JP2010121587A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve startability while suppressing the excess rich condition of fuel. <P>SOLUTION: This control device for an internal combustion engine includes an intake air amount control valve in an intake passage. The device predicts and discriminates that the amount of fuel deposited on the wall face of the intake passage of the internal combustion engine is greater than a reference amount when starting the internal combustion engine. As a result, the device closes the intake air amount control valve when not discriminating that the amount of fuel deposited on the wall face is greater than the reference amount, and controls the opening of the intake air amount control valve to be larger than the opening of closed one when discriminating that the amount of fuel deposited on the wall face is greater than the reference amount. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine. More specifically, the present invention relates to a control device for an internal combustion engine capable of controlling the intake air amount to the internal combustion engine by an intake air amount control valve installed in the intake passage of the internal combustion engine.

  For example, Patent Document 1 describes a control method at the time of starting that controls the intake air amount by fully closing the electronic throttle valve when starting the internal combustion engine. Thus, by fully closing the electronic throttle valve at the start of the internal combustion engine, the intake pipe pressure is lowered, and fuel atomization is promoted.

JP 2007-32479 A JP 20052843 A JP 2000-265877 A JP 2005-23864 A

  However, for example, at the time of starting at a low temperature, a fuel injection amount is generally set to be large. In such a case, if the internal combustion engine is started at a low temperature and then stopped before warming up, a large amount of fuel may remain on the intake port wall surface of the internal combustion engine. In this way, when the internal combustion engine is restarted with a large amount of fuel adhering to the wall surface of the intake port, if the control is performed to reduce the intake pipe pressure by fully closing the electronic throttle valve by the above control, the vaporization of the adhering fuel May be promoted, resulting in a fuel-rich state. In such a case, it is conceivable to reduce the startability. In particular, in environments such as winter, where cold start is likely to occur, fuel with good evaporation characteristics may be used as the fuel and the fuel injection amount may be increased. It is thought that this leads to a decrease in

  Accordingly, in order to solve the above problems, the present invention provides an internal combustion engine control apparatus improved to improve startability while suppressing fuel over-richness.

In order to achieve the above object, a first invention is a control device for an internal combustion engine,
An intake air amount control valve provided in an intake passage of the internal combustion engine;
A prediction determining means for predicting and determining that the amount of fuel attached to the wall surface of the cylinder of the internal combustion engine or the wall surface of the intake passage when starting the internal combustion engine is greater than a reference amount;
If it is not determined that the amount of fuel adhering to the wall surface is larger than the reference amount at the time of starting the internal combustion engine, it is determined that the intake air amount control valve is closed and the amount of fuel adhering to the wall surface is larger than the reference amount. If so, intake air amount control valve control means for controlling the intake air amount control valve to an opening larger than the closed opening;
It is characterized by providing.

According to a second invention, in the first invention,
The prediction determining means determines whether the fuel adhering to the wall surface is equal to the reference when the previous start of the internal combustion engine is a start at a low temperature lower than a reference temperature and is stopped before the warm-up of the internal combustion engine is completed. It is characterized by predicting that the amount is larger than the amount.

  According to the first aspect of the present invention, when the amount of fuel attached to the wall surface is not predicted to be large at the time of starting the internal combustion engine, the intake air pressure is increased by closing the intake air amount control valve (the negative pressure in the intake air passage is reduced). The fuel vaporization can be promoted and the startability can be improved. When it is determined that the amount of fuel attached to the wall surface is large, the opening degree is controlled to be larger than the opening degree where the intake air amount control valve is closed. As a result, fuel overrich can be avoided by reducing the pressure in the intake passage and reducing the amount of fuel vaporized.

  According to the second invention, when the previous start of the internal combustion engine is a start at a low temperature lower than the reference temperature, and the engine is stopped before the warm-up of the internal combustion engine is completed, the amount of fuel adhering to the wall surface is less than the reference amount. It can be predicted that there are many. As a result, it is possible to reliably avoid fuel overrich under the condition that the amount of fuel attached to the wall surface is predicted to increase.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is simplified or omitted.

