JPS63215380A - Welding torch - Google Patents

Abstract

PURPOSE:To prevent the thermal damage of a welding torch by arranging a conductive barrel-shaped body having elastic side walls to a head fitting part and inserting the head base end side into the barrel-shaped body and expanding the elastic side walls to hold a head elastically. CONSTITUTION:A head fitting hole 5 is formed on the tip part of a torch main body 1 and the barrel-shaped body 7 consisting of a cylindrical body 8 and a C-shaped elastic ring 9 is arranged with respect to the hole 5. The cylindrical body 8 is constituted of a conductive material and an external screw part 10 is formed on one end side and the elastic side walls 12 to deform elastically are formed on the other end via slits 11. When a base end member 27 of the head 2 is inserted into the inside of the barrel-shaped body 7 in the fitting hole 5, the outside peripheral surface of the member 27 comes into contact with the inside of the elastic side walls 12 and the sufficient contact area is maintained between the side walls 12 and the member 27. By this method, the thermal damage by the contact resistance of the member 27 with a peripheral member is eliminated and the thermal damage of the welding torch is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a welding torch, and particularly to a welding torch suitable for industrial robot welding equipment.

(Prior Art) Recently, with the automation of welding, industrial robot welding devices have come into practical use. One of the problems with this welding equipment is that if a part of the welding torch breaks down or wears out, the equipment must be temporarily stopped and the operator must replace the part. One of the problems is that it does not work. In order to eliminate such problems, it is conceivable to configure the welding torch so that parts of the welding torch that are prone to failure, wear, etc. can be easily removed from the torch body, and replacement parts can be easily attached. As a conventional example of such a welding device, there can be mentioned, for example, a device for MIG described in Japanese Patent Application Laid-Open No. 61-286071. FIG. 6 shows the attachment structure between the torch body and head of the welding torch in this welding device. In the figure, reference numeral 51 denotes a torch body, and a head attachment hole 52 is formed at its tip (lower side in the figure). A centering member attachment recess 53 is further formed at the bottom of the surrounding wall that defines the head attachment hole 52 (upper side in the figure). A wire feeding hole 54 is opened in the upper side of the figure. An annular groove 55 is formed in the side surface of the peripheral wall defining the head attachment hole 52.
Balls 56 are arranged approximately evenly inside. This ball 56 is urged inwardly into the head attachment hole 52 by a coil spring 57. Further, this annular groove 55 communicates with the vicinity of the exit of the wire feeding hole 54 to the centering member attachment recess 53 through a communication space 58, and a wire cutting member 59 is disposed in this communication space 58. This wire cutting member 59 is located at the tip of the lever-shaped main body (
It has a cutter part 60 at the upper part of the figure, and a protrusion part 61 at the base end, and the protrusion part 61 is urged by a coil spring 62 from the annular groove 55 toward the inside of the head attachment hole 52. . When the protrusion 61 is pushed into the annular groove 55 against this biasing force, the cutter 60 crosses the wire feeding hole 54 due to the lever principle, and at this time the wire 63
It has been like cutting.

Further, a conductive centering member 64 is fitted into the centering member attachment recess 53 . A centering hole 65 is formed in the centering member 64, and the centering hole 65 connects the wire feed hole 54 and the head attachment hole 5. It is designed to communicate with The alignment hole 65 widens conically from the wire feed hole 54 side toward the head attachment hole 52 side.

In the torch body 51, 66 is a shielding gas supply port, and 67 is a cooling water supply port, both of which open toward the head attachment hole 52. On the other hand, the head attachment hole 52
The base end side (upper side in the figure) of the head 70 is inserted and attached to the head 70, and this head 70 has a shield gas nozzle 71 and a wire nozzle (not shown) on the distal end side. , an annular groove 72 is formed on the outer circumferential surface of the proximal end thereof. Furthermore, a conductive conical projection 73 is formed protruding from the base end of the head 70, and adjacent to the conical projection 73, one end side of a shielding gas pipe 74 and a cooling water pipe 75 are connected. One end protrudes. Further, at the top of this conical projection 73, a wire artificial arrow is formed for guiding the wire 63 toward the wire nozzle. In the torch main body 51 and the head 7o having the above configuration, in the attached state, the ball 56 urged by the coil spring 57 protrudes inward of the annular groove 72 of the head 70 and presses the peripheral wall defining the annular groove 72. The head 70 is fixed to the torch body 51, and the outer peripheral surface of the conical protrusion 73 of the head 70 contacts the peripheral wall surface defining the alignment hole 65, thereby simultaneously aligning the head 70 and the torch body 51. becomes. At this time, one end side of the shielding gas pipe 74 and one end side of the cooling water pipe 75 of the head 70 are connected to the shielding gas supply port 66 and the cooling water supply port 67 of the torch body 51, respectively.

