A valve spring generally refers to a helical compression spring for opening and closing the engine valve.
The valve spring expands and compresses 100 million times or more at speeds as high as several thousand times per minute as the engine valve opens and closes.
Therefore, the valve spring must demonstrate extremely high durability, heat resistance, and settling resistance because it is continuously subjected to high-speed repetitive loads during engine operation.
Since the valve spring is used in a very severe environment as an important component that directly affects the performance and reliability of an engine, high quality materials incorporating special treatment in the manufacturing process are necessary.
In valve springs using helical compression springs, the increase in the load at maximum compression (at full opening of the engine valve) results in an increase in friction and wear of the dynamic valve system, leading to increase in fuel consumption.
Conversely, the possibility of a decrease in the load at maximum compression results in the possibility of improving fuel consumption due to the reduction in friction and wear.
In order to reduce the load at maximum compression without lowering the rotation limit of the engine (dynamic valve system), it is necessary to decrease the mass of movable parts in a dynamic valve system.
A beehive valve spring reduces the mass of movable parts (retainers) in a dynamic valve system by adopting a spring shape where the diameter of the coil of the movable side (retainer side) of the spring is minimized. The term “beehive” is used because the shape is similar to a beehive.