JP2565369B2 - Container lid press molding equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention is for forming a metal container lid including a ceiling wall, a cylindrical skirt wall hanging from a peripheral edge of the ceiling wall, and a gripping piece extending from the skirt wall. Related to the container lid press forming apparatus.

[Prior art and its problems]

As a container lid for a glass or synthetic resin container, a metal container lid 2 of the form shown in FIGS. 1 and 2 has recently been put into practical use. The container lid 2 is
The circular top wall 4, a cylindrical skirt wall 6 hanging from the peripheral edge of the top wall 4, and a gripping piece 8 extending from the skirt wall 6.
It consists of and. The gripping piece 8 has a base portion 10 that hangs from the lower end of the skirt wall 6, and a main portion 12 that extends substantially horizontally from the lower end of the base portion 10 outward in the radial direction. The free end of the main part 12 is usually embodied in the shape of a ring on which a finger can be placed. A pair of triangular notches 14 are formed at the lower end of the skirt wall 6 corresponding to both side edges of the base 10 of the grip piece 8. Furthermore, the skirt wall 6 and the top wall 4 have
A pair of breakable lines 16 are formed from the pair of notches 14 extending upward across the skirt wall 6 and further extending the top wall 4 in an appropriate shape. The pair of breakable lines 16 may be so-called scores.

Therefore, according to the experience of the present inventors, FIG. 1 and FIG.
It has been found desirable to modify the container lid 2 of the form shown in the figures to improve it to the form shown in FIGS. 3 and 4.

In the container lid 2 shown in FIG. 3 and FIG. 4, the reinforcing ridges 18 extending over the base portion 10 and the main portion 12 of the grip piece 8 are provided.
Are formed. The first without such reinforcing ridges 18
In the case of the container lid 2 shown in FIGS. 2 and 3, (a) the main portion 12 of the gripping piece 8 when the container lid 2 is conveyed through a chute or the like.
When some external force is applied to the main part 12, the main part 12
As shown by the chain double-dashed line in the figure, it is relatively easily deformed and is not used as it is. (B) When the container lid is detached from the container and the container is opened, the main portion 12 of the gripping piece 8 is It is necessary to pull the finger to pull it to break the pair of breakable lines 16. At this time, the base of the gripping piece 8 is to be broken.
There is a problem that the main portion 12 is deformed as shown by the two-dot chain line in FIG. 2 with respect to 10, and this makes breakage of the pair of breakable lines 16 extremely difficult. Therefore, in the container lid 2 shown in FIG. 3 and FIG.
By this, the bent portion between the base portion 10 and the main portion 12 of the gripping piece 8 is reinforced, and the above problem is solved.

Thus, as shown by the chain double-dashed line in FIGS. 3 and 4, it may be possible to extend the reinforcing ridge 18 upward to the upper end of the skirt wall 6; A separate problem occurs as follows. That is, when the container lid 2 is fastened to the mouth and neck of the container as required, it is necessary to deform the lower portion of the skirt wall 6 inward in the radial direction over the entire circumferential direction. Due to this, such deformation is significantly hindered, and cracks are often generated at the site where the reinforcing ridges 18 are present. Therefore, it is important that the reinforcing ridges 18 extend over the base portion 10 and the main portion 12 of the gripping piece 8 but not over the skirt wall 6.

Further, in the container lid 2 shown in FIGS. 3 and 4, the press molding of the container lid 2 is facilitated, and when the lid is closed, the main portion 12 of the gripping piece 8 is arranged along the mouth and neck of the container. In order to facilitate the operation of deforming downward, the main portion 12 of the gripping piece 8 is not horizontal but downward 15 in the radial outward direction.
It extends at an inclination angle of about 35 degrees.

