JPS61283720A - Suction device for diesel engine - Google Patents

Abstract

PURPOSE:To improve the operation of an engine so better, by operating it even in a case other than at the time of starting excepting acceleration, in case of the engine that installs an on-off valve in a suction pipe of a Diesel engine and closes it at the time of starting, while supplies bypass air to the downstream of this on-off valve when the suction valve opens and its pressure is more than the specified suction pressure. CONSTITUTION:An on-off valve 7 is installed in a suction pipe 6a of a Diesel engine, and a control circuit 25 opens or closes a valve 24 by various driving parameters 26-29 of the engine, then the on-off valve 7 is opened or closed by operation of an actuator 21. A passage 6b, which inhales air by bypassing the on-off valve 7, is installed in the downstream of the on-off valve 7, in the midway in this passage, there is provided with a suction operating valve 10, and when the on-off valve 7 is closed and the specified suction pressure is produced as a suction valve 4 opens, the suction pressure operating valve suddenly opens, performing quick suction into a cylinder 3, thereby causing a temperature rise by adiabatic compression. The on-off valve 7 is operated not only at starting but also in an optional engine driving state, but is not closed at acceleration.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明はディーゼルエンジンの始動促進およびエミッシ
ョンの改善のため、断熱圧縮により吸気温度を上昇させ
るようにした吸気装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake device that increases intake air temperature by adiabatic compression in order to promote starting of a diesel engine and improve emissions.

（ｉ来技術） 従来、実開昭５９−１０７９３６号公報に示されるよう
に、ディーゼルエンジンにおいて始動時に着火性を高め
るため、燃焼室に供給する吸気を断熱圧縮して吸気温度
を上昇させるようにした吸気＠置（始動促進装Ｎ）が知
られている。この装置は、吸気通路に吸気行程の途中で
開作動する開閉弁を設け、具体的には主吸気通路に吸気
絞り弁を設けるとともに、この吸気絞り弁を迂回するバ
イパス吸気通路に開閉弁を設け、始動時から＠機構まで
の低負荷運転状態時に、吸気絞り弁により主吸気通路を
絞った状態で、上記開閉弁を動弁機構あるいは圧力応動
式のＩＦｌｒ１１弁等により吸気行程の途中で開作動さ
せるようにしている。そしてこのような開閉弁の作動に
より、吸気行程の途中までは燃焼室への吸気の導入を制
限し、吸気行程の途中から急激に燃焼室に吸気を導入し
て断熱圧縮を行わせている。この装置によると、エアヒ
ータによって吸気を加熱する場合と比べ、多大のエネル
ギーが電力として消費されることがなく、しかも燃焼室
内で効率良く吸気温度を高めることができる。(i) Previous technology As shown in Japanese Utility Model Application Publication No. 59-107936, in order to improve ignitability when starting a diesel engine, intake air supplied to the combustion chamber is adiabatically compressed to increase the intake air temperature. An intake @ position (starting promotion device N) is known. This device has an on-off valve in the intake passage that opens during the intake stroke. Specifically, an intake throttle valve is provided in the main intake passage, and an on-off valve is provided in the bypass intake passage that bypasses the intake throttle valve. During low-load operation from startup to @mechanism, with the main intake passage throttled by the intake throttle valve, the above-mentioned on-off valve is opened during the intake stroke by the valve mechanism or pressure-responsive IFLr11 valve, etc. I try to let them do it. The operation of the on-off valve restricts the intake air into the combustion chamber until the middle of the intake stroke, and rapidly introduces the intake air into the combustion chamber from the middle of the intake stroke to perform adiabatic compression. According to this device, compared to the case where intake air is heated by an air heater, a large amount of energy is not consumed as electric power, and moreover, the intake air temperature can be efficiently raised in the combustion chamber.

ところで、上記従来の装置は、始動促進のため始動暖機
運転時にのみ上記開閉弁を作動させているが、始ｅａ機
後の通常運転時でも、燃焼温度が低いと排気中に白煙や
未燃焼成分であるＨＣ，ＧＯが発生し易くなるので、上
記開閉弁の作動による断熱圧縮を利用して燃焼温度を上
昇させれば、排気中のＨＣ等の低減に有効なものとなる
。そして、このように開閉弁１０を作動させると吸気導
入が規制されることにより多少は充ａｍが低下する可能
性があるが、ディーゼルエンジンにおいて通常運転時、
本来的に空気過剰率が大きい運転状態にあるので吸気不
足が生じることはなく、良好に燃焼が行われる。ところ
が、加速時には、燃料が増員されるのに伴って多量の吸
気が必要となり、吸気不足が生じると燃料のオーバーリ
ッチによりスモークが発生し易くなるとともに、出力が
低下するため、できるだけ充填量を高めたいという要求
がある。By the way, in the conventional device described above, the on-off valve is operated only during the startup warm-up operation to promote startup, but even during normal operation after the first EA engine, white smoke and non-smoking may occur in the exhaust if the combustion temperature is low. Since HC and GO, which are combustion components, are more likely to be generated, increasing the combustion temperature by utilizing adiabatic compression by the operation of the on-off valve will be effective in reducing HC, etc. in the exhaust gas. When the on-off valve 10 is operated in this way, the intake air intake may be regulated and the charging amount may decrease to some extent, but during normal operation of the diesel engine,
Since the engine is in an operating state where the excess air ratio is inherently large, there is no shortage of intake air, and combustion is performed well. However, when accelerating, a large amount of intake air is required as the fuel is increased, and if insufficient intake air occurs, smoke is likely to occur due to over-rich fuel, and the output will decrease, so the amount of filling should be increased as much as possible. There is a request to do so.

（発明の目的） 本発明はこのような事情に鑑み、吸気の断熱圧縮を利用
して定常運転時等に排気中の白煙やＨＣ等を低減すると
ともに、加速時にスモークの発生を防止し、加速性能を
良好にすることのできるディーゼルエンジンの吸気装置
を提供するものである。(Objective of the Invention) In view of these circumstances, the present invention uses adiabatic compression of intake air to reduce white smoke, HC, etc. in exhaust during steady operation, and also prevents smoke from occurring during acceleration. The present invention provides an intake device for a diesel engine that can improve acceleration performance.

（発明の構成） 本発明は、吸気通路に開閉弁を設け、吸気行程途中まで
は上記開閉弁を閉状態として燃焼室への吸気の導入を制
限し、吸気行程途中で上記開閉弁を開くことにより急激
に吸気を燃焼室に導入して断熱圧縮を行なわせる吸気導
入規制装置を備えたディーゼルエンジンの吸気装置にお
いて、エンジンの加速状態を検出する加速検出手段と、
この加速検出手段の出力に応じ、加速時に上記開閉弁の
作動による吸気導入の規制を解除する方向に上記吸気導
入規制装置を制御する制御手段とを設けたものである。(Structure of the Invention) The present invention provides an on-off valve in the intake passage, closes the on-off valve until the middle of the intake stroke to restrict the introduction of intake air into the combustion chamber, and opens the on-off valve during the intake stroke. In an intake system for a diesel engine equipped with an intake air introduction regulating device that rapidly introduces intake air into a combustion chamber to perform adiabatic compression, an acceleration detection means for detecting an acceleration state of the engine;
A control means is provided for controlling the intake air introduction restriction device in a direction to release the restriction on intake air introduction caused by the operation of the opening/closing valve during acceleration according to the output of the acceleration detection means.

つまり、充填量が多少低下しても支障がない定常運転時
等には開閉弁を作動させて吸気の断熱圧縮が行われるよ
うに吸気導入を規制するが、加速時には吸気導入の規制
を解除する方向に制御することによって充＠恐を確保す
るようにしたものである。In other words, during steady operation where there is no problem even if the filling amount decreases to some extent, the on-off valve is activated to restrict the intake air intake so that adiabatic compression of the intake air is performed, but during acceleration the intake air intake restriction is released. It is designed to ensure fullness by controlling the direction.

（実施例） 第１図乃至第３図は本発明の第１実施例を示す。(Example) 1 to 3 show a first embodiment of the present invention.

これらの図において、１はディーゼルエンジンの各シリ
ンダであって、その内部のピストン２上方には燃焼室３
が形成されており、この燃焼室３には、吸気弁４を備え
た吸気ボート５と、排気弁を備えた排気ボート（図示せ
ず）とが開口している。In these figures, 1 is each cylinder of a diesel engine, and a combustion chamber 3 is located above a piston 2 inside the cylinder.
An intake boat 5 having an intake valve 4 and an exhaust boat (not shown) having an exhaust valve open into the combustion chamber 3.

上記吸気ボート５に連通ずる吸気通路６には、開閉弁１
０によって吸気行程途中までは燃焼室３への吸気の導入
を制限し、吸気行程途中から急激に吸気を燃焼室３に導
入して断熱圧縮を行わせる吸気導入規制装置が設けられ
ている。この吸気導入規制装置は、当実施例では主吸気
通路６ａと、下流端が主吸気通路６ａに開口するＲ１吸
気通路６ｂとからなる吸気通路６が各シリンダ１別に形
成され、かつ、主吸気通路６ａの副吸気通路６ｂ間ロ位
置より上流に吸気絞り弁７が設けられるとともに、吸気
絞り弁７によって主吸気通路６ａが絞られているときに
圧力変化に応じて吸気行程途中で開く自動弁タイプの開
閉弁１０が上記副吸気通路６ｂに設けられていることに
より構成されている。An on-off valve 1 is provided in the intake passage 6 communicating with the intake boat 5.
0 restricts the introduction of intake air into the combustion chamber 3 until the middle of the intake stroke, and suddenly introduces the intake air into the combustion chamber 3 from the middle of the intake stroke to perform adiabatic compression. In this embodiment, the intake passage 6 is formed separately for each cylinder 1, and includes a main intake passage 6a and an R1 intake passage 6b whose downstream end opens into the main intake passage 6a. An automatic valve type in which an intake throttle valve 7 is provided upstream from the auxiliary intake passage 6b position of 6a, and opens in the middle of the intake stroke in response to pressure changes when the main intake passage 6a is throttled by the intake throttle valve 7. An on-off valve 10 is provided in the sub-intake passage 6b.

なお、上記主吸気通路６ａおよび副吸気通路６ｂはそれ
ぞれサージタンク８，９を介して図外のエアクリーナに
接続されている。The main intake passage 6a and the auxiliary intake passage 6b are connected to an air cleaner (not shown) via surge tanks 8 and 9, respectively.

