JP5364631B2 - Cleaning device and cleaning method for plasma arc welding torch - Google Patents

Description

  The present invention relates to a cleaning device and a cleaning method for a plasma arc welding torch.

  In plasma arc welding, a base metal is welded by generating a welding arc between a center electrode and a base material disposed opposite to the center electrode in an operating gas such as argon gas. When this welding is performed, scattered matter in which the filler metal, the base material, and the like are melted by high heat adheres to and accumulates on the tip portion of the nozzle that ejects argon gas. In addition, the base material vaporized by high heat is re-solidified and deposited on the tip of the nozzle where argon gas is ejected or not ejected (the interior of the nozzle tip is cooled with a shield gas) Therefore, it is easy to solidify at a lower temperature than other parts.) Since this deposit may fall on the base material to be welded and deteriorate the quality of the product, it is cleaned after welding for a predetermined time.

For example, the plasma torch cleaning device of Patent Document 1 includes a cleaning drill for cleaning the gas passage at the tip portion of the upper torch body and the upper inner periphery of the lower pressure pad, and a cleaning brush for cleaning the lower portion of the pressure pad. And. According to this plasma torch cleaning device, it is possible to remove spatter adhering to the back of the gas passage.
Further, for example, in the spatter removal method of the arc welding robot torch disclosed in Patent Document 2, the vacuum nozzle of the vacuum generator is arranged in the welding torch nozzle, and the gap formed between the inner surface of the vacuum nozzle and the outer peripheral surface of the welding torch nozzle is formed. A method of sucking and removing spatter adhering to the outer peripheral surface of a welding torch nozzle by generating an air flow is disclosed. According to this, spatter can be peeled off and removed without damaging the welding torch nozzle and the components in the nozzle.

JP 2001-105149 A Japanese Patent Laid-Open No. 7-124747

  However, in the conventional sputter cleaning apparatus or removal method described above, cleaning is performed when mass production of products by welding is interrupted by extinguishing the pilot arc that serves as a starting point when generating a welding arc. . Therefore, it is necessary to interrupt the mass production of the product by welding each time the spatter adhering to the torch is removed, and to turn off and turn on the pilot arc, which becomes a factor of deteriorating the productivity of the product by welding. Moreover, if the pilot arc is frequently turned off and on, there is a concern that the life of the high-frequency power source for generating the pilot arc may be affected.

  The present invention has been made in view of such conventional problems, and it is possible to remove and collect deposits accumulated at the tip of the nozzle in a state where a pilot arc is generated, and to perform a product of plasma arc welding. An object of the present invention is to provide a cleaning device for a plasma arc welding torch capable of improving productivity.

In the present invention, a central electrode is provided in the central portion of a nozzle from which a working gas is ejected, and a mother electrode disposed opposite to the central electrode by a pilot arc generated between the central electrode and the nozzle. A device for cleaning a plasma arc welding torch used for welding by generating a welding arc between the materials,
An inlet for fitting the tip of the nozzle to close the outer periphery of the tip of the nozzle, and an inert gas for blowing an inert gas from the outer periphery to the entire circumference of the tip of the nozzle via a blowing gap A flow path and a suction flow path for sucking the inert gas from the side facing the working gas outlet provided in the central portion of the tip of the nozzle,
In the state in which the pilot arc was generated, the inert gas sprayed from the outer peripheral side from the spray gap to the entire circumference of the tip of the nozzle was sucked into the suction flow path, thereby being deposited on the tip of the nozzle. The plasma arc welding torch cleaning device is configured to remove deposits (claim 1).

The plasma arc welding torch cleaning device of the present invention has a configuration in which a fitting arc, an inert gas flow path, and a suction flow path are provided, and in a state where a pilot arc is generated between the center electrode and the nozzle, The deposit deposited on the tip can be removed.
In the present invention, a minute annular blowing gap is formed at the end of the inert gas flow path in a state where the tip of the nozzle is fitted into the fitting inlet. This blowing gap can be formed in advance by the opening end of the inert gas flow path in a state where the tip of the nozzle is not inserted into the fitting inlet, and is not effective when the nozzle tip is inserted into the fitting inlet. It can also be formed between the open end of the active gas flow path and the tip of the nozzle.

Then, the inert gas that has flowed into the inert gas flow path is blown from the outer periphery to the entire circumference of the nozzle tip from the blowing gap, and the inert gas blown to the nozzle tip is sucked into the suction channel. To do.
As a result, the deposit deposited on the tip of the nozzle can be separated by the inert gas blown at a high speed, and the separated deposit can be collected in the suction channel. Therefore, it is possible to stably collect the peeled deposit without scattering around the cleaning device.

