JP4204057B2 - Cooling device for pilot fuel injection valve for gas engine - Google Patents
Cooling device for pilot fuel injection valve for gas engine Download PDFInfo
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- JP4204057B2 JP4204057B2 JP2006026674A JP2006026674A JP4204057B2 JP 4204057 B2 JP4204057 B2 JP 4204057B2 JP 2006026674 A JP2006026674 A JP 2006026674A JP 2006026674 A JP2006026674 A JP 2006026674A JP 4204057 B2 JP4204057 B2 JP 4204057B2
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- cooling
- fuel injection
- injection valve
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- cooling water
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- 239000000446 fuel Substances 0.000 title claims description 203
- 238000001816 cooling Methods 0.000 title claims description 149
- 238000002347 injection Methods 0.000 title claims description 140
- 239000007924 injection Substances 0.000 title claims description 140
- 239000000498 cooling water Substances 0.000 claims description 116
- 239000007788 liquid Substances 0.000 claims description 30
- 238000011144 upstream manufacturing Methods 0.000 claims description 12
- 238000007599 discharging Methods 0.000 claims description 5
- 239000007789 gas Substances 0.000 description 53
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 238000013021 overheating Methods 0.000 description 4
- 230000002093 peripheral effect Effects 0.000 description 4
- 238000004939 coking Methods 0.000 description 3
- 238000005553 drilling Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 239000002028 Biomass Substances 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
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- 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
- F02M53/00—Fuel-injection apparatus characterised by having heating, cooling or thermally-insulating means
- F02M53/04—Injectors with heating, cooling, or thermally-insulating means
- F02M53/043—Injectors with heating, cooling, or thermally-insulating means with cooling means other than air cooling
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P3/00—Liquid cooling
- F01P3/12—Arrangements for cooling other engine or machine parts
- F01P3/16—Arrangements for cooling other engine or machine parts for cooling fuel injectors or sparking-plugs
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F1/242—Arrangement of spark plugs or injectors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F1/26—Cylinder heads having cooling means
- F02F1/36—Cylinder heads having cooling means for liquid cooling
-
- 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
- F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
- F02M61/14—Arrangements of injectors with respect to engines; Mounting of injectors
-
- 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
- F02D19/06—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 pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
- F02D19/08—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 pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels
- F02D19/10—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 pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels peculiar to compression-ignition engines in which the main fuel is gaseous
- F02D19/105—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 pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels peculiar to compression-ignition engines in which the main fuel is gaseous operating in a special mode, e.g. in a liquid fuel only mode for starting
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
- Fuel-Injection Apparatus (AREA)
Description
本発明は、天然ガス等のガス燃料を主燃料とし、ガス燃料の点火のためにパイロット燃料としての液体燃料を燃料噴射弁から噴射するための燃料噴射弁を備えたガスエンジンに係わり、その燃料噴射弁の冷却能力を向上させるガスエンジン用パイロット燃料噴射弁の冷却装置に関する。 The present invention relates to a gas engine having a fuel injection valve for injecting a liquid fuel as a pilot fuel from a fuel injection valve, using a gas fuel such as natural gas as a main fuel and igniting the gas fuel. The present invention relates to a cooling device for a pilot fuel injection valve for a gas engine that improves the cooling capacity of the injection valve.
この種のガスエンジンは、排気ガス中の窒素酸化物(NOx)の低減や燃費効率の向上を図るためにリーンバーン方式が主流になりつつあり、また、出力の向上を図るうえで吸入空気が過給されるため、ガスエンジンの筒内圧は高圧化している。 In this type of gas engine, the lean burn method is becoming mainstream in order to reduce nitrogen oxide (NOx) in exhaust gas and improve fuel efficiency, and intake air is used to improve output. Since it is supercharged, the cylinder pressure of the gas engine is increased.
また、エネルギの有効利用を図る観点から、ガスエンジンの中には下水処理場から発生する消化ガスや、塵及び廃材を原料としたバイオマスガス等の低カロリー特殊ガスを主燃料として使用するものも知られている。 From the viewpoint of effective energy use, some gas engines use digestion gas generated from sewage treatment plants and low-calorie special gas such as biomass gas made from dust and waste as the main fuel. Are known.
このように、筒内圧が高く、あるいは、主燃料が低カロリー特殊ガスであるような条件下においては、主燃料の安定した点火を図るために大きな点火エネルギを発生させる点火方式が要求されるようになった。 Thus, under conditions where the in-cylinder pressure is high or the main fuel is a low-calorie special gas, an ignition system that generates large ignition energy is required to achieve stable ignition of the main fuel. Became.
このため、一般的なスパープラグによる火花点火方式から、スパープラグの数千倍の点火エネルギを発生させるパイロット燃料噴射による点火方式が主流になりつつあり、このパイロット燃料噴射は燃料噴射弁により実施される(例えば、特許文献1参照)。
しかしながら、主燃料の点火のためにパイロット燃料噴射弁から噴射される液体燃料は非常に少ないため、通常のディーゼルエンジンの燃料噴射弁が多量の燃料を噴射する場合とは異なり、パイロット燃料噴射のための液体燃料自体による燃料噴射弁の冷却、つまり、燃料噴射弁の自己冷却を期待することができない。因みに、ガスエンジンのパイロット燃料噴射弁から噴射される燃料は、同サイズのディーゼルエンジンの燃料噴射弁から噴射される燃料の1〜2%に過ぎない。 However, since the liquid fuel injected from the pilot fuel injection valve for ignition of the main fuel is very small, the fuel injection valve of a normal diesel engine injects a large amount of fuel. The cooling of the fuel injection valve by the liquid fuel itself, that is, the self-cooling of the fuel injection valve cannot be expected. Incidentally, the fuel injected from the pilot fuel injection valve of the gas engine is only 1 to 2% of the fuel injected from the fuel injection valve of the diesel engine of the same size.
このため、燃料噴射弁の先端部が過熱して、その閉弁時における衝撃に起因するノズル先端部の塑性変形、燃料コーキングによる噴孔の閉塞、針弁の焼付き等を招き、燃料噴射弁の寿命を大幅に短縮させてしまうという問題がある。 For this reason, the tip portion of the fuel injection valve is overheated, causing plastic deformation of the nozzle tip portion due to the impact at the time of closing the valve, closing of the injection hole due to fuel coking, seizure of the needle valve, etc. There is a problem of greatly shortening the lifespan.
このような問題を解決するためには、燃料噴射弁の先端部を効果的に冷却する必要があり、このため、燃料噴射弁をシリンダヘッドに取り付けるために使用される弁ホルダ内、あるいは、燃料噴射弁のノズルボディ自体内に冷却孔を形成し、この冷却孔内にシリンダヘッド自体の内部冷却水通路から冷却水を導くことが考えられる。 In order to solve such a problem, it is necessary to cool the tip of the fuel injection valve effectively. For this reason, in the valve holder used for attaching the fuel injection valve to the cylinder head or in the fuel It is conceivable that a cooling hole is formed in the nozzle body itself of the injection valve, and cooling water is guided into the cooling hole from the internal cooling water passage of the cylinder head itself.
