Method for manufacturing diesel engine connecting bar

Abstract

The invention relates to a manufacturing method of a connecting bar of a diesel engine, which comprises the following processing steps: (1) roughly milling an upper end surface (3); (2) taking the upper end surface (3) as a positioning benchmark, correcting circular processing lines of a large hole (11) and a small hole (13); roughly milling a lower end surface (4); expanding the large hole (11) and the small hole (13), and the like. The manufacturing method is characterized in that in the step (10), the rough and precise counterboring of the flush socket (7) and the drilling, the expanding and the reaming of the bolt hole (6) are finished in one step; in the step (2) and the step (12), the large hole (11) and the small hole (13) are simultaneously half precisely bored, the sequential processing is positioned by the large hole (11), the small hole (13) and the upper end surface (3); in the step 22), plating protective layers positioned on the inner surfaces of the large hole (11) and the small hole (13) are chromium plating layers; in the step (23), the surface chemistry treatment adopts nitrogen treatment; and in the step (28), the surface layer strengthening treatment adopts shot blasting. The manufacturing method of a connecting bar of a diesel engine provided by the invention has reasonable step arrangement and can effectively enhance the quality and the efficiency of the processing of the connecting bar.

Description

technical field [0001] The invention relates to a method for manufacturing a connecting rod of a diesel engine, in particular to a method for manufacturing a connecting rod for a medium-speed marine diesel engine. Background technique [0002] There are 43 processes in the manufacturing and processing of traditional diesel engine connecting rods, which are as follows: 1. Roughly grinding the end face; 2. Drilling the small head hole; 3. Chamfering; 4. Pulling the small head hole; Block end face; 6, cutting off; 7, finish drawing both sides, joint surface and semicircle surface; 8, grinding joint surface; 9, middle inspection; 10, drilling bolt holes; 11, rough spot facing seat; ;13, milling the lock slot of the bearing bush; 14, chamfering and drilling oil hole; 15, deburring; Bolt positioning hole, hinge bolt positioning hole; 18, deburring; 19, cleaning; 20, installing bolts; 21, screwing the nut manually; 22, tightening the nut; 23, rough boring big hole; 24, chamfering;...

AI Technical Summary

Problems solved by technology

[0003] The above-mentioned method for manufacturing connecting rods has the following defects: 1. In the traditional process, the processing of the socket and the positioning bolt hole is processed separately. As we all know, the socket and the positioning bolt hole have a high verticality requirement, and processing according to the traditional process will cause It is because of the double clamping that the verticality requirements cannot be guaranteed

2. Each process in the traditional process uses the small head hole and the end faces of the large and small holes as the positioning reference. In this way, the workpiece is not completely positioned, and the freedom of rotation around the center of the small hole is not restricted. The phenomenon of workpiece looseness leads to incorrect processing dimensions

3. In the sixth process of the traditional process, heat treatment is not performed after cutting the bearing cap and the connecting rod body. When the connecting rod cover and the connecting rod body are cut off, the elapsed time is short and the stress is not fully released before transferring to the next process. Processing, will affect product quality

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