WO2013108797A1 - Arc welding method and plasma torch - Google Patents

Arc welding method and plasma torch Download PDF

Info

Publication number
WO2013108797A1
WO2013108797A1 PCT/JP2013/050697 JP2013050697W WO2013108797A1 WO 2013108797 A1 WO2013108797 A1 WO 2013108797A1 JP 2013050697 W JP2013050697 W JP 2013050697W WO 2013108797 A1 WO2013108797 A1 WO 2013108797A1
Authority
WO
WIPO (PCT)
Prior art keywords
nozzle
gas
plasma
ejected
inert gas
Prior art date
Application number
PCT/JP2013/050697
Other languages
French (fr)
Japanese (ja)
Inventor
藤内　啓輝
児玉　哲也
堀向　俊之
達郎 池田
Original Assignee
本田技研工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 本田技研工業株式会社 filed Critical 本田技研工業株式会社
Priority to JP2013554314A priority Critical patent/JP5898238B2/en
Publication of WO2013108797A1 publication Critical patent/WO2013108797A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K10/00—Welding or cutting by means of a plasma
    • B23K10/02—Plasma welding
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/34—Details, e.g. electrodes, nozzles
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/34—Details, e.g. electrodes, nozzles
    • H05H1/3457—Nozzle protection devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/18—Sheet panels
    • B23K2101/185—Tailored blanks