During welding, the wire 63 is fed from the wire feeding hole 54 of the torch body 51 to the tip side of the wire nozzle through the wire aperture at the top of the conical projection 73 of the head 700, and the current is passed through the torch body 51. Side alignment hole 6
It is supplied to the head 70 side from the peripheral wall surface defining 5 through the outer peripheral surface of the conical protrusion 73. The seal gusset is connected from the torch body 51 side to the head 7 through the above connection part.
The cooling water is supplied to the shield gas nozzle 71 of No. 0, and the cooling water is supplied to the head 70 side through the above connection part (although not shown, the cooling water supplied to the head 70 side is supplied to the torch body 51 side. ),
Furthermore, when the head 70 is removed from the torch main body 51, the protrusion 61 of the wire cutting member 59 that has been biased to protrude inward from the annular groove 72 of the head 70 is removed from the annular groove 72 of the head 70.
2 is pushed into the annular groove 55 on the head attachment hole 52 side by the outer circumferential surface on the proximal side of the wire feed hole 54 , and the cutter portion 60 acts like a lever to push the wire feeding hole 54 . The wire 63 is cut across, and the head 70 can be separated from the torch body 51.

In this way, in the conventional welding torch, the head 70
A ball 56 urged by a coil spring 62 projects inside the annular groove 72, and the ball 56 is pressed against the peripheral wall defining the annular groove 72. It can be attached and detached by axial movement. Moreover, when the head 70 is removed, the wire 63 is cut inside the torch body 51 by the wire cutting member 59, so that the head 70 can be removed from the torch body regardless of the state of the portion of the wire 63 protruding from the wire nozzle. 51.

(Problems to be Solved by the Invention) The above welding torch has the following problems. That is, the current is supplied from the torch body 51 side to the head 70 side through the contact portion between the peripheral wall surface defining the alignment hole 65 and the outer peripheral surface of the conical protrusion 73. It is extremely difficult to process these two surfaces so that they match perfectly and make surface contact, so in reality, there is a gap between these two surfaces that occupies a large area, and the contact area is small. is the reality.

As a result, Joule heat caused by the contact resistance concentrates on the contact portion as described above, and the temperature of that portion becomes high, which may cause thermal damage to the contact portion and surrounding members.

This invention has been made to solve the above-mentioned conventional drawbacks, and its purpose is to make it possible to freely attach and detach the head from the torch body only by axial movement, and to make it possible to attach and detach the head from the torch body through which the current flows. It is an object of the present invention to provide a welding torch that can secure a sufficient contact area at a contact portion between a main body and a head, and therefore does not cause thermal damage to the contact portion and surrounding members.

(Means for solving the problem) Therefore, in the welding torch of the present invention, the proximal end side 27 of the head 2 is attached to the head attachment part 5 of the torch body 1, and the head is attached from the torch body 1 side. This welding torch has a structure in which shielding gas and current are supplied to the head 2 side through the attachment part 5, and the head attachment part 5 has an elastic side wall 1.
2... is disposed, and by inserting the proximal end 27 of the head 2 into the tubular body 7 and expanding the elastic side walls 12..., the head 2 The proximal end 27 of the head 2 is elastically held by the cylindrical body 7 in a detachable manner, and current is supplied to the head 2 through the cylindrical body 7.

(Function) In the welding torch configured as described above, the cylindrical body 7 having the elastic side walls 12 is disposed in the head attachment portion 5 of the torch body 1, and the base end side 27 of the head 2 is connected to the cylindrical body 7. The proximal end 27 of the head 2 is elastically held by the cylindrical body 7 by inserting it into the cylindrical body 7 and expanding the elastic side walls 12 .
It is possible to make it detachable from the Moreover, when the elastic side walls 12 of the cylindrical body 7 are expanded by the proximal end 27 of the head 2, they come into close contact with the outer circumferential surface of the proximal end 27 of the head 2, and the current flows through them. It is possible to secure a sufficient contact area of the contact portion, which prevents generation of Joule heat due to large contact resistance, and prevents thermal damage to the contact portion and the surrounding member 1.

(Example) Next, regarding a specific example of the welding torch of this invention,
This will be explained in detail with reference to the drawings.

