| 摘要 |
<p>A thermal barrier (10) fixed to a valve head (12) of a diesel engine poppet valve (14) is disclosed. The barrier includes a thin sheet metal cap 18 having a concave shield portion 18a, an annular fold or corrugation (18b) circumscribing the shield portion, and a cylindrical skirt portion welded to the valve head. The cap and the face portion (12a) of the valve head define an evacuated chamber (20) which is preferably filled with an insulating material (24) which also provides structural support for the shield portion.</p> |
