variable valve timing device

Abstract

The invention discloses a variable valve timing device, which is used to control the opening and closing timing of the valves of the vehicle engine, comprising: a camshaft, used to drive the opening and closing of the valves; a rotary driving part for driving the camshaft, which Able to rotate synchronously with the crankshaft of the engine and relative to the camshaft; a phase adjustment mechanism for changing the relative rotational phase between the rotary drive member and the camshaft to allow adjustment of at least the opening timing of the valves; wherein the phase adjustment mechanism includes The motor is only in transmission connection with the camshaft, and when the valve needs to be opened in advance, the motor drives the camshaft to rotate forward relative to the rotating drive component, thereby opening the valve in advance. Utilizing the variable valve timing device of the present invention can realize the continuous opening of the valve, and under high-speed and high-load working conditions, the intake air volume is larger than that of the prior art; the overall weight of the valve train can be reduced, and the The cylinder head system can be realized with minor changes and has strong versatility.

Description

technical field [0001] The present invention relates to the field of automobiles, and more particularly, to variable valve timing devices. Background technique [0002] It is known from the prior art that the higher the engine speed, the shorter the intake time of the cylinder in one working cycle. At high speed and heavy load, more air intake is required to improve the combustion efficiency of the engine, so that the engine has a higher power output; Achieve good fuel economy. Therefore, more and more vehicle engines employ variable valve timing (VVT) technology to vary the valve timing of the intake and exhaust valves. [0003] The traditional VVT technology can improve the power and fuel economy of the engine to a certain extent by adjusting the opening of the valve in advance, but the valve timing system does not change the duration of the valve opening, and the intake air volume per unit time does not improve much, so for The performance of the engine doesn't help mu...

AI Technical Summary

Problems solved by technology

However, the application defect of this technology is that the mechanism is complex and the power output is not linear enough.

Other continuously variable valve lift technologies, although the smoothness of power output has been improved, but the actuators are more complex

[0004] Comprehensive analysis of several variable valve lift technologies on the market, all of which use the camshaft as the power source to drive complex kinematic pairs and change the valve lift through mechanical movement. Such mechanisms are complex in structure and have many parts, which will inevitably increase the Weight; the movement is cumbersome, which inevitably causes friction loss; too many positions need cooling and lubrication, which has almost strict requirements on the design of the oil circuit; in order to assemble this mechanism, the cylinder head system needs to be modified in a large area, and the versatility is poor

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