JPS649398B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is directed to a surface hardening method for a surface hardened can lid seaming tool for double seaming the opening outer peripheral flange edge of an empty can or a can body filled with contents, together with the outer peripheral curled edge of a can lid to be superposed and polymerized. Related. As shown in FIGS. 1 to 4, the prescribed series of operations performed by the can lid tightening tool are as follows: A can body 2 on which a can lid 1 is placed is carried onto a lifter plate 3 that revolves and rotates on its axis. The can lid 1 is fitted to the upper seaming chuck 4 which synchronously revolves and rotates together with the lifter plate 3 as it rises, and the upper and lower parts are gripped by the seaming chuck 4 and the lifter plate 3, and at the same time primary seaming is performed. The roll 5 comes horizontally and presses the can lid 1 with the annular groove 5a of the primary seaming roll 5 against the outer curled edge 1a of the can lid 1 backed up by the lip 4a of the seaming chuck 4. rapidly rotating around the
The outer peripheral curled edge 1a is rolled under the open outer peripheral flange edge 2a of the can body 2 [see Fig. 3], and then the secondary seaming roll 6 comes horizontally and the can body rolled up by the primary seaming roll 5. 2 and can lid 1
By compressing and filling the outer peripheral flange edge 2a and the outer peripheral curled edge 1a between the annular groove part 6a of the secondary seaming roll 6 and the lip part 4a of the seaming chuck 4, the seaming part α is formed. See figure]. 2
Next, at the same time as the seaming roll 6 retreats, the lifter plate 3 descends, and the can container is automatically carried out of the lifter plate 3. Due to such harsh processing conditions, increased processing speed, and the use of high-hardness lid materials made of stain-free steel, which have recently been frequently used, the life of conventional martensitic stainless steel can lid tightening tools has decreased. As a result, frequent replacement of tightening tools and tool management for maintenance and maintenance become extremely difficult, resulting in lower operating rates and variations in the quality of cans and containers. The appearance of a can lid tightening tool is eagerly awaited. In response to this long-awaited demand, the present invention provides a surface hardening method for a can lid seaming tool that is subjected to surface hardening treatment that has the durability and abrasion resistance of super hardness that guarantees work management and stable high quality of can containers. This is what we intend to provide. An embodiment of the invention will be described with reference to FIG. The can lid tightening tool A that performs the surface hardening method of the present invention is:
A seaming chuck 4 made of martensitic stainless steel or alloy tool steel that fits inside the can lid 1, and an outer peripheral curled edge 1a of the can lid 1 that is adjacent to and overlaps the outer periphery of the seaming chuck 4 so as to be accessible thereto. and a primary seaming roll 5 and a secondary seaming roll 6 made of martensitic stainless steel or alloy tool steel that can freely roll around the outer peripheral flange edge 2a of the can body 2;
A lifter plate made of martensitic stainless steel or alloy tool steel that can be moved up and down, on which a can body 2 with a can lid 1 is placed on the opening, and which moves up and down to push the can lid 1 into a seaming chuck 4. 3, for surface hardening of the required parts of the can lid seaming tool A,
The lip portion 4a of the seaming chuck 4 that is in back-up contact with the inner circumferential surface 1b of the can lid 1 is the one that is most likely to wear out.
In order to prevent the slipping phenomenon with the inner peripheral surface 1b of the can lid 1 that comes into contact with the can lid 1 during back-up work and to exhibit sufficient braking function, the surface is polished by honing or shot peening after grinding to about 5 to 15 microns. The surface is then roughened to form a rough surface, and then exposed to a high temperature atmosphere of a mixed reaction gas containing gaseous titanium tetrachloride, hydrocarbons, and hydrogen for the required reaction time to form a titanium carbide coating treatment on the rough surface. A 5-20 micron pure titanium carbide layer TiC is deposited and coated stably. In addition, the lifter plate 3 is prepared by performing quenching (vacuum quenching) under the time and temperature conditions shown in FIG. After grinding the upper surface of the lifter plate 3, which is most likely to wear due to the sliding action when carrying in and out of the can bottom 2b, a smooth surface is formed by lapping or buffing. A titanium carbide coating treatment similar to that described above is applied from above to stably deposit and coat a pure titanium carbide layer TiC of 5 to 20 microns on the smooth surface. Figure 6 shows martensitic stainless steel
The case of quenching heat treatment conditions for SUS440C is shown,
(SKD11) also describes the quenching heat treatment conditions for SUS440 C and different alloy tool steels.The quenching treatment is finally rapidly cooled to room temperature under nitrogen gas _N2 pressure, H represents time, and M and MIN represent minutes, respectively. . In the figure, reference numeral 7 indicates a downward concave portion at the lower end of the seaming chuck 4, which is attached to the lower end of a knockout rod 9 that vertically and slidably passes through the rotary tube 8 to which the seaming chuck 4 is screwed. Knockout pads that appear and move up and down from within 4b, 10, 11, 1
2 is a bearing. Incidentally, the titanium carbide coating treatment is not limited to the embodiments of the present invention, and naturally includes other possible means. Here, we used conventional martensitic stainless steel SUS440 C which does not have surface hardening, and martensitic stainless steel which was surface hardened by special surface treatment and titanium carbide coating treatment as in the example.
A comparison table is shown in durability tests of seaming chucks 4 and lifter plates 3 made of SUS440 C and alloy tool steel SKD11 (the can lid is made of the aforementioned stain-free steel). However, unit: 10,000 cans/Head SUS440 C: Martensitic stainless steel SKD11: Alloy tool steel HRC: Rockwell hardness.

