JP2016180380A - Control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately discriminate a stroke of each cylinder in starting an internal combustion engine.SOLUTION: A control device includes a cam angle signal detection counter portion, a crank angle signal detection counter portion as a counter portion of a crank angle signal, starting the counting of the crank angle signal with detection of the crank angle signal, resetting the number of times of detection of the cam angle signal detection counter portion and terminating the counting of the crank angle signal when the number of times of detection reaches an upper limit value, reducing the number of times of detection of the crank angle signal by a prescribed number when the cam angle signal is detected, reducing the number of times of detection at a timing determined on the basis of deficit of a pulse of the crank angle signal, and increasing the number of times of detection by a prescribed number at another timing determined on the basis of deficit of the pulse of the crank angle signal corresponding to a specific rotation phase angle, and a cylinder discrimination portion for discriminating a stroke of each cylinder by referring the number of times of detection by the cam angle signal detection counter portion at a timing determined on the basis of the deficit of the pulse of the crank angle signal.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control device for an internal combustion engine that can determine the stroke of each cylinder at the time of starting the internal combustion engine in a timely manner.

  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. An electronic control unit that controls the operation of the internal combustion engine receives a crank angle signal (N signal) and a cam angle signal (G signal) generated in response to cranking when starting the internal combustion engine. The stroke of the cylinder is determined, and then fuel injection (synchronous injection) and ignition are started in accordance with the stroke of each cylinder (for example, refer to the following patent document).

  FIG. 9 shows an example of a pulse train of a crank angle signal and a cam angle signal in a conventional internal combustion engine. A crank angle sensor that outputs a crank angle signal senses the rotation angle of the rotor that rotates integrally with the crankshaft. The rotor is formed with teeth or protrusions at predetermined angles along the rotation direction of the crankshaft. Typically, every time the crankshaft rotates 10 °, teeth or protrusions are placed. The crank angle sensor faces the outer periphery of the rotor, detects that individual teeth or protrusions pass near the sensor, and transmits a pulse signal as a crank angle signal each time.

  However, 36 pulses are not output during one revolution of the crankshaft. The teeth or protrusions of the crankshaft rotor are partially missing, and due to the missing teeth, the crank angle signal pulse train is also partially missing. In the illustrated example, pulses corresponding to the seventeenth, eighteenth, twentieth, twenty-first, thirty-fifth, and thirty-sixth pulses are missing. Based on this defect, it is possible to know the absolute angle of the crankshaft. If the timing of the first pulse after the missing thirty-sixth pulse is 0 ° CA (crank angle), the timing of the nineteenth pulse following the missing eighteenth pulse is 180 ° CA. become.

  The cam angle sensor that outputs the cam angle signal senses the rotation angle of the rotor that rotates integrally with the intake camshaft. The rotor is formed with teeth or protrusions for each angle obtained by dividing one rotation of the camshaft by the number of cylinders. In the case of a three-cylinder engine, teeth or protrusions are arranged each time the camshaft rotates 120 °. 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 above teeth or protrusions are arranged every 240 ° CA in terms of the crank angle. In addition, the rotor is provided with one tooth or protrusion between the teeth or protrusions every 240 ° CA for generating an additional cam angle signal.

  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 transmits a pulse signal as a cam angle signal each time. The cam angle signal in the illustrated example suggests the timing at which each cylinder is deviated toward the advance side by a predetermined crank angle from the vicinity of the compression top dead center or from the compression top dead center. In an internal combustion engine that is accompanied by a so-called phase change type variable valve timing mechanism, it also represents the opening / closing timing of the intake valve in which the cam angle signal is adjusted by the VVT mechanism.

  The conventional cylinder discrimination method is as described below. That is, a control device for an internal combustion engine includes a cam angle signal detection counter unit that counts the number of detected cam angle signals, a crank angle signal detection counter unit that counts the number of detected crank angle signals, and a pulse included in the crank angle signal. And a cylinder discriminating unit that discriminates the stroke of each cylinder with reference to the number detected by the cam angle signal detection counter unit at a timing determined based on the loss of.

  In FIG. 9, two upper and lower stages are shown below the cam angle signal in each case. The upper row (for example, “0, 9, 8, 7, 6, 6, 6, 5, 4, 3, 2, 1, 0” described in the vicinity of a crank angle of 0 ° CA in “normal case”) The count by the crank angle signal detection counter unit is shown. On the other hand, the lower row (for example, “0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0” described near the crank angle 0 ° CA in the “normal case”) Indicates the count by the cam angle signal detection counter unit.

