JPS603983A - Method and device for preventing sticking of spatter to arc welding torch - Google Patents

Abstract

PURPOSE:To prevent easily sticking of a spatter to a torch by spraying an oil mist to the space in the gas nozzle of an arc welding torch thereby forming an oil film on the inside and top end of the gas nozzle as well as a chip. CONSTITUTION:The oil supplied from an oil tank 26 is sprayed in the form of a mist by air flow to the shielding gas ejecting passage 36 in a gas nozzle 32 of a torch 10 enclosing a chip 30 for delivering a wire 12 through a guide hole 34 to keep the inside surface and top end of the nozzle 32 and the surface of the chip 30 wet with the oil. The spatter sticking to the oil film is dislodged by gravity or is blown off by the air flow, thereby preventing the sticking of the spatter and improving the working efficiency of the welding machine. The above-mentioned oil mist is supplied alternately with the shielding gas by connecting an oil mist feeder consisting of a lubricator 22, an oil feed line 23, a distributor 24, etc. via a solenoid-operated directional control valve 18 in the midway of a gas passage 16 for supplying the shielding gas to said nozzle 32.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing spatter from adhering to a first chip used in gas-encapsulated arc welding, and a spatter prevention device suitable for carrying out the method. It is.

This type of torch is normally equipped with a tip that sends out the welding rod from a guide hole, and a gas nozzle that is installed around the tip and spouts out a shielding gas that does not cover the welding point. Spacks scattered from the welding point tend to adhere to the first surface and inner surface of the chip as well as the surface of the chip. When one spatter is deposited, a large number of spatters suddenly appear on top of it, and if left untreated, the flow of shielding gas will be disrupted, causing defects such as blowholes in the weld. Become. For this reason, it has been conventional practice to supply compressed air to a gas nozzle through a passage for supplying shielding gas every time one cycle of welding is completed, and to avoid blowing off the attached spatter by the jet of air. According to this method, it is not necessary to clean the nozzle while welding a length of about 5 to IOm. However, when considering general welding,
If so, it becomes necessary to clean the tip and the gas nozzle every time 10 cycles of welding are completed, resulting in an increase in the number of work steps and a decrease in the operating rate of the entire welding apparatus.

It has also been conventional practice to apply spatter adhesion prevention agents to gas nozzles and chips, but this spatter adhesion prevention agent is applied by directly plunging the tip of the torch into the gel-like adhesion prevention agent. As a result, the gel-like anti-adhesion agent adheres relatively thickly to the inner surface of the gas nozzle, which not only tends to disturb the flow of shielding gas, but also prevents spatter and other foreign matter from adhering to the torch. There was also a drawback that the oxides were mixed into the anti-fouling agent and were then deposited on the gas nozzle etc. together with the anti-fouling agent.

The present invention has been made against the background of the above-mentioned circumstances, and provides a sputtering method that does not cause disturbance of the shielding gas due to the sputter adhesion prevention agent and does not require cleaning the torch for as long as possible. The object of this invention is to provide a method for preventing adhesion and an apparatus suitable for carrying out the method.

A feature of the method invention is that by spraying oil mist into the space within the gas nozzle, the inner surface and tip surface of the gas nozzle, as well as the surface of the tip, are kept wet with oil.

This oil preferably has a viscosity of 150-VC of 20 to 80, particularly preferably 150-VG of 25 to 40. Oil with too high a viscosity is difficult to turn into a paste, and the oil film formed on gas nozzles becomes thicker, making it easier for spatter to adhere to it.On the other hand, oil with too low a viscosity has a thick oil film. This is because it becomes thin and lacks the ability to prevent spatter from directly adhering to gas nozzles and the like.

According to this method, an oil film of an appropriate thickness can be easily formed on the surface of the gas nozzle or chip, and the conventional sputtering method 4
There is no risk of disturbing the flow of shielding gas like anti-stick agents. What's more, the flying sorrel and ivy become entangled with the oil and solidify, making it impossible for them to firmly adhere to the gas nozzle or tip. Therefore, most of the spatter falls off, but even if some spatter sticks to the oil film, if other spatter sticks on top of it, it will fall due to its weight. Therefore, the deposition of spatter that would cause a turbulence that would cause actual damage to the flow of the shielding gas does not occur. Therefore, there is no need to clean the torch for a considerable period of time, and the effects of reducing the number of man-hours and improving the operating rate of the welding equipment can be achieved.

