JPH0679376A - Device for forming shell for can edge - Google Patents

Abstract

PURPOSE: To provide a device for forming by a reciprocating tool only the shell having a preformed curl part, where breakages or wrinkles are not generated, when the shell is attached to a can body. CONSTITUTION: This device is provided with a blank punch, a die and a drawing ring for punching a non-circular blank from a thin plate, and a first set of tools having a forming ring and a punch center and executing a part of curl bending in the outside part of the blank. Furthermore, the device is composed of a panel forming die 86 and a pressing pad 72, a panel forming punch 66 which cooperates with the panel forming die so as to wind a central panel and the blank part between clamped chuck walls around the projection of the panel forming die, for demarcating the shape of the panel wall connecting the chuck wall to the central panel, and a second set of tools having a curl- forming punch 84 and a curl-forming die 64, which finish the curling by extending the end edge of the shell towards the inward lower side of the curl part at equal interval from the chuck wall.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a metal shell used for forming an end portion of a can type container.

[0002]

BACKGROUND OF THE INVENTION Most can-type containers, such as beer cans and soft drink cans, can withstand internal pressure, rough handling and considerable temperature changes, while maintaining a perfect hermetic seal to protect the contents of the can. Need to get. The above types of cans are used in large quantities, in the billions of years a year, and most of the metal currently used to make cans is lightweight and relatively inexpensive.
Aluminum is used because it is easy to process.

[0003] Today's common cans are self-contained with a deep-drawing single body, usually with a narrow middle throat, and an opening can tab and associated score line at the upper end leading to the outwardly extending body curl. It consists of an end for a can with a shell of open construction (the invention relates to this shell). The shell cuts a suitable blank from a thin sheet of metal, shaped the blank to form a central panel shape surrounded by stiffening recesses and thick walls, and interacted with the body curl in the seaming device. By forming the shell curl part that can attach the end part to the can in the required hermetically sealed state,
Manufactured. In most cases, the underside or curl end of the shell is coated with a hermetic admixture to aid in molding the shell.

The shell is the basic component of the can,
Manufactured from blanks. The shell is then processed in the secondary processing equipment to form the desired score line, open can tab and integral joint between shell and open can tab. These are all performed by known methods. The hermetic admixture can be applied to the bottom or bottom of the shell either before or after secondary processing (generally before processing).

[0005]

One of the main efforts by the can end technician is to save material, and thus cost, considerably, so that the can is made using the thinnest possible material. That is. However, there are limits to forming shells using ultra-thin metal because of the integrity of the shell that must be maintained and especially the ability to withstand internal pressure. In order for the thin metal plate to withstand the drawing and processing operations performed on the blank during the forming process of the shell, it is generally necessary to use a metal plate of a slightly thicker thickness and to reduce the thickness of the shell part forming the reinforcing structure. Needs to be dealt with.

In a typical prior art shell forming operation, a blank is cut from a thin sheet of metal, typically steel or aluminum, and then formed into a generally flat center panel and, in this primary stage, from the center panel. A shape with a thick wall extending outward and upward to a curved flange portion. In one prior art method, the blank is formed with a groove around the central panel inside the thick wall. The blank is then curl-bent to form a curl edge on the flange and the curl-bend edge is bent up somewhat at the flange portion.

The partially molded shell is, after curling, sent to another tool where the flange portion is gripped while the curl bending edge is protected in the tool from deformation. If the blank is already grooved,
Next, the groove is corrected. In the absence of the groove, the blank, fixed as described above, is moved against the fixed bearing forces acting on the main part of the central panel.

The shell comprises an unsupported portion that includes an edge of the central panel that overlies the fixed support and extends beyond the support to a portion where a portion of the thick wall is secured. This crushing action compresses the blank to reshape the unsupported metal zone between the thick wall and the central panel and to form a reinforcing groove or recess that extends into the bottom of the thick wall and the periphery of the central panel. can get. For this reason, the shell forming work according to the prior art requires three steps, and forming the reinforcing groove-shaped body on the shell by the above-described method is between the thick wall and the central panel, which is a substantially untreated portion. Of the metal blank zone, resulting in splitting, deformation, or shell thinning of the most important parts of the structure.

