JPS5942180A - Method and device for feeding welding wire - Google Patents

Abstract

PURPOSE:To feed smoothly and stably a welding wire through a curved feed route in the state of automatic and semiautomatic arc welding, by inserting the wire into a hollow guide tube, and feeding the wire while rotating and driving the tube in the circumferential direction. CONSTITUTION:A welding wire 2 let off from a wire reel 1 passes the inside of a conduit cable 4 forming a wire feed route while it is pulled by a wire feede 3 until it is fed to a welding torch 5 by which an arc 7 is generated between the wire and the work 6 and the work is thus welded. The cable 4 is made into the double construction of a sheath 8 and a guide tube 9 therein. The tube 9 is rotated at a high speed by the intermeshing of gears 13 and 11 which are rotated by a motor 12. The wire 2 is thus circumferentially oscillated by the contact resistance at the numerous contact points between the outside peripheral surface of the wire 2 and the inside peripheral surfce of the tube 9, by which the wire 2 is finely oscillated in the tube 9. The feed resistance is thus considerably decreased and the smooth feeding in the curved part is accomplished.

Description

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

Co2 welding or MA which generally uses continuous electrode wire
In automatic and semi-automatic arc welding using consumable electrode methods such as G welding and MIG welding, as well as TIG welding using additive wire, plasma welding, brazing, etc., continuous welding wire is smoothly fed to the welding point. Needless to say, it is necessary to stably supply it to the arc portion.

In particular, there is a considerable distance between the wire reel on which the welding wire is wound and the welding torch operated by the worker, and a flexible conduit cable is used to connect the welding wire between them. In so-called semi-automatic arc welding, in which the wire is passed through the conduit cable and fed to the welding torch, the wire feeder installed on the wire reel side and the wire feed function in the wire guide part of the conduit cable are used for welding. It has been well experienced that this has a significant effect on properties.

Therefore, when welding in semi-automatic arc welding, etc., where the length of the conduit cable needs to be particularly long, or where the conduit cable must be extremely curved at the tip of the welding torch, Although various countermeasures for feeding welding wire smoothly and stably have been considered, none of them have been able to provide sufficiently satisfactory performance.

On the other hand, even in jig arc welding equipment or robot welding equipment, where the positions of the wire reel and welding torch are approximately fixed and the wire feeding route connecting them does not change much, the feeding route is If the wire is extremely curved and the radius of curvature of the curved part is small, the wire feeding will become unstable.Especially in robot welding equipment, fluctuations in the feeding load due to the rotation of the tip of the wrist cannot be avoided. There are many cases.

By the way, various methods have been repeatedly attempted to stabilize and smooth the feeding of the welding wire inserted into the wire guide and to reduce the feeding load within the wire guide. One example of this is a planetary roll type feeding device that has recently begun to be put into practical use around the world.

In other words, if the pressure of the roll and the deflection angle of the roll are set particularly carefully in the feeding device with the welding wire, in addition to the feeding force in the feeding direction, the welding wire will be finely moved in the circumferential direction. This allows the welding wire to vibrate minutely as it is being fed, thereby improving the state of contact with the wire guide.

However, when this technical concept is actually implemented, there is a limit to the transmission distance of the oscillating motion, and the attenuation of the oscillating motion is particularly severe where the wire guide is curved, making it difficult to obtain sufficient effects. It became clear that it could not be done.

Another method to embody this technical concept is, for example, to grip the conduit cable that forms the welding path in one place and mount it on a mechanical swinging device to perform swinging motion. Although some efforts have been made to give
It lacked reality and lacked practicality.

The present invention was made in view of the above circumstances, and its purpose is to actively reduce the feed load in automatic and semi-automatic arc welding, especially when the feed path has curved parts. It is an object of the present invention to provide a welding wire feeding method and an apparatus therefor, which reduce the amount of stress caused by the welding wire and enable stable and smooth feeding of the welding wire.

In order to achieve the above object, the present invention is characterized in that the welding wire is inserted into a hollow guide tube, and the guide tube is rotated in the circumferential direction while welding. This device feeds the wire, and the welding wire is given an oscillating motion from the guide tube that rotates at high speed, and the welding wire is fed while vibrating minutely within the guide tube, which significantly reduces the feeding load. However, the welding shear can be fed stably and smoothly, and the device has a simple configuration and can be implemented at low cost.

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the operating principle of the welding wire feeding device based on the BJ4tg of the present invention, in which numeral 1 denotes a welding wire reel around which a welding wire 2 is wound;
The welding wire 2 fed out from the welding wire 2 is passed through the conduit cable 4 constituting the wire feeding route while being pulled by the wire feeder 3 and fed to the welding torch 5, and an arc is created between it and the workpiece 6. 7 and continuous welding work is performed.

The wire feeder 3 includes a feed roll 3a and a pressure roll 3b.
This is a normal type in which the welding wire 2 is fed in the direction of the arrow α while being compressed by the above, and the drive shaft 3C of the feed roll 3a is connected to the output shaft of the 1-drive moke 3e via a deceleration mechanism 3d.

In addition, the conduit cable 4 described in item 1 has a double structure consisting of an outer sheath 8 and a hollow guide tube 9 that is rotatably accommodated in the inner circumference of the outer sheath 8 over almost its entire length. Then, the welding wire 2 is inserted into the guide tube 9 of the conduit cable 4.

Further, the starting end 9a of the guide tube 9 is connected to a rotating bearing 10.
A gear 11 is fitted to the outer periphery of the guide tube 9, and a gear 13 fixed to the output shaft of the drive motor ]-2 is meshed with the gear 11.
The guide tube 9 is rotationally driven by a drive motor 12.

Next, the welding wire feeding method according to the present invention will be explained in detail based on the above-mentioned device.The welding wire 2 is inserted into the hollow guide tube 9,
The welding wire 2 is fed to the welding torch 5 side by a twist feeder 3 while being rotationally driven in the circumferential direction by a drive motor 12.

According to this method, since the guide tube 9 itself that guides the welding wire 2 rotates at high speed, the contact resistance at countless contact points between the outer peripheral surface of the welding wire 2 and the inner eight surfaces of the guide tube 9 is reduced. , the welding wire 2 is given a swinging motion mainly in the circumferential direction, and the welding wire 2
vibrates minutely within the guide tube 9, and the feeding load is significantly reduced.

In addition, because the curved portion of the guide tube 9 is thicker than the straight portion due to the contact resistance between the welding wire 2 and the guide tube 9, the swinging motion received from the guide tube 9 is also more pronounced in the curved portion of the guide tube 9. , the wire feeding load is also significantly reduced at the curved portion of the feeding path.2 Therefore, even if the feeding path is considerably curved, the feeding load is significantly reduced and the welding wire 2 is Stable and smooth feeding is now possible.

According to this feeding method, the effect obtained by the oscillating motion of the welding wire 2 can be expected to be uniform over the entire length of the rotating guide tube 9. Since the feeding path is long, the swinging motion does not attenuate as the distance from the part that provides the swinging motion increases.

Therefore, even with small diameter wires or soft wires made of aluminum, copper alloy, etc., which are difficult to feed using conventional feeding methods, the method of the present invention allows stable feeding with a small feeding force. It becomes possible to do so.

Figure 2 shows an example of the experimental results when feeding by the feeding method of the present invention.
This is the case when an aluminum wire of mm is fed at a speed of 4771/MEN.

In the same figure, the curve m (2) (3) +4) constitutes a feeding route by winding the conduit cable 4 shown in the figure in a loop shape sequentially from the straight one once, twice, and three times. It shows the relationship between the rotational speed of the guide tube 9 and the wire feeding force in the case of the following.

Under these experimental conditions, even if the feeding path is quite curved, if the guide tube 9 is rotated at a speed of about 1000 times/min, the linear feeding path can be moved without rotating the guide tube 9. This shows that it is possible to feed with an even lower feeding force than when feeding by a conventional feeding method.

By the way, in actual welding work, the welding path is constantly changing as shown in Fig. 2 K It is also uneconomical to maintain and rotate the guide tube 9 at the rotational speed of the guide tube 9, and in particular, in the states (1) and (2), it may not necessarily be necessary to rotate the guide tube 9.

Now, suppose F is shown in Figure 2. If we assume that it is possible to sufficiently feed by the normal feeding method that does not rotate the guide tube up to the feeding force shown by, that is, the feeding load, then the condition of the feeding path is (1
) and (2), the rotational drive of the guide tube 9 may be stopped, and the guide tube 9 may be rotationally driven only in the cases (3) and (4).

An example in this case is shown in FIG. In the figure, reference numeral 20 denotes a feeding force detection means for detecting the feeding force of the welding wire 2. In this embodiment, the welding wire 2 is The required feeding force for feeding is indirectly detected. A detection signal based on the value of the feeding force detected by the feeding force detection means 20 is output to the control circuit 21.

