JP6844512B2 - Abnormality judgment device - Google Patents

Description

The disclosure described in the present specification relates to an abnormality determination device for determining an abnormality of a particulate filter.

As shown in Patent Document 1, a method for determining a particulate filter abnormality is known. The particulate filter is installed in the exhaust passage. An upstream exhaust temperature sensor is arranged in an exhaust passage on the upstream side of the particulate filter. A downstream exhaust temperature sensor is arranged in an exhaust passage on the downstream side of the particulate filter. The output signals of the upstream exhaust temperature sensor and the downstream exhaust temperature sensor are input to the ECU. The ECU detects an abnormality in the particulate filter based on the input output signal.

Japanese Unexamined Patent Publication No. 2006-2736

As described above, the particulate filter abnormality determination method shown in Patent Document 1 requires an upstream exhaust temperature sensor and a downstream exhaust temperature sensor in order to detect an abnormality in the particulate filter. Therefore, there is a problem that the number of parts is large.

Therefore, it is an object of the disclosure described in the present specification to provide an abnormality determination device capable of detecting an abnormality of a particulate filter while suppressing an increase in the number of parts.

One of the disclosures is an exhaust temperature sensor (166) provided on the downstream side of the particulate filter (150) provided in the exhaust passage (130) from which the exhaust gas of the gasoline engine (120) is discharged.
Based on the output change of the exhaust gas temperature sensor during operation changes in gasoline engine change in temperature of the exhaust gas is caused to be discharged into the exhaust passage, it possesses determination unit that determines abnormality of the particulate filter (10), a
The determination unit determines an abnormality of the particulate filter based on the output change of the exhaust temperature sensor after the gasoline engine has changed from the stopped state to the driven state.
One of the other disclosures is an exhaust temperature sensor (166) provided on the downstream side of the particulate filter (150) provided in the exhaust passage (130) from which the exhaust gas of the gasoline engine (120) is discharged.
It has a determination unit (10) for determining an abnormality of the particulate filter based on the output change of the exhaust temperature sensor when the operation of the gasoline engine changes when the temperature of the exhaust gas discharged to the exhaust passage changes.
The determination unit determines an abnormality of the particulate filter based on the output change of the exhaust temperature sensor after the rotation speed of the gasoline engine changes to the rotation speed threshold value for determining a sudden change or more.
One of the other disclosures is an exhaust temperature sensor (166) provided on the downstream side of the particulate filter (150) provided in the exhaust passage (130) from which the exhaust gas of the gasoline engine (120) is discharged.
It has a determination unit (10) for determining an abnormality of the particulate filter based on the output change of the exhaust temperature sensor when the operation of the gasoline engine changes when the temperature of the exhaust gas discharged to the exhaust passage changes.
The determination unit determines the output change of the exhaust temperature sensor after changing from the supply state of gasoline fuel to the gasoline engine to the non-supply state, and the output of the exhaust temperature sensor after changing from the non-supply state of gasoline fuel to the supply state. Determine anomalies in the particulate filter based on at least one of the changes.

When the operating condition of the gasoline engine (120) changes, the temperature of the exhaust gas discharged to the exhaust passage (130) changes. When the exhaust gas discharged to the exhaust passage (130) passes through the particulate filter (150), heat transfer occurs between the particulate filter (150) and the exhaust gas. Therefore, the temperature change of the exhaust gas on the downstream side of the particulate filter (150) is delayed with respect to the temperature change of the exhaust gas on the upstream side of the particulate filter (150). This delay in temperature change is caused by the heat capacity of the particulate filter (150), the temperature of the particulate filter (150), and the temperature of the exhaust gas passing through the particulate filter (150).

Therefore, when the particulate filter (150) is normally attached to the exhaust passage (130), the output of the exhaust temperature sensor (166) provided on the downstream side of the particulate filter (150) is the gasoline engine ( It changes later than the change in the operating condition of 120). If the particulate filter (150) is not attached to the exhaust passage (130) or if there are defects such as holes, heat transfer between the particulate filter (150) and the exhaust gas will not occur or will decrease. .. Therefore, the output of the exhaust temperature sensor (166) follows the change in the operating condition of the gasoline engine (120) without delay as compared with the case where the particulate filter (150) is normally attached to the exhaust passage (130). And change.

Therefore, as described above, an abnormality of the particulate filter (150) is caused based on the output change of the exhaust temperature sensor (166) at the time of the operation change of the gasoline engine (120) in which the temperature change of the exhaust gas of the exhaust passage (130) occurs. It can be determined.

As shown above, it is possible to determine the abnormality of the particulate filter (150) without providing exhaust temperature sensors on the upstream side and the downstream side of the particulate filter, for example. As a result, the increase in the number of parts is suppressed. In addition, the increase in product cost is suppressed.

The reference numbers in parentheses above merely indicate the correspondence with the configurations described in the embodiments described later, and do not limit the technical scope at all.

It is a schematic diagram for demonstrating a combustion system. It is a timing chart for explaining the time change of the detection temperature. It is a flowchart for demonstrating the abnormality determination of a particulate filter. It is a flowchart for demonstrating an abnormality determination condition. It is a flowchart for demonstrating an abnormality determination condition. It is a flowchart for demonstrating an abnormality determination condition.

Hereinafter, embodiments will be described with reference to the drawings.

(First Embodiment)
An abnormality determination device 100 according to the present embodiment and a combustion system 200 including the abnormality determination device 100 will be described with reference to FIGS. 1 to 6.

<Combustion system>
As shown in FIG. 1, the combustion system 200 includes an abnormality determination device 100, an intake passage 110, an engine 120, an exhaust passage 130, a catalytic converter 140, and a PM filter 150. The engine 120 corresponds to a gasoline engine. PM filter is an abbreviation for particulate filter.

The engine 120 includes a cylinder 121, a piston 122, an intake valve 123, an injector 124, an exhaust valve 125, and a spark plug 126. A piston 122 is provided in the cylinder 121. The combustion chamber 120a is partitioned by the cylinder 121 and the piston 122. The piston 122 reciprocates and moves up and down in the cylinder 121.

The cylinder 121 is formed with an opening for communicating the combustion chamber 120a and the intake port of the cylinder head. An intake valve 123 is provided in this opening. Then, an intake pipe having an intake passage 110 configured inside is connected to an intake port via an intake manifold. By driving the intake valve 123, the communication between the combustion chamber 120a and the intake port is controlled. When the piston 122 descends in the cylinder 121 and the capacity of the combustion chamber 120a is increased, the intake valve 123 communicates the combustion chamber 120a with the intake port. As a result, the gas in the intake passage 110 flows into the combustion chamber 120a.

A throttle valve 111 is provided in the intake passage 110 located upstream of the intake port. By adjusting the opening degree of the throttle valve 111, the amount of gas in the intake passage 110 sucked into the engine 120 from the intake passage 110 is adjusted.

The injector 124 injects atomized gasoline fuel into the combustion chamber 120a. The injection of gasoline fuel from the injector 124 into the combustion chamber 120a is performed within the period from the start of the intake stroke to the end of the compression stroke. As a result, a mixed gas in which the gas in the intake passage 110 and the gasoline fuel are mixed is formed in the combustion chamber 120a.

The cylinder 121 is formed with an opening for communicating the combustion chamber 120a and the exhaust port of the engine head. An exhaust valve 125 is provided in this opening. An exhaust pipe having an exhaust passage 130 inside is connected to an exhaust port via an exhaust manifold. By driving the exhaust valve 125, the communication between the combustion chamber 120a and the exhaust port is controlled. When the piston 122 rises in the cylinder 121 and the capacity of the combustion chamber 120a is reduced, the exhaust valve 125 blocks the communication between the combustion chamber 120a and the exhaust port. At this time, the intake valve 123 also blocks the communication between the combustion chamber 120a and the intake port. As a result, the mixed gas in the combustion chamber 120a is compressed.

The spark plug 126 generates a spark discharge in the combustion chamber 120a. The spark discharge at the spark plug 126 is generated when the mixed gas in the combustion chamber 120a is compressed and the piston 122 is located near the top dead center of the cylinder 121. As a result, the mixed gas in the combustion chamber 120a is burned. The mixed gas in the combustion chamber 120a expands, which causes the piston 122 to descend. The kinetic energy of the piston 122 due to this combustion is converted into the rotational energy of the crankshaft. The rotational energy of this crankshaft is output to drive wheels and the like via a power transmission device.

When the piston 122 descends due to the combustion of the mixed gas and then begins to rise, the exhaust valve 125 communicates the combustion chamber 120a with the exhaust port. As a result, the exhaust gas generated by the combustion of the mixed gas is discharged from the combustion chamber 120a to the exhaust port. This exhaust gas is discharged to the exhaust passage 130 via the exhaust manifold.

A catalytic converter 140 and a PM filter 150 are provided in the exhaust passage 130. Assuming that the combustion chamber 120a side of the exhaust passage 130 is upstream and the opposite side is downstream, the catalytic converter 140 is provided on the upstream side of the PM filter 150.

Exhaust gas contains nitrogen oxides, carbon monoxide, and hydrocarbons. The catalytic converter 140 functions to convert these three types of air pollutants into nitrogen, carbon dioxide, and water. Exhaust gas also contains particulate matter. The PM filter 150 functions to remove this particulate matter.

The catalytic converter 140 cannot fully exert its function unless the temperature is high to some extent. Therefore, as will be described later, when the engine 120 is started, the catalytic converter 140 is warmed up by the combustion drive of the engine 120. When a catalyst is applied to the PM filter 150, this catalyst is also warmed up by the combustion drive of the engine 120.

In addition to the above-mentioned components, the combustion system 200 also has a sensor 160 that detects various physical quantities. Examples of the sensor 160 include a rotation angle sensor 161 shown in FIG. 1, a water temperature sensor 162, an air-fuel ratio sensor 163, a flow rate sensor 164, a pressure sensor 165, and an exhaust temperature sensor 166. The sensor 160 includes a throttle opening sensor (not shown), which is different from the sensors shown in the figure.

The rotation angle sensor 161 shown in FIG. 1 detects the rotation speed of the engine 120. The water temperature sensor 162 detects the temperature (cooling water temperature) of a refrigerant such as water that cools the engine 120. The air-fuel ratio sensor 163 detects the air-fuel ratio of the exhaust gas. The flow rate sensor 164 detects the amount of gas in the intake passage 110 sucked into the combustion chamber 120a. The pressure sensor 165 detects the pressure of the exhaust gas. The exhaust temperature sensor 166 detects the temperature of the exhaust gas. The exhaust temperature sensor 166 is also included in the abnormality determination device 100 as described later.

<Abnormality judgment device>
Next, the abnormality determination device 100 will be described. The abnormality determination device 100 includes the ECU 10 and the exhaust temperature sensor 166 described above. The ECU 10 has a microcomputer and a memory. A detection signal of the sensor 160 including the exhaust temperature sensor 166 is input to the ECU 10. Further, the ECU 10 is electrically connected to another vehicle-mounted ECU via wiring (not shown). As a result, a signal is also input to the ECU 10 from the vehicle-mounted ECU. The ECU 10 controls the drive of the engine 120 based on the detection signals of these sensors and the signals input from the vehicle-mounted ECU.

The ECU 10 also plays a role of detecting an abnormality in the PM filter 150. The exhaust temperature sensor 166 is provided on the downstream side of the PM filter 150 in the exhaust passage 130. Therefore, the exhaust temperature sensor 166 detects a temperature change of the exhaust gas on the downstream side of the PM filter 150. The ECU 10 corresponds to the determination unit. The ECU that controls the engine 120 and the ECU that detects an abnormality in the PM filter 150 may be separate.

When the operating condition of the engine 120 changes, the temperature of the exhaust gas discharged to the exhaust passage 130 changes. The exhaust gas flowing through the exhaust passage 130 flows from the upstream to the downstream while the temperature changes due to heat transfer to the walls forming the exhaust passage 130, the catalytic converter 140, the PM filter 150, and the like.

Therefore, when the PM filter 150 is normally attached to the exhaust passage 130, the output change of the exhaust temperature sensor 166 located on the downstream side of the PM filter 150 is changed to the temperature change of the exhaust gas on the upstream side of the PM filter 150. On the other hand, I will be late. On the other hand, when the PM filter 150 is not attached to the exhaust passage 130 or a hole or the like is missing, the heat transfer between the exhaust gas and the PM filter 150 is lost or the amount of heat transfer is reduced. Therefore, the output change of the exhaust temperature sensor 166 follows the temperature change of the exhaust gas on the upstream side of the PM filter 150 without delay as compared with the case where the PM filter 150 is normally attached to the exhaust passage 130.

Therefore, the abnormality of the PM filter 150 can be determined based on the output change of the exhaust temperature sensor 166 downstream of the PM filter 150 when the operation of the engine 120 changes when the temperature of the exhaust gas in the exhaust passage 130 changes.

The operation change of the engine 120 in which the temperature change of the exhaust gas of the exhaust passage 130 occurs greatly occurs, for example, at the following three times. That is, a large temperature change of the exhaust gas in the exhaust passage 130 occurs at the time of cold start, sudden transition, and fuel cut. The cold start is when the engine 120 is started and the cooling water temperature is not so high. The sudden transient is a time when the rotation speed of the engine 120 changes abruptly. The fuel cut is when the supply of gasoline fuel to the engine 120 is stopped.

At the time of cold start, the temperature of the PM filter 150 is about the ambient temperature. Therefore, when the engine 120 starts and starts to discharge the exhaust gas to the exhaust port, the temperature of each part of the exhaust port and the exhaust passage 130 downstream of the exhaust port rises by receiving heat from the exhaust gas. Immediately after a cold start, the temperature difference between the PM filter 150 and the exhaust gas is large. Therefore, when the exhaust gas flows into the PM filter 150, most of the heat of the exhaust gas is consumed to heat the PM filter 150 by heat transfer. This heat transfer from the exhaust gas to the PM filter 150 is continued until the temperature of the PM filter 150 rises to near the temperature of the exhaust gas. Due to this heat transfer, the temperature change of the exhaust gas after passing through the PM filter 150 becomes gentle with respect to the temperature change of the exhaust gas flowing into the PM filter 150. From the above, it is possible to determine the abnormality of the PM filter 150 based on the specific temperature rise of the temperature (detection temperature) detected by the exhaust temperature sensor 166. The delay in following the temperature of the exhaust gas downstream of the PM filter 150 due to heat transfer between the PM filter 150 and the exhaust gas is the temperature difference between the PM filter 150 and the exhaust gas flowing into the PM filter 150 immediately after the cold start, as well as the PM filter. It also depends on the heat capacity of 150 and the pressure loss coefficient.

Strictly speaking, the time change of the detected temperature also depends on the heat capacity and the pressure loss coefficient of the wall forming the exhaust passage 130 on the upstream side of the PM filter 150 and the catalytic converter 140.

During a sudden transition, the temperature of the exhaust gas discharged from the engine 120 to the exhaust port suddenly increases or decreases. Therefore, the temperature difference between the PM filter 150 and the exhaust gas flowing into the PM filter 150 becomes large, and heat transfer occurs between the exhaust gas and the PM filter 150. Therefore, when the PM filter 150 is normally attached to the exhaust passage 130 downstream of the exhaust port, the temperature change of the exhaust gas downstream of the PM filter 150 is slower than when the PM filter 150 is not normally attached. There is expected. From the above, it is possible to determine the abnormality of the PM filter 150 based on the specific change in the detected temperature.

At the time of fuel cut, the exhaust gas burned from the engine 120 to the exhaust port is not discharged. Therefore, the temperature of the gas flowing into the PM filter 150 is lower than the temperature of the PM filter 150 heated by the burned high-temperature exhaust gas. Therefore, when the PM filter 150 is normally attached to the exhaust passage 130 downstream of the exhaust port, the gas passing through the PM filter 150 is warmed by heat transfer with the PM filter 150. Therefore, the temperature drop of the gas after passing through the PM filter 150 is slower than the temperature drop of the gas flowing into the PM filter 150. From the above, it is possible to determine the abnormality of the PM filter 150 based on the specific temperature decrease of the detected temperature.

In addition, for example, even when the intake amount (load) of the gas in the intake passage 110 into the combustion chamber 120a, the ignition timing, the air-fuel ratio, and the like suddenly change, the temperature of the exhaust gas changes significantly. In addition, when an exhaust gas recirculation configuration is adopted in which a part of the exhaust gas discharged to the exhaust port is taken into the combustion chamber 120a again, even if the amount of the exhaust gas sucked into the combustion chamber 120a changes suddenly, even if the amount of the exhaust gas sucked into the combustion chamber 120a changes suddenly. The temperature of the exhaust gas changes significantly. Therefore, it is possible to determine the abnormality of the PM filter 150 based on the temperature change of the exhaust gas downstream of the PM filter 150 when these operating conditions change. In short, when the operating conditions change so that the difference between the temperature of the PM filter 150 and the temperature of the exhaust gas flowing into the PM filter 150 becomes large, PM is based on the temperature change of the exhaust gas downstream of the PM filter 150. The abnormality of the filter 150 can be determined.

<Temperature change in the exhaust passage>
Next, the time change of the detection temperature of the exhaust temperature sensor 166 according to the operation change of the engine 120 will be described with reference to FIG. In FIG. 2, the vehicle speed, engine speed, cooling water temperature, fuel cut flag, air-fuel ratio, exhaust gas temperature directly under the exhaust valve 125, normal detection temperature of PM filter 150, and detection temperature time when PM filter 150 is abnormal are shown. It shows a change.

In the following, for the sake of simplicity, the above fuel cut flag is referred to as an F / C flag. The air-fuel ratio is shown as A / F. The exhaust gas temperature directly below the exhaust valve 125 is referred to as the most upstream exhaust temperature. The detection temperature when the PM filter 150 is normal is referred to as the detection temperature when the filter is normal. The detection temperature when the PM filter 150 is abnormal is referred to as the detection temperature when the filter is abnormal. The same applies to the drawings.

The F / C flag is included in the volatile memory of the ECU 10. The most upstream exhaust temperature is the most upstream temperature of the exhaust port, and is a temperature that can be estimated based on the engine speed and the amount of gas in the intake passage 110 sucked into the combustion chamber 120a. The most upstream exhaust temperature is estimated by the ECU 10. The most upstream exhaust temperature corresponds to the temperature on the upstream side of the particulate filter.

The normal detection temperature of the filter with respect to the most upstream exhaust temperature exhibits a gradual change in temperature as compared with the most upstream exhaust temperature due to heat transfer between the PM filter 150 and the exhaust gas. On the other hand, the temperature change detected when the filter is abnormal is steeper than the detected temperature when the filter is normal because the heat transfer between the PM filter 150 and the exhaust gas is smaller than that when the filter is normal. The detected temperature when the filter is abnormal becomes close to the changing behavior of the most upstream exhaust temperature.

Further, the non-volatile memory of the ECU 10 stores a threshold value for determining a cold start or a sudden transient of the engine 120. That is, as a threshold value for determining the cold start time, the cold threshold value to be compared with the cooling water temperature is stored in the non-volatile memory. As a threshold value for determining the sudden transient time, the sudden transient threshold value to be compared with the time change of the engine speed is stored in the non-volatile memory. Then, the fuel cut threshold value for determining whether or not the fuel cut is continued for a time suitable for determining the abnormality of the PM filter 150 is stored in the non-volatile memory. The cold threshold corresponds to the temperature threshold. The sudden transient threshold corresponds to the rotation speed threshold. The fuel cut threshold corresponds to the time threshold.

Further, the non-volatile memory of the ECU 10 of the present embodiment stores an acceleration diagnostic temperature and a deceleration diagnostic temperature for determining whether or not a temperature change suitable for determining an abnormality of the PM filter 150 can be obtained. ing. The diagnostic temperature during acceleration corresponds to the first temperature. The diagnostic temperature during deceleration corresponds to the second temperature.

During acceleration, the temperature of the exhaust gas discharged from the exhaust port rises due to the temperature rise of the exhaust gas. Accordingly, the temperature of the exhaust gas in the exhaust passage 130 downstream of the exhaust port also rises. Therefore, in order to greatly observe the temperature change of the exhaust gas by the exhaust temperature sensor 166 provided in the exhaust passage 130, it is desired that the temperature of the exhaust gas of the exhaust port is lowered to some extent in advance. The diagnostic temperature during acceleration is a value for determining whether or not this temperature change can be significantly seen when the vehicle is accelerating. The ECU 10 determines that the PM filter 150 is suitable for determining an abnormality when the estimated maximum exhaust gas temperature is lower than the acceleration diagnosis temperature when the vehicle is accelerating.

On the contrary, during deceleration, the temperature of the exhaust gas discharged from the exhaust port drops due to the temperature drop of the exhaust gas. Accordingly, the temperature of the exhaust gas in the exhaust passage 130 downstream of the exhaust port also drops. Therefore, in order to greatly observe the temperature change of the exhaust gas by the exhaust temperature sensor 166 provided in the exhaust passage 130, it is desired that the temperature of the exhaust gas of the exhaust port is high to some extent in advance. The deceleration diagnostic temperature is a value for determining whether or not this temperature change can be significantly seen when the vehicle is decelerating. When the estimated upstream exhaust temperature is higher than the deceleration diagnostic temperature during deceleration of the vehicle, the ECU 10 determines that it is suitable for determining an abnormality of the PM filter 150.

The ECU 10 performs fuel cut during deceleration. Therefore, the ECU 10 compares the deceleration diagnostic temperature with the most upstream exhaust temperature at the time of fuel cut.

In this way, the fuel cut is performed during deceleration. Therefore, the ECU 10 of the present embodiment does not determine whether or not it is a sudden transient during deceleration. The ECU 10 determines whether or not there is a sudden transient during acceleration. Then, the ECU 10 compares the diagnostic temperature at the time of acceleration with the maximum flow exhaust temperature at the time of this sudden transient. Of course, during deceleration without fuel cut, the ECU 10 may determine whether or not it is in a sudden transient.

The ECU 10 compares the cooling water temperature with the cold threshold value at the time of cold start. Therefore, the ECU 10 does not compare the diagnostic temperature with the most upstream exhaust temperature at the time of cold start.

Hereinafter, changes in the operation of the engine 120 and changes in the detected temperature of the exhaust temperature sensor 166 will be specifically described with reference to FIG. At time t0 in FIG. 2, the vehicle is in a stopped state. Therefore, the vehicle speed is zero. The engine speed is zero. The cooling water temperature is about the ambient temperature. The F / C flag is off. A / F indicates lean. As shown by the broken line, the upstream exhaust temperature is not estimated. The detection temperature when the filter is normal and the detection temperature when the filter is abnormal are the ambient temperature, respectively. However, the ECU 10 is in the activated state. The ECU 10 acquires the detection signal of each sensor. The ECU 10 transmits information to the vehicle-mounted ECU.

At time t1, the engine speed increases due to cranking. The engine 120 starts to be driven by combustion. As a result, the cooling water temperature begins to rise. Exhaust gas begins to be discharged to the exhaust port and the exhaust passage 130 downstream thereof. A / F becomes stoichiometric. The catalytic converter 140 begins to warm up. Then, the ECU 10 starts to estimate the most upstream exhaust temperature.

At time t1, the cooling water temperature is lower than the cold threshold. Therefore, the ECU 10 determines that it is at the time of cold start. The temperature detected when the filter is normal rises more slowly than the temperature detected when the filter is abnormal because of heat transfer between the PM filter 150 and the exhaust gas. The filter abnormality detection temperature rises more slowly than the most upstream exhaust temperature due to heat transfer between the walls forming the exhaust passage 130, the catalytic converter 140, the PM filter 150, and the exhaust gas. In the abnormal case where the PM filter 150 is not attached to the exhaust passage 130, heat transfer between the exhaust gas and the PM filter 150 is not performed. Therefore, the temperature change at the time of filter abnormality at this time is closer to the change behavior of the most upstream exhaust temperature than at the time of abnormality in which holes or the like are formed in the PM filter 150.

From time t1 to time t2, the cooling water temperature exceeds the cold threshold. As a result, the ECU 10 determines that the cold start has been completed.

After the time t2, the temperature of the exhaust gas in the exhaust passage 130 continues to rise due to the discharge of the exhaust gas. Therefore, the maximum flow exhaust temperature, the detection temperature when the filter is normal, and the detection temperature when the filter is abnormal also continue to rise. The temperature changes are, in descending order, the most upstream exhaust temperature, the filter abnormality detection temperature, and the filter normal detection temperature.

When the time t3 is reached, the vehicle speed increases and the vehicle is in a running state. Along with this, the engine speed increases. Correspondingly, the temperature changes of the most upstream exhaust temperature, the detected temperature when the filter is normal, and the detected temperature when the filter is abnormal become abrupt. However, the time change of the engine speed at this time is lower than the sudden transient threshold. Therefore, the ECU 10 determines that the engine 120 is not in a sudden transient. This increase in vehicle speed continues until time t4.

After time t4, the vehicle speed becomes constant. For this reason, the temperature changes of the most upstream exhaust temperature, the detected temperature when the filter is abnormal, and the detected temperature when the filter is normal are almost constant.

When the time t5 is reached, the vehicle speed decreases. At this time, the engine speed decreases. The upstream exhaust temperature begins to decrease accordingly. When the filter is abnormal, the detected temperature starts to drop slightly later than the most upstream exhaust temperature. The normal temperature of the filter starts to drop later than the detected temperature when the filter is abnormal.

When the time t6 is reached, the F / C flag is turned on. The supply of gasoline fuel to the engine 120 is stopped and the engine 120 is not supplied. This eliminates the emission of burned exhaust gas. A / F changes from stoichiometric to lean. The temperature change of the most upstream exhaust temperature, the detected temperature when the filter is normal, and the temperature lowered when the filter is abnormal becomes sudden.

After the time t6, the fuel cut is performed, but the continuous time of the fuel cut at this time is shorter than the fuel cut threshold value. Therefore, the ECU 10 determines that the engine 120 is not at the time of fuel cut suitable for determining the abnormality of the PM filter 150.

Further, at the time t6 when the F / C flag is turned on, the maximum flow exhaust temperature is lower than the diagnostic temperature at the time of deceleration. Therefore, also in this respect, the ECU 10 determines that it is not suitable for determining the abnormality of the PM filter 150. The decrease in vehicle speed continues until time t7. The F / C flag is turned off during this time t7. As a result, the supply of gasoline fuel to the engine 120 is restarted.

After time t7, the vehicle speed becomes constant. However, the combustion drive of the engine 120 continues. Therefore, the temperature of the exhaust gas in the exhaust passage 130 rises, albeit in a small amount.

When the time t8 is reached, the warm-up of the catalytic converter 140 is completed. This reduces the engine speed.

From time t8 to time t9, the vehicle speed rises sharply. Along with this, the engine speed also increases sharply. In response to this, the maximum flow exhaust temperature, the detection temperature when the filter is normal, and the detection temperature when the filter is abnormal are also raised. The time change of the engine speed at this time is higher than the sudden transient threshold. Therefore, the ECU 10 determines that the engine 120 is in a sudden transient. The state in which the engine 120 is in a sudden transient state is continued until the time t10.

Further, at the time t9 when the acceleration of this vehicle starts, the maximum flow exhaust temperature is lower than the diagnostic temperature at the time of acceleration. Therefore, the ECU 10 determines that it is suitable for determining the abnormality of the PM filter 150 between the time t9 and the time t10.

As is shown in FIG. 2, the maximum flow exhaust temperature rises as the engine speed increases. When the filter is abnormal, the detection temperature rises slightly later than the most upstream exhaust temperature. The normal temperature of the filter rises behind the detected temperature when the filter is abnormal.

After time t10, the vehicle speed becomes constant. Therefore, the temperature change of the most upstream exhaust temperature becomes almost constant. The temperature change detected when the filter is abnormal is slightly delayed from the maximum exhaust temperature, and the temperature change becomes almost constant. The normal temperature of the filter lags behind the detected temperature when the filter is abnormal, and the temperature change becomes constant.

At time t11, the vehicle speed decreases and the F / C flag turns on. After the time t11, the fuel cut is continued, but the duration is longer than the fuel cut threshold. Further, at the time t11 when the F / C flag is turned on, the maximum flow exhaust temperature is higher than the deceleration diagnostic temperature. Therefore, the ECU 10 determines that the engine 120 is at the time of fuel cut suitable for determining the abnormality of the PM filter 150. At this time, since the duration of the fuel cut is long, the maximum flow exhaust temperature, the detection temperature when the filter is normal, and the detection temperature when the filter is abnormal are each lowered to near the ambient temperature. This fuel cut is continued until time t12.

<Abnormality judgment of PM filter>
Next, the abnormality determination of the PM filter 150 by the ECU 10 will be described with reference to FIGS. 3 to 6.

In step S100 shown in FIG. 3, the ECU 10 determines whether or not the condition for determining the abnormality of the PM filter 150 is satisfied. This abnormality determination condition is the flow shown in FIGS. 4 to 6 described later. When the abnormality determination condition is satisfied, the ECU 10 proceeds to step S200. On the contrary, when the abnormality determination condition is not satisfied, the ECU 10 repeats step S100 to enter the standby state.

Proceeding to step S200, the ECU 10 acquires the temperature on the downstream side of the PM filter 150 detected by the exhaust temperature sensor 166. At this time, the ECU 10 detects the output (detection temperature) of the exhaust temperature sensor 166 at predetermined acquisition timings. Then, the ECU 10 proceeds to step S300.

Proceeding to step S300, the ECU 10 calculates a time change (temperature change) of the exhaust temperature on the downstream side of the PM filter 150 based on the plurality of detected temperatures acquired in step S200 and the acquisition timing. Then, the ECU 10 compares the calculated temperature change with the determination threshold value read out under the abnormality determination condition in step S100, which will be described in detail later. If the temperature change is faster than the determination threshold, the ECU 10 proceeds to step S400. When the temperature change is equal to or less than the determination threshold value, the ECU 10 proceeds to step S500.

Proceeding to step S400, the ECU 10 determines that the PM filter 150 is abnormal. In this case, the ECU 10 notifies the user on the vehicle of the abnormality of the PM filter 150 by lighting an indicator or the like mounted on the vehicle. On the other hand, when the process proceeds to step S500, the ECU 10 determines that the PM filter 150 is normal. Then, the ECU 10 ends the abnormality determination of the PM filter 150.

<Abnormality judgment condition>
Next, the abnormality determination conditions will be described with reference to FIGS. 4 to 6. FIG. 4 is a flow for determining whether or not a cold start is in progress. FIG. 5 is a flow for determining whether or not the exhaust gas of the exhaust port (exhaust passage 130) has a temperature suitable for determining an abnormality of the PM filter 150 at the time of a sudden transient. FIG. 6 is a flow for determining whether or not the exhaust gas of the exhaust port (exhaust passage 130) has a temperature suitable for determining an abnormality of the PM filter 150 at the time of fuel cut.

In step S100, the ECU 10 processes these three abnormality determination conditions in parallel. These three abnormality determination conditions are implemented at the time of cold start, acceleration, and deceleration of the vehicle. Therefore, a plurality of these three abnormality determination conditions are not satisfied at the same time.

The ECU 10 stores a determination threshold value for determining an abnormality of the PM filter 150 in the non-volatile memory. The non-volatile memory of the ECU 10 individually stores determination threshold values corresponding to each of the cold start, sudden transient, and fuel cut.

As will be described later, these three determination threshold values have different values. However, these three determination threshold values may be uniformly set to the same value. Alternatively, three determination threshold values may be determined by multiplying a certain reference value by a coefficient corresponding to each of the three abnormality determination conditions.

<Judgment at cold start>
In step S10 shown in FIG. 4, the ECU 10 determines whether or not the engine 120 has started and the combustion drive has started. If it is determined that the engine 120 has started, the ECU 10 proceeds to step S11. On the contrary, if it is determined that the engine 120 has not started, the ECU 10 repeats step S10 to enter the standby state.

