JP7102873B2 - Exhaust purification device - Google Patents

Description

The present invention relates to an exhaust gas purification device.

Vehicles equipped with an engine may be provided with a PM filter that collects particulate matter (PM: particulate matter) in the exhaust gas emitted by the engine. In such a PM filter, regeneration control of the PM filter is periodically performed in order to prevent clogging (see, for example, Patent Document 1).

In Patent Document 1, PM in the PM filter is burned and removed by leaning the ignition retard angle and the air-fuel ratio at the time of early warm-up control of the catalyst, and the PM filter is regenerated.

JP-A-2015-183607

However, in Patent Document 1, the ignition retard angle and the lean air-fuel ratio may be deteriorated in order to control the early warm-up of the catalyst, which may lead to deterioration of the exhaust gas performance of the engine, and improvement has been desired.

The present invention has been made in view of the above points, and an object of the present invention is to provide an exhaust gas purification device capable of appropriately regenerating a collection filter that collects particulate matter without affecting the exhaust gas performance. And.

The exhaust purification device of one aspect of the present invention includes a catalyst for purifying engine exhaust, a collection filter for collecting particulate matter in the exhaust of the engine, deterioration diagnosis of the catalyst, and regeneration of the collection filter. A control device for performing control is provided, and when the control device determines that the collection filter is to be regenerated, rich combustion and lean combustion are performed to perform deterioration diagnosis of the catalyst, and the rich It is characterized in that the collection filter is regenerated by performing an ignition retard at the time of combustion.

According to the present invention, a collection filter that collects particulate matter can be appropriately regenerated without affecting fuel efficiency.

It is an overall block diagram of the engine control system which concerns on this embodiment. It is a flow chart of the catalyst deterioration diagnosis and GPF regeneration control which concerns on this embodiment. It is a time chart which shows the time-dependent change of the air-fuel ratio and the ignition timing in this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following, a four-wheeled vehicle will be described as an example of a vehicle to which the engine control system according to the present invention is applied, but the application target is not limited to this and can be changed. For example, the present invention may be applied to other types of vehicles such as motorcycles.

The engine control system according to the present embodiment will be described with reference to FIG. FIG. 1 is an overall configuration diagram of an engine control system according to the present embodiment. The engine control system is not limited to the configuration shown below, and can be changed as appropriate.

As shown in FIG. 1, the engine control system 1 according to the present embodiment is configured to control the operation of the engine 2 as an internal combustion engine and its peripheral configuration by an ECU (Electronic Control Unit) 3. .. Although details will be described later, the ECU 3 constitutes the control device of the present application. The engine 2 is composed of, for example, a direct-acting multi-cylinder DOHC (Double OverHead Camshaft) engine. The engine 2 is configured by accommodating a crankshaft 20 in a crankcase (not shown) and including a cylinder 21, a cylinder head 22, and the like.

The piston 23 is housed in the cylinder 21 so as to be reciprocating in a predetermined direction (up and down in FIG. 1). The crankshaft 20 and the piston 23 are connected by a connecting rod 24. In the engine 2, the crankshaft 20 is rotated via the connecting rod 24 by the reciprocating motion of the piston 23 in a predetermined direction.

The internal space of the cylinder head 22 constitutes the combustion chamber 25. A spark plug 26 as an ignition device is provided above the combustion chamber 25. The spark plug 26 ignites at a predetermined timing based on the ignition signal output from the ECU 3, and ignites the air-fuel mixture in the combustion chamber 25.

The cylinder head 22 is formed with an intake port 27a and an exhaust port 27b communicating with the combustion chamber 25. Further, the cylinder head 22 is provided with an intake valve 28a and an exhaust valve 28b corresponding to the intake port 27a and the exhaust port 27b. An intake camshaft 29a and an exhaust camshaft 29b are provided at the upper ends of the intake valve 28a and the exhaust valve 28b.