  The cam angle signal detection counter unit counts up to increase the number of detections by “1” every time a cam angle signal is detected.

  The crank angle signal detection counter unit starts counting the number of detected crank angle signals, triggered by the detection of the cam angle signal. The crank angle signal detection counter unit is a decrement counter, and starts counting down from “9” with the detection of the cam angle signal, and decreases the number by “1” according to the number of detected crank angle signals. Further, when the cam angle signal is detected while counting the number of detected crank angle signals, the crank angle signal detection counter unit increases the count by “3”. However, if a crank angle signal is detected simultaneously with the cam angle signal, a “1” decrease is added to the “3” increase in the count, resulting in a total increase of “2”.

  Then, when the number of detected crank angle signals reaches the upper limit value, the crank angle signal counter section resets the detected number of cam angle signal detection counter sections and ends the counting of the crank angle signal. . That is, the crank angle signal detection counter unit detects the crank angle signal nine times after detecting the cam angle signal (the detected number of crank angle signals reaches “9” which is the upper limit value, in other words, the crank angle signal When the counter value of the counter unit becomes “0”), the detection number (“1” or “2”) of the cam angle signal detection counter unit is reset to “0” and the counting of the crank angle signal is ended. When both the detected number of cam angle signals and the detected number of crank angle signals are reset to the initial value “0”, the crank angle signals are not counted until the next cam angle signal is detected.

The cylinder discriminating unit discriminates the stroke of each cylinder with reference to the number detected by the cam angle signal detection counter unit at a predetermined cylinder discriminating timing determined based on a missing pulse included in the crank angle signal. As indicated by a two-dot chain line in FIG. 9, this cylinder discrimination timing comes twice in a half cycle of the internal combustion engine. In the example shown in FIG.
・ First pattern: 90 ° CA timing after pulse missing (35th and 36th pulse missing due to missing tooth) ・ Second pattern: Continuous pulse missing (missed tooth) After the seventeenth, eighteenth, twentieth and twentieth pulses are lost), cylinder discrimination is performed at a timing of 30 ° CA.

  If the number of detections of the cam angle signal detection counter section referred to by the cylinder discrimination section is “0” at the cylinder discrimination timing of the first pattern, the current time is 150 ° CA before the compression top dead center of the third cylinder. (90 ° CA). On the other hand, if the number detected by the cam angle signal detection counter unit is “1” or “2”, the current time is the timing (450 ° CA) of 30 ° CA before the compression top dead center of the first cylinder. It turns out.

  Further, if the number of detections of the cam angle signal detection counter section referred to by the cylinder determination section is “1” or “2” at the second pattern cylinder determination timing, the current time point is the compression top dead center of the third cylinder. It is found that the timing is (240 ° CA). On the other hand, if the number detected by the cam angle signal detection counter is “0”, it is determined that the current time point is the timing of 120 ° CA before the compression top dead center of the second cylinder (600 ° CA). .

  In actual internal combustion engines, in addition to individual differences due to variations in the shape and dimensions of each part, misalignment of the timing chain (or timing belt) against the sprocket (or pulley), elongation of the timing chain, VVT There is a possibility that the rotational phase of the camshaft in the mechanism is fixed and fixed. In addition, in an internal combustion engine equipped with an electric VVT mechanism, the rotational phase of the camshaft relative to the crankshaft at the time of starting is not uniquely determined. In addition, the electric VVT mechanism has a larger movable range of the rotational phase of the camshaft than the hydraulic VVT mechanism.

For this reason, when starting the internal combustion engine, the cam angle signal is not always emitted at an ideal timing. In some cases, the cam angle signal is detected at a timing deviated from the normal timing toward the advance side or the retard side. In Fig. 9, the following three cases are ideal "normal cases"
・ "Advance case" shifted to the advance side. Specifically, when the internal combustion engine is started, the VVT mechanism has advanced valve timing, and the cam angle signal is advanced by 60 ° CA or more than normal in combination with variations in the shape and dimensions of the parts. Cases that are issued at the same timing ・ "Delayed cases" shifted to the retarded side. Specifically, the timing chain is in an extended state, and a case where the cam angle signal is generated at a timing delayed by 20 ° CA or more than normal in combination with variations in the shape and dimensions of the components is shown.

  Even the conventional cylinder discrimination method can generally cope with the deviation of the cam angle signal toward the advance side or the retard side. However, as in the “advance case” shown in FIG. 9, when the cam angle signal generation timing is greatly advanced from the normal timing, there is a risk of erroneous determination of the stroke of each cylinder. is there. That is, in the first pattern cylinder discrimination timing, even if the timing is actually 30 ° CA before the compression top dead center of the first cylinder (450 ° CA), the detected number of cam angle signal detection counter units is “0”. Therefore, the ECU misidentifies the current time point as the timing of 150 ° CA before the compression top dead center of the third cylinder (90 ° CA). As a result, fuel injection and ignition cannot be executed at an appropriate timing, and the rotation of the internal combustion engine does not accelerate. Therefore, it is necessary to redo cylinder discrimination, and the time spent for cranking is extended.

Japanese Patent Laying-Open No. 2015-021385

  An object of the present invention is to make it possible to correctly determine the stroke of each cylinder when starting an internal combustion engine.

  In the present invention, the crank angle sensor attached to the crankshaft outputs a crank angle signal every time the crankshaft rotates by a unit angle, but does not output the crank angle signal at a predetermined rotation phase angle of the crankshaft. The cam angle sensor attached to the camshaft that rotates following the crankshaft and opens / closes the intake valve or exhaust valve outputs a basic cam angle signal each time the camshaft rotates by a unit angle. A control device for controlling an internal combustion engine that outputs an additional cam angle signal at a predetermined rotational phase angle of the camshaft, the cam angle signal detection counter unit counting the number of detected cam angle signals; A counter unit for counting the number of detected crank angle signals, which is triggered by the detection of the cam angle signal. When the number of detected crank angle signals reaches the upper limit, the detected number of the cam angle signal detection counter unit is reset and the counting of the crank angle signal is completed. When the cam angle signal is detected while counting the number of detected crank angle signals, the number of detected crank angle signals is reduced by a predetermined number and the number of detected crank angle signals is counted while counting the number of detected crank angle signals. Decrease the number of detected crank angle signals by a predetermined number at a timing determined based on the missing pulse of the crank angle signal corresponding to a specific rotational phase angle, and while counting the number of detected crank angle signals, the crankshaft The number of detected crank angle signals is increased by a predetermined number at another timing determined based on a missing pulse of the crank angle signal corresponding to a specific rotational phase angle. A rank angle signal detection counter unit, and a cylinder determination unit that determines the stroke of each cylinder by referring to the number of detections of the cam angle signal detection counter unit at a timing determined based on a missing pulse of the crank angle signal. A control device for an internal combustion engine was configured.

  According to the present invention, the stroke of each cylinder can be correctly determined when the internal combustion engine is started.

The figure which shows schematic structure of the internal combustion engine and control apparatus in one Embodiment of this invention. The figure which shows typically the aspect of the crank angle sensor accompanying the internal combustion engine of the embodiment. The figure which shows typically the aspect of the cam angle sensor accompanying the internal combustion engine of the embodiment. The functional block diagram of the control apparatus of the embodiment. The timing diagram explaining the content of the cylinder discrimination | determination process which the control apparatus of the embodiment performs at the time of start-up of an internal combustion engine. FIG. 6 is an enlarged timing diagram showing a part of FIG. 5. FIG. 6 is an enlarged timing diagram showing a part of FIG. 5. FIG. 6 is an enlarged timing diagram showing a part of FIG. 5. The timing diagram explaining the content of the cylinder discrimination | determination process currently performed at the time of the starting of the conventional internal combustion engine.

  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 in the present embodiment is a spark ignition type 4-stroke gasoline engine, and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). 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, 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 by 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 exhaust gas recirculation device 2 realizes a so-called high pressure loop EGR, and an external EGR that communicates the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3. The passage 21, an EGR cooler 22 provided on the EGR passage 21, and an EGR valve 23 that opens and closes the EGR passage 21 and controls the flow rate of EGR gas flowing through the EGR passage 21 are used as elements. The inlet of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, particularly to the surge tank 33.

  The internal combustion engine of the present embodiment is accompanied by a VVT mechanism 6 that can variably control the opening / closing timing of the intake valve of each cylinder 1. The VVT mechanism 6 is a known electric type (motor drive VVT) in which the rotation phase of the intake camshaft that drives the intake valve of each cylinder 1 with respect to the crankshaft is changed by an electric motor. As is well known, an intake camshaft of an internal combustion engine is supplied with a rotational driving force from a crankshaft that is an output shaft of the internal combustion engine, and rotates following the crankshaft. A winding transmission device (not shown) for transmitting a rotational driving force is interposed between the crankshaft and the intake camshaft. The winding transmission includes a crank sprocket (or pulley) provided on the crankshaft side, a cam sprocket (or pulley) provided on the intake camshaft side, and a timing chain (or pulley) wound around these sprockets (or pulleys). Alternatively, a timing belt is used as an element. The VVT mechanism 6 changes the rotation phase of the intake camshaft relative to the crankshaft by rotating the intake camshaft relative to the cam sprocket, thereby changing the opening / closing timing of the intake valve.

