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:
Jul. 10, 1979
Filed:
Sep. 28, 1977
Tatsumi Furukubo, Susono, JP;
Toyota Jidosha Kogyo Kabushiki Kaisha, Aichi, JP;
Abstract
Disclosed is an apparatus for purifying exhaust gas discharged from an internal combustion engine having four cylinders. The apparatus comprises: an exhaust pipe provided with two entrance pipes, each of which is communicated with two engine cylinders, respectively, and a joint joining the entrance pipes together; a three way catalyzer for converting the exhaust gas disposed at a position downstream of the joint; a secondary air device for supplying secondary air into the exhaust pipe device, the secondary air device being communicated with the first entrance pipe; an air switching device, the entrance of which is communicated with the secondary air device and the exit of which is communicated with the second entrance pipe, for switching secondary air, and; a device for detecting the operating characteristics of the engine and for actuating the air switching device. Utilizing this apparatus, while the engine is cool, a sufficient amount of secondary air is continuously supplied into all of the entrance pipes and can overcome the increase of HC and CO emissions caused by the operation of the choke in the carburetor. On the other hand, when the engine is warmed up, only secondary air is supplied into the first entrance pipe and this causes an oscillation of the secondary air fuel ratio in the three way catalyzer. As a result, a high converting efficiency can be obtained.