JPS6023907B2 - Welding wire feeding device - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention involves inserting a continuous consumable electrode wire (hereinafter referred to as "welding wire") through a wire guide formed by spirally winding a wire, and then circularly winding the wire guide. The present invention relates to an improvement in a welding wire feeding device that feeds welding wire to a welding torch while rotating it in the circumferential direction.

In automatic and semi-automatic arc welding, even when the welding wire feeding path has curved parts, the wire is shaped into a spiral shape to actively reduce the load on the feeder and ensure stable and smooth wire feeding. A welding wire feeding device is sometimes used in which a welding wire is passed through a wire guide formed by winding and the welding wire is fed to a torch while rotating the wire in the circumferential direction. This is related to its improvement.

The above-mentioned welding wire feeding device will be described with reference to prior art FIG. is fed out by a wire feeder, and this welding wire 2 is further continuously fed to a welding torch 5 through a conduit cable 4 that constitutes a wire feed path.The conduit cable 4 is shown in detail in Fig. 2. As shown in the figure, there is a highly flexible outer sheath 8 and a hollow interior formed by spirally winding a wire rod rotatably housed in the inner circumferential portion of the outer sheath 8 over almost its entire length. It has a two-layer structure consisting of a wire guide 9', and the welding wire 2 is fed by passing through the wire guide 9' which rotates in the circumferential direction at high speed.

For this reason, the wire guide 9' is rotatably supported at its starting end 9 by a rotary bearing 101, and a gear 11 iron-mounted on the outer periphery of this rotary bearing 10 is connected to a drive motor 12.
A drive device 14 is engaged with a gear 13 attached to a rotating shaft of
The structure is such that it is rotated in the circumferential direction by receiving the rotational force of.

Therefore, in such a device, the welding wire 2 is continuously fed one after another by the feeder 3 having feeding rollers 3a and 3b, and at the same time the wire guide 9' rotates at high speed in the circumferential direction. , contact resistance at numerous contact points between the outer periphery of the welding wire 2 and the circumferential surface of the wire guide 9' imparts a swinging motion to the welding wire 2 mainly in the circumferential direction, so that the welding wire 2 moves toward the conduit cable 4.
As a result, the feeding resistance is significantly reduced due to minute vibrations within the tube. However, according to recent research results by the present inventors, in such a device, when the wire guide 9' is used with a relatively long length, even if the rotary drive device 14 is rotated stably, The rotation is not uniformly transmitted to the wire guide, causing local unevenness, and the wire feeding speed at the tip of the torch 5 fluctuates greatly, causing the welding arc 7
It was found that this caused problems such as instability and the tendency for defects to occur in welded parts. Therefore, the present inventors
In order to solve such problems, the feeding state of the welding wire 2 within the wire guide 9' of the device according to the above proposal was studied in detail.

Figures 3a to 3d show the measurement results of the rotational speed of the wire guide, the feeding speed of the welding wire, and the wire feeding force in each part of the device.

That is, in the proposed device, as shown in these figures, when the rotational speed N^ of the wire guide 9' in the rotary drive device 14 is gradually increased from 0 to the maximum speed, the rotational speed at the welding torch 5 section eventually increases. The NB vibrates seriously, and as a result, the wire feeding speed VF immediately in front of the arc generating part fluctuates greatly. And this NB
, VF fluctuations tend to increase as the wire guide becomes longer, and when the VF fluctuations are large, the arc becomes unstable. In particular, as the rotational speed of N^ increases, the wire There was a tendency for the NB to vibrate violently in the range where the phenomenon of decreasing feeding force was sufficiently observed. This is because with such a device, although it is possible to reduce the wire feeding load by rotating the wire guide, if the wire guide becomes long, the wire feeding becomes unstable, making it difficult to use practical wire feeding. This shows that the device is not able to fully perform its original function as a feeding device. Summary of the Invention Therefore, the present inventors further studied the above analysis results and arrived at the present invention.