上記開閉弁１０は、副吸気通路６ｂのサージタンク９へ
の開口部に配置されており、弁室１１内に設けられて弁
座１２に上流側から当接する弁体１３と、この弁体１３
に連結軸１４を介して連結されたダイヤフラム１５と、
このダイヤフラム１５により仕切られた２つの室１６．
１７と、その一方の室１６内に設けられて弁体１３を量
弁方向に付勢するリターンスプリング１８とを備えてい
る。そして上記一方の室１６は弁体１３、連結軸１４お
よびダイヤフラム１５を貫通した連通孔１９を介して弁
体１３より下流の副吸気通路６ｂに連通し、他方の室１
７はサージタンク９に連通してほぼ大気圧に保たれてい
る。この構造によると、弁体１３より下流の副吸気通路
６ｂ内に負圧が生じたとき、その負圧が上記一方の室１
６に導入されて両室１６．１７の圧力差により弁体１３
を開く方向の力がダイヤフラム１５に作用する一方、弁
体１３自体に加わる圧力およびリターンスプリング１８
のバネ力は抵抗力となり、かつ、弁体１３が開かれると
弁体１３自体に作用する負圧力は小さくなる。従って、
ダイヤフラム１５および弁体１３の受圧面積を適度に設
定し、かつリターンスプリング１８のバネ力を比較的小
さくしておくことにより、吸気絞り弁７により主吸気通
路６ａが絞られている状態では、燃焼室３内およびこれ
に連通ずる副吸気通路６ｂ下流側に生じる負圧が所定値
以上となる吸気行程途中で弁体１３が開かれ、逆に負圧
が充分に小さくなった時点で弁体１３が閉じられる。他
方、吸気絞り弁７が開かれている状態では、殆ど吸気負
圧が生じないので開閉弁１０の作動が停止され、っまり
閉弁状態に保たれる。なお、上記弁座１２を制振鋼板ま
たはプラスチックで形成するとともに、サージタンク９
の内面に吸音材を装着しておけば、開閉弁１０の作動中
の騒音を低減することができる。The on-off valve 10 is arranged at the opening of the auxiliary intake passage 6b to the surge tank 9, and includes a valve body 13 provided in the valve chamber 11 and abutting the valve seat 12 from the upstream side.
a diaphragm 15 connected to via a connecting shaft 14;
Two chambers 16 separated by this diaphragm 15.
17, and a return spring 18 which is provided in one of the chambers 16 and biases the valve body 13 in the direction of the valve. The one chamber 16 communicates with the auxiliary intake passage 6b downstream of the valve body 13 through a communication hole 19 passing through the valve body 13, the connecting shaft 14, and the diaphragm 15, and the other chamber 1
7 communicates with a surge tank 9 and is maintained at approximately atmospheric pressure. According to this structure, when negative pressure is generated in the auxiliary intake passage 6b downstream of the valve body 13, the negative pressure is transferred to the one chamber 1.
6 and due to the pressure difference between the two chambers 16 and 17, the valve body 13
While the force in the opening direction acts on the diaphragm 15, the pressure on the valve body 13 itself and the return spring 18
The spring force becomes a resistance force, and when the valve body 13 is opened, the negative pressure acting on the valve body 13 itself becomes smaller. Therefore,
By setting the pressure-receiving areas of the diaphragm 15 and the valve body 13 appropriately and keeping the spring force of the return spring 18 relatively small, when the main intake passage 6a is throttled by the intake throttle valve 7, combustion is prevented. The valve body 13 is opened during the intake stroke when the negative pressure generated in the chamber 3 and the downstream side of the auxiliary intake passage 6b communicating therewith exceeds a predetermined value, and conversely, the valve body 13 is opened when the negative pressure becomes sufficiently small. is closed. On the other hand, when the intake throttle valve 7 is open, almost no intake negative pressure is generated, so the operation of the on-off valve 10 is stopped and the valve is kept completely closed. Note that the valve seat 12 is formed of a damping steel plate or plastic, and the surge tank 9 is
If a sound absorbing material is attached to the inner surface of the opening/closing valve 10, noise during operation of the on-off valve 10 can be reduced.

上記主吸気通路６ａに設けられた吸気絞り弁７はアクチ
ュエータ２１に連結されている。このアクチュエータ２
１は例えばダイヤフラム装置により形成され、通路２２
を介して真空ポンプ２３に接続されており、上記通路２
２中には、アクチュエータ２１に真空ポンプ２３がら負
圧を導入する状態と大気を導入する状態とに切替える切
替弁２４が設けられている。そして、アクチュエータ２
１に大気圧が導入されているときは吸気絞り弁７が小開
度に閉じられ、真空ポンプ２３がら負圧が導入されたと
きは吸気絞り弁７が開かれるようにしている。これらア
クチュエータ２１、通路２２、真空ポンプ２３および切
替弁２４により、主吸気通路６ａを絞ってｌ１ＩＩ３Ｊ
１弁１０を作動させる開閉弁作動状態と、主吸気通路６
ａを開通させて開閉弁１０の作動機能を停止させる作動
停止状態とに切替可能な駆動手段が構成されている。An intake throttle valve 7 provided in the main intake passage 6a is connected to an actuator 21. This actuator 2
1 is formed, for example, by a diaphragm device, and the passage 22
It is connected to the vacuum pump 23 via the passage 2.
A switching valve 24 is provided in the actuator 21 to switch between a state in which negative pressure is introduced from the vacuum pump 23 and a state in which atmospheric air is introduced into the actuator 21. And actuator 2
When atmospheric pressure is introduced into the vacuum pump 1, the intake throttle valve 7 is closed to a small opening, and when negative pressure is introduced from the vacuum pump 23, the intake throttle valve 7 is opened. These actuator 21, passage 22, vacuum pump 23 and switching valve 24 throttle the main intake passage 6a and
1 valve 10 operating state and main intake passage 6
A driving means is configured that can be switched to an operation stop state in which the operation function of the on-off valve 10 is stopped by opening the on-off valve 10.

また、上記吸気絞り弁７は、仝閉状態でも主吸気通路６
ａを完全密閉Ｖずに多少は吸気を燃焼室３にリークさせ
るようになっており、このようにしているのは、吸気行
程で開閉弁１０が開かれるまでの間に断熱膨張で吸気温
度が低下することを防止するためである。Further, the intake throttle valve 7 does not close to the main intake passage 6 even in the closed state.
A is not completely sealed, but some intake air is allowed to leak into the combustion chamber 3.The reason for this is that the intake air temperature rises due to adiabatic expansion before the on-off valve 10 is opened during the intake stroke. This is to prevent the temperature from decreasing.

なお、クランキング等の極低回転域では、ピストンリン
グまわりからのリーク割合が多くなり、開閉弁１０の作
動時期の精度が低下するため、吸気絞り弁７の弁軸を中
心よりオフセットさせて、主吸気通路６ａの内壁と吸気
絞り弁７との密着性を高め、吸気絞り弁７まわりのリー
ク割合を低減させてもよい。In addition, in extremely low speed ranges such as during cranking, the leakage rate from around the piston rings increases and the accuracy of the operating timing of the on-off valve 10 decreases, so the valve shaft of the intake throttle valve 7 is offset from the center. The leakage rate around the intake throttle valve 7 may be reduced by increasing the adhesion between the inner wall of the main intake passage 6a and the intake throttle valve 7.

２５は上記駆動手段を制御する制御回路（制御手段）で
あって、マイクロコンピュータ等からなり、上記切替弁
２４に出力する制御信号によってアクチュエータ２１を
制御することにより、上記駆動手段を介して吸気導入規
制装置を制御し、加速時には上記作動停止状態として吸
気導入の規制を解除するようにしている。当実施例では
、始動運転領域および本来的にＨＣ等が発生し易い運転
領域で開閉弁１０を作動させ、それ以外の運転領域では
ｎ閉弁１０の作動機能を停止させるようにし、かつ、開
閉弁１０を作動させる運転ｆｌＡｂＸを冷却水温、吸気
温度、吸気圧力、排気温度等のエンジンの燃焼温度に関
係する変動＆に応じて補正するようにした上で、開閉弁
１０を作動させる運転領域であっても加速時には１７１
１ｗ１弁１０の作動機能を停止させるようにしている。Reference numeral 25 denotes a control circuit (control means) for controlling the drive means, which is composed of a microcomputer or the like, and controls the actuator 21 with a control signal output to the switching valve 24 to introduce intake air through the drive means. The regulation device is controlled so that, during acceleration, the operation is stopped and the regulation of intake air intake is released. In this embodiment, the on-off valve 10 is operated in the starting operation region and the operating region where HC etc. are inherently likely to occur, and the operating function of the n-close valve 10 is stopped in other operating regions. In the operating range in which the on-off valve 10 is operated, the operation flAbX in which the valve 10 is operated is corrected according to fluctuations related to the combustion temperature of the engine such as cooling water temperature, intake air temperature, intake pressure, exhaust temperature, etc. Even if it is, it will be 171 when accelerating.
The operating function of the 1w1 valve 10 is stopped.

このような＆１ｊｉｌｌを行うため、上記制御回路２５
は、燃料噴射ポンプ等に装備された回転数検出手段２６
および負荷検出手段２７等からの運転状態を検出する信
号と、エンジンの燃焼温度に関係する変動量として例え
ば冷却水温を検出する水温センサ２８からの検出信号と
、燃料噴射ポンプのレバー位置の変化を検出する等によ
り加速度を検出する加速検出手段２９からの検出信号と
が入力されている。In order to perform such &1jill, the control circuit 25
is a rotation speed detection means 26 installed in a fuel injection pump, etc.
and a signal that detects the operating state from the load detection means 27, etc., a detection signal from the water temperature sensor 28 that detects, for example, the cooling water temperature as a variation related to the combustion temperature of the engine, and a change in the lever position of the fuel injection pump. A detection signal from an acceleration detection means 29 that detects acceleration by detection or the like is input.

そして上記制御回路２５においては、第４図に示すよう
に、水温に関係なく開閉弁１０を作動させる開閉弁作動
領域Ａおよび水温が低いときのみ開閉弁１０を作動させ
る補正領ＶＬＢが予め設定されている。すなわち、第４
図は横軸をエンジン回転数Ｎ、縦軸を負荷に相当する燃
料噴射１０として上記開閉弁作動領域Ａと、上記補正領
域Ｂと、常に開閉弁１０の作動機能が停止される作動停
止領域Ｃを示している。この図において、Ｌｌは通常運
転時のＲ轟燃料噴６１！Ｉｉライン、Ｌ２は始動時の燃
料増員ライン、Ｌｓは最高速度ライン、Ｌ４は開閉弁作
動領域Ａの限界ライン、Ｌｓは補正領域Ｂの限界ライン
である。この図に示すように、開閉弁作動領域Ａは、始
動運転領域と比較的低回転、低負荷側の運転領域とを含
むように設定されており、また、上記補正領域Ｂは、水
温が低いときにＨＣ等が発生し易くなる領域であって、
その限界ラインＬ５は開閉弁作動領域Ａの限界ラインＬ
４よりある程度高回転側に設定されている。そして上記
限界ラインＬ５より高回転高負荷側が作動停止領域Ｃと
なっている。In the control circuit 25, as shown in FIG. 4, an on-off valve operating range A in which the on-off valve 10 is operated regardless of the water temperature and a correction range VLB in which the on-off valve 10 is operated only when the water temperature is low are set in advance. ing. That is, the fourth
The figure shows the on-off valve operating range A, the correction range B, and the operation stop range C where the operating function of the on-off valve 10 is always stopped, with the horizontal axis representing the engine rotation speed N and the vertical axis representing the fuel injection 10 corresponding to the load. It shows. In this figure, Ll is the R-roaring fuel injection 61! during normal operation. Ii line, L2 is the fuel increase line at startup, Ls is the maximum speed line, L4 is the limit line of the on-off valve operation area A, and Ls is the limit line of the correction area B. As shown in this figure, the on-off valve operating region A is set to include a starting operation region and a comparatively low-speed, low-load operation region, and the above-mentioned correction region B is set to include a starting operation region and a relatively low-speed, low-load operation region. This is an area where HC etc. are likely to occur sometimes,
The limit line L5 is the limit line L of the on-off valve operating area A.
It is set to a certain degree higher rotation side than 4. The operation stop region C is located on the high-speed, high-load side of the limit line L5.

第５図は上記制御回路２５による１、ＩＩ　ｍ　１７１
作をフローチャートによって示したものであって、この
図に示すように制御回路２５は、エンジン回転数および
負荷を検出しくステップＳ１．Ｓ２）、これらの検出信
号に基いて上記開閉弁作動領域Ａにあるか否かを調べる
（ステップ８３　）。そして、開閉弁作動領域へにある
ときは加速度の検出に基いて加速時か否かを調べる（ス
テップ８４　、　Ｓｓ　）、そして、加速時でないとき
は、吸気絞り弁７を小開度に閉じた状態とすることによ
り開閉弁１０を作動させ（ステップＳ６）、加速時には
吸気絞り弁７を開いて主吸気通路６ａを開通させること
により開閉弁１０の作動機能を停止させる（ステップＳ
７）。FIG. 5 shows 1, II m 171 by the control circuit 25.
As shown in this figure, the control circuit 25 detects the engine speed and the load in step S1. S2), based on these detection signals, it is checked whether the on-off valve is in the above-mentioned on-off valve operating range A (step 83). When the on-off valve is in the operating region, it is checked based on the acceleration detection whether or not it is accelerating (step 84, Ss), and when it is not accelerating, the intake throttle valve 7 is closed to a small opening. state, the on-off valve 10 is operated (step S6), and during acceleration, the intake throttle valve 7 is opened to open the main intake passage 6a, thereby stopping the operating function of the on-off valve 10 (step S6).
7).

また、開閉弁作動領域へにないときは補正領域Ｂにある
か否かを調べ（ステップＳ８）、補正領域Ｂにあるとき
は水温補正信号に基いて所定水温（例えば５０℃）以下
か否かを調べる。そして、補正領域Ｂにあって所定水温
以下であるときも、ステップＳａ、ステップ＄５を経て
加速時以外は開閉弁１０を作動させ、加速時は開閉弁１
０の作動機能を停止させる。補正領域Ｂにあって水温が
所定水温より高いときと、開閉弁作動領域Ａおよび補正
領域Ｂのいずれにもないときには、ステップ＄７に移る
ことによりｌ？ｌｌ閉弁１０の作動機能を停止させる。If it is not in the on-off valve operating region, it is checked whether it is in correction region B (step S8), and if it is in correction region B, it is determined whether the water temperature is below a predetermined temperature (for example, 50 degrees Celsius) based on the water temperature correction signal. Find out. Even when the water temperature is in the correction region B and the water temperature is below the predetermined temperature, the on-off valve 10 is operated through step Sa and step $5 except during acceleration;
Stop the operating function of 0. When the water temperature is in the correction region B and is higher than the predetermined water temperature, and when it is not in either the on-off valve operation region A or the correction region B, the process moves to step $7. The operating function of the closing valve 10 is stopped.

上述のごとき吸気装置によると、運転状態が前記開閉弁
作動領域Ａにあるとき、または前記補正領域Ｂにあって
水温が所定値以下のときに、加速・時以外は吸気絞り弁
７により主吸気通路６ａが絞られ、開閉弁１０が吸気行
程の途中で開くように作動される。これにより、吸気行
程の途中までは燃焼室３への吸気導入が制限され、吸気
行程途中から急激に多量の吸気が燃焼室３へ導入されて
吸気の断熱圧縮により燃焼室３内の温度が上昇する。According to the above-described intake system, when the operating state is in the on-off valve operating region A, or when the water temperature is in the correction region B and the water temperature is below a predetermined value, the main intake is controlled by the intake throttle valve 7 except during acceleration. The passage 6a is narrowed and the on-off valve 10 is operated to open in the middle of the intake stroke. As a result, the introduction of intake air into the combustion chamber 3 is restricted until the middle of the intake stroke, and a large amount of intake air is suddenly introduced into the combustion chamber 3 from the middle of the intake stroke, and the temperature inside the combustion chamber 3 increases due to adiabatic compression of the intake air. do.

この際、吸気導入が規制されることにより充填酪が多少
低下したとしても、上記断熱圧縮により燃焼温度は充分
に高められ、かつ空気過剰率が大きい運転状態では燃料
に対して吸気Ｒが不足することはなく、こうして着火性
および燃焼性が高められ、ＨＣ等が低減される。At this time, even if the charging temperature decreases somewhat due to restrictions on intake air introduction, the combustion temperature is sufficiently raised due to the adiabatic compression described above, and in operating conditions with a large excess air ratio, the intake air R is insufficient relative to the fuel. In this way, ignitability and combustibility are improved, and HC etc. are reduced.

また加速時には吸気絞り弁７が開かれて主吸気通路６ａ
が開通することにより、吸気導入の規制が解除され、吸
気行程の全期闇に亘って主吸気通路６ａから燃焼室３に
吸気が自由に導入される。Also, during acceleration, the intake throttle valve 7 is opened and the main intake passage 6a is opened.
By opening, the restriction on intake air introduction is lifted, and intake air is freely introduced into the combustion chamber 3 from the main intake passage 6a throughout the entire intake stroke.

従って加速時には燃料が増量されても吸気不足が生じる
ことがなく、スモークの発生および加速性能の低下が防
止される。Therefore, even if the amount of fuel is increased during acceleration, insufficient air intake will not occur, and smoke generation and deterioration of acceleration performance can be prevented.

さらに当実施例では、運転状態が前記補正領域Ｂにあっ
て水温が所定値より高いとき、または前記作動停止領域
Ｃにあるときにも、本来的に燃焼が良好に行われてＨＣ
等の発生が少ないため、開閉弁１０の作動機能を停止さ
せて吸気導入の規制を解除し、ボンピングロスを低減す
るとともに高回転高負荷時のスモークの発生を防止して
いる。Furthermore, in this embodiment, even when the operating state is in the correction region B and the water temperature is higher than the predetermined value, or when it is in the operation stop region C, combustion is originally performed well and the HC
Since such occurrences are rare, the operating function of the on-off valve 10 is stopped to remove the restriction on intake air introduction, thereby reducing the pumping loss and preventing the occurrence of smoke during high rotations and high loads.

なお、上記実施例では加速時に吸気導入の規制を完全に
解除しているが、吸気絞り弁７を所定開度だけ開いて吸
気導入の規制をある程度緩めるようにしてもよい。In the above embodiment, the restriction on intake air introduction is completely released during acceleration, but the restriction on intake air introduction may be relaxed to some extent by opening the intake throttle valve 7 by a predetermined opening degree.

また、本発明における吸気導入Ｍ制装置および駆動手段
の具体的構造は種々変更可能であって、その数例を次に
説明する。Further, the specific structure of the intake air introduction M control device and the driving means in the present invention can be changed in various ways, and some examples will be explained below.

第６図および第７図に示す第２実施例では、自動弁タイ
プの開閉弁１０が主吸気通路６ａに設けられており、副
吸気通路６ｂは設けられていない。In the second embodiment shown in FIGS. 6 and 7, an automatic valve type on-off valve 10 is provided in the main intake passage 6a, and no sub-intake passage 6b is provided.

この開閉弁１０は、第１実施例のものと同様の構造によ
り圧力変化に応じてＷＵ閉作動するようになっているが
、その端部が主吸気通路６ａに回転軸１０ａを介して取
付けられることにより、主吸気通路６ａ中に位置する状
態と、主吸気通路６ａの側壁に設けられた凹部３０に格
納される状態とに回動可能となっている。そして、この
開閉弁１０が格納位置に回動されると主吸気通路６ａが
開通するとともに開閉弁１０の作動が停止するようにし
ており、このｒＭｗＪ弁１０を回動させるダイヤフラム
Ｍ１等の７クチユエータ３１とこれを働かせるための通
路３２、真空ポンプ３３および切替弁３４等により駆動
手段が構成されている。また、主吸気通路６ａの開閉弁
１０より上流側と下流側との間には小径のリーク通路６
Ｃが設けられ、このリーク通路６Ｇには、吸気の逆流に
よる充填率の低下を防止するためのチェック弁３５が設
けられている。This on-off valve 10 has a structure similar to that of the first embodiment and is configured to close the WU in response to pressure changes, but its end is attached to the main intake passage 6a via a rotating shaft 10a. As a result, it can be rotated between a state where it is located in the main intake passage 6a and a state where it is housed in a recess 30 provided in the side wall of the main intake passage 6a. When the on-off valve 10 is rotated to the retracted position, the main intake passage 6a opens and the on-off valve 10 stops operating. 31, a passage 32 for operating the same, a vacuum pump 33, a switching valve 34, etc. constitute a driving means. Further, a small-diameter leak passage 6 is provided between the upstream side and the downstream side of the on-off valve 10 of the main intake passage 6a.
A check valve 35 is provided in the leak passage 6G to prevent the filling rate from decreasing due to backflow of intake air.

この実施例の装置によっても、開閉弁１０が主吸気通路
６ａ中に位置している状態にあるとき、吸気行程途中ま
ではリーク通路６Ｃから少量の吸気が導入されるだけな
ので燃焼室３内およびこれに連通ずる主吸気通路６ａ下
流側の圧力が次第に低下し、この圧力低下に応じて吸気
行程途中で開閉弁１０が開作動することによりそれ以後
に急激に吸気が導入されて断熱圧縮が行われ、吸気温度
が上昇する。また、ＷＵ閉弁１０を格納位置に回動させ
れば開閉弁１０の作動ｍ能が停止するとともに主吸気通
路６ａが開通する作動停止状態となる。Even with the device of this embodiment, when the on-off valve 10 is located in the main intake passage 6a, only a small amount of intake air is introduced from the leak passage 6C until the middle of the intake stroke, so that the inside of the combustion chamber 3 and The pressure on the downstream side of the main intake passage 6a that communicates with the main intake passage 6a gradually decreases, and in response to this pressure decrease, the on-off valve 10 opens during the intake stroke, and thereafter intake air is suddenly introduced and adiabatic compression is performed. As a result, the intake air temperature increases. Further, when the WU closing valve 10 is rotated to the retracted position, the operation of the opening/closing valve 10 is stopped and the main intake passage 6a is opened, resulting in an inoperative state.

そして制御回路２５・により、前記の第４図に示すよう
な領域設定に基いて駆動装置を１ｉ１１１Ｉするととも
に、加速時には開閉弁１０の作動機能を停止させ、つま
り開閉弁１０を格納位置に回動させることにより、第１
実施例と同様の作用、効果が得られる。Then, the control circuit 25 operates the drive device 1i111I based on the area settings as shown in FIG. By letting
The same functions and effects as in the embodiment can be obtained.

第８図は本発明装置の第３実施例を示し、この実施例で
は、吸気導入ｊＪＩ　Ｉｌｌ　ｉ　２１として、主吸気
通路６ａに吸気絞り弁７が設けられる一方、副吸気通路
６ｂに、エンジン出力軸（図示せず）に連動して回転す
るロータリバルブからなる開閉弁４０が設けられている
。このｎ閉弁４０とエンジン出力軸との間の連動機構（
図示せず）において、吸気行程途中でｎ閉弁４０が開作
動するように開閉弁４０の開閉タイミングが設定されて
いる。FIG. 8 shows a third embodiment of the device of the present invention. In this embodiment, an intake throttle valve 7 is provided in the main intake passage 6a as an intake air introduction jJI Ill i 21, while an intake throttle valve 7 is provided in the auxiliary intake passage 6b. An on-off valve 40 made of a rotary valve that rotates in conjunction with a shaft (not shown) is provided. An interlocking mechanism between this n-closing valve 40 and the engine output shaft (
(not shown), the opening/closing timing of the on-off valve 40 is set so that the n-close valve 40 opens during the intake stroke.

この実施例によっても、吸気絞り弁７により主吸気通路
６ａが絞られた状態では上記ｎ閉弁４０の作動により吸
気導入が規制されて吸気の断熱圧縮が行われる。また、
吸気絞り弁７が開かれると、主吸気通路６ａから燃焼室
３へ吸気が自由に導入されるため、開閉弁１０が回転し
ていても吸気導入の規制は解除され、実質的に開閉弁１
０の作動機能が停止される。従ってこの場合も、上記吸
気絞り弁７に対して第１実施例と同様の駆動手段を設け
るとともに制御回路２５により第１実施例と同様に駆動
手段を制御するようにしておけばよい。Also in this embodiment, when the main intake passage 6a is throttled by the intake throttle valve 7, the introduction of intake air is regulated by the operation of the n-closing valve 40, and adiabatic compression of the intake air is performed. Also,
When the intake throttle valve 7 is opened, intake air is freely introduced from the main intake passage 6a into the combustion chamber 3, so even if the on-off valve 10 is rotating, the restriction on intake air introduction is lifted, and the on-off valve 1 is substantially
0 operating function is deactivated. Therefore, in this case as well, it is sufficient to provide the same driving means as in the first embodiment for the intake throttle valve 7 and to control the driving means by the control circuit 25 in the same manner as in the first embodiment.

また、上記１ＦＩＷ１弁１０とエンジン出力軸との間の
連動機構には連動を遮断する手段を設けておくことによ
り、吸気絞り弁７が開かれたときに開閉弁１０の回転そ
のものが停止されるようにしてもよい。Further, by providing a means for interrupting the interlocking mechanism between the 1FIW1 valve 10 and the engine output shaft, the rotation of the on-off valve 10 itself is stopped when the intake throttle valve 7 is opened. You can do it like this.

