JP2010284666A - Arc welding torch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an arc welding torch capable of stabilizing a center position of a shaft hole of a tip and maintaining a stable state without making a pointed end of a welding wire unsteady even when the welding wire having bending tendency is supplied and urging force is added due to the bending tendency of the welding wire. <P>SOLUTION: The tip 3 has a flange 32 at a center, an upper part is passed through a first shaft hole 21 of a torch body 2, and a coil spring 7 is fitted to the outer circumference of the upper part. The tip is urged to a lower part with the coil spring 7. A wire guide 6 has a third shaft hole 6a to allow the welding wire W to pass through at a pointed end. The tip 3 allows a pointed end to abut on the third shaft hole 6a, and is supported while a gap is arranged between the tip 3 and the inner circumferential surface of the wire guide 6, and heat from the wire guide 6 is hardly transmitted to the tip 3. Shield gas cools the tip 3 in the cylinder of the wire guide 6. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an arc welding torch used for continuously supplying a welding wire for arc welding.

  In arc welding, a tip is coaxially attached to the tip of the torch body, a welding wire that is inserted through the tip hole of the tip and protrudes from the tip of the torch approaches the work piece, and carbon dioxide gas, argon gas, helium gas, etc. An anti-oxidation gas for welding (hereinafter referred to as “shield gas”) is blown from the tip of the torch, the arc generated between the work piece and the welding wire is covered with the shield gas, and air in the atmosphere flows into the weld. The welding object and the welding wire are melted by arc to form a weld bead and welded.

  For example, in a welding torch for gas-encapsulated arc welding described in Japanese Patent Application Laid-Open No. 2007-54872, a small-diameter passage having a small diameter and a shield gas ejection hole is provided in a hollow region where a torch body and a tip are joined and formed in communication. Thus, there is described a configuration in which when the shield gas passes through a small-diameter passage having a small diameter, the flow is restricted and the flow rate of the shield gas is reduced.

JP 2007-54872 A

  In this type of arc welding torch, a tip for inserting a welding wire into a shaft hole is attached to the tip of the torch body at the root portion, and a welding nozzle is attached to the torch body so as to contain the tip. A space as a shield gas flow path is provided between the chips, and the tip of the chip protrudes from the torch body to become a free end. Further, since the welding wire inserted through the shaft hole of the tip is melted and consumed by the arc, it is wound around a reel (not shown) and supplied in a fixed amount from the reel. For this reason, there is a problem that the tip end portion of the tip fluctuates due to the bending flaw of the welding wire, the tip of the welding wire comes off the target position during welding, and the bead meanders.

  The present invention solves the above-mentioned problems, and a tip is coaxially attached to the tip of the torch body, and a welding wire that is inserted through the shaft hole of the tip and protrudes from the tip of the torch is continuously supplied for arc welding. In the arc welding torch used for welding, even if a welding wire wound around a reel and having a bending flaw is supplied and the tip is biased by the bending flaw caused by the welding wire, the center position of the shaft hole of the tip This provides a torch for arc welding that is stable and maintains a stable state without wobbling the tip of the welding wire.

  In order to solve the above-mentioned problem, the invention according to claim 1 has a first shaft hole through which the shield gas and the welding wire pass, and communicates with the first shaft hole in the wall portion near the tip so that the shield gas flows out. A torch body having a gas discharge port, a tip provided with a flange in the center and having a second shaft hole through which the welding wire is inserted, and an upper portion inserted through the first shaft hole of the torch body, A coil spring that is fitted on the outer periphery of the upper part of the tip and is disposed between the tip of the torch body and the flange, and biases the tip downward, and the upper part is attached to the outer periphery near the tip of the torch body. A nozzle body that encloses the tip of the torch body and the tip, a nozzle cover that is coaxially attached to the nozzle body, and that has an opening at the tip, and the welding machine at the tip. Has a third shaft hole through which the nozzle is inserted, protrudes a predetermined length from the opening at the tip of the nozzle cover, is coaxially mounted in the cylinder of the nozzle cover, and abuts the tip of the tip against the third shaft hole The chip is supported by providing a gap between the chip and the inner peripheral surface, and the third shaft hole is opened and closed by the vertical movement of the chip so that a shield gas can pass between the chip and the chip. An arc welding torch comprising a wire guide.

  The arc welding torch of the present invention is inserted into the shaft hole of the nozzle body so that it can move up and down even if it is biased by a bending wire from the welding wire that passes through the shaft hole of the tip. The center position of the shaft hole is stabilized, and the tip of the welding wire is not fluctuated and the stable state is maintained.

It is a longitudinal cross-sectional view which shows Example 1 of this invention. It is the schematic which looked at the wire guide in FIG. 1 from the upper part.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.

  FIG. 1 is a longitudinal sectional view showing Embodiment 1 of the present invention, and FIG. 2 is a schematic view of the wire guide in FIG. 1 as viewed from above.

  In FIG. 1, an arc welding torch 1 includes a torch body 2, a tip 3 that is coaxially mounted on the tip of the torch body 2, and an outer periphery near the tip of the torch body 2. A nozzle body 4 including the chip 3, a nozzle cover 5 having one end attached to the tip of the nozzle body 4, and a wire guide 6 mounted coaxially within the nozzle cover 5 and including the chip 3. It is a configuration.

