JPS58224075A - Welding wire feeding device - Google Patents

Abstract

PURPOSE:To enable stable and smooth feeding of a wire efficiently and without loss, by feeding a welding wire to a guide tube having spiralled of inner peripheral wall, and controlling the driving source of the guide tube detecting the feeding force. CONSTITUTION:A wire feeder 3 and a guide tube driving motor 10 are started simultaneously to feed a welding wire 2 to a conduit cable 4. Feeding is made easy by giving thrust to the wire 2 by spiral inner peripheral wall of a guide tube 9. Load current of the wire feeder 3 is detected by a feeding force detecting device 12 and a signal based on the detected value is outputted to a controlling circuit 13. Basing on the detection signal, the controlling circuit 13 starts the guide tube driving motor 10 when the feeding force, i.e. load current, increases beyond a specified value, and stops the motor 10 when the feeding force decreases below a specified value. Thus, the wire 2 is fed with little change in the feeding force.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding wire feeding device for automatic and semi-automatic arc welding.

CO□ welding and M' generally use continuous electrode wires.
A, () Welding, M G welding, etc., automatic or semi-automatic arc welding using consumable electrode methods, T G welding using additive wire, plasma welding, brazing, etc., when continuous welding wire/ear is used. There is a considerable distance between the welding torch part that smoothly supplies the welding point to the welding point and stably supplies it to the arc part, and the welding torch part operated by the worker, and a flexible conduit cable is used to connect the welding torch part that is operated by the worker. In so-called semi-automatic arc welding, a wire feeder installed on the wire reel side,
It is well-experienced that the wire feed function in the wire gauge within a conduit cable has a significant effect on welding properties.

Therefore, in cases such as semi-automatic arc welding, where the length of the conduit cable must be set particularly long, or where the conduit cable must be extremely curved at the tip of the welding torch, Various countermeasures for smooth and stable feeding have been considered in the past, but none of them have been able to provide sufficiently satisfactory performance.

On the other hand, the positions of the wire reel and welding torch are approximately fixed, and the wire feeding path connecting them does not change much. For example, in jig arc welding equipment or robot welding equipment, the feeding path is fixed. If the wire is extremely curved and the radius of curvature of the curved portion is small, the wire feed should also be carried out at 2°. , 2. . In many cases, fluctuations in the feeding load cannot be avoided due to □- or rotation of the advance end.

Therefore, when feeding the welding wire to a feeding path with such a curved part, the welding wire is rotated in the circumferential direction of the guide tube through which the welding wire is inserted to form the feeding path. A possible method is to actively reduce the feeding load by feeding.

By the way, when such a means is adopted, if a constant curve is always formed in the feed path and the degree of curve hardly changes, the guide tube should be moved at a constant speed during welding work. When moving around a rotating site, the feed path may vary from a nearly straight line to an extremely curved line.

Under these circumstances, it would be unsuitable and uneconomical to always rotate the guide tube at a constant speed.

Furthermore, as mentioned above, in robot welding equipment, for example,
The degree of curvature of the feed path changes constantly as the wrist rotates, and the same holds true here as in semi-automatic arc welding.

The present invention has been made in view of the above circumstances, and its purpose is to provide a feed path with a curved portion in automatic or semi-automatic arc welding, and in particular, in a case where the degree of curvature constantly changes. It is an object of the present invention to provide a welding shear feeding device that can appropriately reduce the feeding load and effectively feed the welding wire stably and smoothly even in such cases.

In order to achieve the above object, the present invention is characterized by being configured as follows.

That is, the welding wire fed by the wire feeder is inserted into the guide tube whose inner peripheral wall is formed in a spiral shape, and the guide tube is rotated in the circumferential direction, and the feeding force is used to feed the welding wire. is detected, and based on the value corresponding to the feeding force, the guide tube is rotated and stopped, or the rotational speed is controlled.As the guide tube rotates, the welding wire receives a thrust in the feeding direction, This thrust force is used to actively reduce the feeding load, and to achieve the above effect, the guide tube is rotated as and when necessary depending on the degree of curvature that occurs in the feeding path. , stability of welding wire,
Moreover, smooth feeding can be carried out effectively and without waste.

