| US 7,484,485 B2 | ||
| Variable-valve-actuation apparatus for internal combustion engine | ||
| Makoto Nakamura, Kanagawa (Japan); and Yoshihiko Yamada, Kanagawa (Japan) | ||
| Assigned to Hitachi, Ltd., Tokyo (Japan) | ||
| Filed on Jun. 15, 2007, as Appl. No. 11/812,197. | ||
| Application 11/812197 is a division of application No. 11/435787, filed on May 18, 2006, abandoned. | ||
| Application 11/435787 is a continuation of application No. 10/627745, filed on Jul. 28, 2003, granted, now 7,047,921. | ||
| Claims priority of application No. 2002-235401 (JP), filed on Aug. 13, 2002. | ||
| Prior Publication US 2007/0245988 A1, Oct. 25, 2007 | ||
| Int. Cl. F01L 1/34 (2006.01) | ||
| U.S. Cl. 123—90.16 [123/90.15; 123/90.17; 123/90.31] | 9 Claims |
| 1. A variable-valve-actuation (VVA) apparatus for an internal combustion engine with a valve, comprising:
a control shaft arranged to be rotatable in accordance with operating conditions of the engine;
an alteration mechanism which changes at least an operating angle of the valve in accordance with rotation of the control
shaft; and
a drive mechanism which rotates the control shaft, the drive mechanism comprising an electric motor and a reduction mechanism,
the reduction mechanism comprising:
an output shaft linked to the motor and having an external thread formed on an outer peripheral surface;
a moving member having an internal thread formed on an inner peripheral surface, wherein the external thread is meshed with
the internal thread, the moving member moving in an axial direction of the output shaft in accordance with rotation of the
output shaft;
a link member having a first end swingably linked to the moving member; and
a linkage swingably linked to a second end of the link member, the linkage rotating the control shaft by torque transmitted
from the link member in accordance with axial movement of the moving member,
wherein when the valve is under control of small operating angle, an angle formed between the link member and the output shaft
is relatively large.
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