JP2009191689A - Fuel injection control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive fuel injection control device capable of highly accurately detecting a rotation angle of a crankshaft, a fuel injection control device stably operable by reducing a voltage variation, and a fuel injection control device without requiring a battery. <P>SOLUTION: This fuel injection control device has a generator 2 composed of a rotor 21 rotating with the crankshaft of an internal combustion engine and having a magnet and a stator 23 having a coil (a charging coil 25), a mechanical detection means (a crank angle sensor 3) for mechanically detecting a rotation angle of the rotor 21, an electric detection means (a control circuit 4) for electrically detecting the rotation angle of the rotor 21 by shaping an output voltage waveform of the coil 25, and a control part (a control part 4) for controlling a fuel injection part 83 based on information on the rotation angle of the rotor 21 detected by the mechanical detection means 3 and the electric detection means 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel injection control device for an internal combustion engine, and more particularly to a technology for detecting a rotation angle of a crankshaft and a technology for combining the internal combustion engine with other peripheral devices.

  As peripheral devices for an internal combustion engine mounted on a motorcycle, a generator, an ignition device, a fuel injection device, and the like are generally equipped. These are not configured separately, but are combined to achieve miniaturization, high functionality, and low cost. Further, in order to appropriately control the fuel injection timing and the ignition timing, it has become common to detect the rotation angle of the crankshaft with a crank angle sensor and perform electronic control with a control unit. As an example of this type of device, Patent Literature 1 discloses a technology of a charge coil for a CDI ignition device, and Patent Literature 2 discloses a technology of a fuel injection control device.

  The technology of Patent Document 1 is directed to a motorcycle engine, and a rotating magnetic field generator (generator) is formed by a rotor with a magnet that rotates together with a crankshaft of the engine and a stator including a coil. Among the plurality of coils, one is a charge coil for a CDI ignition device described later, and the rest is a battery charging coil. And it is comprised so that electric power, such as a fuel-injection apparatus, an illumination lamp, an indicator, may be covered with the battery charged with the coil for battery charging.

  As an ignition device, an induction discharge type is generally used in which an energization current of an ignition coil is interrupted by a power semiconductor element to generate a high voltage and discharge by an ignition plug. The energization current of the induction discharge ignition device is about 3 to 4A. Further, in order to obtain an appropriate ignition timing, Patent Document 1 includes a protrusion partially protruding on the outer peripheral portion of the rotor and a pulsar coil for detecting passage of the protrusion, and a specific rotation of the rotor, that is, the crankshaft. The angle is detected.

On the other hand, in a fuel injection device, it is not sufficient to simply detect a specific angle of the crankshaft in order to optimally control a fuel injection section such as an injector nozzle, and the engine operating condition that changes from moment to moment is increased. There is a need to detect with accuracy. That is, it is necessary to detect the instantaneous rotational speed and rotational acceleration of the crankshaft. Further, as an operation state of the engine, it is preferable to detect the intake pipe pressure when the piston is in the vicinity of the intake bottom dead center. The technology of Patent Document 2 is intended for an engine having a plurality of cylinders, and a crank angle sensor is configured by combining a plurality of convex teeth provided on a rotating body, reference teeth for the number of cylinders, and electromagnetic pickups. Yes. Even in the case of a single-cylinder engine for a motorcycle, it is common to provide about 8 to 24 protrusions on the outer periphery of the rotor of the generator in order to configure the rotation angle sensor integrally with the generator.
JP-A-5-62844 JP 2003-278580 A

  By the way, the projection for detecting the rotation angle on the outer periphery of the rotor of the motorcycle engine has been manufactured by rotating the rotor with high accuracy for each projection and punching it out by press working. Therefore, if a large number of protrusions are provided in order to detect the rotation angle with high accuracy, the cost increases accordingly.

