| 摘要 |
A priority valve is disclosed for controlling fluid flow between a power source and a priority function and secondary function operated by the power source. The priority valve includes a housing having first and second bores formed therein. An inlet passage connects the power source to the first bore while first and second outlet passages connect the first bore to the primary and secondary functions respectively. A valve spool is positioned in the first bore and is movable between a first position permitting fluid flow from the inlet passage to the first outlet passage while blocking fluid flow to the second outlet passage and a second position permitting fluid flow from the inlet passage to the second outlet passage while blocking fluid flow to the first outlet passage. A pin is movably positioned in the second bore and has an enlarged end which extends into the first bore. a load signal passage connects the priority function to the second end of the first bore. When full fluid flow is demanded by the priority function the valve spool moves toward its first position. When the priority valve demands less than full flow, the spool valve moves toward its second position. If the priority function demands pressure approaching a maximum pressure value which can be delivered by the power source the enlarged end of the pin contacts the valve spool and forces it toward its second position. |
