction (counterclockwise direction) with the circumscribing circle in contact with the straight line l. In the position (a) of "Fig. 1", the position Qa where the perpendicular from the center P of the inner mold 1 intersects the surface of the inner mold is on the straight line l, and in the position (b) where the inner mold 1 is rotated 1/6. The position Qb where the perpendicular from the center P of the inner mold 1 intersects the inner mold surface is the highest position, and in the middle of the positions (a) and (b), the position Q where the perpendicular intersects the inner mold surface is Located on the envelope K.

In FIG. 1, the cross section of the inner mold is shown as an equilateral triangle, but for the inner mold having a shape in which the number of repetitions n is an arbitrary number, the envelope k is calculated in the same manner as in FIG. You can ask.

According to the present invention, the polyhedron shape of the outer die is set to the shape and size obtained by subtracting the thickness of the can barrel from the envelope k so that the inner die and the outer die are always synchronized with the can barrel sandwiched therebetween. It is possible to give a predetermined polyhedron structure to the can body without causing damage to the protective coating on the can body surface.

In FIG. 2 showing the principle of the present invention, A
Indicates that the inner mold 1 and the outer mold 2 are provided in a so-called pinion-rack relationship, and B indicates that the inner mold 1 and the outer mold 2 are provided in a so-called pinion-pinion relationship. , C indicate that the inner die 1 and the outer die 2 are provided in a pinion-internal gear relationship. In any of these cases,
The inner mold 1 is inserted inside the can body 3, and the outer mold 2 is arranged outside the can body 3. Further, although it is shown that the polyhedron wall is already formed on the can body 3, in these examples, the polyhedron 4 of the inner mold 1 has the number of circumferential surface repetitions of the polyhedral wall applied to the can body 3 ( One less than the surface repetition number (n)
It will be understood that -1). Furthermore, the outer mold 2
The polyhedral surface 5 of is the envelope cross-sectional shape described in FIG.
Strictly speaking, it is composed of a cross-sectional shape obtained by subtracting the thickness of the can from the envelope.

In a preferred apparatus of the present invention, a plurality of inner molds are provided with a rotating member arranged so as to be able to rotate and revolve around the circumference,
In addition, a mechanism for inserting the rotary member into the inner mold of the can body, an outer mold for molding the polyhedron wall, and a mechanism for discharging from the inner mold of the can body are sequentially provided along the moving path of the inner mold. Preferably, a second rotating member that is coaxial with the rotating member and is spaced apart in the axial direction and that rotates in synchronization with the rotating member, and a second rotating member that slides coaxially with the inner mold in the axial direction. Move the can barrel holding mechanism and the can barrel holding mechanism from the can barrel feeding position to the outer mold forming position, fix the can barrel at this molding position, and move from the molding position to the can barrel discharging position. The can body position control mechanism is arranged so that all operations of insertion, molding and ejection are performed by the rotation of the first and second rotating members and the movement of the can body position control mechanism in a direction perpendicular to this. To do.

By adopting the structure of this apparatus, a plurality of inner molds are engaged with the outer molds while being inserted in the can body, and not only the molding of the polyhedral wall is continuously performed at high speed. The operations such as supplying the can body to the inner mold before molding and removing (discharging) the can body after molding from the inner mold can all be continuously and automatically performed.

In addition, by rotating and running the can body to be molded at a speed synchronized with the inner mold before sandwiching the can body with the inner mold and the outer mold, without giving a shock to the can body,
The molding can be smoothly started. Further, the can body to be molded is engaged with the inner mold via an elastic member so that they cannot rotate relative to each other, so that the above-mentioned rotation advance of the can body can be carried out smoothly and a predetermined polyhedron can be formed. It is possible to ensure that the wall structure fits in the can body.

According to the present invention, as described above, the advantage that the circumferential polyhedron wall can can be manufactured without damaging the can body protective coating film and the like with high production speed and productivity is achieved. It

[0027]

EXAMPLE (Polyhedral wall structure) "FIG. 3" (a is a side surface, b is a partial cross-sectional view) showing an example of a can for canning to which the present invention is applied.
4 and FIG. 4 (top view), the canned can has a can body 3 having openings at both ends and a top and bottom can lids 10 and 10 wound at both ends.
And consists of. The polyhedron wall is formed in a circumferential shape on the can body 3, and the polyhedron wall has a structural unit surface 6, a boundary ridge line 7 where the structural unit surfaces are in contact with each other, and a crossing portion 8 where the boundary ridge lines intersect with each other. The boundary ridge line 7 and the intersecting portion 8 are relatively convex to the outside of the can as compared with the structural unit surface. In this polyhedron wall, adjacent can axis direction arrays of the constituent unit surfaces 6 are arrayed with a phase difference.

In this specific example, the structural unit surface 6 is formed of a quadrilateral (diamond) abcd, and adjacent can axial direction arrays of the structural unit surface 6 are arranged with a phase difference of exactly 1/2. ing. The quadrilateral unit surface 11 shown in FIG.
Fig. 3 is a diagram showing an example of a quadrilateral unit surface 6 of a polyhedral wall used for the can body of "Fig.
Is the structural unit surface 6. Each side ab in the diamond,
bc, cd, and da are sides corresponding to the boundary ridge line 7 formed on the side surface of the can, and have vertices a, b, c, and d that are convex outward.
Corresponds to the intersection 8.

The upper apex a and the lower apex c are located on the circumferential surface having the same diameter, and the left apex b and the right apex d are located on the circumferential surface having the same diameter. When the array has a phase difference of ½, all the vertices are located on the circumferential surface of the same diameter, and as shown in “FIG. 4”, the radii inside the can body corresponding to these vertices are The maximum radius is r. On the other hand, each ridge line ab,
Although bc, cd, and da are projected most radially outward at the ends,
The distance from the center axis of the can, that is, the diameter, decreases as it goes to the middle. If the diameter s of the midpoint of the diagonal line bd in the circumferential direction is taken, this diameter s is smaller than r, and in the case of FIG. 4, it gives the minimum inner radius. When the unit surface on the can body is projected in the axial direction, the apex ac overlaps, but the diagonal line ac in the axial direction ac
Is located radially outward of the diagonal line bd without overlapping with the diagonal line bd in the circumferential direction, it will be understood that the quadrangle abcd is a curved or bent surface.

In FIG. 5, the diamond-shaped dimension as the constituent unit surface is such that, assuming that the length of the circumferential diagonal line bd is W and the height of the axial diagonal line ac is L, W and L are respectively the constituent unit surface. Maximum width in the circumferential direction and maximum length in the axial direction. It is already clear from the above description that the length ac (height L) of the axial diagonal line is different from the actual length in the ac cross section on the structural unit surface, but the length of the circumferential diagonal line bd (W ) And the actual length of the bd cross section on the structural unit surface may differ from each other. For example, in "FIG. 4", the diagonal line bd in the circumferential direction coincides with the bd cross section on the actual constituent unit surface, and their lengths are equal, but "FIG. 5"
In the case of (b) of FIG. 5 showing the ac cross section of (a), the midpoint e of the side ac in this cross section is the diagonal line b in the circumferential direction.
It is located radially outward from the position of d, and therefore the side be
d is larger than the length (W) of the diagonal line bd in the circumferential direction. The distance between the diagonal line between the crossing points that gives the maximum width in the circumferential direction of the structural unit surface and the diagonal line between the crossing points that gives the maximum axial length of the structural unit surface (the length of the line connecting the diagonal lines at right angles) is d0 and the above. If the distance between the position where the measurement line of distance d0 intersects the structural unit surface and the diagonal line between the crossing points that gives the maximum axial length of the structural unit surface is d1, then d1 is smaller than d0 in the case of "Fig. 5" (b). However, conversely, d1 may be greater than or equal to d0.

In a can body in which a polyhedral wall formed by combining such unit constituent surfaces is formed, the constituent unit surfaces are curved or have U-V shaped depressions, as shown in FIG. appear. Such a unit surface configuration and a phase arrangement of approximately ½ provide deformation resistance to the can body, and in addition, the can body surface area before the polyhedral wall is formed and the can body surface area after the polyhedral wall is formed are substantially Molding is possible while keeping them almost equal. Therefore, there is little tendency for damage to the coating film, excellent corrosion resistance is maintained, there is little residual stress after processing, and the coating film adhesion and seam adhesive strength over time during retort sterilization and subsequent aging Dynamic decline is effectively resolved.

