JPS60170574A - Method for repairing welding torch and construction of welding torch for executing said method - Google Patents

Abstract

PURPOSE:To enable automatic and quick repair of a welding torch by providing an assembly constituted integrally of a chip, chip holder, nozzle, etc. removably from a torch body and exchanging the assembly with a fresh assembly. CONSTITUTION:If, for example, a wire 96 and a chip 32 are stuck to each other by melting, the gripping part 62 of a torch body 12 and the gripping part 60 of a cap nut 56 provided to the tip end 10 of a torch are respectively chucked by chucking devices 90, 92. The operator disconnects the part 12 from the end 10 by rotating the nut 56 and retreats the end 10 while feeding the wire 96 by a wire reed roller 94. The wire 96 is cut between the part 12 and the end 10 and thereafter the wire 96 is retreated to the position B and the fresh end 10 is positioned in front of the body part. The nut 56 is rotated by the part 60 and the fresh end 10 is attached to the body part 12 and is fed by the roller 94 until the end of the wire 96 projects by a specified length from the chip 32.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for repairing a /8 joint in a gas-shielded arc welding robot and a welding torch structure suitable for carrying out the method.

In recent years, welding robots for unmanned welding work have rapidly become popular. A kind of welding torch in such a welding robot includes welding 1 to 1 which are operated under automatic control.
- A predetermined welding wire is fed through the tip provided at the tip of the torch, and electricity is supplied to the wire to generate an arc between the wire and the base material, and the arc causes the base material to be While welding is being carried out, there is a method in which shielding gas is ejected from a cylindrical nozzle surrounding the tip toward the welding location of the base metal.

However, in such welding torches, various problems inevitably occur during welding work. For example, during welding work, a wire fed through a tip attaches to the tip and the wire is no longer fed, thereby stopping arc generation, and spatter generated during welding is transferred to the inner surface of the nozzle. If it adheres to the tip or outer surface of the tip or the orifice for ejecting the shielding gas located inside the nozzle, it may cause wear and tear on the tip and nozzle, leading to poor power supply, or block the shielding gas flow path and cause pinholes. Or it may cause blowholes.

Conventional welding robots can detect such an abnormality, stop its operation, and notify the operator of the abnormality, but they do not have a self-repair function. When such an abnormality occurs, the actual situation is that the operator manually repairs the abnormality.

However, when an abnormality is repaired manually, it is necessary to allocate personnel, and the repair work is not only dangerous but also takes time.

For example, if a chip and a wire are welded together, open the safety shelf or safety door installed around the robot, inspect the abnormal part, and then remove the welded part using a bench, file, sander, etc., and remove the welded part from the chip. The process involves replacing the wire with a new one, feeding the wire so that it protrudes a certain length from the tip of the chip, and then closing the safety shelf, safety door, etc., and starting the robot again. It takes a lot of time. During this time, the robot will be in a stopped state, but if the stoppage time is long, the operating rate of the robots will decrease, and moreover, these robots are usually installed in several units along the assembly line of the production line. Therefore, if one robot stops working, the other robots will not be able to operate, resulting in a significant decrease in the overall robot utilization rate and, as a result, a significant decrease in productivity. This causes the problem of storage.

Of course, a device has been considered that automatically replaces the tip alone in response to the above-mentioned abnormality, but this device would be able to automatically replace the tip if an abnormality occurs in other parts of the tip of the torch. It cannot be repaired. Furthermore, in the above-mentioned welding robots, if there is an abnormality in the tips, there are many cases where other parts such as the nozzle and the orifice arranged inside the nozzle are also abnormal. be.

The present invention has been made against this background, and its purpose is to quickly and automatically repair the abnormality using a repair device when an abnormality occurs in the l8 robot. The present invention provides a welding torch structure in a welding robot for carrying out the method, thereby promoting unmanned welding work, eliminating dangers associated with repair work, and increasing the operating rate of welding robots. The goal is to improve productivity.

