JPS61229483A - Production of welding can shell - Google Patents

Abstract

PURPOSE:To concentrate a thermal energy onto the polymer part of can shell blanks and to produce the welding can shell easily without pretreatment by specifying the surface roughness of the pressure face of a wire electrode. CONSTITUTION:One face or both faces of the pressure face of a wire electrode is taken as the surface roughness of 5-800mumRa in the production of a welding can shell. In case of using the wire electrode 1 with the roughness on one face the inner rough face 1A of the pressure faces 1A, 1B of the wire electrode 1 comes into contact with the inner and outer faces of the polymer part of the can shell blank 5. The fine unevenness cut on the surface of the wire electrode is cut into the surface of the can shell blank 5 which is softened by heating during welding, reducing the electric resistance by destroying the thin highly electrical resistance film on the surface of the plate and the contact area between the plate and wire electrode is enlarged. The temp. of the surface of the seaming is kept comparatively lower by releasing the heating from the joining interface of the plate efficiently to the upper and lower rotary electrodes sides and the thermal energy is concentrated onto the polymer part of the can shell blank.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for manufacturing a welded can body, and more specifically to a wire electrode whose surface roughness has been adjusted in advance! This invention relates to a method of manufacturing a welded can body to be used.

[Prior art]

Conventionally, can body welding of round cans such as beverage cans, food cans, art cans, aerosol cans, and square cans such as 18-liter cans has been carried out using a wire *a or a welding machine (so-called Sudronik welding machine). It's here. If the can body material is made of a material with good weldability, such as tin plate or ultra-thin tin-plated steel plate (hereinafter sometimes referred to as LT8), can body welding is easy, and
2. Some airtightness 1. Performance such as strength and corrosion resistance was also good and there were no problems. [7] Chrome-type tin-free steel (hereinafter also referred to as TFS) and other Ni-plated steel sheets, or Ni, Sn and/or Cr, are often used in place of tin due to economical and other requirements.
In the case of multi-layer plated steel plates, welding may be difficult due to the large contact resistance between the plates unless the area to be welded is thoroughly ground or otherwise processed, and even if welding is possible, the finish of the welded area may be poor. There was a problem that I+ was bad.

So this is the problem! In order to solve this problem, improvements were made to the weldability of the can body material, and several improvements were also made to the welding method using welding machines.

For example, rotating electrodes! 1) with increased pressure, or II with increased pressure using an internal pressure method (Japanese Patent Application Laid-Open No. 57-15927
5) Repeated use of wire electrodes C; Wire electrodes! Method of cleaning and shaping to a specified width (Unexamined Japanese Patent Publication No. 56-770)
77) were proposed.

Improvements have also been made to power supply devices.

However, at present, none of the means has solved Q) in practice, and the above-mentioned problem has not yet been completely solved.

In other words, the method of removing the coating by grinding has the disadvantage that the coating dust after grinding adheres to the area around the welded part, and the welded part, which is the part to be ground, has no surface treatment coating, resulting in a significant decrease in corrosion resistance, and even after repair. There are drawbacks such as insufficient recovery. Furthermore, various improvements have been made to welding equipment and welding conditions for the purpose of welding without removing the coating Q) polishing! Even if they try, commercial production tends not to be cost-effective11.Moreover, it has the disadvantage that it is difficult to obtain welded can bodies of stable quality.

However, as far as the present inventors are aware, the technical idea of improving weldability by adjusting the surface roughness of a wire electrode as in the present invention has not yet been proposed.

Therefore, the inventors of the present invention noticed that the surface roughness of the wire electrode is related to weldability, confirmed its effects, found the appropriate roughness range through experiments, and further considered! As a result of this progress, we have arrived at the present invention.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing a welded can body by welding a material conventionally considered difficult to weld, such as TF8, without any pretreatment such as surface grinding of the portion to be welded in the can body blank.

Another object of the present invention is to expand the weldable current range (ACR) regardless of the material of the can body! The purpose of the present invention is to provide a method for manufacturing a welded can body.

Still another object of the present invention is to expand the range of current that can be used to weld any can body material by simply replacing only a few parts of a conventional can body seam welding machine. The purpose is to provide a manufacturing method.

[Structure of the invention]

According to the present invention.

In the method of manufacturing welded can bodies using a seam welding machine using a wire electrode i, one or both sides of the pressure receiving surface of the wire electrode used must be adjusted to a surface roughness of 5 to 800 μm Ra! A method of manufacturing a welded can body is provided.

