JPH0726963A - Two-cycle engine - Google Patents
Two-cycle engineInfo
- Publication number
- JPH0726963A JPH0726963A JP16688793A JP16688793A JPH0726963A JP H0726963 A JPH0726963 A JP H0726963A JP 16688793 A JP16688793 A JP 16688793A JP 16688793 A JP16688793 A JP 16688793A JP H0726963 A JPH0726963 A JP H0726963A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- piston
- fuel injection
- injection means
- exhaust port
- 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.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/12—Other methods of operation
- F02B2075/125—Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber
Landscapes
- Fuel-Injection Apparatus (AREA)
- Combustion Methods Of Internal-Combustion Engines (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は２サイクルエンジンに関
し、特にシリンダ内に直接燃料を噴射する方式の２サイ
クルエンジンに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-cycle engine, and more particularly to a two-cycle engine in which fuel is directly injected into a cylinder.
【０００２】[0002]
【従来の技術】シリンダ内に直接燃料を噴射する方式の
２サイクルエンジンにおいて、燃料噴射手段を燃焼室に
臨む位置に配置すると高温に晒されるために、通常燃料
噴射手段はシリンダ周面に配設されている。特に、例え
ば特開平３−１８６６４号公報等に開示されているよう
に、燃料噴射手段を掃気ポートに配置すると、常に掃気
流にて冷却されるために高温に晒され難く、安定した動
作を容易に確保できるために望ましい。このように掃気
ポートに燃料噴射手段を配置したものにおいてもさらに
図３と図４に示すような２つの方式が知られている。2. Description of the Related Art In a two-cycle engine in which fuel is directly injected into a cylinder, when the fuel injection means is placed at a position facing the combustion chamber, it is exposed to high temperature, and therefore the fuel injection means is usually provided on the cylinder peripheral surface. Has been done. Particularly, as disclosed in, for example, Japanese Patent Laid-Open No. 3-18664, when the fuel injection means is arranged in the scavenging port, the fuel is constantly cooled by the scavenging air flow, so that it is difficult to be exposed to high temperature and stable operation is facilitated. It is desirable because it can be secured. Even in the case where the fuel injection means is arranged in the scavenging port as described above, two methods as shown in FIGS. 3 and 4 are known.
【０００３】図３、図４において、２１はシリンダ、２
２はシリンダヘッド、２３は燃焼室、２４は点火プラ
グ、２５はピストンである。シリンダ２１の周面におけ
るピストン２５の下死点の直上位置において、周方向適
当箇所に排気ポート２６が設けられ、排気ポート２６と
シリンダ２１の中心を結ぶ方向に対してその両側に２対
の掃気ポート２７、２８が設けられ、さらに排気ポート
２６に対向してブースタポート２９が設けられている。
これら掃気ポート２７、２８及びブースタポート２９は
排気ポート２６とは反対側で単一の掃気入口部（図示せ
ず）に連通し、この掃気入口部を介して掃気ポンプ（図
示せず）に接続されている。そして、ブースタポート２
９に燃料噴射手段３０が配設されている。In FIGS. 3 and 4, 21 is a cylinder, 2
2 is a cylinder head, 23 is a combustion chamber, 24 is a spark plug, and 25 is a piston. An exhaust port 26 is provided at an appropriate position in the circumferential direction immediately above the bottom dead center of the piston 25 on the circumferential surface of the cylinder 21, and two pairs of scavenging air are provided on both sides of the direction connecting the exhaust port 26 and the center of the cylinder 21. Ports 27 and 28 are provided, and a booster port 29 is provided opposite to the exhaust port 26.
These scavenging ports 27, 28 and booster port 29 communicate with a single scavenging inlet (not shown) on the side opposite to the exhaust port 26, and are connected to a scavenging pump (not shown) via this scavenging inlet. Has been done. And booster port 2
A fuel injection means 30 is arranged at 9.
【０００４】図３の方式は、ブースタポート２９に斜め
下向きに配設された燃料噴射手段３０からピストン２５
の頂部に向けて直接燃料を噴射し、ピストン２５の頂部
の熱によって燃料を蒸発させ、着火し易い混合気を得る
方式である。In the system shown in FIG. 3, the booster port 29 is arranged obliquely downward from the fuel injection means 30 to the piston 25.
Is a method of directly injecting fuel toward the top of the piston and evaporating the fuel by the heat of the top of the piston 25 to obtain an air-fuel mixture that is easy to ignite.