Further, prior art shells have been industry "earrings" on the peripheral flange and curled edges.
There is a risk of protrusions known as. Normal,
When cutting a metal blank from a feed material which is a sheet drawn from a roll, conventional methods cut the rounded blank and pay little attention to the direction of the crystals passing through the length of the sheet. When a metal (particularly a thin aluminum plate) is formed during the production of a circular shell, the metal tends to be slightly stretched in the crystal direction rather than in the direction perpendicular to the crystal. However, it has not been solved, although it has been known for some time that the primary processing circular blank is somewhat deformed because it is more easily stretched. As mentioned above, the metal “stretches” unevenly
As a result, a slight deformation is observed at the blank edge to be curled. Therefore, only a part of the curl-curved lower end edge is slightly closer to the thick wall in the shell peripheral portion. That is, the curl end is against the thick wall,
It becomes irregular.

As a result of the above situation, two problems arise. If the enlarged "earrings" on the perimeter were manufactured to form the primary sealing means for joining the ends to the can, the curl ends of the blank between the "earrings" would be shorter, at which point the curl ends Since the metal of (2) does not fit perfectly under the curled portion of the can body, it is necessary to use a hermetic admixture to maintain a hermetic seal. When referred to as a perfect seam, it means a state in which there is no extension behind the end or the cover hook.

Alternatively, in order to achieve a hermetic seal between the ends and the body, the edges of the earrings may be completely spliced together during splicing to accommodate the expansion of the "earrings". It is designed to fit well under the curl. However, in this case, the existing portion of the earrings will have residual metal in the cover or end hook that extends into the seam, resulting in a thin can body breaking or curling in the narrow portion. Excessive metal wrinkles in the bent seam, impairing the uniformity of the seam. Whatever the result, after filling and sealing, the incidence of leak-causing cans is unacceptably high. In consideration of the loss of the packaged product and the damage due to the leakage of the contents, such a situation is of course unacceptable.

Accordingly, it is an object of the present invention to substantially solve the problems associated with earrings described above, and further to include the requisite thick wall and the reinforcing panel wall connecting the thick wall and the central panel. It is an object of the present invention to provide a method and a device for producing shells having a uniform thickness throughout.

Further, it is an object of the present invention to provide a shell having an improved peripheral curl portion.

[0014]

In this case, the inner end edge of the curl portion is pre-curl-bent, and when the end portion formed by the shell is attached to the can during the jointing work, the curl portion is curl-bent. It stretches smoothly into the sections to minimize wrinkling of the seams and / or the risk of tearing or cutting the can narrows of the seams.

By molding the shell from a blank that is polygonal rather than circular, the earrings are minimized and the curl inner diameter spaced from the thick wall of the shell is more uniform and concentric. it can. The shape of the blank is such that the blank diameter parallel to the crystal of the thin material from which the blank is formed is smaller than the blank diameter perpendicular to the crystal direction. The diameters in the parallel, right-angle and 45 ° angular directions with respect to the crystallographic direction are different and the transitions of the blank sides are rounded.

As a result of the primary processing of the blank by forming and drawing the blank in a controlled manner and forming the shell, the blank has the desired concentricity, and the intervals of the curl diameter with respect to the thick wall are uniform. A finished shell product with a uniform wall thickness is obtained. As a result, the finished can has a better and more uniform seam, thus minimizing the risk of various accidents.

The present invention also provides a finishing shell with two or more steps of forming the shell in only one reciprocating tool in one or more presses, such as a standard single acting press, and the shell. A method for manufacturing the same is provided.
In order to finish the desired pre-formed curl on the periphery of the shell, it is necessary to additionally perform curling and the like.

