| 摘要 |
<p>A vacuum relief valve (10) for use with internal combustion engines is provided. The valve (10) is connected to the breathing tubes (14, 16) of an engine on one side and to the air induction system of the engine on the opposite side. Under certain conditions during engine operation, the induction system has a tendency to reduce the pressure within the crankcase creating a partial vacuum. The vacuum relief valve (10) is interposed between the induction system and the crankcase and control or limits the amount of partial vacuum thus created to a maximum of seven inches of vacuum or less. This is accomplished by providing means for limiting the size of a passageway (75) through the valve (10) and thereby limit the amount of suction that can be communicated by the induction system to the crankcase. In one embodiment, a spring biased piston (48) is used to control the size of the passageway (75). Other valving mechanisms are also contemplated. An auxiliary pathway (74) to atmosphere is also incorporated into the valve (10) so that the breather tubes (14, 16) can be vented when the passageway (75) through the valve is partially or fully closed.</p> |