【０００５】図４の方式は、ブースタポート２９に斜め
上向きに配設された燃料噴射手段３０から燃焼室２３の
点火プラグ２４の近傍位置に向けて燃料を噴射する方式
である。The system shown in FIG. 4 is a system in which fuel is injected from a fuel injection means 30 disposed obliquely upward in the booster port 29 toward a position near the ignition plug 24 in the combustion chamber 23.
【０００６】[0006]
【発明が解決しようとする課題】ところが、図３に示し
た方式では、ピストン２５の頂部で生成された混合気の
一部が排気ポート２６に洩れてしまうという問題があ
る。特にピストン２５の頂部の温度が低い場合は蒸発速
度が低くピストン２５の頂部に滞留し易いために排気と
ともに流れ易く、また低速回転の場合は排気ポート２６
の開口時間が長いために排気ポート２６に流れ易いとい
う問題がある。However, in the method shown in FIG. 3, there is a problem that a part of the air-fuel mixture generated at the top of the piston 25 leaks to the exhaust port 26. In particular, when the temperature of the top of the piston 25 is low, the evaporation rate is low and it easily stays at the top of the piston 25 so that it easily flows with the exhaust gas, and in the case of low speed rotation, the exhaust port 26
Has a problem in that it easily flows into the exhaust port 26 due to the long opening time.
【０００７】また、図４に示した方式は、混合気がピス
トン２５の頂部から直接排気ポート２６に流れることが
ないように配慮したものであるが、掃気流が図４に矢印
で示すようにシリンダ２１内の上部を通って排気ポート
２６に流れるため、噴出された燃料の噴出速度が速い場
合には、この掃気流に押出されて排気ポート２６に流さ
れるという問題がある。The system shown in FIG. 4 is designed to prevent the air-fuel mixture from directly flowing from the top of the piston 25 to the exhaust port 26, but the scavenging air flow is as shown by the arrow in FIG. Since the fuel flows through the upper portion of the cylinder 21 to the exhaust port 26, when the jet speed of the injected fuel is high, there is a problem in that the scavenging air flows push the fuel into the exhaust port 26.
【０００８】本発明はこのような従来の問題点に鑑み、
シリンダ内に直接燃料を噴射する方式の２サイクルエン
ジンにおいて、安定した着火・燃焼を確保しながら燃料
の排気ポートへの流出を防止することを目的とする。The present invention has been made in view of the above-mentioned conventional problems.
An object of the present invention is to prevent outflow of fuel to an exhaust port while ensuring stable ignition and combustion in a two-cycle engine in which fuel is directly injected into a cylinder.
【０００９】[0009]
【課題を解決するための手段】本発明は、シリンダ周面
に掃気ポートと排気ポートを形成し、掃気ポートに燃料
噴射手段を配設した２サイクルエンジンにおいて、ピス
トン頂部に向けて燃料を噴出するように燃料噴射手段を
配置し、ピストン頂部における燃料噴射手段から燃料を
噴射される部分に、噴出された燃料を燃焼室に向けて案
内するガイド部を形成したことを特徴とする。According to the present invention, in a two-cycle engine in which a scavenging port and an exhaust port are formed on a cylinder peripheral surface, and fuel scavenging port is provided in the scavenging port, fuel is ejected toward the top of the piston. Thus, the fuel injection means is arranged, and a guide portion for guiding the injected fuel toward the combustion chamber is formed at the portion of the piston top where the fuel is injected from the fuel injection means.
【００１０】[0010]
【作用】本発明によれば、燃料噴射手段からピストン頂
部に向けて燃料が噴出されるので、ピストンの熱によっ
て燃料の蒸発が良好に成され、それと同時に噴出された
燃料がガイド部によって燃焼室に向かうように曲げら
れ、掃気流よりやや速度を遅くして燃焼室方向に流れる
ことによって、燃料が排気ポートに直接流出するのを確
実に防止できるとともに、燃焼室近傍に点火し易い混合
気が形成される。According to the present invention, since the fuel is ejected from the fuel injection means toward the top of the piston, the heat of the piston favorably evaporates the fuel, and at the same time, the ejected fuel is guided by the guide portion to the combustion chamber. The flow of fuel toward the combustion chamber is slower than that of the scavenging air, and it is possible to reliably prevent the fuel from directly flowing to the exhaust port. It is formed.
【００１１】[0011]
【実施例】以下、本発明の一実施例を図１を参照して説
明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG.
