JP5102600B2 - Torch tip unit for gas shielded arc welding - Google Patents

Description

  The present invention relates to a gas shielded arc welding torch used for carbon dioxide welding or the like, and relates to a gas shielded arc welding torch tip unit attached to the tip of the torch body.

  A gas shield arc welding torch tip unit generally includes a tip body coupled to a torch body, a tip coupled to the tip of the tip body, and a nozzle surrounding the tip. The nozzle is made of a metal such as copper alloy or stainless steel because it has high strength and good heat resistance. Here, it has been pointed out that the spatter is scattered and adhered to the inner surface of the nozzle tip or tip portion during welding. The metal nozzle is likely to adhere to the spatter and difficult to remove the adhering spatter. And since a nozzle sprays the shield gas which flows inside it on a welding object, the flow of shield gas will be inhibited as the adhesion amount of a sputter | spatter increases to the front-end | tip of this nozzle. When the flow of the shielding gas is inhibited in this way, there arises a problem that blowholes are easily generated in the welded portion.

  Conventionally, various nozzles have been proposed as a configuration in which the spatter hardly adheres. For example, Patent Document 1 proposes that the nozzle is made of stainless steel and has a configuration in which silicon nitride is coated on the inner and outer surfaces of the tip portion. By coating silicon nitride in this way, high heat resistance is exhibited, and since the affinity with molten metal is reduced, there is an effect that sputtering hardly adheres.

Further, Patent Document 2 proposes a configuration including a metal nozzle body and a ceramic or cermet sleeve fitted into the tip of the nozzle body. A ceramic material or a cermet material is a material that hardly adheres to spatter. By covering the inner surface of the tip of the metal nozzle body from the inside with the sleep made of these materials, it is difficult for spatter to adhere to the nozzle tip.
JP-A-3-291169 Japanese Utility Model Publication No. 63-196373

  As described above, when spatter adheres to the tip of the nozzle or the inner surface of the tip during welding, the flow of shield gas is obstructed and causes blowholes. It is necessary. Further, in this removing operation, the attached spatter is difficult to be peeled off, and therefore, for example, the spatter is scraped off with a blade or a gold brush. Therefore, the nozzle itself is easily damaged by this removal operation, and the nozzle must be replaced according to the degree of damage. In the configurations of Patent Documents 1 and 2 described above, it is difficult to attach spatter. However, even if a small amount of spatter adheres, spatter gradually accumulates there. Therefore, even in these configurations, it is necessary to perform the above-described removal operation.

  By the way, in the structure of the above-mentioned patent document 1, since the adhesion of spatter can be suppressed by coating silicon nitride, the period until the above-described removing operation can be made relatively long. However, in the removal operation, the silicon nitride coating layer is easily damaged, and the stainless steel is exposed due to damage to the coating layer. If the stainless steel is exposed in this manner, spatter is likely to adhere to the exposed portion, so that the period until the removal operation is performed is shortened, and as a result, the nozzle replacement time is stopped. That is, the nozzle with this configuration cannot substantially exhibit the desired durability.

  On the other hand, in Patent Documents 1 and 2 described above, the removal work described above is performed because the tip of the nozzle and the inner surface of the tip part to which a relatively large amount of spatter adheres are covered by a coating layer or a ceramic-made sleep. It is possible to lengthen the period until the implementation. However, when the period until the removal operation is performed becomes longer, the adhesion of spatter has become obvious not only at the tip of the nozzle but also at the portion near the rear end. Note that this was not regarded as a problem when the period until the removal operation was performed was relatively short. As described above, even when the sputter adheres to the portion near the rear end of the nozzle as described above, the flow of the shielding gas is hindered, which may cause blowholes. Patent Documents 1 and 2 do not clearly disclose that the region where the coating layer is provided and the region covered with the sleeve made of ceramic are the tip of the nozzle and the inner surface of the tip. Furthermore, the relationship with the shielding gas is not specified. Therefore, even if these structures are used, there is a problem in that spatter adheres to the exposed metal surface near the rear end of the nozzle, and accordingly, the flow of the shielding gas is hindered.

  Further, in the configuration of Patent Document 2 described above, the sleep made of ceramic or the like is disposed by being fitted inside the inner surface of the front end of the metal nozzle body, so that the rear end of the sleep is the nozzle body. A step is formed protruding from the inner surface. If the shield gas flowing from the rear end of the sleep hits this step, the flow is disturbed. Therefore, the flow of the shield gas sprayed on the welded portion is likely to be disturbed, and there is a concern that the welding quality may be affected.

  The present invention proposes a torch tip unit for gas shield arc welding in which spatter does not easily adhere and the shield gas can flow smoothly.

  The present invention is coupled to a torch body provided with a gas flow path through which a shield gas flows, an outflow hole through which the shield gas communicates with the gas flow path, and a through hole through which a welding wire is inserted. A tip body, a tip coupled to the tip of the tip body and energizing a welding wire inserted through the tip body; and the outflow fitting to the tip body so as to cover an outflow hole of the tip body, An insulating orifice provided with a plurality of rectifying holes for rectifying the shield gas flowing out from the hole, and a detachable external fit that is insulated from the chip body so as to surround the orifice and the chip. A gas shield arc welding torch tip unit comprising a cylindrical nozzle that blows out a shielding gas flowing out from a rectifying hole toward an object to be welded, the cylindrical nozzle A metal tube comprising a mounting cylinder part that is detachably attached to the chip body, and a threaded cylinder part that is extended forward of the mounting cylinder part and has a female threaded part on the inner surface of the cylinder. A cylindrical fixed body and a female thread portion of the cylindrical fixed body that is fitted inside the cylindrical fixed body and covers an inner surface region from the inside to the portion facing the rectifying hole of the orifice from the tip of the cylindrical fixed body A cylindrical tube body made of carbon having a protective cylinder portion provided on the outer surface of the cylinder and a nozzle tip tube portion protruding from the tip of the cylindrical fixed body. It is a torch tip unit for gas shielded arc welding characterized by being.

  In such a configuration, the nozzle is composed of a metal cylindrical fixed body and a carbon cylindrical nozzle body. The nozzle is externally fitted and fixed to the chip body by the metal cylindrical fixed body. The inner surface of the metallic cylindrical fixed body is covered from the inside with a carbon cylindrical nozzle body. Here, since the cylindrical nozzle body is made of carbon, it is difficult for spatter to adhere and it is easy to remove the adhering spatter. The cylindrical nozzle body covers the area from the orifice straightening hole to the nozzle tip. Therefore, it is difficult for the spatter to adhere to the nozzle in the region where the shield gas flows from the orifice rectifying hole to the tip of the nozzle, and the flow of the shield gas can be prevented from being hindered by the sputter. Therefore, according to the present invention, it is possible to prevent the flow of the shielding gas from being obstructed, so that it is possible to suppress the problem that blowholes occur in the welded portion as described above, and to improve the welding quality. .

  Further, since the nozzle is detachably fitted to the chip body by the mounting cylindrical portion of the metal cylindrical fixed body, the nozzle is supported and fixed to the chip body by the cylindrical fixed body. For this reason, it is difficult to apply a load to the carbon cylindrical nozzle body, which is a brittle material, when attaching or detaching, and the load tends to concentrate on the mounting cylinder portion of the cylindrical fixed body. Thereby, it can suppress that the cylindrical nozzle body made from carbon which is a brittle material is damaged, and can exhibit sufficient durability. As described above, the nozzle attaching / detaching operation can be performed relatively easily and stably even when the removing operation such as removing the spatter and the maintenance operation are performed. Thus, the nozzle of this structure has the role which a metal cylindrical fixed body attaches and hold | maintains to a chip body, and the carbon cylindrical nozzle body has a role which prevents adhesion of a sputter | spatter.