In addition, a feature of the device invention is that an oil mist supply device is connected via a directional control valve to the middle of the gas passage that supplies shielding gas to the gas nozzle of the arc welding torch, and by switching the directional control valve, the oil mist supply device is connected to the gas nozzle. The purpose is to selectively supply shielding gas and oil mist.

In the device configured in this manner, the shielding gas supply passage and the ejection hole can be used as the oil mist supply passage and the ejection hole, and the configuration of the apparatus can be simplified. Moreover, by simply switching the directional control valve each time a certain length of welding is completed, it is possible to easily and effectively wet the surfaces where spatter from the gas nozzle or chip may adhere.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, 10 is a torch, and this torch 1 (
A guide tube that guides a wire 12 as a consumable electrode from a reel 14, a gas passage 16 that supplies shielding gas, and a not-shown gable that guides welding current are connected to l.

An electromagnetic directional switching valve 18 is provided in the middle of the gas passage 16, and an air passage 20 for supplying compressed air is connected to this directional switching valve 18. A lubricant 22 is provided in the middle of this air passage 20. An oil tank 26 is connected to the lubricator 22 via an oil supply path 23 and a distributor 24. The lubricator 22 uses the flow of compressed air supplied through the air passage 20 to convert the oil supplied from the oil tank 26 into a mist (based on the atomizing principle) and mixes it into the compressed air. Since this is well known, a detailed explanation will be omitted.The compressed air is also led to the oil tank 26 through the air passage 27,
Regardless of the relative height between 6 and the lubricator 22,
Oil always reaches the lubricator 22. Note that the distributor 24 is provided so that the oil tank 26 can be shared by a plurality of torches.

As shown in an enlarged view in FIG. 2, the torch IO includes a main body 28, to which a tip 30 and a gas nozzle 32 are fixed. The chip 30 is a longitudinal member, and a guide hole 34 is formed along the longitudinal direction of the chip 30.
The wire 12 is fed out from the tip of the chip 30 through the guide hole 34. Further, the gas nozzle 32 is a cylindrical member provided to surround the chip 30, and a gas ejection passage 3 with an annular cross section is formed between the gas nozzle 32 and the chip 30.
The shielding gas is ejected from the welding point, that is, the arc generated between the wire 12 and the object to be welded melts the tip of the wire 12 and a part of the object to be welded. It is designed to cover the surrounding area. Note that 38 is a switch for controlling the supply of the wire 12 and shielding gas, and 40 is a guard member for protecting the operator's hands.

When arc welding is performed using the apparatus configured as described above, first, after warming up the torch 10, the electromagnetic directional control valve I8 is switched to the lower position shown in Fig. 1, and the torch lO is compressed. supply air.

This flow of compressed air generates oil mist within the lubricator 22, which is mixed with the compressed air and supplied to the torch 10. While flowing through the gas ejection passage 36, this oil mist lands on the inner surface and tip surface of the gas nozzle 32 and the surface of the tip 30 to form an oil film. This oil mist is ejected periodically every time a certain length of welding is completed. However, since torch 1 () has been sufficiently warmed up after welding, the oil film will be removed from torch 10 even if you do not particularly warm up torch 10 as you would at the start of welding.
The surface of the surface is well covered.

- After the oil mist is spewed out, if the electromagnetic directional control valve l) 3 is switched to the upper position in Fig. 1, the gas passage 1
Shielding gas is supplied to the torch 10 via 6. Therefore, when the switch 38 is turned on, the wire 12 is sent out from the tip of the tip 30, and shielding gas is ejected from the gas nozzle 32 to perform arc welding.

At this time, spatter flies from the welding point toward the torch 10 and collides with the tip 30 and gas nozzle 32, but since these surfaces are dirty with oil, it is difficult for the spatter to land. Moreover, the flying spatter is rapidly cooled and solidified by the oil.
The spatter itself becomes difficult to adhere to. for that,
This prevents spatter from firmly adhering to the thousand knobs 30 and the gas nozzle 32, and most of the spatter falls. Furthermore, even if there is spatter that adheres to the oil film, this adhesion force is small, so if another spatter is deposited on top of it, its weight will exceed the adhesion force, and the spatter will naturally disappear. I fell to
Spatter of a size that causes turbulence in the shielding gas that may cause problems such as turbulence, burrs, or blowholes due to poor encapsulation of the welding point. No accumulation of substances occurs.

