JPS5940104B2 - Coated metal plate manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a coated metal plate in which a through hole is drilled in a coated metal plate material having a resin coating on the surface of a metal substrate such as an iron plate or a steel plate, and the through hole is exposed at the cut end surface of the periphery of the through hole. The purpose is to prevent rust on metal substrates.

Conventionally, in the manufacturing method of such a coated metal plate, there is no suitable method for coating the metal substrate exposed at the cut end surface of the peripheral edge of the through hole, resulting in high costs, so in many cases the metal substrate is left exposed. Ta.

The present invention has been made in view of this background, and will be described below based on an embodiment according to FIG. 1, which shows the processing order, and FIG. 2, which shows the main processing steps.

FIG. 1a and FIG. 2a show a coated metal plate material 1, and a metal substrate 2 made of, for example, a strip material made of steel plate or iron plate.
Resin coating such as vinyl chloride resin or polypropylene resin 3
For example, it is coated by extrusion molding or dipping. FIG. 1b shows the step of pressing the heating punches 4, 4 against the coated metal plate material 1 to heat-melt only the resin coating 3 and punch holes 5, 5.

At this time, the resin pushed away by the heating punch 4 forms a resin build-up portion 6 on the periphery of the hole 5. FIG. 1c and FIG. 2b show the state after such a process. FIG. 1d shows a through hole 7 made by, for example, a drill or a punching die in the metal substrate 2 exposed in the hole 5 obtained through FIG. 1c. Fig. 1e shows that the resin build-up portion 6 is heated and melted using heating molds 8, 8, which have a protrusion Ba that is slightly smaller than the hole 5 and fits loosely into the hole 5, and are in contact with the resin coating 3 surface. This shows a step of covering the exposed metal end face of the through hole 7. FIG. 1f shows a completed coated metal plate obtained through this process. As described above, in the coated metal plate manufacturing method of the present invention, the through-holes are not drilled through the resin coating and the metal substrate all at once, but after the holes for forming the resin build-up portion are formed, the through-holes are drilled, and then the through-holes are drilled through the resin coating and the metal substrate. Since the exposed metal end face of the through hole is covered by heating and melting the embankment, there is no need for special processing or treatment, and there is no need for the assistance of other resin materials. Even the fabricator who purchased the product could easily cover the exposed metal end face of the through hole.

[Brief explanation of the drawing]

1 and 2 show embodiments of the present invention.
The figure shows a cross-sectional view of the coated metal plate and processing equipment showing each processing step,
FIG. 2 is a perspective view of the same as the above showing the main part machining process.

Claims (1)

[Claims] 1. In a coated metal plate material having a resin coating on the surface of the metal substrate, a heated punch is pressed to punch a hole through only the resin coating, and a resin overlay is formed around the hole, and then a metal substrate portion corresponding to the hole is formed. A method for manufacturing a coated metal plate, characterized in that a through-hole is bored through the through-hole, and the resin overlay is heated and melted to cover the exposed metal end surface of the through-hole.