Accordingly, it is an object of the present invention to provide more uniform concentricity of the inner and inner curls to a minimal amount of earring wall, especially more uniform wall thickness and shell periphery at the joint between the wall and the central panel. Providing an ingenious shell for the manufacture of can ends featuring the improved preformed curl above, and a tool capable of producing the shell in large quantities and quickly, preferably a single-acting reciprocating motion. Providing a formal press and the use of polygonal blanks specially designed to match the response of various materials to tools acting in parallel or at right angles to the metal crystals and of the joint between the thick wall and the central panel. It is an object of the present invention to provide an improved manufacturing method of the shell, which includes molding under controlled conditions and can keep the wall thickness of the shell material more uniform.

[0019]

Other objects and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings and the appended claims.

In order that the present invention may be better understood, a detailed description will be given below with reference to the accompanying drawings.

The shell production according to the invention can be roughly divided into two machining operations, each of which can be carried out in a conventional single-acting ram press with a specially designed tool. A Minster P2-45 type press was used, but various other types of press can also be used.

First, a relatively thin metallic material (FIG. 3) that finally forms the shell is fed to one or more working parts in the press. Operate the press ram in each of these primary processing parts,
Separate blank B from the material and partially mold the shell from the blank.

The partially finished shells in each primary section are then transferred to corresponding secondary sections in the same press,
Then, finish molding of the shell is performed, the press is opened, and the finish shell is carried out from the press.

In a preferred embodiment of the invention, during each stroke of the single-acting press, a blank is produced in each primary part and partially finished, while in each secondary part it is partially formed. The finish of the shell is done. Further, the transfer of shells between the processing units is performed by one press stroke so that the shell partially finished in the primary processing unit is finished in the secondary processing unit by the next stroke. However, the primary and secondary parts and their corresponding tools can easily be mounted on another press, with partially finished shells from one press to another (secondary work).
It should be understood that the shells that have been rapidly transferred to or partially finished can be collected from the primary processing section and further processed by the second tool in the secondary processing section.

Blank Shape Referring to FIGS. 1 and 3, a portion S of the sheet metal from which the blank is cut is shown in FIG. The shape of the blank of the portion indicated by B is a polygon, as described later,
The whole is not an exact circle of the same diameter, but the transition from one side to the next is rounded. Referring to FIG.
A typical end-to-can seam seam comprises a body hook BH and an end or cover hook CH, the overlap of which is indicated by the dimension OL.

A quantity of hermetic admixture has been applied between the main barb and the underside of the end, which is not shown in FIG.

The effect of the earrings is to produce very slight overlaps, or to overlap too much,
In the latter case, the end or the cover hook will interfere with the bending of the seam at the seam, or it will become a crystal that breaks the wall of the can body at this seam. It has been found that the shape of the blank B can significantly reduce the influence or deformation of the earrings if properly selected with respect to the crystal of the material indicated by the arrow and symbol in FIG. For example, thin metal sheets, such as aluminum and steel, tend to "stretch" or stretch in the direction of the crystal or at 45 ° to the crystal, rather than perpendicular to the crystal.

Although the displayed numerical values are merely an example, it is possible to understand the basic idea when designing the shape of the blank according to the present invention. As shown in FIG. 3, blank B
The dimension of the horizontal axis I-I of is the maximum dimension. This is because if the blank is processed during shell formation, it will have the least elongation in this direction. For standard size blanks with standard size ends, the general size of this diameter is 75.87 mm (2.987 inch). On the other hand, the vertical diameter V--V of the blank is generally 75.692 mm (2.980 inch). The diameter III-III in each direction of 45 ° with respect to the vertical diameter of the blank is 75.5.
4mm (2.974inch). 22.5 ° for diameter V-V
The blank diameter IV--IV in each direction is 75.743 mm (2.982 inc.
h). The diameter II−−II in each direction of 22.5 ° with respect to the horizontal axis is
It should be 75.794 mm (2.984 inch). In accordance with the present invention, 0.29 mm (0.
When manufactured from aluminum, the blank having the above shape has a rounded curl inner diameter within the range of 0.0762 to 0.127 mm and has a concentricity (described later) of 0.0762 to 0.1762 to the thick wall.
Within 0.127mm, you will get a shell with almost no earrings. The above values are particularly applicable to shells of specific dimensions made of specific metals,
It should also be understood that the present invention is merely an example of its basic idea and application. With these numbers,
The scope of the present invention is not limited.

