The main parts of the forklift's valve mechanism:
Valve: The valve is divided into two types: intake valve and exhaust valve. Its function is to open and close the intake and exhaust passages. It consists of a head and a rod. The head is used to open and close the intake and exhaust channels, and the rod is used to guide the movement of the valve. The intake valve is made of ordinary alloy steel, and the exhaust valve is made of heat-resistant alloy steel, because the head of the exhaust valve is directly in contact with the combustion gas and is heated seriously.
In order to ensure close contact and heat conduction between the valve head and the valve seat, a tapered joint surface is used between the valve head and the valve seat and ground. The angle between the cone surface and the top plane is called the valve cone angle, and the commonly used valve cone angles are 30° and 45°. The valve shaft is the guiding part of the valve motion. A groove is cut at the end of the common valve shaft to install a tapered lock plate.
Valve seat: The valve seat is a circular seat hole directly machined on the cylinder block (side-mounted valve) or cover (overhead-mounted valve), which cooperates with the valve to act as a seal. Some valve seats can be processed into a seat ring with wear-resistant alloy cast iron and embedded in the cylinder block or cylinder head.
Valve guide: its role is to guide the valve to make the correct axial movement, and at the same time also indirectly transfer the heat of the valve stem to the water jacket. In order to facilitate repair and replacement, the valve guide is made separately and then pressed into the cylinder block (or cylinder head). When the valve guide is pressed into the cylinder block (or cylinder head), there should be a certain amount of interference and pressing depth to ensure good heat transfer.
Valve spring: Its function is to ensure the tightness of the valve and the valve seat, and to slow down and overcome the inertial force generated by the valve and other transmission.