JP4799663B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for an internal combustion engine that controls the closing timing of an intake valve at the time of starting in a high compression ratio internal combustion engine.

  Conventionally, as a control device for an internal combustion engine that prevents misfire and smoldering contamination of the internal combustion engine and improves combustion stability and reduces rotation unevenness, for example, there have been the following Patent Documents 1 to 4.

JP 2008-38672 A JP-A-8-158999 JP-A-8-165936 Japanese Patent Laid-Open No. 11-30143

  By the way, in the internal combustion engine, if carbon generated when the air-fuel mixture in the cylinder burns incompletely adheres to the surface of the ignition part of the ignition plug, the insulation resistance value between the center electrode and the ground electrode of the ignition plug decreases. And it becomes difficult for the spark to fly in the regular gap. This phenomenon is generally known as “smoldering fouling” of the spark plug. The occurrence of leakage current (hereinafter referred to as leakage current) between the electrodes of the spark plug due to a decrease in the insulation resistance value between the electrodes of the spark plug is referred to as “smoldering”.

  The above smoldering is likely to occur when idling for a long time or starting in a cold state is repeated, and if a spark plug in a smoldering fouling state is used, a spark will fly at a place other than the regular gap (hereinafter referred to as back jumping). As a result, the ignitability of the air-fuel mixture deteriorates, and the output torque necessary for starting cannot be obtained, and if the rotation speed increases and further smoldering progresses, it may become impossible to start due to misfire. is there.

  In particular, the above-mentioned starting failure tends to occur when the machine is cold. According to the control parameter time chart at the time of cold start shown in FIG. 9, the required voltage until the first explosion (voltage required for discharge in the regular gap) is high at the time of cold start, and the required voltage becomes small after 2nd combustion. Has been revealed in previous studies. It is also well known that the required voltage varies depending on various factors, but it is well known that the regular gap distance of the spark plug, the compression pressure at the ignition timing, and the temperature of the air-fuel mixture in the cylinder are particularly significant. It is a fact. When cold, the required voltage increases because the temperature of the air-fuel mixture in the cylinder is low among the above factors. When the first explosion is completed, the temperature in the cylinder rises, so the required voltage becomes small.

  At the time of smoldering contamination, a leak current is generated before the required voltage required for the first explosion is reached, and the spark does not fly at a regular gap. Further, when the intake air temperature or the cooling water temperature is low, the intake air amount is increased by controlling the advance of the closing timing of the intake valve, which makes it difficult to start.

  However, the control device for an internal combustion engine disclosed in Patent Documents 1 to 3 has not been intended to actively solve such problems. In the method of Patent Document 4, the fuel supplied to the internal combustion engine is relatively reduced as the degree of smoldering fouling in the spark plug increases, but the fuel injection amount is controlled to be reduced at a low temperature start. Then, since a combustible air-fuel mixture cannot be formed sufficiently, there is a possibility that the internal combustion engine cannot be started.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device for an internal combustion engine that can be stably started even if smoldering occurs.

  The present invention comprises smolder detecting means for detecting a smolder that makes it difficult for a spark to fly at a regular gap of an ignition plug, and an intake valve timing control means for controlling the closing timing of the intake valve, and the smolder detecting means at the time of starting In the control apparatus for an internal combustion engine, when the smolder is detected, the compression timing of the internal combustion engine is reduced by retarding the closing timing of the intake valve by the intake valve timing control means.

  According to the present invention, it is possible to avoid a starting failure when smoldering occurs in an internal combustion engine, particularly a high compression ratio internal combustion engine.

1 is a block diagram showing a schematic configuration of a control device for an internal combustion engine according to an embodiment of the present invention. FIG. It is a circuit diagram which shows an example of the concrete structure of the ignition coil provided with the function of the leak current detection apparatus in the control apparatus of the internal combustion engine by this invention. 3 is a flowchart showing an outline of control of the internal combustion engine according to the present invention. It is a figure which shows the valve lift amount of an intake valve with respect to the crank angle (each process) in the control apparatus of the internal combustion engine by this invention. It is a time chart of the output of the leakage current detection apparatus of the control apparatus of the internal combustion engine by this invention. It is a figure which shows the valve lift amount of an intake valve with respect to the crank angle (each process) in the control apparatus of the internal combustion engine by this invention. It is a time chart at the time of not performing the process by this invention with respect to a smoldering fouling plug. It is a time chart at the time of performing the process by this invention with respect to a smoldering fouling plug. It is a time chart of the rotational speed at the time of a start, a required voltage, and a compression pressure. It is a figure which shows the relationship between the compression pressure in ignition timing, and a required voltage. It is a figure which shows the relationship between ignition timing and compression pressure.

  According to the present invention, in a control device for an internal combustion engine, comprising: a smolder detecting means for detecting a smolder that makes it difficult for a spark to fly at a regular gap of an ignition plug; and an intake valve timing control means for controlling a closing timing of the intake valve. When smoldering is detected by the smolder detecting means at the time of starting, the compression pressure of the internal combustion engine is lowered by retarding the closing timing of the intake valve by the intake valve timing control means.

  Specifically, the compression of the internal combustion engine is controlled by retarding the valve closing timing of the intake valve when smoldering before the smoldering progresses until the spark plug electrodes are short-circuited, that is, when the smoldering is detected. Reduce pressure. According to the relationship between the compression pressure and the required voltage shown in FIG. 10, if the compression pressure decreases, the required voltage decreases (point A → point B in the figure), so that it is easy to ignite at the regular gap of the spark plug. As a result, even in a situation where the required voltage is high, such as at a low temperature, it is possible to avoid / suppress / mitigate a starting failure such as a delay in the increase of the rotational speed at the time of starting or a misfire. Furthermore, since it is possible to realize early start-up by shortening the time required until the first and complete explosions, it is possible to obtain the effect of reducing the battery power consumption by shortening the starter driving time.

  In addition, the first explosion detection means for detecting the first explosion of each cylinder is provided, and after the initial explosion of each cylinder at the start is completed, the intake valve closing timing is controlled by the intake valve timing control means. By increasing the intake air amount of the internal combustion engine and increasing the rotational speed, the time required for complete explosion is further shortened.

  Here, the smoldering detection means includes a leakage current detection device that detects a leakage current flowing at that time by applying a predetermined voltage between the center electrode and the ground electrode of the ignition plug, and based on the leakage current in the ignition plug. By detecting the presence or absence of occurrence of smoldering, it is possible to detect smoldering before the occurrence of misfire due to a short circuit between the electrodes of the spark plug, and it is possible to quickly take measures against smoldering.

  Further, by providing an ignition timing control means for controlling the advance of the ignition timing of the internal combustion engine within a range in which knocking due to early ignition does not occur, ignition can be performed when the compression pressure of the internal combustion engine is low, and the required voltage can be reduced. it can. According to the in-cylinder pressure waveform shown in FIG. 11, when the ignition timing in the compression stroke is advanced, the compression pressure at the ignition timing can be reduced, which is an effect obtained. If such an ignition timing control means is provided, a spark can easily fly at a regular gap of the spark plug, so that a starting failure of the internal combustion engine can be avoided / suppressed / relieved.

  Hereinafter, an internal combustion engine control apparatus according to the present invention will be described with reference to the drawings in accordance with an embodiment.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a schematic configuration of a control device for an internal combustion engine according to an embodiment of the present invention. In FIG. 1, an electronically controlled throttle valve 2 that is electronically controlled to adjust the intake air flow rate is provided upstream of an intake system of an engine (internal combustion engine) 1. In order to measure the opening degree of the electronically controlled throttle valve 2, a throttle opening degree sensor 3 is provided.

  Further, an airflow sensor 4 for measuring the intake air flow rate is provided upstream of the electronically controlled throttle valve 2, and the pressure in the surge tank 5 is measured on the engine 1 side downstream of the electronically controlled throttle valve 2. An intake manifold pressure sensor 6 is provided. Note that both the airflow sensor 4 and the intake manifold pressure sensor 6 may be provided, or only one of them may be provided. Further, an electronically controlled EGR valve 7 is connected to the surge tank 5, and an injector 8 for injecting fuel is provided in the intake passage downstream of the surge tank 5. The injector 8 may be provided so that it can be directly injected into the cylinder of the engine 1.

  An intake valve 9 is provided at the end of the intake passage downstream of the surge tank 5, and this intake valve 9 regulates the air-fuel mixture entering the cylinder. The upper end of the intake valve 9 is in contact with the cam surface of the camshaft 10 that rotates according to the driving state of the engine 1. A variable intake valve timing mechanism 11 that opens and closes the cylinder passage by changing the axial position of the intake valve 9 according to the rotational position of the camshaft 10 is provided. The variable intake valve timing mechanism 11 has a cam angle sensor (not shown in FIG. 5) that detects the position (angle) of the camshaft 10 and a function of adjusting the valve closing timing of the intake valve 9 by electric or hydraulic pressure. ing.

  Furthermore, an ignition coil 12 and a spark plug 13 for igniting the air-fuel mixture in the cylinder of the engine 1 are provided. Note that the spark plug 13 is arranged so that its electrode faces the cylinder of the engine 1, and when a required voltage is applied, it sparks to explode the air-fuel mixture. Further, the ignition coil 12 is provided with a function of a leakage current detection device 14 that detects a leakage current that flows by applying a predetermined voltage between the center electrode and the ground electrode of the ignition plug 13. The leak current detection device 14 is also provided with a function of detecting an ion current generated when the air-fuel mixture is burned. In addition, the leakage current detection device 14 may be configured as a separate body from the ignition coil instead of the function provided in the ignition coil. A specific configuration of the ignition coil 12 provided with the function of the leakage current detection device 14 will be described later. Further, a crank angle sensor 15 for detecting an edge of a plate provided on the crankshaft is provided in the engine 1 in order to detect the rotational speed and crank angle of the engine.

  The intake air flow rate S1 measured by the airflow sensor 4, the intake manifold pressure S2 measured by the intake manifold pressure sensor 6, the opening S3 of the electronically controlled throttle valve 2 measured by the throttle opening sensor 3, and the crank angle sensor The pulse S4 synchronized with the edge of the plate provided on the crankshaft output from 15 and the leakage current value S5 and the ionic current value S6 measured by the leakage current detector 14 provided in the spark plug 13 are electronically controlled. The data is input to a unit (hereinafter referred to as “ECU”) 16.

  The ECU 16 is a unit mainly composed of a microcomputer. In addition to the output signals of the sensors and detection devices, the ECU 16 outputs a battery output voltage (not shown in FIG. 1), a starter switch on / off signal (S10), Intake air temperature measured by the air temperature sensor (hereinafter referred to as intake air temperature), cooling water temperature measured by the water temperature sensor (hereinafter referred to as water temperature) (S12), camshaft measured by the variable intake valve timing mechanism 11 A signal at 10 positions (angles) is input. The ECU 16 sets a target value for the closing timing of the intake valve 9 from the input signals using a method described later, and performs target control for performing feedback control so that the closing timing of the intake valve 9 becomes the target value. The valve timing signal S7 is output to the variable intake valve timing mechanism 11. Further, the ECU 16 controls the ignition timing by outputting an energization / cutoff signal S8 to the ignition coil 12 in accordance with various input signals. Furthermore, the ECU 16 also outputs instruction signals to various actuators other than those described above.

