Mechanical variable valve device

Abstract

The invention provides a mechanical variable valve device. The mechanical variable valve device comprises a valve; the middle of the valve is provided with a valve spring, and the top end of the valveis provided with a gear; the gear can rotationally move around the valve, the outer circumference of the gear is connected with a control rod, and the top end of the gear is provided with a flat plate; the flat plate is internally provided with two grooves; the rotation speed ratio of a cam to an engine is 1:2; the surface of the outer circumference of the cam is provided with a pair of second molded lines and a pair of first molded lines from the two ends to the center; and the first molded lines can be matched with the grooves. According to the mechanical variable valve device, the flat plate is driven to rotate by 90 degrees by adjusting the linear motion distance of the control rod, the cooperation law between the cam and the flat plate can be changed, and accordingly the effect thatthe 2 / 4 stroke is changeable is achieved; and the situation that a control mechanism is operated under each work cycle is avoided, however, adjusting is conducted only under the working condition thatthe stroke needs to be changed, control is easy, and engineering application of the variable valve technology is facilitated.

Description

technical field [0001] The invention belongs to the field of engines, and in particular relates to a mechanical variable valve device. Background technique [0002] The internal combustion engine is still the prime mover with the highest thermal efficiency and the largest power per unit volume and unit weight. It is widely used. However, with the gradual shortage of energy in the world and the continuous deterioration of environmental resources, we need internal combustion engines to meet stricter emission regulations and economic indicators. . Traditional internal combustion engines use fixed-profile camshafts to drive valves, which makes the emissions and fuel consumption of internal combustion engines not optimal at all operating points. Therefore, most new internal combustion engines use variable valve technology to control emissions and reduce fuel consumption. [0003] At present, variable valve technology is mainly divided into camshaft-based variable gas distributio...

AI Technical Summary

Problems solved by technology

Compared with the disadvantages of high energy consumption of electromagnetic drive, low and unstable response speed of electric drive, and complex motor-driven system, the camless gas distribution technology of electro-hydraulic drive has relatively simple structure and fast response speed

However, it also has unavoidable disadvantages: the flow rate of the hydraulic system is not enough at high speed, the valve reaches the maximum lift and the seat is fast, and the impact force is large.

Therefore, it is mainly used in low-speed engines such as diesel engines. In addition, it is necessary to use expensive electro-hydraulic servo systems and relatively complex control technologies to accurately control the valve stroke to avoid seating impact, which greatly increases the engine. cost

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