Accordingly, the repair method according to the present invention for achieving this purpose includes an assembly of the tip of the torch integrally including the tip, the tip, a tip holder for holding the tip, and the nozzle. By removing the three-dimensional body from the torch body holding the assembly and then attaching a new torch tip assembly prepared in advance to the torch body, the welding operation removes any damage caused to the torch tip by the welding operation. It is characterized by being designed to eliminate abnormalities.・ If you do this, you will be able to find the defective part or the defective location, or identify the source of the defect before removing the defective part that may occur due to the welding operation at the tip of the torch. There is no need to scrape the welded part, and it is only necessary to replace the torch tip assembly, thus making it possible to automate this work. This facilitates unmanned welding operations and eliminates the dangers associated with welding operations. Furthermore, since replacing the torch tip does not require the troublesome work described above and can be done using a repair device, the time required for the repair work, that is, the replacement work, can be shortened, which improves the robot's operating rate and productivity. This results in the effect of increasing the

Further, in order to carry out such a method, the welding torch suitably used in the present invention includes the tip or a tip holder that holds the tip, and the nozzle. between the torch tip assembly and the torch body, the tip assembly and the torch body holding the The present invention is characterized in that it is provided with a connecting mechanism that connects and disconnects the two.

The welding torch used in such welding robots has a particularly complex structure compared to conventional welding robots because the torch tip of conventional welding robots is separate from the main body and a connecting mechanism is provided between them. It has the advantage that it does not cause problems or increase costs.

Next, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows the main parts of a welding torch of a welding robot that is operated under automatic control.
and a torch main body 12 that holds the torch. The main body portion 12 includes an outer cylinder 14 and an inner cylinder 16, 1B.
Furthermore, a guide pipe 20 that serves as a guide member when feeding the wire is fitted inside the inner cylinder 18. Furthermore, a cylindrical member 22 is disposed at one end of the main body 12 . This cylindrical member 22 has a cylindrical fitting part 24 on the rear end (right end in the figure) side, and this fitting part 24 is an annular recess formed between the outer cylinder 14 and the inner cylinder 16. It is fitted in and fixed. The inner circumferential surface of the cylindrical member 22 is a tapered surface 26 whose diameter gradually increases as it advances toward the tip (left end in the figure), and the outer circumferential surface has a tapered surface 26 that gradually increases in diameter. - A male threaded portion 28 is provided, which forms part of a connecting mechanism that connects the tip end portion 10.

On the other hand, the tip 10 of 1--chi has a tip holder 30 at its center, and the rear end of the tip holder 30 enters the recess formed by the inner cylinders 16 and 18 of the main body 12. I'm forced to. Further, a tip 32 is attached to the opposite end of the tip boulder 30, that is, the tip at the left end in the figure, which is a power supply member for a wire that becomes an electrode when an arc occurs. The lug 32 is screwed onto the tip holder 30 at a threaded portion 34.

Further, a guide pipe 3 is provided on the inner peripheral side of the tip holder 30.
6 is disposed so as to be continuous with the guide pipe 20, and the outer circumferential surface of the guide pipe 36 and the tip holder 30
A predetermined gap is formed between the chip boulder 30 and the inner circumferential surface of the chip boulder 30 , and this gap is used as a gas flow path 38 . The liquid is ejected from a small hole 42 provided in the section into a cylindrical nozzle 44.

Further, an engaging portion 46 is provided in the vicinity of the rear end of the chip holder 30 so as to protrude outward in the radial direction, and its front end surface is an engaging surface 48 that stands up in a direction perpendicular to the axis. . The opposite surface is a tapered surface 50 parallel to the tapered surface 26 of the cylindrical member, and the radial and axial positions of the tip holder 30 are determined by the action of these tapered surfaces 50.26. It is now possible to do so. That is, when assembling the torch tip assembly 10 to the torch main body 12, the tip holder 30 is
A predetermined gap is ensured between the rear end portion and the inner cylinders 16, 18. Note that 52 is a tube that is fitted to the outer peripheral surface of the chip holder 30 due to temperature changes.

Note that an insulating tube 54 is provided approximately at the center of the chip boulder 30.
is fixed by fitting, and the threaded part of the J-colored edge tube 54 has a
A nozzle 44 that surrounds the tips of the tip 32 and the tip holder 30 and forms a predetermined space 45 therebetween is screwed together. And the chip holder 30
The shielding gas guided from the gas flow path 38 inside through the small hole 42 passes through the space 45 and is ejected from the tip of the nozzle 44 to shield the welding point located in front of the nozzle 44 from the atmosphere. -ing