Definitions

  • the present invention relates to an arc welding method and a plasma torch. Specifically, the present invention relates to an arc welding method and a plasma torch used for plasma arc welding.
  • a plasma torch is used for plasma arc welding.
  • Examples of plasma torches include those described in Patent Documents 1 and 2.
  • the plasma torch described in Patent Document 1 includes a center electrode for arc generation and a nozzle that surrounds the center electrode and ejects a working gas for plasma formation, and at least the tip of the center electrode and the nozzle
  • the jet outlet is formed in an elongated shape in a direction substantially perpendicular to the longitudinal axis direction of the center electrode.
  • the plasma torch described in Patent Document 2 uses a main nozzle provided at the tip of the welding torch to flow a first gas (shield gas) that protects the molten pool from the atmosphere, and at the outside of the welding torch.
  • a second gas (plasma gas) having a composition different from that of the first gas is injected toward the arc portion formed at the tip of the welding torch using one or a plurality of external nozzles provided in .
  • the present invention is for solving the above problems, and its purpose is to prevent convection fumes generated by evaporation of galvanizing at a high temperature inside the shield gas from adhering to the tip surface of the nozzle, The purpose is to stabilize the welding quality and suppress the deterioration of the durability of the nozzle.
  • An arc welding method which is a front end surface (for example, described later) of an arc electrode (for example, first nozzle 11 described later) inside a shield gas (for example, shield gas SG described later) ejected in an annular shape.
  • An arc welding method characterized in that an inert gas (for example, an inert gas FG described later) is ejected toward the distal end surface 11c) to form an inert gas layer.
  • the inert gas is ejected toward the tip surface of the arc electrode inside the shield gas ejected in an annular shape, and an inert gas layer is formed.
  • the inert gas is ejected toward the tip surface of the arc electrode inside the shield gas ejected in an annular shape, the inert gas does not interfere with the shield gas. Therefore, the arc electrode is hardly consumed and the welding quality can be stabilized, and the formation of the alloyed layer can be suppressed to suppress the deterioration of the durability of the nozzle.
  • a plasma torch for example, plasma torch 1 described later used for plasma arc welding, which is provided around a rod-shaped electrode (for example, electrode 10 described later), and a plasma gas (for example, A cylindrical first nozzle (for example, a later-described first nozzle 11) that ejects a plasma gas PG (to be described later) and a shield gas (for example, to be described later) provided around the first nozzle and surrounding the plasma gas.
  • a cylindrical second nozzle for example, a second nozzle 12 described later for ejecting the shield gas SG) in an annular shape, and a non-circular shape toward the tip surface of the first nozzle inside the shield gas ejected in an annular shape.
  • a plasma torch comprising: a third nozzle (for example, a third nozzle 13 described later) that ejects an active gas (for example, an inert gas FG described later).
  • the inert gas is jetted toward the tip surface of the first nozzle inside the shield gas jetted in an annular shape from the third nozzle toward the workpiece, and the inert gas layer is formed. It is formed.
  • the inert gas is ejected toward the tip surface of the first nozzle inside the shield gas ejected in an annular shape from the third nozzle toward the workpiece, the inert gas interferes with the shield gas. There is no. Therefore, the first nozzle is hardly consumed and the welding quality can be stabilized, and the formation of the alloyed layer can be suppressed to suppress the decrease in the durability of the nozzle.
  • the inert gas ejected from the third nozzle becomes a gas flow parallel to the tip surface of the first nozzle, and an inert gas layer is formed.
  • the gas flow parallel to the tip surface of the first nozzle of the inert gas is a stable flow along the surface to be protected without being reflected by the tip surface of the first nozzle on the front surface of the tip surface of the first nozzle.
  • a stable inert gas layer can be formed. Thereby, it can prevent that the fumes which generate
  • At least four or more of the third nozzles are arranged at equal intervals in the circumferential direction inside the shield gas ejected in an annular shape from the circumferential direction of the second nozzle.
  • the inert gas is provided so as to cover the tip end surface of the first nozzle evenly for each of the third nozzles arranged at least four equally spaced apart in the circumferential direction.
  • the inert gas ejected from the third nozzle arranged at least four can form a stable inert gas layer covering the entire front end surface of the first nozzle. Thereby, it can prevent that the fumes which generate
  • a plasma torch for example, a plasma torch 1a described later used for plasma arc welding, which is provided around a rod-shaped electrode (for example, an electrode 10 described later), and a plasma gas (for example, A cylindrical first nozzle (for example, a later-described first nozzle 11) that ejects a plasma gas PG (to be described later) and a shield gas (for example, to be described later) provided around the first nozzle and surrounding the plasma gas.
  • Shielding gas SG is directed toward a first outlet (for example, a first outlet 12c described later) and an end surface (for example, a front end surface 11c described later) of the first nozzle.
  • a second nozzle for example, a second nozzle 12 described later having a second nozzle (for example, a second nozzle 12d described later).
  • Plasma torch for example, a plasma torch 1a described later used for plasma arc welding, which is provided around a rod-shaped electrode (for example, an electrode 10 described later), and a plasma gas (for example,
  • the shielding gas is ejected from the second ejection port toward the tip surface of the first nozzle in the inner diameter direction, and a layer of shielding gas is formed.
  • fume that is generated by the galvanizing evaporation at high temperature inside the shield gas that is ejected in an annular shape toward the workpiece so as to surround the plasma gas from the first ejection port is generated from the second ejection port.
  • the layer of the shield gas that is ejected prevents the first nozzle from adhering to the tip surface.
  • a 2nd jet nozzle is located inside a 1st jet nozzle, and shield gas ejected from each of a 1st jet nozzle and a 2nd jet nozzle does not interfere. Therefore, the first nozzle is hardly consumed and the welding quality can be stabilized, and the formation of the alloyed layer can be suppressed to suppress the decrease in the durability of the nozzle.
  • the plasma torch can be reduced in size. Further, since the same shield gas is ejected from the first ejection port and the second ejection port, it is not necessary to prepare many kinds of gases, and the cost can be reduced.
  • the present invention it is possible to prevent the convection fumes generated by evaporation of zinc plating at a high temperature inside the shielding gas from adhering to the tip surface of the nozzle, and to stabilize the welding quality and the durability of the nozzle. Reduction can be suppressed.
  • FIG. 1 It is a schematic diagram which shows schematic structure of the plasma torch concerning the 1st Embodiment of this invention, (a) is a side sectional view, (b) is a bottom view. It is the schematic which shows the state which the fume generate
  • FIG. 1 is a schematic diagram showing a schematic configuration of a plasma torch 1 according to the first embodiment of the present invention, in which (a) is a side sectional view and (b) is a bottom view.
  • the plasma torch 1 is provided around the electrode 10, a cylindrical first nozzle 11 that is provided around the electrode 10 and ejects the plasma gas PG, and is provided around the first nozzle 11 to eject the shield gas SG.
  • the cylindrical 2nd nozzle 12 and the 3rd nozzle 13 which injects the inert gas FG toward the front end surface 11c of the 1st nozzle 11 inside the shield gas SG injected circularly are provided.
  • the first nozzle 11 is a cylindrical member that accommodates the rod-shaped electrode 10 and has a central hole 11 a that is reduced in diameter in accordance with the tip of the electrode 10.
  • a spout 11b is formed at the tip of the center hole 11a.
  • Plasma gas PG is ejected from the ejection port 11b.
  • a front end surface 11c of the first nozzle 11 having a flat annular surface is formed around the ejection port 11b that ejects the plasma gas PG.
  • the second nozzle 12 is a cylindrical member, surrounds the first nozzle 11, and accommodates the first nozzle 11 in the center hole 12a.
  • the second nozzle 12 is provided so as to recede from the tip portion 11 d having the tip surface 11 c of the first nozzle 11, and the tip portion 11 d of the first nozzle 11 protrudes from the second nozzle 12.
  • the tip portion 11d of the first nozzle 11 projects with a reduced diameter toward the tip inside the jet nozzle 12b.
  • An annular jet 12 b is formed between the outer periphery before reaching the tip 11 d of the first nozzle 11 and the inner periphery of the second nozzle 12.
  • the shield gas SG supplied through the gap between the outer periphery of the first nozzle 11 and the inner periphery of the second nozzle 12 is ejected from the annular ejection port 12b.
  • the third nozzle 13 has a small diameter, and in the circumferential direction from the outer side to the inner side of the shield gas SG ejected in an annular shape from the circumferential direction of the second nozzle 12.
  • Four are equally spaced apart. That is, each of the third nozzles 13 extends away from the outer peripheral side of the second nozzle 12 by 90 ° in the circumferential direction, and as shown in FIG. And bent in the inner diameter direction. From the third nozzle 13 bent in the inner diameter direction, the inert gas FG is ejected so as to form a gas flow parallel to the tip surface 11 c of the first nozzle 11.
  • the same gas as the shield gas SG is preferably used as the inert gas FG ejected from the third nozzle 13.
  • a tailored blank material is formed by butt welding a first workpiece, which is a thin plate material, and a second workpiece, which is a plate material, which is thicker than the first workpiece.
  • first and second workpieces galvanized steel sheets or the like are used.
  • the plasma gas PG (arc) generated by receiving the discharge of the energized electrode 10 is ejected from the ejection port 11b of the first nozzle 11, and this plasma gas PG is supplied to the first and second workpieces.
  • the shield gas SG is ejected in an annular shape from the ejection port 12b of the second nozzle 12 toward the first and second workpieces so as to surround the periphery of the plasma gas PG.
  • the shield gas SG flows along the outer peripheral surface of the plasma gas PG while spreading in a direction away from the plasma gas PG, and is sprayed so as to be dispersed in the outer diameter direction with respect to the surface of the molten pool. This prevents the plasma gas PG from contacting the atmosphere outside the shield gas SG.
  • FIG. 2 is a schematic view showing a state in which fume HG is generated in the plasma torch 100 of the prior art. As shown in FIG. 2, convection of the fume HG occurs between the shield gas SG and the plasma gas PG, so that the fume HG adheres to the tip surface 111c of the first nozzle 111 and the fume HG and the first nozzle 111 In some cases, the metal of the front end surface 111c combines to form an alloyed layer.
  • the first nozzle 111 is easily consumed because the alloyed layer has a low melting point, and the weld quality may not be stabilized due to damage of the first nozzle 111. Moreover, durability of the 1st nozzle 111 may also fall by alloying layer formation.
  • an inert gas FG using the same gas as the shield gas SG is ejected from the third nozzle 13.
  • the third nozzle 13 ejects the inert gas FG so as to form a gas flow parallel to the tip surface 11 c of the first nozzle 11, and the four third nozzles 13 are on the circumference of the second nozzle 12.
  • Inert gas FG is ejected from four spaced apart directions. Accordingly, the gas flow of the inert gas FG parallel to the tip surface 11c of the first nozzle 11 is protected on the front surface of the tip surface 11c of the first nozzle 11 without being reflected by the tip surface of the first nozzle 11.
  • FIG. 3 is a schematic view showing a state of forming the layer of the inert gas FG according to the present embodiment. As shown in FIG. 3, the fume HG generated and convected inside the shield gas SG is prevented from adhering to the tip surface 11c of the first nozzle 11 by the layer of the inert gas FG.
  • the inert gas FG which forms a stable inert gas FG layer covering the entire front end surface 11c of the first nozzle 11, becomes a swirl flow between the shield gas SG and the plasma gas PG.
  • the inert gas FG is applied to the tip surface 11c of the first nozzle 11 inside the shield gas SG that is ejected in an annular shape from the third nozzle 13 toward the first and second workpieces.
  • a layer of inert gas FG is sprayed in parallel to form the front surface of the tip surface 11 c of the first nozzle 11. This prevents fume HG generated by the evaporation of zinc plating at a high temperature inside shield gas SG from adhering to tip surface 11c of first nozzle 11 due to the layer of inert gas FG. .
  • the inert gas FG is blown in parallel with the tip surface 11c of the first nozzle 11 inside the shield gas SG that is ejected in an annular shape from the third nozzle 13 toward the first and second workpieces.
  • the active gas FG does not interfere with the shield gas SG. Therefore, the first nozzle 11 is not easily consumed, the welding quality can be stabilized, and the formation of the alloyed layer is suppressed, so that a decrease in durability of the first nozzle 11 can be suppressed.
  • the inert gas FG ejected from the third nozzle 13 becomes a gas flow parallel to the tip surface 11c of the first nozzle 11, and forms a layer of the inert gas FG.
  • the gas flow of the inert gas FG parallel to the front end surface 11c of the first nozzle 11 is on the front surface of the front end surface 11c of the first nozzle 11 without being reflected by the front end surface of the first nozzle 11. Therefore, a stable inert gas FG layer can be formed.
  • the tip surface 11c of the first nozzle 11 is evenly shared and covered for each of the three third nozzles 13 that are equally spaced in the circumferential direction.
  • the inert gas FG ejected from the four arranged third nozzles 13 can form a stable inert gas FG layer covering the entire front end surface 11 c of the first nozzle 11. Thereby, it can prevent that the fumes HG which generate
  • FIG. 4 is a schematic diagram showing a schematic configuration of a plasma torch 1a according to the second embodiment of the present invention.
  • the plasma torch 1a includes a rod-shaped electrode 10, a cylindrical first nozzle 11 that is provided around the electrode 10 and ejects the plasma gas PG, and is provided around the first nozzle 11 so as to surround the plasma gas PG.
  • a second nozzle having a first jet port 12c for jetting the shield gas SG in an annular shape in the axial direction and a second jet port 12d for jetting the shield gas SG in the inner diameter direction toward the tip surface 11c of the first nozzle 11. And comprising.
  • the first nozzle 11 is a cylindrical member that accommodates the rod-shaped electrode 10 and has a central hole 11 a that is reduced in diameter in accordance with the tip of the electrode 10.
  • a spout 11b is formed at the tip of the center hole 11a.
  • Plasma gas PG is ejected from the ejection port 11b.
  • a distal end surface 11c of the first nozzle 11 is formed around the ejection port 11b that ejects the plasma gas PG.
  • the second nozzle 12 is a cylindrical member, surrounds the first nozzle 11, and accommodates the first nozzle 11 in the center hole 12a thereof.
  • the second nozzle 12 is provided so as to recede from the tip portion 11 d having the tip surface 11 c of the first nozzle 11, and the tip portion 11 d of the first nozzle 11 protrudes from the second nozzle 12.
  • the shield gas SG is supplied through a gap between the outer periphery before reaching the tip 11d of the first nozzle 11 and the inner periphery of the second nozzle.
  • the second nozzle 12 includes a plurality of first jet nozzles 12c that are opened in the axial direction at positions retracted from the tip portion 11d having the tip surface 11c of the first nozzle 11, and the first nozzle 11 through the first jet nozzle 12c. And a second jet port 12d that surrounds the tip portion 11d with a cover portion 12e and opens at the position of the tip surface 11c of the first nozzle 11 in the inner diameter direction.
  • the shield gas SG is divided into a plurality of first outlets 12c that are opened in the axial direction and a second outlet 12d that is opened all around in the inner diameter direction, and is annularly formed in the axial direction from the first outlet 12c. It is ejected and ejected in the inner diameter direction from the second ejection port 12d.
  • a tailored blank material is formed by butt welding a first workpiece, which is a thin plate material, and a second workpiece, which is a plate material, which is thicker than the first workpiece.
  • first and second workpieces galvanized steel sheets or the like are used.
  • the plasma gas PG generated by receiving the discharge of the energized electrode 10 is ejected from the ejection port 11b of the first nozzle 11, and this plasma gas PG is supplied to the first and second workpieces.
  • the shield gas SG is ejected in an annular shape from the first ejection port 12c of the second nozzle 12 toward the first and second workpieces so as to surround the periphery of the plasma gas PG.
  • the shield gas SG ejected from the first ejection port 12c flows along the outer peripheral surface of the plasma gas PG while spreading in a direction away from the plasma gas PG, and is dispersed in the outer diameter direction with respect to the surface of the molten pool. Be sprayed. This prevents the plasma gas PG from coming into contact with the atmosphere outside the shield gas SG ejected from the ejection port 11b.
  • FIG. 2 is a schematic diagram showing a state in which fume HG is generated in the plasma torch 100 of the prior art. As shown in FIG. 2, convection of the fume HG occurs between the shield gas SG and the plasma gas PG, so that the fume HG adheres to the tip surface 111 c of the first nozzle 111 and the fume HG and the first nozzle 111 In some cases, the alloyed layer is formed by combining with the metal of the end face 11c.
  • the first nozzle 111 is easily consumed because the alloyed layer has a low melting point, and the weld quality may not be stabilized due to damage of the first nozzle 111. Moreover, durability of the 1st nozzle 111 may also fall by alloying layer formation.
  • the shield gas SG is ejected in the inner diameter direction from the second ejection port 12d that is opened in the whole circumference inward of the second nozzle 12.
  • the second ejection port 1d ejects the shield gas SG so as to be a gas flow parallel to the tip surface 11c of the first nozzle 11, and the second ejection port 12d is entirely on the circumference of the second nozzle 12. Therefore, a stable shield gas SG layer that covers the entire front end surface 11c of the first nozzle 11 is formed.
  • FIG. 4 also shows the formation state of the shield gas SG layer. As shown in FIG.
  • the fume HG generated and convected inside the shield gas SG ejected from the first ejection port 12c toward the first and second workpieces is ejected from the second ejection port 12d in the inner diameter direction.
  • the shield gas SG layer is prevented from adhering to the tip surface 11 c of the first nozzle 11. Therefore, it can suppress that the fume HG adheres to the front end surface 11c of the 1st nozzle 11, and the fume HG and the metal of the front end surface 11c of the 1st nozzle 11 combine, and an alloying layer is formed.
  • the shield gas SG which is ejected from the second ejection port 12d and forms a stable shield gas SG layer covering the entire front end surface 11c of the first nozzle 11, is transferred from the first ejection port 12c to the first and second workpieces. It becomes a swirl flow between the shield gas SG and the plasma gas PG ejected toward the direction.
  • the shield gas SG is ejected from the second ejection port 12d in the inner diameter direction in parallel to the tip surface 11c of the first nozzle 11, and the layer of the shield gas SG is applied to the tip surface of the first nozzle 11. 11c is formed on the front surface.
  • galvanization occurs due to evaporation of the zinc plating at a high temperature inside the shield gas SG that is ejected in an annular shape toward the first and second workpieces so as to surround the plasma gas PG from the first ejection port 12c.
  • the fume HG is prevented from adhering to the tip surface 11c of the first nozzle 11 by the layer of the shield gas SG ejected from the second ejection port 12d. Therefore, it can suppress that the fume HG adheres to the front end surface 11c of the 1st nozzle 11, and the fume HG and the metal of the front end surface 11c of the 1st nozzle 11 combine, and an alloying layer is formed.
  • the 2nd jet nozzle 12d is located inside the 1st jet nozzle 12c, and shield gas SG ejected from each of the 1st jet nozzle 12c and the 2nd jet nozzle 12d does not interfere.
  • the first nozzle 11 is not easily consumed, the welding quality can be stabilized, and the formation of the alloyed layer is suppressed, so that a decrease in durability of the first nozzle 11 can be suppressed. Further, since no other parts such as the third nozzle 13 are provided as in the first embodiment, the plasma torch 1a can be downsized. Further, since the same shielding gas is ejected from the first ejection port 12c and the second ejection port 12d, it is not necessary to prepare many kinds of gases, and the cost can be reduced.
  • the plasma arc welding methods of the first and second embodiments generally have an inert gas such as a shielding gas toward the tip surface of the arc electrode such as the first nozzle inside the shielding gas ejected in an annular shape.
  • an inert gas such as a shielding gas toward the tip surface of the arc electrode such as the first nozzle inside the shielding gas ejected in an annular shape.
  • the inert gas is ejected toward the tip surface of the arc electrode inside the shield gas that is ejected in an annular shape toward the workpiece, and an inert gas layer is formed.
  • the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the scope of the present invention.
  • the number of the third nozzles 13 in the first embodiment may be at least one, and preferably four such that an inert gas FG layer can be formed on the entire front end surface 11 c of the first nozzle 11. It is good to have more.
  • the inert gas FG ejected from the third nozzle 13 in the first embodiment may be the same as or different from the shield gas SG.
  • the form of the 1st jet nozzle 12c of the 2nd nozzle 12 in 2nd Embodiment may be a some opening etc., if the layer of shield gas SG can be formed in the whole surface of the front end surface 11c of the 1st nozzle 11, The shape etc. Is not limited.

