Mechanical Lash Adjuster
First Claim
1. A mechanical lash adjuster comprising:
- a plunger on which a pressing force of a cam in a valve mechanism acts as an axial load;
a plunger engaging member put into thread engagement with the plunger in an axial direction to form a thread engagement portion, the plunger engaging member retained so as not to rotate in a circumferential direction of the thread engagement portion; and
a plunger spring urging the plunger in an opposite direction to a direction in which a urging force of a valve spring acts;
the mechanical lash adjuster interposed between a stem end of a valve urged in a valve closing direction by the valve spring and the cam to adjust a valve clearance,wherein a lead angle and flank angles of thread ridges of threads forming the thread engagement portion are set such thatwhen an axial load acts on the plunger in either of a plunger extension and a plunger contraction direction, the plunger is prevented from sliding and rotating due to friction torque generated in the thread engagement portion so that the threads are made self-sustaining, andwhen a lateral load acts on the plunger, the plunger is allowed to slide and rotate at the thread engagement portion to move in an axial-load acting direction.
1 Assignment
0 Petitions
Accused Products
Abstract
Provided is a mechanical lash adjuster including a plunger, a housing put into thread engagement with the plunger in an axial direction to form a thread engagement portion, the plunger engaging member fixed and retained in a circumferential direction of the thread engagement portion, and a coil spring urging the plunger in a direction opposite to a urging-force acting direction of a coil spring. A lead and flank angles of threads forming the thread engagement portion are set such that when an axial load acts on the plunger in either of a plunger extension and contraction directions, the plunger is made self-sustaining, and when the plunger swings by an amount corresponding to a backlash due to a lateral load, the plunger slides and rotates at the thread engagement portion to move in an axial-load acting direction.
2 Citations
4 Claims
-
1. A mechanical lash adjuster comprising:
-
a plunger on which a pressing force of a cam in a valve mechanism acts as an axial load; a plunger engaging member put into thread engagement with the plunger in an axial direction to form a thread engagement portion, the plunger engaging member retained so as not to rotate in a circumferential direction of the thread engagement portion; and a plunger spring urging the plunger in an opposite direction to a direction in which a urging force of a valve spring acts; the mechanical lash adjuster interposed between a stem end of a valve urged in a valve closing direction by the valve spring and the cam to adjust a valve clearance, wherein a lead angle and flank angles of thread ridges of threads forming the thread engagement portion are set such that when an axial load acts on the plunger in either of a plunger extension and a plunger contraction direction, the plunger is prevented from sliding and rotating due to friction torque generated in the thread engagement portion so that the threads are made self-sustaining, and when a lateral load acts on the plunger, the plunger is allowed to slide and rotate at the thread engagement portion to move in an axial-load acting direction. - View Dependent Claims (2, 3, 4)
-
Specification