【００１２】図１において、１はシリンダ、２はシリン
ダヘッド、３は燃焼室、４は点火プラグ、５はピストン
である。シリンダ１の周面におけるピストン５の下死点
の直上位置において、周方向適当箇所に排気ポート６が
設けられ、排気ポート６とシリンダ１の中心を結ぶ方向
に対してその両側に２対の掃気ポート７、８が設けら
れ、さらに排気ポート６に対向してブースタポート９が
設けられている。これら掃気ポート７、８及びブースタ
ポート９は排気ポート６とは反対側で単一の掃気入口部
（図示せず）に連通し、この掃気入口部を介して掃気ポ
ンプ（図示せず）に接続されている。In FIG. 1, 1 is a cylinder, 2 is a cylinder head, 3 is a combustion chamber, 4 is a spark plug, and 5 is a piston. An exhaust port 6 is provided at an appropriate position in the circumferential direction immediately above the bottom dead center of the piston 5 on the circumferential surface of the cylinder 1, and two pairs of scavenging air are provided on both sides of the direction connecting the exhaust port 6 and the center of the cylinder 1. Ports 7 and 8 are provided, and a booster port 9 is provided opposite to the exhaust port 6. These scavenging ports 7, 8 and booster port 9 communicate with a single scavenging inlet (not shown) on the side opposite to the exhaust port 6, and are connected to a scavenging pump (not shown) via this scavenging inlet. Has been done.
【００１３】ブースタポート９には、ピストン５の頂部
に向けて略水平方向に燃料を噴出するように燃料噴射手
段１０が配置されている。そして、ピストン５の頂部に
燃料噴射手段１０に対向するように突部１１が形成さ
れ、この突部１１の燃料噴射手段１０との対向面に燃料
噴射手段１０から略水平方向に噴射された燃料を上向き
に噴出させるガイド曲面１２が形成されている。A fuel injection means 10 is arranged in the booster port 9 so as to inject fuel in a substantially horizontal direction toward the top of the piston 5. A projection 11 is formed on the top of the piston 5 so as to face the fuel injection means 10. The fuel injected from the fuel injection means 10 in a substantially horizontal direction is formed on the surface of the projection 11 facing the fuel injection means 10. The curved guide surface 12 is formed so as to squirt upward.
【００１４】以上の構成によると、燃料噴射手段１０か
ら略水平方向に燃料が噴出されると、噴出された燃料は
ピストン５の頂部の突部１１に接触し、ピストン５の熱
によって燃料の蒸発が良好に成され、それと同時に噴出
された燃料がガイド曲面１２によって燃焼室３に向かう
ように曲げられて噴出し、掃気流よりやや速度を遅くし
て燃焼室方向に流れるため、燃焼室３まわりに着火し易
い混合気が形成される。かくして、燃料が排気ポート６
に直接流出するのを確実に防止できるとともに、燃焼室
３近傍に点火し易い混合気が形成され、従って安定した
着火・燃焼を確保しながら燃料の排気ポートへの流出を
防止できる。According to the above structure, when the fuel is ejected from the fuel injection means 10 in a substantially horizontal direction, the ejected fuel comes into contact with the protrusion 11 at the top of the piston 5, and the heat of the piston 5 evaporates the fuel. And the fuel injected at the same time is bent toward the combustion chamber 3 by the guide curved surface 12 and ejected, and flows toward the combustion chamber at a speed slightly slower than the scavenging air flow. An air-fuel mixture that easily ignites is formed. Thus, fuel is exhaust port 6
It is possible to surely prevent the fuel from directly flowing to the exhaust chamber, and a mixture that is easily ignited is formed in the vicinity of the combustion chamber 3. Therefore, it is possible to prevent the fuel from flowing to the exhaust port while ensuring stable ignition and combustion.
【００１５】次に、本発明の他の実施例について図２を
参照して説明する。上記実施例ではピストン頂部にガイ
ド曲面１２を形成したが、この実施例ではピストン５の
頂部に燃料噴射手段１０に対向するように突部１３を突
設し、この突部１３に燃料噴射手段１０から略水平方向
に噴射された燃料が通過するＬ字状のガイド通路１４を
形成し、噴出された燃料をガイド通路１４を通過する間
に蒸発させるとともに上向きに方向転換させて燃焼室３
に向けて噴出させるようにしている。Next, another embodiment of the present invention will be described with reference to FIG. In the above embodiment, the guide curved surface 12 is formed on the top of the piston, but in this embodiment, the projection 13 is provided on the top of the piston 5 so as to face the fuel injection means 10, and the fuel injection means 10 is provided on this projection 13. Forming an L-shaped guide passage 14 through which the fuel injected in a substantially horizontal direction passes, and evaporates the ejected fuel while passing through the guide passage 14 and redirects it upward so that the combustion chamber 3
I am trying to make it squirt toward.
