JP7286442B2 - Ignition device for internal combustion engine - Google Patents

Ignition device for internal combustion engine Download PDF

Info

Publication number
JP7286442B2
JP7286442B2 JP2019119629A JP2019119629A JP7286442B2 JP 7286442 B2 JP7286442 B2 JP 7286442B2 JP 2019119629 A JP2019119629 A JP 2019119629A JP 2019119629 A JP2019119629 A JP 2019119629A JP 7286442 B2 JP7286442 B2 JP 7286442B2
Authority
JP
Japan
Prior art keywords
semiconductor switch
voltage
sub
primary coil
ignition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
JP2019119629A
Other languages
Japanese (ja)
Other versions
JP2021004589A (en
Inventor
直樹 樋口
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Astemo Hanshin Ltd
Original Assignee
Hitachi Astemo Hanshin Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Astemo Hanshin Ltd filed Critical Hitachi Astemo Hanshin Ltd
Priority to JP2019119629A priority Critical patent/JP7286442B2/en
Publication of JP2021004589A publication Critical patent/JP2021004589A/en
Application granted granted Critical
Publication of JP7286442B2 publication Critical patent/JP7286442B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Landscapes

  • Ignition Installations For Internal Combustion Engines (AREA)

Description

本発明は、内燃機関の点火プラグに火花放電を生じさせる高電圧を印加するための内燃機関用点火装置に関する。 The present invention relates to an ignition device for an internal combustion engine for applying a high voltage that causes spark discharge to an ignition plug of the internal combustion engine.

内燃機関用点火装置は、内燃機関の点火サイクルを統括的に管理する点火制御装置（例えば、ＥＣＵ）から点火信号を受けて、所要のタイミングで一次コイルへの通電および遮断を制御し、二次コイルに高電圧を発生させる。二次コイルに発生した高電圧により、点火プラグの放電ギャップ間に火花放電を生じさせ、気筒内の燃焼ガスに着火し、気筒内のシリンダを動かす力を得るのである。 An ignition device for an internal combustion engine receives an ignition signal from an ignition control device (e.g., an ECU) that controls the ignition cycle of the internal combustion engine, controls energization and cutoff of the primary coil at required timing, and controls the secondary coil. A high voltage is generated in the coil. The high voltage generated in the secondary coil causes spark discharge between the discharge gaps of the spark plugs, ignites the combustion gas in the cylinder, and obtains the force to move the cylinder within the cylinder.

そして、内燃機関用点火装置では、一次コイルへの通電路をパワートランジスタやＩＧＢＴといった半導体スイッチによって開閉し、一次コイルへの通電・遮断を制御している。半導体スイッチは、その性質上、昇温によって動作が不安定になってしまうので、半導体スイッチが異常状態になってしまった場合、異常な点火動作を強制的に停止させるフェールセーフ機能を設けた発明が提案されている（例えば、特許文献１を参照）。 In an ignition device for an internal combustion engine, a semiconductor switch such as a power transistor or an IGBT opens and closes an electric path to a primary coil to control energization/interruption of the primary coil. A semiconductor switch, by its nature, becomes unstable when the temperature rises. Therefore, when the semiconductor switch becomes abnormal, an invention that provides a fail-safe function that forcibly stops the abnormal ignition operation. has been proposed (see Patent Document 1, for example).

特許文献１に記載されたフェールセーフ機能の概要を図４および図５に基づいて説明する。点火コイルの一次コイル１０１へ直流電源１０２から電源供給する給電路の適所に第１半導体スイッチ１０３を設け、更に、第１半導体スイッチ１０３の接地側（直流電源１０２の低圧側）に第２半導体スイッチ１０４を設ける。そして、制御回路部１０５からの制御信号入力で第１，第２半導体スイッチ１０３，１０４が同時に閉じると、一次コイル１０１への通電路が形成され、一次コイル１０１に一次電流が流れる。また、制御回路１０５は、一次コイル１０１の通電路適所（例えば、第２半導体スイッチ１０４の接地側）に設けたセンス抵抗１０６から一次電流値を検出する。 An overview of the fail-safe function described in Patent Document 1 will be described with reference to FIGS. 4 and 5. FIG. A first semiconductor switch 103 is provided at an appropriate place in the power supply line for supplying power from the DC power supply 102 to the primary coil 101 of the ignition coil, and a second semiconductor switch is provided on the ground side of the first semiconductor switch 103 (low voltage side of the DC power supply 102). 104 is provided. When the first and second semiconductor switches 103 and 104 are simultaneously closed by the input of a control signal from the control circuit section 105 , a current path to the primary coil 101 is formed and the primary current flows through the primary coil 101 . In addition, the control circuit 105 detects the primary current value from a sense resistor 106 provided at an appropriate place in the current path of the primary coil 101 (for example, the ground side of the second semiconductor switch 104).

例えば、第１半導体スイッチ１０３の短絡または損傷によって一次電流値が異常になっているような場合、第２半導体スイッチ１０４をオフにすることで、一次コイル１０１への通電路を開いて異常な点火制御が行われないようにし、内燃機関用点火装置全体を保護する。 For example, if the primary current value is abnormal due to a short circuit or damage to the first semiconductor switch 103, by turning off the second semiconductor switch 104, the current path to the primary coil 101 is opened to prevent abnormal ignition. To prevent control from being performed and to protect the entire ignition system for an internal combustion engine.

また、特許文献１には、第２半導体スイッチ１０４が故障していないかをチェックするためのリーク検出機能を制御回路部１０５に設ける構成も提案されている。制御回路部１０５は、リークチェック線路１０７を介して第１半導体スイッチ１０３と第２半導体スイッチ１０４との間にリークチェック出力を行うことで、リーク検出用のパルス電圧を第２半導体スイッチ１０４に印加する。 Further, Patent Document 1 proposes a configuration in which the control circuit section 105 is provided with a leak detection function for checking whether the second semiconductor switch 104 is faulty. The control circuit unit 105 applies a pulse voltage for leak detection to the second semiconductor switch 104 by performing leak check output between the first semiconductor switch 103 and the second semiconductor switch 104 via the leak check line 107 . do.

例えば、図５の波形図に示すように、一次コイル１０１への給電開始および終了のタイミングを決める点火信号Ｓｉが入力されたタイミングで短パルス状のリークチェックパルスをリークチェック線路１０７へ出力する。第２半導体スイッチ１０４が正常であれば、センス抵抗１０６に電流は流れないが、第２半導体スイッチ１０４が短絡あるいは損傷によって導通していれば、センス抵抗１０６に電流が流れるために、第２半導体スイッチ１０４の異常を検出できる。また、第１半導体スイッチ１０３が短絡または損傷によって導通していれば、第２半導体スイッチ１０４がオフのとき、リークチェック線路１０７には電源電圧が印加されるため、第１半導体スイッチ１０３の異常を検出できる。 For example, as shown in the waveform diagram of FIG. 5, a short leak check pulse is output to the leak check line 107 at the timing when the ignition signal Si that determines the timing of starting and ending power supply to the primary coil 101 is input. If the second semiconductor switch 104 is normal, no current flows through the sense resistor 106. However, if the second semiconductor switch 104 is conductive due to a short circuit or damage, current flows through the sense resistor 106. Abnormality of the switch 104 can be detected. Further, if the first semiconductor switch 103 is conductive due to a short circuit or damage, the power supply voltage is applied to the leak check line 107 when the second semiconductor switch 104 is off. detectable.

米国特許第９７４５９４７号明細書U.S. Pat. No. 9,745,947

しかしながら、特許文献１に記載されている内燃機関用点火装置では、第２半導体スイッチを第１半導体スイッチの接地側に設けているため、フェールセーフ機能が働いて第２半導体スイッチをオフにした場合、第１半導体スイッチの接地側が浮いた状態になる。このため、一次コイルへの通電により蓄えられた高エネルギーが第１半導体スイッチおよびリークチェック線路を介して制御回路部へ一気に流れ込み、制御回路部を破損してしまう危険性がある。 However, in the internal combustion engine ignition device described in Patent Document 1, since the second semiconductor switch is provided on the ground side of the first semiconductor switch, when the second semiconductor switch is turned off by the fail-safe function, , the ground side of the first semiconductor switch is in a floating state. Therefore, there is a risk that the high energy stored by energizing the primary coil will flow into the control circuit section all at once via the first semiconductor switch and the leak check line, damaging the control circuit section.

