Apparatus for purifying exhaust gas

Patent · Tue Jul 10 04:00:00 EDT 1979

OSTI ID:5941410

Furukubo, T

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 enntrance 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,

• Assignee: Toyota Jidosha Kogyo Kabushiki Kaisha
• Patent Number(s): US 4160363
• OSTI ID: 5941410
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330700* -- Advanced Propulsion Systems-- Emission Control
AFTERBURNERS
AIR POLLUTION CONTROL
AUTOMOBILES
CATALYTIC CONVERTERS
DESIGN
EQUIPMENT
EXHAUST GASES
GASEOUS WASTES
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
VEHICLES
WASTES