JP6153342B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine for controlling an intake air amount at start-up.

  In a four-stroke internal combustion engine having a plurality of cylinders, it is necessary to know which stroke each cylinder is currently in and to perform fuel injection control and ignition control.

  The crankshaft of the internal combustion engine is provided with a crank angle sensor for detecting the rotation angle and the engine speed. The crank angle sensor senses the rotation of the rotor fixed to the crankshaft, for example, every 10 ° CA (crank angle).

  A cam angle sensor is also attached to a camshaft that rotates following the crankshaft and opens and closes an intake valve or an exhaust valve of each cylinder. The cam angle sensor senses the rotation of the rotor fixed to the camshaft, for example, at an angle obtained by dividing one rotation by the number of cylinders, for every 120 ° for a three-cylinder engine (240 ° CA if converted to a crank angle). To do.

  An ECU (Electronic Control Unit) that controls the operation of the internal combustion engine refers to the crank angle signal and the cam angle signal, grasps the stroke of each cylinder, and determines the fuel injection timing and ignition timing in the cylinder.

  By the way, although rare, the transmission path between the crank angle sensor and the ECU may be disconnected, or the sensor itself may fail, and the ECU may not be able to receive the crank angle signal. Various techniques have been disclosed so far as fail-safe in such cases. For example, as shown in Patent Document 1, there is an aspect in which the ECU has a function of determining the stroke of each cylinder by referring only to the cam angle signal in advance and maintaining the operation of the internal combustion engine. it can.

  In Patent Document 1, when starting an in-line three-cylinder port-injection spark ignition internal combustion engine, when the ECU cannot receive a crank angle sensor signal, combustion is performed for a specific cylinder every time a cam angle signal is received. Based on the fact that the injection of about half the amount of fuel required and spark ignition continue to be performed alternately, and the cam angle signal reception interval changes (shortens) due to the occurrence of normal fuel. A method for discriminating cylinders is disclosed.

  In Patent Document 2, the intake air intake amount is controlled by controlling the opening of an idle speed control valve (ISC valve) based on the throttle valve opening, the intake pressure, and the engine speed. A technique is disclosed in which the ISC valve is set to be closed in order to suppress unnecessary blow-up of the number of rotations. On the other hand, Patent Document 3 discloses a technique for controlling the intake air amount based on a cam angle signal when an abnormality of the crank angle sensor occurs during traveling.

  By the way, at the time of normal starting, the ISC valve is set to a closed state at the initial time, and after the normal cylinder discrimination by the crank angle sensor and the cam angle sensor is completed, the intake air intake amount is controlled by various controls. Adjusted.

  However, when the crank angle signal cannot be obtained due to a failure of the crank angle sensor, the cylinder discrimination is performed based on other information such as the cam angle sensor as in Patent Document 1 above. Also, the ISC valve is closed. Then, the intake pressure is reduced while the behavior related to the cylinder discrimination is continued with the ISC valve closed. In other words, the longer the cylinder discrimination is performed, the more difficult it is to obtain normal ignition. If this happens, normal ignition is not performed after cylinder discrimination, leading to poor starting, or when using the method of Patent Document 1 above, normal ignition itself is not confirmed and cylinder discrimination itself cannot be performed. .

  In particular, such a problem appears remarkably when the engine temperature of the internal combustion engine is high. This is because at the time of start-up when the engine temperature is high, the viscosity of the lubricating oil is lowered and mechanical loss is reduced, so that the number of revolutions due to cranking is higher than that at the time of cold start, so the intake pressure is significantly reduced.

JP 2008-248740 A JP-A-8-21288 JP-A-10-47142

  The present invention focuses on the above-described problems, and an object of the present invention is to provide a control device for an internal combustion engine that can ensure startability even when a crank angle signal cannot be obtained.

  In order to achieve such an object, the present invention takes the following measures.

That is, the control device for an internal combustion engine according to the present invention is a control device for an internal combustion engine that controls the amount of intake air at the time of start-up. Is determined to be higher than a predetermined threshold value , the cylinder discrimination is made by referring to the cam angle signal obtained from the cam angle sensor without referring to the crank angle signal, and the intake air until the cylinder discrimination is completed. A valve for adjusting the amount is opened, and the opening degree of the valve is increased as the engine temperature is higher.

