Diesel engine cylinder body destressing arc groove main bearing seat structure and machining method thereof

Abstract

The invention relates to a diesel engine cylinder body destressing arc groove main bearing seat structure and a machining method thereof, and belongs to the technical field of diesel engine cylinder bodies. A destressing arc groove is formed in the corner of a main bearing cover mounting surface (11) of a diesel engine cylinder body main bearing seat; the machining sequence of the cylinder body is as follows: 1) firstly, roughly milling a mounting surface of the main bearing cover; (2) sequentially machining a destressing arc (15), an opening surface (13) and a main bearing semicircular hole (12); 3) finally, finish-milling the mounting surface of the main bearing cover; by improving the machining sequence and the machining method, the diesel engine cylinder block main bearing seat stable in structure can be obtained, the influence of cutting deformation and residual stress release on the machining precision and the width size can be effectively eliminated, and the obtained diesel engine cylinder block main bearing seat is high in machining precision, stable in structural performance and good in machining effect. And the stress concentration of the bearing seat can be avoided, and the fatigue safety coefficient is better.

Description

technical field [0001] The invention belongs to the technical field of diesel engine cylinder blocks, and in particular relates to a diesel engine cylinder body stress relief circular arc groove main bearing seat structure and a processing method thereof. Background technique [0002] Light weight and high torque output are two important development directions of domestic commercial diesel engines in recent years, and they are also a strong support for diesel engine manufacturers to maintain market competitiveness. In order to ensure the long-term stable output of high torque, the main bearing seat of the diesel engine cylinder block is required to have excellent structural performance. At present, there are two structures of main bearing seats commonly used in the industry: one is the bearing seat structure that uses the side positioning of the bearing seat, such as the attached figure 1 As shown, the side positioning method requires the bearing seat to bear the pretighten...

AI Technical Summary

Problems solved by technology

Although the arc groove has the function of stress relief, it can eliminate stress concentration, but due to the short positioning length of the side of the main bearing seat of the diesel engine cylinder block, cutting deformation and residual stress release, etc., the final accuracy of the main bearing cap mounting surface is affected. Machining stress relief When the arc groove is used, the side of the bearing seat has low rigidity and easy deformation during processing. Therefore, even if the stress arc groove structure is processed, the width and dimension of the bearing cap mounting surface will be unstable, and the workpiece will be unstable after being placed for a period of time. Width dimension changes, which has a huge impact on the structural performance of the main bearing seat of the diesel engine cylinder block

[0005] Therefore, in order to ensure the stability of the structure of the rounded bearing seat used for the cylinder block of the diesel engine, the current diesel engine block mostly adopts the structure of the rounded bearing seat (as shown in the attached figure 1 ), the processing sequence of this structure is rough and fine milling of the bearing cap mounting surface 11 → rough boring of the main bearing semicircle hole 12 → milling of the gear 13, rough boring of the main bearing semicircle hole 12 → rough and fine milling of the bearing cap mounting surface 11 → milling of the gear 13. Rough and fine milling of the bearing cap mounting surface 11 → milling gear 13 → rough boring of the main bearing semicircle hole 12, although this processing sequence can ensure the machining accuracy of the bearing seat of the diesel engine cylinder block, the structure of the rounded bearing seat processed is Due to the pre-tightening of the main bearing cover bolts and the interference fit between the bearing seat and the main bearing cover, it is easy to cause stress concentration at the corner of the bearing seat, and the structure has the problem of low fatigue strength with the same width

[0006] In addition, at present, C-type fixtures are mostly used in the processing of diesel engine cylinder blocks (as attached Figure 4 And attached Figure 5 ), during the processing of the cylinder block, due to the clamping force, it is easy to cause the deformation of the main bearing seat of the cylinder block

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