JP4055107B2 - Fuel leak detection device for gaseous fuel engine - Google Patents

Fuel leak detection device for gaseous fuel engine Download PDF

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JP4055107B2
JP4055107B2 JP2001192516A JP2001192516A JP4055107B2 JP 4055107 B2 JP4055107 B2 JP 4055107B2 JP 2001192516 A JP2001192516 A JP 2001192516A JP 2001192516 A JP2001192516 A JP 2001192516A JP 4055107 B2 JP4055107 B2 JP 4055107B2
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fuel
value
stop
engine
opening
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JP2003003909A (en
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浩敬 松田
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Suzuki Motor Co Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D19/02—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with gaseous fuels
    • F02D19/025—Failure diagnosis or prevention; Safety measures; Testing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D19/02—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with gaseous fuels
    • F02D19/026—Measuring or estimating parameters related to the fuel supply system
    • F02D19/027—Determining the fuel pressure, temperature or volume flow, the fuel tank fill level or a valve position
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D41/0027—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures the fuel being gaseous
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
    • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
    • F02M21/0218—Details on the gaseous fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
    • F02M21/0221—Fuel storage reservoirs, e.g. cryogenic tanks
    • F02M21/0224—Secondary gaseous fuel storages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
    • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
    • F02M21/0218—Details on the gaseous fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
    • F02M21/029—Arrangement on engines or vehicle bodies; Conversion to gaseous fuel supply systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F02D2041/224—Diagnosis of the fuel system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F02D2041/224—Diagnosis of the fuel system
    • F02D2041/225—Leakage detection
    • 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
    • Y02T10/30—Use of alternative fuels, e.g. biofuels

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Description

【０００１】
【発明の属する技術分野】
この発明は、気体燃料エンジンの燃料漏れ検出装置に係り、特に気体燃料の漏れ検出をエンジンの始動前の車両停止状態で行う気体燃料エンジンの燃料漏れ検出装置に関する。
【０００２】
【従来の技術】
車両には、気体燃料であるＣＮＧ（圧縮天然ガス）を燃料とするエンジンを搭載した気体燃料車両である天然ガス自動車（ＮＧＶ）がある。
【０００３】
このような車両においては、エンジンに供給される気体燃料が充填された燃料容器を設け、この燃料容器が少なくとも主止弁とレギュレータとを介して燃料噴射弁に連結した燃料供給系を設けている。燃料容器内の気体燃料は、燃料供給系の燃料供給管により取り出され、レギュレータ（減圧弁）により所定の圧力・流量に調整され、燃料噴射弁から空気と混合してエンジンに供給される。
【０００４】
また、燃料容器には、一般に、容器元弁に過流防止弁を設けている。この過流防止弁は、例えば燃料配管系の損傷によって一定の流量（エンジンで消費する以上の大容量）以上の気体燃料が流れた場合に、機械的に閉動作し、燃料容器内からの気体燃料の流出を遮断するものである。
【０００５】
このような気体燃料エンジンの燃料漏れ検出装置としては、例えば、特開平９−２４２６１４号公報、特開平１１−１０７８６０号公報、特開１９９６−２７７７５０号公報、特開２００１−４１１０６号公報に開示されている。特開平９−２４２６１４号公報に記載のものは、車両の走行時に、圧力センサの検出する気体燃料の単位時間当たりの現在圧力変化量と予め設定した単位当たりの基本圧力変化量との比が設定値以上の場合に、燃料漏れと判定するものである。特開平１１−１０７８６０号公報に記載のものは、エンジンの停止時に高圧側で気体燃料の温度及び圧力値を検出し、これら検出した各値を記憶させ、そして、エンジンの始動直前に、このエンジン始動直前に検出した気体燃料の温度及び圧力値と前記記憶させた気体燃料の温度及び圧力値とに基づいて、前回のエンジン停止時からエンジン始動直前までの燃料供給系の状態変化により、燃料漏れを判定するものである。特開１９９６−２７７７５０号公報に記載のものは、算出される燃料タンクのタンク消費燃料量と燃料噴射弁の噴射消費燃料量とを基に、燃料供給系からの燃料漏れを判定するものである。特開２００１−４１１０６号公報に記載のものは、エンジンの停止時に、気体燃料の圧力を時間差をおいて検出し、この気体燃料の圧力の検出値を比較して低下量を検出し、この低下量に基づいて燃料漏れを判定するものである。
【０００６】
【発明が解決しようとする課題】
ところで、従来、気体燃料エンジンの燃料漏れ検出装置において、実際、車両で発生する燃料漏れとしては、車両の振動等によって燃料供給系の配管の継手がゆるみ、気体燃料が徐々に漏れて行く場合が多く、このような燃料漏れの防止策としては、圧力センサを用いて、気体燃料の圧力低下を検出しているが、この場合に、エンジンが運転状態で気体燃料の燃料漏れの判定を行うので、迅速に対処することができず、エンジンを停止したり、運転者にその燃料漏れの異常を認識させることが困難であるという不都合があった。
【０００７】
【課題を解決するための手段】
そこで、この発明は、上述の不都合を除去するために、車両に搭載したエンジンに供給される気体燃料が充填された燃料容器を設け、この燃料容器が少なくとも主止弁とレギュレータとを介して燃料噴射弁に連結した燃料供給系を設けた気体燃料エンジンの燃料漏れ検出装置において、前記主止弁と前記燃料噴射弁との間の燃料残圧値を検出可能な燃料残圧検出手段を設け、前記主止弁と前記燃料噴射弁との間の燃料温度を検出可能な燃料温度検出手段を設け、前記燃料温度検出手段で検出された燃料温度に応じて変化する燃料温度補正値を算出する補正値算出部と、前回運転のエンジン停止直前の停止直前燃料残圧値及び停止直前燃料温度補正値を記憶する停止直前記憶部と、イグニションスイッチがオンで且つ前記主止弁が開動作される前の開弁前燃料残圧値及び開弁前燃料温度補正値を検出する開弁前検出部と、前回運転のエンジン停止時から燃料漏れ検出時までの停止後経過時間を検出する停止後経過時間検出部と、前記停止直前燃料残圧値と前記停止直前燃料温度補正値と前記開弁前燃料残圧値と前記開弁前燃料温度補正値と前記停止後経過時間とから燃料漏れを判定する燃料漏れ判定部とを備えた制御手段を設け、前記燃料漏れ判定部は、前記停止直前燃料残圧値と前記停止直前燃料温度補正値との積を第１の記憶値とし、前記開弁前燃料残圧値と前記開弁前燃料温度補正値との積を第１の測定値とし、前記第１の記憶値から前記第１の測定値を引いた値を前記停止後経過時間で割った値が、予め設定された第１の設定値よりも大きい場合には、燃料漏れと判定するとともに、前記第１の設定値は、前回運転のエンジン停止前に気体燃料が前記燃料容器に充填されたか否かによって異なることを特徴とする。
【０００８】
【発明の実施の形態】
この発明は、エンジンの始動前で車両停止状態において気体燃料の漏れを判定することができ、これにより、車両の走行前で運転者にその燃料漏れの異常を認識させることができ、また、気体燃料の漏れ量が多い場合には、エンジンを停止させたりすることができる。
【０００９】
【実施例】
以下図面に基づいてこの発明の実施例を詳細且つ具体的に説明する。図１〜６は、この発明の第１実施例を示すものである。図５、６において、２は気体燃料自動車（以下「車両」という）、４はこの車両２に搭載される例えば３気筒の多気筒用のエンジン、６・６は後輪、８はリアアクスル軸、１０は車体フロア、１２はガス燃料充填装置、１４は燃料供給系を構成するガス燃料供給装置、１６は排気装置、１８はアウタパネルである。
【００１０】
エンジン４には、図５に示す如く、吸気系に、吸気マニホルド２０と、スロットルバルブ２２を備えたスロットルボディ２４と、吸気管２６と、エアクリーナ２８とが設けられ、また、排気系に、排気装置１６を構成するように、排気マニホルド３０と、三元触媒３２と、フロントマフラ３４及びリアマフラ３６を備えた排気管３８とが設けられている。吸気マニホルド２０には、各気筒に対応して第１〜３燃料噴射弁４０−１〜４０−３が取り付けられている。この第１〜３燃料噴射弁４０−１〜４０−３は、図６に示す如く、燃料デリバリパイプ４２に接続している。
【００１１】
車両２には、車体フロア１０よりも下方において、車幅方向に指向するリアアクスル軸８よりも車両２の前方側に、気体燃料としての加圧した圧縮天然ガス（ＣＮＧ）を充填する後側、前側の２つの第１、第２燃料容器４４−１、４４−２が車幅方向に指向し且つ車両２の前後で並んで設置される。
【００１２】
この第１、第２燃料容器４４−１、４４−２の車幅方向の左側には、第１、第２容器元弁４６−１、４６−２が設けられている。また、この第１、第２燃料容器４４−１、４４−２は、充填連絡パイプ４８で連絡されている。
【００１３】
第１燃料容器４４−１には、ガス燃料充填装置１２の燃料充填管５０の一端側が接続されている。この燃料充填管５０の他端側は、アウタパネル１８に取り付けたレセプタクルボックス５２の充填口５４に接続されている。この充填口５４には、フューエルリッド（図示せず）が取り付けられる。
【００１４】
この燃料充填管５０には、充填口５４側から順次に、この充填口５４側からの気体燃料を第１、第２燃料容器４４−１、４４−２側に充填させる燃料充填弁（ボールバルブ）５６と、第１、第２燃料容器４４−１、４４−２側からの気体燃料が充填口５４側に逆流するのを阻止する逆止弁５８とが設けられている。
【００１５】
第２燃料容器４４−２には、ガス燃料供給装置１４の燃料供給管６０の一端側が接続されている。この燃料供給管６０の他端側は、吸気マニホルド２０に取り付けた燃料デリバリパイプ４２に接続されている。
【００１６】
この燃料供給管６０には、第２燃料容器４４−２側から順次に、エンジン４の停止時に該燃料供給管６０を遮断するように閉動作する主止弁（電磁弁）６２と、気体燃料を濾過するガスフィルタ６４と、気体燃料の圧力・流量を一定に調整するレギュレータ（減圧弁）６６とが設けられている。
【００１７】
主止弁６２と燃料噴射弁４０との間の燃料供給管６０には、燃料残圧値（Ｐ）を検出可能な燃料残圧検出手段として残量圧力センサ６８が設けられている。この残量圧力センサ６８には、デジタル燃料計７０とアナログ燃料計７２とが連絡している。
【００１８】
燃料デリバリパイプ４２には、主止弁６２と燃料噴射弁４０との間の燃料温度を検出可能な燃料温度検出手段としての燃料温度センサ７４と、主止弁６２と燃料噴射弁４０との間の燃料圧力を検出可能な燃料圧力検出手段としての燃料圧力センサ７６とが取り付けられている。
【００１９】
また、吸気管２６には、内部の吸気路を流れる吸入空気の温度を検出する吸気温センサ７８が設けられている。スロットルボディ２４には、スロットルバルブ２２の開度状態を検出するスロットルセンサ８０が設けられている。吸気マニホルド２０には、吸気管圧力を検出する吸気管圧力センサ８２が設けられている。排気マニホルド３０には、内部の排気路を流れる排気中の酸素濃度を検出する酸素濃度センサ８４が設けられている。
【００２０】
燃料噴射弁４０と主止弁６２と燃料温度センサ７４と燃料圧力センサ７６と吸気温センサ７８とスロットルセンサ８０と吸気管圧力センサ８２と酸素濃度センサ８４とは、制御手段８６に連絡している。また、この制御手段８６には、エンジン４の冷却水温度を検出する水温センサ８８と、エンジン２のイグニションスイッチ９０と、警告手段としてのダイアグランプ９２と、フューエルリッドの開閉を検出してその信号を出力するフューエルリッドスイッチ９４と、エンジン４のスタータ９６とが連絡している。
【００２１】
このエンジン４で使用する気体燃料の特性は、図２に示す如く、体積一定条件の下で、温度の変化によって圧力も変化してしまい、つまり、温度が高いと圧力も高くなり、また、図３に示す如く、車両２の停止時間が長いと温度が低くなり、更に、図４に示す如く、車両２の停止時間が長いと、燃料漏れがなくても、燃料残圧値が低くなるものである。
【００２２】
制御手段８６には、燃料温度センサ７４で検出された燃料温度に応じて変化する燃料温度補正値（Ｔ）を算出する補正値算出部８６Ａと、前回運転のエンジン停止直前の停止直前燃料残圧値（Ｐｏｆｆ）及び停止直前燃料温度補正値（Ｔｏｆｆ）を記憶する停止直前記憶部８６Ｂと、イグニションスイッチ９０がオンで且つ主止弁６２が開動作される前の現在の開弁前燃料残圧値（Ｐｏｎ）及び開弁前燃料温度補正値（Ｔｏｎ）を検出する開弁前検出部８６Ｃと、前回運転のエンジン停止時から燃料漏れ検出時までの停止後経過時間（Ｈ）を検出する停止後経過時間検出部８６Ｄと、停止直前燃料残圧値（Ｐｏｆｆ）と停止直前燃料温度補正値（Ｔｏｆｆ）と開弁前燃料残圧値（Ｐｏｎ）と開弁前燃料温度補正値（Ｔｏｎ）と停止後経過時間（Ｈ）とから燃料漏れを判定する燃料漏れ判定部８６Ｅと、時間を計測するタイマ８６Ｆとが、備えられている。
【００２３】
燃料漏れ判定部８６Ｅは、停止直前燃料残圧値（Ｐｏｆｆ）と停止直前燃料温度補正値（Ｔｏｆｆ）との積を第１の記憶値（Ｐｏｆｆ＊Ｔｏｆｆ）とし、開弁前燃料残圧値（Ｐｏｎ）と開弁前燃料温度補正値（Ｔｏｎ）との積を第１の測定値（Ｐｏｎ＊Ｔｏｎ）とし、第１の記憶値（Ｐｏｆｆ＊Ｔｏｆｆ）から第１の測定値（Ｐｏｎ＊Ｔｏｎ）を引いた値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）｝を停止後経過時間（Ｈ）で割った値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ｝が、予め設定された二種類の第１の設定値（Ｘ、Ｙ）よりも大きい場合には、燃料漏れと判定するものである。
【００２４】
一つの第１の設定値（Ｘ）と他の第１の設定値（Ｙ）とは、前回運転のエンジン停止前に気体燃料が第１、第２燃料容器４４−１、４４−２に充填されたか否かによって異なるものであり、Ｘ≠Ｙの関係がある。具体的には、前回運転のエンジン停止前に気体燃料が第１、第２燃料容器４４−１、４４−２に充填されていた場合には、一つの第１の設定値（Ｘ）を用い、一方、前回運転のエンジン停止前に気体燃料が第１、第２燃料容器４４−１、４４−２に充填されていない場合には、他の第１の設定値（Ｙ）を用いる。これは、気体燃料の第１、第２燃料容器４４−１、４４−２への充填直後に、第１、第２燃料容器４４−１、４４−２内の燃料温度が高くなり、その後、燃料温度が外気温まで下がるため、燃料圧力もその充填後に低下し、この燃料圧力の低下の影響による燃料漏れの誤判定を防止するのが目的であり、次の燃料漏れ判定を、第１、第２燃料容器４４−１、４４−２への充填直後の場合に、その燃料圧力の低下を考慮して判定を行なうためである。
【００２５】
前回運転のエンジン停止前に気体燃料が第１、第２燃料容器４４−１、４４−２に充填されたか否かの検出は、フューエルリッドの開閉によるフューエルリッドスイッチ９２からの信号の有無による検出方法、あるいは、主止弁６２の開動作の前の開弁前燃料圧力値と主止弁６２の開動作の後の開弁後燃料圧力値とを測定して、この開弁前燃料圧力値と開弁後燃料圧力値との差圧値を設定値と比較することよる検出方法の、少なくとも一方の検出方法を用いている。
【００２６】
制御手段８４は、燃料漏れ判定部８４Ｅが燃料漏れと判定した場合に、警告手段としてのダイアグランプ９２や警告音で燃料漏れを告知し、第１の記憶値（Ｐｏｆｆ＊Ｔｏｆｆ）から第１の測定値（Ｐｏｎ＊Ｔｏｎ）を引いた値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）｝を停止後経過時間（Ｈ）で割った値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ｝が、前記第１の設定値（Ｘ、Ｙ）よりも大きな値に予め設定した第２の設定値（Ｚ）よりも大きい場合には、エンジン４が始動できないように制御する。
【００２７】
次に、この第１実施例の作用を、図１のフローチャートに基づいて説明する。
【００２８】
制御手段８６においては、制御動作の開始前に、前回運転のエンジン停止直前の停止直前燃料残圧値（Ｐｏｆｆ）及び停止直前燃料温度補正係数（Ｔｏｆｆ）を停止直前記憶部８６Ｂに記憶してあり、また、エンジン４の停止時から燃料漏れの検出時までの停止後経過時間（Ｈ）を管理していることが、前提条件となっている。
【００２９】
そして、制御手段８６のプログラムがスタートし（ステップ１０２）、イグニションスイッチ９０をオンとし（ステップ１０４）、このイグニションスイッチ９０のオン後に、主止弁６２を開動作する前の現在の燃料残圧値である開弁前燃料残圧値（Ｐｏｎ）と、現在の燃料温度補正係数である開弁前燃料温度補正係数（Ｔｏｎ）と、前回運転のエンジン停止時から燃料漏れの検出時までの停止後経過時間（Ｈ）とを読み込む（ステップ１０６）。
【００３０】
そして、前回運転のエンジン４の停止前に気体燃料が第１、第２燃料容器４４−１、４４−２に充填されたか否か、つまり、燃料充填後判定条件が成立か否かを判断する（ステップ１０８）。この燃料充填後判定条件は、気体燃料の第１、第２燃料容器４４−１、４４−２への充填直後は、第１、第２燃料容器４４−１、４４−２内の燃料温度が高くなり、その後、燃料温度が外気温まで下がるため、燃料圧力もその充填後に低下し、この燃料圧力の低下の影響による燃料漏れの誤判定を防止するのが目的であり、次の燃料漏れ判定を、気体燃料を第１、第２燃料容器４４−１、４４−２に充填直後の場合に、その燃料圧力の低下を考慮して判定を行なうためである。
【００３１】
このステップ１０８がＹＥＳで、燃料充填後判定条件が成立の場合には、燃料漏れ判定条件が成立したか否かを判断する（ステップ１１０）。つまり、（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ＞Ｘ（一つの第１の設定値）を、判断する。
【００３２】
このステップ１１０がＹＥＳで、燃料漏れ判定条件が成立した場合には、燃料漏れがあり、ダイアグランプ９２を点灯したり、警告音で、運転者にその燃料漏れの異常を認識（告知）させる（ステップ１１４）。
【００３３】
一方、前記ステップ１０８がＮＯで、燃料充填後判定条件が不成立の場合には、燃料漏れ判定条件が成立したか否かを判断する（ステップ１１２）。つまり、（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ＞Ｙ（他の第１の設定値）を、判断する。
【００３４】
このステップ１１２がＹＥＳで、燃料漏れ判定条件が成立した場合には、燃料漏れがあり、ダイアグランプ９２を点灯したり、警告音で運転者にその燃料漏れの異常を認識させる（ステップ１１４）。
【００３５】
そして、ステップ１１４の処理後は、エンジン停止条件が成立したか否かを判断する（ステップ１１６）。つまり、（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ＞Ｚ（第２の設定値）を判断する。これは、燃料残圧の低下が第２の設定値（Ｚ）以上あったかどうかを判断するものであり、つまり、（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ＞Ｚで、エンジン停止条件が成立したか否かを判断する。
【００３６】
このステップ１１６がＹＥＳで、エンジン停止条件が成立した場合には、燃料漏れ量が多くなり（ステップ１１８）、そして、エンジン４が始動できないように、スタータ９６の駆動を停止し（ステップ１２０）、プログラムをエンドとする（ステップ１２２）。
【００３７】
一方、前記ステップ１１０、１１２でＮＯで、燃料漏れ判定条件が不成立の場合には、燃料漏れがないとし（ステップ１２４）、プログラムをエンドとする（ステップ１２２）。
【００３８】
また、前記ステップ１１６がＮＯで、エンジン停止条件が不成立の場合には、直ちにプログラムをエンドとする（ステップ１２２）。
【００３９】
この結果、気体燃料の漏れ検出を、エンジン４の始動前で、車両２の停止状態で行うことで、エンジン４の始動前に運転者にその燃料漏れの異常を認識させることができ、つまり、前回運転のエンジン停止前の燃料残圧値と今回運転の主止弁６２の開動作前の燃料残圧値とにより、エンジン停止（車両停止）中の主止弁６２と燃料噴射弁４０間の燃料漏れを検出して、燃料漏れがあった場合には、警告手段で告知し、また、燃料漏れ量が多い場合には、エンジン４を停止したりすることができる。
【００４０】
また、燃料温度に応じて燃料温度補正係数（Ｔ）を設定しているので、燃料温度の変化による燃料圧力の低下による影響をなくし、燃料漏れの誤判定を防止することができる。
【００４１】
更に、燃料漏れ判定部８６Ｅは、停止直前燃料残圧値（Ｐｏｆｆ）と停止直前燃料温度補正値（Ｔｏｆｆ）との積を第１の記憶値（Ｐｏｆｆ＊Ｔｏｆｆ）とし、開弁前燃料残圧値（Ｐｏｎ）と開弁前燃料温度補正値（Ｔｏｎ）との積を第１の測定値（Ｐｏｎ＊Ｔｏｎ）とし、第１の記憶値（Ｐｏｆｆ＊Ｔｏｆｆ）から第１の測定値（Ｐｏｎ＊Ｔｏｎ）を引いた値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）｝を停止後経過時間（Ｈ）で割った値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ｝が、予め設定された二種類の第１の設定値（Ｘ、Ｙ）よりも大きい場合には、燃料漏れと判定することから、燃料漏れ量を判定するのに、単位時間当たりの漏れ量にて比較しているので、前回運転からのエンジン停止時間の長さに関係なく、正確な燃料漏れ量を検出することができ、また、微少な燃料漏れの検出が可能となる。
【００４２】
また、一つの第１の設定値（Ｘ）と他の第１の設定値（Ｙ）とは、前回運転のエンジン停止前に気体燃料が第１、第２燃料容器４４−１、４４−２に充填されたか否かによって異なることから、気体燃料の第１、第２燃料容器４４−１、４４−２への充填の前後では、燃料圧力が大きく変化するが、気体燃料の第１、第２燃料容器４４−１、４４−２への充填の有無に対応した燃料漏れ判定値を用いて、これにより、正確な燃料漏れの判定が可能となる。
【００４３】
更に、前回運転のエンジン停止前に気体燃料が第１、第２燃料容器４４−１、４４−２に充填されたか否かの検出は、フューエルリッドの開閉によるフューエルリッドスイッチ９４からの信号の有無による検出方法、あるいは、主止弁６２の開動作の前の開弁前燃料圧力値と主止弁６２の開動作の後の開弁後燃料圧力値とを測定して、この開弁前燃料圧力値と開弁後燃料圧力値との差圧値を設定値と比較することよる検出方法の少なくとも一方の検出方法を用いていることから、気体燃料が第１、第２燃料容器４４−１、４４−２に充填されたか否かを、簡単に検出することができる。
【００４４】
更にまた、制御手段８６は、燃料漏れ判定部８６Ｅが燃料漏れと判定した場合に、警告手段としてのダイアグランプ９２や警告音で燃料漏れを告知し、第１の記憶値（Ｐｏｆｆ＊Ｔｏｆｆ）から第１の測定値（Ｐｏｎ＊Ｔｏｎ）を引いた値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）｝を停止後経過時間（Ｈ）で割った値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ｝が、第１の設定値（Ｘ、Ｙ）よりも大きな値に予め設定された第２の設定値（Ｚ）よりも大きい場合には、エンジン４が始動できないように制御することから、燃料漏れ量に応じたエンジン４の制御を行わせることができる。
【００４５】
図７、８は、この発明の第２実施例を示すものである。
【００４６】
この第２実施例においては、上述の第１実施例と同一機能を果たす箇所には同一符号を付して説明する。
【００４７】
この第２実施例の特徴とするところは、以下の点にある。即ち、図７に示す如く、制御手段８６においては、第１実施例における補正値算出部８６Ａと停止直前記憶部８６Ｂと開弁前検出部８６Ｃとタイマ８６Ｆの他に、イグニションスイッチ９０のオン時からの経過時間をエンジン水温と燃料温度とに応じた設定経過時間（Ｈ１）に設定する経過時間設定部８６Ｇを備えるとともに、停止直前燃料残圧値（Ｐｏｆｆ）と停止直前燃料温度補正値（Ｔｏｆｆ）と開弁前燃料残圧値（Ｐｏｎ）と開弁前燃料温度補正値（Ｔｏｎ）と設定経過時間（Ｈ１）とから燃料漏れを判定する燃料漏れ判定部８６Ｈを備えている。
【００４８】
この場合に、この燃料漏れ判定部８６Ｈは、停止直前燃料残圧値（Ｐｏｆｆ）と停止直前燃料温度補正値（Ｔｏｆｆ）との積を第１の記憶値（Ｐｏｆｆ＊Ｔｏｆｆ）とし、開弁前燃料残圧値（Ｐｏｎ）と開弁前燃料温度補正値（Ｔｏｎ）との積を第１の測定値（Ｐｏｎ＊Ｔｏｎ）とし、第１の記憶値（Ｐｏｆｆ＊Ｔｏｆｆ）から第１の測定値（Ｐｏｎ＊Ｔｏｎ）を引いた値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）｝を設定経過時間（Ｈ１）で割った値｛（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ１｝が、予め設定された第１の設定値（Ｘ、Ｙ）よりも大きい場合には、燃料漏れと判定する。
【００４９】
次に、この第２実施例の作用を、図８のフローチャートに基づいて説明する。
【００５０】
制御手段８６においては、制御動作の開始前に、前回運転のエンジン停止直前の停止直前燃料残圧値（Ｐｏｆｆ）及び停止直前燃料温度補正係数（Ｔｏｆｆ）を停止直前記憶部８６Ｂに記憶してあり、また、イグニションスイッチ８８のオン時からの経過時間をエンジン水温と燃料温度とに応じて設定された設定経過時間（Ｈ１）を管理していることが、前提条件となっている。
【００５１】
そして、制御手段８６のプログラムがスタートし（ステップ２０２）、イグニションスイッチ９０をオンとし（ステップ２０４）、このイグニションスイッチ９０のオン後に、主止弁６２を開動作する前の現在の燃料残圧値である開弁前燃料残圧値（Ｐｏｎ）と、現在の燃料温度補正係数である開弁前燃料温度補正係数（Ｔｏｎ）と、イグニションスイッチ９０のオン時からの経過時間をエンジン水温と燃料温度とに応じて設定された設定経過時間（Ｈ１）とを読み込む（ステップ２０６）。
【００５２】
そして、前回運転のエンジン４の停止前に気体燃料が第１、第２燃料容器４４−１、４４−２に充填されたか否か、つまり、燃料充填後判定条件が成立か否かを判断する（ステップ２０８）。この燃料充填後判定条件は、気体燃料の第１、第２燃料容器４４−１、４４−２ーの充填直後は、第１、第２燃料容器４４−１、４４−２内の燃料温度が高くなり、その後、燃料温度が外気温まで下がるため、燃料圧力もその充填後に低下し、この燃料圧力の低下の影響による燃料漏れの誤判定を防止するのが目的であり、次の燃料漏れ判定を、気体燃料を第１、第２燃料容器４４−１、４４−２に充填直後の場合に、その燃料圧力の低下を考慮して判定を行なうためである。
【００５３】
このステップ２０８がＹＥＳで、燃料充填後判定条件が成立の場合には、燃料漏れ判定条件が成立したか否かを判断する（ステップ２１０）。つまり、（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ１＞Ｘ（一つの第１の設定値）を、判断する。
【００５４】
このステップ２１０がＹＥＳで、燃料漏れ判定条件が成立した場合には、燃料漏れがあり、ダイアグランプ９２を点灯したり、警告音で、運転者にその燃料漏れの異常を認識（告知）させる（ステップ２１４）。
【００５５】
一方、前記ステップ２０８がＮＯで、燃料充填後判定条件が不成立の場合には、燃料漏れ判定条件が成立したか否かを判断する（ステップ２１２）。つまり、（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ１＞Ｙ（他の第１の設定値）を、判断する。
【００５６】
このステップ２１２がＹＥＳで、燃料漏れ判定条件が成立した場合には、燃料漏れがあり、ダイアグランプ９２を点灯したり、警告音で運転者にその燃料漏れの異常を認識（告知）させる（ステップ２１４）。
【００５７】
そして、ステップ２１４の処理後は、エンジン停止条件が成立したか否かを判断する（ステップ２１６）。つまり、（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ１＞Ｚ（第２の設定値）を、判断する。これは、燃料残圧の低下が第２の設定値（Ｚ）以上あったかどうかを判断するものであり、（Ｐｏｆｆ＊Ｔｏｆｆ）−（Ｐｏｎ＊Ｔｏｎ）／Ｈ１＞Ｚで、エンジン停止条件が成立したか否かを判断する。
【００５８】
このステップ２１６がＹＥＳで、エンジン停止条件が成立した場合には、燃料漏れ量が多くなり（ステップ２１８）、そして、エンジン４が始動できないように、スタータ９６の駆動を停止し（ステップ２２０）、プログラムをエンドとする（ステップ２２２）。
【００５９】
一方、前記ステップ２１０、２１２でＮＯで、燃料漏れ判定条件が不成立の場合には、燃料漏れがないとし（ステップ２２４）、プログラムをエンドとする（ステップ２２２）。
【００６０】
また、前記ステップ２１６がＮＯで、エンジン停止条件が不成立の場合には、直ちにプログラムをエンドとする（ステップ２２２）。
【００６１】
この結果、この第２実施例によれば、上述の第１実施例と同様な効果を奏するとともに、前回運転のエンジン停止時から燃料漏れの検出時までの停止後経過時間（Ｈ）を測定する代わりに、イグニションスイッチ９０のオン時からの経過時間をエンジン水温と燃料温度とに応じて設定された設定経過時間（Ｈ１）を用いたので、停止後経過時間（Ｈ）を常に監視することなく、燃料漏れを検出することができ、その燃料漏れの検出を簡単にすることができる。
【００６２】
なお、この発明においては、上述の実施例に限定されず、種々改変が可能であることは、勿論である。
【００６３】
例えば、上述の実施例では、前回運転のエンジン停止時から燃料漏れの検出時までの停止時経過時間（Ｈ）を計測したが、この停止時経過時間（Ｈ）の計測を行わず、燃料漏れの検出を行うことも可能である。つまり、前回運転のエンジン停止時からの経過時間を一定値（例えば８時間）又は任意のパラメータから算出した定数で代用し、例えば、今回運転のイグニションスイッチがオンの時に、エンジン水温と燃料温度とが略同じの場合に、一定値を８時間とすると、それ以外では、一定値を４時間とする。これは、エンジン停止後に、エンジンが８時間以上停止すると、エンジン水温、燃料温度が外気温と同値に収束するからである。これにより、燃料漏れの検出をさらに簡単に行うことができる。
【００６４】
また、燃料温度に影響を与える外気温度を考慮して、燃料漏れの検出を正確に行うことも可能である。また、前回の車両停止前の運転の仕方を考慮し、この運転の仕方によって補正係数を変えて、より正確な燃料漏れの検出をすることも可能である。更に、必要燃料量以上に燃料が減少して、いつも必要量よりも燃料が減っている場合に、燃料漏れと判定することも可能である。更にまた、寒冷地や温暖地等で、地域の特性を考慮して、燃料漏れの判定基準を変更し、燃料漏れの判定のブレる要素を省き、燃料漏れの検出を正確に行うことも可能である。
【００６５】
【発明の効果】
以上詳細な説明から明らかなようにこの発明によれば、エンジンの始動前で車両停止状態において気体燃料の漏れを判定することができ、これにより、車両の走行前で運転者にその燃料漏れの異常を認識させることができ、また、気体燃料の漏れ量が多い場合には、エンジンを停止させたりすることが可能となる。
【図面の簡単な説明】
【図１】燃料漏れ検出制御のフローチャートである。
【図２】気体燃料の特性で温度と圧力との関係を示す図である。
【図３】エンジン停止時間と燃料温度との関係を示す図である。
【図４】エンジン停止時間と燃料圧力との関係を示す図である。
【図５】燃料漏れ検出装置のシステム構成図である。
【図６】車両の概略斜視図である。
【図７】第２実施例における燃料漏れ検出装置のシステム構成図である。
【図８】第２実施例における燃料漏れ検出制御のフローチャートである。
【符号の説明】
２ 車両
４ エンジン
１２ ガス燃料充填装置
１４ ガス燃料供給装置
４０ 燃料噴射弁
４４ 燃料容器
６０ 燃料供給管
６２ 主止弁
６６ レギュレータ
６８ 残量圧力センサ
７４ 燃料温度センサ
８０ スロットルセンサ
８６ 制御手段
８８ 水温センサ
９０ イグニションスイッチ
９２ ダイアグランプ
９２ フューエルリッドスイッチ
９６ スタータ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel leak detection device for a gas fuel engine, and more particularly to a fuel leak detection device for a gas fuel engine that detects a leak of gas fuel in a vehicle stop state before the engine is started.
[0002]
[Prior art]
As a vehicle, there is a natural gas vehicle (NGV) that is a gas fuel vehicle equipped with an engine that uses CNG (compressed natural gas) that is a gaseous fuel as fuel.
[0003]
In such a vehicle, a fuel container filled with gaseous fuel to be supplied to the engine is provided, and a fuel supply system is provided in which the fuel container is connected to the fuel injection valve via at least a main stop valve and a regulator. . The gaseous fuel in the fuel container is taken out by the fuel supply pipe of the fuel supply system, adjusted to a predetermined pressure and flow rate by a regulator (pressure reducing valve), mixed with air from the fuel injection valve, and supplied to the engine.
[0004]
Moreover, the fuel container is generally provided with an overflow prevention valve in the container main valve. This overflow prevention valve is mechanically closed when gaseous fuel of a certain flow rate (large capacity that is consumed by the engine) or more flows due to damage to the fuel piping system, for example, and the gas from the fuel container It blocks the outflow of fuel.