  Here, the “predetermined threshold value” is a concept including any temperature as long as the temperature is equal to or lower than the highest temperature in any state of the internal combustion engine. That is, when the “predetermined threshold value” is set to a value higher than the engine temperature indicated at the time of cold start and lower than the temperature indicated at the time of restart from the idling stop, the valve is It is not opened when the crank angle sensor is abnormal, but it is opened at the time of restart from idling stop or at the engine temperature equivalent to that at the time of restart. On the other hand, when the “predetermined threshold” is set to a temperature sufficiently lower than the engine temperature indicated at the time of cold start, the valve is opened in any start-up situation.

  If this is the case, the intake pressure will unnecessarily decrease even when the crankshaft rotation is required more than usual before the cylinder discrimination is completed when the crank angle sensor is abnormal. It can be effectively avoided. Thereby, combustion at the time of cylinder discrimination or after cylinder discrimination can be performed normally. In particular, according to the present invention, the degree of reduction in the intake pressure, which increases in proportion to the rotational speed, is effectively increased by increasing the valve opening as the engine temperature rises when the rotational speed during cranking is higher than during cold starting. Can be offset. As a result, the startability when the crank angle sensor is abnormal can be effectively ensured regardless of the state of the internal combustion engine at the start.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the internal combustion engine which can ensure startability even when a crank angle signal cannot be obtained can be provided.

The figure which shows the whole structure of the internal combustion engine for vehicles in one Embodiment of this invention. The figure explaining the content of the cylinder discrimination | determination process which the control apparatus of the internal combustion engine of the embodiment performs. The timing chart which shows the example of the procedure of the process which the control apparatus of the internal combustion engine of the embodiment performs. The figure explaining the content of the cylinder discrimination | determination process which the control apparatus of the modification of the embodiment performs. The timing chart which concerns on the modification of the embodiment.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of an internal combustion engine for a vehicle in the present embodiment. The internal combustion engine of the present embodiment is a port injection type four-stroke spark ignition engine, and includes three cylinders 1 (one of which is shown in FIG. 1). These cylinders 1 are arranged in series, and the compression top dead center of each cylinder 1 appears at regular intervals, that is, every 240 ° CA.

  In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode. The ignition coil is integrally incorporated in a coil case together with an igniter that is a semiconductor switching element.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, an idle speed control valve (ISC valve) 35, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  The ECU 0 serving as a control device for the internal combustion engine is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like.

  The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, a crank angle signal (N signal) b output from an engine rotation sensor that detects the rotation angle of the crankshaft and the engine speed, An accelerator opening signal c output from a sensor that detects the depression amount of the accelerator pedal or the opening of the throttle valve 32 as an accelerator opening, an IDL signal c1 output from a sensor provided in the ISC valve 35, a battery (not shown) An intake air temperature / intake pressure signal e output from a temperature / pressure sensor that detects the battery voltage d output from the connected battery voltage detector, the intake air temperature and intake air pressure in the intake passage 3 (especially the surge tank 33). A coolant temperature signal f output from a fluid temperature sensor that detects the temperature of the coolant (or coolant) of the internal combustion engine Cam angle signal (G signal) g output from cam angle sensor at multiple cam angles of intake camshaft or exhaust camshaft, output from sensor (or shift position switch) to know shift lever range Shift range signal h or the like is input. The accelerator opening is a so-called required load. The coolant temperature of the internal combustion engine indicates the temperature of the internal combustion engine.

  From the output interface, an ignition signal i is output to the igniter of the spark plug 12, a fuel injection signal j is output to the injector 11, an opening operation signal k is output to the throttle valve 32, and the like.

  The processor of the ECU 0 interprets and executes a program stored in the memory in advance, calculates operation parameters, and controls the operation of the internal combustion engine. The ECU 0 acquires various information a, b, c, d, e, f, g, and h necessary for operation control of the internal combustion engine via the input interface, knows the engine speed, and is filled in the cylinder 1. Estimate the intake volume. Based on the engine speed, the intake air amount, and the like, various operating parameters such as required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, and ignition timing are determined. As the operation parameter determination method itself, a known method can be adopted. The ECU 0 applies various control signals i, j, k corresponding to the operation parameters via the output interface.

