Engine EGR system and diagnosis method thereof

[0086] An engine EGR system 100, such as figure 1 As shown, it includes: an EGR pipeline 1 , a first temperature sensor 2 , an intake manifold 3 and a second temperature sensor 4 .

[0087] Among them, such as figure 1 As shown, the EGR pipeline 1 is provided with an EGR cooler 11 and an EGR valve 12 .

[0088] like figure 1 As shown, the first temperature sensor 2 is connected to the EGR pipeline 1 after the outlet of the EGR valve 12 to detect the exhaust gas temperature at the outlet end of the EGR valve 12 .

[0089] The intake manifold 3 is connected to the EGR pipeline 1 .

[0090] The second temperature sensor 4 is connected to the intake manifold 3 to detect the temperature of the intake manifold 3 .

[0092] An engine EGR system 100, different from Embodiment 1, on the basis of Embodiment 1, such as figure 1 As shown, the intake manifold 3 is provided with an inlet 31 to connect the outlet end of the EGR pipeline 1 , and the second temperature sensor 4 is provided on the intake manifold 3 away from the inlet 31 .

[0093] like figure 2 As shown, the EGR pipeline 1 is provided with an installation boss 13 , the installation boss 13 is arranged close to the intake manifold 3 , and the first temperature sensor 2 is connected to the installation boss 13 .

[0095] An engine EGR system 100 is different from Embodiment 2 in that on the basis of Embodiment 2, the engine EGR system 100 further includes a controller (not shown in the figure), and the controller communicates with the first temperature sensor 2 and the second temperature sensor 2 respectively. Two temperature sensors 4 are electrically connected, the first temperature sensor 2 transmits the measured exhaust gas temperature as the first temperature value to the controller, and the second temperature sensor 4 uses the measured temperature of the intake manifold 3 as the second temperature value It is transmitted to the controller, and the controller judges whether the EGR pipeline 1 is blocked according to the difference between the first temperature value and the second temperature value.

[0096] The engine EGR system 100 also includes an alarm, which is electrically connected to the controller. When the difference between the first temperature value and the second tempe...