Location History:
- Asaka, JP (1987)
- Wako, JP (1989 - 1990)
- Saitama, JP (2002)
Company Filing History:
3 out of 182 
3 out of 10,092 
Years Active: 1987-2002
Title: The Innovations of Tadashi Umeda
Introduction
Tadashi Umeda is a notable inventor based in Wako, Japan. He has made significant contributions to the field of internal combustion engines, holding a total of 6 patents. His work focuses on improving engine performance and efficiency through innovative technologies.
Latest Patents
One of Umeda's latest patents is an ignition timing control device for internal combustion engines. This invention restricts the engine operating region where two ignition plugs ignite at different timings to a specific phase-difference ignition region. In this region, the effects of different ignition timings are remarkably achieved. In other operating regions, simultaneous ignition is performed. The basic ignition timing for the intake ignition plugs is calculated by searching a specific map. In the phase-difference ignition region, the basic ignition timing for the exhaust ignition plugs is also calculated using a map. Conversely, in regions where simultaneous ignition occurs, the basic exhaust ignition timing is set to match the intake ignition timing.
Another significant patent is an air-fuel ratio control method for internal combustion engines. This method involves comparing the concentration of oxygen detected by an O₂ sensor with a predetermined reference value when the engine is in a feedback control region. The air-fuel ratio of the mixture supplied to the engine is controlled based on this comparison. In predetermined high load operating regions, feedback control is interrupted, and the amount of fuel supplied to the engine is increased to enrich the air-fuel ratio.
Career Highlights
Tadashi Umeda has worked with prominent companies in the automotive industry, including Honda Giken Kogyo K.K. and Honda Giken Kogyo Kabushiki Kaisha. His experience in these organizations has allowed him to develop and refine his innovative ideas in engine technology.
Collaborations
Umeda has collaborated with notable coworkers such as Hisashi Igarashi and Kazushige Toshimitsu. Their combined expertise has contributed to the advancement of engine technologies and innovations.
Conclusion
Tadashi Umeda's contributions to the field of internal combustion engines through his patents and collaborations highlight his role as a significant inventor. His innovative approaches continue to influence engine performance and efficiency in the automotive industry.