Automobile engine camshaft neck structure

Abstract

The invention discloses an automobile engine camshaft neck structure which comprises an upper bearing cover, a camshaft, a cylinder cover, camshaft bearing cover bolts and a camshaft front bearing cover and is characterized in that the camshaft is installed on the cylinder cover and is provided with the upper bearing cover; the upper bearing cover and the cylinder cover are fixed together through the camshaft bearing cover bolts; the camshaft front bearing cover is installed at the left part of the camshaft; special-shaped groove structures used for injecting oil are arranged on a shaft neck A section, a shaft neck B section, a shaft neck C section and a shaft neck D section of the camshaft respectively. According to the automobile engine camshaft neck structure, with adoption of three-section type profile design, shaft holes formed by the shaft neck A section, the shaft neck B section, the shaft neck C section and the shaft neck D section of the camshaft, the upper bearing cover and the cylinder cover are in mutual clearance fit; and with adoption of a design of increasing the volume of an oil chamber by opening the special-shaped groove structures, friction of the shaft holes is lowered, the grooving width is reasonably selected, the problem of vibration caused by high-speed rotation is solved, the high-speed NVH requirement is met, and the automobile engine camshaft neck structure is applied to the technical field of automobile engines.

Description

technical field [0001] The invention relates to a camshaft journal structure of an automobile engine in the technical field of automobile engines. Background technique [0002] At present, the automobile engine camshaft is a key part of the automobile engine timing system. In order to meet the needs of the engine to continuously increase the power, certain requirements are put forward for the power loss of the automobile engine, and the matching structure of the cam journal is no exception. In the prior art, the power increase is usually achieved by adjusting the tolerance fit or opening a "ring groove" at the journal. Adjusting the matching size will cause the actual matching state to be poor due to the fluctuation of the physical size of each journal after processing compared with the design size. However, the design of the camshaft with the "ring groove" structure has the advantages of reducing the friction area and increasing the oil reserve at the journal, but the act...

AI Technical Summary

Problems solved by technology

Adjusting the matching size will cause the actual matching state to be poor due to the fluctuation of the physical size of each journal after processing compared with the design size

However, the design of the camshaft with a "ring groove" structure has the advantages of reducing the friction area and increasing the oil reserve at the journal, but the actual power improvement effect is also limited.

On the other hand, due to the further increase of the engine speed, the ring groove structure is likely to cause uneven wear of the camshaft journal due to processing problems, resulting in radial runout, resulting in an increase in engine NVH

The above two measures are limited to power improvement

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