Referring to FIG. 2, there is shown a cross section of the actual shell having the finished shape according to the present invention, which is considerably enlarged beyond the normal size. This shell is, of course, a one-piece metal product, molded from a suitable metal blank and shaped as described above. In its final finished shape, it comprises a flat central panel 10, a recessed reinforcement portion 11 forming a relatively straight upwardly and outwardly extending thick wall and a lip or curl edge portion 13 leading to the curl inner diameter. ing.

Primary Working Section and Operation The press tool of each primary working section is shown in FIGS. 4 to 7. The upper tool works by being connected to the press ram, while
The lower tool is fixed to the press frame.

The lower tool is provided with a die cutting edge 14, and this cutting edge 1
From above 4, the metal material S enters the tool at a material line height approximately indicated by the line 16. The die cutting edge 14 is the die forming ring 1.
8 is firmly supported on a suitable base member. Further, the lower tool is provided with a drawing ring 24 provided between the die forming ring 18 and the die cutting edge 14. A central pressing pad 25 is concentrically provided in the molding ring 18. The throttle ring 24 is supported by a spring (not shown) mounted in the base member. This spring is compressed when the tool is closed and by the pressure exerted on the throttle ring 24.
The center pressing pad 25 is also supported by a spring (not shown) that is compressed by the acting force of the upper tool.

When the tool is opened, the drawing ring 24 and the center pressing pad 25 are held in the lower tool, and the drawing ring 24
Bottom of the pad touches the die cutting edge 14 and the central pressing pad 25
The bottom portion of the base contacts the molding ring 18. At this time, the upper surface of the drawing ring 24 is located slightly below the lowest shearing point of the die cutting edge 14, and the upper surface of the center press pad 25 is slightly above the drawing ring 24 and the lowest shearing point of the die cutting edge 14. It is located below.

The upper tool has a blank punch 3 positioned to cooperate with the aperture ring 24 when the tool is closed.
0 is provided. A knockout positioner 32 is provided above the die forming ring 18, and the shape of the punch center 34 cooperates with the central pressing pad 25 to fix the blank as well as to manufacture a partially finished shell. It has a suitable shape. When the press ram descends, the blank punch 30, knockout positioner 32,
And the punch center 34 is all closed on the lower tool at the same time.

The sequential operation of producing blanks from the material and partially forming the shell in the primary working section is illustrated in FIGS. 4-7. In FIG. 4, the tool is already shown partially closed. Material S enters the tool along the material line indicated at 16 and, as the press ram descends, shears the material between the die cutting edge 14 and the blank punch 30 to produce a flat blank B.

Since the blank punch 30 and the punch center 34 move simultaneously, the lower surface of the blank punch 30 extends somewhat beyond the lower surface of the punch center 34 so that the punch center 34 does not interfere with the material S during the blank punching operation. There is.

Further, the lead distance that the blank punch 30 extends from the punch center 34 is set to be equal to or less than the distance that the upper surface of the center pressing pad 25 is above the upper surface of the drawing ring 24 in the lower tool 12. As a result, the entire panel of the blank B has the punch center 34 and the center pressing pad 2.
5 and then the outermost part of the blank B before the start of the forming process, the blank punch 30 and the drawing ring 2
It is sandwiched between four. The use of central fixing means allows the blank B to be fixed in a central position within the tool during subsequent molding of the shell from the blank. By holding the blank in a central position, the blank is processed in a controlled manner to minimize the irregularity of curled lips on the outer edge of the finishing shell and to make the amount of subsequent seaming material more constant. be able to.

