| 摘要 |
<p>A valve damping piston (16) and a cam follower piston (18) have telescopic sliding fits in opposite ends of a through-bore in the lifter housing. A pressure chamber (20) is cooperatively defined within the housing between the two pistons, and is communicated to the engine oil supply. A lash adjusting piston (32) has a telescopical sliding fit with the exterior axial end of the damping piston, and the two cooperatively define between themselves a lash adjusting chamber (34). The lash adjusting chamber is communicated to the pressure chamber by an axial segment (50) of the telescopic sliding fit of the damping piston to the housing. The clearance provided by this axial segment creates a flow restriction that results in the pressure in the lash adjusting chamber being appreciably lower, 50 % for example, than the pressure in the pressure chamber. The damping piston contains a circumferential groove (48) that is directly communicated to the termination of the axial segment. A radial (46) and then an axial hole (44) in the damper piston communicate the groove to the lash adjusting chamber.</p> |
