EGR valve degradation degree calculation system, internal combustion engine control device, and vehicle

Abstract

The present invention relates to a degradation degree calculation system for an EGR valve, a control device for an internal combustion engine, and a vehicle. The degradation degree calculation system configured to calculate the degradation degree of the EGR valve includes an execution device. The execution device is configured to execute: a pressure acquisition process; a pressure change amount calculation process to calculate the pressure change amount accompanying the opening and closing action of the EGR valve; a differential pressure calculation process to calculate the differential pressure between the upstream side and the downstream side of the EGR valve when the EGR valve is in a closed valve state; and a degradation degree calculation process to calculate the degradation degree of the EGR valve based on the pressure change amount and the differential pressure.

Description

Technical Field

[0001] The present disclosure relates to an EGR valve degradation degree calculation system, an internal combustion engine control device, and a vehicle. Background Art

[0002] For example, as described in Japanese Patent Application Laid-Open No. 2018-123694, an internal combustion engine having an exhaust gas recirculation device that returns a portion of the exhaust gas to the intake air is known. In the internal combustion engine described in Japanese Patent Application Laid-Open No. 2018-123694, fault diagnosis of the EGR valve provided in the exhaust gas recirculation device is performed based on the difference between the pressure when the valve is opened and the pressure when the valve is closed, that is, the pressure variation. Summary of the invention

[0003] As the degradation of the EGR valve progresses, the pressure change amount decreases, so the degradation degree of the EGR valve can be calculated based on the pressure change amount. However, such a pressure change amount also changes due to factors other than the degradation of the EGR valve, so even if the degradation degree is calculated based solely on the pressure change amount, it is difficult to calculate the degradation degree with high accuracy.

[0004] A degradation degree calculation system of an EGR valve according to one embodiment of the present disclosure is applied to an internal combustion engine having an EGR passage connecting an exhaust passage and an intake passage of the internal combustion engine, an EGR valve arranged in the EGR passage, and a pressure sensor arranged on the downstream side of the EGR valve, and is configured to calculate the degradation degree of the EGR valve. The degradation degree calculation system is provided with an execution device. The execution device is configured to execute: a pressure acquisition process for acquiring the pressure detected by the pressure sensor; a pressure change amount calculation process for calculating the pressure change amount accompanying the opening and closing action of the EGR valve, i.e., the pressure change amount; a differential pressure calculation process for calculating the pressure difference between the upstream side and the downstream side of the EGR valve when the EGR valve is in a closed valve state, i.e., the differential pressure; and a degradation degree calculation process for calculating the degradation degree of the EGR valve based on the pressure change amount and the differential pressure.

[0005] The differential pressure affects the pressure variation. According to the EGR valve degradation degree calculation system of one aspect of the present disclosure, the EGR valve degradation degree is calculated based on the pressure variation and the differential pressure, so the degradation degree can be calculated with high accuracy.

[0006] In the degradation degree calculation system according to one aspect of the present disclosure, the execution device may be configured to calculate the degradation degree in the degradation degree calculation process so that the smaller the differential pressure is, the smaller the degradation degree is even for the same pressure change amount.

[0007] Even if the degradation degree of the EGR valve is the same, when the differential pressure is small, the pressure change amount becomes smaller than when the differential pressure is large. That is, when the differential pressure is small, the degradation degree relative to the pressure change amount becomes smaller than when the differential pressure is large. According to the degradation degree calculation system of an embodiment of the present disclosure, in the degradation degree calculation process, the degradation degree can be calculated in such a way that even if the pressure change amount is the same, the smaller the differential pressure, the smaller the degradation degree.

[0008] In a degradation degree calculation system of an embodiment of the present disclosure, the execution device may be configured to execute a speed acquisition process of acquiring the internal combustion engine speed of the internal combustion engine during the opening and closing action of the EGR valve as a reference speed. The execution device may be configured to calculate the degradation degree of the EGR valve based on the pressure change amount, the differential pressure and the reference speed in the degradation degree calculation process.

