JPH0144433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a welding machine for welding the side seam of a metal can body such as a tinplate plate by electric resistance welding. The present invention relates to an improvement of a welded member guide component that guides a welded member between the parts.

The combined structure of a welded member guide part and its peripheral parts in this type of known can body welding machine is shown in FIG.

In these figures, 1 is an upper electrode roll, 2 is a lower electrode roll located directly below the upper electrode roll 1, and 3 is a lower electrode roll.
is a horizontal support component that supports the lower electrode roll at one end (this also supports the intermediate guide component described later); 4 is fixed to the main body wall plate (not shown) of the welding machine; 6 is an intermediate guide component installed on the support component 3 and located immediately in front of the rear guide component 5; , 7 are front guide parts, and the intermediate guide part 6
It is installed in the front cutout part of the support part 3 and above the support part 3, has a tip part 8 located close to between the upper and lower electrode rolls 1 and 2, and has guide grooves 16 and 16' provided up to the tip part 8. It is being Reference numeral 9 denotes a front fixing part for fixing the front guide part 7, which is tightened with a nut 12 by a bolt 10 passing vertically through the horizontal protruding piece 11 fixed to the main body wall plate. There is. 14 (FIG. 2) is a bolt for attaching the front guide component 7 to the flat plate 13 of the front fixing component 9, and 15 and 15' are electrical insulating plates for insulating each of these components.

A is a can body, and both end edges B and C forming a side seam are inserted into the guide grooves 16 and 16' provided in the front guide part 7, respectively. The guide grooves 16 and 16' are similar to the guide grooves 18 and 18'(18' not shown) provided in the intermediate guide part 6, and the guide grooves 19 and 19'(18' provided in the rear guide part 5), respectively.
9' (not shown).

With reference to FIG.
23 is a passage for cooling water to cool the support part 3, 23 is a passage for electrode wires, and left and right notches 24 and 25 are for passage of wiring for paint pipe and paint amount detection, respectively. It is something.

In the device shown in FIGS. 1 and 2, a cylindrical can body made of a metal plate advances from the left in FIG. Guide groove 1 of rear guide part 5
9 and 19', proceed to the right in the figure, pass through the guide grooves 18 and 18' of the intermediate guide part 6, and be guided by the guide grooves 16 and 16' of the front guide part 7, and the tip of the front guide part. 8, the two end edges B and C are fed between the upper and lower electrode rolls 1 and 2 in an overlapping state, and while passing between the two electrodes, they are heated by current resistance and pressurized by both electrode rolls. and then welded. Welding current is from upper electrode roll → can body →
Flows from the lower electrode roll to the supporting parts.

Although not shown as a welding machine for can bodies made of tin plate, it is equipped with wire electrodes that are wound around both upper and lower electrode rolls and move forward as the electrode rolls rotate. A type that is inserted between edge electrodes and welded is currently in use. This welding machine also includes guide parts shown in FIG.

In any case, the can body side seam welding machine has the ability to weld at a speed of 50 m/min, and the frequency is 420 Hz.
The primary current is 120A, the secondary current (= welding current) is
Good welded side seams of metal can bodies have been obtained with 3600A.

The present inventors have been pursuing measures to increase the welding speed and improve production efficiency using the same equipment, and as one experiment, the welding speed was increased to 70 m/min.
When the welding machine was operated with a frequency of 600 Hz and a primary current of 130 A to increase the frequency to 130 A, approximately 10 minutes after the start of operation, cans with poor welding areas and the plating layers on both sides of the welded areas were melted. Some cans had peeling or burnt protective layers. So,
When the operation was stopped and examined, it was found that the guide grooves of the guide parts, especially the guide groove 1 of the tip part 8 of the front guide part 7.
Adhesives were seen at 6 and 16', and the adhesion was found to be tin plating and a protective coating film separated from the can body.

As a result of experiments and measurements conducted to investigate the cause of the above situation, it was found that after the welding machine started operating, the temperature at the tip 8 of the front guide part 7 rose rapidly, and at a frequency of 600 Hz and a primary current of 130 A. is the temperature increase,
It was found that the relationship with the elapsed time from the start of operation is as shown in graph Z shown in FIG.

