Abstract

The elimination of the throttle has recently attracted attention as a means of improving fuel economy through the reduction of pumping loss. The research described in this paper concerned fuel economy, noise and vibration performance and wide-open throttle performance in an engine equipped with an electromagnetic variable valve timing mechanism to enable the throttle to be eliminated.A high-efficiency mechanism equipped with a low voltage drive method from considerations of practical use and constant voltage opening and closing control that has realized short and stable valve contact speed were developed. In comparison with a conventional cam-driven valvetrain, this new valve mechanism has achieved a simulation-based improvement of 7% in fuel economy in the 10.15 mode and a roughly 20% increase in torque at low to mid engine speeds through optimization of valve timing and scavenging effectiveness. In addition, the combination of compact type-integrated hydraulic tappet, dual over-excitation constant voltage control and resin engine cover, has enabled the engine to record the same noise level when idling as an engine with a conventional valvetrain.

References

1. (1) Tuttle, J.: Controlling Engine Load by Means of Late Intake Valve Closing, SAE Paper 800794
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Author (organization or company)

• Chihaya SUGIMOTO（Tochigi R&D Center）
• Atsushi UMEMOTO（Tochigi R&D Center）
• Yasuo SHIMIZU（Tochigi R&D Center）

Publication Information

Article of Honda R&D Technical Review Vol.16 No.2 (159 - 164)

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Citation Information