Thus, the container lid 2 in the form shown in FIGS.
Is formed by subjecting a thin metal plate to which the required preforming has been performed (such preforming will be described later) to the press forming. However, regarding the configuration shown in FIGS. 3 and 4, that is, the container lid 2 having the reinforcing ridges 18, conventionally, the reinforcing ridges 18 as shown by the two-dot chain line in FIGS.
Can be molded in a single press molding process without any inconvenience, if the ridges 18 extend upwards to the upper end of the skirt wall 6, but the reinforcing ridges 18 are the bases of the gripping pieces 8. If it exists over the 10 and the main part 12 but not on the skirt wall 6, it cannot be molded by a single press molding process, and therefore, the reinforcing ridge 18 is not present in the container. Press molding the lid 2,
It was then considered necessary to perform additional press molding to form the reinforcing ridges 18. Therefore, the container lid 2 of the form shown in FIG. 1 and FIG.
When the container lid 2 of the form shown in FIGS. 4 and 5 is improved,
It was believed that manufacturing costs would increase significantly due to the additional press molding.

[Technical problem of the invention]

The present invention has been made in view of the above-mentioned facts, and its main technical problem is to improve the container lid press-molding apparatus to provide the case of the container lid 2 shown in FIGS. 1 and 2. Similarly, the container lid 2 of the form shown in FIGS. 3 and 4 is formed by subjecting a sheet of metal having the required preforming to a single press forming without the need for additional press forming. Is to be able to do.

[Means for Solving the Invention and Action]

As a result of earnest research, the inventors of the present invention have formed a concave portion existing only at the lower end portion at a required angular position of a punch cutter that contributes to drawing processing of a skirt wall in a container lid pressing device,
Contrary to conventional wisdom in press working, when the skirt wall is drawn by the punch cutter, a ridge is once formed on the skirt wall due to the recess, but the ridge is formed according to the progress of the drawing work. It has been found that the above technical problems can be achieved if the ridges are gradually crushed.

That is, according to the present invention, a top wall, a cylindrical skirt wall that hangs from the peripheral edge of the top wall, a gripping piece that has a base that hangs from the skirt wall, and a main portion that extends radially outward from the base. A container lid press-molding device for press-molding a metal container lid consisting of a metal thin plate in which an opening defining the outer contour of the gripping piece is formed, comprising a punch assembly and a die assembly. The punch assembly includes a center punch and a punch cutter that surrounds the center punch and is movable in the axial direction relative to the center punch. The die assembly surrounds the center die and the center die. Further, it includes a die ring that is movable in the axial direction relative to the center die, and a die cutter that surrounds the die ring, and the die cutter has a notch formed at a position corresponding to the gripping piece. The metal thin plate is cut along an arc extending from one edge of the opening to the other edge by cooperation of the outer peripheral edge of the tip of the punch cutter and the inner peripheral edge of the tip of the die cutter, and the punch cutter and the die ring are cut. In a container lid press forming apparatus in which the skirt wall is drawn by moving in the axial direction relative to the center die, a position corresponding to the notch of the die cutter at the lower end of the punch cutter. When the skirt wall is drawn, a ridge is once formed on the skirt wall due to the depression, but the ridge is formed on the skirt wall. The ridges are gradually crushed, and at the end of press molding, due to the recesses, reinforcing ridges are formed which extend over the base portion and the main portion of the gripping piece but not on the skirt wall. , Characterized by Container closure press forming apparatus is provided that.

In a preferred embodiment of the container lid press-molding apparatus of the present invention, the tip surface of the punch cutter and the tip surface of the die ring are inclined toward the die ring side in a radially outward direction. Thus, in the molded container lid, the main portion of the gripping piece extends radially outwardly and is inclined downward at a required angle. Further, a notch is formed in the die ring corresponding to the position of the concave portion of the punch cutter, and the center die cooperates with the concave portion when the punch cutter reaches the press forming end position. A convex portion forming the reinforcing ridge is provided.

[Preferred specific examples of the invention]

Hereinafter, preferred specific examples of the container lid press molding apparatus configured according to the present invention will be described in detail.

Referring to FIG. 5-A, the illustrated container lid press-molding apparatus comprises a fixed base 20 and a movable base 22 mounted above the fixed base 20 so as to be movable up and down. The movable base 22 has a through opening 24 formed therein.
A punch assembly 26 is attached to 24. Also fixed base
A through opening 28 that is concentric with the opening 24 is also formed in the opening 20, and the die assembly 30 is attached to the opening 28.

The punch assembly 26 includes a center punch (knockout punch) 32 and a punch cutter 34 surrounding the center punch 32. The punch cutter 34 having a substantially cylindrical shape as a whole has a large-diameter upper portion 36 and a small-diameter lower portion 38. The large diameter upper part 36 is fixed in the through opening 24 of the movable base 22. The punch cutter 34 has a through opening having a small diameter upper portion 40 and a large diameter lower portion 42. The center punch 32 having a substantially cylindrical shape as a whole includes a head 48 having an outer diameter substantially the same as the inner diameter of the large diameter lower portion 42 of the through opening, and a small diameter upper portion of the through opening extending upward from the head 48. The shaft portion 50 has an outer diameter substantially the same as the inner diameter of 40. The center punch 32 is slidably inserted into the through opening of the punch cutter 34. An annular flange member 54 is fixed to the upper end of the center punch 32 by a bolt 52. Elastic means 56, which may be a compression coil spring, is disposed between the lower surface of the flange member 54 and the upper surface of the punch cutter 34. The elastic means 56 elastically biases the center punch 32 upward with respect to the punch cutter 34. The upward movement of the center punch 32 with respect to the punch cutter 34 is limited by the upper surface of the head 48 of the center punch 32 contacting a shoulder portion 58 formed in the through opening of the punch cutter 34. Above the center punch 32, the stationary contact member 60 is provided.
Is provided.

Next, the die assembly 30 will be described.
30 includes a center die 62, a die ring 64 surrounding the center die 62, and a die ring 66 surrounding the die ring 64. A disc 68 is fixed in the opening 28 of the fixed base 20. In addition, a support board 70 is provided on the upper surface of the fixed base 20.
Has been fixed. As can be seen by referring to FIG. 6 in conjunction with FIGS. 5-A, the support board 70 has a circular main portion 72 which is aligned with the opening 28 formed in the fixed base 20.
And an additional portion 74 extending in the radial direction from a part of the main portion is formed. The circular main part 72 of this opening 76 penetrates the support board 70 in the axial direction, but an additional 74
Extends from the upper surface of the support board 70 to a predetermined depth.
The center die 62, die ring 64 and die cutter 66 are
It is housed in the openings 28 and 76 on the disk 68.
The center die 62 has a large-diameter head portion 78 and a shaft portion 80 extending downward from the head portion 78, and the lower end of the shaft portion 80 is fixed to the upper surface of the disc 68. The die cutter 66 has a bottom wall portion 84 in which a through opening 82 through which the shaft portion 80 of the center die 62 is inserted is formed.
And a side wall portion 86 extending upward from the outer peripheral portion of the bottom wall portion 84, and the bottom wall portion 84 is fixed to the upper surface of the disc 68. As can be seen by referring to FIG. 6 in conjunction with FIGS. 5-A, the die cutter 66 is aligned with the angular position in which the additional portion 74 is present and the die cutter 66 has a notch 88 extending from its upper end to its lower end. Are formed. Therefore, the sectional shape of the side wall portion 86 of the die cutter 66 is not an annular shape continuous in the circumferential direction but an arc shape. The die ring 64 has a bottom wall portion 92 in which a through opening 90 through which the shaft portion 80 of the center die 62 is inserted is formed, and a side wall portion 94 extending upward from the outer peripheral portion of the bottom wall portion 92. The die ring 64 is slidably accommodated between the center die 62 and the die cutter 66 in the axial direction. A plurality of through holes 96 are formed in the disc 68 and the bottom wall portion 84 of the die cutter 66 at intervals in the circumferential direction, and a pressing rod 98 is slidably movable in each of the through holes 96. It is inserted (only one through hole 96 and one pressing rod 98 are shown in FIG. 5-A). Each of the pressing rods 98 is provided with elastic means (not shown) which can be composed of a suitable spring such as a disc spring. Such elastic means elastically biases the die ring 64 upward via the pressing rod 98. Die ring 64
The upper surface of the bottom wall portion 92 of the die center 62
Limited by abutting the underside of the head 78 of the.

The above-described configuration of the illustrated container lid press-molding apparatus is substantially the same as that of the conventional container lid press-molding apparatus. Thus, the illustrated container lid press-forming apparatus constructed according to the present invention has the following improvements.

Continuing the description with reference to FIG. 5-A, the punch assembly
Annular tip surface (ie, lower surface) of punch cutter 34 at 26
Is inclined downwardly from its inner peripheral edge toward its outer peripheral edge (ie, radially outward toward the die assembly 30 side) at an angle of inclination of about 15 to 35 degrees. And, correspondingly, the die ring in the die assembly 30
64 annular tip surfaces (ie, upper surfaces) are also inclined at an inclination angle of about 15 to 30 degrees downward from the inner peripheral edge thereof toward the outer peripheral edge thereof (ie, radially outward toward the die assembly 30 side). It has been confused.

Further, as clearly shown in FIGS. 7 and 8, the lower end portion of the punch cutter 34 in the punch assembly 26 has a recess.
100 are formed. It is important that the recess 100 does not extend upward and exists only at the lower end of the punch cutter 34. The angular position of the recess 100 is determined by the die assembly 30.
The circumferential width of the recess 100 is smaller than the circumferential width of the notch 88 in the die cutter 66 at the angular position of the notch 88. As clearly shown in FIG. 8, it is desirable that the depth of the recess 100 is gradually increased from the outer peripheral edge of the punch cutter 34 toward the inner peripheral edge thereof.

FIG. 9 illustrates a pre-molded body supplied to the container lid press molding apparatus as described above. A preformed body 102 formed by subjecting an appropriate metal thin plate such as an aluminum-based alloy thin plate, a chromic acid treated steel thin plate or a tin plate to a well-known preforming in itself has a substantially U-shaped opening 104. Has been formed. Then, in this opening 104, there is a region 106 that is fitted to the gripping piece 8 in the container lid 2 shown in FIGS. 3 and 4. The free end of this area 106 (9th
The right end portion in the figure) is ring-shaped. The preform 102 is further provided with a base end (9th
A pair of scores 108 extending from both sides (left end in the figure) to the required shape are formed. The score 108 constitutes a pair of breakable lines 16 in the container lid 2 shown in FIGS. 3 and 4. As will be apparent from the description below, the region 112 of the preform 102, which is located inside the circular two-dot chain line 110, is formed on the circular top wall 4 of the container lid 2 shown in FIGS. 3 and 4. To be In addition, the pre-molded body 10
The annular region 116 between the circular two-dot chain line 110 and the circular two-dot chain line 114 at 2 is squeezed against the cylindrical skirt wall 6 of the container lid 2 shown in FIGS. 3 and 4. As shown clearly in FIG. 9, the proximal end of the region 106 (9th
On both sides (the left end in the figure), the openings 104 locally enter the annular region 116, as indicated by the numbers 118 and 120, and the entrance portions 118 and 120 of the openings 104 are shown in FIGS. A pair of notches 14 are formed in the container lid 2 shown in the figure.

The operation and effect of the container lid press-molding apparatus for pressing the pre-molded body 102 so as to press the pre-molded body 102 into the container lid 2 shown in FIGS. 3 and 4 will be described below.

The state of the container lid press molding apparatus shown in FIG. 5-A,
That is, the preform 102 is supplied onto the die assembly 30 in a state in which the punch assembly 26 is separated upward from the die assembly 30. As can be seen by referring to FIG. 9 in conjunction with FIGS. 5-A, the preform 102 fed onto the die assembly 30 will have the center of the circular region 112 at the die assembly 30.
The opening 7 is aligned with the center of the center die (ie, the center of the center die 62) and the region 106 is formed in the support board 70.
Notch 8 formed in additional portion 74 of 6 and die cutter 66
Positioned to correspond to 8.