  In general, a fuel injection device and an inductive discharge type ignition device are connected in parallel as a load of a generator and a battery, and a voltage fluctuation occurs due to intermittent conduction of an ignition coil. May not operate stably and the fuel injection amount may vary. In particular, when the engine is rotating at a low speed, there is a problem that the amount of power generation is small, the voltage drop is remarkable, and it takes a long time to open and close the injector nozzle. Even if the power generation performance of the generator is increased as a countermeasure, not only the cost is increased, but also the friction loss is increased and the fuel consumption is deteriorated.

  Furthermore, in recent years, many motorcycles have been exported to Southeast Asia, etc., and are being used under severe natural environments and inadequate maintenance systems. Therefore, a fuel injection control device and engine that do not require a battery that requires maintenance such as inspection and replacement, and a motorcycle that does not require a battery are expected.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fuel injection control device that can detect the rotation angle of the crankshaft with high accuracy and is low in cost. It is another object of the present invention to provide a fuel injection control device that operates stably with a small voltage fluctuation, and a fuel injection control device that does not require a battery.

  Therefore, in order to solve this problem, the present invention provides not only a crank angle sensor combining a projection and an electromagnetic pickup, but also an electrical detection means for shaping a coil output voltage waveform as a means for detecting the rotation angle of the crankshaft. By using it together, the above object is achieved.

  That is, the fuel injection control device of the present invention is a mechanical detector that mechanically detects a rotation angle of a rotor including a rotor that rotates with a crankshaft of an internal combustion engine and that has a magnet, and a stator that has a coil. Means for electrically detecting the rotation angle of the rotor by shaping the output voltage waveform of the coil, the mechanical detection means, and the rotor detected by the electrical detection means. And a control unit that controls a fuel injection unit that supplies fuel to the internal combustion engine on the basis of information on the rotation angle.

  The present invention is suitable for a configuration in which three components of a generator, an ignition device, and a fuel injection device are combined as peripheral devices of the engine. The fuel injection control device of the present invention can be constituted by a generator, mechanical detection means, electrical detection means, and a control unit.

  The generator generates electric power necessary for peripheral devices of the internal combustion engine such as a fuel injection device, and may also generate electric power necessary for a main engine such as a two-wheeled vehicle on which the internal combustion engine is mounted. The generator can be composed of a rotor that rotates together with the crankshaft of the internal combustion engine and has a magnet, and a stator that has a coil, and acts as a so-called rotating magnetic field type AC generator. Although there is no restriction | limiting in the quantity and arrangement | positioning of a magnet, Naturally, it is preferable to arrange | position N pole and S pole alternately at equal intervals in the circumferential direction. Moreover, there is no restriction | limiting in the number of coils and the number of windings, and it can design suitably according to the electric load which supplies the produced | generated electric power.

  The mechanical detection means is means for mechanically detecting the rotation angle of the rotor. Detecting the rotation angle of the rotor corresponds to detecting the rotation angle of the crankshaft, and further detecting the piston position of the internal combustion engine.

  The mechanical detection means preferably includes a detected portion provided in a circumferential direction of the rotor and a detection sensor fixedly spaced from the rotor and detecting the passage of the detected portion. Further, the detected portion of the mechanical detection means includes a protrusion that displays at least the intake bottom dead center and the compression top dead center of the internal combustion engine, and the detection sensor is an electromagnetic that detects passage of the protrusion. A pickup type sensor may be used.

  Here, the intake bottom dead center does not necessarily mean the crank position where the piston is at the lowest position mechanically, but is known as the intake pipe pressure position correlated with the intake air amount. It means a fixed crank position up to 30 degrees after dead center.

  As the mechanical detection means, the same detection method protrusions and electromagnetic pickup sensors can be used. However, it is not necessary to provide a large number of protrusions as in the prior art, and it is preferable to use a minimum number so that only a specific rotation angle of the crankshaft that is particularly important for control is detected. Specifically, it is preferable to provide a protrusion that displays the intake bottom dead center and the compression top dead center. The intake bottom dead center is an optimal timing for obtaining the intake air amount as described above, and the timing just before the compression top dead center is a timing suitable for ignition.

