JP3754674B2 - Spatter adhesion prevention method and apparatus for inert gas arc welding torch nozzle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In order to prevent spatter from adhering to the torch nozzle used for inert gas arc welding such as MIG welding and TIG welding, the present invention blows high pressure air toward the electrode portion of the torch nozzle heated during welding to Method of preventing spatter adhesion to a torch nozzle for inert gas arc welding to be cooled, a cooling nozzle capable of blowing high-pressure air toward the electrode part of the inert gas arc welding torch nozzle, and high-pressure air connected to the cooling nozzle via a conduit An inert gas arc comprising: a source; an on-off valve interposed in the conduit; and a control unit that opens the on-off valve in response to the electrode portion of the torch nozzle coming to a position facing the nozzle hole of the torch nozzle The present invention relates to an apparatus for preventing spatter adhesion to a welding torch nozzle.
[0002]
[Prior art]
Conventionally, it has already been known that high-pressure air is blown toward an electrode portion of a torch nozzle after an inert gas arc welding operation, for example, as disclosed in Patent Document 1 below.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2-160174
[Problems to be solved by the invention]
Conventionally, after the inert gas arc welding operation, high pressure air is blown toward the electrode portion of the torch nozzle in order to remove spatter adhering to the electrode portion of the torch nozzle during welding.
[0005]
By the way, if high-pressure air is blown onto the electrode part of the torch nozzle as described above and the electrode part is sufficiently cooled (actually about 50 ° C. or less), spatter adheres to the electrode part during the next welding. Was found to decrease significantly. However, if the welding time is relatively long and the electrode part of the torch nozzle is heated to a high temperature, the electrode part is sufficiently cooled unless high pressure air is blown to the electrode part for a relatively long time. However, it becomes impossible to prevent spatter adhesion at the next welding, but long cooling will extend the welding cycle time and adversely affect productivity.
[0006]
The present invention has been made in view of such circumstances, effectively cooling the electrode portion of the torch nozzle in a short time, and effectively preventing spatter from adhering to the electrode portion during the next welding. It is an object of the present invention to provide an apparatus for preventing spatter adhesion to an inert gas arc welding torch nozzle and an apparatus thereof that can contribute to improvement of productivity.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in order to prevent spatter from adhering to the inert gas arc welding torch nozzle, the present invention blows high pressure air toward the electrode portion of the torch nozzle heated at the time of welding. A method for preventing spatter adhesion to an inert gas arc welding torch nozzle for cooling, wherein spraying and mixing cooling water into the high pressure air when spraying high pressure air toward the electrode portion of the torch nozzle is a first feature. To do.
[0008]
According to this first feature, the cooling water sprayed toward the electrode part of the torch nozzle at a high speed along with the high-pressure air has a large specific heat and effectively cools the electrode part together with the air. While significantly reducing the cooling time, it is possible to prevent spatter from adhering to the electrode during the next welding, which can contribute to an improvement in productivity. Moreover, since the cooling water has a large kinetic energy, even when spatter adheres to the electrode portion, it can be effectively removed.
[0009]
The present invention also provides a cooling nozzle capable of blowing high-pressure air toward the electrode portion of the inert gas arc welding torch nozzle, a high-pressure air source connected to the cooling nozzle through a conduit, and an open / close device interposed in the conduit. In a sputter removal apparatus for an inert gas arc welding torch nozzle, comprising: a valve; and a control unit that opens the on-off valve in response to the electrode portion of the torch nozzle coming to a position facing the air nozzle hole of the torch nozzle. A water chamber is formed in the air passage of the cooling nozzle through a partition wall, and a cooling water tank for supplying cooling water to the water chamber is connected to the cooling chamber. A second feature is that a bleed hole for ejecting cooling water from the water chamber to the air passage is formed by the air flow.
[0010]
The partition corresponds to the nozzle inner cylinder 15 in the embodiment of the present invention described later.
[0011]
According to the second feature, when the high-pressure air of the high-pressure air source passes through the air passage of the cooling nozzle at high speed, the cooling water in the water chamber is ejected from the bleed hole and mixed with the air by the ejector effect. The mixed fluid is ejected at high speed toward the electrode part of the torch nozzle, so that the electrode part is effectively cooled. Therefore, the cooling time of the electrode part is greatly shortened and the electrode part is subjected to the next welding. This can prevent the adhesion of spatter and can contribute to the improvement of productivity. Further, even when spatter adheres to the electrode portion, it can be effectively removed.
