| 摘要 |
<p>To reduce the axial length of a slow exhaust valve and thus the size of the valve, a secondary valve seat and a secondary valve body constituting a secondary valve mechanism for restrictively opening a channel connecting a chamber port and a pump port during the first half of the exhaust process in order to limit the exhaust speed are incorporated in a primary valve body in a primary valve mechanism; a secondary-valve-body drive mechanism and a pressure-acting secondary chamber are incorporated inside a primary-valve-body drive member in the primary valve mechanism; and a secondary shaft that connects the secondary valve body and the secondary-valve-body drive member together is disposed inside a primary shaft.</p> |
