TH101690A - Fast idle control unit for the vehicle engine. - Google Patents

Abstract

DC60 (21/05/57) In the rapid idle control unit for a vehicle engine where an auxiliary air valve is inserted into the auxiliary intake passage, bypassing the throttle body, the engine is warmed up, and the engine speed is matched to the target idle engine speed by delaying the ignition timing to prevent misfiring. The end of the warm-up is detected instantaneously and accurately, even in environments where the engine temperature hardly increases, and the rapid idle control is prevented from being unnecessarily extended. The lag sensing device 37 determines whether the total lag from the base ignition timing in the lag control by the ignition timing control device 36 has reached a preset value and outputs a termination signal for the rapid idle control to end when the lag sensing device determines that the total lag has reached the preset value, and the auxiliary air valve control device 35 rotates the auxiliary air valve 25 to be fully closed according to the termination signal output from the lag sensing device 37.

Claims (5)

OCR 08PV 1. The rapid idle control unit for a vehicle's engine consists of: an auxiliary intake passage (24) connected to the intake passage (22) without passing through; a throttle valve (23) provided between the intake passage (22); an auxiliary air valve (25) switchable between fully open and fully closed states and inserted into the auxiliary intake passage (24); a temperature sensing unit (32) which detects an index representing the engine temperature; an engine speed sensing unit (31) which detects the engine speed; an auxiliary air valve control device (35) which rotates the auxiliary air valve (25) to fully open in the rapid idle state and controls the opening and closing of the auxiliary air valve (25) between the fully closed and fully open states; and an ignition timing control device (36) which can control the ignition timing to a minimum lag over the base ignition timing so that the detected engine speed. The engine speed sensing unit (31) in the fast idle state is the target engine speed at fast idle and controls the ignition timing. This fast idle control unit includes a lag sensing device (37) which determines whether the total lag from the base ignition timing in the lag control by the ignition timing control device (36) has reached the set total lag and outputs a termination signal for the fast idle control when it is determined that the total lag has reached the set total lag, and the auxiliary throttle control device (35) rotates the auxiliary throttle (25) to be fully closed in response to the termination signal output from the lag sensing device (37). 2. A rapid idle control unit for the vehicle engine under claim 1, in which the ignition timing control device (36) delays the ignition timing by a first delay at a predetermined time whenever the engine speed detected by the engine speed detection unit (31) is equal to or exceeds the first threshold (NE3) and is lower than the second threshold (NE4) which is greater than the first threshold (NE3), and the ignition timing control device delays the ignition timing by a second delay which is greater than the first delay at a predetermined time whenever the engine speed detected by the engine speed detection unit (31) is equal to or exceeds the second threshold (NE4). 3. A rapid idle control unit for the engine of a vehicle under claim 1 or 2 where the auxiliary air valve control device (35) rotates the auxiliary air valve (25) to be fully closed even before the end signal is output from the lag detection device (37) when the temperature detected by the temperature detection unit (32) exceeds the set temperature before the end signal is output from the lag detection device (37). 4. A rapid idle control unit for the vehicle engine under claim 3, which comprises a throttle angle sensing unit (38) which detects the throttle operation or the state in which the accelerator pedal is pressed, and an idle state judgment device (39) which determines the idle state of the vehicle based on the detection by the throttle angle sensing unit (38), in which case the auxiliary air valve control device (35) keeps the auxiliary air valve (25) fully open even if the temperature detected by the temperature sensing unit (32) exceeds the set temperature before the end signal is output from the lag sensing device (37), when the idle state judgment device (39) determines whether the vehicle is accelerating or idling normally. 5. The rapid idle control unit for the vehicle engine under claim 4, whereby the auxiliary air valve control device (35) rotates the auxiliary air valve (25) to be fully closed at the time when the temperature detected by the temperature sensing unit (32) exceeds the set temperature before the end signal is output from the lag sensing unit (37), when the operating status judgment unit (39) determines that the vehicle has been slowed down or stopped.