Patent Number: 6,332,459

Title: Control system of air-fuel ratio sensor heater temperature for internal combustion engine

Abstract: A system for controlling a temperature of an air-fuel ratio sensor heater of an direct injection spark ignition engine which is operated at an ultra-lean burn combustion or at a pre-mixture charged combustion. In the system, the temperature of the air-fuel ratio sensor is estimated and the supply of current to the heater is determined in terms of a duty ratio in PWM based on the estimated temperature of the air-fuel ratio sensor and is increased when the engine is determined to be operated at the ultra-lean burn combustion. The duty ratio is increased by an augmentative on-time which is determined based on a parameter such as a desired torque, an engine speed and load, or a vehicle speed. The supply of current is also increased when the operation of the EGR is in progress.

Inventors: Ehara; Yasunori (Wako, JP), Nagatani; Shuji (Wako, JP)

Assignee: Honda Giken Kogyo Kabushiki Kaisha

International Classification: F02D 41/14 (20060101); F02D 041/00 ()

Expiration Date: 12/25/2018