しかしながら、前者の弁ホルダ内に冷却水を導く従来の方式では、シリンダヘッドの冷却孔内を流れる冷却水は自然循環により置換されるだけのものであるから、燃料噴射弁の冷却が十分には行なわれない一方、専用ポンプによる強制循環を行なったのでは、構造が複雑となり、コスト高になるという問題がある。 However, in the former method of guiding the cooling water into the former valve holder, the cooling water flowing through the cooling holes of the cylinder head is only replaced by natural circulation, so that the fuel injection valve is sufficiently cooled. On the other hand, if forced circulation by a dedicated pump is performed, there is a problem that the structure becomes complicated and the cost is increased.
また、ノズルボディ内へ冷却水を導く従来の方式では、冷却水はポンプ等により強制循環されるために燃料噴射弁の冷却は一定程度期待できる一方、燃料噴射弁内の構造が複雑となるため、大形の燃料噴射弁に対してのみ適用でき、パイロット燃料噴射のような小形の燃料噴射弁に対しては、加工技術及びコスト上の観点から適用できないという問題がある。 Further, in the conventional method for introducing the cooling water into the nozzle body, the cooling water is forcibly circulated by a pump or the like, so that the fuel injection valve can be expected to be cooled to a certain degree, but the structure inside the fuel injection valve is complicated. However, there is a problem that it can be applied only to a large fuel injection valve, and cannot be applied to a small fuel injection valve such as a pilot fuel injection from the viewpoint of processing technology and cost.
本発明はこのような問題を解決するためになされたもので、小型の噴射弁に対しても適用でき、簡単な構成で且つ安価にして燃料噴射弁の冷却効果を十分に発揮することができる、ガスエンジン用パイロット燃料噴射弁の冷却装置を提供することを課題とする。 The present invention has been made to solve such a problem, and can be applied to a small-sized injection valve, and can sufficiently exhibit the cooling effect of the fuel injection valve with a simple configuration and low cost. Another object of the present invention is to provide a cooling device for a pilot fuel injection valve for a gas engine.
上記の課題を解決するために、本発明が採用する手段は、ガスエンジンのシリンダヘッドに弁ホルダを介して取り付けられると共にパイロット燃料としての液体燃料を噴孔から噴射して液体燃料の自己着火により主燃料としてのガス燃料を点火させる燃料噴射弁と、シリンダヘッド内に冷却水を通すエンジン冷却路を有して冷却水を燃料噴射弁の周囲を経て一方向に強制的に流す冷却水循環路とを備えたガスエンジン用パイロット燃料噴射弁の冷却装置において、弁ホルダの先端部内に設けられて一端が燃料噴射弁よりも上流側のエンジン冷却路に連通する弁ホルダ冷却路と、燃料噴射弁よりも上流側のエンジン冷却路より圧力が低い冷却水循環路の低圧部と弁ホルダ冷却路の他端とを接続する接続路とを具備することにある。 In order to solve the above-described problems, the means employed by the present invention is attached to a cylinder head of a gas engine via a valve holder, and injects liquid fuel as pilot fuel from an injection hole to self-ignite the liquid fuel. A fuel injection valve for igniting gas fuel as the main fuel, and a cooling water circulation path having an engine cooling path for passing cooling water in the cylinder head and forcibly flowing cooling water in one direction around the fuel injection valve; A cooling device for a pilot fuel injection valve for a gas engine, comprising: a valve holder cooling path provided in a tip portion of the valve holder and having one end communicating with an engine cooling path upstream of the fuel injection valve; and a fuel injection valve And a connecting path connecting the low-pressure portion of the cooling water circulation path whose pressure is lower than that of the upstream engine cooling path and the other end of the valve holder cooling path.
上述のガスエンジン用パイロット燃料噴射弁の冷却装置によれば、弁ホルダ冷却路の一端と他端との間に圧力差が存在するので、冷却水循環路のエンジン冷却路に供給された冷却水の一部は、弁ホルダ冷却路の一端から流入して弁ホルダ冷却路内を強制的に通過する。このとき、弁ホルダの先端部は冷却水によって直接的に冷却され、燃料噴射弁のノズル先端部は弁ホルダを介して冷却水によって間接的に冷却される。この後、冷却水は弁ホルダ冷却路の他端から接続路を経て冷却水循環路の低圧部に戻る。 According to the above-described cooling device for a pilot fuel injection valve for a gas engine, since there is a pressure difference between one end and the other end of the valve holder cooling path, the cooling water supplied to the engine cooling path of the cooling water circulation path A part flows in from one end of the valve holder cooling path and forcibly passes through the valve holder cooling path. At this time, the tip of the valve holder is directly cooled by the cooling water, and the nozzle tip of the fuel injection valve is indirectly cooled by the cooling water through the valve holder. Thereafter, the cooling water returns from the other end of the valve holder cooling path to the low pressure portion of the cooling water circulation path through the connection path.
このように、冷却水が弁ホルダ冷却路内を圧力差によって強制的に流れるため、その流量は多く、弁ホルダ冷却路内の冷却水は迅速に置換され、弁ホルダの先端部及び燃料噴射弁のノズル先端部は効果的に冷却される。燃料噴射弁のノズル先端部を冷却する冷却路は弁ホルダ内に設けられ、燃料噴射弁本体に設けられるものではないから、小型の噴射弁に対しても適用することができる。また、弁ホルダ冷却路内の冷却水は圧力差だけで強制循環されるから、従来は必要とされた専用ポンプ等が排除され、簡単な構成で且つ安価にして実施することができる。 In this way, the cooling water is forced to flow in the valve holder cooling path due to the pressure difference, so that the flow rate is large, the cooling water in the valve holder cooling path is quickly replaced, and the tip of the valve holder and the fuel injection valve The nozzle tip is effectively cooled. Since the cooling path for cooling the nozzle tip of the fuel injection valve is provided in the valve holder and is not provided in the fuel injection valve main body, it can be applied to a small injection valve. Further, since the cooling water in the valve holder cooling path is forcibly circulated only by the pressure difference, a dedicated pump or the like that has been conventionally required is eliminated, and it can be implemented with a simple configuration and at a low cost.
又は、本発明が採用する手段は、ガスエンジンのシリンダヘッドに弁ホルダを介して取り付けられると共にパイロット燃料としての液体燃料を噴孔から噴射して液体燃料の自己着火により主燃料としてのガス燃料を点火させる燃料噴射弁を備えたガスエンジン用パイロット燃料噴射弁の冷却装置において、弁ホルダの先端部に設けられると共に噴孔からの液体燃料の噴射を許容しつつ燃料噴射弁のノズル先端部を覆う熱遮蔽キャップを具備することにある。 Alternatively, the means employed by the present invention is attached to the cylinder head of the gas engine via a valve holder, and injects liquid fuel as pilot fuel from the nozzle hole and supplies gas fuel as main fuel by self-ignition of liquid fuel. In a cooling device for a pilot fuel injection valve for a gas engine having a fuel injection valve to be ignited, it is provided at the tip of a valve holder and covers the nozzle tip of the fuel injection valve while allowing the injection of liquid fuel from the injection hole A heat shielding cap is provided.