One embodiment is shown in FIGS. 1 to 5. In FIG. 1, numeral 2 is the torch body, and 2 is the head. As shown in FIGS. 3 and 5, the torch body 1 has wiring, hoses 3, etc. connected to its sides for supplying electric current, shielding gas, and cooling water. Further, on the tip side (lower side in FIG. 3) of the torch body 1, the tip of a conduit 4 for feeding the wire is arranged. - Power cylinder 1 As shown in the figure, a head attachment hole 5 with a circular cross section is formed at the tip of the torch body 1, and the inner periphery of the opening of this head attachment hole 5 is formed. A female threaded portion 6 is formed in the wall. A cylindrical body 7, which will be described below, is disposed in this head attachment hole 5. That is, as shown in FIGS. 1 and 3, this cylindrical body 7 is composed of a cylindrical body 8 and a C-shaped elastic ring 9.
is made of a conductive material, and has a male threaded portion 1o formed on the outer periphery of one end thereof, and a plurality of slits 11 extending from the other end to the vicinity of this male threaded portion 10. That is, in this cylindrical body 8, the side walls 12 between these slits 11 constitute elastic side walls 12 that elastically deform inward and outward of the cylindrical body 8 like a leaf spring. becomes. As shown in FIG. 1, the C-shaped elastic ring 9 is fitted onto the outer periphery of the cylindrical body 8 on the side of the elastic side walls 12.・It is made to tilt inward. As shown in FIG. 1, the cylindrical body 7 configured as described above has elastic side walls 12...
It is inserted into the head attachment hole 5 of the torch main body 1 from the side, and the male threaded part 10 on the cylindrical body 7 side is screwed into the female threaded part 6 on the head attachment hole 5 side, and the torch is inserted into the head attachment hole 5. It will be fixed.

On the other hand, as for the head 2, as shown in FIGS. 3 and 4, a collar 15 extending radially outward is fixed to approximately the center of the head body 14, and the collar 15 is fixed to the tip side (lower side in each figure). Eight portions 16 are formed on the outer periphery. The gas nozzle 17 is fitted into the tip of the head body 14 and screwed onto the vaginal thread 16. At this time, an insulating ring 18 is interposed between the collar 15 and the gas nozzle 17.
The gas nozzle 17 spirals on the male threaded portion 16 until it is tightened between the gas nozzle 17 and the gas nozzle 17. Further, as shown in FIG. 4, a center through hole 20 is formed in the head body 14;
A tapered portion 21 whose diameter decreases from the proximal end toward the distal end is formed on the distal end side of the peripheral wall that defines the circumferential wall. A collet 22 is inserted into the center through hole 20 from its base end opening. This collet 22 is a rod-shaped member having a shaft hole 23 large enough to allow an electrode rod to be inserted therein, and a plurality of slits (not shown) are formed at the tip side of the collet 22, and a plurality of slits (not shown) are formed at the tip end. A tapered portion 24 whose diameter is reduced is formed. The collet 22 is inserted into the center through hole 20 of the head body 14 from the tapered portion 24 side, so that the taper portion 24 of the collet 22 comes into contact with the taper portion 21 of the center through hole 20. Further, as shown in FIGS. 3 and 4, a male threaded portion 26 is formed on the outer peripheral surface of the head body 14 on the proximal side of the position of the collar 15.
A hollow cylindrical base end member 27 is screwed onto the base end member 6 . At this time, the proximal end member 27 is screwed until one end comes into contact with the collar 5 and is tightened by the collar 5 (see FIG. 4). A pressing screw 28 is screwed into the proximal end of the proximal member 27 . This pressing screw 28
screws the inner peripheral part of the proximal end member 27 toward its distal end,
Its distal end surface is brought into contact with the proximal end surface of the collet 22. 20 When the pressing screw 28 is tightened in the abutting state, the taper part 24 of the collet 22
This pressing causes the side wall between the slits on the tip side of the collet 22 to deform inward. The electrode rod is gripped by the inward deformation of this side wall.

Further, an annular groove 3o is formed in the outer peripheral part of the proximal end member 27, and a peripheral wall defining this annular groove 30 has an annular groove 3o formed in the outer circumference of the proximal end member 27.
A plurality of ventilation holes 31 . . . are formed at intervals. Further, as shown in FIG. 4, a vent hole 32 is formed at the tip side of the head body 14 to ventilate the inside of the center through hole 2o and the shield gas blowing part 33 at the tip of the head body 14. being done. That is, the shielding gas supplied inside from the vent holes 31 of the base end member 27 flows inside the base end member 27 and the head body 14 along the outer peripheral surface of the collet 22 to the vent holes 32 of the head body 14. The shielding gas flows through the ventilation hole 32 and is blown out from the shielding gas blowing section 33.

Next, we will explain the attachment operation between the torch body 1 and the head 2.
This will be explained based on the diagram and FIG. First, the base end member 27 side of the head 2 is inserted into the cylindrical body 7 in the head attachment hole 5 of the torch body 1. With this insertion operation, the outer peripheral surface of the base end member 27 comes into contact with the inner surface of the elastic side walls 12 of the cylindrical body 7, and gradually expands the elastic side walls 12. At this time, the C-shaped elastic ring 9 also increases in diameter. The attachment operation is completed when the head 2 has been inserted to the point where the flange 15 of the head 2 comes into contact with the tip end surface of the torch body 1. This state is shown in FIG. 2, and as shown,
The elastic side walls 12... are expanded to a substantially original shape by the base end member 27, and the elastic side walls 2... The inner surface of the base member 27 is elastically pressed against the outer peripheral surface of the proximal end member 27, and comes into close contact with the outer peripheral surface of the proximal end member 27. On the other hand, as for removing the head 2, as is clear, if the head 2 is pulled out toward the distal end, it can be removed only by movement in the axial direction.

On the other hand, current is supplied from the torch body 1 side to the head 2 side via the cylindrical body 7. That is, to explain with reference to FIGS. 1 and 2, the current from the torch body 1 first passes through the threaded portion between the female threaded portion 6 on the head attachment hole 5 side and the male threaded portion 1o on the cylindrical body 7 side. It is supplied to the elastic side walls 12... This current is then supplied to the head 1 side through the contact portion between the inner surface of the elastic side walls 12 and the outer peripheral surface of the proximal end member 27 of the head 1. Note that the current supplied to the head 2 side is supplied from the head body 14 to the electrode rod through the tapered portion 24 of the collet 22.

As described above, in the above embodiment, the cylindrical body 7 having the elastic side walls 12 tilted inward by the C-shaped elastic ring 9 is disposed within the head attachment hole 5 of the torch body 1. By inserting the proximal end member 27 of the head 2 into the cylindrical body 7 and expanding the elastic side walls 12, the proximal end member 27 of the head 1 is elastically held in the cylindrical body 7. Therefore, the head 2 can be attached to and detached from the torch body 1 only by movement in the axial direction.

Moreover, when the head 2 is attached, the inner surfaces of the elastic side walls 12 come into close contact with the outer circumferential surface of the proximal end member 27 of the head 2, ensuring a sufficient contact area and preventing Joule heat in the contact area. Concentration can be prevented, and thermal damage to the contact portion and surrounding members can be prevented.

Although specific embodiments of the welding torch of the present invention have been described above, the present invention is not limited to the above embodiments, and can be implemented with various modifications within the scope of the present invention. For example, the cylindrical body 7 in the above embodiment is configured such that its elastic side walls 12 are tilted inward by the C-shaped elastic ring 9; A cylindrical body tilted inward by plastic working or the like may be used. Also, in the above, TIG
Although an example in which the present invention is applied to a welding torch is shown, it can be similarly applied to a MIG welding torch.

(Effects of the Invention) As described above, in the welding torch of the present invention, the head can be attached to and detached from the torch body only by axial movement, and the head and the torch body side through which the current passes It is possible to ensure a sufficient contact area of the contact portion with the side, and therefore it is possible to prevent thermal damage to the contact portion and surrounding members.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the state before the torch body and head are attached according to an embodiment of the welding torch of the present invention, FIG. 2 is an explanatory diagram showing the state after the torch body and head are attached, and FIG. FIG. 4 is a partially sectional view of the above embodiment, FIG. 5 is an external view of the above embodiment, and FIG. 6 is a partially sectional view of a conventional welding torch. ■... Torch body, 2... Head, 5... Head attachment hole (head attachment part), 7... Cylindrical body, 12...
Elastic side wall, 27... Base end member (base end side of head 2). Figure 1 Figure 2 Figure 6

Claims (1)

[Claims] 1. Connect the proximal end (27) of the head (2) to the torch body (1)
Attach it to the head attachment part (5) of the torch body (1).
This welding torch has a structure in which shielding gas and current are supplied from the side to the head (2) side via the head attachment part (5), and the head attachment part (5) has an elastic side wall ( 1
2) A conductive cylindrical body (7) having... is disposed, and the proximal end (27) of the head (2) is inserted into this cylindrical body (7), and the elastic side wall (12).・By expanding the base end (27) of the head (2), the cylindrical body (
7) to removably elastically hold the current to the cylindrical body (7).
A welding torch characterized in that a welding torch is supplied to a head (2) side through.