  Further, since the nozzle has a configuration in which the cylindrical fixed body and the cylindrical nozzle body are screwed together, it is possible to relatively easily attach and remove both. Therefore, even if one side is damaged, it can be easily replaced.

  As described above, the cylindrical nozzle body of the nozzle covers the orifice rectifying hole. For this purpose, the rear end of the protective cylinder portion of the cylindrical nozzle body is connected to the orifice. The structure which was located behind the current-regulating hole is required. Further, it is preferable that the protective cylinder portion has a rear end portion that is in contact with the outer surface of the orifice behind the rectifying hole in the circumferential direction. Thereby, the air region where the metal surface of the cylindrical fixed body is located behind the protective cylinder portion and the air region where the orifice rectifying hole exists can be partitioned. And it can prevent that a sputter | spatter adheres to the metal surface of the cylindrical fixing body located behind a protection cylinder part.

  The tip body of the gas shield arc welding torch tip unit described above, which is externally fitted to a portion closer to the rear end than the outflow hole of the tip body, and the attachment cylindrical portion of the cylindrical fixed body of the nozzle is detachably attached. The structure provided with the insulation cylinder which insulates and a cylindrical fixing body is proposed.

  In such a configuration, since the tip body and the cylindrical fixed body of the nozzle are insulated by the insulating cylindrical body, it is prevented from conducting to the metallic cylindrical fixed body, and the cylindrical fixed body and the covered body are covered. The effect which prevents that an arc generate | occur | produces between welding materials (welding object) is heightened. In addition, since the tip body and the nozzle are not directly attached, the insulating cylinder or the cylindrical fixed body of the nozzle can be attached even if the attachment site is damaged when the operation of attaching and detaching both is repeated. Just replace it. Therefore, the time and cost required for maintenance can be suppressed.

  The insulating cylinder is preferably composed of an insulating material such as resin, carbon, or ceramic. Further, the portion that contacts the tip body or orifice is formed of an insulating material, and the cylindrical shape of the nozzle. It can also be set as the two-member structure which forms the site | part which contacts a fixed body from a metal material. In the case of the latter configuration, since the portion to be attached to the attachment cylinder portion of the cylindrical fixed body of the nozzle is made of metal, it is possible to exhibit excellent durability with respect to the above-described nozzle attaching / detaching operation.

  In the gas shield arc welding torch tip unit described above, the orifice is provided with a flange protruding outward from the rectifying hole, and the cylindrical fixed body of the nozzle is inward from the inner surface of the cylinder. The orifice is positioned so as to be positioned by sandwiching the flange of the orifice from the front and back of the orifice between the front end of the insulating cylinder and the engagement protrusion of the cylindrical fixed body. The proposed configuration is proposed.

  In this configuration, after the insulating cylinder is externally fitted and fixed to the chip body, the orifice is externally fitted to the chip body so as to contact the front end of the insulating cylinder, and the nozzle is attached to the insulating cylinder. Thus, the orifice can be positioned at a position covering the outflow hole of the tip body. In this way, the orifice can be positioned relatively easily and accurately. Here, the protective cylinder portion of the cylindrical nozzle body of the nozzle is provided so that the rear end thereof is between the rectifying hole of the orifice and the flange portion. And the structure which the rear end of this protection cylinder part contact | abuts on the outer surface of an orifice over the circumferential direction is suitable.

  Alternatively, in the gas shield arc welding torch tip unit described above, the orifice is provided with a flange protruding outward from the rectifying hole, and the cylindrical nozzle body of the nozzle is at the rear end. A locking projection that protrudes inward is provided, and the orifice is positioned by sandwiching the flange portion of the orifice from the front and back thereof between the distal end of the insulating cylinder and the locking projection of the cylindrical nozzle body. Such a configuration is proposed.

  Even in such a configuration, similarly to the above-described configuration, after the orifice is brought into contact with the front end of the insulating cylinder, the nozzle is attached to the insulating cylinder so that the orifice is positioned so as to cover the outflow hole of the chip body. Can be positioned. In this way, the orifice can be positioned relatively easily and accurately. In this configuration, a configuration in which a locking projection formed around the rear end portion of the protective cylinder portion of the cylindrical nozzle body is in contact with the flange portion formed around the orifice is preferable.

  In the gas shield arc welding torch tip unit described above, an outer fitting cylinder portion fitted and fixed to an insulating cylinder, and a cylindrical fixing body of a nozzle extending in front of the outer fitting cylinder portion And an insertion opening cylinder part that forms an annular insertion gap between the front and rear of the mounting cylinder part and the insulating cylinder body. A plurality of fixed holes for insertion, each of which is provided with a plurality of ball insertion holes that expand to the inner diameter of the insertion opening cylinder, A fitting ball that partially protrudes inward, and that is loosely fitted to the outside of the fixed barrel for insertion and supported so as to be movable in the front-rear direction. A holding hole for holding the fitting ball in a state of being fitted in the ball fitting hole, and a fitting ball between the holding hole and a diameter larger than the holding hole. And a floating hole portion that extends forward of the holding hole portion, and holds the fitting ball in the ball fitting hole by the holding hole portion. A slide cylinder that changes the position to a holding position and an insertion position that supports the fitting ball in a freely movable manner by the loose hole portion, and an urging means that urges the slide cylinder in the direction from the insertion position to the holding position. And a fitting groove into which the protruding portion of the fitting ball protruding from the ball fitting hole of the fixing cylindrical body for insertion can be fitted into the mounting cylindrical portion of the cylindrical fixing body of the nozzle. The mounting cylinder portion of the cylindrical fixed body of the nozzle is formed by setting the slide cylinder of the nozzle attaching / detaching member fixed to the insulating cylinder to the insertion position against the urging force of the urging means. The annular difference formed between the insertion opening cylinder of the insertion cylinder and the insulation cylinder The nozzle can be attached to the insulating cylinder by inserting the protruding portion of the fitting ball into the fitting groove of the mounting cylinder by inserting the slide cylinder into the holding position according to the biasing force of the biasing means. A configuration is proposed.

  In such a configuration, the nozzle can be attached and detached by moving the slide cylinder of the nozzle attaching / detaching member attached to the insulating cylinder in the front-rear direction and converting the position into the holding position and the insertion position. More specifically, when the nozzle is attached, the slide cylinder is set to the insertion position against the urging force of the urging means, and the gap between the insertion opening cylinder and the insulating cylinder of the fixed cylinder for insertion is set. After inserting the mounting cylinder portion of the cylindrical fixing body of the nozzle into the annular insertion gap formed in the above, the position of the slide cylinder is changed to the holding position according to the urging force of the urging means. Here, when the slide cylinder is set to the insertion position, the floating hole portion is positioned to face each ball insertion hole of the insertion opening cylinder portion of the fixed insertion cylinder. The fitting ball can move in and out with respect to the floating hole. Therefore, the fitting ball can move so as not to protrude from the inner surface of the insertion opening cylinder, and the attachment cylinder of the cylindrical fixed body of the nozzle can be inserted. After that, when the slide cylinder is set to the holding position, the holding hole portion is positioned so as to oppose each ball fitting hole of the fixed insertion cylinder, so that each fitting ball is fitted to each ball fitting hole. Then, the fitting ball partially protrudes from the inner surface of the insertion opening cylinder. Thereby, the protrusion part of the fitting ball | bowl protruded from the inner surface of the insertion opening cylinder part fits in the insertion groove | channel of the attachment cylinder part of a cylindrical fixed body, and can hold | maintain a nozzle. Further, when removing the nozzle, the mounting cylinder portion of the cylindrical fixed body of the nozzle is pulled out from the annular insertion gap by changing the position of the slide cylinder to the insertion position against the urging force of the urging means. be able to. As described above, since the nozzle can be attached / detached simply by changing the position of the slide cylinder of the nozzle attaching / detaching member between the holding position and the insertion position, the attaching / detaching operation of the nozzle can be performed relatively easily and accurately. Can do. Therefore, it is possible to shorten the work time when performing the spatter removal work and the maintenance work, and the work can be carried out efficiently.

