Valve plug of height adjustment reversing valve and girth welding process thereof for height adjustment system of coal mining machine

Abstract

The invention discloses a valve plug of a height adjustment reversing valve and a girth welding process thereof for a height adjustment system of a coal mining machine. The valve plug comprises a valve plug body, a left plug head and a right plug head; the left plug head and the right plug head are respectively provided with a left annular boss and a right annular boss the outer diameter of whichare the same with the outer diameter of the valve plug body; and the left annular boss and the valve plug body as well as the right annular boss and the valve plug body are respectively fastened and connected through a circular ring-shaped soldering joint which is arranged along the valve plug body radially. The girth welding process comprises the following steps: 1. groove treatment; 2. preheating before welding; 3. girth welding; and 4. heat preservation after welding. The valve plug and the process provided by the invention have the advantages of reasonable design, simple welding steps, good welding quality and long service life of valve plug manufacturing, are convenient to operate, and multiple actual problems of small operation space, smaller effective welding cross section area, lower strength, poor welding quality and higher rejection rate, is inconvenient to operate, the welding quality of the valve plug is not easy to control and the like in welding for the existing valve plug can be solved effectively.

Description

technical field [0001] The invention belongs to the technical field of processing and manufacturing a height adjustment valve group for a shearer height adjustment system, and in particular relates to a height adjustment reversing valve core and a ring welding process thereof for a coal shearer height adjustment system. Background technique [0002] The shearer height adjustment system is set up to realize the height adjustment needs of the shearer drum. Nowadays, the shearer height adjustment system mostly adopts the hydraulic system, which is usually called the shearer height adjustment hydraulic system. In the actual use process, the hydraulic system of the coal mining machine mainly includes the gear pump, the motor that provides power for the gear pump, the height adjustment cylinder and its hydraulic control valve (ie hydraulic lock, etc.), the height adjustment reversing valve, the high pressure relief valve (safety valve), low pressure relief valve, brake solenoid va...

AI Technical Summary

Problems solved by technology

[0006] Depend on figure 1 It can be seen that the square welding seam 4 between the left core head 2 and the right core head 3 and the valve core body 1 is designed along the axial direction of the valve core body 1, and there are the following practical problems in actual use: on the one hand, the operation space in the welding process Small, the rotation of the welding torch is limited, and the weld is prone to virtual welding and poor fusion; on the other hand, because the weld width is only 2mm, the effective cross-sectional area itself is small, and the root of the square weld cannot Welding to reduce the effective cross-sectional area of ​​the weld, and the strength of the weld will also be compromised

In the actual use process, the welding seam desoldering phenomenon occurred many times, which seriously affected the product quality

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