Abstract

Provided is an arc welding method in which inward from shield gas (SG) that is sprayed in a circular shape from second nozzles (12) towards a first and a second workpiece, an inert gas (FG) is sprayed from third nozzles (13) towards a tip surface (11c) of a first nozzle (11), and an inert gas layer is formed. This configuration prevents fume generated from a workpiece surface from adhering to the tip surface (11c) of the first nozzle (11), stabilizes weld quality, and suppresses a reduction in nozzle durability.

Description

アーク溶接方法及びプラズマトーチArc welding method and plasma torch
　本発明は、アーク溶接方法及びプラズマトーチに関する。詳しくは、アーク溶接方法及びプラズマアーク溶接に用いられるプラズマトーチに関する。 The present invention relates to an arc welding method and a plasma torch. Specifically, the present invention relates to an arc welding method and a plasma torch used for plasma arc welding.
　従来、プラズマアーク溶接が知られている。プラズマアーク溶接には、プラズマトーチが用いられる。プラズマトーチとしては、例えば特許文献１、２に記載されたものがある。
　特許文献１に記載されたプラズマトーチは、アーク発生用の中心電極と、中心電極を囲繞してプラズマ形成用の動作ガスを噴出するノズルと、を有し、少なくとも中心電極の先端部とノズルの噴出口とを中心電極の長手軸方向と略直交する方向で細長形状に構成している。
　また特許文献２に記載されたプラズマトーチは、溶接トーチの先端部に備えられたメインノズルを用いて、溶融池を大気から保護する第１のガス（シールドガス）を流すと共に、溶接トーチの外部に設けられた１つ又は複数の外部ノズルを用いて、溶接トーチの先端部に形成されたアーク部分に向けて、第１のガスとは組成の異なる第２のガス（プラズマガス）を噴射する。 Conventionally, plasma arc welding is known. A plasma torch is used for plasma arc welding. Examples of plasma torches include those described in Patent Documents 1 and 2.
The plasma torch described in Patent Document 1 includes a center electrode for arc generation and a nozzle that surrounds the center electrode and ejects a working gas for plasma formation, and at least the tip of the center electrode and the nozzle The jet outlet is formed in an elongated shape in a direction substantially perpendicular to the longitudinal axis direction of the center electrode.
The plasma torch described in Patent Document 2 uses a main nozzle provided at the tip of the welding torch to flow a first gas (shield gas) that protects the molten pool from the atmosphere, and at the outside of the welding torch. A second gas (plasma gas) having a composition different from that of the first gas is injected toward the arc portion formed at the tip of the welding torch using one or a plurality of external nozzles provided in .
特開２００８－２８４５８０号公報JP 2008-284580 A 特開２００５－１７７８２２号公報JP 2005-177822 A
　ここで、亜鉛めっき鋼板にプラズマアーク溶接を施す際には、高温で亜鉛めっきが蒸発することでヒュームが発生する。このとき、シールドガスとプラズマガスとの間でヒュームの対流が発生し、ヒュームがノズルの先端面に付着してヒュームとノズルの先端面の金属とが化合して合金化層が形成される。合金化層は融点が低いためノズルが消耗し易くなり、ノズル損傷により溶接品質が安定しないおそれがある。また、合金化層形成によりノズルの耐久性も低下する。 Here, when plasma arc welding is performed on a galvanized steel sheet, fumes are generated due to evaporation of the galvanizing at a high temperature. At this time, convection of the fume occurs between the shield gas and the plasma gas, the fume adheres to the tip surface of the nozzle, and the fume and the metal on the tip surface of the nozzle combine to form an alloyed layer. Since the alloying layer has a low melting point, the nozzle is easily consumed, and the weld quality may not be stabilized due to the nozzle damage. In addition, the durability of the nozzle also decreases due to the formation of the alloying layer.
　本発明は上記課題を解決するためのもので、その目的は、シールドガスの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームがノズルの先端面に付着することを防止し、溶接品質を安定化させると共にノズルの耐久性低下を抑制することにある。 The present invention is for solving the above problems, and its purpose is to prevent convection fumes generated by evaporation of galvanizing at a high temperature inside the shield gas from adhering to the tip surface of the nozzle, The purpose is to stabilize the welding quality and suppress the deterioration of the durability of the nozzle.
　（１）アーク溶接方法であって、円環状に噴出されるシールドガス（例えば、後述のシールドガスＳＧ）の内側においてアーク電極（例えば、後述の第１ノズル１１）の先端面（例えば、後述の先端面１１ｃ）に向けて不活性ガス（例えば、後述の不活性ガスＦＧ）を噴出し、不活性ガスの層を形成することを特徴とするアーク溶接方法。 (1) An arc welding method, which is a front end surface (for example, described later) of an arc electrode (for example, first nozzle 11 described later) inside a shield gas (for example, shield gas SG described later) ejected in an annular shape. An arc welding method characterized in that an inert gas (for example, an inert gas FG described later) is ejected toward the distal end surface 11c) to form an inert gas layer.
　（１）の発明によると、不活性ガスが、円環状に噴出されるシールドガスの内側においてアーク電極の先端面に向けて噴出され、不活性ガスの層が形成される。
　これにより、シールドガスの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームが、不活性ガスの層によってアーク電極の先端面に付着することが防止される。よって、ヒュームがアーク電極の先端面に付着してヒュームとアーク電極の先端面の金属とが化合して合金化層が形成されることを抑制できる。
　また、不活性ガスが、円環状に噴出されるシールドガスの内側においてアーク電極の先端面に向けて噴出されるので、不活性ガスがシールドガスに干渉することはない。
　したがって、アーク電極が消耗し難くなり溶接品質を安定化できると共に、合金化層の形成が抑制されてノズルの耐久性低下を抑制できる。 According to the invention of (1), the inert gas is ejected toward the tip surface of the arc electrode inside the shield gas ejected in an annular shape, and an inert gas layer is formed.
This prevents fume that is generated by the galvanization of the zinc gas from evaporating at a high temperature inside the shield gas from adhering to the tip surface of the arc electrode by the inert gas layer. Therefore, it can suppress that a fume adheres to the front end surface of an arc electrode, a fume and the metal of the front end surface of an arc electrode combine, and an alloying layer is formed.
Further, since the inert gas is ejected toward the tip surface of the arc electrode inside the shield gas ejected in an annular shape, the inert gas does not interfere with the shield gas.
Therefore, the arc electrode is hardly consumed and the welding quality can be stabilized, and the formation of the alloyed layer can be suppressed to suppress the deterioration of the durability of the nozzle.
　（２）プラズマアーク溶接に用いられるプラズマトーチ（例えば、後述のプラズマトーチ１）であって、棒状の電極（例えば、後述の電極１０）と、当該電極の周囲に設けられ、プラズマガス（例えば、後述のプラズマガスＰＧ）を噴出する円筒形状の第１ノズル（例えば、後述の第１ノズル１１）と、当該第１ノズルの周囲に設けられ、プラズマガスを囲むようにシールドガス（例えば、後述のシールドガスＳＧ）を円環状に噴出する円筒形状の第２ノズル（例えば、後述の第２ノズル１２）と、円環状に噴出されるシールドガスの内側において前記第１ノズルの先端面に向けて不活性ガス（例えば、後述の不活性ガスＦＧ）を噴出する第３ノズル（例えば、後述の第３ノズル１３）と、を備えることを特徴とするプラズマトーチ。 (2) A plasma torch (for example, plasma torch 1 described later) used for plasma arc welding, which is provided around a rod-shaped electrode (for example, electrode 10 described later), and a plasma gas (for example, A cylindrical first nozzle (for example, a later-described first nozzle 11) that ejects a plasma gas PG (to be described later) and a shield gas (for example, to be described later) provided around the first nozzle and surrounding the plasma gas. A cylindrical second nozzle (for example, a second nozzle 12 described later) for ejecting the shield gas SG) in an annular shape, and a non-circular shape toward the tip surface of the first nozzle inside the shield gas ejected in an annular shape. A plasma torch comprising: a third nozzle (for example, a third nozzle 13 described later) that ejects an active gas (for example, an inert gas FG described later).
　（２）の発明によると、不活性ガスが、第３ノズルからワークへ向けて円環状に噴出されるシールドガスの内側において第１ノズルの先端面に向けて噴出され、不活性ガスの層が形成される。
　これにより、シールドガスの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームが、不活性ガスの層によって第１ノズルの先端面に付着することが防止される。よって、ヒュームが第１ノズルの先端面に付着してヒュームと第１ノズルの先端面の金属とが化合して合金化層が形成されることを抑制できる。
　また、不活性ガスが、第３ノズルからワークへ向けて円環状に噴出されるシールドガスの内側において第１ノズルの先端面に向けて噴出されるので、不活性ガスがシールドガスに干渉することはない。
　したがって、第１ノズルが消耗し難くなり溶接品質を安定化できると共に、合金化層の形成が抑制されてノズルの耐久性低下を抑制できる。 According to the invention of (2), the inert gas is jetted toward the tip surface of the first nozzle inside the shield gas jetted in an annular shape from the third nozzle toward the workpiece, and the inert gas layer is formed. It is formed.
This prevents fume that is generated by the galvanization of the zinc gas from evaporating at a high temperature inside the shield gas from adhering to the tip surface of the first nozzle by the inert gas layer. Therefore, it can suppress that a fume adheres to the front end surface of a 1st nozzle, a fume and the metal of the front end surface of a 1st nozzle combine, and an alloying layer is formed.
Further, since the inert gas is ejected toward the tip surface of the first nozzle inside the shield gas ejected in an annular shape from the third nozzle toward the workpiece, the inert gas interferes with the shield gas. There is no.
Therefore, the first nozzle is hardly consumed and the welding quality can be stabilized, and the formation of the alloyed layer can be suppressed to suppress the decrease in the durability of the nozzle.
　（３）前記第３ノズルから噴出される不活性ガスとして、前記シールドガスと同じガスを用いることを特徴とする（２）に記載のプラズマトーチ。 (3) The plasma torch according to (2), wherein the same gas as the shield gas is used as the inert gas ejected from the third nozzle.
　（３）の発明によると、不活性ガスとしてシールドガスと同じガスを用いるので、多種類のガスを用意する必要が無く、低コスト化を図れる。 According to the invention of (3), since the same gas as the shielding gas is used as the inert gas, it is not necessary to prepare many kinds of gases and the cost can be reduced.
　（４）前記第３ノズルは、不活性ガスを前記第１ノズルの先端面に平行なガス流となるように噴出することを特徴とする（２）又は（３）に記載のプラズマトーチ。 (4) The plasma torch according to (2) or (3), wherein the third nozzle ejects an inert gas so as to form a gas flow parallel to a tip surface of the first nozzle.
　（４）の発明によると、第３ノズルから噴出される不活性ガスが第１ノズルの先端面に平行なガス流となり、不活性ガスの層が形成される。不活性ガスの第１ノズルの先端面に平行なガス流は、第１ノズルの先端面の前面において、ガス流が第１ノズルの先端面で反射されず保護すべき表面に沿った安定した流れとなり、安定した不活性ガスの層を形成できる。これにより、シールドガスの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームが、不活性ガスの層によって第１ノズルの先端面に付着することを防止できる。 According to the invention of (4), the inert gas ejected from the third nozzle becomes a gas flow parallel to the tip surface of the first nozzle, and an inert gas layer is formed. The gas flow parallel to the tip surface of the first nozzle of the inert gas is a stable flow along the surface to be protected without being reflected by the tip surface of the first nozzle on the front surface of the tip surface of the first nozzle. Thus, a stable inert gas layer can be formed. Thereby, it can prevent that the fumes which generate | occur | produce by galvanization evaporating at high temperature inside shield gas, and adhere to the front end surface of a 1st nozzle by the layer of an inert gas can be prevented.
　（５）前記第３ノズルは、前記第２ノズルの円周方向から円環状に噴出されるシールドガスの内側に、円周方向で均等に離れて少なくとも４本以上配置されることを特徴とする（２）～（４）のいずれかに記載のプラズマトーチ。 (5) At least four or more of the third nozzles are arranged at equal intervals in the circumferential direction inside the shield gas ejected in an annular shape from the circumferential direction of the second nozzle. (2) The plasma torch according to any one of (4).
　（５）の発明によると、円周方向で均等に離れて少なくとも４本以上配置された第３ノズルの１本ごとに第１ノズルの先端面を均等に分担して覆うように不活性ガスの層を形成するため、４本以上配置された第３ノズルから噴出される不活性ガスは、第１ノズルの先端面の全面を覆う安定した不活性ガスの層を形成できる。これにより、シールドガスの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームが、不活性ガスの層によって第１ノズルの先端面に付着することを防止できる。 According to the invention of (5), the inert gas is provided so as to cover the tip end surface of the first nozzle evenly for each of the third nozzles arranged at least four equally spaced apart in the circumferential direction. In order to form the layer, the inert gas ejected from the third nozzle arranged at least four can form a stable inert gas layer covering the entire front end surface of the first nozzle. Thereby, it can prevent that the fumes which generate | occur | produce by galvanization evaporating at high temperature inside shield gas, and adhere to the front end surface of a 1st nozzle by the layer of an inert gas can be prevented.
