The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 20, 1981
Filed:
May. 23, 1979
Motohisa Miura, Toyota, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A secondary air supply control apparatus for an internal combustion engine comprises an air pump for producing the secondary air flow, a secondary air supply passage leading to an exhaust system of the engine, a bypass passage leading to the atmosphere, and a valve element connected to a diaphragm. The diaphragm constitutes one wall of a pressure chamber which is supplied with a negative intake pressure prevailing in an intake system of the engine, so as to move the valve element to a position at which the secondary air flow is directed to the secondary air supply passage when the negative intake pressure is higher than a predetermined level. There is provided a control unit operable in response to the pressure of the secondary air flow supplied to the exhaust system to apply the atmospheric pressure to the pressure chamber, thereby moving the valve element to another position at which the secondary air flow is directed to the bypass passage when the pressure of the secondary air flow supplied to the exhaust system is increased beyond a level which imposes overload on the air pump.