The constitutional unit surface of the polyhedral wall is constituted by a quadrangle,
It is the best to prevent the deformation of the can due to the external pressure by introducing the structural unit surface into the side wall of the can alternately and firmly. Further, in the case where the diamond-shaped unit surface is smoothly curved around the line bd and the curved portion is arranged so as to be convex inward, the strength of the can is large and the corrosion resistance is particularly excellent.

(Molding Device) In FIG. 6 showing a schematic arrangement of an example of the molding device of the present invention, this device is roughly at least one less than the number of repeating faces in the same direction of the polyhedron to be molded. An inner mold 1 having a polyhedral shape having a number of repetitions, a rotary member 12 in which a plurality of the inner molds 1 are circumferentially arranged so as to be able to rotate and revolve, and a rotary member 12 are sequentially provided along a moving path of the inner mold. It comprises an insertion mechanism 13 for inserting the can body 3 into the inner mold, a molding die 2 for forming a polyhedron wall, and a discharging mechanism 14 from the inner mold of the can body 3. The outer mold 2 has a mold surface 5 having an envelope-shaped cross section, as shown in FIGS. 1 and 2.

The inner die 1 is provided by a rotating member so as to revolve in the counterclockwise direction while rotating in the clockwise direction in the figure, and is inserted into the inner die 1 in the circumferential movement path of the inner die 1. A region I, a can body forming region II, and a region III for discharging the can body 3 from the inner mold 1 are arranged in this order.

At the entrance of the can barrel insertion area I, the rotary feeder 1 for feeding the can barrel so as to come into contact with the moving path t of the inner mold 1.
5, the outer peripheral guide 1 for guiding the can body 3 from the rotary feeder 15 to the can body insertion area I.
6 and an inner circumference guide 17 are provided. Further, a molded can body discharge chute 18 is arranged at the exit of the can body discharge region III so as to be in contact with the can body discharge region III, and an outer peripheral guide 1 for guiding the can body 3 from the can body discharge region III to the discharge chute 18 is also provided.
9 and an inner circumference guide 20 are provided.

In FIG. 7 showing the detailed structure of the apparatus in FIG. 6 and in FIG. 8 showing the drive relationship of the rotary member 12, the machine frames 21a and 21b are driven and rotated by a drive unit (not shown). A drive shaft 22 for rotating is provided rotatably, and the wheel-shaped rotating member 12 is fixed to the drive shaft 22.

A large number of shaft holding brackets 23 are provided on the outer periphery of the rotary member 12, and the shaft holding brackets 23 are provided.
A rotation shaft 24 is rotatably supported in the inside through a bearing 25. The pinion 26 is individually attached to one end of the rotation shaft 24, and the inner mold 1 is fixed to the other end of the rotation shaft 24. A circumferential fixed internal gear 27 is fixed to one machine frame 21a, and the pinion 26 of the rotation shaft 24 is
It meshes with the fixed gear 27.

A flange 28 for supporting one end of the can body 3 is provided on the root side of the inner mold 1 on the axis of rotation. At both ends of the inner mold 1, the can body 3 to be molded is attached to the inner mold 1. On the other hand, elastic member rings 29a and 29b that are engaged and fixed so as to be mutually non-rotatable are provided.

The outer mold 2 is fixed to the machine frame 21c provided along the moving path of the inner mold 1 by fastening means such as bolts 30. The inner mold is also attached to both ends of the outer mold 2. Corresponding to the elastic member rings 29a and 29b, the elastic member restrainers 31a and 31b can be provided.

In order to insert the can body 3 into the inner mold, discharge it from the inner mold, and hold the can body during molding, the rotating member 1 is used.
Provided coaxially with 2 is a position control device, generally designated at 32, for can barrel insertion, fixing during molding and ejection. The can body position control device 32 includes a second rotating member 33 fixed to the drive shaft 22 and a second rotating member 33 via a slide mechanism 34 so as to be coaxial with the rotation shaft 24.
A can body holding mechanism 35 arranged around the and the cam mechanism (position control mechanism) for controlling the drive of the slide mechanism 34.
It consists of 36 and 37.

That is, the second rotating member 33 is provided with a slide rail 38, and a slider 39 which slides on the slide rail. For this slider 39,
A rotation shaft holding bracket 40 is provided so as to be slightly slidable, and a second rotation shaft 41 is rotatably held by the bracket 40 via a bearing 42.