  FIG. 2 is a circuit diagram showing an example of a specific configuration of the ignition coil 12 having the function of the leakage current detection device 14. The ignition coil 12 includes a primary winding 18a and a secondary winding 18b. The battery 17 is connected to the high voltage side of the primary winding 18a of the ignition coil 12 and supplies power. In the power transistor 19, the collector is connected to the low voltage side of the primary winding 18a, the collector is grounded (grounded), the base is connected to the ECU 16, and the primary current flowing through the primary winding 18a is turned on / off. The spark plug 13 shown with the resistor 24 connected in parallel between the high-voltage electrode and the ground electrode has one end connected to the high-voltage side of the secondary winding 18b of the ignition coil 12 and the other end grounded. When the secondary voltage V2 is applied, the air-fuel mixture in the cylinder of the engine 1 is ignited. Here, only the ignition part for one cylinder is representatively shown, but a similar ignition part is provided for each cylinder.

  The leak current detection device 14 detects a leak current value S5 and an ion current value S6 that flow through the spark plug 13. A capacitor 20 serving as a bias power source is connected to the low-voltage side of the secondary winding 18b, and a Zener diode 21 is connected in parallel with the capacitor 20. When the engine 1 is ignited, the secondary voltage V2 induced on the secondary side of the ignition coil 12 is accumulated and used as the bias voltage Vc. The Zener diode 21 has one end connected to the low voltage side of the secondary winding 18b and the other end grounded, and clamps the bias voltage Vc charged in the capacitor 20. The other end of the capacitor 20 is connected to a parallel circuit including a diode 22 and a leak current detecting resistor 23. The other ends of the diode 22 and the resistor 23 are grounded. The resistor 24 connected in parallel to the spark plug 13 is a resistance value between the electrodes of the spark plug 13, and normally, the resistance value between the electrodes of the spark plug 13 where no smoldering contamination occurs is considered infinite.

  Next, the operation of the leakage current detection device 14 will be described. When the primary winding 18a is cut off by the power transistor 19 in response to the energization / cutoff signal S8 at the ignition timing of the engine 1, a negative secondary voltage V2 is generated on the high voltage side of the secondary winding 18b. . As a result, a discharge current flows to the secondary winding 18b side and a spark discharge occurs between the electrodes of the spark plug 13, so that the air-fuel mixture of the engine 1 is ignited and the capacitor 20 is charged. At this time, the charging voltage Vc of the capacitor 20 is arbitrarily set by the Zener diode 21. Further, as the air-fuel mixture burns, ions are generated by the ionizing action around the spark plug 13, so that an ion current flows due to the movement of electrons by the positive bias voltage Vc of the capacitor 20. At this time, by detecting the voltage drop generated in the resistor 23 as the induced voltage value Vi, the ionic current value S6 indicating the combustion state of the air-fuel mixture can be detected. Further, when the spark plug 13 is smoldered and the resistor 24 having a resistance value of MΩ is equivalently present between the electrodes, the bias voltage Vc is applied to the secondary side of the ignition coil 12. A leak current flows between the electrodes of the spark plug 13. At this time, by detecting the voltage drop generated in the resistor 23 as the induced voltage value Vi, it is possible to detect the leakage current value S5 indicating the smoldering contamination state.

  FIG. 3 is a flowchart showing a schematic operation of the control apparatus for an internal combustion engine according to the embodiment of the present invention. The operation will be described below. This operation is basically performed by the control of the ECU 16 in FIG. As shown in FIG. 3, in step 101, an on / off signal S10 of a starter switch (not shown) is read to determine whether or not the engine is in a starting state. If “Yes” is determined here, the process proceeds to step 102. On the other hand, if it is determined as “No”, the operation is out of the range of the feature of the present invention, so that this processing is terminated.

