Variable valve lift (VVL) cam shaft structure

Abstract

The invention discloses a variable valve lift (VVL) cam shaft structure and particularly relates to a VVL cam shaft structure applied to the field of automobile engines. By means of the VVL cam shaft structure provided by the invention, the machining difficulty can be remarkably lowered, the manufacturing cost is greatly reduced, and the structural stability and reliability are guaranteed. The VVL cam shaft structure comprises a central spindle and cam assemblies and further comprises positioning grooves and compaction grooves. The cam assemblies are arranged on the central spindle in a sleeving mode. The central spindle is provided with positioning holes and compaction holes. The cam assemblies comprise high-speed and low-speed cam sets and journals. The positioning grooves, the compaction grooves, the high-speed and low-speed cam sets and the journals are in a split structure. All parts of a cam shaft structure in the prior art are fabricated separately and then assembled on the central spindle, so that the original and quite complicated structure is greatly simplified. Each part is machined independently, so that the machining difficulty is greatly lowered, the machining accuracy is guaranteed more easily, accordingly, mass production of each part can be achieved, and the manufacturing cost of a VVL cam shaft is substantially reduced.

Description

Technical field [0001] The invention relates to a VVL camshaft structure, in particular to a VVL camshaft structure used in the field of automobile engines. Background technique [0002] The engine's valve phase mechanism is responsible for providing the cylinder with fresh air necessary for gasoline combustion and exhausting the exhaust gas after combustion. In terms of working principle, the main function of the valve phase mechanism is to open and close each of them according to a certain time limit. The intake and exhaust valves of the cylinders realize the entire process of air exchange and supply of the engine cylinders. For ordinary engines without variable valve technology, the opening and closing time and lift of the intake and exhaust are fixed, and the valve phase of the engine cannot be changed according to the engine speed. This fixed valve lift is very It is difficult to consider the work needs of the engine at different speeds. Therefore, in order to meet the wor...

AI Technical Summary

Problems solved by technology

[0003] However, the cam assembly composed of the high and low speed cam group and the journal in the prior art is an integral structure, and its structure is relatively complicated, and the cam assembly, especially the high cam and low speed cam, requires high machining accuracy.

In the prior art, since the cam assembly is an integral structure, it is processed as a part in the processing technology. After multiple structures of the cam assembly are combined, there are many factors affecting the processing quality, and different factors affect each other. In addition, high precision requirements for high-speed cams and low-speed cams increase the complexity of the processing technology and greatly increase the difficulty of parts processing

If a certain local structure of a part is not well processed, the entire part will be scrapped, resulting in the current high manufacturing cost of VVL camshafts

Therefore, there is no VVL camshaft structure in the prior art that can significantly reduce processing difficulty, greatly reduce manufacturing costs, and ensure a stable and reliable structure.

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