Diagnostic device for exhaust gas recirculation device
First Claim
1. An engine having an exhaust gas recirculation passage connecting an exhaust passage to an intake passage, the engine comprising:
- temperature detecting means arranged in the exhaust gas recirculation passage for detecting a temperature of an exhaust gas in the exhaust gas recirculation passage;
an exhaust gas recirculation device arranged in the exhaust gas recirculation passage for permitting the passage of the exhaust gas when an engine temperature during a warm-up of the engine exceeds a predetermined set temperature;
discriminating means for discriminating whether a pattern of change in a temperature inside the exhaust gas recirculation passage detected by said temperature detecting means is a normal pattern or an abnormal pattern, wherein the temperature inside said exhaust gas recirculation passage changes abruptly during warm-up at the predetermined set temperature in said normal pattern and the temperature inside said exhaust gas recirculation passage changes gradually during warm-up in said abnormal pattern; and
abnormality judgement means for judging that operation of said exhaust gas recirculation device is abnormal when the pattern of change in the temperature inside the exhaust gas recirculation passage during the warm-up is said abnormal pattern.
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Accused Products
Abstract
A diagnostic device for an exhaust gas recirculation device comprising an exhaust gas recirculation control valve. When the temperature of the engine cooling water exceeds a predetermined temperature, vacuum acts on the vacuum chamber of the exhaust gas recirculation control valve and the supply of the exhaust gas recirculation gas is started. A temperature sensor is arranged in the exhaust gas recirculation passage. When the temperature of the engine cooling water is slightly lower than the predetermined temperature, if the temperature of the interior of the exhaust gas recirculation passage exceeds a predetermined temperature, it is determined that the exhaust gas recirculation control device has malfunctioned.
15 Citations
34 Claims
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1. An engine having an exhaust gas recirculation passage connecting an exhaust passage to an intake passage, the engine comprising:
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temperature detecting means arranged in the exhaust gas recirculation passage for detecting a temperature of an exhaust gas in the exhaust gas recirculation passage; an exhaust gas recirculation device arranged in the exhaust gas recirculation passage for permitting the passage of the exhaust gas when an engine temperature during a warm-up of the engine exceeds a predetermined set temperature; discriminating means for discriminating whether a pattern of change in a temperature inside the exhaust gas recirculation passage detected by said temperature detecting means is a normal pattern or an abnormal pattern, wherein the temperature inside said exhaust gas recirculation passage changes abruptly during warm-up at the predetermined set temperature in said normal pattern and the temperature inside said exhaust gas recirculation passage changes gradually during warm-up in said abnormal pattern; and abnormality judgement means for judging that operation of said exhaust gas recirculation device is abnormal when the pattern of change in the temperature inside the exhaust gas recirculation passage during the warm-up is said abnormal pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification