ENGINE UNIT AND RIDE TYPE VEHICLE

• Main Authors: WAKIMURA MAKOTO, NISHIGAKI MASATAKA, ARAKI YUJI, ISHIZAWA KAZUHIRO
• Format: Patent
• Language: English; Japanese
• Published: 31.08.2017
• Subjects: BLASTING; CYCLES; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; POWERED PROPULSION OF SLEDGES OR; RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; SEPARATION; STEAM ENGINES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES; TRANSPORTING; WEAPONS

PROBLEM TO BE SOLVED: To provide an engine unit including a horizontal cylinder part, capable of suppressing an increase in size while early enhancing the activation of a catalyst, and to provide a ride type vehicle.SOLUTION: The engine unit includes: a single-cylinder four-stroke engine including a horizontal cylinder part and a crank case part; an exhaust passage arranged at least partly neighboring the single-cylinder four-stroke engine; a noise eliminator having an expansion chamber for suppressing the exhaust noise of the single-cylinder four-stroke engine; a main catalyst arranged in the exhaust passage from an exhaust port of the single-cylinder four-stroke engine to the upstream end of the expansion chamber, at a position nearer the expansion chamber than a combustion chamber of the single-cylinder four-stroke engine, and having the highest exhaust emission control ability in the exhaust passage; and a heat insulation member provided over at least one half of the exhaust passage upstream of the main catalyst for suppressing thermal conduction from the exhaust passage to outside air.SELECTED DRAWING: Figure 2 【課題】大型化を抑制し触媒の活性を早期に高めつつ、大型化を抑制することができる、水平シリンダ部を備えたエンジンユニット及び鞍乗型車両を提供すること。【解決手段】このエンジンユニットは、水平シリンダ部およびクランクケース部を含む単気筒４ストロークエンジンと、単気筒４ストロークエンジンに少なくとも一部が隣接して配置された排気通路と、膨張室を有し、単気筒４ストロークエンジンの排気音を抑制する消音器と、単気筒４ストロークエンジンの排気口から膨張室の上流端の間の排気通路において、単気筒４ストロークエンジンの燃焼室より膨張室に近い位置に配置され、かつ、排気通路の中で排ガスの浄化能力が最も高いメイン触媒と、排気通路から外気への熱伝導を抑制し、かつ、メイン触媒より上流の排気通路の少なくとも半分以上に設けられた保温部材と、を備える構成を採る。【選択図】図２