Patent ID: 7341034
Filing Date: 2008-03-11
Classification: F01L

Abstract:
1. A hydraulic tappet comprising: a bottomed cylindrical body; a plunger slidably fitted in the body; a check valve mounted at one end of the plunger so that the check valve is interposed between a high-pressure chamber and an oil chamber, the high-pressure chamber being formed between a closed end of the body and one end of the plunger, the oil chamber formed within the plunger; and a return spring mounted between the body and the plunger to exhibit a spring force for biasing the plunger in a direction to increase the volume of the high-pressure chamber, wherein the return spring is disposed outwardly of the body, and wherein a press-fit bore is provided in the other end of the plunger, the press-fit bore having at its axially outer end a tapered chamfer portion with an axially outward increasing diameter; a cap integrally having a shaft portion extending coaxially with the plunger and a flange portion coaxially connected to the shaft portion is fixed to the other end of the plunger in such a manner that the shaft portion is press-fitted into the press-fit bore until the flange portion is brought into opposed abutment against the other end face of the plunger to close an end of the oil chamber on a side opposite from the high-pressure chamber; an axially extending notch is provided around an outer periphery of the shaft portion so that a first air vent passage leading to the oil chamber is formed between the notch and an inner surface of the press-fit bore; and a groove is provided in the other end face of the plunger with its inner end opening into an inner surface of the chamfer portion so that the groove extends in a radial direction of the plunger to form a second air vent passage between the groove and the flange portion.