JPH0256993B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an improvement in a welding tip applied to a welding torch using a consumable electrode wire and a method for manufacturing the same.

Prior Art Generally, this type of welding torch uses a welding tip with a hole diameter compatible with the consumable electrode wire, but since this welding tip is subject to severe wear, there is a need for a welding tip with a long lifespan. ing. To deal with this, conventional methods have been used, for example, in Figure 1a.
and b were proposed. That is, for example, if the desired consumable electrode wire diameter is d ₁ mm
, there is a diameter d ₂ approximately at the axial center of the chip body 1'.
A small diameter hole of mm, where d ₂ = d ₁ + (0.1 to 0.2) is drilled, and a bottomed hole 10 is made at the tip of the chip body.
2', and after inserting a wear-resistant tip member 2' into this hole, the tip part of the tip body is caulked to integrate the tip body and the tip member.
In this case, for example, when manufacturing a welding tip to be applied to an electrode wire with d ₁ = 1.0 mm, a small-diameter drill with d ₂ = 1.1 to 1.2 mm is used, so the drill easily breaks and the processing process is difficult. This process must be performed at low speed, and the hole with a bottom must be machined with relatively high precision, which is troublesome and is not suitable for mass production.

Since the holes are drilled with a small diameter drill, the holes are eccentric between the base and the tip of the chip body, and the eccentric direction of the holes with respect to the chip body is often not at a constant position.

When the tip of the tip body is caulked, the position at which the tip member is fixed to the tip body is not constant. That is, during the crimping operation, the tip member is fixed at a position deviated in the radial direction with respect to the axis of the tip body, so the drilled hole in the tip part of the tip body and the through hole in the tip member are coaxial. It won't happen.

Due to the above and the above, the hole in the tip body and the through hole in the tip member are eccentric, and since this eccentricity differs for each welding tip, when replacing the welding tip with a new one, , the feeding direction of the electrode wire fed through the welding tip changes. That is, when replacing the welding tip, the reproducibility of the target position of the electrode wire can be ensured, and therefore this type of welding tip cannot be used in an automatic welding machine.

Furthermore, because the wire passage of the welding tip is not straight, the electrode wire is forcibly brought into contact with the inner wall of the passage of the welding tip, thus maintaining smooth feeding of the electrode wire. I can't.

There was a drawback.

In addition to the above methods, shrink fitting, gluing, or brazing have been used as means for attaching the tip member to the tip body, but these attachment methods still have various problems. .

That is, generally during welding, the tip of the welding tip is exposed to arc heat and kept at a high temperature, and the electrode wire is welded to the workpiece during welding.
The so-called stick phenomenon often occurs and an unexpected impact force is applied to the tip member, and the thermal expansion coefficients of the tip body and the wear-resistant tip member are different, so the state of shrink fit or brazing may be affected. There have been cases in which the tip member has separated from the tip body due to the adhesive being released or the bonding state being released due to evaporation of the adhesive, forcing the welding operation to be interrupted. In particular, when attaching the tip member to the tip body by brazing, the tip part of the welding tip is kept in a high temperature state during welding due to the difference in thermal expansion coefficient between the tip member and the tip body. The state of attachment of the tip member by brazing is uncertain,
Moreover, it had the disadvantage that the brazing work was troublesome and was not suitable for mass production.

Purpose of the Invention The present invention has been made in view of the above problems, and is capable of achieving high reproducibility of the aiming position of the electrode wire when replacing the welding tip, ensuring the attachment of the tip member, and facilitating processing. It is an object of the present invention to provide a welding chip that can be mass-produced and has excellent electrode wire feedability, and a method for manufacturing the same.

Embodiments The present invention will now be described in detail with reference to illustrated embodiments.

In FIGS. 2 to 6, reference numeral 1 denotes a chip body with a large diameter hole 101 formed approximately in the axial center.As is well known, this chip body 1 is made of copper or copper alloy, and the tip end thereof is made of copper or copper alloy. That is, at the end in the _Y1 direction, there is a bottomed hole 10 communicating with the large diameter hole 101.
2 are arranged.

Incidentally, a mounting screw 103, for example, is provided on the base side of the chip body 1, that is, the end on the _Y2 direction side. Reference numeral 2 denotes a wear-resistant tip member, which has a through hole 201 formed approximately in its axial center, and an engagement on the outer surface of the tip member 2 for engaging with the tip of the tip body 1. Joining part 3, for example tip member 2
A plurality of grooves extending in the axial direction are formed on the outer circumference of the shaft.

Note that the tip member 2 is formed of, for example, a Cu--W sintered alloy.

In addition, the outer diameter: D ₂ and inner diameter: D ₁ of the tip member 2 are set to appropriate values, for example, D ₁ −D ₂ =0.5 mm, so that the tip member 2 can freely enter the bottomed hole 102. There is. This tip member 2 is inserted into the bottomed hole 102 of the tip body 1, and the outer diameter is slightly smaller than the inner diameter _d4 of the through hole 201 of the tip member 2.
d ₅ hard wire 3 is inserted into the tip member 2 and the tip body 1. Thereafter, the large-diameter portion of the die 4, which has a predetermined diameter-reducing hole and is made of, for example, 41 to 44, and the tip end of the chip are brought relatively close to each other in the axial direction, and swaging is performed from the tip end to the center of the chip. Perform processing. Swaging is performed gradually from the tip to the center of the tip body 1, but since the tip member 2 is restrained in the radial direction by the hard wire 3, the tip of the tip body 1 where the tip member 2 is located Even if the tip member 2 is deformed by swaging, the radial position of the tip member 2 is hardly displaced. Further, as the tip body 1 is swaged from the tip to the center, the large diameter hole 101 of the tip body 1 is constricted inward to fit the hard wire 3. Furthermore, as the tip body 1 is squeezed inward and expanded in the longitudinal direction by the swaging process, the tip of the tip body 1 enters the engagement portion 3 of the tip member 2, for example, a groove, and is firmly engaged. match. Furthermore, reference numeral 5 denotes a support that is in contact with the end of the tip body 1 in the _Y2 direction and moves together with the tip body 1 relative to the die 4 in the axial direction. Ends in _two Y directions are supported. Of course, the hard wire 3 located in the _Y1 direction relative to the tip member 2 is positioned in the radial direction by appropriate means. In this case, as shown in FIG. 4(A), the end face of the support 5 and the tip body 1
Alternatively, as shown in _FIG . 4(B), the mounting screw 103 of the chip body 1 and the support 5 can be screwed together.

As described above, after performing the swaging process from the tip to the desired center of the chip body 1, the hard wire 3 is pulled out. Note that, as shown in FIG. 6, it is preferable to remove the protruding portion formed at the tip end of the tip by swaging by an appropriate process, since this increases the added value of the tip as a welding tip. That is, by removing the protruding portion at the tip end, there is no risk of injury to the operator, and the appearance of the product is improved.

Welding chips manufactured by the above method are
For example, as shown in FIG. 6, a relatively long small diameter hole 1 extends from the approximate center of the tip body 1 to the tip.
04 is formed, but since this small diameter hole 104 is formed to fit the stranded hard wire 3 by swaging processing, this small diameter hole 104 and the through hole 20 of the tip member 2
1 and is arranged substantially coaxially.

Also, since this small diameter hole 104 is formed by swaging to fit the hard wire 3,
Large diameter hole 101 and small diameter hole 10 in chip body 1
The boundary portion with 4 is in communication with an appropriately inclined curved surface.

FIGS. 3b to 3e are views showing main parts of other embodiments of the present invention, and the tip member 2 shown in FIG. is formed. The tip member 2 shown in FIG. 3c has a plurality of countersunk-shaped portions formed on the outer periphery as the engaging portion 3. Further, the tip member 2 shown in FIG. 3d has a tapered portion formed on the outer periphery as the engaging portion 3. Furthermore, the tip member 2 shown in FIG. 3e has a circumferential groove formed in the outer circumferential portion as the engaging portion 3.

If the tip member is formed as shown in FIGS. 3a to 3c, the tip member will be positioned in the long axis direction of the tip body and in the circumferential direction around the long axis, so that the welding tip can be reliably integrated. can be obtained.

The tip member is made of a Cu-W sintered alloy, and the material cost is low and it is easy to manufacture.This wear-resistant tip member guides the electrode wire while passing it through the tip member. Since power can be supplied to the electrode wire over a long period of time, the welding tip can be used for a long period of time. Similarly, the tip member may be formed of an appropriate alloy member having wear resistance and relatively good conductivity, such as Cu--Fe, Be--Cu, Ag--W. Despite this,
The tip member can also be formed of a material with poor electrical conductivity and wear resistance.

Furthermore, screw 1 for mounting on the base side of the torch body.
03 can be a female thread, and by arranging the mounting screw in this way, the welding tip can be easily and reliably attached to and removed from the welding torch. It can also be configured to be detachable by means such as a split clamp means, a set bolt, or a cap nut. Further, the engaging portion on the outer surface of the tip member may have a non-circular cross section or may have an appropriate groove, for example, a knurled groove.

As described above, according to the present invention, the chip body 1
enters the engaging portion 3 of the tip member 2 and the tip member is attached to the tip of the tip body, so there is no risk that the tip member will separate from the tip body even if the welding tip is exposed to high temperatures during welding. . Moreover, since the relatively long small diameter hole 104 and the through hole 201 of the tip member 2 are formed approximately coaxially, the passage of the electrode wire as a welding tip is constant, and therefore even if the welding tip is replaced with a new welding tip, the electrode The reproducibility accuracy of the wire aiming position can be maintained substantially uniformly. Furthermore, together with the fact that the relatively long small diameter hole 104 and the through hole 201 of the tip member 2 are formed approximately coaxially,
Since the large-diameter hole 101 and the small-diameter hole 104 of the chip body are communicated with each other by the inclined curved surface, the feeding performance of the electrode wire is not hindered.

In addition, since the hole previously drilled in the tip body 1 can be the large diameter hole 101, there is less chance of drill breakage, and the large diameter hole in the tip body can be machined at a relatively high speed. Since the hole diameter of the bottomed hole 102 provided at the tip of the chip body 1 may be an approximate value, processing can be easily performed.
In addition, since the welding tips can be manufactured by swaging as described above, they can be mass-produced, and therefore, the welding tips can be manufactured at low cost.

Effects of the Invention As detailed in the above embodiments, according to the present invention,
Even when the welding tip is replaced, the reproducibility of the aiming position of the electrode wire can be maintained almost uniformly, the tip member is securely attached and will not come off, and it is easy to process and weld. It is possible to mass-produce welding tips at low cost, and to obtain long-life welding tips with excellent electrode wire feedability.

[Brief explanation of drawings]

FIGS. 1a and 1b are vertical cross-sectional views for explaining the manufacturing process of a conventional welding tip, and FIGS. 2 and 3a are main views for explaining the pre-process of the welding tip of the present invention. FIG. 2 is a longitudinal section, FIG. 3 a is a longitudinal half section, and FIGS. 3 b to 3 e each show main parts of other embodiments of the present invention. 4a is a longitudinal sectional view for explaining the manufacturing process of the welding chip of the present invention, FIG. 4b is a diagram showing a modification of FIG. 4a, and FIG.
The figure is a sectional view taken along the line -- in FIG. 4, and FIG. 6 is a partially cutaway front view of the welding tip of the present invention. 1... Chip body, 101... Large diameter hole, 102... Bottomed hole, 104... Small diameter hole, 2... Tip member, 20
1...Through hole, 3...Hard wire, 4...Dice.

Claims (1)

[Scope of Claims] 1. A large-diameter hole and a small-diameter hole are provided from the base side toward the tip side, and a wear-resistant tip member is provided on the tip side of the small-diameter hole, and The through hole drilled in the member and the small diameter hole are formed substantially coaxially, and the tip member is held by engagement between an engaging portion formed on an outer surface of the tip member and the tip body. A welding tip. 2. The tip according to claim 1, wherein the tip member is positioned by the engaging portion in the longitudinal direction of the tip body and in the circumferential direction around the longitudinal axis. 3 A large diameter hole is bored approximately in the axial center of the chip body, a bottomed hole communicating with the large diameter hole is provided at the tip, and a small diameter hole passes through the bottomed hole. A hard wire having a diameter slightly smaller than the small diameter hole is inserted into the tip member and the chip body, and the large diameter part of the die having a predetermined diameter reducing hole and the tip end are connected. A swaging process is performed from the tip to the center of the chip while moving them relatively close to each other in the axial direction, and by this swaging process, the drilled hole located from the tip to the center of the chip is separated from the hole after swaging. Welding in which the through hole of the tip member is formed substantially coaxially with the through hole, and the tip member is held on the tip body by engagement between the engagement portion formed on the outer surface of the tip member and the tip tip portion. Method of manufacturing chips for use.