| 摘要 |
OBJECT: To provide a mechanical lash adjuster capable of automatically adjusting increased and decreased valve clearance of a valve. MEANS OF ACHIEVING THE OBJECT: The mechanical lash adjuster (20) is arranged between a cam (19a) and one end of the stem of a valve (10) urged by a valve spring (14). The lash adjuster comprises an unrotatable housing (22) having a thread, a plunger (24) subjected to the force of the cam (19a) and formed with a thread in engagement with the thread of the housing, and a plunger spring urging the plunger against the action of the valve spring (14). The lead and flank angles of the engaging threads are set such that the engagement threads can slidably rotate under a given shaft load applied to the plunger (24) unless the frictional torque TB, generated by the friction between the slidable frictional surface F2 of the plunger (24) and a shaft load transmission member to act on the plunger exceeds the thrust torque TF imparted by the shaft load to the plunger (24). The plunger (24) moves in its axial direction to annihilate an increased or decreased valve clearance when it is movable under a shaft load, thereby automatically correcting the valve clearance. |
