What is the function of the valve guide?
1 Answers
The function of the valve guide is to guide the movement of the valve, ensuring that the valve performs reciprocating linear motion, enabling the valve to correctly fit with the valve seat ring, and transferring the heat from the valve stem to the cylinder head. There are two types of valve guides: integral type and insert type. The integral valve guide directly processes the valve stem hole in the cylinder head; the insert type valve guide is press-fitted with a cylindrical tube into the guide hole in the cylinder head. The installation of the valve guide requires the inner and outer cylindrical surfaces of the valve guide to be processed and then pressed into the valve guide hole of the cylinder head or cylinder block. The inner hole is then precision reamed. To prevent axial rotation, a retaining ring positioning groove is provided, which cooperates with the positioning retaining ring to prevent the guide from moving and falling into the cylinder during operation. A small clearance is generally left between the valve stem and the valve guide to allow the valve stem to move freely in the guide.