Variable valve apparatus of internal combustion engine

摘要

A variable valve apparatus of an internal combustion engine includes a first rocker arm that contacts a cam, a low lift cam provided coaxially with the cam, and a second rocker arm capable of contacting the low lift cam. The apparatus also includes a switching mechanism capable of connecting the first rocker arm and the second rocker arm to each other through pins, valves that open by being pressed by the second rocker arms via hydraulic lash adjusters arranged in the second rocker arms, and an oil supply path formed inside the second rocker arms that supplies oil to the hydraulic lash adjusters. A radius of a base circle of the low lift cam is smaller than a radius of a base circle of the cam.

主权项

1. A variable valve apparatus for an internal combustion engine, comprising:
a camshaft defining a camshaft axis; a cam having a first lift and a first base circle radius, the cam disposed on said camshaft and configured to rotate with the camshaft about the camshaft axis; a first rocker arm includes a roller that contacts the cam, the first rocker arm is rocked by rotation of the cam; a low lift cam that is arranged coaxially with the cam, the low lift cam has a second lift that is less than the first lift, and has a second base circle radius that is less than the first base circle radius; a second rocker arm that is arranged next to the first rocker arm, the second rocker arm includes;
a first end,a second end spaced from the first end,a contact surface disposed between the first end and the second end that can contact the low lift cam, anda rocking center defined by the second rocker arm at the first end; a switching mechanism that includes a plurality of pins and a plurality of pin insertion holes, wherein at least one of the pin insertion holes is formed in each of the first rocker arm and the second rocker arm and at least one of the plurality of pins is movably inserted into each of the pin insertion holes, the switching mechanism switching between a connected state and a non-connected state by moving the pins, the connected state being a state where the first rocker arm and the second rocker arm are connected to each other through the pins and the non-connected state being a state in which the connection of the first rocker arm and the second rocker arm is released; a hydraulic lash adjuster arranged at the second end, opposite the rocking center of the second rocker arm; a valve that opens as a result of being pressed by the second rocker arm via the hydraulic lash adjuster; and an oil supply path that is formed inside the second rocker arm and that supplies oil to the hydraulic lash adjuster; wherein: the second rocker arm contacts the low lift cam directly, and not via a roller; and the oil supply path passes below the contact surface of the second rocker arm with respect to the low lift cam and above the pin insertion holes formed in the second rocker arm.