A composite profile evaluating method includes an adjusting step and a composite profile detecting step. In the adjusting step, a relative position between a fixed cam and a movable cam is adjusted. In the composite profile detecting step, at least either one of a first contact element, which is displaced along a diametrical direction of the fixed cam upon contacting a cam surface of the fixed cam, and a second contact element, which is displaced integrally with the first contact element and along a diametrical direction of the movable cam upon contacting a cam surface of the movable cam, is brought into contact with the cam surface of the fixed cam or the movable cam. In such a state, the composite profile is obtained by rotating the fixed cam and the movable cam, and detecting the amounts of displacement of the first and second contact elements.

A valve mechanism includes: a support shaft immovably fixed to a main body of an internal combustion engine, a main arm swingably supported by the support shaft; two sub-arms arranged at both sides of the main arm; a coupling support portion swingably supporting and coupling the two sub-arms to the main arm; a cam; and a roller rotatably located in the main arm. Each of the two sub-arms includes: a drive unit pressing and driving a valve; and a contact portion contacting a plunger of a lash adjuster, the contact portion has a curved surface slidably contacting a flat surface formed in a tip portion of the plunger and having an arc-like curved surface shape of which a central axis line corresponds to a central swing axis line of the main arm in a state where the cam abuts on the roller in a base circular portion of the cam.

A camshaft for a valve drive of an internal combustion engine having a variable valve opening time may include an outer shaft and an inner shaft that extends through the outer shaft, with the inner shaft being held rotatably with respect to the outer shaft. The camshaft may further include a cam having a multiple-piece configuration, comprising a first part cam and a second part cam. Either the first part cam or the second part cam may be connected fixedly to the outer shaft so as to rotate with it, and the other part cam may be connected fixedly to the inner shaft so as to rotate with it. The camshaft may also include a bearing inner ring of a shaft bearing that is held on the outer shaft, with one of two second part cams comprising an axial attachment that forms at least one part of the bearing inner ring.