  In the present invention, as described above, the tip of the tip body provided with the outflow hole for flowing out the shield gas is connected to the tip for energizing the welding wire, and the insulating property is provided with the rectifying hole for rectifying the shield gas. An orifice is externally fitted to cover the outflow hole of the chip body, and a nozzle for blowing shield gas toward the object to be welded is insulated and fitted to the chip body so as to surround the orifice and the chip body. The nozzle includes a mounting cylindrical portion that is detachably attached to the chip body, and a metal cylindrical fixed body that includes a screwed cylindrical portion that extends forward from the mounting cylindrical portion; This is a carbon cylindrical nozzle body comprising a protective cylinder portion fitted into the cylindrical fixing body by being screwed into the screwing cylindrical portion and a nozzle tip cylinder portion protruding forward from the cylindrical fixing body. . In this configuration, the inner surface of the nozzle from the tip of the nozzle to the orifice rectifying hole is made of carbon, so that it is difficult for spatter to adhere and it is easy to remove adhering spatter. Therefore, it is difficult for spatter to adhere to the region where the shield gas flows from the rectifying hole of the orifice to the tip of the nozzle, and the flow of the shield gas can be prevented from being hindered by the sputter. As a result, it is possible to prolong the period of time until the operation of removing the sputters adhering to the nozzle is performed, and it is possible to improve the durability of the nozzle as a whole, and thus it is possible to reduce the cost required for the welding process as a whole. In addition, the shielding gas can be appropriately blown onto the object to be welded over a long period of time, and the effect of suppressing the occurrence of defects such as the occurrence of blow holes in the welded portion is improved.

  Also, an insulating cylinder that is externally fitted to a portion closer to the rear end than the outflow hole of the chip body and in which the mounting cylinder portion of the cylindrical fixing body of the nozzle is detachably attached, insulates the chip body from the cylindrical fixing body With the structure including the tip, the tip cylindrical body and the metal cylindrical fixed body of the nozzle can be surely insulated by the insulating cylindrical body, and an arc is formed between the cylindrical fixed body and the material to be welded. The effect of suppressing the occurrence of is improved. Even if the nozzle mounting / removal operation is repeatedly performed, the chip body is not damaged.

  In addition, the orifice is provided with a flange portion protruding outward from the rectifying hole, and the cylindrical fixed body of the nozzle is provided with a locking protrusion protruding inward from the inner surface of the cylinder. A configuration is proposed in which the flange portion of the orifice is sandwiched and positioned between the tip of the insulating cylinder and the locking protrusion of the cylindrical fixed body. Or, the orifice is provided with a flange projecting outward at the rear portion of the rectifying hole, and the cylindrical nozzle body of the nozzle is provided with a locking projection protruding inward at the rear end, A configuration is proposed in which the flange portion of the orifice is sandwiched and positioned between the tip of the insulating cylinder and the locking protrusion of the cylindrical nozzle body. In either configuration, the orifice can be positioned relatively easily and accurately.

  In addition, a fixed cylindrical body for insertion attached to an insulating cylindrical body provided with a plurality of ball fitting holes for fitting fitting balls, and holding holes for fitting the fitting balls into the respective ball fitting holes. A slide cylinder that is supported so as to be movable in the front-rear direction with respect to the insertion fixed cylinder, and the slide cylinder, Urging means for urging the holding hole portion so as to be positioned at a holding position opposite to the ball fitting hole of the fixed insertion cylinder, and the slide cylinder is used as the urging force of the urging means. On the other hand, as the insertion position where the floating hole part opposes the ball fitting hole, the cylindrical shape of the nozzle is inserted in the annular insertion gap formed by the insertion opening cylinder part and the insulating cylinder part of the insertion fixing cylinder. The mounting cylinder part of the fixed body can be inserted and removed, and the slide cylinder is urged after the mounting cylinder part is inserted into the annular insertion gap. As the holding position according to the urging force of the step, a protruding portion of each fitting ball that is fitted in each ball fitting hole and partially protrudes inward is provided on the mounting cylinder portion of the cylindrical fixed body A nozzle attaching / detaching member adapted to fix the nozzle by being inserted into the fitting groove formed is provided. In this configuration, the nozzle can be attached / detached by moving the slide cylinder of the nozzle attaching / detaching member fixed and attached to the insulating cylinder to the holding position and the insertion position by moving in the front-rear direction. it can. As described above, the nozzle can be attached and detached with a single touch, and the nozzle can be attached and detached relatively easily and accurately. Therefore, the spatter removal work and the maintenance work can be efficiently performed.

  Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view of a gas shield arc welding torch tip unit 1 according to the first embodiment, and FIG. 2 is an exploded view thereof. The gas shield arc welding torch tip unit 1 includes a tip 2, a tip body 3, an insulating cylinder 4, an orifice 5, and a nozzle 6.

  Here, the chip 2 is provided with an insertion hole 10 penetrating through the center thereof, and is used to energize the welding wire 7 inserted through the insertion hole 10. The tip 2 is attached with its rear end screwed to the tip of the tip body 3. The tip body 3 is provided with a screw portion 11 for screwing into a torch body (not shown) at the rear end thereof, and a male screw portion 12 for screwing the insulating cylinder 4 is screwed in front of the screw portion 11. Is formed. Further, the chip body 3 is provided therein with a through hole 14 penetrating in the longitudinal direction and a gas flow path 15 through which a shield gas flows. When the through hole 14 is screwed into the chip 2, the through hole 14 communicates with the insertion hole 10 of the chip 2 linearly, and the welding wire 7 sent from the torch body is inserted into the insertion hole 10 of the chip 2. In addition, the gas flow path 15 circulates the shield gas sent from the torch body. An outflow hole 13 that communicates the gas flow path 15 and the outside of the chip body 3 is provided at a front portion of the chip body 3, and the shield gas flowing through the gas flow path 15 is discharged from the outflow hole. 13 to flow out.

  The above-mentioned chip 2 and chip body 3 are formed from copper or a copper alloy.

  Further, the insulating cylinder 4 is screwed and fixed to the male body 12 of the chip body 3 described above. The insulating cylinder 4 is composed of a resin-made cylindrical main body 17 and a copper alloy outer shell 18 that is externally fitted and joined to a central portion in the longitudinal direction of the cylindrical main body 17. The shell 18 is caulked and integrated with the cylindrical body 17. Here, the cylindrical main body 17 has a two-stage cylindrical shape having different outer diameters before and after that, and the outer diameter on the front side is smaller than that on the rear side. The outer shell 18 covers only the central portion of the cylindrical main body 17, and the front and rear ends 17 a and 17 b of the cylindrical main body 17 remain exposed. Even in the outer shell body 18, similarly to the cylindrical main body 17, it has a two-stage cylindrical shape, and a male screw portion 20 for coupling to the nozzle 6 described above on the outer surface of the front portion having a small diameter. Is formed. Further, on the inner surface of the cylindrical main body 17, a female screw portion 19 that is screwed with the male screw portion 12 of the chip body 3 is provided.

