Weld torch

Abstract

To facilitate the handling of an electrode rod arranged inside an inner nozzle.SOLUTION: A weld torch 1 comprises an electrode 20, an inner nozzle 50, an outer nozzle 70, and an elastic member 100. The electrode 20 extends along a first direction and has a tip 21 on one side of the first direction. The inner nozzle 50 is arranged outside the electrode rod 20 so that a first gas passage F1 to penetrate a shield gas is formed with the tip 21 of the electrode rod 20. The outer nozzle 70 is arranged outside the inner nozzle 50 so that a second gas passage F2 to penetrate a shield gas is formed with the inner nozzle 50. The elastic member 100 energizes the inner nozzle 50 toward one side of the first direction. This torch is constituted so that the tip 21 of the electrode rod 20 can project from the inner nozzle 50 by moving the inner nozzle 50 to the other side of the first direction against the energization force of the elastic member 100.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a welding torch.

Background Art

[0002] As a prior art document disclosing the configuration of a welding torch, there is Japanese Patent Application Laid-Open No. 2023-42306 (Patent Document 1). The welding torch described in Patent Document 1 includes a non-consumable electrode, an inner nozzle, and an outer nozzle. The inner nozzle is disposed radially outside the non-consumable electrode. The outer nozzle is disposed radially outside the inner nozzle. A first gas flow path is formed between the non-consumable electrode and the inner nozzle. A second gas flow path is formed between the inner nozzle and the outer nozzle. The welding torch performs plasma welding when the inner nozzle is attached, and performs TIG (Tungsten Inert Gas) welding when the inner nozzle is removed.

[0003] As a prior art document disclosing the mounting structure of a nozzle for arc spot welding, there is Japanese Patent Application Laid-Open No. 5-57451 (Patent Document 2). In the mounting structure of the nozzle for arc spot welding described in Patent Document 2, the nozzle for arc spot welding is slidably mounted in the axial direction of the nozzle via a spring at the tip of the welding torch.

[0004] As a prior art document disclosing the configuration of a torch for gas shielded arc welding, there is Japanese Patent Application Laid-Open No. 9-248675 (Patent Document 3). The torch for gas shielded arc welding described in Patent Document 3 includes a nozzle and an electrode rod. The nozzle ejects a shielding gas. The electrode rod is disposed while being inserted into the nozzle. When the ejection port side of the nozzle is brought into contact with the base metal groove, at least the tip side of the nozzle is displaceable left and right with respect to the axis while the electrode rod is fixed in position on the torch axis.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a welding torch, an inner nozzle disposed between an electrode rod and an outer nozzle covers the electrode rod up to the tip side of the electrode rod while keeping a smaller gap with the electrode rod compared to the case of normal TIG welding in order to increase the flow rate of the shielding gas. For this reason, it is difficult to grip the electrode rod disposed inside the inner nozzle when replacing the electrode rod, and it is difficult to handle the electrode rod.

[0007] The present invention has been made to solve the above problems, and an object thereof is to provide a welding torch capable of facilitating handling of an electrode rod disposed inside an inner nozzle.

Means for Solving the Problems

[0008] A welding torch according to the present invention includes an electrode rod, an inner nozzle, an outer nozzle, and an elastic member. The electrode rod extends along a first direction and has a tip portion on one side in the first direction. The inner nozzle is disposed outside the electrode rod such that a first gas flow path for allowing a shielding gas to pass between the tip portion of the electrode rod is formed. The outer nozzle is disposed outside the inner nozzle such that a second gas flow path for allowing a shielding gas to pass between the inner nozzle is formed. The elastic member biases the inner nozzle toward one side in the first direction. The tip portion of the electrode rod is configured to be protrudable from the inner nozzle by moving the inner nozzle in the other direction in the first direction against the biasing force of the elastic member.

[0009] In this case, by moving the inner nozzle in the other direction of the first direction against the biasing force of the elastic member, and protruding the electrode bar from the inner nozzle, when removing the electrode bar from the welding torch when replacing the electrode bar, it is possible to easily grip the electrode bar. Therefore, it is possible to facilitate the handling of the electrode bar disposed inside the inner nozzle.

[0010] The welding torch according to one embodiment of the present invention further includes a centering member. The centering member is provided to coaxially arrange the electrode bar and the inner nozzle. The elastic member biases the inner nozzle via the centering member.

[0011] Thereby, while coaxially arranging the inner nozzle and the electrode bar by the centering member, it is possible to move the inner nozzle in the other direction of the first direction against the biasing force of the elastic member. Therefore, while making the flow of the shielding gas inside the inner nozzle uniform in the circumferential direction of the first direction, it is possible to facilitate the handling of the electrode bar disposed inside the inner nozzle.

Advantages of the Invention

[0012] According to the present invention, it is possible to facilitate the handling of the electrode bar disposed inside the inner nozzle.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] Hereinafter, a welding torch according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the embodiments, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[0015] In the drawings, the first direction in which the electrode rod extends is defined as the DR1 direction. In the first direction (DR1 direction), the side where the electrode rod protrudes from the inner nozzle is defined as one side, and the opposite side is defined as the other side. Also, in FIGS. 2 and 5, the elastic member is shown in a simplified manner.

[0016] First, the overall structure of the welding torch will be described. FIG. 1 is a front view showing the configuration of a welding torch according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view showing the configuration around one side of the electrode rod provided in the welding torch according to an embodiment of the present invention.

[0017] As will be described later, the welding torch 1 according to the present embodiment can perform welding (referred to as PJ-TIG (Plasma Jet Tungsten Inert Gas) welding) that can enhance the concentration of the arc and improve the productivity during welding by making the nozzle through which the shielding gas is jetted have a double structure.

[0018] As shown in FIGS. 1 and 2, the welding torch 1 according to the present embodiment includes a torch part 2 and a handle part 3.

[0019] The torch part 2 is a part for generating an arc and welding a workpiece (not shown). The torch part 2 extends in the first direction (DR1 direction).

[0020] The handle part 3 is a part that is gripped by an operator or a robot. The handle part 3 extends in a direction intersecting the DR1 direction from near the center of the torch part 2 in the DR1 direction.

[0021] The torch unit 2 according to this embodiment includes a torch body 10, a cap 15, an electrode rod 20, a collet 30, a collet body 40, an inner nozzle 50, a nut member 60, an outer nozzle 70, a gas lens collet 80, an elastic member 100, and a centering member 110.

[0022] The torch body 10 is a part connected to the handle portion 3. The torch body 10 includes a cover portion 11 and a conductive portion 12.

[0023] The cover portion 11 is made of an insulating resin member. The cover portion 11 protects the conductive portion 12. The conductive portion 12 is disposed inside the cover portion 11. The conductive portion 12 is in contact with the collet body 40 on the inner peripheral surface. The conductive portion 12 is connected to a water-cooling or air-cooling mechanism (not shown). The conductive portion 12 constitutes a part of the heat transfer path for cooling the electrode rod 20.

[0024] An electric cable (not shown) is disposed inside the cover portion 11. The electric cable is a power supply path for supplying power from a welding power source (not shown) to the electrode rod 20. Specifically, power is supplied from the welding apparatus to the electrode rod 20 via the electric cable, the conductive portion 12, the collet body 40, and the collet 30.

[0025] A gas hose 14 is disposed inside the cover portion 11. The gas hose 14 is a gas supply path for supplying shielding gas to one side of the electrode rod 20. After the shielding gas is supplied into the torch unit 2 from a gas cylinder (not shown) through the gas hose 14, it is supplied to one side of the electrode rod 20 through the gaps between the conductive portion 12, the collet body 40, and the collet 30. The shielding gas is, for example, argon gas. Note that the shielding gas is not limited to argon gas and may be other inert gases such as carbon dioxide gas or helium gas.

