JPH0239652Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a contact tip used for welding.

[Conventional technology]

Conventionally, as a contact chip for welding using a consumable electrode (hereinafter referred to as a wire), those shown in FIGS. 2a and 2b are known. In addition, the figure b
is a sectional view taken along line Y-Y in FIG.

1 in the figure is a cylindrical chip body made of a metal material. This chip body 1 is axially penetrated with a hole 2 having a diameter slightly larger than the outer diameter of a wire fed from a wire reel or the like (not shown).
The upper part of the chip body 1 is a threaded part 3.

[Problems to be solved by the invention] However, according to the conventional contact chip, since the hole 2 with a diameter slightly larger than the outer diameter of the wire is penetrated in the axial direction of the chip body 1, the wire and the chip body The contact with the inner wall of the hole 2 is unstable, and as the diameter of the hole 2 increases due to long-term use, this tendency becomes more pronounced. As a result, welding becomes unstable and a large amount of spatter occurs. Further, the conventional contact tip is discarded when it wears out due to the enlargement of the hole 2.

The present invention was developed in view of the above circumstances, and it is possible to maintain stable contact between the inner wall of the chip body and the wire by sandwiching the wire between the inner walls of the chip body, thereby achieving stable welding under a constant power supply state. The purpose is to provide a contact chip that can be used.

[Means for solving problems]

The present invention provides a welding contact tip using a consumable electrode, which includes a cylindrical first tip body;
A second chip body is provided concentrically in close contact with the outer periphery of the first chip body by brazing and has a coefficient of thermal expansion larger than that of the first chip body, and the first and second chip bodies This contact chip is characterized in that a slit is provided along the axial direction of the main body.

[Function] According to the present invention, by providing the second chip body having a larger coefficient of thermal expansion on the outer periphery of the first chip body, during use of the contact chip,
The inward expansion of the second tip body causes the wire to be compressed against the first tip body, thereby ensuring power supply to the wire and stabilizing welding.

[Implementation row]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 2a and 2b. Note that FIG. b is a sectional view taken along the line X--X in FIG. a.

11 in the figure is a cylindrical first chip body made of, for example, Cr-Cu, which has good electrical conductivity and high wear resistance. This chip body 11 is axially penetrated with a hole 12 that is slightly larger than the outer diameter of a wire fed from a wire reel or the like (not shown). A second chip body 13 having a coefficient of thermal expansion larger than that of the chip body 11 is provided concentrically around the outer periphery of the chip body 11 in close contact with the chip body 11. Here, the first chip body 11 and the second chip body 13 are strongly mechanically coupled, for example, by brazing or the like. The first and second tip bodies 11, 13 are provided with four slits 14 along the axial direction to avoid deformation of the tip bodies 11, 13 in the axial direction.
is provided, and the upper part is a threaded part 15.

In a contact chip having such a structure, the first chip body 11 and the second chip body 13 are
During use, the temperature is kept much higher than room temperature due to radiant heat from the arc and molten pool (not shown) and joule heat due to the welding current passing through itself. Therefore, each of the chip bodies 11, 13
Due to the difference in thermal expansion coefficients, the contact tip bends toward the center toward the tip.

Therefore, according to the present invention, the second chip body 13 having a larger coefficient of thermal expansion than the first chip body 11 is concentrically connected to the outer periphery of the first chip body 11 by brazing or the like. Therefore, the second tip body 13 of the contact tip in use
curves inward toward the tip. Therefore, at the tip of the contact tip, the wire is compressed by the first tip body 11 due to the inward expansion of the second tip body 13, which has a large coefficient of thermal expansion, and the power supply to the wire is ensured, thereby allowing welding. becomes stable. In addition, a slit 14 is provided along the axial direction in each chip body 11, 13.
... is provided, the chip bodies 11, 13
Expansion in the cross-sectional direction of the chip is absorbed, and deformation of the chip body in the axial direction can be avoided. Furthermore, even if the chip bodies 11 and 13 wear out, their tips always deform inward, so that the power supply state does not change and stable welding can be maintained.

In the above embodiment, four slits were provided in the axial direction of each chip body, but the number is not limited to this.

In addition, in the above embodiment, Cr-Cu was used as the material for the first chip body, but this is not limiting, and various combinations may be used as long as the coefficient of thermal expansion of the first chip body is smaller than that of the second chip body. is possible.

[Effect of idea]

As described in detail above, an object of the present invention is to provide a contact chip that can perform stable welding under a constant power supply state.

[Brief explanation of the drawing]

Fig. 1a is a partial sectional view of a contact chip according to an embodiment of the present invention, Fig. 1b is a sectional view taken along the line X-X in Fig. 2a, and Fig. 2a is a partial sectional view of a conventional contact chip. , Figure b is a sectional view taken along the Y-Y line in Figure a. 11, 13... Chip body, 12... Hole, 14
...Slit.

Claims (1)

[Scope of utility model registration request] A contact tip for welding using a consumable electrode includes a cylindrical first tip body, and a concentric ring that is closely attached to the outer periphery of the first tip body by brazing, and which is thermally expanded from the first tip body. A contact tip comprising a second tip body having a large coefficient, and a slit is provided along the axial direction of the first and second tip bodies.