JP2005147016A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce loss generated in a switch element of a constant voltage power supply circuit which provides a microprocessor controlling an engine with power supply voltage at high engine speed. <P>SOLUTION: A rectifying circuit 2 for rectifying output of a magnet-type alternating-current generator 1 is constituted by a hybrid bridge circuit of a diode D1 or D3 and a thyristor Th. Output voltage Vin of the rectifying circuit 2 is inputted into the constant voltage power supply circuit 4 to be converted into constant voltage Vout, and the voltage Vout is given to the microprocessor 5A as power supply voltage. When the engine speed is below set engine speed, the thyristor Th is turned to be ON, and by making the rectifying circuit 2 perform full-wave rectifying operation, shortage of power supply voltage at low engine speed is prevented. When the engine speed exceeds the set engine speed, the thyristor Th is turned to be OFF, and by making the rectifying circuit 2 perform half-wave rectifying operation, voltage inputted into the constant voltage power supply circuit 4 is lowered to reduce the loss generated in a transistor TR1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device for an internal combustion engine that controls accessory devices of the internal combustion engine such as a throttle valve, an ignition device, and a fuel injection device.

  In a control device such as a rotational speed control device (electronic governor) that controls the rotational speed for an internal combustion engine to maintain the indicated value, or an ignition timing control device that controls the ignition timing of the engine, a controller having a microprocessor is provided. It is used to perform arithmetic processing necessary for control. For example, in an electronic governor, a voltage signal obtained from a potentiometer to which a constant voltage is applied at both ends is used as a speed instruction signal for instructing a target rotation speed, and this speed instruction signal and a signal obtained from a speed sensor are Input to the processor. Then, the difference between the rotational speed of the engine detected from the output of the speed sensor and the target rotational speed given by the speed instruction signal is calculated, and the amount of operation of the throttle valve necessary to make the calculated deviation zero is calculated. The rotation speed of the internal combustion engine is made to coincide with the indicated rotation speed by applying a drive current to the actuator that operates the throttle valve so that the throttle valve is displaced by the calculated operation amount.

In this type of internal combustion engine control device, a diode bridge that rectifies the single-phase AC output of a magnet-type AC generator driven by the internal-combustion engine when the power source for a microprocessor, sensor, etc. is obtained from the magnet-type AC generator A full-wave rectifier circuit and a constant-voltage power supply circuit that converts the output of the full-wave rectifier circuit into a constant DC voltage are provided to supply a power supply voltage from the constant-voltage power supply circuit to a microprocessor or the like. Thus, as a control device for an internal combustion engine that applies a power supply voltage to a microprocessor or the like by the output of a magnet generator driven by the internal combustion engine, for example, the one disclosed in Patent Document 1 (fuel injection for an internal combustion engine) Device).
When the output of the full-wave rectifier circuit that rectifies the single-phase AC output of the magnet type AC generator driven by the internal combustion engine is input to the constant voltage power supply circuit, and the power supply voltage is supplied from the constant voltage power supply circuit to the microprocessor, As shown in FIG. 6, the voltage Vin input from the full-wave rectifier circuit to the constant voltage power supply circuit increases in proportion to the increase in the rotational speed N of the internal combustion engine. For example, the constant voltage power supply circuit is controlled to be turned on when the voltage input from the full-wave rectifier circuit is equal to or lower than the set value Vs and to be turned off when the input voltage exceeds the set value Vs. A voltage control switch element such as a transistor is provided, and the output voltage Vout is controlled to be kept at the set value Vs by turning on and off the voltage control switch element. In this case, the rotation speed region where the constant voltage power supply circuit can output a voltage equal to the set value Vs is a region where the output voltage of the full-wave rectifier circuit is equal to or higher than the operation start rotation speed N1 where the output voltage is equal to or higher than the set value Vs. Therefore, a region where the rotational speed is N1 or more is a controllable region where control by the microprocessor is possible.
Japanese Unexamined Patent Publication No. Hei 4-231643

In general, the loss generated in the voltage control switch element of the constant voltage power supply circuit increases as the voltage input to the constant voltage power supply circuit increases. In the conventional internal combustion engine control device, the full-wave rectified output of the magnet type AC generator is input to the constant voltage power supply circuit and converted into a constant DC voltage from the low speed to the high speed of the engine. Loss generated in the voltage control switch element during high-speed rotation of the switch increases, and it is inevitable that heat is generated in the switch element. Therefore, it is necessary to use an expensive element having a large loss rating as a voltage control switching element provided in the constant voltage power supply circuit, and it is inevitable that the cost is increased. In addition, since it is necessary to attach a heat sink having a large heat radiation fin to the voltage control switch element, there is also a problem that the portion of the constant voltage power supply circuit becomes large.
Although a half-wave rectifier circuit may be used as a rectifier circuit that rectifies the output of the magnet type AC generator, when the half-wave rectifier circuit is used, the input voltage of the constant voltage power supply circuit is Vin ′ in FIG. Thus, since the rotational speed reaching the set value Vs is increased, the lower limit rotational speed N1 'of the controllable region in FIG. 6 is increased, and there is a problem that control by the microprocessor cannot be performed at a low engine speed. .