　（６）プラズマアーク溶接に用いられるプラズマトーチ（例えば、後述のプラズマトーチ１ａ）であって、棒状の電極（例えば、後述の電極１０）と、当該電極の周囲に設けられ、プラズマガス（例えば、後述のプラズマガスＰＧ）を噴出する円筒形状の第１ノズル（例えば、後述の第１ノズル１１）と、当該第１ノズルの周囲に設けられ、プラズマガスを囲むようにシールドガス（例えば、後述のシールドガスＳＧ）を軸線方向に円環状に噴出する第１噴出口（例えば、後述の第１噴出口１２ｃ）と前記第１ノズルの先端面（例えば、後述の先端面１１ｃ）に向けてシールドガスを内径方向に噴出する第２噴出口（例えば、後述の第２噴出口１２ｄ）とを有する第２ノズル（例えば、後述の第２ノズル１２）と、を備えることを特徴とするプラズマトーチ。 (6) A plasma torch (for example, a plasma torch 1a described later) used for plasma arc welding, which is provided around a rod-shaped electrode (for example, an electrode 10 described later), and a plasma gas (for example, A cylindrical first nozzle (for example, a later-described first nozzle 11) that ejects a plasma gas PG (to be described later) and a shield gas (for example, to be described later) provided around the first nozzle and surrounding the plasma gas. Shielding gas SG) is directed toward a first outlet (for example, a first outlet 12c described later) and an end surface (for example, a front end surface 11c described later) of the first nozzle. And a second nozzle (for example, a second nozzle 12 described later) having a second nozzle (for example, a second nozzle 12d described later). Plasma torch.
　（６）の発明によると、シールドガスが、第２噴出口から内径方向に第１ノズルの先端面に向けて噴出され、シールドガスの層が形成される。
　これにより、第１噴出口からプラズマガスを囲むようにワークへ向けて円環状に噴出するシールドガスの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームが、第２噴出口から噴出されるシールドガスの層によって第１ノズルの先端面に付着することが防止される。よって、ヒュームが第１ノズルの先端面に付着してヒュームと第１ノズルの先端面の金属とが化合して合金化層が形成されることを抑制できる。
　また、第１噴出口よりも内側に第２噴出口が位置し、第１噴出口及び第２噴出口のそれぞれから噴出されるシールドガス同士が干渉することはない。
　したがって、第１ノズルが消耗し難くなり溶接品質を安定化できると共に、合金化層の形成が抑制されてノズルの耐久性低下を抑制できる。
　また、他のノズルを設けないので、プラズマトーチの小型化を図れる。
　また、第１噴出口及び第２噴出口から同じシールドガスを噴出させるので、多種類のガスを用意する必要が無く、低コスト化を図れる。 According to the invention of (6), the shielding gas is ejected from the second ejection port toward the tip surface of the first nozzle in the inner diameter direction, and a layer of shielding gas is formed.
As a result, fume that is generated by the galvanizing evaporation at high temperature inside the shield gas that is ejected in an annular shape toward the workpiece so as to surround the plasma gas from the first ejection port is generated from the second ejection port. The layer of the shield gas that is ejected prevents the first nozzle from adhering to the tip surface. Therefore, it can suppress that a fume adheres to the front end surface of a 1st nozzle, a fume and the metal of the front end surface of a 1st nozzle combine, and an alloying layer is formed.
Moreover, a 2nd jet nozzle is located inside a 1st jet nozzle, and shield gas ejected from each of a 1st jet nozzle and a 2nd jet nozzle does not interfere.
Therefore, the first nozzle is hardly consumed and the welding quality can be stabilized, and the formation of the alloyed layer can be suppressed to suppress the decrease in the durability of the nozzle.
In addition, since no other nozzle is provided, the plasma torch can be reduced in size.
Further, since the same shield gas is ejected from the first ejection port and the second ejection port, it is not necessary to prepare many kinds of gases, and the cost can be reduced.
　本発明によれば、シールドガスの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームがノズルの先端面に付着することを防止でき、溶接品質を安定化できると共にノズルの耐久性低下を抑制できる。 According to the present invention, it is possible to prevent the convection fumes generated by evaporation of zinc plating at a high temperature inside the shielding gas from adhering to the tip surface of the nozzle, and to stabilize the welding quality and the durability of the nozzle. Reduction can be suppressed.
本発明の第１の実施形態に係るプラズマトーチの概略構成を示す模式図であり、（ａ）が側方断面図であり、（ｂ）が底面図である。It is a schematic diagram which shows schematic structure of the plasma torch concerning the 1st Embodiment of this invention, (a) is a side sectional view, (b) is a bottom view. 従来技術のプラズマトーチにヒュームが発生した状態を示す概略図である。It is the schematic which shows the state which the fume generate | occur | produced in the plasma torch of the prior art. 上記実施形態に係る不活性ガスの層の形成状態を示す概略図である。It is the schematic which shows the formation state of the layer of the inert gas which concerns on the said embodiment. 本発明の第２の実施形態に係るプラズマトーチの概略構成を示す模式図である。It is a schematic diagram which shows schematic structure of the plasma torch concerning the 2nd Embodiment of this invention.
　以下に図面を参照して本発明の実施形態を説明する。 Embodiments of the present invention will be described below with reference to the drawings.
　（第１の実施形態）
　図１は、本発明の第１の実施形態に係るプラズマトーチ１の概略構成を示す模式図であり、（ａ）が側方断面図であり、（ｂ）が底面図である。
　プラズマトーチ１は、棒状の電極１０と、電極１０の周囲に設けられてプラズマガスＰＧを噴出する円筒形状の第１ノズル１１と、第１ノズル１１の周囲に設けられてシールドガスＳＧを噴出する円筒形状の第２ノズル１２と、円環状に噴出されるシールドガスＳＧの内側において第１ノズル１１の先端面１１ｃに向けて不活性ガスＦＧを噴出する第３ノズル１３と、を備える。 (First embodiment)
FIG. 1 is a schematic diagram showing a schematic configuration of a plasma torch 1 according to the first embodiment of the present invention, in which (a) is a side sectional view and (b) is a bottom view.
The plasma torch 1 is provided around the electrode 10, a cylindrical first nozzle 11 that is provided around the electrode 10 and ejects the plasma gas PG, and is provided around the first nozzle 11 to eject the shield gas SG. The cylindrical 2nd nozzle 12 and the 3rd nozzle 13 which injects the inert gas FG toward the front end surface 11c of the 1st nozzle 11 inside the shield gas SG injected circularly are provided.
　第１ノズル１１は、円筒形状部材であり、棒状の電極１０を収容するもので、電極１０の先端に合わせて縮径する中心孔１１ａを有する。中心孔１１ａの先端には、噴出口１１ｂが形成される。噴出口１１ｂからはプラズマガスＰＧが噴出される。プラズマガスＰＧを噴出する噴出口１１ｂの周りには平環状面の第１ノズル１１の先端面１１ｃが形成される。 The first nozzle 11 is a cylindrical member that accommodates the rod-shaped electrode 10 and has a central hole 11 a that is reduced in diameter in accordance with the tip of the electrode 10. A spout 11b is formed at the tip of the center hole 11a. Plasma gas PG is ejected from the ejection port 11b. A front end surface 11c of the first nozzle 11 having a flat annular surface is formed around the ejection port 11b that ejects the plasma gas PG.
　第２ノズル１２は、円筒形状部材であり、第１ノズル１１を囲い、その中心孔１２ａ内に第１ノズル１１を収容する。第２ノズル１２は、第１ノズル１１の先端面１１ｃを有する先端部１１ｄよりも後退して設けられ、第２ノズル１２から第１ノズル１１の先端部１１ｄが突出する。第１ノズル１１の先端部１１ｄは、噴出口１２ｂの内側において先端に向かうにつれて縮径して突出する。第１ノズル１１の先端部１１ｄに到達前の外周と第２ノズル１２の内周との間には、環状の噴出口１２ｂが形成される。環状の噴出口１２ｂからは、第１ノズル１１の外周と第２ノズル１２の内周との間の隙間を通って供給されたシールドガスＳＧが噴出される。 The second nozzle 12 is a cylindrical member, surrounds the first nozzle 11, and accommodates the first nozzle 11 in the center hole 12a. The second nozzle 12 is provided so as to recede from the tip portion 11 d having the tip surface 11 c of the first nozzle 11, and the tip portion 11 d of the first nozzle 11 protrudes from the second nozzle 12. The tip portion 11d of the first nozzle 11 projects with a reduced diameter toward the tip inside the jet nozzle 12b. An annular jet 12 b is formed between the outer periphery before reaching the tip 11 d of the first nozzle 11 and the inner periphery of the second nozzle 12. The shield gas SG supplied through the gap between the outer periphery of the first nozzle 11 and the inner periphery of the second nozzle 12 is ejected from the annular ejection port 12b.
　第３ノズル１３は、第１ノズル１１及び第２ノズル１２とは異なり小径であり、第２ノズル１２の円周方向から円環状に噴出されるシールドガスＳＧの外側から内側に、円周方向で均等に離れて４本配置される。すなわち、第３ノズル１３のそれぞれは、第２ノズル１２の外周側から円周方向で９０°ごとに離れて延出され、図１（ｂ）に示すように、第１ノズル１１の先端部側に内径方向に屈曲して延びる。内径方向に屈曲した第３ノズル１３からは、不活性ガスＦＧが第１ノズル１１の先端面１１ｃに平行なガス流となるように噴出される。
　なお、第３ノズル１３から噴出される不活性ガスＦＧとして、シールドガスＳＧと同じガスを用いることが好ましい。 Unlike the first nozzle 11 and the second nozzle 12, the third nozzle 13 has a small diameter, and in the circumferential direction from the outer side to the inner side of the shield gas SG ejected in an annular shape from the circumferential direction of the second nozzle 12. Four are equally spaced apart. That is, each of the third nozzles 13 extends away from the outer peripheral side of the second nozzle 12 by 90 ° in the circumferential direction, and as shown in FIG. And bent in the inner diameter direction. From the third nozzle 13 bent in the inner diameter direction, the inert gas FG is ejected so as to form a gas flow parallel to the tip surface 11 c of the first nozzle 11.
Note that the same gas as the shield gas SG is preferably used as the inert gas FG ejected from the third nozzle 13.
　次に、プラズマトーチ１を用いたプラズマアーク溶接について、図２及び図３を参照して説明する。プラズマアーク溶接は、厚みが薄い板材である第１ワークと、厚みが第１ワークよりも厚い板材である第２ワークと、を突き合わせ溶接して、テーラードブランク材を形成する。第１、第２ワークとしては、亜鉛めっき鋼板等が用いられる。 Next, plasma arc welding using the plasma torch 1 will be described with reference to FIGS. In plasma arc welding, a tailored blank material is formed by butt welding a first workpiece, which is a thin plate material, and a second workpiece, which is a plate material, which is thicker than the first workpiece. As the first and second workpieces, galvanized steel sheets or the like are used.
　まず、通電させた電極１０の放電を受けて発生させたプラズマガスＰＧ（アーク）を第１ノズル１１の噴出口１１ｂから噴出させ、このプラズマガスＰＧを第１、第２ワークに供給する。
　また同時に、シールドガスＳＧを第２ノズル１２の噴出口１２ｂから、プラズマガスＰＧの周囲を囲むように第１、第２ワークへ向けて円環状に噴出させる。シールドガスＳＧは、プラズマガスＰＧから離れる方向に拡がりながら、プラズマガスＰＧの外周表面に沿って流れ、溶融池の表面に対して外径方向に離散するように吹き付けられる。
　これにより、プラズマガスＰＧが、シールドガスＳＧの外側の大気に接触することが防止される。 First, the plasma gas PG (arc) generated by receiving the discharge of the energized electrode 10 is ejected from the ejection port 11b of the first nozzle 11, and this plasma gas PG is supplied to the first and second workpieces.
At the same time, the shield gas SG is ejected in an annular shape from the ejection port 12b of the second nozzle 12 toward the first and second workpieces so as to surround the periphery of the plasma gas PG. The shield gas SG flows along the outer peripheral surface of the plasma gas PG while spreading in a direction away from the plasma gas PG, and is sprayed so as to be dispersed in the outer diameter direction with respect to the surface of the molten pool.
This prevents the plasma gas PG from contacting the atmosphere outside the shield gas SG.
　このとき、亜鉛めっき鋼板を用いた第１、第２ワークにプラズマアーク溶接を施す際には、高温で亜鉛めっきが蒸発することでヒュームＨＧが発生する。
　図２は、従来技術のプラズマトーチ１００にヒュームＨＧが発生した状態を示す概略図である。図２に示すように、シールドガスＳＧとプラズマガスＰＧとの間でヒュームＨＧの対流が発生するので、ヒュームＨＧが第１ノズル１１１の先端面１１１ｃに付着してヒュームＨＧと第１ノズル１１１の先端面１１１ｃの金属とが化合して合金化層が形成される場合がある。
　合金化層が形成されてしまうと、合金化層は融点が低いため第１ノズル１１１が消耗し易くなり、第１ノズル１１１の損傷により溶接品質が安定しないおそれがある。また、合金化層形成により第１ノズル１１１の耐久性も低下するおそれもある。 At this time, when plasma arc welding is performed on the first and second workpieces using the galvanized steel sheet, fume HG is generated due to evaporation of the galvanizing at a high temperature.
FIG. 2 is a schematic view showing a state in which fume HG is generated in the plasma torch 100 of the prior art. As shown in FIG. 2, convection of the fume HG occurs between the shield gas SG and the plasma gas PG, so that the fume HG adheres to the tip surface 111c of the first nozzle 111 and the fume HG and the first nozzle 111 In some cases, the metal of the front end surface 111c combines to form an alloyed layer.