また、リークチェック出力パルスを生成して第１，第２半導体スイッチの異常をチェックする場合、そのチェックは高インピーダンス状態で行う必要がある。そのため、サージ・ノイズの影響を受けやすく、誤判定が生じやすいという問題が生じる。さらに、異常検知用のリークチェック出力パルスの生成は、点火信号ＳｉのＯＮ（信号レベルがＬからＨ）をトリガーとしているため、リークチェックのタイミングが制限されてしまう。点火信号ＳｉがＯＦＦのときにも、リークチェックを任意で行えることが望ましい。 Also, when generating a leak check output pulse to check for an abnormality in the first and second semiconductor switches, the check must be performed in a high impedance state. As a result, there arises a problem that it is easily affected by surge noise and erroneous determination is likely to occur. Furthermore, since the generation of the leak check output pulse for abnormality detection is triggered by ON of the ignition signal Si (the signal level is from L to H), the leak check timing is restricted. It is desirable that the leak check can be arbitrarily performed even when the ignition signal Si is OFF.

そこで、本発明は、フェールセーフ機能によって一次コイルへの通電を強制的に停止することで、更なる故障が生じる危険性の無い内燃機関用点火装置の提供を目的とする。 SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an ignition device for an internal combustion engine that eliminates the risk of further failure by forcibly stopping the energization of the primary coil using a fail-safe function.

上記課題を解決するための内燃機関用点火装置は、点火サイクルの所要タイミングで入力される点火信号に基づいて、点火コイルの一次コイルに流れる一次電流を通電・遮断制御し、二次側に高電圧を発生させる内燃機関用点火装置において、前記一次コイルと接地点との間に設けられ、前記点火信号のオン・オフに応じて一次コイルから接地点への通電路を開閉する主半導体スイッチと、前記一次コイルと電源との間に設けられ、該電源から前記一次コイルへの通電路を開閉する副半導体スイッチと、前記主半導体スイッチの異常状態を検出することに基づいて、前記副半導体スイッチのオン動作を規制するフェールセーフ手段と、を備えることを特徴とする。 An ignition device for an internal combustion engine for solving the above-mentioned problems controls the energization/cutoff of the primary current flowing through the primary coil of the ignition coil based on the ignition signal input at the required timing of the ignition cycle, thereby increasing the secondary current. a main semiconductor switch provided between the primary coil and a ground point in an ignition device for an internal combustion engine that generates a voltage, for opening and closing an electric path from the primary coil to the ground point according to on/off of the ignition signal; a sub-semiconductor switch provided between the primary coil and a power source for opening and closing an electric path from the power source to the primary coil; and fail-safe means for regulating the ON operation of the.

また、上記構成において、前記フェールセーフ手段は、前記主半導体スイッチが異常状態から正常状態へ復帰したことを検出することに基づいて、前記副半導体スイッチのオン動作規制を解除しても良い。 Further, in the above configuration, the fail-safe means may release the ON operation restriction of the sub semiconductor switch based on detecting that the main semiconductor switch has returned from the abnormal state to the normal state.

また、上記構成において、前記副半導体スイッチとして、Ｐ型ＭＯＳＦＥＴを用い、前記フェールセーフ手段は、前記主半導体スイッチが正常状態のとき、前記点火信号と同期して前記副半導体スイッチのゲート－ソース間電圧を低減させて、電源から前記一次コイルへの通電路を閉じ、前記主半導体スイッチが異常状態のとき、前記副半導体スイッチのゲート－ソース間電圧を通常電圧に保持しても良い。 In the above configuration, a P-type MOSFET is used as the secondary semiconductor switch, and the fail-safe means operates between the gate and source of the secondary semiconductor switch in synchronization with the ignition signal when the main semiconductor switch is in a normal state. The voltage may be reduced to close the current path from the power supply to the primary coil, and the gate-to-source voltage of the secondary semiconductor switch may be maintained at a normal voltage when the primary semiconductor switch is in an abnormal state.

また、上記構成において、前記フェールセーフ手段は、前記副半導体スイッチのドレイン－ソース間を接続する異常検出用抵抗と、前記副半導体スイッチと前記一次コイルとの間に設けた異常検出点の電圧を取得する判定電圧取得線と、前記判定電圧取得線から取得した異常判定電圧と、正常判定閾値である基準電圧とを比較して、正常判定の場合にのみ正常信号を出力する比較器と、前記副半導体スイッチのゲートから前記接地点に至る通電路に設けられ、前記比較器からの正常信号が入力されることで、前記副半導体スイッチのゲートから前記接地点に至る通電路を閉じる正常動作用半導体スイッチと、を備えても良い。 Further, in the above configuration, the fail-safe means includes an abnormality detection resistor connecting between the drain and source of the sub semiconductor switch, and a voltage at an abnormality detection point provided between the sub semiconductor switch and the primary coil. a comparator that compares a determination voltage acquisition line to be acquired, an abnormality determination voltage acquired from the determination voltage acquisition line, and a reference voltage that is a normal determination threshold value, and outputs a normal signal only in the case of normal determination; For normal operation, provided in an electric path from the gate of the sub-semiconductor switch to the grounding point, and closing the conducting path from the gate of the sub-semiconductor switch to the grounding point when a normal signal from the comparator is input. and a semiconductor switch.

また、上記構成において、前記副半導体スイッチとして、ＰＮＰ型で高耐圧のＰＮＰパワートランジスタを用い、前記フェールセーフ手段は、前記主半導体スイッチが正常状態のとき、前記点火信号と同期して前記副半導体スイッチのベース－エミッタ間電圧を低減させて、電源から前記一次コイルへの通電路を閉じ、前記主半導体スイッチが異常状態のとき、前記副半導体スイッチのベース－エミッタ間電圧を通常電圧に保持しても良い。 Further, in the above configuration, a PNP type high voltage PNP power transistor is used as the secondary semiconductor switch, and the fail-safe means operates the secondary semiconductor switch in synchronization with the ignition signal when the main semiconductor switch is in a normal state. reducing the base-emitter voltage of the switch to close the current path from the power supply to the primary coil, and holding the base-emitter voltage of the secondary semiconductor switch at a normal voltage when the main semiconductor switch is in an abnormal state; can be

また、上記構成において、前記フェールセーフ手段は、前記副半導体スイッチのコレクタ－エミッタ間を接続する異常検出用抵抗と、前記副半導体スイッチと前記一次コイルとの間に設けた異常検出点の電圧を取得する判定電圧取得線と、前記判定電圧取得線から取得した異常判定電圧と、正常判定閾値である基準電圧とを比較して、正常判定の場合にのみ正常信号を出力する比較器と、前記副半導体スイッチのベースから前記接地点に至る通電路に設けられ、前記比較器からの正常信号が入力されることで、前記副半導体スイッチのベースから前記接地点に至る通電路を閉じる正常動作用半導体スイッチと、を備えても良い。 Further, in the above configuration, the fail-safe means includes an abnormality detection resistor connecting between the collector and the emitter of the sub semiconductor switch, and a voltage at an abnormality detection point provided between the sub semiconductor switch and the primary coil. a comparator that compares a determination voltage acquisition line to be acquired, an abnormality determination voltage acquired from the determination voltage acquisition line, and a reference voltage that is a normal determination threshold value, and outputs a normal signal only in the case of normal determination; For normal operation, provided in a conducting path from the base of the sub semiconductor switch to the grounding point, and closing the conducting path from the base of the sub semiconductor switch to the grounding point when a normal signal from the comparator is input. and a semiconductor switch.

本発明に係る内燃機関用点火装置によれば、主半導体スイッチが異常状態になった場合、フェールセーフ手段によって、点火コイルと電源との間に設けた副半導体スイッチのオン動作を規制するので、主半導体スイッチの接地側が浮くことがない。よって、一次コイルへの通電により蓄えられたエネルギーは主半導体スイッチから接地点へ流れ、内燃機関用点火装置の更なる故障が生じる危険性はない。 According to the ignition device for an internal combustion engine according to the present invention, when the main semiconductor switch becomes abnormal, the fail-safe means restricts the ON operation of the sub semiconductor switch provided between the ignition coil and the power supply. The ground side of the main semiconductor switch does not float. Thus, the energy stored by energizing the primary coil flows from the main semiconductor switch to ground without risk of further failure of the ignition system for the internal combustion engine.

内燃機関用点火装置の本実施形態を示す概略回路図である。1 is a schematic circuit diagram showing this embodiment of an ignition device for an internal combustion engine; FIG. 正常時の内燃機関用点火装置における要部の信号波形を示す波形図である。FIG. 3 is a waveform diagram showing signal waveforms of main parts in the ignition device for an internal combustion engine during normal operation; 異常時の内燃機関用点火装置における要部の信号波形を示す波形図である。FIG. 4 is a waveform diagram showing signal waveforms of main parts in the ignition device for an internal combustion engine when an abnormality occurs. フェールセーフ機能を備えた従来の内燃機関用点火装置の概略回路図である。1 is a schematic circuit diagram of a conventional internal combustion engine ignition device with a fail-safe function; FIG. 従来の内燃機関用点火装置における要部の信号波形を示す波形図である。FIG. 2 is a waveform diagram showing signal waveforms of main parts in a conventional ignition device for an internal combustion engine;

次に、本発明に係る内燃機関用点火装置１の実施形態を、添付図面に基づいて詳細に説明する。 Next, an embodiment of an internal combustion engine ignition device 1 according to the present invention will be described in detail based on the accompanying drawings.

内燃機関用点火装置１は、点火サイクルの所要タイミングで入力される点火信号Ｓｉに基づいて、点火コイル１０の一次コイル１１に流れる一次電流を通電・遮断制御し、点火コイル１０の二次コイル１２に高電圧を発生させる。二次コイル１２の一方には、図示を省略した点火プラグが接続され、二次コイル１２に発生した高電圧により、点火プラグの放電ギャップ間に火花放電を生じさせる。また、一次コイル１１には、直流電源２０から電源供給を受ける給電路が形成される。 The ignition device 1 for an internal combustion engine controls energization/cutoff of a primary current flowing through a primary coil 11 of an ignition coil 10 based on an ignition signal Si input at a required timing of an ignition cycle. to generate high voltage. A spark plug (not shown) is connected to one side of the secondary coil 12, and the high voltage generated in the secondary coil 12 causes spark discharge between the spark plug discharge gaps. Further, the primary coil 11 is formed with a power supply path for receiving power supply from the DC power supply 20 .

点火コイル１０における一次コイル１１の低圧側と接地点ＧＮＤとの間には、点火信号Ｓｉのオン・オフに応じて一次コイル１１から接地点ＧＮＤへの通電路を開閉する主半導体スイッチ３０を設ける。なお、点火信号Ｓｉは、点火制御装置としてのＥＣＵ４０から点火サイクル中の適宜なタイミングで入力（例えば、信号レベルがＬからＨに変換）するもので、例えば、イグナイタ制御回路５０によって適宜な駆動信号に変換されて主半導体スイッチ３０へ入力される。 Between the low-voltage side of the primary coil 11 in the ignition coil 10 and the ground point GND, there is provided a main semiconductor switch 30 that opens and closes the current path from the primary coil 11 to the ground point GND according to the ON/OFF state of the ignition signal Si. . The ignition signal Si is input from the ECU 40 as an ignition control device at an appropriate timing during the ignition cycle (for example, the signal level is changed from L to H). , and input to the main semiconductor switch 30 .

主半導体スイッチ３０として、例えば、ＩＧＢＴ（Insulated Gate Bipolar Transistor:絶縁ゲートバイポーラトランジスタ）を用いる。この場合、ＩＧＢＴのコレクタ端子を一次コイル１１と接続し、ＩＧＢＴのエミッタ端子を接地点ＧＮＤと接続し、ＩＧＢＴのゲート端子からイグナイタ制御回路５０の駆動信号を入力させれば、イグナイタ制御回路５０によって主半導体スイッチ３０をオン・オフできる。 As the main semiconductor switch 30, for example, an IGBT (Insulated Gate Bipolar Transistor) is used. In this case, if the collector terminal of the IGBT is connected to the primary coil 11, the emitter terminal of the IGBT is connected to the ground point GND, and the drive signal for the igniter control circuit 50 is input from the gate terminal of the IGBT, the igniter control circuit 50 The main semiconductor switch 30 can be turned on and off.

また、一次コイル１１と直流電源２０との間には副半導体スイッチ６０を設け、直流電源２０から一次コイル１１へ至る通電路の開閉を行う。副半導体スイッチ６０として、例えば、Ｐ型ＭＯＳＦＥＴ（Metal-Oxide-Semiconductor Field-Effect Transistor）を用いる。この場合、Ｐ型ＭＯＳＦＥＴのソース端子を直流電源２０と接続し、Ｐ型ＭＯＳＦＥＴのドレイン端子を一次コイル１１と接続し、ゲート端子からフェールセーフ手段７０のコントロール信号を入力させれば、フェールセーフ手段７０によって副半導体スイッチ６０をオン・オフできる。 A secondary semiconductor switch 60 is provided between the primary coil 11 and the DC power supply 20 to open and close an electric path from the DC power supply 20 to the primary coil 11 . As the sub-semiconductor switch 60, for example, a P-type MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is used. In this case, by connecting the source terminal of the P-type MOSFET to the DC power supply 20, connecting the drain terminal of the P-type MOSFET to the primary coil 11, and inputting the control signal of the fail-safe means 70 from the gate terminal, the fail-safe means 70 allows the sub-semiconductor switch 60 to be turned on and off.

フェールセーフ手段７０は、主半導体スイッチ３０の異常状態を検出することに基づいて、副半導体スイッチ６０のオン動作を規制することで、一次コイル１１から主半導体スイッチ３０へ一次電流が流れることを防ぐ。主半導体スイッチ３０の異常が素子の発熱に起因するものであった場合、一次コイル１１への通電を無効化することで主半導体スイッチ３０の温度低下を促し、主半導体スイッチ３０を正常動作可能な状態（正常状態）へ復帰させる。フェールセーフ手段７０は、主半導体スイッチ３０が異常状態から正常状態へ復帰したことを検出すると、副半導体スイッチ６０のオン動作規制を解除する。すなわち、フェールセーフ手段７０は、主半導体スイッチ３０の異常状態検出で一次コイル１１への通電を遮断すると共に、主半導体スイッチ３０の正常状態復帰へ一次コイル１１への通電を再開させることができる。 The fail-safe means 70 prevents the primary current from flowing from the primary coil 11 to the main semiconductor switch 30 by regulating the ON operation of the sub semiconductor switch 60 based on the detection of an abnormal state of the main semiconductor switch 30. . If the abnormality of the main semiconductor switch 30 is caused by the heat generation of the element, the temperature of the main semiconductor switch 30 is accelerated by disabling the energization of the primary coil 11, and the main semiconductor switch 30 can be operated normally. Return to the state (normal state). Fail-safe means 70 cancels ON operation restriction of sub-semiconductor switch 60 when it detects that main semiconductor switch 30 returns from an abnormal state to a normal state. That is, the fail-safe means 70 can cut off the energization of the primary coil 11 upon detection of an abnormal state of the main semiconductor switch 30 and restart the energization of the primary coil 11 so that the main semiconductor switch 30 returns to the normal state.

フェールセーフ手段７０の機能は、耐熱性・耐ノイズ性の高いディスクリート部品を適宜に用いた種々の回路を適宜に組み合わせることで構成できる。しかしながら、図１に示すフェールセーフ手段７０の回路構成であれば、サージ・ノイズの影響を受け難いシンプルな異常検出構造で、しかも、点火信号Ｓｉのオン・オフにかかわらず、常に主半導体スイッチ３０の異常を監視できる。 The function of the fail-safe means 70 can be configured by appropriately combining various circuits using discrete components having high heat resistance and noise resistance. However, the circuit configuration of the fail-safe means 70 shown in FIG. 1 is a simple abnormality detection structure that is not easily affected by surge noise, and the main semiconductor switch 30 is always switched on regardless of whether the ignition signal Si is on or off. abnormalities can be monitored.

フェールセーフ手段７０は、適宜な抵抗成分を含む動作用給電線Ｌ１を介して、直流電源２０から電源供給を受ける。なお、動作用給電線Ｌ１に乗ってフェールセーフ手段７０へ混入したサージ・ノイズから内部素子を保護するために、ショットキーバリアダイオードＳＤを用いた保護回路を設けてある。動作用給電線Ｌ１は、副スイッチ用給電線Ｌ２と比較器用給電線Ｌ３に分岐させる。副スイッチ用給電線Ｌ２の電圧は、副半導体スイッチ６０のソース電圧とほぼ同じ（副半導体スイッチゲート電圧Ｖｇ＝Ｈレベル）であるから、副半導体スイッチ６０はオフのままである。一方、比較器用給電線Ｌ３は、比較器７１の正電源端子＋に接続され、非反転入力Ｖｉｎ＋が反転入力Ｖｉｎ－よりも高いときの出力Ｖｏｕｔの生成に用いられる。なお、比較器７１の負電源端子－は接地点ＧＮＤに接続され、反転入力Ｖｉｎ－が非反転入力Ｖｉｎ＋よりも高いときの出力Ｖｏｕｔは接地電圧となる。 The fail-safe means 70 receives power supply from the DC power supply 20 via an operating power supply line L1 containing an appropriate resistance component. A protection circuit using a Schottky barrier diode SD is provided in order to protect the internal elements from surge noise that enters the fail-safe means 70 on the power supply line L1 for operation. The operation feeder line L1 is branched into a sub-switch feeder line L2 and a comparator feeder line L3. Since the voltage of the sub-switch power supply line L2 is substantially the same as the source voltage of the sub-semiconductor switch 60 (sub-semiconductor switch gate voltage Vg=H level), the sub-semiconductor switch 60 remains off. On the other hand, the comparator power supply line L3 is connected to the positive power supply terminal + of the comparator 71 and used to generate the output Vout when the non-inverting input Vin+ is higher than the inverting input Vin-. The negative power supply terminal - of the comparator 71 is connected to the ground point GND, and the output Vout becomes the ground voltage when the inverting input Vin- is higher than the non-inverting input Vin+.

副半導体スイッチ６０のゲート入力となる副スイッチ用給電線Ｌ２は、副スイッチ動作制御線Ｌ４を介して、正常動作用半導体スイッチ７２（例えば、バイポーラトランジスタで構成）のコレクタ端子に接続する。正常動作用半導体スイッチ７２のエミッタ端子は接地点ＧＮＤに接続され、正常動作用半導体スイッチ７２のベース端子には、比較器７１の出力Ｖｏｕｔが入力される。比較器７１の出力Ｖｏｕｔが正常動作用半導体スイッチ７２のベースに入力されると、副スイッチ動作制御線Ｌ４が接地点ＧＮＤに接続されて副スイッチ素子６０のゲート電圧が下がり（副半導体スイッチゲート電圧Ｖｇ＝Ｌレベル）、副半導体スイッチ６０がオンとなる。すなわち、主半導体スイッチ３０が正常状態か異常状態かの判定を比較器７１で行い、正常状態の比較結果である出力Ｖｏｕｔを正常動作用半導体スイッチ７２のベースに入力してオンにすれば、連携して副半導体スイッチ６０をオフからオンに制御できる。 A sub-switch power supply line L2 serving as a gate input of the sub-semiconductor switch 60 is connected to a collector terminal of a normal-operation semiconductor switch 72 (for example, composed of a bipolar transistor) via a sub-switch operation control line L4. The emitter terminal of the semiconductor switch 72 for normal operation is connected to the ground point GND, and the output Vout of the comparator 71 is input to the base terminal of the semiconductor switch 72 for normal operation. When the output Vout of the comparator 71 is input to the base of the semiconductor switch 72 for normal operation, the sub-switch operation control line L4 is connected to the ground point GND and the gate voltage of the sub-switch element 60 decreases (sub-semiconductor switch gate voltage Vg=L level), the sub-semiconductor switch 60 is turned on. That is, if the comparator 71 judges whether the main semiconductor switch 30 is in a normal state or an abnormal state, and the output Vout, which is the comparison result of the normal state, is input to the base of the semiconductor switch 72 for normal operation to turn it on. Then, the sub-semiconductor switch 60 can be controlled from off to on.

上記のように比較器７１で主半導体スイッチ３０の正常状態と異常状態を判定するための構成を以下に説明する。 A configuration for determining whether the main semiconductor switch 30 is normal or abnormal by the comparator 71 as described above will be described below.

副半導体スイッチ６０のドレイン－ソース間を接続するバイパス線路Ｌ５に高抵抗の異常検出用抵抗７３を設ける。また、副半導体スイッチ６０と一次コイル１１との間に設けた異常検出点７４の異常判定電圧を取得する判定電圧取得線Ｌ６を設け、判定電圧取得線Ｌ６を比較器７１の非反転入力Ｖｉｎ＋に接続する。なお、比較器７１の非反転入力Ｖｉｎ＋が適宜な入力電圧となるように、判定電圧取得線Ｌ６中の抵抗成分や接地点ＧＮＤに接続した接地接続線中の抵抗成分を適宜に定める。また、判定電圧取得線Ｌ６に乗って混入したサージ・ノイズから比較器７１を保護するために、ツェナーダイオードＺＤを用いた保護回路を設けてある。 A high-resistance abnormality detection resistor 73 is provided on the bypass line L5 connecting the drain and source of the sub-semiconductor switch 60 . In addition, a determination voltage acquisition line L6 for acquiring an abnormality determination voltage at an abnormality detection point 74 provided between the secondary semiconductor switch 60 and the primary coil 11 is provided, and the determination voltage acquisition line L6 is connected to the non-inverting input Vin+ of the comparator 71. Connecting. In addition, the resistance component in the determination voltage acquisition line L6 and the resistance component in the ground connection line connected to the ground point GND are appropriately determined so that the non-inverting input Vin+ of the comparator 71 becomes an appropriate input voltage. In addition, a protection circuit using a Zener diode ZD is provided in order to protect the comparator 71 from surge noise mixed on the determination voltage acquisition line L6.

一方、比較器７１の反転入力Ｖｉｎ－には、非反転入力Ｖｉｎ＋の異常判定電圧を正常判定もしくは異常判定に切り分ける閾値（正常判定閾値）とする基準電圧を入力する。この基準電圧は、定電流源等から直接生成しても良いが、本実施形態では、基準電圧生成手段８０によって生成する。基準電圧生成手段８０では、比較器用給電線Ｌ３と比較器７１の反転入力線Ｌ７を接続する第１分圧線Ｌ８ａに設けた第１抵抗８１ａと、第１分圧線Ｌ８ａから接地点ＧＮＤを繋ぐ第２分圧線Ｌ８ｂに設けた第２抵抗８１ｂとで、比較器用給電線Ｌ３の電位を分圧し、基準電圧とする。 On the other hand, to the inverting input Vin- of the comparator 71, a reference voltage is input as a threshold (normality determination threshold) for dividing the abnormality determination voltage of the non-inverting input Vin+ into normality determination or abnormality determination. This reference voltage may be generated directly from a constant current source or the like, but is generated by the reference voltage generating means 80 in this embodiment. In the reference voltage generating means 80, a first resistor 81a provided in a first voltage dividing line L8a connecting the power supply line L3 for the comparator and the inverting input line L7 of the comparator 71, and a ground point GND from the first voltage dividing line L8a. The potential of the power supply line L3 for comparator is divided by the second resistor 81b provided on the second voltage dividing line L8b to be connected to obtain a reference voltage.

また、第２分圧線Ｌ８ｂの適所（例えば、第２抵抗８１ｂよりも接地点ＧＮＤ側）には、基準電圧生成用半導体スイッチ８２（例えば、バイポーラトランジスタで構成）を設けてある。基準電圧生成用半導体スイッチ８２は、コレクタ端子を高圧側、エミッタ端子を接地側に接続し、ＥＣＵ４０からの点火信号Ｓｉを適宜な電圧にしてゲート端子に入力する。よって、点火信号ＳｉがＥＣＵ４０から出力されていないとき、基準電圧生成用半導体スイッチ８２はオフであるから、比較器７１の反転入力線Ｌ７には、比較器用給電線Ｌ３とほぼ同じ電圧（Ｈレベル）が印加される。一方、点火信号ＳｉがＥＣＵ４０から出力されると、基準電圧生成用半導体スイッチ８２がオンとなって第２分圧線Ｌ８ｂが接地点ＧＮＤに接続され、比較器７１の反転入力線Ｌ７には、第１，第２抵抗８１ａ，８１ｂの分圧比に応じた電圧（Ｌレベル）が印加される。すなわち、比較器７１の反転入力Ｖｉｎ－には、点火信号Ｓｉのオン・オフに応じて、異なる基準電圧信号が入力されることとなる。 A reference voltage generating semiconductor switch 82 (for example, composed of a bipolar transistor) is provided at an appropriate position of the second voltage dividing line L8b (for example, closer to the ground point GND than the second resistor 81b). The reference voltage generating semiconductor switch 82 has a collector terminal connected to a high voltage side and an emitter terminal connected to the ground side, and converts the ignition signal Si from the ECU 40 to an appropriate voltage and inputs it to the gate terminal. Therefore, when the ignition signal Si is not output from the ECU 40, the reference voltage generation semiconductor switch 82 is off. ) is applied. On the other hand, when the ignition signal Si is output from the ECU 40, the reference voltage generating semiconductor switch 82 is turned on, the second voltage dividing line L8b is connected to the ground point GND, and the inverting input line L7 of the comparator 71 has A voltage (L level) corresponding to the voltage division ratio of the first and second resistors 81a and 81b is applied. That is, different reference voltage signals are input to the inverting input Vin- of the comparator 71 depending on whether the ignition signal Si is on or off.

ここで、上記のように構成した内燃機関用点火装置１における正常時の動作を、図２の波形図を用いて説明する。 Here, normal operation of the internal combustion engine ignition device 1 configured as described above will be described with reference to the waveform diagram of FIG.

内燃機関用点火装置１が正常な状態において、点火信号Ｓｉが入力されていないとき（信号レベルがＬのとき）、主半導体スイッチ３０および副半導体スイッチ６０は共にオフである。よって、異常検出点７４には、異常検出用抵抗７３を設けたバイパス線路Ｌ５を介して電源電圧に近い高電圧が印加され、判定電圧取得線Ｌ６を介して比較器７１の非反転入力Ｖｉｎ＋には、高電位の異常判定電圧が入力される。このとき、基準電圧生成用半導体スイッチ８２はオフであるから、比較器７１の反転入力Ｖｉｎ－には、比較器用給電線Ｌ３とほぼ同じ電圧（Ｈレベル）が印加される。すなわち、「Ｖｉｎ－＞Ｖｉｎ＋」であるから、比較器７１の出力ＶｏｕｔはＬレベルのままで、正常動作用半導体スイッチ７２はオフを保持し、副スイッチ素子６０のゲート電圧ＶｇはＨレベルであるから、副半導体スイッチ６０もオフを保持する。 When the internal combustion engine ignition device 1 is in a normal state and the ignition signal Si is not input (when the signal level is L), both the main semiconductor switch 30 and the sub semiconductor switch 60 are off. Therefore, a high voltage close to the power supply voltage is applied to the abnormality detection point 74 via the bypass line L5 provided with the abnormality detection resistor 73, and to the non-inverting input Vin+ of the comparator 71 via the determination voltage acquisition line L6. , a high-potential abnormality determination voltage is input. At this time, since the reference voltage generation semiconductor switch 82 is off, the inverting input Vin- of the comparator 71 is applied with substantially the same voltage (H level) as that of the power supply line L3 for the comparator. That is, since "Vin->Vin+", the output Vout of the comparator 71 remains at L level, the normal operation semiconductor switch 72 is kept off, and the gate voltage Vg of the sub-switch element 60 is at H level. Therefore, the sub-semiconductor switch 60 is also kept off.

次いで、内燃機関用点火装置１が正常な状態において、点火信号Ｓｉが入力されると（信号レベルがＨに変わると）、主半導体スイッチ３０がオンになり、一次コイル１１から接地点ＧＮＤに至る通電路が閉じる。同時に、基準電圧生成用半導体スイッチ８２がオンとなって第２分圧線Ｌ８ｂが接地点ＧＮＤに接続され、比較器７１の反転入力線Ｌ７には、第１，第２抵抗８１ａ，８１ｂの分圧比に応じた電圧（Ｌレベル）が印加される。すなわち、「Ｖｉｎ－＜Ｖｉｎ＋」に変化するから、比較器７１の出力ＶｏｕｔはＨレベルとなって正常動作用半導体スイッチ７２をオンにし、副スイッチ素子６０のゲート電圧ＶｇをＬレベルに低下させるから、副半導体スイッチ６０がオンになり、一次コイル１１への正常な通電路が形成され、一次電流Ｉ１が流れる。なお、副半導体スイッチ６０がオンになった後も、異常検出点７４には電源電圧に近い高電圧が印加されるので、比較器７１の非反転入力Ｖｉｎ＋に入力される異常判定電圧は高電位を保持する。よって、「Ｖｉｎ－＜Ｖｉｎ＋」の関係が保持され、比較器７１の出力ＶｏｕｔもＨレベルを保持する。 Next, when the internal combustion engine ignition device 1 is in a normal state, when the ignition signal Si is input (when the signal level changes to H), the main semiconductor switch 30 is turned on, and the primary coil 11 reaches the ground point GND. A power line is closed. At the same time, the semiconductor switch 82 for generating the reference voltage is turned on, the second voltage dividing line L8b is connected to the ground point GND, and the inverting input line L7 of the comparator 71 is connected to the first and second resistors 81a and 81b. A voltage (L level) corresponding to the pressure ratio is applied. That is, since the state changes to "Vin-<Vin+", the output Vout of the comparator 71 becomes H level to turn on the semiconductor switch 72 for normal operation and lower the gate voltage Vg of the sub-switch element 60 to L level. , the sub-semiconductor switch 60 is turned on, a normal current path to the primary coil 11 is formed, and the primary current I1 flows. Since a high voltage close to the power supply voltage is applied to the abnormality detection point 74 even after the secondary semiconductor switch 60 is turned on, the abnormality determination voltage input to the non-inverting input Vin+ of the comparator 71 is at a high potential. hold. Therefore, the relationship "Vin-<Vin+" is maintained, and the output Vout of the comparator 71 is also maintained at H level.

さらに、内燃機関用点火装置１が正常な状態において、点火信号Ｓｉが停止すると（信号レベルがＬに戻ると）、主半導体スイッチ３０がオフになり、一次コイル１１から接地点ＧＮＤに至る通電路が開き、一次電流Ｉ１が遮断される。同時に、基準電圧生成用半導体スイッチ８２がオフとなって、比較器７１の反転入力線Ｌ７には、比較器用給電線Ｌ３とほぼ同じ電圧（Ｈレベル）が印加される。すなわち、「Ｖｉｎ－＞Ｖｉｎ＋」に変化するから、比較器７１の出力ＶｏｕｔはＬレベルとなって正常動作用半導体スイッチ７２をオフにし、副スイッチ素子６０のゲート電圧ＶｇをＨレベルに上昇させるから、副半導体スイッチ６０がオフになる。なお、副半導体スイッチ６０がオフになった後、異常検出点７４には、異常検出用抵抗７３を設けたバイパス線路Ｌ５を介して電源電圧に近い高電圧が印加されるので、比較器７１の非反転入力Ｖｉｎ＋に入力される異常判定電圧は高電位を保持する。よって、「Ｖｉｎ－＜Ｖｉｎ＋」の関係が保持され、比較器７１の出力ＶｏｕｔもＨレベルを保持する。 Further, when the ignition signal Si stops (when the signal level returns to L) while the internal combustion engine ignition device 1 is in a normal state, the main semiconductor switch 30 is turned off, and the current path from the primary coil 11 to the ground point GND is turned off. is opened and the primary current I1 is interrupted. At the same time, the reference voltage generation semiconductor switch 82 is turned off, and almost the same voltage (H level) as that applied to the comparator power supply line L3 is applied to the inverting input line L7 of the comparator 71 . That is, since the change of "Vin->Vin+" occurs, the output Vout of the comparator 71 becomes L level to turn off the semiconductor switch 72 for normal operation and raise the gate voltage Vg of the auxiliary switch element 60 to H level. , the sub-semiconductor switch 60 is turned off. After the secondary semiconductor switch 60 is turned off, a high voltage close to the power supply voltage is applied to the abnormality detection point 74 via the bypass line L5 provided with the abnormality detection resistor 73. The abnormality determination voltage input to the non-inverting input Vin+ holds a high potential. Therefore, the relationship "Vin-<Vin+" is maintained, and the output Vout of the comparator 71 is also maintained at H level.

次に、上記のように構成した内燃機関用点火装置１における異常時の動作を、図３の波形図を用いて説明する。 Next, the operation of the internal combustion engine ignition device 1 configured as described above when there is an abnormality will be described with reference to the waveform diagram of FIG.

内燃機関用点火装置１が異常な状態、例えば、主半導体スイッチ３０が昇温により短絡した状態において、点火信号Ｓｉが入力されていないとき（信号レベルがＬのとき）、副半導体スイッチ６０はオフである。しかしながら、短絡異常の主半導体スイッチ３０によって、一次コイル１１から接地点ＧＮＤへの通電路が閉じた状態となる。このため、一次コイル１１には、異常検出用抵抗７３を設けたバイパス線路Ｌ５を介して一次電流Ｉ１が流れ続けることとなる。ただし、高抵抗の異常検出用抵抗７３を設けてあるため、一次コイル１１への給電量はわずかとなり、飽和に達した微少な一次電流Ｉ１が流れるにとどめ、一次コイル１１による発熱および電力損失を抑制する。また、異常検出点７４には、電源電圧が異常検出用抵抗７３により電圧低下した低い電圧が印加され、判定電圧取得線Ｌ６を介して比較器７１の非反転入力Ｖｉｎ＋には、低電位の異常判定電圧が入力される。このとき、基準電圧生成用半導体スイッチ８２はオフであるから、比較器７１の反転入力Ｖｉｎ－には、比較器用給電線Ｌ３とほぼ同じ電圧（Ｈレベル）が印加される。すなわち、「Ｖｉｎ－＞Ｖｉｎ＋」であるから、比較器７１の出力ＶｏｕｔはＬレベルのままで、正常動作用半導体スイッチ７２はオフを保持し、副スイッチ素子６０のゲート電圧ＶｇはＨレベルであるから、副半導体スイッチ６０もオフを保持する。 When the internal combustion engine ignition device 1 is in an abnormal state, for example, when the main semiconductor switch 30 is short-circuited due to temperature rise, and the ignition signal Si is not input (when the signal level is L), the sub semiconductor switch 60 is turned off. is. However, due to the short-circuited main semiconductor switch 30, the current path from the primary coil 11 to the ground point GND is closed. As a result, the primary current I1 continues to flow through the primary coil 11 through the bypass line L5 provided with the abnormality detection resistor 73 . However, since the high-resistance anomaly detection resistor 73 is provided, the amount of power supplied to the primary coil 11 is small, and only a very small saturated primary current I1 flows. Suppress. Further, a low voltage obtained by lowering the power supply voltage by the abnormality detection resistor 73 is applied to the abnormality detection point 74, and a low potential abnormality is applied to the non-inverting input Vin+ of the comparator 71 via the determination voltage acquisition line L6. A judgment voltage is input. At this time, since the reference voltage generation semiconductor switch 82 is off, the inverting input Vin- of the comparator 71 is applied with substantially the same voltage (H level) as that of the power supply line L3 for the comparator. That is, since "Vin->Vin+", the output Vout of the comparator 71 remains at L level, the normal operation semiconductor switch 72 is kept off, and the gate voltage Vg of the sub-switch element 60 is at H level. Therefore, the sub-semiconductor switch 60 is also kept off.

次いで、内燃機関用点火装置１が異常な状態において、点火信号Ｓｉが入力されると（信号レベルがＨに変わると）、イグナイタ制御回路５０から駆動信号が主半導体スイッチ３０のゲートに入力される。しかしながら、主半導体スイッチ３０は短絡異常で、既に一次コイル１１から接地点ＧＮＤに至る通電路は閉じている。同時に、基準電圧生成用半導体スイッチ８２がオンとなって第２分圧線Ｌ８ｂが接地点ＧＮＤに接続され、比較器７１の反転入力線Ｌ７には、第１，第２抵抗８１ａ，８１ｂの分圧比に応じた電圧（Ｌレベル）が印加される。しかしながら、比較器７１の非反転入力Ｖｉｎ＋に入力されているのは、低電位の異常判定電圧であるから、「Ｖｉｎ－＞Ｖｉｎ＋」が保持され、比較器７１の出力ＶｏｕｔはＬレベルを保持する。よって、正常動作用半導体スイッチ７２はオフを保持し、副スイッチ素子６０のゲート電圧ＶｇはＨレベルであるから、副半導体スイッチ６０もオフを保持する。 Next, when the ignition signal Si is input (when the signal level changes to H) while the internal combustion engine ignition device 1 is in an abnormal state, a drive signal is input from the igniter control circuit 50 to the gate of the main semiconductor switch 30. . However, the main semiconductor switch 30 is short-circuited, and the current path from the primary coil 11 to the ground point GND is already closed. At the same time, the semiconductor switch 82 for generating the reference voltage is turned on, the second voltage dividing line L8b is connected to the ground point GND, and the inverting input line L7 of the comparator 71 is connected to the first and second resistors 81a and 81b. A voltage (L level) corresponding to the pressure ratio is applied. However, since the non-inverting input Vin+ of the comparator 71 is inputted with a low-potential abnormality determination voltage, "Vin->Vin+" is held, and the output Vout of the comparator 71 holds L level. . Therefore, the normal operation semiconductor switch 72 is kept off, and since the gate voltage Vg of the sub-switch element 60 is at the H level, the sub-semiconductor switch 60 is also kept off.

このように、フェールセーフ手段７０は、異常検出用抵抗７３を備えたバイパス線路Ｌ５を設けることで、異常検出点７４の電位レベルから主半導体スイッチ３０の異常状態を検出し、副半導体スイッチ６０のオン動作を規制できる。点火信号Ｓｉによる通電タイミングであっても、副半導体スイッチ６０のオン動作を規制することで、一次電流Ｉ１を抑制すれば、一次コイル１１からの熱放散が抑えられ、温度低下に伴って主半導体スイッチ３０が正常状態へ戻る可能性を高められる。 Thus, the fail-safe means 70 detects an abnormal state of the main semiconductor switch 30 from the potential level of the abnormality detection point 74 by providing the bypass line L5 having the abnormality detection resistor 73, ON operation can be regulated. Even at the energization timing by the ignition signal Si, if the primary current I1 is suppressed by restricting the ON operation of the sub-semiconductor switch 60, the heat dissipation from the primary coil 11 is suppressed, and the temperature of the main semiconductor decreases as the temperature drops. The possibility of the switch 30 returning to its normal state is increased.

そして、主半導体スイッチ３０の短絡異常が解消されて正常状態に戻ったときには、一次コイル１１から接地点ＧＮＤへの通電路が遮断されるので、異常検出点７４の電位レベルから主半導体スイッチ３０が正常状態へ復帰したことを検出できる。主半導体スイッチ３０が正常状態に戻っていれば、点火信号Ｓｉの入力時には、副半導体スイッチ６０のオン動作が規制されることはないので、通常通り、一次コイル１１への通電・遮断制御が実行される。すなわち、フェールセーフ手段７０を用いれば、異常状態を回避するためにフェールセーフ機能が働いた後でも、正常状態へ自動復帰できるのである。 When the short-circuit abnormality of the main semiconductor switch 30 is eliminated and the normal state is restored, the current path from the primary coil 11 to the ground point GND is cut off. It can detect that it has returned to the normal state. If the main semiconductor switch 30 returns to its normal state, the on operation of the sub semiconductor switch 60 is not restricted when the ignition signal Si is input. be done. That is, if the fail-safe means 70 is used, the normal state can be automatically restored even after the fail-safe function works to avoid the abnormal state.

なお、上述した内燃機関用点火装置１では、副半導体スイッチ６０としてＰ型ＭＯＳＦＥＴを用いたが、これに限定されるものではない。例えば、副半導体スイッチ６０としてＰＮＰ型で高耐圧のＰＮＰパワートランジスタを用いても良い。斯くする場合、主半導体スイッチ３０が正常状態のときは、点火信号Ｓｉと同期してＰＮＰパワートランジスタのベース－エミッタ間電圧を低減させて、直流電源２０から一次コイル１１への通電路を閉じる。また、主半導体スイッチ３０が異常状態のときは、ＰＮＰパワートランジスタのベース－エミッタ間電圧を通常電圧に保持することで、ＰＮＰパワートランジスタのオン動作を規制できる。 In the internal combustion engine ignition device 1 described above, a P-type MOSFET is used as the sub-semiconductor switch 60, but the invention is not limited to this. For example, a PNP power transistor with a high withstand voltage may be used as the sub-semiconductor switch 60 . In this case, when the main semiconductor switch 30 is in a normal state, the base-emitter voltage of the PNP power transistor is reduced in synchronism with the ignition signal Si to close the conducting path from the DC power supply 20 to the primary coil 11 . Further, when the main semiconductor switch 30 is in an abnormal state, the ON operation of the PNP power transistor can be regulated by maintaining the base-emitter voltage of the PNP power transistor at a normal voltage.

副半導体スイッチ６０としてＰＮＰ型で高耐圧のＰＮＰパワートランジスタを用いる場合のフェールセーフ手段７０は、副半導体スイッチ６０として、Ｐ型ＭＯＳＦＥＴを用いる場合と同様に構成できる。異常検出用抵抗７３を備えるバイパス線路Ｌ５は、ＰＮＰパワートランジスタのコレクタ－エミッタ間を接続するように設ければ良い。比較器７１の非反転入力Ｖｉｎ＋に入力される異常判定電圧を取得するための判定電圧取得線Ｌ６は、ＰＮＰパワートランジスタと一次コイル１１との間に設けた異常検出点と接続すれば良い。そして、比較器７１が正常判定として出力ＶｏｕｔをＨレベルにすると、ＰＮＰパワートランジスタのベースから接地点ＧＮＤに至る通電路を開閉する正常動作用半導体スイッチ７２がオンとなって、直流電源２０から一次コイル１１への通電回路が閉じるのである。 The fail-safe means 70 in the case of using a PNP-type high-voltage PNP power transistor as the sub-semiconductor switch 60 can be constructed in the same manner as in the case of using a P-type MOSFET as the sub-semiconductor switch 60 . The bypass line L5 having the abnormality detection resistor 73 may be provided so as to connect the collector and emitter of the PNP power transistor. A determination voltage acquisition line L6 for acquiring an abnormality determination voltage input to the non-inverting input Vin+ of the comparator 71 may be connected to an abnormality detection point provided between the PNP power transistor and the primary coil 11 . When the comparator 71 sets the output Vout to H level as a normal judgment, the normal operation semiconductor switch 72 for opening and closing the conducting path from the base of the PNP power transistor to the ground point GND is turned on, and the DC power supply 20 is connected to the primary. The energized circuit to the coil 11 is closed.

上述した本実施形態の内燃機関用点火装置１では、主半導体スイッチ３０を点火コイル１０の接地側に設け、副半導体スイッチ６０を点火コイル１０の電源側に設けているため、異常検出によりフェールセーフ手段７０が作動しても、主半導体スイッチ３０の接地側が浮いた状態にならない。このため、一次コイル１１への通電により蓄えられたエネルギーは短絡異常が生じた主半導体スイッチ３０から接地点ＧＮＤへの電流として消費され、イグナイタ制御回路５０やフェールセーフ手段７０等の内部回路を破損してしまうような事態を避けられる。 In the internal combustion engine ignition device 1 of the present embodiment described above, the main semiconductor switch 30 is provided on the ground side of the ignition coil 10, and the sub semiconductor switch 60 is provided on the power supply side of the ignition coil 10. Therefore, failure safety can be achieved by detecting an abnormality. Actuation of the means 70 does not leave the ground side of the main semiconductor switch 30 floating. Therefore, the energy stored by energizing the primary coil 11 is consumed as a current from the main semiconductor switch 30 in which the short circuit has occurred to the ground point GND, and the internal circuits such as the igniter control circuit 50 and the fail safe means 70 are damaged. You can avoid situations that could happen.

また、本実施形態の内燃機関用点火装置１では、副半導体スイッチ６０のドレイン－ソース間を短絡するバイパス線路Ｌ５に異常検出用抵抗７３を設け、その抵抗から異常検出を行うものとしたので、サージ・ノイズの影響を受け易いリークチェック出力パルスを使う必要が無い。すなわち、リークチェック出力パルスによる異常チェックは、高インピーダンス状態で行う必要があり、サージ・ノイズの影響を受けやすく、誤判定が生じ易いという問題があるのに対して、フェールセーフ手段７０の異常検知では、そのような不具合は生じない。 Further, in the internal combustion engine ignition device 1 of the present embodiment, the abnormality detection resistor 73 is provided in the bypass line L5 that short-circuits between the drain and source of the sub-semiconductor switch 60, and the abnormality is detected from the resistance. There is no need to use the leak check output pulse, which is susceptible to surge noise. That is, the abnormality check by the leak check output pulse needs to be performed in a high impedance state, and is easily affected by surge noise, and there is a problem that an erroneous judgment is likely to occur. Then, such trouble does not occur.

さらに、本実施形態の内燃機関用点火装置１では、正常か異常かを判定する基準となる基準電圧信号を、定電流源などを用いず、点火信号Ｓｉのオン・オフに応じて生成する。正常状態で点火信号Ｓｉがオンのときには「Ｖｉｎ－＜Ｖｉｎ＋」が成立して副半導体スイッチ６０が動作し、正常状態でも点火信号Ｓｉがオフのときには「Ｖｉｎ－＞Ｖｉｎ＋」であるから、副半導体スイッチ６０の動作が規制される。一方、異常状態のときには、点火信号Ｓｉがオンでもオフでも「Ｖｉｎ－＞Ｖｉｎ＋」が成立するので、副半導体スイッチ６０の動作は規制され続ける。すなわち、点火信号Ｓｉのオン・オフにかかわらず、主半導体スイッチ３０の異常監視を常に行うことができる。 Furthermore, in the internal combustion engine ignition device 1 of the present embodiment, the reference voltage signal that serves as a reference for judging normality or abnormality is generated according to the on/off state of the ignition signal Si without using a constant current source or the like. When the ignition signal Si is on in the normal state, "Vin-<Vin+" is established and the sub-semiconductor switch 60 operates. The operation of switch 60 is restricted. On the other hand, in the abnormal state, "Vin->Vin+" holds regardless of whether the ignition signal Si is on or off, so the operation of the sub-semiconductor switch 60 continues to be restricted. That is, regardless of whether the ignition signal Si is on or off, the abnormality monitoring of the main semiconductor switch 30 can always be performed.

以上、本発明に係る内燃機関用点火装置の実施形態を添付図面に基づいて説明したが、本発明は、この実施形態に限定されるものではなく、特許請求の範囲に記載の構成を変更しない範囲で、公知既存の等価な技術手段を転用することにより実施しても構わない。 The embodiments of the internal combustion engine ignition device according to the present invention have been described above with reference to the accompanying drawings. It may be implemented by diverting known and existing equivalent technical means within the scope.

１ 内燃機関用点火装置
１０ 点火コイル
１１ 一次コイル
１２ 二次コイル
２０ 直流電源
３０ 主半導体スイッチ
４０ ＥＣＵ
５０ イグナイタ制御回路
６０ 副半導体スイッチ
７０ フェールセーフ手段
８０ 基準電圧生成手段 1 Ignition Device for Internal Combustion Engine 10 Ignition Coil 11 Primary Coil 12 Secondary Coil 20 DC Power Supply 30 Main Semiconductor Switch 40 ECU
50 igniter control circuit 60 sub-semiconductor switch 70 fail-safe means 80 reference voltage generation means

Claims (6)