  An object of the present invention is to provide a voltage control switch for a constant-voltage power supply circuit while sufficiently reducing a rotation speed at which the operation of the microprocessor is started and preventing a rotation speed region that can be controlled by the microprocessor from being narrowed. It is an object of the present invention to provide a control device for an internal combustion engine in which an inexpensive element having a small loss rating can be used and a heat sink attached to a voltage control switch element can be reduced in size.

  The present invention relates to a rectifier circuit that rectifies the AC output of a magnet type AC generator driven by an internal combustion engine, a constant voltage power supply circuit that converts the output of the rectifier circuit into a constant DC voltage, and the constant voltage power supply circuit. The present invention is directed to a control device for an internal combustion engine that includes a controller that is in an operating state by being supplied with a power supply voltage and controls equipment attached to the internal combustion engine.

  In the present invention, the rectifier circuit includes a mixed bridge circuit in which at least one of a pair of lower sides of the H bridge is configured by a switch element capable of on / off control, and the other side is configured by a diode. It can be switched to a full-wave rectifier circuit and a half-wave rectifier circuit by turning on and off.

  In the present invention, the controller also includes a rotation speed detection means for detecting the rotation speed of the internal combustion engine from the output of the magnet type AC generator, and a mixture when the rotation speed detected by the rotation speed detection means is equal to or lower than the set rotation speed. Rectification operation that controls the switching element according to the rotation speed so that the bridge circuit operates as a full-wave rectification circuit and the mixed bridge circuit operates as a half-wave rectification circuit when the detected rotation speed exceeds the set rotation speed Switching control means is provided.

  As described above, the rectifier circuit that rectifies the output of the magnet type AC generator is configured by the mixed bridge circuit that can be switched between the full-wave rectifier circuit and the half-wave rectifier circuit, and the rotation speed is equal to or lower than the set rotation speed. When the mixing bridge circuit is sometimes operated as a full-wave rectification circuit, and a rectification operation switching control means for switching the mixing bridge circuit from the full-wave rectification circuit to the half-wave rectification circuit when the rotation speed exceeds the set rotation speed is provided. The rotation speed at which the rectifier circuit starts outputting a voltage higher than the set value at a low engine speed can be lowered, and the rotation speed at which the microprocessor starts to operate can be lowered. Also, in the region where the engine rotation speed exceeds the set rotation speed, the rectifier circuit can be operated as a half-wave rectifier circuit, and the voltage input to the constant voltage power supply circuit can be made lower than the conventional one. Loss generated in the voltage control switch element of the constant voltage power supply circuit can be reduced, and heat generation from the switch element can be suppressed.

  In a preferred aspect of the present invention, the rectifier circuit includes the first and second diodes whose cathodes are commonly connected to the positive output terminal, the cathode connected to the anode of the first diode, and the anode to the negative output terminal. And a thyristor having a cathode connected to the anode of the second diode and an anode connected to the negative output terminal.

  In this case, the rectifying operation switching control means provided in the controller detects the rotational speed detected by the rotational speed detecting means and turns on the thyristor to operate the mixed bridge circuit as a full-wave rectifying circuit when the rotational speed detected is equal to or lower than the set rotational speed. The thyristor is controlled in accordance with the rotational speed so that the mixed bridge circuit is operated as a half-wave rectifier circuit while keeping the thyristor in the off state when the rotational speed exceeds the set rotational speed.

  In another preferred aspect of the present invention, the rectifier circuit includes the first and second diodes whose cathodes are commonly connected to the positive output terminal, the cathode connected to the anode of the first diode, and the negative output terminal. And a third bridge having an anode connected thereto, and a MOSFET having a drain connected to the anode of the second diode and a source connected to the negative output terminal.

  In this case, the rectification operation switching control means provided in the controller detects the rotation speed detected by the rotation speed detection means below the set rotation speed, turns off the MOSFET and operates the mixed bridge circuit as a full-wave rectification circuit, and detects it. The MOSFET is controlled according to the rotational speed so that the mixed bridge circuit operates as a half-wave rectifier circuit while keeping the MOSFET on when the rotational speed exceeds the set rotational speed.

  In another preferred aspect of the present invention, the rectifier circuit includes the first and second diodes whose cathodes are commonly connected to the positive output terminal, the cathode connected to the anode of the first diode, and the negative output terminal. And a second thyristor having a cathode connected to the anode of the second diode and an anode connected to the negative output terminal.

  In this case, the rectifying operation switching control means provided in the controller turns on both the first thyristor and the second thyristor when the rotational speed detected by the rotational speed detecting means is equal to or lower than the first set rotational speed. The mixed bridge circuit is operated as a full-wave rectifier circuit, and one of the first thyristor and the second thyristor when the detected rotation speed exceeds the first set rotation speed and less than the second set rotation speed, and The mixed bridge circuit is operated as a half-wave rectifier circuit with the other turned on and off, respectively. When the detected rotational speed exceeds the second set rotational speed, the first thyristor and the second thyristor A state in which one and the other are turned on and off, and a state in which both the first thyristor and the second thyristor are turned off. DOO controlling the first and second thyristor in accordance with the rotational speed to produce alternately.

  When configured in this manner, the output voltage of the generator can be rectified by decimating the output voltage during high-speed rotation of the engine, so that the voltage input to the constant voltage power circuit during the high-speed rotation of the engine can be further reduced to control the voltage. The loss generated in the switch element can be further reduced.