By the way, according to an experiment conducted using Turbine 9O as the oil, even when welding a welding point with a length of 100 m,
There was no spatter that would cause actual damage.It is convenient to be able to weld a length of 100 m without having to clean the torch.The guide hole 34 of the tip 3o The cross-sectional area tends to become elliptical due to the wire passing through it, which has a tendency to curl, and this can cause misalignment during welding, so it is recommended to replace the tip 30 with a new one every time approximately 100 m of welding is performed. In fact, if the gas nozzle 32 is cleaned at the same time as the tip is replaced, the conventional process of removing and attaching a tip that does not need to be replaced just for cleaning can be saved. This reduces the number of man-hours required for cleaning the gas nozzle.In addition, you can always replace the gas nozzle at the same time as replacing the nap.
/77 Jffi'a: If this is done, it will be possible to reliably prevent the occurrence of a situation where welding defects are stopped due to forgetting cleaning and continuing welding work as in the past.

However, in the device of this embodiment, since spatter adhesion force to the gas nozzle 32 and chip 30 is small, if the flow rate of compressed air for spouting oil mist is made sufficiently large, this compressed air will cause the gas nozzle 3 to
It is also possible to blow away the spatter deposited on the 2nd grade, and in this case, the cleaning work itself can be almost entirely omitted.

In the device of this embodiment, as described above, a part of the shield gas supply passage and the shield gas jet hole in the torch 1o can be used as the 4R supply passage and the jet hole of the oil mist (・), and the structure of the device can be simplified. However, it is also possible to provide a dedicated supply passage and jet hole for oil mist.
It is also possible to supply compressed air for blowing away the spatter on the ζj deposits in addition to the compressed air for generating the . In this case, each time a certain length of welding is completed, compressed air is first blown out to blow away the spatter that has settled on the weld, and then a relatively paper-like oil mist is sprayed through the gas nozzle. This has the effect of reducing the amount of oil used compared to the case where the same compressed air is used to both spray oil mist and blow away adhering spatter.

Further, in the above embodiment, the present invention was applied to a semi-automatic arc welding torch that performs welding while holding the torch in hand and manually operating it, but it is also possible to apply the present invention to a fully automatic welding device. . Particularly in this case, the electromagnetic directional control valve can be automatically switched every time a certain length of welding is completed to blow off the 1st deposit spatter and form an oil film, which is very convenient.

Incidentally, when the present invention is applied to semi-automatic arc welding l/-ch, the directional control valve may be manually operated.

In addition, although I will not give examples one by one, special 11'1
It goes without saying that the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a semi-automatic arc welding device including a sprue/7 adhesion prevention device, which is an embodiment of the present invention. Fig. 2 is an enlarged view of the JI torch in Fig. FIG. 3 is a front view showing a section in section. 1oz torch 12: Wire 16: Gas passage 18: Electromagnetic directional valve 20: Air passage 22 Nilbricator 26: Oil tank 3o: Tinop 32: Gas nozzle 34: Guide hole 36: Gas ejection passage Applicant: Toyota Motor Corporation J, IQ Company

Claims (3)

[Claims] (1) Preventing spatter from adhering to an arc welding torch equipped with a tip that sends out a welding rod from a guide hole and a gas nozzle that surrounds the tip and blows out shielding gas to cover the welding point. A method for preventing adhesion of spatter, characterized in that the inner surface and tip surface of the gas nozzle and the surface of the tip are kept wet with oil each time oil mist is sprayed into the space within the gas nozzle. . (2) Spatter may adhere to an arc welding torch that does not send out the welding rod from the guide hole and is equipped with a tip and a gas nozzle that surrounds the tip and spouts out a shielding gas that should not cover the welding point. In this device, an oil mist supply device is connected through a directional switching valve in the middle of a gas passage that supplies shielding gas to the gas nozzle, and the shielding gas and oil mist are mixed by switching the directional switching valve. 1. An arc welding torch anti-bond device, characterized in that the gas can be selectively supplied to the gas nozzle. (3) The oil mist supply device includes a lubricator that generates and mixes oil mist into an air flow having a sufficient flow rate to blow away spatter attached to an oil film formed on the inner surface of the gas nozzle, using the atomizing principle. A sputter adhesion prevention device according to claim 2, which comprises: