JP4218793B2 - Method of retracting welding wire and auxiliary feeding device therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a welding wire retracting method and an auxiliary feeding device therefor, and more particularly, by a main feeding device for controlling the speed of welding wire feeding and an auxiliary feeding device for facilitating the transition of the welding wire in a conduit. The present invention relates to a method for enabling retracting of a welding wire when the welding wire is push-pull-fed to a torch, and an apparatus therefor.
[0002]
[Prior art]
A wire feeding device for controlling the feeding of the welding wire is used in order to feed the welding wire from a wire reel or a pail pack and feed it to the welding torch so that it can be melted with electrical energy and continuously welded smoothly. . The feeding device normally presses with two rolls facing each other in a direction perpendicular to the wire transition direction, and feeds and retracts the wire by the frictional force.
[0003]
The feeding device should basically be able to transfer the welding wire to the torch. However, if the feeding path is long or if there is a great deal of disturbance in the feeding path, a single feeding will be required. There are cases where the feeding resistance cannot be overcome only by the feeding force of the feeding device, or the desired feeding speed cannot be sufficiently generated. In such a case, it becomes impossible to feed or the feeding of the wire becomes unstable, which causes a problem that the welding quality is not stable.
[0004]
By the way, the feeding rolls equipped with the feeding device mounted on the welding robot and the pressure rolls that press and transfer the welding wire in cooperation with the feeding rolls have a small diameter, and the area where each comes into contact with the welding wire There is a limit. If the welding wire has a long feeding path, it is necessary to increase the pressure when trying to increase the feeding force. If the welding wire is soft, such as an aluminum wire, the cross section of the wire is deformed. If the surface is wrinkled, it will cause severe disconnection, which will adversely affect the welding quality.
[0005]
As described above, if there is one feeding device, the burden imposed on it is large, and the momentum motor has a large capacity. It goes without saying that if the weight of the feeding device increases, it will be difficult to mount the welding device near the welding torch that moves through the space due to the movement of the robot arm, and it is much easier to feed the welding wire than the push method. Even harder to hire.
[0006]
Therefore, recently, two feeding devices have been adopted, one on the upstream side near the pail pack and the other on the downstream side near the welding torch, and push-pull the welding wire. Thus, the load on each can be reduced. According to such a feeding device, the capacity of the motor can be reduced by sharing the load, and when it can be mounted in the immediate vicinity of the welding torch, the controllability of the feeding speed of the welding wire is further improved.
[0007]
However, in this case, the following points are problematic. For example, when the feed speed on the pull side is higher than that on the push side, the push side places a burden on the pull side and the wire is pulled or cut. Also, when passing through the roll, it slips and wears or gets scratched. If abrasion powder is generated, clogging occurs in the contact tip of the torch, and the smooth flow of the wire is hindered, which adversely affects the welding performance.
[0008]
If the pull side is slower than the push side, the wire is pressed against the pull side by the push-side feeding device and cannot be fed due to buckling at the joint, or the wire slips when the pressure is weak, as above It is inevitable that negative effects will occur. In view of such a point, consideration is given to adopting an AC servo motor with high controllability as a motor in each feeding device, and driving both in synchronization to enable transition at the same speed.
[0009]
If such a system is adopted, it is possible to control the pull-side feeding device so that the speed and the rising / falling characteristics of the speed are exactly the same as those in the push-side feeding device. Furthermore, even if reverse feed (retract) is required for some reason as well as wire forward feed, there is no particular problem if it has high control performance.
[0010]
However, if an AC servo motor is used, a servo driver for moving the motor is required, the motor itself is much more expensive than a normal induction motor, and synchronous control must be added to the servo motor control. However, it is difficult to cover the difficulty of increasing the complexity of the control system.
[0011]
In order to overcome such an adverse effect and perform the push-pull type feeding method, the present applicant proposes a torque transmission coupling (torque limiter) in Japanese Patent Application Laid-Open No. 2001-262310. One of them made it possible to use an inexpensive induction motor. According to this feeding system, it is not necessary to synchronize the AC servo motor of the main feeding device and the induction motor of the auxiliary feeding device, which greatly contributes to the reduction in the cost of the system.
[0012]
The rotation speed of the induction motor of the auxiliary feeding device is always set higher than the rotation speed generated by the speed controlled by the AC servo motor, and the induction motor output is reduced by the torque limiter and transmitted to the welding wire as a feeding force. At that time, the wire speed passing through the auxiliary feeding device is set to be free of constraints. Accordingly, the auxiliary feeding device can pass the wire at a speed defined by the main feeding device without having to synchronize the motor with the main feeding device. That is, it acts as if the torque limiter has released the speed control.
[0013]
The force applied to the welding wire by the induction motor of the auxiliary feeding device contributes to increase the control accuracy of the wire speed by the main feeding device. Usually, most of the factors that reduce the accuracy of speed control are frictional resistance generated in a guide pipe (conduit) provided to restrain unnecessary movement of the welding wire to guide and protect the transition.
[0014]
Because the welding wire is fed from outside the robot's operating area, the conduit may be 3 meters or more, and in some cases it may reach 20 meters. In any case, the auxiliary feeding device described above is designed to reduce or reduce the frictional resistance acting on the wire when passing through the long conduit.
[0015]
When the feeding force is compensated by such an auxiliary feeding device, the frictional resistance equivalent is reduced from the wire feeding force in the main feeding device, and the AC servo motor is reduced in size and weight. In addition, it can be easily mounted near the welding torch attached to the tip of the robot arm. Since speed control is performed only by the main feeding device, instability of speed control due to push-pull is eliminated, and further, synchronous control is not required, and the cost of the feeding system is promoted.
[0016]
Even if the feed route through the conduit becomes longer or a disturbance load acts on the feed route, as long as the friction resistance equivalent can be compensated by the feed force provided by the torque limiter, the main feed The apparatus can control the wire speed with high accuracy. This auxiliary feeding device can be used not only in a main feeding device equipped with an AC servo motor but also in cooperation with other types of main feeding devices such as a print motor placed on the upper arm of a robot, Wide versatility.
[0017]
[Patent Document 1]
JP 2001-262310 A (page 4-5, FIG. 2-3)
[0018]
[Problems to be solved by the invention]
By the way, in the auxiliary feeding device equipped with a torque limiter that realizes feeding by simply pressing the wire with a constant force by torque control, the retraction operation is a problem. This is because the induction motor adopted for the purpose of reducing the cost is not synchronized with the motor of the main feeding device, and the rotation direction cannot be changed without newly introducing a gear train, even if the rotation of the motor This is because even if the direction can be changed, there is a problem in responsiveness and retraction is not easy due to the fact that it cannot withstand actual use.
[0019]
Incidentally, the retraction is performed when the welding wire comes out of the contact tip and needs to be retracted, but in most cases, it is not necessary to strictly adjust the retraction amount or the speed. Therefore, the retraction may be performed only by reversing the AC servomotor of the main feeding device without driving the induction motor of the auxiliary feeding device. For example, even if the wire is prevented from being retracted by the auxiliary feeder, a conduit passage that is slightly larger than the wire diameter may be able to be secured by substantially bending the wire, for example, by bending the wire if the conduit is long. It is.
[0020]
For example, when the arc does not occur as planned at the arc start at the welding start point, the robot controller is instructed to start the retract. Arc retry (retry) by retraction is programmed to be aborted a predetermined number of times, but if retraction is repeated in response to a command, the wire will repeatedly receive unnecessary force in the conduit. .
[0021]
If the wire buckles due to repeated retraction, even when the wire is subsequently fed forward, smooth transition is hindered until the buckled portion exits the conduit. This not only reduces the stability of the welding quality, but also may stop the adoption of an auxiliary feeder equipped with an induction motor.
[0022]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an auxiliary feed provided with an induction motor and a torque limiter capable of controlling the torque of the output when using a plurality of wire feed devices by the push-pull method. Even when the equipment is used, when the welding wire is retracted, the auxiliary feeding device does not hinder the movement of the wire, and does not apply unnecessary force or deformation to the wire in the conduit. It is another object of the present invention to provide a welding wire retracting method and an auxiliary feeding device for the same, which facilitate smooth forward feeding thereafter.
[0023]
[Means for Solving the Problems]
The present invention relates to a main feeding device that controls the speed of feeding of a welding wire, and an auxiliary feeding device that applies a feeding force against a frictional resistance generated in a conduit by controlling the output of an induction motor or the like to the welding wire. And is applied to a method in which the welding wire is pushed and pulled to the welding torch. The characteristic is that the welding wire 1 is separated by reverse feeding by the main feeding device 9 (see FIG. 9) by separating the pressure roll 16 of the auxiliary feeding device 11 from the feeding roll 15 with reference to FIG. Is to retract.
[0024]
The invention of the apparatus is a welding wire push-pull in which an output of an induction motor or the like is torque controlled so that a feeding force against a frictional resistance generated in a conduit is applied to a welding wire whose speed is controlled by a main feeding device It is applied to the auxiliary feeding device for feeding. This is provided with a roll support 17 that causes the pressure roller 16 that has been supported to face the feed roll 15 that moves the welding wire 1 in cooperation with the pressure roller 16. The pressure resilient member 27 that exerts a pressing force on the feeding roll 15 on the pressure roll 16 via the roll support 17 and pushes back the roll support 17 against the resilient force of the pressure resilient member. The pressure release mechanism 24 that releases the pressure state of the welding wire 1 by separating the pressure roll 16 from the feed roll 15; the feed roll 15 and its induction motor for torque control of the output of the induction motor 22 and the like. And a torque limiter 23 for transmitting torque in a non-contact manner using magnetism. When the welding wire is retracted, the pressure release mechanism 24 pushes back the roll support 17 to separate the pressure roll 16 from the feeding roll 15 and retracts the welding wire 1 by reverse feeding by the main feeding device 9. Is to be able to.
[0025]
As shown in FIG. 6, the roll support 17 is supported at one end and can be tilted to separate the press roll 16 from the feed roll 15. As shown in FIG. An engagement / disengagement unit 32 that can be engaged / disengaged with the pressurizing force adjusting body 25 and prevents tilting at the time of engagement and transmits a pressing force to the feeding roll 15 to the pressure roll 16 is provided. As shown in FIG. 8, the pressure release mechanism 24 may be configured to include a pressing member 34 that pushes back the roll support 17 and an actuator 36 that moves the pressing member back and forth.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Below, the retracting method of the welding wire which concerns on this invention, and the auxiliary feeder for it are demonstrated in detail based on the embodiment. FIG. 9 shows the whole of equipment to be welded by a manipulator. The welding wire 1 can be fed out by a push-pull method and sent to the welding torch 2 and melted with electric energy to weld a workpiece (not shown). In FIG. 9, the wire feeding system 3 according to the present invention is depicted at the top.
[0027]
In the figure, 4 is a manipulator provided with a welding torch 2, 5 is a teach pendant used for teaching the movement of the manipulator in advance, and 6 is a controller for controlling the reproduction operation of the manipulator based on the teaching data. , 7 is a welding power source box, and 8 is a shield gas cylinder.
[0028]
A push-pull type is applied to the wire feeding system 3, a pull-side feeding device 9 is mounted in the vicinity of the welding torch 2 supported by the arms 4 a, 4 b, etc. A feeding device 11 is provided. The welding wire 1 fed out from the wire reel 10 is fed to the welding torch 2 via a conduit 12A that reaches the manipulator 4 and a conduit 12B that moves over the manipulator.
[0029]
In such welding equipment, the pull-side feeding device 9 of the feeding system 3 constitutes a main feeding device that controls the speed of feeding the welding wire, and the push-side feeding device 11 feeds the wire with a constant force by torque control. Auxiliary feeding device that performs the function of just pressing.
[0030]
The main feeding device 9 located on the downstream side of the wire is equipped with an AC servo motor with high control accuracy and excellent responsiveness so that the welding wire 1 is pulled out at a constant speed so as to keep the allowance from the contact tip. The feeding roll mounted on it is driven. On the other hand, the auxiliary feeding device 11 located on the upstream side includes an induction motor and a torque transmission coupling, and applies a force against frictional resistance to the wire 1 moving in the conduit 12. Take up most of the power you need.
[0031]
The motor used in the auxiliary feeding device is not limited to the induction motor, but a motor that is less expensive than the AC servo motor used in the above-mentioned main feeding device such as a DC motor, a synchronous motor, or a step motor is used. (In the present invention, these motors including induction motors are referred to as “induction motors”). Incidentally, an example of the structure of the torque transmission coupling (torque limiter) is described in the aforementioned Japanese Patent Application Laid-Open No. 2001-262310, and therefore detailed description thereof is omitted here.
[0032]
Next, based on the auxiliary feeder 11, the structure of each welding wire feeder will be briefly described. When this device is installed in the vicinity of the wire reel as shown in FIG. 9, as shown in FIGS. 10 (a) and 10 (b), it is held by being supported by the gantry 13 or the like. As shown in FIG. 2, a feed roll 15 and a pressure roll 16 are employed to compress the welding wire 1. The feed roll is rotated by obtaining the driving force of the motor, and the pressure roll is driven to rotate along with the welding wire 1 that is moved by the rotation of the feed roll.
[0033]
The feed roll 15 is always in a fixed position, for example, by being supported by a casing of the feed device. The pressure roll 16 is supported by a roll support 17 and faces the feed roll, or can be moved away from the feed roll by tilting about the fulcrum 17a.
[0034]
In FIG. 2, for example, an inlet guide 18 </ b> A that guides the welding wire 1 from the wire reel 10 to the roll and an outlet guide 18 </ b> B that guides the wire that has passed through the roll to the conduit 12 are provided. The reason why the pressure roll 16 can be separated from and in contact with the feed roll 15 is to make it easier to guide the wire tip to each of these guides.
[0035]
The feed roll 15 is provided with grooves 15a (see also FIG. 8) for pressing the wire, but the pressure roll 16 has only a flat surface. It goes without saying that such grooves are provided as appropriate and are not limited to the combination of the drawings. In the main feeding device 9 (see FIG. 9) for controlling the wire speed by the AC servo motor, a roll system based on the same principle and mechanism as the auxiliary feeding device equipped with the induction motor is employed.
[0036]
By the way, in the present invention, when the pressure roll 16 of the auxiliary feeding device 11 is separated from the feeding roll 15 and the welding wire is retracted by the reverse feeding by the main feeding device, there is a problem after buckling of the welding wire. This is to prevent the phenomenon that appears. The details will be described below.
[0037]
The entire auxiliary feeding device 11 is shown in FIGS. 3 shows the front surface, FIG. 4 shows the side surface, and FIG. 5 shows the flat surface. However, the auxiliary feeding device 11 drives the feeding mechanism 21 and the feeding roll 15 shown in FIG. The induction motor 22 shown, the torque limiter 23 interposed between the feeding mechanism 21 and the induction motor 22, and the pressure roll 16 shown in FIG. The pressure release mechanism 24 shown in FIG.
[0038]
Referring to FIG. 3, the feeding mechanism 21 includes the feeding roll 15, the pressure roll 16, the roll support 17, and the wire guide 18, and the roll support 17 is connected to the feeding roll 15. It functions as a pressure lever for causing the pressure roll 16 to move the welding wire in cooperation with the feed roll 15. The pressure roll 16 can be moved away from the feed roll 15 by tilting as much as shown in FIG. Therefore, in addition to the above-described components, a pressure adjusting body 25 is also provided.
[0039]
One end of the pressure adjusting body 25 is supported by a bracket 26 fixed to the main body casing, and can be tilted from the state indicated by a two-dot chain line as shown in FIG. 7 to the position of the solid line. A pressure resilient member 27 such as a coil spring that exerts a pressing force on the feeding roll 15 on the pressure roll 16 is provided. The pressure adjusting body 25 forms one lever, but a housing 28 is provided in the middle of a shaft portion to be inserted into an engaging claw portion 32 to be described later of the roll support 17. A coil spring 27 is externally fitted to the shaft portion behind the housing 28 applied to the back surface.
[0040]
A step is formed in the middle of the shaft, and the side on which the coil spring 27 is fitted is narrowed. Therefore, the housing 28 fitted on the thin shaft is further in the direction of the fulcrum 29 at the step. It can no longer be displaced. The coil spring 27 is disposed between the housing 28 and a stopper 30 described below, and the housing 28 is always pressed in the step direction. However, when a force toward the stopper 30 is applied to the housing 28, the housing 28 can be slightly displaced along the thin shaft portion while contracting it against the elastic force of the coil spring 27. ing.
[0041]
The stopper 30 also functions as a pressure adjusting member for changing the resilient force of the coil spring 27. This is screwed into a screw 31 engraved on the shaft, and when the stopper 30 is rotated as a pressure handle, the elastic force of the coil spring 27 can be changed by its advancement and retraction. In the figure, the spring is located between the housing 28 and the pressure handle 30 and is sufficient. However, if the inside of the pressure handle 30 is made hollow and a long coil spring can be used, it will be elastic. Easy to fine-tune the force.
[0042]
This pressure adjusting member 30 adjusts the pressure of the welding wire by the feeding roll and the pressure roll. The welding wire has a diameter of, for example, 0.8 to 1.6 mm, and the material is iron or aluminum. The welding wire can be fed with the optimum dredging pressure, even if it is hard and soft, such as a kind, and even with one type of auxiliary feeding device, the application range is expanded, and it is extremely convenient in practical use It becomes. In addition, when using an aluminum wire, it is desirable to employ the auxiliary feeding device according to the present invention regardless of the length of the conduit. This is because aluminum is soft and can easily be wrinkled even if it has a low frictional resistance only by pulling by the main feeding device on the pull side.
[0043]
A little more about the roll support 17 will be described. This can be tilted to separate the pressure roll 16 from the feed roll 15, but can be engaged with and disengaged from the pressure adjusting body 25 described above, and when engaged, the tilt is repelled by the housing 28 and the coil spring 27. Is blocked. If the pressing handle 30 is set so that the elastic force of the coil spring 27 becomes a desired value, the pressing roll 16 generates a saddle pressure corresponding to the elastic force with the feeding roll 15.
[0044]
In order to receive the elastic force, the roll support 17 is formed with an engaging claw portion 32 (see FIG. 4) having a U-shaped notch. This can be engaged / disengaged with the pressure adjusting body 25 and functions as an engagement / disengagement section that elastically blocks the tilting of the roll support body 17 and transmits the pressing force to the feeding roll 15 to the pressure roll 16 when engaged. To do.
[0045]
With respect to the feeding mechanism 21 configured as described above, a pressure release mechanism 24 is provided in the upper half of the main body as can be seen from FIG. As shown in FIG. 1, the roll support 17 is pushed back against the elastic force of the coil spring 27, the two-dot chain pressure roll 16 is separated from the feed roll 15 as shown by a solid line, and welding is performed. It acts to release the overpressure condition of the wire 1.
[0046]
The pressure release mechanism 24 includes a pressing member 34 shown in FIG. 8 that slightly tilts the roll support 17, a link body 35 that moves the pressing member forward and backward, and an actuator 36 that moves the link body. The pressing member 34 functions as a knocker that presses any part of the roll support 17, and is attached to the tip of the main link 35 </ b> A that swings in a seesaw manner, for example.
[0047]
The link body 35 includes a main link 35A and an auxiliary link 35B that swings the link body 35. For example, the knocker 34 advances according to the movement of the solenoid 36 that pulls the rod 37 when energized, and the pressure roll 16 is moved via the roll support body 17. Separated from the feed roll 15. If the drive of the solenoid is stopped, the rod is placed in a free state, but the knocker 34 is restored by the elastic force of the coil spring 27, and eventually the rod 37 is pulled out and returned to its original state.
[0048]
If the auxiliary feeding device is configured in this way, the pressure roll can be separated from the feeding roll, and the welding wire can be retracted by reverse feeding by the main feeding device equipped with an AC servo motor. That is, the auxiliary feeding device compresses the welding wire at the time of retraction, so that the retreating welding wire is not buckled in the conduit. The retract startability is improved, the subsequent wire feeding is smooth, and the welding quality is maintained at a high level. The retract command is executed by the operator pressing a predetermined button on the teach pendant 5 (see FIG. 9) or the like.
[0049]
Since it is not necessary to synchronize between the motor of the auxiliary feeding device and the motor of the main feeding device, the driving-related parts in the auxiliary feeding device can be reduced in price. The feeding force by the torque limiter can be adjusted in the range of 0 to several kg by operating the torque adjusting ring 41 shown in FIG. 4 to select an appropriate transmission rate and screwing and fixing the detent 42. . This also facilitates matching with various types of welding wires. This torque limiter keeps only the transmission torque at a desired value regardless of the rotational speed, so that the feed speed of the push-side roll naturally becomes the speed of the pull-side feeding device.
[0050]
Torque adjustment by the torque limiter is non-contact type torque transmission using magnetism, and the transmission rate can be determined by the scale of the torque adjustment ring 41 attached around the limiter. As described above, not only can the frictional resistance be almost equal, but the eye can be set to a large eye. A reduction gear 43 is installed on the output shaft side of the torque limiter so that the rotation of the induction motor that rotates at a constant speed is reduced so that the rotation of the feed roll is close to the feed speed of the welding wire to some extent. It has become.