As described above, according to the present invention, the rectifier circuit that rectifies the output of the magnet type AC generator is configured by the mixed bridge circuit that can be switched between the full-wave rectifier circuit and the half-wave rectifier circuit, and the rotational speed Rectification operation switching control to operate the mixed bridge circuit as a full-wave rectifier circuit when is below the set rotational speed, and to switch the mixed bridge circuit from the full-wave rectifier circuit to the half-wave rectifier circuit when the rotational speed exceeds the set rotational speed Since the means is provided, the rotation speed at which the rectifier circuit starts to output a voltage higher than the set value can be lowered at the low speed of the engine, and the rotation speed at which the microprocessor starts to operate can be lowered. In the region where the speed exceeds the set rotational speed, the voltage input to the constant voltage power supply circuit is set lower than before, and the voltage control switch of the constant voltage power supply circuit is rotated at high engine speed. It is possible to reduce the loss caused by the pitch element.
Therefore, it is possible to use an inexpensive switch element in the constant voltage power supply circuit without narrowing the rotation speed region that can be controlled by the microprocessor, thereby reducing the cost and reducing the heat sink attached to the switch element. Thus, there is an advantage that the apparatus can be miniaturized.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a first embodiment of the present invention, in which 1 is a magnetic AC generator driven by an internal combustion engine, and 2 is a rectifier for a single-phase AC output of the generator 1. A rectifier circuit, 3 is a power supply capacitor connected between the output terminals of the rectifier circuit, 4 is a constant voltage power supply circuit that converts the output voltage of the rectifier circuit 2 into a constant DC voltage, and 5 is a power supply voltage from the constant voltage power supply circuit 4 It is a controller that controls an apparatus attached to the internal combustion engine when it is given an operating state.

  More specifically, the rectifier circuit 2 is constituted by a mixed bridge circuit in which at least one of the lower sides of the pair of H bridges is constituted by a switch element and the other side is constituted by a diode. In the illustrated example, the cathode is connected to the anode of the first diode D1 and the anode connected to the anode of the first diode D1, and the anode is connected to the anode of the negative output terminal 2b. The rectifier circuit 2 includes a third bridge D3 and a thyristor Th (switch element) having a cathode connected to the anode of the second diode D2 and an anode connected to the negative output terminal 2b. The input terminals 2u and 2v of the rectifier circuit 2 are connected to one end 1a1 and the other end 1a2 of the power generation coil 1a of the magnet type AC generator 1, respectively. The negative output terminal 2b of the rectifier circuit 2 is grounded, and the power supply capacitor 3 is connected between the positive output terminal 2a and the ground. This rectifier circuit operates as a full-wave rectifier circuit when the thyristor Th is turned on, and operates as a half-wave rectifier circuit when the thyristor Th is turned off.

  The constant voltage power circuit 4 includes an NPN transistor TR1 as a voltage control switch having a collector connected to the non-ground side terminal of the power supply capacitor 3, a resistor R1 connected between the collector base of the transistor TR1, and a transistor TR1. It has a Zener diode ZD1 connected between the base and the ground with the anode facing the ground side, and a capacitor C1 connected between the emitter of the transistor TR1 and the ground, and the positive side from the non-ground side terminal of the capacitor C1 The output terminal 4a is derived.

  In this constant voltage circuit, the transistor TR1 is turned on when the output voltage Vout obtained across the capacitor C1 is lower than the set value Vs determined by the sum of the voltage drop by the resistor R1 and the Zener voltage of the Zener diode ZD1. The output voltage of the rectifier circuit 2 is applied to the capacitor C1, and when the output voltage Vout becomes higher than the set value Vs, the transistor TR1 is turned off and the capacitor C1 is disconnected from the rectifier circuit 2. Accordingly, the output voltage Vout obtained across the capacitor C1 is kept at the set value Vs. The set value Vs is set to a voltage suitable for driving the controller 5 (for example, 5 [V]).

  The controller 5 includes a microprocessor 5A, a speed detection signal generation circuit 5B that outputs a speed detection signal having a frequency proportional to the rotational speed of the engine with the output of the generator 1 as an input, and a switch drive circuit 5C. The microprocessor 5A has a power supply terminal 5a and a ground terminal 5b, and the output voltage Vout of the constant voltage power supply circuit 4 is applied between the power supply terminal 5a and the ground terminal 5b.

  The illustrated speed detection signal generation circuit 5B includes an NPN transistor TR2 whose emitter is grounded, a resistor R2 having one end connected to the base of the transistor TR2, a cathode connected to the other end of the resistor R2, and an anode generating power. The diode D5 is connected to the other end 1a2 of the coil 1a, and the collector of the transistor TR2 (the output terminal of the rotation speed detecting means) is connected to the port A1 of the microprocessor 5A. The output voltage Vout of the constant voltage power supply circuit 4 is applied to the port A1 through the pull-up resistor R3.

  In the speed detection signal generating circuit 5B, the transistor TR2 is turned on while the negative half-wave voltage of the AC voltage Ve (see FIG. 5A) generated by the power generating coil 1a exceeds the threshold value. During the period when the potential is L level (low level) and the negative half-wave voltage of the AC voltage Ve is less than the threshold and during the positive half-wave period of the AC voltage Ve, the transistor TR2 is kept off. Therefore, the potential of the collector is kept at the H level (high level). Therefore, the speed detection signal generation circuit 5B generates a rectangular wave-shaped speed detection signal Vn as shown in FIG.