The present invention will be described in detail below using Examples.

Figure 10 shows the wire electrode transfer path in a conventional wire electrode can body seam welding machine! FIG.

In FIG. 4, a bare or plated annealed copper wire having a diameter of 1.3 to 151 Ll is conventionally used for the wire electrode.

The wire electrode 1 is continuously supplied as an annealed copper wire with a circular cross section from a package 2 in the direction of the arrow, and is first guided to a wire mashing device attached to a welding machine. The wire matshu device 3 has a pair of smooth circumferential surfaces! Forming rolls 4A and 4B having
Mild steel wire between forming rolls! It is pressed and rolled to form a flat cross-sectional shape with a pressure-receiving surface necessary for an electrode. At the same time, the annealed copper wire is mechanically hardened and has a suitable hardness.
Ru.

Next, the wire electrode 1 is first used as a can body internal electrode (lower side) and then again as a can body external electrode (upper side), and the can body blank 5 is moved sequentially to the left in FIG. Weld seams. Finally, it is cut into small pieces by a cutting machine 10 and discharged.

The conventional wire mashing device shown in Fig. 410 is shown in Q) above.
11 Consists of a flat or concave roll with a smooth surface 1
In the present invention, as shown in FIGS. 3, 4, 5, and 6, one or both of the forming rolls are provided with knurling or roughness. That is, FIG. 3 is a side view of an embodiment of the present invention in which only four upper forming rolls of the wire mashing apparatus are rough-faced rolls (diagonal), and the lower forming roll 4B is a smooth roll. In this case, the wire electrode is generally reversed midway through. FIG. 4 is an enlarged perspective view of the forming roll in FIG. 3, and FIG. 5 is an enlarged view of the forming roll of another embodiment in which the upper and lower forming rolls are rough-surfaced rolls (twill). In addition, in FIG. 6, two pairs of forming rolls are arranged in tandem, the first stage of smooth forming rolls 4A and 4B perform conventional wire mashing, and the second stage of rough surface forming rolls 4A.
FIG. 4 is a side view showing a device for transferring roughness to both the upper and lower pressure-receiving surfaces of the wire electrode 1 at A and 4BB. In this case, wire electrode 1
does not need to be reversed. Figure 7 shows two pairs of forming rolls that provide a rough surface on only one side as shown in Figure 4! distance! FIG.

In this case, the wire electrode once used as the lower electrode is re-formed by the forming roll and the roughness is transferred again at the same time, so it is supplied as the upper electrode without crushing the rough surface peaks, and the present invention is highly effective. .

Note that at this time, the wire electrode 1 is reversed halfway.

FIGS. 1 and 2 are sectional views showing an embodiment of the present invention at a beam welded portion.

Figure gS1 shows the case of using the wire electrode 1 with roughness on one side as shown in Figure 33 or Figure 7.

The pressure receiving surface IA of the wire electric bridge 1 and the inner assembly surface IA of the IB are in contact with the inner and outer surfaces of the overlapping portion of the can body blank 5. In this case, the same surface of both the lower electrode and the upper electrode is in contact with the can body blank, and the back side is the smooth pressure-receiving surface 1B. The electrical contact is particularly good.

Figure 2 shows both the upper and lower pressure-receiving surfaces of the wire electrode as shown in Figure 15 or Figure 6! This is the case when the surface is roughened.

The embodiment of the present invention is not limited to the cases shown in FIGS. 1 and 82, but has separate wire electrodes for the upper and lower electrodes! An electrode arrangement where the rough surface contacts only the inner surface or only the outer surface of the can body blank using a single wire electrode by feeding or by combining a rough surface forming roll and a smooth surface forming roll! You can also do that.

Even more! It is also possible to intersect the axes of the vertically rotating electrodes as shown in Figure J8.

Materials for the wire electrode used in the present invention include wires made of brass, bronze, beryllium copper, silicon steel, aluminum bronze, silver-containing copper, and silicon bronze as annealed copper wire, hard copper wire, and copper alloy wire. Alternatively, a metal or alloy such as aluminum or aluminum alloy wire having a conductivity of 50% or more and a tensile strength of 15 to 70 KP/m2 is preferably used.

