JPH0330471B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a gas shielded arc welding nozzle, and particularly to a gas shielded arc welding nozzle with improved durability and welding workability. It depends.

(Prior Art) Conventionally used gas shielded arc welding nozzles are integrally formed of metal (copper) and are used by being screwed onto the tip of a welding torch.

(Problems to be Solved by the Invention) In this gas-shielded arc welding nozzle, the tip of the nozzle wears during use, making it easy for welding spatter to adhere, and welding This method has disadvantages in that it requires interruption of work and a great deal of effort to remove firmly adhered spatter. Moreover, the adhering spatter may cause a bridge between the welding tip and the nozzle.
When the nozzle comes into contact with the workpiece during welding work, a short circuit occurs between the welding tip and the workpiece through the nozzle, causing damage to not only the nozzle but also the torch body. . This not only causes the disadvantage of economic loss due to damage to equipment, but also causes psychological pressure on workers who must always be aware of the above-mentioned short-circuit phenomenon during welding work. It is also a contributing factor.

In addition, even in automatic welding using robots, etc., whose application has been rapidly expanding in recent years, from the viewpoint of continuous work over a long period of time, spatter adhesion to the nozzle as described above and the accompanying Preventing damage to equipment has become an important technical challenge.

In order to prevent the above-mentioned drawbacks, it may be possible to form the entire gas-shielded arc welding nozzle from a non-conductive material such as ceramic, but as is well known, ceramics may have notches etc. Since this material is easily damaged, even if a gas-shielded arc welding nozzle of the same shape as a conventional one is formed using this material, it would be extremely difficult to put it into practical use as is.

Therefore, the present applicant filed an earlier application (Japanese Patent Application No. 1983-
No. 200573 (see Japanese Unexamined Patent Publication No. 60-92086)),
A support ring is screwed onto the tip of the welding torch, and a grip claw having an engaging protrusion is formed at the tip of the support ring, while a concave groove is formed around the outer periphery of one end of the ceramic nozzle member. We have proposed a welding nozzle having a structure in which the nozzle member is fixed to the welding torch by fitting the engaging protrusion into the groove.

Although this welding nozzle can eliminate the above-mentioned drawbacks, since the nozzle member is required to have high dimensional accuracy due to the use of the above-mentioned concave-convex fitting, it takes a lot of time to machine it. As a result, the nozzle member becomes expensive.

This invention was made in view of the above, and its purpose is to have a structure that is difficult to attract spatter, has good removability, can prevent the short circuit phenomenon described above, and can be manufactured at low cost. An object of the present invention is to provide a gas-shielded arc welding nozzle whose durability can be improved.

(Means for Solving the Problems) The gas-shielded arc welding nozzle of the present invention, which meets the above object, includes a support ring attached to the tip of a welding torch, and a cylindrical nozzle attached to the tip side of the support ring. The nozzle member has a nozzle member and a holding means for fixing the nozzle member to a support ring, and the nozzle member is formed of ceramics and has a concave groove with an arcuate cross section circumferentially on one end side. and a radially outward protrusion is formed by fitting an elastic ring having a circular cross section into the concave groove, and the holding means is formed with an engagement surface that engages with the protrusion; Furthermore, a pushing mechanism is provided between the support ring and the holding means for pushing the engagement surface that engages with the protrusion toward the welding torch side. .

(Function) Since the nozzle member is used as described above and is made of ceramic, spatter is difficult to adhere to, and its peelability is good, and there is also a barrier between the chip and the object to be welded. It becomes possible to prevent short circuit phenomena, and it becomes possible to improve the durability of the gas shielded arc welding nozzle. Moreover, since welding can be performed with the nozzle member in contact with the workpiece, shielding failure due to the influence of wind can be prevented, and the arc length can always be kept constant, increasing welding work efficiency. It becomes possible to improve.

Moreover, since the above structure is employed, the nozzle member is not required to have high dimensional accuracy, and the nozzle member and, by extension, the entire welding nozzle can be provided at low cost.

Further, since the nozzle member does not have an edge portion, defects such as cracks caused by stress concentration can be prevented.

(Example) Next, the gas shielded arc welding nozzle of the present invention will be described in detail with reference to the accompanying drawings showing specific examples.

