Designer's Corner 421

DN Staff

March 25, 1996

2 Min Read
Designer's Corner

Simplified variable valve timing

Changing the relationship between intake-valve timing with changes in engine speed improves response, emissions, and mileage. But variable valve-timing (VVT) arrangements using stepper motors, multiple solenoids, and so on have been a hard sell with the public. This hydraulic system could change that.

Toyota's VVT-i (for intelligent) uses a helically splined cam-pully adjuster driven by engine oil bled from the standard oil pump. Sensors for cam position and crank position close the control loop for the system's electronic control unit, which signals a hydraulic control valve to change cam-pulley position as needed. Toyota engineers say the system should increase fuel mileage approximately 6% and raise low- and medium-range torque 10% all while lowering NOx and hydrocarbon emissions.

International Public Affairs, Toyota Motor Corp., 4-18 Koraku 1-Chome, Bunkyu-Ku, Tokyo 112, Japan.

Electronic palimpsest

Computer databases can hold reams of data, but can be hard to use. Maps are easy to use, but their data-storage capability, so to speak, is limited. The Cherloc system lets maps serve as gateways to limitless volumes of electronically stored data concerning geographical features. In essence, it's a digitizer without a digitizing tablet.

The system works by embossing maps or other documents with patterns of barely visible raised dots. A hand-held video magnifier coupled to a computer reads the patterns, enabling the system to differentiate between map features separated by distances as small as 100 aem. Once identified, users can add to or extract information about the feature from the computer's database. Applications include military intelligence, as well as resource and facilities management.

Cherloc, 44 Bd. des Etats-Unis, B.P. 65, 85002 La Roche-Sur-Yon Cedex, France, 33-51-44-34-34.

On-the-go CO detector

This portable carbon monoxide detector provides protection from that colorless, odorless hazard when you're away from home. The battery-powered device uses commercially available, 2.25-inch-square plastic cards coated with palladium chloride, which darkens when exposed to CO. A retroreflective photodetector coupled to a microprocessor sounds the alert when the card's reflectivity declines past a pre-set threshold limit. Available in kit form, the unit weighs approximately five oz and operates for six months on a nine-volt battery.

Robert Gaffigan, Cintron, Inc., 22524 Millenbach, St. Clair Shores, MI 48081, 810-293-7614.

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