JP4265121B2 - Internal combustion engine having a combustion heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an internal combustion engine mounted on a vehicle or the like, and more particularly, to an internal combustion engine provided with a combustion heater provided with a combustion chamber independent of the internal combustion engine.
[0002]
[Prior art]
In recent years, in an internal combustion engine mounted in an automobile or the like, a technique has been proposed in which a combustion heater is additionally provided for the purpose of improving the performance of a room heating device when the engine is cold or promoting warm-up of the internal combustion engine.
[0003]
As an internal combustion engine provided with a combustion heater as described above, for example, an “internal combustion engine having a combustion heater” as described in JP-A-11-229978 is known.
[0004]
In the above publication, a combustion heater having a combustion chamber independent of the internal combustion engine, an air supply path for introducing combustion air from a portion downstream of the air flow meter in the intake passage of the internal combustion engine to the combustion heater, and a combustion type An internal combustion engine having a combustion heater provided with a combustion gas discharge path for guiding combustion gas discharged from the heater to an intake passage of the internal combustion engine is disclosed.
[0005]
In the internal combustion engine having the combustion type heater configured as described above, by supplying the combustion gas of the combustion type heater to the intake passage of the internal combustion engine when the internal combustion engine is cold, the temperature of the intake air or the air-fuel mixture is increased, Accordingly, it is possible to promote warm-up and stabilize combustion.
[0006]
[Problems to be solved by the invention]
By the way, when the combustion air is introduced into the combustion heater from the portion downstream of the air flow meter in the intake passage of the internal combustion engine as in the conventional technique described above, a part of the air that has passed through the air flow meter is the combustion heater. Therefore, the amount of air taken into the internal combustion engine becomes smaller than the detected amount of the air flow meter.
[0007]
Here, in the mass flow type internal combustion engine, the fuel injection amount and the EGR (Exhaust Gas Recirculation) gas amount are controlled using the detection amount of the air flow meter as a parameter, so that the detection of the air flow meter is performed as described above. If an error occurs between the amount and the amount of air actually taken into the internal combustion engine, it becomes difficult to accurately control the fuel injection amount and the EGR gas amount.
[0008]
For example, when the amount of air sucked into the internal combustion engine is smaller than the detected amount of the air flow meter, if the fuel injection amount is determined based on the detected amount of the air flow meter, the air-fuel ratio of the air-fuel mixture becomes unnecessarily low. There is a risk of inducing engine output fluctuations and exhaust emission deterioration.
[0009]
Further, when the amount of air sucked into the internal combustion engine becomes smaller than the detection amount of the air flow meter, if the EGR gas amount is feedback controlled based on the detection amount of the air flow meter, the amount of air in the combustion chamber of the internal combustion engine There is a possibility that the ratio of the amount of EGR gas becomes unnecessarily high, leading to a decrease in engine output and a deterioration in operating conditions.
[0011]
  The present invention has been made in view of the various circumstances as described above, and is configured to introduce an internal combustion engine having a combustion heater, particularly a part of the intake air of the internal combustion engine into the combustion heater as combustion air. Internal combustion machineSekiThe air consumed by the combustion heaterAmountAn object of the present invention is to provide a detectable technique, thereby improving the control accuracy of an internal combustion engine.
[0012]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the aforementioned problems.
That is, an internal combustion engine having a combustion heater according to the present invention is:
A combustion heater having a combustion chamber independent of the internal combustion engine;
An intake air amount detecting means disposed in the intake passage of the internal combustion engine for detecting the amount of air flowing through the intake passage;
Air introduction means for introducing combustion air from the intake passage downstream of the intake air amount detection means to the combustion heater;
Air consumption calculation means for calculating the amount of air consumed by the combustion heater;
An intake air amount correcting means for correcting the intake air amount detected by the intake air amount detecting means based on the air consumption calculated by the air consumption calculating means;
Engine control means for controlling the operating state of the internal combustion engine according to the intake air amount corrected by the intake air amount correction means;
It is characterized by having.
[0013]
The internal combustion engine having the combustion heater includes a combustion heater having a combustion chamber independent of the internal combustion engine, intake air amount detection means disposed in the intake passage of the internal combustion engine, and downstream of the intake air amount detection means. In an internal combustion engine having an air introduction means for introducing combustion air from the intake passage to the combustion heater, the detected amount of the intake air quantity detection means is corrected based on the amount of air consumed by the combustion heater, and after correction The greatest feature is that the operating state of the internal combustion engine is controlled in accordance with the amount of intake air.
[0014]
In an internal combustion engine having such a combustion heater, when the combustion heater is in an operating state, part of the air that has passed through the intake air amount detection means is consumed by the combustion heater.
[0015]
At that time, the air consumption calculation means calculates the amount of air consumed by the combustion heater. The intake air amount correcting means corrects the intake air amount detected by the intake air amount detecting means based on the air consumption calculated by the air consumption calculating means. The engine control means controls the operating state of the internal combustion engine using the intake air amount corrected by the intake air amount correction means as a parameter.
[0016]
In this case, the internal combustion engine is controlled based on the amount of air obtained by subtracting the air consumption amount of the combustion heater from the amount of intake air detected by the intake air amount detection means, that is, the amount of air actually sucked into the internal combustion engine. It will be.
[0017]
As a result, the operating state of the internal combustion engine becomes an operating state corresponding to the amount of air actually sucked into the internal combustion engine.
[0018]
In the internal combustion engine having the combustion heater according to the present invention, the air consumption calculation means may calculate the air consumption with the amount of fuel consumed by the combustion heater as a parameter.
[0019]
In this case, by using the amount of fuel consumed by the combustion heater as a parameter, it is possible to specify the amount of air to be used for combustion of that amount of fuel.
[0020]
In the internal combustion engine having the combustion heater according to the present invention, as the engine control means, a means for controlling the fuel injection amount of the internal combustion engine or a part of the exhaust gas of the internal combustion engine is recirculated to the combustion chamber of the internal combustion engine. A means for controlling the exhaust gas recirculation amount by the exhaust gas recirculation mechanism to be performed can be exemplified.
[0021]
For example, when the engine control means is a means for controlling the fuel injection amount of the internal combustion engine, the intake air amount obtained by subtracting the air consumption amount of the combustion heater from the intake air amount detected by the intake air amount detection means, that is, the internal combustion engine The fuel injection amount is controlled using the amount of air actually sucked into the engine as a parameter. In this case, the air-fuel ratio of the air-fuel mixture burned in the internal combustion engine does not unnecessarily decrease.
[0022]
Further, even when the engine control means is a means for controlling the exhaust gas recirculation amount by the exhaust gas recirculation mechanism, the exhaust gas recirculation amount is controlled using the air amount actually taken into the internal combustion engine as a parameter. Become. In this case, the ratio of the EGR gas amount to the air amount in the combustion chamber of the internal combustion engine does not become excessively high.
[0023]
  next,BookAn internal combustion engine having a combustion heater according to the inventionA combustion gas introduction passage for guiding the combustion gas discharged from the combustion heater to the intake passage of the internal combustion engine, an exhaust gas recirculation mechanism for recirculating a part of the exhaust gas of the internal combustion engine to the combustion chamber of the internal combustion engine, and a combustion type An inert gas component amount calculating means for calculating an inert gas component amount contained in the combustion gas discharged from the heater, and an exhaust gas recirculation mechanism based on the inert gas component amount calculated by the inert gas component amount calculating means. And an exhaust gas recirculation amount correction means for correcting the exhaust gas recirculation amount.You may make it.
[0024]
  That is, the fuel according to the present invention.An internal combustion engine having a firing heater is, InsideAn exhaust gas recirculation mechanism (EGR mechanism) that recirculates part of the exhaust gas of the combustion engine to the combustion chamber of the internal combustion engine; and a combustion gas introduction passage that guides the combustion gas discharged from the combustion heater to the intake passage of the internal combustion engineWhen further comprisingThe exhaust gas recirculation amount is corrected based on the amount of inert gas components contained in the combustion gas of the combustion heater.You may make it do.
[0025]
In an internal combustion engine having such a combustion heater, when the combustion heater is in an operating state, the combustion gas discharged from the combustion heater is supplied to the intake passage of the internal combustion engine, and then the air flowing through the intake passage and the internal combustion engine It will be sucked into the combustion chamber.
[0026]
Here, since the combustion gas of the combustion heater contains an inert gas component as in the exhaust of the internal combustion engine, when the combustion gas is supplied to the combustion chamber of the internal combustion engine, the exhaust gas recirculation mechanism As in the case where the exhaust gas is recirculated, the combustion temperature in the internal combustion engine is reduced and the generation amount of nitrogen oxides (NOx) is suppressed. That is, the combustion gas of the combustion heater has the same function as the exhaust gas recirculated by the exhaust gas recirculation mechanism.
[0027]
Therefore, if the exhaust gas recirculation mechanism is activated while the combustion heater is activated, the amount of the inert gas component supplied to the combustion chamber of the internal combustion engine will increase excessively, resulting in a decrease in engine output and exhaust gas. Deterioration of emissions may be triggered.
[0028]
On the other hand, in the internal combustion engine having the combustion heater according to the present invention, the inert gas component amount calculating means calculates the amount of the inert gas component contained in the combustion gas discharged from the combustion heater and recirculates the exhaust gas. The amount correcting unit corrects the exhaust gas recirculation amount based on the inert gas component amount calculated by the inert gas component amount calculating unit.
[0029]
In this case, the amount of exhaust gas recirculated by the exhaust gas recirculation mechanism takes into account the amount of inert gas components supplied from the combustion heater to the combustion chamber of the internal combustion engine, and as a result, the combustion chamber of the internal combustion engine. The amount of the inert gas component supplied to the gas does not increase excessively.
[0030]
The method for correcting the exhaust gas recirculation amount corresponds to the inert gas component amount calculated by the inert gas component amount calculation means from the exhaust amount to be recirculated by the exhaust gas recirculation mechanism when the combustion heater is not operated. A method of subtracting the exhaust amount to be performed can be exemplified.
[0031]
In the internal combustion engine having the combustion heater according to the present invention, the exhaust gas recirculation mechanism includes an exhaust gas recirculation passage that guides exhaust gas from the exhaust passage of the internal combustion engine to the intake passage, and a flow rate of exhaust gas that flows through the exhaust gas recirculation passage An exhaust gas recirculation mechanism having a flow rate adjusting valve for adjusting the air flow rate can be exemplified. In this case, the exhaust gas recirculation amount correcting means may correct the opening degree of the flow rate adjusting valve based on the inert gas component amount calculated by the inert gas component amount calculating means.
[0032]
In the internal combustion engine having the combustion heater according to the present invention, carbon dioxide can be exemplified as the inert gas component. In this case, the inert gas component amount calculation means may calculate the amount of carbon dioxide discharged from the combustion heater using the amount of fuel consumed by the combustion heater as a parameter.
[0033]
The internal combustion engine having the combustion heater according to the present invention adds the combustion gas discharged from the combustion heater to the combustion gas introduction passage for introducing the combustion gas to the intake passage of the internal combustion engine, and the combustion gas discharged from the combustion heater is When it is not necessary to recirculate the exhaust gas when it is provided with a combustion gas introduction passage to the exhaust passage of the engine and passage switching means for selectively connecting one of these two combustion gas introduction passages The passage switching means may operate so that the combustion gas of the combustion heater is guided to the exhaust passage of the internal combustion engine.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of an internal combustion engine having a combustion heater according to the present invention will be described with reference to the drawings.
[0035]
<First Embodiment>
First, a first embodiment of an internal combustion engine having a combustion heater according to the present invention will be described with reference to FIGS.
[0036]
FIG. 1 is a diagram showing an embodiment of an internal combustion engine having a combustion heater.
The internal combustion engine 1 shown in FIG. 1 is a water-cooled in-cylinder injection type diesel engine having four cylinders 1a. The internal combustion engine 1 includes a crank position sensor 30 that outputs a pulse signal each time a crankshaft (not shown) rotates by a predetermined angle, and a water temperature sensor 31 that outputs an electrical signal corresponding to the temperature of cooling water flowing through a water jacket (not shown). Is attached.
[0037]
A fuel injection valve 1b is attached to each cylinder 1a of the internal combustion engine 1 so that its injection hole faces the combustion chamber. Each fuel injection valve 1b communicates with a pressure accumulation chamber (common rail chamber) 1c that stores fuel supplied from a fuel pump (not shown) until a predetermined pressure is reached.
[0038]
In such a fuel injection system, the fuel discharged from the fuel pump is accumulated until reaching a predetermined pressure in the pressure accumulating chamber 1c. The fuel accumulated to a predetermined pressure in the pressure accumulating chamber 1c is applied to the fuel injection valve 1b of each cylinder 1a, and is injected into the combustion chamber of each cylinder 1a when the fuel injection valve 1b is opened.
[0039]
Next, an intake branch pipe 2 is connected to the internal combustion engine 1, and each branch pipe of the intake branch pipe 2 communicates with a combustion chamber of each cylinder 1a via an intake port (not shown). The intake branch pipe 2 is connected to an intake pipe 3, and the intake pipe 3 is connected to an air cleaner box 4 in which an air filter is housed.
[0040]
An air flow meter 29 that outputs an electrical signal corresponding to the mass of the intake air flowing through the intake pipe 3 is attached to a portion of the intake pipe 3 immediately downstream of the air cleaner box 4. This air flow meter 29 corresponds to the intake air amount detecting means according to the present invention.
[0041]
A compressor housing 5 a of a centrifugal supercharger (turbocharger) 5 is provided in a portion of the intake pipe 3 downstream from the air flow meter 29. A compressor wheel (not shown) is rotatably supported in the compressor housing 5a. The rotation shaft of the compressor wheel is connected to the rotation shaft of a turbine wheel rotatably supported in a turbine housing 5b described later, so that the compressor wheel and the turbine wheel rotate together.
[0042]
Subsequently, the intake pipe 3 downstream of the compressor housing 5a is provided with an intercooler 6 that cools the intake air that has become hot when compressed by the compressor housing 5a. The intake pipe 3 downstream of the intercooler 6 is provided with an intake throttle valve 7 for adjusting the intake flow rate in the intake pipe 3, and the intake throttle valve 7 is for intake throttle that drives the intake throttle valve 7 to open and close. An actuator 8 is attached.
[0043]
In the intake system configured as described above, the air flowing into the air cleaner box 4 is removed by dust and dust with an air filter, and then guided to the compressor housing 5a through the intake pipe 3 and compressed in the compressor housing 5a. The The air which has been compressed in the compressor housing 5 a and becomes high temperature is cooled by the intercooler 6. The intake air cooled by the intercooler 6 is adjusted in flow rate by an intake throttle valve 7 as necessary, and then distributed to the combustion chamber of each cylinder 1a through the intake branch pipe 2 and injected from the fuel injection valve 1b. It is burned using fuel as an ignition source.
[0044]
Further, an exhaust branch pipe 9 is connected to the internal combustion engine 1, and each branch pipe of the exhaust branch pipe 9 communicates with a combustion chamber of each cylinder 1a through an exhaust port (not shown). The exhaust branch pipe 9 is connected to an exhaust pipe 10 via a turbine housing 5b of the centrifugal supercharger 5, and the exhaust pipe 10 is connected downstream to a muffler (not shown).
[0045]
In the turbine housing 5b, a turbine wheel connected to the above-described compressor wheel is rotatably mounted, and the turbine wheel is rotated by utilizing the heat energy of the exhaust.
[0046]
An exhaust purification catalyst 11 that purifies harmful gas components in the exhaust is disposed in the middle of the exhaust pipe 10. The exhaust purification catalyst 11 is a catalyst that is activated when the bed temperature of the exhaust purification catalyst 11 is equal to or higher than a predetermined temperature, and can purify harmful gas components in the exhaust.
[0047]
As the exhaust purification catalyst 11 as described above, an oxidation catalyst, a selective reduction type lean NO_XCatalyst, storage reduction type lean NO_XExamples include a catalyst, a diesel particulate filter (DPF), a diesel particulate NOx reduction (DPNR) catalyst, and the like.
[0048]
An air-fuel ratio sensor 38 that outputs an electric signal corresponding to the air-fuel ratio of the exhaust gas flowing through the exhaust pipe 10 is provided in a portion immediately upstream of the exhaust purification catalyst 11 in the exhaust pipe 10.
[0049]
In the exhaust system configured in this way, the air-fuel mixture (burned gas) combusted in the combustion chamber of each cylinder 1a is discharged to the exhaust branch pipe 9 through the exhaust port, and then centrifugally supercharged from the exhaust branch pipe 9 It flows into the turbine housing 5b of the vessel 5. The exhaust gas that has flowed into the turbine housing 5b rotates the turbine wheel using the thermal energy of the exhaust gas. At that time, the rotational torque of the turbine wheel is transmitted to the compressor wheel of the compressor housing 5a described above.
[0050]
The exhaust discharged from the turbine housing 5b flows into the exhaust purification catalyst 11 through the exhaust pipe 10. At this time, if the floor temperature of the exhaust purification catalyst 11 is within the temperature purification window, the exhaust purification catalyst 11 removes or purifies the harmful gas components in the exhaust. Exhaust gas from which harmful gas components have been removed or purified by the exhaust purification catalyst 11 is released into the atmosphere via the muffler.
[0051]
The exhaust branch pipe 9 and the intake branch pipe 2 are connected via an EGR (Exhaust Gas Recirculation) passage 12 for returning a part of the exhaust gas flowing in the exhaust branch pipe 9 to the intake branch pipe 2. It is communicated. In the middle of the EGR passage 12, an EGR valve 13 configured by an electromagnetic valve or the like for changing the flow rate of exhaust gas (hereinafter referred to as EGR gas) flowing in the EGR passage 12 according to the magnitude of applied power, An EGR cooler 120 for cooling the EGR gas flowing through the EGR passage 12 is provided.
[0052]
In the exhaust gas recirculation mechanism configured as described above, when the EGR valve 13 is opened, the EGR passage 12 becomes conductive, and a part of the exhaust gas flowing in the exhaust branch pipe 9 flows into the EGR passage 12 as EGR gas. To do. The EGR gas flowing into the EGR passage 12 is guided to the intake branch pipe 2 through the EGR cooler 120.
[0053]
At that time, in the EGR cooler 120, heat exchange is performed between the EGR gas flowing in the EGR passage 12 and a predetermined refrigerant, thereby cooling the EGR gas.
[0054]
The EGR gas recirculated from the exhaust branch pipe 9 to the intake branch pipe 2 through the EGR passage 12 is guided to the combustion chamber of each cylinder while being mixed with the air flowing from the upstream side of the intake branch pipe 2, and the fuel injection valve The fuel injected from 1b is burned using an ignition source.
[0055]
Here, the EGR gas contains water (H₂O) and carbon dioxide (CO₂) And the like, and an inert gas component having endothermic properties is contained in the mixture, so if EGR gas is contained in the mixture, the combustion temperature of the mixture is lowered. Therefore, the amount of nitrogen oxide (NOx) generated is suppressed.
[0056]
Further, when the EGR gas is cooled in the EGR cooler 120, the temperature of the EGR gas itself is reduced and the volume of the EGR gas is reduced. Therefore, when the EGR gas is supplied into the combustion chamber, the atmospheric temperature in the combustion chamber is reduced. Is not increased unnecessarily, and the amount of air (volume of air) supplied into the combustion chamber is not unnecessarily reduced.
[0057]
Next, the internal combustion engine 1 is provided with a combustion heater 14. As shown in FIG. 2, the combustion heater 14 includes an outer cylinder 140, an intermediate cylinder 141 provided in the outer cylinder 140, and a combustion cylinder 142 provided in the intermediate cylinder 141.
[0058]
Between the outer cylinder 140 and the intermediate cylinder 141, an in-heater cooling water channel 200 for flowing cooling water of the internal combustion engine 1 is formed. The outer cylinder 140 has a cooling water introduction port 143 for taking cooling water into the heater cooling water channel 200 and a cooling water discharge port 144 for discharging cooling water in the heater cooling water channel 200. Is formed.
[0059]
A cooling water introduction pipe 22 is connected to the cooling water introduction port 143, and a cooling water discharge pipe 23 is connected to the cooling water discharge port 144. As shown in FIG. 1, the cooling water introduction pipe 22 and the cooling water discharge pipe 23 are connected to a water jacket (not shown) of the internal combustion engine 1. An electric water pump 24 is provided in the middle of the cooling water introduction pipe 22 so that the cooling water flowing in the water jacket of the internal combustion engine 1 is forcibly sent to the cooling water introduction port 143. On the other hand, in the middle of the cooling water discharge pipe 23, a heater core 25 of the indoor heating device is arranged, and heat of the cooling water flowing through the cooling water discharge pipe 23 is transmitted to the heating air.
[0060]
Connected to the combustion cylinder 142 is a fuel introduction pipe 27 that guides a part of the fuel discharged from the fuel pump for the internal combustion engine 1 to the combustion cylinder 142. Further, although not shown, the combustion cylinder 142 is a vaporization glow plug for vaporizing the fuel supplied by the fuel introduction pipe 27 and an ignition glow for igniting the fuel vaporized by the vaporization glow plug. And a plug. Note that the vaporization glow plug and the ignition glow plug may be combined with a single glow plug.
[0061]
A housing 148 in which a blower fan 149 for sending combustion air to the combustion cylinder 142 and a motor 150 for rotationally driving the blower fan 149 is mounted on the outer cylinder 140.
[0062]
The housing 148 is formed with an intake port 151 for taking combustion air into the housing 148. As shown in FIG. 1, an intake air introduction passage 15 is connected to the intake port 151, and the intake air introduction passage 15 is connected to a portion of the intake pipe 3 between the air flow meter 29 and the compressor housing 5a. .
[0063]
Between the intermediate cylinder 141 and the combustion cylinder 142, a combustion gas passage 201 for flowing the combustion gas generated in the combustion cylinder 142 is formed. A combustion gas discharge port 145 that communicates the combustion gas passage 201 and the outside of the outer cylinder 140 is formed at an appropriate portion of the intermediate cylinder 141.
[0064]
As shown in FIG. 1, a combustion gas discharge passage 17 is connected to the combustion gas discharge port 145, and this combustion gas discharge passage 17 is a portion between the turbine housing 5 b and the exhaust purification catalyst 11 in the exhaust pipe 10. It is connected to the.
[0065]
An intake side exhaust passage 36 is connected to the combustion gas exhaust passage 17 in the middle, and the intake side exhaust passage 36 is connected to the intake branch pipe 2 described above. Here, the portion of the combustion gas discharge passage 17 closer to the combustion heater 14 than the connection portion to the intake side discharge passage 36 is referred to as a first combustion gas discharge passage 17a, and the portion connected to the intake side discharge passage 36 is exhausted. The part on the tube 10 side is referred to as a second combustion gas discharge passage 17b.
[0066]
A three-way switching valve 37 is provided at a connecting portion of the first combustion gas discharge passage 17a, the second combustion gas discharge passage 17b, and the intake side discharge passage 36 described above. The three-way switching valve 37 selectively blocks either one of the second combustion gas discharge passage 17b and the intake side discharge passage 36, so that the first combustion gas discharge passage 17a and the intake side discharge passage 36 are closed. Or conduction between the first combustion gas discharge passage 17a and the second combustion gas discharge passage 17b is selectively established. The three-way switching valve 37 is driven by an actuator such as a step motor.
[0067]
In the combustion type heater 14 configured as described above, the motor 150 operates the blower fan 149 to supply a part of the intake air flowing in the intake pipe 3 to the combustion cylinder 142 of the combustion type heater 14, and the fuel pump is not shown. The fuel in the fuel tank is sucked up and supplied to the combustion cylinder 142 of the combustion heater 14, and the water pump 24 is further operated to supply the cooling water in the water jacket of the internal combustion engine 1 to the cooling water introduction port 143 of the combustion heater 14. Pump. Next, the glow plug of the combustion cylinder 142 is energized, and the mixture of the intake air supplied by the blower fan 149 and the fuel supplied by the fuel pump is combusted in the combustion cylinder 145.
[0068]
The combustion gas burned in the combustion cylinder 145 is pushed out from the combustion cylinder 145 to the combustion gas passage 201 by the pressure of the intake air sent out by the blower fan 149, and then discharged from the combustion gas passage 201 to the combustion gas discharge port 145. The
[0069]
The combustion gas discharged to the combustion gas discharge port 145 flows into the combustion gas discharge passage 17 and is guided to the intake branch pipe 2 or the exhaust pipe 10 via the three-way switching valve 37.
[0070]
On the other hand, the cooling water pumped by the water pump 24 to the cooling water introduction port 143 of the combustion heater 14 is led from the cooling water introduction port 143 to the heater cooling water channel 200 and then cooled after passing through the heater cooling water channel 200. It is discharged to the water discharge port 144.
[0071]
At that time, the heat of the combustion gas flowing through the combustion gas passage 201 is transmitted to the cooling water flowing through the heater cooling water channel 200 through the wall surface of the intermediate cylinder 144, and the temperature of the cooling water rises.
[0072]
The cooling water heated in this way is discharged from the cooling water discharge port 144 to the cooling water discharge pipe 23, returned to the water jacket of the internal combustion engine 1 through the heater core 25, and circulates in the water jacket. In the heater core 25, a part of the heat of the cooling water is transmitted to the heating air to raise the temperature of the heating air.
[0073]
Here, referring back to FIG. 1, the internal combustion engine 1 configured as described above is provided with an electronic control unit (ECU) 28 for controlling the internal combustion engine 1. The ECU 28 is a unit that controls the operation state of the internal combustion engine 1 in accordance with the operation conditions of the internal combustion engine 1 and the request of the driver.
[0074]
In addition to the air flow meter 29, the crank position sensor 30, the water temperature sensor 31, and the air-fuel ratio sensor 38, the ECU 28 outputs an accelerator signal that outputs an electrical signal corresponding to an operation amount (accelerator opening) of an accelerator pedal (not shown). 33, an ignition switch 34, a starter switch 35, and other various sensors are connected via electrical wiring, and output signals from the various sensors described above are input to the ECU 28.
[0075]
Further, the ECU 28 is connected to the fuel injection valve 1b, the intake throttle actuator 8, the EGR valve 13, the combustion heater 14, the electric water pump 24, the three-way switching valve 37, and the like through the electrical wiring. The fuel injection valve 1b, the intake throttle actuator 8, the EGR valve 13, the combustion heater 14, the electric water pump 24, and the three-way switching valve 37 can be controlled using the output signal value of the sensor as a parameter.
[0076]
Here, as shown in FIG. 3, the ECU 28 includes a CPU 281, a ROM 282, a RAM 283, a backup RAM 284, an input port 286, and an output port 287 that are connected to each other via a bidirectional bus 280. And an A / D converter (A / D) 285 connected to the input port 286.
[0077]
The input port 286 receives output signals of sensors that output digital signal format signals such as the crank position sensor 30, the ignition switch 34, the starter switch 35, and the like, and transmits the output signals to the CPU 281 and the RAM 283. .
[0078]
The input port 286 is input via an A / D 285 of a sensor that outputs a signal in an analog signal format, such as the air flow meter 29, the water temperature sensor 31, the accelerator position sensor 33, the air-fuel ratio sensor 38, and the like. The signal is transmitted to the CPU 281 and the RAM 283.
[0079]
The output port 287 is connected to the fuel injection valve 1b, the intake throttle actuator 8, the EGR valve 13, the combustion heater 14, the three-way switching valve 37, the electric water pump 24, and the like via electric wiring, and is output from the CPU 281. The control signal is transmitted to the fuel injection valve 1b, the intake throttle actuator 8, the EGR valve 13, the combustion heater 14, the three-way switching valve 37, or the electric water pump 24.
[0080]
The ROM 282 includes a fuel injection valve control routine for controlling the fuel injection valve 1b, an intake throttle control routine for controlling the intake throttle valve 7, an EGR control routine for controlling the EGR valve 13, a combustion heater 14 and Intake air for correcting the output signal value (intake air amount) of the air flow meter 29 when the combustion heater 14 is operated, in addition to various application programs such as a heater control routine for collectively controlling the three-way switching valve 37 and the electric water pump 24. An amount correction control routine is stored.
[0081]
The ROM 282 stores various control maps in addition to the application programs described above. The control map is, for example, a fuel injection amount control map showing the relationship between the operating state of the internal combustion engine 1 and the basic fuel injection amount (basic fuel injection time), and the relationship between the operating state of the internal combustion engine 1 and the basic fuel injection timing. The fuel injection timing control map shown, the intake throttle valve opening control map showing the relationship between the operating state of the internal combustion engine 1 and the target opening of the intake throttle valve 7, the relationship between the operating state of the internal combustion engine 1 and the target EGR gas amount EGR gas amount control map shown, EGR valve opening control map showing the relationship between the target EGR gas amount and the target opening of the EGR valve 13, and the relationship between the operating state of the internal combustion engine 1 and the operating state of the combustion heater 14 It is a heater control map.
[0082]
The RAM 283 stores output signals from the sensors, calculation results of the CPU 281 and the like. The calculation result is, for example, an engine speed calculated based on a time interval at which the crank position sensor 30 outputs a pulse signal. These data are rewritten to the latest data every time the crank position sensor 30 outputs a pulse signal.
[0083]
The backup RAM 284 is a nonvolatile memory capable of storing data even after the internal combustion engine 1 is stopped.
[0084]
The CPU 281 operates in accordance with an application program stored in the ROM 282 and executes intake air amount correction control that is the gist of the present invention in addition to fuel injection valve control, intake throttle control, EGR control, and combustion heater control. .
[0085]
Here, in the fuel injection control of the diesel engine such as the internal combustion engine 1, the CPU 281 calculates the engine speed based on the time interval at which the crank position sensor 30 outputs the pulse signal, and the output signal of the accelerator position sensor 33. Enter (accelerator opening).
[0086]
The CPU 281 accesses the fuel injection amount control map in the ROM 282 using the engine speed and the accelerator opening as parameters, and calculates a basic injection amount: Qbase corresponding to the engine speed and the accelerator opening.
[0087]
Subsequently, the CPU 281 determines the final fuel injection amount by correcting the basic injection amount: Qbase using the output signal (intake air amount) of the air flow meter 29 as a parameter. This is because if the amount of fuel injected from the fuel injection valve 1b into each cylinder 1a is excessive with respect to the amount of air (oxygen amount) supplied to each cylinder 1a of the internal combustion engine 1, fuel shortage due to lack of oxygen occurs. This is because complete combustion occurs, and as a result, black smoke is discharged from each cylinder 1a.
[0088]
As a correction method for the basic injection amount: Qbase, for example, the maximum fuel injection amount (maximum injection amount: Qfull) within a range in which the generation of black smoke can be suppressed with respect to the intake air amount of each cylinder 1a, A method of setting the smaller one of the maximum injection amount: Qfull and the basic injection amount: Qbase as the final fuel injection amount can be exemplified.
[0089]
Thus, by limiting the fuel injection amount by the maximum injection amount: Qfull, it is possible to suppress the generation of black smoke within an allowable range.
[0090]
By the way, in the internal combustion engine 1 according to the present embodiment, since the intake introduction passage 15 of the combustion heater 14 is connected to a portion of the intake pipe 3 downstream of the air flow meter 29, the combustion heater 14 is in an operating state. The combustion air is supplied from the intake pipe 3 downstream of the air flow meter 29 to the combustion heater 14. That is, when the combustion heater 14 is in an operating state, a part of the intake air that has passed through the air flow meter 29 is consumed by the combustion heater 14.
[0091]
When a portion of the intake air that has passed through the air flow meter 29 is consumed by the combustion heater 14, the air flow meter 29 detects the amount of air actually taken into the internal combustion engine 1 (hereinafter referred to as the actual intake air amount). Less than intake air volume.
[0092]
Under such circumstances, when the maximum injection amount: Qfull is calculated using the output signal of the air flow meter 29 as a parameter, the maximum injection amount: Qfull is excessive with respect to the actual intake air amount of the internal combustion engine 1. . When the basic injection amount: Qbaseg is corrected by the excessive maximum injection amount: Qfull, the final fuel injection amount becomes larger than the range in which the generation of black smoke can be suppressed, and exhaust emission may be deteriorated.
[0093]
In the EGR control of the internal combustion engine 1, the CPU 281 accesses the EGR gas amount control map in the ROM 282 using the engine speed and the accelerator opening as parameters, and the target EGR gas corresponding to the engine speed and the accelerator opening. Calculate the amount. Subsequently, the CPU 281 accesses the EGR valve opening degree control map in the ROM 282 and calculates a target EGR valve opening degree corresponding to the target EGR gas amount.
[0094]
The CPU 281 applies drive power corresponding to the target EGR valve opening to the EGR valve 13 and feedback-controls the opening of the EGR valve 13 using the output signal (intake air amount) of the air flow meter 29 as a parameter.
[0095]
In the EGR valve opening degree feedback control, for example, the CPU 281 determines the target intake air amount of the internal combustion engine 1 using the accelerator opening degree, the engine speed, and the like as parameters. At that time, the relationship between the accelerator opening, the engine speed, and the target intake air amount may be mapped in advance, and the target intake air amount may be calculated from the map, the accelerator opening, and the engine speed. .
[0096]
When the target intake air amount is determined by the above procedure, the CPU 281 compares the intake air amount detected by the air flow meter 11 with the target intake air amount.
[0097]
When the intake air amount detected by the air flow meter 29 is smaller than the target intake air amount, the CPU 281 closes the EGR valve 13 by a predetermined amount. In this case, the amount of EGR gas flowing into the intake branch pipe 2 from the EGR passage 12 decreases, and the amount of EGR gas sucked into each cylinder 1a of the internal combustion engine 1 decreases accordingly. As a result, the amount of air taken into the cylinder 2 of the internal combustion engine 1 increases by the amount that the EGR gas has decreased.
[0098]
On the other hand, when the intake air amount detected by the air flow meter 29 is larger than the target intake air amount, the CPU 281 opens the EGR valve 13 by a predetermined amount. In this case, the amount of EGR gas flowing into the intake branch pipe 2 from the EGR passage 12 increases, and the amount of EGR gas sucked into each cylinder 1a of the internal combustion engine 1 increases accordingly. As a result, the amount of air taken into the cylinder 2 of the internal combustion engine 1 decreases by the amount of EGR gas increased.
[0099]
Incidentally, in the internal combustion engine 1 according to the present embodiment, as described above, since the intake air introduction passage 15 is connected to a portion of the intake pipe 3 downstream of the air flow meter 29, the combustion heater 14 is in an operating state. The actual intake air amount of the internal combustion engine 1 becomes smaller than the intake air amount detected by the air flow meter 29.
[0100]
Under such circumstances, when EGR valve opening degree feedback control is executed using the output signal of the air flow meter 29 as a parameter, the opening degree of the EGR valve 13 is opened corresponding to the intake air amount detected by the air flow meter 29. However, the opening is excessive with respect to the actual intake air amount. Thus, when the opening degree of the EGR valve 13 becomes an excessive opening degree with respect to the actual intake air amount, the EGR gas amount supplied to each cylinder 1a with respect to the air amount supplied to each cylinder 1a of the internal combustion engine 1 Therefore, incomplete combustion of the fuel is induced, and exhaust emission deterioration and engine output decrease may be induced.
[0101]
Therefore, in the internal combustion engine having the combustion heater according to the present embodiment, when the combustion heater 14 is in an operating state, the amount of air consumed by the combustion heater 14 is the amount of intake air detected by the air flow meter 29. Intake air amount correction control is performed based on (hereinafter referred to as heater consumption air amount).
[0102]
Hereinafter, intake air amount correction control in the present embodiment will be described.
When executing the intake air amount correction control, the CPU 281 executes an intake air amount correction control routine as shown in FIG. This intake air amount correction control routine is a routine stored in the ROM 282 in advance, and is a routine that is repeatedly executed by the CPU 281 every predetermined time (for example, every time the crank position sensor 30 outputs a pulse signal).
[0103]
In the intake air amount correction control routine, the CPU 281 first inputs an output signal value (intake air amount): Ga of the air flow meter 29 in S401.
[0104]
In S402, the CPU 281 determines whether or not the combustion heater 14 is in an operating state.
[0105]
If it is determined in S402 that the combustion heater 14 is in an inoperative state, the CPU 281 regards that all of the air that has passed through the air flow meter 29 is supplied to the internal combustion engine 1, and proceeds to S407.
[0106]
In S407, the CPU 281 stores the intake air amount: Ga input in S401 in the RAM 283 as the actual intake air amount, and ends the execution of this routine.
[0107]
On the other hand, if it is determined in S402 that the combustion heater 14 is in an operating state, the CPU 281 detects the air flow meter 29 because a part of the air that has passed through the air flow meter 29 is consumed by the combustion heater 14. Since it is deemed necessary to correct the intake air amount, the process proceeds to S403.
[0108]
In S403, the CPU 281 reads the fuel supply amount calculated by a separate combustion heater control routine. Here, the fuel supply amount indicates the amount of fuel supplied from the fuel pump to the combustion heater 14.
[0109]
In S404, the CPU 281 is consumed by the combustion heater 14 based on the air-fuel ratio of the air-fuel mixture combustible by the combustion heater 14 (for example, the theoretical air-fuel ratio: 14) and the fuel supply amount read in S403. Air amount (heater consumption air amount): Hair is calculated. Specifically, the air consumption ratio: Hair is calculated by integrating the air-fuel ratio and the fuel supply amount.
[0110]
In S405, the CPU 281 calculates an actual intake air amount (= Ga−Hair) by subtracting the heater air consumption amount: Hair calculated in S404 from the intake air amount: Ga input in S401.
[0111]
In S406, the CPU 281 stores the actual intake air amount calculated in S405 in the RAM 283, and ends the execution of this routine.
[0112]
In this case, in the fuel injection control and EGR valve opening feedback control, the CPU 281 uses the actual intake air amount calculated by the intake air amount correction control routine as a parameter, and calculates the maximum injection amount: Qfull and the EGR valve opening. Control.
[0113]
As a result, the maximum injection amount: Qfull and the EGR valve opening are values suitable for the amount of air actually taken into the internal combustion engine 1, so that black smoke and incomplete combustion are prevented, and exhaust emission is prevented. The deterioration of the engine and the decrease in engine output are prevented.
[0114]
Therefore, according to the internal combustion engine having the combustion heater according to the present embodiment, when a part of the air that has passed through the air flow meter 29 is used as combustion air for the combustion heater 14, the internal combustion engine 1 is actually used. It becomes possible to control the operating state of the internal combustion engine 1 based on the amount of air taken in, and thus the control accuracy of the internal combustion engine 1 can be improved.
[0115]
In the present embodiment, the EGR valve is exemplified as means for adjusting the amount of EGR gas. However, the present invention is not limited to this. For example, the intake throttle valve 7 may be used. This is because the flow rate of the EGR gas flowing through the EGR passage 12 changes in accordance with the pressure difference between the exhaust branch pipe 9 and the intake branch pipe 2, so that by changing the opening of the intake throttle valve 7, This is because as the pressure in the pipe 2 changes, the pressure difference between the intake branch pipe 2 and the exhaust branch pipe 9 changes, thereby changing the flow rate of the EGR gas flowing in the EGR passage 12.
[0116]
In the present embodiment, a compression ignition type diesel engine is used as an example of the internal combustion engine according to the present invention. However, it is needless to say that an ignition type gasoline engine may be used.
[0117]
<Second Embodiment>
Next, a second embodiment of an internal combustion engine having a combustion heater according to the present invention will be described with reference to FIGS. Here, a configuration different from the above-described first embodiment will be described, and description of the same configuration will be omitted.
[0118]
In the first embodiment described above, the output signal of the air flow meter 29 used as a parameter for fuel injection control or EGR valve opening feedback control is corrected based on the amount of air consumed by the combustion heater 14. In this embodiment, an example in which the amount of EGR gas is controlled based on the amount of inert gas component contained in the combustion gas from the combustion heater 14 will be described.
[0119]
Since the combustion type heater 14 in the present embodiment uses the same fuel as that of the internal combustion engine 1, the combustion gas discharged from the combustion type heater 14 is carbon dioxide (CO₂) And water (H₂Inert gas components such as 0) are included. Further, the internal combustion engine having the combustion heater according to the embodiment is configured to selectively supply the combustion gas discharged from the combustion heater 14 to either the intake branch pipe 2 or the exhaust pipe 10. ing. Focusing on these points, when the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2, the combustion gas has the same function as the EGR gas.
[0120]
Therefore, if EGR control is executed in a state where the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2, the amount of the inert gas component supplied to each cylinder 1a of the internal combustion engine 1 is excessive. There is a risk that black smoke may be generated due to incomplete combustion or engine output may be reduced.
[0121]
For example, when the EGR control is executed in a state where the combustion heater 14 is in the non-operating state, only the EGR gas from the EGR passage 12 and the EGR valve 13 (hereinafter collectively referred to as an EGR mechanism) is Since it is supplied to each cylinder 1a, the target EGR valve opening is determined based on the engine speed and the accelerator opening, and the opening of the EGR valve 13 is feedback-controlled based on the target EGR valve opening. Then, the amount of EGR gas actually supplied to the internal combustion engine 1 substantially converges to a desired target EGR gas amount as shown in FIG.
[0122]
On the other hand, when the EGR control is performed in a state where the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2, the combustion gas of the combustion heater 14 is added to the EGR gas by the EGR mechanism. Since the EGR gas is supplied to each cylinder 1a of the internal combustion engine 1, when the EGR mechanism is controlled by the same method as when the combustion heater 14 is in the non-operating state, the internal combustion engine 1 is substantially controlled. As shown in FIG. 6, the amount of EGR gas supplied is larger than the desired target EGR gas amount.
[0123]
Therefore, in the EGR control according to the present embodiment, when the EGR control is executed in a state where the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2, the exhaust gas is discharged from the combustion heater 14. The amount of the inert gas component was calculated, and the amount of the EGR gas by the EGR mechanism was controlled in consideration of the amount of the inert gas component.
[0124]
Specifically, the CPU 281 burns the combustion heater 14 based on the amount of fuel consumed by the combustion heater 14 and the air-fuel ratio of the air-fuel mixture combustible by the combustion heater 14 (for example, the theoretical air-fuel ratio = 14). The amount of inert gas component contained in the gas: Hex is calculated, and the target EGR gas amount: Etarget is calculated based on the engine speed, the accelerator opening, and the EGR gas amount control map.
[0125]
The relationship between the amount of fuel consumed by the combustion heater 14, the air-fuel ratio of the air-fuel mixture combustible by the combustion heater 14 and the amount of inert gas component: Hex is experimentally determined in advance and mapped. It may be.
[0126]
Subsequently, the CPU 281 corrects the target EGR gas amount: Etarget based on the inert gas component amount: Hex. Specifically, the CPU 281 calculates a new target EGR gas amount: Eegr by subtracting the inert gas component amount: Hex from the target EGR gas amount: Etarget, and sets the new target EGR gas amount: Eegr. The target EGR gas amount for the EGR mechanism is set. Hereinafter, the target EGR gas amount: Etarget is referred to as a target EGR gas amount final value: Etarget, and the target EGR gas amount: Eegr is referred to as an EGR mechanism target EGR gas amount: Eegr.
[0127]
When the target EGR gas amount for EGR mechanism: Eegr is determined in this way, the CPU 281 accesses the EGR valve opening control map in the ROM 282 using the target EGR gas amount for EGR mechanism: Eegr as a parameter, and the EGR mechanism. Target EGR gas amount: A target EGR valve opening corresponding to Eegr is calculated, and the EGR valve 13 is controlled according to the target EGR valve opening.
[0128]
On the other hand, in the EGR valve opening feedback control, the CPU 281 determines the target intake air amount based on the target EGR gas amount final value: Etarget, and the air amount actually sucked into the internal combustion engine 1 is the target intake air amount. The opening degree of the EGR valve 13 is feedback controlled so as to match. At this time, the actual intake air amount described in the first embodiment is used as the air amount actually sucked into the internal combustion engine 1.
[0129]
When the opening degree of the EGR valve 13 is controlled as described above, the EGR gas amount supplied to the internal combustion engine 1 by the EGR mechanism converges to the EGR mechanism target EGR gas amount: Eegr, and the combustion heater 14 Since the amount of the inert gas component supplied to the engine 1 becomes the inert gas component amount: Hex, the amount of EGR gas actually supplied to the internal combustion engine 1 is the target EGR gas amount for the EGR mechanism: An amount obtained by adding Eegr and the inert gas component amount: Hex, that is, a target EGR gas amount final value: Etarget is converged (see FIG. 7).
[0130]
Hereinafter, EGR control according to the present embodiment will be described with reference to FIG.
FIG. 8 is a flowchart showing an EGR control routine. This EGR control routine is a routine that is repeatedly executed by the CPU 281 every predetermined time (for example, every time the crank position sensor 30 outputs a pulse signal).
[0131]
In the EGR control routine, the CPU 281 first determines whether or not an EGR control execution condition is satisfied in S801. As the EGR control execution condition, for example, an accelerator position sensor 33 in which the output signal (cooling water temperature) of the water temperature sensor 31 is equal to or higher than a predetermined temperature, and the internal combustion engine 1 is continuously operated for a predetermined time or more from the start. The condition that the amount of change in the output signal (accelerator opening) is a positive value can be exemplified.
[0132]
When it is determined that the above-described EGR control execution condition is not satisfied, the CPU 281 performs control to hold the EGR valve 13 in the fully closed state, and temporarily ends the execution of this routine.
[0133]
When the combustion heater 14 is operated under the condition where the EGR control execution condition is not satisfied, the intake side exhaust passage 36 is shut off and the first combustion gas exhaust passage 17a and the second combustion gas exhaust passage are provided. It is preferable to control the three-way switching valve 37 so as to make 17 b conductive so that the combustion gas of the combustion heater 14 does not flow to the intake branch pipe 2.
[0134]
This is because, when the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2 under the condition where the EGR control execution condition is not satisfied, the inert gas component contained in the combustion gas is reduced in the internal combustion engine 1. This is because the fuel is supplied to each cylinder 1a, which may cause a decrease in engine output or black smoke due to incomplete combustion.
[0135]
If it is determined in S801 that the EGR control execution condition is satisfied, the CPU 281 proceeds to S802 and determines whether or not the combustion heater 14 is in an operating state.
[0136]
If it is determined in S802 that the combustion heater 14 is in the non-operating state, the CPU 281 proceeds to S814 and executes normal EGR control as described in the explanation of FIG.
[0137]
If it is determined in S802 that the combustion heater 14 is in the operating state, the CPU 281 proceeds to S803, and whether the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2 of the internal combustion engine 1 or not. That is, it is determined whether or not the three-way switching valve 37 blocks the second combustion gas discharge passage 17b and connects the first combustion gas discharge passage 17a and the intake side discharge passage 36 to each other.
[0138]
If it is determined in S803 that the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2 of the internal combustion engine 1, the CPU 281 proceeds to S804 and the fuel calculated by a separate combustion heater control routine is calculated. Read the supply amount.
[0139]
In S805, the CPU 281 discharges from the combustion heater 14 based on the air-fuel ratio of the air-fuel mixture combustible in the combustion heater 14 (for example, the theoretical air-fuel ratio: 14) and the fuel supply amount read in S804. Inert gas component amount: Hex is calculated.
[0140]
In S806, the CPU 281 reads out the output signal (accelerator opening) and the engine speed of the accelerator position sensor 33 from the RAM 283 and accesses the EGR gas amount control map in the ROM 282 to correspond to the engine speed and the accelerator opening. The target EGR gas amount (target EGR gas amount final value: Etarget) is calculated.
[0141]
In S807, the CPU 281 subtracts the inert gas component amount: Hex calculated in S805 from the target EGR gas amount final value: Etarget calculated in S806 to obtain an EGR mechanism target EGR gas amount: Eegr (= Etarget-Hex) is calculated.
[0142]
In S808, the CPU 281 accesses the EGR valve opening control map in the ROM 282 using the EGR mechanism target EGR gas amount Eegr calculated in S807 as a parameter, and the target corresponding to the EGR mechanism target EGR gas amount Eegr. The EGR valve opening is calculated. Then, the CPU 281 controls the EGR valve 13 according to the target EGR valve opening.
[0143]
Subsequently, the CPU 281 executes feedback control of the EGR valve 13 in S809 to S811.
[0144]
Specifically, first, in step S809, the CPU 281 calculates a target intake air amount corresponding to the target EGR gas amount final value Etarget calculated in step S806.
[0145]
In S810, the CPU 281 calculates the amount of air actually taken into the internal combustion engine 1 (actual intake air amount). As in the first embodiment, the actual intake air amount is calculated by subtracting the heater air consumption amount: Hair from the output signal: Ga of the air flow meter 29 and calculating the actual intake air amount (= Ga−Hair). The method of calculating can be illustrated.
[0146]
In S811, the CPU 281 controls the opening of the EGR valve 13 so that the actual intake air amount (= Ga−Hair) calculated in S810 matches the target intake air amount calculated in S809.
[0147]
Specifically, the CPU 281 compares the actual intake air amount with the target intake air amount, and if the actual intake air amount is greater than the target intake air amount, the EGR gas amount is increased by a predetermined amount. The opening degree of the valve 13 is corrected in the valve opening direction, and when the actual intake air amount is smaller than the target intake air amount, the opening degree of the EGR valve 13 is corrected to the closed side so as to decrease the EGR gas amount by a predetermined amount. To do.
[0148]
In this case, the target EGR gas amount (EGR mechanism target EGR gas amount: Eegr) of the EGR mechanism is the inert gas component amount: Hex supplied from the combustion heater 14 to the internal combustion engine 1 as the target EGR gas amount final value: Since the amount obtained by subtracting from Etarget (= Etarget−Hex), the total amount of EGR gas actually supplied to the internal combustion engine 1 is the target EGR gas amount for EGR mechanism: Eegr and the amount of inert gas component : The amount obtained by adding Hex, that is, the target EGR gas amount final value: Etarget converges.
[0149]
Further, when it is determined in S 803 that the combustion gas of the combustion heater 14 is not supplied to the intake branch pipe 2 of the internal combustion engine 1, that is, the combustion gas of the combustion heater 14 is sent to the exhaust pipe 10 of the internal combustion engine 1. If it is supplied, the CPU 281 proceeds to S812, and calculates the target EGR gas amount final value: Etarget in the same procedure as in S806 described above.
[0150]
Subsequently, in S813, the CPU 281 accesses the EGR valve opening control map in the ROM 282 using the target EGR gas amount final value Etarget calculated in S812 as a parameter, and corresponds to the target EGR gas amount final value Etarget. A target EGR valve opening is calculated. Then, the CPU 281 controls the EGR valve 13 according to the target EGR valve opening.
[0151]
The CPU 281 that has completed the processing of S813 executes feedback control after S809.
[0152]
In this case, the EGR gas amount supplied to the internal combustion engine 1 by the EGR mechanism converges to the target EGR gas amount final value: Etarget. However, since the combustion gas of the combustion heater 14 is not supplied to the internal combustion engine 1, The amount of EGR gas actually supplied to the engine 1 converges to the target EGR gas amount final value: Etarget.
[0153]
As described above, when the CPU 281 executes the EGR control routine, when it becomes necessary to execute the EGR control in a situation where the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2 of the internal combustion engine 1, The target EGR gas amount of the EGR mechanism (EGR mechanism target EGR gas amount: Eegr) is obtained by subtracting the inert gas component amount: Hex supplied from the combustion heater 14 to the internal combustion engine 1 from the target EGR gas amount final value: Etarget. Therefore, the total amount of EGR gas actually supplied to the internal combustion engine 1 is EGR mechanism target EGR gas amount: Eegr and inert gas component amount: Hex. To the target EGR gas amount final value: Etarget.
[0154]
As a result, even when the combustion gas of the combustion heater 14 is supplied to the intake branch pipe 2 of the internal combustion engine 1, the amount of the inert gas component actually supplied to the internal combustion engine 1 is set to a desired amount. Therefore, it is possible to prevent a decrease in engine output and exhaust emission.
[0155]
【The invention's effect】
  According to the internal combustion engine having the combustion heater according to the present invention, the internal combustion engine configured to introduce a part of the intake air of the internal combustion engine into the combustion heater as combustion air.SekiThe air consumed by the combustion heaterAmountThe air actually taken into the internal combustion engine because it can be detected.AmountIt becomes possible to grasp.
[0156]
  As a result, it is possible to improve the control accuracy of the internal combustion engine using the intake air amount as a parameter.Become.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine having a combustion heater according to a first embodiment.
FIG. 2 is a diagram showing the internal configuration of a combustion heater
FIG. 3 is a block diagram showing the internal configuration of the ECU
FIG. 4 is a flowchart showing an intake air amount correction control routine.
FIG. 5 is a diagram (1) showing the relationship between the opening degree of the EGR valve and the amount of EGR gas introduced into the internal combustion engine in EGR control.
FIG. 6 is a diagram (2) showing the relationship between the opening degree of the EGR valve and the amount of EGR gas introduced into the internal combustion engine in EGR control.
FIG. 7 is a diagram showing the relationship between the opening degree of the EGR valve and the amount of EGR gas introduced into the internal combustion engine in EGR control (3)
FIG. 8 is a flowchart showing an EGR control routine.
[Explanation of symbols]
1 ... Internal combustion engine
2 ... Intake branch pipe
3 ... Intake pipe
10. Exhaust pipe
11. Exhaust gas purification catalyst
12. EGR passage
13. EGR valve
14. Combustion heater
15. Intake air intake passage
17. Combustion gas discharge passage
28. ・ ECU
29 ・ Air flow meter
36..Intake side exhaust passage
37. Three-way switching valve

Claims (7)

A combustion heater having a combustion chamber independent of the internal combustion engine;
An intake air amount detecting means disposed in the intake passage of the internal combustion engine for detecting the amount of air flowing through the intake passage;
Air introduction means for introducing combustion air from the intake passage downstream of the intake air amount detection means to the combustion heater;
Air consumption calculation means for calculating the amount of air consumed by the combustion heater;
An intake air amount correcting means for correcting the intake air amount detected by the intake air amount detecting means based on the air consumption calculated by the air consumption calculating means;
Engine control means for controlling the operating state of the internal combustion engine according to the intake air amount corrected by the intake air amount correction means;
An internal combustion engine having a combustion heater.   2. The internal combustion engine having a combustion heater according to claim 1, wherein the air consumption calculation means calculates the air consumption with the amount of fuel consumed by the combustion heater as a parameter.   2. The internal combustion engine having a combustion heater according to claim 1, wherein the engine control means controls the fuel injection quantity of the internal combustion engine using the intake air quantity corrected by the intake air quantity correction means as a parameter. . An exhaust gas recirculation mechanism for recirculating a part of the exhaust gas of the internal combustion engine to a combustion chamber of the internal combustion engine;
2. The combustion heater according to claim 1, wherein the engine control unit controls a recirculation amount of exhaust gas by the exhaust gas recirculation mechanism in accordance with an intake air amount corrected by the intake air amount correction unit. Internal combustion engine. A combustion gas introducing passage for introducing a combustion gas discharged to the intake passage of the internal combustion engine from the previous SL combustion heater,
An exhaust gas recirculation mechanism for recirculating a part of the exhaust gas of the internal combustion engine to a combustion chamber of the internal combustion engine;
An inert gas component amount calculating means for calculating the amount of an inert gas component contained in the combustion gas discharged from the combustion heater;
Exhaust gas recirculation amount correction means for correcting an exhaust gas recirculation amount by the exhaust gas recirculation mechanism based on the inert gas component amount calculated by the inert gas component amount calculation means;
An internal combustion engine having a combustion heater according to claim 1 you, characterized in that the obtaining further Bei. The exhaust gas recirculation mechanism includes an exhaust gas recirculation passage that guides exhaust gas from an exhaust passage of the internal combustion engine to an intake passage, and a flow rate adjustment valve that adjusts a flow rate of exhaust gas flowing through the exhaust gas recirculation passage,
6. The combustion according to claim 5, wherein the exhaust gas recirculation amount correcting means controls the opening degree of the flow rate adjusting valve based on the inert gas component amount calculated by the inert gas component amount calculating means. Internal combustion engine having a heater. The inert gas component is carbon dioxide;
7. The combustion according to claim 6, wherein the inert gas component amount calculating means calculates the amount of carbon dioxide discharged from the combustion heater using the amount of fuel consumed by the combustion heater as a parameter. Internal combustion engine having a heater.

Images