From this graph, 10 minutes after operation, the temperature is approximately 300℃.
It is known that the temperature exceeds 350℃ after 20 minutes, and both edges of the can body slide into contact with the groove wall of the front guide part, which is at such a high temperature, and the coating film on the surface of the can body slides. It was presumed that the tin and tin had peeled off, melted, and adhered to the groove.

Furthermore, when the frequency is 420Hz and the primary current is 120A,
Experimental measurements revealed that the temperature of the front guide parts reaches approximately 180°C 20 minutes after the start of operation, but thereafter the temperature is maintained at approximately 180°C.

The present invention was made as a result of the above-mentioned experiments and research, and even when the known welding machine shown in Fig. 1 is improved and high-speed welding is performed, the plating layer on both sides of the welded part of the can body remains. To provide a can body welding machine that does not melt or cause a protective layer to peel or burn. In order to achieve the above purpose,
The present invention aims to maintain the temperature of the front guide component tip during welding at a temperature that does not damage the surface protective layer of the sliding portion of the can body that contacts and slides on the tip.
A feature of the present invention is that at least one of the front guide component or a component in contact with the front guide component is provided with a passage through which cooling liquid passes.

If welding is performed while cooling the front guide part directly or indirectly by flowing a cooling liquid through a passage provided in at least one of the front guide parts or the parts in contact with the front guide parts, the welding speed can be reduced. Even if the temperature is increased (even if the frequency of the welding current is increased), the temperature of the tip of the front guide component is maintained at a temperature that does not damage the surface protective layer of the sliding part of the can body that contacts and slides on the tip. can do.

Next, a specific example of the present invention will be explained with reference to FIGS. 3 to 5.

3 is a side view mainly showing the welded member guide component in this specific example, FIG. 4 is a cross-sectional view taken from FIG. 3, and FIG. 5 is a partially enlarged view of FIG. 3.

Since the present invention relates to an improvement of the guide parts shown in FIGS. 1 and 2, parts in FIGS. 3, 4, and 5 that are the same as those in FIGS. 1 and 2 are given the same numbers as in FIGS. 1 and 2. That is, 1, 2, 3, 3a, 4, 5, 8, 1
5, 15', 16, 16', 18, 19, 21, 2
2, 23, 24, 25 and A, B, C fall under this category.

The improved parts are the intermediate guide part 36 and the front guide part 37, and the newly added part is the fixing part 41 that fixes these intermediate and front guide parts from above. Note that 42, 43, and 44 are bolts for fixing the fixed portion.

Referring to FIGS. 4 and 5, the intermediate guide part 36 is improved by providing a cooling liquid inlet and outlet ports 46 and 47 in the rear end rising portion 45 of the intermediate guide part 36, and communicating with the inlet 46. Cooling liquid vertical passage 4
8. An outward horizontal passage 49 leading to the tip portion 53 of the part 36, and a passage 5 perpendicular to the plane of the paper at the end of the passage 49.
0, a return horizontal passage 51 provided parallel to the above-mentioned outward horizontal passage 49, and a return vertical passage 5 communicating with the discharge port 47;
2 is provided to allow the cooling liquid to flow back, and the front guide part 37 is improved by combining it with the new fixing part 41. That is, the fixed part 41 is provided with an inlet 61 and an outlet 62 for the cooling liquid at its rear end, and further has an inlet 61 and an outlet 62 for the cooling liquid.
1 and near the tip of the fixed part 41, a passage 64 perpendicular to the plane of the paper at the end point of the passage 63, and a passage 64 provided parallel to the above horizontal passage 63 and communicating with the discharge port 62. A return horizontal passage 65 is provided, while the front guide part 3
7, the forward horizontal passage 63 of the fixed part 41 is connected to the forward and downward passage 71 that descends, and the forward guide part 37
An outgoing horizontal passage 72 that reaches the front of the outgoing horizontal passage 72, and a vertical passage 7 that is perpendicular to the plane of the paper at the front end of the outgoing horizontal passage 72.
3, and from the other end of the vertical passage 73 to the outgoing horizontal passage 7
2, the return horizontal passage 74 is connected to a return downward passage 75 descending from the return horizontal passage 65 of the fixed part 41. The coolant thus entered through the inlet 61 passes through the front guide part 37 and returns to the outlet 62.