[0051]
Incidentally, the adjustment of the transmission torque in the torque limiter is performed at that time if the length of the conduit or the shape of the path changes. This is also done each time the diameter or material of the welding wire changes. In other words, if they do not change, the feeding resistance hardly changes, so once set, adjustment for the same workpiece becomes unnecessary in principle.
[0052]
Incidentally, in FIG. 4, 38 is a power-on switch, and 39 is an inching command button. The latter is used when exchanging the welding wire. If this button is pressed in a state where the pressure of the welding wire is released in advance by, for example, retracting the pressure roll of the main feeding device, auxiliary feeding will be performed. The induction motor 22 of the apparatus 11 can be rotated to automatically pass the wire through the conduit or to the contact tip of the welding torch. As a result, it is possible to reduce the time and labor required for exchanging wires.
[0053]
The actuator employed in the pressure release mechanism is not limited to the solenoid described above, and a known driving device may be used as appropriate. The link body for advancing and retracting the knocker is not limited to the illustrated one, and an appropriate configuration can be selected. In FIG. 4, the plate 40 as a driven member attached to the roll support 17 can be seen in the front.
[0054]
This is to make it easy for the knocker 34 to push the roll support 17 and to allow the roll support 17 to tilt without being obstructed by the pressure adjusting body 25. Therefore, as can be seen from FIG. 8, the knocker 34 can be provided at a position that does not overlap the pressure adjusting body 25. Of course, if the knocker is provided at an appropriate position and can be brought into contact with, for example, the abdomen 32a of the engaging claw portion 32 of the roll support member 17, there is no problem.
[0055]
By the way, in the description of the present invention, one auxiliary feeding device is arranged on the upstream side, but in the case of a long conduit, a second unit can be installed in the middle. Further, the main feeding device can be arranged upstream, and the auxiliary feeding device can be placed on the upper arm of the manipulator. Although the push function and the pull function are reversed, there is no special obstacle in making the frictional resistance cover in the auxiliary feeding device and the speed control in the main feeding device.
[0056]
The auxiliary feeding device only needs to apply a force equal to the feeding resistance generated in the conduit to the welding wire. However, even if a feeding force larger than that is given, no problem occurs in operation. On the other hand, it is clear that even a little smaller power is better than no power. As described above, the magnitude of compensation for the frictional resistance is performed by the torque adjustment ring.
[0057]
Although the main feeding apparatus has been described on the assumption that an AC servo motor is used, the main feeding apparatus does not necessarily have to be a motor of that kind. If at least the auxiliary feeding device is constituted by the induction motor described in this example or the motor described below, the problem of frictional resistance in the conduit and the disadvantage at the time of retracting can be solved as much as possible. The motor used in the auxiliary feeding device is not limited to the induction motor, and a motor that is less expensive than an AC servo motor such as a DC motor, a synchronous motor, or a step motor is used.
[0058]
Further, the welding can be applied not only in the gas shield consumable electrode type arc welding method but also in the gas shield non-consumable electrode type arc welding method such as TIG welding using a filler wire. Furthermore, the present invention can also be applied to arc spraying introduced in JP-A-2001-262310. In the case of this arc spraying, the auxiliary feeding device sends two spraying wires at the same time. However, two torque transmission couplings are driven by one motor, and each roll support is pressed by one press. The release mechanism may be operated simultaneously so that the two electrodes can be wire retracted.
[0059]
The roll support body and the pressure adjusting body described so far have a tilting structure. However, the present invention is not limited to this, and the roll support body and the pressure adjustment body may be guided by a guide rail or the like so that they can advance and retreat. In any case, the present invention can be applied as long as it can exhibit functions such as separation / contact between the rolls, reed pressure of the welding wire, pressure adjustment, and pressure release.
[0060]
【The invention's effect】
According to the present invention, since the pressure roll of the auxiliary feeding device is separated from the feeding roll, it becomes easy to retract the welding wire by reverse feeding by the main feeding device, and the welding operation is facilitated. And can stabilize the welding quality.
[0061]
In the invention of the auxiliary feeding device, the roll support body bearing the pressure roll is pushed back against the elastic force of the pressure elastic member, and the pressure roll is separated from the supply roll to Since the pressure release mechanism that releases the negative pressure state is provided, the auxiliary feeding device does not restrain the movement of the welding wire at the time of release, and the welding wire is not deformed by the reverse feed by the main feeding device. Retract instantly. In addition, torque adjustment by the torque limiter is a non-contact type torque transmission using magnetism, and its transmission rate can be determined. it can. When the length of the conduit or the shape of the path changes, or when the diameter or material of the welding wire changes, the transmission torque can be adjusted each time by the torque limiter.
[0062]
A tiltable roll support body can be engaged with and disengaged from the pressure adjusting body, and includes an engagement / disengagement section that elastically prevents tilting when engaged and transmits a pressing force to the feeding roll to the pressure roll. According to the configuration in which the pressure roll can be separated from the feeding roll by receiving the force to push back by the operation of the actuator, the structure for adding a retract function can be obtained by using the feeding mechanism of the welding wire as it is. Thus, the device can be miniaturized and the number of parts can be minimized.
[Brief description of the drawings]
FIG. 1 is a mechanism diagram for explaining the movement of a welding wire retracting method and auxiliary feeding device according to the present invention.
FIG. 2 is a front view showing a feeding state by partially removing a feeding mechanism.
FIG. 3 is a front view of an auxiliary feeding device.
FIG. 4 is a side view of an auxiliary feeding device.
FIG. 5 is a plan view of an auxiliary feeding device.
FIG. 6 is an operation diagram showing a state in which the roll support in the feeding mechanism is tilted to the maximum extent.
FIG. 7 is an operation diagram illustrating the movement of the pressure adjusting body.
FIG. 8 is an operation diagram illustrating the movement of the pressure release mechanism.
FIG. 9 is a schematic configuration diagram of a welding system using a manipulator.
FIGS. 10A and 10B show an installed state of an auxiliary feeding device arranged in the vicinity of a wire reel, where FIG. 10A is a plan view and FIG. 10B is a front view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Welding wire, 2 ... Welding torch, 3 ... Wire feeding system, 4 ... Manipulator, 9 ... Pull side feeding device (main feeding device), 11 ... Push side feeding device (auxiliary feeding device), 12, 12A, 12B ... Conduit, 15 ... Feed roll, 16 ... Pressure roll, 17 ... Roll support, 22 ... Induction motor, 23 ... Torque limiter (torque transmission coupling), 24 ... Pressure release mechanism, 25 DESCRIPTION OF SYMBOLS ... Pressure adjusting body, 27 ... Pressing elastic member (coil spring), 32 ... Claw part for engagement (engagement / disengagement part), 34 ... Pressing member (knocker), 36 ... Actuator.

Claims (3)

Welding using a main feeding device that controls the speed of welding wire feed and an auxiliary feeding device that gives the welding wire a feeding force against the frictional resistance generated in the conduit by controlling the output of the induction motor, etc. In the method of push-pull feeding the wire to the welding torch,
A method of retracting a welding wire, wherein the pressure roll of the auxiliary feeding device is separated from the feeding roll, and the welding wire is retracted by reverse feeding by the main feeding device. Auxiliary for welding wire push-pull feeding by controlling the torque of the output of the induction motor, etc., so that the feeding force against the frictional resistance generated in the conduit is applied to the welding wire whose speed is controlled by the main feeding device In the feeding device,
A roll support that causes the pressure roll that has been supported to face a feeding roll that moves the welding wire in cooperation with the pressure roll;
A pressure elastic member that exerts a pressing force on the pressure roll on the pressure roll via the roll support;
A pressure release mechanism that pushes back the roll support against the elastic force of the pressure elastic member and releases the pressure state of the welding wire by separating the pressure roll from the feed roll;
A torque limiter that is interposed between a feed roll and the induction motor and the like for torque-controlling the output of the induction motor and the like, and transmits torque in a non-contact manner using magnetism;
When the welding wire is retracted, the pressure release mechanism pushes back the roll support so that the pressure roll is separated from the feeding roll, and the welding wire can be retracted by reverse feeding by the main feeding device. A welding wire auxiliary feeding device characterized by the above. The roll support is supported at one end and can be tilted because the pressure roll is separated from and in contact with the feed roll. The roll support can be engaged with and disengaged from the pressure adjusting body on which the pressure elastic member is mounted. And an engagement / disengagement part that transmits the pressing force to the feeding roll to the pressure roll,
The retractable welding wire auxiliary feeding device according to claim 2, wherein the pressure release mechanism includes a pressing member that pushes back the roll support and an actuator that moves the pressing member back and forth.

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