JP2009167836A - Fuel-injection controlling device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel-injection controlling device of an internal combustion engine capable of controlling fuel pressure accumulated in a pressure-accumulating means to pressure at which exhaust emission capability can be fully exerted without being influenced by variations in properties of an injector, a sensor, etc. <P>SOLUTION: An ECU 30 for controlling fuel supply to the engine 10 having a common rail 12 and an exhaust emission means 40 includes functions as a pressure setting means for setting pressure-accumulated fuel pressure by the common rail 12 according to an operating condition of the engine 10, a first estimating means for estimating a discharge amount of a PM component according to the operating condition, a second estimating means for estimating a discharge amount of the PM component based on detection information by a pressure-difference sensor 45 for detecting a pressure difference between timings before and after the exhaust emission means 40 is varied in an exhaust passage caused by the exhaust of the PM component, and a correction means for comparing the discharge amount PM1 estimated by the first estimating means with the discharge amount PM2 estimated by the second estimating means and correcting the set pressure by the pressure setting means according to a ratio of PM2/PM1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel injection control device for an internal combustion engine, and more particularly to a fuel for an internal combustion engine that accumulates high-pressure accumulator fuel by means of an accumulator and controls the accumulated fuel pressure according to operating conditions of the internal combustion engine. The present invention relates to an injection control device.

  2. Description of the Related Art Conventionally, a common rail type fuel injection control device that enables electronically controlled fuel injection into a cylinder by an injector by accumulating and storing high pressure fuel in an accumulator called a common rail in an internal combustion engine mounted on a vehicle is known. It has been.

  As a fuel injection control device for this type of internal combustion engine, for example, in addition to controlling the fuel pressure accumulated in the common rail according to the operating conditions of the internal combustion engine, nitrogen oxide (hereinafter also referred to as NOx) contained in the exhaust gas. Or a fuel pressure accumulated in the common rail according to the discharge amount of particulate matter (hereinafter also referred to as PM) which is particulate matter contained in the exhaust (for example, patents) Reference 1).

In addition, the amount of PM deposited on the DPF (diesel particulate filter) device, which is an exhaust purification means for collecting and removing PM in the exhaust gas, is estimated from the operating conditions of the internal combustion engine, and the differential pressure across the DPF device is calculated. There is known one that can accurately execute a regeneration process that calculates and burns and removes PM collected and accumulated in a DPF device at a high temperature (see, for example, Patent Document 2).
JP 2004-124935 A JP 2004-132358 A

  However, in the conventional fuel injection control device for an internal combustion engine as described above, there is a variation in injector characteristics or a variation in sensitivity of a common rail pressure sensor that detects the fuel pressure in the common rail. Even if it is set to the optimum value according to the engine speed and load, in consideration of the fact that the common rail pressure changes as shown by symbol A in FIG. 7 due to variations in the characteristics of the injector and common rail pressure sensor. The corrected common rail pressure is not optimal, and the exhaust purification catalyst device and DPF device capable of removing almost all harmful components in the exhaust gas, such as PM and NOx, in the exhaust path are sufficient. There was a problem that it could not be demonstrated.

  For example, the common rail pressure is set to a set pressure that is suitable for the engine speed and the required load, and that has low NOx and is effective for collecting and removing PM. The common rail pressure is set based on the common rail pressure sensor information. Even if it is controlled, if the sensor characteristics vary so that the detected pressure of the common rail pressure sensor becomes larger than the actual value, the common rail pressure becomes a lower common rail pressure as shown by the dotted line PA1 in FIG. Thus, although the PM emission amount decreases, the NOx emission amount that is in a trade-off relationship with the PM emission amount increases. On the other hand, if the sensor characteristics vary so that the detected pressure of the common rail pressure sensor becomes smaller than the actual value, the common rail pressure becomes higher as shown by the dotted line PA2 in the figure, and the PM discharge amount As a result, the PM collection / removal performance by the DPF device may be insufficient.

  Further, in recent diesel engines, a fuel injection schedule for each finer period is set in the fuel injection period from the injector to the cylinder, and the fuel injection amount changes greatly in each period. The value of the correct injection rate (injection amount per unit time) is also likely to vary from injector to injector. For this reason, even if the common rail pressure sensor has good characteristics, the exhaust purification performance varies due to such variations in injector characteristics.

  The present invention has been made in order to solve the above-described conventional problems. The catalyst device is configured to control the pressure of fuel accumulated in the pressure accumulating means without being affected by variations in characteristics of an injector, a fuel pressure sensor, and the like. Another object of the present invention is to provide a fuel injection control device capable of improving the exhaust gas purification performance of an internal combustion engine by controlling the pressure so that the capability of the DPF device can be sufficiently exerted.

  In order to achieve the above object, a fuel injection control device for an internal combustion engine according to the present invention is provided in (1) an injector for injecting fuel, a pressure accumulating means for storing and accumulating fuel supplied to the injector, and an exhaust path. In the fuel injection control device for an internal combustion engine for controlling the supply of the fuel to the internal combustion engine comprising an exhaust purification means, the pressure of the fuel accumulated by the pressure accumulation means is set according to the operating condition of the internal combustion engine Pressure setting means, first estimating means for estimating a discharge amount of a specific exhaust component exhausted from the internal combustion engine according to operating conditions of the internal combustion engine, and the internal combustion engine by exhausting the specific exhaust component A physical quantity detecting means for detecting a specific physical quantity that changes in the exhaust path of the engine, and a second for estimating the exhaust quantity of the specific exhaust component based on detection information of the physical quantity detecting means. The estimation means and the discharge amount of the specific exhaust component estimated by the first estimation means are compared with the discharge amount of the specific exhaust component estimated by the second estimation means, and the result of the comparison And a correcting means for correcting the pressure set by the pressure setting means.

  With this configuration, the estimated value of the first estimating means is in accordance with the characteristics of the internal combustion engine, and the estimated value of the second estimating means reflects the actual emission amount of a specific exhaust component in the exhaust path. It will be a thing. Therefore, even if there is a variation in the characteristics of the injection rate of the injector, the fuel pressure sensor, etc. by correcting the set pressure of the fuel accumulated in the pressure accumulating means according to the comparison result of the two estimated values indicating the variation. Thus, the fuel is accumulated in the pressure accumulating means with the fuel pressure corrected to a value preferable for the exhaust purification performance, and the ability of the exhaust purification catalyst device and the DPF device can be fully exhibited.

  In the fuel injection control device for an internal combustion engine having the configuration described in (1) above, (2) the first estimating means is a particulate matter component exhausted from the internal combustion engine in accordance with operating conditions of the internal combustion engine. Is repeatedly calculated for each first calculation period, and the discharge amount of the particulate matter component calculated for each first calculation period is over a second calculation period that is longer than the first calculation period. The physical quantity detection means detects the differential pressure in the exhaust path before and after the exhaust purification means, and the second estimation means is based on the differential pressure detected by the physical quantity detection means. It is preferable to estimate the amount of collected particulate matter on the exhaust gas purification means in the exhaust path of the internal combustion engine every two calculation periods.

  With this configuration, the accumulated value of the particulate matter component discharge amount accumulated over the second calculation period, and the collected amount of the particulate matter component estimated based on the differential pressure detected by the physical quantity detection means, And the accumulated fuel pressure set value is corrected so that the actual amount of collected particulate matter approaches the integrated value of the particulate matter emission estimated according to the operating conditions of the internal combustion engine. Therefore, the actual change in the amount of collected particulate matter will approach the amount of particulate matter emission estimated from the operating conditions. Therefore, the pressure of the pressure-accumulated fuel is controlled so that the discharge amount of the particulate matter and NOx can be limited to a predetermined value or less without being affected by variations in characteristics of the injector, the pressure-accumulated fuel pressure sensor, and the like.

  In the fuel injection control device for an internal combustion engine having the configuration described in (2) above, (3) the first estimator may exhaust the particles exhausted from the internal combustion engine in accordance with operating conditions of the internal combustion engine. It is preferable to have first map information for specifying the discharge amount of the particulate matter component, and to calculate the discharge amount of the particulate matter component based on the first map information.

  With this configuration, for example, based on the first map information set for the entire operation region of the internal combustion engine, the accumulated pressure is such that the emission amount of particulate matter and NOx can be limited to a predetermined value or less according to the operation condition of the internal combustion engine. While the fuel pressure is controlled, it is possible to set the discharge amount of the specific exhaust component based on the required performance of the internal combustion engine. Note that the first map information is, for example, control map information for all operating regions stored in the memory when the internal combustion engine is adapted, and may reflect the learned value.

  Further, in the fuel injection control device for an internal combustion engine having the configuration described in the above (2) or (3), (4) the second estimation means responds to a differential pressure in the exhaust path before and after the exhaust purification means. Second map information for specifying the amount of particulate matter collected and deposited on the exhaust gas purification means in the exhaust path of the internal combustion engine, and the particulate matter based on the second map information It is preferable to estimate the amount of collected components.

  With this configuration, it is possible to accurately calculate the amount of collected particulate matter on the exhaust purification means from the differential pressure of the exhaust path before and after the exhaust purification means, and to collect the particulate matter components on the actual exhaust purification means. The set value of the accumulated fuel pressure is corrected so that the accumulation amount approaches the collection amount of the particulate matter during the second period estimated from the operating conditions. Note that the second map information is preferably obtained by accurately associating the relationship between the differential pressure before and after the exhaust gas purification unit and the amount of particulate matter collected and deposited on the exhaust gas purification unit by a preliminary experiment.

  In the fuel injection control device for an internal combustion engine having the configuration described in the above (2) to (4), preferably, (5) the second calculation period is the next regeneration process immediately after the regeneration process of the exhaust gas purification means. It is a period until immediately before.

  In this case, the integrated value of the discharge amount of the particulate matter component accumulated over the second calculation period and the collected amount of the particulate matter component estimated based on the differential pressure detected by the physical quantity detection means are It becomes approximate or proportional, and the fuel injection control capable of improving the exhaust purification performance can be executed with high accuracy by correlating the two estimated values without variation.

  In the fuel injection control device for an internal combustion engine having the configuration described in (1) above, (6) the first estimating means is configured to oxidize nitrogen exhausted from the internal combustion engine in accordance with operating conditions of the internal combustion engine. The physical quantity detection means detects the concentration of the nitrogen oxides in the exhaust path upstream of the exhaust purification means, and the second estimation means is detected by the physical quantity detection means. The emission amount of the nitrogen oxide exhausted from the internal combustion engine may be estimated based on the concentration of the nitrogen oxide.

  With this configuration, the emission amount of nitrogen oxides calculated by the first estimation means is compared with the emission amount of nitrogen oxides calculated based on the concentration of nitrogen oxides detected by the physical quantity detection means, Since the set value of the pressure accumulation fuel pressure is corrected so that the actual nitrogen oxide emission amount approaches the nitrogen oxide emission amount estimated from the operating conditions of the internal combustion engine, the characteristics of the injector, the pressure accumulation fuel pressure sensor, etc. The accumulated pressure fuel pressure is controlled so that the emission amount of particulate matter and NOx can be limited to a predetermined value or less without being affected by the variation in the above.

  In the fuel injection control device for an internal combustion engine having the configuration described in (6) above, (7) the first estimation means includes the nitrogen oxides exhausted from the internal combustion engine in accordance with operating conditions of the internal combustion engine. It is preferable to have first map information for specifying the exhaust amount of the exhaust gas, and to calculate the exhaust amount of the nitrogen oxide based on the first map information.

  With this configuration, for example, based on the first map information set for the entire operation region of the internal combustion engine, the accumulated pressure is such that the emission amount of particulate matter and NOx can be limited to a predetermined value or less according to the operation condition of the internal combustion engine. While the fuel pressure is controlled, it is possible to set the discharge amount of the specific exhaust component based on the required performance of the internal combustion engine. Note that the first map information here is, for example, control map information for all operating regions stored in the memory when the internal combustion engine is adapted, and may reflect the learning value.

  In the fuel injection control device for an internal combustion engine having the configuration described in (6) or (7) above, (8) the second estimating unit includes the nitrogen oxide in the exhaust path upstream of the exhaust purification unit. Having second map information for specifying the exhaust amount of the nitrogen oxides exhausted from the internal combustion engine according to the concentration, and calculating the exhaust amount of the nitrogen oxides based on the second map information Is preferred.

  With this configuration, the amount of nitrogen oxide exhausted from the internal combustion engine can be accurately calculated based on the concentration of nitrogen oxide in the exhaust path upstream of the exhaust purification means, and the nitrogen oxide to the actual exhaust purification means can be calculated. The set value of the pressure accumulation fuel pressure is corrected so that the amount of introduced gas approaches the nitrogen oxide emission amount estimated from the operating conditions. In the second map information, the relationship between the detected concentration of nitrogen oxides in the exhaust path upstream of the exhaust gas purification means and the amount of nitrogen oxide emissions from the internal combustion engine is accurately correlated by a preliminary experiment. It should be a thing.

  According to the present invention, the specific estimation estimated by the second estimation means based on the discharge amount of the specific exhaust component according to the operating condition of the internal combustion engine estimated by the first estimation means and the detection information of the physical quantity detection means. By correcting the set pressure of the fuel accumulated in the pressure accumulating means according to the comparison result with the exhaust amount of the exhaust component, even if there are variations in the characteristics of the injector, the fuel pressure sensor, etc., it is preferable in terms of exhaust purification performance Since the fuel is accumulated in the pressure accumulating means with the fuel pressure corrected to the value, the pressure of the fuel accumulated in the pressure accumulating means is not affected by variations in characteristics of the injector, the fuel pressure sensor, etc. It is possible to provide a fuel injection control device that can improve the exhaust gas purification performance of the internal combustion engine by controlling the pressure so that the capability of the catalyst device and the DPF device can be sufficiently exhibited.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic block diagram of a fuel injection control device for an internal combustion engine according to a first embodiment of the present invention, and shows an example in which the present invention is applied to a diesel engine that is a vehicle internal combustion engine. FIG. 2 is a schematic configuration diagram of the exhaust system.

  First, the configuration will be described.

  An engine 10 shown in FIG. 1 is a multi-cylinder diesel engine, and a plurality of injectors 11 for injecting fuel (for example, light oil) into a plurality of cylinders (not shown), for example, four cylinders, and fuel supplied to these injectors 11. And the common rail 12 for storing and accumulating as a common pressure accumulating means, and the fuel sucked through the low pressure fuel pipe L1 when driven using the rotational power of the engine 10, and the high pressure fuel is supplied to the common rail 12 through the high pressure fuel pipe L2. Can be supplied. For example, the cam-plunger variable discharge high-pressure fuel pump 13 and the rotational power of the engine 10 are used to pump fuel from the fuel tank 16 through the low-pressure fuel pipe L1 and supply it to the high-pressure fuel pump 13. The feed pump 15 is provided.

  The injector 11 incorporates, for example, an electromagnetic valve that opens and closes in response to an ON / OFF command signal from an ECU (Electronic Control Unit) 30 described later, and corresponds to the high-pressure fuel supplied from the common rail 12 in response to the command signal from the ECU 30. This is a known electromagnetically controlled needle valve that can be injected into each cylinder (combustion chamber) at an injection timing and an injection rate. Of course, a valve configuration in which a piezo element is built in and opened and closed by the piezo element may be used.

  Although not shown in detail, the common rail 12 includes a plurality of outlet port portions to which fuel supply pipes to the plurality of injectors 11 are connected, and an inlet port portion to which high-pressure discharged fuel from the high-pressure fuel pump 13 is supplied. A common rail pressure sensor 21 to be described later is attached to one end side (left end side in the figure) in the longitudinal direction. The common rail 12 distributes and supplies the fuel pressure supplied from the high-pressure fuel pump 13 to the plurality of injectors 11 while keeping the fuel pressure uniform. A pressure limiter (not shown) is mounted on the common rail 12 so that the internal pressure does not become excessive.

  The high-pressure fuel pump 13 includes a suction control valve 14 that controls the amount of fuel sucked into the pump body, a plurality of regulating valves (not shown) that set the inlet pressure and prevent backflow from the common rail side, A pump unit having a plurality of plungers arranged opposite to each other so that the other is in a pressure stroke during the suction stroke, and a cam that is rotationally driven by power from the crankshaft to drive them. Are known ones.

  The plurality of injectors 11, common rail 12, high pressure fuel pump 13, suction control valve 14, and feed pump 15 constitute a fuel injection device 17 for the engine 10 as a whole, and are controlled by the ECU 30 to the engine 10. The fuel supply can be controlled.

  Although a detailed hardware configuration is not illustrated, the ECU 30 is a nonvolatile memory 34 such as a CPU 31 (Central Processing Unit), a ROM 32 (Read Only Memory), a RAM 33 (Random Access Memory), an EEPROM (Electronically Erasable and Programmable Read Only Memory), or the like. , An input interface circuit 35 including an A / D converter, a buffer and the like, and an output interface circuit 36 including a drive circuit and the like. In FIG. 1, the interface circuit is indicated as I / F.

  The input interface circuit 35 of the ECU 30 has a common rail pressure sensor 21 that detects the pressure of the fuel in the common rail 12, a fuel temperature sensor 22 that detects the temperature of the fuel sucked into the high-pressure fuel pump 13, and a preset value. A rotational speed sensor 23 that outputs an engine rotational speed (rpm) or a signal corresponding to the crank angular speed for each crank angle, an accelerator opening sensor 24 that detects an accelerator opening corresponding to an accelerator pedal depression amount, A water temperature sensor 25 for detecting the temperature of the cooling water is connected, and sensor information from these sensors 21 to 25 is taken into the ECU 30.

  Although an intake path to each cylinder of the engine 10 is not shown, an intake manifold, an intake pipe upstream of the intake manifold, an air cleaner that cleans intake air with a filter upstream of the intake pipe, and turbocharging An intercooler that cools intake air heated by supercharging downstream of the engine, an air flow meter that detects the intake flow rate of fresh air, a throttle valve that adjusts the intake air amount into the engine 10, and an intake air temperature sensor; However, each is mounted to form a known intake device.

  The exhaust path from each cylinder of the engine 10 includes an exhaust manifold (not shown) and exhaust purification means 40 attached to the exhaust pipe 41 on the downstream side thereof.

As shown in FIG. 2, the exhaust purification unit 40 is known to be able to oxidize hydrocarbon HC or carbon monoxide CO that is, for example, an unburned fuel content in exhaust gas to form water H ₂ O or carbon dioxide CO _2. Catalyst device 42 made of an oxidation catalyst, a DPF (diesel particulate filter) device 43 that collects PM components in exhaust gas that has passed through the catalyst device 42, and an exhaust pipe that bypasses the catalyst device 42 and the DPF device 43 More than the bypass pipe 44 attached to 41, the differential pressure sensor 45 attached to the middle part of the bypass pipe 44 and detecting the differential pressure between the both ends of the bypass pipe 44, the catalyst device 42 and the DPF device 43. A NOx sensor 46 that detects the concentration of NOx in the exhaust path on the upstream side (engine 10 side), the exhaust temperature immediately after passing through the catalyst device 42, and the DPF device 43 Exhaust temperature sensors 47a and 47b for detecting the exhaust gas temperature immediately after the exhaust gas sensor 47a and an all-range air-fuel ratio sensor 48 mounted on the exhaust pipe 41 so as to detect the oxygen concentration in the exhaust gas after passing through the DPF device 43 are provided. Yes. Here, the differential pressure sensor 45 is a physical quantity detection unit that detects a differential pressure (specific physical quantity) before and after the DPF device 43 that changes in the exhaust path of the engine 10 due to exhaust of PM components.

  The differential pressure sensor 45, the NOx sensor 46, the exhaust temperature sensors 47a and 47b, and the air-fuel ratio sensor 48 are connected to the input interface circuit 35 of the ECU 30, and the outputs of these sensors 45 to 48 are taken into the ECU 30. A / D conversion is performed for each sensor information.

  On the other hand, the ECU 30 determines the fuel injection timing and fuel injection from the injector 11 of each cylinder according to the operating conditions of the engine 10, such as the engine speed, the required load (required fuel injection amount), the coolant temperature, the fuel temperature, and the like. It has the function of the injection control means for controlling the amount, and is configured to function as the pressure setting means, the first estimation means, the second estimation means, and the correction means referred to in the present invention.

  The ECU 30 as the injection control means calculates the engine speed NE and the accelerator opening Acc based on the outputs of the rotational speed sensor 23 and the accelerator opening sensor 24, for example, and operates the engine from the target injection amount setting map or the arithmetic expression. The fuel injection amount and the fuel injection timing corresponding to the conditions are calculated, and the corresponding injector drive signal is output from the output interface circuit 36 to the injector 11 for each cylinder. More specifically, the ECU 30 calculates a target fuel injection amount from a speed adjustment pattern map (not shown) based on, for example, the accelerator opening Acc and the engine speed NE, and based on the target fuel injection amount and the engine speed NE. The target fuel injection timing is set by referring to a timing map (not shown). Then, an injection pulse width corresponding to the target fuel injection amount, the target fuel injection timing, and the actual common rail pressure Pc is calculated for each cylinder, and an injector drive signal for driving the injector 11 according to the injection pulse width is generated. The injection amount may be corrected according to engine operating conditions such as the engine cooling water temperature Tw, the fuel temperature Tf, the intake pressure and the intake air temperature, and such injector drive control and correction methods themselves are the same as in the prior art.

  The ECU 30 as pressure setting means refers to a supply amount map for setting the fuel supply amount from the high-pressure fuel pump 13 to the common rail 12 according to the operating conditions of the engine 10, for example, the engine speed NE and the target fuel injection amount. The fuel supply amount that regulates the pressure of the fuel accumulated in the common rail 12 is calculated and set based on the supply amount map, and the pressure setting program is stored in the ROM 32 and the nonvolatile memory 34. . In addition, a working memory area for this purpose is set in the RAM 33. The ECU 30 controls the opening of the suction control valve 14 so that the actual common rail pressure Pc detected by the common rail pressure sensor 21 becomes the target common rail pressure, and controls the amount of fuel sucked into the high-pressure fuel pump 13. It has become.

  Further, the ECU 30 as the first estimation means specifies the PM component that is a specific exhaust component exhausted from the engine 10 if the engine speed NE and the load, which are the operation conditions, are specified for the entire operation region of the engine 10. Based on the PM emission amount map that can specify the emission amount, and the PM emission amount map, the PM component emission amount corresponding to the operating condition of the engine 10 is repeatedly calculated and estimated every preset first calculation period. One estimation program is stored in the ROM 32 and the nonvolatile memory 34, and a working memory area for the arithmetic processing is set in the RAM 33. Here, the PM emission amount map is, for example, first map information configured by a part of a control map that is mounted when the engine 10 is adapted / adjusted, and the engine speed NE and the load (fuel injection amount). 2 includes data for estimating the amount of PM component exhausted from the engine 10 at any point in the operating region plane having values on two axes orthogonal to each other. However, not all data at the time of adaptation / adjustment, but data that has been updated by learning with an actual vehicle may be included.

  Further, the ECU 30 as the first estimating means repeatedly calculates the emission amount of the PM component exhausted from the engine 10 from the PM emission amount map according to the operating condition of the engine 10 as described above for each first calculation period. In addition, the PM component emission amount calculated for each first calculation period is integrated over a second calculation period longer than the first calculation period, and the second calculation period is, for example, As a period from immediately after the end of the regeneration process in which the PM accumulated in the DPF device 43 is burned and removed at a regular or irregular time interval to immediately before the start of the next regeneration process (hereinafter referred to as a period before the regeneration of the DPF device 43) Is set. Alternatively, the second calculation period is set as a time shorter than the period before the regeneration of the DPF device 43, for example, every time the travel distance of the vehicle 100 km elapses. The period may be reset to zero.

  The ECU 30 as the second estimating means specifies the amount of PM component accumulated in the DPF device 43 based on the detection information of the differential pressure sensor 45 (PM emission amount in a second calculation period described later). And a PM collection / deposition amount map that estimates the PM collection / deposition amount corresponding to the differential pressure detected by the differential pressure sensor 45 based on the PM collection / deposition amount map. Two estimation programs are stored in the ROM 32 and the nonvolatile memory 34, and a working memory area for the arithmetic processing is set in the RAM 33. Here, the PM collection / accumulation amount map is obtained by a differential pressure across the DPF device 43 (a differential pressure in the exhaust path before and after the exhaust purification unit 40) obtained by a previous experiment using the engine 10 and a DPF at the time of the differential pressure. This is the second map information that can identify the amount of PM component collected and accumulated in the DPF device 43 by specifying the differential pressure across the DPF device 43 based on the data of the amount of collected PM component accumulated in the device 43. , All of them may include interpolation data created based on the data instead of the experimental result data.

  The ECU 30 as the correcting means compares the PM component emission amount PM1 estimated by the first estimating means with the PM component collection and deposition amount PM2 estimated by the second estimating means as a ratio PM2 / PM1 between them. Then, a map for setting a correction amount for correcting the common rail pressure set by the pressure setting means according to the comparison result, for example, a correction amount setting map as shown in FIG. 5, and a correction amount setting map thereof And a correction program for calculating a correction amount for correcting the common rail pressure accumulated in the common rail 12 for each second calculation period in the ROM 32 and the nonvolatile memory 34, and its arithmetic processing A working memory area for this purpose is set in the RAM 33.

  As shown in FIG. 5, the PM component emission amount PM1 estimated by the first estimating means (hereinafter also referred to as estimated value PM1) and the PM component collected and accumulated amount estimated by the second estimating means. When the ratio PM2 / PM1 to PM2 (hereinafter also referred to as the estimated value PM2) is 1 and there is no variation, the correction amount of the common rail pressure is zero, and as shown in FIGS. 4 and 5, the ratio PM2 / PM1 When there is a variation that exceeds 1, the correction amount is set to a positive value, that is, on the PM emission reduction side. When there is a variation such that the ratio PM2 / PM1 is less than 1, the correction amount is a negative value. That is, it is set on the increase side of the PM emission amount.

  Although not shown, the engine 10 is equipped with a known EGR device (exhaust gas recirculation device) that recirculates part of the exhaust gas from the exhaust path to the intake path side, thereby effectively reducing NOx. It is the structure which aims.

  Next, the operation will be described.

  During the operation of the engine 10, the ECU 30 as the injection control means calculates the engine speed Ne based on the detection value of the rotation speed sensor 23, and A / D converts the detection value of the accelerator opening sensor 24 to accelerator. The opening degree Acc is calculated, and based on the operating conditions such as the engine speed Ne and the accelerator opening degree Acc, the fuel injection amount and the fuel injection timing corresponding to the operating condition are calculated from the target injection amount setting map or the arithmetic expression. Is done. Based on the target fuel injection amount and the engine speed Ne, the supply amount map is referred to, and the target common rail pressure is calculated. The calculated value is stored in the RAM 33 as appropriate. Further, when the difference from the pressure command value stored in the RAM 33 is small as a result of the previous time and it is determined that the target common rail pressure is hardly changed, the target common rail pressure is maintained as it is, and the significant change amount If it is determined, the target common rail pressure is updated.

  During the operation of the engine 10, the ECU 30 functions as a pressure setting unit, so that fuel is supplied from the high-pressure fuel pump 13 to the common rail 12 according to the operating conditions of the engine 10, for example, the engine speed NE and the target fuel injection amount. An actual common rail detected by the common rail pressure sensor 21 is calculated by referring to a supply amount map for setting the amount, and a fuel supply amount for defining the fuel pressure accumulated in the common rail 12 is calculated and set based on the supply amount map. The opening degree of the suction control valve 14 is controlled so that the pressure Pc becomes the target common rail pressure.

  Further, as shown in the flowchart of FIG. 3, the ECU 30 functions as the first estimating means, and is set according to the operating conditions such as the engine speed NE and the load of the engine 10 or according to the operating conditions. In accordance with the common rail pressure Pc, the emission amount of the PM component exhausted from the engine 10 is repeatedly calculated and estimated for each first calculation period based on the PM emission amount map (step S11). Further, at this time, the function of the ECU 30 as the first estimating means repeatedly calculates the exhaust amount of the PM component exhausted from the engine 10 based on the PM exhaust amount map for each first calculation period. The PM component emission amount calculated every one calculation period is sequentially integrated over a second calculation period longer than the first calculation period.

  On the other hand, by the function as the second estimating means of the ECU 30, the amount of PM component accumulated in the DPF device 43 based on the detection information of the differential pressure sensor 45, that is, the PM discharge amount within the second calculation period, Based on the PM collection / deposition amount map, it is estimated for each second calculation period (step S12).

  In this state, the second calculation period is set as a period shorter than the pre-regeneration period of the DPF device 43 or the pre-regeneration period of the DPF device 43, for example, every time the travel distance of the vehicle passes 100 km, The estimated value PM1 of the PM component emission amount by the first estimating means is in accordance with the characteristics of the engine 10, and the estimated value PM2 of the PM component emission amount by the second estimating means is the actual PM component in the exhaust path. The amount of emissions is reflected.

  Further, in this state, the function of the ECU 30 as the correcting means causes both the estimated value PM1 of the PM component discharge amount by the first estimating means and the estimated value PM2 of the PM component collection and deposition amount by the second estimating means to both. The ratio PM2 / PM1 is compared, and a correction amount for correcting the common rail pressure already set by the pressure setting means is calculated based on the correction amount setting map in accordance with the comparison result (step) S13). Then, this correction amount is added to the common rail pressure already set by the function of the pressure setting means (in FIG. 3, the common rail pressure is simply referred to as rail pressure), and the final target common rail pressure corrected according to the correction amount. Is determined (step S14).

  Therefore, the set pressure of the fuel accumulated in the common rail 12 is based on the comparison result PM2 / PM1 between the two estimated values PM1 and PM2, while using the required characteristics of the engine 10 as a reference, the injection rate of the injector 11 and the common rail pressure sensor 21 As shown in FIG. 4, the injector is corrected according to the amount of PM collected and deposited in the DPF device 43 as a result of the actual operation of the engine 10 including the influence of variations in the detection characteristics of the injector. As shown in FIG. 4 and FIG. 5, the influence of the variation is shown so as to suppress the variation in the PM emission amount even if the influence A of the variation of the injection rate of 11 or the detection characteristics of the common rail pressure sensor 21 exists. When the ratio PM2 / PM1 exceeds 1, the correction amount is a positive value, that is, the PM emission amount decreases, and when the ratio PM2 / PM1 is less than 1. Is set to an increase side of the correction amount, that is, the PM emission amount, so that the fuel is stored and accumulated in the common rail 12 at a pressure corrected to a value preferable for exhaust purification performance, and the DPF device for exhaust purification The ability of 43 can be fully exhibited.

  In the present embodiment, the ECU 30 as the first estimating means repeatedly calculates the exhaust amount of the PM component exhausted from the engine 10 according to the operating condition of the engine 10 for each first calculation period, and the first The PM component emission amount calculated every one calculation period is integrated over a second calculation period longer than the first calculation period, and the ECU 30 serving as the second estimation means performs a differential pressure every second calculation period. Based on the differential pressure detected by the sensor 45, the amount of PM component collected and accumulated in the DPF device 43 in the exhaust path of the engine 10 is estimated, and the ECU 30 as the correcting means is integrated over the second calculation period. Depending on the comparison result between the integrated value of the component discharge amount and the amount of collected PM accumulated on the DPF device 43 estimated based on the differential pressure detected by the differential pressure sensor 45, The common rail pressure Pc so that the actual amount of PM collected and accumulated on 43 approaches the integrated value of the PM emission estimated according to the operating conditions of the engine 10 without variation (proportional to the catalyst of the catalyst device 42). Therefore, the actual change in the collected amount of PM tends to approach the PM emission amount estimated from the operating conditions. Therefore, the common rail pressure Pc is controlled so that the discharge amount of PM and NOx can be limited to a predetermined value or less without being affected by variations in characteristics of the injector 11 and the common rail pressure sensor 21 and the like.

  Further, the ECU 30 as the first estimating means has first map information for specifying the emission amount of the PM component exhausted from the engine 10 according to the operating condition of the engine 10, and based on the first map information. Since the PM component emission amount is calculated according to the operating condition of the engine 10, PM and NOx of PM and NOx are determined according to the operating condition of the engine 10 based on the first map information set for the entire operating region of the engine 10. The common rail pressure Pc is controlled so that the emission amount can be limited to a predetermined value or less, and the emission amount of the PM component can be set based on the required performance of the engine 10.

  Further, the ECU 30 as the second estimating means specifies the amount of PM component collected and accumulated in the DPF device 43 in the exhaust path of the engine 10 according to the differential pressure in the exhaust path before and after the DPF device 43. Since the amount of collected PM accumulated on the DPF device 43 is estimated based on the second map information, the differential pressure of the exhaust path before and after the DPF device 43 is The amount of collected PM deposition can be calculated with high accuracy.

  Further, since the second calculation period is set to a period immediately after the regeneration process of the DPF device 43 until immediately before the next regeneration process, the integrated value of the PM component emission amount accumulated over the second calculation period and The amount of PM component collected and accumulated in the DPF device 43 estimated based on the differential pressure detected by the differential pressure sensor 45 becomes approximate or proportional, and the estimated values PM1 and PM2 approach each other without variation. It is possible to accurately execute fuel injection control that can improve the exhaust purification performance.

  As described above, according to the fuel injection control device for the internal combustion engine of the present embodiment, the PM component discharge amount according to the operating condition of the engine 10 estimated by the ECU 30 as the first estimating means, and the differential pressure sensor 45. The set pressure of the fuel accumulated in the common rail 12 is corrected by the ECU 30 as the correction means according to the comparison result with the emission amount of the PM component estimated by the ECU 30 as the second estimation means based on the detected information of Even if the injection rate of the injector 11 and the detection characteristics of the common rail pressure sensor 21 vary, the fuel is accumulated in the common rail 12 with the fuel pressure corrected to a preferable value in terms of exhaust purification performance. The catalyst device does not affect the pressure of the fuel accumulated in the fuel tank 12 without being affected by variations in characteristics of the injector 11 and the fuel pressure sensor. The ability of 2 and the DPF device 43 is controlled to a pressure capable of sufficiently exhibited, it is possible to provide a fuel injection control apparatus capable of improving the exhaust gas purification performance of the engine 10.

  In the above-described first embodiment, the specific exhaust component of the engine 10 is the PM component. However, as described below, the NOx component may be the specific exhaust component.

(Second Embodiment)
FIG. 6 is a flowchart showing a control program of the fuel injection control device for the internal combustion engine according to the second embodiment of the present invention. Since the present embodiment has a configuration similar to that of the first embodiment described above, each component will be described with the same reference numerals as those of the similar components shown in FIGS. Therefore, the configuration diagram is omitted.

  In the internal combustion engine fuel injection control device of the present embodiment, as in the above-described embodiment, the ECU 30 operates the engine 10 such as the engine speed, the required load (required fuel injection amount), the coolant temperature, In addition to the function of injection control means for controlling the timing and amount of fuel injection from the injector 11 of each cylinder in accordance with the fuel temperature, etc., the pressure setting means, the first estimation means, the second It is configured to function as estimation means and correction means.

  The ECU 30 as the injection control means calculates the engine speed NE and the accelerator opening Acc based on the outputs of the rotational speed sensor 23 and the accelerator opening sensor 24, for example, and operates the engine from the target injection amount setting map or the arithmetic expression. The fuel injection amount and the fuel injection timing corresponding to the conditions are calculated, and the corresponding injector drive signal is output from the output interface circuit 36 to the injector 11 for each cylinder. Specifically, the ECU 30 calculates a target fuel injection amount from a speed adjustment pattern map (not shown) based on, for example, the accelerator opening Acc and the engine speed NE, and based on the target fuel injection amount and the engine speed NE. The target fuel injection timing is set by referring to a timing map (not shown). Then, an injection pulse width corresponding to the target fuel injection amount, the target fuel injection timing, and the actual common rail pressure Pc is calculated for each cylinder, and an injector drive signal for driving the injector 11 according to the injection pulse width is generated.

  The ECU 30 as pressure setting means refers to a supply amount map for setting the fuel supply amount from the high-pressure fuel pump 13 to the common rail 12 according to the operating conditions of the engine 10, for example, the engine speed NE and the target fuel injection amount. The fuel supply amount that regulates the pressure of the fuel accumulated in the common rail 12 is calculated and set based on the supply amount map, and the pressure setting program is stored in the ROM 32 and the nonvolatile memory 34. . In addition, a working memory area for this purpose is set in the RAM 33. The ECU 30 controls the opening of the suction control valve 14 so that the actual common rail pressure Pc detected by the common rail pressure sensor 21 becomes the target common rail pressure, and controls the amount of fuel sucked into the high-pressure fuel pump 13. To do.

  Further, if the ECU 30 as the first estimating means specifies the engine speed NE and the load that are the operating conditions for the entire operation region of the engine 10, the ECU 30 determines the NOx component that is a specific exhaust component exhausted from the engine 10. A NOx emission map that can specify the emission amount, and a first estimation program that repeatedly calculates and estimates the NOx component emission amount according to the operating conditions of the engine 10 from the NOx emission map for each preset calculation period; Are stored in the ROM 32 and the nonvolatile memory 34, and a working memory area for the arithmetic processing is set in the RAM 33. Here, the NOx emission map is, for example, first map information composed of a part of a control map mounted when adapting / adjusting the engine 10, and the engine speed NE and load (fuel injection amount). Includes data for estimating the emission amount of NOx components exhausted from the engine 10 at arbitrary points in the operation region plane having values on two axes orthogonal to each other. However, not all data at the time of adaptation / adjustment, but data that has been updated by learning with an actual vehicle may be included.

The ECU 30 as the second estimating means specifies the NOx emission amount of the engine 10 based on the concentration of the NOx component in the exhaust path upstream of the catalyst device 42 of the exhaust purification means 40 that is detection information of the NOx sensor 46. In the ROM 32 and the nonvolatile memory 34, and a second estimation program for calculating and estimating the NOx emission amount corresponding to the NOx concentration detected by the NOx sensor 46 based on the NOx emission amount map. The working memory area for the arithmetic processing is set in the RAM 33. Here, the NOx emission amount map is created on the basis of the NOx concentration on the upstream side of the catalyst device 42 obtained by the previous experiment using the engine 10 and the data of the NOx emission amount of the engine 10 at that concentration. If the NOx concentration on the upstream side of the device 42 is specified, it is the second map information that can specify the NOx emission amount of the engine 10, and all of them include not the experimental result data but the interpolation data created based on the data It may be. Further, in the present embodiment, the catalyst device 42 is configured by a reduction catalyst that can reduce NOx in the exhaust gas to NO ₂ or NO and react with HC or CO in the exhaust gas to form N ₂ , for example. .

  The ECU 30 as the correction unit compares the NOx component emission amount N1 estimated by the first estimation unit and the NOx component emission amount N2 estimated by the second estimation unit as a ratio N2 / N1 between them. A correction amount setting map for setting a correction amount for correcting the common rail pressure Pc set by the pressure setting means according to the result of the comparison, and every calculation period set in advance based on the correction amount setting map A correction program for calculating a correction amount for correcting the common rail pressure Pc accumulated in the common rail 12 is stored in the ROM 32 and the nonvolatile memory 34, and a working memory area for the arithmetic processing is stored in the RAM 33. It is set up.

  The NOx component emission amount N1 estimated by the first estimation means (hereinafter also referred to as an estimated value N1) and the NOx component collection amount N2 estimated by the second estimation means (hereinafter referred to as the estimated value N2). When the ratio N2 / N1 is 1, the correction amount of the common rail pressure is zero, and when the ratio N2 / N1 exceeds 1, the correction amount is set on the decrease side of the NOx emission amount, and the ratio N2 When / N1 is less than 1, the correction amount is set to increase the NOx emission amount. Further, contrary to the relationship between PM and common rail pressure shown in FIG. 4, NOx increases on the side where the set value of common rail pressure becomes lower. That is, since the direction of increasing PM on the vertical axis in FIG. 4 is the NOx decreasing side, the direction of increase / decrease of the correction amount (positive / negative) is opposite to that described above.

  In the present embodiment, the ECU 30 functions as the first estimating means, so that it depends on the operating conditions such as the engine speed NE and the load of the engine 10 or on the common rail pressure Pc set according to the operating conditions. Thus, the emission amount of the NOx component exhausted from the engine 10 is repeatedly calculated and estimated for each of the preset calculation periods based on the NOx emission amount map (step S21).

  On the other hand, by the function as the second estimating means of the ECU 30, the concentration of the NOx component in the exhaust path on the upstream side of the catalytic device 42 is estimated for each calculation period based on the NOx emission map based on the detection information of the NOx sensor 46. (Step S22).

  In this state, the estimated value N1 of the NOx component emission amount by the first estimating means is in accordance with the characteristics of the engine 10, and the estimated value N2 of the NOx component emission amount by the second estimating means is in the exhaust path. This reflects the actual emission amount of NOx components.

  Further, in this state, the function of the ECU 30 as a correction unit causes the estimated value N1 of the NOx component emission amount by the first estimation unit and the estimated value N2 of the NOx component emission amount by the second estimation unit to be a ratio of both. A correction amount for correcting the common rail pressure Pc already set by the pressure setting means is calculated based on the correction amount setting map in accordance with the comparison result indicating N2 / N1 and showing the influence of variation. (Step S23). Then, this correction amount is added to the common rail pressure already set by the function of the pressure setting means (in FIG. 6, the common rail pressure is simply referred to as rail pressure), and the final target common rail pressure corrected according to the correction amount. Is determined (step S24).

  Therefore, the set pressure of the fuel accumulated in the common rail 12 is based on the comparison result N2 / N1 between the two estimated values N1 and N2, and based on the required characteristics of the engine 10, the injection rate of the injector 11 and the common rail pressure sensor 21 As a result of the actual operation of the engine 10 including the influence of variations in the detection characteristics, etc., correction is made in accordance with the NOx concentration appearing upstream of the catalyst device 42, and the injection rate of the injector 11 and the common rail pressure sensor 21 are corrected. When the ratio N2 / N1 exceeds 1, the correction amount is on the decrease side of the NOx emission amount and the ratio N2 / N1 is less than 1 so as to suppress the variation in the NOx emission amount Is set to increase the NOx emission amount, the fuel is supplied to the common rail at a pressure corrected to a preferable value for exhaust purification performance. It would be stored, accumulated in 2, so the capacity of the catalyst device 42 for exhaust gas purification can be sufficiently exhibited.

  As described above, also in the present embodiment, the NOx emission amount calculated by the ECU 30 as the first estimating means and the NOx emission amount calculated based on the NOx concentration detected by the NOx sensor 46 are obtained. The set value of the common rail pressure is corrected so that the actual NOx emission amount approaches the NOx emission amount estimated from the operating conditions of the internal combustion engine, so that the characteristics of the injector 11, the common rail pressure sensor 21, etc. The common rail pressure is controlled so that the discharge amount of the PM component and the NOx component can be limited to a predetermined value or less without being affected by the variation.

  Further, the ECU 30 as the first estimating means has first map information for specifying the exhaust amount of NOx exhausted from the engine 10 in accordance with the operating condition of the engine 10, and based on the first map information. Since the exhaust amount of NOx exhausted from the engine 10 is calculated at the same time, for example, based on the first map information set for the entire operation region of the engine 10, the PM component and NOx component are discharged according to the operating conditions of the engine 10 The common rail pressure is controlled so that the amount can be limited to a specified value or less, and the NOx emission amount can be set based on the required performance of the engine 10.

  Further, the ECU 30 as the second estimating means has second map information for specifying the amount of NOx exhausted from the engine 10 in accordance with the NOx concentration in the exhaust path upstream of the exhaust purification means 40. Since the NOx exhaust amount is estimated based on the second map information, the NOx exhaust amount exhausted from the engine 10 is accurately calculated based on the NOx concentration in the exhaust path upstream of the exhaust purification means 40. Thus, the set value of the common rail pressure is corrected so that the actual amount of NOx introduced into the exhaust gas purification means 40 approaches the NOx emission amount estimated from the operating conditions.

  Therefore, also in this embodiment, the same effect as the first embodiment described above can be expected.

  In the second embodiment, an arithmetic expression may be used instead of the first map information that specifies the exhaust amount of NOx exhausted from the engine 10 according to the operating conditions of the engine 10. In addition, although the specific exhaust component is one of the PM component and the NOx component, the respective exhaust amounts are estimated using both components that are in a trade-off relationship as the specific exhaust component, and the respective comparison results (ratio PM2) / PM1 and the ratio N2 / N1), the correction amount of the common rail pressure can also be calculated.

  As described above, the fuel injection control device for an internal combustion engine according to the present invention includes the discharge amount of the specific exhaust component according to the operating condition of the internal combustion engine estimated by the first estimation means and the detection information of the physical quantity detection means. By correcting the set pressure of the fuel accumulated in the pressure accumulating means according to the comparison result with the discharge amount of the specific exhaust component estimated by the second estimating means based on the injection rate, the injection rate of the injector and the fuel pressure sensor Even if there is a variation in the characteristics of the fuel, the fuel is accumulated in the pressure accumulating means with the fuel pressure corrected to a preferable value for the exhaust purification performance, so the pressure of the fuel accumulated in the pressure accumulating means is changed to the injector or It is possible to improve the exhaust gas purification performance of the internal combustion engine by controlling the pressure so that the capacity of the catalyst device and the DPF device can be fully exerted without being affected by variations in characteristics of the fuel pressure sensor or the like. The fuel injection control device of the internal combustion engine, in particular, the fuel injected into the cylinder by the injector is accumulated at a high pressure by the pressure accumulating means, and the accumulated fuel pressure is obtained. This is useful for a fuel injection control device for an internal combustion engine that controls the engine according to the operating conditions of the internal combustion engine.

1 is a schematic block configuration diagram of a fuel injection control device for an internal combustion engine according to a first embodiment of the present invention. 1 is a schematic configuration diagram of an exhaust system of an internal combustion engine according to a first embodiment of the present invention. It is a flowchart which shows the schematic process sequence of the correction process program of the common rail pressure in the fuel-injection control apparatus of the internal combustion engine which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the relationship between PM emission amount and common rail pressure in the internal combustion engine which concerns on the 1st Embodiment of this invention. It is explanatory drawing of the correction amount setting map for setting the correction amount according to the comparison result of two estimated values in the fuel-injection control apparatus of the internal combustion engine which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the schematic process sequence of the correction process program of the common rail pressure in the fuel-injection control apparatus of the internal combustion engine which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the relationship between PM discharge | emission amount and common rail pressure in the conventional internal combustion engine.

Explanation of symbols

10 engines (internal combustion engines, diesel engines)
11 Injector (fuel injection means)
12 Common rail (pressure accumulation means)
13 High-pressure fuel pump 14 Suction control valve (supply amount control means)
15 Feed pump 17 Fuel injection device 21 Common rail pressure sensor (fuel pressure sensor)
22 Fuel temperature sensor (operating condition detection means)
23 Rotational speed sensor (engine speed sensor, operating condition detection means)
24 Accelerator opening sensor (operating condition detection means)
25 Water temperature sensor (Operating condition detection means)
30 ECU (electronic control unit, injection control means, pressure setting means, first estimation means, second estimation means, correction means)
40 Exhaust purification means 42 Catalytic device (oxidation catalyst, reduction catalyst)
43 DPF (diesel particulate filter) device 45 Differential pressure sensor (physical quantity detection means)
46 NOx sensor (physical quantity detection means)
N1 Estimated value of NOx component emission by the first estimating means N2 Estimated value of NOx component emission by the second estimating means N2 / N1 ratio (comparison result)
PM1 Estimated value of PM component emission by the first estimation means PM2 Estimated value of PM component emission by the second estimation means PM2 / PM1 ratio (comparison result)

Claims (8)

An internal combustion engine for controlling supply of fuel to an internal combustion engine comprising: an injector for injecting fuel; a pressure accumulating means for storing and accumulating fuel supplied to the injector; and an exhaust purification means provided in an exhaust path. In the fuel injection control device,
Pressure setting means for setting the pressure of the fuel accumulated by the pressure accumulating means in accordance with operating conditions of the internal combustion engine;
First estimating means for estimating a discharge amount of a specific exhaust component exhausted from the internal combustion engine according to an operating condition of the internal combustion engine;
Physical quantity detection means for detecting a specific physical quantity that changes in the exhaust path of the internal combustion engine due to exhaust of the specific exhaust component;
Second estimation means for estimating an emission amount of the specific exhaust component based on detection information of the physical quantity detection means;
The discharge amount of the specific exhaust component estimated by the first estimation means is compared with the discharge amount of the specific exhaust component estimated by the second estimation means, and the discharge amount of the specific exhaust component is compared with the result of the comparison. A fuel injection control device for an internal combustion engine, comprising: correction means for correcting the pressure set by the pressure setting means. The first estimating means repeatedly calculates the emission amount of the particulate matter component exhausted from the internal combustion engine for each first calculation period according to the operating condition of the internal combustion engine, and the first calculation period The particulate matter component discharge amount calculated every time is integrated over a second calculation period longer than the first calculation period,
The physical quantity detection means detects a differential pressure in the exhaust path before and after the exhaust purification means;
The particulate matter to the exhaust purification unit in the exhaust path of the internal combustion engine for each second calculation period based on the differential pressure detected by the physical quantity detection unit by the second estimation unit. 2. The fuel injection control device for an internal combustion engine according to claim 1, wherein the amount of collected and accumulated components is estimated.   The first estimating means has first map information for specifying an emission amount of the particulate matter component exhausted from the internal combustion engine according to an operating condition of the internal combustion engine, and the first map information 3. The fuel injection control device for an internal combustion engine according to claim 2, wherein an emission amount of the particulate matter component is calculated based on the engine.   The second estimating means specifies the amount of particulate matter collected and deposited on the exhaust purification means in the exhaust path of the internal combustion engine according to the differential pressure in the exhaust path before and after the exhaust purification means. 4. The fuel for an internal combustion engine according to claim 2, further comprising second map information, wherein the collection amount of the particulate matter component is estimated based on the second map information. 5. Injection control device.   5. The method according to claim 2, wherein the second calculation period is a period from immediately after the regeneration process of the exhaust gas purification unit to immediately before the next regeneration process. 6. Fuel injection control device for internal combustion engine. The first estimating means calculates an exhaust amount of nitrogen oxides exhausted from the internal combustion engine according to an operating condition of the internal combustion engine;
The physical quantity detection means detects the concentration of the nitrogen oxides in the exhaust path upstream of the exhaust purification means;
The second estimation means estimates the emission amount of the nitrogen oxides exhausted from the internal combustion engine based on the concentration of the nitrogen oxides detected by the physical quantity detection means. A fuel injection control device for an internal combustion engine according to claim 1.   The first estimating means has first map information for specifying an exhaust amount of the nitrogen oxides exhausted from the internal combustion engine according to an operating condition of the internal combustion engine, and the first map information 7. The fuel injection control device for an internal combustion engine according to claim 6, wherein the exhaust amount of the nitrogen oxide is calculated based on the base. Second map information in which the second estimating means specifies the exhaust amount of the nitrogen oxides exhausted from the internal combustion engine in accordance with the concentration of the nitrogen oxides in the exhaust path upstream of the exhaust purification means. 8. The fuel injection control device for an internal combustion engine according to claim 6, wherein the exhaust amount of the nitrogen oxide is calculated based on the second map information.

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