JP2010163996A - Low pressure egr device - Google Patents

Low pressure egr device Download PDF

Info

Publication number
JP2010163996A
JP2010163996A JP2009007534A JP2009007534A JP2010163996A JP 2010163996 A JP2010163996 A JP 2010163996A JP 2009007534 A JP2009007534 A JP 2009007534A JP 2009007534 A JP2009007534 A JP 2009007534A JP 2010163996 A JP2010163996 A JP 2010163996A
Authority
JP
Japan
Prior art keywords
egr
pressure egr
intake valve
intake
low
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
Application number
JP2009007534A
Other languages
Japanese (ja)
Inventor
Akira Furukawa
晃 古川
Osamu Shimane
修 島根
Shinsuke Miyazaki
真輔 宮崎
Yuichiro Moriya
勇一朗 守谷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Corp
Original Assignee
Denso Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Denso Corp filed Critical Denso Corp
Priority to JP2009007534A priority Critical patent/JP2010163996A/en
Publication of JP2010163996A publication Critical patent/JP2010163996A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Landscapes

  • Exhaust-Gas Circulating Devices (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low pressure EGR device which can drive both a low pressure EGR adjusting valve and an intake valve by one electric motor and satisfy both characteristics required by the low pressure EGR adjusting valve and by the intake valve. <P>SOLUTION: An EGR driving gear 8 of a low pressure EGR adjusting valve 5 is driven by employing an electric motor. An intake valve driving gear 9 of an intake valve 6 is driven by the EGR driving gear 8. When an opening of the low pressure EGR adjusting valve 5 is smaller than a prescribed opening, the EGR driving gear 8 and intake valve driving gear 9 come into a non-meshed "low concentration control state" to turn and control the low pressure EGR adjusting valve 5 only. When an opening of the low pressure EGR adjusting valve 5 is larger than a prescribed opening, the EGR driving gear 8 and intake valve driving gear 9 come into a meshed "high concentration control state" to simultaneously turn and control the low pressure EGR adjusting valve 5 and intake valve 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、エンジン（燃料の燃焼により動力を発生させる内燃機関）の排気ガスの一部を、吸気通路の低吸気負圧発生範囲（スロットルバルブの吸気上流など、吸気負圧の発生が弱い範囲）に戻す低圧ＥＧＲ装置に関する。   The present invention relates to a part of the exhaust gas of an engine (an internal combustion engine that generates power by combustion of fuel), a low intake negative pressure generation range in the intake passage (a range where intake negative pressure is weak, such as upstream of intake of a throttle valve). This relates to a low pressure EGR device that is returned to ().

本発明の背景技術を、図７、図８を参照して説明する。なお、符号は後述する［発明を実施するための形態］および［実施例］と同一機能物に同一符号を付したものである。
〔従来技術〕
エンジン２のＮＯｘ（窒素酸化物）の発生を抑える技術として、高圧ＥＧＲ装置３１が知られている。この高圧ＥＧＲ装置３１の概略を図７を参照して説明する。
高圧ＥＧＲ装置３１は、従来より一般的にＥＧＲ装置と呼ばれているものであり、排気ガスの一部をＥＧＲガスとしてスロットルバルブ２６の吸気下流側（高負圧発生範囲）に戻すことで、吸気の一部に不燃ガスであるＥＧＲガスを混入させて、エンジン燃焼室の燃焼温度を抑え、効果的にＮＯｘの発生を抑える技術である。 The background art of the present invention will be described with reference to FIGS. In addition, the code | symbol attaches | subjects the same code | symbol to the same function thing as [the form for inventing] and [Example] which are mentioned later.
[Conventional technology]
As a technique for suppressing the generation of NOx (nitrogen oxide) in the engine 2, a high-pressure EGR device 31 is known. An outline of the high-pressure EGR device 31 will be described with reference to FIG.
The high-pressure EGR device 31 is generally called an EGR device in the past, and by returning a part of the exhaust gas as EGR gas to the intake downstream side (high negative pressure generation range) of the throttle valve 26, This is a technique in which EGR gas, which is non-combustible gas, is mixed in a part of intake air to suppress the combustion temperature in the engine combustion chamber and effectively suppress the generation of NOx.

