What are the precautions when using valve spring seats?

What are the precautions when using valve spring seats?

The function of the engine valve spring is to ensure that the valve can closely fit the valve seat or valve seat ring when closed, overcome the inertial force generated by the valve train when the valve is opened, and ensure that the transmission components are always in contact with the cam and under control. As the valve spring bears alternating springs, in order to ensure reliable operation, it should have appropriate stiffness, sufficient fatigue strength, and service life. Valve springs are usually made of high carbon manganese steel. In order to improve its fatigue strength, it is also necessary to polish or peen the surface of the spring steel wire. To avoid corrosion, the surface of the spring steel wire is galvanized and phosphatized.

When the operating frequency of a valve spring approaches its natural frequency or an integer multiple of its natural frequency, the valve spring will resonate and periodically damage its valve train, which may not only affect the valve but also break the spring. To prevent resonance, the following measures can generally be taken:

1. Using double valve springs, the general method is to install two inner and outer springs with different diameters and opposite rotation directions for each valve. This is because the natural frequencies of the two springs are different, so when one of the springs resonates, the other can play a damping role.

2. The use of variable pitch valve springs is characterized by a non fixed natural frequency, which can avoid resonance.

3. The valve spring seat manufacturer uses a conical valve spring, which is also due to the different stiffness of the spring on the shaft, so the natural frequency is not fixed.

4. When using equal pitch valve springs, spring vibration dampers can be installed externally to attenuate vibration.