点火サイクルの所要タイミングで入力される点火信号に基づいて、点火コイルの一次コイルに流れる一次電流を通電・遮断制御し、二次側に高電圧を発生させる内燃機関用点火装置において、
前記一次コイルと接地点との間に設けられ、前記点火信号のオン・オフに応じて前記一次コイルから前記接地点への通電路を開閉する主半導体スイッチと、
前記一次コイルと電源との間に設けられ、該電源から前記一次コイルへの通電路を開閉する副半導体スイッチと、
前記主半導体スイッチの異常状態を検出することに基づいて、前記副半導体スイッチのオン動作を規制するフェールセーフ手段と、
を備え、
前記副半導体スイッチとして、Ｐ型ＭＯＳＦＥＴを用い、
前記フェールセーフ手段は、前記主半導体スイッチが正常状態のとき、前記点火信号と同期して前記副半導体スイッチのゲート－ソース間電圧を低減させて、前記電源から前記一次コイルへの前記通電路を閉じ、前記主半導体スイッチが異常状態のとき、前記副半導体スイッチのゲート－ソース間電圧を通常電圧に保持する、
ことを特徴とする内燃機関用点火装置。 An ignition device for an internal combustion engine that controls energization/cutoff of a primary current flowing through a primary coil of an ignition coil based on an ignition signal input at a required timing of an ignition cycle to generate a high voltage on the secondary side,
a main semiconductor switch provided between the primary coil and the grounding point for opening and closing an electric path from the primary coil to the grounding point according to on/off of the ignition signal;
a sub-semiconductor switch provided between the primary coil and a power supply for opening and closing an electric path from the power supply to the primary coil;
fail-safe means for regulating the ON operation of the sub-semiconductor switch based on detection of an abnormal state of the main semiconductor switch;
with
Using a P-type MOSFET as the sub semiconductor switch,
When the main semiconductor switch is in a normal state, the fail-safe means reduces the voltage between the gate and the source of the sub semiconductor switch in synchronization with the ignition signal to close the current path from the power supply to the primary coil. closed to hold the gate-source voltage of the secondary semiconductor switch at a normal voltage when the primary semiconductor switch is in an abnormal state;
An ignition device for an internal combustion engine, characterized by: 前記フェールセーフ手段は、前記主半導体スイッチが異常状態から正常状態へ復帰したことを検出することに基づいて、前記副半導体スイッチのオン動作規制を解除することを特徴とする請求項１に記載の内燃機関用点火装置。 2. The fail-safe means according to claim 1, wherein said fail-safe means cancels ON operation restriction of said sub-semiconductor switch based on detecting that said main semiconductor switch has returned from an abnormal state to a normal state. Ignition device for internal combustion engines. 前記フェールセーフ手段は、
前記副半導体スイッチのドレイン－ソース間を接続する異常検出用抵抗と、
前記副半導体スイッチと前記一次コイルとの間に設けた異常検出点の電圧を取得する判定電圧取得線と、
前記判定電圧取得線から取得した異常判定電圧と、正常判定閾値である基準電圧とを比較して、正常判定の場合にのみ正常信号を出力する比較器と、
前記副半導体スイッチのゲートから前記接地点に至る通電路に設けられ、前記比較器からの正常信号が入力されることで、前記副半導体スイッチのゲートから前記接地点に至る前記通電路を閉じる正常動作用半導体スイッチと、
を備えることを特徴とする請求項１又は請求項２に記載の内燃機関用点火装置。 The fail-safe means are
an abnormality detection resistor connecting between the drain and source of the sub-semiconductor switch;
a determination voltage acquisition line for acquiring a voltage at an abnormality detection point provided between the secondary semiconductor switch and the primary coil;
a comparator that compares the abnormality determination voltage acquired from the determination voltage acquisition line with a reference voltage that is a normality determination threshold, and outputs a normal signal only in the case of normality determination;
A normal circuit is provided in the conducting path from the gate of the sub-semiconductor switch to the grounding point, and closes the conducting path from the gate of the sub-semiconductor switch to the grounding point by inputting a normal signal from the comparator. an operating semiconductor switch;
3. The ignition device for an internal combustion engine according to claim 1, comprising : 点火サイクルの所要タイミングで入力される点火信号に基づいて、点火コイルの一次コイルに流れる一次電流を通電・遮断制御し、二次側に高電圧を発生させる内燃機関用点火装置において、 An ignition device for an internal combustion engine that controls energization/cutoff of a primary current flowing through a primary coil of an ignition coil based on an ignition signal input at a required timing of an ignition cycle to generate a high voltage on the secondary side,
前記一次コイルと接地点との間に設けられ、前記点火信号のオン・オフに応じて前記一次コイルから前記接地点への通電路を開閉する主半導体スイッチと、 a main semiconductor switch provided between the primary coil and the grounding point for opening and closing an electric path from the primary coil to the grounding point according to on/off of the ignition signal;
前記一次コイルと電源との間に設けられ、該電源から前記一次コイルへの通電路を開閉する副半導体スイッチと、 a sub-semiconductor switch provided between the primary coil and a power supply for opening and closing an electric path from the power supply to the primary coil;
前記主半導体スイッチの異常状態を検出することに基づいて、前記副半導体スイッチのオン動作を規制するフェールセーフ手段と、 fail-safe means for regulating the ON operation of the sub-semiconductor switch based on detection of an abnormal state of the main semiconductor switch;
を備え、 with
前記副半導体スイッチとして、ＰＮＰ型で高耐圧のＰＮＰパワートランジスタを用い、 A PNP power transistor with a high withstand voltage is used as the secondary semiconductor switch,
前記フェールセーフ手段は、前記主半導体スイッチが正常状態のとき、前記点火信号と同期して前記副半導体スイッチのベース－エミッタ間電圧を低減させて、前記電源から前記一次コイルへの前記通電路を閉じ、前記主半導体スイッチが異常状態のとき、前記副半導体スイッチのベース－エミッタ間電圧を通常電圧に保持する、 When the main semiconductor switch is in a normal state, the fail-safe means reduces the base-emitter voltage of the sub semiconductor switch in synchronism with the ignition signal to close the current path from the power supply to the primary coil. closed to hold the base-emitter voltage of the secondary semiconductor switch at a normal voltage when the primary semiconductor switch is in an abnormal state;
ことを特徴とする内燃機関用点火装置。 An ignition device for an internal combustion engine, characterized by: 前記フェールセーフ手段は、前記主半導体スイッチが異常状態から正常状態へ復帰したことを検出することに基づいて、前記副半導体スイッチのオン動作規制を解除することを特徴とする請求項４に記載の内燃機関用点火装置。 5. The fail-safe means according to claim 4 , wherein said fail-safe means cancels ON operation restriction of said sub-semiconductor switch based on detecting that said main semiconductor switch returns from an abnormal state to a normal state. Ignition device for internal combustion engines. 前記フェールセーフ手段は、
前記副半導体スイッチのコレクタ－エミッタ間を接続する異常検出用抵抗と、
前記副半導体スイッチと前記一次コイルとの間に設けた異常検出点の電圧を取得する判定電圧取得線と、
前記判定電圧取得線から取得した異常判定電圧と、正常判定閾値である基準電圧とを比較して、正常判定の場合にのみ正常信号を出力する比較器と、
前記副半導体スイッチのベースから前記接地点に至る通電路に設けられ、前記比較器からの正常信号が入力されることで、前記副半導体スイッチのベースから前記接地点に至る前記通電路を閉じる正常動作用半導体スイッチと、
を備えることを特徴とする請求項４又は請求項５に記載の内燃機関用点火装置。 The fail-safe means are
an abnormality detection resistor connecting between the collector and the emitter of the secondary semiconductor switch;
a determination voltage acquisition line for acquiring a voltage at an abnormality detection point provided between the secondary semiconductor switch and the primary coil;
a comparator that compares the abnormality determination voltage acquired from the determination voltage acquisition line with a reference voltage that is a normality determination threshold, and outputs a normal signal only in the case of normality determination;
A normalization circuit is provided in the conducting path from the base of the sub semiconductor switch to the grounding point, and closes the conducting path from the base of the subsemiconductor switch to the grounding point when a normal signal from the comparator is input. an operating semiconductor switch;
The ignition device for an internal combustion engine according to claim 4 or 5, characterized by comprising:
JP2019119629A 2019-06-27 2019-06-27 Ignition device for internal combustion engine Active JP7286442B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2019119629A JP7286442B2 (en) 2019-06-27 2019-06-27 Ignition device for internal combustion engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2019119629A JP7286442B2 (en) 2019-06-27 2019-06-27 Ignition device for internal combustion engine

Publications (2)

Publication Number Publication Date
JP2021004589A JP2021004589A (en) 2021-01-14
JP7286442B2 true JP7286442B2 (en) 2023-06-05

Family

ID=74097591

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2019119629A Active JP7286442B2 (en) 2019-06-27 2019-06-27 Ignition device for internal combustion engine

Country Status (1)

Country Link
JP (1) JP7286442B2 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002061558A (en) 2000-08-21 2002-02-28 Kokusan Denki Co Ltd Ignition device for internal combustion engine
JP2002157027A (en) 2000-11-20 2002-05-31 Mitsubishi Electric Corp Power conversion device and semiconductor device
JP2002303238A (en) 2001-04-05 2002-10-18 Nippon Soken Inc Ignition device for internal combustion engine
JP2003314419A (en) 2002-04-26 2003-11-06 Kokusan Denki Co Ltd Ignition device for internal combustion engine

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5827099Y2 (en) * 1976-11-24 1983-06-11 日本電気株式会社 Internal combustion engine ignition system
US9745947B2 (en) * 2013-08-08 2017-08-29 Fairchild Semiconductor Corporation Ignition control circuit with short circuit protection

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002061558A (en) 2000-08-21 2002-02-28 Kokusan Denki Co Ltd Ignition device for internal combustion engine
JP2002157027A (en) 2000-11-20 2002-05-31 Mitsubishi Electric Corp Power conversion device and semiconductor device
JP2002303238A (en) 2001-04-05 2002-10-18 Nippon Soken Inc Ignition device for internal combustion engine
JP2003314419A (en) 2002-04-26 2003-11-06 Kokusan Denki Co Ltd Ignition device for internal combustion engine

Also Published As

Publication number Publication date
JP2021004589A (en) 2021-01-14

Similar Documents

Publication Publication Date Title
US8006678B2 (en) Igniter system
JP5203859B2 (en) Failure diagnosis device for electromagnetic load circuit
US10340908B2 (en) Half-bridge driver fault diagnostic system and method
US9745947B2 (en) Ignition control circuit with short circuit protection
EP1763137B1 (en) A driver circuit
US9698574B2 (en) Method of forming an igniter circuit and structure therefor
US20060152865A1 (en) Circuit for protecting a transistor from an open secondary ignition coil
US9525273B1 (en) Method of forming an igniter circuit and structure therefor
US9419523B2 (en) Method for identifying a short-line fault or a line interruption for a switched inductive load
US11879929B2 (en) Method and device for automatically testing a switching member
JP2017210936A (en) Fault diagnosis equipment for electromagnetic load driving circuit
US5483406A (en) Overvoltage protection circuit
US20080218002A1 (en) Control system
US20180323776A1 (en) Safe control of a consumer
US10535989B2 (en) Semiconductor apparatus
JP4445021B2 (en) Internal combustion engine ignition device
US8284535B2 (en) Backup tripping function for a circuit breaker with microcontroller-based fault detection
JP2014060266A (en) Solenoid valve drive device
JP7286442B2 (en) Ignition device for internal combustion engine
KR101876517B1 (en) An Apparatus And A Method For Blocking Overcurrent
JP2004505359A (en) Mode switching power supply control
KR102100861B1 (en) An Apparatus And A Method For Testing A Low-side Driving IC
JP2008011347A (en) Load disconnection detection circuit
US6333604B1 (en) Integrated ignition circuit and method
US8116056B2 (en) Low voltage startup timer for a microcontroller-based circuit breaker

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20220329

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20230110

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20230112

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20230302

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20230509

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20230524

R150 Certificate of patent or registration of utility model

Ref document number: 7286442

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150