Proceeding to step S11, the ECU 10 determines whether or not it is within a predetermined time after the engine 120 is started. The predetermined time can be appropriately set by the user. For example, a few seconds such as 2 seconds can be adopted as the predetermined time. If it is within a predetermined time after the engine 120 is started, the ECU 10 proceeds to step S12. When a predetermined time has elapsed since the engine 120 was started, the ECU 10 returns to step S10.

Proceeding to step S12, the ECU 10 determines whether or not the cooling water temperature is equal to or lower than the cold threshold value. This cold threshold can be appropriately set by the user. For example, the cold threshold value can be a temperature slightly higher than the atmospheric temperature such as 40 ° C. When the cooling water temperature is equal to or lower than the cold threshold value, the ECU 10 proceeds to step S13. When a predetermined time has elapsed since the engine 120 was started, the ECU 10 returns to step S10.

Proceeding to step S13, the ECU 10 determines that it is a cold start. Then, the ECU 10 reads the determination threshold value at the time of cold start from the non-volatile memory. After this, the ECU 10 proceeds to step S200.

This determination threshold value can be determined based on the temperature change of the PM filter 150 when the catalytic converter 140 is warmed up. Therefore, this determination threshold depends on the heat capacity of the PM filter 150.

For example, when the temperature change of the PM filter 150 during warm-up is about 11.3 ° C./sec, this determination threshold value can be determined by multiplying this by a coefficient such as 0.7. The determination threshold in this case is 7.9 ° C./sec. This determination threshold corresponds to the follow threshold.

In the following, the coefficient is also used to determine the determination threshold value. As a matter of course, the values of these coefficients can be appropriately set by experiments, simulations, and the like.

<Judgment at the time of sudden transient>
In step S30 shown in FIG. 5, the ECU 10 determines whether or not the engine 120 is in the combustion drive state. When the engine 120 is in the combustion drive state, the ECU 10 proceeds to step S31. On the contrary, when the engine 120 is not driven by combustion, the ECU 10 repeats step S30 to enter the standby state.

Proceeding to step S31, the ECU 10 determines whether or not the time change when the engine speed increases is equal to or greater than the sudden transient threshold value. This sudden transient threshold can be appropriately set by the user. For example, a sudden transient threshold value of several tens of rpm / sec such as 16 rpm / sec can be adopted. When the engine speed is equal to or higher than the sudden transient threshold value, the ECU 10 proceeds to step S32. If the engine speed is lower than the sudden transient threshold, the ECU 10 returns to step S30.

Proceeding to step S32, the ECU 10 estimates the maximum flow exhaust temperature when the engine speed becomes equal to or higher than the sudden transient threshold value based on the detection signals of the rotation angle sensor 161 and the flow rate sensor 164. Then, the ECU 10 proceeds to step S33.

Proceeding to step S33, the ECU 10 determines whether or not the maximum flow exhaust temperature is equal to or lower than the diagnostic temperature during acceleration. The diagnostic temperature during acceleration can be appropriately set by the user. For example, the diagnostic temperature during acceleration can be 400 ° C. or the like. When the upstream exhaust gas temperature is equal to or lower than the acceleration diagnostic temperature, the ECU 10 proceeds to step S34. If the most upstream exhaust temperature is higher than the accelerated diagnostic temperature, the ECU 10 returns to step S30.

Proceeding to step S34, the ECU 10 determines that it is in a sudden transient and that the exhaust gas of the exhaust port (exhaust passage 130) has a temperature suitable for determining an abnormality of the PM filter 150. Then, the ECU 10 reads the determination threshold value at the time of sudden transient from the non-volatile memory. After this, the ECU 10 proceeds to step S200.

This determination threshold is the time of the most upstream exhaust temperature when the time change of the engine speed is about the sudden transient threshold used in step S31 and the most upstream exhaust temperature is about the diagnostic temperature at acceleration used in step S33. It can be decided based on the change.

The time change of the most upstream exhaust temperature at this time is, for example, 2.8 ° C./sec. This determination threshold can be determined by multiplying this by a coefficient such as 0.7. The determination threshold in this case is 1.96 ° C./sec.

Needless to say, this determination threshold value may be determined based on the temperature change on the downstream side of the PM filter 150, which depends on the heat capacity of the PM filter 150, rather than the time change of the upstream exhaust temperature. Under the above conditions, when the PM filter 150 is normally provided in the exhaust passage 130, the temperature change on the downstream side thereof is 1.1 ° C./sec. This determination threshold can be determined by multiplying this by a coefficient such as 1.7. The determination threshold in this case is 1.87 ° C./sec.

More simply, this determination threshold can be appropriately set between 2.8 ° C./sec and 1.1 ° C./sec. For example, as the determination threshold value, 1.9 ° C./sec between these can be adopted.

<Judgment at F / C>
In step S50 shown in FIG. 6, the ECU 10 determines whether or not the F / C flag is on. When the F / C flag is on, the ECU 10 proceeds to step S51. On the contrary, when the F / C flag is off, the ECU 10 repeats step S50 to enter the standby state.

Proceeding to step S51, the ECU 10 estimates the most upstream exhaust temperature when the F / C flag is turned on, based on the detection signals of the rotation angle sensor 161 and the flow rate sensor 164. Then, the ECU 10 proceeds to step S52.

Proceeding to step S52, the ECU 10 determines whether or not the maximum flow exhaust temperature is equal to or higher than the deceleration diagnostic temperature. The diagnostic temperature during deceleration can be appropriately set by the user. For example, the diagnostic temperature during deceleration can be 660 ° C. or the like. If the most upstream exhaust temperature is equal to or higher than the deceleration diagnostic temperature, the ECU 10 proceeds to step S53. If the most upstream exhaust temperature is lower than the deceleration diagnostic temperature, the ECU 10 returns to step S50.

Proceeding to step S53, the ECU 10 determines whether or not the on-time of the F / C flag is equal to or greater than the fuel cut threshold value. This fuel cut threshold can be appropriately set by the user. For example, the fuel cut threshold value can be several tens of seconds, such as 19 seconds. When the on time of the F / C flag is equal to or longer than the fuel cut threshold value, the ECU 10 proceeds to step S54. If the on time of the F / C flag is less than the fuel cut threshold value, the ECU 10 returns to step S50.

Proceeding to step S54, the ECU 10 determines that the fuel is cut and the exhaust gas of the exhaust port (exhaust passage 130) has a temperature suitable for determining an abnormality of the PM filter 150. Then, the ECU 10 reads the determination threshold value at the time of fuel cut from the non-volatile memory. After this, the ECU 10 proceeds to step S200.

This determination threshold value is the maximum flow exhaust temperature when the on-time of the F / C flag is about the fuel cut threshold value used in step S51 and the maximum flow exhaust temperature is about the deceleration diagnosis temperature used in step S52. It can be determined based on changes over time.

The time change of the most upstream exhaust temperature at this time is, for example, −6.0 ° C./sec. This determination threshold can be determined by multiplying this by a coefficient such as 0.7. The determination threshold in this case is -4.2 ° C./sec.

The above-mentioned determination threshold value may be determined based on the temperature change on the downstream side of the PM filter 150, which depends on the heat capacity of the PM filter 150, instead of the time change of the most upstream exhaust temperature. Under the above conditions, when the PM filter 150 is normally provided in the exhaust passage 130, the temperature change on the downstream side thereof is −3.0 ° C./sec. This determination threshold can be determined by multiplying this by a coefficient such as 1.6. The determination threshold in this case is -4.8 ° C./sec.

More simply, this determination threshold can be appropriately set as long as it is between −6.0 ° C./sec and −3.0 ° C./sec. For example, as the determination threshold value, −4.5 ° C./sec between these can be adopted.

<Effect>
Next, the operation and effect of the abnormality determination device 100 according to the present embodiment will be described. As described above, the operation change of the engine 120 in which the temperature change of the exhaust gas in the exhaust passage 130 occurs can be detected based on the outputs of various sensors mounted on the vehicle. As described in detail above, the output change of the exhaust temperature sensor 166 when the operation of the engine 120 changes is different when the PM filter 150 is normally attached to the exhaust passage 130 and when the PM filter 150 is not attached or has holes. It is different from the case where an abnormality has occurred. Therefore, it is possible to determine the abnormality of the PM filter 150 based on the output of various sensors mounted on the vehicle and the output change of the exhaust temperature sensor 166 provided downstream of the PM filter 150.

In this way, for example, it is possible to determine the abnormality of the PM filter 150 without providing the exhaust temperature sensors on the upstream side and the downstream side of the PM filter. As a result, the increase in the number of parts is suppressed. In addition, the increase in product cost is suppressed.

The ECU 10 detects an output change of the exhaust temperature sensor 166 at the time of a cold start, a sudden transient, and a fuel cut in which a large temperature change of the exhaust passage 130 occurs. As a result, it is possible to prevent the output change of the exhaust temperature sensor 166 from becoming small. Therefore, it is suppressed that the abnormality determination accuracy of the PM filter 150 is lowered.

The ECU 10 detects an output change of the exhaust temperature sensor 166 when the maximum flow exhaust temperature is equal to or lower than the diagnosis temperature at the time of acceleration in a sudden transient when the vehicle speed increases. Further, the ECU 10 detects an output change of the exhaust temperature sensor 166 when the duration of the fuel cut is equal to or longer than the fuel threshold value and the maximum flow exhaust temperature is equal to or higher than the deceleration diagnostic temperature at the time of fuel cut when the vehicle speed decreases.

As a result, it is more effectively suppressed that the output change of the exhaust temperature sensor 166 becomes small. Therefore, it is more effectively suppressed that the abnormality determination accuracy of the PM filter 150 is lowered.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure can be variously modified and implemented without being limited to the above-described embodiments and within a range that does not deviate from the gist of the present disclosure. Is.

(First modification)
In this embodiment, an example of determining an abnormality of the PM filter 150 at the time of fuel cutting is shown. However, as shown after the time t12 in FIG. 2, after the fuel cut is completed, the temperature of the exhaust gas in the exhaust passage 130 changes significantly due to the exhaust gas discharged due to the start of fuel supply. Therefore, the abnormality of the PM filter 150 may be determined at the end of the fuel cut when the non-supply of gasoline fuel is switched to the supply.

(Second modification)
In the present embodiment, an example of determining whether or not to determine the abnormality of the PM filter 150 at the time of sudden transition is shown based on the time change of the engine speed and the maximum flow exhaust temperature. Further, in addition to the condition, after the warm-up of the catalytic converter 140 is completed, the abnormality of the PM filter 150 may be determined at the time of sudden transition based on the time change of the engine speed and the maximum exhaust gas temperature.

Further, an example of determining whether or not to determine an abnormality of the PM filter 150 at the time of fuel cut is shown based on the maximum flow exhaust temperature and the on-time of the F / C flag. In the same manner, in addition to further conditions, after the catalytic converter 140 has been warmed up, the abnormality of the PM filter 150 may be determined at the time of fuel cut based on the maximum flow exhaust temperature and the on-time of the F / C flag. ..

The catalytic converter 140 also has a heat capacity. Therefore, when the warm-up of the catalytic converter 140 is not completed, the catalytic converter 140 positively receives the heat of the exhaust gas. As a result, the temperature change on the downstream side of the catalytic converter 140 may become gradual. That is, there is a possibility that the output change of the exhaust temperature sensor 166 becomes gradual.

Therefore, after the warm-up of the catalytic converter 140 is completed as described above, the abnormality of the PM filter 150 at the time of sudden transient and the fuel cut is determined. As a result, the output of the exhaust temperature sensor 166 is likely to change. As a result, it is possible to suppress a decrease in the accuracy of determining the abnormality of the PM filter 150.

(Third variant)
As described above, an example of determining an abnormality of the PM filter 150 in consideration of the difference between the maximum flow exhaust temperature and the diagnostic temperature at the time of sudden transient and the time of fuel cut is shown. However, the abnormality of the PM filter 150 may be determined at the time of sudden transient and at the time of fuel cut without considering the difference between the maximum flow exhaust temperature and the diagnostic temperature.

(Fourth modification)
In this embodiment, an example is shown in which one determination threshold value for each abnormality determination condition is stored in the non-volatile memory. On the other hand, it is also possible to adopt a configuration in which a map for the determination threshold value according to the engine speed and the intake amount (load) of the gas in the intake passage 110 into the combustion chamber 120a is stored in the non-volatile memory.

(Fifth variant)
In the present embodiment, it is determined whether or not it is a sudden transient based on the time change of the engine speed. However, unlike this, it may be determined whether or not it is a sudden transient based on the time change of the intake amount (load) of the gas in the intake passage 110 into the combustion chamber 120a.

10 ... ECU, 100 ... Abnormality determination device, 110 ... Intake passage, 120 ... Engine, 130 ... Exhaust passage, 140 ... Catalytic converter, 150 ... PM filter, 160 ... Sensor, 166 ... Exhaust temperature sensor, 200 ... Combustion system

Claims (17)

An exhaust temperature sensor (166) provided on the downstream side of the particulate filter (150) provided in the exhaust passage (130) from which the exhaust gas of the gasoline engine (120) is discharged, and
A determination unit (10) for determining an abnormality of the particulate filter based on an output change of the exhaust temperature sensor when the operation of the gasoline engine changes when the temperature of the exhaust gas discharged to the exhaust passage changes. have a,
The determination unit is an abnormality determination device that determines an abnormality of the particulate filter based on an output change of the exhaust temperature sensor after the gasoline engine has changed from a stopped state to a driving state. When the temperature of the cooling water for cooling the gasoline engine is equal to or lower than the temperature threshold, the determination unit determines the patty based on the output change of the exhaust temperature sensor after the gasoline engine is changed from the stopped state to the driven state. The abnormality determination device according to claim 1 , wherein the abnormality of the curate filter is determined. A claim that the determination unit determines an abnormality of the particulate filter based on an output change of the exhaust temperature sensor after the rotation speed of the gasoline engine changes to a rotation speed threshold value or more for determining a sudden change. 1 or the abnormality determination device according to claim 2. An exhaust temperature sensor (166) provided on the downstream side of the particulate filter (150) provided in the exhaust passage (130) from which the exhaust gas of the gasoline engine (120) is discharged, and
A determination unit (10) for determining an abnormality of the particulate filter based on an output change of the exhaust temperature sensor when the operation of the gasoline engine changes when the temperature of the exhaust gas discharged to the exhaust passage changes. Have,
The determination unit determines an abnormality of the particulate filter based on an output change of the exhaust temperature sensor after the rotation speed of the gasoline engine changes to a rotation speed threshold value or more for determining a sudden change. apparatus. The determination unit is on the upstream side opposite to the downstream side of the particulate filter in the exhaust passage based on the rotation speed of the gasoline engine and the intake amount of gas in the intake passage (110) to the gasoline engine. When the temperature is estimated and the estimated temperature is equal to or lower than the first temperature, the particulate filter of the particulate filter is based on the output change of the exhaust temperature sensor after the rotation speed of the gasoline engine rises above the rotation speed threshold. The abnormality determination device according to claim 3 or 4, wherein the abnormality is determined. The fourth or fifth aspect of the present invention, wherein the determination unit determines an abnormality of the particulate filter based on an output change of the exhaust temperature sensor after the gasoline engine has changed from a stopped state to a driven state. Abnormality judgment device. When the temperature of the cooling water for cooling the gasoline engine is equal to or lower than the temperature threshold, the determination unit determines the patty based on the output change of the exhaust temperature sensor after the gasoline engine is changed from the stopped state to the driven state. The abnormality determination device according to claim 6, wherein the abnormality of the curate filter is determined. The determination unit determines the output change of the exhaust temperature sensor after changing from the supply state of gasoline fuel to the gasoline engine to the non-supply state, and the determination unit after changing from the non-supply state of gasoline fuel to the supply state. The abnormality determination device according to any one of claims 1 to 7, wherein the abnormality of the particulate filter is determined based on at least one of the output changes of the exhaust temperature sensor. An exhaust temperature sensor (166) provided on the downstream side of the particulate filter (150) provided in the exhaust passage (130) from which the exhaust gas of the gasoline engine (120) is discharged, and
A determination unit (10) for determining an abnormality of the particulate filter based on an output change of the exhaust temperature sensor when the operation of the gasoline engine changes when the temperature of the exhaust gas discharged to the exhaust passage changes. Have,
The determination unit determines the output change of the exhaust temperature sensor after changing from the supply state of gasoline fuel to the gasoline engine to the non-supply state, and the determination unit after changing from the non-supply state of gasoline fuel to the supply state. An abnormality determination device for determining an abnormality of the particulate filter based on at least one of the output changes of the exhaust temperature sensor. When the non-supply state of the gasoline fuel to the gasoline engine continues for a time threshold, the determination unit of the exhaust temperature sensor after changing from the supply state of the gasoline fuel to the gasoline engine to the non-supply state. The abnormality determination device according to claim 8 or 9 , wherein an abnormality of the particulate filter is determined based on an output change. The determination unit is on the upstream side opposite to the downstream side of the particulate filter in the exhaust passage based on the rotation speed of the gasoline engine and the intake amount of gas in the intake passage (110) to the gasoline engine. The temperature is estimated, and when the estimated temperature is the second temperature or higher, the patty is based on the output change of the exhaust temperature sensor after changing from the supply state of the gasoline fuel to the gasoline engine to the non-supply state. The abnormality determination device according to any one of claims 8 to 10, wherein the abnormality of the curate filter is determined. According to any one of claims 9 to 11, the determination unit determines an abnormality of the particulate filter based on an output change of the exhaust temperature sensor after the gasoline engine has changed from a stopped state to a driven state. The described abnormality determination device. When the temperature of the cooling water for cooling the gasoline engine is equal to or lower than the temperature threshold, the determination unit determines the patty based on the output change of the exhaust temperature sensor after the gasoline engine is changed from the stopped state to the driven state. The abnormality determination device according to claim 12, wherein the abnormality of the curate filter is determined. A claim that the determination unit determines an abnormality of the particulate filter based on an output change of the exhaust temperature sensor after the rotation speed of the gasoline engine changes to a rotation speed threshold value or more for determining a sudden change. The abnormality determination device according to any one of 9 to 13. The determination unit is on the upstream side opposite to the downstream side of the particulate filter in the exhaust passage based on the rotation speed of the gasoline engine and the intake amount of gas in the intake passage (110) to the gasoline engine. When the temperature is estimated and the estimated temperature is equal to or lower than the first temperature, the particulate filter of the particulate filter is based on the output change of the exhaust temperature sensor after the rotation speed of the gasoline engine rises above the rotation speed threshold. The abnormality determination device according to claim 14, wherein the abnormality is determined. Any of claims 1 to 15, wherein the determination unit determines that an abnormality has occurred in the particulate filter when the output change of the exhaust temperature sensor is faster than the follow-up threshold value depending on the heat capacity of the particulate filter. The abnormality determination device according to item 1. When the output change of the exhaust temperature sensor is faster than the judgment threshold value depending on the temperature change on the upstream side opposite to the downstream side of the particulate filter in the exhaust passage, the determination unit uses the particulate filter. The abnormality determination device according to any one of claims 1 to 15, which determines that an abnormality has occurred.

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