WO2013088886A1 - Faulty combustion prevention system for diesel engine - Google Patents

Faulty combustion prevention system for diesel engine Download PDF

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Publication number
WO2013088886A1
WO2013088886A1 PCT/JP2012/079340 JP2012079340W WO2013088886A1 WO 2013088886 A1 WO2013088886 A1 WO 2013088886A1 JP 2012079340 W JP2012079340 W JP 2012079340W WO 2013088886 A1 WO2013088886 A1 WO 2013088886A1
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Prior art keywords
diesel engine
prevention system
abnormal combustion
cylinder
combustion prevention
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PCT/JP2012/079340
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French (fr)
Japanese (ja)
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崇 原
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いすゞ自動車株式会社
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Publication of WO2013088886A1 publication Critical patent/WO2013088886A1/en

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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
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/3809—Common rail control systems
    • F02D41/3836—Controlling the fuel pressure
    • F02D41/3863—Controlling the fuel pressure by controlling the flow out of the common rail, e.g. using pressure relief valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
    • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
    • F02D13/0276—Actuation of an additional valve for a special application, e.g. for decompression, exhaust gas recirculation or cylinder scavenging
    • 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
    • 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
    • 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
    • Y02T10/12—Improving ICE efficiencies
    • 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

Definitions

  • the present invention relates to a system for preventing abnormal combustion of a diesel engine. More specifically, the present invention can prevent the occurrence of abnormal combustion at the time of engine start due to fuel leakage into a combustion chamber in a diesel engine using liquefied gas as fuel. The present invention relates to a system for preventing abnormal combustion of diesel engines.
  • a liquefied gas such as dimethyl ether (DME) is used instead of conventional diesel fuel oil, as described in Japanese Patent Application Publication No. 2007-239651. It is being considered for use.
  • DME dimethyl ether
  • This liquefied gas has the property of easily leaking to the outside in the form of gas from the seat portion of the injection nozzle that injects fuel into the combustion chamber. Furthermore, since the liquefied gas has a lower viscosity than that of light oil, the sheet portion of the injection nozzle is likely to be worn out, which promotes leakage to the outside.
  • the liquefied gas remaining in the injection nozzle is vaporized due to a decrease in pressure, thereby causing a leak from the seat portion into the combustion chamber.
  • a fuel leak of liquefied gas occurs when the engine is stopped, abnormal combustion may occur at the first explosion when the engine is started, and in the worst case, the cylinder liner or the piston ring may be damaged. This becomes more prominent when a common rail type injection device that injects fuel at a high pressure is used.
  • An object of the present invention is to provide a system for preventing abnormal combustion of a diesel engine that can prevent the occurrence of abnormal combustion at the time of engine start in a diesel engine using liquefied gas as a fuel at low cost.
  • a system for preventing abnormal combustion of a diesel engine according to the present invention that achieves the above object is a diesel engine that prevents abnormal combustion caused by fuel leakage from an injection nozzle installed in a cylinder of a diesel engine using liquefied gas as a fuel into a combustion chamber.
  • a system for preventing abnormal combustion of an engine a connecting pipe that connects a pair of cylinders whose strokes are different from each other by 360 °, a relief valve that opens and closes a connecting portion between the connecting pipe and the pair of cylinders, and both Open / close means for operating the relief valve, and control means for controlling the open / close means.
  • control means When the control means receives a start request for the diesel engine, the control means rotates the crankshaft with a starter, and When one of the cylinders is at least in the compression stroke, the opening / closing means opens both the relief valves. It is characterized in performing control for closing their relief valve normally after a predetermined period of time.
  • abnormal combustion prevention system for a diesel engine by attaching a check valve in the middle of the connecting pipe, abnormal combustion can be prevented for a specific cylinder of a pair of cylinders.
  • the connecting pipe is composed of two branch pipes joined at both ends, and a check valve is attached to each of the branch pipes so as to be opposite to each other so that liquefaction is stored in the cylinder due to fuel leak.
  • the gas premixed gas can be effectively scavenged.
  • the abnormal combustion prevention system of a diesel engine has a fuel leak detection means, and the control means has at least one of the cylinders in the compression stroke only when the fuel leak detection means detects a fuel leak of liquefied gas.
  • both relief valves are opened, and control is performed such that these relief valves are always closed after a predetermined period of time, thereby preventing delay in starting the diesel engine.
  • control means always closes both the relief valves after 2 to 3 cycles of the cylinder, thereby completely scavenging the premixed mixture of liquefied gas stored in the combustion chamber due to fuel leakage, and after starting diesel The engine operation can be prevented from being affected.
  • the diesel engine abnormal combustion prevention system of the present invention is suitably used for a general internal combustion engine using liquefied gas as fuel.
  • the gas in the combustion chamber moves to the other where the strokes are 360 ° out of phase with each other. Since the premixed gas of the liquefied gas stored in one cylinder is scavenged to the outside and the compression ignition is suppressed due to fuel leak, the occurrence of abnormal combustion is prevented. be able to.
  • FIG. 1 is a configuration diagram of an abnormal combustion prevention system for a diesel engine according to a first embodiment of the present invention.
  • FIG. 2 is an enlarged view showing a configuration of a pair of cylinder portions in FIG.
  • FIG. 3 is an explanatory diagram when the first cylinder in FIG. 2 is in the compression stroke.
  • FIG. 4 is a flowchart showing the function of the control means in the first embodiment.
  • FIG. 5 is an explanatory diagram when the third cylinder in FIG. 2 is in the compression stroke.
  • FIG. 6 is an enlarged view showing another example of the configuration of the pair of cylinder portions in FIG. 1.
  • FIG. 7 is an explanatory diagram when the first cylinder is in the compression stroke in FIG.
  • FIG. 1 is a configuration diagram of an abnormal combustion prevention system for a diesel engine according to a first embodiment of the present invention.
  • FIG. 2 is an enlarged view showing a configuration of a pair of cylinder portions in FIG.
  • FIG. 3 is an explanatory diagram when the first cylinder
  • FIG. 8 is an enlarged view showing still another example of the configuration of the pair of cylinder portions in FIG.
  • FIG. 9 is a configuration diagram of the abnormal combustion prevention system for a diesel engine according to the second embodiment of the present invention.
  • FIG. 10 is a flowchart showing the function of the control means in the second embodiment.
  • FIG. 1 and 2 show an abnormal combustion prevention system for a diesel engine according to a first embodiment of the present invention.
