Method for high-frequency welding of pipe fittings for plates with different thicknesses

Abstract

The invention relates to a welding method for manufacturing a pipe fitting by rolling materials with different thicknesses, in particular to a method for manufacturing a high-frequency welding pipe fitting by rolling materials with different thicknesses, which comprises the following steps of: rolling welding butt joint surfaces of the materials with different thicknesses so as to reduce the difference between the thicknesses of two sides; the unequal-thickness materials are rolled into pipe fittings; carrying out high-frequency welding on a longitudinal seam of the circular tube; and carrying out post-treatment on the pipe fitting. According to the method for high-frequency welding of the pipe fitting through the unequal-thickness materials, the two side edges, used for welding, of the unequal-thickness materials are rolled, so that the height difference of welding is reduced, the thickness tends to be equal, then reliable welding is guaranteed, the requirements for the performance such as the strength of the pipe can be met, meanwhile, the weight of the pipe fitting is reduced, and the cost is reduced. And low cost and light weight are realized.

Description

Technical Field

[0001] The present invention relates to a welding method for rolling unequal-thickness plates into pipe fittings, and in particular to a method for high-frequency welding of unequal-thickness plate pipe fittings. Background Art

[0002] Variable-thickness plates are also known as unequal-thickness rolled plates, abbreviated as TRB (tailored rolled blanks) abroad and VRB (variable-thickness rolled blanks) in China. Researched by a certain university in Germany, during the steel plate rolling process, by controlling the roll gap, the thickness of the plate changes in the rolling direction, and is controlled in real time by a computer to obtain the required material plate thickness combination. Since the thickness combination of VRB plates can be freely adjusted, it can be adjusted according to the stress mode of automotive parts to achieve equal-strength replacement, reduce the number of parts, expand the design space of automotive parts, and achieve automotive lightweighting.

[0003] Welded pipes are widely used in various internal structural parts of automobiles. At present, the vast majority of welded pipes are produced by uncoiling narrow coils and continuous multi-roll forming, and then using high-frequency welding. However, this kind of welded pipe is processed from plates with uniform thickness, that is, processed from equal-thickness plates. For pipes formed by rolling unequal-thickness plates, high-frequency welding cannot be used, and usually laser welding is used. For example, a processing method for unequal-thickness welded pipes disclosed in CN 104772566A uses laser welding to solve the problem that high-frequency welding cannot be used. Due to the high equipment cost of laser welding, the penetration ability of thick-walled pipes is limited, the requirements for weld gaps are high, the auxiliary equipment needs to be improved, and the speed of laser welding is slow, and high-speed continuous welding cannot be carried out. The overall welding efficiency is lower than that of high-frequency welding, and the welding cost is also significantly higher than that of high-frequency welding. Summary of the Invention

[0004] To solve the above problems, the present invention provides a method for high-frequency welding of unequal-thickness plate pipe fittings, and the specific technical solution is as follows:

[0005] A method for high-frequency welding of unequal-thickness plate pipe fittings includes the following steps:

[0006] Roll the two sides of the unequal-thickness plate to reduce the difference in thickness between the two sides;

[0007] Roll the unequal-thickness plate into a round pipe;

[0008] Perform high-frequency welding on the longitudinal seam of the round pipe;

[0009] Perform post-treatment on the round pipe.

[0010] Preferably, the thickness on both sides of the unequal-thickness plate is roll-pressed to the minimum thickness of the original unequal-thickness plate + 0.3 to 0.7 mm.

[0011] Preferably, when roll-pressing both sides of the unequal-thickness plate, it includes rough rolling first and then finish rolling.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] A method for high-frequency welding of pipe fittings with unequal-thickness plates provided by the present invention roll-presses the two sides used for welding of the unequal-thickness plate to reduce the height difference of welding, making it tend to be of equal thickness, thereby ensuring reliable welding, only meeting the strength requirements of the pipe, and at the same time reducing the welding cost. Description of the Drawings

[0014] Figure 1 is a schematic diagram of roll-pressing both sides of the unequal-thickness plate;

[0015] Figure 2 is a cross-sectional metallographic diagram of a 2.3-mm-thick plate rolled into a circle and welded. Detailed Embodiments

[0016] The present invention will be further described in conjunction with the accompanying drawings.

[0017] As Figure 1 shown, a method for high-frequency welding of pipe fittings with unequal-thickness plates includes the following steps:

[0018] Roll-press both sides of the unequal-thickness plate to reduce the difference in thickness between the two sides;

[0019] Roll the unequal-thickness plate into a round pipe;

[0020] Perform high-frequency welding on the longitudinal seam of the round pipe;

[0021] Perform post-treatment on the round pipe, and the post-treatment includes: cooling the round pipe, sizing and straightening, and cutting.

[0022] Among them, the thickness on both sides of the unequal-thickness plate is roll-pressed to the minimum thickness of the original unequal-thickness plate + 0.3 to 0.7 mm.

[0023] When roll-pressing both sides of the unequal-thickness plate, it includes rough rolling first and then finish rolling.

[0024] Rolling into a round pipe, performing variable-frequency high-frequency welding on the longitudinal seam, cooling the round pipe, sizing and straightening, and cutting are all prior arts and will not be described in detail here.

[0025] The roll-pressing of both sides of the unequal-thickness plate is carried out before the plate is rolled into a circle.

[0026] Before roll-pressing, it also includes loading, shearing, storing, and feeding.

[0027] AsFigure 2 As shown, according to the cross-sectional metallographic image of the 2.3 mm thick plate rolled welding, it can be seen that the welding quality is good and the weld is uniform.

[0028] High-frequency welding can be achieved well for thin plates and thick plates of unequal thickness.

[0029] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the protection scope of the claims of the present invention.

Claims

1. A method for high-frequency welding of pipe fittings with unequal-thickness plates, characterized in that, It includes the following steps: Roll both sides of the unequal-thickness plate to reduce the difference in thickness between the two sides; Roll the unequal-thickness plate into a round tube; Perform high-frequency welding on the longitudinal seam of the round tube; Perform post-treatment on the round tube.

2. A method for high-frequency welding of unequal-thickness plate pipe fittings according to claim 1, characterized in that The thickness of both sides of the unequal-thickness plate is rolled to the minimum thickness of the original unequal-thickness plate + 0.3 - 0.7 mm.

3. A method for high-frequency welding pipe fittings of unequal-thickness plates according to claim 1, characterized in that, When rolling both sides of the unequal-thickness plate, it includes rough rolling first and then finish rolling.

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