What is the engine "timing system"?

Timing system is an important part of engine valve mechanism and one of the important factors to ensure the smooth breathing of engine. By controlling the opening and closing time of the valve, the timing system accurately realizes the opening and closing of the corresponding intake valve and exhaust valve, so that sufficient fresh air can be timely into the cylinder, exhaust gas can be timely discharged from the cylinder, so as to ensure that the engine has a normal and good power output performance.

Timing system executive element

At present, the main working process of most engine timing system is: the camshaft is driven by the crankshaft through the chain or belt, and the valve tappet is rotated by the CAM working surface to push the valve into the cylinder, so as to realize the valve is opened; After the CAM face is rotated, the valve will return to position under the action of the valve spring and the valve will be closed.

Which is better, a timing belt or a timing chain?

Timing system transmission parts are divided into timing chain and timing belt two, a lot of people are concerned about what kind of transmission form is better. The timing belt has been applied in the engine for a long time, the technology is mature, the cost is low, the noise is small, but the need for regular inspection and maintenance, generally 5~ 100 thousand kilometers need to be replaced. Timing chain has the advantages of compact structure, high transmission power, high reliability and wear resistance, lifelong maintenance free, but compared with the traditional timing belt, its noise is generally a little bigger. If you cannot determine the timing belt replacement cycle, you can take the maintenance cycle specified by the automobile manufacturer as the standard. The maintenance cycle stipulated by manufacturers of different car models is not completely the same. The specific replacement cycle shall be subject to the requirements of automobile manufacturers. But nothing is guaranteed. With advances in technology, some cars now have toothed silent chains that are even quieter than the timing belts. It is believed that the wide use of this timing chain will bring more convenience to the majority of car users.

Toothed mute chain

At present, the common timing chain is mainly divided into sleeve roller chain and tooth chain two types. Among them, the roller chain is affected by its innate structure, the rotation noise will be more obvious than the timing belt, and the transmission resistance and inertia will be correspondingly larger. We commonly known as the "silent chain" adopts the toothed structure design, the transmission into the tooth is softer, the impact is smaller, the operation is more stable, and it does not produce noise chain roller structure, therefore, in the noise level performance is better than the traditional timing belt.