| 摘要 |
<p>A combination valve, in particular for secondary air fans in internal combustion engines with controlled three-way catalytic converters, has a valve body (21) provided with a valve inlet and valve outlet (22, 23), integrating a pneumatically actuated shut-off valve (24) and a backflow prevention valve (25) with blocking effective to the valve inlet and outlet (22, 23). In order to ensure reliable closing of the shut-off valve (24) on a drop in pressure at the valve inlet (22) and also in the event of a leaking backflow prevention valve (25), the valve element (37) of the shut-off valve (24) is mounted on the side facing the valve outlet (23) of the closing element in the backflow prevention valve (25) which takes the form of a leaf spring (48). The valve element (37) of the shut-off valve (24) is connected to a actuating piston (34, 35) by means of a valve lifter (36) axially guided in the valve body and passing centrally through the leaf spring (48). The actuating piston (34, 35) is subjected to negative pressure in order to open the shut-off valve (24) and is subjected to positive pressure to close the shut-off valve (24). <IMAGE></p> |