  The microprocessor 5A interrupts the program at the rise or fall of the speed detection signal to detect the speed detection signal generation interval, and calculates the engine speed from the detected speed detection signal generation interval. The rotation speed calculation means is constituted by the process of calculating the rotation speed by the microprocessor, and the rotation speed detection means is constituted by the rotation speed calculation means and the speed detection signal generation circuit 5B.

  The switch drive circuit 5C is a circuit that gives a trigger signal to the thyristor Th when a switch-on command is generated from the microprocessor 5A. The resistor R4, one end of which is connected to the positive output terminal 2a of the rectifier circuit 2, and the resistor Connected between diodes D6 and D7 whose anode is connected to the other end of R4, NPN transistor TR3 whose collector is connected to the anode of diode D6 and whose emitter is grounded, and between the cathode of diode D7 and the gate of thyristor Th. And a resistor R6 connected between the base of the transistor TR3 and the port A2 of the microprocessor 5A.

  The controller 5 causes the microprocessor 5A to execute a predetermined program, in addition to the rotation speed calculation means, an ignition timing control means for controlling the ignition timing of the internal combustion engine with respect to the detected rotation speed, Various controls, such as a fuel injection control means for controlling the fuel injection amount with respect to various control conditions such as the throttle valve opening, and a rotational speed control means for controlling the throttle valve so as to keep the engine rotational speed at the indicated rotational speed. Configure the means as needed.

  In the present invention, the rotational speed N detected by the rotational speed detecting means is further set to the set rotational speed Ns1 in addition to the control means conventionally provided such as the ignition timing control means, the fuel injection control means, and the rotational speed control means. A switch on / off command is issued from the port A2 to the switch drive circuit 5C at the following times, and a switch off command is given from the port A2 to the switch drive circuit 5C when the detected rotational speed exceeds the set rotational speed Ns1. The means is constituted by a microprocessor 5A. Then, by this switch on / off command generation means and the switch drive circuit 5C, the full-wave rectification of the mixed bridge circuit constituting the rectifier circuit 2 when the rotational speed N detected by the rotational speed detecting means is less than or equal to the set rotational speed Ns1. Rectification that controls the thyristor Th (switch element) according to the rotational speed N so that the mixed bridge circuit operates as a half-wave rectifier circuit when operated as a circuit and the detected rotational speed exceeds the set rotational speed Ns1. An operation switching control means is configured.

  FIG. 7 shows a flowchart showing an algorithm of a task to be executed by the microprocessor in order to constitute the switch on / off command generating means. The task in FIG. 7 is executed at regular time intervals (for example, 80 [msec]). When this task is started, first, the rotational speed N calculated in another task and stored in the RAM is read in step 1, and whether the rotational speed N read in step 2 is equal to or lower than the set rotational speed Ns1. Determine. As a result, if the rotational speed N is equal to or lower than the set rotational speed Ns1, a switch-on command is generated by setting the potential of the port A2 to L level (low level) in step 3, and this task is terminated. If it is determined in step 2 that the rotational speed N is not less than or equal to the set rotational speed Ns1 (exceeds the set rotational speed), the process proceeds to step 4 to switch the port A2 potential to H level (high level). Generates an off command and ends this task.

  In the embodiment shown in FIG. 1, when the internal combustion engine rotates, the magnet type AC generator 1 generates an AC voltage Ve as shown in FIG. 5A, and the waveform shown in FIG. 5B from the rectifier circuit 2. Is output. The waveform indicated by the broken line in FIG. 5B is the voltage across the power supply capacitor 3, and this voltage is applied to the constant voltage power supply circuit 4 as the input voltage Vin. When the rotation speed is equal to or lower than the set rotation speed Ns1, the microprocessor sets the potential of the port A2 to the L level and generates a switch-on command, so that the transistor TR3 of the switch drive circuit 5C holds the off state. In this state, a trigger signal is applied to the thyristor Th from the power supply capacitor 3 through the diode D7 and the resistor R5, so that the thyristor Th is turned on when a forward voltage is applied between its anode and cathode. At this time, the rectifier circuit 2 operates as a full-wave rectifier circuit, and a voltage having a waveform obtained by full-wave rectifying the generator output voltage Ve as shown in the region from time t1 to t2 shown at the left end of FIG. Output from the rectifier circuit 2. Therefore, when the engine rotates at a low speed, the input voltage Vin of the constant voltage power supply circuit 4 reaches the set value Vs when the rotation speed N reaches the operation start rotation speed N1, as shown by the curve b in FIG. A DC voltage Vout having a set value Vs is output from the power supply circuit 4, and the microprocessor 5A enters an operating state. Accordingly, various controls by the microprocessor can be performed even at a low engine speed.

  When the rotational speed of the engine exceeds the set rotational speed Ns1, the microprocessor sets the potential of the port A2 to H level and generates a switch-off command. At this time, since the transistor TR3 is turned on, the trigger signal applied to the thyristor Th is bypassed from the thyristor Th through the diode D6 and the transistor TR3. Therefore, the thyristor Th cannot be turned on. At this time, since the rectifier circuit 2 operates as a half-wave rectifier circuit, the input voltage Vin of the constant voltage power supply circuit decreases as shown by a curve b shown in FIG. The Vin vs. N characteristic indicated by the straight line a in FIG. 2 is the same as the Vin vs. N characteristic indicated by the solid line in FIG.

When the transistor TR1 is used as the voltage control switch element of the constant voltage power supply circuit 4 as in the illustrated example, the loss Pd generated in the transistor is the collector current ic and the collector-emitter voltage Vce (= Vin−Vout). Is given by the following equation.
Pd = Vce × ic
= (Vin−Vout) × ic (1)

  Therefore, when the input voltage Vin of the constant voltage power supply circuit rises in proportion to the rotational speed of the engine as shown by the straight line a in FIG. 6, the loss generated in the transistor TR1 increases at the high speed of the engine. The fever increases. On the other hand, in the embodiment shown in FIG. 1, by turning off the thyristor Th in a region where the rotational speed exceeds the set rotational speed Ns1, the rectifier circuit 2 is operated as a half-wave rectifier circuit, and the constant voltage power supply Since the input voltage Vin of the circuit is lowered, the loss generated in the transistor TR1 at the time of high engine speed can be reduced, and the heat generated from the transistor can be reduced.

  As described above, according to the present invention, since the rectifier circuit 2 is operated as a full-wave rectifier circuit at a low engine speed, the rotational speed N1 at which the rectifier circuit 2 starts outputting a voltage higher than the set value Vs is reduced. The rotational speed at which the microprocessor 5A starts operating can be lowered. Further, in the region where the engine rotational speed N exceeds the set rotational speed Ns1, the rectifier circuit 2 can be operated as a half-wave rectifier circuit so that the voltage Vin input to the constant voltage power circuit 4 can be made lower than before. Loss generated in the voltage control switch element of the constant voltage power circuit during high-speed rotation of the engine can be reduced, and heat generation from the switch element can be suppressed.

  FIG. 3 shows a second embodiment of the present invention. In the embodiment of FIG. 1, the thyristor Th is used as a switch element provided in the rectifier circuit. However, in the embodiment shown in FIG. 3, a MOSFET F1 is used as the switch element instead of the thyristor. That is, in this embodiment, the cathode is connected to the anode of the first diode D1 and the anode connected to the anode of the first diode D1, and the anode connected to the anode of the first output terminal 2b. The rectifier circuit 2 is constituted by a mixed bridge circuit composed of a third diode D3 connected to the MOSFET F1 and a MOSFET F1 whose drain is connected to the anode of the second diode D2 and whose source is connected to the negative output terminal 2b. ing. A parasitic diode D4 is formed between the drain and source of the MOSFET F1.

  In this rectifier circuit, when the MOSFET F1 is in the OFF state, the diodes D1 to D3 and the parasitic diode D4 of the MOSFET constitute a full-wave rectifier circuit. When the MOSFET is on, the other end 1a2 of the power generation coil 1a is grounded, so that the rectifier circuit 2 operates as a half-wave rectifier circuit.

  The switch driving circuit 5C has an emitter connected to the ground, an NPN transistor TR3 whose base is connected to the port A2 of the microprocessor through a resistor R6, an emitter connected to the positive output terminal 2a of the rectifier circuit 2, and a base which is a resistor. The transistor TR4 is connected to the collector of the transistor TR3 through the resistor R7, and the resistor R8 is connected between the collector of the transistor TR4 and the gate of the MOSFET. In this switch drive circuit, when the potential at the port A2 of the microcomputer is set to the H level and the transistor TR3 is turned on, the transistor TR4 is turned on to give a drive signal to the MOSFET F1, and the potential at the port A2 When the transistor TR3 is turned off and the transistor TR3 is turned off, the transistor TR4 is turned off and the supply of the drive signal to the MOSFET is stopped.

  As in the embodiment shown in FIG. 1, the controller 5 includes a rotational speed detection means for detecting the rotational speed from the speed detection signal Vn output from the speed detection signal generation circuit 5B. The controller 5 also generates a switch-off command by setting the potential of the port A2 to L level when the rotational speed detected by the rotational speed detection means is equal to or lower than the set rotational speed, and when the rotational speed exceeds the set rotational speed. And a switch on / off command generating means for generating a switch on command by setting the potential of the port A2 to the H level. By this switch on / off command generating means and the switch drive circuit 5C, the MOSFET is operated when the rotational speed is lower than the set rotational speed. The mixed bridge circuit is operated as a full-wave rectifier circuit in an off state, and when the detected rotational speed exceeds the set rotational speed, the MOSFET is kept on and the mixed bridge circuit is operated as a half-wave rectifier circuit. Thus, the rectifying operation switching control means for controlling the MOSFET according to the rotational speed is configured.

  FIG. 8 is a flowchart showing an example of a task algorithm executed by the microprocessor in order to constitute the switch on / off command generating means. The flow chart shown in FIG. 8 corresponds to a case where Step 3 and Step 4 in FIG. 7 are interchanged.

  In the embodiment shown in FIG. 3, since the other end 1a2 of the generator coil 1a is grounded through the MOSFET F1 in the region where the rotational speed exceeds the set rotational speed Ns1, a speed detection signal is generated even in the region where the rotational speed is higher than the set rotational speed. For this purpose, the anode of the diode D5 of the speed detection signal generating circuit 5B is connected to one end 1a1 of the power generation coil 1a. In this case, the waveform of the speed detection signal Vn is a waveform obtained by inverting the waveform shown in FIG. The other configuration of the embodiment shown in FIG. 3 is the same as that of the embodiment shown in FIG.