[Table] From the above data, it can be seen that for seaming chucks, SKD11 has a base material with a hardness lowered from the typical HRC of 60 to 62 to 57 to 59. In addition, in the case of lifter plates, those with surface hardening have a service life about five times longer than those without surface hardening. In manufacturing the seaming rolls 5, 6 and seaming chuck 4 of the can lid seaming tool A which is subjected to the surface hardening method of the present invention, martensitic stainless steel with high quenching hardness is used as pre- and post-quenching heat treatment for titanium carbide coating treatment. Or, by using alloy tool steel as the base material, the pure titanium carbide layer TiC, which is precipitated and coated with titanium carbide coating, adheres well and stably to the surface of the base material without fear of peeling. Since the alloy tool steel also has viscosity, it was also confirmed that it is effective in eliminating the cracking phenomenon that has frequently occurred in the past on the seaming chuck 4, which is subjected to repeated impact loads by the seaming rolls 5 and 6. In this way, the can lid tightening tool A that performs the surface hardening method of the present invention has at least the outer surface parts of the seaming chuck and lifter plate that are most likely to be worn out coated with titanium carbide to have an ultra-high hardness finish. Abrasion resistance and durability are dramatically improved,
Due to the long life, fewer tools need to be replaced, which increases the conversion rate, and also greatly simplifies tool management for maintenance, inspection and maintenance, as well as production work management, which further improves the quality of cans and containers and meets the demands for high-speed mass production. satisfy. However, since the pure titanium/carbide TiC surface hardening layer has a small coefficient of friction, it is more likely to slip, but since the lip portion 4a of the seaming chuck 4 has been treated to prevent slipping, the seaming accuracy increases and sealing performance is improved. In addition to ensuring perfect quality stability, the upper surface of the lifter plate 3 has been smoothed to further reduce the friction coefficient of the pure titanium carbide layer TiC itself, reducing wear to the highest possible level. It has excellent effects such as dramatically extending the lifespan.

[Brief explanation of drawings]

Figures 1 to 4 are explanatory diagrams of a series of prescribed step-by-step processing using a can lid seaming tool, and Figure 5 shows a can lid seaming tool that performs the surface hardening method of the present invention and a seaming head to which it is attached. The central vertical cross-sectional view and FIG. 6 show a time chart of the quenching heat treatment conditions for the seaming roll as a preliminary treatment. A...Can lid tightening tool, 1...Can lid, 1a...Outer curled edge, 1b...Inner circumferential surface, 2...Can body, 2a
...Outer flange edge, 3...Lifter plate,
4... seaming chuck, 4a... lip part,
5...Primary seaming roll, 6...Secondary seaming roll, TiC...Pure titanium carbide layer.

Claims (1)

[Scope of Claims] 1. In a seaming tool comprising a seaming chuck, a seaming roll, and a lifter plate, the lifter plate is subjected to heat treatment as a quenching treatment in which at least carbon of the base material is precipitated on the surface of the base material as a preliminary treatment. A can lid tightening tool which increases the surface hardness of the lifter plate by smoothing at least the upper surface of the lifter plate on which the bottom surface of the can body is placed and then applying a titanium carbide coating treatment to the surface. surface hardening method. 2 Titanium carbide coating treatment involves exposing the material to a high-temperature atmosphere of a mixed reaction gas containing gaseous titanium tetrachloride, hydrocarbons, and hydrogen for the required reaction time to precipitate a layer of pure titanium carbide of 5 to 20 microns on the outer surface. A method for hardening the surface of a can lid seaming tool according to claim 1.