Automobile exhaust gas recirculation valve and automobile

Abstract

The present application relates to an automobile exhaust gas recirculation valve and an automobile, belonging to the field of automobile technology. The exhaust gas recirculation valve includes a housing, an electric control valve plate, a temperature measuring module, a pressure measuring module and a control unit. The temperature measuring module is used to measure the exhaust gas temperature at the second through hole of the housing, the pressure measuring module is used to measure the first pressure at the air inlet end and the second pressure at the air outlet end of the housing, and the control unit is used to determine the baseline exhaust gas mass flow rate based on the baseline exhaust gas recirculation rate, and based on the exhaust gas temperature, the first pressure and the second pressure, determine the actual exhaust gas mass flow rate entering the intake duct, and then compare the actual exhaust gas mass flow rate with the baseline exhaust gas mass flow rate. When the actual exhaust gas mass flow rate is less than the baseline exhaust gas mass flow rate, the opening of the electric control valve plate is increased, and when the actual exhaust gas mass flow rate is greater than the baseline exhaust gas mass flow rate, the opening of the electric control valve plate is reduced. By adopting the present application, the deviation between the actual EGR rate and the preset EGR rate can be reduced.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to an automobile exhaust gas recirculation valve and an automobile. Background Art

[0002] With the development of automobile technology, it is becoming increasingly important to accurately reduce pollutant emissions. The current mainstream strategy for reducing pollutant emissions is to install an EGR (Exhaust Gas Recirculation) valve to re-introduce the exhaust gas generated after engine combustion into the intake side of the engine, mix it with fresh air and then burn it again to reduce the emission of exhaust pollutants. The proportional relationship between the exhaust gas and fresh air introduced into the intake side of the engine is the EGR rate, EGR rate = (exhaust gas mass flow) / (exhaust gas mass flow + fresh air mass flow). When the car is driving, there may be a deviation between the actual EGR rate and the preset EGR rate. At this time, it is necessary to adjust the valve core opening to adjust the actual EGR rate to the preset EGR rate to minimize the emission of exhaust pollutants.

[0003] Currently, the mass flow of fresh air introduced into the intake side of the engine is usually constant. By changing the valve core opening of the EGR valve, the mass flow of exhaust gas introduced into the intake side of the engine is adjusted, thereby adjusting the actual EGR rate.

[0004] However, current EGR valves calculate the volume of exhaust gas introduced to the engine's intake side based on the pressure differential across the valve core. This volume is then multiplied by the average density of the exhaust gas to calculate the mass flow rate of exhaust gas introduced to the engine's intake side, thereby determining the actual EGR rate. When the density of the exhaust gas changes due to temperature fluctuations, the EGR valve cannot adjust the valve core opening accordingly, resulting in a significant deviation between the actual EGR rate and the preset EGR rate. Summary of the Invention

[0005] The embodiments of the present application provide an automobile exhaust gas recirculation valve and an automobile, which can solve the technical problems existing in the related art. The technical solutions are as follows:

[0006] In a first aspect, an embodiment of the present application provides an automobile exhaust gas recirculation valve, the automobile exhaust gas recirculation valve comprising a housing, an electric control valve plate, a temperature measurement module, a pressure measurement module, and a control unit;

[0007] The outer wall of the housing has a first through hole, the first through hole includes an air inlet end and an air outlet end, the air inlet end is used to communicate with the exhaust port of the automobile engine, and the air outlet end is used to communicate with the air intake duct of the automobile engine, and a second through hole is provided on the side wall of the first through hole;

[0008] The electric control valve plate is located in the first through hole and is connected to the inner wall of the first through hole. When the electric control valve plate is opened, the air inlet end and the air outlet end are connected.

[0009] The temperature measuring module is located in the second through hole and connected to the inner wall of the second through hole, and the temperature measuring module is used to measure the exhaust gas temperature at the second through hole;

[0010] The pressure measuring module includes a first pressure sensor and a second pressure sensor, the first pressure sensor is located on a side close to the air inlet end and connected to the inner wall of the first through hole, the second pressure sensor is located on a side close to the air outlet end and connected to the inner wall of the first through hole, the first pressure sensor is used to measure a first pressure on the side of the air inlet end, and the second pressure sensor is used to measure a second pressure on the side of the air outlet end;

[0011] The control unit is electrically connected to the electric control valve plate, the temperature measurement module, the first pressure sensor, and the second pressure sensor, respectively, and is used to:

[0012] determining a reference exhaust gas mass flow rate entering the intake passage based on a reference exhaust gas recirculation rate and a reference fresh air mass flow rate entering the intake passage;

[0013] Whenever a preset cycle is reached, the pressure difference across the electronically controlled valve plate is determined based on the currently detected first pressure and second pressure, the density of the exhaust gas is determined based on the exhaust gas temperature at the second through hole, the actual exhaust gas mass flow rate entering the intake duct is determined based on the pressure difference across the electronically controlled valve plate and the density of the exhaust gas, the actual exhaust gas mass flow rate is compared with the reference exhaust gas mass flow rate, if the actual exhaust gas mass flow rate is greater than the reference exhaust gas mass flow rate, the opening of the electronically controlled valve plate is reduced by a preset value, and if the actual exhaust gas mass flow rate is less than the reference exhaust gas mass flow rate, the opening of the electronically controlled valve plate is increased by the preset value.