  FIG. 4 shows a third embodiment of the present invention. In this embodiment, the first and second diodes D1 and D2 whose cathodes are commonly connected to the positive output terminal 2a, and the first diode are shown. The first thyristor Th1 has a cathode connected to the anode of D1, and the anode is connected to the negative output terminal 2b. The cathode is connected to the anode of the second diode D2, and the anode is connected to the negative output terminal 2b. The rectifier circuit 2 is composed of a mixed bridge circuit including the second thyristor Th2.

  The switch drive circuit 5C includes a circuit that drives the first thyristor Th1 and a circuit that drives the second thyristor Th2. A circuit for driving the first thyristor Th1 includes a resistor R41 having one end connected to the positive output terminal 2a of the rectifier circuit 2, diodes D61 and D71 having an anode connected to the other end of the resistor R41, a diode NPN transistor TR31 whose collector is connected to the cathode of D61 and whose emitter is grounded, resistor R51 connected between the cathode of diode D71 and the gate of thyristor Th1, the base of transistor TR31 and the port of microprocessor 5A It consists of a resistor R61 connected between A2. The circuit for driving the second thyristor Th2 includes a resistor R42 having one end connected to the positive output terminal 2a of the rectifier circuit 2, diodes D62 and D72 having an anode connected to the other end of the resistor R42, An NPN transistor TR32 whose collector is connected to the cathode of the diode D62 and whose emitter is grounded, a resistor R52 connected between the cathode of the diode D72 and the gate of the thyristor Th2, the base of the transistor TR32, and the microprocessor 5A It comprises a resistor R62 connected between the port A3. The operation of the circuit for driving the first thyristor Th1 and the circuit for driving the second thyristor Th2 are the same as the operation of the switch drive circuit 5C shown in FIG. That is, when the transistor TR61 is in the off state and when the transistor TR62 is in the off state, a trigger signal is given to the thyristors Th1 and Th2, respectively, and when the transistor TR61 is in the on state and when the transistor TR62 is in the on state. The supply of trigger signals to the thyristors Th1 and Th2 is stopped.

  As in the embodiment shown in FIG. 1, the controller 5 is provided with a rotational speed detecting means for detecting the rotational speed from the speed detection signal Vn output from the speed detection signal generating circuit 5B. The controller 5 also instructs an ON command to turn on the first thyristor Th1 and the second thyristor Th2 when the rotational speed detected by the rotational speed detection means is equal to or lower than the first set rotational speed Ns1. When the rotation speed exceeds the first set rotation speed Ns2 and is less than the second set rotation speed Ns2 (> Ns1), one of the first thyristor Th1 and the second thyristor Th2 is turned on. When an on command to turn on and an off command to turn the other off are generated and the rotation speed exceeds the second set rotation speed Ns2, one of the first thyristor Th1 and the second thyristor Th2 is turned on. A state in which an on command to turn on and an off command to turn off the other are generated for a predetermined period, and a turn off command to turn off both the first thyristor Th1 and the second thyristor Th2. A switch on / off command generating means for alternately generating a period state is provided, and the switch on / off command generating means and the switch drive circuit 5C are used to switch the first speed when the rotational speed is equal to or lower than the first set rotational speed Ns1. Both the first thyristor Th1 and the second thyristor Th2 are turned on to operate the mixed bridge circuit constituting the rectifier circuit 2 as a full-wave rectifier circuit, and the detected rotational speed exceeds the first set rotational speed Ns2. When the rotation speed is less than the second set rotational speed Ns2 (> Ns1), one of the first thyristor Th1 and the second thyristor Th2 is turned on and the other is turned off to operate the mixed bridge circuit as a half-wave rectifier circuit. When the detected rotational speed exceeds the second set rotational speed Ns2, one of the first thyristor Th1 and the second thyristor Th2 is turned on. The first state is changed according to the rotational speed so as to alternately generate a state in which the other is turned off for a predetermined period and a state in which both the first thyristor Th1 and the second thyristor Th2 are turned off for a predetermined period. And rectification operation switching control means for controlling the second thyristor.

  FIG. 9 is a flowchart showing an example of a task algorithm executed by the microprocessor at a minute time interval in order to constitute the switch on / off command generating means. In the case of this algorithm, the rotational speed N is read in step 1, and the rotational speed N is compared with the first set rotational speed Ns1 in step 2. As a result, when N.ltoreq.Ns1, a first switch-on command is issued to instruct to turn on the first thyristor Th1 by setting the potential of the port A2 to L level in step 3, and in step 4, the port A3. Is set to the L level, a second switch-on command is issued to command the second thyristor Th2 to be turned on.

  If it is determined in step 2 that N ≦ Ns1 is not satisfied (N> Ns1), the process proceeds to step 5 where the rotational speed N is compared with the second set rotational speed Ns2. As a result, when N.ltoreq.Ns2, a first switch-off command is issued in step 6 to instruct to turn off the first thyristor Th1 by setting the potential of the port A2 to H level, and in step 7, the port A3. To generate a second switch-on command for commanding the second thyristor Th2 to be in an ON state.

  When it is determined in step 5 that N ≦ Ns2 is not satisfied (when it is determined that N> Ns2), in step 8, the speed detection signal Vn falls (a negative half wave of the generator output voltage Ve). Is detected, and if so, the process proceeds to step 9 to determine whether the flag is 0 or not. Since the flag is initially 0, the process proceeds to step 10 to generate a first switch-off command for commanding to turn off the first thyristor Th1 by setting the potential of the port A2 to the H level. Then, the second switch-off command is issued to command the second thyristor Th2 to be turned off by setting the potential of the port A3 to the H level. Thereafter, in step 12, the flag is set to 1 and this task is terminated. If it is determined in step 8 that the falling edge of the speed detection signal has not been detected (rising edge has been detected), this task is terminated without doing anything thereafter. If it is determined in step 8 that the falling of the speed detection signal Vn is detected, and it is determined in step 9 that the flag is not 0 (1), the process proceeds to step 13 to generate a first switch-on command. In step 14, a second switch-off command is generated. Thereafter, in step 15, the flag is set to 0 and this task is terminated.

  When the switch on / off command generating means is configured as shown in FIG. 9, when the rotational speed N exceeds the first set rotational speed Ns1 at time t2 shown in FIG. Since the first switch-off command and the second switch-on command are generated, the first thyristor Th1 is turned off and the second thyristor Th2 is turned on. Accordingly, a positive half-wave voltage output from the power generation coil 1 a is output through the rectifier circuit 2. Further, after the rotation speed N exceeds the second set rotation speed Ns2 at time t3, when the rising of the negative half wave of the output voltage of the power generation coil 1a is detected from the level change of the speed detection signal Vn, FIG. Since steps 10 and 11 are executed to generate the first switch-off command and the second switch-off command, both the first thyristor Th1 and the second thyristor Th2 are turned off, and the rectifier circuit 2 outputs an output. Stop. Thereafter, when the rising of the negative half-wave of the output voltage of the power generating coil 1a is detected again, steps 13 and 14 in FIG. 9 are executed to generate the first switch-on command and the second switch-off command. One thyristor is turned on, and the second thyristor Th2 is turned off. In this state, the negative half-wave voltage of the output of the power generation coil 1 a is output through the rectifier circuit 2.

When the above control is performed, the region from time t1 to t2 in FIG. 5 is a full-wave rectification region in which the rectifier circuit operates as a full-wave rectifier circuit, and the region from time t2 to t3 is the rectifier circuit. Becomes a half-wave rectification region operating as a half-wave rectification circuit. The region after time t3 includes a state in which the rectifier circuit stops outputting for a predetermined period (in the above example, a period of one cycle of the generator output), and a state in which the rectifier circuit performs a half-wave rectification operation for a predetermined period. Are generated alternately and become a thinning control region in which the output of the generator is thinned out at a predetermined cycle.
In the case of the embodiment shown in FIG. 1 and the embodiment shown in FIG. 3, the region after time t3 in FIG. 5 is also a half-wave rectification region.

  According to the embodiment shown in FIG. 4, since the output of the rectifier circuit is thinned out at a predetermined cycle in the region where the rotational speed exceeds the second set rotational speed Ns2, the input voltage Vin versus rotation of the constant voltage power supply circuit The speed N characteristic becomes a characteristic like a curve c shown by a wavy line in FIG. 2, and the voltage input to the constant voltage power circuit is further lowered in a high speed region where the rotational speed exceeds the second set rotational speed Ns2. The loss generated in the transistor TR1 can be reduced.

  In the example shown in FIG. 9, the first switch-on command is generated at step 13 and the second switch-off command is generated at step 14, but the first switch-off command is generated at step 13 and the first switch-off command is generated at step 14. A two-switch-on command may be generated to output a positive half-wave voltage of the power generation coil 1a during half-wave rectification.

  In the example shown in FIG. 9, in the region where the rotation speed exceeds the second set rotation speed Ns2, the rectification operation of the one-cycle period rectifier circuit of the generator output is stopped, and the next one-cycle period rectifier circuit is set. The operation is performed as a half-wave rectifier circuit. In a region where the rotational speed exceeds the second set rotational speed Ns2, the rectifier circuit stops outputting for a predetermined period, and the rectifier circuit performs a half-wave rectification operation for a predetermined period. It is sufficient that the output of the generator is thinned out in a predetermined cycle alternately with the state in which the rectifying operation is performed, and the method for setting the period in which the rectifier circuit stops operating and the period in which the half-wave rectifying operation is performed is described above. It is not limited to examples.

1 is a circuit diagram showing a configuration of a first exemplary embodiment of the present invention. It is the graph which showed roughly the characteristic which gives the relationship between the input voltage of the constant voltage circuit of the control apparatus concerning this invention, and rotational speed. It is the circuit diagram which showed the structure of the 2nd Embodiment of this invention. It is the circuit diagram which showed the structure of the 3rd Embodiment of this invention. It is the wave form diagram which showed the voltage output from a generator, the voltage output from a rectifier circuit, and the speed detection signal output from a speed detection signal generation circuit in embodiment of this invention. It is the graph which showed roughly the characteristic which gives the relationship between the voltage input into a constant voltage power supply circuit, and a rotational speed in the conventional control apparatus. It is the flowchart which showed an example of the algorithm of the task which a microprocessor performs in the 1st Embodiment of this invention. It is the flowchart which showed an example of the algorithm of the task which a microprocessor performs in the 2nd Embodiment of this invention. It is the flowchart which showed an example of the algorithm of the task which a microprocessor performs in the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnet type AC generator 2 Rectifier circuit 3 Power supply capacitor 4 Constant voltage power supply circuit 5 Controller 5A Microprocessor 5B Speed detection signal generation circuit 5C Switch drive circuit Th, Th1, Th2 Thyristor F1 MOSFET

