WO2018020704A1

WO2018020704A1 - Control device for internal combustion engine

Info

Publication number: WO2018020704A1
Application number: PCT/JP2017/000407
Authority: WO
Inventors: 井上　裕介
Original assignee: デンソートリム株式会社
Priority date: 2016-07-26
Filing date: 2017-01-10
Publication date: 2018-02-01

Abstract

A control device having an internal combustion engine control unit for executing control of an internal combustion engine, and a duty control unit for charging a capacitor from a converter circuit. The duty control unit changes the duty ratio for the ON time and the OFF time of a switching element. After a high-precision period in which the duty ratio is controlled with a high precision, the duty control unit switches to a low-precision period in which the duty ratio is controlled with a low precision that is lower than the high precision. The control device has: a reservation control unit that, when processes of the internal combustion engine control unit are generated during the high-precision period, reserves a portion of the processes of the internal combustion control unit so as to be executed later; and a post-execution control unit that executes the portion of the processes during or after the low-precision period. Thus, it is possible to provide a control device for an internal combustion engine that achieves internal combustion engine control and power conversion control.

Description

Control device for internal combustion engine

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2016-146420 filed on July 26, 2016, and the disclosure of the basic application is incorporated into this application by reference.

The disclosure in this specification relates to a control device for an internal combustion engine.

Patent Document 1 discloses an ignition device for an internal combustion engine and its control. When such control for the ignition device is executed by a control device called a microcomputer, it is necessary to perform the calculation within a limited time depending on the rotational speed of the internal combustion engine. Furthermore, there is a case where a power conversion device for converting a power supply voltage is provided for an internal combustion engine device. For example, an ignition device that requires a high voltage or a fuel injection device that requires a high voltage requires a power converter. In this case, the control device performs control for the power conversion device in addition to the original control for the internal combustion engine.

Japanese Patent Laying-Open No. 2015-175361

In the configuration of the prior art, the resources of the control device are insufficient due to the control for the internal combustion engine (hereinafter also referred to as internal combustion engine control) and the control for the power conversion device (hereinafter also referred to as power conversion control). There are things to do.

In the above-mentioned viewpoints or other viewpoints not mentioned, further improvements are required for the control device for the internal combustion engine.

One disclosed object is to provide a control device for an internal combustion engine in which both internal combustion engine control and power conversion control are compatible.

The control device for an internal combustion engine disclosed herein includes a converter circuit (14) that converts the voltage of a power source into a high voltage by switching of a switching element, and a capacitor (34) that is charged by the converter circuit and supplies power to an internal combustion engine device. And a control device (17) for controlling the converter circuit. The control device changes the duty ratio between the ON time and the OFF time of the internal combustion engine controller (160, 171-174) that executes control for the internal combustion engine and the switching element, and controls the duty ratio with high accuracy. A duty control unit (150) for charging the capacitor from the converter circuit by switching to a low precision period (DC2) for controlling the duty ratio to a low precision lower than the high precision after the high precision period (DC1) to be performed; When a process of the internal combustion engine control unit occurs, a reservation control unit (175) that reserves a part of the process of the internal combustion engine control unit to be executed later, and a part of the process after the low-accuracy period And a post-execution control unit (180).

According to the disclosed control device for an internal combustion engine, the capacitor is charged from the converter circuit and discharged to the equipment of the internal combustion engine. Charging by the converter circuit is controlled by the control device. The control device has an internal combustion engine control unit and controls the internal combustion engine. The control device has a duty control unit and controls charging. Charging is performed by changing the duty ratio between the ON time and the OFF time of the switching element. In addition, the charging is performed by switching to a low precision period in which the duty ratio is adjusted to a low precision lower than the high precision after a high precision period in which the duty ratio is adjusted with high precision. For this reason, charging suitable for the capacitor is possible. The control device executes both processing as an internal combustion engine control unit and processing as a duty control unit. The control device has a reservation control unit. When the processing of the internal combustion engine control unit occurs during the high accuracy period, the reservation control unit reserves a part of the processing of the internal combustion engine control unit to be executed later. That is, the control device controls the duty ratio with high accuracy without executing some processing. Therefore, the resource of the control device is used to control the duty ratio with high accuracy. The control device has a post-execution control unit. The post-execution control unit executes the reserved partial processing after the low accuracy period. Thereby, the control for the internal combustion engine and the power conversion control for controlling the duty ratio for charging the capacitor can be executed by effectively using the resources of the control device.

The plurality of modes disclosed in this specification adopt different technical means to achieve each purpose. The reference numerals in parentheses described in the claims and this section exemplify the correspondence with the embodiments described later, and are not intended to limit the technical scope. The objects, features, and advantages disclosed in this specification will become more apparent with reference to the following detailed description and accompanying drawings.

1 is a block diagram of an internal combustion engine system according to a first embodiment. It is a flowchart which shows a charging process. It is a graph which shows the relationship between OFF time and the frequency | count of switching. It is a wave form diagram which shows an example of the action | operation in ON time and OFF time. It is a flowchart which shows the interruption process of an internal combustion engine. It is a flowchart which shows the interruption process of an internal combustion engine. It is a flowchart which shows a reservation process. It is a wave form diagram which shows an example of the action | operation in a charging process and an interruption process. It is a wave form diagram which shows an example of the action | operation in a charging process and an interruption process.

A plurality of embodiments will be described with reference to the drawings. In embodiments, functionally and / or structurally corresponding parts and / or associated parts may be assigned the same reference signs or reference signs that differ by more than a hundred. For the corresponding parts and / or associated parts, the description of other embodiments can be referred to.