If the alloyed layer is formed, the first nozzle 111 is easily consumed because the alloyed layer has a low melting point, and the weld quality may not be stabilized due to damage of the first nozzle 111. Moreover, durability of the 1st nozzle 111 may also fall by alloying layer formation.
　そこで、本実施形態では、シールドガスＳＧと同じガスを用いた不活性ガスＦＧを、第３ノズル１３から噴出させる。第３ノズル１３は、不活性ガスＦＧを第１ノズル１１の先端面１１ｃに平行なガス流となるように噴出し、更に４本の第３ノズル１３は、第２ノズル１２の円周上等間隔空けた４方向から不活性ガスＦＧを噴出する。これより、不活性ガスＦＧの第１ノズル１１の先端面１１ｃに平行なガス流は、第１ノズル１１の先端面１１ｃの前面において、ガス流が第１ノズルの先端面で反射されず保護すべき表面に沿った安定した流れとなり、安定した不活性ガスＦＧの層を形成する。また各第３ノズル１３が噴出する不活性ガスＦＧは、第１ノズル１１の先端面１１ｃを均等に分担して覆うことができ、４本の第３ノズル１３では、第１ノズル１１の先端面１１ｃの全面を覆う安定した不活性ガスＦＧの層を形成する。
　図３は、本実施形態に係る不活性ガスＦＧの層の形成状態を示す概略図である。図３に示すように、シールドガスＳＧの内側で発生して対流するヒュームＨＧが、不活性ガスＦＧの層によって第１ノズル１１の先端面１１ｃに付着することが防止される。
　よって、ヒュームＨＧが第１ノズル１１の先端面１１ｃに付着してヒュームＨＧと第１ノズル１１の先端面１１ｃの金属とが化合して合金化層が形成されることを抑制できる。したがって、第１ノズル１１が消耗し難くなり溶接品質を安定化できると共に、合金化層の形成が抑制されて第１ノズル１１の耐久性低下を抑制できる。
　なお、第１ノズル１１の先端面１１ｃの全面を覆う安定した不活性ガスＦＧの層を形成した不活性ガスＦＧは、シールドガスＳＧとプラズマガスＰＧとの間の旋回流となる。 Therefore, in the present embodiment, an inert gas FG using the same gas as the shield gas SG is ejected from the third nozzle 13. The third nozzle 13 ejects the inert gas FG so as to form a gas flow parallel to the tip surface 11 c of the first nozzle 11, and the four third nozzles 13 are on the circumference of the second nozzle 12. Inert gas FG is ejected from four spaced apart directions. Accordingly, the gas flow of the inert gas FG parallel to the tip surface 11c of the first nozzle 11 is protected on the front surface of the tip surface 11c of the first nozzle 11 without being reflected by the tip surface of the first nozzle 11. A stable flow along the power surface is formed, and a stable inert gas FG layer is formed. Further, the inert gas FG ejected from each third nozzle 13 can equally cover and cover the front end surface 11 c of the first nozzle 11, and the four third nozzles 13 have the front end surface of the first nozzle 11. A stable inert gas FG layer covering the entire surface of 11c is formed.
FIG. 3 is a schematic view showing a state of forming the layer of the inert gas FG according to the present embodiment. As shown in FIG. 3, the fume HG generated and convected inside the shield gas SG is prevented from adhering to the tip surface 11c of the first nozzle 11 by the layer of the inert gas FG.
Therefore, it can suppress that the fume HG adheres to the front end surface 11c of the 1st nozzle 11, and the fume HG and the metal of the front end surface 11c of the 1st nozzle 11 combine, and an alloying layer is formed. Therefore, the first nozzle 11 is not easily consumed, the welding quality can be stabilized, and the formation of the alloyed layer is suppressed, so that a decrease in durability of the first nozzle 11 can be suppressed.
The inert gas FG, which forms a stable inert gas FG layer covering the entire front end surface 11c of the first nozzle 11, becomes a swirl flow between the shield gas SG and the plasma gas PG.
　以上の実施形態によれば以下の効果を奏する。
　（１）本実施形態によると、不活性ガスＦＧが、第３ノズル１３から第１、第２ワークへ向けて円環状に噴出されるシールドガスＳＧの内側において第１ノズル１１の先端面１１ｃに平行に吹き付けられ、不活性ガスＦＧの層を第１ノズル１１の先端面１１ｃの前面に形成する。
　これにより、シールドガスＳＧの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームＨＧが、不活性ガスＦＧの層によって第１ノズル１１の先端面１１ｃに付着することが防止される。よって、ヒュームＨＧが第１ノズル１１の先端面１１ｃに付着してヒュームＨＧと第１ノズル１１の先端面１１ｃの金属とが化合して合金化層が形成されることを抑制できる。
　また、不活性ガスＦＧが、第３ノズル１３から第１、第２ワークへ向けて円環状に噴出されるシールドガスＳＧの内側において第１ノズル１１の先端面１１ｃに平行に吹き付けられるので、不活性ガスＦＧがシールドガスＳＧに干渉することはない。
　したがって、第１ノズル１１が消耗し難くなり溶接品質を安定化できると共に、合金化層の形成が抑制されて第１ノズル１１の耐久性低下を抑制できる。 According to the above embodiment, there exist the following effects.
(1) According to the present embodiment, the inert gas FG is applied to the tip surface 11c of the first nozzle 11 inside the shield gas SG that is ejected in an annular shape from the third nozzle 13 toward the first and second workpieces. A layer of inert gas FG is sprayed in parallel to form the front surface of the tip surface 11 c of the first nozzle 11.
This prevents fume HG generated by the evaporation of zinc plating at a high temperature inside shield gas SG from adhering to tip surface 11c of first nozzle 11 due to the layer of inert gas FG. . Therefore, it can suppress that the fume HG adheres to the front end surface 11c of the 1st nozzle 11, and the fume HG and the metal of the front end surface 11c of the 1st nozzle 11 combine, and an alloying layer is formed.
Further, the inert gas FG is blown in parallel with the tip surface 11c of the first nozzle 11 inside the shield gas SG that is ejected in an annular shape from the third nozzle 13 toward the first and second workpieces. The active gas FG does not interfere with the shield gas SG.
Therefore, the first nozzle 11 is not easily consumed, the welding quality can be stabilized, and the formation of the alloyed layer is suppressed, so that a decrease in durability of the first nozzle 11 can be suppressed.
　（２）本実施形態によると、不活性ガスＦＧとしてシールドガスＳＧと同じガスを用いるので、多種類のガスを用意する必要が無く、低コスト化を図れる。 (2) According to this embodiment, since the same gas as the shield gas SG is used as the inert gas FG, it is not necessary to prepare many kinds of gases, and the cost can be reduced.
　（３）本実施形態によると、第３ノズル１３から噴出される不活性ガスＦＧが第１ノズル１１の先端面１１ｃに平行なガス流となり、不活性ガスＦＧの層を形成する。不活性ガスＦＧの第１ノズル１１の先端面１１ｃに平行なガス流は、第１ノズル１１の先端面１１ｃの前面において、ガス流が第１ノズルの先端面で反射されず保護すべき表面に沿った安定した流れとなり、安定した不活性ガスＦＧの層を形成できる。これにより、シールドガスＳＧの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームＨＧが、不活性ガスＦＧの層によって第１ノズル１１の先端面１１ｃに付着することを防止できる。 (3) According to the present embodiment, the inert gas FG ejected from the third nozzle 13 becomes a gas flow parallel to the tip surface 11c of the first nozzle 11, and forms a layer of the inert gas FG. The gas flow of the inert gas FG parallel to the front end surface 11c of the first nozzle 11 is on the front surface of the front end surface 11c of the first nozzle 11 without being reflected by the front end surface of the first nozzle 11. Therefore, a stable inert gas FG layer can be formed. Thereby, it can prevent that the fumes HG which generate | occur | produces when zinc plating evaporates at high temperature inside shield gas SG, and adheres to the front end surface 11c of the 1st nozzle 11 with the layer of the inert gas FG.
　（４）本実施形態によると、円周方向で均等に離れて４本配置された第３ノズル１３の１本ごとに第１ノズル１１の先端面１１ｃを均等に分担して覆うように不活性ガスの層を形成するため、４本配置された第３ノズル１３から噴出される不活性ガスＦＧは第１ノズル１１の先端面１１ｃの全面を覆う安定した不活性ガスＦＧの層を形成できる。これにより、シールドガスＳＧの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームＨＧが、不活性ガスＦＧの層によって第１ノズル１１の先端面１１ｃに付着することを防止できる。 (4) According to the present embodiment, the tip surface 11c of the first nozzle 11 is evenly shared and covered for each of the three third nozzles 13 that are equally spaced in the circumferential direction. In order to form the gas layer, the inert gas FG ejected from the four arranged third nozzles 13 can form a stable inert gas FG layer covering the entire front end surface 11 c of the first nozzle 11. Thereby, it can prevent that the fumes HG which generate | occur | produces when zinc plating evaporates at high temperature inside shield gas SG, and adheres to the front end surface 11c of the 1st nozzle 11 with the layer of the inert gas FG.
　（第２の実施形態）
　図４は、本発明の第２の実施形態に係るプラズマトーチ１ａの概略構成を示す模式図である。
　プラズマトーチ１ａは、棒状の電極１０と、電極１０の周囲に設けられてプラズマガスＰＧを噴出する円筒形状の第１ノズル１１と、第１ノズル１１の周囲に設けられてプラズマガスＰＧを囲むようにシールドガスＳＧを軸線方向に円環状に噴出する第１噴出口１２ｃと第１ノズル１１の先端面１１ｃに向けてシールドガスＳＧを内径方向に噴出する第２噴出口１２ｄとを有する第２ノズルと、を備える。 (Second Embodiment)
FIG. 4 is a schematic diagram showing a schematic configuration of a plasma torch 1a according to the second embodiment of the present invention.
The plasma torch 1a includes a rod-shaped electrode 10, a cylindrical first nozzle 11 that is provided around the electrode 10 and ejects the plasma gas PG, and is provided around the first nozzle 11 so as to surround the plasma gas PG. A second nozzle having a first jet port 12c for jetting the shield gas SG in an annular shape in the axial direction and a second jet port 12d for jetting the shield gas SG in the inner diameter direction toward the tip surface 11c of the first nozzle 11. And comprising.
　第１ノズル１１は、円筒形状部材であり、棒状の電極１０を収容するもので、電極１０の先端に合わせて縮径する中心孔１１ａを有する。中心孔１１ａの先端には、噴出口１１ｂが形成される。噴出口１１ｂからはプラズマガスＰＧが噴出される。プラズマガスＰＧを噴出する噴出口１１ｂの周りには第１ノズル１１の先端面１１ｃが形成される The first nozzle 11 is a cylindrical member that accommodates the rod-shaped electrode 10 and has a central hole 11 a that is reduced in diameter in accordance with the tip of the electrode 10. A spout 11b is formed at the tip of the center hole 11a. Plasma gas PG is ejected from the ejection port 11b. A distal end surface 11c of the first nozzle 11 is formed around the ejection port 11b that ejects the plasma gas PG.
　第２ノズル１２は、円筒形状部材であり、第１ノズル１１を囲い、その中心孔１２ａ内に第１ノズル１１を収容する。第２ノズル１２は、第１ノズル１１の先端面１１ｃを有する先端部１１ｄよりも後退して設けられ、第２ノズル１２から第１ノズル１１の先端部１１ｄが突出する。第１ノズル１１の先端部１１ｄに到達前の外周と第２ノズルの内周との間の隙間を通ってシールドガスＳＧを供給する。
　第２ノズル１２は、第１ノズル１１の先端面１１ｃを有する先端部１１ｄよりも後退した位置で軸線方向に開口した複数の第１噴出口１２ｃと、第１噴出口１２ｃから第１ノズル１１の先端部１１ｄをカバー部１２ｅで囲って第１ノズル１１の先端面１１ｃの位置に内径方向に全周的に開口した第２噴出口１２ｄと、を有する。シールドガスＳＧは、軸線方向に開口した複数の第１噴出口１２ｃと、内径方向に全周的に開口した第２噴出口１２ｄとに分かれて、第１噴出口１２ｃから軸線方向に円環状に噴出され、第２噴出口１２ｄから内径方向に噴出される。 The second nozzle 12 is a cylindrical member, surrounds the first nozzle 11, and accommodates the first nozzle 11 in the center hole 12a thereof. The second nozzle 12 is provided so as to recede from the tip portion 11 d having the tip surface 11 c of the first nozzle 11, and the tip portion 11 d of the first nozzle 11 protrudes from the second nozzle 12. The shield gas SG is supplied through a gap between the outer periphery before reaching the tip 11d of the first nozzle 11 and the inner periphery of the second nozzle.
The second nozzle 12 includes a plurality of first jet nozzles 12c that are opened in the axial direction at positions retracted from the tip portion 11d having the tip surface 11c of the first nozzle 11, and the first nozzle 11 through the first jet nozzle 12c. And a second jet port 12d that surrounds the tip portion 11d with a cover portion 12e and opens at the position of the tip surface 11c of the first nozzle 11 in the inner diameter direction. The shield gas SG is divided into a plurality of first outlets 12c that are opened in the axial direction and a second outlet 12d that is opened all around in the inner diameter direction, and is annularly formed in the axial direction from the first outlet 12c. It is ejected and ejected in the inner diameter direction from the second ejection port 12d.
　次に、プラズマトーチ１ａを用いたプラズマアーク溶接について、図２及び図４を参照して説明する。プラズマアーク溶接は、厚みが薄い板材である第１ワークと、厚みが第１ワークよりも厚い板材である第２ワークと、を突き合わせ溶接して、テーラードブランク材を形成する。第１、第２ワークとしては、亜鉛めっき鋼板等が用いられる。 Next, plasma arc welding using the plasma torch 1a will be described with reference to FIGS. In plasma arc welding, a tailored blank material is formed by butt welding a first workpiece, which is a thin plate material, and a second workpiece, which is a plate material, which is thicker than the first workpiece. As the first and second workpieces, galvanized steel sheets or the like are used.
