JPH0256512B2 - - Google Patents
Info
- Publication number
- JPH0256512B2 JPH0256512B2 JP58241259A JP24125983A JPH0256512B2 JP H0256512 B2 JPH0256512 B2 JP H0256512B2 JP 58241259 A JP58241259 A JP 58241259A JP 24125983 A JP24125983 A JP 24125983A JP H0256512 B2 JPH0256512 B2 JP H0256512B2
- Authority
- JP
- Japan
- Prior art keywords
- needle valve
- cylindrical
- nozzle
- oil reservoir
- passage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000446 fuel Substances 0.000 claims description 44
- 238000002347 injection Methods 0.000 claims description 33
- 239000007924 injection Substances 0.000 claims description 33
- 230000001105 regulatory effect Effects 0.000 description 13
- 238000002485 combustion reaction Methods 0.000 description 11
- 239000000567 combustion gas Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 241000255925 Diptera Species 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000007751 thermal spraying Methods 0.000 description 1
Classifications
-
- 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
- F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
- F02M61/10—Other injectors with elongated valve bodies, i.e. of needle-valve type
-
- 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
- F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
- F02M45/12—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship providing a continuous cyclic delivery with variable pressure
-
- 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
- F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
この発明は、主として直接噴射式デイーゼル機
関等に用いられる所謂ホールノズル形式の燃料噴
射ノズルの改良に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an improvement in a so-called hole nozzle type fuel injection nozzle used mainly in direct injection diesel engines and the like.
従来の技術
従来の燃料噴射ノズルとしては、例えば第１図
に示すものが知られている（実開昭54−112918
号）。即ち、第１図に示す１はその先端部が中雅
の略円錐形に形成されたノズルボデイ、２は該ノ
ズルボデイ１内に摺動自在に収納されるニードル
バルブである。Prior Art As a conventional fuel injection nozzle, for example, the one shown in Fig.
issue). That is, numeral 1 shown in FIG. 1 is a nozzle body whose tip end is formed into a substantially conical shape, and numeral 2 is a needle valve slidably housed within the nozzle body 1. As shown in FIG.
上記ノズルボデイ１は、同図に示す如く自身の
略中央内部に油溜り部３が形成され、該油溜り部
３の下部には油溜り部３の燃料を先端方向に導く
通路部４が形成されており、またノズルボデイ１
の先端部には内壁面にノズルシート部５が形成さ
れていると共に、該ノズルシート部５の位置に複
数の噴孔６が形成されている。他方ニードルバル
ブ２は、上部に有する摺動部７の下方に上記油溜
り部３内に位置する受圧面部８が形成され、該受
圧面部８の下部に上記通路部４内に嵌挿されるシ
ヤフト部９が形成されており、該シヤフト部９の
先端部には上記ノズルシート部５に着座して噴孔
６を閉止する略円錐形のフエイス部１０と、燃料
圧力を受ける受圧面部１１が形成されている。 As shown in the figure, the nozzle body 1 has an oil reservoir 3 formed approximately in the center thereof, and a passage 4 that guides the fuel in the oil reservoir 3 toward the distal end thereof. and nozzle body 1
A nozzle seat portion 5 is formed on the inner wall surface of the tip portion, and a plurality of nozzle holes 6 are formed at the positions of the nozzle seat portion 5. On the other hand, the needle valve 2 has a pressure receiving surface section 8 located in the oil reservoir section 3 formed below the sliding section 7 provided at the upper part, and a shaft section fitted into the passage section 4 at the lower part of the pressure receiving surface section 8. A substantially conical face portion 10 that seats on the nozzle seat portion 5 and closes the nozzle hole 6, and a pressure receiving surface portion 11 that receives fuel pressure are formed at the tip of the shaft portion 9. ing.
このような燃料噴射ノズルにおいては、燃料導
入孔１２から油溜り部３に供給された燃料の圧力
があがると、燃料の圧力が受圧面部８，１１に作
用してニードルバルブ２を図中上方に押し上げる
ニードルバルブ２が押し上げられ、ノズルシート
部５とニードルフエイス部１０との間に間〓が生
じ、通路部４を経て上記間〓を通過した燃料がノ
ズルボデイ１の先端方向に流れ込み噴孔６から燃
焼室内（図示せず）に噴射される。 In such a fuel injection nozzle, when the pressure of the fuel supplied from the fuel introduction hole 12 to the oil reservoir 3 increases, the pressure of the fuel acts on the pressure receiving surfaces 8 and 11, causing the needle valve 2 to move upward in the figure. The pushing up needle valve 2 is pushed up, a gap is created between the nozzle seat part 5 and the needle eighth part 10, and the fuel that has passed through the gap via the passage part 4 flows toward the tip of the nozzle body 1 from the nozzle hole 6. The fuel is injected into the combustion chamber (not shown).
発明が解決しようとする課題
しかしながら、このような従来の燃料噴射ノズ
ルにあつては、ニードルバルブがリフトされるに
従つてノズルシート部とニードルフエイス部との
間〓に形成される流路面積が急激に増加するよう
になつていたため、噴孔から噴射される燃料量が
第５図中破線で示すように、噴孔の開口総面積で
決定される流量まで急激に増加した。したがつ
て、噴射初期に多量の燃料が燃焼室に噴射され、
この多量の燃料が急激に燃焼する。その結果、急
激な温度上昇による排気ガス中のNOx濃度の増
加と急激な圧力上昇による燃焼騒音の増加とをき
たすという問題があつた。Problems to be Solved by the Invention However, in such conventional fuel injection nozzles, as the needle valve is lifted, the flow path area formed between the nozzle seat part and the needle eighth part increases. As the amount of fuel injected from the nozzle holes increased rapidly, the amount of fuel injected from the nozzle holes rapidly increased to the flow rate determined by the total opening area of the nozzle holes, as shown by the broken line in FIG. Therefore, a large amount of fuel is injected into the combustion chamber at the beginning of injection,
This large amount of fuel burns rapidly. As a result, there were problems in that the NOx concentration in the exhaust gas increased due to the rapid temperature rise and the combustion noise increased due to the rapid pressure rise.
そこで、例えば実開昭58−189366号公報に記載
された技術のように、ニードルバルブに燃料通路
面積を噴孔の総開口面積よりも小さく挟める略円
環状の流量規制部を設け、該流量規制部のニード
ルバルブのリフト方向の長さがニードルバルブの
最大リフト長さよりも短く設定し、これによつて
燃料噴射初期の噴射流量を少量に制御するものも
提供されている。 Therefore, as in the technology described in Japanese Utility Model Application Publication No. 58-189366, for example, a substantially annular flow rate regulating part is provided in the needle valve to make the fuel passage area smaller than the total opening area of the nozzle hole, and the flow rate is regulated. There is also a system in which the length of the needle valve in the lift direction is set shorter than the maximum lift length of the needle valve, thereby controlling the injection flow rate at the initial stage of fuel injection to a small amount.
しかし、この公報記載の従来例にあつては、流
量規制部がニードルバルブの最大リフト時におい
て燃料通路内に位置せずに油溜り部内に位置する
ため、ニードルバルブの最大リフト時から下降中
に、該ニードルバルブの横振れ等に起因して流量
規制部の下端縁が油溜り部の下端縁に乗り上げて
ニードルバルブが作動不良を起こす。この結果、
燃料噴射後期における噴射遅れが生じ、例えば減
速時の運転性が悪化するといつた問題がある。 However, in the conventional example described in this publication, the flow rate regulating part is not located in the fuel passage when the needle valve is at its maximum lift, but is located inside the oil reservoir. Due to the lateral vibration of the needle valve, the lower edge of the flow rate regulating part rides on the lower edge of the oil reservoir, causing malfunction of the needle valve. As a result,
There is a problem in that an injection delay occurs in the later stages of fuel injection, and for example, drivability during deceleration deteriorates.
