A METHODE FOR AIR FUEL RATIO CONTROLLING OF AUTOMATIC TRANSMISSION IN VEHICLE

• Main Author: KWON, O JIN
• Format: Patent
• Language: English; Korean
• Published: 08.05.2004
• Edition: 7
• Subjects: BLASTING; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MECHANICAL ENGINEERING; WEAPONS

PURPOSE: An engine air amount control method of an automatic transmission is provided to prevent the undershooting of engine rpm(revolutions per minute) when a gearshift lever is shifted to a travel range(D or R). CONSTITUTION: An engine air amount control method of an automatic transmission comprises steps of setting up a dashpot by the throttle valve opening degree to the coolant temperature stored to a memory, to control engine idle air amount of a neutral state and outputting a control signal(S100); receiving a gearshift lever position change applied from a shift control device and deciding whether the gearshift lever is shifted from a neutral range to a travel range(S105); deciding the satisfying state of an engine air amount compensation condition(S110); adding a predetermined value to first additional air amount compensation and raising the air amount to second additional air amount and then outputting an engine air amount compensation control signal after maintaining the air amount for the holding time by the coolant temperature(S120); raising the air amount to the first additional air amount compensation and outputting the engine air amount compensation control signal after maintaining the air amount for the holding time by the coolant temperature(S130); deciding whether the gearshift lever is shifted from the travel range to the neutral range while maintaining idle by travel range air amount control(S140,S150); outputting a control signal to maintain idle of the neutral range after reducing the air amount to a predetermined gain by the basic air amount difference of the travel range and the neutral range(S160); deciding operation state of an engine and finishing all programs and returning to the initial step if the engine is turned off(S170). 본 발명은 자동 변속기 차량에서 엔진 고온 시동 직후 엔진 회전수가 높은 상태 또는 변속단 중립(N)단 상태에서 무부하 주행 직후 엔진 회전수가 떨어지는 도중에 변속레버가 주행(D 또는 R)단으로 절환될 시, 엔진 회전수의 언더 숫(Undershoot)됨을 방지할 목적으로; 냉각수온 별, 스로틀 밸브 개도 별 중립단 아이들 공기량 제어를 수행하는 단계와; 변속레버 전환여부를 판단하는 단계와; 변속레버가 주행단으로 절환됨이 판단되면 엔진 공기량 제어 조건 만족여부를 판단하는 단계와; 주행단 공기량 제어 후, 아이들 공기량을 유지하며 변속레버 중립단으로 전환여부를 판단하는 단계와; 엔진 공기량을 주행단과 중립단 차이만큼 소정의 게인으로 감량 후, 중립단으로 아이들 공기량 유지하는 단계로 이루어져 있어서, 운전성 및 상품성을 향상시킬 수 있는 효과가 있다.