Embodiment 1 FIG.
FIG. 1 is a diagram for explaining a control device for an internal combustion engine and a peripheral structure thereof according to an embodiment of the present invention. An intake passage 12 and an exhaust passage 14 communicate with the internal combustion engine 10. The intake passage 12 includes an air filter 16 at an upstream end. The air filter 16 is assembled with an intake air temperature sensor 18 for detecting the intake air temperature THA (ie, the outside air temperature).

  An air flow meter 20 is disposed downstream of the air filter 16. An electronic throttle valve 22 (intake air amount control valve) is provided downstream of the air flow meter 20. A throttle motor 24 that is an actuator for driving the electronic throttle valve 22 is provided at one end of the shaft of the electronic throttle valve 22, and a throttle opening degree sensor 26 that detects the opening degree of the electronic throttle valve 22 is provided at the other end. Is provided. The electronic throttle valve 22 is driven to open and close by a throttle motor 24 based on an accelerator opening detected by an accelerator opening sensor and a throttle opening command value determined from each control signal of an electronic control device attached to the engine. It is what is done.

  A surge tank 28 is provided downstream of the electronic throttle valve 22. Further, a fuel injection valve 30 for injecting fuel into the intake port of the internal combustion engine 10 is disposed further downstream of the surge tank 28.

  The internal combustion engine 10 includes an intake valve 32 (intake valve) and an exhaust valve 34. The intake valve 32 is connected to a variable valve timing (VVT) 36 for changing the lift amount and / or the operating angle of the intake valve 32. An ignition plug (not shown) is provided in the cylinder of the internal combustion engine 10 to ignite the fuel sprayed in the cylinder. Further, a piston 38 that reciprocates inside the cylinder is provided in the cylinder. Further, a water temperature sensor 40 for detecting the cooling water temperature is attached to the internal combustion engine 10.

  The piston 38 is coupled to a crankshaft 42 that is rotationally driven by the reciprocating motion. The vehicle drive system and accessories (air conditioner compressor, alternator, torque converter, power steering pump, etc.) are driven by the rotational torque of the crankshaft 42. Connected to the crankshaft 42 is a starter 44 (starting device) for rotating the crankshaft 42 at the time of starting. A crank angle sensor 46 for detecting the rotation angle of the crankshaft 42 is attached in the vicinity of the crankshaft 42.

  As shown in FIG. 1, the control device of this embodiment includes an ECU (Electronic Control Unit) 50. In addition to the various sensors described above, the ECU 50 includes a KCS sensor that detects the occurrence of knocking, and various sensors (not shown) for detecting vehicle speed, engine speed, exhaust temperature, lubricating oil temperature, catalyst bed temperature, and the like. It is connected. The ECU 50 is connected to the actuators such as the throttle motor 24, the fuel injection valve 30, and the variable valve mechanism 36 described above.

  By the way, in the system of this embodiment, when the internal combustion engine 10 is normally started, control is performed such that the electronic throttle valve 22 is closed and fully closed. Thereby, since the intake pipe negative pressure increases, fuel vaporization can be promoted. Therefore, combustion can be stabilized and startability can be improved. Further, when the electronic throttle valve 22 is fully closed at the time of starting, the intake pipe pressure can be quickly reduced. Therefore, the steady state can be established early, and the controllability of the fuel injection amount and the air-fuel ratio can be improved. Here, even when the electronic throttle valve 22 is “fully closed”, the electronic throttle valve 22 has a predetermined gap between the inner wall surface of the intake passage 12 and does not become a completely sealed state. ing.

  However, for example, when starting at a low temperature below the freezing point, a fuel injection amount at the time of starting may be set to be large assuming that the fuel vaporization rate is low. Further, when fuel is attached to the intake port or the wall surface in the cylinder, the fuel attached to the wall surface (fuel attached to the wall surface) is atomized and supplied to the combustion chamber as fuel. Accordingly, the amount of fuel actually supplied into the combustion chamber is increased by the amount supplied by atomizing the wall-attached fuel.

  Here, in the case where the previous start is a start in a low temperature environment and the internal combustion engine 10 is stopped before the internal combustion engine 10 is warmed up, the intake port is kept while the fuel supplied at the start is not vaporized. It is thought that it is in the state which adhered many. In such a case, when fuel vaporization is promoted by performing full-closed control of the electronic throttle valve 22 at the next restart, a large amount of fuel adhering to the wall surface is vaporized, and the fuel supplied into the fuel chamber Will increase. When such restart is further started in a low-temperature environment (low-temperature restart), a large amount of fuel is supplied and a large amount of fuel attached to the wall surface is easily atomized. For this reason, in the case of a low temperature restart, the fuel tends to be in an excessive state.

  On the other hand, by performing the fully closed control of the electronic throttle valve 22, the amount of intake air at the time of starting becomes smaller than usual. Therefore, if the electronic throttle valve 22 is fully closed during normal temperature restart, the fuel over-rich state is likely to occur, and the startability may be reduced.

  Therefore, in the first embodiment, the throttle opening is fully closed in the case of a low temperature restart in which the fuel adhering amount in the intake port is large at the previous stop and the current fuel injection amount is predicted to increase. The opening θ1 has a smaller closing amount than θ0. Thereby, the amount of intake air can be increased. Moreover, since the intake pipe negative pressure at the time of starting can be suppressed small, the amount of fuel to be atomized can be suppressed. Therefore, it is possible to suppress the fuel over-rich state even at a low temperature restart.

  FIG. 2 is a graph for explaining the relationship between the throttle opening and the intake pipe negative pressure. In FIG. 2, the horizontal axis represents the elapsed time from the start of the internal combustion engine 10, and the vertical axis represents the throttle opening or intake pipe negative pressure.

  A broken line (a) in FIG. 2 shows a state in which the throttle opening of the electronic throttle valve 22 is fully closed during normal startup. In this case, as indicated by a broken line (b), the intake pipe pressure decreases (intake pipe negative pressure is increased) at an early stage. However, if misfire occurs due to fuel overrich, the engine speed does not increase as shown by the broken line (c), and the startability is reduced.

  On the other hand, when the throttle opening is set to an opening θ1 (> θ0) smaller than the fully closed θ0 as shown by the solid line (A) in FIG. 2, the amount of decrease in the intake pipe pressure is as shown by the solid line (B). In other words, the intake pipe negative pressure is reduced. In this case, since fuel over-rich can be avoided, the engine speed can be increased at an early stage as shown by the solid line (C).

  FIG. 3 is a flowchart for illustrating a control routine executed by ECU 50 in the first embodiment of the present invention. The routine shown in FIG. 3 is executed every time the internal combustion engine 10 is started.

  In the routine of FIG. 3, first, it is determined whether or not the current start is a low temperature restart (S2). Here, the previous internal combustion engine is based on the temperature at the previous start, the temperature of the internal combustion engine 10 at the stop, etc. detected by the output of the intake air temperature sensor 18 at the previous start, the output of the water temperature sensor 40 at the previous stop, or the like. The starting and stopping states of the are determined. Whether or not the current start is low is determined based on the output of the intake air temperature sensor 18 or the like. As a result, it is recognized that the previous start is a low-temperature start and that the internal combustion engine has stopped before the warm-up of the internal combustion engine 10 is completed, and that this start is a start in a low-temperature environment. If it is, it is determined that the low-temperature restart has occurred.

  If it is determined in step S2 that the restart is a low temperature, the closing amount of the electronic throttle valve 22 is calculated in step S4. The closing amount calculated here is the closing amount when the throttle opening is the opening θ1 larger than the fully closed θ0 from the current opening. Therefore, the closing amount is smaller than that at the fully closed time. It becomes.

  On the other hand, if the low temperature restart is not recognized in step S2, the closing amount of the electronic throttle valve 22 is calculated in step S6. The closing amount calculated here is a closing amount that makes the electronic throttle valve 22 be fully closed θ0 from the current throttle opening.