  In the vicinity of the tip of the torch body 2, a cylindrical insulating member is coaxially fixed to the outside, and a male screw 2a is formed on the outer periphery of the insulating member. And the front-end | tip part 2b is formed by having a level | step difference from the external thread 2a, and reducing a diameter. The torch body 2 is provided with a first shaft hole 21 through which the shield gas passes along the length direction, and communicates with the first shaft hole 21 at an equal angle around the axis of the tip end portion 2b so that the shield gas flows out to the outside. A plurality of (for example, four) gas discharge ports 22 are opened, and a welding wire W is supplied through the first shaft hole 21.

  The chip 3 is made of chrome copper and has a second shaft hole 31 penetrating the center. A flange 32 is formed on the outer periphery near the center in the axial direction. The tip 3 is formed such that the diameter of the tip portion 34 from the upper end to the flange 32 is smaller than the diameter of the upper portion 33 from the upper end to the flange 32, and the tip vicinity 34a is formed in a tapered conical shape. In the chip 3, a part of the upper portion 33 is inserted into the first shaft hole 21 of the torch body 2, and the coil spring 7 is fitted on the outer periphery of the upper portion 33.

  The upper end 7a of the coil spring 7 is in contact with the front end surface 2c of the torch body 2, and the front end 7b is in contact with the flange 32 to urge the chip 3 downward.

  In the tip 3, the upper portion 33 is inserted into the first shaft hole 21 of the torch body 2, the second shaft hole 31 communicates with the first shaft hole 21, and the welding wire W supplied from the first shaft hole 21 is the first. The biaxial hole 31 is inserted.

  The tip 3 has a structure that is biased downward by the coil spring 7. When the tip 3 is biased up and down by the welding wire W, the tip 3 can be inserted through the first shaft hole 21 and moved in the axial direction.

  The nozzle body 4 is a cylindrical body, and female threads 4a and 4b are formed in the upper end and the tip end cylinder. The nozzle body 4 is attached to the torch body 2 with the female screw 4a screwed to the male screw 2a in the vicinity of the tip of the torch body 2. The nozzle body 4 includes the tip 2b of the torch body 2 and the tip 3 and is contained in the cylinder. A first gas passage 41 through which the shield gas supplied from the gas discharge port 22 passes is formed.

  The nozzle cover 5 is a cylindrical body, and in the upper part, a male screw 5a is formed on the outer periphery, a cylindrical hole 5b is formed inside, and a small-diameter opening 5c is provided at the tip of the hole 5b. A male screw 5 a is screwed into a female screw 4 b at the tip of the nozzle body 4 and attached to the tip of the nozzle body 4.

  The wire guide 6 is made of heat-resistant and wear-resistant ceramics, the upper part is formed in a thick square flange 61, and the tip part 62 is a cylindrical tapered tube with a center in the axial direction. A third shaft hole 6a is provided so as to penetrate therethrough.

  As shown in FIG. 2, the four corners of the square flange 61 are chamfered in a circular arc cross section within a predetermined angle range, and the wire guide 6 is fitted in the cylindrical hole 5 b of the nozzle cover 5. Although it is movable, it is attached so that the chamfered outer peripheral surfaces of the four corners of the flange 61 are in sliding contact with the inner peripheral surface of the cylindrical hole 5 b and maintain a coaxial position with respect to the nozzle cover 5. In addition, four second gas passages 6b having a D-shaped cross section are formed between the circular hole 5b of the nozzle cover 5 and the outer peripheral portion of the flange 61. In the lower part of the second gas passage 6b, an empty portion 63 for storing the shield gas that has passed through the second gas passage 6b is provided.

  The wire guide 6 is provided with a plurality of (for example, six) gas jets 64 at the distal end portion 62 for allowing the shield gas to flow out by communicating with the gas passage 41 at an equal angle around the axis of the portion adjacent to the flange 61. Yes. In a state where the wire guide 6 is attached to the nozzle cover 5, the tip end portion 62 partially protrudes from the opening 5 c of the nozzle cover 5 and is arranged coaxially, and the opening 5 c is an annular gas outlet.

  The wire guide 6 has a third tip in which the tip of the tip 3 comes into contact with the inner tip of the third shaft hole 6a and is biased downward in the cylinder, and the shield gas passes between the tip 3 and the inner peripheral surface 6d. A gas passage 65 is formed. The shield gas that has passed through the third gas passage 65 flows out of the gas jet port 64, is supplied to the empty portion 63, and merges with the shield gas that has passed through the second gas passage 6b. The shield gas supplied to the empty portion 63 is jetted to the outside from the narrow annular opening 5 c at the tip of the nozzle cover 5.

  Since the wire guide 6 has the tip 62 projecting from the opening 5c of the nozzle cover 5 by a sufficient length, most of the spatter scattered on the tip of the nozzle body 4 can be received by the tip surface 6c.

  Next, the operation during welding of the arc welding torch 1 will be described. At the time of welding, the welding wire W is supplied to the torch body 2 from a reel (not shown), the welding wire W projected from the wire guide 6 at the tip of the arc welding torch 1 is brought close to the workpiece 100, and the annular opening 5c. The welding object 100 and the welding wire W are melted by arc while blowing out the shielding gas to form a weld bead 101 and welding.

  At the time of welding, the arc welding torch 1 is biased so that the tip 3 is swung outwardly by the bending of the welding wire W wound around the reel. At this time, the tip 3 is inserted into the first shaft hole 21 of the torch body 2 and can move in the axial direction, and the center position of the second shaft hole 31 of the tip 3 is moved by the wire guide 6 described later. It is stable and maintains the stable state without the tip of the welding wire W wobbling.

  Further, the wire guide 6 has a configuration in which the tip 3a of the tip 3 contained in the cylinder is in contact with the inner tip 6e of the third shaft hole 6a and pressed downward, so that the wire guide 6 was overheated during welding. The heat from the wire guide 6 is not easily transmitted to the chip 3, and the shield gas passes through the third gas passage 65 between the inner peripheral surface 6 d and the chip 3 in the cylinder to cool the chip 3. Thermal expansion is kept small.

  Still, since the heat from the wire guide 6 overheated during welding is transmitted to the tip 3, the tip 3 of the ceramic wire guide 6 and the tip 3 made of metal are different in the nozzle body 4 from the difference in thermal expansion coefficient. Expands. In this case, since the expanded portion of the tip 3 moves in the axial direction through the first shaft hole 21, the ceramic wire guide 6 is not excessively pressed by the thermal expansion of the tip 3.

  Further, during welding, the wire guide 6 is moved up and down by changing the state of the pressure pressed downward by the tip 3a of the tip 3 contained in the cylinder coming into contact with the inner tip 6e of the third shaft hole 6a. Vibration may occur. When the wire guide 6 vibrates up and down, the chamfered outer peripheral surfaces of the four corners of the flange 61 are in sliding contact with the inner peripheral surface of the cylindrical hole 5 b of the nozzle cover 5. Since the center position of the hole 5b is maintained, the center position of the second shaft hole 31 of the chip 3 is stabilized.

  Thus, even if the tip 3 is urged by the welding wire W or expands by the heat of arc welding, the tip 3 can be moved in the axial direction through the first shaft hole 21, and the wire guide 6 can also be moved. Since the center position is maintained in the hole 5 b of the nozzle cover 5, the center position of the second shaft hole 31 of the tip 3 is stabilized, and the tip of the welding wire W fed from the wire guide 6 is not fluctuated and maintained in a stable state. To do.

  Further, since the arc welding torch of the present invention is provided with the wire guide 6 protruding coaxially from the opening 5c of the nozzle cover 5, the spatter scattered at the tip of the wire guide 6 has rushed to the annular opening 5c. However, since it is shielded by the front end surface 6c of the wire guide 6 on the near side and hardly adheres to the opening 5c, the annular opening 5c is not clogged by sputtering, and the amount of shield gas injection is not limited, and the welding operation is being performed. In addition, it is possible to avoid a situation where the welding work such as replacement of the nozzle or removal of the spatter in the spatter guard is interrupted, and an efficient welding work can be performed.

DESCRIPTION OF SYMBOLS 1 Arc welding torch 2 Torch main body 2a, 5a Male screw 2b, 34, 62 Tip part 2c Tip surface 3 Tip 3a Tip 4 Nozzle body 4a, 4b Female screw 5 Nozzle cover 5b Hole 5c Opening 6 Wire guide 6a 3rd shaft hole 6b Second gas passage 6c Front end surface 7 Coil spring 7a Upper end 7b Front end 21 First shaft hole 22 Gas discharge port 31 Second shaft hole 32 Flange 33 Upper portion 34a Near the front end 41 First gas passage 61 Square flange 63 Empty portion 64 Gas jet Outlet 65 Third gas passage 100 Work piece 101 Weld bead W Welding wire

Claims (1)

A torch body having a first shaft hole through which a shield gas and a welding wire pass and having a gas discharge port through which the shield gas flows out in communication with the first shaft hole in a wall near the tip;
A tip provided with a flange in the center, having a second shaft hole through which the welding wire is inserted, and an upper portion being inserted into the first shaft hole of the torch body,
A coil spring that is fitted on the outer periphery of the upper part of the chip and disposed between the tip of the torch body and the flange, and biases the chip downward;
An upper part is attached to the outer periphery in the vicinity of the tip of the torch body, and a nozzle body that contains the tip and the tip in the vicinity of the tip of the torch body;
A nozzle cover that is coaxially attached to the nozzle body and has an opening at the tip;
A third axial hole through which the welding wire is inserted; a predetermined length that protrudes from an opening at the distal end of the nozzle cover; and is coaxially mounted in the cylinder of the nozzle cover. The tip is brought into contact with and supported by a gap between the tip and the inner peripheral surface, and the third shaft hole is opened and closed by the vertical movement of the tip so that a shield gas can pass between the tip and the tip. A wire guide formed on
An arc welding torch characterized by comprising:

Images