  • liquefied gas 2 such as dimethyl ether (DME) is supplied to a common rail 3 by a high-pressure pump (not shown).
  • DME dimethyl ether
  • a high-pressure pump not shown
  • a high-pressure pump not shown
  • injection nozzles 5 that are accumulated in the engine and controlled by an ECU (Engine Control Unit) 4 for combustion and expansion.
  • ECU Engine Control Unit
  • the piston 9 in the cylinder 8 is reciprocated.
  • the liquefied gas 2 is self-ignited in the order of the first cylinder 6A ⁇ the third cylinder 6C ⁇ the fourth cylinder 6D ⁇ the second cylinder 6B.
  • the gas after combustion is sent from the combustion chamber 7 to the exhaust pipe 11 when the exhaust valve 10 is opened, and is released into the atmosphere.
  • the intake valve 12 is opened, air is introduced from the intake pipe 13 into the combustion chamber 7 and compressed by the piston 9.
  • the abnormal combustion prevention system of the present invention includes a pair of cylinders 6 whose strokes are different from each other in crank angle and 360 ° phase, specifically, a combination of the first cylinder 6A and the third cylinder 6C, and the second cylinders 6B and 4B.
  • Examples of the opening / closing means 20 of the relief valve 21 include an actuator or a motor using hydraulic pressure or pneumatic pressure.
  • the control means 22 is composed of a CPU (Central Processing Unit) equipped with a storage unit. Signal lines (one point) are connected to the opening / closing means 20, the starter 14, the rotational position sensor 23 for detecting the stroke state of the cylinders 6A to 6D, and the ECU 4, respectively. Connected through a chain line). In the configuration of FIG. 1, the control unit 22 and the ECU 4 are separated, but the ECU 4 may be integrated with the function of the control unit 22.
  • CPU Central Processing Unit
  • the control means 22 rotates the pinion 16 with the cell motor 15 of the starter 14, and the pinion 16 Is extended and fitted to the ring gear 17 to rotate the crankshaft 18 (S20). At this time, the relief valves 21a and 21c in the first cylinder 6A and the third cylinder 6C are both closed.
  • the predetermined period until the relief valve 21 is normally closed is desirably two to three cycles after the start of the engine.
  • the relief valve 21 may be opened in a stroke other than the compression stroke of the cylinder 6.
  • the pre-mixed gas of the liquefied gas 2 stored in the combustion chamber 7 due to fuel leak is completely scavenged by opening the relief valve 21 in the expansion stroke, exhaust stroke, and intake stroke following the compression stroke, that is, the entire stroke.
  • the opening / closing means 20 can be controlled more easily.
  • a check valve 24 may be attached as shown in FIG.
  • the check valve 24 is attached so that the upstream side faces the first cylinder 6A, that is, the gas flows in the connecting pipe 19 from the first cylinder 6A to the third cylinder 6C.
  • the ball catch type valve is illustrated as a type of the check valve 24, it is not limited to this.
  • the connecting pipe 19 is composed of two branch pipes 25X and 25Y joined at both ends, and the check valves 24X and 24Y are opposite to each other in the branch pipes 25X and 25Y, respectively. You may make it attach so that.
  • the premixed gas from the first cylinder 6A passes through the connecting pipe 19, no backflow from the third cylinder 6C occurs, so that it is stored in the combustion chamber 7a of the first cylinder 6A.
  • the premixed gas of the liquefied gas 2 can be effectively scavenged. This is the same when scavenging the premixed gas of the liquefied gas 2 stored in the third cylinder 6C.
  • FIG. 9 shows an abnormal combustion prevention system for a diesel engine according to the second embodiment of the present invention.
  • this abnormal combustion prevention system is provided with an oxygen sensor 26 as a fuel leak detection means attached to each of the intake pipe 13 and the exhaust pipe 11 communicating with each of the cylinders 6A to 6D. They are connected by signal lines.
  • the control means 22 rotates the pinion 16 with the cell motor 15 of the starter 14 and extends the pinion 16 Then, the crankshaft 18 is rotated by being fitted to the ring gear 17 (S20). At this time, both the relief valves 21a and 21c are closed.
  • the measured values of the oxygen sensor 26 attached to the intake pipe 13 and the exhaust pipe 11 are compared (S22). If the difference is equal to or greater than a predetermined value (S24), the combustion chamber 7 is stopped while the engine is stopped. It is determined that there has been a fuel leak of the liquefied gas 2 into the interior, and the stroke of each cylinder 6A to 6D is detected from the rotational position sensor 27 (S30), and is opened and closed when the first cylinder 6A is in the compression stroke
  • the means 20 opens both the relief valves 21a and 21c in the first cylinder 6A and the third cylinder 6C (S40). Then, both relief valves 21a and 21c are normally closed after a predetermined period (S50).
  • the attachment positions of the oxygen sensor 26 in the intake pipe 13 and the exhaust pipe 11 are not particularly limited.
  • the oxygen sensor 26 is a large-diameter portion in which the intake pipe 13 and the exhaust pipe 11 extending from the cylinders 6A to 6D converge to one. May be.
  • abnormal combustion prevention system of the present invention is not limited to the automobile diesel engine 1 as described above, but can be applied to other internal combustion engines using the liquefied gas 2 as fuel.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Abstract

In a diesel engine that uses liquefied gas as fuel, a faulty combustion prevention system for preventing faulty combustion in the diesel engine caused by the leakage of fuel to the combustion chambers from injection nozzles arranged on the air cylinders, wherein the combustion chambers (7a, 7c) of a pair of air cylinders (6A, 6C) having a phase difference of 360° for the stroke are formed connected by a connecting pipe (19) via their respective escape valves (21a, 2ac). In this faulty combustion prevention system for a diesel engine, when the diesel engine (1) starts, both of the escape valves (21a, 21c) are opened at least when one air cylinder (6A) is in the compression stroke.

Description

ディーゼルエンジンの異常燃焼防止システムAbnormal combustion prevention system for diesel engine
　本発明は、ディーゼルエンジンの異常燃焼防止システムに関し、更に詳しくは、液化ガスを燃料とするディーゼルエンジンにおける燃焼室内への燃料リークによるエンジン始動時の異常燃焼の発生を、低コストで防止することができるディーゼルエンジンの異常燃焼防止システムに関する。 The present invention relates to a system for preventing abnormal combustion of a diesel engine. More specifically, the present invention can prevent the occurrence of abnormal combustion at the time of engine start due to fuel leakage into a combustion chamber in a diesel engine using liquefied gas as fuel. The present invention relates to a system for preventing abnormal combustion of diesel engines.
