JPH07259694A - Structure of unit injector - Google Patents
Structure of unit injectorInfo
- Publication number
- JPH07259694A JPH07259694A JP5158994A JP5158994A JPH07259694A JP H07259694 A JPH07259694 A JP H07259694A JP 5158994 A JP5158994 A JP 5158994A JP 5158994 A JP5158994 A JP 5158994A JP H07259694 A JPH07259694 A JP H07259694A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- plunger
- shaped chamber
- cylinder
- leakage
- 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.)
- Granted
Links
Landscapes
- Fuel-Injection Apparatus (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、特にディーゼルエンジ
ンに好適なユニットインジェクタの構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a unit injector structure particularly suitable for diesel engines.
【０００２】[0002]
【従来の技術】従来のユニットインジェクタの構造を図
２に示す。この図は電子制御方式のユニットインジェク
タであって、図示しないロッカーアームによりスプリン
グシート１がコイルスプリング２に抗してプランジャー
３を降下させると、燃料溜まり４に充填された燃料は通
路５を通りノズル６の先端より噴射され、余剰燃料は通
路７を通って図示しない燃料タンクへ戻るようになって
いる。2. Description of the Related Art The structure of a conventional unit injector is shown in FIG. This figure shows an electronically controlled unit injector. When a spring seat 1 lowers a plunger 3 against a coil spring 2 by a rocker arm (not shown), the fuel filled in a fuel reservoir 4 passes through a passage 5. Excess fuel injected from the tip of the nozzle 6 returns to a fuel tank (not shown) through the passage 7.
【０００３】そして噴射終りは走行状態及び設定条件に
より信号が入力されてなり、具体的にはソレノイド８が
通電して燃料溜まり４の圧力を逃がすようになってい
る。またプランジャー３の降下時に図中影線で示すガイ
ド９内部の容積１０が縮小するため、この容積部分１０
と外気との間にエア抜きの穴１１が穿設されている。図
３は図２の要部を拡大した図で丸で囲んだＡ部がエア抜
きの穴１１である。At the end of injection, a signal is input depending on the running condition and the set conditions. Specifically, the solenoid 8 is energized to release the pressure in the fuel pool 4. Further, when the plunger 3 descends, the volume 10 inside the guide 9 shown by the shaded area in the figure decreases, so that this volume portion 10
An air vent hole 11 is provided between the air and the outside air. FIG. 3 is an enlarged view of the main part of FIG. 2, and the portion A surrounded by a circle is the air vent hole 11.
【０００４】[0004]
【発明が解決しようとする課題】しかし上記した従来の
ユニットインジェクタの構造では、燃料噴射時にプラン
ジャー３とボディ１２との隙間Ｇを伝わって上昇する燃
料漏れは燃料スピル経路に高圧シール部１３を設けてい
るが、ここでシールできなかった燃料は更に上昇して、
シリンダの上部に穿設した低圧シール部であるところの
リング状室１４に至り、エア抜き穴１１を通って外部へ
漏出する。漏出した燃料は結局エンジン内部で潤滑オイ
ルと混合するという問題点があった。本出願人による実
開昭６３−２１７６５及び実開昭６３−７３５７０にお
いて、ユニットインジェクタの技術が開示されている
が、上記問題点を解決するものではない。However, in the structure of the conventional unit injector described above, the fuel leak rising through the gap G between the plunger 3 and the body 12 at the time of fuel injection is caused by the high pressure seal portion 13 in the fuel spill path. Although it is provided, the fuel that could not be sealed here rises further,
It reaches the ring-shaped chamber 14, which is a low-pressure seal portion formed in the upper part of the cylinder, and leaks to the outside through the air vent hole 11. There was a problem that the leaked fuel eventually mixed with the lubricating oil inside the engine. The technique of the unit injector is disclosed in Japanese Utility Model Laid-Open Nos. 63-21765 and 63-73570 by the present applicant, but it does not solve the above problems.
【０００５】本発明は、プランジャから漏れた燃料をエ
ンジンオイルと混合しないユニットインジェクタの構造
を提供することを目的とする。An object of the present invention is to provide a structure of a unit injector which does not mix fuel leaking from a plunger with engine oil.
【０００６】[0006]
【課題を解決するための手段】本発明によれば、スプリ
ングシートを介してロッカーアームにより上下動するプ
ランジャが摺動していて、ボディに穿設されたシリンダ
の上部にリング状室を設け、そのリング状室と燃料タン
クの大気側とを燃料戻り配管で連通したことを特徴とす
るユニットインジェクタの構造。According to the present invention, a plunger that moves up and down by a rocker arm slides through a spring seat, and a ring-shaped chamber is provided in an upper portion of a cylinder bored in a body. A structure of a unit injector characterized in that the ring-shaped chamber and the atmosphere side of the fuel tank are connected by a fuel return pipe.
【０００７】[0007]
【作用】上記のように構成されたユニットインジェクタ
の構造によれば、プランジャが摺動するシリンダの上部
にリング状室を設けたので、プランジャとシリンダとの
隙間を通って上昇する漏れた燃料はリング状室に溜ま
り、更にリング状室に溜まった燃料は燃料戻り配管によ
り燃料タンクへ回収される。According to the structure of the unit injector constructed as described above, since the ring-shaped chamber is provided in the upper portion of the cylinder on which the plunger slides, the leaked fuel rising through the gap between the plunger and the cylinder is prevented. The fuel that has accumulated in the ring-shaped chamber and that has further accumulated in the ring-shaped chamber is collected in the fuel tank through the fuel return pipe.
【０００８】[0008]
【実施例】以下、図面を参照して本発明の実施例を説明
する。Embodiments of the present invention will be described below with reference to the drawings.