Based on the detection signal, this control circuit 21 controls the feeding force,
In other words, the guide tube drive motor 2 is stopped when the load current exceeds a certain value and starts increasing, and when the load current decreases below the certain value.

With this configuration, if the state of the feeding path is (3) or (4), as shown in FIG.
Then, the guide tube drive motor 2 is energized and driven one rotation until the rotation speed of the guide tube 9 reaches N3 or N4, and the feeding load is F. If the condition of the feeding path is +1) or (2), the feed will be fed by a normal feeding method that does not rotate the guide tube 9, and the guide tube 9 will not be necessary. There is no need to rotate it any further.

Although the control circuit 21 has been described here to control the guide tube and the drive motor 2 on and off based on the detection signal detected by the feeding force detection means 20, the control circuit 21 is not limited to such a detailed control method. For example, the guide duplex drive motor 2 may be feedback-controlled so that the feeding force is reduced.

Further, as other means for detecting the feeding force, for example, a tensile force sensor or a pressure sensor (strain A gauge, etc.) may be inserted, and the feeding reaction force accompanying feeding of the welding wire 2 may be detected by the sensor.

By the way, the drive mechanism for driving the guide tube 9 is not limited to the one in the above embodiment, but for example, as shown in FIG. The welding wire 2 may be inserted into the rotating shaft 31, and the guide tube 9 may be directly connected to one end of the rotating shaft 31 via a connector 32 so that the axes of both shafts coincide with each other. In this way, there is no need for a rotating bearing for supporting the shaft, guide tube 9, gears, etc., and the structure is simpler (16°) and easier to handle than the one shown in FIG.

Further, according to the feeding method of the present invention, for example, as can be understood from FIG.
The practical range is approximately 0 Orpm-30Q Q rpm, which means that the speed of the oscillating movement of the welding wire 2 transmitted from the guide tube 9 in the circumferential direction is within the feeding speed range of 1 m of the welding wheel 2. However, this rotational speed range also substantially coincides with the practical rotational range of a general motor used for this type of rotational drive.

Therefore, as shown in FIG. 4, if the guide tube 9 is directly connected to the output shaft of the motor and is directly rotated and driven, there is no need to provide a special speed reduction mechanism, and the welding wire feeder according to the present invention This is extremely suitable as a guide tube drive mechanism.

Further, the wire feeder used in the present apparatus is not limited to the one shown in FIG. 1, and for example, a planetary roll type wire feeder as shown in FIG. 5 can also be used.

In this wire feeder, a cylindrical bracket 42 is fitted to an output shaft 41 of a motor 40, and a pair of support arms 44, 44 are attached to support protrusions 43, 43 integrally provided on the outer circumference of the bracket 42. are pivotally supported at their intermediate portions via pins 45.45, and feed rolls 46.46 are rotatably supported at one end of each support arm 44.44. A guide roll 47.4'7 is attached to each other end so that it can rotate freely ((
It is pivoted.

In addition, one end of each support arm 44, 44 is bent in a direction crossing each other, so that each feed roll 46, 46 forms a constant angle of deviation with respect to the feeding direction α of the welding wire 2. , and 1 so that they intersect with each other.

Additionally, a coil spring 50 is attached to the outer periphery of the bracket 42.
and a tapered tube 52 having a tapered circumferential surface 51 on its outer periphery are slidably inserted into each other, and the guide rolls 47 and 47 are connected to the tapered circumferential surface 5 of the tapered tube 52.
1, and one end surface of the adjustment ring 53 screwed onto the outer periphery of the bracket 42 is brought into contact with one end surface of the tapered tube 52, and the tapered tube 52 is moved forward or backward by adjusting the rotation of the adjustment ring 53. Moving bar, feeding roll 46.4
The pressure applied to the welding wire 2 by pi is adjusted and released. In this embodiment as well, the output shaft 41 of the motor 40 is hollow and has a pipe shape, and the welding wire 2 is inserted into the output shaft 41.

If such a wire feeder of the Hiko planetary roll type is used, there is no need to provide a special speed reduction mechanism, and a small and compact G'l can be achieved.

If it is not necessary to individually control the feeding speed of the welding wire 2 and the rotational speed of the guide tube 9, a common drive motor 40 is used as shown in FIG. What is necessary is to connect the tube 9 and the wire feeder to the other end, which further simplifies the configuration.

FIG. 6 shows an embodiment that is applied when the welding wire 2 has a considerably long feeding path, and the planetary roll type twist feeder 60 shown in FIG. A guide tube drive motor 61 is disposed in the middle of the conduit cable 4 to feed the welding wire 2 and rotate the guide tube 9 at the same time. motor 61
A guide tube 9 is connected to both ends of the output shaft 62.

Needless to say, in this case, it is necessary to control the drive motor of the wire feeder 60 and the guide tube drive motor 61 so that they operate in conjunction with each other.

By the way, as can be understood from the operating principle described above, the conduit cable 4 used in the present invention is composed of a jacket 8 and a guide tube 9 rotatably housed within the jacket 8. Of these, the guide tube 9 has flexibility. For example, a tube made of synthetic resin is used, but usually it is shown in Figure 7(a) in consideration of strength, durability, etc.
(b) (C) KIt is suitable that the structure is as shown in the example.

FIG. 7(a) shows a hollow tube 70 made of synthetic resin in which fine metal wires 71 and 72 are spirally wound in two layers around the outer periphery of the hollow tube 70 to ensure rigidity as a guide tube.

Figure 7(b) shows the guide tube shown in Figure 7(3) with an outer cover 74.
The figure shows the one coated with. In addition, FIG. 7(c) shows a hollow tube 75 in which thin metal wires parallel to each other are arranged in the circumferential direction.
A guide tube is constructed by winding a thin metal wire 76 around the outer periphery of this hollow tube 75.

The inner circumferential surface of these guide tubes must be smooth or nearly smooth in order to insert the welding wire, and there should be an appropriate gap between the outer circumference of the guide tube and the jacket as necessary. Powdered or liquid lubricants, lubricating oil, etc. may also be included.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the present invention. FIG. 2 is a graph showing the relationship between the rotational speed of the guide tube and the twist feeding force when the feeding route is varied. A schematic diagram showing another embodiment of the invention, FIG. 4 is a sectional view showing another embodiment of the guide tube drive source in the invention,
FIG. 5 is a cross-sectional view of main parts showing another embodiment of the wire feeder according to the present invention, FIG. 6 is a schematic diagram showing another embodiment of the present invention, and FIGS. 7(a) (b) (c ) are perspective views showing other embodiments of the guide tube in the present invention. 2 - Welding gear 3... Wire feeder 9... Guide tube 10, 11.12. l 3... Guide tube drive source 20 - Feeding force detection means 21... Control circuit 30... Guide tube drive source 3... Rotating shaft 40... Wire feeder 41... Rotating shaft 60.
61... Guide tube drive source patent applicant Osaka Electric Co., Ltd. agent Patent attorney Takashi Suzue

Claims (1)

[Claims] fl Welding characterized by inserting a welding wire into a hollow guide tube and feeding the welding wire while rotating the guide tube once in the circumferential direction. Tsuya feeding method. (2) A wire feeder that feeds the welding wire, a guide tube with a hollow interior through which the welding wire fed by the welding wire feeder is inserted, and this guide tube is rotationally driven in the circumferential direction. A welding wire feeding device comprising a guide duplex drive source. (3) A welding wire feeder that feeds the welding wire, a hollow guide tube through which the welding wire fed by the welding wire is inserted, and a guide that rotates the guide duplex in its circumferential direction. A tube drive source, a feed force detection means for detecting a feed force for feeding the welding wire, and an on/off control or speed control of the guide tube drive source according to the feed force detected by the feed force detection means. A welding shear feeding device characterized by comprising a control circuit for performing the welding shear. (4) A hollow hole is provided in the rotating shaft of the guide tube drive source or the motor constituting the drive source, and a welding wire is inserted into the rotating shaft, and both guide tubes are connected to the rotating shaft. The welding wire feeding device according to claim 2, wherein the welding wire feeding device is directly connected with their axes aligned. (5) The wire feeder has a hollow hole in the rotating shaft of the motor that constitutes the drive source of the feeder, and the welding wire is inserted into the rotating shaft, and the rotating shaft is equipped with a planetary roll system. The welding wire feeding device according to claim 2, characterized in that the welding wire feeding device is provided with a feeding roll mechanism according to the invention. (6) The welding shear feeding device according to claim 2, wherein the guide tube and the drive source also serve as the drive source of the wire feeder. (7) The guide tube drive source is composed of a plurality of motors whose speeds are controlled in conjunction with each other, and the entire length or part of the guide tube is rotationally driven by the motors connected to both ends of the guide tube. The welding wire feeding device according to claim 2, characterized in that: