Abstract: The present invention provides a shim for a valve drive mechanism which is interposed between a pad surface of a rocker arm and a stem end surface of a valve. The shim includes a ship top surface that is contacted by the pad surface. The shim top surface is rotated about a center thereof to be cut, is provided with a center hole at the center thereof, and is shaped such that the pad surface does not contact an intersection line between an inner peripheral surface of the center hole and the shim top surface when the rocker arm is swung.

Abstract: A rocker arm unit which constitutes a valve gear of an internal combustion engine, includes a lash adjuster including a cylindrical body and a plunger formed into a cylindrical shape and accommodated in the body, a rocker arm extending in a direction perpendicular to a vertical direction, and a clip configured to be fixed to an upper end of the body and formed with a retainer having a retaining portion which is configured to be swaged onto an inner circumferential surface of the upper end of the body. The clip has an extension extending integrally from the retainer. The extension has an upper end engaged with the rocker arm to prevent the rocker arm from falling off the lash adjuster. The retaining portion is configured to abut against the stepped portion of the plunger from above to prevent the plunger from coming off upwardly out of the body.

Abstract: The present invention provides a shim for a valve drive mechanism which is interposed between a pad surface of a rocker arm and a stem end surface of a valve. The shim includes a ship top surface that is contacted by the pad surface. The shim top surface is rotated about a center thereof to be cut, is provided with a center hole at the center thereof, and is shaped such that the pad surface does not contact an intersection line between an inner peripheral surface of the center hole and the shim top surface when the rocker arm is swung.

Abstract: A rocker arm unit comprises a lash adjuster having a plunger extending axially and a cylindrical body which houses the plunger so that the plunger is slidable; a rocker arm supported by an upper end of the plunger and swung with the supported position serving as a pivot; and a clip which is fixed to the body so as to extend from the fixed position to engage the rocker arm, thereby restricting drop of the rocker arm out of the lash adjuster.