First Embodiment FIG. 1 shows an internal combustion engine system 1 as an example. The internal combustion engine system 1 has an internal combustion engine (ENG) 2 as a power source. The internal combustion engine 2 is a spark ignition type internal combustion engine. The internal combustion engine 2 is a so-called gasoline engine that uses gasoline as fuel. The internal combustion engine system 1 includes a generator (ACG) 3 driven by the internal combustion engine 2. The generator 3 is an AC generator. The internal combustion engine system 1 provides a generator system that supplies power by a generator 3. At the same time, the internal combustion engine system 1 may provide a power system such as a ground traveling vehicle, a ship, an aircraft, and a work machine. In this embodiment, the internal combustion engine system 1 is mounted on a relatively small vehicle. An example of such a vehicle is a motorcycle.

The internal combustion engine system 1 is configured as a power supply device for supplying electric power to an electric load mounted on a vehicle and driving it. The internal combustion engine system 1 includes an internal combustion engine load drive device for driving an electric load. The electrical load may include main electrical equipment for operating the internal combustion engine 2 and additional electrical equipment. The main electrical equipment may include, for example, a starter motor, an ignition device, and / or a fuel supply device. The internal combustion engine system 1 includes an internal combustion engine ignition device for supplying electric power to the ignition device. Additional electrical equipment may include, for example, headlamps, turn signals, and / or meters. Some of these electrical devices temporarily require a large amount of power that exceeds the power that can be supplied by the power supply voltage. The load driving device for an internal combustion engine has a power conversion function in order to supply temporary high power.

The internal combustion engine system 1 is also configured as a power source for vehicle travel. The internal combustion engine 2 is connected to a vehicle propulsion mechanism via a transmission or the like. Therefore, when the rotational speed of the internal combustion engine 2 increases or decreases, the speed, sound, and the like change, and the vehicle user senses the change. A vehicle user may feel uncomfortable if the change in the rotational speed unintended by the vehicle user is abrupt and / or large.

The internal combustion engine system 1 has a power supply circuit (REC-REG) 4. The power supply circuit 4 may include a rectifier circuit (REC) and a voltage adjustment circuit (REG). The rectifier circuit rectifies AC power output from the generator 3 and outputs DC power. The voltage adjustment circuit adjusts the voltage output from the generator 3 to a predetermined adjustment voltage.

The internal combustion engine system 1 has a battery 5 that is charged by electric power output from the power supply circuit 4. The battery 5 supplies electric power to the electric device. The battery 5 supplies electric power to main electric devices such as a starter motor for starting the internal combustion engine 2. The battery 5 also supplies power to additional electrical equipment such as a headlamp.

The internal combustion engine system 1 has an ignition device 10. The ignition device 10 generates a spark for operating the internal combustion engine 2 by the electric power supplied from the generator 3, the power supply circuit 4 and the battery 5. The ignition device 10 includes an ignition circuit 6, an ignition coil 7, and a spark plug 8. The ignition circuit 6 energizes the ignition coil 7 and interrupts the energization. The ignition circuit 6 provides a control device for an internal combustion engine. The ignition coil 7 generates a high voltage necessary for the spark plug 8 to generate a spark. The ignition circuit 6 controls the intermittent timing of energization to the ignition coil 7 so that a spark is generated in the spark plug 8 at a predetermined ignition timing. Furthermore, the ignition circuit 6 includes a power conversion function for adjusting the energization power to the ignition coil 7. The ignition circuit 6 has a boosting function for supplying large power to the ignition coil 7.

The ignition coil 7 generates a high voltage using an electromagnetically coupled primary coil and secondary coil. Therefore, the ignition coil 7 and the ignition device 10 including the ignition coil 7 are inductive electric loads. The ignition circuit 6 provides an inductive load driving circuit or an inductive load power circuit for operating the inductive electric load by supplying electric power to the inductive electric load. The ignition coil 7 intermittently generates a high voltage. Therefore, the ignition coil 7 and the ignition device 10 including the ignition coil 7 are also referred to as intermittently driven electric loads. The ignition circuit 6 provides an intermittent load driving circuit or an intermittent load power supply circuit that intermittently outputs large power.

The ignition circuit 6 has a power supply terminal 11. The ignition circuit 6 receives power via the power supply terminal 11. The power supply terminal 11 is connected to the power supply circuit 4 and the battery 5. The ignition circuit 6 includes a diode 12 that receives power from the power supply terminal 11. The ignition circuit 6 receives the power supply voltage VB via the power supply terminal 11 and the diode 12.

The ignition circuit 6 has a DC-DC converter circuit 14 (hereinafter referred to as a converter circuit 14). The converter circuit 14 converts the power supply voltage VB input from the power supply terminal 11. Converter circuit 14 is also called a booster circuit. The converter circuit 14 provides a power conversion device.

The converter circuit 14 includes a transformer 31 that is an insulating transformer. The transformer 31 is an inductive element. The transformer 31 includes a primary coil fed from the power supply terminal 11 and a secondary coil connected to a load circuit described later. The transformer 31 inputs a power supply voltage to the primary coil, and output power from the secondary coil charges a capacitor 34 described later.

The converter circuit 14 has a switching element 32. The switching element 32 is arranged in series in a closed circuit passing through the power supply terminal 11 and the primary coil so that the current Itp flowing to the primary coil of the transformer 31 is intermittent. The switching element 32 is provided on the ground side of the primary coil of the transformer 31. The switching element 32 is provided by an FET. The switching element 32 can be provided by various elements such as a power transistor and an IGBT.

The converter circuit 14 includes a rectifying element 33 and a capacitor 34. The rectifying element 33 is arranged in a closed circuit including the secondary coil of the transformer 31. The rectifying element 33 is provided by a diode. The capacitor 34 is arranged in a closed circuit including the secondary coil of the transformer 31. The capacitor 34 is charged with electric power supplied from the converter circuit 14. The capacitor 34 is also an element constituting a part of the CDI circuit 15 described later. The converter circuit 14 converts the voltage of the power source into a high voltage by switching of the switching element 32. The capacitor 34 is charged by the converter circuit 14 and supplies power to the ignition coil 7 that is a device of the internal combustion engine 2.

The switching element 32 is controlled to be repeatedly turned on and off by the control device 17 described later. The switching element 32 is switched from the off state to the on state in one driving cycle, and is switched from the on state to the off state after the on time Ton, and is controlled to maintain the off state during the off time Toff. The Further, the switching element 32 is controlled to repeat a plurality of driving cycles. Such control is called switching drive or switching control.

The switching element 32 is switching-driven so as to charge the capacitor 34 to a predetermined voltage level in a period between the ignition timings. For example, the switching element 32 repeats on / off according to a preset switching sequence. A high voltage is induced on the secondary side of the transformer 31 by the switching of the switching element 32. The high voltage is rectified by the rectifying element 33 and the capacitor 34 is charged.

Thus, the converter circuit 14 gradually charges the capacitor 34 when the switching element 32 is driven to be switched. As a result, the capacitor 34 is gradually charged, and the voltage of the capacitor 34 gradually increases.

The ignition circuit 6 has a CDI circuit 15. CDI means Capacitor Discharge Ignition. The CDI circuit 15 is a load circuit supplied with power from the converter circuit 14. The CDI circuit 15 supplies the primary current supplied to the ignition coil 7 by discharging from the capacitor 34. The CDI circuit 15 supplies large energy to the primary coil of the ignition coil 7. As a result, a high voltage is stably generated at the secondary side output of the ignition coil 7. As a result, a strong spark can be stably generated in the spark plug 8.

The CDI circuit 15 has a thyristor 41. The thyristor 41 provides a switching circuit for opening and closing a discharge circuit including the capacitor 34 and the ignition coil 7, that is, a closed circuit. The CDI circuit 15 provides a discharge circuit that discharges the electric charge charged in the capacitor 34 to the ignition coil 7 that is a device of the internal combustion engine. The primary current is supplied from the capacitor 34 to the ignition coil 7 by firing the thyristor 41. As the thyristor 41 is extinguished, the primary current is cut off. The CDI circuit 15 supplies the electric charge of the capacitor 34 to the ignition coil 7 at the ignition timing. The capacitor 34 described above is also a part of the CDI circuit 15. Capacitor 34 and converter circuit 14 may be viewed as part of CDI circuit 15.

The ignition circuit 6 has a control device (CNTL) 17. The control device 17 drives the switching element 32 by supplying the switching signal SQ to the switching element 32. Further, the ignition circuit 6 has a clock circuit 18. The clock circuit 18 supplies a timing signal for the control device 17 to execute arithmetic processing.

The control device 17 is an electronic control device (Electronic Control Unit). The control device has at least one arithmetic processing unit (CPU) and at least one memory device (MMR) as a storage medium for storing programs and data. The control device 17 is provided by a microcomputer provided with a computer-readable storage medium. The storage medium is a non-transitional tangible storage medium that stores a computer-readable program in a non-temporary manner. The storage medium can be provided by a semiconductor memory or a magnetic disk. The control device 17 can be provided by a computer or a set of computer resources linked by a data communication device. The program is executed by the control device 17 to cause the control device 17 to function as the device described in this specification, and to cause the control device 17 to perform the method described in this specification. The calculation speed of the control device 17 varies depending on various factors such as the capability of the calculation processing device, the memory read / write speed, and the memory capacity. One or more of these elements are called resources.

The control device 17 provides various elements. At least some of these elements can be referred to as blocks for performing functions. In another aspect, at least some of these elements can be referred to as modules or sections that are interpreted as configurations. The means and / or functions provided by the control device can be provided by software recorded in a substantial memory device and a computer that executes the software, software only, hardware only, or a combination thereof. For example, if the controller 17 is provided by an electronic circuit that is hardware, it can be provided by a digital circuit including a number of logic circuits, or an analog circuit.

The control device 17 has a first output terminal OUT1 that outputs a switching signal SQ for switching and driving the switching element 32. The signal output to the first output terminal OUT1 has a predetermined duty ratio Dt. The control device 17 has a second output terminal OUT2 that outputs an ignition signal Ig for firing the thyristor 41.

The control device 17 is also a boost control device that operates the converter circuit 14 so as to charge the capacitor 34. The control device 17 outputs a switching signal SQ for the switching element 32. The switching signal SQ is set to match the charging characteristics of the capacitor 34.

For example, the cycle of the switching signal SQ is set to be shorter as the charging of the capacitor 34 progresses. The on time Ton of the switching signal SQ can be set according to the power supply voltage VB. The duty ratio Dt of the switching signal SQ can be set to increase as the charging of the capacitor 34 progresses. The duty ratio Dt can be set so that the OFF time gradually decreases in a series of charging sequences including a plurality of switching operations. The duty ratio Dt can be expressed as Dt = Ton / (Ton + Toff) based on the on time Ton and the off time Toff.

The switching signal SQ is set so that the capacitor 34 can be charged to a predetermined voltage level during one ignition and the next ignition, in other words, during the period between the discharge of the capacitor 34 and the next discharge. . The switching signal SQ corresponds to a series of charging sequences for gradually charging the capacitor 34 by the converter circuit 14 in another stepwise manner. A series of charging sequences includes a plurality of driving cycles. In one driving cycle, the switching element 32 is switched from the off state to the on state, and after being kept on for the on time Ton, is switched from the on state to the off state, and remains off for the off time Toff. .

The control device 17 starts a series of charging sequences when one ignition is completed. The control device 17 ends the series of charging sequences before the next ignition is required. The control device 17 is a charge control device that executes a series of charging sequences for charging the capacitor 34 to a predetermined voltage level.

A series of charge sequences may be characterized by the number of drive cycles, for example. A series of charging sequences may be characterized by, for example, an on time Ton. A series of charging sequences may be characterized, for example, by an off time Toff. A series of charging sequences may be characterized by a duty ratio Dt in the driving cycle, for example. The series of charging sequences may be characterized by a combination of at least two of the number of times, the on time Ton, the off time Toff, and the duty ratio Dt. In this embodiment, the sequence of charging sequences is characterized by an on time Ton and an off time Toff.

The control device 17 gradually changes the duty ratio Dt of the switching signal SQ in a series of charging sequences. The duty ratio Dt is set so that the capacitor 34 can be charged appropriately. For example, a small duty ratio Dt is set at the beginning of a series of charging sequences, and a large duty ratio Dt is set at a later stage. The duty ratio Dt can be changed by changing the off time Toff while keeping the on time Ton constant. The duty ratio Dt may be changed by changing the on-time Ton while keeping the off-time Toff constant. The duty ratio Dt may be changed by changing both the on time Ton and the off time Toff.

When the ignition timing comes, the control device 17 ignites the thyristor 41 to generate an ignition spark in the spark plug 8. The control device 17 is also an ignition control device. The control device 17 inputs a reference signal Pin for controlling the ignition timing.

The internal combustion engine system 1 includes a rotation angle detector 13. The rotation angle detector 13 detects the rotation angle of the internal combustion engine 2. The rotation angle detector 13 outputs a signal indicating the rotation angle of the internal combustion engine 2, that is, the rotation position. The rotation angle detector 13 outputs a reference signal Pin at a position that serves as a reference for rotation of the internal combustion engine 2. The rotation angle detector 13 outputs a pre-pulse and a post-pulse. The previous pulse indicates the most advanced position. The rear pulse indicates a reference position. In some cases, ignition is performed further later than the reference position. The rotation angle detector 13 is provided by, for example, a signal rotor 21 that rotates together with the internal combustion engine 2 and a pulse pickup 22.

The ignition device 10 includes a signal processing circuit (SIGP) 16 for processing a signal output from the rotation angle detector 13. The control device 17 includes an input terminal IN for inputting the reference signal Pin from the rotation angle detector 13 and the signal processing circuit 16.

The configuration for causing the converter circuit 14 to oscillate by using a switching signal generated by the control device 17 for ignition control using the clock circuit 18 can be referred to as separately excited oscillation. On the other hand, the configuration in which the oscillation circuit is configured to oscillate the converter circuit 14 can be called self-excited oscillation. For example, a self-excited oscillation circuit that switches energization to the primary coil in response to the secondary side voltage of the converter circuit 14 can be used. When a self-excited oscillation circuit is used, the switching frequency and / or the duty ratio may vary depending on the element constant of the oscillation circuit, for example, the RC time constant. For example, the energization time and the duty ratio vary depending on the temperature characteristics of the element. As a result, the temperature characteristics of the element may greatly affect the charging efficiency of the CDI circuit 15 by the converter circuit 14.

The control device 17 constitutes a separately-excited oscillation type power conversion circuit. The control device 17 is a microcomputer and uses a clock circuit 18. The clock circuit 18 generates a clock signal having a predetermined period. Therefore, it is possible to output a rectangular pulse wave whose output changes at an accurate interval and an accurate timing. The control device 17 executes high-precision control and low-precision control with a resolution that depends on the clock signal supplied from the clock circuit 18. For this reason, it is possible to suppress an adverse effect due to inevitable temperature characteristics in the self-excited oscillation circuit.

In the following description, a period of a series of charging sequences is given a name such as a charging period, a switching period, or a DC-DC converter period. The duration of the series of charging sequences is called the converter time DCtime. In addition, the switching number SWnum of the switching element 32 in that period is referred to as switching number, SQ number, ON-OFF number, and the like.

In this embodiment, the converter circuit 14 provides a power conversion device. On the other hand, the ignition coil 7 provides equipment for the internal combustion engine. Internal combustion engine control is provided by ignition control ignited by the CDI circuit 15. Power conversion control is provided by duty control to efficiently charge the capacitor 34 to a high voltage. The power conversion control is also called PWM (Pulse Width Modulation) control because the switching signal SQ is subjected to pulse width modulation. The control device 17 controls the CDI circuit 15 that provides a discharge circuit by the internal combustion engine controller, and controls both the converter circuit 14 and the CDI circuit 15 that is a discharge circuit.

The charging process 150 illustrated in FIG. The control device 17 executes the charging process 150 during a period between one ignition and the next ignition. The charging process 150 provides power conversion control.

In step 151, the control device 17 determines whether or not the converter time DCtime is less than a predetermined threshold time Tht. The threshold time Tht defines an upper limit period of a series of charging sequences. In other words, the maximum time for which the switching element 32 is switched is defined. If converter time DCtime is less than predetermined threshold time Tht, the routine proceeds to step 152. After converter time DCtime reaches predetermined threshold time Tht, the process proceeds to step 157.

In step 152, the control device 17 determines whether or not the switching number SWnum of the switching element 32 is less than a predetermined threshold number Thn. The threshold number Thn defines an upper limit number in a series of charging sequences. In other words, the maximum number of times that the switching element 32 is switched is defined. If the switching count SWnum is less than the predetermined threshold time Thn, the process proceeds to step 153. After the switching number SWnum reaches a predetermined threshold number Thn, the process proceeds to step 155.

In step 153, the control device 17 sets the ON time Ton and the OFF time Toff of the switching element 32. Here, an initial ON time Ton and an OFF time Toff in a series of charging sequences for charging the capacitor 34 are set. For example, a relatively long ON time Ton and a relatively long OFF time Toff are set.

In step 154, the control device 17 controls the ON time Ton and the OFF time Toff with high accuracy. That is, the output of the output terminal OUT1 is controlled so that the time set in step 153 is accurately realized. For example, the maximum accuracy that can be provided by the controller 17 is provided. That is, in the initial stage of a series of charging sequences, a highly accurate control is provided by placing a high computational load on the resources of the control device 17 that can be received. In other words, highly accurate control that can be performed by the control device 17 is provided. Specifically, the ON time Ton and the OFF time Toff are controlled with a predetermined accuracy. For example, the determination is performed every ON time Ton and OFF time Toff so that the maximum error of the first time T1 (0.5 μs (microseconds)) is obtained.

In step 155, the control device 17 sets an ON time Ton and an OFF time Toff. Here, an ON time Ton and an OFF time Toff in the latter period are set in a series of charging sequences for charging the capacitor 34. For example, a relatively short ON time Ton and a relatively short OFF time Toff are set.

In step 156, the control device 17 controls the ON time Ton and the OFF time Toff with low accuracy. That is, the output of the output terminal OUT1 is controlled so as to realize the time set in step 155. For example, a low precision that does not press the arithmetic processing of the control device 17 is given. That is, in the latter part of the series of charging sequences, low precision control is provided by placing a low computational load on the resource of the control device 17 so that other arithmetic processing can be executed. In other words, low-accuracy control that can be realized without the time restriction on the arithmetic processing for the other control by the control device 17 is provided. Specifically, the ON time Ton and the OFF time Toff are controlled with lower accuracy than in step 154. For example, the determination is performed every ON time Ton and OFF time Toff so as to be the maximum error of the second time T2. The second time T2 is longer than the first time T1. The second time T2 is longer than 10 times the first time T1.

In step 157, switching of the switching element 32 is stopped. For this reason, a series of charging processes are completed.

The charging process 150 changes the duty ratio between the ON time and OFF time of the switching element. In addition, the charging process 150 switches to the low accuracy period in which the duty ratio is controlled to be lower than the high accuracy after the high accuracy period in which the duty ratio is controlled with high accuracy. The charging process 150 provides a duty control unit that charges the capacitor 34 from the converter circuit 14. The control device 17 has a duty control unit and controls charging. Charging is performed by changing the duty ratio between the ON time and OFF time of the switching element 32. In addition, the charging is performed by switching to a low precision period in which the duty ratio is adjusted to a low precision lower than the high precision after a high precision period in which the duty ratio is adjusted with high precision. For this reason, charging suitable for the capacitor 34 is possible.

FIG. 3 shows an example of the OFF time Toff for charging the capacitor 34. The OFF time Toff decreases exponentially. One or both of the ON time Ton and the OFF time Toff can be stored in the memory and set by the map. That is, at least one of the ON time Ton and the OFF time Toff is stored in the memory of the control device 17.

FIG. 4 shows an example of the operation of the converter circuit 14. In the figure, a switching signal SQ, an input current Itp, and an output current Its are shown. When a series of charging sequences is started at time t11, an ON time Ton and an OFF time Toff are set. The switching signal SQ changes to SQ1, SQ2, SQ3,... As the capacitor 34 is charged. The switching signal SQ is set so that at least the OFF time Toff becomes shorter as time elapses.

The switching signal SQ is set so as to change from the OFF state to the ON state after the charging current Its becomes zero. For example, the charging current Its is zero before time t12. Similarly, the charging current Its is zero before the times t13 and t14. Thus, after the charging current Its becomes zero, the high-precision control in step 154 and the low-precision control in step 156 are set so that the switching signal SQ changes from the OFF state to the ON state. Yes.

If the ON time Ton is too long, undesirable heat generation may occur in the primary coil or secondary coil of the transformer 31. The ON time Ton is desirably set to an upper limit value, for example, 8 μs (microseconds). If the ON time Ton is too short, the charging efficiency of the capacitor 34 may be reduced. The ON time Ton is desirably set to a lower limit of 4 μs (microseconds), for example. The ON time Ton is preferably selected from a lower limit value and an upper limit value. The ON time Ton is, for example, 6.5 μs (microseconds). Furthermore, considering the variation in the characteristics of the elements constituting the circuit and the temperature characteristics of the characteristics of the elements that are manifested by the temperature rise during use, the maximum error of the ON time Ton is 0.5 μs (microseconds) or less. It is desirable to be.

The pre-pulse processing 160 illustrated in FIG. When the previous pulse signal is input from the rotation angle detector 13, the control device 17 executes the previous pulse processing 160. The pre-pulse processing 160 provides a pre-pulse control unit that consumes the charge of the capacitor 34 based on the pre-pulse.

In step 161, the control device 17 executes a process to be executed by the previous pulse interrupt. For example, in step 161, processing that should be based on the generation time of the previous pulse is executed. Specifically, processing related to the determination of the ignition pulse, that is, the position of the previous pulse for calculating the advance amount or the retard amount from the reference position is executed. In addition, about the setting of an ignition angle, a patent document can be used by reference.

In step 162, the control device 17 determines whether or not calculation ignition is necessary. The determination in step 162 is also a determination of whether or not ignition angle control is necessary. If it is determined in step 162 that the calculated ignition is necessary, the process proceeds to step 163. If it is determined in step 162 that the calculated ignition is not necessary, the process is terminated.

In step 163, the control device 17 executes a calculation ignition process. The calculation ignition process is one of the processes to be executed by the previous pulse interrupt. In step 163, processing for measuring the time from the previous pulse and generating the ignition signal Ig is executed. Specifically, the ignition signal Ig is generated by timer processing from the generation timing of the previous pulse. In many cases, an ignition signal is generated by a later pulse. As a result, ignition that is more advanced than the rear pulse is realized. The timing up to the ignition signal Ig can be obtained by calculation. For this reason, the control for generating the ignition signal Ig on the basis of the previous pulse is called arithmetic ignition. Step 163 is also a previous pulse control unit. Step 163 provides an arithmetic ignition control unit that calculates the ignition timing based on the previous pulse.

The post-pulse processing 170 illustrated in FIG. When a subsequent pulse signal is input from the rotation angle detector 13, the control device 17 executes a post-pulse process 170. The post-pulse processing 170 provides a post-pulse control unit that consumes the charge of the capacitor 34 based on the post-pulse.

In step 171, the control device 17 executes a process to be executed by a post-pulse interrupt. Specifically, processing related to the rotational speed, rotational position, etc. calculated from the post-pulse is executed.

In step 172, the control device 17 determines whether or not it is after step 163. That is, it is determined whether or not a post-pulse is detected after the calculation ignition process is started in step 163. The determination in step 172 is executed as a determination at the current ignition timing. If it is determined in step 172 that step 163 is not executed in the current ignition, the process proceeds to step 173. In step 172, if it is after step 162 is executed in the current ignition, the process proceeds to step 175. In this case, the calculated ignition is executed after the previous pulse. Computed ignition may be performed after a post-pulse.

The process of step 172 is also a process of evaluating the state of the charging process 150. In many cases, the charging process 150 is started after the calculation ignition process is executed. In addition, since it is the initial stage of the charging process 150, a highly accurate process is executed. Even if the timing of the calculation ignition is after the post-pulse, the calculation load is concentrated because the charging process 150 is started after the post-pulse. That is, the determination in step 172 is also a determination as to whether or not the charging process 150 is being executed. In other words, the determination in step 172 is also a determination as to whether or not the duty drive control for causing the converter circuit 14 to oscillate is performed. The charging process 150 performs high-accuracy control at an early stage and performs low-accuracy control at a later stage. For this reason, the determination in step 172 is also a determination of whether or not the charging process 150 is highly accurate. Step 172 provides a determination unit that determines whether or not the processing by the previous pulse control unit has been started or has been executed based on the preceding previous pulse in response to the subsequent pulse. .

In step 173, the control device 17 executes a fixed ignition process. If it is determined in step 172 that the calculated ignition has not been executed, fixed ignition is necessary. Therefore, the control device 17 executes a fixed ignition process. The fixed ignition process is one of processes that should be executed by a post-pulse interrupt. In step 173, the ignition signal Ig is generated based on the post-pulse. As a result, ignition with a post-pulse is realized. Step 173 is also a post-pulse control unit. Step 163 provides a fixed ignition controller that ignites in response to a post-pulse.

In step 174, the control device 17 executes a plurality of partial processes that should have been executed in synchronization with the post-pulse. These partial processes are processes to be executed when the crankshaft of the internal combustion engine 2 is at a predetermined reference position, and are therefore referred to as crank synchronization processes. For example, processing of a rotation speed signal to be executed in response to the post pulse is executed. Step 174 provides a non-reservation control unit that executes a part of the process immediately without performing a part of the process when the process of the internal combustion engine control unit occurs during the low accuracy period.

The whole of the pre-pulse process 160 and the whole of the post-pulse process 170 provide an internal combustion engine control unit that executes control for the internal combustion engine 2. In particular, the entire pre-pulse processing 160 and steps 171 to 174 of the post-pulse processing 170 execute ignition control for the internal combustion engine 2.

In step 175, the control device 17 sets a flag to be executed later without executing at least one of a plurality of processes to be executed in synchronization with the subsequent pulse. In other words, the process is reserved. Step 175 is a process for reserving at least a part of the crank synchronization process at a later time. In this embodiment, all processing called crank synchronization processing is executed at a later time. Processing for setting post-execution is called reservation processing, postponement processing, post-transmission processing, and the like.

When going through step 175, it is after step 163 is executed. For this reason, ignition has been performed. For this reason, the charging process 150 is also started. The charging process 150 is performed with high accuracy in the initial stage. Therefore, the control device 17 is under a high calculation load for the charging process 150. In this case, it is desirable to prioritize the charging process 150 and postpone the other processes. This is because, since the voltage fluctuation of the capacitor 34 is large at the beginning of charging, it is efficient to control the ON time and OFF time with high accuracy.

Step 175 provides a reservation control unit for reserving a part of the process of the internal combustion engine control unit to be executed later when the process of the internal combustion engine control unit occurs during the high accuracy period. If the determination unit provided in step 172 is positively determined, the reservation control unit provided in step 175 reserves a partial process to be executed later. When the ignition control unit provided in step 163 ignites, the reservation control unit provided in step 175 reserves a part of the processing to be executed later.

7 is executed by the control device 17. The post-execution process 180 shown in FIG. The control device 17 executes a post-execution process 180 when the calculation load on the control device 17 decreases. The control device 17 executes a post-execution process 180 when the charging process 150 has low accuracy. The post-execution process 180 provides a post-execution control unit that executes some processes after the low-accuracy period.

In step 181, the control device 17 determines whether or not post-execution is set. If it is determined in step 181 that post-execution is set, the process proceeds to step 182. If it is determined in step 181 that post-execution is not set, the process is terminated.

In step 182, the control device 17 later executes a partial process that is at least one of a plurality of processes to be executed in synchronization with the post-pulse and not executed for the post-execution. That is, some processes are executed with a delay. Here, all processing called crank synchronization processing is executed.

In step 183, the set state for subsequent execution is cleared. Step 183 provides a release unit for releasing the reservation after partial processing is executed after the low-accuracy period.

FIG. 8 shows the operation when fixed ignition is executed. The horizontal axis is indicated by the rotation angle ANG of the internal combustion engine. In the figure, the switching signal SQ is schematically shown with a constant ON time Ton. The front pulse and the rear pulse are detected at the falling timing.

At time t21, the previous pulse is detected. At time t21, the pre-pulse interrupt process PR1 shown in

steps

161 and 162 is executed. Eventually, a post-pulse is detected at time t22. After time t22, post-pulse interruption and fixed ignition processing PR2 shown in steps 171 to 173 is executed, and fixed ignition IgF is executed. Further, after the process PR2, a crank synchronization process PR3 shown in step 174 is executed. After the fixed ignition IgF, the charging process 150 is started.

The high-precision period DC1 and the low-precision period DC2 are included in the series of charging sequences. The charging process 150 shifts to a low-accuracy process from time t23. The process PR3 and the charging process 150 can be executed without conflict. In particular, at the beginning of the charging process 150, the ON time Ton and the OFF time Toff are long. For this reason, the process PR3 and the switching for the charging process 150 do not compete. The ON time Ton and the OFF time Toff are simulated to illustrate that the switching is performed, and the width is an example.

FIG. 9 shows the operation when the calculated ignition is executed. FIG. 9 corresponds to FIG.

At time t31, the process PR4 shown in steps 161-163 is executed. Thereby, the calculated ignition IgA is executed.

Eventually, a post-pulse is detected at time t32. After time t32, the process PR5 shown in steps 171-175 is executed. When the processing of the internal combustion engine control unit occurs during the high-accuracy period DC1, the reservation control unit provided in step 175 reserves a part of the processing of the internal combustion engine control unit to be executed later. That is, the control device 17 controls the duty ratio with high accuracy without executing some processing. Therefore, the resource of the control device 17 is used to control the duty ratio with high accuracy.

At time t33, the charging process 150 enters the low accuracy period DC2. At time t33, the post-execution condition is satisfied. That is, the calculation load of the control device 17 is reduced. After time t33, process PR6 shown in steps 181 to 183 is executed. The post-execution control unit provided by step 182 executes some of the reserved processes after the low-accuracy period. That is, in the process PR6, the crank synchronization process that was not executed before is executed. As a result, it is possible to complete the processing required during ignition without increasing the calculation load of the control device 17 in the high-accuracy period DC1 in the charging processing 150.

8 and 9, if the high accuracy period DC1 is too long, the control to be performed in the low accuracy period DC2 may not be performed in the period until the next reference signal Pin is input. If the high-accuracy period DC1 is too short, there is a case where control to be performed in the high-accuracy period DC1, that is, accurate control from the ON time Ton to the OFF time Toff may not be performed. Considering such drawbacks, the high accuracy period DC1 is set so as to give a margin including an error. In other words, the high-accuracy period DC1 is an element that may cause a decrease in charging efficiency of the capacitor 34. The high accuracy period DC1 is obtained from the maximum rotational speed of the internal combustion engine 2 and the time that requires strict control to charge the capacitor 34. It is sufficient that the time from the beginning of the low accuracy period DC2 to the subsequent reference signal Pin is 1 ms (milliseconds). For example, the high accuracy period DC1 is set to about 4 ms (milliseconds). When the maximum rotation speed of the internal combustion engine 2 is set to 12000 rpm (the number of rotations per minute), one cycle is 5 ms (milliseconds). (Milliseconds).

When the control device 17 has a high processing capability, the control device 17 obtains surplus processing capability by controlling the duty ratio with low accuracy. The reserved partial processing can be executed by the surplus capacity. From another viewpoint, it is possible to make the charging process 150 and the ignition process compatible by using the control device 17 having a low processing capacity. There is provided an internal combustion engine control device in which ignition control for internal combustion engine control and charging processing 150 as power conversion control are compatible.

According to the embodiment described above, the internal combustion engine control for changing the ignition timing of the CDI circuit 15 for the internal combustion engine 2 and the power conversion control for changing the duty of the converter circuit 14 for the capacitor 34 are compatible. An internal combustion engine controller is provided. Moreover, the internal combustion engine control in which the ignition control for the internal combustion engine control that must be executed at predetermined intervals and the high-accuracy power conversion control of the converter circuit 14 are achieved by effectively using the resources of the control device 17. An apparatus is provided. Therefore, from one viewpoint, it is possible to use an inexpensive control device having only a low processing capacity. From another viewpoint, it is possible to use surplus arithmetic processing capacity for other control.

Other Embodiments The disclosure herein is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations by those skilled in the art based thereon. For example, the disclosure is not limited to the combinations of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure may have additional parts that can be added to the embodiments. The disclosure includes those in which parts and / or elements of the embodiments are omitted. The disclosure encompasses the replacement or combination of parts and / or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. Some technical scope disclosed is shown by the description of the scope of claims, and should be understood to include all modifications within the meaning and scope equivalent to the description of the scope of claims.

