EGR cooler structure for engine

Abstract

An EGR cooler structure for an engine comprises an EGR cooler, an air inlet chamber, an air outlet chamber, an EGR valve and a water inlet pipe, the air inlet chamber and the air outlet chamber are connected to the two ends of the EGR cooler respectively to form an EGR cooler body structure, the EGR valve is connected to the outer side of the air outlet chamber, and the water inlet pipe is connected to the upper side of the end, close to the air outlet chamber, of the EGR cooler. The EGR cooler body structure is obliquely installed on the outer surface of the cylinder cover, the air inlet chamber is located at the obliquely-downward end, the included angle between the central axis of the EGR cooler body structure and the horizontal plane is larger than or equal to 15 degrees and smaller than or equal to 90 degrees after the EGR cooler body structure is installed, and the highest point of the water inlet pipe is connected with a branch pipe penetrating through an inner cavity of the water inlet pipe. According to the utility model, the EGR flow can be diagnosed, the automatic exhaust of the engine can be realized, the reliability of the cooler is improved, and the service life of the cooler is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to an EGR cooler structure for an engine. Background Art

[0002] The Atkinson cycle engine pushes part of the gas that has entered the combustion chamber into the intake manifold by closing the intake valve late, increasing the intake manifold pressure and reducing pumping losses, thereby reducing partial load fuel consumption. The compression ratio of the Atkinson cycle engine is usually very large. When the compression ratio increases, the tendency of knock increases. By introducing external cooling EGR to reduce the combustion temperature to avoid knock, the purpose of improving fuel economy and reducing NOx emissions is achieved.

[0003] The existing engine EGR cooler structure is as follows Figure 1 As shown, the EGR cooler is installed horizontally outside the engine, and the cooler water inlet pipe is connected to the engine water outlet pipe. The shortcomings of this prior art are: 1. After adding an external EGR cooler, from the perspective of calibration strategy, the exhaust gas temperature cannot be calculated, and the charging model and ignition angle cannot be corrected; 2. The cooler is installed on the engine, and the cooler is connected in series in the vehicle heating pipe. The cooler water inlet pipe is at the highest position of the engine. The vehicle cooling system uses manual coolant filling, and the engine is difficult to exhaust. Especially in the aftermarket, the cooler water pipe is manually unplugged for exhaust. Unclear exhaust will cause the engine water temperature to be high, the vehicle has torque limitation, etc., causing customer complaints; 3. Regardless of whether the engine is longitudinally or transversely mounted, the cooler is usually arranged in a horizontal direction. In the later user use process, the cooler cannot be discharged due to the presence of condensed water, resulting in carbon deposition and gumming on the surface of the fins inside the cooler, which blocks the cooler, thereby causing engine performance degradation, fuel consumption and emissions. Summary of the invention

[0004] The purpose of the utility model is to provide an EGR cooler structure for an engine in view of the defects of the above-mentioned prior art, which can diagnose the EGR flow rate and realize automatic exhaust of the engine, thereby improving the reliability of the cooler and extending the service life of the cooler.

[0005] The technical solution adopted by the utility model to achieve the above-mentioned purpose is: an EGR cooler structure for an engine, including an EGR cooler, an air intake chamber, an air outlet chamber, an EGR valve, and a water inlet pipe. The air intake chamber and the air outlet chamber are respectively connected at both ends of the EGR cooler to form an EGR cooler main structure, the EGR valve is connected to the outer side of the air outlet chamber, the water inlet pipe is connected to the upper side of one end of the EGR cooler close to the air outlet chamber, the EGR cooler main structure is obliquely installed on the outer surface of the cylinder head, and the air intake chamber is located at the end inclined downward. After the EGR cooler main structure is installed, the angle between the central axis of the EGR cooler main structure and the horizontal plane is greater than or equal to 15° and less than or equal to 90°.

[0006] A further technical solution of the utility model is: a branch pipe penetrating the inner cavity of the water inlet pipe is connected to the highest point of the water inlet pipe.

[0007] A further technical solution of the utility model is that the bottom of the air inlet of the air inlet chamber is flush with or lower than the bottom of the air inlet chamber.

[0008] A further technical solution of the utility model is: a sensor mounting seat is provided on the outer surface of the upper end of the outlet chamber, and a sensor mounting hole is provided on the top surface of the sensor mounting seat, which extends downward and penetrates through the wall thickness of the upper end of the outlet chamber and is connected to the inner cavity of the outlet chamber, and the EGR upstream temperature sensor is installed on the sensor mounting seat.

[0009] A further technical solution of the utility model is that the axis of the sensor mounting hole inside the sensor mounting seat is parallel to the air outlet flange surface at the outer end of the air outlet chamber, and the axis of the sensor mounting hole intersects with the center of the airway.

[0010] The utility model discloses an EGR cooler structure for an engine, which has the following beneficial effects: an EGR cooler main structure is obliquely installed on the outer surface of a cylinder head, an air intake chamber is located at one end that is inclined downward, an air inlet of an air intake flange is at the bottom of the air intake chamber, and the bottom of the air intake port is flush with or lower than the bottom of the air intake chamber, so that condensed water generated inside the EGR cooler flows into the EGR intake pipe, thereby avoiding clogging of the EGR cooler and extending the service life of the cooler; a sensor mounting seat is added to the EGR cooler and an EGR upstream temperature sensor is installed, and an EGR downstream temperature sensor is installed after the EGR valve, so as to diagnose the EGR flow rate and solve the problem of calibration; a branch pipe is added to the highest point of the water inlet pipe to achieve the purpose of automatic exhaust of the engine.

[0011] The following is a further description of the EGR cooler structure for an engine of the utility model in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1It is a schematic diagram of an EGR cooler for a prior art engine installed on a cylinder head;

[0013] Figure 2 This is a structural schematic diagram of an EGR cooler structure for an engine according to the utility model;

[0014] Figure 3 yes Figure 2 A cross-sectional view of an EGR cooler;

[0015] Explanation of the accompanying numbers: 1-engine water outlet pipe, 2-cooler water inlet pipe, 3-cylinder head, 4-exhaust manifold, 5-EGR cooler, 6-EGR valve, 7-exhaust air chamber, 8-sensor mounting seat, 9-EGR upstream temperature sensor, 10-water inlet pipe, 11-branch pipe, 13-cooler water outlet pipe, 14-intake air chamber, 15-intake flange, 16-outlet flange surface, 17-axis of sensor mounting hole, 18-airway center, 19-intake port, 20-intake port bottom, 21-intake air chamber bottom. DETAILED DESCRIPTION

[0016] like Figure 2 , Figure 3 As shown, the utility model provides an EGR cooler structure for an engine, comprising an EGR cooler 5, an air intake chamber 14, an air outlet chamber 7, an EGR valve 6, and a water inlet pipe 10.

[0017] like Figure 2 , Figure 3 As shown, the air inlet chamber 14 and the air outlet chamber 7 are respectively connected at both ends of the EGR cooler 5 to form the main structure of the EGR cooler. A sensor mounting seat 8 is provided on the outer surface of the upper end of the air outlet chamber 7. The top surface of the sensor mounting seat 8 is provided with a sensor mounting hole extending downward and penetrating the wall thickness of the upper end of the air outlet chamber 7 to connect to the inner cavity of the air outlet chamber 7. The axis 17 of the sensor mounting hole is perpendicular to and intersects with the central axis of the EGR cooler main structure (that is, the airway center 18 of the EGR cooler 5). The axis 17 of the sensor mounting hole inside the sensor mounting seat 8 is also parallel to the air outlet flange surface 16 at the outer end of the air outlet chamber. The axis 17 of the sensor mounting hole intersects with the airway center 18. The EGR upstream temperature sensor 9 is installed on the sensor mounting seat 8 to ensure that the temperature sensing section of the EGR upstream temperature sensor 9 is within the range of ±5mm from the airflow center 18. The above is to ensure that the temperature sensing section of the EGR upstream temperature sensor 9 is almost equal to the surface of the metal shell, so as to avoid the problem of inaccurate detection due to thermal radiation from the metal surface. The EGR valve 6 is connected to the outside of the outlet flange surface 16 outside the outlet chamber 7 .

[0018] The water inlet pipe 10 is connected to the upper side of one end of the EGR cooler 5 near the outlet air chamber 7, and a branch pipe 11 that penetrates the inner cavity of the water inlet pipe 10 is connected to the highest point of the water inlet pipe 10. The branch pipe 11 is set at the highest point of the water inlet pipe 10. When working, the EGR cooler water inlet pipe 2 is connected to the engine, and the EGR cooler water outlet pipe 13 is connected to the vehicle heater water inlet pipe. The purpose of setting the branch pipe 11 in the water inlet pipe is to discharge the gas in the water jacket inside the engine into the expansion kettle through the branch pipe 11 when the vehicle is filled with coolant, so as to achieve automatic exhaust.

[0019] During assembly, the EGR cooler main structure is installed obliquely on the outer surface of the cylinder head, and the intake air chamber 14 is located at the end that is inclined downward. After the EGR cooler main structure is installed, the angle between the central axis of the EGR cooler main structure and the horizontal plane is greater than or equal to 15° and less than or equal to 90°, and the air inlet bottom 20 of the intake air chamber 14 is flush with or lower than the intake air chamber bottom 21. In this embodiment, Figure 2 , 3 As shown, after the main structure of the EGR cooler is installed, the angle between the central axis of the main structure of the EGR cooler and the horizontal plane is equal to 15°, and the bottom 20 of the air inlet of the air intake chamber 14 is flush with the bottom 21 of the air intake chamber. The purpose of this design is to allow the condensed water generated inside the EGR cooler 5 to flow into the EGR intake pipe to avoid clogging the EGR cooler 5. Of course, as a variation of the present invention, after the main structure of the EGR cooler is installed, the angle between the central axis of the main structure of the EGR cooler and the horizontal plane can also be other values ​​greater than or equal to 15° and less than or equal to 90°, and the bottom 20 of the air inlet of the air intake chamber 14 can also be lower than the bottom 21 of the air intake chamber, all of which have the same technical effects as the present invention.

[0020] The above embodiments are only preferred embodiments of the present invention. The structure of the present invention is not limited to the forms listed in the above embodiments. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An EGR cooler structure for an engine, comprising an EGR cooler (5), an air intake chamber (14), an air outlet chamber (7), an EGR valve (6), and a water inlet pipe (10), wherein the air intake chamber (14) and the air outlet chamber (7) are respectively connected to both ends of the EGR cooler (5) to form a main structure of the EGR cooler, the EGR valve (6) is connected to the outside of the air outlet chamber (7), and the water inlet pipe (10) is connected to the upper side of one end of the EGR cooler (5) close to the air outlet chamber (7), characterized in that: The EGR cooler main structure is installed obliquely on the outer surface of the cylinder head, and the air intake chamber (14) is located at the end inclined downward. After the EGR cooler main structure is installed, the angle between the central axis of the EGR cooler main structure and the horizontal plane is greater than or equal to 15° and less than or equal to 90°.

2. The EGR cooler structure for an engine as claimed in claim 1, characterized in that: The highest point of the water inlet pipe (10) is connected to a branch pipe (11) that passes through the inner cavity of the water inlet pipe (10).

3. The EGR cooler structure for an engine as claimed in claim 1, characterized in that: The air inlet bottom (20) of the air inlet chamber (14) is flush with or lower than the air inlet chamber bottom (21).

4. The EGR cooler structure for an engine as claimed in claim 1, characterized in that: A sensor mounting seat (8) is provided on the outer surface of the upper end of the outlet air chamber, and a sensor mounting hole is provided on the top surface of the sensor mounting seat (8) that extends downward and penetrates through the wall thickness of the upper end of the outlet air chamber and is connected to the inner cavity of the outlet air chamber (7). The EGR upstream temperature sensor (9) is mounted on the sensor mounting seat (8).

5. The EGR cooler structure for an engine as claimed in claim 4, characterized in that: The axis (17) of the sensor mounting hole inside the sensor mounting seat (8) is parallel to the outlet flange surface (16) at the outer end of the outlet air chamber (7), and the axis (17) of the sensor mounting hole intersects with the center (18) of the air passage.

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