  Further, the inert gas in the blowing gap flows from the outer peripheral side of the nozzle tip to the inner peripheral side, and is sucked to the side of the central portion of the nozzle tip facing the working gas ejection port. Thereby, it can prevent that the inert gas sprayed on the front-end | tip part of the nozzle and the deposit peeled off from the front-end | tip part of a nozzle flow into a working gas jet outlet. Therefore, in the state where the pilot arc is generated between the center electrode and the nozzle, the deposit deposited on the tip of the nozzle can be removed and recovered.

  In the present invention, the torch can be cleaned while holding the pilot arc without stopping the production of the product to be plasma arc welded. Plasma arc welding can be started. Therefore, the productivity of products that perform plasma arc welding can be improved.

  Therefore, according to the cleaning device for a plasma arc welding torch of the present invention, it is possible to remove and collect deposits deposited on the tip of the nozzle in a state where a pilot arc is generated, and to perform plasma arc welding. Productivity can be improved.

Cross-sectional explanatory drawing which expands and shows a part of cleaning apparatus which cleans the torch in an Example. Cross-sectional explanatory drawing which expands and shows the periphery of the spray gap of the cleaning apparatus in an Example. Cross-sectional explanatory drawing which shows the formation state of the inflow port of the inert gas with respect to the inert gas flow path in an Example. Cross-sectional explanatory drawing which shows the state which moves a cleaning apparatus with respect to the torch in an Example. Explanatory drawing which shows the state which performs plasma arc welding with a torch in an Example. Cross-sectional explanatory drawing which expands and shows the periphery of the other spray gap of the cleaning apparatus in an Example.

A preferred embodiment of the above-described plasma arc welding torch cleaning device of the present invention will be described.
In the present invention, the inert gas flow path is formed in an annular shape centering on the tip of the nozzle, and the outer peripheral portion of the annular inert gas flow path has a tangential direction. An inflow port through which an inert gas flows is formed, and the inert gas is swirled in the inert gas channel by flowing the inert gas into the inert gas channel from the inflow port. The swirling inert gas is preferably blown from the blowing gap to the tip of the nozzle.
In this case, the deposit deposited on the tip of the nozzle can be separated by the swirling flow of the inert gas. Therefore, the deposit can be removed more effectively.

In addition, the inlet has one side inlet for turning the inert gas to one side in the circumferential direction of the inert gas flow path, and turns the inert gas to the other side in the circumferential direction of the inert gas flow path. And the other side inlet for causing the inert gas flow from the one side inlet to the inert gas flow path to generate a flow of inert gas swirling in one circumferential direction, By blowing the inert gas swirling in one circumferential direction from the blowing gap to the tip of the nozzle, and by flowing the inert gas from the other inlet to the inert gas flow path. A flow of inert gas swirling to the other side in the circumferential direction and repeating the other side blowing operation of blowing the inert gas swirling to the other side in the circumferential direction from the blowing gap to the tip of the nozzle Good to Shii (claim 3).
In this case, the swirling flow of the inert gas can collide with the deposit accumulated at the tip of the nozzle alternately from one side in the circumferential direction and the other side in the circumferential direction, and the deposit is peeled off. Force can be generated effectively. Therefore, the deposit can be more effectively removed.

Further, it is preferable that the annular inert gas flow path is formed with a width that gradually decreases toward the blowing gap.
In this case, it is possible to easily generate a high-speed swirling flow of the inert gas with respect to the tip portion of the nozzle.

Embodiments of a cleaning apparatus for a plasma arc welding torch according to the present invention will be described below with reference to the drawings.
The plasma arc welding torch 6 cleaning device 1 of this example cleans the torch 6 used for plasma arc welding as shown in FIG. The torch 6 is provided with a center electrode 61 in the center of the nozzle 62 from which the working gas G1 is ejected, and a pilot arc P generated between the center electrode 61 and the nozzle 62 as shown in FIG. Welding is performed by generating a welding arc W between the electrode 61 and the base material 8 disposed opposite thereto.

  As shown in FIGS. 1 and 2, the cleaning device 1 includes a fitting inlet 22 that fits the tip 621 of the nozzle 62 and closes the tip 621 of the nozzle 62, and a tip 621 of the nozzle 62 through the blowing gap 21. The inert gas flow path 2 for blowing the inert gas G3 from the outer peripheral side to the entire circumference of the nozzle 62 and the inert gas G3 from the side facing the working gas outlet 622 provided at the center of the tip 621 of the nozzle 62 And a suction channel 3 for suction. In the state where the pilot arc P is generated, the cleaning device 1 sucks the inert gas G3 sprayed from the spray gap 21 to the entire circumference of the tip portion 621 of the nozzle 62 from the outer peripheral side to the suction flow path 3. The deposit T deposited on the tip 621 of the nozzle 62 is removed.

Below, it demonstrates in full detail with reference to FIGS. 1-6 about the cleaning apparatus 1 of this example.
As shown in FIG. 4, the cleaning device 1 is installed in a welding device 5 for placing a base material 8 on a table and performing plasma arc welding. The torch 6 is disposed in the lower part of the movable part in the welding apparatus 5 with the working gas outlet 622 facing downward.
Moreover, the cleaning apparatus 1 is installed on the table of the welding apparatus 5 so that it can be moved up and down via the lifting apparatus 51. When the torch 6 is moved to a predetermined cleaning position 601 above the table, the lifting device 51 raises the cleaning device 1 so that the tip 621 of the nozzle 62 in the torch 6 is fitted into the fitting inlet 22. ing.

The pilot arc P generated between the center electrode 61 and the nozzle 62 is generated by a high frequency generator in the welding apparatus 5.
As shown in FIG. 1, the center electrode 61 of this example is a tungsten electrode, and a water cooling channel into which cooling water flows is formed in the nozzle 62. The working gas G <b> 1 flows around the center electrode 61 in the nozzle 62 and is ejected from the working gas ejection port 622. Further, a shield gas cap 63 for flowing a shield gas G2 for blocking the welding arc W from the atmosphere is mounted on the outer periphery of the nozzle 62. Then, the shield gas G2 is ejected from the opening tip of the shield gas cap 63 (see FIG. 5).

  The operating gas G1, shield gas G2, and inert gas G3 in this example are all argon gas. Further, as the inert gas G3, a gas other than argon gas can be used. However, when the dew point of the inert gas G3 is high, the moisture in the inert gas G3 enters the torch 6 during the cleaning of the torch 6, and the dew point of the working gas G1 may be increased to deteriorate the welding quality. Therefore, it is preferable to use a dry gas having a sufficiently low dew point as the inert gas G3.

As shown in FIG. 2, the tip 621 of the nozzle 62 has a conical diameter reduction, and a working gas ejection port 622 is formed at the center of the tip formed in a flat shape. The inert gas flow path 2 of this example is formed in an annular shape centering on the tip 621 of the nozzle 62. The fitting opening 22 is formed as a tapered hole along the conical tip 621 of the nozzle 62.
The blowing gap 21 of this example was formed in advance by the open end of the inert gas flow path 2 in a state where the tip 621 of the nozzle 62 was not inserted into the fitting inlet 22. The spray gap 21 is open in the vicinity of the outer peripheral corner of the tip 621 of the nozzle 62.

  On the other hand, as shown in FIG. 6, when the tip end 621 of the nozzle 62 is inserted into the fitting inlet 22, the blowing gap 21 is formed between the opening end of the inert gas flow path 2 and the tip end 621 of the nozzle 62. It can also be formed in between. In this case, the blowing gap 21 is open at the center side portion of the outer peripheral corner of the tip end portion 621 of the nozzle 62.

  As shown in FIG. 1 and FIG. 2, the inert gas flow path 2 has a tip 621 of the nozzle 62 that is formed with respect to one flow path forming member 4 </ b> A formed in a shape having the suction flow path 3 on the inner peripheral side. It is formed by assembling the other flow path forming member 4B having the fitting inlet 22 to be fitted. The other flow path forming member 4B is formed by forming an insertion port 22 at the center of the plate shape. One flow path forming member 4A is formed with a protrusion 41 that decreases in a conical shape toward the tip, and the suction port 31 of the suction flow path 3 is formed at the center of the tip of the protrusion 41. Has been. The blowing gap 21 of the inert gas flow path 2 has an annular inner periphery between the outer edge of the fitting inlet 22 in one flow path forming member 4A and the outer edge of the suction port 31 in the other flow path forming member 4B. Opened to the side.

The opening end of the inert gas channel 2 communicates with the fitting inlet 22 and the suction port 31 as a blowing gap.
Further, the center side portion of the annular inert gas flow path 2 includes the inclined outer peripheral surface 411 of the conical protrusion 41 of the one flow path forming member 4A and the back surface 42 of the other flow path forming member 4B. Thus, the width is gradually reduced toward the blowing gap 21 (center tip).

The diameter of the suction port 31 is larger than the diameter of the working gas jet port 622, and the blowing gap 21 is formed in an annular shape around the working gas jet port 622.
As shown in FIG. 3, an inflow port 23 through which the inert gas G <b> 3 flows from the tangential direction is formed in the outer peripheral portion of the annular inert gas flow path 2. The inflow ports 23 of this example are formed in parallel with each other on both sides of tangent lines parallel to each other drawn on the outer periphery of the annular inert gas flow path 2.

  The inlet 23 for the inert gas G3 has one inlet 23A for turning the inert gas G3 to one side in the circumferential direction of the inert gas channel 2, and the other side in the circumferential direction of the inert gas channel 2 And the other side inlet 23B for swirling the inert gas G3. An inflow port 23 formed on one end side of one tangent and an inflow port 23 formed on the other end side of the other tangent line of the inert gas G3 swirling clockwise in the inert gas flow path 2 in FIG. The inflow port 23 formed on the other end side of one tangent line and the inflow port 23 formed on one end side of the other tangent line functions as one side inlet port 23A for forming the swirl flow. It functions as the other side inlet 23B for forming the swirling flow of the inert gas G3 swirling counterclockwise in the active gas flow path 2.

The cleaning device 1 of this example is configured to spray a swirling flow of the inert gas G3 from the spray gap to the tip portion 621 of the nozzle 62. The cleaning device 1 has a one-side spraying operation in which a swirl flow swirling from the spray gap 21 to the one side in the circumferential direction with respect to the tip portion 621 of the nozzle 62 and a circumferential direction from the spray gap 21 to the tip portion 621 of the nozzle 62. It is comprised so that the other side spraying operation which sprays the swirl | vortex flow swirling to the other side may be repeated alternately.
In the one-side blowing operation, the inert gas G3 swirling in the circumferential direction one side in the inert gas channel 2 by flowing the inert gas G3 into the inert gas channel 2 from the two one-side inlets 23A. Generate a flow of Moreover, in the other side blowing operation, the inert gas G3 is caused to flow into the inert gas flow path 2 from the two other side inlets 23B, thereby turning the inert gas flow path 2 to the other side in the circumferential direction. A flow of gas G3 is generated.

  Although not shown, the cleaning device 1 is connected to a supply source of the inert gas G3 that supplies the inert gas flow path 2 with the inert gas G3 pressurized to a predetermined pressure higher than the atmospheric pressure. . The cleaning device 1 is connected to a suction device such as a vacuum pump that performs suction from the suction flow path 3. The one-side spraying operation and the other-side spraying operation can be performed by a switching operation of a valve provided in a supply source that supplies the inert gas channel 3 to the inert gas channel 3.

The cleaning device 1 for the plasma arc welding torch 6 of this example is configured to provide a pilot arc P between the center electrode 61 and the nozzle 62 by providing a fitting inlet 22, an inert gas flow path 2 and a suction flow path 3. In the generated state, the deposit T deposited on the tip 621 of the nozzle 62 can be removed.
In this example, a minute annular blowing gap 21 for blowing the inert gas G3 at high speed to the tip end portion 621 of the nozzle 62 fitted into the fitting inlet 22 is formed at the opening end of the inert gas flow path 2. doing. The inert gas G3 that has flowed into the inert gas flow path 2 is blown from the blowing gap 21 to the entire circumference of the tip end portion 621 of the nozzle 62 at a high speed while being swung from the outer peripheral side, and is also blown to the tip end portion 621 of the nozzle 62. The inert gas G3 is sucked into the suction flow path 3.

  Further, from the blowing gap 21 to the tip portion 621 of the nozzle 62, the high-speed swirling flow of the inert gas G3 swirling to the one side in the circumferential direction and the high-speed swirling flow of the inert gas G3 swirling to the other side in the circumferential direction are alternated. Spray repeatedly. Thereby, the swirl | flow of the inert gas G3 can be made to collide with the deposit T deposited on the front-end | tip part 621 of the nozzle 62 alternately from the circumferential direction one side and the circumferential direction other side, and this deposit T It is possible to effectively generate a force for peeling off. Therefore, the deposit T deposited on the tip 621 of the nozzle 62 can be effectively peeled off, and the peeled deposit T can be collected in the suction flow path 3. Further, the peeled deposit T can be stably recovered without being scattered around the cleaning device 1.

  Further, the inert gas G3 in the blowing gap 21 flows from the outer peripheral side to the inner peripheral side of the tip portion 621 of the nozzle 62 while turning to the one side in the circumferential direction or the other side in the circumferential direction, and the center of the tip portion 621 of the nozzle 62 The portion is sucked to the side facing the working gas outlet 622. Thereby, it is possible to prevent the inert gas G3 blown to the tip portion 621 of the nozzle 62 and the deposit T peeled from the tip portion 621 of the nozzle 62 from flowing into the working gas ejection port 622. Therefore, in a state where the pilot arc P is generated between the center electrode 61 and the nozzle 62, the deposit T deposited on the tip 621 of the nozzle 62 can be removed and recovered.

  In this example, the torch 6 can be cleaned while holding the pilot arc P without stopping the production of the product to be plasma arc welded. Plasma arc welding can be started for 8. Therefore, the productivity of products that perform plasma arc welding can be improved.

  Therefore, according to the cleaning device 1 of the plasma arc welding torch 6 of this example, the deposit T deposited on the tip 621 of the nozzle 62 can be removed and recovered in a state where the pilot arc P is generated, Productivity of products that perform plasma arc welding can be improved.

DESCRIPTION OF SYMBOLS 1 Cleaning apparatus 2 Inert gas flow path 21 Blowing gap 22 Fitting inlet 23 Inlet 23A One side inlet 23B The other side inlet 3 Suction channel 31 Suction port 6 Plasma arc welding torch 61 Center electrode 62 Nozzle 621 Tip 622 Operating gas outlet 8 Base material P Pilot arc W Welding arc T Deposit G1 Operating gas G2 Shielding gas G3 Inert gas

Claims (4)

A central electrode is provided in the central portion of the nozzle from which the working gas is ejected, and a pilot arc generated between the central electrode and the nozzle causes a gap between the central electrode and the base material disposed opposite to the central electrode. An apparatus for cleaning a plasma arc welding torch used for welding by generating a welding arc
An inlet for fitting the tip of the nozzle to close the outer periphery of the tip of the nozzle, and an inert gas for blowing an inert gas from the outer periphery to the entire circumference of the tip of the nozzle via a blowing gap A flow path and a suction flow path for sucking the inert gas from the side facing the working gas outlet provided in the central portion of the tip of the nozzle,
In the state in which the pilot arc was generated, the inert gas sprayed from the outer peripheral side from the spray gap to the entire circumference of the tip of the nozzle was sucked into the suction flow path, thereby being deposited on the tip of the nozzle. A cleaning apparatus for a plasma arc welding torch, characterized by being configured to remove deposits. The cleaning device for a plasma arc welding torch according to claim 1, wherein the inert gas flow path is formed in an annular shape centering on a tip portion of the nozzle,
In the outer periphery of the annular inert gas flow path, an inflow port through which the inert gas flows from the tangential direction is formed,
By flowing an inert gas into the inert gas flow path from the inlet, the inert gas is swirled in the inert gas flow path, and the swirling inert gas is discharged from the blowing gap to the nozzle. A cleaning device for a plasma arc welding torch, characterized in that the device is sprayed to the tip of the torch. 3. The plasma arc welding torch cleaning device according to claim 2, wherein the inlet includes a one-side inlet for swirling an inert gas toward one side in a circumferential direction of the inert gas flow path, and the inert gas. There is an inlet on the other side for swirling the inert gas to the other side in the circumferential direction of the gas flow path,
By flowing an inert gas from the one side inlet to the inert gas flow path, a flow of inert gas swirling in one circumferential direction is generated, and an inert gas swirling in one circumferential direction is generated. Inert gas swirling to the other side in the circumferential direction by blowing one side of the nozzle from the blowing gap to the tip of the nozzle and by flowing an inert gas from the other side inlet to the inert gas flow path The plasma arc welding torch is configured to repeat the above-mentioned other side spraying operation in which an inert gas swirling to the other side in the circumferential direction is sprayed from the above-mentioned spraying gap to the tip of the nozzle. Cleaning equipment.   4. The plasma arc welding torch cleaning device according to claim 2 or 3, wherein the annular inert gas flow path is formed with a width gradually reduced toward the blowing gap. A plasma arc welding torch cleaning device characterized by the above.

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