JPH09295152A - Nozzle tip for submerged arc welding equipment - Google Patents

Abstract

(57) Abstract: In the process of feeding a welding wire through a tip in a submerged arc welding apparatus, a plating shaving that is scraped when the wire passes through an upper feeding mechanism is dropped and accumulated in the tip. Thus, there is provided a chip capable of solving a trouble that clogging or an arc is generated and the feeding of the welding wire is stopped. SOLUTION: An introduction hole having an inner diameter is inserted into an inner peripheral surface of a connection portion 22 having a large inner diameter in a welding wire supply tip 20 so that an outer diameter fitted into the connection portion and an outer diameter of a welding wire 23 are slidably inserted. Welding wire 2 is provided with synthetic resin ring 26, which is slippery and has heat resistance and insulation.
3 is inserted into the introduction hole 27 of the ring 26, and the plating slag 28 falling from above is received on the ring 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to holding a tip of a welding wire in a submerged arc welding apparatus in which a granular flux is placed in a welding groove and the tip of the welding wire is inserted into the granular flux to generate an arc. The present invention relates to the improvement of a chip for use.

[0002]

2. Description of the Related Art Conventionally, in a submerged arc welding apparatus, as shown in FIGS. 4 and 5, a long welding wire 1 fed from a winding drum (not shown) above the apparatus is corrected by a straightening apparatus 2. After being straightened, it is fed downward through the feed mounting 3 driven by the motor 4, and the tip of this wire 1 is inserted into the granular flux 6 contained in the welding groove 5, The tip of the welding wire 1 inserted into the flux 6 is inside a guide tube 7 connected to a welding power source attached to the lower end of the feed attachment 3 and a nozzle-shaped tip 8 attached to the tip of the guide tube 7. And then inserted into the granular flux 6.

Further, as shown in FIG. 6, the nozzle-shaped tip 8 is provided with a connecting portion 9 consisting of a female screw having a large inner diameter, which is connected to the lower end of the guide tube 7 at the inner upper portion thereof. A welding wire guide insertion hole 10 having a diameter smaller than that of the connection portion 9 is formed at the lower end of the connection portion 9, and the connection portion 9 and the guide insertion hole 10 are connected by a tapered inclined surface 11. ing.

[0004]

In the conventional submerged arc welding apparatus, the welding wire 1 is used as described above.
Is continuously fed through the inside of the tip 8 having the tapered inclined surface 11 between the connecting portion 9 on the inner upper side and the guide insertion hole 10 on the lower end, so that after a long time, the welding wire 1 The thin copper-plated slag 12 provided on the surface is scraped and accumulated on the inclined surface 11, and the accumulated plating slag 12
As a result, the guide insertion hole 10 is clogged, and a failure occurs in which the feeding of the welding wire 1 is stopped during the welding operation.

The welding wire 1 is coated with a thin copper plating on the surface of the core wire for low carbon steel in order to provide rust prevention and conductivity. As described above, the plating slag 12 of the welding wire is inside the tip 8. The long welding wire 1 is straightened by the straightening device 2 as described above or accumulated on the inclined surface 11, or as shown in FIG. 3a and the pressure roller 3b are sandwiched between the pressure roller 3b and the pressure roller 3b while passing therethrough, so that the plating layer on the surface of the welding wire 1 is continuously bitten and scratched, and the scraped plating residue falls. This is because they are integrated on the inclined surface 11 in the lower chip 8.

As described above, the inclined surface 1 in the chip 8
When the plating slag 12 of the welding wire drops on the welding wire 1, the plating slag 12 moves along with the passing movement of the welding wire 1 and the inclined surface 11
It is gradually deposited and accumulated in the valley portion between the welding wire 1 and the welding wire 1 above, and then these plating slags 12 become a conductor between the welding wire 1 and the tip 8 and arc in the tip. Occurs. Further, when the arc begins to occur in the tip in this way, even before the feeding of the welding wire 1 is not stopped, welding conditions such as current, voltage, welding speed, etc. change and defects occur in the welded portion. As a result, this welding defect must be repaired later.

As described above, the plating slag 12 in the tip 8 is melted by the high heat of the generated arc and changes into a slag-like substance, so this slag-like substance is guided and inserted from the welding wire 1 and the inclined surface 11. The gap between the inner wall surface of the hole 10 and the portion thereof solidifies to cause clogging, and finally the feeding of the welding wire is completely stopped.

Of course, once an arc is generated in the tip 7 in this way, the tip 8 cannot be reused and is discarded, and is replaced with a new one. Therefore, in the past, the welding wire was suddenly stopped during the welding process, and it was often necessary to perform the work in the middle stage to replace the tip. It has been a serious problem that the number of working hours is increased and the working efficiency is lowered due to the occurrence of parts and the frequent replacement of chips.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the conventional submerged arc welding apparatus, and prevents the welding wire from being clogged in the tip holding the tip of the welding wire due to the plating slag. The purpose of the present invention is to reduce the wire feeding stoppage phenomenon that occurs due to this clogging, reduce the frequency of chip replacement, and improve work efficiency and economic efficiency.

As means for achieving the above object,
The invention of claim 1 concerning the nozzle tip of this submerged arc welding device is a welding wire having a connection part having a large inner diameter at the inner upper part and a welding wire guide insertion hole having a diameter smaller than the connection part at the lower end of the connection part. Inside the connection portion of the supply tip, the outer diameter to be fitted to the inner peripheral surface of the connection portion and the introduction diameter of the inner diameter into which the outer diameter of the welding wire is slidably inserted, slippery and heat resistant, insulation A ring made of synthetic resin having properties is disposed, and the welding wire is passed through the ring introduction hole and then conducted to the guide insertion hole.