Moreover, these chips 32. Tip holder 30° nozzle 4
The torch tip 10 as an assembly including the torch 4 and the like is attached to the torch main body 12 with a cap nut 56. That is, the cap nut 56 is provided with an engagement portion 58 that engages with the engagement portion 46 of the tip holder 3o, which prevents the cap nut 56 from coming off the tip holder 30, and also prevents the cap nut 56 from separating from the tip holder 30. When the nut 56 is screwed into the male threaded portion 28 of the main body portion 12, the engaging portions 46° 58
As a result of this engagement, the tapered surface 50 of the tip holder 3° is pressed against the tapered surface 26 of the main body portion 12. Further, the outer peripheral part of the bag nand 56 has a polygonal shape such as a hexagonal shape, or has no unevenness in the circumferential direction by processing such as row 1 or soto processing, and is made into a second gripping part 60, to which a rotational operation force is applied. It looks like this. On the other hand, the main body part 12 is provided with a third grip part 62 having a large diameter and a circular cross section for holding the main body part 12 non-rotatably when applying a rotational operation force to the bag nand 56.

Note that the outer circumferential surface of the first gripping portion 62 is knurled and has an uneven shape along the circumferential direction.

Next, another embodiment of the present invention will be described based on FIG.

In this embodiment, the torch tip 64 is connected to the tip holder 66.
This figure shows an example in which the torch can be attached to the torch main body 70 by fitting the male threaded part 68 of the torch to the female thread 73 of the torch main body 7o. 74 is a nozzle, and 76 is an insulating tube, and these structures are substantially the same as those in the first embodiment. An orifice member 74 is disposed between the tip holder 66 and the nozzle 74, and the shielding gas sent through the gas flow path 80 enters the inside of the nozzle 74 through the small hole 82 of the orifice 78. The gas is ejected through the gas passage 45 in the nozzle 74, and is ejected to the external welding location. In addition,
The orifice member 78 is connected to the tip holder 6 on the inner peripheral surface.
6, and the nozzle 7 is fitted on the outer peripheral surface of the base end.
It is engaged with the engagement recess of No. 4.

In addition, a tapered surface 86 is formed at the tip of the outside @ 84 that forms the main body of the torch body 70, and the diameter gradually increases as it goes toward the first end. Then, a tapered surface 8 parallel to this tapered surface 86
8 is formed, and when the torch tip 64 is assembled to the main body 70, the assembly position of the tip 64 is defined by matching these tapered surfaces 86, 88. .

Note that in this embodiment, the main body part 70 has a
The structure of the gripping part 102 is similar to that of the previous embodiment, but the second gripping part 104 provided at the tip 64 is provided on the outer circumference of the insulating tube 76.

Next, in a welding robot having a welding I/-ch composed of such a torch main body and a tip assembly, a wire and a tip, a 32.72 inch l8 joint, and a tip 32
．． In the event that an abnormality occurs such as wear and tear on the gas flow path 72 or blockage of the gas flow path 45, 38.degree. 80, a method for repairing the problem will be described.

First, the repair procedure when an abnormality occurs in the welding robot equipped with the torch shown in FIG. 1, for example when the wire and the tip 32 are welded together, will be explained with reference to FIGS. 3 to 8.

When such an abnormality occurs, first, the abnormality detection device of the welding robot 7 is activated and a detection signal is generated. Based on this detection signal, the torch is retracted to a predetermined position. Thereupon, the first gripping portion 62 of the torch body 12 and the second gripping portion 6° of the cap nut 56 of the torch tip 10 are each chucked by the jacking device 90.92. In this state, Fukuro Nando 56,
By rotating in the direction indicated by the arrow in FIG. 3, the connection between the torch tip 10 and the torch main body 12 is released. Next, as shown in FIG. 4, the entire torch tip 10 is held by a predetermined moving device (not shown) and moved back to the right in the figure.

At this time, the wire feeding roller 94 is rotated in the direction of the arrow to feed the wire 96 by the amount by which the tip end 10 has retreated. The wire 96 is moved together with the torch tip 10 because the tip of the wire 96 becomes spherical during the welding process and cannot pass inside the tip 32.

When the torch tip 10 is retracted, the wire 96 is cut at the portion between the main body 12 and the tip 10 (the portion indicated by the arrow in FIG. 3), and then the wire 96 is cut as shown in FIG. 6. Reverse the feed roller 94 and move the tip of the wire 96 to the sixth
It can be retracted to a position B (not shown) and the torch tip 10 can be moved to another position. Then, a new torch tip 10 prepared in advance is placed in front of the torch main body 12, and then the second gripping portion 60 of the cap nut 56 is chucked again and rotated in the direction of the arrow in FIG. , a new torch tip 10 is attached to the main body 12.