[0014] In one possible implementation, the second through hole includes a first hole segment and a second hole segment, the first hole segment and the second hole segment are coaxial, the first hole segment is located on a side of the second hole segment close to the first through hole and is connected to the first through hole, and the aperture of the second hole segment is larger than the aperture of the first hole segment.

[0015] In one possible implementation, the temperature measurement module includes a cover, a pressing block and a sensing unit, the cover having a hollow cylindrical structure, the cover portion being located in the first hole segment, the outer wall of the cover being connected to the inner wall of the first hole segment, the pressing block having an annular structure, the pressing block being located in the second hole segment, the outer wall of the pressing block being connected to the inner wall of the second hole segment, the inner wall of the pressing block being connected to the outer wall of the cover, the sensing unit being located in the cover and connected to the inner wall of the cover, the sensing unit being electrically connected to the control unit for measuring the exhaust gas temperature at the second hole segment.

[0016] In a possible implementation, the cover is made of copper or aluminum alloy.

[0017] In a possible implementation, the sensing unit is a negative temperature coefficient thermistor.

[0018] In one possible implementation, the exhaust gas recirculation valve further includes a sealing gasket having an annular structure. The sealing gasket is located in the second hole segment and on the side of the clamping block close to the first hole segment. The outer wall of the sealing gasket is in contact with the inner wall of the second hole segment, and the inner wall of the sealing gasket is in contact with the outer wall of the cover.

[0019] In a possible implementation, the sealing gasket is made of polytetrafluoroethylene.

[0020] In one possible implementation, the comparing the actual exhaust gas mass flow rate with the reference exhaust gas mass flow rate, and if the actual exhaust gas mass flow rate is greater than the reference exhaust gas mass flow rate, reducing the opening of the electronically controlled valve plate by a preset value; and if the actual exhaust gas mass flow rate is less than the reference exhaust gas mass flow rate, increasing the opening of the electronically controlled valve plate by the preset value, includes:

[0021] Calculate the difference between the actual exhaust gas mass flow rate and the reference exhaust gas mass flow rate. If the difference is positive and within a first numerical range, reduce the opening of the electrically controlled valve plate by a first preset value. If the difference is positive and within a second numerical range, reduce the opening of the electrically controlled valve plate by a second preset value. If the difference is negative and within a third numerical range, increase the opening of the electrically controlled valve plate by the first preset value. If the difference is negative and within a fourth numerical range, increase the opening of the electrically controlled valve plate by the second preset value. The minimum value of the second numerical range is greater than the maximum value of the first numerical range, the maximum value of the fourth numerical range is less than the minimum value of the third numerical range, and the second preset value is greater than the first preset value.

[0022] In a possible implementation, the preset period is 0.1 seconds.

[0023] In a second aspect, an embodiment of the present application provides a car, comprising an exhaust gas recirculation valve as described in the first aspect and possible implementations thereof.

[0024] The technical solutions provided by the embodiments of the present application include at least the following beneficial effects:

[0025] An embodiment of the present application provides an exhaust gas recirculation valve, wherein a temperature measurement module is used to measure the exhaust gas temperature at a second through hole of a housing, a pressure measurement module is used to measure a first pressure at an intake end and a second pressure at an outlet end of the housing, and a control unit is used to determine a reference exhaust gas mass flow rate based on a reference exhaust gas recirculation rate, and to determine an actual exhaust gas mass flow rate entering an intake passage based on the exhaust gas temperature, the first pressure, and the second pressure. The control unit then compares the actual exhaust gas mass flow rate with the reference exhaust gas mass flow rate, and increases the opening of an electronically controlled valve plate when the actual exhaust gas mass flow rate is less than the reference exhaust gas mass flow rate, and decreases the opening of the electronically controlled valve plate when the actual exhaust gas mass flow rate is greater than the reference exhaust gas mass flow rate. In this way, the control unit can adjust the actual exhaust gas recirculation rate by controlling the opening of the electronically controlled valve plate, so that the actual exhaust gas mass flow rate approaches a preset exhaust gas mass flow rate, thereby reducing the deviation between the actual exhaust gas mass flow rate and the preset exhaust gas mass flow rate.

[0026] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 This is a schematic structural diagram of an exhaust gas recirculation valve shown in an embodiment of the present application;

[0029] Figure 2 This is a schematic structural diagram of an exhaust gas recirculation valve shown in an embodiment of the present application;

[0030] Figure 3 This is a flow chart showing a control unit controlling the opening of an electric-controlled valve plate according to an embodiment of the present application.

[0031] Legend

[0032] 1. Shell;

[0033] 11, first through hole; 12, second through hole; 11a, air inlet; 11b, air outlet;

[0034] 121, first hole segment; 122, second hole segment; 111, third hole segment; 112, fourth hole segment;

[0035] 2. Electric control valve plate;

[0036] 3. Temperature measurement module;

[0037] 31. Cover; 32. Pressing block; 33. Sensing unit;

[0038] 4. Pressure measurement module;

[0039] 41. First pressure sensor; 42. Second pressure sensor;

[0040] 5. Control unit;

[0041] 6. Sealing gasket. DETAILED DESCRIPTION

[0042] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0043] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the present disclosure belongs. The words “first”, “second”, “third” and similar terms used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as “a” or “an” do not indicate a quantity limitation, but rather indicate the presence of at least one. Words such as “include” or “comprise” mean that the elements or objects appearing before “include” or “comprises” include the elements or objects listed after “include” or “comprises” and their equivalents, and do not exclude other elements or objects. Words such as “connect” or “connected” are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Up”, “down”, “left”, “right” and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0044] The automobile exhaust gas recirculation (EGR) valve is an important component in the automobile engine air circulation system, which can effectively reduce the emission of nitrogen oxides in automobile exhaust gas. Nitrogen oxides are a kind of other pollutants that cause great environmental pollution, and are mainly generated under high temperature and oxygen-rich conditions. During the air circulation process, the exhaust gas recirculation valve directly introduces part of the exhaust gas into the engine intake side, or mixes part of the exhaust gas with fresh gas and then introduces it into the engine intake side. Since the main component of exhaust gas, carbon dioxide, has a large specific heat capacity, it can reduce the maximum temperature of engine combustion to a certain extent. At the same time, the increase in carbon dioxide content can reduce the oxygen content of engine combustion, thereby reducing the amount of nitrogen oxides generated. When using the exhaust gas recirculation valve, it is necessary to control the opening of the exhaust gas recirculation valve to adjust the content of exhaust gas introduced into the engine intake side.

[0045] The embodiment of the present application provides an automobile exhaust gas recirculation valve, such as Figure 1 As shown, the exhaust gas recirculation valve includes a housing 1 , an electric control valve plate 2 , a temperature measuring module 3 , a pressure measuring module 4 and a control unit 5 .

[0046] Next, the various parts of the exhaust gas recirculation valve are analyzed separately:

[0047] 1. Shell 1

[0048] The housing 1 is a component of the exhaust gas recirculation valve used to connect the exhaust gas outlet and the exhaust gas inlet of the engine.

[0049] like Figure 1 As shown, the housing 1 has a columnar structure, and the housing 1 has a first through hole 11 passing through both ends of the columnar structure.

[0050] The first through hole 11 includes an air inlet end 11a and an air outlet end 11b. The air inlet end 11a of the first through hole 11 is used to be connected to the exhaust port of the automobile engine, and the air outlet end 11b of the first through hole 11 is used to be connected to the air intake duct of the automobile engine.

[0051] Optionally, the first through hole 11 may be a circular through hole.

[0052] In this way, the difficulty of processing the first through hole 11 can be reduced.

[0053] Optionally, the first through hole 11 may be a square through hole.

[0054] In this way, it is convenient to install the electric control valve plate 2 on the inner wall of the first through hole 11 .

[0055] Optionally, the inner diameter of the gas outlet end 11 b may be larger than the inner diameter of the gas inlet end 11 a .

[0056] In one example, Figure 1As shown, the first through hole 11 may include a third hole segment 111 and a fourth hole segment 112 , and the third hole segment 111 and the fourth hole segment 112 are coaxial.

[0057] The third hole section 111 is a circular through hole, and its inner diameter is a first value d1.

[0058] The fourth hole segment 112 is a truncated cone-shaped through hole. The inner wall of the fourth hole segment 112 at one end close to the third hole segment 111 and the inner wall at one end away from the third hole segment 111 are smoothly transitioned. The inner diameter of the fourth hole segment 112 at one end close to the third hole segment 111 is a first value d1, and the inner diameter of the fourth hole segment 112 at one end away from the third hole segment 111 is a second value d2, and the second value d2 is greater than the first value d1.

[0059] Exemplarily, the relationship between the second value d2 and the first value d1 may satisfy the relationship, d2=1.2d1.

[0060] In this way, the flow of exhaust gas into the intake duct of the automobile engine can be reduced, and the pressure value in the engine can be reduced to a certain extent.

[0061] Optionally, the housing 1 may be an integrally formed component.

[0062] In practice, when processing the housing 1 , the third hole segment 111 and the fourth hole segment 112 may be sequentially processed and formed at both ends of the columnar structure.

[0063] like Figure 1 As shown, the housing 1 has a second through hole 12 that passes through the wall of the third hole section 111 and the outer wall of the housing 1. The second through hole 12 is located at one end of the third hole section 111 close to the air inlet end 11a and is used to accommodate the temperature measurement module 3.

[0064] Optionally, the second through hole 12 may be a stepped through hole.

[0065] like Figure 2 As shown, the second through hole 12 includes a first hole segment 121 and a second hole segment 122. The first hole segment 121 and the second hole segment 122 are coaxial. The first hole segment 121 is located on the side of the second hole segment 122 close to the third hole segment 111 and is connected to the third hole segment 111. The aperture of the second hole segment 122 is larger than the aperture of the first hole segment 121.

[0066] Optionally, the second through hole 12 may be a circular through hole.

[0067] In this way, the overall strength of the housing 1 can be improved.

[0068] The length of the second through hole 12 may be a first length L1 .

[0069] The length of the first hole section 121 may be a second length L2, and the length of the second hole section 122 may be a third length L3. The second length L2 and the third length L3 satisfy: L2+L3=L1.

[0070] In one example, the second length L2 and the third length L3 may be equal.

[0071] In this way, the difficulty of processing the second through hole 12 can be reduced.

[0072] The material of the shell 1 can be a high-temperature resistant alloy material, such as nickel-based alloy, rhenium-iridium alloy, etc. The implementation of this application does not limit the material of the shell 1.

[0073] In this way, the difficulty of processing the second through hole 12 can be reduced.

[0074] 2. Electric control valve plate 2

[0075] The electronically controlled valve plate 2 is a component of the exhaust gas recirculation valve used to control whether the exhaust port of the engine and the exhaust gas inlet are connected or disconnected. The electronically controlled valve plate 2 is electrically connected to the control unit 5 .

[0076] like Figure 1 As shown, the electric control valve plate 2 is located in the third hole section 111 of the first through hole 11 , and is located on the side of the second through hole 12 away from the air inlet end 11 a , and is connected to the inner wall of the first through hole 11 .

[0077] In practice, when the electric control valve plate 2 is opened, the air inlet end 11a and the air outlet end 11b are connected. When the electric control valve plate 2 is closed, the electric control valve plate 2 still has a slight opening, and the air inlet end 11a and the air outlet end 11b are almost not connected.

[0078] 3. Temperature measurement module 3

[0079] The temperature measurement module 3 is a component in the exhaust gas recirculation valve for measuring the temperature at the intake end 11 a.

[0080] like Figure 1 As shown, the temperature measurement module 3 is located in the second through hole 12 and is connected to the inner wall of the second through hole 12 .

[0081] The temperature measurement module 3 may include a cover 31 , a pressing block 32 and a sensor unit 33 .

[0082] Cover 31

[0083] The cover 31 is a component of the temperature measurement module 3 used to protect the sensor unit 33 from direct contact with exhaust gas.

[0084] like Figure 2As shown, a portion of the cover 31 is located in the first hole section 121, and another portion is located in the second hole section 122. The cover 31 has a hollow columnar structure with one end open, and the columnar structure can be a cylindrical structure.

[0085] The length of the cover 31 may be a fourth length L4 , which is greater than the first length L1 . An end of the cover 31 away from the first through hole 11 is flush with the outer wall of the housing 1 .

[0086] In one example, the fourth length L4 and the first length L1 may satisfy the relationship: L4=1.1L1.

[0087] In this way, the end of the cover 31 close to the first through hole 11 can extend into the first through hole 11, thereby improving the accuracy of temperature detection.

[0088] The outer diameter of the cover 31 is the same as the inner diameter of the first hole section 121 , and the outer wall of the cover 31 is in contact with the inner wall of the first hole section 121 .

[0089] Optionally, an interference fit may be formed between the outer wall of the cover 31 and the inner wall of the first hole section 121 .

[0090] In this way, the fixing stability of the cover 31 can be improved.

[0091] Optionally, an end of the cover 31 away from the first through hole 11 has an opening, and an end of the cover 31 close to the first through hole 11 has a closed structure.

[0092] In this way, the exhaust gas can be prevented from entering the second through hole 12 and directly contacting the sensing unit 33 , thereby increasing the service life of the temperature measuring module 3 .

[0093] Optionally, the cover 31 may be made of copper or aluminum alloy.

[0094] In this way, the cover 31 can remain stable and not deform after coming into contact with high-temperature exhaust gas, thereby increasing the service life of the temperature measurement module 3.

[0095] The material of the cover 31 can also be a polymer material with good thermal conductivity, such as thermal conductive composite plastic, thermal conductive rubber, etc. The embodiment of the present application does not limit the material of the cover 31.

[0096] Compression block 32

[0097] The pressing block 32 is a component in the temperature measurement module 3 used to fix the cover 31 .

[0098] like Figure 2As shown, the pressing block 32 has an annular structure and is located in the second hole section 122 . The outer wall of the pressing block 32 is connected to the inner wall of the second hole section 122 , and the inner wall of the pressing block 32 is connected to the inner wall of the cover 31 .

[0099] The outer diameter of the clamping block 32 can be the same as the inner diameter of the second hole section 122, and the outer wall of the clamping block 32 is in contact with the inner wall of the second hole section 122. The inner diameter of the clamping block 32 can be the same as the inner diameter of the second hole section 122, and the outer wall of the clamping block 32 is in contact with the inner wall of the second hole section 122.

[0100] The length of the pressing block 32 is equal to the second length L2.

[0101] Optionally, an outer wall of the pressing block 32 and an inner wall of the second hole section 122 may be interference fit, and an inner wall of the pressing block 32 and an inner wall of the portion of the cover 31 located in the second hole section 122 may be interference fit.

[0102] In this way, the pressing block 32 can tighten the portion of the cover 31 located in the second hole section 122 , thereby improving the fixing stability of the cover 31 .

[0103] Optionally, the pressing block 32 may be an elastic member.

[0104] In this way, the fixing stability of the cover 31 can be improved.

[0105] Sensing unit 33

[0106] The sensing unit 33 is a component in the temperature measurement module 3 for measuring the real-time temperature at the air inlet end 11 a and is electrically connected to the control unit 5 .

[0107] like Figure 2 As shown, the sensing unit 33 is located in the cavity of the cover 31 and is connected to the inner wall of the cavity of the cover 31. The sensing unit 33 is a negative temperature coefficient thermistor.

[0108] In practice, the sensing unit 33 is connected via wires to an external circuit, which includes a protective resistor and an ammeter. When the temperature at the air inlet end 11a rises, the temperature inside the cover 31 also rises accordingly, the resistance of the negative temperature coefficient thermistor decreases, and the ammeter reading increases. When the temperature at the air inlet end 11a drops, the temperature inside the cover 31 also drops accordingly, the resistance of the negative temperature coefficient thermistor increases, and the ammeter reading decreases. Therefore, the real-time temperature at the air inlet end 11a can be determined based on the ammeter reading.

[0109] Optionally, the sensing unit 33 may be an electrically controlled thermometer, which is electrically connected to the control unit 5 .

[0110] 4. Pressure measurement module 4

[0111] The pressure measuring module 4 is a component in the exhaust gas recirculation valve for measuring the pressure values ​​at both ends of the first through hole 11 .

[0112] The pressure measuring module 4 includes a first pressure sensor 41 and a second pressure sensor 42 . The first pressure sensor 41 and the second pressure sensor 42 are both electrically connected to the control unit 5 .

[0113] The first pressure sensor 41 is a component in the pressure measuring module 4 for measuring a first pressure value on one side of the air inlet end 11 a .

[0114] like Figure 1 As shown, the first pressure sensor 41 is located in the first through hole 11 and on a side of the electric control valve plate 2 close to the air inlet end 11 a and is connected to the inner wall of the first through hole 11 .

[0115] The second pressure sensor 42 is a component in the pressure measuring module 4 for measuring a second pressure value on one side of the gas outlet end 11 b .

[0116] like Figure 1 As shown, the second pressure sensor 42 is located in the first through hole 11 and on a side of the electric control valve plate 2 close to the gas outlet end 11 b , and is connected to the inner wall of the first through hole 11 .

[0117] 5. Control Unit 5

[0118] The control unit 5 is a component in the exhaust gas recirculation valve for controlling the opening of the electronically controlled valve plate 2 .

[0119] The control unit 5 is electrically connected to the electric control valve plate 2, the temperature measuring module 3, the first pressure sensor 41 and the second pressure sensor 42. The control unit 5 can be a processor. The process of the control unit 5 controlling the opening of the electric control valve plate 2 is as follows: Figure 3 shown.

[0120] S301 : Determine a reference exhaust gas mass flow rate entering the intake duct based on a reference exhaust gas recirculation rate and a reference fresh air mass flow rate entering the intake duct.

[0121] In practice, different vehicle models can be equipped with a baseline EGR rate based on actual conditions when leaving the factory. The baseline EGR rate typically ranges from 10% to 20%. The EGR rate is calculated as: EGR rate = (exhaust gas mass flow) / (exhaust gas mass flow + fresh air mass flow). Assuming a baseline EGR rate of 15%, the required baseline exhaust gas mass flow entering the engine intake can be determined based on the baseline fresh air mass flow entering the engine intake and the standard EGR rate.

[0122] S302 : Whenever a preset period is reached, the pressure difference between the two sides of the electric control valve plate 2 is determined based on the currently detected first pressure and the second pressure.

[0123] Optionally, the preset period may be 0.1 seconds.

[0124] In implementation, the control unit 5 can obtain the first pressure measured by the first pressure sensor 41 and the second pressure measured by the second pressure sensor 42 according to a preset cycle, and calculate the absolute value of the difference between the first pressure and the second pressure, and determine the difference as the pressure difference on both sides of the electric control valve plate 2 whenever the preset cycle is reached.

[0125] S303: Determine the density of the exhaust gas based on the exhaust gas temperature at the second through hole 12, and determine the actual exhaust gas mass flow rate entering the intake duct based on the pressure difference across the electronically controlled valve plate 2 and the density of the exhaust gas.

[0126] In implementation, the processor may pre-store a table of correspondence between the ammeter reading and temperature, and a table of correspondence between the exhaust gas temperature and the exhaust gas density. The correspondence between the ammeter reading and temperature is shown in Table 1, and the correspondence between the exhaust gas temperature and the exhaust gas density is shown in Table 2.

[0127] Whenever the preset period is reached, the control unit 5 can determine the real-time temperature at the intake end 11a based on the reading of the ammeter connected to the sensor unit and the corresponding relationship between the reading and the temperature. Next, the control unit 5 can determine the density of the exhaust gas based on the determined exhaust gas temperature at the intake end 11a and the corresponding relationship between the exhaust gas temperature and the exhaust gas density. Finally, the control unit 5 can calculate the actual exhaust gas mass flow rate entering the intake duct based on the mass flow calculation formula, the pressure difference on both sides of the electric control valve plate 2, and the density of the exhaust gas. The mass flow calculation formula is shown in Formula (1).

[0128]

[0129] Wherein, Q is the actual exhaust gas mass flow rate, S is the cross-sectional area of ​​the intake end 11 a , G is the density of the exhaust gas at the intake end 11 a , and ( P1 - P2 ) is the pressure difference on both sides of the electric control valve plate 2 .

[0130] Table 1 - Correspondence between ammeter reading and exhaust gas temperature

[0131]

[0132] Table 2 - Correspondence between exhaust gas temperature and exhaust gas density

[0133]

[0134] S304: Compare the actual exhaust gas mass flow rate with the reference exhaust gas mass flow rate. If the actual exhaust gas mass flow rate is greater than the reference exhaust gas mass flow rate, reduce the opening of the electronically controlled valve plate 2 by a preset value. If the actual exhaust gas mass flow rate is less than the reference exhaust gas mass flow rate, increase the opening of the electronically controlled valve plate 2 by a preset value.

[0135] The preset value may be 5% of the full opening of the electric control valve plate 2 .

[0136] In implementation, the control unit 5 can compare the actual exhaust gas mass flow rate and the benchmark exhaust gas mass flow rate within each preset cycle. If the actual exhaust gas mass flow rate is greater than the benchmark exhaust gas mass flow rate, the opening of the electronically controlled valve plate 2 will be reduced by 5%; if the actual exhaust gas mass flow rate is greater than the benchmark exhaust gas mass flow rate, the opening of the electronically controlled valve plate 2 will be increased by 5%.

[0137] In this way, the control unit 5 can adjust the actual exhaust gas mass flow rate by controlling the opening of the electronically controlled valve plate 2. When the opening of the electronically controlled valve plate 2 increases, the actual exhaust gas mass flow rate increases. When the opening of the electronically controlled valve plate 2 decreases, the actual exhaust gas mass flow rate decreases, so that the actual EGR rate approaches the benchmark EGR rate.

[0138] Optionally, the above-mentioned comparison of the actual exhaust gas mass flow rate and the reference exhaust gas mass flow rate, if the actual exhaust gas mass flow rate is greater than the reference exhaust gas mass flow rate, reducing the opening of the electronically controlled valve plate 2 by a preset value; if the actual exhaust gas mass flow rate is less than the reference exhaust gas mass flow rate, increasing the opening of the electronically controlled valve plate 2 by a preset value, may include:

[0139] Calculate the difference between the actual exhaust gas mass flow rate and the reference exhaust gas mass flow rate. If the difference is positive and within the first numerical range, reduce the opening of the electronically controlled valve plate 2 by the first preset value. If the difference is positive and within the second numerical range, reduce the opening of the electronically controlled valve plate 2 by the second preset value. If the difference is negative and within the third numerical range, increase the opening of the electronically controlled valve plate 2 by the first preset value. If the difference is negative and within the fourth numerical range, increase the opening of the electronically controlled valve plate 2 by the second preset value.

