JP2873838B2 - Exhaust suction device for internal combustion engine - Google Patents
Exhaust suction device for internal combustion engineInfo
- Publication number
- JP2873838B2 JP2873838B2 JP1262201A JP26220189A JP2873838B2 JP 2873838 B2 JP2873838 B2 JP 2873838B2 JP 1262201 A JP1262201 A JP 1262201A JP 26220189 A JP26220189 A JP 26220189A JP 2873838 B2 JP2873838 B2 JP 2873838B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust
- intake
- internal combustion
- combustion engine
- opened
- 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
Landscapes
- Characterised By The Charging Evacuation (AREA)
- Exhaust-Gas Circulating Devices (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、内燃機関の吸気行程中に排気管内の排気の
一部をシリンダに逆流させて新気に混入し、圧縮比の増
大、未燃焼物の燃焼、燃焼温度の低下等の作用を行なわ
せるようにしたい、いわゆる内部EGRに関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a technique for causing a part of exhaust gas in an exhaust pipe to flow back into a cylinder and mix with fresh air during an intake stroke of an internal combustion engine. The present invention relates to a so-called internal EGR, which is intended to perform an action such as combustion of a combusted material and a decrease in a combustion temperature.
（従来の技術） 従来の内部EGRは、吸気弁と排気弁のオーバーラップ
期間に排気管内の脈動波の正圧波を適合させて既燃ガス
をシリンダ内に逆流させているのが一般である。(Prior Art) The conventional internal EGR generally makes the burned gas flow back into the cylinder by adapting the positive pressure wave of the pulsating wave in the exhaust pipe during the overlap period between the intake valve and the exhaust valve.
（発明が解決しようとする課題） しかし、前記の従来技術においては、エンジンの中速
回転時のバルブオーバラップ時に、排気管の大きな正圧
波が作用して排気吸入量が多くなり、新気吸気量が減少
するため、有効圧縮比は増大するものの出力が低下し、
中速においてトルクが谷状に低下する傾向が見られる。(Problems to be Solved by the Invention) However, in the above-described prior art, when the engine overlaps at a middle speed of the engine, a large positive pressure wave in the exhaust pipe acts to increase the exhaust intake amount, and the fresh air intake is increased. Because the volume decreases, the effective compression ratio increases but the output decreases,
At a middle speed, the torque tends to decrease like a valley.
この不具合を解決するために本発明者等は、さきに実
開昭64−46428に示される技術を考案し、機関速度に応
じて排気管の絞りを調節して正圧波を制御し、トルク低
下現象を防止した。しかしこの技術においては、排気管
の絞り調節する機構が複雑でコスト高になる難点があ
る。In order to solve this problem, the present inventors have devised the technique described in Japanese Utility Model Application Laid-Open No. 64-46428, and controlled the positive pressure wave by adjusting the throttle of the exhaust pipe according to the engine speed to reduce the torque reduction. The phenomenon was prevented. However, in this technique, there is a problem that the mechanism for adjusting the throttle of the exhaust pipe is complicated and costly.
したがって、本発明は、前記の夫々の従来技術のもつ
難点を解決することを課題とする。Therefore, an object of the present invention is to solve the above-mentioned disadvantages of the related art.
（課題を解決するための手段） 本発明における前記課題の解決手段は、クランク軸の
回転に同期して開閉し、かつ排気終期と吸気初期にオー
バラップして開放される吸気弁及び排気弁を備え、排気
口に断面積が略一定の排気管を接続した内燃機関におい
て、排気弁は、前記オーバラップの後の吸気行程中に再
度短期間開放されるリフト機構を備え、排気管は、機関
運転中の前記リフト機構の短期間開放時に排気管内に正
圧を生じさせるための絞りを端末部に有することを特徴
とする。(Means for Solving the Problems) A means for solving the problems in the present invention is to provide an intake valve and an exhaust valve which open and close in synchronization with the rotation of a crankshaft, and which are opened by overlapping at the end of exhaust and at the beginning of intake. In an internal combustion engine in which an exhaust pipe having a substantially constant cross-sectional area is connected to an exhaust port, the exhaust valve is provided with a lift mechanism that is opened again for a short period during an intake stroke after the overlap, and the exhaust pipe is connected to the engine. A throttle for generating a positive pressure in the exhaust pipe when the lift mechanism is opened for a short time during operation is provided at a terminal portion.
（作 用） 前記の手段を備えることにより、中速時にも排気管の
絞りによってバルブオーバーラップ時に排気脈動波の負
圧波を発生させてシリンダの新気吸入量を増大させるこ
とができる。更に、全回転域で吸気行程中に排気弁を短
期間開くから、排気を正圧波により内部EGRを行なうこ
とが可能となり実圧縮比を高めることができる。(Operation) With the provision of the above-described means, a negative pressure wave of an exhaust pulsation wave can be generated at the time of valve overlap by a throttle of the exhaust pipe even at a medium speed, thereby increasing the intake amount of fresh air into the cylinder. Further, since the exhaust valve is opened for a short time during the intake stroke in the entire rotation range, the internal EGR can be performed on the exhaust by the positive pressure wave, and the actual compression ratio can be increased.
（実施例） 以下、図面を参照して本発明の実施例を説明する。第
１図は多気筒内燃機関１の縦断面図で、該内燃機関１
は、シリンダ２、ピストン３及びシリンダヘッド４で燃
焼室５を形成し、該燃焼室５に通じる吸気口６と排気口
７には、吸気弁８と排気弁９が配置され、各弁８、９
は、吸気カム10と排気カム11でクランク軸の回転に同期
して開閉される。(Example) Hereinafter, an example of the present invention is described with reference to drawings. FIG. 1 is a longitudinal sectional view of a multi-cylinder internal combustion engine 1.
A combustion chamber 5 is formed by the cylinder 2, the piston 3 and the cylinder head 4, and an intake valve 8 and an exhaust valve 9 are disposed at an intake port 6 and an exhaust port 7 communicating with the combustion chamber 5, respectively. 9
Is opened and closed by the intake cam 10 and the exhaust cam 11 in synchronization with the rotation of the crankshaft.
しかして該排気カム11には、リフト機構として通常の
排気を行なわせるためのカム面11aの他に、小カム面11b
が設けてあり、該小カム面11bによって吸気弁８が開放
する吸気行程中に短期間だけ排気弁９を開放するように
してある。Thus, the exhaust cam 11 has a small cam surface 11b in addition to the cam surface 11a for performing normal exhaust as a lift mechanism.
The exhaust valve 9 is opened only for a short time during the intake stroke in which the intake valve 8 is opened by the small cam surface 11b.
また、排気口７に接続される排気管12は、略一定の断
面積をもち、かつ端末に絞り13を備えており、他のシリ
ンダの排気管と共に合流管14の集合部15で合流しマフラ
16に連通している。機関が４気筒の場合は、第２図に示
すように４本の排気管が集合部15に集合する。The exhaust pipe 12 connected to the exhaust port 7 has a substantially constant cross-sectional area and is provided with a throttle 13 at the end.
Communicates with 16. When the engine is a four-cylinder engine, four exhaust pipes are collected in the collecting part 15 as shown in FIG.
排気口７内の圧力変動の態様は、機関速度によって異
なり、絞りのない従来の排気管12においては、高速、中
速、低速において夫々曲線A1、A2、A3のように変動し、
絞り13がある場合は、点線B1、B2、B3のように変動す
る。絞りがない場合は、IO、EC間のバルブオーバラップ
時に、高速時の曲線A1と低速時の曲線A3においては
A11、A31の如く負圧になるが、中速時における曲線A2で
はA21に示すように正圧が作用して前記のように燃焼室
５への新気の吸入が減少される。しかし、絞り13を有す
る曲線B2においては、B21に示すように負圧となって新
気の吸入を助ける。The mode of the pressure fluctuation in the exhaust port 7 varies depending on the engine speed, and in the conventional exhaust pipe 12 having no throttle, the pressure fluctuates as a curve A 1 , A 2 , A 3 at a high speed, a medium speed, and a low speed, respectively.
When the aperture 13 is present, it fluctuates as indicated by dotted lines B 1 , B 2 and B 3 . If there is no stop, IO, when the valve overlap between the EC, the curve A 1 and the curve A 3 in low speed at the time of high speed
Becomes a negative pressure as A 11, A 31, the intake of fresh air acts positive pressure is as shown in curve A 2 in A 21 at medium speed into the combustion chamber 5 as described above is reduced . However, in the curve B 2 having aperture 13, help intake of fresh air becomes negative as shown in B 21.
また、小カム面11bによって排気弁が再度開く期間ｅ
では、排気口７内は、B12、B22、B32として示すように
いずれも正圧になり、吸気負圧と共働して燃焼室５へ排
気が吸入される内部EGRが行なわれる。Further, a period e during which the exhaust valve is opened again by the small cam surface 11b.
So the inside of the exhaust port 7, both as shown as B 12, B 22, B 32 becomes positive pressure, exhaust to the combustion chamber 5 is made the internal EGR sucked in cooperation with the intake negative pressure.
（発明の効果） 以上のように、本発明においてはどの変速域において
も、バルブオーバラップ時に排気口内に負圧波が作用し
て新気の吸入を増大させることができ、また排気弁が一
旦閉じた吸気行程中に、排気カムの小カム面により排気
弁の再開放が強制的に行なわれて正圧を生じさせながら
内部EGRを行なうので、充填効率が高い上に有効圧縮比
が増大するから熱効率が高く、したがって燃費が低減す
る効果がある。更に、排気中の未燃焼分の再燃焼、燃焼
温度の低下等が行なわれて排気浄化に役立つ効果があ
る。(Effects of the Invention) As described above, in the present invention, in any shift range, a negative pressure wave acts in the exhaust port at the time of valve overlap to increase the intake of fresh air, and the exhaust valve is closed once. During the intake stroke, the exhaust cam is forcibly reopened by the small cam surface of the exhaust cam and internal EGR is performed while generating positive pressure, so the filling efficiency is high and the effective compression ratio increases. The heat efficiency is high, and thus the fuel efficiency is reduced. Further, reburning of the unburned portion in the exhaust gas, lowering of the combustion temperature, and the like are performed, which is effective in purifying the exhaust gas.
第１図は本発明の実施例の縦断面図、第２図は排気系の
略図、第３図は排気口出口における排気圧力の変動を示
すグラフである。 ７……排気口、８……吸気弁 ９……排気弁、11……排気カム 11a……排気カム面、11b……小カム面 12……排気管、13……絞りFIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is a schematic diagram of an exhaust system, and FIG. 3 is a graph showing a change in exhaust pressure at an exhaust outlet. 7 ... exhaust port, 8 ... intake valve 9 ... exhaust valve, 11 ... exhaust cam 11a ... exhaust cam surface, 11b ... small cam surface 12 ... exhaust pipe, 13 ... throttle
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) F02M 25/07 510 F02B 29/00 F02B 27/04 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 6 , DB name) F02M 25/07 510 F02B 29/00 F02B 27/04
Claims (1)
排気終期と吸気初期にオーバラップして開放される吸気
弁及び排気弁を備え、排気口に断面積が略一定の排気管
を接続した内燃機関において、排気弁は、前記オーバラ
ップの後の吸気行程中に再度短期間開放されるリフト機
構を備え、排気管は、機関運転中の前記リフト機構の短
期間開放時に排気管内に正圧を生じさせるための絞りを
端末部に有することを特徴とする内燃機関の排気吸入装
置。An exhaust pipe having an intake pipe and an exhaust valve which opens and closes in synchronization with the rotation of a crankshaft, and is opened at the end of exhaust and at the beginning of intake so as to overlap with each other, and has a substantially constant cross-sectional area at an exhaust port. In the connected internal combustion engine, the exhaust valve includes a lift mechanism that is opened again for a short time during the intake stroke after the overlap, and the exhaust pipe is placed in the exhaust pipe when the lift mechanism is opened for a short time during engine operation. An exhaust suction device for an internal combustion engine, comprising a throttle at a terminal portion for generating a positive pressure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1262201A JP2873838B2 (en) | 1989-10-09 | 1989-10-09 | Exhaust suction device for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1262201A JP2873838B2 (en) | 1989-10-09 | 1989-10-09 | Exhaust suction device for internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03124951A JPH03124951A (en) | 1991-05-28 |
| JP2873838B2 true JP2873838B2 (en) | 1999-03-24 |
Family
ID=17372486
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1262201A Expired - Fee Related JP2873838B2 (en) | 1989-10-09 | 1989-10-09 | Exhaust suction device for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2873838B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6102874B2 (en) * | 2014-09-26 | 2017-03-29 | マツダ株式会社 | Exhaust system for multi-cylinder engine |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01127933U (en) * | 1988-02-25 | 1989-08-31 |
-
1989
- 1989-10-09 JP JP1262201A patent/JP2873838B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03124951A (en) | 1991-05-28 |
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