That is, the present invention provides a welding method in which a welding wire is passed through a wire guide formed by winding a wire in a spiral shape, and the welding wire is fed to a torch while rotating this wire guide in the circumferential direction. The gist of the wire feeding device is that the wire guides are constructed in a multi-layer structure with at least two or more layers stacked so that adjacent wire guides are wound in opposite directions, and thereby the welding wire can be fed. It is an object of the present invention to provide a welding wire feeding device that can always feed welding wire stably even if the feeding path becomes long or has a large degree of curvature. EXAMPLES Below, the structure of a wire guide that constitutes the main part of the present invention will be explained in detail with reference to the accompanying drawings.

Fig. 4 shows a cutaway view of the main part of the conduit cable, and the wire guide has a two-layer structure in which a small-diameter wire guide 92 is tightly inserted into a large-diameter wire guide 91, and both guides Both of the wires 91 and 92 are formed by spirally winding wire rods such as rope wires, and the winding directions thereof are opposite to each other. Reference numeral 8 denotes the outer sheath of the conduit cable 4 made of a flexible material, and the welding wire 2 is inserted into the hollow part of the small guide 92 arranged inside.

FIG. 5 is a diagram showing only the structure of the wire guide, in which spiral wire sections 91 to 94 with stepwise different diameters are arranged in four winding directions such that adjacent ones are wound in opposite directions.
It is constructed by layering the vehicle in close contact with a layered structure.

It has been confirmed that this type of wire guide has a four-layer structure that makes rotational unevenness more difficult to occur when transmitting rotational force than the one shown in Figure 4, and that the wire guide itself can be easily controlled. In terms of wire rod diameter, it is possible to reduce the diameter of the wire so that good properties can be obtained.In addition, the wire guide can be inserted into the wire guide and rotated efficiently even with rotational force, and the welding wire can always be fed stably even if the wire guide is curved. It has various advantages such as being able to provide

FIG. 6 shows still another embodiment of the wire guide, in which the spiral wire rods 91 to 94 forming the guide are all formed into double windings.

When the wire guide is constructed with two or more multiple windings, it may be constructed in an appropriate combination with the single winding described above. As shown in these embodiment figures, the wire guides 91 to 94 all constitute a multilayer body made of spiral wire rods,
The winding direction of each spiral is such that adjacent spirals face opposite directions.

In a rotary wire guide, it is necessary to adjust the rotational force transmission ability, flexibility, and finished dimensions depending on the length of the feeding path and the shape of the curve. It is useful to adjust not only the diameter but also the layers and number of turns, and the examples shown in these examples expand the applicability of the wire guide and are very effective in practice. In addition, in these embodiments, if oil insulating paper is inserted between each guide, the lubricating oil injected to make the wire guide rotate smoothly can be prevented from entering the inside and adhering to the welding wire. It can be effectively prevented and is very beneficial.

Functions and Effects of the Invention Next, the functions and effects of the wire guide in the device of the present invention will be explained in comparison with the device proposed above.

Generally, in order to rotate a wire guide housed in a conduit cable, a rotational force sufficient to overcome the frictional resistance of the sheath and the contact area between the welding wire and the wire guide is required. transmitted from the source by the wire guide itself. However, as the wire guide becomes relatively long, the number of trailing parts increases, which increases frictional resistance and requires a large rotational force, causing the wire guide to undergo elastic deformation due to torsional force. will occur. Now, referring again to FIG. 2, we will discuss the wire guide in the above device.

