US 7,565,887 B2
Valve actuation device of internal combustion engine
Seiji Tsuruta, Kanagawa (Japan); and Mikihiro Kajiura, Tokyo (Japan)
Assigned to Hitachi, Ltd., Tokyo (Japan)
Filed on Jun. 05, 2006, as Appl. No. 11/446,138.
Claims priority of application No. 2005-178955 (JP), filed on Jun. 20, 2005; and application No. 2006-124956 (JP), filed on Apr. 28, 2006.
Prior Publication US 2006/0283412 A1, Dec. 21, 2006
Int. Cl. F01L 1/34 (2006.01)
U.S. Cl. 123—90.16  [123/90.39; 123/90.44; 74/569] 19 Claims
OG exemplary drawing
 
1. A valve actuation device of an internal combustion engine, comprising:
a cam shaft having thereon at least first and second cams that are different in profile;
a first rocker arm that is in contact with the first cam to be swung, the first rocker arm being adapted to actuate an engine valve;
a second rocker arm that is in contact with the second cam to be swung;
a coupling mechanism that selectively couples and uncouples the first and second rocker arms; and
an electric actuating mechanism that actuates the coupling mechanism with an electric power for the selective coupling and uncoupling,
wherein the coupling mechanism comprises:
a control shaft, having an axis, that is rotated about its axis by the electric actuating mechanism;
a control cam integrally formed on the control shaft;
a plunger that is axially moved with one end thereof slidably contacting the control cam; and
a lock mechanism that induces a mutually locked condition between the first and second rocker arms when the plunger is moved axially in one direction and a mutually unlocked condition between the first and second rocker arms when the plunger is moved axially in the other direction.