After that, the movable base 22 is lowered, and hence the punch assembly.
26 descending begins. When the punch assembly 26 is lowered to the position shown in FIG. 5-B, the punch assembly 26
The preforming body 102 is separated from one edge of the opening 104 by the cutting action of the outer peripheral edge of the punch cutter 34 (ie, the lower end) and the inner peripheral edge of the die cutter 66 (ie, the upper edge) in the die assembly 30 in cooperation with each other. A circular arc extending to the edge, that is, the ninth
It is cut along the arcuate portion extending from the point 122 on the two-dot chain line 114 shown in the figure to the point 124 in the counterclockwise direction. Thus, the pre-molded body 102 is separated into the useful portion existing inside the arc portion and the opening 104 and the unnecessary portion located outside thereof.

The moveable base 22, and therefore the punch assembly 26, continues to be lowered further through the position shown in FIG. 5-C to the position shown in FIG. 5-D. As a result, the punch cutter 34 of the punch assembly 26 presses the die ring 64 of the die assembly 30 via the preform 102, and the dieing 64 acts by the pressing rod 98 as elastic means (not shown). It is gradually lowered against the elastic biasing action of. During this time, the annular area 116 (the ninth area) of the preformed body 102 is formed by the drawing action of the punch cutter 34.
(Fig.) Is gradually drawn along the outer peripheral surface of the large diameter head 78 of the center die 62 of the die assembly 30 to form the cylindrical skirt wall 6
(Figs. 3 and 4). Also, the pre-molded body
The region 106 in 102 is bent along the inner peripheral edge of the tip (ie, the lower end) of the punch cutter 34, and the die assembly 30.
The base 10 extending along the outer peripheral surface of the large-diameter head 78 of the center die 62 (and thus hanging from the lower end of the cylindrical skirt wall 6), the tip (ie, lower end) surface of the punch cutter 34, and the tip of the die ring 64. (That is, the upper end) and the main portion 12 extending along the surface. Since the front end surface of the punch cutter 34 and the front end surface of the die ring 64 are inclined downward from the inner peripheral edge toward the outer peripheral edge at an inclination angle which may be about 15 to 35 degrees, the region 106 of the preformed body 102 is inclined. The main portion 12 of the gripping piece 8 formed from is not horizontal but extends outward in the radial direction inclining downward at an inclination angle of about 15 to 35 degrees.

While the punch cutter 34 in the punch assembly 26 is lowered through the position shown in FIG. 5-C to the position shown in FIG. 5-D, the following notable processing is further performed. To be done. As clearly shown in FIGS. 7 and 8, a recess 100 is formed at the lower end of the punch cutter 34 in the punch assembly 26. Therefore, as can be understood by referring to FIG. 5-C, the punch cutter 34
The annular region 1 in the pre-molded body 102 by the drawing action of
When 16 (FIG. 9) is gradually drawn on the skirt wall 6, a ridge 126 is locally formed on the skirt wall 6 due to the recess 100. However, since the concave portion 100 is formed only at the lower end portion of the punch cutter 34, as can be understood by comparing and referring to FIGS. hand,
A portion of the punch cutter 34 immediately above the recess 100 acts on the ridge 126, and the ridge 126 is gradually crushed. Thus, when the punch cutter 34 is lowered to the position shown in FIG. 5-D, all of the ridges 126 once formed on the skirt wall 6 are crushed, and the ridges resulting from the recesses 100 are gripping pieces. Only the reinforcing ridges 18 (FIGS. 3 and 4) extending over the base portion 10 and the main portion 12 of FIG.