As the press ram continues to move downwards, the blank punch 30, the support ring 32 and the punch center 3
All four keep moving at the same time. In the position shown in FIG. 5, the blank is still blank punch 30 and aperture ring 2.
4 and the punch center 34 and the center presser pad 25
The shell forming operation is started on the die forming ring 18 while being sandwiched between the two.

Referring to FIG. 6, the punch center 34
It can be seen that the press ram continues to move downward while B starts to form the thick wall 12 with respect to blank B. The blank is no longer held between the blank punch 30 and the draw ring 24, but is still held between the punch center 34 and the center press pad 25, and the draw ring 24 is no longer forming the shell. Do not control. The clearance between the inner diameter of the blank punch 30 and the outer diameter of the die molding ring 18 is selected to be a value that allows the blank B to be appropriately molded by an appropriate resistance force. The inner diameter of the blank punch 30 is slightly narrowed above the curved portion 49 (enlarged for clarity). Therefore, the fourth
As can be seen by comparing FIG. 5 and FIG. 5, the resistance force acting on the outermost portion of the blank B increases immediately before the end of the press stroke. As a result, the portion of the shell 48 is squeezed more closely on the die forming ring 18, so that the curled portion of the shell 48 extends to the edge of the shell 48 without a straight line portion or a curl lacking portion.

In FIG. 7, the tool is shown closed and the bottom of the press ram abutting a suitable stop block. Upon completion of the first stage of the shell forming operation, the flat central panel 10 has reached a relatively large radius of curvature 52 and has been gently stretched so as not to overwork the material in that area. This large radius of curvature portion 52 forms the connection between the thick wall 52 and the central panel 10 and, subsequently, the recess of the shell and the panel forming radius. Since the radius is relatively large, the shell has a sufficient wall thickness, while the concave portion later has a radius that does not cause a gap. From FIG. 7, the inner wall of the central molding ring 18 of the die and the punch center 3
The reverse bending force acting on the outer wall of 4 provides a straight thick wall 12 that does not bend either inward or outward so that the shell can fit exactly into the secondary tool.

The shell is further provided with a lip body 53 extending generally outwardly and upwardly from the thick wall 51, but with a generally downward curve. The lip body 53 is provided with two different curved portions, and the cross-sectional shape of the lip body 53 is a "seagull wing" shape. The portion adjacent to the thick wall 12 is provided with a relatively slightly curved portion to provide an upwardly extending lip body 53, while the outermost portion is provided with a relatively steep downward curved portion by the die forming ring 18. There is. However, the outer edge of the lip body 53 is positioned not above the portion where the lip body 53 connects to the thick wall 12 of the shell but at least flatly with the connecting portion.

When the tool is closed, the knockout positioner 32 does not contact the partially finished shell. When the molding operation is completed, the press ram is raised, the tool is released, and the shell is held in the blank punch 30 by its lip body 53 being tightly fitted in the blank punch 30, and the shell is moved upward by the upper tool. Be lifted. When the lower portion of the shell exceeds the material line height shown at 16 in FIG. 3, the blank punch 30 and punch center 34 continue to rise with the press ram while the knockout positioner
32 stops its ascending movement. When the upward movement of the knockout positioner 32 stops, the shell preform contacts the knockout positioner, which pushes the shell preform out of the still-moving blank punch 30.

The partially finished shell 48 is then held in place on the knockout positioner 32 by the vacuum pressure acting on the surface of the punch center 34 through a suitable vacuum path in the upper tool. Then, this vacuum pressure causes the shell preform to remain adsorbed on the surface of the knockout positioner 32 until it is carried out.