  Further, the above-described orifice 5 is fitted from the front of the chip body 3 and is disposed in contact with the front end 17a of the insulating cylinder 4 screwed into the chip body 3. The orifice 5 has a cylindrical shape made of ceramic, and a plurality of rectifying holes 22 penetrating inward and outward are provided at substantially equal intervals in the circumferential direction (see FIGS. 1B and 2). The orifice 5 is disposed at a position covering the outflow hole 13 of the chip body 3 so that the shield gas that has flowed out of the outflow hole 13 flows out of the plurality of rectifying holes 22. By providing the plurality of rectifying holes 22 at substantially equal intervals in the circumferential direction, the shield gas can be rectified and flowed in the circumferential direction. Further, a flange 21 protruding outward is formed at the rear end of the orifice 5. That is, the collar portion 21 is provided at a rear portion of the rectifying hole 22. And the outer peripheral surface of the orifice 5 comprises the shape which inclines ahead except the collar part 21. FIG.

  The tip body 3 is covered by the orifice 5 and the insulating cylinder 4 except for the front end portion thereof, and spatter is prevented from adhering to the rear portion of the tip body 3.

  In addition, the nozzle 6 is screwed to the male screw portion 20 of the insulating cylinder 4 screwed to the chip body 3 described above. The nozzle 6 has a role of blowing the shield gas that has flowed out of the rectifying hole 22 of the orifice 5 toward the object to be welded. In this nozzle 6, a metal cylindrical fixing body 25 provided with a female screw portion 28 to be screwed into the male screw portion 20 of the insulating cylinder 4, and the cylindrical fixing body 25 are screwed. It is comprised from the cylindrical nozzle body 31 made from carbon.

  In the first embodiment, the cylindrical fixed body 25 is formed of brass and chrome plated. The cylindrical nozzle body 31 is formed from an isotropic graphite material. The isotropic graphite material may be manufactured by any of CIP (rubber press) molding, in-mold molding, and extrusion molding.

  The above-described metal cylindrical fixed body 25 includes a cylindrical mounting tube portion 26 in which the female screw portion 28 is formed on the inner surface of the cylinder, and a cylindrical screw extending forward from the mounting tube portion 26. The inner cylinder portion 27 is provided with a female screw portion 29 on the inner surface of the cylinder.

  The carbon cylindrical nozzle body 31 described above is fitted into the threaded tube portion 27 of the cylindrical fixed body 25 and covers the inner surface of the threaded tube portion 27 from the inside. The nozzle tip cylinder part 33 which protrudes ahead of the body 25 and constitutes the tip part of the nozzle 6 is integrally formed. The protective cylinder portion 32 is provided with a male screw portion 35 that is screwed with the female screw portion 29 of the screwing tube portion 27 of the cylindrical fixed body 25 on the outer surface of the cylinder. And the latching protrusion 30 which protrudes inward from the inner surface is formed in the rear-end part of this protection cylinder part 32. As shown in FIG. The locking projection 30 abuts the flange 21 of the orifice 5 from the front by screwing the nozzle 6 into the insulating cylinder 4. The orifice 5 is positioned at a position covering the outflow hole 13 of the tip body 3 by sandwiching the flange portion 21 of the orifice 5 between the locking projection 30 and the front end 17a of the insulating cylinder 4. The length of the protective cylinder portion 32 of the cylindrical nozzle body 31 is such that the length from the tip of the cylindrical fixed body 25 to the flange portion 21 of the orifice 5 is obtained in a state where the nozzle 6 is screwed into the insulating cylinder body 4. Is set. Thus, the carbon cylindrical nozzle body 31 covers the inner surface of the metal cylindrical fixed body 25 from the inside in front of the flange portion 21 of the orifice 5 by the protective cylinder portion 32. The cylindrical nozzle body 31 has a smooth inner surface from the locking projection 30 to the front end.

  In addition, the protection cylinder part 32 of this cylindrical nozzle body 31 is provided so that the latching protrusion 30 may contact | abut over the collar part 21 of the orifice 5 over the circumferential direction. As a result, the shield gas that has flowed out of the rectifying hole 22 of the orifice 5 is less likely to move backward and easily flows out from the front of the nozzle 6.

  The gas shield arc welding torch tip unit 1 described above is attached to the tip body 3 with the threaded portion 11 screwed into the torch body, and is used for arc welding. In this arc welding, the shield gas flowing out from the rectifying hole 22 of the orifice 5 is blown out toward the object to be welded, and is conducted to the welding wire 7 through the tip body 3 and the tip 2 for welding. The carbon cylindrical nozzle body 31 of the nozzle 6 surrounds the orifice 5 and the tip 2 in the region from the rectifying hole 22 of the orifice 5 to the tip of the nozzle 6 (FIG. 1 ( B)), the spatter generated during welding is difficult to adhere to the cylindrical inner surface and tip of the cylindrical nozzle body 31. That is, in the configuration of the first embodiment, it is difficult for spatter to adhere not only to the tip of the nozzle 6 and the inner surface of the tip, but also to the region from the tip of the nozzle 6 to the rectifying hole 22 of the orifice 5. It is surrounded by a carbon cylindrical nozzle body 31 (see FIG. 1B). As described above, in the region where the shield gas flows from the rectifying hole 22 of the orifice 5 to the tip of the nozzle 6, it is difficult for spatter to adhere to the inner surface of the nozzle 6. Can be prevented. Therefore, it is possible to prevent the occurrence of blowholes due to poor outflow of shield gas.

  Further, since it is difficult for spatter to adhere, the period until the removal operation for removing spatter adhering to the nozzle 6 can be made relatively long. Furthermore, since the cylindrical nozzle body 31 is made of carbon, it can be removed relatively easily even if spatter adheres as described above. Therefore, the cylindrical nozzle body 31 is not easily damaged by the removal operation of the spatter, and the effect of suppressing the adhesion of the spatter can be exhibited for a relatively long time by repeating the removal operation. As described above, since the nozzle 6 has high durability and hardly adheres to the spatter, according to the configuration of the first embodiment, it is possible to stably maintain a desired welding quality for a relatively long period of time. .

  If the carbon protective cylinder portion 32 is configured to extend forward from the position of the rectifying hole 22 of the orifice 5, a cylindrical fixed body is provided between the rectifying hole 22 and the protective cylinder portion 32. The inner surface of 25 will be exposed. In this case, spatter is likely to adhere to the exposed metal inner surface of the cylindrical fixed body 25, and the flow of the shield gas flowing out from the rectifying hole 22 is hindered by the adhesion of the spatter. Thereby, a blowhole may arise in a welding part and stability of welding quality will fall.

  Furthermore, in the first embodiment, as described above, the nozzle 6 has a two-member configuration of the metal cylindrical fixed body 25 and the carbon cylindrical nozzle body 31, and the cylindrical fixed body 25. Thus, the chip body 3 is attached via the insulating cylinder 4. Therefore, in order to carry out the spatter removal work and maintenance as described above, even if the work of removing and attaching the nozzle 6 is repeated, it is difficult to cause problems such as damage to the female screw portion 28, and it is sufficient. Has excellent durability.

  Furthermore, since the cylindrical fixed body 25 and the cylindrical nozzle body 31 are integrated by screwing, the load acting on both is the entire of the female screw part 29 and the male screw part 35 that are screwed together. Act on. Therefore, stress concentration can be relaxed. In particular, since the carbon material is a brittle material as compared with the metal material, the carbon material is easily damaged by a load due to stress concentration. Therefore, the configuration of the first embodiment is a connecting portion between the cylindrical fixed body 25 and the cylindrical nozzle body 31. It is effective for enhancing the durability. In comparison with this, for example, in the configuration of the above-described conventional patent document 2, since the sleeve made of the ceramic material is screwed to the nozzle body made of the metal material, Stress concentration tends to occur. If the sleeve of Patent Document 2 is made of a carbon material, the screwed portion will be worn away immediately. Thus, in the nozzle 6 of the first embodiment, superior durability can be exhibited as compared with the configuration of the conventional Patent Document 2.