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

  The input interface of the ECU 0 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 b output from an engine rotation sensor that detects the rotation angle of the crankshaft and the engine speed, and an accelerator pedal. Accelerator opening signal c output from a sensor that detects the amount of depression of the engine or the opening of the throttle valve 32 as an accelerator opening (so-called required load), output from a water temperature sensor that detects a cooling water temperature that indicates the temperature of the internal combustion engine The cooling water temperature signal d, the battery current / voltage signal e output from the current / voltage sensor that detects the terminal current and / or terminal voltage of the vehicle battery, and the intake air temperature in the intake passage 3 (particularly, the surge tank 33) And the intake air temperature / intake pressure signal f output from the temperature / pressure sensor for detecting the intake pressure, the intake camshaft The cam angle signal g output from the cam angle sensor at a number of cam angles, output from a sensor (such as a brake switch or a master cylinder pressure sensor) that detects whether the brake pedal is depressed or the brake pedal is depressed. A brake signal h or the like is input.

  Here, the crank angle signal b and the cam angle signal g will be supplemented. As shown in FIG. 2, the crank angle sensor senses the rotation angle of the rotor 75 that is fixed to the crankshaft and rotates integrally with the crankshaft. The rotor 75 is formed with teeth or projections 76 at every predetermined angle along the rotation direction of the crankshaft. Typically, each time the crankshaft rotates 10 °, a tooth or projection 76 is placed. The crank angle sensor faces the outer periphery of the rotor 75, detects that each tooth or protrusion 76 passes near the sensor, and transmits a pulse signal as the crank angle signal b each time. The ECU 0 receives this pulse as the crank angle signal b.

  However, the crank angle sensor does not output 36 pulses during one rotation of the crankshaft. The teeth or protrusions 76 of the crankshaft rotor 75 are partially missing. In the example shown in FIG. 2, the seventeenth, eighteenth, twentyth, and twentyth first missing tooth portions 761 and the thirty fifth and thirty sixth missing tooth portions 762 are roughly divided into two. There are missing tooth portions 761 and 762. The missing tooth portions 761 and 762 each correspond to a specific rotational phase angle of the crankshaft. That is, the continuous missing tooth portion 761 corresponds to 180 ° CA and 540 ° CA, and the single missing tooth portion 762 corresponds to 0 ° CA and 360 ° CA, and the position between them is about 180 ° CA. There is a phase difference.

  As shown in FIGS. 5 to 8, the pulse train of the crank angle signal b is also partially lost due to the above-mentioned missing tooth portions 761 and 762. Based on this deficiency, it is possible to know the absolute angle (posture) of the crankshaft, in other words, the current position of the piston of each cylinder 1. If the timing of the first pulse after the missing thirty-sixth pulse is 0 ° CA (or 360 ° CA), the timing of the nineteenth pulse following the missing eighteenth pulse is 180 °. That is, CA (or 540 ° CA). The timing of the 0 ° CA pulse is substantially equal to the compression top dead center of a specific cylinder (second cylinder in the illustrated example) 1.

  As shown in FIG. 3, the cam angle sensor also senses the rotation angle of the rotor 77 that is fixed to the cam shaft and rotates integrally with the cam shaft. The rotor 77 is formed with teeth or protrusions 78 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, teeth or protrusions 78 are arranged every time the camshaft rotates 120 °. The camshaft is rotated by receiving a rotational driving force transmitted from the crankshaft via a winding transmission mechanism, and its rotational speed is one-half that of the crankshaft. Therefore, the above-described teeth or protrusions 78 are arranged every 240 ° CA in terms of the crank angle. In addition, in the present embodiment, the rotor 77 is provided with one tooth or protrusion 79 for generating an additional cam angle signal g between the teeth or protrusions 78 every 240 ° CA.

  The cam angle sensor faces the outer periphery of the rotor 77, detects that individual teeth or protrusions 78 and 79 pass in the vicinity of the sensor, and transmits a pulse signal as the cam angle signal g each time. The ECU 0 receives this pulse as the cam angle signal g. The basic cam angle signal g generated due to the teeth or protrusions 78 indicates that one of the cylinders 1 has reached a predetermined stroke. As shown in FIGS. 5 to 8, the basic cam angle signal g output from the cam angle sensor attached to the intake camshaft is a crank angle from the compression top dead center in each cylinder 1 (in “normal case”, 60 ° CA) Suggests timing of advance. The basic cam angle signal g also represents the intake valve timing (the advance amount) adjusted by the VVT mechanism 6. By referring to both the crank angle signal b and the cam angle signal g, in addition to being able to determine and know the current stroke of each cylinder 1, the current intake valve timing embodied by the VVT mechanism 6 becomes clear. .

