JPS623694B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for forming a mouthpiece of a metal container such as a tin can, a pail can, or a small can.

Conventional caps for metal containers are manufactured separately from the top plate of the container, and the skirt of the cap and the periphery of the opening provided in the top plate of the metal container are fixed by soldering or caulked into a seam shape. Fixed.

Among the above-mentioned conventional methods, the method using soldering has a great leakage prevention effect, but it is very time-consuming, so recently, the method of fixing by caulking has been mostly replaced.

However, with this type of crimping method, the crimped part is damaged or loosened by external impact, and leakage is discovered after the top plate is attached to the can body, resulting in many cases of cans being discarded as defective. There is.

Also, JP-A-52-152384 and Utility Model Application No. 1972-152384
- There are methods and devices for integrally molding the cap from the top plate, such as the known technology described in Publication No. 17662, but these known technologies use an inner mold and an outer mold that do not rotate.
Furthermore, since each mold is divided into a plurality of pieces for opening and closing, there is a problem in that the bead portion of the cap part wrinkles due to the gaps between the pieces during molding.

An object of the present invention is to solve the problems of the conventional cap part as described above.

That is, in this invention, a recessed part is provided in a part of a metal plate, an opening is provided in the center of this recessed part, and a top plate that protrudes into the recessed part in a cylindrical shape with the periphery of this opening as a base is used as a base. A top plate cradle is provided to receive the top plate with the top facing downward, and the pedestal is provided with an opening into which the base of the top plate fits, and a protrusion which fits into the inner surface of the periphery of the recessed part of the top plate. Above the table, it is driven by a cylinder or motor and rotates while descending.
An inner mold is provided that rotates and fits into the cap part in a contracted state, then expands and molds the inside of the cap using the protrusion at the lower end, then contracts and rises, and below the pedestal it rises in an expanded state. It has a circumferential groove that fits into the outside of the mouthpiece, and then shrinks to hold the outside of the mouthpiece and into which the protrusion on the outside of the mouthpiece pushed out by the protrusion of the inner mold is fitted. An outer mold that expands and descends after being molded is provided, and below this outer mold there is a cylinder for raising and lowering the outer mold and for opening and closing the outer mold, and an inner mold opening/closing cylinder that opens and closes the inner mold. The inner mold expansion member, which is raised and lowered by the inner mold opening/closing cylinder, is rotatable.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the inventive device will be described in detail below with reference to the accompanying drawings.

1 and 2 are a front view and a side view of an apparatus for carrying out the method of the present invention, in which 1 is its main body, and an arm 3 is directed forward from the upper end of a rising portion 2 at the rear of this main body 1. It is provided.

4 is a top plate pedestal fixed on the main body 1, and 5 is a tapered protrusion provided on a part of this pedestal 4 for fitting the base, and the inside thereof forms an opening 6 as shown in Fig. 3. ing.

A cylinder 7 and a motor 8 operated by hydraulic pressure or air are provided before and after the arm 3.
A rotary piston rod 9 is fitted into the cylinder 7, and the rod 9 is driven by the motor 8.

Further, a cylinder 10 operated by hydraulic pressure or air is provided at the lower part of the arm 3, and this cylinder 1
A top plate holding frame 12 is fixed to the lower end of the piston rod 11 that protrudes downward.
Both ends of a plate spring 13 bent into a shallow V-shape are slidably attached to the lower part of the body through elongated holes and set screws, as shown in FIG.

The upper end of the cylinder 14 is fixed to the lower end of the rod 9. The cylindrical body 14 has an open bottom end as shown in FIGS. 4 and 5, and a plurality of rollers 15 that rotate in the circumferential direction are provided at the bottom end.

Further, an inner mold A is provided inside this cylindrical body 14. As shown in FIGS. 4 and 5, this inner mold A has a plurality of grooves 16 extending from the lower end of the tapered cylindrical body whose lower end is open to the vicinity of the upper end.
7 can be opened and closed, and a plurality of semicircular protrusions 18 are formed on the outside of the lower end of each piece 17.

Reference numeral 19 denotes a hydraulic or pneumatic inner mold opening/closing cylinder provided in the main body 1, which is concentric with the cylindrical body 14. This cylinder 19 has a frame 20 on the outside, and an outer cylinder 21 for lifting and lowering and opening/closing is fixed to the upper end of this frame 20 and is concentric with the cylinder 19.

Reference numeral 22 in FIGS. 4 and 5 is a piston fitted in the cylinder 21, and a piston rod 23 protruding above the cylinder 19 slidably passes through the lower end of the cylinder 21 and the center of the piston 22.
An O-ring is fitted in the portion where the rod 23 passes through the cylinder 21 and piston 22 to maintain airtightness. Further, at the bottom of this cylinder 21, an inlet 24 and an outlet 25 for a pressure fluid such as oil pressure or air are provided.
is provided.

In FIGS. 4 and 5, 26 is the rod 2.
Cup ring 2 with a built-in bearing at the upper end of 3
A tapered expanding member 28 is fixed to the upper end of the rod, and a rotating body 29 is provided at the lower part of the rod. The inner ring of this rotary body is fixed to a rod 26 using a ball bearing, and the outer ring is a rotary body 29.

A collect piece 30 divided into a plurality of parts is arranged in a cylindrical shape with a slight gap between each part above the piston 22, and the lower end thereof is fixed to the upper surface of the piston 22. The lower end of a piece 31 is fixed to the upper end of each collet piece 30, and the pieces 31 are arranged in a cylindrical shape with appropriate gaps between them to form an outer mold B. A semicircular circumferential groove 32 corresponding to the protrusion 18 of the inner mold A is provided in the inner mold A.

The outer circumference of the upper end of each of the above collect pieces 30 is a tapered outer circumferential surface 33 with a small diameter at the upper part, and the cylinder 21
A tapered inner circumferential surface 34 that contacts the tapered outer circumferential surface 33 is formed on the inner circumference of the upper end of the cylinder 21, and a spring 35 is provided between the inner circumference of the cylinder 21 and the group of collect pieces 30 to press down the group of collect pieces 30.

Reference numeral 36 in FIG. 3 denotes a plurality of limit switches mounted within the pedestal 4 at appropriate intervals, with only the operating pieces 37 thereof protruding above the pedestal 4. This limit switch 36 is for operating the cylinder 10.

FIG. 6 shows the main part of the top plate 38 formed by press working in the first step, and around it is an L-shaped peripheral edge 3.
9 is provided, and the base portion 40 is formed into a cylindrical shape, with an annular recessed portion 41 around the periphery thereof.

In addition, when the container is circular, the top plate 38 may have a disc shape,
In the case of a rectangular shape, it is a rectangular shape and the size varies depending on the capacity of the container, but the pedestal 4 can also be exchanged with circular or square shapes of various sizes, but in the illustrated example, it is a circular shape. be.

The apparatus for carrying out the molding method of the present invention has the above-mentioned configuration, and a method for molding a mouthpiece on a top plate using this apparatus will be described below.

First, in another press machine, the 6th
Top plate 3 made of tin plate etc. shaped as shown in the figure
8 and fit the cap part 40 into the opening 6 of the pedestal 4 as shown in FIG.
is fitted on the outer periphery of the pedestal 4.

When the top plate 38 is attached to the pedestal 4 in this way, the operating piece 37 of the limit switch 36 is pressed, so the solenoid valve is activated, the cylinder 10 is activated, the piston rod 11 is lowered, and the leaf spring 13 at the lower end of the presser frame 12 is pressed against the top plate 36. is pressed onto the pedestal 4 and extends horizontally to fix the top plate 38.

On the other hand, the cylindrical body 14 and the inner mold A have already started rotating due to the motor 8 started by the start switch.
As mentioned above, after the leaf spring 13 is lowered, the cylinder 7 is activated by the action of the solenoid valve caused by the activation of a delay relay or the like.
When the piston rod 9 begins to descend and the roller 15 at the lower end of the cylinder body 14 comes into contact with the top plate 38 as shown in FIG.
The cylindrical body 14 continues to rotate at the same position. At this time, the lower end of each piece 17 of the inner mold A is fitted inside the mouthpiece 40.

When the above condition occurs, pressurized fluid flows in from the inlet 24 through the operation of an automatically activated solenoid valve or a foot valve by the operator, pushing up the piston 22 and raising each collect piece 30. The tapered outer circumferential surface 33 of 30 rises and contracts while contacting the tapered inner circumferential surface 34 of the cylinder 21, and the upper end of each piece 31 of the outer mold B at its upper end is contracted and positioned outside the mouthpiece 40. The cylinder 19 is then operated by actuation of the solenoid valve by the action of the delay relay, raising its piston rod 23 and rotary rod 26, and opening the expanding member 28 at its upper end.
is pushed into the lower part of the inner mold A, and each piece 17 thereof is expanded, and the rotating body 29 is held in a state in which it contacts the inside of each piece 17 and rotates together with the inner mold A, as shown in FIG.

In the above state, each piece 1 is expanded as shown in Figure 5.
The protrusion 18 of No. 7 rotates while pushing out the inside of the mouthpiece 40, and the outside of the extruded mouthpiece 40 is received by the circumferential groove 32 of each piece 31 of the outer mold B and is molded into a desired shape.

After this state is maintained for a certain period of time to form the base portion 40, the cylinder 19 is first activated by the action of a solenoid valve such as a timer, and the expansion member 28 is
When the rotating body 29 is lowered to reduce the inner mold A, a solenoid valve is actuated by a limit switch or the like, and the pressure fluid in the cylinder 21 is discharged from the outlet 25, the piston 22 is lowered by the spring 35, and the outer mold B is also lowered. Expand and descend.

After that, cylinders 7 and 1 are activated by the action of relays and solenoid valves.
0 operates in sequence to raise the inner mold A and the cylindrical body 14, and finally to raise the top plate presser frame 12 and leaf spring 13, completing a series of molding operations.
When removed and turned over, it becomes a mouthpiece 40 which has an arc-shaped bent part 42 as shown in FIG. 7 and is integrated with the top plate 38 whose lower part is tapered. The container is completed by fixing it to the upper edge.

After molding in this manner, a conventional crown cap can be attached to the base portion 40.

As described above, the device of the present invention has a recessed part in a part of the metal plate, an opening in the center of the recessed part, and a cylindrical shape protruding into the recessed part using the peripheral edge of the opening as a base part. Fix the top plate to the top plate holder with the base facing downward, fit the base into the opening provided in the top plate holder, and insert the protrusion around the opening into the inner surface of the peripheral wall of the recessed part of the top plate. Since it is fitted, the base forming part of the top plate is held in an extremely stable state. In addition, the inner mold is lowered and fitted into the base of the top plate held in this way, and the outer mold is fitted from below to the outside of the base, and the inner mold is expanded while holding the outside of the base with the outer mold. By rotating, the inner side of the mouthpiece is pushed out by the protrusion of the inner mold, and the outside of this extruded part is fitted into the circumferential groove on the inner periphery of the outer mold to form the mouthpiece, and then the outer mold and the inner mold are removed from the mouthpiece. Since the inner mold rotates to form a mouthpiece with a bent part, that is, a bead part, it is more similar to drawing than press working, and therefore, a split mold that does not rotate is used. There is no risk of wrinkles occurring in the bead portions, unlike when molding is done using a molding method, and a product with extremely smooth bead portions can be obtained. In addition, by providing an outer mold lifting/lowering opening/closing cylinder for raising and lowering the outer mold as well as opening/closing the outer mold, and an inner mold opening/closing cylinder for opening and closing the inner mold, the inner mold and the outer mold can be separated. Opening and closing should be done from below,
In particular, the expanding member of the inner mold that is raised and lowered by the cylinder for opening and closing the inner mold is rotatable, so it can be expanded without any problem even if the inner mold is rotating.After molding, the outer mold opens and descends. Since the inner mold shrinks and rises, there are advantages such as easy removal of the top plate after molding.

[Brief explanation of the drawing]

Fig. 1 is a front view showing one embodiment of the device of the present invention, Fig. 2 is a side view of the same as above, Fig. 3 is a partially enlarged cross-sectional plan view, and Figs. 4 and 5 show each operation of the main parts. FIG. 6 is a partial longitudinal sectional front view of the top plate before processing the base part, and FIG. 7 is a partial vertical front view of the top plate after processing the base part. 4...Top plate pedestal, 5...Protrusion, 6...Opening, 7...Cylinder, 8...Motor, 17, 31...piece, 18...Protrusion, 19...Inner mold opening/closing cylinder, 21...Outer mold lifting/lowering opening/closing Cylinder, 26...Rotary rod, 27...
Coupling ring, 28... Expansion member, 29... Rotating body,
32... Circumferential groove, 38... Top plate, 40... Mouth part, 41...
Recessed part, A...Inner mold, B...Outer mold.

Claims (1)

[Claims] 1 A recessed part is provided in a part of the metal plate, an opening is provided in the center of this recessed part, and the top plate is made to protrude into the recessed part in a cylindrical shape with the periphery of this opening as the base, and the base is turned downward. A top plate holder is provided to receive the
This pedestal is provided with an opening into which the base of the top plate fits, and a protrusion which fits into the inner surface of the circumferential wall of the recessed part of the top plate, and above the top pedestal, the cradle is rotated by a cylinder or a motor. It descends, rotates and fits into the cap part in a contracted state, and then expands while continuing to rotate, forming the inside of the cap with the protrusion at the lower end, and then providing an inner mold that shrinks and rises. At the bottom, there is a periphery that rises in an expanded state and fits into the outside of the mouthpiece, and then contracts to hold the outside of the mouthpiece and fit into the protrusion on the outside of the mouthpiece pushed out by the protrusion of the inner mold. An outer mold having a groove that expands and descends after the mouthpiece is molded is provided, and below this outer mold there is an outer mold lifting/lowering/opening/closing cylinder that lifts and lowers the outer mold and also opens and closes the outer mold. 1. An apparatus for forming a mouthpiece of a metal container, characterized in that an inner mold opening/closing cylinder for opening and closing a mold is provided, and an expanding member of the inner mold that is raised and lowered by the inner mold opening/closing cylinder is rotatable.