[0026] On the other side of the torch body 10, a cap 15 is arranged. The cap 15 is composed of an insulating resin member. The cap 15 prevents the other side of the electrode rod 20 from being exposed from the torch body 10. The cap 15 is screwed onto the torch body 10. The cap 15 is in contact with the other side of the collet 30. When the cap 15 is tightened onto the torch body 10, the collet 30 is pushed in one direction. As a result, the collet 30 comes into contact with the collet body 40 and the collet 30 is fixed.

[0027] On one side of the cover part 11, an adapter 16 is arranged. The adapter 16 is made of an insulating material. Inside the adapter 16, while forming a part of the flow path of the shielding gas, it protects the collet body 40.

[0028] The electrode rod 20 is the part where an arc is generated on one side when power is supplied during welding. The electrode rod 20 is composed of, for example, tungsten. Note that the electrode rod 20 is not limited to being composed of tungsten, and may be composed of a tungsten alloy or other high melting point materials.

[0029] The electrode rod 20 extends along the first direction (DR1 direction). The electrode rod 20 has a tip portion 21 on one side in the first direction (DR1 direction). The tip portion 21 is pointed. The tip portion 21 has a tip angle in the range of, for example, 45° or more and 60° or less. The arc is generated around the apex of the tip portion 21 of the electrode rod 20.

[0030] The collet 30 is housed inside the collet body 40. The collet 30 is in contact with a part of the electrode rod 20 and supports the electrode rod 20. In the present embodiment, the collet 30 supports the electrode rod 20 in contact with the supported region R1 of the electrode rod 20. The collet 30 is provided so as to be capable of supplying power by coming into contact with the collet body 40 on one side. The collet 30 constitutes a part of the heat transfer path for cooling the electrode rod 20.

[0031] The collet body 40 is a cylindrical member that supports a part of the outer periphery of the collet 30. The collet body 40 has a convex shape on the inner diameter side on one side. The collet body 40 contacts one side of the outer periphery of the collet 30 in the convex shape and supports the collet 30.

[0032] The collet body 40 is composed of a conductor. The collet body 40 is composed mainly of, for example, copper. The collet body 40 constitutes a part of the heat transfer path for cooling the electrode bar 20.

[0033] The inner nozzle 50 is provided on one side of the torch part 2. The inner nozzle 50 is composed of a metal material.

[0034] The inner nozzle 50 is disposed outside the electrode bar 20. The inner nozzle 50 is provided so as to cover the tip 21 of the electrode bar 20.

[0035] The inner nozzle 50 in the present embodiment extends in the first direction (DR1 direction) while leaving a gap with the electrode bar 20 in the circumferential direction of the first direction (DR1 direction). As a result, the inner nozzle 50 is disposed outside the electrode bar 20 so that a first gas flow path F1 for allowing the shielding gas to pass between the inner nozzle 50 and the tip 21 of the electrode bar 20 is formed.

[0036] The nut member 60 is provided to support the inner nozzle 50 in the first direction (DR1 direction). The nut member 60 supports the inner nozzle 50 in the first direction (DR1 direction) inside thereof. The nut member 60 is screwed with the collet body 40 on the other side in the first direction (DR1 direction). The nut member 60 is composed of a metal material.

[0037] The outer nozzle 70 is disposed outside the inner nozzle 50. The outer nozzle 70 is provided so that one end of the inner nozzle 50 and the tip 21 of the electrode bar 20 are exposed.

[0038] In the present embodiment, the outer nozzle 70 extends in the first direction (DR1 direction) while leaving a gap from the inner nozzle 50 in the circumferential direction of the first direction. As a result, the outer nozzle 70 is disposed outside the inner nozzle 50 so that a second gas flow path F2 for allowing the shielding gas to pass between the outer nozzle 70 and the inner nozzle 50 is formed.

[0039] The gas lens collet 80 is fixed to the outside in the radial direction of the collet body 40. The gas lens collet 80 is disposed so as to form a part of the second gas flow path F2 for allowing the shielding gas to pass. A plurality of through holes 81 for allowing the shielding gas to pass are provided in the gas lens collet 80 at intervals in the circumferential direction of the first direction.