  The electrical detection means is means for electrically detecting the rotation angle of the rotor. As is well known, a sinusoidal AC output voltage is ideally induced in a coil disposed in an alternating magnetic field generated by rotation of a magnet. Since there is a fixed relationship between the phase of the AC output voltage and the rotation angle of the rotor, the rotation angle of the rotor can be detected by shaping the output voltage waveform.

  Preferably, the electrical detection means compares the output voltage of the coil with a constant threshold voltage and shapes it into a rectangular wave. Further, the threshold voltage of the electrical detection means may be provided on the positive side and the negative side of the output voltage of the coil.

  In order to shape the AC output voltage into a rectangular wave, for example, a circuit having a comparator element can be used. That is, the output voltage of the coil is set as the comparator input voltage, the constant threshold voltage is set as the comparator reference voltage, the comparator output is set to High only when the former is equal to or higher than the latter, and is set to Low otherwise, thereby generating a rectangular wave. can get. At this time, the rectangular wave is detected in a time zone in which the output voltage of the coil increases on the positive side. If the threshold voltage is also provided on the negative side, it is possible to detect a time period during which the output voltage of the coil increases on the negative side. Furthermore, if the threshold voltage is changed to a plurality, the plurality of rectangular waves having different time widths are shaped and generated, and the output voltage waveform can be accurately detected. Since the arrangement of the magnets of the rotor is independent of the position of the protrusions on the outer periphery, the difference between the rotation angles of the two can be freely designed. In other words, the mechanical detection means and the electrical detection means can detect different rotation angles independent of each other. Therefore, the rotation angles of the rotor and the crankshaft can be detected with high accuracy.

  The control unit controls the supply of fuel to the internal combustion engine based on information on the detected mechanical rotation angle and electrical rotation angle. The control unit can grasp the rotation angles of the rotor and the crankshaft based on the detected mechanical rotation angle and electrical rotation angle. Further, the rotation speed and the rotation acceleration can be calculated from the relationship between the change amount of the rotation angle and the elapsed time. And a control part can control a fuel injection part, for example, an injector nozzle, referring also to information of other sensors based on a rotation angle, a rotation speed, and a rotation acceleration of a crankshaft.

  In the fuel injection control device of the present invention described above, the output voltage waveform of the generator coil is shaped to electrically detect the rotation angle of the crankshaft, so that the protrusion detected by the electromagnetic pickup sensor is minimized. Even if the number is limited, highly accurate detection can be performed. Since the generator coil is generally provided from the past, it is not necessary to add a new one. Therefore, the cost can be reduced by the amount of the protrusions reduced.

  Next, application modes of the present invention will be described. Preferably, the coil of the generator is a charging coil that charges an ignition capacitor of a capacitor discharge ignition device of the internal combustion engine, and the control unit also controls the discharge timing of the ignition capacitor. Further, either positive or negative of the AC output of the charging coil may be used for charging the ignition capacitor, and the other may be used for the power source of the control unit.

  The fuel injection control device of the present invention is preferably configured in combination with a capacitor discharge type (CDI type) ignition device. In this ignition device, a high voltage is induced by causing the electric charge accumulated in the ignition capacitor to flow through the ignition coil, and a discharge is generated by the ignition plug. By connecting a charging coil for charging the ignition capacitor to the electrical detection means of the present invention, voltage phase information can be obtained. On the other hand, the control unit is shared by the fuel injection control device and the ignition device, and shares information on the rotational angle of the rotor detected by the mechanical detection means and the electrical detection means, so that the discharge timing of the ignition capacitor, i.e., ignition. Timing can be controlled. For example, it is possible to control so that the charge of the ignition capacitor is discharged at a timing immediately before the compression top dead center detected by the mechanical detection means.