　ディーゼルエンジンの排ガスによる大気汚染の対策として、従来からの燃料である軽油の代わりに、例えば日本出願の特開２００７－２３９６５１号公報に記載されているように、ジメチルエーテル（ＤＭＥ）などの液化ガスを使用することが検討されている。 As a countermeasure against air pollution due to exhaust gas from diesel engines, a liquefied gas such as dimethyl ether (DME) is used instead of conventional diesel fuel oil, as described in Japanese Patent Application Publication No. 2007-239651. It is being considered for use.
　この液化ガスは、燃焼室内に燃料を噴射する噴射ノズルのシート部からガス状となって外部へリークしやすいという性質がある。更に、液化ガスは軽油よりも粘度が低いので、噴射ノズルのシート部が摩耗しやすくなるため、外部へのリークが助長されることになる。 This liquefied gas has the property of easily leaking to the outside in the form of gas from the seat portion of the injection nozzle that injects fuel into the combustion chamber. Furthermore, since the liquefied gas has a lower viscosity than that of light oil, the sheet portion of the injection nozzle is likely to be worn out, which promotes leakage to the outside.
　特に、エンジン停止時においては、噴射ノズル内に残留した液化ガスが、圧力の低下により気化することで、シート部から燃焼室内へのリークが発生する。このようにエンジン停止時に液化ガスの燃料リークが発生すると、エンジン始動時に初爆で異常燃焼を起こして、最悪の場合にはシリンダライナやピストンリングが破損するおそれがある。このことは、高圧で燃料を噴射するコモンレール式の噴射装置を用いた場合に一層顕著になる。 In particular, when the engine is stopped, the liquefied gas remaining in the injection nozzle is vaporized due to a decrease in pressure, thereby causing a leak from the seat portion into the combustion chamber. Thus, when a fuel leak of liquefied gas occurs when the engine is stopped, abnormal combustion may occur at the first explosion when the engine is started, and in the worst case, the cylinder liner or the piston ring may be damaged. This becomes more prominent when a common rail type injection device that injects fuel at a high pressure is used.
　このような問題を解決するためには、エンジン始動時に吸排気バルブを開閉させて燃焼室内に滞留する液化ガスを掃気することが考えられるが、可変動弁機構の追加やそれを制御する制御ロジックが必要となるため、エンジンの構成が複雑となってコストが大幅に増加することになる。 In order to solve such problems, it is conceivable to open and close the intake and exhaust valves when starting the engine to scavenge liquefied gas that remains in the combustion chamber. However, the addition of a variable valve mechanism and control logic that controls it Therefore, the configuration of the engine is complicated and the cost is greatly increased.
　そのため、液化ガスを燃料とするディーゼルエンジンについて、エンジン始動時の異常燃焼の発生を、簡易な構成と機能によって低コストで防止することができるシステムが求められている。 For this reason, there is a demand for a system that can prevent the occurrence of abnormal combustion at the time of engine start at a low cost with a simple configuration and function for a diesel engine using liquefied gas as fuel.
日本出願の特開２００７－２３９６５１号公報Japanese Patent Application Publication No. 2007-239651
　本発明の目的は、液化ガスを燃料とするディーゼルエンジンにおけるエンジン始動時の異常燃焼の発生を、低コストで防止することができるディーゼルエンジンの異常燃焼防止システムを提供することにある。 An object of the present invention is to provide a system for preventing abnormal combustion of a diesel engine that can prevent the occurrence of abnormal combustion at the time of engine start in a diesel engine using liquefied gas as a fuel at low cost.
　上記の目的を達成する本発明のディーゼルエンジンの異常燃焼防止システムは、液化ガスを燃料とするディーゼルエンジンの気筒に設置された噴射ノズルから燃焼室内への燃料リークに起因する異常燃焼を防止するディーゼルエンジンの異常燃焼防止システムであって、互いに行程が３６０°位相が異なる一対の気筒を接続する連結管と、前記連結管と前記一対の気筒との接続部をそれぞれ開閉する逃がし弁と、それら両方の逃がし弁を操作する開閉手段と、前記開閉手段を制御する制御手段とを備え、前記制御手段は、前記ディーセルエンジンの始動要求を受けると、スタータでクランク軸を回転駆動させるとともに、前記一対の気筒のうち片方の気筒が少なくとも圧縮行程にあるときに前記開閉手段により前記両方の逃がし弁を開弁し、所定の期間後にそれらの逃がし弁を常時閉弁する制御を行うことを特徴とするものである。 A system for preventing abnormal combustion of a diesel engine according to the present invention that achieves the above object is a diesel engine that prevents abnormal combustion caused by fuel leakage from an injection nozzle installed in a cylinder of a diesel engine using liquefied gas as a fuel into a combustion chamber. A system for preventing abnormal combustion of an engine, a connecting pipe that connects a pair of cylinders whose strokes are different from each other by 360 °, a relief valve that opens and closes a connecting portion between the connecting pipe and the pair of cylinders, and both Open / close means for operating the relief valve, and control means for controlling the open / close means. When the control means receives a start request for the diesel engine, the control means rotates the crankshaft with a starter, and When one of the cylinders is at least in the compression stroke, the opening / closing means opens both the relief valves. It is characterized in performing control for closing their relief valve normally after a predetermined period of time.
　上記のディーゼルエンジンの異常燃焼防止システムにおいては、連結管の途中に逆止弁を取り付けることにより、一対の気筒のうち特定の気筒を対象にして異常燃焼を防止することができる。 In the above-described abnormal combustion prevention system for a diesel engine, by attaching a check valve in the middle of the connecting pipe, abnormal combustion can be prevented for a specific cylinder of a pair of cylinders.
　また、上記の連結管を両端部が合流する２本の支管から構成するとともに、それらの支管に互いに逆向きになるように逆止弁をそれぞれ取り付けることで、燃料リークにより気筒内に貯留する液化ガスの予混合気を効果的に掃気することができる。 In addition, the connecting pipe is composed of two branch pipes joined at both ends, and a check valve is attached to each of the branch pipes so as to be opposite to each other so that liquefaction is stored in the cylinder due to fuel leak. The gas premixed gas can be effectively scavenged.
　ディーゼルエンジンの異常燃焼防止システムが燃料リーク検知手段を有し、制御手段は燃料リーク検知手段が液化ガスの燃料リークを検知した場合にのみ、一対の気筒のうち片方の気筒が少なくとも圧縮行程にあるときに開閉手段により両方の逃がし弁を開弁し、所定の期間後にそれらの逃がし弁を常時閉弁する制御を行うことで、ディーゼルエンジンの始動が遅れるのを防ぐことができる。 The abnormal combustion prevention system of a diesel engine has a fuel leak detection means, and the control means has at least one of the cylinders in the compression stroke only when the fuel leak detection means detects a fuel leak of liquefied gas. Sometimes, by opening and closing means, both relief valves are opened, and control is performed such that these relief valves are always closed after a predetermined period of time, thereby preventing delay in starting the diesel engine.
　また、制御手段は、両方の逃がし弁を気筒の２～３サイクル後に常時閉弁することで、燃料リークにより燃焼室内に貯留する液化ガスの予混合気を完全に掃気できるとともに、始動後のディーゼルエンジンの運転に影響を与えないようにすることができる。 In addition, the control means always closes both the relief valves after 2 to 3 cycles of the cylinder, thereby completely scavenging the premixed mixture of liquefied gas stored in the combustion chamber due to fuel leakage, and after starting diesel The engine operation can be prevented from being affected.
　本発明のディーゼルエンジンの異常燃焼防止システムは、液化ガスを燃料とする一般の内燃機関に好適に用いられる。 The diesel engine abnormal combustion prevention system of the present invention is suitably used for a general internal combustion engine using liquefied gas as fuel.
　本発明のディーゼルエンジンの異常燃焼防止システムによれば、エンジン始動時において一対の気筒の片方が少なくとも圧縮行程にあるときに、その燃焼室内の気体を互いに行程が３６０°位相が異なる他方へ移動して外部へ排気させるようにしたので、燃料リークにより片方の気筒内に貯留している液化ガスの予混合気が、外部へ掃気されて圧縮着火が抑制されるため、異常燃焼の発生を防止することができる。 According to the abnormal combustion prevention system for a diesel engine of the present invention, when at least one of a pair of cylinders is in a compression stroke at the time of starting the engine, the gas in the combustion chamber moves to the other where the strokes are 360 ° out of phase with each other. Since the premixed gas of the liquefied gas stored in one cylinder is scavenged to the outside and the compression ignition is suppressed due to fuel leak, the occurrence of abnormal combustion is prevented. be able to.
　また、異常燃焼防止システムの構成及び機能が簡易であるため、コストの増加を抑えることができる。 Also, since the configuration and function of the abnormal combustion prevention system are simple, an increase in cost can be suppressed.
図１は、本発明の第１の実施形態からなるディーゼルエンジンの異常燃焼防止システムの構成図である。FIG. 1 is a configuration diagram of an abnormal combustion prevention system for a diesel engine according to a first embodiment of the present invention. 図２は、図１における一対の気筒部分の構成を示す拡大図である。FIG. 2 is an enlarged view showing a configuration of a pair of cylinder portions in FIG. 図３は、図２において１番気筒が圧縮行程にあるときの説明図である。FIG. 3 is an explanatory diagram when the first cylinder in FIG. 2 is in the compression stroke. 図４は、第１の実施形態における制御手段の機能を示すフロー図である。FIG. 4 is a flowchart showing the function of the control means in the first embodiment. 図５は、図２において３番気筒が圧縮行程にあるときの説明図である。FIG. 5 is an explanatory diagram when the third cylinder in FIG. 2 is in the compression stroke. 図６は、図１における一対の気筒部分の構成の別の例を示す拡大図である。FIG. 6 is an enlarged view showing another example of the configuration of the pair of cylinder portions in FIG. 1. 図７は、図６において１番気筒が圧縮行程にあるときの説明図である。FIG. 7 is an explanatory diagram when the first cylinder is in the compression stroke in FIG. 図８は、図１における一対の気筒部分の構成の更に別の例を示す拡大図である。FIG. 8 is an enlarged view showing still another example of the configuration of the pair of cylinder portions in FIG. 図９は、本発明の第２の実施形態からなるディーゼルエンジンの異常燃焼防止システムの構成図である。FIG. 9 is a configuration diagram of the abnormal combustion prevention system for a diesel engine according to the second embodiment of the present invention. 図１０は、第２の実施形態における制御手段の機能を示すフロー図である。FIG. 10 is a flowchart showing the function of the control means in the second embodiment.
　以下に、本発明の実施の形態について、図面を参照して説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
　図１、２は、本発明の第１の実施形態からなるディーゼルエンジンの異常燃焼防止システムを示す。 1 and 2 show an abnormal combustion prevention system for a diesel engine according to a first embodiment of the present invention.
　このディーゼルエンジンの異常燃焼防止システム（以下、「異常燃焼防止システム」という。）が装備されるディーゼルエンジン１では、ジメチルエーテル（ＤＭＥ）などの液化ガス２が、高圧ポンプ（図示せず）によりコモンレール３内で蓄圧され、ＥＣＵ（Engine Control Unit）４により制御された噴射ノズル５を通じて複数（図１では４個）の気筒６Ａ～６Ｄの燃焼室７内の圧縮空気中にそれぞれ噴射されて燃焼・膨張することで、シリンダ８内のピストン９を往復動させるようになっている。それら４個の気筒６Ａ～６Ｄは、１番気筒６Ａ→３番気筒６Ｃ→４番気筒６Ｄ→２番気筒６Ｂの順に液化ガス２が自着火する。 In a diesel engine 1 equipped with this diesel engine abnormal combustion prevention system (hereinafter referred to as “abnormal combustion prevention system”), liquefied gas 2 such as dimethyl ether (DME) is supplied to a common rail 3 by a high-pressure pump (not shown). Are injected into compressed air in the combustion chambers 7 of a plurality of cylinders 6A to 6D (four in FIG. 1) through injection nozzles 5 that are accumulated in the engine and controlled by an ECU (Engine Control Unit) 4 for combustion and expansion. By doing so, the piston 9 in the cylinder 8 is reciprocated. In these four cylinders 6A to 6D, the liquefied gas 2 is self-ignited in the order of the first cylinder 6A → the third cylinder 6C → the fourth cylinder 6D → the second cylinder 6B.