  In step 102, it is confirmed that the initial explosion of each cylinder of the engine has not been completed. The initial explosion of the engine may be determined that the initial explosion is completed when the detection level of the ion current value S6 measured by the leak current detection device 14 is equal to or higher than a predetermined value, or measured by the intake manifold pressure sensor 6. The initial explosion is completed based on the absolute value or rate of change of the sudden decrease change of the intake manifold pressure value S2 and the sudden increase change of the output signal (both not shown) of the in-cylinder pressure sensor that measures the pressure in the cylinder It may be determined that the initial explosion has been completed when the periodic change of the pulse S4 synchronized with the edge of the plate provided on the crankshaft output from the crank angle sensor 15 has decreased by a predetermined amount or more. May be. If it is determined as “Yes” in step 102 and the initial explosion is not completed, the process proceeds to step 104. If it is determined “No” and the initial explosion is completed, the process proceeds to step 103.

  In step 103, after the valve closing timing of the intake valve 9 is controlled to advance from a preset target value at the time of starting, the intake air amount of the engine is increased to promote the increase of the rotational speed, and then the present processing is performed. Exit. Hereinafter, the effect of step 103 will be specifically described with reference to the valve lift amount of the intake valve with respect to the crank angle (each step of the engine cycle) shown in FIG. By shifting the preset valve lift 201 at the start to the valve lift 202, the target value A point of the valve closing timing is shifted to the B point on the advance side. Thereby, the opening period of the intake valve 9 in the intake stroke can be extended from the period 203 to the period 204, and the intake air amount of the engine can be increased. When the intake air amount increases, the engine load increases, so the output torque also increases, and the increase in the engine rotation speed can be promoted. By taking such means, it is possible to obtain an effect of shortening the time required from the start to the complete explosion.

  On the other hand, in step 104, it is determined whether smoldering contamination has occurred in the spark plug 13 based on the leakage current value S5 measured by the leakage current detector 14. FIG. 5 is a time chart of the energization / cutoff signal S8 at the start, that is, cranking, the secondary voltage V2, the bias voltage Vc, and the output of the leakage current detector 14 with / without smoldering contamination in the circuit diagram of FIG. A method for determining whether or not smoldering contamination has occurred will be described.

  First, when the energization / cutoff signal S8 is energized and the power transistor 19 is turned on, a current flows through the primary winding 18a of the ignition coil 12. Next, when the energization / shutoff signal S8 is turned off and the power transistor 19 is turned off, when the primary current is cut off, a high voltage is induced in the secondary winding 18b of the ignition coil 12, and the discharge current is reduced. As a result, spark discharge occurs in the spark plug 13 and the capacitor 20 is charged at the same time. Here, the leakage current value S5 and the ionic current value S6 are not detected over a certain time T1 after the start of discharge because the absolute amount of the bias voltage Vc charged in the capacitor 20 is larger than the secondary voltage V2 generated by ignition. Because it is small. After that, since the secondary voltage V2 rapidly decreases due to the discharge, when the bias voltage Vc becomes the operation period T2-T3 in which the absolute value of the secondary voltage V2 is exceeded, a leakage current or an ionic current is detected. become able to. When the bias voltage Vc decreases and reaches the end time of T3, the leakage current and the ion current cannot be detected.

  After the bias voltage Vc exceeds the absolute value of the secondary voltage V2, the ignition coil 12 tries to release residual magnetic energy, and LC resonance occurs between the inductance L of the secondary winding 18b and the capacitance C of the capacitor 20. LC resonance current flows. Since the LC resonance current is detected as a voltage drop generated in the leak current detecting resistor 23, a sudden change appears in the output of the leak current detection device as shown in FIG. However, this is residual magnetic noise, not ion current or leakage current. The above-described LC resonance current (A) is not caused by combustion ions, but is generated regardless of the presence or absence of combustion.

  Subsequently, after the LC resonance current of (a) in FIG. 5 flows, ion currents (b) and (c) flow. The ionic current (b) is an ionic current associated with the combustion reaction, and its reaction formula is as follows.