  The additional cam angle signal g generated due to the teeth or protrusions 79 corresponds to a specific rotational phase angle of the camshaft and assists in determining the stroke of each cylinder 1. In the example shown in FIG. 5 to FIG. 8, a predetermined crank angle (specifically, from the pulse of the basic cam angle signal g indicating the timing at which the crank angle is advanced from the compression top dead center of the third cylinder 1). (60 ° CA) A pulse of the additional cam angle signal g exists at the delayed timing. When these two cam angle signal g pulses are successively received at a predetermined (60 ° CA) interval that is apparent from the pulse train of the crank angle signal b, the compression top dead of the third cylinder 1 is received together with the latter pulse. You can see that the dots are coming.

  From the output interface of the ECU 0, the ignition signal i for the igniter, the fuel injection signal j for the injector 11, the opening operation signal k for the throttle valve 32, the opening operation signal l for the EGR valve 23, VVT. An intake valve timing control signal n or the like is output to the mechanism 6.

  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, etc., the required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, required EGR rate (or EGR rate) Volume), opening / closing timing of the intake valve, and the like. The ECU 0 applies various control signals i, j, k, l, and n corresponding to the operation parameters via the output interface.

  Further, the ECU 0 inputs a control signal o to an electric motor (starter motor or ISG (Integrated Starter Generator)) when the internal combustion engine is started (a cold start or a return from an idling stop). Then, cranking is performed by rotating the crankshaft by the electric motor. Cranking ends when the internal combustion engine starts from the first explosion to a continuous explosion and the engine speed, that is, the rotation speed of the crankshaft, exceeds a judgment value determined according to the coolant temperature, etc. (assuming that the explosion has been completed) To do.

  When starting the internal combustion engine that is stopped, the ECU 0 according to the present embodiment supplies fuel to all the cylinders 1 almost simultaneously with the start of cranking (immediately before, simultaneously with, or immediately after the start of cranking). Asynchronous injection is performed. Then, the crank angle signal b and the cam angle signal g generated with the rotation of the crankshaft are received, and the stroke of each cylinder 1 is determined. When the determination of the stroke of each cylinder 1 is completed, spark ignition for each cylinder 1 and synchronous injection for injecting fuel individually for each cylinder 1 are started. Spark ignition is performed at a timing near the compression top dead center of each cylinder 1, and synchronous injection is performed at a timing near the exhaust top dead center of each cylinder 1.

  Hereinafter, the cylinder discrimination method of this embodiment will be described in detail. In the present embodiment, the ECU 0 according to the program, the cam angle signal detection counter unit 101 for counting the number of detected cam angle signals g shown in FIG. 4, and the crank angle signal detection counter unit 102 for counting the number of detected crank angle signals b. In addition, a function as a cylinder discriminating unit 103 that discriminates the stroke of each cylinder 1 with reference to the number detected by the cam angle signal detection counter unit 101 at a timing determined based on a missing pulse included in the crank angle signal b. Demonstrate.

  In FIG. 5 to FIG. 8, two upper and lower stages are shown below the cam angle signal g in each case. The upper row shows the count by the crank angle signal detection counter unit 102. On the other hand, the lower part shows an example of counting by the cam angle signal detection counter unit 101.

  The cam angle signal detection counter unit 101 counts up to increase the number of detections by “1” each time the cam angle signal g is detected.

  The crank angle signal detection counter unit 102 starts counting the number of detected crank angle signals b triggered by the detection of the cam angle signal g. The crank angle signal detection counter unit 102 is a decrement counter, starts counting down from “9” with the detection of the cam angle signal g, and decreases the number by “1” according to the number of detected crank angle signals b. Further, when the cam angle signal g is detected while counting the number of detected crank angle signals b, the crank angle signal detection counter unit 102 increases the count by a predetermined number, for example, “3”. However, when the crank angle signal b is detected at the same time as the cam angle signal g, a “1” decrease is added to the “3” increase in the count, resulting in a total increase of “2”. In the example shown in FIGS. 5 to 8, the count by the crank angle signal counter unit 102 increases from “3” to “5” before and after the timing of 240 ° CA in the “normal case”.