課題を解決するための手段
この発明は、上記従来の問題点に鑑みて案出さ
れたもので、とりわけニードルバルブのシヤフト
部の基部に設けられた円柱部と、該円柱部より下
部のシヤフト部に設けられ、上記円柱部と同径で
かつその外周面に複数の縦溝が形成された円柱状
の案内部とを備え、上記円柱部の外壁面と上記通
路部の内壁面間に形成される流路の断面積を上記
噴孔の開口総面積よりも少さく設定し、且つ上記
油溜り部側の流路端縁と上記円柱部の先端縁間の
長さをニードルバルブのリフト長さよりも短く設
定する一方、上記油溜り部側の流路端縁と上記案
内部先端間の長さを上記ニードルバルブのリフト
長さよりも長く設定し、上記円柱部の外壁面と上
記通路部の内壁面との間に形成される流路の断面
積と上記案内部の縦溝の総断面積を加えた面積を
上記噴孔の開口総面積よりも大きく設定したこと
を特徴としている。Means for Solving the Problems The present invention has been devised in view of the above-mentioned problems of the conventional art, and particularly relates to a cylindrical portion provided at the base of the shaft portion of a needle valve, and a shaft portion below the cylindrical portion. and a cylindrical guide part having the same diameter as the cylindrical part and having a plurality of vertical grooves formed on its outer peripheral surface, the guide part being formed between the outer wall surface of the cylindrical part and the inner wall surface of the passage part. The cross-sectional area of the flow path is set to be smaller than the total opening area of the nozzle hole, and the length between the end edge of the flow path on the oil reservoir side and the tip edge of the cylindrical portion is set to be smaller than the lift length of the needle valve. While also setting the length between the edge of the flow path on the oil reservoir side and the tip of the guide part longer than the lift length of the needle valve, the outer wall surface of the cylindrical part and the inner part of the passage part are set to be shorter. The present invention is characterized in that the sum of the cross-sectional area of the flow path formed between the wall surface and the total cross-sectional area of the vertical grooves of the guide portion is set to be larger than the total opening area of the nozzle holes.
作 用
上記構成の本考案によれば、燃料噴射ノズルか
らの燃料噴射量を段階的に増加させることにより
急激な燃焼が防止できることは勿論のこと、ニー
ドルバルブの昇降中には案内部が通路部内に常時
位置し、かつ各縦溝内に圧力燃焼を通過させるた
め、つまり該圧力燃料が通路部の内壁面と案内部
外周面との間の流路内を均一巾で流下するため、
該案内部は常に通路部の中心位置に保持され、し
たがつて円柱部も通路部の中心位置に保持され
る。また、円柱部と案内部が同径になつているの
で、ニードルバルブの最大リフト時（円柱部は油
溜り部内）から下降中において案内部が円柱部を
通路部内へ滑らかに案内することができる。Effects According to the present invention having the above configuration, it is possible to prevent sudden combustion by increasing the amount of fuel injected from the fuel injection nozzle in stages, and also to prevent the guide part from moving inside the passage part while the needle valve is going up and down. In order to allow pressure combustion to pass through each vertical groove, that is, the pressure fuel flows down with a uniform width in the flow path between the inner wall surface of the passage part and the outer peripheral surface of the guide part,
The guide portion is always held at the center of the passage, and therefore the cylindrical portion is also held at the center of the passage. In addition, since the cylindrical part and the guide part have the same diameter, the guide part can smoothly guide the cylindrical part into the passage part from when the needle valve is at its maximum lift (the cylindrical part is inside the oil reservoir) to when it is descending. .
本発明の実施例
以下、本発明の具体的な実施例を図面に基づい
て詳細に説明する。Embodiments of the present invention Hereinafter, specific embodiments of the present invention will be described in detail based on the drawings.
第２図は本発明に係る第１実施例の全体構成を
示し、第３図は同実施例の要部を示している。即
ち、第２図に示す１１はノズルボデイ、１２は該
ノズルボデイ１１内に摺動自在に収納されたニー
ドルバルブである。 FIG. 2 shows the overall configuration of a first embodiment of the present invention, and FIG. 3 shows the main parts of the same embodiment. That is, 11 shown in FIG. 2 is a nozzle body, and 12 is a needle valve slidably housed within the nozzle body 11.
ノズルボデイ１１は、略中央内部に縦断面略楕
円形の油溜り部１３が形成されると共に、該油溜
り部１３の下部には、該油溜り部１３から先端部
に亘つて通路部１４が形成され、また、ボデイ１
１の先端部にサツクホール部１５及び略円錐形の
ノズルシート部１６を有し、且つこのノズルシー
ト部１６に開口するように複数の噴孔１７が貫通
形成されている。 The nozzle body 11 has an oil reservoir 13 having a substantially elliptical vertical cross section formed inside the center thereof, and a passage 14 extending from the oil reservoir 13 to the tip thereof at the lower part of the oil reservoir 13. and also body 1
1 has a suction hole part 15 and a substantially conical nozzle seat part 16 at the tip thereof, and a plurality of nozzle holes 17 are formed through the nozzle seat part 16 so as to open therein.
