JP4821758B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention includes a supercharger and can be injected into a combustion chamber in addition to an intake passage, that is, an internal combustion engine that controls an internal combustion engine in which both port injection and in-cylinder injection (or direct injection) are performed. The present invention relates to the technical field of control devices.

  As a control device for this type of internal combustion engine, in Patent Document 1 and the like, when it is determined that deposit fuel has been generated at the injection port of a direct injection injector that injects into a cylinder, the injection ratio of fuel from the port injector A control device that changes (port injection ratio) to 100% is disclosed. According to this control device, by setting the direct injection ratio to 0%, the cooling effect caused by the vaporization heat of the fuel injected by itself is lost at the tip temperature of the injection port of the direct injection injector. For this reason, it is said that the inside of the cylinder can be heated to high temperature by the combustion heat energy, and the deposit fuel can be burned out.

JP 2006-37743 A JP 2005-90457 A

  However, according to Patent Document 1 and the like described above, in an internal combustion engine that is supercharged by a supercharger, if the port injection ratio is always 100% regardless of the travel region and the load, the intake air corresponding to the supercharging is taken into account. The following two problems are mainly caused by the fact that the amount and the fuel injection amount are increased as compared with an internal combustion engine that is not supercharged. That is, as a first problem, when knocking is likely to occur due to supercharging in the internal combustion engine, a shift to the retard side of the ignition timing that is generally performed is merely: There is a possibility of ignition failure in the combustion chamber. For this reason, there arises a technical problem that there is a possibility that the temperature of the catalyst provided in the exhaust passage, that is, the so-called catalyst bed temperature may rise due to the combustion generated in the exhaust passage other than the combustion chamber. The second problem is that when the port injection ratio is always 100% regardless of the travel area and load, the intake system and the exhaust system are switched during the valve overlap period when both the intake and exhaust valves are open. Fuel that flows (or blows through) without being burned may increase. For this reason, unburned fuel may be exposed to high-temperature exhaust gas and steamed, and may be smoked (ie, soot) and discharged in large quantities. As a result, due to the occurrence of smoke, a technical problem arises that the catalyst bed temperature described above may increase.

  Therefore, the present invention has been made in view of the above-mentioned problems, for example, and it is possible to realize the burning out of the deposit fuel while suppressing the occurrence of inconvenience in the operation of the internal combustion engine such as the occurrence of knocking or the discharge of smoke. It is an object of the present invention to provide a control device for a possible internal combustion engine.

In order to solve the above-described problem, an internal combustion engine control apparatus according to the present invention is an internal combustion engine control apparatus that controls an internal combustion engine that includes a supercharger, and includes a first predetermined amount in a cylinder of the internal combustion engine. A first fuel injection means capable of injecting fuel, a second fuel injection means capable of injecting a second predetermined amount of fuel into the intake passage of the internal combustion engine, and igniting the fuel in the cylinder at a predetermined ignition timing When raising the temperatures of the ignition means and the injection port of the first fuel injection means, the first predetermined amount and the second location are determined based on the supercharging pressure by the supercharger and the engine speed of the internal combustion engine. The first fuel injection means and the second fuel injection are changed so as to change the first ratio of the first predetermined amount to the total injection amount and the second ratio of the second predetermined amount to the total injection amount. Controlling at least one of the injection means Together with the supercharging pressure, the first ratio, based on said second rate and the engine speed, and control means for controlling said ignition means to vary the predetermined ignition timing, the control means When the temperature is increased and the engine speed is larger than a predetermined number and the supercharging pressure is within a predetermined range including zero, the second ratio is set to be larger than the first ratio. The at least one injection unit is controlled, and the predetermined ignition timing is controlled to be advanced from a maximum torque ignition timing that is an ignition timing at which the torque generated by the internal combustion engine is maximum. .

  According to the control apparatus for an internal combustion engine according to the present invention, in the internal combustion engine, fuel injection by the first and second fuel injection means is executed at a fuel injection ratio corresponding to the operating condition, for example, and supercharging by the supercharger is performed. It is executed as appropriate. During such normal operation of the internal combustion engine, the operation of removing the deposit fuel in the first fuel injection means is appropriately performed as follows.

  That is, when the temperature of the injection port of the first fuel injection means is increased for the purpose of removing deposit fuel in the first fuel injection means, the first ratio (for example, described later) is controlled by at least one of the injection means under the control of the control means. The direct injection ratio) and the second ratio (for example, a port injection ratio described later) are changed based on the supercharging pressure, in other words, depending on the magnitude of the supercharging pressure. At this time, based on not only the supercharging pressure but also other parameters (for example, engine speed, load, etc.), for example, for each position or region on the coordinate plane formed by the supercharging pressure and the other parameters. The first and second ratios may be varied. Here, the “first ratio” according to the present invention is defined based on at least (i) the supercharging pressure, and means a ratio of the first predetermined amount to be injected by the first fuel injection means with respect to the total injection amount. . Typically, in addition to (i) supercharging pressure, (ii) the degree of cooling that the cylinder is cooled by the fuel injected into the cylinder, and (iii) the occurrence of smoke is suppressed by the fuel injected into the cylinder This is the ratio of the first predetermined amount to be injected by the prescribed first fuel injection means based on the degree of suppression to be made with respect to the total injection amount. The “second ratio” according to the present invention is typically (i) based on the supercharging pressure as in the case of the above-mentioned first ratio. Typically, in addition to this, (ii) the degree of cooling of the cylinder and (iii ) Based on the degree of smoke suppression, it means the ratio of the second predetermined amount to be injected by the second fuel injection means that is prescribed to the total injection amount. If any one of the first ratio and the second ratio is determined, either the first ratio or the second ratio may be determined by subtracting the determined one from 100%. More specifically, the second ratio is changed in a direction approaching, for example, 70% by at least one of the injection units, and the first ratio is changed in a direction approaching, for example, 30%.

  Note that “%” relating to the ratio of fuel injected in the present application is a relative ratio of the first ratio and the second ratio, and basically means “weight%” throughout, but the same fuel. May be volume%, and may be dimensionless in the sense of the relative proportion between the injection means.

  The predetermined ignition timing is changed based on the supercharging pressure, the first ratio, and the second ratio under the control of the control means before or after the change in the first and second ratios. . For example, the ignition timing is changed so that ignition is executed in accordance with the maximum torque ignition timing (MBT) determined based on the supercharging pressure, the first ratio, and the second ratio. At this time, based on not only the supercharging pressure, the first ratio and the second ratio, but also other parameters (for example, engine speed, load), for example, a coordinate plane stretched between the supercharging pressure and the other parameters. The first and second ratios may be changed for each position or region.