  Further, the ECU 0 inputs a control signal o to a starter motor or a motor generator (not shown) at the time of starting the internal combustion engine (a cold start or a return from an idling stop) Cranking for rotating the crankshaft of the internal combustion engine is performed by the motor. Cranking ends from the first explosion to the consecutive explosion, and ends when the engine speed exceeds a threshold determined according to the cooling water temperature or the like (assuming that the explosion has been completed).

  The crank angle signal b will be supplemented. The crank angle signal b is output from the crank angle sensor at an interval of 10 ° CA, for example, so that no signal is output at the 17th, 18th, 20th, 21st, 35th and 36th timings, for example. It is configured.

  It supplements regarding the cam angle signal g. The cam angle sensor senses the rotation angle of a rotor that is fixed to the camshaft and rotates integrally with the camshaft. The rotor is formed with teeth or protrusions at every angle obtained by dividing at least one rotation of the camshaft by the number of cylinders. In the case of a three-cylinder engine, a crank angle reference position signal g1 in which teeth or protrusions are arranged every 120 ° is included. The camshaft is rotated by receiving a rotational driving force from the crankshaft via a winding transmission mechanism or the like, and its rotational speed is one half of that of the crankshaft. Therefore, the teeth or protrusions related to the crank angle reference position signal g1 are arranged every 240 ° CA in terms of the crank angle.

  In addition, the cam angle sensor outputs the cylinder discrimination signal g2 with the same configuration only once during 720 ° CA, for example, at a timing in the vicinity of the output of the crank angle reference position signal g1 related to the second cylinder. Thereby, it is possible to accurately determine which cylinder the crank angle reference position signal g1 relates to.

  The cam angle sensor faces the outer periphery of the rotor, detects that individual teeth or protrusions pass in the vicinity of the sensor, and uses the crank angle reference position signal g1 and the cylinder discrimination signal g2 as the cam angle signal g each time. As a pulse signal. The ECU 0 is connected to a cam angle sensor via a cam angle signal line, and receives a pulse as a cam angle signal g through the cam angle signal line.

  The crank angle reference position signal g1 is a signal indicating that any one of the cylinders 1 has reached a predetermined stroke. For example, a cam angle sensor is attached to the intake camshaft, and a signal g output from the cam angle sensor is in the vicinity of the compression top dead center in each cylinder 1 or x ° CA (30 ° CA to 30 ° CA from the compression top dead center). This indicates a timing deviating toward the advance side by a value within a range of 70 ° CA. Incidentally, in an internal combustion engine with a so-called phase change type variable valve timing mechanism, the crank angle reference position signal g1 also represents the valve timing adjusted by the mechanism.

  Normally, the ECU 0 knows the current stroke of each cylinder 1 by referring to both the crank angle signal b and the cam angle signal g, and injects fuel at an appropriate fuel injection timing in each cylinder 1. The mixture is ignited at a proper ignition timing.

  In this embodiment, when the ECU 0 can no longer receive the crank angle signal b, the current stroke of each cylinder 1 is known only by the cam angle signal g, and the fuel injection timing and the ignition timing are determined. ing.

  FIG. 2 shows the contents of the cylinder discrimination process that is executed by the ECU 0 of the present embodiment and refers only to the cam angle signal g. When the ECU 0 cannot receive the crank angle sensor signal b and each time the cam angle signal g is received, the ECU 0 injects about half the amount of fuel required for combustion and spark ignition to one specific cylinder 1. And alternately. Meanwhile, it is not necessary to perform fuel injection or spark ignition for the other two cylinders 1. Then, the expansion stroke of the cylinder 1 is known from the fact that the reception interval of the cam angle signal g is changed, that is, shortened.

  Paying attention to one specific cylinder 1, the cam angle signal g represents one of the intake stroke, the vicinity of or near the compression top dead center, and the exhaust stroke.

  In the cylinder 1, when approximately half of the required amount of fuel is injected according to the cam angle signal g received during the exhaust stroke, the intake valve is closed, so that the fuel temporarily stays at the intake port and then comes later. It is sucked into the cylinder 1 in the intake stroke.

  Even if spark ignition is attempted in accordance with the cam angle signal g received during the subsequent intake stroke, the atmosphere in the combustion chamber of the cylinder 1 is not sufficiently fueled (the air-fuel ratio is excessively lean), and the fuel is not ignited. Combustion does not occur. The fuel in the cylinder 1 is discharged out of the cylinder 1 in the next exhaust stroke.

