JPH0324288Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a contact chip for an electric welding machine used in gas-shielded arc welding, which performs welding using argon gas, CO ₂ gas, etc. as a shielding gas.

(Prior art) A contact chip for gas-shielded arc welding secures sufficient gas contact between the wire and the wire feeding hole provided in the center, and
It is generally manufactured from a chromium-copper alloy that has excellent conductivity and hardness to prevent wear caused by contact with wires, but it has the disadvantage that the tip is easily damaged by high heat. In order to solve this drawback, it has been proposed to provide a ceramic tip guide with a flange at the tip of the contact tip, as shown in Japanese Utility Model Application Publication No. 52-26630. Although this made it possible to prevent wear on the tip of the contact tip, there was a problem in that it was impossible to prevent wear on the entire wire feed hole of the contact tip because the heat of welding was conducted throughout the contact tip.

(Problems to be solved by the invention) This invention solves the conventional problems as described above, has excellent heat resistance and abrasion resistance, and can always feed the wire stably without the risk of the wire getting caught. It was developed for the purpose of being a contact chip for electric welding machines, which is capable of long life and has a long life.

(Means for Solving the Problems) The present invention has a contact tip made of chromium copper alloy with a wire feed hole in the center.
A ceramic chip with a center hole with the same diameter as the wire feed hole and a flange part on the rear end that fits tightly with the contact chip body is installed, and a cap is screwed into the threaded part on the outer periphery of the tip of the contact chip body. The flange part of the ceramic chip is fixed in a pressed state by the inner step part, and a hollow case having a hollow part with a larger diameter than the contact chip body and a center part at the rear end is placed over the outer periphery of the contact chip body, and the contact This device is characterized in that a cooling cavity is formed between the chip body and the hollow case.

(Example) Next, the present invention will be explained in more detail with reference to the illustrated example.

In FIG. 1, numeral 1 is a contact chip body made of chromium-copper alloy having a wire feeding hole 2 in its center, and 3 is a hollow case having a hollow portion with a diameter slightly larger than that of the contact chip body 1. As shown in the figure, the hollow case 3 is placed over the outer periphery of the contact tip body 1 from the rear end, and the contact tip body 1 is placed around the outer periphery of the tip, leaving a cooling air 12 around the hollow part. It is fitted and fixed using the threaded portion 4. Reference numeral 5 denotes a ceramic chip attached to the tip of the contact chip body 1. The ceramic chip 5 has a center hole 6 having the same diameter as the wire feed hole 2, and a flange portion 7 at its rear end that is in close contact with the tip surface of the contact chip body 1. Reference numeral 8 denotes a cap screwed onto the outer circumferential threaded portion 4 of the tip end portion of the contact tip body 1. The cap 8 is equipped with a hole 9 into which the ceramic chip 5 can be fitted, and an inner step 10 following the hole 9. The inner step 10 presses the flange 7 of the ceramic chip 5.
The flange portion 7 of the ceramic chip 5 is brought into close contact with the front end surface of the contact chip body 1. Also,
The cooling air 12 formed between the contact chip main body 1 and the hollow case 3 includes the hollow case 3.
Gas supplied together with the wire flows through a central hole 11 provided at the rear end to cool the contact chip body 1 from the outer periphery.

(Function) With this structure, the wire feed hole 2 of the contact tip body 1 made of chromium-copper alloy
As with conventional contact tips, a welding wire is automatically sent out from the contact tip body 1, and the workpiece is arc welded in a cutoff gas atmosphere by energizing the wire through the contact tip body 1. However, in the present invention, a ceramic chip 5 with a center hole 6 having the same diameter as the wire feed hole 2 is attached to the tip of the contact tip body 1, so that when this tip is heated by welding heat, Also, there is no risk that the wire feed hole 2 of the contact tip body 1 will be abraded or thermally deformed by the wire. Moreover, in the present invention, sealing gas is allowed to flow from the center hole 11 into the air space 12 between the contact chip body 1 and the hollow case 3 placed over its outer periphery to cool the contact chip body 1 from the outer periphery. As a result, wear of the entire contact tip body 1 is extremely small, and long-term service life is possible. Furthermore, in the present invention, the ceramic chip 5 is fixed to the tip surface of the contact chip body 1 with the flange part 7 at the rear end being strongly pressed by the inner step part 10 of the cap 8, so that welding heat can be easily removed. Even when the ceramic chip 5 is heated, there is no possibility that a gap will be formed between the rear end of the ceramic chip 5 and the front end surface of the contact chip body 1. For this reason, in the device of the present invention, there is no risk that wire scraps will accumulate in the gap or that the wire will get caught, and the wire can be fed out stably at all times.

(Effects of the invention) As is clear from the above explanation, this invention has advantages such as the tip of the contact tip is not damaged by heat and there is little wear, so welding can always be performed at an accurate position. In addition, since there is no risk of the ceramic chip becoming loose, the wire will not get caught, making it possible to always feed the wire stably.Furthermore, by cooling the contact chip body with shielding gas, the contact chip In addition to suppressing wear on the main body and enabling long-term service life, the hollow case and contact chip main body are separated, so even when the contact chip main body becomes worn out, only the contact chip main body can be removed from the hollow case and replaced. By doing so, running costs can be significantly reduced. Therefore, the present invention has extremely great practical value as a contact chip for electric welding machines that eliminates the problems of the conventional technology.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention. 1...Contact chip body, 2...Wire feed hole, 3...Hollow case, 4...Threaded part, 5
... Ceramic chip, 6 ... Center hole, 7 ... Flange part, 8 ... Cap, 10 ... Inner step part,
11...Central hole, 12...Empty.

Claims (1)

[Scope of utility model registration request] A contact tip body 1 made of chromium-copper alloy with a wire feed hole 2 in the center has a center hole 6 having the same diameter as the wire feed hole 2 at the tip thereof, and a flange portion 7 that comes into close contact with the contact tip body 1 at the rear end. The flange 7 of the ceramic chip 5 is fixed in a pressed state by the inner stepped part 10 of the cap 8 which is screwed into the threaded part 4 on the outer periphery of the tip of the contact chip body 1, and the contact chip 5 is fixed in a pressed state. A hollow case 3 having a hollow portion with a larger diameter than the main body 1 and having a center hole 11 at the rear end is placed over the outer periphery of the contact chip main body 1, and a cooling air space is provided between the contact chip main body 1 and the hollow case 3. A contact chip for an electric welding machine, characterized in that it has a shape of 12.