Honda Giken Kogyo Kabushiki Kaisha

Yoshinobu Isobe

Eiji Kishida

Hiroaki Iwasaki

Shumpei Hasegawa

Fumio Hara

The so called air intake side secondary air supply system for an internal combustion engine includes first and second secondary air supply passages leading to an intake air passage on a downstream side of a throttle valve. The system is provided with a delay device in the second secondary air supply passage on an upstream side of an open/close valve disposed in the second secondary air supply passage, a pressure supply passage which provides communication between a pressure chamber of an air control valve disposed in the first secondary air supply passage and a part of the second secondary air supply passage between the delay device and the open/close valve, a second air supply delay means disposed in said pressure supply passage and a pressure control means for supplying a pressure for reducing the opening degree of the air control valve into said pressure supply passage during a predetermined operating condition of the engine.

Air intake side secondary air supply system for an internal combustion

The so called air intake side secondary air supply system for an internal combustion engine, having first and second secondary air supply passages leading to an intake air passage on downstream side of a throttle valve is, provided with a delay device in the second secondary air supply passage on upstream side of an open/close valve disposed in the second secondary air supply passage, a pressure supply passage which provides communication between a pressure chamber of an air control valve disposed in the first secondary air supply passage and a part of the second secondary air supply passage between the delay device and the open/close valve, and a pressure control means for supplying a pressure capable of reducing an opening degree of the air control valve into a part of the second secondary air supply passage between the open/close valve and the delay device in response to a predetermined operating condition of the engine. Thus, a range of the air-fuel ratio control is determined according to the operating condition of the engine.

The so called air intake side secondary air supply system for an internal combustion engine, having first and second secondary air supply passages leading to an intake air passage on downstream side of a throttle valve is provided with a delay device in the second secondary air supply passage on upstream side of an open/close valve disposed in the second secondary air supply passage, and a pressure supply passage which provides communication between a pressure chamber of an air control valve disposed in the first secondary air supply passage and a part of the second secondary air supply passage between the delay device and the open/close valve. Thus, one of the secondary air supply passages is utilized as a passage for introducing a vacuum into the pressure chamber of the air control valve and the open/close valve is used as a switch device for switching over between the atmospheric pressure and the vacuum which are to be introduced into the pressure chamber of the air control valve.

An intake secondary air supply system for adding air to the intake of an internal combustion engine under certain sensed conditions, such as an excessively rich air-fuel ratio detected by an oxygen sensor in the exhaust system, wherein two separate secondary air supply passages are provided and separately controlled by vacuum responsive valves. One of such valves is controlled to open and close over a period of time to provide a changing supply of secondary air while the other valve is connected through a solenoid operated valve to the engine intake to provide an immmediate opening or closing of that secondary air supply. Vacuum controls responsive to engine operating condition serve to operate the vacuum responsive valves although in one embodiment one of such valves is operated by a constant regulated vacuum.

Growing community of inventors

Tokyo, Japan

Yoshinobu Isobe