  Next, the throttle opening is controlled based on the closing amount calculated in step S4 or step S6 (S8). Here, a control signal is issued from the ECU 50 to the throttle motor 24, and the electronic throttle valve 22 is controlled to a predetermined opening by the throttle motor 24 based on this control signal. Thereafter, the current process ends.

  As described above, according to the first embodiment, it is possible to prevent the fuel from becoming over-rich even in the case of a low temperature restart such as an intake port where the amount of fuel attached to the wall surface is large. Therefore, the startability is improved by fully closing the electronic throttle valve 22 and, in an environment where the fuel is rich, the throttle opening is increased to some extent to increase the intake air amount and decrease the fuel vaporization amount. In addition, it is possible to suppress a decrease in startability due to fuel overrich.

  In the first embodiment, by executing step S2, the “prediction determination means” of the present invention is realized, and by executing steps S4 or S6 and S8, “intake air amount control valve” Control means "is realized.

  In the first embodiment, a case where the temperature is restarted is assumed as a case where the amount of fuel attached to the wall surface is large, and in this case, the case where the opening degree θ1 of the electronic throttle valve 22 is larger than the fully closed θ0 has been described. . However, the present invention is not limited to this, and other conditions for increasing the amount of fuel on the wall surface are set, and similarly, the electronic throttle valve 22 is controlled to start with an opening larger than fully closed. It may be.

  Further, the case where the temperature is below the freezing point has been described as the cold start condition. However, "cold start" here is not necessarily an environment below the freezing point. For example, the temperature when the fuel vaporization rate is lowered to some extent and the startability is judged to be lower is set as the reference temperature, The start when the temperature is low may be a “cold start”.

  Further, in the first embodiment, the case where the closing amount of the electronic throttle valve 22 is calculated in each of the case where the amount of fuel attached to the wall surface is large and the case where it is not so has been described. However, the calculation and setting method of the throttle opening is not limited to this.

  FIG. 4 is a flowchart for illustrating another routine of the first embodiment of the present invention. The routine shown in FIG. 4 is a routine that is executed every time the engine is started instead of the routine shown in FIG. In the routine of FIG. 4, at the time of start-up, a closing amount at which the opening of the electronic throttle valve 22 is fully closed is calculated (S10). Thereafter, similarly to step S2 in FIG. 3, it is determined whether or not the current start is a low temperature restart (S12). If it is determined that the engine is restarted at a low temperature, a reduction with respect to the throttle closing amount at which the throttle opening is fully closed is calculated (S14). Thereafter, the throttle closing amount is calculated again (S16). Here, a value obtained by subtracting the reduction amount from the fully closed throttle closing amount is calculated as the closing amount.

  When the low temperature restart is not recognized in step S12, or after the throttle closing amount is recalculated in step S16, the electronic throttle valve 22 is controlled based on the calculated closing amount (S18). Specifically, when the low temperature restart is not recognized in step S12, the throttle opening is controlled in accordance with the closing amount at which the throttle is fully closed. The electronic throttle valve 22 is controlled with a small closing amount.

  Even in such a control routine, the opening degree of the electronic throttle valve 22 can be made larger than that in the fully closed state at the time of low-temperature restart at which over-rich is likely to occur. Therefore, it becomes possible to prevent the fuel from being rich. Further, the present invention is not limited to such a control routine, and control may be executed in accordance with a routine other than those shown in FIGS.

  In the routine of FIG. 4, the “prediction determination unit” of the present invention is realized by executing step S12, and “intake air amount” is realized by executing steps S10 and S18 or S14 and S16 and S18. "Control valve control means" is realized.

  In the first embodiment, the case where the electronic throttle valve 22 is fully closed has been described in cases other than the low temperature restart. However, the present invention is not limited to this. As long as the throttle opening at the low temperature restart is controlled to be larger than the opening at the time other than the low temperature restart, The opening may not be fully closed. However, since it is necessary to increase the intake pipe negative pressure by closing the electronic throttle valve 22, it is effective to set the opening close to full closure.

Embodiment 2. FIG.
The system of the second embodiment has the same configuration as the system of FIG. Further, the system of the second embodiment improves the startability by performing the control to fully close the electronic throttle valve 22 at the time of starting, as in the system of the first embodiment. In the second embodiment, when it is determined that the amount of fuel adhering to the wall surface is large, the starter at the time of starting is replaced with a control in which the closing amount of the electronic throttle valve 22 is smaller than the closing amount of the fully closed state. Control is performed to reduce the intake pipe negative pressure by reducing the cranking rotational speed by 44.

  FIG. 5 is a diagram for illustrating the relationship between the cranking rotation speed at the start and the intake pipe pressure in the second embodiment of the present invention. When the cranking rotational speed at the start is relatively large as shown by the broken line (a) in FIG. 5, the intake pipe pressure becomes relatively small (the intake pipe negative pressure is large) as shown by the broken line (b). On the other hand, when the cranking rotational speed is decreased as indicated by the solid line (A), the intake pipe pressure increases (intake pipe negative pressure is small) as indicated by the solid line (B).

  Therefore, in the case of the low temperature restart where the amount of fuel adhering to the wall surface is predicted to be large, the electronic throttle valve 22 is fully closed to control to increase the intake pipe negative pressure, and at the same time the voltage supplied to the starter 44 is reduced. And reducing the cranking speed. Thereby, in the case of low temperature restart, the intake pipe negative pressure can be reduced as compared with the normal start. Thereby, vaporization of the wall surface adhering fuel can be suppressed to some extent in the low temperature restart where the amount of the wall surface adhering fuel is large, and the fuel over-rich can be prevented.

  FIG. 6 is a flowchart for illustrating a control routine executed by ECU 50 in the second embodiment of the present invention. The routine shown in FIG. 6 is a routine that is executed every time the internal combustion engine 10 is started, instead of the routine of FIG.

  In the routine of FIG. 6, first, it is determined whether or not it is a low temperature restart (S20). The determination as to whether or not it is a low temperature restart is performed by the same method as in step S2 of FIG. In step S20, when it is recognized that the restart is a low temperature, in step S22, the supply voltage to the starter 44 is set to a small voltage V1 at the time of the low temperature restart. On the other hand, when it is not recognized that the restart is a low temperature in step S20, the supply voltage is set to the normal starting voltage V0 (> V1) in step S24.

  When the supply voltage to the starter 44 is set in step S22 or step S24, control of the electronic throttle valve 22 is then executed so that the electronic throttle valve 22 is fully closed (S26). Next, the starter 44 is operated by the set supply voltage (S28). As a result, when the restart is not a low temperature, the starter 44 is operated by a normal voltage VO and started at a high cranking speed. On the other hand, in the case of the low temperature restart, the starter 44 is operated by the voltage V1 lower than the normal voltage VO, and is started at a low cranking speed. Thereafter, the current process ends.

  As described above, according to the system of the second embodiment, by reducing the cranking rotation speed at the time of low temperature restart, it is possible to suppress an increase in intake pipe negative pressure and avoid fuel over-richness. it can.

  In the second embodiment, the case of low temperature restart is set as a condition where the amount of fuel attached to the wall surface is large. However, the present invention is not limited to this, and other conditions may be set when the amount of wall surface fuel adhesion increases. In addition, as in the first embodiment, the low temperature start condition is not limited to below the freezing point. For example, the temperature at which the fuel vaporization rate is reduced to some extent and the startability is determined to be reduced, The reference temperature may be used, and the starting when the temperature is lower than the reference temperature may be “low temperature”.

  In the second embodiment, the case where the electronic throttle valve 22 is fully closed at the time of starting has been described. However, the present invention is not limited to this, and the electronic throttle valve 22 may not be fully closed as long as the electronic throttle valve 22 is set to an opening smaller than that during normal operation and the intake pipe negative pressure is ensured. Good.

  In the second embodiment, the “prediction determination unit” of the present invention is realized by executing step S20, and the “intake air amount control valve control unit” is realized by executing step S26. By executing step S22 or S24 and step S28, the “cranking rotation speed control means” is realized.

Embodiment 3 FIG.
The system of the third embodiment has the same configuration as the system of FIG. Also in the system according to the third embodiment, the control for fully closing the electronic throttle valve 22 is executed when the internal combustion engine 10 is normally started. However, in the system of the first embodiment, the opening degree of the electronic throttle valve 22 is set to a larger opening degree than the fully closed at the time of low temperature restart, whereas in the system of the third embodiment, at the time of low temperature restart. Performs control to avoid fuel overrich by changing the valve timing of the intake valve 32.

  FIG. 7 is a diagram for explaining the intake valve timing at the normal time and the valve timing when the valve is closed earlier or slower than the normal time. In the valve timing at the normal start shown in FIG. 7, the intake valve 32 is opened when the piston 38 is near the position of TDC (top dead center), and the intake valve 32 is closed after exceeding the intake BDC (intake bottom dead center). It is done. On the other hand, when the valve is closed early or late, the valve closing timing is controlled so that the intake valve 32 is closed at a position farther from the intake BDC than the normal valve closing timing.

  FIG. 8 is a diagram for explaining the relationship between the closing timing of the intake valve 32 and the actual compression ratio or the compression end temperature. The amount of the air-fuel mixture introduced into the cylinder during the intake stroke depends on the position of the piston 38 when the valve is closed. That is, in the case of early closing and late closing where the valve is closed at a position away from the intake BDC, the intake air amount becomes a small amount corresponding to the piston position at the valve closing timing. Therefore, as shown in FIG. 8, the actual compression ratio is small in the case of early closing or late closing. Further, the compression end temperature indicating the temperature when the air-fuel mixture in the cylinder is compressed also decreases accordingly.

  In the third embodiment, at the time of starting when the amount of fuel adhering to the wall surface is large, such as when restarting at a low temperature, the electronic throttle valve 22 is fully closed and the intake valve is quickly closed, so that the actual compression in the cylinder is performed. Try to keep the ratio low. Thereby, vaporization of the fuel in the cylinder can be suppressed, and the fuel over-rich state can be avoided. By setting the timing for early closing, if it is expected that a valve stamp that interferes with the piston 38 and the intake valve 32 that has reached or near the top dead center will occur, the operating angle is also changed. .

  FIG. 9 is a flowchart for illustrating a control routine executed by ECU 50 in the third embodiment of the present invention. The routine of FIG. 9 is a routine that is executed every time the internal combustion engine 10 is started, instead of the routine of FIG.

  In the routine of FIG. 9, it is first determined whether or not it is a low temperature restart (S30). This determination is performed in the same manner as step S2 of the routine of FIG. If it is determined in step S30 that the restart is a low temperature, the early closing timing is calculated as the closing timing of the intake valve 32 (S32). On the other hand, when it is not recognized that the restart is a low temperature in step S30, a normal timing is calculated as the closing timing of the intake valve 32 (S34).

  After step S32 or step S34, the electronic throttle valve 22 is then controlled to be fully closed (S36). Next, the valve timing calculated in step S32 or S34 is controlled (S38). The valve timing is controlled by the early closing timing calculated in S32 or S34 by issuing a control signal to the variable valve mechanism 36 installed in the intake valve 32. Thereafter, the current process ends.

  As described above, according to the third embodiment, the actual compression ratio in the cylinder at the time of start-up can be kept low during the low-temperature restart at which fuel overrich is likely to occur. As a result, the amount of fuel vaporization can be reduced to prevent the fuel from becoming rich. Therefore, at the time of normal start, control to fully close the electronic throttle valve 22 is executed to improve startability, and in the state where the fuel is over-rich, the startability can be prevented from being lowered. Startability can be improved.

  In the embodiment, the case has been described in which the intake valve 32 is controlled to the timing of early closing. However, the present invention is not limited to this. For example, the intake valve 32 may be closed later than usual. Also in this case, as shown in FIG. 8, the actual compression ratio and the compression end temperature can be lowered, and the vaporization of fuel can be suppressed. Moreover, it is not limited to either early closing or late closing, and early closing or late closing may be appropriately selected depending on other starting conditions or the like. Further, the valve timing of the intake valve 32 at the normal start follows the control executed according to various conditions at the start. In the third embodiment, the valve timing of the intake valve 32 at the normal time is closed early or late at the low temperature restart with respect to the normal valve timing set by the control at the normal start. Is described.

  In the third embodiment, the case of low temperature restart is set as a condition where the amount of fuel attached to the wall surface is large. However, the present invention is not limited to this, and other conditions may be set when the amount of wall surface fuel adhesion increases. In addition, as in the first embodiment, the low temperature start condition is not limited to below the freezing point. For example, the temperature at which the vaporization rate of the fuel is reduced to some extent and the startability is determined to be reduced, The reference temperature may be used, and the starting when the temperature is lower than the reference temperature may be “low temperature”.

  In the third embodiment, the “prediction determination unit” of the present invention is realized by executing step S30, and the “intake air amount control valve control unit” is realized by executing step S36. By executing S32 or S34 and S38, the “intake valve control means” is realized.

  In other parts as well, when referring to the number of each element, quantity, quantity, range, etc. in this embodiment, unless otherwise specified or clearly specified in principle. Thus, the present invention is not limited to the number mentioned. Further, the structure, steps in the method, and the like described in this embodiment are not necessarily essential to the present invention unless otherwise specified or clearly specified in principle.

It is a schematic diagram for demonstrating the structure of the control apparatus of the internal combustion engine in Embodiment 1 of this invention, and its peripheral device. It is a figure for demonstrating the relationship between the throttle opening and intake pipe negative pressure in Embodiment 2 of this invention. It is a flowchart for demonstrating the control routine which ECU performs in Embodiment 1 of this invention. It is a flowchart for demonstrating the routine of the other control in Embodiment 1 of this invention. It is a figure for demonstrating the relationship between the cranking rotation speed and intake pipe negative pressure in Embodiment 2 of this invention. It is a flowchart for demonstrating the control routine which ECU performs in Embodiment 2 of this invention. It is a figure for demonstrating the valve closing timing of the intake valve in Embodiment 3 of this invention. It is a figure for demonstrating the relationship between the valve closing timing of an intake valve in Embodiment 3 of this invention, and an actual compression ratio or compression end temperature. It is a flowchart for demonstrating the control routine which ECU performs in Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Intake passage 14 Exhaust passage 18 Intake temperature sensor 22 Electronic throttle valve 24 Throttle motor 30 Fuel injection valve 32 Intake valve 36 Variable valve mechanism 38 Piston 40 Water temperature sensor 42 Crankshaft 44 Starter 50 ECU

Claims (2)

An intake air amount control valve provided in an intake passage of the internal combustion engine;
A prediction determining means for predicting and determining that the amount of fuel attached to the wall surface of the cylinder of the internal combustion engine or the wall surface of the intake passage when starting the internal combustion engine is greater than a reference amount;
If it is not determined that the amount of fuel adhering to the wall surface is larger than the reference amount at the time of starting the internal combustion engine, it is determined that the intake air amount control valve is closed and the amount of fuel adhering to the wall surface is larger than the reference amount. If so, intake air amount control valve control means for controlling the intake air amount control valve to an opening larger than the closed opening;
A control device for an internal combustion engine, comprising:   The prediction determining means determines whether the fuel adhering to the wall surface is equal to the reference when the previous start of the internal combustion engine is a start at a low temperature lower than a reference temperature and is stopped before the warm-up of the internal combustion engine is completed. 2. The control apparatus for an internal combustion engine according to claim 1, wherein the determination is made by predicting that the amount is larger than the amount.

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