JP2017020468A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress clogging of a catalyst device.SOLUTION: A control device 200 for an internal combustion engine 100 includes an exhaust flow rate increase control section for increasing a flow rate of exhaust gas flowing into a catalyst device 431 by controlling at least one of an intake throttle valve 36, a variable nozzle 52c or an EGR valve 38 when required load for an engine body 1 becomes zero from a state where a flow rate or pressure of intake air sucked to the engine body 1 is equal to or higher than a predetermined value. The exhaust flow rate increase control section is configured to control the intake throttle valve 36 to the valve opening side when controlling the intake throttle valve 36, control the variable nozzle 52c to the valve opening side when controlling the variable nozzle 52c, and control the EGR valve 38 to the valve closing side when controlling the EGR valve 38.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for an internal combustion engine.

  In Patent Document 1, exhaust gas is blown from the lateral direction of the front end surface of an exhaust purification device (a filter carrying an oxidation catalyst) provided in an exhaust passage of an engine body, so that the particulates accumulated on the front end surface of the exhaust purification device. An internal combustion engine configured to blow off curates (particulate matter) is disclosed.

Japanese Patent Laid-Open No. 2006-9663

  However, if the flow rate of the exhaust gas blown to the front end surface of the exhaust purification device is small, it is difficult to blow off the particulates deposited on the front end surface of the exhaust purification device, and the exhaust purification device may be clogged.

  The present invention has been made paying attention to such problems, and it is easy to blow away particulates deposited on the front end surface of the exhaust purification device provided in the exhaust passage, thereby suppressing clogging of the exhaust purification device. With the goal.

  In order to solve the above-described problems, according to an aspect of the present invention, an engine body, a catalyst device that is provided in an exhaust passage of the engine body and purifies exhaust gas, and an exhaust passage that is downstream of the catalyst device are provided. And a particulate collection device that collects particulates in the exhaust, and as a catalyst inflow exhaust flow rate adjustment unit capable of adjusting the flow rate of exhaust gas flowing into the catalyst device, the intake passage of the engine body An intake throttle valve for adjusting the flow rate of intake air that is provided and is sucked into the engine body, a variable nozzle for adjusting the flow rate of exhaust gas that drives the turbine of the exhaust turbocharger, or an exhaust passage and an intake passage. A control device that controls an internal combustion engine that is provided in a connected EGR passage and includes at least one EGR valve for adjusting a flow rate of exhaust gas recirculated from the exhaust passage to the intake passage. When the required load on the engine body becomes zero when the flow rate or pressure of the intake air sucked into the engine body exceeds a predetermined value, the catalyst is controlled by controlling at least one of the intake throttle valve, the variable nozzle or the EGR valve An exhaust flow rate increase control unit for increasing the flow rate of the exhaust gas flowing into the apparatus is provided. When the intake flow rate increase control unit controls the intake throttle valve, the intake throttle valve is controlled to open, and the variable nozzle is controlled. At this time, the variable nozzle is controlled to the valve opening side, and when the EGR valve is controlled, the EGR valve is controlled to the valve closing side.

  According to this aspect of the present invention, since the flow rate of the exhaust gas flowing into the catalyst device (exhaust gas purification device) is increased when a predetermined condition is satisfied, the particulates accumulated on the front end surface of the catalyst device are easily blown away. And clogging of the catalyst device can be suppressed.

FIG. 1 is a schematic configuration diagram of an internal combustion engine and an electronic control unit that controls the internal combustion engine according to an embodiment of the present invention. FIG. 2 shows a catalyst required for blowing away the accumulated particulates from the front end face when the internal combustion engine is operated under a certain operating condition and the particulates are deposited on the front end face of the catalyst device. It is a figure which shows the time change of the inlet pressure of an apparatus. FIG. 3 is a flowchart for explaining exhaust flow rate increase control according to an embodiment of the present invention. FIG. 4 is a diagram showing the relationship between the intake air amount or the intake pressure and the differential pressure across the catalyst device when the exhaust gas flow rate increase control is performed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are assigned to similar components.

  FIG. 1 is a schematic configuration diagram of an internal combustion engine 100 and an electronic control unit 200 that controls the internal combustion engine 100 according to an embodiment of the present invention.

  The internal combustion engine 100 includes an engine body 1, a fuel injection device 2, an intake device 3, and an exhaust device 4.

  The engine body 1 compresses and ignites fuel in a combustion chamber formed in each cylinder 10 to generate power for driving a vehicle, for example.

  The fuel injection device 2 includes an electronically controlled fuel injection valve 20, a common rail 21, a supply pump 22, and a fuel tank 23. The fuel injection amount (injection time) and the injection pressure of fuel injected from the fuel injection valve 20 are as follows. And it is comprised so that injection timing can be changed.

  One fuel injection valve 20 is provided in each cylinder 10 so as to face the combustion chamber of each cylinder 10. The valve opening time (injection time) and the valve opening timing (injection timing) of the fuel injection valve 20 are changed by a control signal from the electronic control unit 200, and when the fuel injection valve 20 is opened, the fuel injection valve 20 opens to the combustion chamber. Fuel is injected into the tank. Each fuel injection valve 20 is connected to the common rail 21 via an injection pipe 24.

  The common rail 21 is connected to the fuel tank 23 via a pressure feed pipe 25. A supply pump 22 for pressurizing the fuel stored in the fuel tank 23 and supplying it to the common rail 21 is provided in the middle of the pressure feeding pipe 25. The common rail 21 temporarily stores the high-pressure fuel pumped from the supply pump 22. When the fuel injection valve 20 is opened, the high-pressure fuel stored in the common rail 21 is injected from the fuel injection valve 20 into the combustion chamber via the injection pipe 24. The common rail 21 has a rail pressure sensor 211 for detecting the fuel pressure in the common rail 21 (hereinafter referred to as “rail pressure”), that is, the pressure (injection pressure) of fuel injected from the fuel injection valve 20 into the combustion chamber. Provided.

  The supply pump 22 is configured to be able to change the discharge amount, and the discharge amount of the supply pump 22 is changed by a control signal from the electronic control unit 200. By controlling the discharge amount of the supply pump 22, the fuel pressure (rail pressure) in the common rail 21, that is, the injection pressure of the fuel injection valve 20 is controlled.

  The intake device 3 is a device for guiding intake air into a cylinder, and includes an intake passage 30, an intake manifold 31, and an EGR (Exhaust Gas Recirculation) passage 32.

  One end of the intake passage 30 is connected to the air cleaner 34, and the other end is connected to the intake collector 31 a of the intake manifold 31. In the intake passage 30, an air flow meter 212, a compressor 51 of the variable displacement type exhaust turbocharger 5, an intercooler 35, and an intake throttle valve 36 are provided in order from the upstream.

  The air flow meter 212 detects the flow rate of intake air (hereinafter referred to as “intake amount”) taken into the intake passage 30 via the air cleaner 34.

  The compressor 51 includes a compressor housing 51a and a compressor wheel 51b disposed in the compressor housing 51a. The compressor wheel 51b is rotationally driven by the turbine wheel 52b of the exhaust turbocharger 5 mounted on the same axis, and compresses and discharges the intake air flowing into the compressor housing 51a. The turbine 52 of the exhaust turbocharger 5 is provided with a variable nozzle 52c for controlling the rotational speed of the turbine wheel 52b. By controlling the rotational speed of the turbine wheel 52b by the variable nozzle 52c, the compressor housing 51a. The pressure (supercharging pressure) of the intake air discharged from the inside is controlled.

  The intercooler 35 is a heat exchanger that cools the intake air that has been compressed by the compressor 51 to a high temperature, for example, with traveling wind or cooling water.

  The intake throttle valve 36 adjusts the intake air amount introduced into the intake manifold 31 by changing the passage cross-sectional area of the intake passage 30. The intake throttle valve 36 is driven to open and close by a throttle actuator 36a, and its opening (intake throttle valve opening) is detected by a throttle sensor 213.

  The intake manifold 31 is connected to the engine body 1 and distributes the intake air flowing in from the intake passage 30 to each cylinder 10 evenly. An intake collector 31a of the intake manifold 31 detects an intake pressure sensor 214 for detecting the pressure of intake air (intake pressure) sucked into the cylinder and a temperature of intake air (intake air temperature) sucked into the cylinder. An intake air temperature sensor 215 is provided.

  The EGR passage 32 communicates the exhaust manifold 41 and the intake collector 31a of the intake manifold 31, and is a passage for returning a part of the exhaust discharged from each cylinder 10 to the intake collector 31a by a pressure difference. Hereinafter, the exhaust gas flowing into the EGR passage 32 is referred to as “EGR gas”. By recirculating the EGR gas to the intake collector 31a and thus to each cylinder 10, the combustion temperature can be reduced and the emission of nitrogen oxides (NOx) can be suppressed. The EGR passage 32 is provided with an EGR cooler 37 and an EGR valve 38 in order from the upstream.

  The EGR cooler 37 is a heat exchanger for cooling the EGR gas with, for example, traveling wind or cooling water.

  The EGR valve 38 is an electromagnetic valve whose opening degree can be adjusted continuously or stepwise, and the opening degree is controlled by the electronic control unit 200. By controlling the opening degree of the EGR valve 38 and adjusting the flow rate of the EGR gas that is recirculated to the intake collector 31a, the EGR rate (the ratio of EGR gas in the intake air) is controlled.

  The exhaust device 4 is a device for discharging exhaust gas from the inside of the cylinder, and includes an exhaust manifold 41 and an exhaust passage 42.

  The exhaust manifold 41 is connected to the engine body 1 and collectively introduces exhaust discharged from each cylinder 10 into the exhaust passage 42.

  In the exhaust passage 42, a turbine 52 of the exhaust turbocharger 5 and an exhaust purification device 43 are provided in order from the upstream.

  The turbine 52 includes a turbine housing 52a and a turbine wheel 52b disposed in the turbine housing 52a. The turbine wheel 52b is rotationally driven by the energy of the exhaust gas flowing into the turbine housing 52a, and drives the compressor wheel 51b attached on the same axis.

  The variable nozzle 52c described above is provided outside the turbine wheel 52b. The variable nozzle 52 c functions as a throttle valve, and the nozzle opening (valve opening) of the variable nozzle 52 c is controlled by the electronic control unit 200. By changing the nozzle opening degree of the variable nozzle 52c, the flow rate of the exhaust gas that drives the turbine wheel 52b can be changed in the turbine housing 52a. That is, by changing the nozzle opening degree of the variable nozzle 52c, the intake wheel pressure (supercharging pressure) can be changed by changing the rotational speed of the turbine wheel 52b. Specifically, when the nozzle opening of the variable nozzle 52c is reduced (the variable nozzle 52c is throttled), the exhaust flow rate increases, the rotational speed of the turbine wheel 52b increases, and the intake pressure increases.

  The exhaust purification device 43 is a device for purifying exhaust gas and discharging it to the outside air, and includes a catalyst device 431 and a particulate collection device 432.

  The catalyst device 431 has an exhaust purification catalyst supported on a carrier. The exhaust purification catalyst is, for example, an oxidation catalyst (two-way catalyst) or a three-way catalyst, and is not limited to these, and an appropriate catalyst can be used depending on the type and application of the internal combustion engine 100. In this embodiment, an oxidation catalyst is used as the exhaust purification catalyst. When an oxidation catalyst is used as the exhaust purification catalyst, hydrocarbon (HC) and carbon monoxide (CO), which are harmful substances in the exhaust, are oxidized and removed by the oxidation catalyst.

  The particulate collection device 432 is provided downstream of the catalyst device 431 in the exhaust flow direction. The particulate collection device 432 incorporates a wall flow type particulate filter, and collects particulates in the exhaust gas by passing the exhaust gas introduced therein through the particulate filter.

  The electronic control unit 200 is composed of a digital computer and is connected to each other by a bi-directional bus 201. A ROM (read only memory) 202, a RAM (random access memory) 203, a CPU (microprocessor) 204, an input port 205, and an output port 206.

  Output signals from the rail pressure sensor 211, the air flow meter 212, the throttle sensor 213, the intake pressure sensor 214, the intake air temperature sensor 215, and the like are input to the input port 205 via the corresponding AD converters 207. Further, the output voltage of the load sensor 217 that generates an output voltage proportional to the depression amount of the accelerator pedal 221 (hereinafter referred to as “accelerator depression amount”) L is input to the input port 205 via the corresponding AD converter 207. Entered. Further, an output signal of a crank angle sensor 218 that generates an output pulse every time the crankshaft of the engine body 1 rotates, for example, 15 ° is input to the input port 205 as a signal for calculating the engine rotational speed N and the like. . As described above, output signals of various sensors necessary for controlling the internal combustion engine 100 are input to the input port 205.

  The output port 206 is connected to the fuel injection valve 20, the supply pump 22, the throttle actuator 36a, the EGR valve 38, the variable nozzle 52c, and the like via a corresponding drive circuit 208.

  The internal combustion engine 100 is configured as described above, and the particulates in the exhaust gas are collected by the particulate collection device 432. However, in this embodiment, since the catalyst device 431 is arranged on the upstream side of the particulate collection device 432, the particulates adhere to and accumulate on the front end surface (end surface on the upstream side in the exhaust flow direction) of the catalyst device 431. There is. If particulates accumulate on the front end face of the catalyst device 431, the catalyst device 431 may be clogged. Further, the particulates deposited on the front end surface of the catalyst device 431 may adhere to the front end surface during operation of the internal combustion engine 100. If the particulates deposited on the front end face of the catalyst device 431 are fixed, it becomes difficult to remove the particulates deposited on the front end face of the catalyst device 431. Therefore, it is desirable that the particulates deposited on the front end face of the catalyst device 431 are appropriately removed before adhering.

  FIG. 2 shows that when the internal combustion engine 100 is operated under a certain operating condition and particulates are deposited on the front end face of the catalyst device 431, the accumulated particulates are blown away and removed from the front end face. It is a figure which shows the time change of the inlet pressure (in other words, the flow volume of the exhaust gas which flows in into the catalyst 431) of a simple catalyst apparatus 431. As shown in FIG. 2, it can be seen that the pressure (flow rate) required to blow away the particulates increases with the passage of time, and increases greatly after a certain time (120 minutes in this example).

  Therefore, in the present embodiment, when the predetermined condition is satisfied, the exhaust gas flow rate increase control is performed to increase the flow rate of the exhaust gas flowing into the catalyst device 431 from the normal time. Thereby, before the particulates deposited on the front end face of the catalyst device 431 are fixed, the particulates deposited on the front end face of the catalyst device 431 can be blown off by exhaust gas. Hereinafter, the exhaust gas flow rate increase control according to this embodiment will be described.

  FIG. 3 is a flowchart illustrating the exhaust flow rate increase control performed by the electronic control unit 200. The electronic control unit 200 repeatedly executes this routine at a predetermined calculation cycle while the internal combustion engine 100 is operating.

  In step S <b> 1, the electronic control unit 200 determines whether or not the exhaust gas flow rate increase control execution flag F is set to 0. The exhaust flow rate increase control in-progress flag F is a flag whose initial value is set to 0, and is set to 1 when the exhaust flow rate increase control is started. The electronic control unit 200 proceeds to step S2 if the exhaust flow rate increase control execution flag F is 0, and proceeds to step S5 if the exhaust flow rate increase control execution flag F is 1.

  In step S2, the electronic control unit 200 determines whether or not a predetermined condition is satisfied. Specifically, the electronic control unit 200 determines whether or not the accelerator depression amount has become zero from a state where the intake air amount is a predetermined amount or more or the intake pressure is a predetermined pressure or more. That is, it is determined whether or not the required load on the engine body 1 has become zero from the state in which the engine body 1 is operated at a certain load or higher. When the predetermined condition is established, the electronic control unit 200 proceeds to the process of step S3 and starts the exhaust gas flow rate increase control. On the other hand, if the predetermined condition is not satisfied, the electronic control unit 200 ends the current process without starting the exhaust flow rate increase control.

  In step S <b> 3, the electronic control unit 200 controls a component (catalyst inflow exhaust gas flow rate adjusting unit) that can adjust the flow rate of the exhaust gas flowing into the catalyst device 431 among the components included in the internal combustion engine 100. Exhaust flow rate increase control is started to increase the flow rate of the exhaust gas flowing into the catalyst device 431 from the normal time. In the case of the internal combustion engine 100 according to the present embodiment, examples of such components include the intake throttle valve 36, the variable nozzle 52c, and the EGR valve 38. Therefore, the electronic control unit 200 according to the present embodiment opens the intake throttle valve 36 and the variable nozzle 52c in order to increase the flow rate of the exhaust gas flowing into the catalyst device 431 from the normal time when a predetermined condition is satisfied. And the EGR valve 38 is controlled to the closed side to be fully closed.

  Note that when the accelerator depression amount becomes zero during normal operation (when exhaust gas flow rate increase control is not performed), the intake throttle valve 36, the variable nozzle 52c, and the EGR valve 38 are controlled as follows.

  When the accelerator depression amount becomes zero, the intake throttle valve 36 is normally closed rather than fully opened in order to suppress the temperature decrease of the exhaust purification catalyst of the catalyst device 431 and to secure the braking force by the engine brake. Controlled to the side. As a result, the flow rate of the exhaust gas flowing into the catalyst device 431 is reduced to suppress the temperature decrease of the exhaust purification catalyst, and the pumping loss is increased to ensure the braking force by the engine brake.

  When the accelerator depression amount becomes zero, the variable nozzle 52c is normally controlled to the valve closing side rather than the fully opened state in order to ensure acceleration when the accelerator pedal 221 is subsequently depressed. As a result, the flow rate of the exhaust gas that drives the turbine wheel 52b is reduced by the variable nozzle 52c, and the flow rate of the exhaust gas that drives the turbine wheel 52b increases. Therefore, it is possible to suppress a decrease in the supercharging pressure (intake pressure) of the exhaust turbocharger 5 while the accelerator depression amount is zero.

  When the accelerator depression amount becomes zero, the EGR valve 38 is normally controlled to the valve opening side rather than the fully closed state in order to suppress a temperature drop of the exhaust purification catalyst of the catalyst device 431. As a result, a part of the exhaust gas is recirculated to reduce the flow rate of the exhaust gas flowing into the catalyst device 431, thereby suppressing the temperature reduction of the exhaust purification catalyst.

  As described above, in the present embodiment, the exhaust flow rate increase control is started when the accelerator depression amount becomes zero from a state where the intake amount is equal to or greater than the predetermined amount or the intake pressure is equal to or greater than the predetermined pressure.

  As shown in FIG. 4, when the exhaust gas flow rate increase control is performed from a state where the intake air amount or the intake pressure is large, the differential pressure across the catalyst device 431 increases, and the particulates are blown off from the front end surface of the catalyst device 431. This is because it becomes easier.

  Further, when the accelerator depression amount becomes zero from a state where the intake air amount is greater than or equal to a predetermined amount or the intake air pressure is greater than or equal to a predetermined pressure, that is, from the state where the engine body 1 is operated with a certain load or more When the required load on the engine becomes zero, the fuel cut control for stopping the fuel injection from each fuel injection valve 20 is performed until the engine speed decreases to the idle speed. Therefore, during this fuel cut control, the opening degree of the intake throttle valve 36, the variable nozzle 52c and the EGR valve 38 is controlled to increase the flow rate of the exhaust gas flowing into the catalyst device 431, thereby deteriorating fuel consumption and exhaust emission. This is because the particulates accumulated on the front end face of the catalyst device 431 can be blown off by the exhaust gas.

  In step S <b> 4, the electronic control unit 200 sets the exhaust flow rate increase control execution flag F to 1.

  In step S5, the electronic control unit 200 determines whether or not the accelerator pedal 221 is depressed during the exhaust gas flow amount increase control. If the accelerator depression amount is zero, the electronic control unit 200 determines that the accelerator pedal 221 is not depressed and proceeds to the processing of step S10. If the accelerator depression amount is not zero, the electronic control unit 200 forcibly controls the exhaust gas flow amount increase control. To end the process, the process proceeds to step S8.

  In step S6, the electronic control unit 200 determines whether or not a predetermined time has elapsed since the start of the exhaust gas flow amount increase control. The electronic control unit 200 proceeds to the process of step S7 if the predetermined time has not elapsed since the start of the exhaust gas flow amount increase control, and proceeds to the process of step S8 if the predetermined time has elapsed.

  When the exhaust gas flow rate increase control is performed, the temperature of the exhaust purification catalyst of the catalyst device 431 is likely to decrease because the intake throttle valve 36 is not fully closed as in the normal state, but is fully opened. The braking force by the engine brake is also reduced. Therefore, by limiting the time during which the exhaust gas flow rate increase control is performed in step S6, the exhaust gas flow rate increase control is performed while the particulates accumulated on the front end surface of the catalyst device 431 are blown off by the exhaust gas by the exhaust gas flow rate increase control. A decrease in temperature of the exhaust purification catalyst and a decrease in braking force due to engine braking can be minimized.

  In step S <b> 7, the electronic control unit 200 continuously performs the exhaust gas flow amount increase control, maintains the intake throttle valve 36 and the variable nozzle 52 c fully open, and maintains the EGR valve 38 fully closed.

  In step S8, the electronic control unit 200 ends the exhaust gas flow rate increase control. If the accelerator depression amount is zero at this time, the above-described normal control is performed on the intake throttle valve 36, the variable nozzle 52c, and the EGR valve 38.

  In step S <b> 9, the electronic control unit 200 returns the exhaust flow rate increase control execution flag F to 0.

  In the above embodiment, when the exhaust gas flow rate increase control is performed, all of the intake throttle valve 36, the variable nozzle 52c and the EGR valve 38 are controlled to increase the flow rate of the exhaust gas flowing into the catalyst device 431. At least one of these may be controlled to increase the flow rate of the exhaust gas flowing into the catalyst device 431. In addition, the internal combustion engine 100 according to the present embodiment has an intake throttle valve 36, a variable nozzle 52c, and an EGR valve 38 as components (catalyst inflow exhaust flow rate adjusting unit) that can adjust the flow rate of exhaust gas flowing into the catalyst device 431. However, the exhaust gas flow rate increase control may be performed in an internal combustion engine including at least one of these three components.

  According to the present embodiment described above, the engine body 1, the catalyst device 431 that is provided in the exhaust passage 42 of the engine body 1 and purifies exhaust gas, and the exhaust passage 42 that is downstream of the catalyst device 431. And a particulate collection device 432 that collects particulates in the exhaust, and as a catalyst inflow exhaust flow rate adjustment unit capable of adjusting the flow rate of the exhaust gas flowing into the catalyst device 431, the intake air of the engine body 1 An intake throttle valve 36 provided in the passage 30 for adjusting the flow rate of intake air taken into the engine body 1, a variable nozzle 52c for adjusting the flow rate of exhaust gas for driving the turbine 52 of the exhaust turbocharger 5, or An EG for adjusting the flow rate of exhaust gas that is provided in the EGR passage 32 connecting the exhaust passage 42 and the intake passage 30 and recirculates from the exhaust passage 42 to the intake passage 30. The electronic control unit 200 (control device) that controls the internal combustion engine 100 including at least one of the valves 38 requires a required load on the engine body 1 from a state where the flow rate or pressure of intake air sucked into the engine body 1 is equal to or higher than a predetermined value. When the engine reaches zero, an exhaust flow rate increase control unit is provided that controls at least one of the intake throttle valve 36, the variable nozzle 52c, or the EGR valve 38 to increase the flow rate of the exhaust gas flowing into the catalyst device 431. The exhaust flow rate increase control unit controls the intake throttle valve 36 to the valve opening side when controlling the intake throttle valve 36, and controls the variable nozzle 52c to the valve opening side when controlling the variable nozzle 52c. When the valve 38 is controlled, the EGR valve 38 is controlled to the valve closing side.

  As described above, when the required load on the engine body 1 becomes zero from the state where the flow rate or pressure of the intake air sucked into the engine body 1 is equal to or higher than a predetermined value, the flow rate of the exhaust gas flowing into the catalyst device 431 is increased. Therefore, the particulates deposited on the front end face of the catalyst device 431 can be easily blown off, and clogging of the catalyst device 431 can be suppressed.

  In particular, by increasing the flow rate of the exhaust gas flowing into the catalyst device 431 from a state where the flow rate or pressure of the intake air sucked into the engine body 1 is equal to or higher than a predetermined value, the exhaust gas flow rate increase control is performed. Since the front-rear differential pressure can be increased, the particulates can be blown off from the front end face of the catalyst device 431 more easily.

  Further, when the required load on the engine body 1 becomes zero when the flow rate or pressure of the intake air sucked into the engine body 1 is equal to or higher than a predetermined value, each fuel injection valve is operated until the engine rotation speed decreases to the idle rotation speed. Fuel cut control for stopping fuel injection from 20 is performed. Therefore, during this fuel cut control, the opening degree of the intake throttle valve 36, the variable nozzle 52c and the EGR valve 38 is controlled to increase the flow rate of the exhaust gas flowing into the catalyst device 431, thereby deteriorating fuel consumption and exhaust emission. The particulates deposited on the front end face of the catalyst device 431 can be blown off by the exhaust gas without exhausting.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  For example, in the above-described embodiment, the internal combustion engine 100 is configured to perform compression self-ignition combustion in the engine body 1, but the internal combustion engine 100 may be configured to perform spark ignition combustion.

DESCRIPTION OF SYMBOLS 1 Engine body 30 Intake passage 32 EGR passage 36 Intake throttle valve 38 EGR valve 42 Exhaust passage 52 Turbine 52c Variable nozzle 100 Internal combustion engine 200 Electronic control unit (control device)
431 Catalytic device 432 Particulate collector

Claims (1)

The engine body,
A catalyst device for purifying exhaust gas provided in an exhaust passage of the engine body;
A particulate collection device that is provided in the exhaust passage downstream of the catalyst device and collects particulates in the exhaust; and
With
Intake air for adjusting the flow rate of intake air that is provided in the intake passage of the engine body and is sucked into the engine body as a catalyst inflow exhaust flow rate adjustment unit capable of adjusting the flow rate of exhaust gas flowing into the catalyst device Reflux from the exhaust passage to the intake passage is provided in a throttle valve, a variable nozzle for adjusting the exhaust flow rate for driving the turbine of the exhaust turbocharger, or an EGR passage connecting the exhaust passage and the intake passage. A control device for an internal combustion engine that controls an internal combustion engine including at least one EGR valve for adjusting a flow rate of exhaust gas.
When the required load on the engine body becomes zero when the flow rate or pressure of the intake air sucked into the engine body exceeds a predetermined value, at least one of the intake throttle valve, the variable nozzle, or the EGR valve is An exhaust flow rate increase control unit for controlling and increasing the flow rate of the exhaust gas flowing into the catalyst device;
The exhaust flow rate increase control unit controls the intake throttle valve to the valve opening side when controlling the intake throttle valve, controls the variable nozzle to the valve opening side when controlling the variable nozzle, and the EGR When controlling the valve, the EGR valve is controlled to the valve closing side.
Control device for internal combustion engine.

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