Upon completion of the primary processing operation for Ciel, Ciel is secondary processed by a transfer device as described in US Patent Application No. (DRT002P2) filed by the same applicant as the present application on the same date as the US application of the present application. It is transferred to a corresponding one of a plurality of tools in the section, and finish forming is performed.

Secondary Working Section Tool and Operation The secondary working section tool includes an upper tool 61 supported on a press ram and a lower tool 62 supported on a press bed, as shown in FIGS. 8 to 11. To do. The lower tool 62 includes a curl die 64 and a panel forming punch 66,
Both are fixed on a suitable base member. An insert 71 is provided in the panel forming die. A plurality of springs 74 (not shown) mounted in the base member supporting the lower tool
A spring pressing pad 72 supported by is provided concentrically between the curl die 64 and the panel forming punch 66. A fitting 75 for connecting a vacuum source reaches into vacuum paths 76 and 78 provided to apply a vacuum pressure to the upper surface of the panel forming punch 66.

The upper tool 61 comprises a curl forming punch positioner 84 having a projection 85 which defines the forming characteristics of the lower surface of the curl forming punch positioner 84. In addition, the panel forming die 86 is generally mounted for movement with the panel forming punch positioner 84. The panel forming die 86 is supported from the press ram via a plurality of springs 90 (not shown) selected to allow a "pause" period for the descending movement of the panel forming die 86 during the lowering of the press ram. .

Panel forming die 86, panel forming punch
The positioners 84 and their fixtures are provided with vacuum passages 92 and 93, respectively, so that a vacuum pressure can be applied to the lower surface of the panel forming die 86.

The details of the sequential work of the shell finishing in each secondary processing section are shown in FIGS. 9 to 11. The shell preform enters the open tool in the secondary section and is properly positioned on the lower tool. The large radius portion 52 and the thick wall are supported by spring retainer pads 72,
The entire center panel 10 is supported somewhat above the insert 71. The shell preform is positioned and held in place by the vacuum pressure acting on the upper surface of the panel forming punch 66.

In FIG. 9, the panel forming die 86 is connected to the thick wall 12 by descending the press ram, and the thick wall 12 is fixed between the panel forming die 86 and the spring pressing pad 72. Since the spring pressure acting on the panel forming die 86 can be retracted more easily than that of the spring supporting the pressing pad, the panel forming die 86 once receives the thick wall 12
When it comes into contact with, it is held in place by the spring retainer pad 72 and begins to pause even if the press ram continues to descend.
Then, the panel forming punch positioner 84 contacts the lip body 53.

As is apparent from FIGS. 9 and 10, by continuing the downward movement of the press ram, the panel molding punch positioner 84 is moved to the shell lip 53 of the shell.
Begins to extrude into its desired final shape. The shell preform has a panel forming die 86 and a spring retainer pad 72.
It remains fixed in between and the panel forming die 86 remains paused until the bottom of the spacer 96 contacts the base plate, as shown in FIG. 8, by the downward movement of the press ram.

Once the bottom of the spacer 96 is in contact with the base plate, the press ram further lowers the tool, causing the panel forming die 86 to move downward, as shown in FIG. The pressing pad 72 is also moved downward. The insert 71 now has a raised portion 9 positioned relative to the shell preform panel 50.
1 is provided. The lowering movement of the spring retainer pad 72 causes the panel 50 to fully rise relative to the rest of the shell preform, reducing the distance between the upper end of the shell preform and the panel 50.

The shell material from the large radius of curvature portion 52 begins to open from the spring retainer pad 72 and the panel forming punch 66 and panel forming die (FIGS. 9 and 10).
Wrap around the edge of. This winding operation is performed under a precision control condition with almost no drawing of the shell material, and by correcting the large radius of curvature portion 52 to form the recess 98, it is possible to manufacture a pressure-resistant panel for finishing shell. it can. This resists the tendency of panel 50 to bend downward during shell molding, resulting in a flat finished panel. At the same time, the shell lip body 53 enters the curl die 64 and is subjected to finishing shaping processing.