　まず、通電させた電極１０の放電を受けて発生させたプラズマガスＰＧを第１ノズル１１の噴出口１１ｂから噴出させ、このプラズマガスＰＧを第１、第２ワークに供給する。
　また同時に、シールドガスＳＧを第２ノズル１２の第１噴出口１２ｃから、プラズマガスＰＧの周囲を囲むように第１、第２ワークへ向けて円環状に噴出させる。第１噴出口１２ｃから噴出されるシールドガスＳＧは、プラズマガスＰＧから離れる方向に拡がりながら、プラズマガスＰＧの外周表面に沿って流れ、溶融池の表面に対して外径方向に離散するように吹き付けられる。
　これにより、プラズマガスＰＧが、噴出口１１ｂから噴出されるシールドガスＳＧの外側の大気に接触することが防止される。 First, the plasma gas PG generated by receiving the discharge of the energized electrode 10 is ejected from the ejection port 11b of the first nozzle 11, and this plasma gas PG is supplied to the first and second workpieces.
At the same time, the shield gas SG is ejected in an annular shape from the first ejection port 12c of the second nozzle 12 toward the first and second workpieces so as to surround the periphery of the plasma gas PG. The shield gas SG ejected from the first ejection port 12c flows along the outer peripheral surface of the plasma gas PG while spreading in a direction away from the plasma gas PG, and is dispersed in the outer diameter direction with respect to the surface of the molten pool. Be sprayed.
This prevents the plasma gas PG from coming into contact with the atmosphere outside the shield gas SG ejected from the ejection port 11b.
　このとき、亜鉛めっき鋼板を用いた第１、第２ワークにプラズマアーク溶接を施す際には、高温で亜鉛めっきが蒸発することで第１の実施形態と同様にヒュームＨＧが発生する。
　図２は、従来技術のプラズマトーチ１００にヒュームＨＧが発生した状態を示す概略図である。図２に示すように、シールドガスＳＧとプラズマガスＰＧとの間でヒュームＨＧの対流が発生するので、ヒュームＨＧが第１ノズル１１１の先端面１１１ｃに付着してヒュームＨＧと第１ノズル１１１の先端面１１ｃの金属とが化合して合金化層が形成される場合がある。
　合金化層が形成されてしまうと、合金化層は融点が低いため第１ノズル１１１が消耗し易くなり、第１ノズル１１１の損傷により溶接品質が安定しないおそれがある。また、合金化層形成により第１ノズル１１１の耐久性も低下するおそれもある。 At this time, when plasma arc welding is performed on the first and second workpieces using the galvanized steel sheet, fume HG is generated as in the first embodiment due to evaporation of the galvanizing at a high temperature.
FIG. 2 is a schematic diagram showing a state in which fume HG is generated in the plasma torch 100 of the prior art. As shown in FIG. 2, convection of the fume HG occurs between the shield gas SG and the plasma gas PG, so that the fume HG adheres to the tip surface 111 c of the first nozzle 111 and the fume HG and the first nozzle 111 In some cases, the alloyed layer is formed by combining with the metal of the end face 11c.
If the alloyed layer is formed, the first nozzle 111 is easily consumed because the alloyed layer has a low melting point, and the weld quality may not be stabilized due to damage of the first nozzle 111. Moreover, durability of the 1st nozzle 111 may also fall by alloying layer formation.
　そこで、本実施形態では、シールドガスＳＧを、第２ノズル１２の内向きに全周的に開口した第２噴出口１２ｄから内径方向に噴出させる。第２噴出口１ｄは、シールドガスＳＧを第１ノズル１１の先端面１１ｃに平行なガス流となるように噴出し、更に第２噴出口１２ｄは第２ノズル１２の円周上に全周的に開口しているので、第１ノズル１１の先端面１１ｃの全面を覆う安定したシールドガスＳＧの層を形成する。
　図４にはシールドガスＳＧの層の形成状態をも示した。図４に示すように、第１噴出口１２ｃから第１、第２ワークへ向けて噴出されるシールドガスＳＧの内側で発生して対流するヒュームＨＧが、第２噴出口１２ｄから内径方向に噴出されるシールドガスＳＧの層によって第１ノズル１１の先端面１１ｃに付着することが防止される。
　よって、ヒュームＨＧが第１ノズル１１の先端面１１ｃに付着してヒュームＨＧと第１ノズル１１の先端面１１ｃの金属とが化合して合金化層が形成されることを抑制できる。したがって、第１ノズル１１が消耗し難くなり溶接品質を安定化できると共に、合金化層の形成が抑制されて第１ノズル１１の耐久性低下を抑制できる。
　なお、第２噴出口１２ｄから噴出され第１ノズル１１の先端面１１ｃの全面を覆う安定したシールドガスＳＧの層を形成したシールドガスＳＧは、第１噴出口１２ｃから第１、第２ワークへ向けて噴出されるシールドガスＳＧとプラズマガスＰＧとの間の旋回流となる。 Therefore, in the present embodiment, the shield gas SG is ejected in the inner diameter direction from the second ejection port 12d that is opened in the whole circumference inward of the second nozzle 12. The second ejection port 1d ejects the shield gas SG so as to be a gas flow parallel to the tip surface 11c of the first nozzle 11, and the second ejection port 12d is entirely on the circumference of the second nozzle 12. Therefore, a stable shield gas SG layer that covers the entire front end surface 11c of the first nozzle 11 is formed.
FIG. 4 also shows the formation state of the shield gas SG layer. As shown in FIG. 4, the fume HG generated and convected inside the shield gas SG ejected from the first ejection port 12c toward the first and second workpieces is ejected from the second ejection port 12d in the inner diameter direction. The shield gas SG layer is prevented from adhering to the tip surface 11 c of the first nozzle 11.
Therefore, it can suppress that the fume HG adheres to the front end surface 11c of the 1st nozzle 11, and the fume HG and the metal of the front end surface 11c of the 1st nozzle 11 combine, and an alloying layer is formed. Therefore, the first nozzle 11 is not easily consumed, the welding quality can be stabilized, and the formation of the alloyed layer is suppressed, so that a decrease in durability of the first nozzle 11 can be suppressed.
The shield gas SG, which is ejected from the second ejection port 12d and forms a stable shield gas SG layer covering the entire front end surface 11c of the first nozzle 11, is transferred from the first ejection port 12c to the first and second workpieces. It becomes a swirl flow between the shield gas SG and the plasma gas PG ejected toward the direction.
　以上の実施形態によれば以下の効果を奏する。
　（５）本実施形態によると、シールドガスＳＧが、第２噴出口１２ｄから内径方向に第１ノズル１１の先端面１１ｃに平行に噴出し、シールドガスＳＧの層を第１ノズル１１の先端面１１ｃの前面に形成する。
　これにより、第１噴出口１２ｃからプラズマガスＰＧを囲むように第１、第２ワークへ向けて円環状に噴出するシールドガスＳＧの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームＨＧが、第２噴出口１２ｄから噴出されるシールドガスＳＧの層によって第１ノズル１１の先端面１１ｃに付着することが防止される。よって、ヒュームＨＧが第１ノズル１１の先端面１１ｃに付着してヒュームＨＧと第１ノズル１１の先端面１１ｃの金属とが化合して合金化層が形成されることを抑制できる。
　また、第１噴出口１２ｃよりも内側に第２噴出口１２ｄが位置し、第１噴出口１２ｃ及び第２噴出口１２ｄのそれぞれから噴出されるシールドガスＳＧ同士が干渉することはない。
　したがって、第１ノズル１１が消耗し難くなり溶接品質を安定化できると共に、合金化層の形成が抑制されて第１ノズル１１の耐久性低下を抑制できる。
　また、第１の実施形態のように第３ノズル１３といった他の部品を設けないので、プラズマトーチ１ａの小型化を図れる。
　また、第１噴出口１２ｃ及び第２噴出口１２ｄから同じシールドガスを噴出させるので、多種類のガスを用意する必要が無く、低コスト化を図れる。 According to the above embodiment, there exist the following effects.
(5) According to the present embodiment, the shield gas SG is ejected from the second ejection port 12d in the inner diameter direction in parallel to the tip surface 11c of the first nozzle 11, and the layer of the shield gas SG is applied to the tip surface of the first nozzle 11. 11c is formed on the front surface.
As a result, galvanization occurs due to evaporation of the zinc plating at a high temperature inside the shield gas SG that is ejected in an annular shape toward the first and second workpieces so as to surround the plasma gas PG from the first ejection port 12c. The fume HG is prevented from adhering to the tip surface 11c of the first nozzle 11 by the layer of the shield gas SG ejected from the second ejection port 12d. Therefore, it can suppress that the fume HG adheres to the front end surface 11c of the 1st nozzle 11, and the fume HG and the metal of the front end surface 11c of the 1st nozzle 11 combine, and an alloying layer is formed.
Moreover, the 2nd jet nozzle 12d is located inside the 1st jet nozzle 12c, and shield gas SG ejected from each of the 1st jet nozzle 12c and the 2nd jet nozzle 12d does not interfere.
Therefore, the first nozzle 11 is not easily consumed, the welding quality can be stabilized, and the formation of the alloyed layer is suppressed, so that a decrease in durability of the first nozzle 11 can be suppressed.
Further, since no other parts such as the third nozzle 13 are provided as in the first embodiment, the plasma torch 1a can be downsized.
Further, since the same shielding gas is ejected from the first ejection port 12c and the second ejection port 12d, it is not necessary to prepare many kinds of gases, and the cost can be reduced.
　なお、上記第１、第２の実施形態のプラズマアーク溶接方法は、総じて、円環状に噴出されるシールドガスの内側において第１ノズルといったアーク電極の先端面に向けてシールドガス等の不活性ガスを噴出し、ワーク表面から発生するヒュームをアーク電極の先端面に付着させないことを特徴とするアーク溶接方法の発明として捉えることができる。
　（６）この発明によると、不活性ガスが、ワーク方向に向けて円環状に噴出されるシールドガスの内側においてアーク電極の先端面に向けて噴出され、不活性ガスの層が形成される。これにより、シールドガスの内側において高温で亜鉛めっきが蒸発することにより発生して対流するヒュームが、不活性ガスの層によってアーク電極の先端面に付着することが防止される。よって、ヒュームがアーク電極の先端面に付着してヒュームとアーク電極の先端面の金属とが化合して合金化層が形成されることを抑制できる。また、不活性ガスが、ワーク方向に向けて円環状に噴出されるシールドガスの内側においてアーク電極の先端面に向けて噴出されるので、不活性ガスがシールドガスに干渉することはない。したがって、アーク電極が消耗し難くなり溶接品質を安定化できると共に、合金化層の形成が抑制されてノズルの耐久性低下を抑制できる。 The plasma arc welding methods of the first and second embodiments generally have an inert gas such as a shielding gas toward the tip surface of the arc electrode such as the first nozzle inside the shielding gas ejected in an annular shape. Can be grasped as an invention of an arc welding method characterized in that fumes generated from the work surface are not adhered to the tip surface of the arc electrode.
(6) According to the present invention, the inert gas is ejected toward the tip surface of the arc electrode inside the shield gas that is ejected in an annular shape toward the workpiece, and an inert gas layer is formed. This prevents fume that is generated by the galvanization of the zinc gas from evaporating at a high temperature inside the shield gas from adhering to the tip surface of the arc electrode by the inert gas layer. Therefore, it can suppress that a fume adheres to the front end surface of an arc electrode, a fume and the metal of the front end surface of an arc electrode combine, and an alloying layer is formed. Further, since the inert gas is ejected toward the tip surface of the arc electrode inside the shield gas that is ejected in an annular shape toward the workpiece, the inert gas does not interfere with the shield gas. Therefore, the arc electrode is hardly consumed and the welding quality can be stabilized, and the formation of the alloyed layer can be suppressed to suppress the deterioration of the durability of the nozzle.
　なお、本発明は上記実施形態に限定されず、本発明の目的を達成できる範囲で変形、改良等を行っても、本発明の範囲に包含される。
　例えば、第１の実施形態における第３ノズル１３の本数は、少なくとも１本以上あればよく、好ましくは第１ノズル１１の先端面１１ｃの全面に不活性ガスＦＧの層を形成できるように４本以上あるとよい。
　第１の実施形態における第３ノズル１３から噴出される不活性ガスＦＧは、シールドガスＳＧと同じものでもよいし、異なるものでもよい。
　また、第２の実施形態における第２ノズル１２の第１噴出口１２ｃの形態は、第１ノズル１１の先端面１１ｃの全面にシールドガスＳＧの層を形成できれば複数の開口等でもよくその形状等は限定されない。 Note that the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the scope of the present invention.
For example, the number of the third nozzles 13 in the first embodiment may be at least one, and preferably four such that an inert gas FG layer can be formed on the entire front end surface 11 c of the first nozzle 11. It is good to have more.
The inert gas FG ejected from the third nozzle 13 in the first embodiment may be the same as or different from the shield gas SG.
Moreover, the form of the 1st jet nozzle 12c of the 2nd nozzle 12 in 2nd Embodiment may be a some opening etc., if the layer of shield gas SG can be formed in the whole surface of the front end surface 11c of the 1st nozzle 11, The shape etc. Is not limited.
　１…プラズマトーチ
　１０…電極
　１１…第１ノズル（アーク電極）
　１１ａ…中心孔
　１１ｂ…噴出口
　１１ｃ…先端面
　１１ｄ…先端部
　１２…第２ノズル
　１２ａ…中心孔
　１２ｂ…噴出口
　１２ｃ…第１噴出口
　１２ｄ…第２噴出口
　１２ｅ…カバー部
　１３…第３ノズル
　１００…プラズマトーチ
　１１１…第１ノズル
　１１１ｃ…先端面 DESCRIPTION OF SYMBOLS 1 ... Plasma torch 10 ... Electrode 11 ... 1st nozzle (arc electrode)
11a ... center hole 11b ... outlet 11c ... tip surface 11d ... tip 12 ... second nozzle 12a ... center hole 12b ... outlet 12c ... first outlet 12d ... second outlet 12e ... cover part 13 ... third nozzle 100 ... plasma torch 111 ... first nozzle 111c ... tip surface