[0009] Depending on the arrangement position of the pressure sensor, the difference in intake air flow caused by the difference in internal combustion engine speed may sometimes affect the pressure change. According to the EGR valve degradation degree calculation system of one embodiment of the present disclosure, in addition to the pressure change and the differential pressure, the internal combustion engine speed is further considered to calculate the EGR valve degradation degree. Therefore, even if the intake manifold or the surge tank is provided with the pressure sensor, the EGR valve degradation degree can be calculated with high accuracy.

[0010] In the degradation degree calculation system of the present disclosure, the execution device may be configured to calculate the degradation degree in the degradation degree calculation process so that the degradation degree becomes smaller as the engine speed becomes higher even when the pressure change amount is the same.

[0011] Even if the degradation degree of the EGR valve is the same, when the internal combustion engine speed is high, the pressure change amount becomes smaller than when the internal combustion engine speed is low. That is, when the internal combustion engine speed is high, the degradation degree corresponding to the pressure change amount becomes smaller than when the internal combustion engine speed is low. According to a degradation degree calculation system of an EGR valve of one embodiment of the present disclosure, in the degradation degree calculation process, the degradation degree can be calculated in such a way that even if the pressure change amount is the same, the degradation degree becomes smaller when the internal combustion engine speed is higher.

[0012] It should be noted that the pressure sensor can be arranged in the intake manifold or the surge tank of the internal combustion engine as a location where the pressure change is affected by the difference in intake air flow caused by the difference in the speed of the internal combustion engine. In the degradation degree calculation system disclosed in the present invention, the pressure sensor can be arranged in the intake manifold or the surge tank of the internal combustion engine.

[0013] In a degradation degree calculation system of one embodiment of the present disclosure, the pressure sensor may be provided in the EGR passage at a position between a position connected to the intake passage and a position provided with the EGR valve. When the pressure sensor is provided in the EGR passage at a position between a position where the EGR passage is connected to the intake passage and the EGR valve, the pressure detected by the pressure sensor becomes a pressure corresponding to the flow rate of the EGR gas and is not easily affected by the intake flow rate. Therefore, according to a degradation degree calculation system of an EGR valve of one embodiment of the present disclosure, it is possible to suppress the influence of the internal combustion engine speed on the above-mentioned pressure change amount, thereby also being able to calculate the degradation degree of the EGR valve with high accuracy.

[0014] It should be noted that the control device of the internal combustion engine may include the execution device in the above-mentioned degradation degree calculation system. In addition, the control device of the internal combustion engine may be included in a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Features, advantages and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like numerals represent like elements, and in which:

[0016] Figure 1 is a schematic diagram of an internal combustion engine in one embodiment.

[0017] Figure 2 It is a flowchart showing the process steps executed by the control device of this embodiment.

[0018] Figure 3 It is a conceptual diagram showing the correspondence relationship among the pressure change amount, differential pressure, reference rotation speed, and degree of degradation.

[0019] Figure 4 It is a timing chart showing the operation of this embodiment.

[0020] Figure 5 It is a schematic diagram of an internal combustion engine in a modified example of the embodiment.

[0021] Figure 6 It is a schematic diagram showing the configuration of a degradation degree calculation system in a modification example of the embodiment. DETAILED DESCRIPTION

[0022] <Structure of internal combustion engine>

[0023] In the following, regarding an embodiment in which a degradation degree calculation system of an EGR valve is applied to an internal combustion engine mounted on a vehicle, referring to Figure 1 to Figure 4 To explain.

[0024] like Figure 1As shown, in the internal combustion engine 1 mounted on the vehicle 500, air is sucked into the combustion chamber 2 through the intake passage 3 and the intake port 3a, and the fuel injected from the fuel injection valve 4 is supplied to the combustion chamber 2. When the mixture composed of air and fuel is ignited by the spark plug 5, the mixture is burned, the piston 6 reciprocates, and the output shaft of the internal combustion engine 1, that is, the crankshaft 7, rotates. The burned mixture is discharged from the combustion chamber 2 to the exhaust passage 8 as exhaust gas.

[0025] The intake passage 3 of the internal combustion engine 1 includes a surge tank 11 and an intake manifold 3A. A throttle valve 29 for adjusting the amount of intake air is provided in the intake passage 3 on the intake upstream side of the surge tank 11. The opening of the throttle valve 29 is adjusted by an electric motor. The intake manifold 3A for distributing the air in the surge tank 11 to each cylinder of the internal combustion engine 1 is connected to the intake downstream side of the surge tank 11.

[0026] An intake port 3a connected to the intake manifold 3A is provided with an intake valve 9. An exhaust port 8a connected to the exhaust passage 8 is provided with an exhaust valve 10. The intake valve 9 is provided with a variable valve mechanism 21 for changing the valve timing of the intake valve 9.

[0027] The internal combustion engine 1 is provided with an exhaust gas recirculation device for returning a part of the exhaust gas to the intake passage 3. The exhaust gas recirculation device includes an EGR passage 50, an EGR cooler 51, an EGR valve 52, and the like. The EGR passage 50 is a passage that connects the pressure surge tank 11 constituting a part of the intake passage 3 and the exhaust passage 8. The EGR valve 52 is provided in the middle of the EGR passage 50. When the EGR valve 52 is opened, the exhaust gas (EGR gas) flows into the EGR passage 50. The EGR cooler 51 is provided in the EGR passage 50 at the upstream side (that is, the exhaust passage 8 side) of the EGR valve 52.

[0028] The control device 100 controls the control amount (intake air amount, injection fuel amount, etc.) of the internal combustion engine 1 by operating various operation object devices such as the throttle 29, the fuel injection valve 4, the spark plug 5, the variable valve mechanism 21, and the EGR valve 52.

[0029] The control device 100 includes a central processing unit (hereinafter referred to as CPU) 110, a memory 120 storing control programs and data, etc. The control device 100 executes the control of the control amount and each process described below by the CPU 110 executing the program stored in the memory 120. The CPU 110 and the memory 120 constitute an execution device.

[0030] When controlling the control amount, the control device 100 refers to the operation amount of the accelerator pedal detected by the accelerator position sensor 31, i.e., the accelerator operation amount ACCP, and the opening degree of the throttle valve 29 detected by the throttle sensor 32, i.e., the throttle opening TA. In addition, the control device 100 refers to the intake air amount GA detected by the air flow meter 33 and the pressure in the surge tank 11 detected by the pressure sensor 34, i.e., the intake pressure PM. The pressure sensor 34 is a pressure sensor arranged on the downstream side of the EGR valve 52. In addition, the control device 100 refers to the coolant temperature THW detected by the coolant temperature sensor 35, the vehicle speed SP of the vehicle 500 detected by the vehicle speed sensor 36, and the output signal Scr of the crank angle sensor 37. In addition, the control device 100 refers to the output signal Scf of the cam angle sensor 38 and the atmospheric pressure PA detected by the atmospheric pressure sensor 39. It should be noted that the control device 100 detects the crank angle and the internal combustion engine speed NE based on the output signal Scr of the crank angle sensor 37. In addition, the control device 100 calculates the internal combustion engine load ratio KL based on the internal combustion engine speed NE and the intake air amount GA. In addition, the control device 100 detects the valve timing VT of the intake valve 9 based on the output signal Scf of the cam angle sensor 38.

[0031] The control device 100 calculates the target value of the valve timing VT of the intake valve 9, i.e., the target valve timing VTp, based on the operating state of the internal combustion engine such as the internal combustion engine speed NE and the internal combustion engine load ratio KL. And the control device 100 controls the variable valve mechanism 21 in such a way that the valve timing VT coincides with the target valve timing VTp.

[0032] In addition, the control device 100 calculates the command value for adjusting the amount of exhaust gas flowing into the intake passage 3 via the EGR passage 50 (EGR amount), i.e., the target EGR rate EGp, based on the operating state of the internal combustion engine such as the internal combustion engine speed NE and the internal combustion engine load ratio KL. It should be noted that the EGR rate is the ratio of the EGR amount to the total amount of in-cylinder filling gas. And the control device 100 calculates the target opening degree of the EGR valve 52 at which the actual EGR rate becomes the target EGR rate EGp based on the target EGR rate EGp and the intake air amount GA, and adjusts the opening degree of the EGR valve 52 in such a way that the actual opening degree becomes the target opening degree.

[0033] <Calculation of Degradation Degree of EGR Valve>

[0034] The residual components in the EGR gas adhere to the EGR valve 52. Therefore, as the accumulation of such residual components increases, the flow rate of the gas passing through the EGR valve 52 gradually decreases. In the present embodiment, such a decrease in the gas flow rate caused by the passage of time is referred to as the degradation of the EGR valve 52, and the control device 100 calculates the degree of degradation of such EGR valve 52, that is, the degradation degree. It should be noted that in the present embodiment, the larger the value of the degradation degree, the more advanced the degradation is.

[0035] The calculation of the degradation degree R is described below. Figure 2 2 shows the process steps involved in calculating the degree of degradation R. Figure 2 The processing shown is implemented by CPU 110 executing a program stored in memory 120. It should be noted that Figure 2 The processing shown is started when the calculation conditions of the degradation degree R are satisfied. Examples of the calculation conditions of the degradation degree R include the following: fuel cut during deceleration is being executed and the combustion of the air-fuel mixture is stopped, and a predetermined time or travel distance has passed since the last calculation of the degradation degree R. In addition, if the EGR valve 52 is not in a fully closed state at the time when the calculation conditions of the degradation degree R are satisfied, the EGR valve 52 is fully closed and then started. Figure 2 Processing shown.

[0036] It should be noted that, hereinafter, step numbers are represented by numerals with "S" at the beginning. When this process is started, first, the CPU 110 sets a fixed value VTa as a target valve timing VTp of the intake valve 9 ( S100 ).

[0037] Next, the CPU 110 determines whether the change of the valve timing is completed, that is, whether the valve timing VT has reached the fixed value VTa ( S110 ). If the change of the valve timing is not completed ( S110 : No), the CPU 110 repeats the determination of S110 .

[0038] On the other hand, when it is determined that the change of the valve timing has been completed (S110: Yes), the CPU 110 determines whether a predetermined time Tw1 has passed since the change of the valve timing was completed (S120). As the predetermined time Tw1, a time required until the change of the intake pressure PM caused by the change of the valve timing converges is set. And, when it is determined that the predetermined time Tw1 has not passed (S120: No), the CPU 110 repeats the determination of S120.

[0039] On the other hand, when it is determined that the predetermined time Tw1 has elapsed (S120: YES), the CPU 110 executes a pressure acquisition process for acquiring the current intake pressure PM as a first pressure PM1 (S130). The first pressure PM1 is the intake pressure PM when the EGR valve 52 is closed.

[0040] Next, the CPU 110 opens the EGR valve 52 (S140). In S140, the CPU 110 controls the EGR valve 52 so that the EGR valve 52 is in a fully open state. Next, the CPU 110 determines whether a predetermined time Tw2 has passed since the EGR valve 52 was opened (S150). As the predetermined time Tw2, the time required until the increase in the intake pressure PM generated by opening the EGR valve 52 in S140 converges is set.

[0041] Furthermore, when it is determined that the predetermined time Tw2 has not passed (S150: No), the CPU 110 repeats the determination of S150. On the other hand, when it is determined that the predetermined time Tw2 has passed (S150: Yes), the CPU 110 executes a pressure acquisition process of acquiring the current intake pressure PM as the second pressure PM2, and executes a speed acquisition process of acquiring the current internal combustion engine speed NE as the reference speed NEs (S160). The second pressure PM2 is the intake pressure PM when the EGR valve 52 is open.

[0042] Next, the CPU 110 closes the EGR valve 52 (S170). In S170, the CPU 110 controls the EGR valve 52 so that the EGR valve 52 is in a fully closed state. Next, the CPU 110 determines whether a predetermined time Tw3 has passed since the EGR valve 52 was closed (S180). As the predetermined time Tw3, the time required until the decrease in the intake pressure PM generated by closing the EGR valve 52 in S170 converges is set.

[0043] If it is determined that the predetermined time Tw3 has not passed (S180: No), the CPU 110 repeats the determination of S180. On the other hand, if it is determined that the predetermined time Tw3 has passed (S180: Yes), the CPU 110 executes a pressure acquisition process (S190) to acquire the current intake pressure PM as the third pressure PM3. The third pressure PM3 is the intake pressure PM when the EGR valve 52 is closed.

[0044] Next, the CPU 110 performs a pressure change calculation process for calculating a pressure change ΔP and a differential pressure calculation process for calculating a differential pressure Pba (S200). The pressure change ΔP is a pressure change associated with the opening and closing action of the EGR valve 52, and is a value obtained based on the above-mentioned first pressure PM1, second pressure PM2, and third pressure PM3 according to the following formula (1).

[0045] ΔP=PM2-{(PM1+PM3) / 2}…(1)

[0046] In addition, the differential pressure Pba is the pressure difference between the upstream side (exhaust passage side) and the downstream side (intake passage side) of the EGR valve 52 when the EGR valve 52 is in the closed valve state, and is a value obtained according to the following formula (2) based on the above-mentioned first pressure PM1 and third pressure PM3 and the atmospheric pressure PA obtained when executing the process of S200. It should be noted that the pressure on the upstream side of the EGR valve 52 (that is, the pressure in the exhaust passage 8) is related to the atmospheric pressure PA during the execution of fuel cut-off. Therefore, in this embodiment, the atmospheric pressure PA is used as a value representing the pressure on the upstream side of the EGR valve 52.

[0047] Pba=PA-{(PM1+PM3) / 2}…(2)

[0048] Incidentally, the value of {(PM1+PM3) / 2} in the above equations (1) and (2) is the arithmetic average PMclav of the intake pressure PM when the EGR valve 52 is closed, that is, the first pressure PM1 and the third pressure PM3.

[0049] Next, the CPU 110 performs a degradation degree calculation process (S210) for calculating the degradation degree R based on the pressure change amount ΔP, the differential pressure Pba, and the reference rotation speed NEs. More specifically, a map defining the correspondence between the pressure change amount ΔP, the differential pressure Pba, and the reference rotation speed NEs and the degradation degree R is stored in the memory 120 as a degradation degree map. Then, the CPU 110 calculates the degradation degree R by referring to the degradation degree map.

[0050] like Figure 3 As shown, the value of the degradation degree R increases in the order of degradation degree Ra, degradation degree Rb, and degradation degree Rc. And, the greater the pressure change ΔP, the smaller the calculated degradation degree R. In addition, even if the pressure change ΔP is the same, the smaller the differential pressure Pba, the smaller the calculated degradation degree R. In addition, even if the pressure change ΔP is the same, the higher the reference speed NEs, the smaller the calculated degradation degree R.

[0051] When the calculation of the degradation degree R is completed in this way, the CPU 110 then restarts the normal control of the valve timing, that is, changes the target valve timing VTp set to the fixed value VTa in the above S100 to a value set according to the engine operating state (S220), and ends the present processing.

[0052] <Function>

[0053] The function of this embodiment is described below. Figure 4 It is shown in Figure 2 The effect obtained by a series of treatments shown.

[0054] When the calculation of the degradation degree R starts at time t1, the valve timing VT of the intake valve 9 gradually changes toward the fixed value VTa. And when the change of the valve timing is completed at time t2, the first pressure PM1 is obtained at time t3 after a predetermined time Tw1 has passed from this time point, and the EGR valve 52 is changed from the closed valve state to the open valve state.

[0055] At time t4 when a predetermined time Tw2 has elapsed from time t3, the second pressure PM2 and the reference speed NEs are acquired. In addition, the EGR valve 52 is changed from the open valve state to the closed valve state.

[0056] At time t5 after a predetermined time Tw3 has passed from time t4, the third pressure PM3 is acquired. After acquiring the third pressure PM3, the pressure change ΔP and the differential pressure Pba are calculated, and the degree of degradation R is calculated based on these values ​​and the reference speed NEs. When the calculation of the degree of degradation R is completed, the calculation of the degree of degradation is completed, and the valve timing VT of the intake valve 9 is changed from the fixed value VTa to a variable value corresponding to the operating state of the internal combustion engine.

[0057] <Effect>

[0058] The effects of this embodiment will be described.

[0059] (1) As degradation of the EGR valve 52 progresses, the pressure variation ΔP described above decreases, and thus the pressure variation ΔP is a value correlated with the degradation degree R. Here, the pressure difference Pba described above affects the pressure variation ΔP.

[0060] That is, even if the degradation degree R of the EGR valve 52 is the same, when the differential pressure Pba is small, the pressure change amount ΔP becomes smaller than when the differential pressure Pba is large. In other words, when the differential pressure Pba is small, the degradation degree R relative to the pressure change amount ΔP becomes smaller than when the differential pressure Pba is large.

[0061] Therefore, in this embodiment, if Figure 3 As shown, even for the same pressure change ΔP, the degradation degree R is calculated such that the smaller the differential pressure Pba, the smaller the degradation degree R. Since the degradation degree R of the EGR valve 52 is calculated based on the pressure change ΔP and the differential pressure Pba, the degradation degree R can be calculated with high accuracy.

[0062] (2) When the pressure sensor 34 for detecting the intake pressure PM is provided in the surge tank 11 or the intake manifold 3A of the internal combustion engine 1, the pressure change ΔP is affected by the difference in intake air flow rate caused by the difference in engine speed.

[0063] That is, at the same intake pressure PM, if the engine speed increases, the flow rate of the intake air flowing in the intake passage 3 increases. Here, the flow rate of the EGR gas passing through the EGR valve 52 is affected by the intake pressure, so even if the intake flow rate increases, if the intake pressure does not change, the flow rate of the EGR gas is substantially constant. Therefore, if the intake flow rate increases, the ratio of the EGR gas to the intake air amount decreases. If the ratio of the EGR gas to the intake air amount decreases, the effect of the opening of the EGR valve 52 on the intake pressure PM becomes smaller, so the pressure change ΔP becomes smaller.

[0064] Therefore, even if the degradation degree R of the EGR valve 52 is the same, the pressure change ΔP becomes smaller when the engine speed is high than when the engine speed is low. In other words, the degradation degree R corresponding to the pressure change ΔP becomes smaller when the engine speed is high than when the engine speed is low.

[0065] Therefore, in this embodiment, if Figure 3 As shown in FIG. 1 , even with the same pressure change amount ΔP, the degradation degree R is calculated so that the degradation degree R becomes smaller as the reference speed NEs becomes higher. In this way, the degradation degree R of the EGR valve 52 is calculated by taking into account the engine speed such as the reference speed NEs in addition to the pressure change amount ΔP and the differential pressure Pba. Therefore, even when the pressure sensor 34 is provided in the surge tank 11, the degradation degree R of the EGR valve 52 can be calculated with high accuracy.

[0066] (3) Since the degree of degradation R of the EGR valve 52 can be calculated, maintenance and the like can be performed before the EGR valve 52 fails. Therefore, for example, it is also possible to prevent a malfunction from occurring in the EGR valve 52 in advance.

[0067] <Change example>

[0068] The above-mentioned embodiment can be implemented by modification as follows. The above-mentioned embodiment and the following modification examples can be implemented by combining with each other within the range that there is no technical contradiction.

[0069] Although the downstream side of the EGR passage 50 is connected to the surge tank 11 , such a connection location may be any location on the downstream side of the throttle valve 29 in the intake passage 3 , and may be changed as appropriate.

[0070] The arithmetic mean PMclav of the first pressure PM1 and the third pressure PM3 is calculated as the intake pressure PM when the EGR valve 52 is closed. Alternatively, the first pressure PM1 or the third pressure PM3 may be used as the intake pressure PM when the EGR valve 52 is closed.

[0071] As a value indicating the pressure on the upstream side of the EGR valve 52, the atmospheric pressure PA is used, but the pressure in the exhaust passage 8 may be used instead of the atmospheric pressure PA. When calculating the degradation degree R, the EGR valve 52 is opened so that the EGR valve 52 is in a fully opened state, but it is not necessarily required to be in a fully opened state, and the opening degree of the EGR valve 52 may be controlled so that the opening degree of the EGR valve 52 becomes larger than a predetermined value.

[0072] When calculating the degradation degree R, the EGR valve 52 is closed so that the EGR valve 52 is fully closed. However, it is not necessarily required to be fully closed, and the opening degree of the EGR valve 52 may be controlled so that the opening degree is reduced to a predetermined value or less.

[0073] The pressure sensor 34 may be provided in the intake manifold 3A. Even in this case, the same effects as those of the above-described embodiment can be obtained by the above-described calculation process of the degree of degradation.

[0074] In the above embodiment, the reference rotation speed NEs may be omitted when calculating the degree of degradation R. Even in this case, effects other than the above (2) can be obtained.

[0075] like Figure 5 As shown, a pressure sensor 340 may be provided in the downstream passage 50L, which is a part of the EGR passage 50 and connects the EGR valve 52 and the pressure stabilizing tank 11 of the intake passage 3. That is, a pressure sensor 340 is provided in the EGR passage 50 at a position between the position connected to the pressure stabilizing tank 11 and the EGR valve 52. The pressure sensor 340 is a pressure sensor disposed on the downstream side of the EGR valve 52. And the pressure P detected by the pressure sensor 340 is input to the control device 100. And, when calculating the above-mentioned degradation degree R, the above-mentioned pressure change amount ΔP and the differential pressure Pba may be obtained by obtaining the pressure P instead of the above-mentioned intake pressure PM.

[0076] In this way, when a pressure sensor is provided at a position between the portion connected to the intake passage 3 and the EGR valve 52 in the EGR passage 50, the pressure detected by the pressure sensor becomes a pressure corresponding to the flow rate of the EGR gas, and is not easily affected by the intake flow rate. Therefore, when the pressure sensor 340 is provided at the position shown in this modification, the influence of the internal combustion engine speed on the pressure change amount ΔP can be suppressed. Therefore, even if the reference speed NEs is omitted when calculating the degradation degree R, the degradation degree R of the EGR valve 52 can be calculated with high accuracy.

[0077] In the above embodiment, the degradation degree R is calculated by the actuator mounted on the vehicle 500. Alternatively, the degradation degree R may be calculated by an actuator installed outside the vehicle 500. Figure 6 Shown in.

[0078] like Figure 6 As shown, the control device 100 mounted on the vehicle 500 or 600 includes a communication device 130 and can communicate with the data analysis center 300 via the external network 200 using the communication device 130. In this modification, the CPU 110 and the memory 120 of the control device 100 constitute a first execution device.

[0079] The data analysis center 300 analyzes data transmitted from a plurality of vehicles 500, 600, etc. The data analysis center 300 includes a CPU 310, a memory 320, and a communication device 330, which can communicate via a local network. It should be noted that in this embodiment, the CPU 310 and the memory 320 constitute a second execution device.

[0080] Furthermore, CPU 110 executes Figure 2 The CPU 110 performs the processing of S100 to S190 shown in the figure, and after completing the processing of S190, performs the processing of S220. In addition, the CPU 110 sends the first pressure PM1, the second pressure PM2, the reference speed NEs, and the third pressure PM3 obtained in the processing of S130, S160, and S190 to the data analysis center 300. The CPU 310 of the data analysis center 300 receives the data and executes Figure 2 The process of S200 and S210 shown in the figure calculates the degradation degree R. It should be noted that the process of S200 may be performed by the CPU 110 on the vehicle side, and the pressure change amount ΔP, the differential pressure Pba, and the reference rotation speed NEs may be transmitted to the data analysis center 300 .

[0081] In the case of this modification, for example, compared with the case where the calculation of the degree of degradation R is performed in the CPU 110 on the vehicle side, the calculation load of the CPU 110 can be reduced.

[0082] The execution device is not limited to having a CPU and a memory and executing software processing. For example, it may also have a dedicated hardware circuit (such as an ASIC, etc.) that processes at least a part of the software processing executed in the above-mentioned embodiments and modified examples. That is, the execution device can be any of the following structures (a) to (c).

[0083] (a) A processing device that executes all of the above-mentioned processing according to a program and a program storage device such as a memory that stores the program are provided.

[0084] (b) A processing device and a program storage device for executing part of the above-mentioned processing according to a program, and a dedicated hardware circuit for executing the remaining processing are provided.

[0085] (c) A dedicated hardware circuit is provided to execute all the above-mentioned processing.

[0086] Here, there may be multiple software processing circuits or dedicated hardware circuits including the processing device and the program storage device. That is, the above-mentioned processing may be performed by a processing circuit including at least one of one or more software processing circuits and one or more dedicated hardware circuits.

Claims

1. A system for calculating the degree of degradation of an EGR valve, applied to an internal combustion engine having an EGR passage connecting an exhaust passage and an intake passage of the internal combustion engine, an EGR valve provided in the EGR passage, and a pressure sensor arranged on the downstream side of the EGR valve, configured to calculate the degree of degradation of the EGR valve, characterized in that: An execution device configured to execute the following processing is provided: A pressure acquisition process is used to acquire the pressure detected by the pressure sensor; a pressure variation calculation process for calculating a pressure variation which is a variation of the pressure accompanying the opening and closing operation of the EGR valve; a differential pressure calculation process for calculating a differential pressure which is a pressure difference between an upstream side and a downstream side of the EGR valve when the EGR valve is in a closed state; and a degradation degree calculation process of calculating the degradation degree of the EGR valve based on the pressure change amount and the differential pressure, The execution device is composed of: executing a speed acquisition process of acquiring the engine speed of the internal combustion engine during the opening and closing operation of the EGR valve as a reference speed, and In the degradation degree calculation process, the degradation degree of the EGR valve is calculated based on the pressure change amount, the differential pressure, and the reference rotation speed.

2. The EGR valve degradation degree calculation system according to claim 1, characterized in that: The actuator is configured to calculate the degree of degradation in the degree of degradation calculation process so that the degree of degradation decreases as the differential pressure decreases even when the pressure change amount is the same.

3. The EGR valve degradation degree calculation system according to claim 1 or 2, characterized in that: The actuator is configured to calculate the degree of degradation in the degree of degradation calculation process so that the degree of degradation decreases as the engine speed increases even when the amount of pressure change is the same.

4. The EGR valve degradation degree calculation system according to claim 1, characterized in that: The pressure sensor is arranged on the intake manifold or the pressure regulating tank of the internal combustion engine.

5. The EGR valve degradation degree calculation system according to claim 1 or 2, characterized in that: The pressure sensor is provided in the EGR passage at a location between a location connected to the intake passage and a location where the EGR valve is provided. 6 . A control device for an internal combustion engine, comprising the execution device in the degradation degree calculation system according to claim 1 .

7. A vehicle comprising the control device for the internal combustion engine according to claim 6.

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