[0040] On one side of the gas lens collet 80, a gas lens 82 for laminarizing the flow of the shielding gas is disposed between the gas lens collet 80 and the collet body 40.

[0041] The elastic member 100 and the centering member 110 are disposed between the collet body 40 and the inner nozzle 50 in the first direction (DR1 direction). Details of the elastic member 100 and the centering member 110 will be described later.

[0042] As described above, the welding torch 1 in the present embodiment includes the inner nozzle 50 and the outer nozzle 70. The shielding gas can be doubly ejected from the inner nozzle 50 and the outer nozzle 70.

[0043] As shown in FIG. 2, the cross-sectional area of the first gas flow path F1 is smaller than that of the second gas flow path F2. Generally, the smaller the cross-sectional area of the flow path of the fluid, the faster the flow velocity of the fluid. For this reason, the flow velocity of the shielding gas flowing through the first gas flow path F1 is faster than the flow velocity of the shielding gas flowing through the second gas flow path F2.

[0044] The first gas flow path F1 is closer to the electrode rod 20 than the second gas flow path F2. The high-speed shielding gas ejected from the first gas flow path F1 maintains the shape of the arc generated at the electrode rod 20 thin during welding, or removes the metal vapor (fume) generated from the workpiece during welding from around the electrode rod 20. Thereby, compared with normal TIG welding, the penetration of the workpiece can be increased, or the welding speed can be improved.

[0045] Next, the configurations of the elastic member 100 and the centering member 110 provided in the welding torch 1 will be described. FIG. 3 is a perspective view showing the configurations of the elastic member and the centering member according to an embodiment of the present invention. FIG. 4 is a cross-sectional view showing the configurations of the elastic member and the centering member according to an embodiment of the present invention.

[0046] As shown in FIGS. 2 to 4, the elastic member 100 is, for example, a spring. Specifically, the elastic member 100 in the present embodiment is a coil spring. The elastic member 100 is arranged in a state where it can expand and contract in the first direction (DR1 direction). The electrode rod 20 is inserted through the inner peripheral portion of the elastic member 100 which is a spring. Note that the elastic member 100 is not limited to a coil spring, and may be a leaf spring. Further, the elastic member 100 may be any member that can expand and contract in the first direction, and may be heat-resistant rubber or the like.

[0047] The biasing force of the elastic member 100 is appropriately set within a range where the elastic member 100 can be elastically deformed by the pressing of an operator or a robot and the inner nozzle 50 can be sufficiently pressed against the nut member 60 for positioning.

[0048] The elastic member 100 is arranged in the first direction (DR1 direction) at a position closer to the supported region R1 of the electrode rod 20 than the midpoint C1 between the supported region R1 of the electrode rod 20 and the tip 21 of the electrode rod 20. Note that the position where the elastic member 100 is arranged is not limited as long as it is a position that biases the inner nozzle 50 to one side.

[0049] The elastic member 100 is made of, for example, ceramic. Note that the elastic member 100 may be made of a metal such as steel. The elastic member 100 may be made of either ceramic or metal as long as it has heat resistance capable of withstanding the heat generated by the electrode rod 20 during welding.

[0050] The centering member 110 is mainly provided for coaxially arranging the electrode rod 20 and the inner nozzle 50.

[0051] The centering member 110 is made of, for example, ceramic. Note that the centering member 110 may be made of a metal such as copper. The centering member 110 may be made of either ceramic or metal as long as it has heat resistance capable of withstanding the heat generated by the electrode rod 20 during welding.

[0052] The centering member 110 has a first member 120 and a second member 130. The first member 120 and the second member 130 are arranged side by side in the first direction (DR1 direction).

[0053] The first member 120 is provided with a first through hole 121 having an axis center along the first direction (DR1 direction). The electrode rod 20 is slidably inserted into the first through hole 121. The first outer peripheral surface 122 of the first member 120 has a tapered shape in which the outer diameter gradually decreases toward one side.

