摘要 |
The present invention relates to fuel injectors having a free floating plunger. Traditional tappet assemblies include a plunger that is mechanically coupled to the tappet, and therefore, cannot be uncoupled over a portion of its movement during an injection event. In the event of a plunger seizure in a traditional tappet assembly, the tappet spring can be prevented from expanding, which can cause major valve train and engine damage. In addition, because the plunger in traditional tappet assemblies is moved to its upward position under the action of the tappet spring, the fuel passages can depressurize if fuel cannot refill the fuel pressurization chamber as quickly as the plunger retracts, causing cavitation bubbles. Therefore, the present invention utilizes a plunger that is not mechanically coupled to the tappet and can uncouple from the tappet during the injection event to address these and other problems related to plunger wear and failure.
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