  Even if approximately half of the required amount of fuel is injected in response to the cam angle signal g received at or near the compression top dead center, the fuel remains in the intake port because the intake valve is closed, It is not introduced into the cylinder 1.

  Even if spark ignition is attempted according to the cam angle signal g received during the next exhaust stroke, combustion does not occur due to fuel shortage. The most recently injected fuel still remains in the intake port.

  However, when fuel is injected in accordance with the cam angle signal g received during the reintroducing intake stroke, the most recent injection (that is, near the compression top dead center or at the timing before) and the current injection are obtained. Together, the fuel reaches an amount necessary for combustion, and is sucked into the cylinder 1.

  Therefore, when spark ignition is performed according to the cam angle signal g received at the timing near or before the compression top dead center, an expansion stroke is performed based on the normal ignition nb that ignites the fuel and performs flame propagation combustion, The crankshaft and camshaft are accelerated. As a result, since the time required until the next cam angle signal g is received is shortened, the compression top dead center and the expansion stroke timing of the cylinder 1 are determined. As a result, the stroke of each cylinder 1 can be determined.

  In the above description, the cylinder discrimination is completed when the normal ignition nb is determined once. Therefore, in this embodiment, as shown in FIG. 3, in order to increase the discrimination accuracy, the cylinder discrimination is completed by judging the normal ignition nb twice. In this case, the cylinder discrimination may be completed when it is determined that the normal ignition nb is the second time. FIG. 3 shows a case where such normal ignition nb is determined twice. That is, in the figure, it can be confirmed that the normal ignition nb has been performed twice at the time of cylinder discrimination by showing the temporary increase in the rotational speed twice.

  In addition, the present embodiment is a valve for adjusting the intake air amount until the cylinder discrimination is completed in order to ensure the startability of the internal combustion engine in a situation where the ECU 0 cannot receive the crank angle signal b. The ISC valve 35 is opened, and the opening degree of the ISC valve 35 is increased as the coolant temperature (cooling water temperature) as an example of the engine temperature index of the internal combustion engine increases.

  Specifically, in the present embodiment, the ECU 0 is in a situation where the crank angle signal b cannot be received, and the coolant temperature used as the engine temperature index corresponds to a threshold value where the engine temperature is higher than the temperature indicated at the cold start. It is set so that the opening of the ISC valve 35 is corrected to a value larger than zero until the cylinder discrimination is completed only when the temperature is equal to or higher than the predetermined temperature. That is, the correction of the intake air amount according to the present embodiment is not performed at the time of cold start, but is performed only when the rotational speed at the time of cranking is high, including at the time of restart from idling stop. In the present embodiment, the predetermined temperature of the coolant temperature is set as described above. Of course, if the predetermined temperature is set to a value sufficiently lower than that at the time of cold start, the crank temperature is set regardless of the engine temperature. Needless to say, the opening of the ISC valve 35 is corrected to a value larger than zero until the angular signal b cannot be received and the cylinder discrimination is completed.

  More specifically, in this embodiment, when the coolant temperature exceeds a predetermined temperature, the opening of the ISC valve 35 is increased in proportion to the temperature rise. Here, the opening of the ISC valve 35 may be a step that increases steplessly or may increase stepwise depending on the coolant temperature. Further, the opening degree of the ISC valve 35 may be set by further combining an index other than the coolant temperature. In that case, the ECU 0 stores in advance a map in which the correspondence between the opening degree of the ISC valve 35, the coolant temperature, and other indicators is stored, and the opening degree of the corresponding ISC valve 35 is appropriately determined from the map when necessary. You may make it control by reading.

  FIG. 3 shows a timing chart when executing the control according to the present embodiment. The control which concerns on this embodiment is demonstrated along the same figure.

  First, for example, when restarting from an idling stop, the starter motor is first started and cranking is started. At this time, since the crank angle signal b is not received, the cylinder discrimination is not completed, and accordingly, cranking is started with the ISC valve 35 closed. When the crank angle signal b cannot be received for a predetermined time or more, the ECU 0 determines that the crank angle sensor is abnormal, determines the engine temperature from the coolant temperature signal f, and only a predetermined opening corresponding to the engine temperature. The ISC valve 35 is opened. Since the cranking is continued until the ISC valve 35 is opened, the air in the cylinder is sequentially discharged, so that the intake pipe pressure gradually decreases.

