| 摘要 |
A hydraulic valve lifter for use between a cam and a valve in an engine valve train includes a hydraulic lash adjuster element of varying length for acting in the valve train between the cam and valve, an expansion spring for extending the length of the lash adjuster to take up lash in the valve train between valve opening events, and a lash spring stronger than the expansion spring but weaker than a valve spring of an associated engine valve. The lash spring biases the adjuster element against the expansion spring and shortens the effective lash adjusting length of the valve lifter a small amount to maintain a sufficient amount of lash in the valve train between valve opening events to prevent holding open of the valve during cold engine operation. Various embodiments are disclosed.
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