| 摘要 |
<p>A non-return valve (10) employed in a pre-combustion chamber (12) for a gas fuelled internal combustion engine is described. The non-return valve (10) comprises a body (30) having an inlet passage (32), and an outlet passage (34) which is in fluid communication with the inlet passage (32) via an intermediate passage (38) of reduced diameter. A valve ball (36) is provided within the outlet passage (34) and is movable between a first position in which it closes the outlet passage, and a second position in which the outlet passage (34) is open to allow the flow of fluid through the valve (10). An annular valve seat (40, figure 2) on the outlet side of the intermediate passage (38) is provided, against which the valve ball (36) rests in the first position. The outlet passage (34) is provided with a cover member (42) having several apertures (44, figure 3b) to allow the flow of gas through the outlet passage (34). Cover member (42) is screwed into the body (30) and has the dual function of retaining the valve ball (36) within the outlet passage (34) and of quenching the back flow of high temperature fluids back into the outlet passage (34). THe internal diameter of intermediate passage (38) is selected to obtain a predetermined flow rate of gaseous fuel through the non-return valve (10) to achieve the desired gas to air ratio in the pre-combustion chamber (12).</p> |