  FIG. 3 is a sectional view of the gas shield arc welding torch tip unit 51 of the second embodiment, and FIG. 4 is an exploded view thereof. The gas shield arc welding torch tip unit 51 includes a tip 2, a tip body 3, an insulating cylinder 4, and an orifice 5 similar to those in the first embodiment. The nozzle 52 is screwed onto the insulating cylinder 4 and attached.

  The nozzle 52 according to the second embodiment has a two-member configuration including a metal cylindrical fixed body 55 and a carbon cylindrical nozzle body 61. The metal cylindrical fixed body 55 includes a mounting cylinder portion 56 in which a female screw portion 60 that is screwed with the male screw portion 20 of the insulating cylinder body 4 is provided on the inner surface of the cylinder, and extends forward from the mounting cylinder portion 56. The female screw portion 59 that is screwed to the cylindrical nozzle body 61 includes a screwed tube portion 57 provided on the inner surface of the cylinder. The cylindrical fixed body 55 is formed with a locking projection 64 around the front side of the female screw portion 60 so as to protrude inward. When the female threaded portion 60 of the mounting cylindrical portion 56 of the cylindrical fixed body 55 is screwed into the male threaded portion 20 of the insulating cylindrical body 4, the locking protrusion 64 is formed on the orifice 5 that is externally fitted to the chip body 3. It comes into contact with the flange 21 from its front side. That is, the orifice 5 has its flange 21 sandwiched from the front and rear by the locking projection 64 of the cylindrical fixing body 55 of the nozzle 52 and the front end 17a of the insulating cylinder 4 so that the outflow hole 13 of the tip body 3 is formed. Positioned at the covering position. The cylindrical nozzle body 61 has a smooth inner surface.

  The cylindrical nozzle body 61 includes a protective cylinder portion 62 provided with a male screw portion 65 screwed with the female screw portion 59 of the screwing cylinder portion 57 of the cylindrical fixed body 55, and a front side from the cylindrical fixed body 55. A nozzle tip cylinder portion 63 that protrudes toward the tip and forms the tip portion of the nozzle 52 is integrally formed. Similarly to the first embodiment, the protective cylinder portion 62 is screwed with the screwing cylinder portion 57 of the cylindrical fixing body 55 to cover the cylindrical inner surface of the cylindrical fixing body 55 from the inside thereof. Here, the length of the protective cylinder portion 62 is shorter than the length from the tip of the cylindrical fixed body 55 to the locking projection 64 and the rectification of the orifice 5 positioned by the locking projection 64 is performed. The length is set to be longer than the length reaching the hole 22. That is, the carbon cylindrical nozzle body 61 covers the rectifying hole 22 of the orifice 5 with the protective cylinder portion 62, and the cylinder of the metallic cylindrical fixed body 55 is located in the front region of the rectifying hole 22. The inner surface is covered from the inner side (see FIG. 3B).

  The rear end of the protective cylinder portion 62 of the cylindrical nozzle body 61 is in contact with the outer surface of the orifice 5 between the rectifying hole 22 and the flange portion 21 of the orifice 5 in the circumferential direction. Is provided. As a result, the shield gas that has flowed out of the rectifying hole 22 of the orifice 5 is less likely to move backward and easily flows out from the front of the nozzle 52.

  In the second embodiment, as described above, the metal cylindrical fixed body 55 of the nozzle 52 is provided with the locking protrusion 64 that comes into contact with the flange portion 21 of the orifice 5, and the carbon cylindrical nozzle body. 61 is configured such that no locking projection is provided. The components other than the nozzle 52 are the same as those of the first embodiment described above, and the same components are denoted by the same reference numerals and the description thereof is omitted.

  Even in the gas shield arc welding torch tip unit 51 of the second embodiment, a region where the shield gas flows from the rectifying hole 22 of the orifice 5 to the tip of the nozzle 52 is formed as a cylindrical cylindrical nozzle body made of carbon. Since it coat | covers with 61, it is hard to adhere a sputter | spatter and can prevent that the flow of shield gas is obstructed by adhesion | attachment of this sputter | spatter. Further, the carbon cylindrical nozzle body 61 is easy to remove even if spatter adheres. Furthermore, since the nozzle 52 is screwed into the insulating cylinder 4 with the metal cylindrical fixed body 55, the desired durability can be exhibited even if the nozzle 52 is repeatedly detached and attached for maintenance or the like. As described above, even in the second embodiment, it is possible to achieve the same effects as those in the first embodiment.

  FIG. 5 is a sectional view of the gas shield arc welding torch tip unit 71 of the third embodiment, and FIG. 6 is an exploded view thereof. The gas shield arc welding torch tip unit 71 includes a tip 2, a tip body 3, an insulating cylinder 74, an orifice 5, a nozzle 72, and a nozzle attaching / detaching member 73. The tip 2, the tip body 3, and the orifice 5 are the same as those in the first embodiment.

  The above-described insulating cylindrical body 74 has a two-stage cylindrical shape in which cylinders having different outer peripheral diameters are integrated in the front and rear, and the outer peripheral diameter of the front cylindrical portion 74a compared to the outer peripheral diameter of the rear cylindrical portion 74b. Is a configuration with a small diameter. The insulating cylinder 74 is made of resin, and a groove (not shown) is provided along the circumferential direction in the rear cylindrical portion 74b having a large outer diameter. Then, a fixing C-ring 77 protruding outward is fitted in this groove. The insulating cylinder 74 is formed with an internal thread 78 on the inner surface thereof, which is screwed with the external thread 12 of the chip body 3 as in the first embodiment. Then, the orifice 5 is fitted into the tip body 3 into which the insulating cylinder 74 is screwed and brought into contact with the front end of the insulating cylinder 74 so that the orifice 5 covers the outflow hole 13 of the chip body 3. Arranged.

  On the other hand, the nozzle attaching / detaching member 73 is for attaching, fixing, and removing the nozzle 72. As shown in FIGS. 5 to 7, the nozzle attaching / detaching member 73 includes an insertion fixing cylinder 101 that is externally fitted and fixed to the insulating cylinder 74, a plurality of fitting balls 120, and an insertion fixing cylinder. A slide cylinder 103 is supported by the body 101 so as to be movable in the front-rear direction, and a coil spring 104 that biases the slide cylinder 103 forward. The coil spring 104 constitutes an urging means according to the present invention.

  Here, the fixed cylindrical body 101 for insertion includes an outer fitting cylindrical portion 114 that is fitted on the rear cylindrical portion 74b of the insulating cylindrical body 74, and a predetermined outer portion that extends forward from the outer fitting cylindrical portion 114. It consists of the insertion opening cylinder part 110 of a diameter. The outer fitting cylindrical portion 114 has an outer diameter larger than the outer diameter of the insertion opening cylindrical portion 110. Further, the inner diameter of the insertion opening cylinder 110 is larger than the inner diameter of the outer fitting cylinder 114. An annular insertion gap 127 is formed between the insertion opening cylindrical portion 110 and the front cylindrical portion 74a and the rear cylindrical portion 74b of the insulating cylindrical body 74. And the annular step part 113 is formed in the site | part which both couple | bonds by the internal diameter difference of the external fitting cylinder part 114 and the insertion opening cylinder part 110. FIG. The annular step 113 contacts the fixing C ring 77 fitted to the insulating cylinder 74 when the insertion fixing cylinder 101 is externally fitted from the rear side of the insulating cylinder 74, and This is for determining the front position of the fixed cylinder 101 for use.

  A fixing band 79 is externally fitted to a portion of the rear cylindrical portion 74 b of the insulating cylindrical body 74 that is located behind the fixed cylindrical body 101 for insertion. The outer fitting cylinder part 114 fitted to the rear cylindrical part 74b by the fixing band 79 fitted to the rear cylindrical part 74b and the fixing C ring 77 fitted to the rear cylindrical part 74b Directional positioning has been made.

  A plurality of ball fitting holes 115 penetrating inward and outward are formed at equal intervals in the circumferential direction in the insertion opening cylinder part 110 of the fixed insertion cylinder 101 (see FIG. 7). The ball fitting hole 115 is provided so that a hole diameter opened on the inner surface of the insertion opening cylinder portion 110 is a predetermined hole diameter, and gradually expands outward from the predetermined hole diameter. That is, the ball fitting hole 115 is an inclined circumferential surface in which the hole circumferential surface expands outward. Further, a circumferential groove 116 for fitting the fixing C-ring 117 is formed in front of the ball fitting hole 115 (see FIG. 7).

  The fitting balls 120 each having a diameter larger than the diameter of the hole on the inner surface of the insertion opening cylinder portion 110 are arranged in each ball fitting hole 115 of the fixed insertion cylinder 101 described above. . Furthermore, the diameter dimension of the fitting ball 120 is set larger than the plate thickness of the insertion opening cylinder part 110. The fitting ball 120 partially protrudes inward from the ball fitting hole 115 in a state of fitting into the ball fitting hole 115. And in this fitted state, it protrudes partially outward from the ball fitting hole 115.

  Moreover, in the above-mentioned slide cylinder 103, it is cylindrical and has a sliding hole 121 that opens rearward, a floating hole 122 that opens forward, and the sliding hole 121 and the floating hole 122. A holding hole 123 provided between the two is coupled in the front-rear direction. Here, the sliding hole portion 121 is provided with an inner diameter dimension that is slidably fitted to the outer fitting cylindrical portion 114 of the insertion fixing cylindrical body 101. In addition, the holding hole portion 123 has an inner diameter dimension that abuts on the outer end of each fitting ball 120 in a state where the fitting ball 120 is fitted in each ball fitting hole 115 of the fixing tubular body 101 for insertion. Is provided. That is, the holding hole 123 is positioned at a position facing the ball fitting hole 115 of the insertion fixing cylindrical body 101 so that the holding ball 123 abuts the outer end of the fitting ball 120 and the fitting ball 120 is fitted into the ball. The hole 115 is held in a state where it is fitted. The holding hole portion 123 has a smaller inner diameter than the sliding hole portion 121, and an annular step portion 125 is formed at a site where both of them are coupled. Further, the loose hole portion 122 has an inner diameter that is larger than that of the holding hole portion 123 described above, and is located at a position facing the ball fitting hole 115 of the fixed tubular body 101 for insertion. The fitting balls 120 arranged in the respective ball fitting holes 115 are allowed to move inward and outward between the ball-to-ball fitting holes 115 and the floating hole portions 122. Here, the inner diameter dimension of the floating hole portion 122 is such that the fitting ball 120 is inserted into the insertion opening cylinder of the fixed fixing cylinder 101 in a state where the outer end of the fitting ball 120 is in contact with the floating hole portion 122. It is set so as not to protrude inward from the inner surface of the portion 110.

  In the slide cylinder 103, since the inner diameters of the holding hole portion 123 and the floating hole portion 122 are different from each other, an annular step portion 128 is formed at a portion where both of them are coupled. The annular step portion 128 is in contact with the fixing C-ring 117 fitted to the insertion fixing cylinder 101 described above. Here, the fixing C-ring 117 has a smaller diameter than the floating hole portion 122 and a larger diameter than the holding hole portion 123. That is, after the slide cylinder 103 is externally fitted to the insertion fixing cylinder 101 from the front, the fixing C ring 117 is fitted into the circumferential groove 116 of the insertion fixation cylinder 101, thereby the slide cylinder. 103 is restricted from moving forward because the annular step 128 abuts against the fixing C-ring 117.

  The coil spring 104 described above has an inner diameter larger than the outer diameter of the insertion opening cylinder portion 110 of the insertion fixing cylinder 101 and an outer diameter larger than the inner diameter of the sliding hole 121 of the slide cylinder 103. It is getting smaller. The coil spring 104 is inserted from the front into the insertion opening cylinder 110 of the insertion fixing cylinder 101 and supported by the outer fitting cylinder 114. After this, the front end of the coil spring 104 is supported by the annular step portion 125 of the slide cylinder 103 by externally fitting the slide cylinder 103 from the front of the fixed insertion cylinder 101. In this way, the coil spring 104 is disposed so as to be sandwiched between the outer fitting cylinder part 114 of the insertion fixing cylinder 101 and the annular step part 125 of the slide cylinder 103.

  The configuration of the nozzle attaching / detaching member 73 will be further described in detail. As an assembling procedure of the nozzle attaching / detaching member 73, first, the fitting balls 120 are respectively arranged in the ball fitting holes 115 of the insertion fixing cylinder 101, and the insertion opening cylinder of the insertion fixing cylinder 101 is arranged. The coil spring 104 is loosely fitted to the portion 110. Then, the slide cylinder 103 is externally fitted from the front of the insertion fixed cylinder 101, and the coil spring 104 is connected by the external fitting cylinder 114 of the insertion fixed cylinder 101 and the annular step 125 of the slide cylinder 103. Hold it. The slide cylinder 103 is pushed further backward against the urging force of the coil spring 104, the circumferential groove 116 of the fixed cylinder 101 for insertion is exposed in front of the slide cylinder 103, and the fixing C is fixed to the circumferential groove 116. The ring 117 is fitted. Then, by releasing the load that pushed the slide cylinder 103 rearward, the slide cylinder 103 moves forward in accordance with the urging force of the coil spring 104, and the annular step portion 128 and the fixing C ring 117 abut against each other. Held in contact.

  At a position where the slide cylinder 103 is held by the urging force of the coil spring 104 and the fixing C ring 117, the holding hole 123 of the slide cylinder 103 is formed in the ball fitting hole 115 of the insertion fixing cylinder 101. It becomes the position to face. Each fitting ball 120 is held in a state in which its outer end is in contact with the holding hole 123 and fitted in each ball fitting hole 115, so that the fitting ball 120 is partially inward. Project to A portion of the fitting ball 120 that protrudes inward from the ball fitting hole 115 is a protruding portion 120a according to the present invention. The position of the slide cylinder 103 is a holding position according to the present invention (see FIGS. 5 and 8A).

  Further, the slide cylinder 103 is pushed backward from the holding position against the urging force of the coil spring 104, and the loose hole portion 122 is set to a position facing the ball fitting hole 115 of the insertion fixing cylinder 101. At this position, each fitting ball 120 can move inward and outward between the respective ball fitting hole 115 and the loose hole portion 122. The position of the slide cylinder 103 is the insertion position according to the present invention. In order to keep the slide cylinder 103 in the insertion position, a force that resists the urging force of the coil spring 104 is required. When this force is removed, the slide cylinder 103 is held at the holding position according to the urging force of the coil spring 104. Will be held back automatically.