  Here, the fixed time from when the starter motor is started to when the ISC valve 35 is opened is not particularly limited, but is set to a time until the driver does not feel uncomfortable upon restart from the idling stop. It is desirable. Further, in the present embodiment, the cylinder discrimination involves combustion injection and combustion. Therefore, when the ISC valve 35 is opened or when the ISC valve 35 is opened, the intake pressure sufficient to quickly perform normal ignition nb may be set. preferable. That is, the predetermined time may be set in advance as a predetermined time, or may be a time until the value of the intake pressure falls below a predetermined value.

  Then, the cylinder discrimination process shown in FIG. 2 is performed in a state where the ISC valve 35 is opened. As described above, in the figure, it is considered that the cylinder discrimination is completed when the normal ignition nb is performed twice, and the normal ignition is performed. Therefore, during that period, the ISC valve 35 is opened by the predetermined opening degree. The situation continues. When the cylinder discrimination is completed and normal fuel injection and ignition are performed on each cylinder 1, the complete explosion is reached and the rotational speed increases rapidly. Here, in this embodiment, since the opening degree of the ISC valve 35 at the time of cylinder discrimination is set to a larger opening degree than that at the time of normal idling, if the opening degree is continued, the rotational speed is higher than the required idling rotational speed. It gets bigger. Therefore, in this embodiment, when the cylinder discrimination is completed, the opening speed of the ISC valve 35 is gradually decreased, so that the rotation speed is unnecessarily increased, so that so-called blow-up is effectively avoided and the required rotation speed is quickly achieved. I have to.

  As described above, according to the present embodiment, the intake pressure is not required even at the time of fail-safe that requires more rotation of the crankshaft than usual until the cylinder discrimination is completed when the crank angle sensor is abnormal. The reduction is effectively avoided. As a result, normal ignition nb at the time of cylinder discrimination can be suitably performed. In particular, according to the present invention, the opening of the ISC valve 35 is increased as the engine temperature rises, which is higher in the cranking speed than in the cold start, thereby increasing the suction proportional to the cranking speed. It effectively cancels out the decrease in atmospheric pressure. As a result, the startability when the crank angle sensor is abnormal is effectively secured regardless of the state of the internal combustion engine at the time of start.

<Modification>
Below, the modification of the said embodiment is demonstrated. In the modification, the same components as those shown in the embodiment are given the same reference numerals, and detailed description thereof is omitted.

  Here, the operation at the time of cranking in the internal combustion engine will be described with reference to FIG. 4 in order to explain the operation of the starting cylinder discrimination program according to this modification.

  FIG. 4 shows the timing at which the crank angle signal b indicating that the piston is at the top dead center is output, the strokes of the first, second and third cylinders, the behavior of the battery voltage d supplied during cranking, and the cranking. The timing at which the cam angle sensor signal g, that is, the crank angle reference position signal g1 and the cylinder discrimination signal g2 is output at each time is schematically shown. In the figure, the notation of intake, compression, expansion, and exhaust indicates that the period is an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke, respectively. The crank angle signal b, which is a solid arrow, is output at 10 ° CA intervals from the crank angle sensors of the three cylinders 1 as described above, and the arrow is illustrated as the crank angle signal b. The location indicates only the timing at which each piston is at top dead center. Further, for convenience of explanation, this figure is shown from the compression stroke after the intake stroke in the first cylinder.

  As shown in FIG. 4, the timing at which the crank angle signal b is output at the left end in the drawing is the timing at which the first cylinder is ignited at the end of the compression stroke. At this time, the second cylinder opens the intake valve and is in the intake stroke. At this time, the third cylinder opens the exhaust valve and is in the exhaust stroke. In other words, at this time, the three cylinders 1 simultaneously reach the timing when the mechanical loss is large. As a result, the load applied to the starter motor or the motor generator becomes the largest, so that the battery voltage d supplied to the starter motor or the motor generator takes a minimum value p. After that, the load becomes small and the battery voltage d rises once and the timing at which the third cylinder becomes exhaust top dead center is reached, and the crank angle signal b is output accordingly. Then, when the crank angle signal b is output next, the second cylinder is at the end of the compression stroke and is ignited. At this time, the third cylinder is in the intake stroke to open the intake valve and the first cylinder is in the exhaust stroke to open the exhaust valve, and all three cylinders 1 are at the same time when the mechanical loss is large. Will be. That is, similarly to the above, the battery voltage d takes the minimum value again. That is, at the timing when any one of the cylinders 1 becomes the compression top dead center, the battery voltage d at the time of cranking always shows the minimum value p as shown in the figure.