At the end of the second rotary shaft 41 facing the inner mold, a can barrel end holding portion 44 having a magnet 43 for attracting a can barrel inside is fixed. Further, the rotation shaft holding bracket 40 is provided with an extension portion 45 so as to extend more than the can body end portion holding portion 44, and this extension portion 45 also has a can body side wall suction portion 46 provided with a magnet 43. And a support roller 47 that rotatably supports the side wall of the can body.

On the other hand, a cam mechanism 36 for loading and unloading the can body is fixed to the machine frame 21b. The cam mechanism 36 includes a cam groove 48 and a cam follower 49 inserted in the cam groove, and is connected to the cam slider 39 by a connecting frame 50. In FIG. 7, the cam follower 49 on the left side of the drive shaft 22, and thus the can body holding mechanism 35, is in the lowermost advanced position, and thus the can body 3 is inserted in the inner mold 1. . Further, the cam follower 49 on the right side of the drive shaft 22, and hence the can body holding mechanism 35, is in the lowermost retracted position, so that the can body 3 is pulled out from the inner mold 1.

A second position regulating cam 37 is provided to firmly hold the can body between the inner flange 28 and the can body end holding portion 43. That is, while the cam follower 51 is rotatably provided on the outer peripheral end of the rotation shaft holding bracket 40,
The cam groove 52 is provided in the machine frame 21C provided along the outer mold 2,
By controlling the position of the second rotation shaft holding bracket 40 by engaging them, the holding of the can body 3 during molding is made firm.

In FIG. 9 for explaining the run-up of the can body 3 prior to the start of molding, the inner mold 1 and the can body 3 before entering the molding zone II are loosely engaged via the rubber rings 29a and 29b. The rotations of the two do not necessarily match. In this state, the center axis of the inner mold 1 and the center axis of the can body 3 are substantially coincident with each other. On the other hand, in the molding area II, the center locus P1 of the inner mold and the center locus P3 of the can body do not coincide with each other, and P1 is P
Outside of 3. In the preferred embodiment of the present invention, the introduction side end portion 53 of the outer die 2 is provided with an inclined portion 54 having a gradually decreasing diameter, and the portion provided with the inclined portion 54 is defined as the approach section IV.

As a result, the inner surface of the can body 3 and the inner mold 1 gradually come into close contact with each other via the rubber rings 29a and 29b, and the can body 3 moves from the center locus P1 of the inner mold 1 to the can body center locus P at the time of molding.
It is possible to smoothly shift to No. 3 and rotate the can body at a speed synchronized with the inner mold prior to molding.

The device of the present invention is not limited to the structure shown in the drawings as long as the spirit of the present invention is satisfied. For example, as the cam mechanisms 36 and 37, a combination of a fluid pressure sliding mechanism and a limit switch can be used instead of the cam mechanism. For holding the can body by the can body holding mechanism 35, suction by suction instead of a magnet or holding by a known grip mechanism can be used.

(Operation) In the specific example shown in the figure, the can body is molded in the following order. (A) The can body holding mechanism 35 is at the uppermost retracted position by the cam mechanism 36, and in this state, the can body 3 is supplied from the rotary feeder 15 to the can body holding mechanism 35, and the can body end holding portion is provided. 44, can body side wall suction portion 46, support roller 47
Held by.

(B) The first and second rotating members rotate,
When the inner mold 1 passes through the can body insertion area I, the can body holding mechanism 35
The can body 3 is inserted into the inner mold 1 by advancing to the lowermost insertion position by the cam mechanism 36. One end of the can body 3 is held by a flange 28 attached to the inner mold, and the other end is held by a can body end holding portion 44.

(C) The can body 3 inserted into the inner mold 1 engages with the inclined portion 54 of the inlet 53 of the outer mold 2, so that the can body 3 is inserted through the elastic member rings 29a and 29b. It is tightly engaged with the mold and rotated at a speed synchronized with the inner mold 1.

(D) The can body 3 is sandwiched between an inner mold 1 having a polyhedral shape and an outer mold 2 having an envelope surface shape, and moves while rotating and revolving in a molding zone II to form a polyhedral wall structure. To be done.

(E) The first and second rotating members rotate,
When the inner mold 1 passes through the can body discharge area III, the can body holding mechanism 35
Is retracted to the rightmost discharge position by the cam mechanism 36,
The can body 3 is pulled out from the inner mold 1.

(F) When the can barrel holding mechanism 35 reaches the can barrel discharge chute 18, the can barrel end holding portion 44, the can barrel side wall suction portion 46, and the support roller 47 are deenergized and held. The rear can body 3 is discharged to the discharge chute 18. The above operation is continuously performed for each of the plurality of inner molds.

(Can body) The present invention can be applied to a can body made of any metal plate. As the metal plate, various surface-treated steel plates and light metal plates such as aluminum are used. As the surface-treated steel sheet, a cold-rolled steel sheet or a secondary cold-rolled sheet after being annealed, was subjected to one or more surface treatments such as zinc plating, tin plating, nickel plating, electrolytic chromic acid treatment, and chromic acid treatment. Any thing can be used. An example of a suitable surface treated steel sheet is an electrolytic chromic acid treated steel sheet,
0 to 200 mg / m ^ 2 metallic chromium layer and 1 to 50 m
It has a chromium oxide layer of g / m ^ 2 (calculated as metallic chromium), which is excellent in the combination of coating film adhesion and corrosion resistance. Another example of the surface-treated steel sheet is 0.
A hard tin plate having a tin plating amount of 5 to 11.2 mg / m ^ 2. This tin plate is 0.5 in terms of metallic chromium
It is desirable that chromic acid or chromic acid / phosphoric acid treatment of 100 to 100 mg / m ^ 2 is performed.

As the light metal plate, an aluminum alloy plate is used in addition to the so-called pure aluminum plate. An aluminum alloy plate excellent in corrosion resistance and workability has a Mn: 0.
2 to 1.5% by weight, Mg: 0.8 to 5% by weight, Z
n: 0.25 to 0.3% by weight, Cu: 0.15 to 0.25% by weight, the balance being Al. These light metal plates are also preferably subjected to chromic acid treatment or chromic acid / phosphoric acid treatment so that the amount of chromium becomes 3 to 300 mg / m ^ 2 in terms of metal chromium.

The thickness t of the metal in the body of the can can be variously changed, but even if the thickness is set small, it is possible to obtain an excellent pair by selecting the number n and α of the constituent unit faces in a predetermined range. Achieving retortability is one of the advantages of the present invention. The specific thickness varies depending on the maximum radius of the can body and the type of metal, but in the case of surface-treated steel plate, it is 0.08
To 0.24 mm, especially 0.12 to 0.17 mm thin steel plates and aluminum plates, 0.1 to 0.4 mm,
In particular, by selecting a thin aluminum plate having a predetermined thickness from 0.14 to 0.3 mm, a can having high external pressure strength can be obtained.

In the present invention, it is remarkable that even if the metal plate is subjected to the resin protective coating at any stage prior to the polyhedral engraving and the polyhedral engraving operation is performed, the protective coating layer is not damaged. It is an advantage. The protective coating is formed by providing a protective coating or laminating a thermoplastic resin film.

As the protective coating, any protective coating composed of thermosetting and thermoplastic resins: modified epoxy coating such as phenol-epoxy coating, amino-epoxy coating, etc .: vinyl chloride-vinyl acetate copolymer, vinyl chloride. -Partially saponified vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, epoxy modified-,
Epoxyamino-modified or epoxyphenol-modified vinyl such as vinyl paint or modified vinyl paint: Acrylic resin-based paint: Styrene-butadiene-based copolymer or other synthetic rubber-based paint, etc., alone or in combination of two or more. It

These paints are used in the form of an organic solvent solution such as enamel or lacquer, or in the form of an aqueous dispersion or aqueous solution, such as roller coating, spray coating, dip coating, electrostatic coating, and electrophoretic coating. Shaped on metal material. Of course, when the resin paint is thermosetting, the paint is baked if necessary. From the viewpoint of corrosion resistance and workability, the protective coating film preferably has a thickness (dry state) of generally 2 to 30 μm, particularly 3 to 20 μm. Further, in order to improve the processability, various lubricants can be contained in the coating film.

As the thermoplastic resin film used for lamination, polyethylene, polypropylene, ethylene-
Propylene copolymer, ethylene-vinyl acetate copolymer,
Olefin-based resin films such as ethylene-acrylic ester copolymers and ionomers: Polyester films such as polyethylene terephthalate, polybutylene terephthalate, ethylene terephthalate / isophthalate copolymers: nylon 6, nylon 6,6, nylon 11, nylon 12, etc. Polyamide film: polyvinyl chloride film: polyvinylidene chloride film. These films may be unstretched or biaxially stretched. Its thickness is generally 3 to 50 μ
m, particularly preferably in the range of 5 to 40 μm.
Lamination of the film on the metal plate is carried out by a heat fusion method, dry lamination, extrusion coating method or the like. When the adhesiveness (heat fusion property) between the film and the metal plate is poor, for example, a urethane type is used. An adhesive, an epoxy adhesive, an acid-modified olefin resin adhesive, a copolyamide adhesive, or a copolyester adhesive can be interposed.

In the case of a three-piece can, the above resin-coated plate is used, and this is molded into a tubular shape, and the end line portion not coated with the resin is welded by an electric resistance welding method known per se. Coat to make a can body. Further, the end line portion can be heat-bonded with a nylon adhesive to form a can body, and when a metal tin layer is present on the end line portion, they can be joined by soldering.

Further, in the case of a two-piece can, the coated metal plate is subjected to drawing or deep drawing so that the total drawing ratio is 1.1.
To 4.0, especially 1.5 to 3.0, a bottomed can barrel is manufactured, and polyhedrons are engraved on the bottomed can barrel. Of course, during deep drawing or subsequent thereto, thinning processing by bending and stretching or ironing processing can be performed. When performing ironing, a resin coating may be provided in advance, or a resin coating may be provided on the can body after the ironing.

Further, in the present invention, the constituent unit surface of the polyhedron wall is not limited to a quadrangle, but can be of course another polygon, for example, a hexagon. That is, the polygonal structural unit surface has a boundary ridge line where the structural unit surfaces are in contact with each other and an intersecting portion where the boundary ridge lines intersect with each other, and the boundary ridge line and the intersecting portion are radially outward relative to the structural unit surface. As long as the convex points and the axial arrangement of the constituent unit surfaces adjacent to each other in the circumferential direction are arranged with a constant phase difference,
It may be any polygon.

Furthermore, the shape of each structural unit surface is a polygon with rounded corners, or a circle or an ellipse, and a constant radius of curvature R is achieved without making the boundary ridges and the vertices at which the boundary ridges intersect with each other into sharp corners. Can be formed to have. Furthermore, the present invention can be applied to so-called bead cans. For example, a circumferential bead may be provided at a small distance from the winding portion, and a polyhedral wall composed of constituent unit surfaces may be engraved between the upper and lower circumferential beads.

[0065]

According to the present invention, in forming a circumferential polyhedron wall on at least a part of a can body, an inner mold having a can body side wall inserted into the can body and an outer mold disposed outside the can body. And a polyhedral shape having a number of repetitions that is at least one less than the number of repetitions of the circumferential surface of the polyhedron wall on which the inner mold is to be formed, and the outer mold is moved from the center of the inner mold to the outer mold. The inner mold has a shape obtained by subtracting approximately the thickness of the can body from the envelope at the position where the perpendicular line of the inner mold surface intersects the vertical line and the number of repetitions of the circumferential surface of the polyhedron wall to be molded and at least the same number of repetitions. By moving the outer mold and the outer mold in synchronization with each other to perform molding, the circumferential polyhedral wall can can be manufactured at high production speed and productivity without damaging the coating film on the can body. It can be manufactured.

Further, with the above-mentioned device configuration,
The inner and outer molds for forming polyhedrons can be smoothly meshed in a state that they are always synchronized, and moreover, all of the can barrel supply to the molding zone, polyhedron wall molding, and can barrel discharge from the molding zone The operation can be continuously and automatically performed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing how to form an envelope in an outer mold.

FIG. 2 is a layout diagram of an inner mold and an outer mold for explaining the principle of the present invention.

3 (a) and 3 (b) are a side view and a vertical sectional view, respectively, of an example in which a quadrilateral of a can for can of the present invention is used as a structural unit surface.

FIG. 4 is a horizontal sectional view of the can of FIG.

5 (a) and 5 (b) are a plan view and a cross-sectional view of an example of a structural unit surface formed on the side surface of the can for can of FIG.

FIG. 6 is a top view showing a schematic arrangement of an example of the molding apparatus of the present invention.