  On the other hand, the nozzle 72 described above has a two-member configuration including a metal cylindrical fixed body 85 and a carbon cylindrical nozzle body 31. Here, the cylindrical nozzle body 31 has the same configuration as that of the first embodiment described above, and a locking projection 30 is formed around the rear end portion of the protective cylinder portion 32. The metal cylindrical fixed body 85 includes a screwed cylinder part 87 into which the protective cylinder part 32 of the cylindrical nozzle body 31 is fitted, and a mounting cylinder part extending rearward from the screwed cylinder part 87. 86. A female screw part 89 that is screwed with the male screw part 35 provided in the protective cylinder part 32 of the cylindrical nozzle body 31 is provided on the cylindrical inner surface of the screwing cylinder part 87. The mounting cylinder portion 86 has an inner diameter that can be fitted onto the front cylindrical portion 74a of the insulating cylinder 74 described above, and is attached to the insertion opening 110 of the fixed cylinder 101 for insertion of the nozzle attaching / detaching member 73 described above. It has an outer diameter that can be fitted. Thereby, in a state where the nozzle attaching / detaching member 73 is attached to the insulating cylinder 74, the front cylindrical portion 74 a of the insulating cylinder 74 and the insertion opening 110 of the fixing cylinder 101 for inserting the nozzle attaching / detaching member 73, The mounting tube portion 86 of the nozzle 72 can be inserted into the annular insertion gap 127 formed between them (see FIG. 8).

  Here, as described above, the fitting ball 120 partially protrudes from the inner surface of the insertion opening 110 of the nozzle attaching / detaching member 73 and holds the outer diameter of the mounting cylindrical portion 86 of the cylindrical fixed body 85. In this state, as shown in FIG. 8 (A), it is set so that it cannot be inserted into the annular insertion gap 127. That is, when the nozzle attaching / detaching member 73 is in the holding position of the slide cylinder 103, the attachment cylinder portion 86 of the nozzle 72 cannot be inserted into the annular insertion gap 127. In addition, by setting the slide cylinder 103 to the insertion position, as shown in FIGS. 8B and 8C, the fitting ball 120 can be moved so as not to protrude from the ball fitting hole 115, so that the mounting cylinder portion 86 can be inserted into the annular insertion gap 127.

  Further, a fitting groove 95 is formed on the outer periphery of the mounting tube portion 86 of the cylindrical fixed body 85. The fitting groove 95 allows the projection 120 a of the fitting ball 120 protruding inward from the ball fitting hole 115 of the nozzle attaching / detaching member 73 to be fitted. That is, as described above, the slide cylinder 103 of the nozzle attaching / detaching member 73 is set as the insertion position, and after the attachment cylinder portion 86 of the nozzle 72 is inserted into the annular insertion gap 127, the slide cylinder 103 is set as the holding position. Thus, the protruding portion 120a of the fitting ball 120 protruding from each ball fitting hole 115 is fitted into the fitting groove 95 (see FIG. 8C). Thereby, the attachment cylinder part 86 cannot be moved in the front-rear direction, so that it cannot escape from the annular insertion gap 127, and the nozzle 72 can be attached to the nozzle attaching / detaching member 73 and held.

  Further, an opening support portion 94 having a large inner diameter that can be externally fitted to the rear cylindrical portion 74b of the insulating cylindrical body 74 is formed at the rear end of the mounting cylindrical portion 86 (see FIG. 6). The opening support portion 94 is for defining an insertion position when the mounting tube portion 86 is inserted into the annular insertion gap 127 (see FIG. 8C). That is, the mounting cylinder portion 86 is inserted into the annular insertion gap 127 and the opening support portion 94 is brought into contact with the rear cylindrical portion 74 b of the insulating cylinder 74. In this abutting state, the fitting groove 95 of the mounting cylinder portion 86 is positioned so as to face the ball fitting hole 115 of the fixed insertion cylinder 101.

  The nozzle 72 has the same configuration as that of the first embodiment described above except that the nozzle 72 includes the cylindrical fixing body 85 having the mounting cylinder portion 86 described above, and details thereof are omitted.

Next, the process of attaching / detaching the nozzle 72 using the nozzle attaching / detaching member 73 described above will be described.
As in the first embodiment, the chip 2 and the chip body 3 are screwed together, and the insulating cylinder 74 is screwed and fixed to the chip body 3. Then, the orifice 5 is fitted from the front of the chip 2 so as to be in contact with the front end of the insulating cylinder 74.

  As described above, the nozzle attaching / detaching member 73 is externally fitted to the insulating cylinder 74 from the rear, and the annular step 113 of the insertion fixing cylinder 101 is fitted to the fixing C ring 77 fitted to the insulating cylinder 74. Abut. Then, the fixing band 79 is externally fitted to the insulating cylinder 74 from the rear side of the nozzle attaching / detaching member 73, abuts against the rear end portion of the insertion fixing cylinder 101, and is fixedly held on the insulating cylinder 74 at this position. . As a result, the nozzle attaching / detaching member 73 is sandwiched and held between the fixing C-ring 77 and the fixing band 79 as shown in FIG. 8A. The nozzle attaching / detaching member 73 is in a state in which the slide cylinder 103 is held at the holding position by the biasing force of the coil spring 104.

  The slide cylinder 103 of the nozzle attaching / detaching member 73 is pushed backward, and the slide cylinder 103 is set to the insertion position as shown in FIG. In this insertion position, as described above, the fitting ball 120 disposed in each ball fitting hole 115 can move inward and outward between the ball fitting hole 115 and the floating hole portion 122. It can move so as not to protrude inward from the ball fitting hole 115. With the slide cylinder 103 kept in the insertion position as described above, the nozzle 72 is inserted from the front of the tip 2 as shown in FIGS. 8B and 8C, and the cylindrical fixed body of the nozzle 72 is inserted. The 85 mounting cylinders 86 are inserted into an annular insertion gap 127 formed between the insertion fixing cylinder 101 and the insulating cylinder 74 of the nozzle attaching / detaching member 73. Here, as described above, since the slide cylinder 103 is in the insertion position, each fitting ball 120 can move freely, and the attachment cylinder portion 86 can be easily inserted into the annular insertion gap 127. Thereafter, the force for keeping the slide cylinder 103 in the insertion position is released, and the slide cylinder 103 is converted into the holding position in accordance with the urging force of the coil spring 104 (see FIG. 5). As a result, each fitting ball 120 is fitted into the respective ball fitting hole 115, so that the protruding portion 120 a of the fitting ball 120 protruding from the inner surface of the insertion fixing cylindrical body 101 is formed on the screwed cylindrical portion 86. It is inserted into the insertion groove 95. Since the slide cylinder 103 is held at the holding position by the urging force of the coil spring 104, the protruding portion 120a of the fitting ball 120 fitted in each ball fitting hole 115 is held in a state of being fitted in the fitting groove 95, The mounting cylinder portion 86 is held in a state of being inserted into the annular insertion gap 127. In this way, the nozzle 72 is attached to and held by the nozzle attaching / detaching member 73.

  Here, in a state where the nozzle 72 is attached, as shown in FIG. 5, the locking projection 30 of the carbon cylindrical nozzle body 31 constituting the nozzle 72 abuts on the flange portion 21 of the orifice 5, The orifice 5 is positioned and held with the insulating cylinder 74.

  In this way, the nozzle 72 is attached by the nozzle attaching / detaching member 73 to constitute the gas shield arc welding torch tip unit 71 of the third embodiment. Next, when removing the nozzle 72, the nozzle 72 can be pulled out and removed by pushing the slide cylinder 103 of the nozzle attaching / detaching member 73 backward to the insertion position. As described above, the configuration of the third embodiment compares the operation of attaching / detaching the nozzle 72 by moving the slide cylinder 103 of the nozzle attaching / detaching member 73 in the front-rear direction and converting the position to the insertion position and the holding position. Can be done easily. In other words, it can be said that the configuration of the third embodiment can detach the nozzle 72 by so-called one-touch. With this configuration, when performing a maintenance operation or the like, the attachment / detachment operation of the nozzle 72 can be performed easily and in a short time, and the work efficiency can be improved.

