JPH0316208B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides a modification that prevents variations in can height reduction.
Related to expansion molding equipment for DI cans. Generally, when a DI can is expanded to enlarge the outer periphery of the can body, the can height usually decreases, but the rate at which the can height decreases varies from can to can, and also from part to part within the same can. This means that the variation in the height of the expanded empty cans has increased, and the variation in the height of the cans may become a problem in the subsequent seaming process. The present invention aims to provide an expansion molding apparatus for deformed DI cans that prevents this variation in can height reduction, and is as follows. The present invention installs a bottom shear pad on the outside of the bottom of a DI can for regulating the advancement of an expander pin and a flange shear pad pressing device, and a bottom support ring that approximates the bottom wall surface on the inside of the can bottom. A flange shear pad is installed inside the can, and a flange shear pad is provided on the outside of the can flange, which resembles the flange shape and prevents fluctuations in flange length, and inside the can, a plurality of segmented segments having ring-shaped protrusions on the outer periphery are installed. Then, an inclined hole that fits the slope of the tip of the expander pin is bored in the common axis of these divided segments, and the expander pin and flange shear pad are pressed to press the divided segment and the flange shear pad. This is an expansion molding device for deformed DI cans, which is characterized by the installation of this device. The present invention will be further explained based on embodiments shown in the drawings. FIGS. 1 and 2 are longitudinal sectional views of an apparatus for expanding and molding modified DI cans according to the present invention, and FIG. 1 shows a state in which a DI can 1 that has been subjected to neck-in processing and flanging before expansion molding is loaded. and DI can 1 has flange shear pad 4.
and is held by the bottom pusher pad 7. That is, FIG. 1 shows the state before the cam 9 held by the cam rolls 8, 8 at the left end of the expander pin 3 expands the segment 5, and the segment 5 is pulled toward the central axis by a spring (not shown), and the DI This makes it easier to search for Can 1. The flange shear pad 4 is also connected to the cam 1 via the cam roll 10.
1, but this is also the state before activation. Fig. 2 shows a state in which a deformed DI can 2 is formed by expand molding, and the expander pin 3 expands the segment 5 actuated by the cam 9 via the cam rolls 8, 8, deforming the DI can 1 in the radial direction. The bottom of the can is pressed against the support ring 6 in the axial direction by the bottom push shear pad 7, and the flange part is also pushed by the cam 11 via the cam roll 10, so that the can bottom is expanded and simultaneously reduced in the axial direction of the can. This is a state in which the pad 4 is actuated and pressed in the direction of the can axis. That is, in order to prevent variations in can height reduction, the can height of the deformed DI can is regulated by the bottom push shear pad 7 and the flange push shear pad 4 during molding, and the can height is molded to a predetermined can height. Figure 3 shows the operating timing diagram of the expand molding device, with time (t) on the horizontal axis and operating state (L) on the vertical axis, where A is the bottom push shear pad and B is the flange push shear pad. C and C are expander pins 3. Next, we will explain the operation over time. When A completes loading DI can 1 before expansion molding,
starts operating. B presses the bottom of the can.
(A is operated by a pneumatic cylinder and presses the bottom of the can as the can height decreases. However, the pressing force is strong enough not to buckle the DI can 1.) At the same time, C is activated. Start and expand the can diameter. (C) is the point where the can is completely held in segment 5, at which point B starts operating and C stops operating (D) That is, B also stops operating when segment 5 is fully expanded. , the molding of the modified DI can 2 is completed. After completion of molding, the expander pin 3 reversely operates at E after a certain period of time, and the segment also reduces its diameter by the force of a spring (not shown), returning to the state of (B) at (G). Also, E is also E.
The cam 11 begins to move away from the cam roll 10 and moves away from the flange of the can due to the force of a spring (not shown) (F), returning to the state shown in (C). In case of (A), the pneumatic cylinder operates in reverse at the time (G) when all the operations in (C) are completed, and at (H) it returns to the state of (A). Next, Table 1 shows the results of an experiment comparing the variations in can height between the modified DI cans molded according to the present invention and the modified DI cans without the use of the support ring 6 and flange pusher pad 4.

[Table] The DI can used in the above experiment before expansion molding was made of aluminum, with a can diameter of 94 mm, a can height of 151 mm, and an expansion rate of 8%. It can be seen from Table 1 that the present invention using a support ring and flange push shear pad is superior.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of the expand molding device showing the state before expansion molding, Fig. 2 is a longitudinal cross-sectional view of the expand molding device showing the state during expand molding, and Fig. 3 shows the operation timing of the expand molding device. It is a line diagram. 1... DI can before expansion molding, 2... Deformed DI can, 3... Expander pin, 4... Flange shear pad, 5... Segment, 6
...Support ring, 7...Bottom push pad, 8...Cam roll, 9...Cam, 10...
Cam roll, 11...cam.

Claims (1)

[Claims] 1. A bottom shear pad for regulating the advancement of the expander pin and flange shear pad pressing device is installed on the outside of the bottom of the DI can, and a bottom support ring that approximates the bottom wall surface is installed inside the can bottom. , a flange shear pad similar to the flange shape and for preventing fluctuations in flange length is provided on the outside of the can flange, and a plurality of segmented segments having ring-shaped protrusions on the outer periphery are installed inside the can. Drill an inclined hole that fits the slope of the tip of the expander pin in the common axis of the divided segments, and install an expander pin and flange shear pad pressing device to press the divided segment and the flange shear pad. This is an expansion molding device for deformed DI cans.