他方、上記ニードルバルブ１２は、同図に示す
如くニードル摺動部１８の下部に上記油溜り部１
３内に位置する略円錐形の受圧面部１９が形成さ
れ、該受圧面部１９の下部には上記通路部１４内
に嵌挿するシヤフト部２０が形成されており、該
シヤフト部２０の先端部には上記ノズルシート部
１６に着座して上記噴孔１７を閉止する略円錐状
のフエイス部２１が形成されている。更に、上記
受圧面部１９直下のシヤフト部２０基部には燃料
の流量制御部Ｃが形成されている。 On the other hand, the needle valve 12 has the oil reservoir 1 at the lower part of the needle sliding part 18, as shown in the figure.
A substantially conical pressure receiving surface portion 19 is formed within the passage 14, and a shaft portion 20 that fits into the passage portion 14 is formed at the lower part of the pressure receiving surface portion 19. A substantially conical face portion 21 is formed which seats on the nozzle seat portion 16 and closes the nozzle hole 17 . Further, a fuel flow rate control section C is formed at the base of the shaft section 20 directly below the pressure receiving surface section 19.
即ち、第３に示す如くシヤフト部２０の基部に
円柱部３２が形成され、該円柱部３２の外周面３
２ａと上記通路部１４の内壁面１４ａ間に形成さ
れる環状流路３６の断面積が上記噴孔１７の開口
総面積よりも小さく設定され、且つニードルバル
ブ１２の閉弁時における上記油溜り部１３側に面
する流路３６の上端縁３６ａと円柱部３２の下端
縁３２ｂ間の長さｈがニードルバルブ１２のリフ
ト長さよりも短く設定されている。そして、上記
流路３６の断面積と噴孔１７の開口総面積の割合
は燃料噴射初期の噴射量をどの程度に抑制するか
によつて適宜決定され、また、上記流路３６の上
端縁３６ａと円柱部３２の下端縁３２ｂ間の長さ
ｈは、少量に規制する初期燃料のの噴射時間をど
の程度持続させるかによつて適宜決定される。ま
た、ノズルボデイ１１の通路部１４上部に一定深
さの円筒部３４が形成されている。 That is, as shown in FIG.
2a and the inner wall surface 14a of the passage section 14, the cross-sectional area of the annular flow path 36 is set to be smaller than the total opening area of the nozzle holes 17, and the oil reservoir section when the needle valve 12 is closed. The length h between the upper end edge 36a of the flow path 36 facing the 13 side and the lower end edge 32b of the cylindrical part 32 is set shorter than the lift length of the needle valve 12. The ratio of the cross-sectional area of the flow path 36 to the total opening area of the nozzle holes 17 is appropriately determined depending on how much the injection amount at the initial stage of fuel injection is to be suppressed. The length h between the lower end edge 32b of the cylindrical portion 32 and the lower end edge 32b of the cylindrical portion 32 is appropriately determined depending on how long the injection time of the initial fuel, which is regulated to a small amount, is maintained. Further, a cylindrical portion 34 having a constant depth is formed above the passage portion 14 of the nozzle body 11.
