変速ピストン・クランク機構を用いたガソりン機関の高圧縮比・高効率

摘要

In order to avoid knocking phenomena and also to reduce the cooling loss, the authors have studied a new piston-crank mechanism with various specifications. At first, numerical simulations to predict thermal efficiency and knocking limit were performed using 0-D model to confirm the idea. As a result, high compression ratio operation was found possible with a short combustion period. Next, a model engine was designed and built to evaluate the predicted result. A couple of leaf-shaped gears to move piston faster than usual engine near TDC was chosen to achieve higher thermal efficiency. Experimental results showed that higher indicated and brake thermal efficiency can be obtained and that lower exhaust gas emissions also can be obtained.%ガソりン機関は軽量・コンパクト・ハイパワーで低 コストと言う特長を生かして自動車用，特に乗用車用 内燃機関の主流を占めているが，ディーゼル機関と比 較した場合，有毒排気ガス低減性能は優れているもの の，熱効率の点で劣っており，その改善が最大の課題 である．