Further, the invention of claim 2 is characterized in that the ring fitted to the inner peripheral surface of the connecting portion of the chip is made of tetrafluoroethylene resin.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of a nozzle tip of a submerged arc welding apparatus according to the present invention will be described based on an embodiment shown in the drawings. FIG. 1 shows a nozzle tip 20 according to the present invention.
2 is a longitudinal sectional view taken along the length direction of FIG. 2, and FIG. 2 is a lateral sectional view taken along the line AA of FIG. 1. The chip 20 is made of a metal cylindrical body made of copper.

Further, the tip 20 is provided with an internal threaded connecting portion 22 having a large inner diameter, which is connected to the lower end of the upper guide tube 21 at the inner upper portion thereof.
Has a welding wire guide insertion hole 24 having a diameter smaller than that of the connecting portion 22 for holding the lower end of the welding wire 23, and a tapered inclined surface is provided between the connecting portion 22 and the guide inserting portion 24. It is connected by 25.

Above the inclined surface 25 inside the connecting portion 22 of the tip 20, the outer diameter of the welding wire 23 and the outer diameter of the size fitting to the inner peripheral surface of the connecting portion 22 slide. A slippery synthetic resin ring 26 having heat resistance and insulation properties, which has an inner diameter introducing hole 27 that can be inserted, is fitted, and the welding wire 23 passes through the inside of the introducing hole 27 of the ring 26 and then downwardly. The guide insertion hole 24 is electrically connected.

The ring 26 smoothly slides on the outer peripheral surface of the welding wire 23 passing through the inside of the introduction hole 27, and the tip 20.
It is preferable that the friction coefficient be small so that it can be fed into the guide insertion hole 24, and that it has heat resistance and insulation properties, specifically arc resistance. Teflon (registered trademark) is the most suitable. Alternatively, a melamine resin may be used.

[0016]

According to the nozzle tip of the present invention, the welding wire 23 passes while receiving the crimping force of the straightening device 2 or the feeding device 3 above, so that the plating layer on the surface is damaged. Ring 2 with plating slag 28 below
Even if the plating slag 28 falls onto the flat plate 6, the position where the plating slag 28 falls is on the horizontal plane of the ring 26, so that all the falling plating slags 28 are collected only around the introduction hole 27 in contact with the welding wire 23. It disperses and collects on the ring plane without doing.

Further, the introduction hole 27 of the ring 26 has an inner diameter through which the welding wire 23 can be slidably inserted, that is, the outer peripheral surface of the welding wire 23 and the inner peripheral surface of the introduction hole 27 are in close contact with each other without a large gap. Therefore, the plating slag 28 that has fallen around the introduction hole 27 is not drawn into the inside of the introduction hole 27 even when the welding wire 23 moves, and easily falls in the direction of the lower inclined surface 25. There is no. Therefore, unlike the conventional tip, the plating slag that drops from above is not drawn into the trough between the inclined surface and the welding wire and adhered and fixed, so that the plating slag 28 is formed on the slippery ring 26. This means that they are integrated on a plane in a relatively easy-to-move state.

Therefore, before the start of the welding work of the day and at the end of the welding work, the tip 20 is removed from the guide tube 21 and high-pressure air is blown into the female screw connection portion 22, The plating residue 28 on the ring 26 can be easily blown off to the outside, and as a result, it is possible to maintain a state where the plating residue is not accumulated in the tip for a relatively long period of time, and the plating residue of the welding wire is retained. It is possible to greatly reduce the clogging due to the arcing caused by the above and the wire feed stop phenomenon due to the clogging, and it is possible to expect the working efficiency to be greatly improved.

Further, the life of the chip can be remarkably extended by creating a condition for easily removing the plating slag accumulated in the chip, and the defects of the welded part due to the arc generation due to the plating slag can be reduced. Because you can
It is possible to significantly reduce the work of repairing welding defects as in the past, and to improve work efficiency in that there is no need to repair welding defects, and to reduce costs by significantly reducing the amount of chip wear. Can be expected.

Regarding the reduction of chip consumption, in the past, one welding machine consumed 8 chips per day on average, whereas by using the chips according to the present invention, It has been found that the number can be reduced to four, which is half of the conventional one, and annual cost savings of 4 million yen or more can be expected.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a configuration of a chip according to the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view of a ring.

FIG. 4 is a perspective view showing a welding wire feeding mechanism in a conventional welding device.

FIG. 5 is a sectional view taken along line BB in FIG. 4;

FIG. 6 is a vertical sectional view of a tip in a conventional welding device.

[Explanation of symbols]

 20: Tip 21: Guide tube 22: Connection part 23: Welding wire 24: Wire guide insertion hole 25: Inclined surface 26: Ring 27: Introduction hole 28: Plating residue

Claims (2)

[Claims] 1. A connection part of a welding wire supply tip having a connection part having a large inner diameter at an inner upper part and a welding wire guide insertion hole having a smaller diameter than the connection part at a lower end of the connection part, and inside the connection part. A slippery, heat-resistant and insulating synthetic resin ring having an introduction hole with an inner diameter that allows the outer diameter of the welding wire and the outer diameter of the welding wire to be slidably inserted is provided. A nozzle tip for a submerged arc welding device, wherein a welding wire is passed through the ring introduction hole and then conducted to a guide insertion hole. 2. A nozzle tip for a submerged arc welding apparatus according to claim 1, wherein the ring fitted to the inner peripheral surface of the connecting portion is made of ethylene tetrafluoride resin.