| 摘要 |
In some hydraulically actuated fuel injectors, a pressure communication passage extends from a pilot valve to the underside of a spool valve to control movement of the same. For the spool valve to move, a substantial amount of fluid flow past the pilot valve is required due to the relatively large amount of fluid that must be displaced by movement of the spool valve member. However, during cold start, when the oil in the pressure communication passage is relatively viscous, it is difficult to move enough fluid past the relatively small flow area through the pilot valve to allow the spool valve to advance to its upper position. Therefore, the fuel injector of the present invention includes a pressure communication passage that is connected to the underside of the spool valve to be separated from the branch that passes through the pilot valve.
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