The tool is shown in the closed position in FIG. The finish shell 48 has a recess 98 and a hook, ie an outer curl edge of relatively small radius of curvature,
It comprises a pressure-resistant panel 50 surrounded by a die curl bending lip 53 suitable for seaming on a can. The reason why the "seagull wing" lip body 53 is formed in the primary working portion 10 will be easily understood. The outer portion of the lip body 53 is pre-curled to have a relatively steep radius that extends to the edge of the shell, so that the outermost portion of the lip body 53 resists die curl and maintains a relatively straight state. You can overcome natural tendencies. In the primary processing portion, the curved portion of the lip body 53 is formed so as not to be steeper, and extends not only outward from the thick wall 12 but also upward, so that the die curl bending processing of the outermost portion is performed. Inside, the lip body 53 can obtain some movement distance. If the lip body 53 is formed in the primary processing portion so as to extend from the thick wall 12 at a desired finishing angle, the outer end edge portion cannot be satisfactorily subjected to die curl bending processing.

As a result of the above work, the wall thickness is uniform over the entire cross section, and the wall thickness 12 and the curl inner diameter, that is, the distance between the end edges of the curl bending lip body 53 is uniform. A shell can be manufactured.

Another embodiment of the upper tool is shown in FIG. 12, where the finishing shell is coined and reinforced around the outer edge of the panel adjacent wall 98. Although the shell coining is typically done in a separate coining press, the embodiment of FIG. 12 allows coining as part of the molding process, eliminating the need for separate equipment and steps. An annular groove for accommodating the coining ring 97 and the spacer 99 is provided in the center of the panel molding die 86. The pressure applying pressure ring 97 is fixed by the retainer 101 attached to the panel forming die 86. The spacer 99 is such that when the tool is completely opened as shown in FIG.
It is selected to provide sufficient compressive force to contact A and properly coin the outer edge of panel 50 of shell 10A.

When the tool begins to open, the panel forming die 8
The vacuum pressure acting on the shell 10A through the vacuum passage 92 of 6 causes the shell 10A to be raised together with the upper tool 61. Vacuum pressure is also applied to the shell 1 from the panel forming punch 66.
Since it acts on 0A and lifts the shell 10A from the lower tool 62, it is necessary to apply a higher vacuum pressure to the upper side of the shell 10A than to the lower side. Further, the upward movement of the press pad 72 by the spring 74 serves to facilitate the initial ejection of the shell 10A from the lower tool 62. Once the shell panel 50 has a panel forming punch 66 and an insert 71.
When the work surface is separated from the work surface, a low-pressure vacuum is released through an opening (not shown) additionally provided in the work surface.

As a result, in order to lift the finishing shell 48 from the lower tool 62, a small amount of vacuum needs to be applied to the upper tool 61.

After the upper tool 61 lifts the shell 10A far enough from the lower tool 62, the raising operation of the retainer 80 and the panel forming die 86 continues, while the raising operation of the panel forming punch positioner 84 stops. Immediately after the above part is separated from the shell 84, the shell is separated from the secondary processing part tool and is carried out of the shell forming apparatus.

Although the methods and products described above, and the apparatus for practicing the methods, constitute preferred embodiments of the present invention, the invention is not limited to the methods, products and apparatus, but rather the claims. It should be understood that modifications can be made without departing from the scope of the invention described in the scope of.

[Brief description of drawings]

FIG. 1 is a plan view of a general beverage can with a part cut away to show a cross section of a joint portion between a can body and an end portion.

FIG. 2 is a cut-away reduced cross-sectional view of a can end shell provided by the present invention.

FIG. 3 is a partial view of a thin metallic material showing the shape of a blank to be cut according to the present invention.