In FIG. 1, reference numeral 1 denotes a welding torch, and a support ring 2 is screwed onto the tip of the torch, and a cylindrical nozzle member 3 is attached to the tip of the support ring 2.
At the same time, a retaining ring 4 serving as a retaining means is screwed onto the outer peripheral portion of the supporting ring 2. The support ring 2 is provided with threaded parts 5 and 6 on its inner and outer peripheral parts, respectively, and the inner threaded part 5 is screwed onto the tip of the welding torch 1. A step 7 extending in the axial direction is formed at the tip of the support ring 2, and one end of the nozzle member 3 is fitted into the step 7.

The nozzle member 3 is a cylindrical member, and grooves 8, 8 are provided around the outer periphery near both ends of the nozzle member 3, respectively. A ring spring 9 is fitted into one of the recesses 8, and this ring spring 9 serves as a protrusion that engages with an engagement surface to be described later. To form this nozzle member 3, non-conductive materials such as ceramics are used, and among them, Si ₃ N ₄ and ceramics mainly composed of it have excellent high-temperature strength, abrasion resistance, and thermal shock resistance. It has been confirmed that this material is particularly preferable as a material for the nozzle member 3. In addition, we also conducted a test using a nozzle member 3 made of Al _{2 O 3 in} addition to the above-mentioned Si ₃ N 4 etc., but the nozzle member 3 made of Si ₃ N ₄ etc. was far superior in terms of both the amount of spatter attached and the spatter removability. It was confirmed that it is excellent.

The retaining ring 4 is provided with a threaded portion 10 on the inner periphery of its base, which can be threadedly engaged with a threaded portion provided on the outer periphery of the support ring 2, and a threaded portion 10 that can be threaded inward in the radial direction at the tip thereof. an engagement surface 11 in which a protrusion is formed, and the inner surface of the protrusion can engage with the ring spring 9;
It is said that

Note that various materials can be used to form the support ring 2 and the retaining ring 4, but only materials that have good workability and that can effectively cool the nozzle member 3 from the welding torch main body side are used. Copper-based materials such as copper and brass are particularly suitable in that they have good thermal conductivity.

The gas shielded arc welding nozzle described above is assembled using the following procedure. First, the internal threaded portion 5 of the support ring 2 is screwed onto the tip of the welding torch 1, and one end of the nozzle member 3 is fitted into the stepped portion 7 provided at the tip of the support ring 2. In this state, the retaining ring 4 is screwed onto the outer peripheral threaded portion 6 of the supporting ring 2. In this case, when the retaining ring 4 is rotated, the retaining ring 4 moves toward the torch 1 side,
Along with this, the engaging surface 11 also moves toward the torch 1 side. Then, the engagement surface 11 comes into contact with the ring spring 9 of the nozzle member 3, and from this state, the retaining ring 4
When the nozzle member 3 is rotated, the nozzle member 3 is pressed toward the torch 1 via the ring spring 9, and is held in a pressed state within the stepped portion 7 of the support ring 2.

In the above-mentioned welding nozzle, since the nozzle member 3 made of ceramics is arranged at the tip, it is difficult for spatter to adhere, and even if spatter adheres, it is easy to peel off, and furthermore, it is easy to separate the chip from the welded object. It is possible to prevent a short circuit phenomenon between the welding nozzle and an object, and it is possible to improve the durability of the welding nozzle.
Moreover, since welding can be performed with the nozzle member in contact with the workpiece, it is possible to prevent shield failure due to the influence of wind, and the arc length can always be kept constant, increasing welding work efficiency. It becomes possible to improve.

In addition, because we adopted the mounting structure as described above,
Unlike conventional nozzle members 3, high dimensional accuracy is not required, machining becomes easy, and nozzle members 3, and by extension welding nozzles, can be provided at low cost.

FIG. 2 shows a modification of the support ring 2 and the retaining ring 4. That is, in the above embodiment, a structure was shown in which the threaded portions 6 and 10 of both rings 2 and 4 are screwed together to move with the engagement surface 11, but in this embodiment, a projection is provided on the outer peripheral surface of the support ring 2. 12, and the retaining ring 4 is provided with the protrusion 12.
A guide groove 13 into which the is inserted is provided. In this case as well, it is possible to hold the nozzle member 3 in the same manner as in the above embodiment. Note that the guide groove 13 may be provided at an angle as shown by a solid line in the same figure, or may be formed in a straight line like a groove 13a shown by a broken line in the same figure. In some cases, although not shown, a structure may be adopted in which a spring is attached to the protrusion 12 and the nozzle member 3 is held using the elasticity of the spring.

FIG. 3 shows still another modification of the retaining ring 4. The retaining ring 4 in this case is the support ring 2
A cylindrical member 14 rotatably supported on the outer periphery of
and a ring piece 15 screwed onto the inner periphery of the tip of the cylindrical member 14. By rotating the cylindrical member 14 or the ring piece 15, the ring piece 15 is attached to the torch 1 side via the screw. It is structured so that it can be moved to

FIG. 4 shows a modification of the retaining ring 4, in which the engaging surface 11 is formed in a tapered shape. By tapering the engagement surface 11 in this way, the ring spring 9, that is, the nozzle member 3, is pressed and held not only in the axial direction but also inward in the radial direction, so that the nozzle member 3 can be held more easily. It becomes possible to hold it even more reliably. Note that in order to press and hold the nozzle member 3 inward in the radial direction as described above, the nozzle member 3 is integrally formed with a protrusion, and this protrusion and the engagement surface of the retaining ring are connected together. This is also possible by forming it into a tapered shape.

FIG. 5 shows a modification of the retaining ring 4. The retaining ring 4 in this case is composed of a cylindrical member 14 and a ring piece 15, similar to the one shown in FIG. It has a structure in which the nozzle member 3 is pressed and held inward in the axial direction and radial direction by the tapered surface 16.

Note that the nozzle member 3 in the first embodiment is provided with two grooves 8, 8 near both ends. Of course, it is also possible to provide the groove 8 only at one end so that it can be reversed and used again.

Although one embodiment of the gas shielded arc welding nozzle of the present invention has been described above, the gas shielded arc welding nozzle of the present invention is not limited to the above embodiment, and can be implemented with various modifications. It is. For example, in the above, an example is shown in which the nozzle member is integrally formed of ceramics, but as shown in FIG. may also be used.

(Effects of the Invention) The gas-shielded arc welding nozzle of the present invention is configured as described above. Therefore, according to the gas-shielded arc welding nozzle of the present invention, spatter is difficult to adhere to, and its peeling is prevented. In addition, it is possible to prevent a short circuit phenomenon between the chip and the workpiece to be welded, and as a result, it is possible to improve the durability of the gas-shielded arc welding nozzle. Moreover, since welding can be performed with the nozzle member in contact with the workpiece, shielding failure due to the influence of wind can be prevented, and the arc length can always be kept constant, increasing welding work efficiency. It becomes possible to improve. It has been confirmed that the average service life of the gas-shielded arc welding nozzle of the present invention is several times longer than that of conventional nozzles. Moreover, since the nozzle member is not required to have high dimensional accuracy as in the past, machining becomes easy, and therefore the nozzle member, and by extension, the welding nozzle, can be provided at low cost.

Further, since the nozzle member does not have an edge portion, it is possible to prevent the occurrence of cracks caused by stress concentration, and the durability of the nozzle member and, by extension, the life of the entire nozzle can be improved.

[Brief explanation of the drawing]

Fig. 1 is a central vertical sectional view of an embodiment of the gas shielded arc welding nozzle of the present invention, Fig. 2 a and b
3 is a partial sectional view showing a modified example of the support ring and the retaining ring, FIG. 3 is a longitudinal sectional view of the main part showing another modified example of the retaining ring, and FIG. 4 is a main part showing another modified example of the retaining ring. FIG. 5 is a longitudinal sectional view of the main part showing a modification of the retaining ring, and FIG. 6 is a partial sectional view showing a modification of the nozzle member. 1...Welding torch, 2...Support ring, 3...
Nozzle member, 4... Retaining ring, 6... Threaded part,
8... Concave groove, 9... Ring spring, 10... Threaded portion, 11... Engaging surface.

Claims (1)

[Claims] 1. The nozzle member has a support ring attached to the tip of the welding torch, a cylindrical nozzle member attached to the tip side of the support ring, and a holding means for fixing the nozzle member to the support ring. is formed of ceramics, and has a concave groove with an arcuate cross section around one end, and
A radially outward protrusion is formed by fitting an elastic ring with a circular cross section into the groove, and the holding means has an engagement surface that engages with the protrusion;
Further, a pushing mechanism is provided between the support ring and the holding means to push the engagement surface that engages with the protrusion toward the welding torch. Welding nozzle.