【００１６】この実施例によると、ガイド通路１４にて
燃料の噴出方向をより強く規制できるので、図１の実施
例の場合よりもより確実に混合気を点火プラグ４の付近
に集めることができ、リーン燃焼においても安定した着
火・燃焼を確保できる。According to this embodiment, the direction of fuel injection can be regulated more strongly in the guide passage 14, so that the air-fuel mixture can be more reliably collected near the ignition plug 4 than in the case of the embodiment of FIG. Also, stable ignition and combustion can be secured even in lean combustion.
【００１７】[0017]
【発明の効果】本発明の２サイクルエンジンによれば、
以上のように燃料噴射手段からピストン頂部に向けて燃
料が噴出されるので、ピストンの熱によって燃料の蒸発
が良好に成され、それと同時に噴出された燃料がガイド
部によって燃焼室に向かうように曲げられることによっ
て、燃料が排気ポートに直接流出するのを確実に防止で
きるとともに、燃焼室近傍に点火し易い混合気を形成で
き、安定した着火・燃焼を確保しながら燃料の排気ポー
トへの流出を防止することができる。According to the two-cycle engine of the present invention,
As described above, the fuel is ejected from the fuel injection means toward the top of the piston, so that the heat of the piston favorably evaporates the fuel, and at the same time, the ejected fuel is bent by the guide portion toward the combustion chamber. As a result, it is possible to reliably prevent the fuel from directly flowing to the exhaust port, and to form an air-fuel mixture that is easy to ignite in the vicinity of the combustion chamber, while ensuring stable ignition / combustion while allowing the fuel to flow to the exhaust port. Can be prevented.
【図１】本発明の２サイクルエンジンにおける一実施例
の縦断面図である。FIG. 1 is a vertical sectional view of an embodiment of a two-stroke engine of the present invention.
【図２】本発明の２サイクルエンジンにおける他の実施
例の縦断面図である。FIG. 2 is a vertical sectional view of another embodiment of the two-stroke engine of the present invention.
【図３】従来例の２サイクルエンジンの縦断面図であ
る。FIG. 3 is a vertical sectional view of a conventional two-cycle engine.
【図４】他の従来例の２サイクルエンジンの縦断面図で
ある。FIG. 4 is a vertical cross-sectional view of another conventional two-cycle engine.
１ シリンダ ３ 燃焼室 ５ ピストン ６ 排気ポート ９ ブースタポート（掃気ポート） １０ 燃料噴射手段 １２ ガイド曲面 １４ ガイド通路 1 Cylinder 3 Combustion Chamber 5 Piston 6 Exhaust Port 9 Booster Port (Scavenging Port) 10 Fuel Injection Means 12 Guide Curved Surface 14 Guide Passage
Claims (1)
を形成し、掃気ポートに燃料噴射手段を配設した２サイ
クルエンジンにおいて、ピストン頂部に向けて燃料を噴
出するように燃料噴射手段を配置し、ピストン頂部にお
ける燃料噴射手段から燃料を噴射される部分に、噴出さ
れた燃料を燃焼室に向けて案内するガイド部を形成した
ことを特徴とする２サイクルエンジン。1. A two-cycle engine in which a scavenging port and an exhaust port are formed on a cylinder circumferential surface, and fuel scavenging means is provided in the scavenging port, and the fuel injecting means is arranged so as to inject fuel toward the top of the piston. A two-cycle engine, characterized in that a guide portion for guiding the injected fuel toward the combustion chamber is formed at a portion of the piston top where the fuel is injected from the fuel injection means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16688793A JPH0726963A (en) | 1993-07-06 | 1993-07-06 | Two-cycle engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16688793A JPH0726963A (en) | 1993-07-06 | 1993-07-06 | Two-cycle engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0726963A true JPH0726963A (en) | 1995-01-27 |
Family
ID=15839468
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16688793A Pending JPH0726963A (en) | 1993-07-06 | 1993-07-06 | Two-cycle engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0726963A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000077359A1 (en) * | 1999-06-11 | 2000-12-21 | Hitachi, Ltd. | Cylinder injection engine and method of combusting the engine |
| WO2023162144A1 (en) * | 2022-02-25 | 2023-08-31 | 株式会社やまびこ | Air intake-type two-stroke engine |
-
1993
- 1993-07-06 JP JP16688793A patent/JPH0726963A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000077359A1 (en) * | 1999-06-11 | 2000-12-21 | Hitachi, Ltd. | Cylinder injection engine and method of combusting the engine |
| US6659075B1 (en) | 1999-06-11 | 2003-12-09 | Hitachi, Ltd. | Cylinder injection engine and method of combusting engine |
| WO2023162144A1 (en) * | 2022-02-25 | 2023-08-31 | 株式会社やまびこ | Air intake-type two-stroke engine |
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