FIG. 4 is a partial enlarged view (about 2.5 times) of a tool for forming a partially finished shell for use in the primary working portion according to the present invention.

FIG. 5 is a partial enlarged view (about 2.5 times) of a tool for forming a partially finished shell for use in the primary working portion according to the present invention.

FIG. 6 is a partially enlarged view (about 2.5 times) of a tool for forming a partially finished shell for use in a primary working portion according to the present invention.

FIG. 7 is a view showing a peripheral shape of a tool for forming a partially finished shell, which is used in the primary working portion according to the present invention.

FIG. 8 is a similar enlarged view of a part of the tool for finishing the forming of the shell in the secondary processing part according to the present invention and a view showing the sequential work thereof.

FIG. 9 is a similar enlarged view of a part of the tool for finishing the forming of the shell in the secondary working portion according to the present invention and a view showing the sequential work thereof.

FIG. 10 is a similar enlarged view of a part of a tool for finishing the forming of a shell in a secondary processing part according to the present invention and a view showing a sequential operation thereof.

FIG. 11 is a similar enlarged view of a part of the tool for finishing the forming of the shell in the secondary working part according to the present invention and a view showing the sequential work thereof.

FIG. 12 is a view showing a modified example of the secondary processing portion, FIGS.
It is a figure similar to 1.

[Explanation of symbols]

 S ... Thin metal material CH ... Cover hook 10 ... Flat center panel 11 ... Recessed portion 12 ... Thick wall 13 ... Curl edge 14 ... Die cutting edge 16 ... Material line height 18 ... Die forming ring 24 ... diaphragm ring 25 ... center press pad 30 ... blank punch 32 ... knockout positioner 34 ... punch center 48 ... shell 49 ... curved part 52 ... large radius part 53 ... lip body 61 ... upper tool 62 ... lower tool 64 ... curl die 66 ... panel Molding punch 71 ... Insert 72 ... Spring pressing pad 74 ... Spring 76, 78 ... Vacuum path 84 ... Molding punch / positioner 86 ... Panel molding die 90 ... Spring 92, 93 ... Vacuum path 97 ... Coining ring 99 ... Spacer 101 ... Retainer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Omar El Brown 45429, Ohio, United States, Napolline Drive, Dayton 148 (72) Inventor Amal Sea Fraise 45429, Ohio, United States, West Stroop Road 355 (72) Inventor James Earl Greg 45066, Ohio, USA, Factory Road 410, Boxing Road, Boxing 477 (72) Inventor David Kay Wayne 45459, Ohio, USA Lightbeam Drive 311

Claims (2)

[Claims] A blank punch (30) constructed and arranged for separating a rounded non-circular blank from a sheet in an apparatus for producing can end shells only by reciprocating tooling. ,
A die (24) and a draw ring (24) cooperate with a forming ring (18) and a punch center (25) which cooperate with the blank to enclose the central panel and form an upwardly and outwardly extending wall. A first set of tools having the drawing ring, the forming ring, the blank punch, and the punch center cooperating to form a partially curled portion on the outer portion of the blank; And a presser having a structure capable of gripping the wall of the partially formed blank on the inside of the formed part and on the outside of the central panel and forming the thick part on the inside, and the panel forming die (86) so arranged. Pad (72)
And around the protrusion of the panel forming die that defines the shape of the panel wall connecting the thick wall and the central panel, so that the blank portion between the central panel and the grasped thick wall is wound around the panel forming die. Curl the outer portion of the shell by molding the panel forming punch (66) cooperating with (86) and the edge of the shell and extending inwardly and inwardly from the thick wall at the lower side of the curl portion. Forming a shell for a can end, characterized in that it comprises a second set of tools having a structure capable of finishing and having a curl forming punch (84) and a curl forming die (64) so arranged. apparatus. 2. The can end shell forming apparatus of claim 1, wherein the tools of the first and second sets can be mounted in a reciprocating press in close proximity to each other. .