Mechanical variable valve drive device

Abstract

The invention provides a mechanical variable valve drive device which comprises a valve. A valve spring is arranged in the middle of the valve, and a gear is mounted at the top of the valve and can dorotating motion around the valve. The periphery of the gear is connected with a control rod, a flat plate is mounted at the top of the gear, a groove is formed in the flat plate, a cam is arranged above the flat plate, and a valve clearance is arranged between the cam and the flat plate. According to the mechanical variable valve drive device, the flat plate can rotate by 180 degrees by adjustingthe linear motion distance of the control rod, the cooperation rule of a first molded line, a second molded line and the groove in the flat plate can be changed, and therefore 2 / 4 stroke variation isachieved, a control mechanism does not need to be operated under every work cycle, and the control mechanism is adjusted only under the work condition that the stroke needs to be changed; and controlis simple, and engineering application of the variable valve technology is facilitated.

Description

technical field [0001] The invention belongs to the field of engines, in particular to a mechanical variable valve driving 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 distribution te...

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

Images