  Therefore, in this modification, when the crank angle signal b cannot be detected by the crank angle sensor at the time of cranking, the voltage extreme value is obtained from the behavior of the battery voltage d as shown in FIG. 2 inputted from the battery voltage detector. The timing showing a certain minimum value p is regarded as the compression top dead center of any cylinder 1, and the stroke of the cylinder 1 is determined together with the timing at which the crank angle reference position signal g1 and the cylinder determination signal g2 are output. .

  Specifically, it is possible to accurately determine which cylinder 1 is at the compression top dead center from the timing when the cylinder determination signal g2 is output and the timing when the minimum value p is reached. In particular, in the present embodiment, the crank angle reference position signal g1 is output at a timing different by x ° CA. That is, the intake air amount, the ignition timing, and the like can be specified by performing cylinder determination in consideration of the timing at which the minimum value p is output and the timing at which the crank angle reference position signal g1 is output.

  Therefore, in this modified example, during the cylinder discrimination as described above, the ISC valve 35, which is a valve, is adjusted to adjust the intake air amount until the cylinder discrimination is completed, as in the above-described embodiment. The higher the coolant temperature (cooling water temperature) as an example of the engine temperature index, the larger the opening of the ISC valve.

  FIG. 5 shows a time chart at start-up according to the modification. As shown in the figure, in this modified example, unlike the above embodiment, fuel injection and ignition are not performed at the time of cylinder discrimination. Therefore, the rotation speed during cylinder discrimination is constant depending on the cranking by the starter motor. Other behavior is the same as in the above embodiment. That is, according to this modification as well, the startability can be effectively secured even when the crank angle signal b cannot be obtained.

  As described above, according to this modification, the intake pressure is not required even at the time of fail-safe operation that requires more rotation of the crankshaft than usual until the cylinder discrimination is completed when the crank angle sensor is abnormal. A decrease is effectively avoided. As a result, the intake pressure is secured even during combustion after cylinder discrimination, and the combustion is performed normally.

  As mentioned above, although the actual form of this invention was demonstrated, the specific structure of each part is not limited only to embodiment mentioned above, A various deformation | transformation is possible in the range which does not deviate from the meaning of this invention.

  For example, in the above embodiment, the aspect in which the ISC valve is arranged in the intake system has been disclosed. The idle speed may be maintained by appropriately controlling the electronic throttle valve. In the above embodiment and the modification, the engine temperature is estimated based on the cooling water temperature, and the correction amount of the intake air amount is set. Of course, the temperature of the lubricating oil circulating in the internal combustion engine or the internal combustion engine is connected. The correction of the intake air amount may be set by estimating the engine temperature of the internal combustion engine based on the temperature of the lubricating oil in the torque converter or transmission. Further, specific modes such as normal cylinder discrimination and a specific correction amount of the intake air amount are not limited to those of the above embodiment, and various modes including the existing ones are applied. be able to.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used as a control device for an internal combustion engine for controlling the intake air intake amount at the time of starting.

0 ... ECU
1 ... Cylinder 35 ... Idle speed control valve (ISC valve)
b ... Crank angle signal f ... Coolant temperature signal

Claims (1)

A control device for an internal combustion engine that controls the amount of intake air at start-up,
The cam angle obtained from the cam angle sensor without referring to the crank angle signal when it is determined that the crank angle signal cannot be obtained from the crank angle sensor and the engine temperature of the internal combustion engine is higher than a predetermined threshold value. The cylinder is discriminated by referring to the signal, and the valve for adjusting the intake air amount is opened until the cylinder discrimination is completed,
The control apparatus for an internal combustion engine, wherein the opening degree of the valve is increased as the engine temperature is higher.

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