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

FIG. 1 is a schematic diagram showing the operating principle of the welding wire feeder according to the present invention, in which 1 is a wire reel around which welding wire 2 is wound, and the welding wire is fed out from the wire reel 1. 2 is passed through a conduit cable 4 constituting a wire feeding path while being pulled by a wire feeder 3, and is fed to a welding torch 5, generating an arc 7 between it and the workpiece 6 to continuously weld the wire. Welding work will be carried out.

The wire feeder 3 includes a feed roll 3a and a pressure roll 3b.
, L-1/(Therefore, while pressing the welding wire 2 -3
Connected to the output shaft of e.

By the way, it has a double structure consisting of the conduit cable 4I/'i jacket 8 and a guide tube 9 rotatably housed in the inner circumferential part of the jacket 8 over approximately its length. The inner circumferential wall of the guide tube 9 through which the welding wire 2 is inserted has a spiral shape.The guide tube 9 in this embodiment is a helical spring made of a thin metal wire wound in a spiral shape.

A wire feeder 3 is attached to one end of this guide tube 9.
The output shaft 10a of a guide tube drive motor 10 inserted between the proximal end of the conduit winter pull 4 is connected via a connector 11, and the welding wire 2 is passed through the guide tube through the drive motor 10. 9 side is rotated at high speed in the circumferential direction.

The welding wire 2 is guided into the guide tube 9 by passing through the cylindrical output shaft 10a.

Reference numeral 12 in the figure is a feeding force detection means for detecting the feeding force for feeding the welding wire, and in this embodiment, the welding is performed by detecting the load current of the wire feeder 3, that is, the load current of the drive motor 3e. The required feeding force for feeding the wire 2 is indirectly detected.

A detection signal based on the value of the feeding force detected by the feeding force detection means 12 is output to the control circuit 13.

This control circuit 13 controls the feeding force based on the detection signal.
In other words, when the load current increases beyond a certain value /C, the guide tube drive motor 10 is started and controlled! In addition, when the load current decreases below a certain value, the guide tube drive motor 10 is controlled to stop.

Next, the operation of the device based on this embodiment will be explained.

　　　　　,.

Now, suppose the wire feeder 3 and the guide tube drive motor 1
0 at the same time to feed the welding wire 2 into the conduit cable 4, the welding wire 2 receives thrust in the direction of bending the welding wire 2 from the spiral inner peripheral wall of the guide tube 9 rotating at high speed. This thrust significantly reduces the feeding load generated by the feeding resistance inside the guide tube, so even if the feeding path is curved and the feeding load is large, the Due to the rotation, the feeding load is reduced to a negligible extent, and the welding wire 2 can be stably and smoothly fed to the welding torch 5.

Here, the correlation between the rotational speed N of the guide tube 90 and the wire feeding force, that is, the load power application of the wire feeder 3, is as follows.
As shown in FIG. 2, the feeding route for feeding the welding wire 2 is as follows.
When we examine the cases where the state is changed from a straight state to a state with one, two, and three loops, we find that the curve t+)t t2)+ (31
1(4) was obtained.

That is, curve (1) is for the case where the feed path is straight, and curve (2) is for the case where the feed path involves one, two, and three loops, respectively. It is.

Therefore, when the load power detected by the feeding force detection means 12 becomes larger than IO, the control circuit 3. C
If the setting is made to start the y-C chi-to-arb drive%, -JIO, then in the case of curve (3), that is, when there are two loops in the feed path, the drive motor 1
The load power application gradually decreases with the rotation of 0, and when the rotational speed of the guide tube 9 reaches N5VC, the load power work decreases to ■O''!.

Furthermore, if the current is continued to be applied to the guide tube drive motor 10, the rotational speed N of the guide tube 9 will decrease to N.
3, and the load power construction further decreases, but if it is set to cut off the power to the drive motor 10 when the load power construction reaches (work 0 - △ work), the load power construction can be reduced. The welding wire 2 can be fed with the feeding force changing slightly within the range from (work 〇-△work) to IO, that is, with the feeding force hardly changing.

By the way, in actual welding work, the feed path is constantly changing, especially when the worker moves around the welding site while holding the welding torch by hand, as in semi-automatic arc welding. For example, as shown in FIG.
~(4), which constantly changes.

Now, suppose that the feeding path changes from state (3) to (4) in the same figure.
), the curve (3) in Figure 3
) to the state of curve (4).