Claims (6)

  1. 　アーク溶接方法であって、
    　円環状に噴出されるシールドガスの内側においてアーク電極の先端面に向けて不活性ガスを噴出し、不活性ガスの層を形成することを特徴とするアーク溶接方法。     Arc welding method,
    An arc welding method characterized in that an inert gas is ejected toward a tip surface of an arc electrode inside a shield gas ejected in an annular shape to form an inert gas layer.
  2. 　プラズマアーク溶接に用いられるプラズマトーチであって、
    　棒状の電極と、
    　当該電極の周囲に設けられ、プラズマガスを噴出する円筒形状の第１ノズルと、
    　当該第１ノズルの周囲に設けられ、プラズマガスを囲むようにシールドガスを円環状に噴出する円筒形状の第２ノズルと、
    　円環状に噴出されるシールドガスの内側において前記第１ノズルの先端面に向けて不活性ガスを噴出する第３ノズルと、を備えることを特徴とするプラズマトーチ。     A plasma torch used for plasma arc welding,
    A rod-shaped electrode;
    A cylindrical first nozzle that is provided around the electrode and ejects plasma gas;
    A cylindrical second nozzle that is provided around the first nozzle and that jets the shielding gas in an annular shape so as to surround the plasma gas;
    A plasma torch comprising: a third nozzle that ejects an inert gas toward a tip surface of the first nozzle inside a shield gas ejected in an annular shape.
  3. 　前記第３ノズルから噴出される不活性ガスとして、前記シールドガスと同じガスを用いることを特徴とする請求項２に記載のプラズマトーチ。 The plasma torch according to claim 2, wherein the same gas as the shield gas is used as the inert gas ejected from the third nozzle.
  4. 　前記第３ノズルは、不活性ガスを前記第１ノズルの先端面に平行なガス流となるように噴出することを特徴とする請求項２又は３に記載のプラズマトーチ。 The plasma torch according to claim 2 or 3, wherein the third nozzle ejects an inert gas so as to form a gas flow parallel to a tip surface of the first nozzle.
  5. 　前記第３ノズルは、前記第２ノズルの円周方向から円環状に噴出されるシールドガスの内側に、円周方向で均等に離れて少なくとも４本以上配置されることを特徴とする請求項２～４のいずれかに記載のプラズマトーチ。 The at least four or more of the third nozzles are arranged inside the shielding gas ejected in an annular shape from the circumferential direction of the second nozzle and are equally spaced in the circumferential direction. The plasma torch according to any one of 1 to 4.
  6. 　プラズマアーク溶接に用いられるプラズマトーチであって、
    　棒状の電極と、
    　当該電極の周囲に設けられ、プラズマガスを噴出する円筒形状の第１ノズルと、
    　当該第１ノズルの周囲に設けられ、プラズマガスを囲むようにシールドガスを軸線方向に円環状に噴出する第１噴出口と前記第１ノズルの先端面に向けてシールドガスを内径方向に噴出する第２噴出口とを有する第２ノズルと、を備えることを特徴とするプラズマトーチ。     A plasma torch used for plasma arc welding,
    A rod-shaped electrode;
    A cylindrical first nozzle that is provided around the electrode and ejects plasma gas;
    Provided around the first nozzle, a shield gas is jetted in an inner diameter direction toward a first jet port for jetting a shield gas in an annular shape in an axial direction so as to surround the plasma gas, and a tip surface of the first nozzle. A plasma torch comprising: a second nozzle having a second ejection port.
PCT/JP2013/050697 2012-01-18 2013-01-16 Arc welding method and plasma torch WO2013108797A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2013554314A JP5898238B2 (en) 2012-01-18 2013-01-16 Arc welding method and plasma torch