  In the above-described aspect, the energization current is smaller than that of the conventional induction discharge ignition device, so that the output voltage of the charging coil is stabilized and the detection accuracy of the electrical detection means is improved. In addition, fluctuations in the output voltage and battery terminal voltage of a battery charging coil separately provided in the generator are reduced, and the operation of the fuel injection unit driven by the battery is also stabilized. For example, variations in the operation of the injector nozzle due to voltage fluctuations are reduced.

  In addition, by connecting the output terminal of the charging coil to the ignition capacitor via a rectifier diode, either the positive or negative half wave can be used for charging, but the reverse half wave cannot be used for charging. This half-wave on the opposite pole side can be used as the power source of the control unit, and as a result, the fuel injection control device can be made battery-free.

  Furthermore, the internal combustion engine may be a single-cylinder engine mounted on a motorcycle, and one of the plurality of coils provided in the generator may be connected to the electrical detection means.

  The fuel injection control device of the present invention is suitable for a single-cylinder engine having a relatively small generator capacity when combined with a capacitor discharge type (CDI type) ignition device. The generator can be provided with a plurality of coils, and any coil can be connected to the electrical detection means, and is not limited to the above-described charging coil. Further, if the electric power of an electric load such as an illumination lamp mounted on the two-wheeled vehicle is covered by a plurality of coils, a two-wheeled vehicle that does not require a battery can be configured. In this case, for example, a kick-type starter is preferably provided to start the engine, and after the engine is started, continuous operation can be performed with electric power generated by the generator.

  In the fuel injection control device of the present invention, since the electric detection means for shaping the output voltage waveform of the generator coil and electrically detecting the rotation angle of the crankshaft is provided, the protrusion detected by the electromagnetic pickup sensor is provided. Even with the minimum number, highly accurate detection can be performed. Since the generator coil is generally provided, it is not necessary to add a new one. Therefore, the cost can be reduced by reducing the number of protrusions.

  Further, in the aspect combined with the capacitor discharge ignition device, the energization current on the ignition device side is small and the output voltage of the charging coil is stabilized, so that the detection accuracy of the electrical detection means is improved and the fuel driven by the battery The operation of the injection unit is also stabilized. Furthermore, a fuel injection control device that does not require a battery, an engine, and a motorcycle that does not require a battery can also be configured.

  Next, the present invention will be described in more detail with reference to embodiments. FIG. 1 is a circuit diagram illustrating a fuel injection control device according to an embodiment of the present invention used in a two-cylinder single cylinder engine. The fuel injection control device 1 according to the embodiment includes a generator 2, a crank angle sensor 3, a control circuit 4 also serving as an electrical detection means and a control unit of the present invention, a control power source unit 5, and a capacitor discharge type ignition formed in combination. The apparatus unit 6 and the general-purpose power supply unit 7 are configured.

  The generator 2 generates electric power necessary for engine peripheral devices including the fuel injection device 1 itself and lamps and indicators of motorcycles. The generator 2 includes a rotor 21 that rotates together with an unillustrated engine crankshaft, and a stator 23 having coils 25 and 26. An 8-pole magnet is provided inside the rotor 21, and N and S poles are alternately arranged at equal intervals in the circumferential direction. FIG. 2 is a diagram illustrating the stator 23 of the generator 2. The stator 23 includes a stator core 28 having eight winding portions, and one charging coil 25 and seven general purpose coils 26 are wound around the winding portion. Output terminals 25 </ b> A and 25 </ b> B of the charging coil 25 are connected to the control circuit 4, the control power supply unit 5, and the ignition device unit 6. The seven general-purpose coils 26 are connected in series, and the output terminal 26A at the high voltage end, the intermediate output terminal 26B, and the ground terminal 26C at the ground end are connected to the general-purpose power supply unit 7, respectively. When the rotor 21 rotates, the magnetic field of the magnet rotates, the output voltage V1 is output from the charging coil 25, and the output voltage V2 is output from the general-purpose coil 26.