When the preform 102 is formed on the container lid 2 shown in FIGS. 3 and 4 as described above, the movable base 22 is raised,
Therefore, the punch assembly 26 is raised. In response to the raising of the punch cutter 34 in the punch assembly 26, the die ring 64 in the die assembly 30 is raised and thus shaped by the elastic biasing means of the elastic means (not shown) acting through the push rod 98. The container lid 2 is a punch cutter
It is raised in association with 34. Punch assembly 26 is fifth
When it is lifted to the position shown in FIG. 6E, the head of the bolt 52 screwed to the upper end of the center punch 32 contacts the stationary contact member 60, which prevents the center punch 32 from rising. . Therefore, when the punch cutter 34 together with the movable base 22 is raised to the position shown in FIG. 5-F, the center punch 32 is lowered relative to the punch cutter 34 against the elastic biasing action of the elastic means 56. Then, the container lid 2 that has been raised in association with the punch cutter 34 is dropped downward. Thus, the molded container lid 2 is disengaged from the punch assembly 26 and removed from the pressing apparatus by suitable ejection means (not shown), which itself may be of a known form. Needless to say, the separated unnecessary portion of the pre-molded body 102 is also discharged from the pressing device by an appropriate discharging means (not shown).

10-A, FIG. 10-B, FIG. 11 and FIG. 12 show a modified example of the container lid press molding apparatus constructed according to the present invention. In this modification, as understood from FIGS. 10-A and 11, the die ring 64 is formed with a notch 128 extending from its upper end to its lower end. Therefore, the side wall portion 94 of the die ring 64 has an arcuate cross-sectional shape instead of the annular shape continuous in the circumferential direction. The angular position of the notch 128 is aligned with the angular position of the recess 100 of the punch cutter 34 in the punch assembly 26. The circumferential width of the notch 128 may be substantially the same as or slightly larger than the circumferential width of the recess 100. Further, in the modified example, as clearly shown in FIG. 12, a convex portion 130 protruding radially outward is formed at the lower end of the large diameter head 78 of the center die 62. The formation of the convex portion 130 is complementary to the shape of the concave portion 100 of the punch cutter 34 in the punch assembly 26, and the axial dimension thereof is gradually reduced outward in the radial direction. The angular position of the convex portion 130 is aligned with the angular position of the concave portion 100.
Other configurations of the modification excluding the notch 128 and the protrusion 130 described above may be substantially the same as the configuration of the above-described specific example.

Also in the modified example as described above, just before the final point of the container lid press molding process, that is, immediately before the punch assembly 26 reaches the lowermost position shown in FIG. The container lid press molding is performed. When the die ring 64 is moved down with respect to the center die 62 in the die assembly 30, the protrusions 130 formed on the center die 62 relatively rise along the notches 128 formed on the die ring 64. Be punished. When the punch assembly 26 is lowered to the lowest position, as shown in FIG. 10-B, the center die 62 is formed on the inner surface or lower surface of the reinforcing ridge 18 formed due to the existence of the recess 100 in the punch cutter 34.
The protrusions 130 are brought into contact with each other, and the reinforcing ridges 18 are thus subjected to the actions of the recesses 100 and the protrusions 130 from both the upper surface and the lower surface thereof, and are forced into the shapes defined by the recesses 100 and the protrusions 130. Is transformed into. Therefore, as compared with the above-described specific example in which the convex portion 130 does not exist, the reinforcing ridge 18 is formed in a specific shape with sufficient accuracy.

〔The invention's effect〕

As described above in detail, according to the container lid pressing apparatus improved according to the present invention, the container lid 2 of the preferred embodiment shown in FIGS. 3 and 4 requires additional press molding. Can be formed by subjecting a sheet of metal, which has been subjected to the required preforming, to a single press forming, without forming a considerable increase in the manufacturing cost.