When a rotational force in the A direction is applied to a wire guide 9' made of a spirally wound wire as shown in FIG. 2, the wire guide 9' is The wire guide 9' is twisted and deformed to increase the spiral fold D, and the deformation accumulates and continues to rotate with a delay, and eventually when the rotational force transmitted to the resistance of the friction part overcomes the wire guide 9', the wire guide 9' As it rotates, Spiral Yomogi D returns to its original size. but,
From the next moment, the wire guide 9' begins to undergo torsional deformation again, and this state is repeated. Furthermore, when a rotational force is applied to the wire guide 9' in the direction B, the spiral fold D is torsionally deformed to become smaller, and the rotational force is intermittently transmitted in the same manner as described above. It is also considered that the wire guide 9' causes periodic unevenness in its rotation, that is, a kind of vibration. However, in contrast to such a structure, in the device of the present invention using the wire guide 9 as shown in FIGS. If we consider the case where a rotational force is applied to the wire guide in the A direction in the winding direction of the spiral, the inner guide will resist the frictional resistance of the wire and the outer sheath, and
At the same time, the outer guide tries to deform so that its spiral fold D2 becomes smaller. As a result, the mutual deformations act against each other, increasing the rigidity against torsional force in the rotational direction, and making it possible to stably transmit a large rotational force with a small amount of deformation. Finally, Figures 7a to 7d show the above-mentioned third
The measurement results of the rotational speed of the wire guide, the feeding speed of the welding wire, and the wire feeding force in each part of the apparatus of the present invention corresponding to FIGS. a to 3d are shown.

As can be understood from this measurement result, according to the device of the present invention, even when N^ is gradually increased from 0 to the maximum speed, N8 stably follows it and there is no large rotational irregularity at any rotation speed. This does not occur, and the wire feeding speed VF is stable even in the range where the wire feeding force PF is sufficiently reduced, and the wire guide is rotated at high speed to become very small.
It was confirmed that the wire could be fed with the feeding force and that a stable arc could be maintained. As detailed above,
According to the present invention, the welding wire feeding characteristics are always stable even when the welding wire feeding path is set to its maximum length or curved. If the welding wire feeding path is greatly curved,
It has the advantage that good welding results can be obtained even in automatic welding using robots, etc., which often undergoes complex changes.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the prior invention device of the present applicant;
Fig. 2 is an enlarged vertical cross-sectional view of the rhombus part of the wire guide shown in Fig. 1, Figs. 3a to 3d are characteristic diagrams of the device shown in Fig. 1, and Fig. 3a is a diagram showing the characteristics of the device shown in Fig. 1. The rotational speed of the wire guide, Fig. 3b shows the feeding speed of the welding wire at the welding torch section, Fig. 3c shows the feeding speed of the welding wire just before arc generation, and Fig. 3d shows the feeding force of the wire. The graphs shown respectively, FIG. 4 is a cutaway view of the main part showing one embodiment of the wire guide which is the key point of the present invention, FIG. 5 is a diagram of another example, FIG. 6 is a diagram of yet another embodiment, and FIG. 7a - Fig. 7d are characteristic diagrams of the device of the present invention corresponding to Figs. 3a - 3d, in which Fig. 7a shows the rotational speed of the wire guide in the rotary drive device, and Fig. 7b shows the welding speed at the welding torch section. FIG. 7c is a graph showing the wire feeding speed, FIG. 7c is a graph showing the welding wire feeding speed immediately before arc generation, and FIG. 7d is a graph showing the wire feeding force. 91 to 94 are wire guides, 4 is a conduit cable,
Reference numeral 9 denotes a multilayer body composed of wire guides. Figure 1 Figure 2 Figure 3a Figure 3b Figure 3c Figure 3d Figure M Figure 5 Figure 6 Figure 7a Figure 7b Figure 7c Figure 7d

Claims (1)

[Claims] 1. A welding wire is inserted into a wire guide formed by winding a wire in a spiral shape, and the welding wire is continuously fed while rotating this wire guide in the circumferential direction. A welding wire feeding device, characterized in that the wire guides are constructed in a multi-layered body in which at least two or more layers are stacked so that adjacent wire guides are wound in opposite directions. 2. The welding wire feed according to claim 1, wherein at least one wire guide among the wire guides constituting the layered body is formed by winding a wire rod in two or more multiple turns. Device.