[0005]
Examples of such a fuel leak detection device for a gaseous fuel engine are disclosed in Japanese Patent Laid-Open Nos. 9-242614, 11-107860, 1996-277750, and 2001-41106. ing. In Japanese Patent Laid-Open No. 9-242614, a ratio between a current pressure change amount per unit time of gaseous fuel detected by a pressure sensor and a basic pressure change amount per unit set when the vehicle travels is set. When the value is greater than or equal to the value, it is determined that the fuel leaks. Japanese Patent Application Laid-Open No. 11-107860 detects the temperature and pressure value of gaseous fuel on the high pressure side when the engine is stopped, stores these detected values, and immediately before starting the engine Based on the temperature and pressure values of the gaseous fuel detected immediately before starting and the stored temperature and pressure values of the gaseous fuel, fuel leakage may occur due to a change in the state of the fuel supply system from the previous engine stop to immediately before the engine starts. Is determined. Japanese Patent Laid-Open No. 1996-277750 determines fuel leakage from the fuel supply system based on the calculated fuel consumption amount of the fuel tank and the fuel consumption amount of the fuel injection valve. . Japanese Patent Application Laid-Open No. 2001-41106 detects the pressure of the gaseous fuel at a time difference when the engine is stopped, compares the detected value of the pressure of the gaseous fuel to detect the amount of decrease, and this decrease. The fuel leakage is determined based on the amount.
[0006]
[Problems to be solved by the invention]
By the way, in the conventional fuel leak detection device of a gas fuel engine, as a fuel leak that actually occurs in a vehicle, a joint of a piping of a fuel supply system may be loosened due to a vibration of the vehicle and the gaseous fuel may gradually leak. In many cases, such a fuel leak prevention measure uses a pressure sensor to detect a drop in the pressure of gaseous fuel. However, there is a problem in that it is difficult to quickly deal with it, and it is difficult to stop the engine or make the driver recognize the abnormality of the fuel leak.
[0007]
[Means for Solving the Problems]
Therefore, in order to eliminate the above-mentioned inconvenience, the present invention is provided with a fuel container filled with gaseous fuel supplied to an engine mounted on a vehicle, and this fuel container is a fuel via at least a main stop valve and a regulator. In a fuel leakage detection device for a gaseous fuel engine provided with a fuel supply system connected to an injection valve, a fuel residual pressure detection means capable of detecting a fuel residual pressure value between the main stop valve and the fuel injection valve is provided, A fuel temperature detection means capable of detecting a fuel temperature between the main stop valve and the fuel injection valve is provided, and a correction for calculating a fuel temperature correction value that changes according to the fuel temperature detected by the fuel temperature detection means A value calculation unit, a storage unit immediately before stopping immediately before stopping the engine and a fuel temperature correction value immediately before stopping, and a storage unit immediately before stopping, in which the ignition switch is on and the main stop valve is opened. A pre-valve fuel residual pressure value and a pre-valve fuel temperature correction value, and a post-stop elapsed time that detects the post-stop elapsed time from when the engine stopped during the previous operation to when a fuel leak was detected Fuel leakage is determined from the detection unit, the fuel residual pressure value immediately before stop, the fuel temperature correction value immediately before stop, the fuel residual pressure value before valve opening, the fuel temperature correction value before valve opening, and the elapsed time after stop. A fuel leak detector and With Provide control means The fuel leakage determination unit uses a product of the fuel residual pressure value immediately before stop and the fuel temperature correction value immediately before stop as a first stored value, and the fuel residual pressure value before valve opening and the fuel temperature correction before valve opening. A value obtained by subtracting the first measured value from the first stored value by the product of the value and the first stored value is divided by the elapsed time after the stop. If it is greater than the value, it is determined that the fuel has leaked, and the first set value differs depending on whether or not gaseous fuel is filled in the fuel container before stopping the engine in the previous operation. It is characterized by that.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
This invention , Gas fuel leakage can be determined when the vehicle is stopped before the engine is started. This allows the driver to recognize the fuel leakage abnormality before the vehicle travels. If there are many, the engine can be stopped.
[0009]
【Example】
Embodiments of the present invention will be described in detail and specifically with reference to the drawings. 1 to 6 show a first embodiment of the present invention. 5 and 6, 2 is a gas fuel vehicle (hereinafter referred to as “vehicle”), 4 is an engine for a multi-cylinder, for example, 3 cylinders mounted on the vehicle 2, 6 and 6 are rear wheels, and 8 is a rear axle shaft. 10 is a vehicle body floor, 12 is a gas fuel filling device, 14 is a gas fuel supply device constituting a fuel supply system, 16 is an exhaust device, and 18 is an outer panel.
[0010]
As shown in FIG. 5, the engine 4 is provided with an intake manifold 20, a throttle body 24 having a throttle valve 22, an intake pipe 26, and an air cleaner 28 in the intake system. An exhaust manifold 30, a three-way catalyst 32, and an exhaust pipe 38 including a front muffler 34 and a rear muffler 36 are provided so as to constitute the device 16. The intake manifold 20 is provided with first to third fuel injection valves 40-1 to 40-3 corresponding to the respective cylinders. The first to third fuel injection valves 40-1 to 40-3 are connected to a fuel delivery pipe 42 as shown in FIG.
[0011]
A rear side in which the vehicle 2 is filled with pressurized compressed natural gas (CNG) as gaseous fuel on the front side of the vehicle 2 below the rear axle shaft 8 oriented in the vehicle width direction below the vehicle body floor 10. The two first and second fuel containers 44-1 and 44-2 on the front side are installed side by side in the vehicle width direction and in front of and behind the vehicle 2.
[0012]
First and second container main valves 46-1 and 46-2 are provided on the left side of the first and second fuel containers 44-1 and 44-2 in the vehicle width direction. The first and second fuel containers 44-1 and 44-2 are connected by a filling communication pipe 48.
[0013]
One end of a fuel filling pipe 50 of the gas fuel filling device 12 is connected to the first fuel container 44-1. The other end side of the fuel filling pipe 50 is connected to a filling port 54 of a receptacle box 52 attached to the outer panel 18. A fuel lid (not shown) is attached to the filling port 54.
[0014]
In this fuel filling pipe 50, a fuel filling valve (ball valve) for filling gaseous fuel from the filling port 54 side into the first and second fuel containers 44-1 and 44-2 side sequentially from the filling port 54 side. ) 56 and a check valve 58 for preventing the gaseous fuel from the first and second fuel containers 44-1 and 44-2 from flowing back to the filling port 54 side.
[0015]
One end of a fuel supply pipe 60 of the gas fuel supply device 14 is connected to the second fuel container 44-2. The other end of the fuel supply pipe 60 is connected to a fuel delivery pipe 42 attached to the intake manifold 20.
[0016]
The fuel supply pipe 60 includes, in order from the second fuel container 44-2 side, a main stop valve (solenoid valve) 62 that closes to shut off the fuel supply pipe 60 when the engine 4 is stopped, and gaseous fuel. And a regulator (pressure reducing valve) 66 for adjusting the pressure and flow rate of the gaseous fuel to be constant.
[0017]
A fuel supply pipe 60 between the main stop valve 62 and the fuel injection valve 40 is provided with a remaining pressure sensor 68 as fuel remaining pressure detecting means capable of detecting the fuel remaining pressure value (P). A digital fuel gauge 70 and an analog fuel gauge 72 are in communication with the remaining pressure sensor 68.
[0018]
The fuel delivery pipe 42 includes a fuel temperature sensor 74 as a fuel temperature detecting means capable of detecting a fuel temperature between the main stop valve 62 and the fuel injection valve 40, and between the main stop valve 62 and the fuel injection valve 40. A fuel pressure sensor 76 as a fuel pressure detecting means capable of detecting the fuel pressure is attached.
[0019]
The intake pipe 26 is provided with an intake air temperature sensor 78 for detecting the temperature of intake air flowing through the internal intake passage. The throttle body 24 is provided with a throttle sensor 80 that detects the opening state of the throttle valve 22. The intake manifold 20 is provided with an intake pipe pressure sensor 82 for detecting the intake pipe pressure. The exhaust manifold 30 is provided with an oxygen concentration sensor 84 for detecting the oxygen concentration in the exhaust flowing through the internal exhaust passage.
[0020]
The fuel injection valve 40, the main stop valve 62, the fuel temperature sensor 74, the fuel pressure sensor 76, the intake air temperature sensor 78, the throttle sensor 80, the intake pipe pressure sensor 82, and the oxygen concentration sensor 84 communicate with the control means 86. . Further, the control means 86 detects the coolant temperature of the engine 4, the ignition switch 90 of the engine 2, the diagnosis lamp 92 as warning means, and the opening / closing of the fuel lid and outputs the signal. The fuel lid switch 94 for output and the starter 96 of the engine 4 communicate with each other.
[0021]
As shown in FIG. 2, the characteristic of the gaseous fuel used in the engine 4 is that the pressure also changes due to a change in temperature under a constant volume condition, that is, the pressure increases as the temperature increases. As shown in FIG. 3, when the stop time of the vehicle 2 is long, the temperature becomes low, and as shown in FIG. 4, when the stop time of the vehicle 2 is long, the residual fuel pressure value becomes low even if there is no fuel leakage. It is.