In the above embodiment, an ignition coil is used as an electric load driven intermittently. Instead of this, a fuel injection valve may be used. As the electric load driven intermittently, an inductive load may be used, or a capacitive load may be used. As the inductive load, for example, a high voltage electromagnetic coil for driving the injection valve is used. In addition, a piezoelectric element is used as a capacitive load. The piezo element generates a mechanical displacement according to the accumulated electric charge. The piezo element is used, for example, in a fuel injection valve that interrupts fuel injection.

In the above embodiment, the converter circuit 14 is provided by a chopper circuit including the transformer 31. Instead, various booster circuits can be used. For example, a chopper circuit including a reactor coil may be used as the converter circuit 14.

In the above embodiment, the post-execution process 180 is executed when the charging process 150 enters the low-accuracy period DC2. Instead, the post-execution process 180 may be executed after the charging process 150 is completely stopped.

In the above-described embodiment, the power conversion control, that is, the control of the switching element 32 of the converter circuit 14 is switched to two stages of the high accuracy period DC1 and the low accuracy period DC2. However, the accuracy may be a plurality of steps such as three steps, or may be stepless. The low accuracy period DC2 may coincide with a saturation period in which the duty ratio is constant.

In the above embodiment, the fixed ignition IgF is executed in response to the post-pulse. Alternatively, the most retarded ignition may be performed after the post-pulse. Further, the most advanced ignition may be performed before the previous pulse.

In the above embodiment, the internal combustion engine 2 includes the signal rotor 21. Alternatively, the signal rotor may be included in the rotor of the generator (ACG). In the above embodiment, the signal processing circuit 16 is provided. Alternatively, the signal processing circuit may be omitted. For example, a Hall sensor including a sensor element and an accompanying circuit can be used instead of the pulse pickup.

Claims

A converter circuit (14) for converting the voltage of the power source into a high voltage by switching of the switching element;
A capacitor (34) charged by the converter circuit and supplying power to the internal combustion engine equipment;
A control device (17) for controlling the converter circuit,
The controller is
An internal combustion engine control section (160, 171-174) for executing control for the internal combustion engine;
The duty ratio between the ON time and the OFF time of the switching element is changed, and the duty ratio is controlled to a low precision lower than the high precision after the high precision period (DC1) for controlling the duty ratio with a high precision. A duty control unit (150) for switching to the low precision period (DC2) and charging the capacitor from the converter circuit;
A reservation control unit (175) for reserving a part of the processing of the internal combustion engine control unit to be executed later when processing of the internal combustion engine control unit occurs during the high-accuracy period;
A control device for an internal combustion engine, comprising: a post-execution control unit (180) that executes the partial processing after the low-accuracy period.
And a discharge circuit (15) for discharging the electric charge charged in the capacitor to the device of the internal combustion engine,
2. The control device for an internal combustion engine according to claim 1, wherein the control device controls the discharge circuit by the internal combustion engine control unit and controls both the converter circuit and the discharge circuit. 3.
The converter circuit is
A power supply voltage is input to the primary coil, and the secondary coil includes a transformer (31) that charges the capacitor.
3. The control device for an internal combustion engine according to claim 1, wherein the switching element is a switching element that is provided on a ground side of the primary coil of the transformer and interrupts a current (Itp) flowing through the primary coil.
The control device includes an input terminal (IN) that receives a signal from a rotation angle detector (13) that outputs a front pulse and a rear pulse at a position serving as a reference for rotation of the internal combustion engine,
The internal combustion engine controller is
A pre-pulse control unit (163) for consuming the charge of the capacitor based on the pre-pulse;
A post-pulse control unit (173) for consuming the charge of the capacitor based on the post-pulse;
A determination unit (172) that determines whether or not the processing by the previous pulse control unit has been executed based on the preceding previous pulse in response to the subsequent pulse;
The control apparatus for an internal combustion engine according to any one of claims 1 to 3, wherein the reservation control unit reserves the partial processing to be executed later when the determination unit is positively determined.
The device is an ignition coil (17);
The pre-pulse control unit is a calculation ignition control unit (163) that calculates an ignition timing based on the pre-pulse,
The post-pulse control unit is a fixed ignition control unit that ignites in response to the post-pulse,
The control device for an internal combustion engine according to claim 4, wherein the reservation control unit reserves the partial processing to be executed later when ignited by the arithmetic ignition control unit.
The said apparatus is an ignition coil (17), and the said capacitor | condenser and the said converter circuit are a part of CDI circuit which supplies the electric charge of the said capacitor | condenser to the said ignition coil in an ignition timing. A control device for an internal combustion engine according to claim 1.
The internal combustion engine control according to any one of claims 1 to 6, wherein the duty control unit controls the duty ratio so that the OFF time is gradually shortened in a series of charging sequences including a plurality of the switching operations. apparatus.
The said post-execution control part (180) has the cancellation | release part (183) which cancels | releases the said reservation, after performing the said partial process after the said low precision period. Control device for internal combustion engine.
And a clock circuit (18) for generating a clock signal having a predetermined period,
The said control apparatus is a microcomputer which performs the said high precision control and the said low precision control with the resolution depending on the clock signal supplied from the said clock circuit. Control device for internal combustion engine.
The said control apparatus is provided with the non-reservation control part (174) which performs the said partial process immediately, without performing later, if the process of the said internal combustion engine control part generate | occur | produces in the said low precision period. The control device for an internal combustion engine according to claim 9.