上述のガスエンジン用パイロット燃料噴射弁の冷却装置によれば、熱遮蔽キャップが、主燃料の燃焼に伴い発生する高温の燃焼ガスからノズル先端部に伝達される輻射熱を低減し、ノズル先端部の温度上昇を大幅に抑制する。熱遮蔽キャップは弁ホルダの先端部に設けられ、燃料噴射弁本体に設けられるものではないから、小型の噴射弁に対しても適用することができる。また、この熱遮蔽キャップは簡単な構成で且つ安価にして実施することができる。 According to the above-described cooling device for a pilot fuel injection valve for a gas engine, the heat shielding cap reduces the radiant heat transferred from the high-temperature combustion gas generated by the combustion of the main fuel to the nozzle tip, and the nozzle tip Greatly suppresses temperature rise. Since the heat shielding cap is provided at the tip of the valve holder and is not provided in the fuel injection valve body, it can also be applied to a small injection valve. In addition, the heat shielding cap can be implemented with a simple configuration and at a low cost.
又は、本発明が採用する手段は、ガスエンジンのシリンダヘッドに弁ホルダを介して取り付けられると共にパイロット燃料としての液体燃料を噴孔から噴射して液体燃料の自己着火により主燃料としてのガス燃料を点火させる燃料噴射弁と、シリンダヘッド内に冷却水を通すエンジン冷却路を有して冷却水を燃料噴射弁の周囲を経て一方向に強制的に流す冷却水循環路とを備えたガスエンジン用パイロット燃料噴射弁の冷却装置において、弁ホルダの先端部内に設けられて一端が燃料噴射弁よりも上流側のエンジン冷却路に連通する弁ホルダ冷却路と、燃料噴射弁よりも上流側のエンジン冷却路より圧力が低い冷却水循環路の低圧部と弁ホルダ冷却路の他端とを接続する接続路と、弁ホルダの先端部に設けられると共に噴孔からの液体燃料の噴射を許容しつつ燃料噴射弁のノズル先端部を覆う熱遮蔽キャップとを具備することにある。 Alternatively, the means employed by the present invention is attached to the cylinder head of the gas engine via a valve holder, and injects liquid fuel as pilot fuel from the nozzle hole and supplies gas fuel as main fuel by self-ignition of liquid fuel. A pilot for a gas engine having a fuel injection valve to be ignited and a cooling water circulation path having an engine cooling path for passing cooling water through the cylinder head and forcibly flowing the cooling water in one direction through the periphery of the fuel injection valve In a cooling device for a fuel injection valve, a valve holder cooling passage that is provided in a tip portion of the valve holder and has one end communicating with an engine cooling passage upstream of the fuel injection valve, and an engine cooling passage upstream of the fuel injection valve A connection path that connects the low pressure part of the cooling water circulation path having a lower pressure and the other end of the valve holder cooling path, and a liquid fuel from the nozzle hole provided at the tip of the valve holder It is to include a heat shield cap covering the nozzle tip of the fuel injection valve while permitting morphism.
上述のガスエンジン用パイロット燃料噴射弁の冷却装置によれば、上述の弁ホルダ冷却路内を強制的に流れる冷却水による冷却と、熱遮蔽キャップによる輻射熱の遮蔽による冷却との相乗作用により、燃料噴射弁におけるノズル先端部の冷却をさらに効果的に行なうことができ、燃料噴射弁の寿命を大幅に延ばすことができる。 According to the above-described cooling device for the pilot fuel injection valve for a gas engine, the fuel by the synergistic effect of the cooling by the cooling water forcibly flowing in the valve holder cooling path and the cooling by the radiation shielding by the heat shielding cap. The nozzle tip portion of the injection valve can be cooled more effectively, and the life of the fuel injection valve can be greatly extended.
上記ガスエンジン用パイロット燃料噴射弁の冷却装置において、冷却水循環路は、燃料噴射弁の下流側にオリフィスを備え、接続路は、オリフィスの下流側にて冷却水循環路に接続されていることが望ましい。オリフィスは冷却水循環路中に簡易に圧力差を作り出すことができる一手段であり、これにより弁ホルダ冷却路の両端間に所望の圧力差を発生させることができる。 In the cooling system for a pilot fuel injection valve for a gas engine, the cooling water circulation path preferably includes an orifice on the downstream side of the fuel injection valve, and the connection path is preferably connected to the cooling water circulation path on the downstream side of the orifice. . The orifice is a means by which a pressure difference can be easily created in the cooling water circulation path, whereby a desired pressure difference can be generated between both ends of the valve holder cooling path.
上記ガスエンジン用パイロット燃料噴射弁の冷却装置において、弁ホルダ冷却路は、一端と他端との間に遮蔽キャップの近傍にてノズル先端部を囲むように配設された環状部を有することが望ましい。このような環状部内を流れる冷却水はノズル先端部をその周方向に均一に冷却すると共に、熱遮蔽キャップは弁ホルダの先端部に設けられているから、その冷却にも寄与する。 In the cooling device for a pilot fuel injection valve for a gas engine, the valve holder cooling path may have an annular portion disposed between one end and the other end so as to surround the nozzle tip in the vicinity of the shielding cap. desirable. The cooling water flowing in such an annular portion uniformly cools the nozzle tip in the circumferential direction, and the heat shielding cap is provided at the tip of the valve holder, thereby contributing to the cooling.
上記ガスエンジン用パイロット燃料噴射弁の冷却装置において、弁ホルダ冷却路は、冷却水を環状部に導入する内円柱状の入口ポートと冷却水を環状部から排出させる内円柱状の出口ポートとを有し、入口ポート及び出口ポートは、弁ホルダの軸心から放射状に穿設されていることが望ましい。このように内円柱状の入口ポート及び出口ポートは、弁ホルダの軸心から放射状に穿設されているから、弁ホルダの外側からのドリリングにより簡単に形成することができる。 In the cooling device for a pilot fuel injection valve for a gas engine, the valve holder cooling path includes an inner cylindrical inlet port for introducing cooling water into the annular portion and an inner cylindrical outlet port for discharging cooling water from the annular portion. Preferably, the inlet port and the outlet port are bored radially from the axis of the valve holder. As described above, the inner cylindrical inlet port and outlet port are formed in a radial manner from the axial center of the valve holder, and thus can be easily formed by drilling from the outside of the valve holder.
上記ガスエンジン用パイロット燃料噴射弁の冷却装置において、エンジン冷却路は、弁ホルダを外側から囲む冷却ジャケットを有することが望ましい。このような冷却ジャケットは、燃料噴射弁全体の冷却に大きく寄与することができる。 In the cooling device for a pilot fuel injection valve for a gas engine, the engine cooling path preferably has a cooling jacket surrounding the valve holder from the outside. Such a cooling jacket can greatly contribute to cooling of the entire fuel injection valve.
本発明のガスエンジン用パイロット燃料噴射弁の冷却装置は、ガスエンジンのシリンダヘッドに弁ホルダを介して取り付けられると共にパイロット燃料としての液体燃料を噴孔から噴射して液体燃料の自己着火により主燃料としてのガス燃料を点火させる燃料噴射弁と、シリンダヘッド内に冷却水を通すエンジン冷却路を有して冷却水を燃料噴射弁の周囲を経て一方向に強制的に流す冷却水循環路とを備え、弁ホルダの先端部内に設けられて一端が燃料噴射弁よりも上流側のエンジン冷却路に連通する弁ホルダ冷却路と、燃料噴射弁よりも上流側のエンジン冷却路より圧力が低い冷却水循環路の低圧部と弁ホルダ冷却路の他端とを接続する接続路とを具備する。 A cooling device for a pilot fuel injection valve for a gas engine according to the present invention is attached to a cylinder head of a gas engine via a valve holder, and injects liquid fuel as pilot fuel from an injection hole to self-ignite the liquid fuel. A fuel injection valve for igniting the gas fuel, and a cooling water circulation path having an engine cooling path for passing the cooling water in the cylinder head and forcibly flowing the cooling water in one direction through the periphery of the fuel injection valve A valve holder cooling path provided in the tip of the valve holder and having one end communicating with an engine cooling path upstream of the fuel injection valve, and a cooling water circulation path having a lower pressure than the engine cooling path upstream of the fuel injection valve And a connection path connecting the other end of the valve holder cooling path.
又は、ガスエンジンのシリンダヘッドに弁ホルダを介して取り付けられると共にパイロ
ット燃料としての液体燃料を噴孔から噴射して液体燃料の自己着火により主燃料としてのガス燃料を点火させる燃料噴射弁を備え、弁ホルダの先端部に設けられると共に噴孔からの液体燃料の噴射を許容しつつ燃料噴射弁のノズル先端部を覆う熱遮蔽キャップを具備する。
Or a fuel injection valve that is attached to a cylinder head of a gas engine via a valve holder and injects liquid fuel as pilot fuel from an injection hole and ignites gas fuel as main fuel by self-ignition of liquid fuel, A heat shielding cap is provided at the tip of the valve holder and covers the nozzle tip of the fuel injection valve while allowing injection of liquid fuel from the nozzle hole.
又は、本発明のガスエンジン用パイロット燃料噴射弁の冷却装置は、ガスエンジンのシリンダヘッドに弁ホルダを介して取り付けられると共にパイロット燃料としての液体燃料を噴孔から噴射して液体燃料の自己着火により主燃料としてのガス燃料を点火させる燃料噴射弁と、シリンダヘッド内に冷却水を通すエンジン冷却路を有して冷却水を燃料噴射弁の周囲を経て一方向に強制的に流す冷却水循環路とを備えたガスエンジン用パイロット燃料噴射弁の冷却装置において、弁ホルダの先端部内に設けられて一端が燃料噴射弁よりも上流側のエンジン冷却路に連通する弁ホルダ冷却路と、燃料噴射弁よりも上流側のエンジン冷却路より圧力が低い冷却水循環路の低圧部と弁ホルダ冷却路の他端とを接続する接続路と、弁ホルダの先端部に設けられると共に噴孔からの液体燃料の噴射を許容しつつ燃料噴射弁のノズル先端部を覆う熱遮蔽キャップとを具備する。 Alternatively, the cooling device for a pilot fuel injection valve for a gas engine according to the present invention is attached to a cylinder head of a gas engine via a valve holder and injects liquid fuel as pilot fuel from a nozzle hole by self-ignition of the liquid fuel. A fuel injection valve for igniting gas fuel as the main fuel, and a cooling water circulation path having an engine cooling path for passing cooling water in the cylinder head and forcibly flowing cooling water in one direction around the fuel injection valve; A cooling device for a pilot fuel injection valve for a gas engine, comprising: a valve holder cooling path provided in a tip portion of the valve holder and having one end communicating with an engine cooling path upstream of the fuel injection valve; and a fuel injection valve Also provided at the tip of the valve holder and a connection path connecting the low pressure part of the cooling water circulation path whose pressure is lower than the engine cooling path on the upstream side and the other end of the valve holder cooling path ; And a heat shield cap covering the nozzle tip of the fuel injection valve while permitting injection of liquid fuel from the injection holes with the.
したがって、本発明のガスエンジン用パイロット燃料噴射弁の冷却装置は、小型の噴射弁に対しても適用でき、簡単な構成で且つ安価にして燃料噴射弁の冷却効果を十分に発揮することができるという優れた効果を奏する。この結果、過熱によるノズル先端部の塑性変形、燃料コーキングによる噴孔の閉塞、針弁の焼付き等の不具合を回避することができ、燃料噴射弁の長寿命化を図ることができる。 Therefore, the pilot fuel injection valve cooling device for a gas engine according to the present invention can be applied to a small injection valve, and can sufficiently exhibit the cooling effect of the fuel injection valve with a simple configuration and low cost. There is an excellent effect. As a result, problems such as plastic deformation of the nozzle tip due to overheating, blockage of the nozzle hole due to fuel coking, and seizure of the needle valve can be avoided, and the life of the fuel injection valve can be extended.
図1は、発電システムの駆動源として使用されるガスエンジン2を示し、ガスエンジン2の出力軸は発電機4に連結されている。このガスエンジン2は、例えば6気筒#1〜#6からなり、各気筒#は主燃料として天然ガス等のガス燃料に加え、このガス燃料の点火に使用される液体燃料の供給を受ける。この液体燃料は、各気筒#内に図2に示す燃料噴射弁32から噴射され、噴射された液体燃料は自己着火により主燃料であるガス燃料を安定して点火させる。 FIG. 1 shows a gas engine 2 used as a drive source of a power generation system, and an output shaft of the gas engine 2 is connected to a generator 4. The gas engine 2 includes, for example, six cylinders # 1 to # 6, and each cylinder # receives supply of liquid fuel used for ignition of the gas fuel in addition to gas fuel such as natural gas as a main fuel. This liquid fuel is injected into each cylinder # from the fuel injection valve 32 shown in FIG. 2, and the injected liquid fuel stably ignites the gas fuel as the main fuel by self-ignition.
図1には、ガスエンジン2のシリンダヘッド内を通じて冷却水を循環させる冷却水循環路6が示される。冷却水循環路6は、シリンダヘッドに通じるエンジン冷却路8と、エンジン2と冷却器18を結ぶ外部冷却路7とを有する。 FIG. 1 shows a cooling water circulation path 6 for circulating cooling water through the cylinder head of the gas engine 2. The cooling water circulation path 6 includes an engine cooling path 8 that leads to the cylinder head, and an external cooling path 7 that connects the engine 2 and the cooler 18.
詳しくは、エンジン冷却路8は、シリンダヘッドの内部を通る冷却水通路10と、この冷却水通路10から分岐されて各気筒#に冷却水を導く分岐路14と、シリンダヘッドの外部に取り付けられて各気筒#からの冷却水を排出するシリンダ出口枝管15と、このシリンダ出口枝管15の冷却水を集合する冷却水出口主管16とを有する。 Specifically, the engine cooling path 8 is attached to the outside of the cylinder head, the cooling water path 10 passing through the inside of the cylinder head, the branch path 14 branched from the cooling water path 10 and leading the cooling water to each cylinder #. The cylinder outlet branch pipe 15 for discharging the cooling water from each cylinder # and the cooling water outlet main pipe 16 for collecting the cooling water of the cylinder outlet branch pipe 15 are provided.