Furthermore, these copper, aluminum or their alloy wires are subjected to surface treatments such as plating to improve contact resistance! It can also be used as

Metals with relatively low melting points and good conductivity such as tin, zinc, aluminum, and silver are suitable for plating.Metals for plating include hot-dip plating, electroplating, sputtering, vacuum steaming,
Means such as ion brating and CvD can also be used.

In addition, the roughness given to the wire electrode is 5 to 8 in the present invention.
00 μRa. Note that Ra is as defined in JI8o). This is because if the roughness is less than 5μRa, the effect of the present invention will not be recognized, while if it exceeds 800μRa, false wire cutting accidents will occur (+), and the strength of the welded part of the can body will tend to decrease. It is from.

If the roughness is small, it will be matte or scratch-like, but if the roughness is large, around 50 μRa, flat, twilled, or slanted/grained Z can be used.

And a wire electrode with these chisel-like notches on one side! When welding using it! As shown in figure J9, the nugget 15 is generated corresponding to the crest of the wire electrode l, so the nugget pitch t! It can be controlled by the lth pitch. In other words, Figure 9 shows rough chisel-like notches! Wire electrode attached! It is a sectional view showing the state where can body blank is welded using it.

This invention! An example of the applied welding results will be briefly described.

The wire electrode forming roll has a pitch of approximately 0.4111 and a depth of approximately 350 μm! Motsu twill roll! The copper wire was formed into a width of 2 km and used for welding.

As a result of welding experiments using TFS-CTv as the material to be welded, it was found that both the strength and sealing properties of the welded part were excellent, and the appearance was also retransferred to the surface of the fume seam part with the notches transferred to the electrode wire. A beautiful geometric pattern was formed. Furthermore, electron microscopic observation of the seam surface revealed that the chromium film remained on one surface, and unlike the conventional grinding method, there was no risk of deterioration in corrosion resistance.

[Action of the invention]

The reason for the improvement in weldability according to the present invention is considered as follows.

During welding, the fine irregularities carved on the surface of the wire electrode dig into the surface of the can body blank 5, which has been softened by heat generation, and destroy the thin high electrical resistance coating on the surface of the plate, lowering the electrical resistance. In addition to reducing the heat generated from the parts, by expanding the contact area between the plate and the wire electrode, and by efficiently dissipating the heat generated from the bonding interface of the plates to the vertically rotating electrode side, the temperature of the seam surface is always relatively low. It is thought that this is because it is possible to concentrate thermal energy on the overlapping portion of the can body blank.

〔Effect of the invention〕

By implementing the present invention, all of the above objectives are achieved.

In other words, surface-treated steel sheets like TF8, which were previously difficult to weld without pretreatment! Welded can bodies can now be easily manufactured without pretreatment.

In addition, chromate CR is expanded in cold-rolled steel sheets, N1-plated steel sheets, Cr-plated steel sheets, ultra-thin Sn-plated steel sheets with a thickness of less than 5, galvanized steel sheets, or even these, which has the effect of making welding easier. .

[Brief explanation of drawings]

The mX diagram and FIG. 2 are sectional views of the seam weld according to the embodiment of the present invention, and FIG. 3 is a side view of the embodiment showing the wire electrode path when roughening is imparted to one side. Figure J4 is an enlarged perspective view of the forming roll in Figure 3, Figure 5 is a perspective view of another embodiment, Figures 6 and 7 are side views showing wire electrode paths in another embodiment, and Figure 8 is an enlarged perspective view of the forming roll in Figure 3. The $9 figure, which shows an example of an embodiment in which the axes of the vertically rotating electrodes are crossed, shows how nuggets are formed! Side sectional view shown, No. 10
The figure is a side view of a conventional wire electrode path. 1...Wire electrode, IA, IB...Curved pressure receiving surface, 4...Wire mashing device, 4A, 4B...Curved forming roll, 4AA, 4BB... Forming roll, 5...
... Can body blank, 6A, 6B... Rotating electrode, 7A, 7B... Electrode groove, 15...
... Nugget.

Claims (3)

[Claims] (1) A welded can body manufacturing method using a seam welding machine using a wire electrode, characterized in that one or both sides of the pressure-receiving surface of the wire electrode used is adjusted to a surface roughness of 5 to 800 μm Ra. How to manufacture the body. (2) Claim 1 in which the surface roughness adjustment of the wire electrode is performed by a wire mashing mechanism attached to a seam welding machine.
Method for manufacturing the welded can body described in Section 1. (3) The method for manufacturing a welded can body according to claims 1 and 2, wherein the welded can body material is tin-free steel.