| 摘要 |
PURPOSE: To provide a ceramic valve guide assembly permitting shrink fitting force not to be lost even if the operating temperature of an engine rises, thereby attaining an engine with high efficiency and durability. CONSTITUTION: This valve guide assembly 52 includes a lower securing element 84, an upper securing element 88, and a spring 108 disposed between the two elements and serving as a separation means 106 so as to surround a ceramic valve guide 70 in the circumferential direction. The lower securing element 84 includes a set of fitting truncated cone elements 90 formed out of an internal element 94 and an external element 96 coaxial to the internal element. The upper securing element includes a set of fitting truncated cone elements 98 in the same way. When mounted on an engine, a valve spring 56 presses the spring 108, so that axial load is applied radially to the lower securing element and the upper securing element so as to forcibly-connect the ceramic valve guide 70 to a cylinder head 18. |