そして、上記ニードルバルブ１２は、上記円柱
部３２の下部に円環状溝３３を挟んで円柱状案内
部３５が形成されている。該案内部３５は、上記
円柱部３２と同径に設定され、その外周面には燃
料バイパス用の縦溝３５ａが軸方向に沿つて複数
形成されている。また、案内部３５は、ニードル
バルブ１２の最大リフト時でも上記円筒部３４内
に残留する位置に形成されている。更に、上記円
柱部３２の外壁面３２ａと円筒部３４の内壁面つ
まり通路部１４の内壁面１４ａ間に形成される環
状流路３６の断面積と、上記案内部３５の縦溝３
５ａの総断面積を加えた面積は、噴孔１７の開口
総面積より大きくなるように設定されている。 In the needle valve 12, a cylindrical guide portion 35 is formed at the bottom of the cylindrical portion 32 with an annular groove 33 interposed therebetween. The guide portion 35 is set to have the same diameter as the cylindrical portion 32, and a plurality of vertical grooves 35a for fuel bypass are formed along the axial direction on its outer peripheral surface. Further, the guide portion 35 is formed at a position where it remains within the cylindrical portion 34 even when the needle valve 12 is at its maximum lift. Furthermore, the cross-sectional area of the annular flow path 36 formed between the outer wall surface 32a of the cylindrical portion 32 and the inner wall surface of the cylindrical portion 34, that is, the inner wall surface 14a of the passage portion 14, and the vertical groove 3 of the guide portion 35 are
The area including the total cross-sectional area of the nozzle holes 17 is set to be larger than the total opening area of the nozzle holes 17.
次に、上記構成の燃料噴射ノズルの作用を説明
する。 Next, the operation of the fuel injection nozzle having the above configuration will be explained.
先ず、図外の燃料噴射ポンプにより油溜り部１
３に供給された燃料の圧力が増大すると、受圧面
部１９に作用する圧力によつてニードルバルブ１
２が押し上げられ、噴孔１７が開口されるが、バ
ルブリフトの初期つまり上記流量制御部Ｃの長さ
ｈを下廻るリフト量の間は、燃料流量が環状流路
３６の断面積により決定され、その結果比較的少
ない噴射量に規制される。そして、バルブリフト
量が上記の長さｈを上廻ると、規制を解除された
燃料がその量を増加しながら先端方向へ流入する
ため、以後の噴射量は噴孔１７の開口総面積によ
り決定される。 First, oil sump 1 is pumped by a fuel injection pump (not shown).
When the pressure of the fuel supplied to 3 increases, the pressure acting on the pressure receiving surface 19 causes the needle valve 1 to
2 is pushed up and the nozzle hole 17 is opened, but at the initial stage of the valve lift, that is, during the lift amount below the length h of the flow rate control section C, the fuel flow rate is determined by the cross-sectional area of the annular flow path 36. As a result, the injection amount is restricted to a relatively small amount. When the valve lift amount exceeds the above-mentioned length h, the amount of unregulated fuel increases and flows toward the tip, so the subsequent injection amount is determined by the total opening area of the nozzle hole 17. be done.
従つて、第５図の実線に示すように、燃料噴射
量は、噴射初期（領域ｈ）においては比較的少な
く、噴射後期（領域ｘ）においては比較的多くな
るように、段階的に増加する特性が得られる。即
ち、噴射初期のｈ領域では流量規制部Ｃによつて
燃料噴射量が少量に規制されるので、急激な燃焼
が防止され排気ガス中のNOx濃度や燃焼騒音を
著しく低減でき、更に、噴射後期のｘ領域では規
制が解除されて溶射量が序々に増加するので、通
常の燃焼状態が得られる。 Therefore, as shown by the solid line in FIG. 5, the fuel injection amount increases step by step, from being relatively small at the early stage of injection (region h) to relatively large at the late stage of injection (region x). characteristics are obtained. That is, in the h region at the early stage of injection, the fuel injection amount is regulated to a small amount by the flow rate regulating part C, so rapid combustion is prevented and the NOx concentration in the exhaust gas and combustion noise can be significantly reduced. In the x region, the regulation is lifted and the amount of thermal spraying gradually increases, resulting in a normal combustion state.
