| 摘要 |
<p>A cooled valve seat insert (4) for an exhaust valve (2) for a Diesel engine comprises means for circulating cooling medium adjacent the valve seat (3) of the insert (4). In order to avoid a circumferentially extending cavity in the insert at the seat (3) of the insert and in order to secure a well defined guiding of the cooling medium, the means for circulating the cooling medium consist of a number of blind holes (17) distributed along a circle. The bottoms (18) of the holes (17) are arranged adjacent the valve seat (3) and the blind holes open into an annular duct (10) in the insert (4). By means of guiding baffles (19) inserted into the blind holes (17), the holes (17) are divided into a feeding duct (21) and a return duct (22). The feeding ducts and the return ducts communicate at the bottoms (18) of the holes (17). The annular duct (10) is by partition means (60) divided into cooling medium inlet and cooling medium outlet chambers (61 and 62) which communicate with the feeding ducts and the return ducts (21 and 22, respectively) of the blind holes (17).</p> |