Claims (4)

A rectifier circuit for rectifying the AC output of a magnet type AC generator driven by an internal combustion engine, a constant voltage power circuit for converting the output voltage of the rectifier circuit to a constant DC voltage, and a power supply voltage from the constant voltage power circuit. A control device for an internal combustion engine comprising a controller that is in an operating state by being given and controls a device attached to the internal combustion engine;
The rectifier circuit is composed of a mixed bridge circuit in which at least one of a pair of lower sides of the H bridge is configured by a switch element and the other side is configured by a diode. Configured to be switched to a wave rectifier circuit,
The controller includes: a rotation speed detection unit that detects a rotation speed of the internal combustion engine from an output of the magnet type AC generator; and the mixing bridge when the rotation speed detected by the rotation speed detection unit is equal to or lower than a set rotation speed. The circuit is operated as a full-wave rectifier circuit, and the switch element is controlled according to the rotational speed so that the mixed bridge circuit is operated as a half-wave rectifier circuit when the detected rotational speed exceeds a set rotational speed. Rectifying operation switching control means,
A control device for an internal combustion engine. A rectifier circuit for rectifying the AC output of a magnet type AC generator driven by an internal combustion engine, a constant voltage power circuit for converting the output voltage of the rectifier circuit to a constant DC voltage, and a power supply voltage from the constant voltage power circuit. A control device for an internal combustion engine comprising a controller that is in an operating state by being given and controls a device attached to the internal combustion engine;
The rectifier circuit includes a first diode and a second diode, the cathode of which is commonly connected to the positive output terminal, and a third of which the cathode is connected to the anode of the first diode and the anode is connected to the negative output terminal. And a thyristor having a cathode connected to the anode of the second diode and an anode connected to the negative output terminal, and a mixed bridge circuit comprising:
The controller includes a rotation speed detection means for detecting a rotation speed of the internal combustion engine from an output of the magnet type AC generator, and the thyristor when the rotation speed detected by the rotation speed detection means is equal to or less than a set rotation speed. The mixed bridge circuit is operated as a full-wave rectifier circuit in the on state, and the mixed bridge circuit is operated as a half-wave rectifier circuit when the detected rotational speed exceeds a set rotational speed and the thyristor is maintained in an off state. Rectifying operation switching control means for controlling the thyristor according to the rotational speed so as to make it,
A control device for an internal combustion engine. A rectifier circuit for rectifying the AC output of a magnet type AC generator driven by an internal combustion engine, a constant voltage power circuit for converting the output voltage of the rectifier circuit to a constant DC voltage, and a power supply voltage from the constant voltage power circuit. A control device for an internal combustion engine comprising a controller that is in an operating state by being given and controls a device attached to the internal combustion engine;
The rectifier circuit includes a first diode and a second diode, the cathode of which is commonly connected to the positive output terminal, and a third of which the cathode is connected to the anode of the first diode and the anode is connected to the negative output terminal. And a MOSFET having a drain connected to the anode of the second diode and a source connected to the negative-side output terminal.
The controller includes a rotation speed detection means for detecting a rotation speed of the internal combustion engine from the output of the magnet type AC generator, and the MOSFET when the rotation speed detected by the rotation speed detection means is equal to or lower than a set rotation speed. The mixed bridge circuit is operated as a full-wave rectifier circuit in an off state, and the mixed bridge circuit is operated as a half-wave rectifier circuit while keeping the MOSFET on when the detected rotational speed exceeds a set rotational speed. Rectifying operation switching control means for controlling the MOSFET according to the rotational speed so as to
A control device for an internal combustion engine. A rectifier circuit for rectifying the AC output of a magnet type AC generator driven by an internal combustion engine, a constant voltage power circuit for converting the output voltage of the rectifier circuit to a constant DC voltage, and a power supply voltage from the constant voltage power circuit. A control device for an internal combustion engine comprising a controller that is in an operating state by being given and controls a device attached to the internal combustion engine;
The rectifier circuit includes first and second diodes having a cathode commonly connected to a positive output terminal, a first diode having a cathode connected to an anode of the first diode, and an anode connected to the negative output terminal. A thyristor and a second thyristor having a cathode connected to the anode of the second diode and an anode connected to the negative output terminal,
The controller includes: a rotation speed detection unit that detects a rotation speed of the internal combustion engine from an output of the magnet type AC generator; and a rotation speed detected by the rotation speed detection unit is equal to or less than a first set rotation speed. Both the first thyristor and the second thyristor are turned on to operate the mixed bridge circuit as a full-wave rectifier circuit, and the detected rotation speed exceeds the first set rotation speed and the second set rotation When the speed is less than the speed, one of the first thyristor and the second thyristor is turned on and the other is turned off to operate the mixed bridge circuit as a half-wave rectifier circuit. When the set rotational speed of 2 is exceeded, a state in which one of the first thyristor and the second thyristor is turned on and the other is turned off; Rectifying operation switching control means for controlling the first and second thyristors according to the rotational speed so as to alternately generate a state in which both the first thyristor and the second thyristor are turned off. That
A control device for an internal combustion engine.

Images