[0054] The first member 120 has a function of coaxially arranging the electrode rod 20 and the inner nozzle 50. In the first member 120, the electrode rod 20 is slidably inserted into the first through hole 121, and the first outer peripheral surface 122 comes into contact with the inner nozzle 50, whereby the electrode rod 20 and the inner nozzle 50 are coaxially arranged.

[0055] The second member 130 is provided with a second through hole 131 having an axis center along the first direction (DR1 direction). The electrode rod 20 is slidably inserted into the second through hole 131. The second outer peripheral surface 132 of the second member 130 has a tapered shape in which the outer diameter gradually decreases toward the other side.

[0056] The second member 130 has a function of coaxially arranging the electrode rod 20 and the collet body 40. In the second member 130, the electrode rod 20 is slidably inserted into the second through hole 131, and the second outer peripheral surface 132 contacts the collet body 40, whereby the electrode rod 20 and the collet body 40 are coaxially arranged.

[0057] The centering member 110 has a tapered outer peripheral surface that is inclined in the first direction (DR1 direction), so that a biasing force can be applied in both the first direction (DR1 direction) and the direction orthogonal to the first direction (DR1 direction). Therefore, the component members can be coaxially arranged with a simple configuration.

[0058] The elastic member 100 is disposed between the first member 120 and the second member 130 of the centering member 110. The first member 120 and the second member 130 are formed with circumferential groove portions into which the elastic member 100 can be fitted. The elastic member 100 is fitted into the circumferential groove portion and fixed to the centering member 110.

[0059] The position of the collet body 40 is fixed in the torch unit 2. The second member 130 is disposed on one side of the collet body 40. The elastic member 100 is connected to the second member 130. Thereby, the elastic member 100 biases the inner nozzle 50 toward one in the first direction (DR1 direction). The elastic member 100 in the present embodiment biases the inner nozzle 50 via the first member 120 of the centering member 110.

[0060] When the inner nozzle 50 is pressed toward the other side in the first direction (DR1 direction), the first member 120 of the centering member 110 is pressed. Since the first member 120 is connected to the elastic member 100, the elastic member 100 contracts due to the pressing. When the elastic member 100 contracts, the first member 120 moves toward the other side in the first direction (DR1 direction). Together with the first member 120, the inner nozzle 50 also moves toward the other side in the first direction (DR1 direction). In this way, the inner nozzle 50 can be moved toward the other side in the first direction (DR1 direction) against the biasing force of the elastic member 100. Thereby, the tip portion 21 of the electrode rod 20 is configured to be able to protrude from the inner nozzle 50. In the present embodiment, by moving the inner nozzle 50 2 mm toward the other side in the first direction (DR1 direction), the tip portion 21 of the electrode rod 20 is configured to be able to protrude from the inner nozzle 50.

[0061] Note that the "protrusion" of the tip portion 21 of the electrode rod 20 in this specification means that, when viewed from the direction orthogonal to the first direction, the protruding length of the tip portion 21 of the electrode rod 20 from the inner nozzle 50 is longer in the state after moving the inner nozzle 50 toward the other side in the first direction than in the state before moving the inner nozzle 50 toward the other side in the first direction. Therefore, in the state before moving the inner nozzle 50 toward the other side in the first direction, the tip portion 21 of the electrode rod 20 does not have to protrude from the inner nozzle 50 when viewed from the direction orthogonal to the first direction.

[0062] Next, a procedure for replacing the electrode rod 20 from the welding torch 1 will be described. FIG. 5 is a partial cross-sectional view showing a state in which the electrode rod provided in the welding torch according to an embodiment of the present invention protrudes from the inner nozzle.

[0063] When the electrode rod 20 is consumed by welding, it is necessary to remove the electrode rod 20 from the welding torch 1 and attach a new electrode rod 20. As shown in FIGS. 1 and 5, when removing the electrode rod 20, first, loosen the cap 15 with respect to the torch body 10. As a result, the restraint of the collet 30 by the cap 15 is released. When the restraint of the collet 30 is released, the electrode rod 20 supported by the collet 30 becomes in a removable state (unclamped state). Grasp the tip 21 of the electrode rod 20 and remove the electrode rod 20 from the collet 30. Note that the operation of removing the electrode rod 20 may be performed by, for example, either an operator or a robot.

