Variable valve lift system, engine and automobile

Abstract

The invention relates to a variable valve lift system, an engine and a car. The variable valve lift system comprises a valve, a first gear, a second gear and a driving part; the valve is provided with a valve head and a valve rod; the first gear is provided with a columnar inner circumferential face which is provided first helical teeth; the second gear is sleeved with the first gear, is coaxially connected with the valve rod, and is provided with a columnar outer circumferential face, and the columnar outer circumferential face is provided with second helical teeth meshed with the first helical teeth; and the driving part is used for driving the first gear to rotate, the second gear is rotated by rotation of the first gear to drive the valve to move in the axial direction. By means of the system, transmission of the first gear is converted into rectilinear motion of the second gear through the meshed helical teeth, then the valve is driven by the second gear to move in the axial direction, and therefore the lift of the valve is continuously changed to adjust the valve opening degree, and the continuously variable valve lift is achieved.

Description

technical field [0001] The invention relates to the field of automobiles, in particular to a variable valve lift system, an engine and an automobile. Background technique [0002] The valve of the engine can be compared to a door. The angle and time of the door opening determine the air flow in and out. The larger the opening angle of the door and the longer the opening time, the greater the air flow in and out, otherwise the smaller the air flow in and out. Thus, the concepts of valve lift and valve timing are born, wherein the valve lift is like the angle at which the door is opened (referred to as the valve opening), and the valve timing is like the time at which the door is opened. [0003] Among them, for the valve lift, when the car is running at a low speed, the engine power required is small, so the intake and exhaust volume requirements are small, and a relatively small valve lift is required; when the car is running at a high speed, the required engine power The ...

AI Technical Summary

Problems solved by technology

[0006] BMW's Valtronic and Nissan's VVEL use switchable intermediate transmission mechanisms to achieve continuous variable valve lift. The advantage of these two systems is that they can achieve continuous variable valve lift. The disadvantage is that the switchable intermediate transmission mechanism requires a set of The control and transmission device is used to drive its work, the structure is complicated, and the control and transmission device is located outside the cylinder, which takes up a large space, squeezes the space for accommodating the cylinder, and limits the selection range of the cylinder, thereby limiting Engine maximum output power

[0007] It can be seen that in the existing variable valve lift technology, the valve lift system with a relatively simple structure can only realize stepwise variable valve lift, while the valve lift system that can realize continuously variable valve lift has a complex structure. , and requires a larger engine space

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