CH + O → CHO ⁺ + e ⁻
CHO ⁺ + H ₂ O → CO + H ₃ O ⁺

  The ionic current (c) is an ionic current associated with the thermal ionization of burned gas, and its reaction formula is as follows.

NO → NO ⁺ + e ⁻

  These ion currents are detected only when combustion occurs.

  When a current (d) corresponding to a leakage current is detected after a predetermined period T2 during which an ionic current is generated by combustion, it is determined whether the spark plug 13 is in a smoldering contamination state. In this way, when the bias voltage Vc is applied to the secondary winding 18b of the ignition coil 12 during the non-burning period T3, the smoldering contamination state of the ignition plug 13 is directly detected by measuring the current flowing through the resistor 23. can do. Whether or not smoldering contamination has occurred can be determined whether or not smoldering contamination is present when the period T4 in which the leakage current value S5 in the non-combustion period T3 exceeds the determination threshold A shown in FIG. Alternatively, when the integrated value of the leakage current value S5 in the non-combustion period T3 exceeds the determination threshold B, it may be determined that there is smoldering contamination.

  If “Yes” is determined in Step 104, the process proceeds to Step 106, while if “No” is determined, the process proceeds to Step 105. In step 105, the valve closing timing of the intake valve 9 is feedback-controlled to a preset target value at startup (target value without smoldering stain), and the process returns to step 101 again to repeat the processing. Note that the feedback control of the closing timing of the intake valve 9 is performed by the target valve closing timing signal S7 transmitted from the ECU 16 to the variable intake valve timing mechanism 11 and the camshaft 10 transmitted from the variable intake valve timing mechanism 11 to the ECU 16. This is performed by exchanging the position (angle) signal S11.

  In step 106, the timing of closing the intake valve 9 to a preset target value (target value when smoldering contamination is present) is retarded, and the target timing is set within a range where knocking due to early ignition does not occur. Advancing control to the angular amount (target value when smoldering stain is present). After the valve closing timing is retarded and the ignition timing advanced in step 106, the process returns to step 101 again to repeat the process.

  Hereinafter, the effect obtained by delaying the closing timing of the intake valve 9 in step 106 will be specifically described with reference to the valve lift amount of the intake valve with respect to the crank angle (each step of the engine cycle) shown in FIG. To do. By shifting the preset valve lift 211 at the start to the valve lift 212, the target value A point of the valve closing timing can be shifted to the C point on the retard side. Thereby, the opening period of the intake valve 9 in the intake stroke can be shortened from the period 213 to the period 214, and the opening period of the intake valve 9 in the exhaust stroke becomes the period 215. Therefore, the air once sucked into the cylinder The amount of air that pushes back toward the surge tank can be increased. By adopting such a method, the compression pressure of the engine 1 is lowered and the required voltage of the spark plug 13 is lowered. Therefore, it is possible to create an in-cylinder environment that is easy to ignite with a regular gap of the spark plug 13. Further, the effect of advance control of the ignition timing in step 106 is that, as shown in FIG. 11, the compression pressure of the engine 1 at the ignition timing can be reduced, so that the required voltage of the spark plug 13 is reduced, It is possible to create an environment in the cylinder that is easily ignited by a regular gap of the spark plug 13.

  The effects of the present invention thus far will be described with reference to a time chart of control parameters at the start. FIG. 7 shows a time chart in the case where the processing according to the embodiment of the present invention is not performed on the spark plug in which smoldering contamination has occurred. The time T1 from the start of cranking to the first explosion, the time T2 from the start of cranking to the complete explosion, and the starter driving period T3 are as shown in FIG. 7 and are compared with the case where no smoldering contamination occurs. Therefore, all of T1, T2, and T3 are relatively long. The ignition timing and the valve closing timing at the start are fixed to target values corresponding to the operation state such as the water temperature, and advance / retard angle control is performed after the initial explosion is completed.