さらに他の実施例として、第２実施例に示すような主吸
気通路とリーク通路とからなる吸気通路構成で、エンジ
ン出力軸に連動して吸気行程の途中で開くロータリバル
ブタイプの開閉弁を主吸気通路に設けてもよい。この場
合、［Ｆ１１閉弁を開状態に停止させることのできる運
動遮断手段、または開閉弁の開閉タイミングを変えるこ
とのできる開閉タイミング可変手段を連動機構に組込む
ことにより、吸気導入の規Ｉｌｌを解除し、または緩め
ることができ、このような手段を制御回路によって制御
すればよい。As another embodiment, an intake passage configuration consisting of a main intake passage and a leak passage as shown in the second embodiment, and a rotary valve type on-off valve that opens in the middle of the intake stroke in conjunction with the engine output shaft is used as the main intake passage. It may also be provided in the intake passage. In this case, by incorporating into the interlocking mechanism a movement blocking means that can stop the F11 closing valve in the open state or an opening/closing timing variable means that can change the opening/closing timing of the opening/closing valve, the intake air introduction regulation Ill can be canceled. or loosening, and such means may be controlled by a control circuit.

（発明の効果） 以上のように本発明は、吸気通路に設けた開閉弁を吸気
行程の途中で開いて吸気の断熱圧縮を行わせる吸気導入
規制装置を備えるとともに、空気過剰率が大きい定常運
転時等には上記開ｎ弁を作動させ、加速時には上記開閉
弁の作動による吸気導入の規制を解除する方向に制御し
ているため、吸気の断熱圧縮による温度上昇を利用して
排気中のＨＣ等をできるだけ低減しつつ、燃料が増量さ
れる加速時に吸気不足が生じることを防止し、加速時の
スモークの発生および加速性能の低下を防止することが
できるものである。(Effects of the Invention) As described above, the present invention includes an intake air introduction regulating device that opens the on-off valve provided in the intake passage in the middle of the intake stroke to perform adiabatic compression of the intake air, and also provides for steady operation with a large excess air ratio. During acceleration, the above-mentioned on-off valve is operated, and during acceleration, the control is performed in such a direction that the restriction on intake air intake due to the operation of the above-mentioned on-off valve is released, so that the HC in the exhaust gas is It is possible to prevent insufficient air intake from occurring during acceleration when the amount of fuel is increased, and to prevent the occurrence of smoke during acceleration and deterioration of acceleration performance while reducing the above as much as possible.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の第１実施例の装置の概略平面図、第２
図はこの装置の縦断側面図、第３図は開閉弁の拡大断面
図、第４図は開閉弁作動領域および作動停止領域を示す
説明図、第５図は制御のフローチャート、第６図は第２
実施例の装置の縦断側面図、第７図は第６図の■−■翰
に沿った断面図、第８図は第３実施例を示す縦断側面図
である。 １・・・シリンダ、３・・・燃焼室、４・・・吸気弁、
６・・・吸気通路、７・・・吸気絞り弁、１０・・・開
閉弁、４０・・・開閉弁、２１．３１・・・アクチュエ
ータ、２５・・・制御回路、２９・・・加速検出手段。 第　　２　　図 第　　３　　図 第　　４　　図 第　　５　　図FIG. 1 is a schematic plan view of a device according to a first embodiment of the present invention, and FIG.
The figure is a vertical side view of this device, Figure 3 is an enlarged sectional view of the on-off valve, Figure 4 is an explanatory diagram showing the on-off valve operation area and operation stop area, Figure 5 is a control flowchart, and Figure 6 is an 2
FIG. 7 is a cross-sectional view taken along line 1--2 in FIG. 6, and FIG. 8 is a vertical side view showing the third embodiment. 1... Cylinder, 3... Combustion chamber, 4... Intake valve,
6... Intake passage, 7... Intake throttle valve, 10... On-off valve, 40... On-off valve, 21.31... Actuator, 25... Control circuit, 29... Acceleration detection means. Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

【特許請求の範囲】[Claims] １、吸気通路に開閉弁を設け、吸気行程途中までは上記
開閉弁を閉状態として燃焼室への吸気の導入を制限し、
吸気行程途中で上記開閉弁を開くことにより急激に吸気
を燃焼室に導入して断熱圧縮を行なわせる吸気導入規制
装置を備えたディーゼルエンジンの吸気装置において、
エンジンの加速状態を検出する加速検出手段と、この加
速検出手段の出力に応じ、加速時に上記開閉弁の作動に
よる吸気導入の規制を解除する方向に上記吸気導入規制
装置を制御する制御手段とを設けたことを特徴とするデ
ィーゼルエンジンの吸気装置。1. An on-off valve is provided in the intake passage, and the on-off valve is closed until the middle of the intake stroke to restrict the introduction of intake air into the combustion chamber.
In an intake system for a diesel engine equipped with an intake air introduction regulating device that rapidly introduces intake air into a combustion chamber to perform adiabatic compression by opening the on-off valve during the intake stroke,
an acceleration detection means for detecting an acceleration state of the engine; and a control means for controlling the intake air introduction regulating device in a direction to release the regulation of intake air introduction by the operation of the on-off valve during acceleration according to the output of the acceleration detection means. An intake system for a diesel engine characterized by the following: