Exhaust gas purification device removal determination device

Abstract

To provide a removal determination device of an exhaust emission control device which can improve determination accuracy for determining whether or not the exhaust emission control device is removed from an exhaust pipe.SOLUTION: A removal determination device of an exhaust emission control device comprises an input temperature sensor 15 for detecting an upstream-side temperature of a casing 14 which communicates with an exhaust pipe 9 of an engine 1, and an output temperature sensor 16 for detecting a downstream-side temperature of the casing 14, and also comprises an engine stop time acquisition unit 19 for acquiring a time from when the engine 1 stops until it is started, and a determination unit 22 for determining whether or not the exhaust emission control device 13 is arranged in the casing 14 on the basis of an input temperature detected by the input temperature sensor 15 and an output temperature detected by the output temperature sensor 16 when the from when the engine 1 stops until it is started is equal to or longer than a preset prescribed time.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a device for determining whether or not a device for purifying engine exhaust has been removed from an exhaust pipe.

Background Art

[0002] Patent Document 1 describes an exhaust system including an outer cylinder communicating with an exhaust pipe, an inner cylinder disposed at a predetermined interval from the inner surface of the outer cylinder on the central axis of the outer cylinder, an HC adsorbent provided between the outer cylinder and the inner cylinder, and a switching valve disposed upstream of the inner cylinder. In this exhaust system, by closing the upstream side of the inner cylinder with the switching valve, exhaust flows downstream only through the bypass flow path between the outer cylinder and the inner cylinder. Further, by opening the upstream side of the inner cylinder with the switching valve, exhaust flows downstream through the bypass flow path and the hollow portion of the inner cylinder (hereinafter referred to as the normal flow path).

[0003] A diagnostic device for diagnosing a failure of this switching valve is described in Patent Document 1. This diagnostic device includes a first temperature sensor provided downstream of the inner cylinder and a second temperature sensor provided in an upstream portion of the bypass flow path. Specifically, the diagnostic device diagnoses a failure of the switching valve based on whether or not a difference between a first temperature area, which is an integrated value of the temperature detected by the first temperature sensor after starting the engine, and a second temperature area, which is an integrated value of the temperature detected by the second temperature sensor, is a difference corresponding to an opening / closing instruction of the switching valve.

[0004] When only one of the bypass flow path and the normal flow path allows exhaust to flow and short-time running is repeated, the initial temperature detected by a sensor provided in either one is high, and there is a possibility of misjudging a failure of the switching valve. Therefore, the diagnostic device described in Patent Document 1 is configured to diagnose a failure of the switching valve only when the engine water temperature at engine start is less than a threshold value, the decrease amount of the engine water temperature from the end of the previous trip is greater than the threshold value, and the integrated intake air amount in the previous trip is greater than the threshold value.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The order in which each temperature sensor described in Patent Document 1 receives the heat of the exhaust gas is different between the case where the switching valve is opened and the case where the switching valve is closed. Therefore, it is possible to determine whether or not the switching valve has become inoperable according to the magnitude relationship (i.e., temperature difference) between the first temperature area based on the temperature detected by the first temperature sensor and the second temperature area based on the temperature detected by the second temperature sensor. Currently, an exhaust gas purification device such as a gasoline particulate filter (hereinafter referred to as GPF) provided in the exhaust pipe may be intentionally removed from the exhaust pipe due to theft or the like. Even when the exhaust gas purification device is removed from the exhaust pipe in this way, since the flow direction of the exhaust gas does not change regardless of the presence or absence of the exhaust gas purification device, the failure diagnosis device described in Patent Document 1 cannot be immediately diverted. Therefore, there has been room for developing a device for accurately determining that the exhaust gas purification device has been removed.

[0007] The present invention has been made by paying attention to the above - mentioned technical problems, and an object thereof is to provide a removal determination device for an exhaust gas purification device that can improve the determination accuracy as to whether or not the exhaust gas purification device has been removed from the exhaust pipe.

Means for Solving the Problems

[0008] The present invention is a removal determination device for an exhaust gas purification device that determines whether an exhaust gas purification device is housed inside a casing communicating with an exhaust pipe of an engine. The removal determination device includes an input temperature sensor that detects the temperature on the upstream side of the casing, an output temperature sensor that detects the temperature on the downstream side of the casing, and a controller that determines the presence or absence of the exhaust gas purification device inside the casing. The controller includes an engine stop time acquisition unit that acquires the time from when the engine stops until it starts, and a determination unit that determines whether the exhaust gas purification device is disposed inside the casing based on the input temperature detected by the input temperature sensor and the output temperature detected by the output temperature sensor when the time from when the engine stops until it starts is equal to or longer than a predetermined time. Furthermore, when the difference between the integrated amount of exhaust gas from the start of starting the engine required for the input temperature to reach a first predetermined temperature determined in advance and the integrated amount required for the output temperature to reach the first predetermined temperature is equal to or greater than a first threshold value determined in advance, the determination unit determines that the exhaust gas purification device is disposed within the casing. It is characterized by the above. 。 Moreover, the present invention relates to a removal determination device for an exhaust gas purification device that determines whether an exhaust gas purification device is housed inside a casing communicating with an exhaust pipe of an engine. The device includes an input temperature sensor that detects the temperature on the upstream side of the casing, an output temperature sensor that detects the temperature on the downstream side of the casing, and a controller that determines the presence or absence of the exhaust gas purification device within the casing. The controller includes an engine stop time acquisition unit that acquires the time from when the engine stops until it starts, and a determination unit that determines whether the exhaust gas purification device is disposed within the casing based on the input temperature detected by the input temperature sensor and the output temperature detected by the output temperature sensor when the time from when the engine stops until it starts is equal to or greater than a predetermined time determined in advance. The determination unit determines that the exhaust gas purification device is disposed within the casing when the difference between the integrated amount of exhaust gas required for the input temperature to rise from a second predetermined temperature to a third predetermined temperature determined in advance and the integrated amount of exhaust gas required for the output temperature to rise from the second predetermined temperature to the third predetermined temperature is equal to or greater than a second threshold value determined in advance. Furthermore, the present invention is a removal determination device for an exhaust gas purification device that determines that the exhaust gas purification device is housed inside a casing communicating with an exhaust pipe of an engine, the removal determination device including: an input temperature sensor that detects a temperature on the upstream side of the casing; an output temperature sensor that detects a temperature on the downstream side of the casing; and a controller that determines the presence or absence of the exhaust gas purification device inside the casing. The controller includes an engine stop time acquisition unit that acquires the time from when the engine stops until it starts, and a determination unit that, when the time from when the engine stops until it starts is equal to or longer than a predetermined time, determines whether or not the exhaust gas purification device is disposed inside the casing based on the input temperature detected by the input temperature sensor and the output temperature detected by the output temperature sensor. The determination unit determines that the exhaust gas purification device is disposed inside the casing when the rate of change over time of the output temperature with respect to the rate of change over time of the input temperature at the time when the input temperature reaches a predetermined fourth predetermined temperature is equal to or less than a predetermined third threshold value.

[0009] In the present invention, the controller may be configured to obtain the integrated amount of exhaust gas after starting the engine, and determine whether the exhaust gas purification device is disposed inside the casing by the determination unit when the integrated amount is equal to or greater than a predetermined amount.

[0010] In the present invention, when the exhaust gas purification device is provided inside the casing, a predetermined integrated amount at which the input temperature becomes equal to or higher than the dew point temperature of moisture and the output temperature becomes lower than the dew point temperature is obtained in advance, and the predetermined amount may include the predetermined integrated amount.

[0011] In the present invention, the controller may be configured to determine whether the exhaust gas purification device is disposed inside the casing by the determination unit when the input temperature is equal to or higher than a predetermined temperature.

Advantages of the Invention

[0016] According to the present invention, when the time from when the engine stops until it starts is equal to or longer than a predetermined time, it is determined whether an exhaust purification device for purifying the exhaust of the engine is present in the exhaust pipe based on the input temperature and the output temperature of a casing for housing the exhaust purification device. Therefore, it is possible to determine the presence or absence of the exhaust purification device in the exhaust pipe from a state where the temperature in the engine and the exhaust pipe has decreased. In addition, it is possible to prevent an incorrect determination of the presence or absence of the exhaust purification device due to a change in the input temperature due to the thermal energy remaining in the engine and the exhaust pipe, and a change in the output temperature due to the thermal energy remaining in the exhaust purification device.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiment for Carrying Out the Invention

[0018] The present invention will be described based on the embodiments shown in the drawings. It should be noted that the embodiments described below are merely examples of the case where the present invention is embodied, and do not limit the present invention.

[0019] An example of an engine and an exhaust purification device to which the removal determination device in the embodiment of the present invention is applied is schematically shown in FIG. 1. The engine 1 shown in FIG. 1 is configured to generate power by burning a mixture of fuel such as gasoline or diesel and air, similar to a conventional engine. Specifically, in the engine 1, a plurality of cylinders 2 for burning the mixture are formed in the engine block 3. Each cylinder 2 is provided with a spark plug 4 for igniting the mixture.

[0020] An intake pipe 5 for taking in outside air is connected to the engine block 3 via an intake manifold 6. In this intake pipe 5, in addition to various members such as an air cleaner (not shown), a throttle valve 7 for controlling the amount of air flowing in the intake pipe 5 based on the driver's accelerator operation amount and the like is provided. The intake pipe 5 is provided with a throttle opening sensor 8 for detecting the opening degree of the throttle valve 7.

[0021] An exhaust pipe 9 for discharging the exhaust generated by burning the mixture in each cylinder 2 to the outside of the vehicle is connected to the engine block 3 via an exhaust manifold 10.

[0022] This exhaust pipe 9 is provided with various devices for purifying unburned gases (carbon monoxide (CO) and hydrocarbons (HC)) and nitrogen oxides (NOx) contained in the exhaust gas, and for collecting particulate matter. In the example shown in FIG. 1, the exhaust pipe 9 is provided with a catalyst device 11 such as an oxidation catalyst (two-way catalyst) or a three-way catalyst for purifying unburned gases and NOx, and downstream of the catalyst device 11, a PM collection device 12 for collecting particulate matter is provided.

[0023] In an embodiment of the present invention, a wall flow type filter 13 is adopted as the PM collection device 12 which is an exhaust gas purification device. Specifically, the PM collection device 12 is a filter 13 called a GPF (Gasoline Particulate Filter), and a three-way catalyst is supported on the filter 13. Therefore, unburned gases and NOx contained in the exhaust gas discharged from the catalyst device 11 can be effectively purified by the PM collection device 12. In the following description, the filter 13 is simply referred to as the GPF13.

[0024] The GPF13 has an outer diameter substantially the same as the inner diameter of a casing 14 formed by expanding a part of the diameter of the exhaust pipe 9, and is assembled inside the casing 14. That is, the casing 14 is provided in communication with the exhaust pipe 9, and is configured such that all of the exhaust gas that has flowed to the casing 14 passes through the inside of the GPF13.

[0025] In order to detect the temperature of the exhaust gas flowing into the GPF13, an input temperature sensor 15 is provided between the catalyst device 11 and the GPF13. In addition, an output temperature sensor 16 is provided on the downstream side of the GPF13 in order to detect the temperature of the exhaust gas flowing out of the GPF13. In other words, the input temperature sensor 15 detects the temperature on the upstream side of the casing 14, and the output temperature sensor 16 detects the temperature on the downstream side of the casing 14.

[0026] The above throttle opening sensor 8, each temperature sensor 15, 16, and soak timer 17 are connected to an electronic control unit (hereinafter referred to as ECU) 18 corresponding to the "controller" in the embodiment of the present invention. The soak timer 17 is configured to measure the elapsed time (soak time) since the ignition is turned off.

[0027] Similar to a conventional ECU, the ECU 18 is mainly composed of a microcomputer and is configured to determine the presence or absence of the GPF 13 based on the input signals and maps, arithmetic expressions, etc. stored in advance. Note that signals from other sensors, such as the signal of a sensor that detects the engine speed, can also be input to the ECU 18.

[0028] The ECU 18 includes a soak time acquisition unit 19, an engine control unit 20, a temperature acquisition unit 21, and a GPF determination unit 22. Specifically, the soak time acquisition unit 19 functions as an "engine stop time acquisition unit" that acquires the time from when the engine 1 stops until it starts. In the embodiment of the present invention, the soak time measured by the soak timer 17 is transmitted to the soak time acquisition unit 19.

[0029] The engine control unit 20 is configured to control the start and stop of the engine 1 and, in addition, control the output of the engine 1 according to the required driving force based on the accelerator operation amount, etc. The temperature acquisition unit 21 is configured to acquire the temperatures detected by the input temperature sensor 15 and the output temperature sensor 16 and output them to the GPF determination unit 22. The GPF determination unit 22 is configured to determine whether the GPF 13 has been removed from the exhaust pipe 9 based on the temperature information input from the temperature acquisition unit 21. In other words, it is configured to confirm the presence or absence of the GPF 13 in the exhaust pipe 9. This GPF determination unit 22 corresponds to the "determination unit" in the embodiment of the present invention.

[0030] FIG. 2 shows a flowchart for explaining an example of control executed by the ECU 18. In the control example shown here, when the engine 1 is started from a state where the temperature of the engine 1 is less than a predetermined temperature, the presence or absence of the GPF 13 is determined. In step S1, it is determined whether or not a prerequisite for determining the presence or absence of the GPF 13 is satisfied. Specifically, in step S1, it is determined whether or not the soak time is equal to or longer than a predetermined time set in advance. This predetermined time is set based on the results of experiments and simulations to be the time required for the temperatures in the engine 1 and the exhaust pipe 9 to drop to a temperature equivalent to the outside air. When the removal determination device in the present embodiment is applied to a hybrid vehicle capable of stopping the engine 1 and traveling with a motor as another driving power source, in step S1, instead of the soak time, it may be determined whether or not the elapsed time since the engine 1 was stopped is equal to or longer than a predetermined time. Thus, in step S1, it is determined whether or not the time from when the engine 1 is stopped until it is started is equal to or longer than a predetermined time set in advance.

[0031] If it is negatively determined in step S1 because the prerequisite for determining the presence or absence of the GPF 13 in the exhaust pipe 9 is not satisfied, this routine is terminated once. On the contrary, if it is positively determined in step S1 because the prerequisite for determining the presence or absence of the GPF 13 in the exhaust pipe 9 is satisfied, the process proceeds to step S2, and it is determined whether or not the environmental conditions for determining the presence or absence of the GPF 13 are satisfied. Specifically, in step S2, it is determined whether or not the environment is under a predetermined atmospheric pressure or higher according to regulations.

[0032] If it is negatively determined in step S2 because the environmental conditions are not satisfied, this routine is terminated once. On the contrary, if it is positively determined in step S2 because the environmental conditions are satisfied, the process proceeds to step S3, and it is determined whether or not the engine 1 is started. The determination in step S3 can be made based on, for example, a signal output from the engine control unit 20 to the engine 1.

[0033] When the negative determination is made in step S3 because engine 1 is not started, the process returns to step S1, and the determination in step S3 is repeated until engine 1 is started. On the contrary, when the positive determination is made in step S3 because engine 1 is started, the process proceeds to step S4 to determine whether a monitoring prohibition condition is satisfied, which is a condition where the temperature of the exhaust does not increase substantially (monotonically). Therefore, for example, the monitoring prohibition condition is satisfied when there is a possibility that engine 1 stalls or when the output of engine 1 increases at a rate equal to or higher than a predetermined increase rate.

[0034] When the positive determination is made in step S4 because the monitoring prohibition condition is satisfied, this routine is terminated once. On the contrary, when the negative determination is made in step S4 because the monitoring prohibition condition is not satisfied, the process proceeds to step S5 to perform the calculation of the detected parameter.

[0035] In this control example, the input temperature sensor 1 5 and out Force temperature sensor 1 The temperature detected at 6, and the presence or absence of GPF13 in the exhaust pipe 9 is determined based on the integrated amount of the exhaust gas supplied to GPF13. The integrated amount of the exhaust gas supplied to GPF13 can be calculated, for example, from the detection value of the throttle opening sensor 8. In the following description, the integrated amount of the exhaust gas supplied to GPF13 is referred to as the integrated air amount for convenience.

[0036] FIG. 3(a) shows the result of verifying the relationship between the integrated air amount in the state where GPF13 is provided in the exhaust pipe 9 and the temperatures detected by the respective temperature sensors 15 and 16. On the other hand, FIG. 3(b) shows the result of verifying the relationship between the integrated air amount in the state where GPF13 is not provided in the exhaust pipe 9 and the temperatures detected by the respective temperature sensors 15 and 16.

[0037] The verification shown in FIG. 3 was performed by driving the experimental vehicle based on the high-speed high-acceleration test cycle pattern (US06) of the Supplemental Federal Test Procedure (SFTP) and the Worldwide Harmonized Light Vehicles Test Procedure (WLTP). Note that the driving pattern based on WLTP is a relatively gentle driving pattern compared to the driving pattern based on US06. In FIGS. 3(a) and 3(b), the thick curve shows the verification result of the above relationship when driving based on the driving pattern of US06, the thin curve shows the verification result of the above relationship when driving based on the driving pattern of WLTP, the dashed line shows the input temperature detected by the input temperature sensor 15, and the solid line shows the output temperature detected by the output temperature sensor 16.

[0038] As shown in FIG. 3(a), when the GPF 13 is provided in the exhaust pipe 9, when the integrated air amount is equal to or less than a predetermined amount G1, the difference between the input temperature and the output temperature is extremely small and almost constant (stagnant state). In other words, the input temperature and the output temperature are stagnant. Thereafter, when the integrated air amount increases more than the predetermined amount G1, the input temperature starts to increase regardless of the driving pattern, while the output temperature remains constant. Specifically, the input temperature and the output temperature stagnate at the dew point temperature of water. Further, when the GPF 13 is provided in the exhaust pipe 9, the heat capacity of the exhaust pipe 9 is increased by the GPF 13. In this case, when the integrated air amount (the thermal energy input to the GPF 13) becomes more than the predetermined amount G1, the input temperature starts to rise. However, since heat is absorbed by the GPF 13, the output temperature still remains stagnant in this situation.

[0039] On the other hand, as shown in FIG. 3(b), when the GPF 13 is not provided in the exhaust pipe 9, the difference between the input temperature and the output temperature is small in any driving pattern. Further, since the flow resistance of the exhaust is small, the exhaust containing relatively a large amount of moisture in the exhaust pipe 9 is quickly discharged. As a result, the input temperature and the output temperature rise almost without stagnation.

[0040] Therefore, in the control example shown here, the presence or absence of the GPF 13 in the exhaust pipe 9 is determined based on the integrated air quantity and the temperatures detected by the respective temperature sensors 15 and 16. Accordingly, in step S5, the integrated air quantity since the engine 1 starts to operate is calculated.

[0041] In step S6, it is determined whether or not the determination start condition is satisfied. Specifically, in step S6, when it is assumed that the GPF 13 is disposed in the exhaust pipe 9, it is determined whether or not it is under the condition that a significant difference occurs between the input temperature and the output temperature. For example, as shown in FIGS. 3(a) and 3(b), it is determined whether or not the integrated air quantity has reached a predetermined quantity Gp or more, or whether or not the input temperature has reached a predetermined temperature T1 or more. More specifically, it is determined whether or not the integrated air quantity has reached the integrated air quantity at which it can be estimated that the input temperature is equal to or higher than the dew point temperature of moisture and the output temperature is lower than the dew point temperature of moisture. This integrated air quantity corresponds to the "predetermined quantity" and "predetermined integrated quantity" in the embodiment of the present invention.

[0042] If it is negatively determined in step S6 because the determination start condition is not satisfied, the process returns to step S4. On the contrary, if it is positively determined in step S6 because the determination start condition is satisfied, the process proceeds to step S7, and a determination value for determining the presence or absence of the GPF 13 in the exhaust pipe 9 is calculated.

[0043] Specifically, the difference between the input temperature and the output temperature at a predetermined integrated air quantity Gp corresponding to the "first determination value" is calculated. Therefore, the predetermined integrated air quantity Gp is a value at which a significant difference occurs between the input temperature and the output temperature when the GPF 13 is provided, and a value at which the difference between the input temperature and the output temperature is minute when the GPF 13 is not provided, based on the results of experiments, simulations, etc. Note that the predetermined integrated air quantity Gp may be set to a value different from the value used in the determination in step S6.

[0044] In step S7, a difference ΔG between the integrated air amount required for the input temperature to reach a predetermined first predetermined temperature T1 and the integrated air amount required for the output temperature to reach the first predetermined temperature T1 may be calculated. Specifically, when the GPF 13 is provided in the exhaust pipe 9, the first predetermined temperature T1 is such that the difference ΔG between the integrated air amount required for the input temperature to reach the first predetermined temperature T1 and the integrated air amount required for the output temperature to reach the first predetermined temperature T1 increases from a predetermined value. When the GPF 13 is not provided, the first predetermined temperature T1 is set to a temperature at which the above-described difference ΔG is equal to or less than the predetermined value. The first predetermined temperature T1 can be determined in advance based on the results of experiments, simulations, or the like.

[0045] In step S7, a difference between the integrated air amount required for the input temperature to rise from a predetermined second predetermined temperature T2 to a third predetermined temperature T3 and the integrated air amount required for the output temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 may be calculated. Specifically, when the GPF 13 is provided in the exhaust pipe 9, the second predetermined temperature T2 and the third predetermined temperature T3 are such that the difference between the integrated air amount required for the input temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 and the integrated air amount required for the output temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 increases from a predetermined value. When the GPF 13 is not provided in the exhaust pipe 9, the second predetermined temperature T2 and the third predetermined temperature T3 are set to temperatures at which the difference between the integrated air amount required for the input temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 and the integrated air amount required for the output temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 is equal to or less than the predetermined value. The second predetermined temperature T2 and the third predetermined temperature T3 can be determined in advance based on the results of experiments, simulations, or the like.

[0046] In step S8 following step S7, it is determined whether the GPF 13 is provided in the exhaust pipe 9 based on the determination value calculated in step S7. For example, when the difference between the input temperature and the output temperature (i.e., the determination value) at a predetermined integrated air amount Gp is calculated in step S7, it is determined in step S8 whether the determination value is equal to or greater than a predetermined first threshold value. When this determination value is equal to or greater than the first threshold value, it is determined that the GPF 13 is provided in the exhaust pipe 9.

[0047] When the difference between the integrated air amount required for the input temperature to reach the first predetermined temperature T1 in step S7 and the integrated air amount required for the output temperature to reach the first predetermined temperature T1 (i.e., the determination value) is calculated, it is determined whether the determination value is equal to or greater than a predetermined second threshold value. When this determination value is equal to or greater than the second threshold value, it is determined that the GPF 13 is provided in the exhaust pipe 9.

[0048] When the difference between the integrated air amount required for the input temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 in step S7 and the integrated air amount required for the output temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 (i.e., the determination value) is calculated, it is determined whether the determination value is equal to or greater than a predetermined third threshold value. When this determination value is equal to or greater than the third threshold value, it is determined that the GPF 13 is provided in the exhaust pipe 9.

[0049] If it is affirmatively determined in step S8 that the GPF 13 is provided in the exhaust pipe 9, the process proceeds to step S9, and it is determined that the exhaust pipe 9 is functioning normally. Then, this routine is terminated once. On the contrary, if it is negatively determined in step S8 that the GPF 13 is not provided in the exhaust pipe 9, the process proceeds to step S10, and it is determined that an abnormality has occurred in the exhaust pipe 9, and this routine is terminated once. In this case, the abnormality of the exhaust pipe 9 may be notified to the driver, and the operating conditions of the engine 1 may be changed.

[0050] FIG. 4(a) shows an example in which the GPF 13 is provided in the exhaust pipe 9 and the input temperature and the output temperature are measured when the engine 1 is restarted in a short time (i.e., the soak time is less than a predetermined time), and FIG. 4(b) shows an example in which the GPF 13 is provided in the exhaust pipe 9 and the input temperature and the output temperature are measured when the engine 1 is restarted for a long time (i.e., the soak time is equal to or more than the predetermined time). In FIG. 4, the solid line indicates the input temperature and the broken line indicates the output temperature.

[0051] As shown in FIG. 4(a), when the engine 1 is restarted in a short time, since the initial temperature of the GPF 13 is high, the exhaust temperature passing through the GPF 13 becomes high by restarting the engine 1. As a result, the difference between the input temperature and the output temperature at the time of a predetermined integrated air amount Gp becomes small. Or, the difference between the integrated air amount required until the output temperature rises to the first predetermined temperature T1 and the integrated air amount required until the input temperature rises to the first predetermined temperature T2 becomes small. Alternatively, the difference between the integrated air amount required for the input temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 and the integrated air amount required for the output temperature to rise between the second predetermined temperature T2 and the third predetermined temperature T3 becomes small. Therefore, in this case, there is a possibility of misjudgment if the GPF 13 is not provided in the exhaust pipe 9.

[0052] On the other hand, when the engine 1 is restarted for a long time as shown in FIG. 4(b), since the initial temperature of the GPF 13 is low, after the engine 1 is restarted, until the GPF 13 heats up, the output temperature stagnates near the dew point temperature. As a result, the difference between the input temperature and the output temperature at the predetermined integrated air volume Gp increases. Or, the difference between the integrated air volume required for the output temperature to rise to the first predetermined temperature T1 and the integrated air volume required for the input temperature to rise to the first predetermined temperature T2 increases. Or, the difference between the integrated air volume required for the input temperature to rise from the second predetermined temperature T2 to the third predetermined temperature T3 and the integrated air volume required for the output temperature to rise between the second predetermined temperature T2 and the third predetermined temperature T3 increases. That is, in a state where the temperature in the engine 1 and the exhaust pipe 9 has decreased, the presence or absence of the GPF 13 in the exhaust pipe 9 can be determined. That is, in this state, the residual thermal energy in the engine 1 and the exhaust pipe 9 does not act on the input temperature, and the residual thermal energy in the GPF 13 does not act on the output temperature. Therefore, it is possible to prevent an incorrect determination of the presence or absence of the GPF 13 in the exhaust pipe 9, and it is possible to accurately determine the presence or absence of the GPF 13 in the exhaust pipe 9.

[0053] Also, in the above-described control example, the presence or absence of the GPF 13 in the exhaust pipe 9 is determined based on the integrated air volume, that is, the thermal energy input to the GPF 13. Therefore, it is not necessary to set a threshold value for determining the presence or absence of the GPF 13 in the exhaust pipe 9 according to the driving pattern, and it is possible to prevent the relationship between the input temperature and the output temperature from changing according to the driving pattern. As a result, the determination of the presence or absence of the GPF 13 can be simplified.

[0054] Furthermore, when the GPF13 is disposed in the exhaust pipe 9, it is possible to prevent misjudgment by determining the presence or absence of the GPF13 under conditions where a significant difference occurs between the input temperature and the output temperature. Specifically, on the condition that the input temperature is equal to or higher than the dew point temperature of moisture and the integrated air volume is estimated to be such that the output temperature is lower than the dew point temperature of moisture, the presence or absence of the GPF13 in the exhaust pipe 9 is determined. Therefore, when the GPF13 is provided in the exhaust pipe 9, the input temperature increases relatively rapidly, while the output temperature stagnates below the dew point temperature. As a result, the difference between the input temperature and the output temperature becomes significantly large, and the determination system for the presence or absence of the GPF13 in the exhaust pipe 9 can be improved.

[0055] As shown in FIGS. 3(a) and 3(b), when the GPF13 is provided in the exhaust pipe 9, the output temperature stagnates while the input temperature increases at an integrated air volume of a predetermined value G1 or more. On the other hand, when the GPF13 is not provided in the exhaust pipe 9, the input temperature and the output temperature increase regardless of the integrated air volume. In other words, at an integrated air volume of a predetermined value G1 or more, the rate of change of the output temperature with respect to the rate of change of the input temperature is smaller when the GPF13 is provided in the exhaust pipe 9 than when the GPF13 is not provided in the exhaust pipe 9.

[0056] FIG. 5(a) shows, by a broken line, the relationship between the integrated air volume and the time rate of change of the input temperature in a state where the GPF13 is provided in the exhaust pipe 9, and shows, by a solid line, the relationship between the integrated air volume and the time rate of change of the output temperature. On the other hand, FIG. 5(b) shows, by a broken line, the relationship between the integrated air volume and the time rate of change of the input temperature in a state where the GPF13 is not provided in the exhaust pipe 9, and shows, by a solid line, the relationship between the integrated air volume and the time rate of change of the output temperature. Also, similar to FIGS. 3(a) and 3(b), the verification results in the driving pattern based on US06 are shown by thick curves, and the verification results in the driving pattern based on WLTP are shown by thin curves.

[0057] As shown in Fig. 5(a), when the GPF 13 is provided in the exhaust pipe 9, the integrated air amount is equal to or greater than a predetermined amount G1, and while the time change rate of the input temperature rapidly increases, the time change rate of the output temperature is maintained at a low level. As described with reference to Fig. 3(a), the output temperature stagnates near the dew point temperature of moisture. Therefore, in this case, when the integrated air amount is equal to or greater than the predetermined amount G1, the difference between the time change rate of the input temperature and the time change rate of the output temperature becomes large.

[0058] On the other hand, as shown in Fig. 5(b), when the GPF 13 is not provided in the exhaust pipe 9, the difference between the time change rate of the input temperature and the time change rate of the output temperature increases or decreases regardless of the integrated air amount. That is, a significant difference between the time change rate of the input temperature and the time change rate of the output temperature as in the case where the GPF 13 is provided in the exhaust pipe 9 does not occur.

[0059] Therefore, the removal determination device in the embodiment of the present invention may be configured to determine whether the difference between the time change rate of the input temperature and the time change rate of the output temperature is equal to or greater than a predetermined difference when the integrated air amount is equal to or greater than a predetermined amount G1, and determine that the GPF 13 has been removed when the difference is less than the predetermined difference.

[0060] When the vehicle to which the removal determination device in the embodiment of the present invention is applied accelerates rapidly, the input temperature and the output temperature increase in a short time, whereas when accelerating with a small acceleration, the input temperature and the output temperature increase over a long time. Therefore, it is necessary to determine a threshold value for whether the GPF 13 is provided according to the driving manner, that is, the driving manner of the engine 1. Therefore, in the control example shown in Fig. 2, the presence or absence of the GPF 13 in the exhaust pipe 9 is determined by comparing the input temperature and the output temperature based on the thermal energy supplied to the exhaust pipe 9.

[0061] However, as shown in FIG. 6(a), when the GPF 13 is provided in the exhaust pipe 9, after a predetermined time has elapsed since the engine 1 is started, the output temperature rises with a delay with respect to the input temperature. On the other hand, as shown in FIG. 6(b), when the GPF 13 is not provided in the exhaust pipe 9, at the time when a predetermined time has elapsed since the engine 1 is started, the input temperature and the output temperature rise almost simultaneously. Therefore, the removal determination device in the embodiment of the present invention may be configured to measure the time difference until reaching a predetermined temperature and the difference between the input temperature and the output temperature after a predetermined time, and determine the presence or absence of the GPF 13 in the exhaust pipe 9 based on the measured values.

[0062] Further, the removal determination device in the embodiment of the present invention may be configured to determine the presence or absence of the GPF 13 in the exhaust pipe 9 based on the time change rate of the output temperature with respect to the time change rate of the input temperature when the input temperature reaches a predetermined temperature. FIG. 7 shows the result of verifying the relationship between the time change rate of the input temperature and the time change rate of the output temperature when the input temperature reaches a predetermined temperature. The verification results are plotted with "●", and a fourth threshold value for determining the presence or absence of the GPF 13 in the exhaust pipe 9 is shown by a solid line. The region above this fourth threshold value is the region where the GPF 13 is not provided in the exhaust pipe 9. That is, when the time change rate of the output temperature with respect to the time change rate of the input temperature is equal to or less than a predetermined fourth threshold value, it is determined that the GPF 13 is provided in the exhaust pipe 9. Note that the above-mentioned predetermined temperature corresponds to the "fourth predetermined temperature" in the embodiment of the present invention, and may be set to a value different from the value used for the determination in step S6.

[0063] By thus determining the presence or absence of the GPF 13 in the exhaust pipe 9 based on the time change rate of the output temperature with respect to the time change rate of the input temperature when the input temperature reaches a predetermined temperature, the presence or absence of the GPF 13 in the exhaust pipe 9 can be accurately determined regardless of the driving pattern.

Explanation of Reference Numerals

[0064] 1 Engine 8 Throttle opening sensor 9 Exhaust pipe 11 Catalytic converter 12 PM collection device 13 Exhaust gas purification device (GPF) 14 Casing 15 Input temperature sensor 16 Output temperature sensor 17 Soak timer 18 Electronic control unit (ECU) 19 Soak time acquisition unit 20 Engine control unit 21 Temperature acquisition unit 22 GPF determination unit

Claims

1. An exhaust gas purification device removal determination device that determines whether an exhaust gas purification device is housed inside a casing communicating with an exhaust pipe of an engine, an input temperature sensor that detects the temperature on the upstream side of the casing, an output temperature sensor that detects the temperature on the downstream side of the casing, and a controller that determines the presence or absence of the exhaust gas purification device inside the casing, wherein the controller, has an engine stop time acquisition unit that acquires the time from when the engine stops until it starts, and when the time from when the engine stops until it starts is equal to or longer than a predetermined time, based on the input temperature detected by the input temperature sensor and the output temperature detected by the output temperature sensor, has a determination unit that determines whether the exhaust gas purification device is disposed inside the casing. The determination unit determines that the exhaust gas purification device is disposed inside the casing when the difference between the integrated amount of exhaust gas from when the engine is started until the input temperature reaches a first predetermined temperature and the integrated amount required for the output temperature to reach the first predetermined temperature is equal to or greater than a first threshold value. An exhaust gas purification device removal determination device characterized by the above.

2. An exhaust gas purification device removal determination device that determines whether an exhaust gas purification device is housed inside a casing communicating with an exhaust pipe of an engine, an input temperature sensor that detects the temperature on the upstream side of the casing, an output temperature sensor that detects the temperature on the downstream side of the casing, and a controller that determines the presence or absence of the exhaust gas purification device inside the casing, wherein the controller, has an engine stop time acquisition unit that acquires the time from when the engine stops until it starts, When the time from when the engine stops until it starts is equal to or longer than a predetermined time, a determination unit that determines whether or not the exhaust gas purification device is disposed in the casing based on the input temperature detected by the input temperature sensor and the output temperature detected by the output temperature sensor. The determination unit determines that the exhaust gas purification device is disposed in the casing when the difference between the integrated amount of exhaust gas required for the input temperature to rise from a second predetermined temperature to a third predetermined temperature and the integrated amount of exhaust gas required for the output temperature to rise from the second predetermined temperature to the third predetermined temperature is equal to or greater than a second threshold value. An exhaust gas purification device removal determination device characterized by the above.

3. An exhaust gas purification device removal determination device that determines that an exhaust gas purification device is housed inside a casing that communicates with an exhaust pipe of an engine, An input temperature sensor that detects the temperature on the upstream side of the casing, An output temperature sensor that detects the temperature on the downstream side of the casing, A controller that determines the presence or absence of the exhaust gas purification device in the casing, The controller, An engine stop time acquisition unit that acquires the time from when the engine stops until it starts, When the time from when the engine stops until it starts is equal to or longer than a predetermined time, a determination unit that determines whether or not the exhaust gas purification device is disposed in the casing based on the input temperature detected by the input temperature sensor and the output temperature detected by the output temperature sensor. The determination unit determines that the exhaust gas purification device is disposed in the casing when the rate of change of the output temperature with respect to the rate of change of the input temperature at the time when the input temperature reaches a fourth predetermined temperature is equal to or less than a third threshold value. An exhaust gas purification device removal determination device characterized by the above.

4. A device for determining removal of an exhaust gas purification device according to any one of claims 1 to 3, wherein the controller, obtains an integrated amount of exhaust gas since starting of the engine, and is configured to determine, by the determination unit, whether the exhaust gas purification device is disposed in the casing when the integrated amount is equal to or more than a predetermined amount. A device for determining removal of an exhaust gas purification device, characterized by the above.

5. A device for determining removal of an exhaust gas purification device according to claim 4, wherein when the exhaust gas purification device is provided in the casing, a predetermined integrated amount at which the input temperature becomes equal to or more than the dew point temperature of moisture and the output temperature becomes less than the dew point temperature is obtained in advance, and the predetermined amount includes the predetermined integrated amount. A device for determining removal of an exhaust gas purification device, characterized by the above.

6. A device for determining removal of an exhaust gas purification device according to any one of claims 1 to 3, wherein the controller, is configured to determine, by the determination unit, whether the exhaust gas purification device is disposed in the casing when the input temperature is equal to or more than a predetermined temperature. A device for determining removal of an exhaust gas purification device, characterized by the above.

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