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012007744 2012-01-18
JP2012-007744 2012-01-18

Publications (1)

Publication Number Publication Date
WO2013108797A1 true WO2013108797A1 (en) 2013-07-25

Family

ID=48799222

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/050697 WO2013108797A1 (en) 2012-01-18 2013-01-16 Arc welding method and plasma torch

Country Status (2)

Country Link
JP (1) JP5898238B2 (en)
WO (1) WO2013108797A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016042595A1 (en) * 2014-09-16 2016-03-24 富士機械製造株式会社 Plasma gas irradiation device
WO2018037468A1 (en) 2016-08-22 2018-03-01 富士機械製造株式会社 Plasma irradiation device and plasma irradiation method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02504603A (en) * 1988-06-07 1990-12-27 ハイパーサーム，インコーポレイテッド Plasma arc torch and cutting method
JPH05234695A (en) * 1992-02-19 1993-09-10 Nippon Steel Weld Prod & Eng Co Ltd Untransferred plasma jet oscillation method and plasma jet device
JPH1043865A (en) * 1996-07-31 1998-02-17 Koike Sanso Kogyo Co Ltd Plasma torch
JPH1058147A (en) * 1996-08-14 1998-03-03 Sumitomo Metal Ind Ltd Torch for plasma arc welding
JP2004243374A (en) * 2003-02-14 2004-09-02 Nippon Steel Weld Prod & Eng Co Ltd Plasma torch
JP2009172644A (en) * 2008-01-25 2009-08-06 Nippon Steel & Sumikin Welding Co Ltd Plasma welding method for galvanized steel sheet

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060185773A1 (en) * 2005-02-22 2006-08-24 Canadian Oil Sands Limited Lightweight wear-resistant weld overlay

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02504603A (en) * 1988-06-07 1990-12-27 ハイパーサーム，インコーポレイテッド Plasma arc torch and cutting method
JPH05234695A (en) * 1992-02-19 1993-09-10 Nippon Steel Weld Prod & Eng Co Ltd Untransferred plasma jet oscillation method and plasma jet device
JPH1043865A (en) * 1996-07-31 1998-02-17 Koike Sanso Kogyo Co Ltd Plasma torch
JPH1058147A (en) * 1996-08-14 1998-03-03 Sumitomo Metal Ind Ltd Torch for plasma arc welding
JP2004243374A (en) * 2003-02-14 2004-09-02 Nippon Steel Weld Prod & Eng Co Ltd Plasma torch
JP2009172644A (en) * 2008-01-25 2009-08-06 Nippon Steel & Sumikin Welding Co Ltd Plasma welding method for galvanized steel sheet

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016042595A1 (en) * 2014-09-16 2016-03-24 富士機械製造株式会社 Plasma gas irradiation device
KR20170056524A (en) * 2014-09-16 2017-05-23 후지 기카이 세이조 가부시키가이샤 Plasma gas irradiation device
JPWO2016042595A1 (en) * 2014-09-16 2017-07-13 富士機械製造株式会社 Plasma gas irradiation device
US9960017B2 (en) 2014-09-16 2018-05-01 Fuji Machine Mfg. Co., Ltd. Plasma gas jetting device
KR102105235B1 (en) * 2014-09-16 2020-04-27 가부시키가이샤 후지 Plasma gas irradiation device
WO2018037468A1 (en) 2016-08-22 2018-03-01 富士機械製造株式会社 Plasma irradiation device and plasma irradiation method

Also Published As

Publication number Publication date
JPWO2013108797A1 (en) 2015-05-11
JP5898238B2 (en) 2016-04-06

Similar Documents

Publication Publication Date Title
JP5364517B2 (en) Plasma torch and plasma arc welding method
US7737383B2 (en) Contoured shield orifice for a plasma arc torch
US20090107958A1 (en) Torch and Contact Tip for Gas Metal Arc Welding
US7935909B2 (en) Hybrid shield device for a plasma arc torch
US9126288B2 (en) Laser cutting method, laser cutting nozzle, and laser cutting device
WO2006122256B1 (en) Generating discrete gas jets in plasma arc torch applications
EP2941320B1 (en) Device for thermal coating of a surface
JP5898238B2 (en) Arc welding method and plasma torch
JP2016016430A (en) Welding equipment with double nozzle
KR101939850B1 (en) A Torch Structure for MIG Welding Apparatus
CN104289799A (en) Narrow gap welding current contact nozzle with aluminum oxide insulating coating
CN107848059A (en) Gas-shielded arc welding method
US20090057277A1 (en) Drag tip for a plasma cutting torch
US20160045972A1 (en) Method for manufacturing welded article, welding method, and welding device
WO2018159038A1 (en) Arc welding method for hot-dip galvanized steel sheet, and method for manufacturing welded member
JP5078143B2 (en) Plasma welding method for galvanized steel sheet
JP2017520409A (en) Application of plasma cutting torch assembly and its wear parts
JP2013052395A (en) Arc welding torch
JP2016044320A (en) Plasma spray coating apparatus
JPH1043865A (en) Plasma torch
JP7260451B2 (en) Insert tips, insert caps, plasma welding torches and plasma welding equipment
JP2018126745A (en) Tip structure of arc welder
WO2017221470A1 (en) Arc welding method for hot-dip galvanized steel sheet and method for manufacturing welded member
CN110369842A (en) Embedded tip, the powder of plasma arc powder surfacing spray guiding piece and plasma arc powder surfacing welding gun
US20180036837A1 (en) Welding device, welding method, and turbine blade

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13738712

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2013554314

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13738712

Country of ref document: EP

Kind code of ref document: A1