  In contrast to the above, FIG. 8 shows a time chart when processing according to the embodiment of the present invention is performed on a spark plug in which smoldering fouling has occurred. From the leakage current value S5 detected by the leakage current detector 14 after the initial ignition immediately after the start of cranking, it is determined that the spark plug 13 is in a smoldering contamination state, and the ignition timing of the next cycle is controlled to advance. Further, the closing timing of the intake valve 9 is retarded to a preset target value. As a result, the required voltage after the 2nd ignition can be reduced, and sparks can easily fly in the regular gap before the occurrence of the back jump. Therefore, the time T1 ′ from the start of cranking to the first explosion is compared with T1. Can be shortened. Further, by controlling the advance of the closing timing of the intake valve 9 after the initial explosion is completed, the same effect as that described above in Step 103 can be obtained. At this time, the ignition timing is advanced / retarded according to the operating state such as the rotational speed and load of the engine 1. As a result, the time T2 'from the start of cranking to the complete explosion can be shortened compared to T2. Furthermore, the starter driving period T3 'can be shortened compared to T3 by shortening the time from the start of cranking to the first explosion.

  As described above, starting failure of the engine 1 due to leakage current occurring before reaching the required voltage required for the first explosion can be avoided. In addition, even in a situation where the closing timing of the intake valve 9 is advanced to increase the intake air amount, such as when the intake air temperature or the water temperature is low, smoldering can be achieved by adopting this method. Even if the contamination occurs, the starting failure can be avoided. Furthermore, the effect of reducing the power consumption of the battery can be obtained by shortening the starter driving period.

  The above embodiments are merely examples for carrying out the present invention, and the present invention is not limited to such specific embodiments, and within the scope of the gist of the present invention described in the claims. Various other embodiments are possible. In the above embodiment, the process for delaying the closing timing of the intake valve and the process for controlling the advancement of the ignition timing are performed in parallel. However, the order may be determined and performed in series. The ignition timing may be controlled to a target value that is adapted to the intake air temperature and water temperature at the time of starting by performing only the processing for advance / retard control of the intake valve closing timing.

  1 engine (internal combustion engine), 2 electronically controlled throttle valve, 3 throttle opening sensor, 4 airflow sensor, 5 surge tank, 6 intake manifold pressure sensor, 7 electronically controlled EGR valve, 8 injector, 9 intake valve, 10 camshaft , 11 Variable intake valve timing mechanism, 12 Ignition coil, 13 Spark plug, 14 Leakage current detection device, 15 Crank angle sensor, 16 ECU, 17 Battery, 18a Primary winding, 18b Secondary winding, 19 Power transistor, 20 Capacitor , 21 Zener diode, 22 diode, 23 resistor, 24 resistor.

Claims (4)

  A smolder detecting means for detecting a smolder that makes it difficult for a spark to fly at a regular gap of the spark plug, and an intake valve timing control means for controlling the closing timing of the intake valve, and detecting the smolder by the smolder detecting means at the time of starting In this case, the control apparatus for an internal combustion engine is characterized in that the compression timing of the internal combustion engine is lowered by retarding the closing timing of the intake valve by the intake valve timing control means.   An initial explosion detecting means for detecting the initial explosion of each cylinder is provided, and after the initial explosion of each cylinder is completed, the intake valve timing control means controls the advance timing of the closing timing of the intake valve, whereby the intake of the internal combustion engine 2. The control device for an internal combustion engine according to claim 1, wherein the amount of air is increased to increase the rotational speed.   The smoldering detecting means includes a leakage current detection device that detects a leakage current that flows by applying a predetermined voltage between a center electrode and a ground electrode of the ignition plug, and the ignition plug is based on the leakage current. 3. The control device for an internal combustion engine according to claim 1, wherein presence or absence of occurrence of smoldering is detected.   4. The control apparatus for an internal combustion engine according to claim 1, further comprising ignition timing control means for controlling the advance of the ignition timing of the internal combustion engine within a range in which knocking due to early ignition does not occur. .

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