外部冷却路7は、冷却水通路10の冷却水機関入口2aと冷却水出口主管16の冷却水機関出口2bとを接続し、外部冷却路7中には、冷却水を冷却するための冷却器18が配置されている。また、外部冷却路7には、冷却器18と冷却水機関入口2aとの間にポンプ20が介挿され、ポンプ20は冷却水機関入口2aに向けて冷却水を吐出する。このため、冷却水循環路6内の冷却水は、冷却水通路10から分岐路14及びシリンダ出口枝管15を経て、冷却水出口主管16に流れるように強制的に循環される。 The external cooling path 7 connects the cooling water engine inlet 2 a of the cooling water passage 10 and the cooling water engine outlet 2 b of the cooling water outlet main pipe 16, and a cooler for cooling the cooling water in the external cooling path 7. 18 is arranged. In the external cooling path 7, a pump 20 is interposed between the cooler 18 and the cooling water engine inlet 2a, and the pump 20 discharges cooling water toward the cooling water engine inlet 2a. For this reason, the cooling water in the cooling water circulation path 6 is forcibly circulated so as to flow from the cooling water path 10 to the cooling water outlet main pipe 16 via the branch path 14 and the cylinder outlet branch pipe 15.
外部冷却路7には、冷却器18と冷却水機関出口2bとの間に温度調整弁22が介挿され、温度調整弁22はバイパス路24を介して、冷却器18とポンプ20との間の外部冷却路7に接続されている。詳しくは、温度調整弁22は三方弁からなり、冷却器18の入口側に流す冷却水量とポンプ20の吸い込み側に流す冷却水量との配分を調整し、これに
よりポンプ20から吐出される冷却水の温度を調整する。
In the external cooling path 7, a temperature adjustment valve 22 is inserted between the cooler 18 and the cooling water engine outlet 2 b, and the temperature adjustment valve 22 is interposed between the cooler 18 and the pump 20 via the bypass path 24. The external cooling path 7 is connected. Specifically, the temperature adjustment valve 22 is a three-way valve, and adjusts the distribution of the amount of cooling water flowing to the inlet side of the cooler 18 and the amount of cooling water flowing to the suction side of the pump 20, thereby cooling water discharged from the pump 20. Adjust the temperature.
ここで、図1中の符号26,28は冷却水循環路6内に冷却水を補給するための補給弁と、冷却水循環路6から冷却水を排出するための排出弁とをそれぞれ示す。 Here, reference numerals 26 and 28 in FIG. 1 denote a supply valve for supplying cooling water into the cooling water circulation path 6 and a discharge valve for discharging cooling water from the cooling water circulation path 6, respectively.
図2は、ガスエンジン2のシリンダヘッド30の断面図であり、上述の分岐路14が各気筒#の燃料噴射弁32を挟むようにその両側に配設され、これら両側の分岐路14は環状連結室14aによって一端連結される。分岐路14から燃料噴射弁32の周囲を通った冷却水は、図示しない上方のシリンダヘッド冷却室12に入ってシリンダヘッド30を冷却したのち、シリンダヘッド30の外部に取り付けられた上述のシリンダ出口枝管15へ排出される。 FIG. 2 is a cross-sectional view of the cylinder head 30 of the gas engine 2. The above-described branch passages 14 are arranged on both sides so as to sandwich the fuel injection valve 32 of each cylinder #, and the branch passages 14 on both sides are annular. One end is connected by the connection chamber 14a. The cooling water that has passed through the periphery of the fuel injection valve 32 from the branch path 14 enters the upper cylinder head cooling chamber 12 (not shown), cools the cylinder head 30, and then the above-described cylinder outlet attached to the outside of the cylinder head 30. It is discharged to the branch pipe 15.
各気筒#の燃料噴射弁32は、シリンダヘッド30に弁ホルダ34を介して取り付けられ、弁ホルダ34はその燃料噴射弁32の先端部を囲んでいる。図2中の符号36は、燃料噴射弁32に液体燃料を供給するための燃料路を示し、この燃料路36の中を通る図示しない燃料管が図示しない燃料分配ポンプに接続されている。 The fuel injection valve 32 for each cylinder # is attached to the cylinder head 30 via a valve holder 34, and the valve holder 34 surrounds the tip of the fuel injection valve 32. 2 indicates a fuel path for supplying liquid fuel to the fuel injection valve 32, and a fuel pipe (not shown) passing through the fuel path 36 is connected to a fuel distribution pump (not shown).
各燃料噴射弁32と組をなす弁ホルダ34の先端部及びその周辺部は同一の構成を有するので、1つの弁ホルダ34の先端部及びその周辺部について、図3を参照して説明する。 Since the tip end portion and its peripheral portion of the valve holder 34 paired with each fuel injection valve 32 have the same configuration, the tip portion of one valve holder 34 and its peripheral portion will be described with reference to FIG.
シリンダヘッド30には燃料噴射弁32のための装着孔38が形成され、装着孔38の内周面と弁ホルダ34の外周面との間に冷却ジャケット40と環状室42とが上下に形成されている。冷却ジャケット40と環状室42とは互いに独立して設けられ、冷却ジャケット40は弁ホルダ34の軸線方向に、つまり燃料噴射弁32の軸線方向に延び、上述の分岐路14を横断する。このように、冷却ジャケット40は弁ホルダ34を介して燃料噴射弁32を冷却する。 A mounting hole 38 for the fuel injection valve 32 is formed in the cylinder head 30, and a cooling jacket 40 and an annular chamber 42 are formed vertically between the inner peripheral surface of the mounting hole 38 and the outer peripheral surface of the valve holder 34. ing. The cooling jacket 40 and the annular chamber 42 are provided independently of each other. The cooling jacket 40 extends in the axial direction of the valve holder 34, that is, in the axial direction of the fuel injection valve 32, and crosses the above-described branch path 14. Thus, the cooling jacket 40 cools the fuel injection valve 32 via the valve holder 34.
弁ホルダ34の先端部にはその内部に弁ホルダ冷却路44が形成され、弁ホルダ冷却路44は冷却ジャケット40の下端に接続された一端と、環状室42に接続された他端とを有する。詳しくは、弁ホルダ冷却路44はその一部に環状部46を含み、この環状部46は、燃料噴射弁32のノズルボディ48の先端部を囲むように配置されている。 A valve holder cooling path 44 is formed inside the tip of the valve holder 34, and the valve holder cooling path 44 has one end connected to the lower end of the cooling jacket 40 and the other end connected to the annular chamber 42. . Specifically, the valve holder cooling path 44 includes an annular portion 46 in a part thereof, and the annular portion 46 is disposed so as to surround the tip end portion of the nozzle body 48 of the fuel injection valve 32.