[0140] The minimum value of the second numerical range is greater than the maximum value of the first numerical range, the maximum value of the fourth numerical range is less than the minimum value of the third numerical range, and the second preset value is greater than the first preset value.

[0141] In one example, the first numerical range may be [0, 5%), the second numerical range may be [5%, 20%], the third numerical range may be (-5%, 0], the fourth numerical range may be [-20%, -5%], the first preset numerical value may be 2.5% of the total opening of the electric control valve plate 2, and the second preset numerical value may be 5% of the total opening of the electric control valve plate 2.

[0142] Thus, when the deviation between the actual exhaust gas mass flow rate and the reference exhaust gas mass flow rate is large, the control unit 5 can increase or decrease the opening of the electronically controlled valve plate 2 by a large value to make the actual exhaust gas mass flow rate approach the reference exhaust gas mass flow rate as quickly as possible. When the deviation between the actual exhaust gas mass flow rate and the reference exhaust gas mass flow rate is small, the control unit 5 can increase or decrease the opening of the electronically controlled valve plate 2 by a small value to improve the adjustment accuracy.

[0143] Below, the optional structural features of the automobile exhaust gas recirculation valve are introduced:

[0144] Structural feature 1: the automobile exhaust gas recirculation valve may further include a sealing gasket 6 .

[0145] like Figure 2 As shown, the sealing gasket 6 has an annular structure. The sealing gasket 6 is located in the second hole section 122 and on the side of the clamping block 32 close to the first hole section 121. The outer wall of the sealing gasket 6 is in contact with the second hole section 122, and the inner wall of the sealing gasket 6 is in contact with the outer wall of the cover 31.

[0146] Optionally, an interference fit may be formed between the outer wall of the sealing gasket 6 and the inner wall of the second hole section 122 , and an interference fit may be formed between the inner wall of the sealing gasket 6 and the outer wall of the cover 31 .

[0147] Optionally, the sealing gasket 6 may be made of polytetrafluoroethylene.

[0148] In this way, the sealing gasket 6 can seal the gap between the second hole section 122 and the cover 31 to prevent exhaust gas leakage.

[0149] In the exhaust gas recirculation valve provided in the embodiment of the present application, the temperature measurement module 3 is used to measure the exhaust gas temperature at the second through hole 12 of the housing 1, the pressure measurement module 4 is used to measure the first pressure at the intake end 11a and the second pressure at the outlet end 11b of the housing 1, and the control unit 5 is used to determine a reference exhaust gas mass flow rate based on the reference exhaust gas recirculation rate, determine the actual exhaust gas mass flow rate entering the intake duct based on the exhaust gas temperature, the first pressure, and the second pressure, and compare the actual exhaust gas mass flow rate with the reference exhaust gas mass flow rate. If the actual exhaust gas mass flow rate is less than the reference exhaust gas mass flow rate, the opening of the electronically controlled valve plate 2 is increased, and if the actual exhaust gas mass flow rate is greater than the reference exhaust gas mass flow rate, the opening of the electronically controlled valve plate 2 is decreased. Thus, by controlling the opening of the electronically controlled valve plate 2, the control unit 5 can adjust the actual EGR rate so that the actual EGR rate approaches the preset EGR rate, thereby reducing the deviation between the actual EGR rate and the preset EGR rate.

[0150] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An automobile exhaust gas recirculation valve, characterized in that: The automobile exhaust gas recirculation valve comprises a housing (1), an electric control valve plate (2), a temperature measurement module (3), a pressure measurement module (4) and a control unit (5); The outer wall of the housing (1) has a first through hole (11), the first through hole (11) includes an air inlet end (11a) and an air outlet end (11b), the air inlet end (11a) is used to communicate with the exhaust port of the automobile engine, and the air outlet end (11b) is used to communicate with the air intake duct of the automobile engine, a second through hole (12) is provided on the side wall of the first through hole (11), the length of the second through hole (12) is a first length L1, the second through hole (12) includes a first hole section (121) and a second hole section (122), the first hole section (121) and the second hole section (122) are coaxial, the first hole section (121) is located on a side of the second hole section (122) close to the first through hole (11), and is connected to the first through hole (11), the aperture of the second hole section (122) is larger than the aperture of the first hole section (121); The electric control valve plate (2) is located in the first through hole (11) and is connected to the inner wall of the first through hole (11); when the electric control valve plate (2) is opened, the air inlet end (11a) and the air outlet end (11b) are in communication; The temperature measuring module (3) comprises a cover (31), a pressing block (32) and a sensing unit (33); the cover (31) has a hollow columnar structure; one end of the cover (31) away from the first through hole (11) is flush with the outer wall of the housing (1); the length of the cover (31) is a fourth length L4; the fourth length L4 and the first length L1 satisfy the relationship: L4=1.1L1; the cover (31) is partially located in the first hole section (121); the outer wall of the cover (31) is flush with the first through hole (11); The inner wall of the first hole section (121) is connected, the pressing block (32) has an annular structure, the pressing block (32) is located in the second hole section (122), the outer wall of the pressing block (32) is connected to the inner wall of the second hole section (122), the inner wall of the pressing block (32) is connected to the outer wall of the cover (31), the sensing unit (33) is located in the cover (31) and is connected to the inner wall of the cover (31), and the sensing unit (33) is used to measure the temperature inside the cover (31); The pressure measuring module (4) comprises a first pressure sensor (41) and a second pressure sensor (42), wherein the first pressure sensor (41) is located on a side close to the air inlet end (11a) and is connected to the inner wall of the first through hole (11), and the second pressure sensor (42) is located on a side close to the air outlet end (11b) and is connected to the inner wall of the first through hole (11), the first pressure sensor (41) is used to measure a first pressure on a side of the air inlet end (11a), and the second pressure sensor (42) is used to measure a second pressure on a side of the air outlet end (11b); The control unit (5) is electrically connected to the electric control valve plate (2), the sensing unit (33), the first pressure sensor (41) and the second pressure sensor (42), respectively, and the control unit (5) is used to: determining a reference exhaust gas mass flow rate entering the intake passage based on a reference exhaust gas recirculation rate and a reference fresh air mass flow rate entering the intake passage; Whenever a preset cycle is reached, the pressure difference between the two sides of the electric control valve plate (2) is determined based on the currently detected first pressure and the second pressure, the density of the exhaust gas is determined based on the exhaust gas temperature at the second through hole (12), the actual exhaust gas mass flow entering the intake duct is determined based on the pressure difference between the two sides of the electric control valve plate (2) and the density of the exhaust gas, the actual exhaust gas mass flow and the reference exhaust gas mass flow are compared, if the actual exhaust gas mass flow is greater than the reference exhaust gas mass flow, the opening of the electric control valve plate (2) is reduced by a preset value, if the actual exhaust gas mass flow is less than the reference exhaust gas mass flow, the opening of the electric control valve plate (2) is increased by the preset value.

2. The exhaust gas recirculation valve according to claim 1, characterized in that The cover (31) is made of copper or aluminum alloy.

3. The exhaust gas recirculation valve according to claim 1, characterized in that The sensing unit (33) is a negative temperature coefficient thermistor.

4. The exhaust gas recirculation valve according to claim 1, characterized in that The exhaust gas recirculation valve further includes a sealing gasket (6) having an annular structure. The sealing gasket (6) is located in the second hole section (122) and on the side of the pressing block (32) close to the first hole section (121). The outer wall of the sealing gasket (6) is in contact with the inner wall of the second hole section (122), and the inner wall of the sealing gasket (6) is in contact with the outer wall of the cover (31).

5. The exhaust gas recirculation valve according to claim 4, characterized in that The sealing gasket (6) is made of polytetrafluoroethylene.

6. The exhaust gas recirculation valve according to claim 1, characterized in that The comparing the actual exhaust gas mass flow rate with the reference exhaust gas mass flow rate, and if the actual exhaust gas mass flow rate is greater than the reference exhaust gas mass flow rate, reducing the opening of the electric control valve plate (2) by a preset value, and if the actual exhaust gas mass flow rate is less than the reference exhaust gas mass flow rate, increasing the opening of the electric control valve plate (2) by the preset value, comprises: The difference between the actual exhaust gas mass flow and the reference exhaust gas mass flow is calculated. If the difference is a positive value and is within a first numerical range, the opening of the electric control valve plate (2) is reduced by a first preset value. If the difference is a positive value and is within a second numerical range, the opening of the electric control valve plate (2) is reduced by a second preset value. If the difference is a negative value and is within a third numerical range, the opening of the electric control valve plate (2) is increased by the first preset value. If the difference is a negative value and is within a fourth numerical range, the opening of the electric control valve plate (2) is increased by the second preset value. The minimum value of the second numerical range is greater than the maximum value of the first numerical range, the maximum value of the fourth numerical range is less than the minimum value of the third numerical range, and the second preset value is greater than the first preset value.

7. The exhaust gas recirculation valve according to claim 1, characterized in that The preset period is 0.1 seconds.

8. An automobile, characterized in that: The automobile comprises the exhaust gas recirculation valve according to any one of claims 1 to 7.

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