Title:
EXHAUST GAS PURIFIER FOR INTERNAL COMBUSTION ENGINE
Document Type and Number:
Japanese Patent JPS54121322
Kind Code:
A
Abstract:
PURPOSE:To decrease the quantity of harmful substances and prevent the overheating of a catalyst, by opening and closing an exhaust gas purigying EGR control valve and a secondary air shifting valve reciprocally to each other. CONSTITUTION:A catalytic converter 5 is provided at the exhaust pipe 3 of an internal combustion engine 1. An EGR pipe 11, 12 equipped with the EGR control valve 10 extends from the exhaust pipe at the upstream side of the converter 5 to the intake pipe 4 of the engine to return a part of the exhaust gas to the intake pipe. Secondary air is conducted from an air pump 14 into the exhaust pipe 3 through the secondary air shifting valve 20. When the temperature of the engine is higher than a predetermined level, the negative pressure of the intake pipe is introduced into negative pressure chambers 15, 23 of the control valve 10 and the shifting valve 20 through a thermosensitive negative pressure shifting valve 30. When an EGR valve element 16 is closed, an air valve element 24 is open. When the EGR valve element 16 is open, the air valve element 24 is closed.
Inventors:
WAKITA NOBUAKI
IGARASHI KOUHEI
IGARASHI KOUHEI
Application Number:
JP2779578A
Publication Date:
September 20, 1979
Filing Date:
March 13, 1978
Export Citation:
Assignee:
TOYOTA MOTOR CO LTD
International Classes:
F02B75/10; F01N3/10; F01N3/22; F02D21/08; F02D37/00; (IPC1-7): F01N3/10; F02B75/10; F02D21/08