[0022]
The control means 86 includes a correction value calculation unit 86A for calculating a fuel temperature correction value (T) that changes in accordance with the fuel temperature detected by the fuel temperature sensor 74, and a fuel residual pressure immediately before stopping the engine immediately before stopping the engine in the previous operation. A value (Poff) and a fuel temperature correction value (Toff) immediately before stop, and a current fuel residual pressure before opening before the main stop valve 62 is opened while the ignition switch 90 is on. 86C for detecting a value (Pon) and a pre-valve fuel temperature correction value (Ton), and a stop for detecting a post-stop elapsed time (H) from the time of engine stop to the time of fuel leakage detection in the previous operation. The post-elapsed time detection unit 86D, the fuel residual pressure value immediately before stop (Poff), the fuel temperature correction value immediately before stop (Toff), the fuel residual pressure value before opening (Pon), and the fuel temperature correction value before opening (Ton) Elapsed time after stopping And fuel leakage determining unit 86E determines fuel leakage from the H), a timer 86F for measuring a time, are provided.
[0023]
The fuel leakage determination unit 86E sets the product of the fuel residual pressure value immediately before stop (Poff) and the fuel temperature correction value immediately before stop (Toff) as the first stored value (Poff * Toff), and sets the fuel residual pressure value before valve opening ( Pon) and the pre-valve fuel temperature correction value (Ton) as the first measured value (Pon * Ton), and the first measured value (Pon * Ton) from the first stored value (Poff * Toff) A value {(Poff * Toff) − (Pon * Ton) / H} obtained by dividing the value {(Poff * Toff) − (Pon * Ton)} by the elapsed time (H) after stopping is set in advance. When it is larger than the two types of first set values (X, Y), it is determined that the fuel leaks.
[0024]
One first set value (X) and another first set value (Y) indicate that the first and second fuel containers 44-1 and 44-2 are filled with gaseous fuel before the engine is stopped in the previous operation. Depending on whether or not it has been done, there is a relationship of X ≠ Y. Specifically, when the first and second fuel containers 44-1 and 44-2 are filled with the gaseous fuel before the engine is stopped in the previous operation, one first set value (X) is used. On the other hand, when the first and second fuel containers 44-1 and 44-2 are not filled with the gaseous fuel before the engine stop in the previous operation, the other first set value (Y) is used. This is because immediately after the first and second fuel containers 44-1 and 44-2 are filled with gaseous fuel, the fuel temperature in the first and second fuel containers 44-1 and 44-2 increases, Since the fuel temperature falls to the outside temperature, the fuel pressure also decreases after the filling, and the purpose is to prevent erroneous determination of fuel leakage due to the influence of the decrease in fuel pressure. This is because in the case immediately after filling the second fuel containers 44-1 and 44-2, the determination is made in consideration of the decrease in the fuel pressure.
[0025]
Detection of whether or not gaseous fuel is filled in the first and second fuel containers 44-1 and 44-2 before stopping the engine in the previous operation is a detection method based on the presence or absence of a signal from the fuel lid switch 92 by opening and closing the fuel lid, Alternatively, the fuel pressure value before opening before the opening operation of the main stop valve 62 and the fuel pressure value after opening after the opening operation of the main stop valve 62 are measured. At least one of the detection methods by comparing the differential pressure value with the post-valve fuel pressure value with a set value is used.
[0026]
When the fuel leakage determination unit 84E determines that the fuel has leaked, the control means 84 notifies the fuel leakage with a diagnostic lamp 92 or a warning sound as warning means, and the first stored value (Poff * Toff) indicates the first. The value obtained by subtracting the measured value (Pon * Ton) {(Poff * Toff) − (Pon * Ton)} divided by the elapsed time (H) after stopping {(Poff * Toff) − (Pon * Ton) / H } Is greater than the second set value (Z) preset to a value greater than the first set value (X, Y), the engine 4 is controlled so that it cannot be started.
[0027]
Next, the operation of the first embodiment will be described based on the flowchart of FIG.
[0028]
In the control means 86, the fuel residual pressure value (Poff) immediately before stopping immediately before the engine stop and the fuel temperature correction coefficient (Toff) immediately before stopping are stored in the memory unit 86B immediately before stopping before starting the control operation. In addition, it is a precondition that the post-stop elapsed time (H) from when the engine 4 is stopped to when fuel leakage is detected is managed.
[0029]
Then, the program of the control means 86 is started (step 102), the ignition switch 90 is turned on (step 104), and the current residual fuel pressure value before the main stop valve 62 is opened after the ignition switch 90 is turned on. The fuel residual pressure value before opening (Pon), the fuel temperature correction coefficient before opening that is the current fuel temperature correction coefficient (Ton), and after the stop from the previous engine stop to the fuel leak detection The elapsed time (H) is read (step 106).
[0030]
Then, it is determined whether or not the gaseous fuel is filled in the first and second fuel containers 44-1 and 44-2 before stopping the engine 4 in the previous operation, that is, whether or not a determination condition after fuel filling is satisfied. (Step 108). The determination condition after fuel filling is that the fuel temperature in the first and second fuel containers 44-1 and 44-2 is immediately after filling the first and second fuel containers 44-1 and 44-2 with gaseous fuel. After that, since the fuel temperature drops to the outside temperature, the fuel pressure also decreases after filling, and the purpose is to prevent misjudgment of fuel leak due to the effect of this fuel pressure drop. This is because the determination is made in consideration of the decrease in the fuel pressure when the first and second fuel containers 44-1 and 44-2 are filled with the gaseous fuel.
[0031]
If the determination in step 108 is YES and the determination condition after fuel filling is satisfied, it is determined whether or not the fuel leakage determination condition is satisfied (step 110). That is, (Poff * Toff) − (Pon * Ton) / H> X (one first set value) is determined.
[0032]
If this step 110 is YES and the fuel leak judgment condition is satisfied, there is a fuel leak, the diagnostic lamp 92 is turned on, or the driver is made aware (notified) of the fuel leak abnormality by a warning sound ( Step 114).
[0033]
On the other hand, if step 108 is NO and the determination condition after fuel filling is not satisfied, it is determined whether the fuel leakage determination condition is satisfied (step 112). That is, (Poff * Toff) − (Pon * Ton) / H> Y (other first set value) is determined.
[0034]
If this step 112 is YES and the fuel leak judgment condition is satisfied, there is a fuel leak, the diagnostic lamp 92 is turned on, and the driver is made aware of the abnormality of the fuel leak by a warning sound (step 114).
[0035]
Then, after the process of step 114, it is determined whether or not an engine stop condition is satisfied (step 116). That is, (Poff * Toff) − (Pon * Ton) / H> Z (second set value) is determined. This is to determine whether or not the decrease in the residual fuel pressure is greater than or equal to the second set value (Z), that is, (Poff * Toff) − (Pon * Ton) / H> Z and the engine stop condition is It is determined whether or not it is established.
[0036]
If this step 116 is YES and the engine stop condition is satisfied, the amount of fuel leakage increases (step 118), and the drive of the starter 96 is stopped so that the engine 4 cannot be started (step 120). The program is ended (step 122).
[0037]
On the other hand, if NO in steps 110 and 112 and the fuel leak determination condition is not satisfied, it is determined that there is no fuel leak (step 124), and the program is ended (step 122).
[0038]
If NO in step 116 and the engine stop condition is not satisfied, the program is immediately ended (step 122).
[0039]
As a result, the leak detection of the gaseous fuel is performed in the stop state of the vehicle 2 before the engine 4 is started, so that the driver can recognize the fuel leak abnormality before the engine 4 is started. Based on the fuel residual pressure value before the engine stop in the previous operation and the fuel residual pressure value before the opening operation of the main stop valve 62 in the current operation, between the main stop valve 62 and the fuel injection valve 40 during the engine stop (vehicle stop). When a fuel leak is detected, if there is a fuel leak, a warning means notifies the user. If the fuel leak amount is large, the engine 4 can be stopped.
[0040]
Further, since the fuel temperature correction coefficient (T) is set according to the fuel temperature, it is possible to eliminate the influence due to the decrease in the fuel pressure due to the change in the fuel temperature, and to prevent the erroneous determination of the fuel leakage.
[0041]
Further, the fuel leakage determination unit 86E sets the product of the fuel residual pressure value immediately before stop (Poff) and the fuel temperature correction value immediately before stop (Toff) as the first stored value (Poff * Toff), and the fuel residual pressure before valve opening. The product of the value (Pon) and the pre-valve fuel temperature correction value (Ton) is defined as the first measured value (Pon * Ton), and the first measured value (Pon * Ton) is calculated from the first stored value (Poff * Toff). The value {(Poff * Toff) − (Pon * Ton) / H} obtained by dividing the value {(Poff * Toff) − (Pon * Ton)} by subtracting Ton) by the elapsed time (H) after stopping is set in advance. When it is larger than the two first set values (X, Y), it is determined that the fuel leaks. Therefore, in order to determine the amount of fuel leakage, the amount of leakage per unit time is compared. So, regardless of the length of engine stop time since the last operation Can be accurately detected fuel leakage quantity, also, it is possible to detect the minute fuel leakage.
[0042]
In addition, one first set value (X) and the other first set value (Y) indicate that the first and second fuel containers 44-1 and 44-2 are used for the gaseous fuel before the previous engine stop. The fuel pressure changes greatly before and after filling the first and second fuel containers 44-1 and 44-2 with the gaseous fuel. 2 By using the fuel leak determination value corresponding to whether or not the fuel containers 44-1 and 44-2 are filled, it becomes possible to accurately determine the fuel leak.
[0043]
Further, whether or not the gaseous fuel is filled in the first and second fuel containers 44-1 and 44-2 before stopping the engine in the previous operation is detected by the presence or absence of a signal from the fuel lid switch 94 by opening and closing the fuel lid. The fuel pressure value before opening before the opening operation of the main stop valve 62 and the fuel pressure value after opening after the opening operation of the main stop valve 62 are measured, and the fuel pressure value before opening the valve is measured. And the fuel pressure value after opening of the valve is compared with a set value, at least one of the detection methods is used, so that the gaseous fuel is the first and second fuel containers 44-1, 44. -2 can be easily detected.
[0044]
Furthermore, when the fuel leakage determination unit 86E determines that the fuel has leaked, the control unit 86 notifies the fuel leakage with a diagnosis lamp 92 or a warning sound as a warning unit, and from the first stored value (Poff * Toff). A value {(Poff * Toff)-(Pon * Ton) obtained by dividing a value {(Poff * Toff)-(Pon * Ton)} obtained by subtracting the first measurement value (Pon * Ton) by an elapsed time (H) after stopping. ) / H} is controlled so that the engine 4 cannot be started when it is larger than the second set value (Z) preset to a value greater than the first set value (X, Y). Thus, the engine 4 can be controlled in accordance with the amount of fuel leakage.
[0045]
7 and 8 show a second embodiment of the present invention.
[0046]
In the second embodiment, portions that perform the same functions as those of the first embodiment will be described with the same reference numerals.
[0047]
The features of the second embodiment are as follows. That is, as shown in FIG. 7, in the control means 86, when the ignition switch 90 is turned on in addition to the correction value calculation section 86A, the storage section 86B, the pre-valve detection section 86C, and the timer 86F in the first embodiment. Is provided with an elapsed time setting unit 86G for setting the elapsed time from the engine to the set elapsed time (H1) according to the engine water temperature and the fuel temperature, the fuel residual pressure value immediately before stop (Poff), and the fuel temperature correction value immediately before stop (Toff) ), A fuel residual pressure value before opening (Pon), a fuel temperature correction value before opening (Ton), and a set elapsed time (H1), a fuel leakage determination unit 86H is provided.
[0048]
In this case, the fuel leakage determination unit 86H sets the product of the fuel residual pressure value immediately before stop (Poff) and the fuel temperature correction value immediately before stop (Toff) as the first stored value (Poff * Toff), and before opening the valve. The product of the residual fuel pressure value (Pon) and the pre-valve fuel temperature correction value (Ton) is defined as the first measured value (Pon * Ton), and the first measured value from the first stored value (Poff * Toff). A value {(Poff * Toff) − (Pon * Ton) / H1} obtained by dividing the value {(Poff * Toff) − (Pon * Ton)} by subtracting (Pon * Ton)} by the set elapsed time (H1) is When it is larger than the first set value (X, Y) set in advance, it is determined that the fuel leaks.
[0049]
Next, the operation of the second embodiment will be described based on the flowchart of FIG.
[0050]
In the control means 86, the fuel residual pressure value (Poff) immediately before stopping immediately before the engine stop and the fuel temperature correction coefficient (Toff) immediately before stopping are stored in the memory unit 86B immediately before stopping before starting the control operation. Further, it is a precondition that the set elapsed time (H1) set in accordance with the engine water temperature and the fuel temperature is managed as the elapsed time from when the ignition switch 88 is turned on.
[0051]
Then, the program of the control means 86 is started (step 202), the ignition switch 90 is turned on (step 204), and the current residual fuel pressure value before the main stop valve 62 is opened after the ignition switch 90 is turned on. The fuel residual pressure value before valve opening (Pon), the fuel temperature correction coefficient before valve opening (Ton) that is the current fuel temperature correction coefficient, and the elapsed time from when the ignition switch 90 is turned on are determined as the engine water temperature and the fuel temperature. The set elapsed time (H1) set in accordance with is read (step 206).
[0052]
Then, it is determined whether or not the gaseous fuel is filled in the first and second fuel containers 44-1 and 44-2 before stopping the engine 4 in the previous operation, that is, whether or not a determination condition after fuel filling is satisfied. (Step 208). The determination condition after fuel filling is that the fuel temperature in the first and second fuel containers 44-1 and 44-2 is immediately after filling the first and second fuel containers 44-1 and 44-2 of gaseous fuel. After that, since the fuel temperature drops to the outside temperature, the fuel pressure also decreases after filling, and the purpose is to prevent misjudgment of fuel leak due to the effect of this fuel pressure drop. This is because the determination is made in consideration of the decrease in the fuel pressure when the first and second fuel containers 44-1 and 44-2 are filled with the gaseous fuel.
[0053]
If this step 208 is YES and the determination condition after fuel filling is satisfied, it is determined whether or not the fuel leakage determination condition is satisfied (step 210). That is, (Poff * Toff) − (Pon * Ton) / H1> X (one first set value) is determined.
[0054]
If this step 210 is YES and the fuel leak judgment condition is satisfied, there is a fuel leak, the diagnostic lamp 92 is turned on, or the driver is made aware (notified) of the fuel leak abnormality by a warning sound ( Step 214).
[0055]
On the other hand, if step 208 is NO and the determination condition after fuel filling is not satisfied, it is determined whether or not the fuel leakage determination condition is satisfied (step 212). That is, (Poff * Toff) − (Pon * Ton) / H1> Y (other first set value) is determined.
[0056]
If this step 212 is YES and the fuel leak judgment condition is satisfied, there is a fuel leak, the diagnostic lamp 92 is turned on, and the driver recognizes (notifies) the abnormality of the fuel leak with a warning sound (step) 214).
[0057]
Then, after the process of step 214, it is determined whether or not an engine stop condition is satisfied (step 216). That is, (Poff * Toff) − (Pon * Ton) / H1> Z (second set value) is determined. This is to determine whether or not the decrease in the residual fuel pressure is equal to or greater than the second set value (Z). The engine stop condition is satisfied when (Poff * Toff) − (Pon * Ton) / H1> Z. Determine whether or not.
[0058]
If this step 216 is YES and the engine stop condition is satisfied, the amount of fuel leakage increases (step 218), and the drive of the starter 96 is stopped so that the engine 4 cannot be started (step 220). The program is ended (step 222).
[0059]
On the other hand, if NO in steps 210 and 212 and the fuel leak determination condition is not satisfied, it is determined that there is no fuel leak (step 224), and the program is ended (step 222).
[0060]
If step 216 is NO and the engine stop condition is not satisfied, the program is immediately ended (step 222).
[0061]
As a result, according to the second embodiment, the same effect as in the first embodiment described above can be obtained, and the post-stop elapsed time (H) from when the engine was stopped during the previous operation to when fuel leak was detected is measured. Instead, since the set elapsed time (H1) set in accordance with the engine water temperature and the fuel temperature is used as the elapsed time from when the ignition switch 90 is turned on, the post-stop elapsed time (H) is not always monitored. The fuel leak can be detected, and the detection of the fuel leak can be simplified.
[0062]
Of course, the present invention is not limited to the above-described embodiments, and various modifications are possible.
[0063]
For example, in the above-described embodiment, the stop elapsed time (H) from when the engine was stopped during the previous operation to when the fuel leak was detected was measured. However, this stop elapsed time (H) was not measured and the fuel leak occurred. It is also possible to perform detection. In other words, the elapsed time from when the engine stopped in the previous operation is replaced with a constant value (for example, 8 hours) or a constant calculated from an arbitrary parameter. For example, when the ignition switch for the current operation is on, If the constant value is 8 hours, the constant value is 4 hours otherwise. This is because the engine water temperature and the fuel temperature converge to the same value as the outside air temperature when the engine is stopped for 8 hours or more after the engine is stopped. Thereby, the detection of fuel leakage can be performed more easily.
[0064]
In addition, it is possible to accurately detect the fuel leakage in consideration of the outside air temperature that affects the fuel temperature. It is also possible to detect the fuel leakage more accurately by considering the way of driving before the previous vehicle stop and changing the correction coefficient depending on the way of driving. Further, it is possible to determine that the fuel has leaked when the fuel has decreased more than the required amount of fuel and the fuel has always decreased more than the required amount. Furthermore, it is possible to accurately detect fuel leaks by changing the criteria for judging fuel leaks in cold and warm regions, taking into account regional characteristics, and eliminating the factors that make fuel leak judgments blurry. It is.
