JP2010169032A - Engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the deterioration of drivability by determining whether or not it is possible to respond to an acceleration request when acceleration is requested during regeneration control over a collecting device for collecting a particulate matter. <P>SOLUTION: During the regeneration control over a DPF, it is checked whether or not acceleration is requested from a driver (S2). When the acceleration is requested, it is determined whether or not torque is outputted if an air volume with respect to the acceleration request (S3) is increased. When torque capable of being outputted is sufficient, the currently active regeneration control over the DPF is stopped (S4), and each correction amount of engine control corresponding to the acceleration request is calculated (S5). Then, each correction amount is applied to fuel injection control, intake air control, supercharging pressure control or the like, and the quick acceleration in response to the acceleration request is performed (S6). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine control device including a collection device that collects particulate matter contained in exhaust gas.

  In recent years, in vehicles such as automobiles, particulate matter (PM) contained in exhaust gas from engines, particularly diesel engines, is filtered and collected as part of an exhaust gas purification device that purifies exhaust gas from engines. It is equipped with a collection device. Such a collecting device is generally composed of a filter called DPF (Diesel Particulate Filter).

  However, since the filtration and collection performance of the DPF is lowered due to PM accumulation, it is necessary to forcibly perform regeneration control for removing the accumulated PM and regenerating it to the initial state. The regeneration control of the DPF is generally control for forcibly burning the PM accumulated in the DPF by raising the temperature of the exhaust gas. The exhaust gas temperature is deteriorated excessively, or conversely, the exhaust gas is exhausted. It is necessary to prevent a decrease in regeneration efficiency due to a decrease in temperature.

For this reason, in Patent Document 1, the target exhaust λ and the target intake air amount are set from the required torque according to the operating state when collecting the DPF PM, and the intake air amount is appropriately controlled, whereby the exhaust temperature rises. A technique for preventing the deterioration of the DPF has been proposed. Patent Document 2 proposes a technique for suppressing the temperature drop of the DPF by reducing the intake air amount of the engine when the regeneration control of the DPF is interrupted when the vehicle is decelerated or the like. Further, Patent Document 3 proposes a technique for interrupting the DPF regeneration control when the exhaust gas temperature becomes a predetermined value or less during a traffic jam.
JP 2007-177461 A JP 2006-152841 A JP 2006-316712 A

  As described above, the DPF regeneration control is a control for increasing the exhaust temperature by decreasing the intake air amount of the engine or lowering the supercharging pressure. Therefore, when the throttle valve is closed and the turbocharger is provided, control such as lowering the supercharging pressure is performed. However, when such control is actively performed, drivability deteriorates such as a decrease in acceleration response. Will be invited.

  The present invention has been made in view of the above circumstances, and when there is an acceleration request during regeneration control of a collection device that collects particulate matter, it is determined whether or not the acceleration request can be met and drivability is improved. An object of the present invention is to provide an engine control device capable of preventing deterioration.

  In order to achieve the above object, an engine control apparatus according to the present invention provides an engine control apparatus equipped with a collection device that collects particulate matter contained in exhaust gas, and the particulate matter deposited on the collection device. A regeneration control unit that executes regeneration control for removing substances according to operating conditions, and when there is an acceleration request during execution of the regeneration control, based on the requested torque at the time of the acceleration request, by the regeneration control unit A regeneration interruption determination unit that determines whether or not to interrupt the regeneration control, and if it is determined that the regeneration control is interrupted during execution of the regeneration control, calculates a correction amount for engine control corresponding to the acceleration request. And a control correction amount calculation unit.

  According to the present invention, when there is an acceleration request during the regeneration control of the collection device, whether or not the regeneration control is interrupted by determining whether or not the acceleration request can be met based on the requested torque at that time. Therefore, it is possible to prevent the drivability from deteriorating.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 relate to an embodiment of the present invention, FIG. 1 is an overall configuration diagram of an engine system, FIG. 2 is a block diagram of a DPF regeneration / engine control correction system, and FIG. 3 is an acceleration determination flag for DPF regeneration. 4 is an explanatory diagram of an acceleration determination torque deviation determination flag for DPF regeneration, FIG. 5 is an explanatory diagram showing a relationship between a guard injection amount and an air mass correction injection amount, and FIG. 6 is an acceleration determination air mass correction injection amount deviation for regeneration. FIG. 7 is an explanatory diagram showing an open loop control region and a feedback control region in supercharging pressure control, FIG. 8 is an explanatory diagram of an engine control correction amount, and FIG. 9 is a flowchart of a DPF regeneration interruption determination process. is there.

  In FIG. 1, reference numeral 1 denotes an engine, and in the present embodiment, a diesel engine (hereinafter simply referred to as “engine”). An intake passage 5 and an exhaust passage 6 are communicated with the combustion chamber 2 of the engine 1 through an intake valve 3 and an exhaust valve 4. An intake chamber 40 is formed on the upstream side of the intake passage 5, and a throttle valve 10 is interposed upstream of the intake chamber 40. An intake pressure sensor 37 that detects the air pressure downstream of the throttle valve 10 as an absolute pressure is exposed to the intake chamber 40.

  The throttle valve 10 is connected to an intake actuator 11 that adjusts the opening of the throttle valve 10 by a control signal from an electronic control unit (ECU 50) and controls the intake amount (fresh air amount). Further, an intercooler 12 is interposed upstream of the throttle valve 10, and a compressor 13 a of the turbocharger 13 is interposed upstream of the intercooler 12. Further, an air cleaner 14 is interposed on the upstream side of the compressor 13 a of the turbocharger 13, and an intake air amount sensor 16 incorporating an intake air temperature sensor 15 for detecting the intake air temperature is interposed on the downstream side of the air cleaner 14. Has been.

  On the other hand, the turbine 13 b of the turbocharger 13 is interposed in the exhaust passage 6 of the engine 1, and the exhaust passage 6 on the upstream side of the turbine 13 b is connected to the downstream side of the throttle valve 10 via the exhaust gas recirculation (EGR) passage 17. The intake passage 5 is connected by bypass. The EGR passage 17 is provided with an EGR control valve 18 that controls the amount of EGR by a control signal from the ECU 50, and an EGR cooler 19 that cools the EGR gas.

  In the present embodiment, the turbocharger 13 is a well-known variable nozzle turbocharger (VGT), and a vane of a variable nozzle provided around the turbine 13b is a link mechanism (see FIG. (Not shown) is connected to the negative pressure actuated actuator 20. A negative pressure control electromagnetic valve 21 controlled by the ECU 50 is connected to the pressure introduction pipe of the actuator 20, and negative pressure from a negative pressure source (not shown) is regulated by the negative pressure control electromagnetic valve 21 to be supplied to the actuator 20. be introduced.

  Thereby, the vane opening degree of the variable nozzle of the turbocharger 13 is varied, the flow rate of the exhaust gas blown to the turbine 13b is adjusted, the turbine rotational speed is varied, and the supercharging pressure is controlled. That is, when the vane opening degree of the variable nozzle is changed in the closing direction by the operation of the actuator 20, the exhaust gas flow rate is increased and the supercharging pressure is increased. On the other hand, when the vane opening degree changes in the opening direction, the exhaust gas flow rate becomes slow and the supercharging pressure decreases.

  The exhaust passage 6 on the downstream side of the turbine 13b communicates with a DOC (Diesel Oxidation Catalyst) 22 that mainly oxidizes hydrocarbons (HC) in the exhaust gas by a catalytic reaction. On the downstream side of DOC22, particulate matter (PM) such as Soot (soot, carbon soot), SOF (Soluble Organic Fraction), SO4 (sulfate) in exhaust gas is contained in DOC12. After a DPF (Diesel Particulate Filter) 23, which is a collection device that collects on the downstream side, is disposed and the exhaust gas that has passed through the turbine 13b is purified to a predetermined level when passing through the DOC 22 and the DPF 23 The exhaust muffler (not shown) is discharged.

  A temperature sensor 7 that detects the temperature of the exhaust gas flowing into the DOC 22 is exposed upstream of the DOC 22, and a temperature sensor 8 that detects the temperature of the exhaust gas discharged from the DPF 23 is exposed downstream of the DPF 23. ing. Furthermore, upstream and downstream of the DPF 23 are communicated with a differential pressure sensor 9 that detects a differential pressure between the inlet pressure and the outlet pressure of the DPF 23.

  The DOC 22 is formed by supporting a noble metal such as platinum or palladium or a metal oxide such as alumina on the surface of a ceramic carrier made of, for example, a cordierite honeycomb structure. The DPF 23 is formed, for example, by forming heat-resistant ceramics such as cordierite into a honeycomb structure, and sealing a large number of cells serving as gas flow paths so that the inlet side or the outlet side are staggered. When exhaust gas flows into the exhaust gas, the exhaust gas flows downstream while passing through the porous partition wall of the DPF 23. During this time, PM in the exhaust gas is collected and gradually accumulated.

  Next, the fuel injection system of the engine 1 will be described. The engine 1 employs a well-known common rail fuel injection system, and an injector 25 controlled by the ECU 50 is exposed to the combustion chamber 2. A glow plug 26 whose energization is controlled by a glow controller 27 is exposed near the injection nozzle of the injector 25 in the combustion chamber 2.

  The injector 25 is connected to a common rail 29 via a fuel pipe 28 branched to each cylinder. A supply pump 30 that sucks up and pressurizes fuel from a fuel tank (not shown) is connected to the common rail 29. The fuel boosted to a high pressure by the supply pump 30 is accumulated in the common rail 29, and the high-pressure fuel is supplied to the injector 25 of each cylinder via the fuel pipe 28 to each cylinder.

  The supply pump 30 is provided with, for example, an inner cam type pressure feeding system and an intake amount adjustment method using an electromagnetic valve, and an intake adjustment electromagnetic valve 31 for adjusting the intake amount, and a fuel temperature sensor 32 for detecting a fuel temperature are provided in the main body. It is built in. A signal from the fuel temperature sensor 32 of the supply pump 30 is input to the ECU 50 together with a signal from the fuel pressure sensor 33 that detects the fuel pressure (rail pressure) in the common rail 29, and is processed together with signals from other sensors. . Then, the ECU 50 feedback-controls the discharge pressure of the supply pump 30, that is, the fuel pressure of the common rail 29, for example, to an optimum value according to the engine speed and the load via the intake metering solenoid valve 31.

  Next, an electronic control system centering on the ECU 50 will be described. The ECU 50 is configured to include a peripheral circuit such as an A / D converter, a timer, a counter, and various logic circuits, with a microcomputer including a CPU, a ROM, a RAM, an I / O interface and the like as a center. The ECU 50 includes an intake air temperature sensor 15, an intake air amount sensor 16, a fuel temperature sensor 32, a fuel pressure sensor 33, a water temperature sensor 34 that faces the cooling water passage of the engine 1 and detects the cooling water temperature, and a rotational position of the crankshaft 1 a. A crank angle sensor 35 that detects the amount of depression, an accelerator pedal sensor 36 that detects the amount of depression of the accelerator pedal, an intake pressure sensor 37 that faces the intake chamber 40, an atmospheric pressure sensor 38 that detects atmospheric pressure, and other various sensors (not shown) A signal from a switch or a switch is input.

  The ECU 50 is further connected to an in-vehicle network (not shown) based on a communication protocol such as CAN (Controller Area Network), for example, and a plurality of ECUs connected to the in-vehicle network and a transmission for controlling the transmission. It exchanges data with other ECUs such as an ECU and a brake ECU that controls a brake, and exchanges various information.

  The ECU 50 controls the fuel pressure control, the fuel injection control, the intake air control, the supercharging pressure control, the EGR based on signals from the above-described various sensors for detecting the engine operating state and various control information input via the in-vehicle network. Various engine controls such as control are executed, and the operating state of the engine 1 is maintained in an optimum state.

  In this engine control, during normal running, the fuel injection amount and the injection timing are determined by referring to a map or the like according to the engine speed based on the signal from the crank angle sensor 35 and the accelerator opening based on the signal from the accelerator pedal sensor 36. For example, high-pressure fuel is injected from the injector 25 in a multi-stage injection pattern around the top dead center of the piston combining pre-injection and main injection, thereby stabilizing combustion and reducing exhaust emissions.

  Further, the ECU 50 executes regeneration control for regenerating the DPF 23 at a predetermined timing in parallel with normal engine control. In regeneration control of the DPF 23, gas containing incomplete combustion components is intentionally discharged from the engine and burned (oxidized) in the DOC 22 to incinerate PM trapped in the DPF 23 by the generated heat and filter the filter. This is a regeneration process. By reducing the amount of intake air by intake control and lowering the supercharging pressure by supercharging pressure control, the temperature of the exhaust gas supplied to the DPF 23 is raised and collected and deposited in the DPF 23. Incinerated PM is removed by incineration.

  Further, the ECU 50 monitors whether or not there is an acceleration request from the driver during execution of the DPF regeneration control, and determines whether to continue or interrupt the DPF regeneration control when there is an acceleration request. Whether or not to interrupt the DPF regeneration control is determined based on the required torque at the time of acceleration request, and when it is determined that the DPF regeneration control is to be interrupted, the engine 1 is obtained so that rapid acceleration according to the driver's request can be obtained. The control amount such as the intake air amount and the supercharging pressure is corrected based on the required torque to prevent the drivability from deteriorating.

  Therefore, the ECU 50 includes a DPF regeneration control unit 51, a DPF regeneration interruption determination unit 52, and an engine control correction amount calculation unit 53 as functions related to the DPF regeneration / engine control correction system, as shown in FIG.

  The DPF regeneration control unit 51 performs regeneration control of the DPF 23 according to operating conditions. Specifically, the PM deposition rate of the DPF 23 is estimated, and when the estimated PM deposition rate exceeds a preset specified value, DPF regeneration control is started. The PM deposition rate is estimated based on the engine operating state, the differential pressure on the upstream and downstream sides of the DPF 23, the exhaust gas temperature, and the like.

  For example, a map of PM emission based on the engine speed and the fuel injection amount is prepared in advance by experiment or simulation, and the PM deposition rate is estimated based on this map, or the inlet of the DPF 23 is detected by the differential pressure sensor 9. The pressure difference between the pressure and the outlet pressure is detected, and the PM deposition rate is estimated based on this pressure difference.

  When estimating the PM deposition rate based on the exhaust temperature, the PM deposition rate is estimated by examining the degree of increase in the exhaust gas temperature based on the change in the heat capacity of the DPF 23 according to the PM deposition amount. That is, the DPF 23 has a relatively small heat capacity when the PM accumulation amount is small, and the temperature rises relatively earlier than the inflowing exhaust gas. On the other hand, when the PM accumulation amount increases, the heat capacity of the DPF 23 increases and the temperature due to the inflowing exhaust gas increases. The rise will be relatively gradual.

  Since the rise in temperature of the DPF 23 is reflected in the exhaust temperature on the outlet side of the DPF 23, the exhaust temperature on the outlet side of the DPF 23 is detected by the temperature sensor 8, and the PM deposition rate is determined by checking the exhaust temperature rise rate θv. Can be estimated.

For example, as shown in the following formula (1), in order to eliminate the influence of the heat capacity other than the accumulated PM, that is, the heat capacity of only the DPF 23, the exhaust temperature rise rate when the PM deposition rate is 0 (after the DPF regeneration operation ends) The PM deposition rate Y is obtained by multiplying the difference between θv0 and the maximum value θvmax of the exhaust gas temperature rising speed detected during the subsequent operation by the conversion coefficient k.
Y = k × (θv0−θvmax) (1)

  The conversion coefficient k is a coefficient for converting the difference in the exhaust gas temperature increase rate into the PM accumulation amount. The conversion coefficient k is obtained by referring to a map based on the engine speed and the accelerator opening, and the accelerator speed increases as the engine speed increases. The conversion coefficient k is set so as to increase as the opening degree increases.

  The above PM deposition rate estimation processing can be used alone or in combination. When the PM deposition rate exceeds a specified value, the DPF regeneration control unit 51 operates the temperature of the exhaust gas supplied to the DPF 23 in a normal operation. The regeneration process for regenerating the filter by incinerating the PM deposited on the DPF 23 is started, and when the PM deposition rate Y becomes almost zero, the DPF regeneration process is terminated.

  In this case, if the DPF regeneration control unit 51 is instructed to interrupt the DPF regeneration control by the DPF regeneration interruption determination unit 52 before the PM deposition rate becomes almost zero and the DPF regeneration process is terminated, the DPF regeneration control unit 51 performs the DPF regeneration control. Interrupt. Discontinuation of DPF regeneration control means that the temperature rise control of exhaust gas by the intake throttle is temporarily stopped in order to respond to the driver's acceleration request. Depending on the operating conditions, post injection or the like is performed, Prevents temperature drop.

  The DPF regeneration interruption determination unit 52 monitors the presence or absence of an acceleration request from the driver during execution of the DPF regeneration control, and determines whether to continue or interrupt the DPF regeneration control when there is an acceleration request. Specifically, when the acceleration judgment flag XACCREG for DPF regeneration is 1 (logical value: true), the DPF regeneration control unit 51 is instructed to suspend DPF regeneration control and the engine control correction amount calculation unit 53 is accelerated. The calculation of the correction amount of the engine control corresponding to the request is instructed, and the calculated correction amount is applied to the engine control so that quick acceleration can be obtained in response to the driver's acceleration request.

  Specifically, as shown in FIG. 3, the DPF regeneration acceleration determination flag XACCREG includes a first flag XDACCTRLRQREG for determining an acceleration request during DPF regeneration and an engine output torque margin that can respond to the acceleration request. It is generated by the logical product with the second flag XDACCQMAFREG to be determined.

  The first flag XDACCTRRQREG is a flag for determining whether the driver is requesting further acceleration, and a torque deviation DACCRQRQREG between the pre-control engine required torque TRQPVDC and the final engine required torque TRQENG is set as a determination threshold DACCTRRQREGTH. Generated by comparing. Hereinafter, the first flag XDACCTRRQREG will be referred to as “DPF regeneration acceleration determination torque deviation determination flag XDACCTRQREG”.

  The pre-control engine required torque TRQPVDC is a torque obtained by calculating a torque corresponding to the acceleration requested by the driver based on the accelerator opening ACC and the engine speed NE, and adding the driving torque of the auxiliary equipment to this torque. . The final required engine torque TRQENG is a torque calculated by limiting the maximum fuel injection amount (a guard injection amount QLMT described later) determined by the current engine speed and the intake air amount.

  Therefore, the driver requests further acceleration by comparing the torque deviation DACCTRQREG, which is the difference between the pre-control engine required torque TRQPVDC including the torque corresponding to the acceleration request, and the final engine required torque TRQENG with a determination threshold value. It can be determined whether or not.

  The torque deviation threshold DACCTRQREGTH, which is a determination threshold, is a DPF previously created by experiment or simulation using the engine speed NE based on the signal from the crank angle sensor 35 and the atmospheric pressure PATM based on the signal from the atmospheric pressure sensor 38. It is determined with reference to the regeneration acceleration determination torque deviation threshold value calculation map MDACCTRQREGTH. The reason why the engine speed and the atmospheric pressure are used in the calculation of the torque deviation threshold DACCTRQREGTH is to match the use area of the engine with the engine speed. The reason why the atmospheric pressure is used is to adjust the condition of high altitude (low atmospheric pressure) where the influence on drivability becomes significant.

  As shown in FIG. 4, the DPF regeneration acceleration judgment torque deviation judgment flag XDACCTRLRQREG generated by comparing the torque deviation DACCRQREG with the torque deviation threshold DACCRQREGTH has a logical value of true (1) or a logical value of false (0) as shown in FIG. ) Is set.

  That is, the DPF regeneration acceleration determination torque deviation determination flag XDACCTRLRQREG is maintained at XDACCTRLRQREG = 0 and the torque deviation threshold DACACTRQREGTH is equal to the hysteresis deviation when the torque deviation DACCTRQREG is smaller than the torque deviation threshold DACCTRQREGTH plus the hysteresis component KDACCTRQREGHS. When it becomes larger than the value obtained by adding KDACCTRQREGHS, XDACCTRLRQREG is set to 1. After XDACCTRLRQREG = 1 is set, when the torque deviation DACCTRQREG decreases and becomes smaller than the torque deviation threshold DACACTRQREGTH, XDACCTRLRQREG is cleared to zero.

  On the other hand, the second flag XDACCQMAFREG is a flag for determining whether there is a margin of torque from the viewpoint of whether torque can be generated if the current air amount is increased, and the fuel calculated from the current intake air amount Generated by comparing the air mass correction injection amount deviation DACCQMAFREG, which is the difference between the air mass correction injection amount QMAF, which is the injection amount, and the guard injection amount QLMT, according to the engine speed NE, with the air mass correction injection amount deviation threshold DACCQMAFREGTH, which is the determination threshold value. Is done. Hereinafter, the second flag XDACCQMAFREG is referred to as a “DPF regeneration acceleration determination air mass correction injection amount deviation determination flag XDACCQMAFREG”.

  The guard injection amount QLMT is the maximum fuel injection amount that is limited according to the supercharging pressure in order to prevent the occurrence of smoke and the like, and as shown in FIG. 5, the guard injection amount that regulates the maximum value of the fuel injection amount Q The difference between the QLMT and the fuel injection amount (air mass corrected injection amount) QMAF calculated from the current intake air amount indicates a margin of torque that can be output. Therefore, by comparing the air mass correction injection amount deviation DACCQMAFREG, which is the difference between the air mass correction injection amount QMAF and the guard injection amount QLMT, with the determination threshold value, it is possible to determine the torque margin in the current operating state.

  The air mass correction injection amount deviation threshold DACCQMAFREGTH is determined with reference to the DPF regeneration acceleration determination air mass correction injection amount deviation threshold calculation map MDACCQMAFREGTH created in advance through experiments or simulations using the engine speed NE and the atmospheric pressure PATM. The Here, the engine speed and the atmospheric pressure are used in order to adjust the conditions of the high altitude (low pressure) where the influence on the drivability becomes significant due to the atmospheric pressure in accordance with the engine usage area depending on the engine speed. is there.

  The acceleration determination air mass correction injection amount deviation determination flag XDACCQMAFREG for DPF regeneration is based on a comparison between the air mass correction injection amount deviation DACCQMAFREG and the air mass correction injection amount deviation threshold DACCQMAFREGTH, as shown in FIG. The value is set to false (0).

  That is, the DPF regeneration acceleration determination air mass correction injection amount deviation determination flag XDACCQMAFREG is set to XDACCQMAFREG = 1 when the air mass correction injection amount deviation DACCQMAFREG is smaller than the value obtained by adding the air mass correction injection amount deviation threshold DACCQMAFREGTH to the hysteresis amount KDACCQMAFREGHS. When the air mass correction injection amount deviation DACCQMAFREG becomes larger than the value obtained by adding the hysteresis amount KDACCQMAFREGHS to the air mass correction injection amount deviation threshold DACCQMAFREGTH, XDACCQMAFREG = 0 is cleared. After XDACCQMAFREG = 0 is cleared, when the air mass correction injection amount deviation DACCQMAFREG decreases and becomes smaller than the air mass correction injection amount deviation threshold DACCQMAFREGTH, XDACCQMAFREG = 1 is set.

  When the DPF regeneration acceleration determination torque deviation determination flag XDACCRQRQREG is XDACCRQRQREG = 1, and when the DPF regeneration acceleration determination air mass correction injection amount deviation determination flag XDACCQMAFREG is 1, XDACCQMAFREG = 1, the acceleration determination flag XACCREG for XPFREG is XACCREG = 1 When the condition of XACCREG = 1 is satisfied, the DPF regeneration interruption determination unit 52 instructs the DPF regeneration control unit 51 to interrupt the DPF regeneration control, and at the same time, the engine control correction amount calculation unit 53 corrects the engine control amount. Instructs value calculation.

  The engine control correction amount calculation unit 53 calculates the engine control correction amount according to an instruction from the DPF regeneration interruption determination unit 52. In the present embodiment, as shown in FIG. 7, the supercharging pressure control by the turbocharger 13 is performed with respect to the operating region based on the engine speed NE and the engine load (for example, the fuel injection amount Q). Switching between open loop control and supercharging pressure feedback (F / B) control is executed, and the following control parameters are corrected as the engine control amount corresponding to the acceleration request.

  The correction of the control parameter corresponding to the acceleration request is not limited to the following, and it is possible to correct by correcting at least one of the following control parameters.

  The supercharging pressure open loop control is a control executed in a low rotation and low load region, and maintains a variable nozzle opening degree of the turbocharger 13 through the negative pressure actuated actuator 20 to maintain a negative pressure. The control solenoid valve 21 is driven with a predetermined control duty. During this supercharging pressure open loop control, the intake air amount through the throttle valve 10 is feedback-controlled to a predetermined target intake air amount.

  On the other hand, the supercharging pressure feedback control is a control executed in a high rotation / high load region where the supercharging pressure response is good, and the intake pipe pressure (actual supercharging pressure) detected by the intake pressure sensor 37 is the engine rotation. The PI (proportional integral) control to the target intake pressure is performed so as to converge to the target boost pressure set based on the number and the engine load, and the negative pressure control electromagnetic valve 21 is driven with a corresponding control duty. At this time, the intake air amount through the throttle valve 10 is controlled in an open loop.

  Therefore, in the present embodiment, in order to correct the air amount and fuel injection amount of the engine in response to the driver's acceleration request, the intake opening during DPF regeneration, which is a correction amount when controlling the opening of the throttle valve 10, is adjusted. Acceleration correction amount THRACACCREG, DPF regeneration target correction amount MAFCACCREG for correcting the target intake air amount, and DPF regeneration time that is a correction amount for the control duty for driving the negative pressure control solenoid valve 21 of the turbocharger 13 A VGT drive duty acceleration correction amount VGTACREG and a DPF regeneration target intake pressure acceleration correction amount MAPACCREG for correcting the target intake pressure are calculated.

  As shown in FIG. 8, each correction amount is calculated with reference to each map created in advance through experiments or simulations using the engine speed NE and the torque deviation DACCTRQREG. That is, based on the engine speed NE and the torque deviation DACCTRQREG, the DPF regeneration intake opening acceleration correction amount calculation map MTHRACREG, the DPF regeneration target intake air acceleration correction amount calculation map MMAFACREG, the DPF regeneration VGT drive duty acceleration correction amount The calculation map MVGTACREG and the DPF regeneration target intake pressure acceleration correction amount calculation map MMAPACCREG are referred to, and the DPF regeneration intake opening acceleration correction amount THRACCREG, the DPF regeneration target intake air acceleration correction amount MAFACACCREG, and the DPF regeneration VGT drive duty, respectively. The acceleration correction amount VGTACCREG and the DPF regeneration target intake pressure acceleration correction amount MAPACCREG are calculated.

  Here, the engine speed NE and the torque deviation DACCRQREG are used to calculate each control correction amount based on the difference between the driver's required torque and the current torque based on the torque deviation according to the engine usage range according to the engine speed. This is for calculating a necessary correction amount.

  Each of the above correction amounts is applied to fuel injection control, intake air control, and supercharging pressure control, and the engine output torque is increased in response to the driver's acceleration request. Thereby, even during the DPF regeneration control in which drivability is likely to deteriorate, it is possible to realize quick acceleration according to the driver's request.

  Next, the DPF regeneration interruption determination process in the ECU 50 will be described with reference to the flowchart of FIG.

  First, in the first step S1, it is checked whether or not DPF regeneration control is currently being performed. If the DPF regeneration control is not in progress, this process is skipped. If the DPF regeneration control is in progress, the process proceeds to step S2 to refer to the DPF regeneration acceleration determination torque deviation determination flag XDACCTRLRQREG to determine whether or not there is an acceleration request from the driver. Investigate.

  In step S1, when XDACCTRQREG = 0, that is, when there is no acceleration request, this process is exited, and when XDACCTRQREG = 1, there is an acceleration request, the process proceeds to step S2. In step S2, the DPF regeneration acceleration determination air mass correction injection amount deviation determination flag XDACCQMAFREG is referred to and it is determined whether or not torque can be generated by increasing the air amount in response to the acceleration request.

  As a result, if XDACCQMAFREG = 0 and there is no allowance for torque that can be output in response to the acceleration request, the process exits from step S3. On the other hand, if XDACCQMAFREG = 1 and there is a margin in the torque that can be output, the process proceeds from step S3 to step S4, and the currently executed DPF regeneration control is interrupted.

  Further, in step S5 following step S4, each engine control correction amount corresponding to the acceleration request is calculated. Each correction amount is calculated based on the engine speed NE and a torque deviation DACCTRQREG that is a difference between the pre-control engine request torque TRQPVDC including the torque corresponding to the acceleration request and the final engine request torque TRQENG. Then, in step S6, each correction amount is applied to fuel injection control, intake air control, supercharging pressure control, and the like to realize quick acceleration corresponding to the acceleration request.

  As described above, in the present embodiment, when there is a driver acceleration request during the regeneration control of the DPF 23, it is determined whether to interrupt the DPF regeneration control based on the requested torque at the time of the acceleration request. As a result, rapid acceleration can be obtained even during DPF regeneration control in which drivability is likely to deteriorate, and the PM collection performance of DPF 23 is effectively maintained by DPF regeneration control without sacrificing drivability. be able to.

  In the above embodiment, the diesel engine is described as an example of the engine. However, the present invention can also be applied to other engines that include particulate matter in the exhaust gas, such as an in-cylinder fuel injection gasoline engine. It is.

Overall configuration of the engine system Block diagram of DPF regeneration / engine control correction system Explanatory drawing of acceleration judgment flag for DPF regeneration Explanatory drawing of acceleration judgment torque deviation judgment flag for DPF regeneration Explanatory drawing which shows the relationship between guard injection quantity and air mass correction injection quantity Explanatory drawing of the acceleration determination air mass correction injection amount deviation determination flag for regeneration Explanatory diagram showing an open loop control region and a feedback control region in supercharging pressure control Illustration of engine control correction amount Flowchart of DPF regeneration interruption determination process

1 engine 23 DPF (collector)
50 ECU (electronic control unit)
51 DPF regeneration control unit 52 DPF regeneration interruption determination unit 53 Engine control correction amount calculation unit DACCTRQREG Torque deviation

Claims (5)

In an engine control device equipped with a collection device for collecting particulate matter contained in exhaust gas,
A regeneration control unit for performing regeneration control for removing particulate matter accumulated in the collection device according to operating conditions;
When there is an acceleration request during execution of the regeneration control, a regeneration interruption determination unit that determines whether to interrupt the regeneration control by the regeneration control unit based on a request torque at the time of the acceleration request;
An engine control apparatus comprising: a control correction amount calculation unit that calculates a correction amount of engine control corresponding to the acceleration request when it is determined that the regeneration control is interrupted during the execution of the regeneration control.   The regeneration interruption determination unit performs the regeneration control by a first determination unit that determines an acceleration request during the regeneration control and a second determination unit that determines a margin of an output torque of the engine that can respond to the acceleration request. 2. The engine control apparatus according to claim 1, wherein it is determined whether or not to interrupt the engine.   The first determination means determines the acceleration request when a deviation between a requested torque at the time of the acceleration request and a torque calculated by limiting the maximum injection amount determined from the current operation state is equal to or greater than a predetermined threshold. The engine control apparatus according to claim 1, wherein it is determined that the engine is present.   The second determination means determines that there is a margin of the output torque when the deviation between the fuel injection amount calculated from the current intake air amount and the maximum injection amount is equal to or greater than a predetermined threshold. The engine control device according to claim 2 or 3, characterized in that:   The control correction amount calculation unit, when it is determined that the regeneration control is interrupted, calculates at least one correction amount of an intake air amount, an intake air pressure, a throttle opening, and a supercharging pressure. Item 5. The engine control device according to any one of Items 1 to 4.

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