| 摘要 |
PURPOSE:To prevent fogging that the liquid fuel sticks to an ignition plug by forming an intake port wall face having a high bottom wall face guiding the intake air to the side near the ignition plug and a low bottom wall face guiding the intake air to the side apart from the ignition plug inside the intake port of a spark-ignition internal-combustion engine. CONSTITUTION:An intake port 2 sucking the air-fuel mixture through an intake valve 1 provided on a combustion chamber 3 is formed with a high-port section 12 near an ignition plug 5 provided at the upper section of the combustion chamber and a low-port section 13 apart from the ignition plug 5. Part of the air-fuel mixture flowing into the intake port 2 is guided to the high port section 12 having a high-port bottom section, is guided to the upside of an intake valve 17, and is guided near the ignition plug 5. Liquid fuel flows down to an intake port bottom section 16, passes through the low-port section 13 having a low-port bottom section, passes below the intake valve 1, and is sucked into the combustion chamber 3, thereby fogging that the liquid fuel sticks to the ignition plug 5 can be prevented. |