Therefore, the load current construction increases from 0 to 1, and the guide tube drive motor 10 is energized by the control circuit 13, so the rotational speed N of the guide tube 9 increases from N3 to N.
4, and the load power construction again changes from (work 0 - △ work) to 1
It is automatically controlled to stay within the range of 0.

Therefore, even if the feed path 4 for feeding the welding wire constantly changes between (3) and (4) as shown in FIG. 2, the welding wire will always be fed with a constant feeding force. Stable and smooth feeding can be effectively performed without unnecessary rotation of the guide tube 9.

On the other hand, if the feed path is straight (l) as shown in Figure 2, or if there is only one loop (2), then curves (1) and (2) in Figure 3 guide tube 9
A: Even in the stopped state, the load current is lower than Io, so the guide tube drive motor 10 is not started.

In other words, this is a region in which there is no need to rotate the guide tube 9 to reduce the feeding force when the feeding path is straight or in a curved state with about one loop; In this case, the guide tube 9 is fed by a normal feeding method, that is, a method in which the guide tube 9 does not rotate.

Further, as soon as the feed path changes from the state (1) or (2) to the state (3) or (4) in FIG. 2, the guide tube drive motor 10 is started and the control as described above is performed. It is something that can be done.

In the above embodiment, the wire feeding force is indirectly detected by the load current of the wire feeder 3.
Needless to say, the feeding force detection means in the present invention is not limited to such means.

Other means for detecting the wire feeding force include, for example, the first
A tensile force or pressure sensor (such as a strain gauge) is inserted between the wire feeder 3 shown in the figure and a base (not shown) on which the wire feeder 3 is installed, and the welding wire 2 is The feeding reaction force accompanying feeding may be detected by the sensor.

- Still, the above setting current IO needs to be set to a value that takes into consideration the diameter, material, etc. of the welding wire 2 and allows stable and smooth feeding without buckling the welding wire 2 during feeding. Needless to say, there is.

In the above embodiment, the guide tube drive motor 10 is controlled to be turned on and off when the load current of the wire feeder 3 reaches a predetermined value, that is, 0 and (0 - △). However, the present invention is not limited to such a control method. For example, the guide tube drive motor 10 may be feedback-controlled so that the load current is always 10.

As described above, the present invention allows welding by inserting a welding wire into a guide tube whose inner peripheral wall is formed in a spiral shape and rotating the guide tube in its circumferential direction. In addition to actively reducing the required feeding force at the top, the required feeding force is detected by a feeding force detection means, and the rotation and stop control or speed control of the guide tube is performed based on the detection results. Because it is a thing,
Depending on the degree of curvature that occurs in the feeding path, the guide tube can be rotated as much as necessary to reduce the required feeding force, allowing stable and smooth feeding of welding wire without waste. It is possible to provide a welding shear feeding device that can effectively perform welding.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing one embodiment of the present invention, FIG. 2 is a schematic diagram showing each side of a curved portion that occurs in the feed path, and FIG. 3 is a diagram showing the rotational speed of the guide tube and the wire feed in the embodiment. It is a graph which shows the relationship with the load current of a feeder. j') 2... Welding wire 3... Wire feeder 9.
... Guide tube 10 ... Guide tube drive source 12 ... Feeding force detection means 13 ... Control circuit patent applicant Osaka Electric Co., Ltd. agent Patent attorney Takashi Suzue - Fig. 2 Fig. 3

Claims (1)

[Scope of Claims] +1) A wire feeder that feeds a welding wire, a guide tube whose inner peripheral wall has a spiral shape through which the welding wire fed by the wire feeder is inserted, and this guide tube. A guide tube driving source that rotationally drives the guide tube in the circumferential direction, a feeding force detecting means that detects the feeding force for feeding the welding wire, and a value corresponding to the feeding force detected by the feeding force detecting means. 1. A welding wire feeding device comprising a control circuit for controlling on/off or speed of a guide tube drive source. (2) Claim 1, characterized in that the feeding force detection means detects a load current of the wire feeder, and a change in the feeding force is detected by a change in the load current. Welding wire feeding device as described in . (3) The welding wire feeding device according to claim 1, wherein the guide tube is formed of a helical spring made of a wire wound helically.