| 摘要 |
A modular compound valve assembly for an automotive oil filter includes a relief valve subassembly and a clean-side anti-drainback valve subassembly sharing a common unitary valve body. In one preferred form, the valve body is formed of a stepped cylinder, wherein axially opposed surfaces of a first step comprise respective seats for first and second springs utilized in the two valve subassemblies. The first spring (for the relief valve) is entirely contained within the valve body, while the second spring (for the anti-drainback valve) is external to the valve body although supported thereon. The second spring is a frustoconically-shaped spring biased between the first step of the valve body and an external circular disc spaced from but fixed to a plunger of the anti-drainback valve. To the extent that the anti-drainback plunger is adapted for being seated within the valve body, the compound valve assembly offers greater flexibility in stocking inventories of valve subassemblies for in-field selection and modification. For example, the anti-drainback valve subassembly may be "piggybacked" onto the relief valve subassembly without requirement of special tools. Finally, in the same preferred form, the anti-drainback subassembly includes a pair of struts fixed to the circular disc, wherein the second spring is maintained under constant compression between the disc and step of the valve body to close the anti-drainback plunger, and hence to avoid leakage of clean oil from the filter, upon shutdown of an associated engine.
|
