JPH0781538B2 - 2-cycle engine cylinder - Google Patents
2-cycle engine cylinderInfo
- Publication number
- JPH0781538B2 JPH0781538B2 JP60239485A JP23948585A JPH0781538B2 JP H0781538 B2 JPH0781538 B2 JP H0781538B2 JP 60239485 A JP60239485 A JP 60239485A JP 23948585 A JP23948585 A JP 23948585A JP H0781538 B2 JPH0781538 B2 JP H0781538B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust port
- sleeve
- exhaust
- upper edge
- cycle engine
- 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 - Fee Related
Links
Classifications
-
- 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
- F02F1/18—Other cylinders
- F02F1/22—Other cylinders characterised by having ports in cylinder wall for scavenging or charging
-
- 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
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)
Description
【発明の詳細な説明】 〔発明の技術分野〕 この発明は、２サイクルエンジンのシリンダに関する。Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a cylinder of a two-cycle engine.
〔従来の技術〕 第３図に一部の縦断面を示すように、シリンダバレル１
にスリーブ２が圧入されて構成される２サイクルエンジ
ンのシリンダにおいては、排気ポート３がシリンダバレ
ル１からスリーブ２にわたって設けられるが、従来の排
気ポート３の形状は、シリンダバレル１とスリーブ２の
角度が同一であり、排気タイミングを早くまたは遅くす
るためにはシリンダバレル１の排気ポート寸法をそれぞ
れ変えることによって対処していた。そのため排気タイ
ミングを早める高速回転型エンジンと、排気タイミング
を遅めに設定する低速回転型エンジンとの各仕様に合せ
てシリンダバレル１を変えなければならず、シリンダバ
レルの共通化が図れず、コストアップを招いていた。[Prior Art] As shown in a partial vertical cross section in FIG.
In a cylinder of a two-cycle engine in which the sleeve 2 is press-fitted into the cylinder, the exhaust port 3 is provided from the cylinder barrel 1 to the sleeve 2. However, the conventional exhaust port 3 has a shape in which the angle between the cylinder barrel 1 and the sleeve 2 is set. However, in order to speed up or slow down the exhaust timing, the size of the exhaust port of the cylinder barrel 1 is changed. Therefore, the cylinder barrel 1 has to be changed according to the specifications of the high-speed rotation type engine that accelerates the exhaust timing and the low-speed rotation type engine that sets the exhaust timing later, and the cylinder barrel cannot be shared, resulting in cost reduction. I was invited up.
また、特開昭56−47642号公報には２サイクルエンジン
のシリンダが開示されており、このシリンダでは排気ポ
ートに面取りを行なうことによって高速回転域に適合さ
れた２サイクルエンジンが示されている。Further, Japanese Unexamined Patent Publication No. 56-47642 discloses a cylinder of a two-cycle engine, and in this cylinder, a two-cycle engine adapted to a high speed rotation range by chamfering an exhaust port is shown.
従来の２サイクルエンジンにおいては、シリンダのスリ
ーブに形成される排気ポートの上縁は、スリーブ外側よ
りスリーブ内側が高くなるように面取部を形成したシリ
ンダが知られているが、その面取部は排気ポート上縁中
心部に形成したものや、排気ポート上縁部の全幅に亘っ
て面取部を一様に形成したものがある。In a conventional two-cycle engine, a cylinder is known in which a chamfered portion is formed so that the upper edge of an exhaust port formed in the sleeve of the cylinder is higher inside the sleeve than outside the sleeve. Include those formed at the center of the upper edge of the exhaust port, and those in which the chamfered portion is formed uniformly over the entire width of the upper edge of the exhaust port.
また、排気ポートの上縁部全幅に亘って面取部を一様に
形成した２サイクルエンジンのシリンダでも排気ポート
の開口面積の増大が図れるが、高速回転型エンジンとし
て必ずしも充分ではなかったり、また、面取部を排気ポ
ートの幅方向全幅に亘って一様に形成しても、排気直後
の実質的な排気量の増大に充分に寄与しないため、ガス
交換がスムーズに行なわれず、出力性能の向上が期待し
た程得られない問題があった。Further, the opening area of the exhaust port can be increased even in a cylinder of a two-cycle engine in which the chamfered portion is uniformly formed over the entire width of the upper edge of the exhaust port, but this is not always sufficient as a high-speed engine. Even if the chamfered portion is formed uniformly over the entire width in the width direction of the exhaust port, it does not sufficiently contribute to the substantial increase in the exhaust amount immediately after exhaust, so that gas exchange is not performed smoothly and output performance is improved. There was a problem that improvement was not obtained as expected.
一方、排気直後の実質的な排気量の増大は、排気ポート
の開口幅（左右幅）を増大させれば達成できるが、排気
ポートの開口幅の増大はピストンリングの引っ掛かりを
生じさせ、ピストンの円滑かつ滑かな摺動を阻害させる
要因となっている。On the other hand, a substantial increase in the exhaust amount immediately after exhaust can be achieved by increasing the opening width (horizontal width) of the exhaust port, but increasing the opening width of the exhaust port causes the piston ring to be caught, and This is a factor that hinders smooth and smooth sliding.
本発明は、上述した事情を考慮してなされたもので、排
気ポート上縁部に形成される面取部を工夫することで、
高速回転型エンジンに適し、排気直後の実質的な排気量
を増大させて排気ガスを迅速かつスムーズに排気させ、
エンジン排気工程時のガス交換を効率よく行ない、出力
性能の向上を一層図る一方、ピストンの円滑な摺動を保
証できる２サイクルエンジンのシリンダを提供すること
を目的とする。The present invention has been made in consideration of the above circumstances, and by devising the chamfered portion formed at the upper edge of the exhaust port,
Suitable for high-speed rotation type engine, increase the substantial displacement immediately after exhaust to exhaust exhaust gas quickly and smoothly,
An object of the present invention is to provide a cylinder of a two-cycle engine that can efficiently perform gas exchange during an engine exhaust process and further improve output performance, while ensuring smooth sliding of a piston.
本発明に係る２サイクルエンジンのシリンダは、上述し
た目的を達成するために、シリンダバレルにスリーブを
圧入してなる２サイクルエンジンにおいて、シリンダバ
レルに設けられている排気ポートにスリーブの排気ポー
トを連通させ、上記スリーブの排気ポートの上縁部にス
リーブ外側よりスリーブ内側が高くなるように排気ポー
ト全幅にわたって斜めに傾斜した面取部を形成し、この
面取部はスリーブ内側の上縁をスリーブ外側の上縁より
平坦に形成することにより、上記面取部の面積を排気ポ
ート上縁部中央より両側に向って増大させたものであ
る。In order to achieve the above-mentioned object, a cylinder of a two-cycle engine according to the present invention is a two-cycle engine in which a sleeve is press-fitted into a cylinder barrel, and an exhaust port of the sleeve communicates with an exhaust port provided in the cylinder barrel. The chamfered part is formed at the upper edge of the exhaust port of the sleeve so that the inner side of the sleeve is higher than the outer side of the sleeve. By forming the chamfered portion to be flatter than the upper edge of the exhaust port, the area of the chamfered portion is increased toward both sides from the center of the upper edge portion of the exhaust port.
この２サイクルエンジンのシリンダは、シリンダを構成
するシリンダバレルとスリーブに設けられる排気ポート
を連通させ、スリーブの排気ポートの上縁部にその全幅
に亘ってスリーブ外側よりスリーブの内側が高くなるよ
うに斜めに傾斜した面取部を形成し、この面取部の面積
は排気ポート上縁部中央より両側に向って増大させたの
で、排気ポート両側コーナ部のポート開口面積を増大さ
せることができ、排気直後における実質的な排気量を増
加させることができる。このため、排気直後に排気ガス
を迅速かつスムーズに排出させることができてガス交換
が良好に行なわれ、出力性能の向上が図れ、高速回転型
エンジンに適したものとなる。In the cylinder of this two-cycle engine, the cylinder barrel that constitutes the cylinder and the exhaust port provided in the sleeve communicate with each other, and the inside of the sleeve is higher than the outside of the sleeve over the entire width of the upper edge of the exhaust port of the sleeve. Since a chamfered portion that is inclined obliquely is formed and the area of this chamfered portion is increased toward both sides from the center of the upper edge of the exhaust port, it is possible to increase the port opening area of the corner portions on both sides of the exhaust port. It is possible to increase the substantial exhaust amount immediately after exhaust. Therefore, the exhaust gas can be discharged quickly and smoothly immediately after the exhaust, the gas can be exchanged favorably, the output performance can be improved, and the engine is suitable for the high-speed rotation type engine.
排気ポートの開口面積を増大させても、排気ポートの
（左右）開口幅を増大させることがないので、ピストン
リングの引っ掛かりを防止でき、ピストンの円滑な摺動
を保証することができる。排気ポートの開口面積の増加
の割に、排気ポートの（左右）幅を増大させることがな
い。Even if the opening area of the exhaust port is increased, the (left and right) opening width of the exhaust port is not increased, so that the piston ring can be prevented from being caught and the smooth sliding of the piston can be guaranteed. The (left and right) width of the exhaust port is not increased in spite of the increase in the opening area of the exhaust port.
以下この発明の実施例を第１図および第２図により、第
３図と共通する部材には同一符号を用いて説明する。An embodiment of the present invention will be described below with reference to FIGS. 1 and 2 by using the same reference numerals for members common to those in FIG.
第１図は高速回転型２サイクルエンジンの場合を示して
おり、この２サイクルエンジンのシリンダはシリンダバ
レル１内にスリーブ２を嵌合させて一体的に構成され
る。FIG. 1 shows the case of a high-speed rotation type two-cycle engine. The cylinder of this two-cycle engine is integrally formed by fitting a sleeve 2 in a cylinder barrel 1.
高速回転型エンジンの場合は、第２図（Ａ）にそのスリ
ーブ２に開口する矩形状の排気ポート３の拡大正面を、
第２図（Ｂ）に排気ポート３の断面をそれぞれ示す。ス
リーブ２の排気ポート３の上縁3Aが角度αをもってスリ
ーブ外側よりスリーブ内側が高くなるように上向きに斜
めに面取りされた面取部４が形成されている。この面取
部４はぼほ矩形の排気ポートの全幅にわたって形成さ
れ、第２図（Ａ）に示すように面取部４はスリーブ内側
の上縁3Aがスリーブ外側の上縁より平坦に形成されるこ
とにより、面取部４の面積は中央部より両側に行くに従
って増大するように形成されている。スリーブ２の排気
ポート３はシリンダバレル１の排気ポートになめらかに
連通している。In the case of a high-speed rotary engine, the enlarged front view of the rectangular exhaust port 3 opening in the sleeve 2 is shown in FIG.
FIG. 2B shows a cross section of the exhaust port 3. An upper edge 3A of the exhaust port 3 of the sleeve 2 has a chamfered portion 4 which is chamfered upward at an angle α so that the inside of the sleeve is higher than the outside of the sleeve. The chamfered portion 4 is formed over the entire width of the exhaust port having a rectangular shape. As shown in FIG. 2 (A), the chamfered portion 4 is formed such that the upper edge 3A inside the sleeve is flatter than the upper edge outside the sleeve. As a result, the area of the chamfered portion 4 is formed so as to increase from the central portion toward both sides. The exhaust port 3 of the sleeve 2 smoothly communicates with the exhaust port of the cylinder barrel 1.
したがって、この２サイクルエンジンのシリンダによれ
ば、ピストンの排気行程時におけるガスの交換が上向き
の面取部４が排気ポート３の全幅にわたって形成され、
面取部４の面積は中央部より両側に行くに従って増大さ
せたので、排気ポート３の幅方向両側コーナ部のポート
開口面積を増大させることができ、排気ガスの排気をス
ムーズにかつ迅速に行なうことができる。排気ポート３
の上縁3A部に面取部を形成することにより、排気タイミ
ングが早くなるため高回転域での出力を増大させること
ができ、スポーツ型車輌に適する高速回転型２サイクル
エンジンとなる。Therefore, according to the cylinder of the two-cycle engine, the chamfered portion 4 for upwardly exchanging gas during the exhaust stroke of the piston is formed over the entire width of the exhaust port 3,
Since the area of the chamfered portion 4 is increased from the central portion toward both sides, the port opening area of the corner portions on both sides in the width direction of the exhaust port 3 can be increased, and the exhaust gas can be exhausted smoothly and quickly. be able to. Exhaust port 3
By forming the chamfered portion on the upper edge 3A portion, the exhaust timing becomes earlier, so that the output in the high rotation speed range can be increased, and the high-speed rotation type two-cycle engine suitable for the sports type vehicle can be obtained.
このように高速回転型エンジンにおいてシリンダバレル
１に圧入されるスリーブ２の排気ポート３の上縁形状を
上向き傾斜の面取部４を付加することにより、その面取
部４の傾斜方向に選択するだけで高速回転型エンジンの
仕様に対応することができる。Thus, in the high-speed rotary engine, the upper edge shape of the exhaust port 3 of the sleeve 2 that is press-fitted into the cylinder barrel 1 is selected in the inclination direction of the chamfered portion 4 by adding the chamfered portion 4 that is inclined upward. It is possible to meet the specifications of a high-speed rotation type engine alone.
以上説明したように発明においては、シリンダバレルに
スリーブを圧入してなる２サイクルエンジンにおいて、
シリンダバレルに設けられる排気ポートにスリーブの排
気ポートを連通させ、上記スリーブの排気ポートの上縁
部にスリーブ外側よりスリーブ内側が高くなるように排
気ポート全幅にわたって斜めに傾斜した面取部を形成
し、この面取部はスリーブ内側の上縁がスリーブ外側の
上縁より平坦に形成されることにより、上記面取部の面
積を排気ポート上縁部中央より両側に向った増大させた
ので、排気ポートの幅方向両側コーナ部のポート開口面
積を増大させた高速型２サイクルエンジンとすることが
でき、排気直後の状態で実質的な排気量が増大し、排気
ガスを迅速かつスムーズに排出させることができ、エン
ジンの排気工程時のガス交換が量的に円滑かつ良好とな
り、エンジンの出力性能の向上を一層図ることができ
る。As described above, in the invention, in the two-cycle engine in which the sleeve is press-fitted into the cylinder barrel,
The exhaust port of the sleeve is communicated with the exhaust port provided in the cylinder barrel, and a chamfered portion that is obliquely inclined over the entire width of the exhaust port is formed at the upper edge of the exhaust port of the sleeve so that the inside of the sleeve is higher than the outside of the sleeve. Since the chamfered portion is formed so that the upper edge of the inside of the sleeve is flatter than the upper edge of the outer side of the sleeve, the area of the chamfered portion is increased toward both sides from the center of the upper edge of the exhaust port. A high-speed two-cycle engine with an increased port opening area at both corners in the width direction of the port can be achieved, and the substantial amount of exhaust gas increases immediately after exhaust, and exhaust gas can be discharged quickly and smoothly. As a result, the gas exchange in the exhaust process of the engine becomes quantitatively smooth and favorable, and the output performance of the engine can be further improved.
排気ポートの上縁部に形成される面取部の面積を両側に
向って増大させると、排気ポートの幅方向両側コーナ部
をポート開口面積として有効に活用でき、排気ポートの
開口幅を増大させなくても、増大させるものと等価とな
る。排気ポート開口幅の増大には限界があるが、本発明
でき、排気ポートの開口面積の実質的な増加の割には排
気ポートの開口幅を増大させなくてよいから、ピストン
リングの引っ掛かりを有効的に防止でき、ピストンの円
滑な摺動を保証することができる。By increasing the area of the chamfer formed at the upper edge of the exhaust port toward both sides, the corners on both sides in the width direction of the exhaust port can be effectively used as the port opening area, and the opening width of the exhaust port can be increased. Even without it, it is equivalent to increasing. Although there is a limit to the increase in the exhaust port opening width, the present invention can be applied, and since the exhaust port opening width does not have to be increased for the substantial increase in the exhaust port opening area, the piston ring is effectively caught. Therefore, the smooth sliding of the piston can be guaranteed.
第１図はこの発明の高速回転型エンジンとした場合の一
実施例を示す縦断面図、第２図（Ａ）は第１図における
スリーブに開口する排気ポートの拡大正面図、第２図
（Ｂ）はスリーブの排気ポートの断面図、第３図は従来
のエンジンのシリンダを示す一部の断面図である。 １……シリンダバレル、２……スリーブ、３……排気ポ
ート、3A……排気ポートの上縁、４……面取部。FIG. 1 is a longitudinal sectional view showing an embodiment of the high-speed engine of the present invention, FIG. 2 (A) is an enlarged front view of an exhaust port opening in a sleeve in FIG. 1, and FIG. B) is a sectional view of the exhaust port of the sleeve, and FIG. 3 is a partial sectional view showing a cylinder of a conventional engine. 1 ... Cylinder barrel, 2 ... Sleeve, 3 ... Exhaust port, 3A ... Upper edge of exhaust port, 4 ... Chamfer.
Claims (1)
２サイクルエンジンにおいて、シリンダバレルに設けら
れる排気ポートにスリーブの排気ポートを連通させ、上
記スリーブの排気ポートの上縁部にスリーブ外側よりス
リーブ内側が高くなるように排気ポート全幅にわたって
斜めに傾斜した面取部を形成し、この面取部はスリーブ
内側の上縁をスリーブ外側の上縁より平坦に形成するこ
とにより、上記面取部の面積を排気ポート上縁部中央よ
り両側に向って増大させたことを特徴とする２サイクル
エンジンのシリンダ。1. In a two-cycle engine having a sleeve press-fitted into a cylinder barrel, an exhaust port of the sleeve is communicated with an exhaust port provided in the cylinder barrel, and an upper edge portion of the exhaust port of the sleeve is inside the sleeve from outside the sleeve. The chamfered portion is formed so as to be inclined over the entire width of the exhaust port so that the height of the chamfered portion becomes larger. Is increased from the center of the upper edge of the exhaust port toward both sides, and is a cylinder of a two-cycle engine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60239485A JPH0781538B2 (en) | 1985-10-28 | 1985-10-28 | 2-cycle engine cylinder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60239485A JPH0781538B2 (en) | 1985-10-28 | 1985-10-28 | 2-cycle engine cylinder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6299660A JPS6299660A (en) | 1987-05-09 |
| JPH0781538B2 true JPH0781538B2 (en) | 1995-08-30 |
Family
ID=17045476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60239485A Expired - Fee Related JPH0781538B2 (en) | 1985-10-28 | 1985-10-28 | 2-cycle engine cylinder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0781538B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT402323B (en) * | 1992-01-16 | 1997-04-25 | Avl Verbrennungskraft Messtech | TWO-STROKE INTERNAL COMBUSTION ENGINE |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS527486A (en) * | 1975-07-04 | 1977-01-20 | Agency Of Ind Science & Technol | Preparation of high-purity maltose |
| JPS5647642A (en) * | 1979-09-27 | 1981-04-30 | Yamaha Motor Co Ltd | Two-cycle engine |
| JPS5728843A (en) * | 1980-07-29 | 1982-02-16 | Sanshin Ind Co Ltd | Cylinder block for two-cycle internal combustion engine |
-
1985
- 1985-10-28 JP JP60239485A patent/JPH0781538B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6299660A (en) | 1987-05-09 |
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| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |