1374976 九、發明說明： 【發明所屬之技術領域】 本發明涉及-種車輛弓I擎之供油方法及其裝置，特別是一 種以加壓空氣促進燃油霧化之供油技術。 【先前技術】 —按，一般汽油引擎採取均質（H〇mogeneous)混合，其稀 薄燃燒極限父制於預混式燃燒(premixed c〇mbusti〇n)的火焰 φ特性與燃油的化學性質，以市售無鉛汽油做為燃油時，空燃 比一般無法達到25以上，若要提升稀薄燃燒極限，則必需 對引擎的結構或在熱力循環上做改進，在韓國大學與現代汽 車（Hyundai Motor)等共同發表的研究中，探討不同渦旋比 與贺油正時對火星塞附近空燃比及稀油極m(Lean Misfire Limit)的影響(如圖6所示），發現當渦旋比為〇，氣門開時 (0-180 deg CA)喷油會造成火星塞附近空燃比(AFR)較大，稀 油極限下降；如果渦旋比為4.02，氣門開時(0_180 deg CA) 喷油會造成火星塞附近空燃比（AFR)較小，稀油極限上升此 Φ 即層狀燃燒的效果。 此外，在燃油引擎供油裝置中，包含有一種進氣道喷射 系統(Port Fuel Injection, PFI) ’該進氣道噴射系統之設計係 將燃油噴入進氣道中，於進氣門關閉時喷射，讓燃油有較多 的時間蒸發與混合’惟’其缺點是氣道壁面會有燃油油膜， 造成在加減速的暫態時進入汽缸的燃油量不準確。 在燃油引擎供油裝置中，包含另一種缸内直接喷射 (Gasoline Direct Injection，GDI)把燃油直接喷進汽缸裡， 5 -1374976 進氣系統只吸入純空氣，並使用火花點火，惟，其有下列缺 (1) 喷油嘴接觸缸内高溫燃燒氣體，容易積碳與損壞。 (2) 燃油油滴粒徑需25；czm以下，喷嘴霧化能力要求較 南。 (3) 燃料喷射壓力較高約50-100 atm，燃油喷射系統成 本增加。 (4) 引擎運轉特性直接受喷油正時影響，需要精確的控 鲁制，否則無法達到提昇馬力與節省耗能之目的。 (5) 引擎全負荷時空燃比跟一般汽油引擎一樣，是接近 化學理論值（Stoichiometric Air Fuel Ratio)稍遭的均質 (Homogeneous)混合氣，中低負荷卻是高度稀薄燃燒，其 轉換之控制技術較困難。 (6) 稀薄燃燒的廢氣中含過多氧氣，觸媒轉換器對於 NOx轉化故軍1良低’需要使用到較昂貴的觸媒轉化器，如 稀油燃燒觸媒（Lean Burn Catalyst)或NOx吸附觸媒 聲（NOx-absorber Catalyst)。 在燃油引擎供油裝置中’更加包含另一種半直接缸内嘴 射（Semi-Direct Injection，SDI)，其特點在於將燃油直接噴入 汽缸，但是並未將喷油嘴放置於汽缸内部，而是將嗅油嘴 放置在進氣道上’在早期半直接喷射系統主要用於改良二行 程汽油引擎之油氣短路（Short Circuit)問題，以減少排氣汗 染與提升燃油經濟性。 ' 因此，SDI即具有PFI與GDI兩方面的優點，SDI和1374976 IX. Description of the Invention: [Technical Field] The present invention relates to a method and apparatus for supplying fuel to a vehicle, and more particularly to an oil supply technique for promoting fuel atomization by pressurized air. [Prior Art] - Press, the general gasoline engine adopts homogenous (H〇mogeneous) mixing, and its lean burning limit is based on the pre-mixed combustion (premixed c〇mbusti〇n) flame φ characteristics and fuel chemical properties. When unleaded petrol is sold as fuel, the air-fuel ratio generally cannot reach 25 or more. To increase the lean burn limit, it is necessary to improve the structure of the engine or the thermal cycle, and jointly publish it at Korea University and Hyundai Motor. In the study, the effects of different vortex ratios and eutectic timing on the air-fuel ratio near the Mars plug and the Lean Misfire Limit (see Figure 6) were investigated. It was found that when the vortex ratio is 〇, the valve opens. When the fuel is injected (0-180 deg CA), the air-fuel ratio (AFR) near the spark plug is large, and the lean oil limit is reduced. If the vortex ratio is 4.02, when the valve is open (0_180 deg CA), the fuel injection will cause the vicinity of the spark plug. The air-fuel ratio (AFR) is small, and the lean oil limit rises. This Φ is the effect of layered combustion. In addition, in the fuel engine oil supply device, a port fuel injection system (PFI) is included. The port injection system is designed to inject fuel into the intake port and spray when the intake valve is closed. It allows the fuel to have more time to evaporate and mix. 'The only disadvantage is that there will be a fuel film on the air passage wall, which will cause the fuel quantity entering the cylinder during the transient of acceleration and deceleration to be inaccurate. In the fuel engine oil supply device, another type of in-cylinder direct injection (GDI) is used to directly inject fuel into the cylinder. The 5 -1374976 intake system only draws in pure air and uses spark ignition, but it has The following defects (1) The injector contacts the high-temperature combustion gas in the cylinder, which is easy to deposit carbon and damage. (2) The particle size of the fuel oil droplets needs to be 25; czm or less, and the atomization capacity of the nozzle is relatively small. (3) The fuel injection pressure is about 50-100 atm higher, and the cost of the fuel injection system is increased. (4) The engine running characteristics are directly affected by the injection timing, and precise control is required. Otherwise, the horsepower and energy saving cannot be achieved. (5) The engine's full-load air-fuel ratio is the same as that of a normal gasoline engine. It is a homogeneous (Homogeneous) mixture close to the Stoichiometric Air Fuel Ratio. The medium and low load is highly lean combustion, and its conversion control technology is better. difficult. (6) Excessive oxygen is contained in the lean-burning exhaust gas, and the catalytic converter is low in NOx conversion. It requires the use of more expensive catalytic converters, such as Lean Burn Catalyst or NOx adsorption. NOx-absorber Catalyst. In the fuel-engine oil supply unit, there is another semi-direct injection (SDI), which is characterized in that fuel is directly injected into the cylinder, but the injector is not placed inside the cylinder. The sniffer nozzle is placed on the intake port. The early semi-direct injection system was mainly used to improve the short circuit problem of the two-stroke gasoline engine to reduce exhaust pollution and improve fuel economy. Therefore, SDI has the advantages of both PFI and GDI, SDI and