[Brief description of drawings]

1 and 2 are a perspective view and a side view, respectively, showing a metallic container lid that has been conventionally put into practical use. FIG. 3 and FIG. 4 are a perspective view and a side view, respectively, showing a preferred form of the metal container lid. FIGS. 5-A to 5-F show one specific example of the container lid press-molding apparatus improved according to the present invention for manufacturing the container lid shown in FIGS. 3 and 4 in a molding step. 6A to 6C are cross-sectional views at various stages. FIG. 6 is a plan view showing a die assembly in the container lid press-molding apparatus shown in FIGS. 5-A to 5-F. FIG. 7 is a perspective view showing the punch cutter of the punch assembly in the container lid press molding apparatus shown in FIGS. 5-A to 5-F. FIG. 8 is a sectional view taken along the line AA in FIG. 7. FIG. 9 is a plan view showing a pre-molded article supplied to the container lid press-molding apparatus shown in FIGS. 5-A to 5-F. FIGS. 10-A and 10-B are sectional views corresponding to FIGS. 5-A and 5-D, showing a modified example of the container lid press-molding apparatus improved according to the present invention. FIG. 11 is a plan view similar to FIG. 6, showing a die assembly in the container lid press molding apparatus shown in FIGS. 10-A and 10-B. FIG. 12 is a perspective view showing the center die of the die assembly in the container lid press molding apparatus shown in FIGS. 10-A and 10-B. 2 ... Container lid 4 ... Circular top wall 6 ... Cylindrical skirt wall 8 ... Gripping piece 10 ... Gripping piece base 12 ... Gripping piece main part 18 ... Reinforcing ridge 26 ... Punch assembly 30 …… Die assembly 32 …… Center punch 34 …… Punch cutter 62 …… Center die 64 …… Die ring 66 …… Die cutter 88 …… Die cutter notch 100 …… Punch cutter recess 102 …… Preform 104 …… Aperture of front molded body 128 …… Notch of die ring 130 …… Convex part of center die

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisashi Nakajima 2-12 Mayor Hiratsuka, Kanagawa Pref. Japan Crane Cork Co., Ltd. Hiratakutsuka ▼ (72) Inventor Seiji Fukushi 2-12 Mayor Hiratsuka, Kanagawa Prefecture Japan Crown Cork Co., Ltd. Hira ▲ Tsuka ▼ Factory (56) References Japanese Patent Publication Sho 44-6879 (JP, B1)

Claims (3)

(57) [Claims] 1. A metal comprising a ceiling wall, a cylindrical skirt wall hanging down from a peripheral edge of the ceiling wall, a gripping piece having a base hanging down from the skirt wall and a main portion extending radially outward from the base. What is claimed is: 1. A container lid press-molding apparatus for press-molding a container lid made from a thin metal plate having an opening that defines the outline of the gripping piece, the punch comprising a punch assembly and a die assembly. The solid body includes a center punch and a punch cutter that surrounds the center punch and is movable in the axial direction relative to the center punch. The die assembly includes a center die, the center die, and the center die. A die ring that is movable in the axial direction relative to the die ring and a die cutter that surrounds the die ring, and the notch is formed in the die cutter at a position corresponding to the gripping piece. The thin metal plate is cut along an arc extending from one edge to the other edge of the opening by the cooperation of the outer peripheral edge of the tip of the punch cutter and the inner peripheral edge of the tip of the die cutter, and the punch cutter and the die ring are attached to the center die. In the container lid press-molding device in which the skirt wall is drawn by moving in the axial direction relative to the relative position, at the position corresponding to the notch of the die cutter at the lower end of the punch cutter, A recess is formed, and when the skirt wall is drawn, a ridge is once formed on the skirt wall due to the recess, but the ridge is gradually formed as the drawing process progresses. At the end of press-molding, due to the concave portion, a reinforcing ridge existing over the base portion and the main portion of the gripping piece but not on the skirt wall is formed. Characteristic content Lid press-forming device. 2. The container lid press molding apparatus according to claim 1, wherein the tip surface of the punch cutter and the tip surface of the die ring are inclined toward the die ring side in a radially outward direction. 3. A notch is formed in the die ring corresponding to the position of the recess of the punch cutter, and the center die cooperates with the recess when the punch cutter is at the press forming end position. The container lid press molding apparatus according to claim 1 or 2, wherein a convex portion that forms the reinforcing ridge is provided.