  Further, the crank angle signal counter unit 102 counts when a missing crank angle signal b corresponding to a specific rotational phase angle of the crankshaft is detected while counting the number of detected crank angle signals b. A predetermined number, for example, “1” is increased. In the present embodiment, a crank angle signal detection counter is provided on the condition that a single missing pulse of the crank angle signal b (missing thirty-fifth and thirty-sixth pulses caused by the missing tooth portion 762) is detected. The number of detected parts 102 is increased by “1”. However, since the crank angle signal b is detected at the same time, a “1” decrease is added to the “1” increase of the count, and the total does not increase or decrease. In the example shown in FIGS. 5 to 8, the crank angle signal counter 102 counts before and after the 0 ° CA timing in the “normal case” and before and after the 180 ° CA timing in the “advance case”. Is maintained at “6”.

  In addition, the crank angle signal counter unit 102 detects a missing crank angle signal b corresponding to another specific rotational phase angle of the crankshaft while counting the number of detected crank angle signals b. Then, the count is decreased by a predetermined number, for example, “3”. In the present embodiment, on the condition that the continuous missing of the pulse of the crank angle signal b (the 17th, 18th, 20th, and 20th first pulse missing due to the missing tooth portion 761) is detected. The number of detections of the crank angle signal detection counter unit 102 is reduced by “3”. However, since the crank angle signal b is detected at the same time, a “1” decrease is added to a “3” decrease in the count, and a total decrease is “4”. In the example shown in FIGS. 5 to 8, the count by the crank angle signal counter unit 102 decreases from “9” to “5” before and after the 210 ° CA timing in the “normal case”.

  The crank angle signal counter unit 102 resets the detected number of the cam angle signal detection counter unit 101 when the number of detected crank angle signals b reaches a predetermined upper limit value. Finish counting b. That is, after detecting the cam angle signal g, the crank angle signal detection counter unit 102 detects the crank angle signal b nine times (the number of detected crank angle signals b reaches “9” which is the upper limit value, in other words, When the counter value of the crank angle signal counter unit 102 becomes “0”), the detection number (“1” or “2”) of the cam angle signal detection counter unit 101 is reset to “0”, and the crank angle signal is reset. Finish counting b. When the number of detected cam angle signals g and the number of detected crank angle signals b are both reset to the initial value “0”, the crank angle signal b is not counted until the cam angle signal g is next detected.

  Incidentally, in order to detect a missing pulse of the crank angle signal b, it is necessary to further receive three pulses corresponding to 30 ° CA generated immediately after the missing. It is only after receiving the third pulse of the crank angle signal b that the 35th and 36th pulses are missing. Similarly, it is found after the reception of the twenty-fourth pulse of the crank angle signal b that the seventeenth, eighteenth, twentieth and twentieth pulses are missing. After knowing the occurrence of the missing pulse of the crank angle signal b, the ECU 0 increases the detected number of the crank angle signal counter unit 102 by “1” or decreases “3” by going back to the time immediately after the missing. Will be.

The cylinder discriminating unit 103 discriminates the stroke of each cylinder 1 with reference to the number detected by the cam angle signal detection counter unit 101 at a predetermined timing determined based on the missing pulse included in the crank angle signal b. As shown by a two-dot chain line in FIGS. 5 to 8, this cylinder discrimination timing comes twice in a half cycle of the internal combustion engine. In the example shown,
• First pattern: 90 ° CA timing after single missing pulse (missing 35th and 36th pulses due to missing tooth portion 762) • Second pattern: Continuous missing pulse (missing tooth portion) The timing after the loss of the 17th, 18th, 20th, and 20th pulses due to 761 (or the timing of 10 ° CA after the continuous loss)
Cylinder discrimination is performed with.

  If the number of detections of the cam angle signal detection counter unit 101 referred to by the cylinder discrimination unit 103 is “0” at the cylinder discrimination timing of the first pattern, the current time is 150 before the compression top dead center of the third cylinder 1. It turns out that the timing is 90 ° CA (90 ° CA). In other words, spark ignition is executed at the timing of the compression top dead center of the third cylinder 1 that comes after that (the timing becomes clear by the crank angle signal b), and the fuel injected asynchronously in the third cylinder 1 An expansion stroke can be performed by igniting and burning. On the other hand, if the number detected by the cam angle signal detection counter unit 101 is “1” or “2”, the current time is 30 ° CA before the compression top dead center of the first cylinder (450 ° CA). It turns out that there is. Then, the spark ignition is executed at the timing of the compression top dead center of the first cylinder 1 that comes after that, and the expansion stroke in which the fuel injected asynchronously in the first cylinder 1 is ignited and burned can be performed.