[0012]
In addition, since the ejector effect is used for spraying the cooling water, a special pump for pressurizing and supplying the cooling water is unnecessary, and the apparatus can be simplified and the cost can be reduced.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on preferred examples of the present invention shown in the accompanying drawings.
[0014]
FIG. 1 is a side view of an inert gas arc welding apparatus equipped with a device for preventing spatter adhesion to a torch nozzle according to the present invention, and FIG. 2 is an enlarged longitudinal sectional view of a cooling nozzle portion in FIG.
[0015]
On the floor of the welding plant, a welding robot 3 and a control unit 4 for controlling the operation of the welding robot 3 are installed adjacent to the conveyor 1 that conveys the workpiece 2 to be welded. A torch nozzle 6 for MIG welding is attached to the tip of the articulated arm 5 of the welding robot 3. A cooling nozzle 7 for the torch nozzle 6 is disposed on the support base 2 in the vicinity of the welding work robot 3. The welding robot 3 moves the torch nozzle 6 according to a command from the control unit 4 by moving the predetermined origin (A) → the cooling position (B) facing the cooling nozzle 7 → the welding start position (C) → the welding work → the origin. (A) is repeated.
[0016]
A high pressure air source 8 and a cooling water tank 9 are connected to the cooling nozzle 7 via a first conduit 10 and a second conduit 11, respectively. A first on-off valve 12 for opening and closing the first conduit 10 is provided in the middle of the first conduit 10. In addition, a second on-off valve 13 for opening and closing the second conduit 11 is interposed in the middle of the second conduit 11. Both the first and second on-off valves 12 and 13 are normally closed, and when the torch nozzle 6 comes to a position facing the cooling nozzle 7, both are opened by a command from the control unit 4. Yes.
[0017]
In FIG. 2, the cooling nozzle 7 includes a nozzle inner cylinder 15 having a hollow portion as an air passage 15a, and a nozzle outer cylinder 16 surrounding the nozzle inner cylinder 15 concentrically. The inner cylinder 15 is formed so that the diameter of the air passage 15a is reduced from the lower end toward the upper end, and the upper end is a nozzle hole 18. A connecting cylinder 15 ′ is integrally formed at the lower end of the inner cylinder 15, and the downstream end of the first conduit 10 is connected to it. The upper and lower ends of the outer cylinder 16 are liquid-tightly connected to the inner cylinder 15, and a water chamber 16 a is defined between the outer cylinder 16 and the inner cylinder 15. A plurality of bleed holes 19, 19... Communicating with 15a are formed. A connecting pipe 16 'connected to the water chamber 16a is integrally formed on the lower side wall of the outer cylinder 16, and the downstream end of the second conduit 11 is connected to the connecting pipe 16'.
[0018]
Next, the operation of this embodiment will be described.
[0019]
When the welding work robot 3 completes the welding of the workpiece 2 on the conveyor 1 by the torch nozzle 6, the torch nozzle 6 is once returned to a predetermined origin (A), and then the electrode portion is opposed to the nozzle hole 18 of the cooling nozzle 7. Move to cooling position (B). Accordingly, the first and second on-off valves 12 and 13 are opened by a command from the control unit 4, so that the high-pressure air from the high-pressure air source 8 passes through the first conduit 10 and the air passage 15a of the cooling nozzle 7, It ejects from the nozzle hole 18 toward the electrode part of the torch nozzle 6. At the same time, the cooling water 14 in the cooling water tank 9 flows into the water chamber 16 a in the outer cylinder 16 through the second conduit 11. Then, due to the ejector effect caused by the high-speed air flow in the air passage 15a, the cooling water 14 in the water chamber 16a is sprayed into the air passage 15a from the plurality of bleed holes 19, 19 and mixed with the air. Therefore, a mixed fluid of air and cooling water 14 is ejected from the nozzle hole 18 at a high speed for a certain time toward the electrode portion of the torch nozzle 6. The cooling time in this case is set so that the electrode part is sufficiently below about 50 ° C.
[0020]
Thus, the cooling water sprayed toward the electrode part of the torch nozzle 6 at high speed along with the high-pressure air has a large specific heat and effectively cools the electrode part together with the air. Therefore, the cooling time of the electrode part is reduced. While greatly shortening, it is possible to prevent spatter from adhering to the electrode during the next welding, which can contribute to productivity improvement. Moreover, since the cooling water has a large kinetic energy, even when spatter adheres to the electrode portion, it can be effectively removed.
[0021]
Further, as described above, the cooling water 14 in the water chamber 16a is mixed with the air passing through the air passage 15a by utilizing the ejector effect caused by the high-speed air flow in the air passage 15a. There is no need for a special pump to supply, so that the device can be simplified and the cost can be reduced.
[0022]
The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, the present invention can be applied to cooling and spatter removal of a TIG welding torch nozzle.
[0023]
【The invention's effect】
As described above, according to the first feature of the present invention, in order to prevent spatter from adhering to the inert gas arc welding torch nozzle, high pressure air is blown toward the electrode portion of the torch nozzle heated during welding. A method for preventing spatter adhesion to an inert gas arc welding torch nozzle that cools the torch nozzle by spraying and mixing cooling water to the high pressure air when spraying high pressure air toward the electrode portion of the torch nozzle. Cooling water sprayed toward the electrode part of the torch nozzle at high speed along with the air effectively cools the electrode part, greatly shortening the cooling time of the electrode part, and to the electrode part during the next welding This can prevent the adhesion of spatter and can contribute to the improvement of productivity. Moreover, since the cooling water has a large kinetic energy, even when spatter adheres to the electrode portion, it can be effectively removed.
[0024]
According to a second aspect of the present invention, a cooling nozzle capable of blowing high pressure air toward the electrode portion of the inert gas arc welding torch nozzle, a high pressure air source connected to the cooling nozzle via a conduit, A torch nozzle for inert gas arc welding, comprising: an on-off valve interposed in a conduit; and a control unit that opens the on-off valve when the electrode portion of the torch nozzle comes to a position facing the air nozzle hole of the torch nozzle In the sputter removal apparatus, a water chamber is formed in the air passage of the cooling nozzle through a partition wall, and a cooling water tank for supplying cooling water to the water chamber is connected to the partition wall. Since the bleed hole for ejecting the cooling water from the water chamber to the air passage is formed by the high-speed air flow generated in the air passage, the mixed fluid of high-pressure air and cooling water is By spraying at high speed toward the electrode part of the nozzle, the electrode part is effectively cooled, and the cooling time of the electrode part is greatly shortened, while preventing spatter from adhering to the electrode part during the next welding. Can contribute to the improvement of productivity. Further, even when spatter adheres to the electrode portion, it can be effectively removed. In addition, since the ejector effect is used for spraying the cooling water, a special pump for pressurizing and supplying the cooling water is unnecessary, and the apparatus can be simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view of an inert gas arc welding apparatus equipped with a device for preventing spatter adhesion to a torch nozzle according to the present invention. FIG. 2 is an enlarged vertical sectional view of a cooling nozzle portion in FIG.
3 ... Welding work Welding robot 4 ... Control unit 6 ... Torch nozzle 7 ... Cooling nozzle 8 ... High pressure air source 9 ... Cooling water Tank 10 ··· Conduit 12 ··· On-off valve 14 ··· Cooling water 15 ··· Partition (nozzle inner cylinder)
15a ... Air passage 16a ... Water chamber 18 ... Injection hole 19 ... Bleed hole

Claims (2)

In order to prevent spatter from adhering to the inert gas arc welding torch nozzle (6), high pressure air is blown toward the electrode portion of the torch nozzle (6) heated during welding to cool the torch nozzle (6). A method for preventing spatter adhesion to a torch nozzle for inert gas arc welding,
A method for preventing spatter adhesion to an inert gas arc welding torch nozzle, characterized in that when high pressure air is blown toward the electrode portion of the torch nozzle (6), cooling water (14) is sprayed and mixed with the high pressure air. A cooling nozzle (7) capable of blowing high-pressure air toward the electrode part of the inert gas arc welding torch nozzle (6), and a high-pressure air source (8) connected to the cooling nozzle (7) via a conduit (10) And the opening / closing valve (12) interposed in the conduit (10) and the electrode part of the torch nozzle (6) have come to a position facing the nozzle hole (18) of the torch nozzle (6). A spatter adhesion preventing device for an inert gas arc welding torch nozzle comprising a control unit (4) for opening the on-off valve (12),
In the cooling nozzle (7), a water chamber (17a) is formed in the air passage (15a) through a partition wall (15), and cooling water is supplied to the water chamber (17a). A tank (9) is connected, and cooling water (14) is ejected from the water chamber (17a) to the air passage (15a) to the partition wall (15) by a high-speed air flow generated in the air passage (15a). An apparatus for preventing spatter adhesion to a torch nozzle for inert gas arc welding, wherein a bleed hole (19) is provided.

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