[0065]
【The invention's effect】
As is apparent from the detailed description above, according to the present invention. , Gas fuel leakage can be determined when the vehicle is stopped before the engine is started. This allows the driver to recognize an abnormality in the fuel leakage before the vehicle travels. When there are many, it becomes possible to stop an engine.
[Brief description of the drawings]
FIG. 1 is a flowchart of fuel leakage detection control.
FIG. 2 is a diagram showing the relationship between temperature and pressure in the characteristics of gaseous fuel.
FIG. 3 is a graph showing the relationship between engine stop time and fuel temperature.
FIG. 4 is a diagram showing the relationship between engine stop time and fuel pressure.
FIG. 5 is a system configuration diagram of a fuel leak detection device.
FIG. 6 is a schematic perspective view of a vehicle.
FIG. 7 is a system configuration diagram of a fuel leak detection device according to a second embodiment.
FIG. 8 is a flowchart of fuel leak detection control in the second embodiment.
[Explanation of symbols]
2 Vehicle
4 engine
12 Gas fuel filling device
14 Gas fuel supply device
40 Fuel injector
44 Fuel container
60 Fuel supply pipe
62 Main stop valve
66 Regulator
68 Residual pressure sensor
74 Fuel temperature sensor
80 Throttle sensor
86 Control means
88 Water temperature sensor
90 Ignition switch
92 diag lamp
92 Fuel lid switch
96 Starter

Claims (3)

車両に搭載したエンジンに供給される気体燃料が充填された燃料容器を設け、この燃料容器が少なくとも主止弁とレギュレータとを介して燃料噴射弁に連結した燃料供給系を設けた気体燃料エンジンの燃料漏れ検出装置において、前記主止弁と前記燃料噴射弁との間の燃料残圧値を検出可能な燃料残圧検出手段を設け、前記主止弁と前記燃料噴射弁との間の燃料温度を検出可能な燃料温度検出手段を設け、前記燃料温度検出手段で検出された燃料温度に応じて変化する燃料温度補正値を算出する補正値算出部と、前回運転のエンジン停止直前の停止直前燃料残圧値及び停止直前燃料温度補正値を記憶する停止直前記憶部と、イグニションスイッチがオンで且つ前記主止弁が開動作される前の開弁前燃料残圧値及び開弁前燃料温度補正値を検出する開弁前検出部と、前回運転のエンジン停止時から燃料漏れ検出時までの停止後経過時間を検出する停止後経過時間検出部と、前記停止直前燃料残圧値と前記停止直前燃料温度補正値と前記開弁前燃料残圧値と前記開弁前燃料温度補正値と前記停止後経過時間とから燃料漏れを判定する燃料漏れ判定部とを備えた制御手段を設け、前記燃料漏れ判定部は、前記停止直前燃料残圧値と前記停止直前燃料温度補正値との積を第１の記憶値とし、前記開弁前燃料残圧値と前記開弁前燃料温度補正値との積を第１の測定値とし、前記第１の記憶値から前記第１の測定値を引いた値を前記停止後経過時間で割った値が、予め設定された第１の設定値よりも大きい場合には、燃料漏れと判定するとともに、前記第１の設定値は、前回運転のエンジン停止前に気体燃料が前記燃料容器に充填されたか否かによって異なることを特徴とする気体燃料エンジンの燃料漏れ検出装置。A gas fuel engine provided with a fuel container filled with gaseous fuel to be supplied to an engine mounted on a vehicle and provided with a fuel supply system in which the fuel container is connected to a fuel injection valve via at least a main stop valve and a regulator. In the fuel leakage detection device, a fuel residual pressure detecting means capable of detecting a fuel residual pressure value between the main stop valve and the fuel injection valve is provided, and a fuel temperature between the main stop valve and the fuel injection valve is provided. A fuel temperature detecting means capable of detecting the fuel temperature, a correction value calculating section for calculating a fuel temperature correction value that changes in accordance with the fuel temperature detected by the fuel temperature detecting means, and a fuel immediately before stopping immediately before stopping the engine in the previous operation A storage unit immediately before stop for storing a residual pressure value and a fuel temperature correction value immediately before stop, and a fuel residual pressure value before opening and a fuel temperature correction before opening before the main stop valve is opened when the ignition switch is on Detect value A detection unit before opening, a post-stop elapsed time detection unit that detects a post-stop elapsed time from when the engine stopped during the previous operation to a fuel leak detection, the fuel residual pressure value immediately before stop and the fuel temperature correction immediately before stop a control means and a determining fuel leakage determination unit value and the valve opening before the fuel remaining pressure value and the valve opening before the fuel temperature correction value fuel leakage from said stop after elapsed time provided, the fuel leakage determining portion Is the product of the fuel residual pressure value immediately before stop and the fuel temperature correction value immediately before stop as a first stored value, and the product of the fuel residual pressure value before valve opening and the fuel temperature correction value before valve opening is When a value obtained by subtracting the first measured value from the first stored value and dividing the value after the stop by the elapsed time after the stop is larger than the first set value set in advance In addition, it is determined that the fuel leaks, and the first set value is determined by the previous engine stop. Fuel leakage detection system of the gaseous fuel engine gaseous fuel, characterized in that different depending on whether filled in the fuel container. 前記前回運転のエンジン停止前に気体燃料が前記燃料容器に充填されたか否かの検出は、フューエルリッドの開閉によるフューエルリッドスイッチからの信号の有無による検出方法、あるいは、前記主止弁の開動作の前の開弁前燃料圧力値と前記主止弁の開動作の後の開弁後燃料圧力値とを測定して、この開弁前燃料圧力値と開弁後燃料圧力値との差圧値を設定値と比較することよる検出方法の少なくとも一方の検出方法を用いることを特徴とする請求項１に記載の気体燃料エンジンの燃料漏れ検出装置。 Whether the fuel container has been filled with the gaseous fuel before the engine stop in the previous operation is detected by the detection method based on the presence or absence of a signal from the fuel lid switch by opening or closing the fuel lid, or before the opening operation of the main stop valve The fuel pressure value before opening and the fuel pressure value after opening after the opening operation of the main stop valve are measured, and the differential pressure value between the fuel pressure value before opening and the fuel pressure value after opening is measured. fuel leakage detection system of the gaseous fuel engine of claim 1, wherein Rukoto using at least one detection method of the detection method by comparing it with the set value. 前記制御手段は、前記燃料漏れ判定部が燃料漏れと判定した場合に、警告手段で燃料漏れを告知し、前記第１の記憶値から前記第１の測定値を引いた値を前記停止後経過時間で割った値が、前記第１の設定値よりも大きな値に予め設定された第２の設定値よりも大きい場合には、前記エンジンが始動できないように制御することを特徴とする請求項１に記載の気体燃料エンジンの燃料漏れ検出装置。 When the fuel leakage determination unit determines that the fuel leakage has occurred, the control means notifies the fuel leakage by a warning means, and a value obtained by subtracting the first measured value from the first stored value has elapsed after the stop. according divided by time, wherein when the first is greater than the second set value which is previously set to a value larger than the set value, said engine characterized that you controlled not be started Item 2. A fuel leak detection device for a gaseous fuel engine according to Item 1 .
JP2001192516A 2001-06-26 2001-06-26 Fuel leak detection device for gaseous fuel engine Expired - Fee Related JP4055107B2 (en)

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DE10335152B4 (en) * 2003-07-31 2005-08-04 Siemens Ag Operating method and monitoring device for a gas-fueled internal combustion engine
JP4912471B2 (en) 2006-10-26 2012-04-11 ボルボ ラストバグナー アーベー Internal combustion engine for use with pressurized low viscosity fuel
JP4881715B2 (en) * 2006-12-22 2012-02-22 日産自動車株式会社 Control device for hybrid vehicle
EP2177741A1 (en) * 2008-10-15 2010-04-21 Magneti Marelli Powertrain S.p.A. Method for diagnosing a gaseous fuel feeding system for an internal combustion engine
DE102011081928A1 (en) * 2011-08-31 2013-02-28 Man Diesel & Turbo Se Method for monitoring check valves arranged in gas supply lines of a gas engine
EP2772627B1 (en) * 2011-10-26 2018-03-21 Toyota Jidosha Kabushiki Kaisha Fuel property determination system for vehicle
JP5742682B2 (en) * 2011-11-18 2015-07-01 トヨタ自動車株式会社 Start control device for internal combustion engine
JP6060067B2 (en) * 2013-11-28 2017-01-11 愛三工業株式会社 Gas fuel supply device
JP6650194B2 (en) * 2014-04-21 2020-02-19 株式会社ケーヒン Detection device and detection method
CN113482823B (en) * 2021-07-02 2023-03-03 东风商用车有限公司 Method and device for diagnosing fault of fuel injection system and automobile with device

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