JPH0353824Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is an automatic welding device for pipe joints, more specifically, a slidable work clamp equipped with a torch and a wire supply device that supplies wire to the torch. The present invention relates to an apparatus suitable for MIG welding an aluminum pipe joint to a thin-walled aluminum pipe having a thickness of approximately 3 mm or less.

(Prior art) When MIG welding a pipe joint to this kind of thin-walled pipe,
In order to compensate for the instability of the arc in the low current range, pulsed DIG welding has recently been adopted, and by adopting this pulsed DIG welding, it has become possible to weld pipe joints to relatively thin-walled pipes.

(Problem that the invention aims to solve) However, even in pulsed welding, if conventional automatic welding equipment is used, heat input to the welded part will increase when the tube has a thin wall thickness of about 3 mm or less. It became difficult to control the welding process, causing holes, etc., and it was not possible to perform automatic MIG welding at high speed.

(Means for solving the problem) The automatic welding device for pipe joints according to the present invention was devised in view of the above-mentioned problems.
An automatic pipe joint welding device that is equipped with a wire supply device that supplies wire to a torch, and a work clamp section that clamps the end of a workpiece consisting of a pipe and a pipe joint, and that automatically clamps the workpiece and welds the pipe joint. The work clamp section has a cylindrical abutment that abuts the end surface of the tube at its tip on the workpiece fixing side, and a cylindrical abutment that protrudes from the abutment and has an outer diameter smaller than the inner diameter of the tube when closed. A split mold having an outer diameter that presses against the inner wall of the pipe when opened, and a mandrel that is movable in the axial direction within the stopper and the split mold and has an outer diameter that expands the split mold. It is characterized by the fact that it is equipped with

(Example) A first example showing an example of an automatic welding device according to the present invention.
In the figures and FIG. 2, 1 is a drive side work clamp part, 2 is a driven side work clamp part, and a torch support stand 3 is fixed to each of these work clamp parts 1 and 2, and these torch supports A torch 3a is attached to the stand 3 so as to be slidable in the vertical direction. These torches 3a are moved up and down by a motor 3b, and the torch support base 3 is also provided with a wire supply device 3d for supplying a wire 3c to the torch 3a.

The work clamp parts 1 and 2 consist of fixed parts 1a and 2a fixed to the base 4 and sliding parts 1b and 2b attached to these fixed parts 1a and 2a so as to be slidable in the length direction of the base 4. The sliding parts 1b and 2b are driven by a hydraulic system (not shown). A work rotation device 1c is mounted on the sliding portion 1b of the drive-side work clamp portion 1. In addition, cylindrical butts 1d and 2d are provided at the ends of the workpiece clamping parts 1 and 2 on the workpiece fixing side.
The split molds 1e and 2e with a large number of splits are provided protrudingly, and tapered mandrels 1f and 2f that can move forward and backward in the axial direction of the split molds 1e and 2e are provided inside, and the above-mentioned The forward movement of the supports 1d and 2d (movement toward each other) clamps the workpiece 8 consisting of the pipe 5 and the pipe fittings 6 and 7, and positions the workpiece 8 in the length direction, while the mandrels 1f, As 2f advances, the split dies 1e, 2e are expanded, and the split dies 1e, 2e are brought into pressure contact with the inner circumferential wall surface of the work 8. That is, split mold 1
e, 2e have an outer diameter smaller than the inner diameter of the tube 5 in the closed state, and have an outer diameter that presses against the inner wall of the tube 5 in the open state, and the mandrels 1f, 2f are
It has an outer diameter that expands the split molds 1e and 2e.

Work holders 9, 9 are provided upright on the base 4 for receiving and discharging the work 8 and positioning the work 8 in the height direction, and the work 8 can be easily moved between these work holders 9, 9. Receiving rollers 10, 10 are provided upright.

Welding is performed by connecting the control device 11, MIG welding machine 12, and cooling water circulation device (not shown) to the automatic welding device for pipe joints configured as described above.
Reference numeral 13 indicates power supply wiring, 14 indicates a cooling water pipe, and 15 indicates a supply pipe for Ar gas as a shielding gas.