[0064] Here, the inner nozzle 50 covers the electrode rod 20 up to the tip side of the electrode rod 20 while keeping the gap with the electrode rod 20 smaller compared to the case of normal TIG welding in order to increase the flow rate of the shielding gas. Further, the tip 21 of the electrode rod 20 has a pointed shape. For this reason, it is difficult to grasp the tip 21 of the electrode rod 20 in order to remove the electrode rod 20, and it is difficult to handle the electrode rod 20.

[0065] In the welding torch 1 of the present embodiment, the inner nozzle 50 is moved in the other direction (direction A in FIG. 5) of the first direction against the biasing force of the elastic member 100. As a result, the tip 21 of the electrode rod 20 protrudes from the inner nozzle 50. Since the tip 21 of the electrode rod 20 becomes easier to grasp, the electrode rod 20 can be easily removed from the collet 30.

[0066] In the welding torch 1 according to an embodiment of the present invention, by moving the inner nozzle 50 in the other direction of the first direction (DR1 direction) against the biasing force of the elastic member 100, and protruding the electrode rod 20 from the inner nozzle 50, when replacing the electrode rod 20, it is possible to make it easier to grasp the electrode rod 20 when removing the electrode rod 20 from the welding torch 1. As a result, the handling of the electrode rod 20 disposed inside the inner nozzle 50 can be facilitated.

[0067] In the welding torch 1 according to an embodiment of the present invention, the elastic member 100 biases the inner nozzle 50 via the centering member 110, so that while the centering member 110 coaxializes the inner nozzle 50 and the electrode rod 20, the inner nozzle 50 can be moved to the other side in the first direction (DR1 direction) against the biasing force of the elastic member 100. As a result, while making the flow of the shielding gas inside the inner nozzle 50 uniform in the circumferential direction of the first direction, the handling of the electrode rod 20 disposed inside the inner nozzle 50 can be facilitated.

[0068] In the welding torch 1 according to an embodiment of the present invention, when replacing the electrode rod 20, compared with the case of replacing the electrode rod 20 after removing the inner nozzle 50, the electrode rod 20 can be easily replaced by protruding the electrode rod 20 from the inner nozzle 50 without the need for the operation of removing the inner nozzle 50, so that the efficiency of the replacement operation of the electrode rod 20 can be improved.

[0069] Note that the centering member 110 does not necessarily have to be provided. Further, the elastic member 100 may be configured to be built in the inner nozzle 50 or the collet body 40.

[0070] Note that the above-described embodiments disclosed this time are illustrative in all respects and do not serve as a basis for restrictive interpretation. Therefore, the technical scope of the present disclosure is not interpreted only by the above-described embodiments. Further, all changes within the meaning and scope equivalent to the claims are included. In the description of the above-described embodiments, combinable configurations may be combined with each other.

Explanation of Reference Numerals

[0071] 1 Welding torch, 20 Electrode rod, 21 Tip portion, 30 Collet, 50 Inner nozzle, 70 Outer nozzle, 100 Elastic member, 110 Centering member, F1 First gas flow path, F2 Second gas flow path.

Claims

Claim 1 An electrode rod extending along a first direction and having a tip at one side of the first direction, An inner nozzle disposed outside the electrode rod such that a first gas flow path for allowing a shielding gas to pass between the tip of the electrode rod is formed, An outer nozzle disposed outside the inner nozzle such that a second gas flow path for allowing a shielding gas to pass between the inner nozzle is formed, And an elastic member for biasing the inner nozzle toward the one side of the first direction, A welding torch configured such that the tip of the electrode rod can protrude from the inner nozzle by moving the inner nozzle in the other direction of the first direction against the biasing force of the elastic member. Claim 2 Further comprising a centering member for coaxially arranging the electrode rod and the inner nozzle, The welding torch according to claim 1, wherein the elastic member biases the inner nozzle via the centering member.

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