  Even in the gas shield arc welding torch tip unit 71 of the third embodiment, the region where the shield gas flows from the rectifying hole 22 of the orifice 4 to the tip of the nozzle 72 with the nozzle 72 attached is made of carbon. Since it is surrounded by the cylindrical nozzle body 31, it is difficult for spatter to adhere during welding, and even if spatter adheres, it can be removed relatively easily. As described above, even in the third embodiment, the same effects as those of the first and second embodiments can be exhibited.

  On the other hand, in the configuration in which the nozzle is screwed into the insulating cylinder of the first and second embodiments described above, the metal cylindrical fixing body is provided with a hexagonal nut portion on the outer periphery thereof. Also good. This makes it possible to more easily and stably perform the operation of screwing the nozzle into and removing the nozzle from the insulating cylinder.

  Further, in the configuration of the third embodiment described above, the insulating cylinder 74 is made of resin. However, like the first and second embodiments, a metal outer shell is coated so as to cover the resin one. It can also be configured by integrating the body.

  The present invention is not limited to the above-described embodiments, and can be appropriately used within the scope of the gist of the present invention.

4A is a longitudinal sectional view of the torch tip unit 1 for gas shielded arc welding according to the first embodiment, and FIG. 4B is a longitudinal sectional view for explaining the relationship between the rectifying hole 22 of the orifice 5 and the nozzle tip tubular portion 33. FIG. . It is an exploded view of the torch tip unit 1 for gas shielded arc welding same as the above. 5A is a longitudinal sectional view of a gas shield arc welding torch tip unit 51 of the second embodiment, and FIG. 5B is a longitudinal sectional view for explaining the relationship between a rectifying hole 22 of an orifice 5 and a nozzle tip tubular portion 63. FIG. . It is an exploded view of the torch tip unit 51 for gas shielded arc welding same as the above. FIG. 6 is a longitudinal sectional view of a gas shield arc welding torch tip unit 71 of a third embodiment. It is an exploded view of the torch tip unit 71 for gas shielded arc welding same as the above. 4 is an exploded view of a nozzle attaching / detaching member 73. FIG. It is explanatory drawing which shows the process in which the nozzle 72 is attached or detached to the nozzle attaching / detaching member 73. FIG.

Explanation of symbols

1,51,71 Torch tip unit for gas shielded arc welding
2 Tip 3 Tip body 4, 74 Insulating cylinder 5 Orifice 6, 52, 72 Nozzle
7 Welding wire 13 Outflow hole
14 through hole 15 gas flow path 21 collar portion 22 rectifying hole 25, 55, 85 cylindrical fixed body 26, 56, 86 mounting cylinder portion 27, 57, 87 threaded cylinder portion 29, 59, 89 female thread portion 30, 64 Locking projections 31, 61 Cylindrical nozzle body 32, 62 Protective cylinder part 33, 63 Nozzle tip cylinder part 35, 65 Male thread part 73 Nozzle attaching / detaching member 95 Insertion groove 101 Insertion fixed cylinder 103 Slide cylinder 104 Coil spring (Biasing means)
110 insertion opening cylinder part 114 outer fitting cylinder part 115 ball fitting hole 122 idle hole part 123 holding hole part 120 fitting ball 120a protrusion part 127 annular insertion gap

Claims (2)

A chip body coupled to the torch body, provided with a gas flow path through which the shield gas flows, an outflow hole through which the shield gas communicated with the gas flow path flows out, and a through hole through which the welding wire is inserted;
A tip coupled to the tip of the tip body and energized to a welding wire inserted through the tip body;
An insulating orifice that is externally fitted to the chip body so as to cover the outflow hole of the chip body, and is provided with a plurality of rectifying holes for rectifying the shield gas flowing out of the outflow hole;
A gas shield arc including a cylindrical nozzle that is insulated and detachably fitted to the tip body so as to surround the orifice and the tip, and blows out the shielding gas flowing out from the rectifying hole of the orifice toward the welding target A welding torch tip unit,
A cylindrical nozzle
A metal cylinder comprising a mounting cylinder part that is detachably attached to the chip body, and a threaded cylinder part that is provided in front of the mounting cylinder part and that is provided with a female thread part on the inner surface of the cylinder. Shaped fixed body,
A male screw that is fitted in the cylindrical fixing body and covers the inner surface region from the inner side from the tip of the cylindrical fixing body to the portion facing the rectifying hole of the orifice from the inside, and is screwed into the female screw portion of the cylindrical fixing body The part is composed of a protective cylinder part provided on the outer surface of the cylinder, and a cylindrical nozzle body made of carbon comprising a nozzle tip cylinder part protruding from the tip of the cylindrical fixed body ,
Further, an insulating cylinder that is externally fitted to a portion closer to the rear end than the outflow hole of the chip body and in which the mounting cylinder portion of the cylindrical fixing body of the nozzle is detachably attached, insulates the chip body from the cylindrical fixing body. With
The orifice includes a flange projecting outward at the rear part of the rectifying hole, and the cylindrical fixing body of the nozzle includes a locking projection projecting inward from the inner surface of the cylinder,
Positioning the orifice by sandwiching the flange portion of the orifice from the front and back between the tip of the insulating cylinder and the locking projection of the cylindrical fixed body,
The protective cylinder portion of the cylindrical nozzle body is provided so that the rear end thereof is in contact with the outer surface of the orifice between the rectifying hole and the flange portion of the orifice over the circumferential direction thereof. > A torch tip unit for gas shielded arc welding. A chip body coupled to the torch body, provided with a gas flow path through which the shield gas flows, an outflow hole through which the shield gas communicated with the gas flow path flows out, and a through hole through which the welding wire is inserted;
A tip coupled to the tip of the tip body and energized to a welding wire inserted through the tip body;
An insulating orifice that is externally fitted to the chip body so as to cover the outflow hole of the chip body, and is provided with a plurality of rectifying holes for rectifying the shield gas flowing out of the outflow hole;
A gas shield arc including a cylindrical nozzle that is insulated and detachably fitted to the tip body so as to surround the orifice and the tip, and blows out the shielding gas flowing out from the rectifying hole of the orifice toward the welding target A welding torch tip unit,
A cylindrical nozzle
A metal cylinder comprising a mounting cylinder part that is detachably attached to the chip body, and a threaded cylinder part that is provided in front of the mounting cylinder part and that is provided with a female thread part on the inner surface of the cylinder. Shaped fixed body,
A male screw that is fitted in the cylindrical fixing body and covers the inner surface region from the inner side from the tip of the cylindrical fixing body to the portion facing the rectifying hole of the orifice from the inside, and is screwed into the female screw portion of the cylindrical fixing body parts is composed of a protective tube portion provided on the outer cylindrical surface, the carbon-made cylindrical nozzle body and a nozzle tip tube portion protruding from the distal end of the cylindrical fixed body,
Further, an insulating cylinder that is externally fitted to a portion closer to the rear end than the outflow hole of the chip body and in which the mounting cylinder portion of the cylindrical fixing body of the nozzle is detachably attached is provided to insulate the tip body from the cylindrical fixing body. Prepared,
The orifice includes a flange projecting outward at the rear portion of the rectifying hole, and the cylindrical nozzle body of the nozzle includes a locking projection protruding inward at the rear end,
The gas is characterized in that the orifice is positioned by sandwiching the flange portion of the orifice from the front and back thereof by the tip of the insulating cylinder and the locking projection of the cylindrical nozzle body. Torch tip unit for shielded arc welding.

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