FIG. 7 is a side view showing the detailed structure of the apparatus shown in FIG. 6;

FIG. 8 is an arrangement view showing a drive relationship of a rotating member 12.

FIG. 9 is an explanatory diagram of an approaching rotation device of the device shown in FIG. 6;

[Explanation of symbols]

 1 Inner type 2 Outer type 3 Can barrel 4 Polyhedron 5 Polyhedron type surface 6 Constitutional unit surface 7 Boundary ridge line 8 Apex 10 Top and bottom can lid 11 Quadrilateral unit surface 12 Rotating member 13 Insertion mechanism 14 Discharging mechanism 15 Rotary feeder 16 Outer peripheral guide 17 Inside Circumferential guide 18 Forming can barrel discharge shout 19 Outer peripheral guide 20 Inner peripheral guide 21a Machine frame 21b Machine frame 21c Machine frame 22 Drive shaft 23 Shaft holding bracket 24 Rotation shaft 25 Bearing 26 Pinion 27 Fixed gear 28 Flange 29a Elastic member ring 29b Elastic member Ring 30 Bolt 31a Elastic member restraint 31b Elastic member restraint 32 Can body position control mechanism 33 Rotating member 34 Slide mechanism 35 Can body holding mechanism 36 Cam mechanism 37 Cam mechanism 38 Slide rail 39 Slider 40 Bracket 40 41 Auto rotation Axis 43 Magnet 44 Can end holding part 45 Extension part 46 Canister side wall suction part 47 Support roller 48 Cam groove 49 Cam follower 50 Coupling frame 51 Cam follower 52 Cam groove 53 Inlet end

Claims (5)

[Claims] 1. A method of manufacturing a can in which a circumferential polyhedron wall is formed on at least a part of a can body, wherein an inner mold having a can body side wall inserted into the can body and an outer mold disposed outside the can body. Sandwiched between
It is assumed that the inner mold has a polyhedron shape with a number of repetitions that is at least one less than the number of repetitions of the circumferential surface of the polyhedron wall to be molded, and the outer mold is relatively moved between the outer mold and the inner mold. At this time, at least the same number as the number of repetitions of the surface in the circumferential direction of the polyhedron wall to be molded and the shape obtained by subtracting almost the can barrel thickness from the envelope at the position where the perpendicular from the center of the inner mold to the outer mold and the surface of the inner mold intersect. The method for manufacturing a circumferential polyhedral wall can is characterized in that the inner mold and the outer mold are synchronously moved relative to each other to perform molding. 2. The manufacturing method according to claim 1, wherein the can body to be molded is rotated at a speed synchronized with the inner mold prior to being sandwiched between the inner mold and the outer mold. 3. The manufacturing method according to claim 1, wherein the can body to be molded is engaged with the inner mold via an elastic member such that they cannot rotate relative to each other. 4. A can manufacturing apparatus in which a circumferential polyhedral wall is formed on at least a part of a can body, and a polyhedral shape having a number of repetitions which is at least one less than the number of repetitions of the circumferential surface of the polyhedral wall to be molded. An inner mold having; a rotating member in which a plurality of the inner molds are arranged circumferentially so as to be able to rotate and revolve; and a mechanism for inserting a can body into the inner mold, which is sequentially provided along a moving path of the inner member. , A discharging mechanism from the outer mold for molding the polyhedron wall and the inner mold of the can body, and when the outer mold and the inner mold are relatively moved, the outer mold for molding the polyhedron wall is from the center of the inner mold. A mold surface having a shape obtained by subtracting only the thickness of the can barrel from the envelope at the position where the perpendicular to the outer mold and the surface of the inner mold intersect, and the number of repetitions at least equal to the number of repetitions of the circumferential surface of the polyhedral wall to be molded. A manufacturing apparatus comprising: 5. A second rotating member that is coaxial with the rotating member and is axially spaced apart, and that rotates in synchronization with the rotating member; and a second rotating member that is coaxial with the inner mold and axially. The slidably arranged can barrel holding mechanism and the can barrel holding mechanism are moved from the can barrel feeding position to the molding position of the outer mold, the can barrel is fixed at this molding position, and from the molding position to the can barrel discharging position. The manufacturing apparatus according to claim 4, further comprising a can body position control mechanism for moving the can body position.