　燃焼後のガスは、排気弁１０の開放時に燃焼室７から排気管１１へ送られて大気中へ放出される。その一方で、吸気弁１２の開放時に吸気管１３から燃焼室７内へ空気が導入されてピストン９により圧縮される。 The gas after combustion is sent from the combustion chamber 7 to the exhaust pipe 11 when the exhaust valve 10 is opened, and is released into the atmosphere. On the other hand, when the intake valve 12 is opened, air is introduced from the intake pipe 13 into the combustion chamber 7 and compressed by the piston 9.
　エンジン始動時においては、スタータ１４のセルモータ１５により回転駆動されたピニオン１６が伸長してリングギア１７に嵌合させることで、クランク軸１８を回転させてクランキングを行うようになっている。 When the engine is started, the pinion 16 that is rotationally driven by the cell motor 15 of the starter 14 is extended and engaged with the ring gear 17, whereby the crankshaft 18 is rotated to perform cranking.
　本発明の異常燃焼防止システムは、互いに行程がクランク角度で３６０°位相が異なっている一対の気筒６、具体的には１番気筒６Ａと３番気筒６Ｃの組み合わせ、及び２番気筒６Ｂと４番気筒６Ｄの組み合わせにおける燃焼室７同士を接続する連結管１９と、その連結管１９と気筒６Ａ～６Ｄとの接続部に取り付けられて開閉手段２０により操作される逃がし弁２１と、制御手段２２とから構成される。 The abnormal combustion prevention system of the present invention includes a pair of cylinders 6 whose strokes are different from each other in crank angle and 360 ° phase, specifically, a combination of the first cylinder 6A and the third cylinder 6C, and the second cylinders 6B and 4B. A connecting pipe 19 for connecting the combustion chambers 7 in the combination of the numbered cylinder 6D, a relief valve 21 attached to a connecting portion between the connecting pipe 19 and the cylinders 6A to 6D and operated by the opening / closing means 20, and a control means 22 It consists of.
　逃がし弁２１の開閉手段２０としては、油圧又は空圧を利用したアクチュエーターやモータなどが例示される。制御手段２２は、記憶部を備えたＣＰＵ（Central Processing Unit）から構成され、開閉手段２０、スタータ１４、気筒６Ａ～６Ｄの行程状態を検知する回転位置センサ２３及びＥＣＵ４のそれぞれに信号線（一点鎖線で示す）を通じて接続している。なお、図１の構成では、制御手段２２とＥＣＵ４とを別体としているが、ＥＣＵ４に制御手段２２の機能を持たせて一体化するようにしてもよい。 Examples of the opening / closing means 20 of the relief valve 21 include an actuator or a motor using hydraulic pressure or pneumatic pressure. The control means 22 is composed of a CPU (Central Processing Unit) equipped with a storage unit. Signal lines (one point) are connected to the opening / closing means 20, the starter 14, the rotational position sensor 23 for detecting the stroke state of the cylinders 6A to 6D, and the ECU 4, respectively. Connected through a chain line). In the configuration of FIG. 1, the control unit 22 and the ECU 4 are separated, but the ECU 4 may be integrated with the function of the control unit 22.
　このような構成を有する異常燃焼防止システムの機能を、図３に示す１番気筒６Ａ及び３番気筒６Ｃの組み合わせを例にして、図４のフロー図を基に以下に説明する。 The function of the abnormal combustion prevention system having such a configuration will be described below with reference to the flowchart of FIG. 4 taking the combination of the first cylinder 6A and the third cylinder 6C shown in FIG. 3 as an example.
　制御手段２２は、停止状態にあるディーゼルエンジン１に対して始動要求が発せられたことがＥＣＵ４から入力されると（Ｓ１０）、スタータ１４のセルモータ１５でピニオン１６を回転駆動するとともに、そのピニオン１６を伸長してリングギア１７に嵌合させてクランク軸１８を回転させる（Ｓ２０）。なお、このとき１番気筒６Ａ及び３番気筒６Ｃにおける逃がし弁２１ａ、２１ｃは両方とも閉弁している。 When it is input from the ECU 4 that the start request is issued to the diesel engine 1 in the stopped state (S10), the control means 22 rotates the pinion 16 with the cell motor 15 of the starter 14, and the pinion 16 Is extended and fitted to the ring gear 17 to rotate the crankshaft 18 (S20). At this time, the relief valves 21a and 21c in the first cylinder 6A and the third cylinder 6C are both closed.
　次に、各気筒６Ａ～６Ｄの行程を回転位置センサ２３から検知し（Ｓ３０）、１番気筒６Ａが圧縮行程にあるときに、開閉手段２０ａ、２０ｃにより逃がし弁２１ａ、２１ｃを両方とも開弁する（Ｓ４０）。その結果、ピストン９ａの上昇により生じたシリンダ８ａ内の圧力増加により、１番気筒６Ａの燃焼室７ａ内の気体は、連結管１９を通じて３番気筒６Ｃの燃焼室７ｃへ移動して、排気管１１ｃから外部へ排気されることになる。従って、エンジン停止時に噴射ノズル５ａから１番気筒６Ａの燃焼室７ａ内に液化ガス２の燃料リークがあった場合には、燃焼室７ａ内に滞留する液化ガス２の予混合気の少なくとも一部が、連結管１９を通じて３番気筒６Ｃの排気管１１ｃから外部へ掃気されることになる。そして、所定の期間後に両方の逃がし弁２１ａ、２１ｃを常時閉弁した状態にする（Ｓ５０）。 Next, the strokes of the respective cylinders 6A to 6D are detected from the rotational position sensor 23 (S30). When the first cylinder 6A is in the compression stroke, both the relief valves 21a and 21c are opened by the opening / closing means 20a and 20c. (S40). As a result, the gas in the combustion chamber 7a of the first cylinder 6A moves to the combustion chamber 7c of the third cylinder 6C through the connecting pipe 19 due to the pressure increase in the cylinder 8a caused by the rise of the piston 9a, and the exhaust pipe The air is exhausted from 11c to the outside. Therefore, when there is a fuel leak of the liquefied gas 2 from the injection nozzle 5a into the combustion chamber 7a of the first cylinder 6A when the engine is stopped, at least a part of the premixed gas of the liquefied gas 2 staying in the combustion chamber 7a. However, the gas is scavenged from the exhaust pipe 11c of the third cylinder 6C to the outside through the connecting pipe 19. Then, both relief valves 21a and 21c are normally closed after a predetermined period (S50).
　なお、上記では１番気筒６Ａが圧縮行程にあるときを例示したが、他方の３番気筒６Ｃが圧縮行程にあるときには、図５に示すように、ピストン９ｃの上昇により生じたシリンダ８ｃ内の圧力増加により、エンジン停止時に噴射ノズル５ｃから３番気筒６Ｃの燃焼室７ｃ内に液化ガス２の燃料リークがあった場合には、燃焼室７ｃ内に滞留する液化ガス２の予混合気の少なくとも一部が、連結管１９を通じて１番気筒６Ａの燃焼室７ａへ流れて、排気管１１ａから外部へ掃気されることになる。 In the above, the case where the first cylinder 6A is in the compression stroke is illustrated, but when the other third cylinder 6C is in the compression stroke, as shown in FIG. 5, the inside of the cylinder 8c generated by the rise of the piston 9c is shown. If there is a fuel leak of the liquefied gas 2 from the injection nozzle 5c into the combustion chamber 7c of the third cylinder 6C due to the increase in pressure, at least the premixed gas of the liquefied gas 2 staying in the combustion chamber 7c A part flows to the combustion chamber 7a of the first cylinder 6A through the connecting pipe 19 and is scavenged to the outside from the exhaust pipe 11a.
　このように、エンジン始動時において、互いに行程が３６０°位相が異なる一対の気筒６Ａ、６Ｃのうち片方の気筒６Ａが少なくとも圧縮行程にあるときに、その燃焼室７ａ内の気体を他方の気筒６Ｃへ移動して外部へ排気させるようにしたので、燃料リークにより片方の気筒６Ａ内に貯留している液化ガス２の予混合気が、外部へ掃気されて圧縮着火が抑制されるため、異常燃焼の発生を防止することができる。 In this way, when the engine is started, when one cylinder 6A is at least in the compression stroke among the pair of cylinders 6A, 6C whose strokes are different from each other by 360 °, the gas in the combustion chamber 7a is transferred to the other cylinder 6C. Because the premixed gas of the liquefied gas 2 stored in one cylinder 6A is scavenged to the outside and the compression ignition is suppressed due to the fuel leak, the abnormal combustion occurs. Can be prevented.
　また、一対の気筒６Ａ、６Ｃ間を連結管１９で接続し、その両端に逃がし弁２１ａ、２１ｃを設けて単純制御するだけでよいため、異常燃焼防止システムの構成及び機能が簡易となるのでコストの増加を抑えることができる。 In addition, since a pair of cylinders 6A and 6C are connected by a connecting pipe 19, and it is only necessary to provide relief valves 21a and 21c at both ends of the cylinder 6 for simple control, the configuration and function of the abnormal combustion prevention system can be simplified. Can be suppressed.
　逃がし弁２１を常時閉弁するまでの所定の期間は、エンジン始動開始から気筒６の２～３サイクル後とすることが望ましい。そのようにすることで、燃料リークにより燃焼室７内に貯留する液化ガス２の予混合気を完全にエンジン外部へ掃気できるとともに、ディーゼルエンジン１の運転に影響を与えないようにすることができる。 The predetermined period until the relief valve 21 is normally closed is desirably two to three cycles after the start of the engine. By doing so, the premixed gas of the liquefied gas 2 stored in the combustion chamber 7 due to fuel leak can be completely scavenged to the outside of the engine, and the operation of the diesel engine 1 can be prevented from being affected. .
　逃がし弁２１は、気筒６の圧縮行程以外の行程においても開弁するようにしてもよい。例えば、圧縮行程に続く膨張行程、排気行程及び吸気行程、つまり全行程で逃がし弁２１を開弁することで、燃料リークにより燃焼室７内に貯留する液化ガス２の予混合気を完全に掃気することができるとともに、開閉手段２０の制御をより容易に行うことが可能になる。 The relief valve 21 may be opened in a stroke other than the compression stroke of the cylinder 6. For example, the pre-mixed gas of the liquefied gas 2 stored in the combustion chamber 7 due to fuel leak is completely scavenged by opening the relief valve 21 in the expansion stroke, exhaust stroke, and intake stroke following the compression stroke, that is, the entire stroke. In addition, the opening / closing means 20 can be controlled more easily.
　上記の連結管１９の途中には、図６に示すように、逆止弁２４を取り付けるようにしてもよい。なお、図６では、上流側が１番気筒６Ａに向くように、つまり１番気筒６Ａから３番気筒６Ｃへ向けて連結管１９内を気体が流れるように、逆止弁２４を取り付けている。また、逆止弁２４の形式としてボールキャッチ式の弁を例示しているが、これに限るものではない。 In the middle of the connecting pipe 19, a check valve 24 may be attached as shown in FIG. In FIG. 6, the check valve 24 is attached so that the upstream side faces the first cylinder 6A, that is, the gas flows in the connecting pipe 19 from the first cylinder 6A to the third cylinder 6C. Moreover, although the ball catch type valve is illustrated as a type of the check valve 24, it is not limited to this.
　このようにすることで、逆止弁２４の取付方向を変えることにより、一対の気筒６のうち特定の気筒６を対象にして、エンジン始動時における異常燃焼の発生を防止する効果を及ぼすことができる。つまり、図６のケースでは、３番気筒６Ｃの状態の如何にかかわらず、図７に示すように、連結管１９内の気体の流れが常に１番気筒６Ａから３番気筒６Ｃへ向かうので、１番気筒６Ａのみを対象としてエンジン始動時における異常燃焼の発生を防止できるのである。 In this way, by changing the mounting direction of the check valve 24, the effect of preventing the occurrence of abnormal combustion at the time of starting the engine can be exerted on a specific cylinder 6 of the pair of cylinders 6. it can. That is, in the case of FIG. 6, regardless of the state of the third cylinder 6C, as shown in FIG. 7, the gas flow in the connecting pipe 19 always goes from the first cylinder 6A to the third cylinder 6C. It is possible to prevent the occurrence of abnormal combustion when starting the engine only for the first cylinder 6A.
　また、図８に示すように、連結管１９を、両端が合流する２本の支管２５Ｘ、２５Ｙから構成するとともに、それらの支管２５Ｘ、２５Ｙにそれぞれ逆止弁２４Ｘ、２４Ｙを互いに逆向きになるように取り付けるようにしてもよい。このようにすることで、１番気筒６Ａからの予混合気が連結管１９を通過するときに、３番気筒６Ｃからの逆流が発生しないため、１番気筒６Ａの燃焼室７ａ内に貯留する液化ガス２の予混合気を効果的に掃気することができる。このことは、３番気筒６Ｃに貯留する液化ガス２の予混合気を掃気する場合も同様である。 Further, as shown in FIG. 8, the connecting pipe 19 is composed of two branch pipes 25X and 25Y joined at both ends, and the check valves 24X and 24Y are opposite to each other in the branch pipes 25X and 25Y, respectively. You may make it attach so that. In this way, when the premixed gas from the first cylinder 6A passes through the connecting pipe 19, no backflow from the third cylinder 6C occurs, so that it is stored in the combustion chamber 7a of the first cylinder 6A. The premixed gas of the liquefied gas 2 can be effectively scavenged. This is the same when scavenging the premixed gas of the liquefied gas 2 stored in the third cylinder 6C.
　図９は、本発明の第２の実施形態からなるディーゼルエンジンの異常燃焼防止システムを示す。 FIG. 9 shows an abnormal combustion prevention system for a diesel engine according to the second embodiment of the present invention.
　この異常燃焼防止システムは、図１に示す実施形態について、各気筒６Ａ～６Ｄに連通する吸気管１３及び排気管１１のそれぞれに燃料リーク検知手段である酸素センサ２６を取り付けて、制御手段２２と信号線で接続したものである。 In the embodiment shown in FIG. 1, this abnormal combustion prevention system is provided with an oxygen sensor 26 as a fuel leak detection means attached to each of the intake pipe 13 and the exhaust pipe 11 communicating with each of the cylinders 6A to 6D. They are connected by signal lines.
　このような構成を有する異常燃焼防止システムの機能を、図３に示す１番気筒６Ａ及び３番気筒６Ｃの組み合わせを例にして、図１０に示すフロー図を基に以下に説明する。 The function of the abnormal combustion prevention system having such a configuration will be described below with reference to the flowchart shown in FIG. 10, taking as an example the combination of the first cylinder 6A and the third cylinder 6C shown in FIG.
　制御手段２２は、停止状態にあるディーゼルエンジンに対して始動要求が発せられたことをＥＣＵ４から入力されると（Ｓ１０）、スタータ１４のセルモータ１５でピニオン１６を回転駆動するとともに、ピニオン１６を伸長してリングギア１７に嵌合させることでクランク軸１８を回転させる（Ｓ２０）。なお、このとき両方の逃がし弁２１ａ、２１ｃは閉弁している。 When it is input from the ECU 4 that the start request is issued to the diesel engine in the stopped state (S10), the control means 22 rotates the pinion 16 with the cell motor 15 of the starter 14 and extends the pinion 16 Then, the crankshaft 18 is rotated by being fitted to the ring gear 17 (S20). At this time, both the relief valves 21a and 21c are closed.
　次に、吸気管１３及び排気管１１に取り付けられた酸素センサ２６の測定値を比較し（Ｓ２２）、その差が所定の値以上である場合には（Ｓ２４）、エンジン停止中に燃焼室７内への液化ガス２の燃料リークがあったものと判断し、各気筒６Ａ～６Ｄの行程を回転位置センサ２７から検知して（Ｓ３０）、１番気筒６Ａが圧縮行程にあるときに、開閉手段２０により１番気筒６Ａ及び３番気筒６Ｃにおける逃がし弁２１ａ、２１ｃを両方とも開弁する（Ｓ４０）。そして、所定の期間後に両方の逃がし弁２１ａ、２１ｃを常時閉弁した状態にする（Ｓ５０）。 Next, the measured values of the oxygen sensor 26 attached to the intake pipe 13 and the exhaust pipe 11 are compared (S22). If the difference is equal to or greater than a predetermined value (S24), the combustion chamber 7 is stopped while the engine is stopped. It is determined that there has been a fuel leak of the liquefied gas 2 into the interior, and the stroke of each cylinder 6A to 6D is detected from the rotational position sensor 27 (S30), and is opened and closed when the first cylinder 6A is in the compression stroke The means 20 opens both the relief valves 21a and 21c in the first cylinder 6A and the third cylinder 6C (S40). Then, both relief valves 21a and 21c are normally closed after a predetermined period (S50).
　一方、酸素センサ２６の測定値の差が所定の値未満である場合には（Ｓ２４）、燃料リークがなかったものと判断し、両方の逃がし弁２１ａ、２１ｃを常時閉弁したままにする（Ｓ６０）。 On the other hand, if the difference between the measured values of the oxygen sensor 26 is less than the predetermined value (S24), it is determined that there is no fuel leak, and both the relief valves 21a and 21c are kept closed at all times (S24). S60).
　このようにすることで、噴射ノズル５からの液化ガス２の燃料リークがなかった場合には、エンジン始動時の初爆が通常の圧縮比で正常に行われるため、ディーゼルエンジン１の始動が遅れる（もたつく）のを防ぐことができる。 By doing in this way, when there is no fuel leak of the liquefied gas 2 from the injection nozzle 5, since the initial explosion at the time of engine start is normally performed with a normal compression ratio, the start of the diesel engine 1 is delayed. Can be prevented.
　酸素センサ２６の吸気管１３及び排気管１１における取付位置は特に限定するものではなく、例えば、各気筒６Ａ～６Ｄから延びる吸気管１３及び排気管１１がそれぞれ１本に収束する太径部であってもよい。 The attachment positions of the oxygen sensor 26 in the intake pipe 13 and the exhaust pipe 11 are not particularly limited. For example, the oxygen sensor 26 is a large-diameter portion in which the intake pipe 13 and the exhaust pipe 11 extending from the cylinders 6A to 6D converge to one. May be.
　本発明の異常燃焼防止システムの用途は、上述したような自動車用のディーゼルエンジン１に限るものではなく、液化ガス２を燃料とするその他の内燃機関にも適用することができる。 The use of the abnormal combustion prevention system of the present invention is not limited to the automobile diesel engine 1 as described above, but can be applied to other internal combustion engines using the liquefied gas 2 as fuel.
１　ディーゼルエンジン
２　液化ガス
３　コモンレール
４　ＥＣＵ
５　噴射ノズル
６　気筒
６Ａ　１番気筒
６Ｂ　２番気筒
６Ｃ　３番気筒
６Ｄ　４番気筒
７　燃焼室
８　シリンダ
９　ピストン
１０　排気弁
１１　排気管
１２　吸気弁
１３　吸気管
１４　スタータ
１５　セルモータ
１６　ピニオン
１７　リングギア
１８　クランク軸
１９　連結管
２０　開閉手段
２１　逃がし弁
２２　制御手段
２３　回転位置センサ
２４　逆止弁
２５ｘ、２５ｙ　支管
２６　酸素センサ 1 Diesel engine 2 Liquefied gas 3 Common rail 4 ECU
5 Injection nozzle 6 Cylinder 6A 1st cylinder 6B 2nd cylinder 6C 3rd cylinder 6D 4th cylinder 7 Combustion chamber 8 Cylinder 10 Piston 10 Exhaust valve 11 Exhaust pipe 12 Intake valve 13 Intake pipe 14 Starter 15 Cell motor 16 Pinion 17 Ring gear 18 Crankshaft 19 Connecting pipe 20 Opening / closing means 21 Relief valve 22 Control means 23 Rotation position sensor 24 Check valves 25x, 25y Branch pipe 26 Oxygen sensor

Claims (6)

  1. 　液化ガスを燃料とするディーゼルエンジンの気筒に設置された噴射ノズルから燃焼室内への燃料リークに起因する異常燃焼を防止するディーゼルエンジンの異常燃焼防止システムであって、
    　互いに行程が３６０°位相が異なる一対の気筒を接続する連結管と、前記連結管と前記一対の気筒との接続部をそれぞれ開閉する逃がし弁と、それら両方の逃がし弁を操作する開閉手段と、前記開閉手段を制御する制御手段とを備え、
    　前記制御手段は、前記ディーセルエンジンの始動要求を受けると、スタータでクランク軸を回転駆動させるとともに、前記一対の気筒のうち片方の気筒が少なくとも圧縮行程にあるときに前記開閉手段により前記両方の逃がし弁を開弁し、所定の期間後にそれらの逃がし弁を常時閉弁する制御を行うことを特徴とするディーゼルエンジンの異常燃焼防止システム。     An abnormal combustion prevention system for a diesel engine for preventing abnormal combustion caused by fuel leakage from an injection nozzle installed in a cylinder of a diesel engine using liquefied gas as fuel, into a combustion chamber,
    A connecting pipe that connects a pair of cylinders whose strokes are different from each other in 360 ° phase, a relief valve that opens and closes a connecting portion between the connecting pipe and the pair of cylinders, and an opening / closing means that operates both of the relief valves; Control means for controlling the opening and closing means,
    When the control unit receives a request to start the diesel engine, the control unit rotates the crankshaft with a starter, and when one of the pair of cylinders is at least in a compression stroke, the opening / closing unit releases the both. An abnormal combustion prevention system for a diesel engine, characterized in that the valve is opened and the relief valve is normally closed after a predetermined period.
  2. 　前記連結管の途中に逆止弁を取り付けた請求項１に記載のディーゼルエンジンの異常燃焼防止システム。 The abnormal combustion prevention system for a diesel engine according to claim 1, wherein a check valve is attached in the middle of the connecting pipe.
  3. 　前記連結管を両端部が合流する２本の支管から構成するとともに、それらの支管に互いに逆向きになるように逆止弁をそれぞれ取り付けた請求項１に記載のディーゼルエンジンの異常燃焼防止システム。 2. The abnormal combustion prevention system for a diesel engine according to claim 1, wherein the connecting pipe is composed of two branch pipes joined at both ends, and check valves are attached to the branch pipes in opposite directions.
  4. 　前記ディーゼルエンジンの異常燃焼防止システムが燃料リーク検知手段を有し、
    　前記制御手段は、前記燃料リーク検知手段が前記液化ガスの燃料リークを検知した場合にのみ、前記一対の気筒のうち片方の気筒が少なくとも圧縮行程にあるときに前記開閉手段により前記両方の逃がし弁を開弁し、所定の期間後にそれらの逃がし弁を常時閉弁する制御を行う請求項１～３のいずれかに記載のディーゼルエンジンの異常燃焼防止システム。     The diesel engine abnormal combustion prevention system has a fuel leak detection means,
    Only when the fuel leak detection means detects a fuel leak of the liquefied gas, the control means is configured to open both the release valves by the opening / closing means when one of the pair of cylinders is at least in a compression stroke. The abnormal combustion prevention system for a diesel engine according to any one of claims 1 to 3, wherein control is performed so that the relief valves are normally closed after a predetermined period of time.
  5. 　前記制御手段は、前記両方の逃がし弁を前記片方の気筒の２～３サイクル後に常時閉弁する請求項１～４のいずれかに記載のディーゼルエンジンの異常燃焼防止システム。 The abnormal combustion prevention system for a diesel engine according to any one of claims 1 to 4, wherein the control means always closes both the relief valves after two to three cycles of the one cylinder.
  6. 　請求項１～５のいずれかに記載のディーゼルエンジンの異常燃焼防止システムを搭載したことを特徴とする内燃機関。 An internal combustion engine comprising the diesel engine abnormal combustion prevention system according to any one of claims 1 to 5.
PCT/JP2012/079340 2011-12-13 2012-11-13 Faulty combustion prevention system for diesel engine WO2013088886A1 (en)

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JPH01125827U (en) * 1988-02-23 1989-08-28
JPH0734913A (en) * 1993-07-15 1995-02-03 Mitsumasa Fukuda Internal combustion engine
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JP2011122531A (en) * 2009-12-11 2011-06-23 Mazda Motor Corp Control device for dual-fuel engine

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62195414A (en) * 1986-02-21 1987-08-28 Mitsubishi Motors Corp Four-cycle reciprocating type supercharged engine
JPH01125827U (en) * 1988-02-23 1989-08-28
JPH0734913A (en) * 1993-07-15 1995-02-03 Mitsumasa Fukuda Internal combustion engine
WO2002084088A1 (en) * 2001-04-09 2002-10-24 Daihatsu Motor Co.,Ltd. Multiple cylinder internal combustion engine
JP2004353562A (en) * 2003-05-29 2004-12-16 Toyota Motor Corp Dimethyl ether compression ignition engine
JP2011122531A (en) * 2009-12-11 2011-06-23 Mazda Motor Corp Control device for dual-fuel engine

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