Fixture for welding thin-walled tube and flange

Abstract

The utility model relates to a clamp for welding a thin-walled tube and a flange. The clamp is characterized in that a copper core shaft is provided with a shielding gas output channel opening and an annular shielding gas channel; a large hole positioning shaft is embedded in a Z-direction positioning plate, a small hole positioning pin is embedded in a clamp base, a copper core shaft is embedded in the large hole positioning shaft, and a back inert shielding gas input inlet pipeline penetrates through the clamp base, the Z-direction positioning plate and the large hole positioning shaft and then is in sealed threaded connection with the copper core shaft. And small holes for outputting protective gas on the back surface of the welding seam are uniformly distributed in the circumferential direction of the copper core shaft and are connected with one another through an annular channel to form a gas protection cavity. The repair rate of unqualified products is reduced, the repair cost is reduced, and the rejection rate of the products is reduced; the method has the advantages of improving the weld quality and enhancing the weld strength.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of clamps of thin-walled pipe and flange welding, in particular to the clamp of pipe wall thickness less than or equal to 1.2mm pipe and thick wall welding, applied to the field of automobile exhaust system manufacturing and related structure use. BACKGROUND

[0002] At present, when thick wall flange (greater than 8mm) and pipe (wall thickness less than 1.2mm) are welded for automobile production, the way of adopting welding protective gas is gas shielded welding pool technology of welding gun, which is easy to produce welding quality defects at weld: penetration, burn-through and back weld are easy to be oxidized by air (weld oxidation) to reduce weld strength. The workpiece welded in the use process will vibrate and crack due to the vibration and jolt of vehicle body, which has the risk of potential safety accidents. SUMMARY

[0003] The utility model aims at providing a kind of clamp of thin-walled pipe and flange welding, which is thin-walled pipe with wall thickness less than or equal to 1.2mm and flange shielded metal arc welding, welding protective gas is also passed in the workpiece when welding, and the outside corner joint weld of pipe and flange can pass welding protective inert gas in the pipe, which reduces the repair rate of unqualified products, reduces repair cost and reduces product scrap rate; It has the advantages of improving weld quality and increasing weld strength.

[0004] The technical scheme of the utility model is realized as follows: a kind of clamp of thin-walled pipe and flange welding, including Z direction positioning plate, big hole positioning shaft, small hole positioning pin, copper core shaft, back inert protective gas input import pipeline;Its characterized in that: copper core shaft is equipped with output protective gas passage and ring type protective gas passage;Z direction positioning plate is embeddedly connected with clamp base, big hole positioning shaft is embedded in Z direction positioning plate, small hole positioning pin is embedded into clamp base, copper core shaft is embedded into big hole positioning shaft, back inert protective gas input import pipeline is sealed screw thread connection with copper core shaft after passing through clamp base, Z direction positioning plate and big hole positioning shaft;Copper core shaft is uniformly distributed with 6-10 output weld back protective gas small holes of 4mm in diameter in circumferential direction, and these uniformly distributed small holes are connected with each other by an annular passage, forming a weld back interconnected gas protection cavity.

[0005] The utility model has the positive effect that a weld back interconnected gas protection cavity is formed in the circumferential direction of copper core shaft to isolate air and weld penetration or potential weld back penetration from reacting with molten pool, so as to prevent weld from producing overoxidation defects and improve weld quality and strength. It reduces the repair rate of unqualified products, reduces repair cost and reduces product scrap rate. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1The utility model discloses a structure schematic view. PREFERRED EMBODIMENT

[0007] The utility model will be further described in connection with the drawings: as Figure 1 A kind of fixture for thin-walled pipe and flange welding shown in the drawing, including pedestal 1, Z direction locating plate 2, large hole positioning shaft 3, small hole positioning pin 4, copper core shaft 5, back inert gas input import pipeline 6;It is characterized by: copper core shaft 5 is equipped with output protective gas passage mouth 7 and annular protective gas passage 8;Z direction locating plate 2 is embeddedly connected with fixture pedestal 1, large hole positioning shaft 3 is embedded in Z direction locating plate 2, small hole positioning pin 4 is embedded into fixture pedestal 1, copper core shaft 5 is embedded into large hole positioning shaft 3, back inert gas input import pipeline 6 is sealed screw thread connection with copper core shaft 5 after passing through fixture pedestal 1, Z direction locating plate 2 and large hole positioning shaft 3;Copper core shaft 5 circumferential direction evenly distributed 6-10 small holes of the diameter 4mm of output weld back surface protective gas, and these evenly distributed small holes are connected with each other by an annular passage, form a weld back surface interconnecting gas protection cavity.

[0008] Taking two-hole flange welding as an example, when working, the large plane of the flange is positioned on the Z direction locating plate 2, the welding position large hole of the flange is positioned in the X and Y directions by the pin shaft made of steel material, and the rotation direction of the flange is controlled by the small hole positioning pin 4 of the flange.

[0009] First, align the large hole of the flange with the large hole positioning shaft 3 and the small hole of the flange with the small hole positioning pin 4, then place the flange on the Z direction locating plate 2, and start the switch to clamp the flange by the flange clamping block 9. This will constrain the axis of the large hole of the flange and ensure the consistency of the weld position of different workpieces. The small hole positioning pin 4 controls the rotation direction of the flange and ensures the relative size of the pipe and the flange.

[0010] Then, align the hole of the pipe with the copper core shaft 5, insert the copper core shaft 5 into the pipe, and make the end face of the pipe adhere to the end face of the large hole positioning shaft 3, then clamp the pipe to ensure the consistency of the pipe assembly, and finally start the equipment to perform welding operation.

[0011] When performing manual, semi-automatic or robot automatic arc welding, inert protective gas is input into the protective gas inlet at the same time. During the welding process, the protective gas plays a protective role in the pipe, and the gas flow rate is different due to different welding parameters, different base materials or external environment, etc.

[0012] When the inner surface of the thin-walled pipe with a wall thickness less than or equal to 1.2 mm is overheated during welding, the base material at the weld of the inner surface of the pipe is in a liquid state or a solid-liquid mixed state. At this time, the welding inert gas input at the back of the pipe base material is used to isolate air from participating in the reaction of the pipe in liquid or solid-liquid mixed state with air to ensure the quality of the weld and improve the welding strength.

Claims

1. A kind of thin-walled pipe and flange welding fixture, including Z direction positioning plate, big hole positioning shaft, small hole positioning pin, copper core shaft, back inert gas input import pipeline;Its characterized in that: The copper mandrel is provided with an output protective gas passage port and a ring-shaped protective gas passage; the Z-direction positioning plate is embeddedly connected with the clamp base, the large-hole positioning shaft is embedded in the Z-direction positioning plate, the small-hole positioning pin is embedded in the clamp base, the copper mandrel is embedded in the large-hole positioning shaft, and the back inert protective gas input inlet pipeline is in sealed threaded connection with the copper mandrel after penetrating through the clamp base, the Z-direction positioning plate and the large-hole positioning shaft; the copper mandrel is uniformly provided with 6-10 small holes with a diameter of 4 mm for outputting the back protective gas of the welding seam, and the uniformly distributed small holes are connected with each other through an annular passage to form a gas protection cavity connected with each other at the back of the welding seam.

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