Once the torch tip 10 is attached, the feed roller 94 is rotated in the direction of the arrow in FIG. 8 to feed the wire 96 until the tip protrudes from the tip 32 by a certain length. The feeding amount of the wire 96 is determined by placing a sensor in front of the chip 32, and when the sensor detects that the wire protrudes by a predetermined length, the feeding operation of the feeding roller 96 is determined. By stopping it, it can be determined automatically and accurately.

In this way, when the wire 96 has been fed by a predetermined amount, the welding robot is in a state where the abnormality has been resolved, that is, the defective part has been repaired, and the welding torch starts working again based on the activation signal issued at this time. They are moved to different positions and welding operations are performed in a predetermined order. Note that the distal end portion 10 removed from the main body portion 12 can be reused by replacing defective parts.

Next, other embodiments of the welding method according to the present invention are shown in FIGS.
This will be explained based on FIG. 15.

As in the previous embodiment, when welding occurs between a wire and a chip as an abnormality due to welding operation, a wire welding signal is generated, and based on this signal, welding 1.-
is retracted to a predetermined position shown in FIG. At the retracted position, the degree of welding of the welded portion is determined, and depending on the degree of welding, the chip 72 is cut by the cutting tool 98 or the chip is cut by the ω1 grindstone 100, as shown in FIGS. 10 and 11. 72 The tip is ground. By cutting or grinding, the wire tip 96 and the tip 7 are
2 are separated, the feed roller 94 is rotated in the direction of the arrow in FIG. 12, the wire 96 is retracted, and its tip is retreated to the position indicated by B in FIG. Next, the torch tip 64 is rotated in the direction indicated by the arrow in FIG. 12, and the male thread 68 of the tip 64 and the female thread 73 of the torch body 70 are unscrewed, Torch tip 64 is removed from torch body 70. FIG. 13 shows this state. Next, a new torch tip 64 prepared separately is fitted into the torch main body 70, and the second gripping part 104 is fitted into the torch main body 70.
At this point, it is rotated in the direction shown by the arrow in FIG. 14, and then attached to the torch body 70. After the torch tip 64 is attached to the 1--ch body 70,
The feeding roller 94 is rotated to feed out the wire 96, so that the tip thereof protrudes a certain amount from the tip of the chip 72. At this point, the replacement of the torch tip, ie the repair of the welding robot, is completed, and then the entire torch is returned to the welding position again.

In this way, the above method involves replacing the entire torch tip assembly as a means of repairing an abnormality in a welding robot, which simplifies the work and therefore allows this work to be performed automatically by a machine. becomes.

That is, as in the conventional case, the nozzles 44, 74, the tip 3
2, 72, orifice 78, etc., first find the abnormal part, file the abnormal part,
If it is necessary to remove these parts from the tip of the torch after sanding them with a sander, etc., and if there is a narrow gap in which to insert tools such as files, the work itself may be difficult. Because it is difficult,
It has been difficult to automate these tasks, but with the above method, it is only necessary to operate on the specified parts in a predetermined order and in a fixed procedure, making it possible to repair defective parts. Since these tasks can be automated and are simple and easy, the time required for the tasks is significantly reduced, increasing the operating rate of welding robots and improving productivity.

Moreover, even if such a method is adopted, regarding the normal parts of the removed torch tip 10.64,
The removed torch tip can be disassembled separately and used for new use, so there is no need to waste normal parts.

In addition, as mentioned above, since repair work can be performed automatically, it is no longer necessary to allocate personnel to monitor welding robots, which eliminates the dangers that previously occurred. , various effects occur.

Further, the above-described welding robot configured to carry out these methods has the tip 10.64 of the welding torch
The tip portion 10.64 and the body portion 12.70 are constructed as a separate and integral assembly from the body portion 12.70.
70, there is also a connecting clasp structure for connecting or separating the two using a screw mechanism. ．． 64 and main body part 1
2.70, the first gripping part 62.102 and the second gripping part 60.104 are simply provided, and the structure is particularly complicated compared to conventional robots, and the equipment cost is particularly high. It never becomes expensive.

Note that a device for automatically replacing the tip end of 1--chi can be provided in the welding robot itself, or can be provided separately.

Although the embodiments of the present invention have been described in detail above, the present invention can also be implemented in other different forms and aspects.

For example, before gripping the second gripping part at the tip of 1-chi with a chuck device, air blow the gripping part to remove dirt caused by welding work, and when gripping the second gripping part, In addition, it is possible to prevent the dirt from getting stuck in the threaded part of the torch tip or the main body, and it is also possible to use another fluid instead of air to clean the grip part of the torch tip. Of course, it is also possible to clean 'tlJ.

In addition, the connection mechanism between the torch tip assembly and the torch main body includes a structure in which the tip assembly and the main body are connected or separated by a rotational operation such as a Shibetsu-like screw mechanism, or a structure in which one of them is connected or separated. It may also have a mechanism that allows it to be inserted into another object and locked as is.

In addition, it is also possible to add or delete steps other than those in the above embodiments without departing from the spirit of the present invention.

Furthermore, in the welding torch in the welding robot saw 1- according to the present invention, the 16th
It is of course possible to provide a flat gripping surface 106 as shown in the figure, or to form the cross-sectional shape of the gripping part into a polygonal shape such as a square or hexagon.

Furthermore, the chip and the chip holder that holds it can be made into an integral structure as well as separate structures as illustrated, and the cap nut 5 in the embodiment shown in FIG.
6 may be provided on the torch main body 12 side, and in that case, the first gripping portion provided on the torch tip 10 will hold the torch tip 10 so as not to rotate. , a rotational operating force is applied to the second gripping portion provided on the bag nand.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are respectively 1Ji plane views showing essential parts of a welding torch of a welding robot according to an embodiment of the present invention. FIGS. 3 to 8 are schematic diagrams for explaining one embodiment of the repair method according to the present invention, and FIGS.
The figures are schematic diagrams for explaining operations in other embodiments of the present invention. 10. 64: Torch tip 12. 70: Torch body 28. 68: Male thread 30. 66: Tip holder 32.72: Chip 44.74: Nozzle 46.58: Engagement part 56 Two-bag nand 60.104: Second gripping part 62.102: Second gripping part 73: Female thread part 96: Wire Fig. 7 Trial Fig. 8 Figure 14 Figure 16

Claims (5)

[Claims] (1) A wire is fed through a tip provided at the tip of a welding torch that is operated under automatic control, and electricity is supplied to the wire to generate an arc between the wire and a predetermined base material. a gas-shielded arc that welds the base metal with the arc, and jets shielding gas toward the welding location of the base metal from a cylindrical nozzle surrounding the tip; A method for repairing the welding torch in a welding robot, the assembly of the torch tip integrally comprising the tip, the tip, a tip boulder holding the tip, and the nozzle; The abnormality caused in the torch tip by the welding operation is resolved by removing it from the torch body to be held and then attaching a new torch tip assembly prepared in advance to the torch body. A method for repairing a welding torch in a gas-shielded arc welding robot, characterized in that: (2) A wire is fed through a knob provided at the tip of a welding torch that is operated under automatic control, and electricity is supplied to the wire to create an arc between the wire and a predetermined base material. In a welding robot, the arc is generated and the base metal is welded by the arc, while a shielding gas is ejected from a cylindrical nozzle surrounding the tip toward the welding location of the base metal. As a welding torch, the torch tip, which includes the tip or the tip, the tip boulder that holds it, and the nozzle, is separate from and integral with the torch body that holds the tip. While configured as an assembly, a connecting mechanism is provided between the torch tip assembly and the torch body for connecting or disconnecting the torch tip assembly and the torch body. The welding torch structure of the featured arc gas welding robot. (3) The connecting mechanism connects or disconnects the torch tip assembly and the torch main body by rotation in a forward or reverse direction, and the connecting mechanism connects or disconnects the torch tip assembly and the torch body, and The connecting mechanism is provided with a second gripping portion to apply a rotational operating force, and the torch body or the tip assembly is provided with a second gripping portion for gripping these in a non-rotatable manner. Welding torch structure according to scope 2. (4) The connection mechanism has a male threaded portion formed on either the torch main body or the torch tip assembly, and a female threaded portion formed on the other, and the threaded portion of the threaded portion is formed on the other. The welding torch structure according to claim 2 or 3, wherein the torch main body portion and the torch tip assembly are connected based on the combination. (5) The connecting mechanism includes a male threaded portion formed on either the torch main body portion or the torch tip assembly, and an axially movable member screwed into the male threaded portion.
A cap nut is formed on the side to which the cap nut is attached, and is engaged in the axial direction with respect to the cap nut when the cap nut is tightened into the male threaded portion. and an engaging portion that irremovably presses the end of the torch tip assembly against the torch main body by a pressing force based on the tightening. The described welding 1--chi structure.