しかも、この実施例では、案内部３５がニード
ルバルブ昇降中に円筒部３４内に常時残留し、か
つ円環状溝３３を介して自身の各縦溝３５ａ内を
圧力燃料が通過する、すなわち該圧力燃料が円筒
部３４の内壁面と案内部３５の外周面との間の流
路３６内を全体が円筒状の均一巾で流下するた
め、該案内部３５は圧力燃料の該案内部３５の外
周面に対する均一な反力により常に通路部１４の
中心位置に保持される。したがつて、円柱部３２
も通路部１４の中心位置に保持されることにな
る。また、円柱部３２と案内部３５が同径に設定
されているため、たとえ案内部３５が円筒部３４
の内壁面に摺接しつつ下降してもそれに追随する
形で円柱部３２も円筒部３４内に滑らかに案内さ
れる。この結果、円柱部３２の下端部３２ｂが、
油溜り部１３の下端縁つまり円筒部３４の上端縁
３６に対して干渉したりあるいは乗り上げること
が確実に防止される。 Moreover, in this embodiment, the guide part 35 always remains in the cylindrical part 34 while the needle valve is being raised and lowered, and the pressurized fuel passes through the respective longitudinal grooves 35a of the guide part 35 through the annular groove 33, that is, the pressure Since the fuel flows down within the flow path 36 between the inner wall surface of the cylindrical portion 34 and the outer circumferential surface of the guide portion 35 with a uniform cylindrical width as a whole, the guide portion 35 is arranged so that the pressure fuel flows along the outer circumference of the guide portion 35. It is always held at the center position of the passage section 14 by a uniform reaction force against the surface. Therefore, the columnar part 32
is also held at the center position of the passage section 14. Furthermore, since the cylindrical portion 32 and the guide portion 35 are set to have the same diameter, even if the guide portion 35 is
Even if the cylinder part 32 descends while slidingly contacting the inner wall surface of the cylinder part 34, the cylinder part 32 is also smoothly guided into the cylinder part 34 to follow the movement. As a result, the lower end 32b of the columnar part 32 is
It is reliably prevented from interfering with or running over the lower edge of the oil reservoir portion 13, that is, the upper edge 36 of the cylindrical portion 34.
第４図は本発明の第２実施例を示し、ニードル
バルブ１２の構成は第１実施例の場合と同様であ
るが、ノズルボデイ１１の通路部１４の直径を第
２実施例の場合より大径に形成し、該通路部１４
上部にボデイ１１とは別材の円筒部材４０を嵌合
させて流量規制部Ｃの一部を形成させている。従
つて、第１実施例の場合と同様の効果を有するこ
とは勿論であるが、円筒部材４０を単に交換する
だけで燃料の規制流量を変化させることができる
ので、種々の機関に広く利用できる。 FIG. 4 shows a second embodiment of the present invention, in which the configuration of the needle valve 12 is the same as that in the first embodiment, but the diameter of the passage section 14 of the nozzle body 11 is made larger than that in the second embodiment. and the passage portion 14
A cylindrical member 40 made of a separate material from the body 11 is fitted into the upper part to form a part of the flow rate regulating part C. Therefore, it goes without saying that it has the same effect as the first embodiment, but it can be widely used in various engines because the regulated flow rate of fuel can be changed by simply replacing the cylindrical member 40. .
更に、上記各実施例は、流量規制部Ｃが高温の
燃焼ガスに晒されるノズルボデイの先端部から離
れた上部位置に形成されている為、熱膨張の影響
を受けにくく、流量規制手段の精度が一層良好化
できるばかりか、燃焼ガス逆流によるカーボン附
着の心配がないので耐久性も優れさらに噴霧の分
配もよい。 Furthermore, in each of the above embodiments, since the flow rate regulating portion C is formed at an upper position away from the tip of the nozzle body that is exposed to high-temperature combustion gas, it is less susceptible to thermal expansion and the accuracy of the flow rate regulating means is improved. Not only can this be improved, but there is no need to worry about carbon adhesion due to combustion gas backflow, so durability is excellent and spray distribution is also good.
また、ニードルバルブの円柱部がニードルバル
ブ摺動部の近傍に形成されているため、両者の同
軸度が得られやすく成形上の精度が良くなる。 Further, since the cylindrical portion of the needle valve is formed near the sliding portion of the needle valve, coaxiality between the two can be easily obtained, and molding accuracy is improved.
発明の効果
以上の説明で明らかなように、本発明によれ
ば、噴射ノズルによれば、バルブリフトに伴い燃
料噴射量が段階的に増加するような噴射特性を得
ることができ、噴射初期の燃料噴射量を少量に抑
制して、急激な燃焼を防止できる。従つて、良好
な初期燃焼を得ることができ、排気ガス中の
NOx濃度の低減ならびに燃焼騒音の低減を達成
できる。Effects of the Invention As is clear from the above explanation, according to the present invention, the injection nozzle can obtain an injection characteristic in which the amount of fuel injection increases step by step with the valve lift, and Sudden combustion can be prevented by suppressing the fuel injection amount to a small amount. Therefore, good initial combustion can be obtained and the exhaust gas
A reduction in NOx concentration and combustion noise can be achieved.
しかも、ニードルバルブの昇降中に案内部の縦
溝内を通過する圧力燃料によつて該案内部が常時
通路部の中心位置に保持され、したがつて円柱部
も通路部の中心位置に保持される。また、円柱部
と案内部とが同径になつているため、案内部によ
る通路部内への案内性が良好となり、円柱部が通
路部内へ滑らかに挿入する。この結果、ニードル
バルブ下降時における円柱部の油溜り部下端縁に
対する乗り上げが確実に防止される。これによつ
てニードルバルブの常時円滑な作動が得られ、燃
料噴射後期における噴射遅れが防止される。した
がつて、減速時の良好な運転性が確保される
更に、流量規制部はノズルボデイの略中央に形
成されているため、熱膨張の影響を受けにくく流
量規制手段の精度が一層良好化できるばかりか、
燃焼ガス逆流によるカーボン附着の心配がないの
で耐久性も優れさらに噴霧の分配もよい。 Moreover, the guide part is always held at the center position of the passage part by the pressure fuel passing through the vertical groove of the guide part while the needle valve is being raised and lowered, and therefore the cylindrical part is also held at the center position of the passage part. Ru. In addition, since the cylindrical portion and the guide portion have the same diameter, the guide portion has good guiding performance into the passage portion, and the cylindrical portion is smoothly inserted into the passage portion. As a result, the cylindrical portion is reliably prevented from running over the lower edge of the oil reservoir when the needle valve is lowered. This ensures smooth operation of the needle valve at all times, and prevents injection delays in the latter stages of fuel injection. Therefore, good operability during deceleration is ensured.Furthermore, since the flow rate regulating section is formed approximately in the center of the nozzle body, it is less susceptible to thermal expansion and the accuracy of the flow rate regulating means can be further improved. mosquito,
There is no need to worry about carbon adhesion due to combustion gas backflow, so durability is excellent and spray distribution is also good.
第１図は従来の燃料噴射ノズルの全体を示す断
面図、第２図は本発明に係る噴射ノズルの第１実
施例を示す断面図、第３図は第１実施例の要部を
示す断面図、第４図は本発明の第２実施例を示す
断面図、第５図は本発明の燃料ノズルの噴射特性
を従来のものと比較して示す特性図である。
１１……ノズルボデイ、１２……ニードルバル
ブ、１３……油溜り部、１４……通路部、１４ａ
……通路部内壁面、１７……噴孔、１９……受圧
面部、２０……シヤフト部、２１……フエイス
部、３２……円柱部、３２ａ……円柱部の外壁
面、３２ｂ……円柱部の下端縁、３５……案内
部、３５ａ……縦溝、３６……環状流路、３６ａ
……環状流路の上端縁。
Fig. 1 is a sectional view showing the entire conventional fuel injection nozzle, Fig. 2 is a sectional view showing a first embodiment of the injection nozzle according to the present invention, and Fig. 3 is a sectional view showing the main parts of the first embodiment. FIG. 4 is a sectional view showing a second embodiment of the present invention, and FIG. 5 is a characteristic diagram showing the injection characteristics of the fuel nozzle of the present invention in comparison with a conventional one. 11... Nozzle body, 12... Needle valve, 13... Oil reservoir section, 14... Passage section, 14a
...Inner wall surface of passage portion, 17...Nozzle hole, 19...Pressure receiving surface portion, 20...Shaft portion, 21...Face portion, 32...Cylindrical portion, 32a...Outer wall surface of columnar portion, 32b...Cylindrical portion lower end edge, 35...guiding section, 35a...vertical groove, 36...annular channel, 36a
...The upper edge of the annular channel.
