| 摘要 |
PROBLEM TO BE SOLVED: To provide an intake/exhaust valve device for an engine that enables elongation of service lives of a poppet valve and a valve cap.SOLUTION: The intake/exhaust valve device for an engine includes a poppet valve 1 and a valve cap 3 fitted to a valve shaft end 2 of the poppet valve 1. Maximum width chamfered portions 6 are arranged at a valve cap opening edge 5, leaving predetermined intervals in the circumferential direction, and remaining opening edge portions 7 between the maximum width chamfered portions 6, 6, adjacent to each other comprise small width chamfered portions 8 each having a radial width W2 smaller than a radial width W1 of the maximum width chamfered portion 6. A peripheral edge portion 11 of a valve shaft end surface 10 comprises a small width chamfered portion 12 having a radial width W3 smaller than the radial width W1 of the maximum width chamfered portion 6. A valve cap abutment surface 13 of the valve shaft end surface 10 on the inner side of the peripheral edge portion 11 of the valve shaft end surface 10 is brought into close contact with a valve cap back end surface 14. |