  If the number of detections of the cam angle signal detection counter unit 101 referred to by the cylinder discrimination unit 103 is “1” or “2” at the cylinder discrimination timing of the second pattern, the current time point is the compression of the third cylinder. It turns out that the timing is 30 ° CA to 20 ° CA (210 ° CA to 220 ° CA) before top dead center. Then, the spark ignition is executed at the timing of the compression top dead center of the third cylinder 1 that comes after that, and an expansion stroke can be performed in which the fuel injected asynchronously in the third cylinder 1 is ignited and burned. On the other hand, if the number detected by the cam angle signal detection counter unit 101 is “0”, the current time is 150 ° CA to 140 ° CA before the compression top dead center of the second cylinder (570 ° CA to 580). ° CA). In this case, the spark ignition is executed at the timing of the compression top dead center of the second cylinder 1 that comes after that, and the expansion stroke in which the fuel injected asynchronously in the second cylinder 1 is ignited and burned can be performed.

  In an actual internal combustion engine, in addition to individual differences due to variations in the shape and dimensions of each part, the position shift of the timing chain with respect to the sprocket, the extension of the timing chain, and the rotational phase of the camshaft in the VVT mechanism 6 are fixed. May become immobile. In addition, in the internal combustion engine in which the electric VVT mechanism 6 is mounted, the rotational phase of the camshaft relative to the crankshaft at the time of starting is not uniquely determined. In addition, the electric VVT mechanism 6 has a larger movable range of the rotational phase of the camshaft than the hydraulic VVT mechanism.

For this reason, when starting the internal combustion engine, the cam angle signal g is not always emitted at an ideal timing. In some cases, the cam angle signal g is detected at a timing that deviates from the normal timing toward the advance side or the retard side. 5 to 8, the following three cases are ideal: “normal case”
・ "Advance case" shifted to the advance side. More specifically, the valve timing when the VVT mechanism 6 is advanced at the start of the internal combustion engine is realized, and the cam angle signal g is 80 ° CA or more than normal in combination with variations in the shape and dimensions of the parts. Cases that occur when the timing is advanced-"Delayed cases" that deviate to the retarded side. Specifically, the timing chain is in an extended state, and a case where the cam angle signal g is generated at a timing delayed by 20 ° CA or more than normal in combination with variations in the shape and dimensions of the components is shown.

  The ECU 0 of the present embodiment can correctly determine the cylinder even in the “advance case” and the “delay case”, and can quickly start the internal combustion engine. In the “advance case”, when performing cylinder discrimination at the cylinder discrimination timing of the first pattern, if the current time is the timing of 30 ° CA (450 ° CA) before the compression top dead center of the first cylinder, When the cylinder discrimination timing is reached, the detected number of the cam angle signal counter unit 101 and the crank angle signal counter unit 102 is still “1”, so that it is possible to correctly discriminate the stroke of each cylinder 1 of the internal combustion engine. .

  Further, in the “delayed case”, when cylinder discrimination is performed at the cylinder discrimination timing of the second pattern, the current time is 150 ° CA to 140 ° CA before the compression top dead center of the second cylinder (540 ° CA to 550 ° CA), the count of the crank angle signal counter unit 102 is subtracted to “0” due to the continuous missing of the pulse of the crank angle signal b that appears immediately before the cylinder discrimination timing is reached, and accordingly, the cam angle signal counter Since the detected number of the part 101 is reset to “0” and the cylinder discrimination timing can be reached in this state, it is possible to correctly discriminate the stroke of each cylinder 1 of the internal combustion engine.

