| 摘要 |
A columnar hydraulic tappet comprises a housing (2). A plunger (1) is correspondingly mounted in the housing. A high-pressure cavity (10) for a hydraulic medium extends between a sealing base of the plunger and the lower side of the housing. The high-pressure cavity can be sealed by means of a check valve opened towards the high-pressure cavity. An outer ring groove (13) for hydraulic medium circulation is formed in the outer diameter of the housing, an inner ring groove (8) for hydraulic medium circulation is formed in the radial inner side of the housing, and one or more housing oil holes (7) are formed between the inner ring groove and the outer ring groove. The plunger consists of a sealed hemispherical head portion (11), a rod portion and a main body portion. An inward-concave neck portion (4) is disposed between the head portion and the rod portion of the plunger, and the wall thickness of the neck portion is 105% to 120% of the wall thickness of the rest of the plunger. The wall thickness of the low-strength region of the plunger of the hydraulic tappet is increased, and both a requirement for increasing an oil storage amount in the plunger chamber and a requirement for improving fatigue strength are considered. |