【０００９】図１は本発明の実施例を示す図であり、従
来と同一または同等の部品は同一符号を付し説明を省略
する。この図において、リング状室１４と大気とを連通
するエア抜き穴１１の開口部に接手１７を介して燃料戻
り管１６の一端が接続され、他端は燃料タンク１５の大
気側に接続されている。FIG. 1 is a diagram showing an embodiment of the present invention, in which the same or equivalent parts as in the prior art are designated by the same reference numerals and their description is omitted. In this figure, one end of the fuel return pipe 16 is connected to the opening of the air vent hole 11 that communicates the ring-shaped chamber 14 with the atmosphere via a joint 17, and the other end is connected to the atmosphere side of the fuel tank 15. There is.
【００１０】以下、図１を参照して作用について説明す
る。The operation will be described below with reference to FIG.
【００１１】プランジャー３が上昇するときプランジャ
３とボディ１２との隙間Ｇを伝わって上昇する燃料漏れ
は、低圧シール部１４に至りエア抜き穴１１を経由して
燃料戻り管１６を通って燃料タンク１５に戻る。When the plunger 3 rises, the fuel leak which rises through the gap G between the plunger 3 and the body 12 reaches the low pressure seal portion 14, passes through the air vent hole 11 and passes through the fuel return pipe 16 and the fuel. Return to tank 15.
【００１２】[0012]
【発明の効果】本発明は、以上説明したように構成され
ているので、プランジャー３の上昇時に隙間Ｇを通って
漏れる燃料は燃料タンクに戻されてエンジンオイルと混
合せず、またリング状室１４には大気が作用しているの
でスプリングシート１の作動に影響されない。Since the present invention is constructed as described above, the fuel leaking through the gap G when the plunger 3 rises is not returned to the fuel tank and does not mix with the engine oil, and the ring shape is also provided. Since the atmosphere acts on the chamber 14, it is not affected by the operation of the spring seat 1.
【図１】本発明による実施例を示す模式図。FIG. 1 is a schematic view showing an embodiment according to the present invention.
【図２】従来のユニットインジェクタを示す断面図。FIG. 2 is a sectional view showing a conventional unit injector.
【図３】本発明が指向される部分の拡大図。FIG. 3 is an enlarged view of a portion to which the present invention is directed.
１・・・スプリングシート ２・・・コイルスプリング ３・・・プランジャー ４・・・燃料溜まり ５、７・・・通路 ６・・・ノズル ８・・・ソレノイド ９・・・ガイド １０・・・内部の容積 １１・・・エア抜き穴 １２・・・ボディ １３・・・高圧シール部 １４・・・低圧シール部たるリング状室 １５・・・燃料タンク １６・・・燃料戻り管 １７・・・接手 1 ... Spring seat 2 ... Coil spring 3 ... Plunger 4 ... Fuel sump 5, 7 ... Passage 6 ... Nozzle 8 ... Solenoid 9 ... Guide 10 ... Internal volume 11 ... Air bleed hole 12 ... Body 13 ... High-pressure seal part 14 ... Ring-shaped chamber as low-pressure seal part 15 ... Fuel tank 16 ... Fuel return pipe 17 ... Joint
Claims (1)
アームにより上下動するプランジャが摺動していて、ボ
ディに穿設されたシリンダの上部にリング状室を設け、
そのリング状室と燃料タンクの大気側とを燃料戻り配管
で連通したことを特徴とするユニットインジェクタの構
造。1. A plunger, which moves up and down by a rocker arm through a spring seat, slides, and a ring-shaped chamber is provided in an upper portion of a cylinder bored in a body,
A structure of a unit injector characterized in that the ring-shaped chamber and the atmosphere side of the fuel tank are connected by a fuel return pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5158994A JP2950491B2 (en) | 1994-03-23 | 1994-03-23 | Unit injector structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5158994A JP2950491B2 (en) | 1994-03-23 | 1994-03-23 | Unit injector structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07259694A true JPH07259694A (en) | 1995-10-09 |
| JP2950491B2 JP2950491B2 (en) | 1999-09-20 |
Family
ID=12891115
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5158994A Expired - Lifetime JP2950491B2 (en) | 1994-03-23 | 1994-03-23 | Unit injector structure |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2950491B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20030016702A (en) * | 2001-08-21 | 2003-03-03 | 현대자동차주식회사 | Electronic unit injector having a fuel leaking protection device |
| KR20040017596A (en) * | 2002-08-22 | 2004-02-27 | 현대자동차주식회사 | Injector for preventing fuel leaking in diesel engine |
| JP2007332808A (en) * | 2006-06-13 | 2007-12-27 | Nikki Co Ltd | Fuel feed system |
| CN104234882A (en) * | 2014-08-21 | 2014-12-24 | 内蒙古欧意德发动机有限公司 | Oil return pipe assembly |
-
1994
- 1994-03-23 JP JP5158994A patent/JP2950491B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20030016702A (en) * | 2001-08-21 | 2003-03-03 | 현대자동차주식회사 | Electronic unit injector having a fuel leaking protection device |
| KR20040017596A (en) * | 2002-08-22 | 2004-02-27 | 현대자동차주식회사 | Injector for preventing fuel leaking in diesel engine |
| JP2007332808A (en) * | 2006-06-13 | 2007-12-27 | Nikki Co Ltd | Fuel feed system |
| JP4624961B2 (en) * | 2006-06-13 | 2011-02-02 | 株式会社ニッキ | Fuel supply system |
| CN104234882A (en) * | 2014-08-21 | 2014-12-24 | 内蒙古欧意德发动机有限公司 | Oil return pipe assembly |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2950491B2 (en) | 1999-09-20 |
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