The workpiece 8 to be welded is equipped with a male pipe joint 6 and a female pipe joint 7, for example, as shown in Fig. 3, and can connect two coaxially arranged pipes with a single touch, making it ideal for desert areas. Mainly used for irrigation, aluminum pipe diameter approximately 50mm to 150mm, wall thickness
It is about 1.3 to 1.5 mm.

To weld the workpiece 8 using the automatic welding device for pipe fittings described above, first, the workpiece 8 with the pipe fittings 6 and 7 set at both ends of the pipe 5 is fed to the workpiece holders 9 and 9. The butts 1d and 2d are advanced toward the workpiece 8 by a hydraulic device, and the split dies 1e and 2e are inserted into both ends of the tube 5 at the same time as the butts 1d and 2d are brought into contact with both end surfaces of the tube 5, respectively. Next, the mandrels 1f and 2f are advanced in the axial direction of the split molds 1e and 2e to expand the split molds 1e and 2e.
e and 2e are pressed against the inner circumferential wall surface of the pipe 5 to fix the workpiece 8, and at the same time, both ends of the pipe 5 are expanded to eliminate the gap in the weld between the pipe 5 and the pipe fittings 6 and 7. do.

Next, while driving the work rotation device 1c of the drive-side work clamp section 1, the torches 3a, 3a are lowered toward the welded parts at the ends of the pipe joints 6, 7,
Pulse DOMIG welding is performed while rotating the workpiece 8. The workpiece rotation device 1c is set to such an extent that the circumferential rotational speed of the workpiece 8 is 1 m/min, and the welding current is controlled as a so-called slope control such that the welding current is sloped up at the start and sloped down at the time of cratering treatment. .

When the welding is completed, the torches 3a, 3a are raised and returned, and the mandrels 1f, 2f are moved back to release the pressure on the workpiece 8 by the split molds 1e, 2e. 8 is released, and the workpiece 8 is discharged from the welding device.

According to the above-described embodiment, the workpiece 8 is securely fixed by expanding the split molds 1e and 2e, and at the same time, the gap between the pipe 5 and the pipe fittings 6 and 7 is eliminated to maintain a good close contact state. Furthermore, since the split dies 1e and 2e are positioned inside the welded part of the workpiece 8 during welding, these split dies 1e and 2e have the effect of turning the thin-walled pipe 5 into a thick-walled pipe. This makes it possible to perform high-speed, automatic pulsed MIG welding of pipes 5 with a thickness of approximately 1 mm, without requiring delicate control of heat input, which is especially necessary when welding thin-walled pipes. It becomes possible to apply

In the above embodiment, a pair of torches 3a, 3a are arranged and welding is performed at both ends of the workpiece at the same time, but the structure is not limited to this, and it is difficult to perform welding. It is also possible to provide only one end of the workpiece clamping section and a mere driven-side work clamping section without a torch or the like disposed at the other end.

(Effects of the invention) According to the automatic welding device for pipe joints according to the invention,
1 without requiring delicate control of heat input during welding.
This makes it possible to perform high-speed automatic pulse-domig welding of pipe joints on pipes as thin as mm.

[Brief explanation of the drawing]

FIG. 1 is a schematic partial longitudinal sectional view showing the entire embodiment of the present invention, FIG. 2 is a partial vertical sectional view of the main part, and FIG. 3 is a vertical sectional side view of a workpiece. 1... Drive side work clamp section, 2... Drive side work clamp section, 1
e, 2e... split mold, 1f, 2f... mandrel,
3a...Torch, 3c...Wire, 3d...Wire supply device, 5...Pipe, 6, 7...Pipe joint, 8...
…work.

Claims (1)

[Scope of utility model registration request] A pipe joint that is equipped with a torch, a wire supply device that supplies wire to the torch, and a work clamp section that clamps the end of a workpiece consisting of a pipe and a pipe joint, and that automatically clamps the workpiece and welds the pipe joint. The workpiece clamp section is an automatic welding device, and the workpiece clamp section includes a cylindrical abutment that abuts the end surface of the tube at the tip of the workpiece fixing side, and a cylindrical abutment that protrudes from the abutment and is smaller than the inner diameter of the tube in a closed state. A split mold having an outer diameter that presses against the inner wall of the pipe when opened, and an outer diameter that allows the split mold to be moved forward and backward in the axial direction within the stopper and the split mold to expand the split mold. An automatic welding device for pipe fittings, characterized in that it is equipped with a mandrel.