In the processing of Bare Engine and assemblies, the processing and positioning methods of the rod end face, the top and side of the small head, and the side of the large head are adopted.

In the processing of the connecting rod cover in the process of processing the oblique joint surface from the bolt hole to the stop, the processing and positioning methods of its end face, the two seat faces of the bolt, and the side face of the bolt seat are adopted.

This repeated positioning has high accuracy, stable and reliable positioning, and the clamping method can make the parts deform less and is easy to operate. It can be used in various processes from rough processing to fine processing.

Due to the unification of the positioning reference, the size and position of the positioning point in each process are the same. These are stable processes, which provide good conditions for ensuring processing accuracy.

The shape accuracy and position accuracy requirements are very high, but the rigidity is poor and it is easy to deform. The main processing surfaces of Bare Engine are large and small head holes, two end faces, the joint surface of the connecting rod cover and the connecting rod body, and bolts, etc.

The secondary surfaces are oil holes, lock grooves, etc. There are also processes such as weighing and deweighting, inspection, cleaning and deburring.

MG Roewe Maxus Engine are die forgings, and the processing allowance of the holes is large, and residual stress is easily generated during cutting. Therefore, when arranging the process, each main surface should be rough and the finishing process is separate.

In this way, the deformation caused by roughing can be corrected in semi-finishing. The deformation caused by semi-finishing can be corrected in the finishing process to meet the technical requirements of the parts, and the positioning reference is processed first in the process arrangement.