A variable hydraulic valve mechanism for a 2-4 stroke engine without a valve spring

Abstract

The invention provides a two-four stroke variable hydraulic valve mechanism for a valveless spring engine, which includes a movable cam, a stator and a valve; the movable cam is sleeved on the stator and can rotate around the stator; a first hydraulic cylinder is arranged inside the stator and the first piston, the lower end of the piston rod of the first piston is fixedly connected to the roller; the upper end of the valve rod is fixedly connected to the second hydraulic cylinder, the second hydraulic cylinder is provided with a second piston, and the upper end of the piston rod of the second piston is fixedly connected to the roller; the movable cam There are guide grooves that cooperate with the rollers inside, and the upper and lower surfaces of the guide grooves are respectively provided with a first molded line and a second molded line; by controlling the pressure and pressure of the hydraulic fluid in the first hydraulic cylinder and the second hydraulic cylinder The direction of movement can change the cooperation law between the roller and the first and second molded lines, so as to realize the change of two or four strokes. The invention cancels the valve spring, can realize higher inflation efficiency, and at the same time, the control is simple, which is beneficial to the engineering application of the variable valve technology.

Description

technical field [0001] The invention belongs to the technical field of variable valve hydraulic actuators for engines, and in particular relates to a variable hydraulic valve mechanism for two or four stroke engines without valve springs. 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. 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 va...

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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