Piston engine valve timing and variable lift driving system

Abstract

The invention discloses a piston engine valve timing and variable lift driving system. On the basis of the shear thickening fluid critical speed phase change characteristic and the cam speed change curve driving rule, the effective length of a shear thickening tappet changing in the same direction as change of rotation speed of a cam is adaptively obtained according to the change of the rotation speed of the cam (or the rotation speed of an engine), the opening advance angle, the lift and the closing delay angle of a valve are automatically adjusted, and thus the dynamic property, the strengthening degree, the low temperature startability, the low speed stability, the economical efficiency and the exhaust cleanliness of the engine are improved. According to the technical scheme, the system is free of electronic control, simple in mechanical structure, reliable in work, convenient to arrange, low in cost, easy to maintain, smooth in engine power output and capable of being widely applied to driving valves of various piston engines.

Description

technical field [0001] The invention relates to a driving technology of piston engine valves, in particular to the technical field of valve cam driving technology with variable opening advance angle, closing delay angle and lift of piston engine valves. Background technique [0002] At present, improving engine performance (including power, economy, reinforcement, exhaust cleanliness, low-speed stability and low-temperature startability, etc.) has become the most important goal pursued by engine technology research. The research results of piston engine structure optimization, combustion mechanism and experiments tell us: valve timing (corresponding to valve opening advance angle, closing delay angle and holding opening angle. They refer to: engine piston compression top dead center or exhaust The top dead center is the reference point, the crankshaft angle corresponding to the early opening time of the valve, the delayed closing time and the continuous opening time, the val...

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Problems solved by technology

[0004] Problems in the above technical solutions: ① VVT technology has a complex structure and difficult control. Practice has proved that it has no obvious effect on improving engine performance; ② i-VTEC technology has complex structure, difficult control, poor linearity of power output, and improved engine performance. Not ideal; ③MIVEC technology, the structure is more complicated, the control is more difficult, the power output is not linear enough, and the engine performance improvement is not ideal; ④VVEL technology, the structure and control are very complicated, and the layout and control are difficult; ⑤Double-VANOS technology, the structure is very complicated, more difficult to control

In short, the above-mentioned technologies, due to the use of electronic control technology and relatively complex mechanical structures, all have the problems of many fault points, low reliability, high cost, difficult structural layout and maintenance, and some of them have little effect on improving engine performance. not ideal

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