Using the guide parts shown in Figures 3 to 5, water at 7°C is forcibly sent into the passages of the intermediate guide part and the front guide part, and while cooling both parts,
Run the welding machine at 600Hz, primary current 130A, every minute
Can bodies were welded at a speed of 500 cans.

During continuous operation for several hours, there were no welding defects.

Furthermore, when operating under the same conditions as above, the relationship between time and the temperature of the tip of the guide part is shown as Y in Fig. 6.
This is shown in the graph below.

The present inventors measured the relationship between the temperature of the tip portion 8 of the front guide part 8 and the operating time by changing the frequency and current value when the front guide part according to the present invention without the cooling means is used. The results are shown in FIG. It is known that the temperature at the tip increases as the frequency increases or as the current value increases. On the other hand, the workpiece to be welded is heated by contacting the front guide part, but if the degree of heating is such that it does not damage the plated metal or protective coating on the surface, the protective layer will not peel off. Experiments have shown that this method does not cause welding defects. For example, in the case of tin plate, its limit temperature is about 200°C. Therefore, when the cooling means according to the present invention is not provided, even if the occurrence of poorly welded cans is fully predicted from the perspective of FIG. 6 (Z curve) and FIG. 7, the present invention can be applied to prevent the occurrence. can be avoided.

In the above specific example, the fixed part 41 and the intermediate guide part 3
6. Cooling fluid was passed through all of the front guide parts 37 to cool them, but the point is that the front guide parts, especially the tip of the parts, should be cooled so that the temperature does not reach the limit temperature. The temperature of the tip 8 may be controlled by sufficiently cooling both or one of the intermediate guide component and the fixed component that are in contact with each other, and by cooling the front guide component with these cooled components.

As shown in the graph of Fig. 7, the temperature rise at the tip varies depending on the frequency and current value, so when the frequency is low and the current value is small, even if only the intermediate guide parts are cooled, the tip of the front guide part can be heated to the desired temperature. The temperature can be controlled.

In the above specific example, the cooling fluid was inevitably introduced from the fixed part 41 to the front guide part 37 due to the structure of the welding machine, but if the structure allows it, the cooling fluid may be introduced directly to the front guide part.

[Brief explanation of drawings]

FIG. 1 is a side view showing a combination configuration of a welded member guide part and its peripheral parts in a known can body welding machine, FIG. 2 is a sectional view taken along the line taken in FIG. 1, and FIG. FIG. 4 is a cross-sectional view taken along the line of FIG. 3, FIG. 5 is a partially enlarged view of FIG. 3, and FIGS. 6 and 7 are both Graph showing the relationship between the elapsed time after the start of welding and the temperature rise at the tip of the front guide component, 1... Upper electrode roll, 2... Lower electrode roll, 3
...Supporting parts, 36...Intermediate guide parts, 37...
Front guide part (8... its tip, 16, 16'
...Guide groove), A... Can body, B, C... Both ends of can body, 71-75... Coolant passage for front guide parts, 46-52, 61-65... Front guide parts 37 Coolant passages for parts in contact with.

Claims (1)

[Scope of Claims] 1. A can body welding machine that welds the overlapping portion of a can body, which has both overlapping edges that are welded to form a side seam portion, by passing the overlapping portion between an upper electrode roll and a lower electrode roll. The welding machine has a horizontal support part that supports the electrode roll at one end, and a guide groove that has a tip portion located close to both the upper and lower electrodes and guides both edges of the can body, respectively. The front guide part is provided above the support part, and the welding current is applied from the upper electrode roll to the can body to the lower electrode roll. →In a can body welding machine that flows in the order of support parts, the temperature of the tip of the front guide part during welding is set to a temperature that does not damage the surface protective layer of the sliding part of the can body that contacts and slides on the tip. A can body welding machine characterized in that a passage for passing a cooling fluid is provided in at least one of the front guide part or a part in contact with the front guide part in order to maintain the can body welding machine.