  Here, in particular, according to a study by the present inventor, after removing the deposit fuel in the first fuel injection means, the first ratio is changed to 0% and the second ratio is changed to 100%. The three ratios mentioned above (i.e., (i) supercharging pressure, (ii) cylinder), while the first ratio approaches 0% to 30% and the second ratio approaches 100% to 70%. From the standpoint of achieving a good balance between the degree of cooling of (iii) and the degree of suppression of smoke). More specifically, for example, a first predetermined amount of fuel corresponding to a first ratio of 30% of the total injection amount is directly injected into the cylinder. Therefore, due to the vaporization latent heat effect of the fuel in the combustion chamber, An increase in the temperature in the combustion chamber (particularly the gas temperature in the combustion chamber) can be significantly suppressed as compared with the case where fuel is not injected into the cylinder. For this reason, the temperature in the combustion chamber can be lowered, and as a result, the occurrence of knocking can be avoided or suppressed.

  Further, for example, since a first predetermined amount of fuel corresponding to a first ratio of 30% of the total injection amount is directly injected into the cylinder, a valve overlap period in which both the intake valve and the exhaust valve are open. The fuel that flows (or blows through) without being combusted from the intake system to the exhaust system in the engine increases, so that 100% of the total injection amount is injected into the intake passage, the port injection ratio becomes 100%, and the fuel is injected into the cylinder. As compared with the case where no is injected, it can be significantly suppressed. For this reason, it is possible to effectively suppress the unburned fuel from being discharged as smoke (that is, soot).

  Thus, since the degree of occurrence of knocking or the magnitude of the knock margin changes by changing the supercharging pressure, the first ratio and the second ratio, the supercharging pressure, so as to avoid or suppress knocking, By changing the predetermined ignition timing based on the first ratio and the second ratio, knocking can be avoided or suppressed. That is, by controlling the injection ratio and the ignition timing more cooperatively (or organically) and with high accuracy, for example, (i) the above-described latent effect of vaporization of fuel in the combustion chamber, and (ii) valve overlap. (Iii) By changing the predetermined ignition timing based on the magnitude of the degree of occurrence of knocking that has changed, it is possible to avoid the occurrence of knocking, to suppress the emission of smoke, and to deposit fuel It is possible to achieve a balance (balance) and coexistence with burnout. As a result, by minimizing the degree of retard when the ignition timing is shifted to the retard side, it is possible to suppress shortage of ignition voltage and effectively prevent the occurrence of misfire.

As described above, according to the control apparatus of the present invention, it is possible to realize the burning out of the deposit fuel while suppressing the occurrence of inconveniences in the operation of the internal combustion engine such as the occurrence of knocking and the discharge of smoke.
Further, in the present invention, the control means increases the temperature, and when the engine speed is larger than a predetermined number and the supercharging pressure is within a predetermined range including zero, the second ratio is set to the second ratio. The at least one injection means is controlled to be larger than the first ratio, and the predetermined ignition timing is advanced from the maximum torque ignition timing which is an ignition timing at which the torque generated by the internal combustion engine becomes maximum. Thus, the ignition means is controlled.
Since it is configured in this manner, when the temperature of the injection port of the first fuel injection means is increased, the engine speed is larger than the predetermined number and the boost pressure is within a predetermined range including zero. In the case where the engine speed is larger than a predetermined number and the supercharging pressure is in a predetermined area including zero on a coordinate plane having the supercharging pressure and the engine speed as two axes (that is, in the area B described later). In the case), the second ratio is made larger than the first ratio by at least one of the injection means under the control of the control means. In parallel with or in parallel with this, the ignition means causes the predetermined ignition timing to be advanced from the maximum torque ignition timing (MBT) that is the ignition timing at which the torque generated by the internal combustion engine becomes maximum (that is, the ignition timing). , Approaching the bottom dead center of the compression stroke). For example, a first predetermined amount of fuel corresponding to 30% of the total injection amount is injected into the cylinder by the first fuel injection means, and a second predetermined amount of fuel corresponding to, for example, 70% is injected by the second fuel injection means. Is injected into the intake passage. Since the first predetermined amount of fuel corresponding to 30% is directly injected into the cylinder, the increase in the temperature in the combustion chamber during the compression stroke is caused by the vaporization latent heat effect of the fuel in the combustion chamber. Compared with the case where it is not injected, it is possible to suppress significantly. In addition, since the first predetermined amount of fuel corresponding to 30% is directly injected into the cylinder, the intake system and the exhaust system are changed during the valve overlap period in which both the intake valve and the exhaust valve are open. An increase in the amount of fuel flowing without being combusted can be significantly suppressed as compared with a case where 100% of the total injection amount is injected into the intake passage and no fuel is injected into the cylinder.
On the other hand, as described above, the degree of occurrence of knocking is reduced and the so-called knock margin is large, so that the ignition timing is shifted to the delay side (that is, retarded) in order to avoid or suppress knocking. Since the necessity is almost eliminated, as a result, the ignition timing can be relatively shifted (that is, advanced) to the advance side.
In particular, in an internal combustion engine equipped with a supercharger, when the engine speed is larger than a predetermined number and the supercharging pressure is within a predetermined range including zero, the knock margin is relatively increased. Specifically, in an internal combustion engine equipped with a supercharger, even if the pressure loss due to the air flowing through the intake port is high, a large amount of air flows into the cylinder due to the supercharging pressure, that is, it is pushed in. Can do. For this reason, the tumble flow in the cylinder can be strengthened by the shape of the intake port. As a result, in the region where the piston sliding speed increases and the air intake amount begins to increase, if the engine speed of the internal combustion engine is greater than the predetermined number and the boost pressure is within the predetermined range including zero, the knock margin The degree is increased.
As a result, the ignition timing when the retard control is performed can be shifted to the advance side from the MBT, as a matter of course, due to the remarkably large knock margin. Specifically, the ignition timing is shifted to the advance side toward the compression bottom dead center from the MBT. Therefore, ignition can be performed in a state where the in-cylinder pressure is relatively low (that is, a state where the in-cylinder pressure is not increased). As a result, it is possible to raise the temperature of the combustion gas, and in turn, it is possible to promote the burning of the deposit fuel adhering to the injection port of the first fuel injection means.

According to the present invention, when the temperature of the injection port of the first fuel injection means is increased, the first ratio and the second ratio are increased by the boost pressure and the engine by at least one injection means under the control of the control means. It is changed based on the rotation speed. Here, the degree of occurrence of knocking or the magnitude of the knock margin also depends on the engine speed. Therefore, based on the supercharging pressure and the engine speed, the first and second ratios are changed so as to avoid or suppress knocking, and based on the supercharging pressure, the engine speed, the first ratio, and the second ratio. The knocking can be avoided or suppressed by changing the predetermined ignition timing. In other words, by controlling the injection ratio and ignition timing in a more coordinated and highly accurate manner, it is possible to achieve a balance and avoidance of knocking occurrence, suppression of smoke emission, and burning of deposit fuel. It is.

  In this aspect, when the temperature is increased, the control means separates the first ratio and the second for each of a plurality of regions divided on a coordinate plane having the supercharging pressure and the engine speed as two axes. The ignition means is controlled to control the at least one injection means so as to change a ratio, and to change the predetermined ignition timing based on the first ratio and the second ratio for each of the plurality of regions. You may control.

  If comprised in this way, when raising the temperature of the injection port of a 1st fuel-injection means, a 1st ratio and a 2nd ratio are the coordinates which make a supercharging pressure and an engine speed biaxial by at least one injection means It is changed for each of a plurality of areas divided on the surface. In such a plurality of areas, if the specifications of the internal combustion engine are specifically specified, the degree of occurrence of knocking and the degree of smoke emission are experimentally or empirically changed while changing the supercharging pressure and engine speed. Alternatively, or by examining theoretical calculation or simulation, the first and second ratios where knocking does not occur, or the first and second ratios where smoke is not discharged can be specified in advance. Therefore, if the first and second ratios to be changed for each of a plurality of preset areas are held in a map or table divided into a plurality of areas, that is, stored as data in a memory in advance. In the actual operation, the first ratio and the second ratio can be easily and quickly changed based on the supercharging pressure and the engine speed. It should be noted that instead of the map or the table, a function for each preset region that uses the supercharging pressure and the engine speed as parameters and outputs the first and second ratios may be adopted. Further, since the predetermined ignition timing may be changed based on the first ratio and the second ratio for each of the presettable areas in this way, a map or table for each area obtained in advance through experiments or the like. By using a function or the like, it is possible to change easily and quickly.

  As a result of the above, it is possible to achieve a balance and coexistence of avoidance of knocking, suppression of smoke emission, and burning of deposit fuel by a relatively simple control operation.

  In another aspect of the control apparatus for an internal combustion engine according to the present invention, the control means increases the temperature, and when the supercharging pressure is within a positive pressure range that promotes intake and exhaust, The at least one injection means is controlled so that the second ratio is larger than the first ratio, and the predetermined ignition timing is added to the supercharging pressure, the first ratio, and the second ratio, The ignition means is controlled to change based on the degree of occurrence of knocking in the internal combustion engine.

  According to this aspect, when the temperature of the injection port of the first fuel injection means is increased, the supercharging pressure is within a positive pressure range that promotes intake and exhaust (for example, in the case of the region C described later) ), The second ratio is made larger than the first ratio by at least one of the injection means under the control of the control means. At the same time or in parallel, the ignition means changes the predetermined ignition timing based on the degree of occurrence of knocking in the internal combustion engine in addition to the supercharging pressure, the first ratio, and the second ratio. Be made. For example, a first predetermined amount of fuel corresponding to 30% of the total injection amount is injected into the cylinder, and a second predetermined amount of fuel corresponding to, for example, 70% is injected into the intake passage. As a result, for example, a first predetermined amount of fuel corresponding to 30% is directly injected into the cylinder, so that the increase in the temperature in the combustion chamber during the compression stroke is caused by the latent heat of vaporization of the fuel in the combustion chamber. Compared with the case where fuel is not injected into the fuel cell, it can be significantly suppressed. In addition, it is possible to remarkably suppress an increase in fuel flowing without being burned from the intake system to the exhaust system during the valve overlap period in which both the intake valve and the exhaust valve are open.

  In particular, when the supercharging pressure is in a positive pressure range that promotes intake and exhaust, it is highly necessary to increase the first ratio in terms of relatively avoiding the occurrence of knocking and suppressing smoke discharge. . More specifically, the first ratio is changed from, for example, 31% to 33% of the total injection amount, and the second ratio is changed from, for example, 69% to 67% of the total injection amount. It's okay. In this case, as a trade-off, the temperature of the injection port increases due to the cooling effect of the cylinder temperature, but does not increase to the burnout temperature of the deposit fuel, but promotes the generation of deposit fuel (while the fuel is kept semi-dry). There is a possibility that it will only rise to the deposit fuel acceleration temperature. Therefore, the first ratio is increased to achieve a balance (balance) between control mainly aimed at avoiding the occurrence of knocking and suppressing smoke emission, and control mainly aimed at reducing the first ratio and burning out deposit fuel. Note that it is strictly necessary to

  On the other hand, when the engine speed of the internal combustion engine is larger than a predetermined number and the supercharging pressure is in a positive pressure range that promotes intake and exhaust, the degree of knocking and the unburned fuel is smoked (ie, soot). The degree of discharge becomes relatively large. For this reason, based on the knock margin, the ignition timing is shifted to the delay side, for example, from the maximum torque ignition timing (MBT), that is, the ignition timing is retarded from the maximum torque ignition timing (the top dead center of the compression stroke). To change.

  As a result, by controlling the injection ratio and the ignition timing with higher accuracy, it is possible to achieve a balance between avoidance of knocking, suppression of smoke emission, and burning of deposit fuel.

  In another aspect of the control apparatus for an internal combustion engine according to the present invention, the control means increases the temperature, and when the supercharging pressure is within a negative pressure range that does not promote intake and exhaust, The at least one injection unit is controlled so that the second ratio is 100%, and the predetermined ignition timing is set to a maximum torque ignition timing (MBT) that is an ignition timing at which the torque generated by the internal combustion engine becomes maximum. The ignition means is controlled so as to approach.

  According to this aspect, when the temperature of the injection port of the first fuel injection unit is raised, the supercharging pressure is in a negative pressure range that does not promote intake and exhaust (that is, in the case of the region A described later) ), And the second ratio is set to 100% by at least one of the injection means under the control of the control means. In parallel with or in parallel with this, the ignition means brings the predetermined ignition timing close to the maximum torque ignition timing (MBT). Here, according to the research of the present inventor, for example, by switching from a traveling state where the first ratio is 100% to a traveling state where the second ratio is 100%, mixing of fuel in the combustion chamber is promoted, It has been found that the MBT moves to the top dead center side. Therefore, it is preferable to correct the ignition timing while changing the ignition timing to the advance side or the retard side based on the movement amount corresponding to the movement of the MBT. Accordingly, in such a case, the movement of the MBT can be absorbed by setting the second ratio to 100% and bringing the predetermined ignition timing close to the maximum torque ignition timing (MBT) or substantially reaching the maximum torque ignition timing. Torque that is the engine output of the engine can be generated efficiently. Thereby, it is possible to effectively prevent deterioration of fuel consumption.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  In the following embodiments, description will be given of a case where the control device for an internal combustion engine of the present invention is applied to a port and a direct injection engine.

(1) Basic Configuration First, the basic configuration of the port and the direct injection engine according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a block diagram conceptually showing the basic configuration of the port and the direct injection engine according to this embodiment, and FIG. 2 is a cross section of the port and the direct injection engine according to the present embodiment. FIG. 3 is a cross-sectional view conceptually showing a cross section of an injector included in a port and an in-cylinder injection engine according to the present embodiment.

  As shown in FIG. 1, a direct injection injector 11 d together with a spark plug 13 is provided for each cylinder in a port and a cylinder head portion of a cylinder 2 of the direct injection type engine 1 according to the present embodiment. A port injector 11p is provided in each intake passage communicating with each cylinder. In addition, the port and the direct injection type engine 1 according to the present embodiment include a supercharging pressure (that is, an intake pressure) in the intake system, in addition to an air-fuel ratio sensor that measures the air-fuel ratio in the intake system and the exhaust system (not shown). It is equipped with a supercharging pressure sensor that measures the atmospheric pressure.

  As shown in FIG. 2, the direct injection injector 11d is attached to the cylinder 2 at an angle, for example, and directly injects fuel into the cylinder 2 (that is, the combustion chamber). Further, for example, a cavity 6 is formed at the top of the piston 5 that reciprocates in the cylinder 2. The fuel injected from the direct injection injector 11d flows through the cylinder 2 as a swirl flow or a tumble flow through the cavity 6.

  Further, as shown in FIG. 3, the direct injection injector 11 d includes a swirl valve that injects fuel from the injection hole 113 after the swirl portion 112 forms a swirling flow. In this embodiment, a groove is provided in the needle 111 of the direct injection injector 11d, and a swirling flow is formed by the fuel flowing into the sac portion 112 through the groove.

  In FIG. 1 again, the direct injection injector 11d is supplied with fuel via the fuel supply unit 14. More specifically, the fuel supply unit 14 is connected to the fuel tank 16 while being connected to the direct injection injector 11 d via the fuel pipe 15. The fuel supply unit 14 includes, for example, a high pressure fuel pump (not shown), and high pressure fuel can be supplied to the injector 11d by the high pressure fuel pump. At this time, the fuel supply unit 14 includes a pressure regulating valve that regulates the fuel supplied from the high-pressure fuel pump to a desired pressure. The fuel whose pressure is adjusted in the pressure regulating valve is supplied to the direct injection injector 11d and then injected into the cylinder 2 with the pressure adjusted in the pressure regulating valve (or with the pressure adjusted according to the pressure adjusted in the pressure regulating valve). Is done.

  The fuel injection operation from the direct injection injector 11 is controlled by the operation of the ECU 30. Particularly, the direct injection injector is provided by the operation of the injection period setting unit 302 for setting the period during which the fuel is injected, the injection number setting unit 303 for setting the number of times the fuel is injected, the injection control unit 304, and the like. The fuel injection operation from 11 is controlled. The operation of the spark plug 13 is controlled by the operation of the ECU 30 (particularly, the operation of the ignition timing control unit 305 and the like provided in the ECU 30). The operation of the fuel supply unit 14 (that is, the pressure adjustment) is controlled by the operation of the ECU 30 (particularly, the operation of the fuel pressure setting unit 301 provided in the ECU 30).

  Then, the air taken into the combustion chamber 5 through the intake manifold 3 and the intake port 7 (see FIG. 2) and the fuel injected from the direct injection injector 11d and the port injector 11p are mixed in the combustion chamber 5. As the spark plug 13 sparks, the mixed gas burns in the combustion chamber 5. The exhaust gas after combustion is discharged to the outside of the port and the in-cylinder injection engine 1 through the exhaust port 8 (see FIG. 2) and the exhaust manifold 4.

  Under the present circumstances, the knocking sensor 12 is provided in the cylinder head part of the cylinder 2 of the cylinder injection type engine 1 which concerns on this embodiment for every cylinder. The knocking sensor 12 can detect the occurrence of knocking for each cylinder. When the occurrence of knocking is detected, a knocking detection signal indicating that the occurrence of knocking has been detected is output from the knocking sensor 12 to the ECU 30.

  Further, as shown in FIG. 1, the port and in-cylinder injection engine 1 includes an exhaust turbine 21, a compressor 22, a rotor shaft 23, an air cleaner 24, and an intercooler 25.

  Exhaust gas discharged from the port and the cylinder 2 of the in-cylinder injection engine 1 is sprayed to the exhaust turbine 21 via the exhaust manifold 4. The exhaust turbine 21 is rotated by the exhaust gas. As the exhaust turbine 21 rotates, the compressor 22 connected to the exhaust turbine 21 via the rotor shaft 23 also rotates in the same manner. At this time, the intake air supplied to the compressor 12 via the air cleaner 24 is compressed by the rotation of the compressor 22 and then passes through the intercooler 25 and the temperature thereof is lowered. Thereafter, the compressed intake air is supplied to the port and the cylinder 2 of the direct injection type engine 1 through the intake manifold 3.

  The direct injector 11d constitutes a specific example of “first fuel injection means” in the present invention, and the port injector 11p constitutes a specific example of “second fuel injection means” in the present invention. ing. Further, the fuel pressure setting unit 301, the injection number setting unit 303, the injection control unit 304, the injection period setting unit 302, and the ignition timing control unit 30 constitute one specific example of “control means” in the present invention. The spark plug 13 constitutes a specific example of “igniting means” in the present invention.

(2) Operation Principle Next, the operation principle of the control device for an internal combustion engine according to the present embodiment will be described with reference to FIGS.

(2-1) Control Process First, a control process in the control device for an internal combustion engine according to the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing the flow of control processing in the control apparatus for an internal combustion engine according to this embodiment. This control process is repeatedly executed by the ECU at a predetermined cycle such as several tens of microseconds or several microseconds.

  As shown in FIG. 4, first, under the control of the ECU 30, a realization ratio of the target air-fuel ratio of the fuel injection system related to fuel injection, that is, a so-called learning value is calculated (step S101). Here, the “realization ratio of the target air-fuel ratio” according to the present embodiment is the ratio of the air-fuel ratio actually measured by the actually injected fuel with the target air-fuel ratio instructed by the ECU 30 as a reference. means. The presence / absence of the deposit fuel and the generation amount can be estimated by the realization ratio of the target air-fuel ratio. Specifically, when the ECU 30 instructs fuel injection to achieve the target air-fuel ratio, but the actually measured air-fuel ratio is on the lean side, the deposit fuel has increased. It can be estimated that the fuel injection amount is reduced. On the other hand, if the ECU 30 instructs fuel injection to achieve the target air-fuel ratio, and the actually measured air-fuel ratio is also close to the target air-fuel ratio, the deposit fuel has no effect on the fuel injection. It can be estimated that there are few. The target air-fuel ratio realization ratio is determined by a target air-fuel ratio instructed by the ECU 30, a fuel injection amount to be injected to realize the target air-fuel ratio, a predetermined function using a measured air-fuel ratio as a variable, a predetermined map, or the like. May be calculated.

  Next, under the control of the ECU 30, it is determined whether or not deposit fuel is generated, depending on whether or not the calculated realization ratio of the target air-fuel ratio of the fuel injection system is within an allowable range (step S102). Here, when it is determined that deposit fuel is generated (step S102: Yes), the engine speed and the intake pressure (or supercharging pressure) of the internal combustion engine are detected under the control of the ECU 30 ( Step S103).

  Next, under the control of the ECU 30, based on a predetermined map for burning out deposit fuel using as input information an operating region that can be specified by the detected engine speed of the internal combustion engine and the intake pressure (or supercharging pressure). The port injection ratio, the direct injection ratio, and the ignition timing are determined (step S104). The details of the predetermined map for burning out deposit fuel will be described later with the operation region as input information and the port injection ratio, direct injection ratio, and ignition timing as output information.

  Next, under the control of the ECU 30, the port injector 11p and the direct injection injector 11d are driven so that fuel is injected at the determined port injection ratio and direct injection ratio, and ignition is performed at the determined ignition timing. Thus, the spark plug is driven (step S106).

  On the other hand, if it is not determined that the deposit fuel is generated as a result of the determination in step S102 described above (step S102: No), under the control of the ECU 30, the port injection ratio, the direct injection ratio, And the ignition timing is determined (step S105).

  In particular, in this step S102, it is determined whether or not the deposit fuel needs to be burned out by determining whether or not there is a decrease in the flow rate of the direct injection injector 11d, and when there is no decrease in the flow rate of the direct injection injector 11d, It is preferable to carry out a control process that determines that it does not exist and increases the chance of returning to the process of determining the injection ratio and the ignition timing using a normal map (standard map).

  As a result, when the engine speed of the internal combustion engine is larger than a predetermined number and the supercharging pressure is larger than a positive predetermined pressure that promotes intake and exhaust, the main purpose is to avoid the occurrence of knocking and to suppress the discharge of smoke. It is possible to more easily realize the control of the injection ratio and the ignition timing.

(2-2) Predetermined Map Next, a predetermined map used for control processing in the control apparatus for an internal combustion engine according to the present embodiment will be described with reference to FIGS. FIG. 5 is a table showing a predetermined map for defining the relationship among the port injection ratio, the ignition timing, and the operation region according to the present embodiment. FIG. 6 is a graph showing the relationship among the operating region, the supercharging pressure (that is, the intake pressure) of the internal combustion engine, and the engine speed according to the present embodiment. FIG. 7 is a table showing the relationship among the port injection ratio, the trace knock value, and the operation region according to the present embodiment.

  In the control processing according to the present embodiment, a predetermined map for changing the port injection ratio and the ignition timing is used for each operation region.

  Specifically, as shown in FIG. 5, in the operation region A (hereinafter referred to as region A as appropriate), the ignition timing is made to follow MBT (Minimum Spark Advance for Best Torque) and the port injection ratio ( That is, the second ratio) according to the present invention is set to 100%. In other words, the ignition timing is brought close to MBT, and the direct injection ratio (that is, the first ratio according to the present invention) is set to 0%. Here, the region A according to the present embodiment is an operation region in which the supercharging pressure is a negative pressure range in which intake and exhaust are not promoted, as shown in FIG. In this region A, the supercharging pressure tends to approach zero as the engine speed increases.

  On the other hand, as shown in FIG. 5, in the operation region B (hereinafter referred to as region B as appropriate), the ignition timing is advanced from the MBT, and the port injection ratio is set to about 70%. In other words, the ignition timing is brought closer to the bottom dead center of the compression stroke than MBT, and the direct injection ratio is set to about 30%. Here, the region B according to the present embodiment is an operating region where the engine speed of the internal combustion engine is larger than a predetermined number Kb and the supercharging pressure is zero as shown in FIG. It is. Here, the predetermined number according to the present embodiment is an operation region where the supercharging pressure is a predetermined range including zero, and there is a possibility that knocking may occur when the amount of air flowing into the cylinder of the internal combustion engine is changed. As a value obtained by adding a slight margin to the value of the engine speed with little or no, it is possible to obtain the values individually and experimentally, theoretically, empirically, by simulation or the like. In this region B, the supercharging pressure tends to increase as the engine speed increases.

  On the other hand, as shown in FIG. 5, in the operation region C (hereinafter referred to as region C as appropriate), for example, the ignition timing is retarded from the MBT to ensure a sufficient knock margin and to perform port injection. Set the percentage to about 70%. In other words, for example, the ignition timing is made closer to the top dead center of the compression stroke than MBT, a sufficient knock margin is secured, and the direct injection ratio is set to about 30%. Here, as shown in FIG. 6, the region C according to the present embodiment is a positive pressure at which the engine speed of the internal combustion engine is greater than a predetermined number Kc and the boost pressure promotes intake and exhaust. This is an operating region that is a range. In addition, as shown in FIG. 6, the region C is an operation region in which the engine speed of the internal combustion engine is smaller than a predetermined number Kc and the supercharging pressure is a predetermined range including zero.

  On the other hand, in the operation region D (hereinafter, appropriately referred to as region D), the main purpose is to avoid the occurrence of knocking and to suppress the discharge of smoke, and the control for burning out the deposit fuel is stopped. Here, as shown in FIG. 6, the region D according to the present embodiment is a positive predetermined value in which the engine speed of the internal combustion engine is larger than a predetermined number Kd and the supercharging pressure promotes intake and exhaust. This is an operating region larger than the pressure Pd.

  Hereinafter, the details of each region will be described more specifically. In order to clarify the description, the description proceeds in the order of region B, region C, region A, and region D.

(2-2-1) Region B
In the region B where the engine speed of the internal combustion engine is larger than the predetermined number and the supercharging pressure is within a predetermined range including zero, the direct injection injector 11d (that is, the first fuel according to the present invention) is controlled under the control of the ECU 30. According to a specific example of the injection means, for example, a first predetermined amount of fuel corresponding to a direct injection ratio of 30% of the total injection amount is injected into the cylinder. A second predetermined amount of fuel corresponding to, for example, a port injection ratio of 70% is injected into the intake passage by the port injector 11p (that is, a specific example of the second fuel injection means according to the present invention). Thereby, for example, a first predetermined amount of fuel corresponding to a direct injection ratio of 30% is directly injected into the cylinder, so that the temperature in the combustion chamber during the compression stroke (by the latent heat effect of vaporization in the combustion chamber) In particular, an increase in gas temperature) in the combustion chamber can be significantly suppressed as compared with the case where fuel is not injected into the cylinder. For this reason, the temperature in the combustion chamber can be lowered, and as a result, the occurrence of knocking can be avoided or suppressed.

  Note that, by reducing the port injection ratio by the horizontal arrow in FIG. 5, the temperature of the cylinder is lowered and the degree of knocking (knock occurrence degree) is reduced. The degree is shown to be higher. In other words, the horizontal arrows in FIG. 5 indicate that increasing the port injection ratio increases the temperature of the cylinder and increases the degree of knocking, that is, reduces the knocking margin. Has been. In particular, in this embodiment, it is possible to set the port injection ratio mainly in the range of 50% to 100% and to set the direct injection ratio mainly in the range of 50% to 0%. This is preferable from the viewpoint of burning out the 11d deposit fuel.

  In addition, since a first predetermined amount of fuel corresponding to, for example, a direct injection ratio of 30% of the total injection amount is directly injected into the cylinder, both the intake valve and the exhaust valve are opened. During the lap period, the fuel that flows (or blows through) without being burned from the intake system to the exhaust system increases, so that 100% of the total injection amount is injected into the intake passage, the port injection ratio becomes 100%, Compared with the case where fuel is not injected into the fuel cell, it can be significantly suppressed. For this reason, it is possible to effectively suppress the unburned fuel from being discharged as smoke (that is, soot). In addition, this shows that the amount of smoke generated is reduced by reducing the port injection ratio by the horizontal arrow in FIG. In other words, the horizontal arrows in FIG. 5 indicate that the amount of smoke generated is increased by increasing the port injection ratio.

  On the other hand, since the direct injection ratio is set to about 30% as described above, the degree of occurrence of knocking is reduced, and the so-called knock margin is large, so that ignition is performed to avoid or suppress knocking. Since there is almost no need to shift the timing to the delay side (that is, to retard), as a result, the ignition timing can be relatively shifted to the advance side (that is, advanced).

  In particular, in an internal combustion engine equipped with a supercharger, when the engine speed is larger than a predetermined number and the supercharging pressure is in a predetermined range including zero (the supercharging pressure described later promotes intake and exhaust. Compared to the positive pressure range), the knock margin is increased. Specifically, in an internal combustion engine equipped with a supercharger, even if the pressure loss due to the air flowing through the intake port is high, a large amount of air flows into the cylinder due to the supercharging pressure, that is, it is pushed in. Can do. For this reason, the tumble flow in the cylinder can be strengthened by the shape of the intake port. Thereby, in the region where the sliding speed of the piston increases and the air intake amount starts to increase, when the engine speed of the internal combustion engine is larger than the predetermined number and the supercharging pressure is within a predetermined range including zero, Increased knock margin.

  As a result, the ignition timing when the retard control is performed can be shifted to the advance side from the MBT, as a matter of course, due to the remarkably large knock margin. Specifically, the ignition timing is shifted to the advance side toward the compression bottom dead center from the MBT. Therefore, ignition can be performed in a state where the in-cylinder pressure is relatively low (that is, a state where the in-cylinder pressure is not increased). As a result, it is possible to raise the temperature of the combustion gas, and consequently, it is possible to promote the burning of the deposit fuel adhering to the injection port of the direct injection injector 11d.

  Note that this is indicated by the vertical arrows in FIG. 5 that the combustion timing is raised and raised by shifting the ignition timing to the advance side. In other words, the vertical arrow in FIG. 5 indicates that the ignition timing is shifted to the retard side, thereby lowering the combustion gas temperature without increasing it. In general, the vertical arrow in FIG. 5 indicates that the degree of occurrence of knocking is increased by shifting the ignition timing to the advance side. In addition, the vertical arrow in FIG. 5 indicates that the degree of misfire is generally reduced by shifting the ignition timing to the advance side. This is because when the ignition timing is shifted to the bottom dead center side of the compression stroke, ignition is performed in a state where the in-cylinder pressure (that is, the gas pressure in the combustion chamber) is reduced. As a result, the voltage required for ignition is reduced. This is because the ignition is reliably performed without increasing the value.

  Specifically, as shown in FIG. 7, in region B, the trace knock value indicating the most advanced ignition timing among the ignition timings that do not cause knocking increases as the port injection ratio approaches 0% to 100%. The MBT is closer to the area A than will be described later. The trace knock value can be expressed as a value obtained by subtracting the most advanced ignition timing at which knocking starts from the MBT ignition timing. In region B, as described above, the port injection ratio is set to 70%, and the ignition timing is set to the trace knock value indicating the most advanced ignition timing among the ignition timings at which knocking does not occur at this time. Thus, it is possible to increase the temperature of the combustion gas, and consequently, it is possible to promote the burning of the deposit fuel adhering to the injection port of the direct injection injector 11d.

(2-2-2) Region C
In the region C where the supercharging pressure is a positive pressure range that promotes intake and exhaust, the direct injection injector 11d under the control of the ECU 30 performs a first injection corresponding to a direct injection ratio of 30% of the total injection amount, for example. A predetermined amount of fuel is injected into the cylinder. A second predetermined amount of fuel corresponding to, for example, a port injection ratio of 70% is injected into the intake passage by the port injector 11p. Thereby, for example, a first predetermined amount of fuel corresponding to a direct injection ratio of 30% is directly injected into the cylinder, so that the temperature in the combustion chamber during the compression stroke (by the latent heat effect of vaporization in the combustion chamber) In particular, an increase in gas temperature) in the combustion chamber can be significantly suppressed as compared with the case where fuel is not injected into the cylinder. For this reason, the temperature in the combustion chamber can be lowered, and as a result, the occurrence of knocking can be avoided or suppressed. In addition, for example, a first predetermined amount of fuel corresponding to 31% is directly injected into the cylinder, and therefore, from the intake system to the exhaust system during the valve overlap period in which both the intake valve and the exhaust valve are open. It is possible to remarkably suppress the increase in the fuel that flows (or blows through) without being combusted compared to the case where the fuel is not injected into the cylinder. For this reason, it is possible to effectively suppress the unburned fuel from being discharged as smoke (that is, soot).

  In particular, in the region C where the supercharging pressure is a positive pressure range that promotes intake and exhaust, compared to the region B described above, the direct injection is performed in terms of avoiding the occurrence of knocking and suppressing smoke discharge. There is a high need to increase the injection rate. More specifically, the first ratio is changed slightly from 31% to 33% of the total injection amount, for example, and the second ratio is changed from 69% to 67 of the total injection amount, for example. It may be changed to the decreasing side by a small amount such as%. In this case, as a trade-off, the temperature of the injection port increases due to the cooling effect of the cylinder temperature, but does not increase to the burnout temperature of the deposit fuel, but promotes the generation of deposit fuel (while the fuel is kept semi-dry). There is a possibility that it will only rise to the deposit fuel acceleration temperature. Therefore, a balance between the main purpose of increasing the direct injection ratio, avoiding knocking, and suppressing smoke emission, and the control aiming at burning out of the deposit fuel, reducing the direct injection ratio. Note that it is strictly necessary to achieve balance and balance.

  On the other hand, in the region C where the supercharging pressure is a positive pressure range that promotes intake and exhaust, the degree of occurrence of knocking and the degree to which unburned fuel is smoked (that is, soot) is discharged. Compared to the region B described above, it becomes larger. Therefore, in addition to the change in the direct injection ratio and the port injection ratio, in general (average or passive or simply) the ignition timing based on the degree of occurrence of knocking, that is, the knock margin, Shifting to the delay side of the maximum torque ignition timing (MBT), that is, changing to a retard side of the maximum torque ignition timing (approaching the top dead center of the compression stroke). Furthermore, when the retard control for delaying the ignition timing is performed, it is preferable to determine the above-described direct injection ratio while preventing the ignition request voltage from being insufficient and misfire. Here, the retard control according to the present embodiment is a control of the ignition timing in the case of performing high supercharging in a low rotation state, and by simply shifting the ignition timing to the delay side, the occurrence of knocking is prevented. It means a control operation of ignition timing to avoid or suppress.

  As a result, by controlling the injection ratio and the ignition timing in a coordinated (or organic) manner with high accuracy, a balance between avoidance of knocking and suppression of smoke emission and burning of deposit fuel ( Balance) and balance can be realized.

  More specifically, as shown in FIG. 7, in region C, the trace knock value indicating the most advanced ignition timing among the ignition timings that do not cause knocking increases as the port injection ratio approaches 0% to 100%. , Away from MBT toward the retarded angle side. In region C, as described above, the port injection ratio is set to 69%, and the ignition timing is set to the trace knock value indicating the most advanced ignition timing among the ignition timings at which knocking does not occur at this time. As a result, it is possible not only to avoid the occurrence of knocking, but also to achieve a balance and balance between the suppression of smoke emission and the burning of deposit fuel.

(2-2-3) Region A
In the region A where the supercharging pressure is a negative pressure range that does not promote intake and exhaust, as described above, the ignition timing is made to follow the MBT, and the port injection ratio is set to 100%. Specifically, by switching from the traveling state in which the direct injection ratio is 100% to the traveling state in which the port injection ratio is 100%, mixing of fuel in the combustion chamber is promoted and MBT is increased. It has been found to move to the dead center side. It is preferable to correct the ignition timing while changing the ignition timing to the advance side or the retard side based on the movement amount corresponding to the movement of the MBT. As a result, the movement of the MBT is absorbed, and the torque that is the engine output of the internal combustion engine is generated more efficiently, so that it is possible to effectively prevent the deterioration of fuel consumption.

  Specifically, as shown in FIG. 7, in region A, the trace knock value indicating the most advanced ignition timing among the ignition timings that do not cause knocking brings the port injection ratio from 0% to 100%. To approach MBT. In the region A, as described above, the port injection ratio is set to 100%, and the ignition timing is set to the MBT that is retarded from the trace knock value at this time. Since a certain torque is generated more efficiently, it is possible to effectively prevent deterioration of fuel consumption.

(2-2-4) Region D
In the region D where the engine speed of the internal combustion engine is larger than a predetermined number and the supercharging pressure is larger than a predetermined positive pressure for promoting intake and exhaust, the main purpose is to avoid the occurrence of knocking and to suppress the discharge of smoke. At the same time, the control for burning the deposit fuel is stopped. That is, even if the direct injection ratio, port injection ratio, and ignition timing described above are changed in order to burn out the deposit fuel, the injection is performed under normal control using a standard map. Determine the ratio and ignition timing.

  In particular, it is determined whether or not the deposit fuel needs to be burned out depending on whether or not the flow rate of the direct injection injector 11d is decreased. If there is no decrease in the flow rate of the direct injection injector 11d, it is determined that no deposit fuel is present. It is preferable to perform a control process that increases the opportunity to return to the process of determining the injection ratio and the ignition timing using a standard map.

  As a result, when the engine speed of the internal combustion engine is larger than a predetermined number and the supercharging pressure is larger than a positive predetermined pressure that promotes intake and exhaust, the main purpose is to avoid the occurrence of knocking and to suppress the discharge of smoke. It is possible to more easily realize the control of the injection ratio and the ignition timing.

(3) Examination of action and effect according to this embodiment Next, the action and effect according to this embodiment will be examined with reference to FIGS. FIG. 8 shows three variables (smoke generation amount, ignition amount) for the port injection ratio, the direct injection ratio, the load, and the operation region when the engine speed is a predetermined value Ki according to the present embodiment. It is a table group (Drawing 8 (a), Drawing 8 (b), and Drawing 8 (c)) showing change of time and a trace knock value. FIG. 9 is a graph showing a relationship among the port injection ratio, the load, and the amount of smoke generated according to the present embodiment. The engine speed Ki is shown in FIG. 6 described above.

  First, the region A, the region B, the region C, and the region D are defined in more detail when the engine speed is Ki. It should be noted that the load of the internal combustion engine changes from a low value to a high value as it changes from region A, region B, region C, and region D.

  As shown in FIG. 8A, the region A shows the amount of smoke generated regardless of whether the port injection ratio is 100% or the direct injection ratio is 100%. It may mean a region that can be almost eliminated. In addition, as shown in FIG. 8C, this region A is ignited regardless of whether the port injection ratio is 100% or the direct injection ratio is 100%. It may mean an area where MBT can be used as a time.

  In the region B, as shown in FIG. 8 (a), when the port injection ratio is 100%, the amount of smoke generated increases rapidly, so it is preferable to change the direct injection ratio so as to approach 100%. It may mean an area. In addition, as shown in FIG. 8C, this region B is ignited regardless of whether the port injection ratio is 100% or the direct injection ratio is 100%. It may mean an area where MBT can be used as a time. As described above, in the region B, as shown in FIG. 6 described above, in the region where the engine speed of the internal combustion engine is smaller than the predetermined number Kb, the inflow amount of air flowing into the cylinder of the internal combustion engine is small. Since knocking occurs, it can be removed.

  In the region C, as shown in FIG. 8A, the amount of smoke generated is the same regardless of whether the port injection ratio is 100% or the direct injection ratio is 100%. This may mean an area that increases as compared to the area A and the area B. In addition, as shown in FIG. 8C, in the region C, when the port injection ratio is 100%, the trace knock value is largely shifted to the retard side compared to the region A and the region B. Therefore, it may mean a region in which it is preferable to change the direct injection ratio in a direction approaching 100% and accordingly change the ignition timing to the advance side as shown in FIG.

  In the region D, as shown in FIG. 8A, the amount of smoke generated is the same regardless of whether the port injection ratio is 100% or the direct injection ratio is 100%. , Region A, region B, and region C may be referred to as increasing regions. In addition, as shown in FIG. 8C, this region D is traced regardless of whether the port injection ratio is 100% or the direct injection ratio is 100%. It may mean a region where the knock value is shifted to the retard side compared to region A, region B, and region C.

  As described above, according to the present embodiment, the port injection ratio is changed in a direction approaching 70%, for example, based on the supercharging pressure and the load, in other words, the direct injection ratio is changed in a direction approaching 30%, for example. Correspondingly, the ignition timing is changed. In this way, by controlling the injection ratio and the ignition timing more cooperatively (or organically) and with high accuracy, it is possible to avoid occurrence of knocking, suppress smoke emission, and burn out deposit fuel. It is possible to achieve equilibrium and balance. As a result, by minimizing the degree of retard when the ignition timing is shifted to the retard side, it is possible to suppress shortage of ignition voltage and effectively prevent the occurrence of misfire.

  In an internal combustion engine that is supercharged by a supercharger, if the port injection ratio is always 100% regardless of the operating region and load, the intake air amount and the fuel injection amount are not supercharged corresponding to the supercharging. Due to the increase compared to the internal combustion engine, the following two problems are mainly caused.

  That is, as a first problem, in addition to the fact that knocking is likely to occur due to supercharging, there is no fuel directly injected into the cylinder, and the fuel is vaporized to the cylinder due to heat of vaporization. As the cooling effect decreases, the temperature of the cylinder and the temperature of the combustion gas in the cylinder rise. For this reason, knocking is more likely to occur, so that it becomes necessary to shift the ignition timing to a more retarded side than usual. Due to this significant shift of the ignition timing to the retarded angle, the required voltage for ignition may increase, and ignition failure may occur in the combustion chamber. There is a possibility that the temperature of the exhaust gas in the vicinity of the inlet of the turbine may increase, and the so-called catalyst bed temperature provided in the exhaust passage may increase.

  The second problem is that when the port injection ratio is always 100% regardless of the operating range and load, the intake system and exhaust system are switched during the valve overlap period when both the intake and exhaust valves are open. Fuel that flows (or blows through) without being burned may increase. For this reason, unburned fuel may be exposed to high-temperature exhaust gas and steamed, and may be smoked (ie, soot) and discharged in large quantities. As a result, due to the occurrence of smoke, the temperature of the exhaust gas near the inlet of the exhaust turbine may increase, and the so-called catalyst bed temperature provided in the exhaust passage may increase. . Specifically, as shown in FIG. 8 (a) and FIG. 9, it was found that as the port injection ratio approaches 100%, the amount of smoke generated increases as the load on the internal combustion engine increases. ing.

  On the other hand, according to the present embodiment, as described above, the port injection ratio is changed in a direction approaching, for example, 70% based on the supercharging pressure and the load, in other words, the direct injection ratio is set to, for example, 30. The ignition timing is changed accordingly. In this way, by controlling the injection ratio and the ignition timing more cooperatively (or organically) and with high accuracy, it is possible to avoid occurrence of knocking, suppress smoke emission, and burn out deposit fuel. It is possible to achieve equilibrium and balance. As a result, by minimizing the degree of retard when the ignition timing is shifted to the retard side, it is possible to suppress shortage of ignition voltage and effectively prevent the occurrence of misfire.

  In the embodiment described above, the control is performed using the intake air amount as a value indicating the load or the supercharging pressure of the internal combustion engine, but the fuel injection amount may be used instead.

  The present invention is not limited to the above-described embodiments, and may be implemented in various forms. For example, the present invention is not limited to a gasoline engine, and may be applied to various internal combustion engines that use diesel gasoline or other fuels. In particular, in a diesel gasoline engine, the ignition timing may be changed by changing the injection amount or injection timing of diesel fuel, or the injection amount or injection timing of main injection or pilot injection.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and the control of the internal combustion engine accompanying such a change. The apparatus is also included in the technical scope of the present invention.

It is a block diagram which shows notionally the basic composition of the port which concerns on this embodiment, and a cylinder injection type engine. It is sectional drawing which shows notionally the cross section of the port which concerns on this embodiment, and a cylinder injection type engine. It is sectional drawing which shows notionally the cross section of the injector with which the port which concerns on this embodiment, and a cylinder injection type engine are provided. 3 is a flowchart showing a flow of control processing in the control device for an internal combustion engine according to the present embodiment. It is the table which showed the predetermined map which prescribes | regulates the relationship between a port injection ratio, ignition timing, and an operation area | region based on this embodiment. 4 is a graph showing a relationship among an operation region, a supercharging pressure (that is, intake pressure) of an internal combustion engine, and an engine speed according to the present embodiment. It is the table which showed the relationship between a port injection ratio, a trace knock value, and an operation area | region based on this embodiment. According to the present embodiment, when the engine speed is a predetermined value Ki, three variables (smoke generation amount, ignition timing, and trace knock value) for the port injection ratio, the direct injection ratio, the load, and the operation region It is the table group (FIG. 8 (a), FIG.8 (b), and FIG.8 (c)) which showed the change. It is the graph which showed the relationship in the amount of generation | occurrence | production of the port injection ratio, load, and smoke based on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Port and cylinder injection type engine 2 Cylinder 3 Intake manifold 4 Exhaust manifold 5 Piston 6 Cavity 7 Intake port 8 Exhaust port 11d Direct-injection injector 11p Port injector 12 Knocking sensor 13 Spark plug 14 Fuel supply unit 15 Fuel pipe 16 Fuel tank 21 Exhaust turbine 22 Compressor 23 Rotor shaft 24 Air cleaner 25 Intercooler 30 ECU
301 Fuel Pressure Setting Unit 302 Injection Period Setting Unit 303 Injection Number Setting Unit 304 Injection Control Unit 305 Ignition Timing Control Unit

Claims (4)

A control device for an internal combustion engine for controlling an internal combustion engine including a supercharger,
First fuel injection means capable of injecting a first predetermined amount of fuel into the cylinder of the internal combustion engine;
Second fuel injection means capable of injecting a second predetermined amount of fuel into the intake passage of the internal combustion engine;
Ignition means for igniting the fuel in the cylinder at a predetermined ignition timing;
When raising the temperature of the injection port of the first fuel injection means, the first predetermined amount and the second predetermined amount are summed based on the supercharging pressure by the supercharger and the engine speed of the internal combustion engine . At least one of the first fuel injection means and the second fuel injection means so as to change the first ratio of the first predetermined amount to the total injection amount and the second ratio of the second predetermined amount to the total injection amount. Control means for controlling one of the injection means and controlling the ignition means so as to change the predetermined ignition timing based on the supercharging pressure, the first ratio , the second ratio, and the engine speed ; equipped with a,
In the case where the temperature is increased and the engine speed is larger than a predetermined number and the supercharging pressure is within a predetermined range including zero, the control means increases the second ratio above the first ratio. And controlling the at least one injection means so that the predetermined ignition timing is advanced from a maximum torque ignition timing that is an ignition timing at which the torque generated by the internal combustion engine is maximum. Control means
A control device for an internal combustion engine. When the temperature is increased, the control means changes the first ratio and the second ratio for each of a plurality of regions divided on a coordinate plane having the supercharging pressure and the engine speed as two axes. And controlling the at least one injection means and controlling the ignition means so as to change the predetermined ignition timing based on the first ratio and the second ratio for each of the plurality of regions. The control apparatus for an internal combustion engine according to claim 1 , wherein the control apparatus is an internal combustion engine. The control means is configured to increase the second ratio to be greater than the first ratio when the temperature is increased and the supercharging pressure is within a positive pressure range that promotes intake and exhaust. At least one injection unit is controlled, and the predetermined ignition timing is changed based on the degree of occurrence of knocking in the internal combustion engine in addition to the supercharging pressure, the first ratio, and the second ratio. 3. The control device for an internal combustion engine according to claim 1, wherein the ignition means is controlled. When the temperature is increased and the supercharging pressure is in a negative pressure range that does not promote intake and exhaust, the control means is configured to set the second ratio to 100%. 2. The injection means is controlled, and the ignition means is controlled so that the predetermined ignition timing approaches a maximum torque ignition timing that is an ignition timing at which a torque generated by the internal combustion engine is maximum. The control device for an internal combustion engine according to any one of claims 1 to 3 .

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