JPS6024279A - Arc welding device - Google Patents

Abstract

PURPOSE:To guide stably a wire electrode and to improve the accuracy in holding the tip position of the wire electrode by attaching a tip guide having high heat resistance to the tip of a current-conducting member. CONSTITUTION:A chip 10 for current conduction consists of a member 11 for current conduction of chromium copper or the like having good electrical conductivity and fairly high resistance to wear and a guide 12 consisting of a material having an insulating characteristic and having heat resistance. Said guide is attached to the tip of the member 11 to unite the entire part to one body. When a wire electrode 1 having a bending set is applied to the chip 10 and if the length L3 of, for example, the guide 12 is made to about 2/3 the extension L2, 2/3 of the extension L2 is held by the guide 12 and the fluctuation in the tip position of the electrode 1 is kept within about 1/3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an arc welding device, and particularly to a hot wire T.
The present invention relates to a welding device suitable for IG welding, consumable electrode arc welding, etc.

FIG. 1 shows the situation near the arc generating part of normal consumable electrode arc welding. FIG. 2 is a sectional view showing the state of the tip of the welding torch. In the figure, gas-shielded arc welding using a consumable electrode generates an arc 4 between a wire electrode 1 and a base metal 2 in an atmosphere of sealing gas G coming out of a nozzle 3 to form a bead 5. In this case, a conductive contact tip 7 is generally attached to the tip of the wire guide 6 for contacting the wire electrode 1 and supplying electricity.

In a device with this configuration, the distance M (hereinafter referred to as "effective extension") from the last contact energizing point on the torch side to the tip of the wire electrode 1 forming the arc 4 is kept short and as constant as possible. Holding it is a condition for stable welding work. This is because the resistance heat generation and resistance drop between the effective extensions L/) greatly affect the stability of the arc. The diameter of the hole for passing the wire electrode provided in the contact tip 7 for contact energization is, for example, an outer diameter of 1.2 mm.

If it is a wire electrode, the diameter is about 1.41, which is a size that the wire electrode 1 can easily pass through. For this reason, the wire electrode should have a radius of curvature of about 200 mm, for example.
By providing a strong bend, sufficient electrical contact can be obtained within the contact tip 7.

However, the distance from the tip of the contact tip 7 to the tip of the wire forming the arc (hereinafter referred to as "extension") is usually relatively long, about 15 to 25 mm, in order to keep the contact tip 7 away from the arc. It is. Therefore, as shown by △χ in FIG.
Displaced with respect to line 2o. As a result, the direction of the bending of the wire electrode 1 changes while the wire electrode 1 is being fed.
Occasionally, the tip of the wire electrode swings, causing the bead 5 to meander during automatic welding, and a solution to this problem is strongly desired.

In addition, since the wire wire 41Tfi, l is wound around the spool and is pulled out one after another, the wire electrodes on the outside and inside of the spool have different bending patterns, and as a result, as the wire electrodes wear out, the wire The position of the tip of the electrode will also inevitably shift. In order to prevent such misalignment and meandering, it is possible to remove the bends in the wire electrode before feeding it, but if this is done, the contact between the wire electrode and the contact tip becomes unstable and arcing may occur. becomes unstable and cannot be put to practical use. Therefore, attempts have been made to make the wire straight to remove any bending, and to bend the wire passage hole of the contact tip 7 to improve contact energization, but as the contact tip 7 wears out, the wire tip position changes. was unavoidable. Furthermore, since the extension L2 must be relatively long in order to protect the contact tip 7 itself from the heat of the arc, the problem of amplifying the displacement of the wire tip position due to the long extension L remains unsolved.

In hot wire TIG welding, in which the wire is heated with electricity, similar problems occur even more seriously. Figure 3 shows the state near the arc generating part in normal hot wire TIG welding, where the gap between the non-consumable tungsten electrode 8 and the base metal 2 is within the seal gas G flowing out from the nozzle 3. An arc 4 is generated to form a molten pool 9. In order to form the weld metal with high efficiency, the wire electrode 1 is energized between the contact tip 7 and the base material 2, thereby resistively heating the wire to almost the extent that the wire is melted. For this purpose, the extension L is 20~5om.
Generally, the value is larger than that of normal arc welding. On the other hand, the base material 2 is melted by the arc 4, but if the arc current value is small, such as 120 A, the molten pool 9 formed will naturally be small. However, in hot wire TIG welding, it is necessary to accurately position the tip of the wire electrode 1 in the middle between the rear end of the molten pool 9 and the arc 4. If it is too close to the arc side, the arc will be disturbed and the molten pool will be If it is too close to the rear end side, the bead shape will be poor. Therefore, the precision required for the position of the tip of the wire electrode is extremely strict, for example, +0.5 mm.

However, in reality, contact energization is performed using a contact tip similar to the arc welding using the aforementioned consumable electrode, and this combined with the fact that the extension L2 is large as described above, causes the wire to become strongly bent. In particular, this is a technical problem when automating hot wire TIG welding with low current, ie, with small molten pool formation.

An object of the present invention is to provide a welding device that eliminates the problems of the prior art described above and prevents fluctuations in the position of the tip of the electrode wire.

In short, this invention uses a tip guide made of a heat-resistant material as the tip of the current-carrying tip, and arranges a current-carrying member on top of this guide to make the extension small.
In addition, if necessary, the welding device is such that the axial center of the hole through which the wire electrode passes is changed to improve the contact property of the wire electrode.

Examples of the present invention will be described below.

FIG. 4 and FIG. 5 show the first embodiment, which shows the current-carrying chip]-00 structure. Current-carrying chip], 0 is a current-carrying member with good conductivity such as chromium copper and considerable wear resistance, and 1 is made of an insulating and heat-resistant material (e.g. ceramic). Glue, braze, and fit the tip guide 12.

Using means such as screwing, the tip y11 of this current-carrying member 1]9 is
1 to integrate the whole. This chip]
, 0 has a hole for passing the electrode wire through it]
3 and 13'' are substantially the same diameter and coaxially formed and arranged through the current carrying member 11 and the tip guide 12.

This energized wire electrode has a normal bend.
If 0 is applied, for example, as shown in Fig. 5, if the length TJs of the tip kite 12 is about the extension T4),
9. One of extensions 1+2 goes first.9. It will be held by the lil guide 12, and the tip of the wire electrode],
f! 4 position fluctuations are suppressed to approximately -.

FIG. 6 shows a second embodiment. In the above-mentioned embodiment, the contact energization position to the wire electrode moves to the upper side of the current-carrying member 11, and the effective extension L1 tends to become larger. For this reason, there is a slight problem in consumable electrode arc welding in which changes in the effective extension L8 greatly affect welding accuracy.

However, the above-mentioned embodiment is limited to application to hot wire T welding equipment, etc. in which the amount of heat input to the hot wire is controlled so that the heat generation state to the wire electrode 1 does not change even if the effective extension L8 changes. will be done. This embodiment further improves this point. In this embodiment, the current-carrying member 11 is attached obliquely to the wire guide 6 so that the wire passing hole of the wire guide 6 and the axis of the hole of the current-carrying member 11 are changed in direction. With such a structure, even if the bending of the wire electrode is removed, stable contact energization can be performed at a predetermined position of the energizing member 11. Furthermore, since the inner diameter of the hole in the tip guide 12 can be made small enough to be approximately equal to the outer diameter of the wire electrode 1, the tip position of the wire electrode can be stabilized and the effective extension can be stabilized with sufficient precision for practical use. I can do it.

FIG. 7 shows a third embodiment. In this embodiment, the axis of the tip guide 12 is set obliquely with respect to the current-carrying part A'A]1, so that the current-carrying member]1 and the wire 1 are brought into contact with each other at f=J. In this embodiment as well, substantially the same effects as in the above-mentioned embodiment can be achieved by using a wire with no bends.

FIG. 8 shows a fourth embodiment. Second. In the third embodiment, the axis of the current-carrying member 11 or the distal guide 12 is disposed obliquely to displace the hole for passing the wire, whereas in this embodiment, the distal guide 12 is energized. The wire 1 is brought into contact with a predetermined position of the current-carrying portion 11 by moving the member 11 in parallel in the diametrical direction to displace the axis of the wire passage hole. Furthermore, although not shown, substantially the same effect can be obtained by moving the current-carrying member 11 parallel to the wire guide 6.

By implementing this invention, various effects such as those described below can be achieved.

(a) Sufficiently stable contact energization can be performed even when using a wire with no bends.

(b) Since a tip guide made of a highly heat-resistant ceramic tube is attached to the tip of the current-carrying member, the wire electrode can be more stably guided close to the base material, improving the accuracy of holding the wire electrode tip position. Much improved.

(c) In a consumable i-polar arc welding robot, the robot's arm with a welding torch attached to its tip is swung around to perform welding work in various postures, so the direction of the bend in the wire electrode is more likely to change. According to this invention, automatic welding using a robot can be easily performed.

(2) It also becomes possible to easily automate small current hot wire TIG welding, which requires strict wire electrode tip position accuracy.

[Brief explanation of the drawing]

Figure 1 shows 1 of conventional gas shield consumable electrode arc welding.
- Fig. 2 is a sectional view of the wire guide and contact tip, Fig. 3 is a partial sectional view of the torch of the pot wire T-welding device, and Figs. 4 and 5 are the sections of the present invention]
FIG. 6 is a cross-sectional view of a current-carrying chip showing an example of
FIG. 7 is a cross-sectional view of the current-carrying chip showing the third embodiment, and FIG. 8 is a cross-sectional view of the current-carrying chip showing the fourth embodiment. 1... Wire electrode 4... Arc 6... Wire guide 10... Energizing tip 1]...... Conveying member 12・・・・・・Tip guide

Claims (1)

[Claims] 1. In a device that performs welding by generating an arc by applying electricity to a consumable electrode, a heat-resistant tip guide is attached to the tip of the current-carrying member, and the length of the consumable electrode protrudes from the tip of the tip guide. An arc welding device that is characterized by a reduced amount of heat. 2. The arc welding device according to claim 1, wherein the tip guide has insulation properties in addition to heat resistance. 3. The arc welding apparatus according to claim 2, wherein the tip guide is made of ceramic. 4. Changing the direction of the 1Iq11 core of the wire electrode passage hole of the wire guide and the axis of the wire electrode energization hole of the current-carrying member,
Or a patent characterized in that the wire electrode passing hole of the current carrying member and the wire electrode passing hole of the tip guide are changed in direction so that the wire electrode passing through the inside comes into contact with substantially a predetermined position of the current carrying member. An arc welding device according to any one of claims 1 to 3. 5. A patent characterized in that the axis of the wire electrode passing hole is arranged and formed by bending and changing the direction of the wire guide and the current-carrying member, or by bending and changing the direction of the current-carrying member and the tip guide. The arc welding device according to claim 4. 6. Change the direction of the axis of the hole for passing the wire electrode by moving the wire guide and the current-carrying member parallel to the axial cross-section, or by moving the current-carrying member and the tip guide parallel to the axial cross-section. The arc welding device according to claim 4, characterized in that the arc welding device is formed by moving in parallel.