Automatic welding method for hydraulic hard tube assembly

Abstract

The invention belongs to the technical field of welding and relates to a welding technology for a hydraulic hard tube, in particular to an automatic welding method for a hydraulic hard tube assembly. By the adoption of the automatic welding method for the hydraulic hard tube assembly, the welding ratio of automatic welding is high, and the welding quality is stable when the hydraulic hard tube assembly is welded. According to the technical scheme, the automatic welding method for the hydraulic hard tube assembly comprises the following steps that firstly, a welding groove of a guide tube and a welding groove of a spherical joint in the hydraulic hard tube assembly are machined to be plain ends; secondly, the guide tube and the spherical joint of the hydraulic hard tube assembly generated after the first step are grouped, and the inner diameter and the outer diameter of the position, where the spherical joint and the guide tube are grouped, of the spherical joint are machined to be equal to the inner diameter and the outer diameter of the guide tube respectively; thirdly, the guide tube and the spherical joint of the hydraulic hard tube assembly generated after the second step are in butt joint with each other and located; fourthly, spot welding is conducted on the guide tube and the spherical joint of the hydraulic hard tube assembly generated after the third step; fifthly, automatic welding is conducted on the guide tube and the spherical joint of the hydraulic hard tube assembly generated after the fourth step.

Description

technical field [0001] An automatic welding method for a hydraulic hard pipe assembly belongs to the field of welding technology, in particular to a welding technology involving hydraulic hard pipes. Background technique [0002] The main implementation standard of the hydraulic hard pipe assembly is Q / Dc322-2008 "37° hard pipe assembly commonly used in hydraulic systems", and the main parameters are shown in Table 1. [0003] [0004] It can be seen from Table 1 that the material and welding groove of the conduit and ball joint are the same, but the specifications and wall thickness are different. Due to the implementation of different specifications and standards for catheters and spherical joints, the structural dimensions of the inner and outer diameters of the two are inconsistent, and they cannot be combined in the state of equal inner and outer diameters. There are three main manifestations: a. The inner diameter and outer diameter of the catheter and the ball hea...

AI Technical Summary

Problems solved by technology

[0007] The shortcomings of closed self-fluxing TIG all-position welding are: a. Welding wall thickness ≤ 2mm, not covering the welding wall thickness of hard pipe assembly ≤ 4.5mm; b. The inner and outer diameters of the welds are required to be equal, while the inner and outer diameters of the tube and the spherical joint in the hard pipe assembly are basically unequal, so the scope of application of this method is very small; c. In the case that the inner and outer diameters of the conduit and the spherical joint of the hard pipe assembly are basically unequal, it is difficult to quickly ensure the butt joint gap ≤ 0.2mm and the butt misalignment ≤ 0.2mm, which will inevitably reduce production efficiency; d. The clamping straight section is generally ≥ 21mm, which cannot be welded in the case of a hard tube assembly with a sharp bend but no straight section, and a clamping straight section < 21mm; e. The welding groove is flat, while the welding groove of the hard pipe assembly is V-shaped, that is, to adapt to this welding method, it is necessary to carry out flat processing on the conduit and the spherical joint

[0008] The disadvantages of open filling wire TIG all-position welding are: a. TIG welding is used for welding, which can be welded with or without filler wire

That is, when the welding wall thickness is greater than 3.5mm, both the conduit and the joint need to be grooved in a J shape. However, due to factors such as long size, complex shape, and short straight line for clamping, it is difficult to make a J-shaped groove. Into difficult to use this method of welding; b. The inner and outer diameters of the welds are required to be equal, while the inner and outer diameters of the tube and the spherical joint in the hard pipe assembly are basically unequal, so the scope of application of this method is very small; c. In the hard tube assembly, when the inner and outer diameters of the tube and the spherical joint are basically unequal, it is difficult to quickly ensure the butt joint gap ≤ 0.2mm and the butt misalignment ≤ 0.2mm, which will inevitably reduce production efficiency; d. The clamping straight section is generally ≥132mm, which cannot be welded for the hard pipe assembly where the conduit has a sharp bend but no straight section, and the clamping straight section is <132mm; e. When the welding wall thickness is less than or equal to 3.5mm, the welding groove is flat, while the welding groove of the hard pipe assembly is V-shaped, that is, to adapt to this welding method, it is necessary to carry out flat processing on the conduit and the spherical joint

[0009] The disadvantages of open wire filling TIG horizontal welding are: a. The inner and outer diameters of the welds are required to be equal, while the inner and outer diameters of the conduit and the ball joint in the hard pipe assembly are basically unequal, so the scope of application of this method is very small; b. In the case of tubes and ball joints in the hard tube assembly with basically unequal inner and outer diameters, it is difficult to quickly ensure that the butt joint gap is ≤0.2mm and the wrong side of the butt joint is ≤0.2mm, which will inevitably reduce production efficiency; c. The clamping straight section is generally ≥90mm, which cannot be welded for the hard pipe assembly where the conduit has a sharp bend but no straight section, and the clamping straight section is less than 90mm; d. The welding groove is flat, while the welding groove of the hard pipe assembly is V-shaped, that is, to adapt to this welding method, it is necessary to carry out flat processing on the conduit and the spherical joint

[0010] To sum up, no matter what kind of automatic welding technology is difficult to be widely used in the welding process of hydraulic hard pipe assembly, the welding rate of automatic welding is low, and the welding quality is not stable enough

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