摘要 |
<p>A valve controlling the rate of air flow from a supply pump to an engine exhaust system directs the air flow to the exhaust system through an orifice in a diaphragm valve which is associated with a valve seat separating the air supply from an excess air discharge port. The pressures acting on the diaphragm displace the diaphragm from the valve seat the amount necessary for the rate of air flow through the orifice to the exhaust system to be proportional to the rate of exhaust flow through the exhaust system and for the excess air flow supplied by the pump to be discharged through the excess air port.</p> |