A cam chain (not shown) is bridged to the crankshaft 20, the intake camshaft 29a, and the exhaust camshaft 29b. The rotation of the crankshaft 20 is transmitted to the intake camshaft 29a and the exhaust camshaft 29b via the cam chain. By rotating the intake camshaft 29a and the exhaust camshaft 29b, the intake valve 28a and the exhaust valve 28b are reciprocated toward the combustion chamber 25 at a predetermined timing.

An intake pipe 10 is connected to the upstream end of the intake port 27a via an intake manifold (not shown). The passage in the intake pipe 10 and the intake port 27a form an intake passage for intake air. An air cleaner 11, a throttle valve 12, and a surge tank 13 are provided in the middle of the intake pipe 10 from the upstream side. An air amount sensor 40 is provided in the intake pipe 10 between the air cleaner 11 and the throttle valve 12. The air amount sensor 40 detects the amount of intake air (mass flow rate) that passes through the air cleaner 11 and flows through the intake pipe 10, and outputs the detected value to the ECU 3.

The throttle valve 12 includes, for example, a butterfly valve, and is opened and closed in response to a command from the ECU 3 to adjust the flow rate (intake air amount) of the intake air flowing in the intake pipe 10. The surge tank 13 has a sufficiently large volume as compared with the intake pipe 10 and prevents the pulsation of the intake air. The surge tank 13 is provided with an intake pressure sensor 41. The intake pressure sensor 41 detects the pressure (intake pressure) of the intake air in the surge tank 13 and outputs the detected value to the ECU 3. The ECU 3 can estimate the engine load from the above-mentioned intake air amount and intake pressure.

The intake pipe 10 (or intake port 27a) on the downstream side of the surge tank 13 is provided with an injector 14 as a fuel injection device for injecting fuel. The injector 14 injects a predetermined amount of fuel into the intake pipe 10 (or the intake port 27a) in response to a command from the ECU 3. That is, the engine 2 according to the present embodiment is composed of a so-called port injection type engine.

An exhaust pipe 15 is connected to the downstream end of the exhaust port 27b via an exhaust manifold (not shown). The passages in the exhaust port 27b and the exhaust pipe 15 form an exhaust gas exhaust path. A catalyst 16 for purifying the exhaust (exhaust gas) of the engine 2 is provided in the middle of the exhaust pipe 15 as a part of the exhaust purification device. The catalyst 16 is composed of, for example, a three-way catalyst, and converts pollutants (carbon monoxide, hydrocarbons, nitrogen oxides, etc.) in the exhaust gas into harmless substances (carbon monoxide, water, nitrogen, etc.). When the engine 2 is a diesel engine, for example, an oxidation catalyst is used as the catalyst 16.

A first exhaust gas sensor 16a and a second exhaust gas sensor 16b for detecting a predetermined component in the exhaust gas are arranged before and after the catalyst 16 (upstream side and downstream side). The first exhaust gas sensor 16a may be called an upstream side sensor, and the second exhaust gas sensor 16b may be called a downstream side sensor. The first exhaust gas sensor 16a and the second exhaust gas sensor 16b are composed of, for example, a zirconia type oxygen sensor, and the output (current value) changes according to the oxygen concentration in the exhaust gas. The first exhaust gas sensor 16a and the second exhaust gas sensor 16b output each detected value (current value) to the ECU 3. The first exhaust gas sensor 16a and the second exhaust gas sensor 16b are not limited to the oxygen sensor, and may be, for example, an air-fuel ratio sensor that detects the air-fuel ratio of the exhaust gas flowing in front of and behind the catalyst 16.

The exhaust pipe 15 on the downstream side of the catalyst 16 is provided with a GPF 17 (Particulate Filter) as a collection filter for collecting particulate matter (PM: Particulate Matter) such as soot in the exhaust generated by the combustion of the engine 2. ing. Temperature sensors 18a and 18b are provided before and after (upstream and downstream) of the GPF 17. The temperature sensors 18a and 18b detect the exhaust gas temperature before and after the GPF 17, and output the detected value to the ECU 3.

Further, the GPF 17 is provided with a differential pressure sensor 19. The differential pressure sensor 19 detects the pressure difference before and after the GPF 17, and outputs the detected value to the ECU 3. The ECU 3 can estimate the clogging state of the GPF 17, that is, the amount of PM collected from the pressure difference.

In the engine 2 configured in this way, the intake air that has passed through the air cleaner 11 flows into the intake port 27a through the surge tank 13 after the flow rate is adjusted by the throttle valve 12. At this time, fuel is injected from the injector 14 at a predetermined timing, and the intake air and the fuel are mixed in the intake port 27a. The air-fuel mixture of intake air and fuel flows into the combustion chamber 25 at the timing when the intake valve 28a is opened, is compressed in the combustion chamber 25, and is then ignited by the spark plug 26 at a predetermined timing. The exhaust gas after being ignited and burned is discharged to the outside from the exhaust port 27b through the exhaust pipe 15. At this time, the exhaust gas is purified by the catalyst 16, PM is collected by the GPF 17, and then the exhaust noise is reduced by a muffler (not shown).

Further, the engine 2 is provided with a water temperature sensor 42 for detecting the engine water temperature and a crank sensor 43 for detecting the phase of the crankshaft 20. Each detection value of the water temperature sensor 42 and the crank sensor 43 is output to the ECU 3. It is possible to calculate the engine speed from the output of the crank sensor 43.

Further, the vehicle is provided with a vehicle speed sensor 44 for detecting the vehicle speed, a brake pedal 45, and an accelerator pedal 46. The detected value of the vehicle speed sensor 44 is output to the ECU 3. The brake pedal 45 constitutes a braking means for generating a braking force on the vehicle, and outputs a predetermined electric signal corresponding to the stepping amount (stepping force) to the ECU 3. The accelerator pedal 46 constitutes an accelerating means for generating an accelerating force in the vehicle, and outputs a predetermined electric signal corresponding to the depression amount (treading force) to the ECU 3.

The ECU 3 controls the operation of the entire vehicle including various configurations inside and outside the engine 2. The ECU 3 is composed of a processor, a memory, and the like that execute various processes. The memory is composed of a storage medium such as a ROM (Read Only Memory) or a RAM (Random Access Memory) depending on the application. A control program or the like that controls the various configurations described above is stored in the memory.

For example, the ECU 3 determines the state of the vehicle from various sensors provided in the vehicle, and controls the drive of the spark plug 26, the injector 14, the throttle valve 12, and the like. Further, as will be described in detail later, the ECU 3 performs a deterioration diagnosis of the catalyst 16 based on the temperature of the catalyst 16 and the air-fuel ratio before and after the catalyst, and further controls the regeneration of the GPF 17 based on the temperature of the GPF 17 and the amount of PM deposited. do. The ECU 3 stores a predetermined threshold value in advance in order to carry out the above control.

The exhaust gas purification device according to the present embodiment includes the above-mentioned engine 2 and its peripheral configurations (catalyst 16, GPF 17, ECU 3, various sensors, etc.).

By the way, in the exhaust purification device of a vehicle engine, the PF that collects PM in the exhaust gas may be clogged due to the accumulation of PM. Therefore, so-called filter regeneration control is performed, in which the PF temperature is raised and the PM is burned to eliminate the clogging of the PF.

As this kind of control, for example, when the amount of PM accumulated in the PF becomes a predetermined amount or more, the ignition timing of the engine is delayed more than usual, and the fuel is burned on the downstream side of the exhaust gas. As a result, the temperature of the PF is raised and the engine is lean-burned so that the residual oxygen concentration in the exhaust pipe around the PF increases, so that the PM in the PF is burned and the PF is regenerated.

However, if the ignition timing is simply retarded for PF regeneration, fuel efficiency and exhaust gas performance may deteriorate.

Therefore, the present inventor has come up with the present invention by paying attention to controlling the engine so as to repeat rich combustion and lean combustion on the downstream side of the exhaust gas when performing the deterioration diagnosis of the catalyst. Specifically, in the present embodiment, when the ECU 3 determines that the GPF 17 is to be regenerated, the rich combustion and the lean combustion are performed to diagnose the deterioration of the catalyst 16, and the ignition retard angle at the time of the rich combustion is performed. By carrying out the above, the regeneration of GPF17 is carried out. That is, the gist of the present invention is to match the timing of performing the deterioration diagnosis of the catalyst 16 with the timing of performing the regeneration control of the GPF 17.

According to this configuration, it is possible to simultaneously carry out the deterioration diagnosis of the catalyst 16 and the regeneration control of the GPF 17 by performing the ignition retard at the time of rich combustion at the time of the deterioration diagnosis of the catalyst 16. Therefore, it is possible to suppress deterioration of fuel consumption and exhaust gas performance as compared with the case where the deterioration diagnosis of the catalyst 16 and the regeneration control of the GPF 17 are performed separately. Further, since the exhaust gas of the engine 2 can be raised in temperature by carrying out the ignition retardation, the GPF 17 can be appropriately regenerated even when the oxidation reaction of the catalyst 16 is small due to the deterioration of the catalyst 16. It is possible to do.

Further, when carrying out the ignition retard, it is preferable to increase the fuel injection amount and the intake air amount based on the required torque of the occupant and the retard amount of the ignition retard. In this case, even if the output drops due to the ignition retard, it is possible to correct the decrease. Therefore, it is possible to drive the vehicle with the torque required by the occupant while raising the temperature of the GPF 17 due to the ignition retard angle, and it is possible to prevent a deterioration in running performance due to the regeneration of the GPF 17.

Next, the control flow according to the present embodiment will be described with reference to FIG. FIG. 2 is a flow chart of catalyst deterioration diagnosis and GPF regeneration control according to the present embodiment. In the flow shown below, unless otherwise specified, the main body of the operation (calculation (calculation), judgment, etc.) is the ECU.

As shown in FIG. 2, when the control is started, in step ST101, the ECU 3 determines whether or not the warm-up of the catalyst 16 is completed. The warm-up refers to a state in which the catalyst has risen to an active temperature at which the exhaust gas can be purified. The ECU 3 can determine, for example, the completion of warming up the catalyst 16 from the temperature of the exhaust gas flowing in the vicinity of the catalyst 16, the temperature of the GPF 17 (detected values of the temperature sensors 18a and 18b), and the like. When the warm-up of the catalyst 16 is completed (step ST101: YES), the process proceeds to step ST102. If the warm-up of the catalyst 16 is not completed (step ST101: NO), the process of step ST101 is repeated.

In step ST102, the ECU 3 determines whether or not the amount of PM deposited in the GPF 17 is equal to or greater than the specified amount. The PM deposit amount can be predicted from, for example, the detected value of the differential pressure sensor 19. When the amount of PM deposited is equal to or greater than the specified amount (step ST102: YES), it is considered that the GPF17 needs to be regenerated, and the process proceeds to step ST103. When the amount of PM deposited is less than the specified amount (step ST102: NO), it is considered that the regeneration of GPF17 is unnecessary, and the control ends.

In step ST103, the ECU 3 starts the deterioration diagnosis of the catalyst 16 and the regeneration control of the GPF 17. Then, the process proceeds to step ST104.

In step ST104, the ECU 3 implements rich combustion control. The ECU 3 generates an air-fuel mixture having a high air-fuel ratio and richly burns the engine 2 by, for example, increasing the fuel injection amount or reducing the intake air amount. Then, the process proceeds to step ST105.

In step ST105, the ECU 3 determines whether or not the first exhaust gas sensor 16a has detected a rich state of exhaust gas. The ECU 3 determines, for example, that it is rich when the oxygen concentration in the exhaust gas is equal to or less than a predetermined concentration, and determines that it is lean when the oxygen concentration is higher than the predetermined concentration. When the first exhaust gas sensor 16a detects the rich state (step ST105: YES), the process proceeds to step ST106. When the first exhaust gas sensor 16a detects the lean state (step ST105: NO), the process returns to the process of step ST104.

In step ST106, the ECU 3 determines whether or not the temperature of the GPF 17 is equal to or lower than the predetermined temperature. This predetermined temperature is a temperature at which PM collected in the PF can be burned. When the temperature of GPF 17 is equal to or lower than the predetermined temperature (step ST106: YES), the process proceeds to step ST107. When the temperature of GPF 17 is higher than the predetermined temperature (step ST106: NO), the process proceeds to step ST109.

In step ST107, the ECU 3 performs ignition retard control. Specifically, the ECU 3 controls the spark plug 26 so as to retard the ignition timing by a predetermined retardation amount. Then, the process proceeds to step ST108.

In step ST108, the ECU 3 determines whether or not the temperature of the GPF 17 is equal to or higher than a predetermined temperature. When the temperature of GPF17 is equal to or higher than the predetermined temperature (step ST108: YES), the process proceeds to step ST109. When the temperature of GPF17 is lower than the predetermined temperature (step ST108: NO), the process returns to the process of step ST107.

In step ST109, the ECU 3 returns the ignition timing to normal. That is, the ECU 3 sets the amount of retardation of the ignition retardation to zero. Then, the process proceeds to step ST110.

In step ST110, the ECU 3 determines whether or not the second exhaust gas sensor 16b has detected a rich state of exhaust gas. The ECU 3 determines, for example, that it is rich when the oxygen concentration in the exhaust gas is equal to or higher than a predetermined concentration, and determines that it is lean when the oxygen concentration is less than the predetermined concentration. When the second exhaust gas sensor 16b detects the rich state (step ST110: YES), the process proceeds to step ST111. When the second exhaust gas sensor 16b detects the lean state (step ST110: NO), the process of step ST110 is repeated.

In step ST111, the ECU 3 implements lean combustion control. The ECU 3 produces a (small) air-fuel mixture having a low air-fuel ratio by, for example, reducing the fuel injection amount or increasing the intake air amount, and lean-burns the engine 2. Then, the process proceeds to step ST112.

In step ST112, the ECU 3 determines whether or not both the first exhaust gas sensor 16a and the second exhaust gas sensor 16b have detected the lean state of the exhaust gas. When both the first exhaust gas sensor 16a and the second exhaust gas sensor 16b detect the lean state of the exhaust gas (step ST112: YES), the time from the lean detection of the first exhaust gas sensor 16a to the lean detection of the second exhaust gas sensor 16b. If is shorter than the predetermined time, the ECU 3 determines that the catalyst 16 has deteriorated, and the control ends. Further, in this case, if the time from the lean detection of the first exhaust gas sensor 16a to the lean detection of the second exhaust gas sensor 16b is a predetermined time or more, the ECU 3 determines that the catalyst 16 has not deteriorated and controls it. Is finished. On the other hand, when both the first exhaust gas sensor 16a and the second exhaust gas sensor 16b do not detect the lean state of the exhaust gas (step ST112: NO), the process returns to the process of step ST111.

As described above, in the present embodiment, the ignition retard angle is implemented so as to raise the temperature of the GPF 17 during the rich combustion of the air-fuel ratio in the deterioration diagnosis control of the catalyst 16. Thereby, it is possible to burn and remove the PM accumulated in the GPF 17 during the lean combustion of the air-fuel ratio in the deterioration diagnosis control of the catalyst 16. That is, by simultaneously performing the deterioration diagnosis of the catalyst 16 and the regeneration control of the GPF 17, it is possible to suppress deterioration of fuel consumption and exhaust gas performance as compared with the case where each control is performed separately. Further, by performing the two controls at the same time, it is possible to shorten the time required for the control.

Further, in the present embodiment, as described above, the temperature of the GPF 17 is determined in steps ST106 and ST108, and the amount of retardation of the ignition retardation is controlled in steps ST107 and ST109 based on the result. That is, the ECU 3 sets the retard amount of the ignition retard according to the temperature of the GPF 17. At this time, it is preferable that the amount of retardation of the ignition retardation is set larger as the difference between the current temperature of GPF 17 and the target temperature which is the combustible temperature of PM is larger.

According to this configuration, for example, when the temperature of GPF17 is relatively low, that is, when the difference between the current temperature and the target temperature of GPF17 is larger than a predetermined value, the temperature of GPF17 can be increased at an early stage by increasing the retard angle amount. It is possible to increase. On the other hand, when the temperature of GPF17 is relatively high, that is, when the difference between the current temperature of GPF17 and the target temperature is less than or equal to a predetermined value, the amount of retard angle is made relatively small to cause the GPF17 to overrise due to ignition retardation. It is possible to appropriately regenerate the GPF 17 while preventing the temperature.

Next, with reference to FIG. 3, changes over time in the air-fuel ratio and ignition timing when the control according to the present embodiment is applied will be described. FIG. 3 is a time chart showing changes over time in the air-fuel ratio and ignition timing in the present embodiment. In FIG. 3, the horizontal axis indicates time, and the vertical axis indicates the air-fuel ratio and ignition timing in order from the top. The time chart shown in FIG. 3 is merely an example, and the time chart is not limited to this and can be changed as appropriate.

As shown in FIG. 3, at the start of this control, the air-fuel ratio is controlled to the target air-fuel ratio, and the ignition timing is controlled to the normal ignition timing. After the deterioration diagnosis of the catalyst 16 and the regeneration control of the GPF 17 are started, the ECU 3 executes the rich combustion control at the timing of T1 to increase the fuel injection amount, for example.

After that, when the first exhaust gas sensor 16a detects the richness of the air-fuel ratio at the timing of T2 during the rich combustion control, the ECU 3 performs ignition retard control and retards the ignition timing by a predetermined retard amount. After that, the exhaust gas temperature can be raised by the retardation timing of the ignition timing, and the GPF 17 can be raised. As a result, PM deposited on GPF17 can be burned and removed.

After that, when the second exhaust gas sensor 16b detects the richness of the air-fuel ratio at the timing of T3, the ECU 3 switches from the rich combustion control to the lean combustion control, for example, reducing the fuel injection amount. At the same time, the ECU 3 returns the ignition timing to the normal ignition timing.

After that, when the second exhaust gas sensor 16b detects the lean air-fuel ratio at the timing of T4, the ECU 3 controls to return the air-fuel ratio to the target air-fuel ratio. This makes it possible to diagnose the deterioration of the catalyst 16. After that, if the regeneration of GPF 17 is not completed, the rich fuel control is performed again. In addition, in FIG. 3, the case where the ignition timing is returned to the normal state (the ignition retardation is stopped) at the timing of switching to lean combustion has been described, but the present invention is not limited to this. For example, if it can be determined that the temperature of the GPF 17 rises to a predetermined temperature before T3 and the regeneration of GPF 17 is completed, the ignition retard may be stopped before T3. Thereby, the excessive temperature rise of GPF17 can be suppressed.

As described above, in the present embodiment, the ignition retard angle is performed at the time of rich combustion, and the deterioration diagnosis of the catalyst 16 and the regeneration control of the GPF 17 are simultaneously performed, so that the fuel consumption and the exhaust gas performance are achieved. It is possible to appropriately regenerate GPF17 without affecting the fuel consumption.

In the above embodiment, the port injection type engine 2 has been described as an example, but the present invention is not limited to this configuration. For example, the direct injection type engine 2 may be used.

Further, in the above-described embodiment, the gasoline engine has been described as an example, but the present invention is not limited to this. This control can be applied even to a diesel engine.

Further, in the above embodiment, the DOHC engine has been described as an example, but the present invention is not limited to this. The engine 2 may be a SOHC (Single OverHead Camshaft) engine.

Further, in the above embodiment, in the flow shown in FIG. 2, the case where the ignition timing is returned to the normal state (the ignition retardation is stopped) before the second exhaust gas sensor 16b detects richness has been described. Not limited. For example, the ignition retard may be stopped when the first exhaust gas sensor 16a detects rich and then the second exhaust gas sensor 16b detects rich. According to this configuration, it is possible to determine whether or not the ignition retard is implemented based on the first exhaust gas sensor 16a and the second exhaust gas sensor 16b detecting richness, and the output decreases (torque reduction) due to the ignition retard. It is possible to suppress the influence of.

Moreover, although the present embodiment and the modified example have been described, as another embodiment of the present invention, the above-described embodiment and the modified example may be combined in whole or in part.

Further, the embodiment of the present invention is not limited to the above-described embodiment, and may be variously modified, replaced, or modified without departing from the spirit of the technical idea of the present invention. Further, if the technical idea of the present invention can be realized in another way by the advancement of the technique or another technique derived from the technique, the method may be used. Therefore, the scope of claims covers all embodiments that may be included within the scope of the technical idea of the present invention.

As described above, the present invention has the effect that a collection filter that collects particulate matter can be appropriately regenerated without affecting fuel efficiency, and is particularly applicable to an exhaust gas purification device for vehicles. It is useful.

1: Control system 2: Engine 3: ECU
10: Intake pipe 11: Air cleaner 12: Throttle valve 13: Surge tank 14: Injector 15: Exhaust pipe 16: Catalyst 16a: First exhaust gas sensor 16b: Second exhaust gas sensor 18a: Temperature sensor 18b: Temperature sensor 19: Differential pressure sensor 20: Cylinder shaft 21: Cylinder 22: Cylinder head 23: Piston 24: Conrod 25: Combustion chamber 26: Spark plug 27a: Intake port 27b: Exhaust port 28a: Intake valve 28b: Exhaust valve 29a: Intake camshaft 29b: Exhaust cam Shaft 40: Air volume sensor 41: Intake pressure sensor 42: Water temperature sensor 43: Cylinder sensor 44: Vehicle speed sensor 45: Brake pedal 46: Accelerator pedal

Claims (4)

A catalyst that purifies engine exhaust,
A collection filter that collects particulate matter in the exhaust of the engine,
A control device for performing deterioration diagnosis of the catalyst and regeneration control of the collection filter is provided.
When the control device determines that the collection filter is to be regenerated, the rich combustion and the lean combustion are performed to perform the deterioration diagnosis of the catalyst, and the ignition retard angle is performed at the time of the rich combustion. An exhaust gas purification device characterized in that the collection filter is regenerated. A catalyst that purifies engine exhaust,
A collection filter that collects particulate matter in the exhaust of the engine,
The first exhaust gas sensor arranged on the upstream side of the catalyst and
A second exhaust gas sensor arranged on the downstream side of the catalyst,
A control device for performing deterioration diagnosis of the catalyst and regeneration control of the collection filter is provided.
When the control device determines that the collection filter is to be regenerated, the control device performs rich combustion and lean combustion based on the outputs of the first exhaust gas sensor and the second exhaust gas sensor to diagnose the deterioration of the catalyst. The ignition retard angle is executed at the time of the rich combustion, and the ignition retard angle is stopped when the first exhaust gas sensor detects the rich and then the second exhaust gas sensor detects the rich, and lean. An exhaust gas purification device characterized in that the collection filter is regenerated by shifting to combustion. The first or second aspect of claim 1 or 2 , wherein when carrying out the ignition retardation, the fuel injection amount and the intake air amount are increased based on the required torque of the occupant and the retardation amount of the ignition retardation. The described exhaust purification device. The exhaust purification according to any one of claims 1 to 3, wherein the retard amount of the ignition retard is set larger as the difference between the current temperature and the target temperature of the collection filter is larger. Device.

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