  In the present embodiment, the crank angle sensor 75 associated with the crankshaft outputs a crank angle signal b each time the crankshaft rotates by a unit angle, and at the predetermined rotational phase angle of the crankshaft, the crank angle signal b is output. The cam angle sensor 77 associated with the camshaft that rotates following the crankshaft and opens and closes the intake valve drives the basic cam angle signal g each time the camshaft rotates by a unit angle. In addition to outputting, a control device 0 for controlling an internal combustion engine that outputs an additional cam angle signal g at a predetermined rotational phase angle of the camshaft, the cam for counting the number of detected cam angle signals g An angle signal detection counter unit 101 and a counter unit for counting the number of detected crank angle signals b, triggered by detection of the cam angle signal g Counting the number of detected crank angle signals b is started, and when the number of detected crank angle signals b reaches the upper limit, the number of detected cam angle signal detection counters 101 is reset and the crank angle signal b is reset. When the counting of the angle signal b is completed and the cam angle signal g is detected while the number of detected crank angle signals b is being counted, the number of detected crank angle signals b is reduced by a predetermined number, and While counting the number of detections, the crank angle signal b of the crank angle signal b is determined at a timing (in this embodiment, a single missing timing) determined based on a missing crank angle signal pulse corresponding to a specific rotational phase angle of the crankshaft. While the number of detections is reduced by a predetermined number and the number of detections of the crank angle signal b is being counted, the pulse of the crank angle signal corresponding to a specific rotational phase angle of the crankshaft is counted. A crank angle signal detection counter unit 102 that increases the number of detected crank angle signals b by a predetermined number at another timing determined in accordance with the loss (in this embodiment, the timing of continuous loss), and missing pulses of the crank angle signal b The control device 0 of the internal combustion engine comprising the cylinder discriminating unit 103 that discriminates the stroke of each cylinder 1 by referring to the number detected by the cam angle signal detection counter unit 101 at a timing determined based on the above.

  According to this embodiment, the stroke of each cylinder 1 can be correctly determined when starting the internal combustion engine, which contributes to shortening the time required for starting the internal combustion engine.

  The present invention is not limited to the embodiment described in detail above. For example, the crank angle signal detection counter unit 102 may be a total counter that counts up by increasing the number of detected crank angle signals b by “1” from “1” when the cam angle signal b is detected.

  The cam angle sensor may detect the rotation of the rotor fixed to the exhaust camshaft that opens and closes the exhaust valve and outputs a basic cam angle signal and an additional cam angle signal.

  The specific aspect of the VVT mechanism is arbitrary and is not uniquely limited. In addition to a mode in which the camshaft rotation phase with respect to the crankshaft is advanced / retarded by hydraulic pressure or an electric motor, a plurality of cams for opening and closing the intake valve and / or the exhaust valve are prepared and used appropriately. There are known ones in which the lever ratio of the rocker arm is changed by an electric motor, and ones in which an intake valve and / or an exhaust valve are electromagnetic solenoid valves, etc., which are allowed to be selected and used from these various mechanisms. . Of course, the present invention can also be applied to control of an internal combustion engine that does not include a VVT mechanism.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to control at the time of starting an internal combustion engine mounted on a vehicle or the like.

0 ... Control unit (ECU)
DESCRIPTION OF SYMBOLS 101 ... Cam angle signal counter part 102 ... Crank angle signal counter part 103 ... Cylinder discrimination | determination part 1 ... Cylinder 11 ... Injector 12 ... Spark plug 3 ... Intake passage 4 ... Exhaust passage 75 ... Crank angle sensor 77 ... Cam angle sensor b ... Crank Angle signal g ... Cam angle signal

Claims (1)

The crank angle sensor attached to the crankshaft outputs a crank angle signal every time the crankshaft rotates by a unit angle, and eliminates the crank angle signal without outputting the crank angle signal at a predetermined rotation phase angle of the crankshaft. Yes,
The camshaft sensor attached to the camshaft that rotates following the crankshaft and opens / closes the intake or exhaust valve outputs a basic cam angle signal every time the camshaft rotates by a unit angle. A control device for controlling an internal combustion engine that outputs an additional cam angle signal at a predetermined rotational phase angle,
A cam angle signal detection counter for counting the number of detected cam angle signals;
It is a counter unit that counts the number of detected crank angle signals, starts counting the number of detected crank angle signals triggered by the detection of the cam angle signal, and sets the detected number of detected crank angle signals to the upper limit value. If the cam angle signal is detected, the detected number of the cam angle signal detection counter is reset and the counting of the crank angle signal is finished. When the cam angle signal is detected while counting the detected number of the crank angle signal, the crank angle signal is detected. The number of detected angular signals is reduced by a predetermined number, and the crank angle is detected at a timing determined based on a missing crank angle signal pulse corresponding to a specific rotational phase angle of the crankshaft while counting the detected number of crank angle signals. Crank corresponding to a specific rotation phase angle of the crankshaft while the number of detected angle signals is reduced by a predetermined number and the number of detected crank angle signals is counted. A crank angle signal detecting counter unit for increasing a predetermined number of detection number of crank angle signal at another timing determined based on loss of signal pulses,
A control apparatus for an internal combustion engine, comprising: a cylinder determining unit that determines a stroke of each cylinder by referring to the number detected by the cam angle signal detection counter unit at a timing determined based on a missing pulse of a crank angle signal.

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