Claims (1)
在に収納されるニードルバルブとを備え、上記ノ
ズルボデイは略中央内部に形成された油溜り部
と、該油溜り部から先端部に亘つて形成された通
路部と、先端に形成された噴孔とを有し、他方上
記ニードルバルブは上記油溜り部の位置に形成さ
れた受圧面部と、該受圧面部の端部に形成され上
記通路部に嵌挿されるシヤフト部と、該シヤフト
部の先端部に形成されたフエイス部と、上記シヤ
フト部の基部に設けられた円柱部と、該円柱部よ
り下部のシヤフト部に設けられ、上記円柱部と同
径でかつその外周面に複数の縦溝が形成された円
柱状の案内部とを備え、上記円柱部の外壁面と上
記通路部の内壁面間に形成される流路の断面積を
上記噴孔の開口総面積よりも小さく設定し、且つ
上記油溜り部側の流路端縁と上記円柱部の先端縁
間の長さをニードルバルブのリフト長さよりも短
く設定する一方、上記油溜り部側の流路端縁と上
記案内部先端間の長さを上記ニードルバルブのリ
フト長さよりも長く設定し、上記円柱部の外壁面
と上記通路部の内壁面との間に形成される流路の
断面積と上記案内部の縦溝の総断面積を加えた面
積を上記噴孔の開口総面積よりも大きく設定した
ことを特徴とする燃料噴射ノズル。1 Comprising a nozzle body and a needle valve slidably housed in the nozzle body, the nozzle body has an oil reservoir formed approximately in the center, and a passage formed from the oil reservoir to the tip. The needle valve has a pressure receiving surface portion formed at the position of the oil reservoir portion, and a pressure receiving surface portion formed at an end portion of the pressure receiving surface portion and fitted into the passage portion. A shaft portion, a face portion formed at the tip of the shaft portion, a cylindrical portion provided at the base of the shaft portion, and a face portion provided on the shaft portion below the cylindrical portion, and having the same diameter as the cylindrical portion. and a cylindrical guide portion having a plurality of longitudinal grooves formed on its outer circumferential surface, and the cross-sectional area of the flow path formed between the outer wall surface of the cylindrical portion and the inner wall surface of the passage portion is defined as the cross-sectional area of the nozzle hole. The opening area is set smaller than the total opening area, and the length between the flow path edge on the oil reservoir side and the tip edge of the cylindrical part is set shorter than the lift length of the needle valve, while the length on the oil reservoir side is set to be smaller than the total opening area. The length between the edge of the flow path and the tip of the guide section is set to be longer than the lift length of the needle valve, and the disconnection of the flow path formed between the outer wall surface of the cylindrical section and the inner wall surface of the passage section is set to be longer than the lift length of the needle valve. A fuel injection nozzle characterized in that the sum of the area and the total cross-sectional area of the longitudinal grooves of the guide portion is set to be larger than the total opening area of the nozzle holes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24125983A JPS60132065A (en) | 1983-12-20 | 1983-12-20 | Fuel injection nozzle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24125983A JPS60132065A (en) | 1983-12-20 | 1983-12-20 | Fuel injection nozzle |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60132065A JPS60132065A (en) | 1985-07-13 |
| JPH0256512B2 true JPH0256512B2 (en) | 1990-11-30 |
Family
ID=17071579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24125983A Granted JPS60132065A (en) | 1983-12-20 | 1983-12-20 | Fuel injection nozzle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60132065A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10346210A1 (en) * | 2003-10-06 | 2005-04-21 | Bosch Gmbh Robert | Fuel injection unit for internal combustion engine of motor vehicle, comprises flow section between pressure chamber and the connection to the release section |
| DE102004025729A1 (en) * | 2004-05-26 | 2005-12-15 | Robert Bosch Gmbh | Fuel injection valve for an internal combustion engine |
| JP2009138614A (en) * | 2007-12-05 | 2009-06-25 | Mitsubishi Heavy Ind Ltd | Fuel injection valve of pressure accumulation-type fuel injection device |
| EP2083165A1 (en) * | 2008-01-22 | 2009-07-29 | Delphi Technologies, Inc. | Injection nozzle |
| DE102013209251A1 (en) * | 2013-05-17 | 2014-11-20 | Robert Bosch Gmbh | Fuel injection valve for internal combustion engines |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58189366U (en) * | 1982-06-09 | 1983-12-16 | 日産自動車株式会社 | Hole type fuel injection nozzle |
-
1983
- 1983-12-20 JP JP24125983A patent/JPS60132065A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60132065A (en) | 1985-07-13 |
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