図4に示すように、環状部46は冷却ジャケット40に対して2つの入口ポート50を介して連通し、環状室42に対して2つの出口ポート52を介して連通する。図3及び図4に示すように、これら入口ポート50及び出口ポート52は、環状部46からノズルボディ48に沿って延びる軸方向部と、この軸方向部と冷却ジャケット40又は環状室42とを接続する傾斜部とを有する。 As shown in FIG. 4, the annular portion 46 communicates with the cooling jacket 40 via two inlet ports 50 and communicates with the annular chamber 42 via two outlet ports 52. As shown in FIGS. 3 and 4, the inlet port 50 and the outlet port 52 include an axial portion extending from the annular portion 46 along the nozzle body 48, and the axial portion and the cooling jacket 40 or the annular chamber 42. And an inclined portion to be connected.
すなわち、弁ホルダ冷却路44は、冷却水を環状部46に導入する内円柱状の入口ポート50と、冷却水を環状部46から排出させる内円柱状の出口ポート52とを有し、この入口ポート50及び出口ポート52は、図4に示すように、弁ホルダ34の軸心から放射状に穿設されているため、弁ホルダ34の外側からのドリリングによって簡単に形成することができる。また、環状室42に対する入口ポート50の流出口と出口ポート52の流入口は、環状室42の直径方向に互い離隔するように配置されている。 That is, the valve holder cooling path 44 has an inner cylindrical inlet port 50 for introducing cooling water into the annular portion 46 and an inner cylindrical outlet port 52 for discharging the cooling water from the annular portion 46. As shown in FIG. 4, the port 50 and the outlet port 52 are formed by radial drilling from the axial center of the valve holder 34, and thus can be easily formed by drilling from the outside of the valve holder 34. The outlet of the inlet port 50 with respect to the annular chamber 42 and the inlet of the outlet port 52 are arranged so as to be separated from each other in the diameter direction of the annular chamber 42.
一方、シリンダヘッド30内には環状室42から延びる内部接続路53が形成され、この内部接続路53は、シリンダヘッド30の外部に取り付けられた接続枝管54を介して弁ホルダ冷却水集合管56(図1参照)に接続されている。また、この弁ホルダ冷却水集合管56に対しては、他の気筒#の環状室42から内部接続路53を介して延びる接続枝
管54も、それぞれ接続されている。
On the other hand, an internal connection path 53 extending from the annular chamber 42 is formed in the cylinder head 30, and this internal connection path 53 is connected to the valve holder cooling water collecting pipe via a connection branch pipe 54 attached to the outside of the cylinder head 30. 56 (see FIG. 1). Further, connection branch pipes 54 extending from the annular chambers 42 of the other cylinders # via the internal connection paths 53 are also connected to the valve holder cooling water collecting pipe 56.
図1に示されるように、弁ホルダ冷却水集合管56はガスエンジン2の外側に配置された外部接続管58に接続され、この外部接続管58は上述の冷却水循環路6に設けた低圧部に接続されている。具体的には、冷却水循環路6の外部冷却路7にはオリフィス60が介挿され、このオリフィス60は冷却水出口主管16の冷却水機関出口2bと温度調整弁22との間に配設されている。 As shown in FIG. 1, the valve holder cooling water collecting pipe 56 is connected to an external connecting pipe 58 disposed outside the gas engine 2, and the external connecting pipe 58 is a low pressure section provided in the above-described cooling water circulation path 6. It is connected to the. Specifically, an orifice 60 is inserted in the external cooling path 7 of the cooling water circulation path 6, and the orifice 60 is disposed between the cooling water engine outlet 2 b of the cooling water outlet main pipe 16 and the temperature adjustment valve 22. ing.
オリフィス60は外部冷却路7内を流れる冷却水の流量を絞ることにより、オリフィス60よりも下流側の外部冷却路7の内圧をエンジン冷却路8の内圧よりも低圧に保持し、外部接続管58は外部冷却路7において、このオリフィス60と温度調整弁22との間に接続されている。上述の環状室42、内部接続路53、接続枝管54、弁ホルダ冷却水集合管56及び外部接続管58は、弁ホルダ34内の弁ホルダ冷却路44を冷却水循環路6の低圧部に接続する接続路を形成する。 The orifice 60 restricts the flow rate of the cooling water flowing in the external cooling passage 7 to maintain the internal pressure of the external cooling passage 7 downstream of the orifice 60 at a lower pressure than the internal pressure of the engine cooling passage 8. Is connected between the orifice 60 and the temperature control valve 22 in the external cooling path 7. The annular chamber 42, the internal connection path 53, the connection branch pipe 54, the valve holder cooling water collecting pipe 56 and the external connection pipe 58 described above connect the valve holder cooling path 44 in the valve holder 34 to the low pressure portion of the cooling water circulation path 6. A connection path is formed.
図3に示されるように、弁ホルダ34の先端部には熱遮蔽キャップ62が一体に取り付けられ、熱遮蔽キャップ62は上述の弁ホルダ冷却路44の環状部46に近接して配設される。熱遮蔽キャップ62は燃料噴射弁32におけるノズルボディ48の先端部を覆う一方、この先端部に穿設された噴孔に対応する位置に開口部64を有する。 As shown in FIG. 3, a heat shield cap 62 is integrally attached to the distal end portion of the valve holder 34, and the heat shield cap 62 is disposed in the vicinity of the annular portion 46 of the valve holder cooling path 44 described above. . The heat shielding cap 62 covers the tip of the nozzle body 48 in the fuel injection valve 32 and has an opening 64 at a position corresponding to the nozzle hole drilled in the tip.
この開口部64は、燃料噴射弁32の開弁時に噴孔から噴射される液体燃料の噴霧を遮ることなく通過させ、液体燃料の霧化特性を低下させることはない。具体的には、燃料噴射弁32の噴孔は、例えば周方向に等間隔に3個が配設され、各噴孔は略20°の噴射角度で燃料を噴射する。これに対して熱遮蔽キャップ62の各開口部64は、外側が広い内円錐状に形成され、その内円錐の開き角度は噴孔の燃料噴射角度よりもやや大きい角度に形成される。上述の燃料噴射弁32の他の構成は、例えば、従来のディーゼルエンジン機関自動燃料弁やコモンレール方式電子制御燃料噴射弁と同様の方式ものであり公知であるから、その詳細な説明は省略する。 The opening 64 allows the spray of liquid fuel injected from the nozzle hole to pass without being blocked when the fuel injection valve 32 is opened, and does not deteriorate the atomization characteristics of the liquid fuel. Specifically, for example, three injection holes of the fuel injection valve 32 are arranged at equal intervals in the circumferential direction, and each injection hole injects fuel at an injection angle of approximately 20 °. On the other hand, each opening 64 of the heat shielding cap 62 is formed in an inner cone shape having a wide outer side, and the opening angle of the inner cone is formed to be slightly larger than the fuel injection angle of the injection hole. Other configurations of the fuel injection valve 32 described above are known and are similar to conventional diesel engine engine automatic fuel valves and common rail electronically controlled fuel injection valves, for example, and thus detailed description thereof is omitted.
上述の燃料噴射弁32の冷却装置によれば、弁ホルダ34の先端部内に形成した弁ホルダ冷却路44の一端が冷却水循環路6のエンジン冷却路8、具体的には冷却ジャケット40に接続され、その他端が接続路42,53,54,56,58を介してオリフィス60よりも下流側の冷却水循環路6の低圧部に接続されているので、弁ホルダ34を挟む弁ホルダ冷却路44の両端間で圧力差が発生する。このため、図3及び図4に示すように、エンジン冷却路8内を流れる冷却水の一部は弁ホルダ冷却路44の一端から流入し、その環状部46を経て弁ホルダ冷却路44の他端から流出するように強制的に流れる。 According to the cooling device for the fuel injection valve 32 described above, one end of the valve holder cooling path 44 formed in the tip of the valve holder 34 is connected to the engine cooling path 8 of the cooling water circulation path 6, specifically, the cooling jacket 40. Since the other end is connected to the low pressure portion of the cooling water circulation path 6 on the downstream side of the orifice 60 via the connection paths 42, 53, 54, 56, 58, the valve holder cooling path 44 sandwiching the valve holder 34 A pressure difference occurs between both ends. For this reason, as shown in FIGS. 3 and 4, a part of the cooling water flowing in the engine cooling path 8 flows from one end of the valve holder cooling path 44 and passes through the annular portion 46 to the other part of the valve holder cooling path 44. Forced to flow out of the edge.
したがって、弁ホルダ34の先端部内を通じて多量の冷却水が流れるから、この冷却水によって弁ホルダ34の先端部、つまり、燃料噴射弁32の先端部の過熱が効果的に防止される。このため、燃料噴射弁32の閉弁時に針弁68がノズルボディ48の弁座に衝突しても、その衝撃によってノズルボディ48の先端部に塑性変形が発生するようなことはない。また、ノズルボディ48の噴孔が燃料コーキングより閉塞されることもなく、ノズルボディ48に対して針弁68が焼付くこともない。 Accordingly, since a large amount of cooling water flows through the inside of the tip end portion of the valve holder 34, overheating of the tip end portion of the valve holder 34, that is, the tip end portion of the fuel injection valve 32 is effectively prevented by this cooling water. For this reason, even if the needle valve 68 collides with the valve seat of the nozzle body 48 when the fuel injection valve 32 is closed, the impact does not cause plastic deformation at the tip of the nozzle body 48. Further, the nozzle hole of the nozzle body 48 is not blocked by the fuel coking, and the needle valve 68 is not seized against the nozzle body 48.
上述したように弁ホルダ冷却路44の両端間の圧力差は、冷却水循環路6にオリフィス60を介挿するだけで得られるから、弁ホルダ冷却路44に冷却水を強制的に導入するための専用ポンプが不要となり、簡単な構成で且つ安価にして燃料噴射弁32の先端部を効果的に冷却でき、燃料噴射弁32の長寿命化が達成される。 As described above, the pressure difference between the both ends of the valve holder cooling path 44 can be obtained only by inserting the orifice 60 in the cooling water circulation path 6, so that the cooling water is forcibly introduced into the valve holder cooling path 44. A dedicated pump is not required, the tip portion of the fuel injection valve 32 can be effectively cooled with a simple structure and at a low cost, and the life of the fuel injection valve 32 is extended.
また、弁ホルダ冷却路44の環状部46はノズルボディ48の先端部を囲み、しかも環
状部46に対する入口ポート50の流出口及び出口ポート52の流入口が環状部46の直径方向に互いに離隔して配設されているので、環状部46内の冷却水はノズルボディ48の周方向に一様に流れ、ノズルボディ48の先端部をその周方向に均一に冷却することができる。
The annular portion 46 of the valve holder cooling path 44 surrounds the tip of the nozzle body 48, and the outlet of the inlet port 50 and the inlet of the outlet port 52 with respect to the annular portion 46 are separated from each other in the diametrical direction of the annular portion 46. Therefore, the cooling water in the annular portion 46 flows uniformly in the circumferential direction of the nozzle body 48, and the tip portion of the nozzle body 48 can be cooled uniformly in the circumferential direction.
さらに、弁ホルダ34の先端部に取り付けた熱遮蔽キャップ62は、主燃料であるガス燃料の燃焼に起因する輻射熱が燃料噴射弁32の先端部、つまり、ノズルボディ48の先端部に加わるのを防ぎ、ノズルボディ48の過熱を効果的に防止する。しかも、熱遮蔽キャップ62は弁ホルダ冷却路44の環状部46の近傍に配設されているので、熱遮蔽キャップ62も弁ホルダ冷却路44内を流れる冷却水により冷却され、熱遮蔽キャップ62の過熱も防止される。 Furthermore, the heat shielding cap 62 attached to the tip of the valve holder 34 prevents the radiant heat resulting from the combustion of the gas fuel that is the main fuel from being applied to the tip of the fuel injection valve 32, that is, the tip of the nozzle body 48. This effectively prevents the nozzle body 48 from overheating. In addition, since the heat shielding cap 62 is disposed in the vicinity of the annular portion 46 of the valve holder cooling path 44, the heat shielding cap 62 is also cooled by the cooling water flowing in the valve holder cooling path 44, and the heat shielding cap 62 Overheating is also prevented.
本発明は上述した一実施例に制約されるものではなく、種々の変形が可能である。例えば、冷却装置は、オリフィス60に代えて減圧弁を備えてもよいし、弁ホルダ冷却路44の具体的なレイアウトも任意に変更可能である。 The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the cooling device may include a pressure reducing valve instead of the orifice 60, and the specific layout of the valve holder cooling path 44 can be arbitrarily changed.
以下の2つの実施例と1つの比較例について、図3に示す弁ホルダ34の先端部A点及びノズルボディ48の先端部B点の温度を、実測データにより比較検証する。
(実施内容)
比較例:従来の冷却水の自然循環による冷却装置を実施した燃料噴射弁
実施例1:本発明に係る冷却水の強制循環による冷却装置だけを実施した燃料噴射弁
実施例2:本発明に係る冷却水の強制循環による冷却装置及び熱遮蔽キャップによる冷
却装置の双方を実施した燃料噴射弁
使用エンジン:シリンダ径200mm、ストローク300mm
測定時のエンジン運転状態:回転速度900rpm、正味平均有効圧20bar
For the following two examples and one comparative example, the temperatures of the tip A point of the valve holder 34 and the tip B point of the nozzle body 48 shown in FIG.
(Implementation content)
Comparative Example: Fuel Injection Valve Implementing a Cooling Device by Conventional Circulation of Cooling Water Example 1: Fuel Injection Valve Implementing Only a Cooling Device by Forced Circulation of Cooling Water According to the Present Invention Example 2: According to the Present Invention Cooling by forced circulation of cooling water and cooling by heat shielding cap
Fuel injection valve with both rejection devices Engine: cylinder diameter 200mm, stroke 300mm
Engine operating state at the time of measurement: rotational speed 900 rpm, net average effective pressure 20 bar
(実施結果)
弁ホルダの先端部の温度 ノズルボディの先端部の温度
比較例: 305°C 350°C
実施例1: 195°C(110°C) 280°C(70°C)
実施例2: 170°C(135°C) 250°C(100°C)
( )内は比較例との温度差を示す。
(Implementation results)
Temperature at the tip of the valve holder Temperature at the tip of the nozzle body Comparative example: 305 ° C 350 ° C
Example 1: 195 ° C (110 ° C) 280 ° C (70 ° C)
Example 2: 170 ° C (135 ° C) 250 ° C (100 ° C)
The parentheses indicate the temperature difference from the comparative example.
(結論)
本発明に係る冷却水の強制循環による冷却装置を実施した燃料噴射弁は、従来の冷却水の自然循環による冷却装置を実施した燃料噴射弁に対して、ノズルボディの先端部の温度が70°Cだけ改善された。また、本発明に係る冷却水の強制循環による冷却装置及び熱遮蔽キャップによる冷却装置の双方を実施した燃料噴射弁は、ノズルボディの先端部の温度が100°Cだけ改善された。これより、熱遮蔽キャップによる冷却装置の改善分は約30°Cと推定される。
(Conclusion)
The fuel injection valve in which the cooling device by forced circulation of cooling water according to the present invention is implemented has a temperature at the tip of the nozzle body of 70 ° with respect to the fuel injection valve in which the cooling device by natural circulation of conventional cooling water is implemented. Only C was improved. Further, in the fuel injection valve in which both the cooling device by forced circulation of the cooling water and the cooling device by the heat shielding cap according to the present invention are implemented, the temperature of the tip portion of the nozzle body is improved by 100 ° C. From this, the improvement of the cooling device by the heat shielding cap is estimated to be about 30 ° C.
このように、冷却水の強制循環による冷却装置及び熱遮蔽キャップによる冷却装置とも、ノズルボディの先端部の温度について大幅な改善が見られた。 As described above, both the cooling device using forced circulation of cooling water and the cooling device using the heat shielding cap have greatly improved the temperature at the tip of the nozzle body.
2 ガスエンジン
2a 冷却水機関入口
2b 冷却水機関出口
4 発電機
6 冷却水循環路
7 外部冷却路
8 エンジン冷却路
10 冷却水通路
12 シリンダヘッド冷却室
14 分岐路
14a 環状連結室
15 シリンダ出口枝管
16 冷却水出口主管
18 冷却器
20 ポンプ
22 温度調整弁
24 バイパス路
26 補給弁
28 排出弁
30 シリンダヘッド
32 燃料噴射弁
34 弁ホルダ
36 燃料路
38 装着孔
40 冷却ジャケット
42 環状室(接続路)
44 弁ホルダ冷却路
46 環状部
48 ノズルボディ
50 入口ポート
52 出口ポート
53 内部接続路(接続路)
54 接続枝管(接続路)
56 弁ホルダ冷却水集合管(接続路)
58 外部接続管(接続路)
60 オリフィス
62 熱遮蔽キャップ
64 開口部
68 針弁
2 Gas engine 2a Cooling water engine inlet 2b Cooling water engine outlet 4 Generator 6 Cooling water circulation path 7 External cooling path 8 Engine cooling path 10 Cooling water path 12 Cylinder head cooling chamber 14 Branch path 14a Annular connection chamber 15 Cylinder outlet branch pipe 16 Cooling water outlet main pipe 18 Cooler 20 Pump 22 Temperature adjustment valve 24 Bypass path 26 Supply valve 28 Drain valve 30 Cylinder head 32 Fuel injection valve 34 Valve holder 36 Fuel path 38 Mounting hole 40 Cooling jacket 42 Annular chamber (connection path)
44 Valve holder cooling path 46 Annular part 48 Nozzle body 50 Inlet port 52 Outlet port 53 Internal connection path (connection path)
54 Connection branch pipe (connection path)
56 Valve holder cooling water collecting pipe (connection path)
58 External connection pipe (connection path)
60 Orifice 62 Heat shielding cap 64 Opening 68 Needle valve
Claims (5)
Priority Applications (1)
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JP2006026674A JP4204057B2 (en) | 2006-02-03 | 2006-02-03 | Cooling device for pilot fuel injection valve for gas engine |
Applications Claiming Priority (1)
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JP2006026674A JP4204057B2 (en) | 2006-02-03 | 2006-02-03 | Cooling device for pilot fuel injection valve for gas engine |
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JP2007205295A JP2007205295A (en) | 2007-08-16 |
JP4204057B2 true JP4204057B2 (en) | 2009-01-07 |
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JP2009191672A (en) * | 2008-02-13 | 2009-08-27 | Mitsubishi Heavy Ind Ltd | Fuel injection valve device |
JP4559503B2 (en) * | 2008-04-25 | 2010-10-06 | ダイハツディーゼル株式会社 | Fuel injection valve cooling system |
JP5800606B2 (en) * | 2011-07-06 | 2015-10-28 | ダイハツ工業株式会社 | EGR valve cooling structure |
CN103161632B (en) * | 2011-12-14 | 2015-05-13 | 淄博柴油机总公司 | Cooling system of duel fuel engine oil sprayer |
KR102032569B1 (en) * | 2013-04-26 | 2019-10-16 | 한국조선해양 주식회사 | Water jacket structure for cylinder head of dual fuel engine |
KR20140143283A (en) * | 2013-06-05 | 2014-12-16 | 현대중공업 주식회사 | Nozzle cooling system using the internal lubricating oil of engine |
DE102014224343A1 (en) * | 2014-11-28 | 2016-06-02 | Robert Bosch Gmbh | Gas injector with improved thermal properties |
JP6951799B1 (en) * | 2020-07-22 | 2021-10-20 | 株式会社 小山ガレージ | Cooling device for the spark plug arrangement part |
US11286876B1 (en) * | 2021-07-06 | 2022-03-29 | Caterpillar Inc. | Cylinder head assembly and cylinder head having igniter cooling moat |
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JPS58130075U (en) * | 1982-02-26 | 1983-09-02 | ヤンマーディーゼル株式会社 | Fuel injection valve cooling system |
JPH03141861A (en) * | 1989-10-27 | 1991-06-17 | Isuzu Motors Ltd | Binary fluid fine-pulverizing spray nozzle device |
JPH0491362A (en) * | 1990-07-31 | 1992-03-24 | Kubota Corp | Nozzle tip part heat preventing device for fuel injection nozzle of diesel engine |
JPH11241662A (en) * | 1998-02-26 | 1999-09-07 | Mitsubishi Electric Corp | Fuel injection valve into cylinder |
JP2000345940A (en) * | 1999-06-01 | 2000-12-12 | Kubota Corp | Fuel injection device of engine |
JP3676964B2 (en) * | 2000-06-27 | 2005-07-27 | 新潟原動機株式会社 | Dual fuel engine |
JP4021678B2 (en) * | 2002-02-18 | 2007-12-12 | 新潟原動機株式会社 | Pilot ignition gas engine starting method and starting apparatus |
JP2005214042A (en) * | 2004-01-28 | 2005-08-11 | Toyota Motor Corp | Internal combustion engine, device for controlling operation of internal combustion engine, and method for controlling operation of internal combustion engine |
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