  The crank angle sensor 3 corresponds to the mechanical detection means of the present invention, and is a means for mechanically detecting the rotation angle of the rotor 21. The crank angle sensor 3 includes three protrusions 31 to 33 provided on the outer periphery of the rotor 21 and an electromagnetic pickup 34 that detects passage due to rotation of the protrusions 31 to 33. The first protrusion 31 that is long in the circumferential direction displays immediately before the compression top dead center of the piston, and the second protrusion that is provided slightly forward of the first protrusion 31 predicts the first protrusion 31. . The third protrusion 33 provided on the substantially opposite side of the first protrusion 31 displays the intake bottom dead center of the piston. The electromagnetic pickup 34 is connected to the angle input terminal 42 of the control circuit 4, and outputs a positive pulse at the moment when these protrusions 31 to 33 arrive, and outputs a negative pulse at the moment of separation. .

  The electrical detection means of the present invention that electrically detects the rotation angle of the rotor 21 is constituted by a processing circuit in the control circuit 4. Specifically, the two output terminals 25A and 25B of the charging coil 25 are connected to the positive side input terminal 41A and the negative side input terminal 41B of the control circuit 4, respectively. Then, the processing circuit compares the voltage at the positive input terminal 41A with the positive threshold voltage to perform rectangular wave shaping, and compares the voltage at the negative input terminal 41B with the negative threshold voltage. The rectangular wave is shaped by the above, and the rotation angle of the rotor 21 is obtained based on each rectangular wave.

  The ignition device section 6 includes an ignition capacitor 61, an ignition coil 62, an ignition thyristor 63, and an ignition plug 64. As shown in FIG. 1, the primary coil of the rectifier diode 65, the ignition capacitor 61, and the ignition coil 62 are connected in series in order from the positive output terminal 25 </ b> A of the charging coil 25, and then connected to the ground point G. ing. Further, an ignition thyristor 63 is connected from the connection point 66 of the rectifier diode 65 and the ignition capacitor 61 toward the ground point G, and the ignition capacitor 61, the primary coil of the ignition coil 62, and the ignition thyristor 63. Thus, a closed circuit is formed. The high-voltage side terminal of the secondary coil of the ignition coil 62 is connected to one end of the spark plug 64, and the other end of the spark plug 64 is grounded.

  In the ignition device 6, charges are accumulated in the ignition capacitor 61 by the positive output voltage of the charging coil 25, the ignition thyristor 63 is turned on by the ignition command from the ignition command output terminal 46 of the control circuit 4, and the charge becomes transient. A current ID flows through the closed circuit, and a voltage is induced in the primary coil of the ignition coil 62. As a result, a high voltage is induced in the secondary coil of the ignition coil 62, and a discharge is generated in the gap of the spark plug 64 to perform ignition.

  The control power supply unit 5 supplies power to the control circuit 4 and includes a control power supply regulator 51 and a control power supply capacitor 52. The input side of the control power regulator 51 is connected to the output terminals 25A and 25B of the charging coil 25, and the output side is connected to the control power capacitor 52 and the power terminals 43 and 43E of the control circuit 4. Note that one power supply terminal 43E of the control circuit 4 is connected to the ground point G of the ignition device unit 6 and has a reference potential. The control power supply regulator 51 rectifies and smoothes the output voltage of the charging coil 25 to obtain a constant control power supply voltage and supplies it to the control circuit 4. The control power supply capacitor 52 accumulates and discharges charges to compensate for the power supply voltage during the time period when the control power supply regulator 51 does not function.

  The general-purpose power supply unit 7 serves as a power supply for the entire motorcycle, and includes a regulator 71 and a battery 72. The input side of the regulator 71 is connected to the general-purpose coil 26, and the output side is connected to the battery 72 and the power supply bus 73. The regulator 71 rectifies and smoothes the output voltage of the general-purpose coil 26 to obtain a constant power supply voltage, charges the battery 72 and supplies power to the electric load in the motorcycle via the power bus 73. The battery 72 supplies power to the control circuit 4 via the constant voltage circuit 74, and the control circuit 4 operates even when the control power supply unit 5 is not functioning. In other words, the battery 72 can use all electric loads even when the engine is stopped.

  In addition, since the rotor 21 rotates and the generator 2 functions after the engine is started, the battery 72 during traveling of the two-wheeled vehicle is not necessary. In other words, the battery 72 can be eliminated if a kick-type starting device is provided to start the engine.

  The control circuit 4 serves not only as the control unit of the fuel injection control device 1 but also as the control unit of the ignition device unit 6, and is configured by incorporating a processing circuit serving as an electrical detection means as described above. Yes. In addition to the angle input terminal 42 to which the electromagnetic pickup 34 is connected and the input terminals 41A and 41B to which the charging coil 25 is connected, the control circuit 4 includes an intake pressure input terminal 44 to which the intake pressure sensor 81 is connected, an engine temperature sensor The temperature input terminal 45 to which 82 is connected is provided. In addition to the ignition command output terminal 46 for controlling the ignition thyristor 63, the control circuit 4 controls the injection command output terminal 47 for controlling the injector nozzle 83 of the fuel injection unit and the idling speed control valve 84 for controlling the idling speed control valve 84. An indicator control terminal 49 for controlling the terminal 48 and the indicator lamp 85 is provided. The control circuit 4 includes a microcomputer and is configured to perform predetermined control by software.

  Next, the operation and action of the fuel injection control device 1 of the embodiment of the present invention configured as described above will be described with reference to FIG. FIG. 3 is a diagram showing electrical signal waveforms at various parts in the embodiment of FIG. The horizontal axis in the figure is a time axis, and shows four strokes of explosion-exhaust-intake-compression, that is, approximately two piston reciprocations. The waveforms are, in order from the top, (1) stroke, (2) no-load output voltage V0 of the charging coil 25, (3) mechanical detection signal M0 of the electromagnetic pickup 34, and (4) mechanical shaping signal M1 obtained by shaping it. (5) Charging voltage VC of ignition capacitor 61 and (6) positive-side electrical shaping signal E1 obtained by shaping the positive-side voltage of charging coil 25, (7) control power supply voltage VD of control power supply unit 5 and (8) charging A negative side electric shaping signal E2 obtained by shaping the negative side voltage of the coil 25, (9) an intake pipe pressure P1 detected by the intake pressure sensor 81, and (10) an injection command signal S1 for controlling the injector nozzle 83.

  In FIG. 3, in the engine operating state, the rotor 21 makes one rotation while the piston makes one reciprocation, so that the 8-pole magnet passes through the charging coil 25 and the AC output voltage V1 for four waveforms is obtained. The AC output voltage V1 of the charging coil 25 is a sinusoidal no-load output voltage V0 shown in FIG. 3 (2) when there is no load, and actually has a slightly distorted waveform. In addition, when the rotor 21 rotates once counterclockwise in FIG. 1, the three protrusions 31 to 33 pass in front of the electromagnetic pickup 34, and (3) mechanical detection signal M0 of positive and negative three pulses is obtained. . When the control circuit 4 shapes the rectangular wave from the positive pulse to the negative pulse, (4) a mechanical shaping signal M1 having three rectangular waves is obtained. Since the time width of the mechanical shaping signal M1 corresponds to the circumferential length of the protrusion, the control unit can detect the end point of the long waveform following the short waveform as the ignition timing immediately before the compression top dead center. it can. Further, the control unit can detect the end point of the isolated short waveform as the measurement timing of the intake pipe pressure at the intake bottom dead center.

  Next, the positive voltage of the output voltage V1 of the charging coil 25 is applied to the ignition capacitor 61 by the action of the rectifier diode 65 in the previous stage. Due to the positive voltage, electric charge is accumulated in the ignition capacitor 61, and the charging voltage VC gradually increases as shown in FIG. Then, the ignition thyristor 63 is conducted at the ignition timing immediately before the compression top dead center, the accumulated charge is discharged as the transient current ID, and the charge voltage VC returns to zero.

  The output voltage V1 of the charging coil 25 is taken in by the wiring branched from the front side of the rectifier diode 65 to the input terminal 41A of the control circuit 4. The processing circuit in the control circuit 4 obtains (6) positive-side electrical shaping signal E1 based on the waveform of the output voltage V1. FIG. 4 is a diagram for explaining electrical detection means for obtaining the positive electrical shaping signal E1 in the embodiment of FIG. As shown in the figure, the processing circuit compares the charging voltage VC1 when the electric charge flows into the ignition capacitor 61 and is charged with the threshold voltage VN, and outputs High when the former is large. It has become. As a result, in the present embodiment, the positive side electrical shaping signal E1 having four rectangular waves is obtained while the rotor 21 makes one revolution. The falling edge of the positive-side electrical shaping signal E1 theoretically coincides with the positive-side peak point of the output voltage V1 of the charging coil 25, but is actually affected by a time lag in a circuit element or the like. Therefore, correction may be performed when the control circuit 4 converts the rotation angle of the crankshaft.

  The control power supply unit 5 uses the negative side voltage of the output voltage V1 of the charging coil 25. In other words, the control power supply regulator 51 functions to supply power to the control circuit 4 and accumulate electric charges in the control power supply capacitor 52 in a time zone in which the no-load output voltage V0 in FIG. When the output voltage V1 is positive, the control power supply regulator 51 does not function, and the control power supply capacitor 52 discharges electric charges to supply power to the control circuit 4. A large capacitance is selected for the control power supply capacitor 52 to such an extent that a voltage drop due to charge discharge is not hindered. Therefore, the control power supply voltage VD has a sawtooth waveform as shown in FIG.

  Further, the internal voltage VD1 is taken in by the wiring branched from the inside of the control power supply regulator 51 to the input terminal 41B of the control circuit 4. The processing circuit in the control circuit 4 obtains (8) the negative electrical shaping signal E2 based on the waveform of the internal voltage VD1. FIG. 5 is a diagram for explaining electrical detection means for obtaining the negative electrical shaping signal E2 in the embodiment of FIG. As shown in the figure, the processing circuit compares the internal voltage VD1 with the threshold voltage VM, and outputs High when the former is large. As a result, in this embodiment, the negative electrical shaping signal E2 having four rectangular waves is obtained while the rotor 21 makes one rotation. The negative side electrical shaping signal E2 is generated on the negative side of the output voltage V1 of the charging coil 25.

  Next, a method for controlling the fuel injection unit by the control circuit 4 will be described. In the control unit of the control circuit 4, the rotor is based on the mechanical shaping signal M1 composed of three rectangular waves, and the positive electrical shaping signal E1 and the negative electrical shaping signal E2 each composed of four rectangular waves. 21, that is, the rotation angle of the crankshaft is obtained with high accuracy. Further, the rotational speed and rotational acceleration are obtained by calculation from the relationship between the rotational angle and the elapsed time. Further, the information of the intake pressure sensor 81 at the intake bottom dead center is read based on the mechanical shaping signal M1, and the intake detection pressure Pin correlated with the intake air amount is obtained from the intake pipe pressure P1. Further, the engine temperature is obtained from the information of the engine temperature sensor 82. Then, taking these various quantities into consideration, the timing for turning on and off the injection command signal S1 is determined and sent to the injector nozzle 83 so as to be able to inject an appropriate amount of fuel just in time for the intake stroke. is doing. Although many inventions have been made regarding the determination of the fuel injection timing and will not be described in detail here, in the example of FIG. 3 (10), the injection command signal S1 is sent from a short time before the intake stroke starts to the middle of the intake stroke. Yes.

  The control circuit 4 sends an ignition command to the ignition thyristor 63 of the ignition device unit as described above, transmits a control command to the idling speed control valve 84, and is operating or abnormal to the indicator lamp 85. Information such as presence / absence is sent.

  As described above, the fuel injection control device 1 of the present embodiment detects the rotation angle of the rotor 21 by using the mechanical detection means using the conventional crank angle sensor 3 together with the electrical detection means. Yes. In the present embodiment, three mechanically detected rectangular waves and four positive and negative four total detected electrically detected rectangular waves are obtained, which requires 8 to 24 protrusions. Detection can be performed with the same accuracy as a crank angle sensor. Therefore, according to the present embodiment, the number of protrusions can be reduced, and the cost can be reduced accordingly.

It is a circuit diagram explaining the fuel-injection control apparatus of the Example of this invention. It is a figure explaining the stator of a generator in the Example of FIG. It is a figure which shows the electrical signal waveform of each part in the Example of FIG. It is a figure explaining the electrical detection means which calculates | requires a positive side electrical shaping signal in the Example of FIG. It is a figure explaining the electrical detection means which calculates | requires a negative side electrical shaping signal in the Example of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Fuel-injection control apparatus 2: Generator 21: Rotor 23: Stator 25: Charging coil 26: General-purpose coil 3: Crank angle sensor 31-33: Protrusion part 34: Electromagnetic pick-up 4: Control circuit (electric detection means and control) Part)
41A, 41B: Input terminal 42: Angle input terminal 44: Intake pressure input terminal 45: Temperature input terminal 47: Injection command output terminal 5: Control power supply unit 51: Control power supply regulator 52: Control power supply capacitor 6: Ignition device part 7: General-purpose power source 71: Regulator 72: Battery 74: Constant voltage circuit 81: Intake pressure sensor 82: Engine temperature sensor 83: Injector nozzle

Claims (8)

A generator comprising a rotor rotating with a crankshaft of an internal combustion engine and having a magnet, and a stator having a coil;
Mechanical detection means for mechanically detecting the rotation angle of the rotor;
Electrical detection means for electrically detecting the rotation angle of the rotor by shaping the output voltage waveform of the coil;
A control unit that controls a fuel injection unit that supplies fuel to the internal combustion engine based on information on the rotation angle of the rotor detected by the mechanical detection unit and the electrical detection unit;
A fuel injection control device comprising:   2. The fuel injection control device according to claim 1, wherein the electrical detection unit compares the output voltage of the coil with a constant threshold voltage and shapes the output voltage into a rectangular wave.   The fuel injection control device according to claim 2, wherein the threshold voltage of the electrical detection means is provided on each of a positive side and a negative side of the output voltage of the coil.   The said mechanical detection means has a to-be-detected part provided in the circumferential direction of the said rotor, and a detection sensor fixed apart from this rotor and detecting the passage of this to-be-detected part. The fuel injection control device according to any one of the above.   The detected portion of the mechanical detection means includes at least a protrusion that displays an intake bottom dead center and a compression top dead center of the internal combustion engine, and the detection sensor detects an electromagnetic pickup that detects passage of the protrusion. The fuel injection control device according to claim 4, wherein the fuel injection control device is a sensor.   The coil of the generator is a charging coil that charges an ignition capacitor of a capacitor discharge ignition device of the internal combustion engine, and the control unit also controls the discharge timing of the ignition capacitor. A fuel injection control device according to claim 1.   The fuel injection control device according to claim 6, wherein either one of positive and negative of the AC output of the charging coil is used for charging the ignition capacitor, and the other is used for a power source of the control unit.   The said internal combustion engine is a single cylinder engine mounted in a two-wheeled vehicle, and one of the said coils provided in two or more by the said generator is connected to the said electrical detection means. Fuel injection control device.

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