なお、高圧ＥＧＲ装置３１においてＥＧＲガスを吸気側へ戻す高圧ＥＧＲ流路３２には、高圧ＥＧＲ流路３２の開度調整を行なう高圧ＥＧＲ調整弁３３が設けられており、この高圧ＥＧＲ調整弁３３は、エンジン２の運転状態（エンジン回転数、エンジン負荷など）に応じたＥＧＲ量が得られるように、ＥＣＵ（エンジン・コントロール・ユニットの略）により開度制御される。   In the high pressure EGR device 31, the high pressure EGR flow path 32 that returns the EGR gas to the intake side is provided with a high pressure EGR adjustment valve 33 that adjusts the opening degree of the high pressure EGR flow path 32, and this high pressure EGR adjustment valve 33. Is controlled by an ECU (abbreviation of engine control unit) so that an EGR amount corresponding to the operating state (engine speed, engine load, etc.) of the engine 2 is obtained.

一方、エンジン２には、ＮＯｘの発生をより少なくするための技術が常に要求されている。
近年では、ＮＯｘの発生をより少なくするための技術として、高圧ＥＧＲ装置３１とは別に、低圧ＥＧＲ装置１を搭載する技術が提案されている（例えば、特許文献１参照）。この低圧ＥＧＲ装置１の概略を図８を参照して説明する。
低圧ＥＧＲ装置１は、排気通路２２における低排気圧範囲（ＤＰＦ２９の排気下流側など、排気圧が低い範囲）の排気ガスの一部を、吸気通路３における低吸気負圧発生範囲（スロットルバルブ２６の吸気上流側の吸気通路３で、且つ吸気負圧の発生が弱い範囲）に戻すことで、少量のＥＧＲガスをエンジン２に戻す装置である。 On the other hand, the engine 2 is always required to have a technique for reducing the generation of NOx.
In recent years, as a technique for reducing the generation of NOx, a technique for mounting the low-pressure EGR device 1 in addition to the high-pressure EGR device 31 has been proposed (see, for example, Patent Document 1). An outline of the low-pressure EGR device 1 will be described with reference to FIG.
The low-pressure EGR device 1 uses a part of the exhaust gas in a low exhaust pressure range in the exhaust passage 22 (a range where the exhaust pressure is low, such as the exhaust downstream side of the DPF 29) as a low intake negative pressure generation range (throttle valve 26 in the intake passage 3). This is a device for returning a small amount of EGR gas to the engine 2 by returning to the intake passage 3 on the upstream side of the intake air and in a range where the generation of intake negative pressure is weak.

具体的に、例えば、ターボチャージャを搭載する車両の低圧ＥＧＲ装置１は、排気タービン２８の排気下流側のＥＧＲガスを、コンプレッサ２４の吸気上流側に戻す装置であり、低排気圧範囲の排気ガスが低吸気負圧範囲に戻されることで、少量のＥＧＲガスをエンジン２に戻すことが可能になる。
このため、高圧ＥＧＲ装置３１では実現困難であった、例えばエンジン負荷の大きい運転領域など、低濃度のＥＧＲガスが求められる運転領域であってもＮＯｘを抑えることが可能になる。 Specifically, for example, the low-pressure EGR device 1 for a vehicle equipped with a turbocharger is a device that returns EGR gas on the exhaust downstream side of the exhaust turbine 28 to the intake upstream side of the compressor 24, and exhaust gas in a low exhaust pressure range. Is returned to the low intake negative pressure range, a small amount of EGR gas can be returned to the engine 2.
For this reason, it is possible to suppress NOx even in an operation region where low-concentration EGR gas is required, such as an operation region where the engine load is large, which is difficult to realize with the high-pressure EGR device 31.

なお、低圧ＥＧＲ装置１においてＥＧＲガスを吸気側へ戻す低圧ＥＧＲ流路４には、低圧ＥＧＲ流路４の開度調整を行なう低圧ＥＧＲ調整弁５が設けられており、この低圧ＥＧＲ調整弁５も、上述した高圧ＥＧＲ調整弁３３と同様、エンジン２の運転状態（エンジン回転数、エンジン負荷など）に応じたＥＧＲ量が得られるように、ＥＣＵにより開度制御される。   The low pressure EGR flow path 4 for returning the EGR gas to the intake side in the low pressure EGR device 1 is provided with a low pressure EGR adjustment valve 5 for adjusting the opening degree of the low pressure EGR flow path 4. Similarly to the high pressure EGR adjustment valve 33 described above, the opening degree is controlled by the ECU so that an EGR amount corresponding to the operating state (engine speed, engine load, etc.) of the engine 2 can be obtained.

〔従来技術の問題点〕
低圧ＥＧＲ装置１は、排気通路２２における低排気圧範囲の排気ガスの一部を、吸気通路３における低吸気負圧発生範囲に戻すものである。
このため、低圧ＥＧＲ装置１は、少量のＥＧＲガスをエンジン２に戻すことを得意とする反面、低圧ＥＧＲ装置１を用いて多量のＥＧＲガスをエンジン２に戻すことが困難であった。即ち、低圧ＥＧＲ装置１を用いて多量のＥＧＲガスをエンジン２に戻すことが要求されるエンジンの運転領域が存在しても、その要求に対応することができなかった。 [Problems of the prior art]
The low pressure EGR device 1 returns a part of the exhaust gas in the low exhaust pressure range in the exhaust passage 22 to the low intake negative pressure generation range in the intake passage 3.
For this reason, the low pressure EGR device 1 is good at returning a small amount of EGR gas to the engine 2, but it is difficult to return a large amount of EGR gas to the engine 2 using the low pressure EGR device 1. That is, even if there is an engine operating region in which a large amount of EGR gas is required to be returned to the engine 2 using the low-pressure EGR device 1, the request cannot be met.

そこで、低圧ＥＧＲ装置１がＥＧＲガスを戻す部位の吸気通路３に、吸気負圧を発生可能な吸気弁６（吸気負圧発生用バルブ）を設け、低圧ＥＧＲ装置１を用いて多量のＥＧＲ装置を用いて多量のＥＧＲガスをエンジン２へ戻したい運転領域では、吸気弁６を閉じる方向（吸気負圧が発生する方向）に制御することが考えられる。即ち、低圧ＥＧＲ装置１により大きなＥＧＲ量を得たい運転領域では、吸気弁６で吸気負圧を発生させて多量のＥＧＲガスをエンジン２に戻すことが考えられる。   Therefore, an intake valve 6 (intake negative pressure generating valve) capable of generating intake negative pressure is provided in the intake passage 3 where the low pressure EGR device 1 returns EGR gas, and a large amount of EGR device is used by using the low pressure EGR device 1. In an operation region where a large amount of EGR gas is desired to be returned to the engine 2 using, it is conceivable to control the intake valve 6 in the closing direction (the direction in which intake negative pressure is generated). That is, in an operation region where a large EGR amount is desired to be obtained by the low pressure EGR device 1, it is conceivable that a large amount of EGR gas is returned to the engine 2 by generating an intake negative pressure by the intake valve 6.

しかるに、低圧ＥＧＲ調整弁５は、上述したように、エンジン回転数やエンジン負荷等に応じて開度制御されるものである。
一方、吸気弁６は、低圧ＥＧＲ装置１により大きなＥＧＲ量を得たい運転領域の時だけ、閉じる方向に制御されるものである。 However, as described above, the opening degree of the low pressure EGR adjustment valve 5 is controlled according to the engine speed, the engine load, and the like.
On the other hand, the intake valve 6 is controlled in the closing direction only when the low-pressure EGR device 1 is in the operating region where it is desired to obtain a large EGR amount.

このように、低圧ＥＧＲ調整弁５と吸気弁６は、それぞれが別の運転要因に基づいて作動制御されるものであるため、低圧ＥＧＲ調整弁５と吸気弁６は、それぞれが独立して操作される。
このため、低圧ＥＧＲ調整弁５を駆動するための専用のアクチュエータＪ１と、吸気弁６を駆動するための専用のアクチュエータＪ２とが必要となり、コストアップ、体格アップ、重量アップの要因になっていた。 As described above, since the low pressure EGR adjustment valve 5 and the intake valve 6 are controlled according to different operating factors, the low pressure EGR adjustment valve 5 and the intake valve 6 are independently operated. Is done.
For this reason, a dedicated actuator J1 for driving the low-pressure EGR adjustment valve 5 and a dedicated actuator J2 for driving the intake valve 6 are required, resulting in an increase in cost, physique and weight. .

そこで、低圧ＥＧＲ調整弁５と吸気弁６の両方を、１つのアクチュエータで駆動する要求がある（例えば、特許文献２、３参照）。
しかし、１つのアクチュエータによって、低圧ＥＧＲ調整弁５と吸気弁６の両方を駆動すると、低圧ＥＧＲ調整弁５と吸気弁６が常に同時に作動してしまい、それぞれの目的にあった特性が得られなくなってしまう。
このため、従来技術では、コストアップ、体格アップ、重量アップしてでも、低圧ＥＧＲ調整弁５を駆動するための専用のアクチュエータＪ１と、吸気弁６を駆動するための専用のアクチュエータＪ２とを設けていた。 Therefore, there is a demand to drive both the low pressure EGR adjustment valve 5 and the intake valve 6 with one actuator (for example, see Patent Documents 2 and 3).
However, if both the low-pressure EGR adjustment valve 5 and the intake valve 6 are driven by one actuator, the low-pressure EGR adjustment valve 5 and the intake valve 6 are always operated simultaneously, and characteristics suitable for each purpose cannot be obtained. End up.
For this reason, in the prior art, a dedicated actuator J1 for driving the low pressure EGR regulating valve 5 and a dedicated actuator J2 for driving the intake valve 6 are provided even if the cost, body size and weight are increased. It was.

特開２００８−１５０９５５号公報JP 2008-150955 A 特開２００７−１３２３０５号公報JP 2007-132305 A 特開２００７−０９２６６４号公報JP 2007-092664 A

本発明は、上記問題点に鑑みてなされたものであり、その目的は、低圧ＥＧＲ調整弁と吸気弁の両方を１つのアクチュエータで駆動可能であり、且つ低圧ＥＧＲ調整弁に要求される特性と吸気弁に要求される特性の両方を満足できる低圧ＥＧＲ装置の提供にある。   The present invention has been made in view of the above-described problems, and has an object of being able to drive both the low pressure EGR adjustment valve and the intake valve with one actuator and required characteristics of the low pressure EGR adjustment valve. An object of the present invention is to provide a low pressure EGR device that can satisfy both of the characteristics required for an intake valve.

上記の目的を達成するために、本発明は以下の構成を採用する。
○低圧ＥＧＲ装置は、低圧ＥＧＲ調整弁を回転駆動するアクチュエータと、低圧ＥＧＲ調整弁を駆動するＥＧＲ駆動歯車と、吸気弁を駆動する吸気弁駆動歯車とを備える。
○低圧ＥＧＲ装置は、吸気弁が吸気通路を全開に開く全開時に、吸気弁駆動歯車に形成された凹部に係合するロックピンと、このロックピンを吸気弁駆動歯車に向けて押し付けるレバーとを有するロック機構を備える。 In order to achieve the above object, the present invention adopts the following configuration.
The low pressure EGR device includes an actuator that rotationally drives the low pressure EGR adjustment valve, an EGR drive gear that drives the low pressure EGR adjustment valve, and an intake valve drive gear that drives the intake valve.
The low-pressure EGR device has a lock pin that engages a recess formed in the intake valve drive gear and a lever that presses the lock pin toward the intake valve drive gear when the intake valve fully opens the intake passage. A locking mechanism is provided.

○ＥＧＲ駆動歯車には、低圧ＥＧＲ調整弁の開度が所定開度より小さく、低圧ＥＧＲ装置を用いて少量のＥＧＲガスをエンジンへ戻す「低濃度制御状態」の時に、吸気弁駆動歯車に設けられた吸気弁入力ギヤ歯に対して非係合となり、ＥＧＲ駆動歯車の回転力を吸気弁駆動歯車に非伝達とするギヤ歯除去部が設けられる。
○ＥＧＲ駆動歯車には、低圧ＥＧＲ調整弁の開度が所定開度より大きく、低圧ＥＧＲ装置を用いて多量のＥＧＲガスをエンジンへ戻す「高濃度制御状態」の時に、吸気弁入力ギヤ歯に噛合して、ＥＧＲ駆動歯車の回転力を吸気弁駆動歯車に伝達し、吸気弁の開度を可変するＥＧＲ出力ギヤ歯が設けられる。
○ＥＧＲ駆動歯車には、ＥＧＲ出力ギヤ歯が吸気弁入力ギヤ歯に噛合する状態の時のみレバーを押圧操作して、ロックピンを凹部から外す押圧カムが設けられる。 ○ The EGR drive gear is provided on the intake valve drive gear when the low pressure EGR adjustment valve is smaller than a predetermined opening and a small amount of EGR gas is returned to the engine using the low pressure EGR device. A gear tooth removal unit is provided that is disengaged from the intake valve input gear teeth and that does not transmit the rotational force of the EGR drive gear to the intake valve drive gear.
○ The EGR drive gear has a low-pressure EGR adjustment valve opening larger than the predetermined opening, and when it is in a “high concentration control state” where a large amount of EGR gas is returned to the engine using the low-pressure EGR device, the intake valve input gear teeth The EGR output gear teeth that mesh and transmit the rotational force of the EGR drive gear to the intake valve drive gear and vary the opening degree of the intake valve are provided.
O The EGR drive gear is provided with a pressing cam that presses the lever and removes the lock pin from the recess only when the EGR output gear teeth mesh with the intake valve input gear teeth.

本発明は、上記の構成を採用することにより、以下の作用を奏する。
＜低圧ＥＧＲ装置を用いて少量のＥＧＲガスをエンジンに戻す低濃度制御時＞
エンジンの運転状態が、エンジン負荷が大きい運転状態など、低圧ＥＧＲ装置を用いて少量のＥＧＲガス量をエンジンへ戻す「低濃度制御状態」が望まれる運転状態になると、低圧ＥＧＲ装置は、次のように作動する。
（１）先ず、吸気弁が最大開度に切り替わった状態であるか否かの判断を行なう。
（２）吸気弁が最大開度に切り替わっていない状態の場合は、ＥＧＲ駆動歯車と吸気弁駆動歯車が噛合した状態であり、アクチュエータを作動させて低圧ＥＧＲ調整弁の開度を所定開度より小さくする。すると、ＥＧＲ駆動歯車と吸気弁駆動歯車が非噛合状態となるとともに、ロック機構により吸気弁が最大開度でロックされる。
（３）吸気弁が最大開度でロックされた状態では、アクチュエータによって低圧ＥＧＲ調整弁を回動制御してＥＧＲ量をコントロールする。
このように、「低濃度制御状態」では、ＥＧＲ駆動歯車に設けられたギヤ歯除去部によって、ＥＧＲ出力ギヤ歯と吸気弁入力ギヤ歯とが非係合となって、吸気弁が最大開度の状態で保たれる。
即ち、吸気弁が最大開度に設定された状態のままで、低圧ＥＧＲ調整弁を回動操作して少量のＥＧＲ量をコントロールすることができる。 The present invention exhibits the following effects by adopting the above configuration.
<During low concentration control using a low pressure EGR device to return a small amount of EGR gas to the engine>
When the operation state of the engine becomes an operation state where a “low concentration control state” in which a small amount of EGR gas is returned to the engine using a low pressure EGR device, such as an operation state where the engine load is large, the low pressure EGR device Operates as follows.
(1) First, it is determined whether or not the intake valve is switched to the maximum opening.
(2) When the intake valve is not switched to the maximum opening, the EGR drive gear and the intake valve drive gear are engaged with each other, and the actuator is operated so that the opening of the low pressure EGR adjustment valve is greater than the predetermined opening. Make it smaller. Then, the EGR drive gear and the intake valve drive gear are disengaged, and the intake valve is locked at the maximum opening by the lock mechanism.
(3) In a state where the intake valve is locked at the maximum opening, the EGR amount is controlled by controlling the rotation of the low pressure EGR adjustment valve by the actuator.
As described above, in the “low concentration control state”, the EGR output gear teeth and the intake valve input gear teeth are disengaged by the gear tooth removal portion provided in the EGR drive gear, and the intake valve is at the maximum opening degree. Kept in a state.
That is, a small amount of EGR can be controlled by rotating the low pressure EGR adjustment valve while the intake valve is set to the maximum opening.

＜低圧ＥＧＲ装置を用いて多量のＥＧＲガスをエンジンに戻す高濃度制御時＞
エンジンの運転状態が、エンジン負荷が中程度の運転状態など、低圧ＥＧＲ装置を用いて少量のＥＧＲガス量をエンジンへ戻す「高濃度制御状態」が望まれる運転状態になると、低圧ＥＧＲ装置は、次のように作動する。
（１）先ず、吸気弁が最大開度に切り替わった状態であるか否かの判断を行なう。
（２）吸気弁が最大開度に切り替わっている状態の場合は、ＥＧＲ駆動歯車と吸気弁駆動歯車が噛合していない状態であり、アクチュエータを作動させて低圧ＥＧＲ調整弁の開度を所定開度より大きくする。すると、ロック機構による吸気弁のロックが解除されるとともに、ＥＧＲ駆動歯車と吸気弁駆動歯車が噛合状態となる。
（３）吸気弁のロックが解除された状態では、ＥＧＲ駆動歯車と吸気弁駆動歯車が噛合状態であるため、低圧ＥＧＲ調整弁と吸気弁を連動させて作動させることができる。即ち、アクチュエータの作動により、低圧ＥＧＲ調整弁の開度を大きくしながら、吸気弁の開度を小さくして、ＥＧＲ量のコントロールと、低圧ＥＧＲ装置がＥＧＲガスを戻す部位の吸気負圧のコントロールとを、同時に行なう。
このように「高濃度制御状態」では、ＥＧＲ出力ギヤ歯と吸気弁入力ギヤ歯とが噛合して、低圧ＥＧＲ調整弁の開度調整と、低圧ＥＧＲ装置がＥＧＲガスを戻す部位の吸気負圧の調整とを同時に制御することができ、低圧ＥＧＲ装置において多量のＥＧＲ量をコントロールすることができる。 <During high-concentration control using a low-pressure EGR device to return a large amount of EGR gas to the engine>
When the operating state of the engine becomes an operating state where a “high concentration control state” in which a small amount of EGR gas is returned to the engine using a low pressure EGR device, such as an operating state with a medium engine load, the low pressure EGR device It operates as follows.
(1) First, it is determined whether or not the intake valve is switched to the maximum opening.
(2) When the intake valve is switched to the maximum opening, the EGR drive gear and the intake valve drive gear are not meshed, and the actuator is activated to open the opening of the low pressure EGR adjustment valve. Larger than degree. Then, the lock of the intake valve by the lock mechanism is released, and the EGR drive gear and the intake valve drive gear are engaged.
(3) Since the EGR drive gear and the intake valve drive gear are meshed when the intake valve is unlocked, the low pressure EGR adjustment valve and the intake valve can be operated in conjunction with each other. That is, by operating the actuator, while increasing the opening of the low pressure EGR adjustment valve, the opening of the intake valve is decreased to control the EGR amount and the control of the intake negative pressure at the portion where the low pressure EGR device returns EGR gas. And simultaneously.
Thus, in the “high concentration control state”, the EGR output gear teeth and the intake valve input gear teeth mesh with each other to adjust the opening of the low pressure EGR adjustment valve, and the intake negative pressure at the portion where the low pressure EGR device returns EGR gas. Can be controlled simultaneously, and a large amount of EGR can be controlled in the low pressure EGR device.

本発明の低圧ＥＧＲ装置は、上述したように、１つのアクチュエータによって低圧ＥＧＲ調整弁を回動操作するのみで、（ｉ）吸気弁を最大開度に設定した状態を保ったままで、低圧ＥＧＲ調整弁を回動操作して、少量のＥＧＲガス量をエンジンに戻すことができるとともに、（ｉｉ）低圧ＥＧＲ調整弁の開度調整と、吸気弁の開度調整とを同時に回動操作して、低圧ＥＧＲ装置を用いて多量のＥＧＲガス量をエンジンに戻すことができる。
即ち、本発明の低圧ＥＧＲ装置は、低圧ＥＧＲ調整弁と吸気弁の両方を１つのアクチュエータで駆動可能であり、且つ低圧ＥＧＲ調整弁に要求される特性と吸気弁に要求される特性の両方を満足することができる。
このように、低圧ＥＧＲ調整弁と吸気弁の両方を１つのアクチュエータで駆動できるため、低圧ＥＧＲ装置のコストを抑えることができるとともに、低圧ＥＧＲ装置の小型化および軽量化を図ることができる。 As described above, the low-pressure EGR device according to the present invention only rotates the low-pressure EGR adjustment valve with one actuator, and (i) the low-pressure EGR adjustment is performed while the intake valve is kept at the maximum opening degree. A small amount of EGR gas can be returned to the engine by rotating the valve, and (ii) the opening adjustment of the low-pressure EGR adjustment valve and the opening adjustment of the intake valve are simultaneously rotated, A large amount of EGR gas can be returned to the engine using the low pressure EGR device.
That is, the low-pressure EGR device of the present invention can drive both the low-pressure EGR adjustment valve and the intake valve with one actuator, and has both the characteristics required for the low-pressure EGR adjustment valve and the characteristics required for the intake valve. Can be satisfied.
Thus, since both the low pressure EGR adjustment valve and the intake valve can be driven by one actuator, the cost of the low pressure EGR device can be suppressed, and the low pressure EGR device can be reduced in size and weight.

低圧ＥＧＲ調整弁と吸気弁の駆動機構を示す概略断面図、およびＥＧＲ駆動歯車の概略図である（実施例１）。FIG. 2 is a schematic cross-sectional view showing a drive mechanism for a low-pressure EGR adjustment valve and an intake valve, and a schematic view of an EGR drive gear (Example 1). 「低濃度制御状態」から「高濃度制御状態」に至る作動説明図である（実施例１）。FIG. 6 is an operation explanatory diagram from a “low concentration control state” to a “high concentration control state” (Example 1). 「低濃度制御状態」と「高濃度制御状態」の作動説明図である（実施例１）。FIG. 3 is an operation explanatory diagram of a “low concentration control state” and a “high concentration control state” (Example 1). 低圧ＥＧＲ調整弁の回転角度に応じた低圧ＥＧＲ調整弁の開度と、吸気弁の開度を示すグラフである（実施例１）。(Example 1) which is a graph which shows the opening degree of the low pressure EGR regulating valve according to the rotation angle of the low pressure EGR regulating valve, and the opening degree of the intake valve. エンジンの吸排気システムの概略説明図である（実施例１）。1 is a schematic explanatory diagram of an intake / exhaust system for an engine (Example 1). 高圧／低圧ＥＧＲ量制御プログラムにおけるＥＧＲ制御の説明図である（実施例１）。(Example 1) which is explanatory drawing of EGR control in a high voltage / low pressure EGR amount control program. エンジンの吸排気システムの概略説明図である（従来例１）。It is a schematic explanatory drawing of the engine intake-exhaust system (conventional example 1). エンジンの吸排気システムの概略説明図である（従来例２）。It is a schematic explanatory drawing of an engine intake-exhaust system (conventional example 2).

図１〜図６を参照して［発明を実施するための形態］を説明する。
低圧ＥＧＲ装置１は、エンジン２の排気ガスの一部を、吸気通路３における低吸気負圧発生範囲に戻す低圧ＥＧＲ流路４と、この低圧ＥＧＲ流路４の開度を調整することでＥＧＲガスの流量調整を行なう低圧ＥＧＲ調整弁５と、低圧ＥＧＲ流路４と吸気通路３との接合部より吸気通路３の吸気上流側の開度を可変可能な吸気弁６とを具備する。 [Mode for Carrying Out the Invention] will be described with reference to FIGS.
The low pressure EGR device 1 adjusts the opening of the low pressure EGR flow path 4 and the low pressure EGR flow path 4 for returning a part of the exhaust gas of the engine 2 to the low intake negative pressure generation range in the intake passage 3. A low-pressure EGR adjustment valve 5 that adjusts the flow rate of gas, and an intake valve 6 that can vary the opening upstream of the intake passage 3 from the joint between the low-pressure EGR passage 4 and the intake passage 3 are provided.

この低圧ＥＧＲ装置１は、低圧ＥＧＲ調整弁５を回転駆動する電動モータ７（アクチュエータの一例）と、低圧ＥＧＲ調整弁５を駆動するＥＧＲ駆動歯車８と、吸気弁６を駆動する吸気弁駆動歯車９とを備える。
また、低圧ＥＧＲ装置１は、吸気弁６が吸気通路３を全開に開く全開時に、吸気弁駆動歯車９に形成された凹部１１に係合するロックピン１２と、このロックピン１２を吸気弁駆動歯車９に向けて押し付けるレバー１３とを有するロック機構１４を備える。 The low pressure EGR device 1 includes an electric motor 7 (an example of an actuator) that rotationally drives the low pressure EGR adjustment valve 5, an EGR drive gear 8 that drives the low pressure EGR adjustment valve 5, and an intake valve drive gear that drives the intake valve 6. 9.
The low pressure EGR device 1 also has a lock pin 12 that engages with a recess 11 formed in the intake valve drive gear 9 when the intake valve 6 opens the intake passage 3 fully open, and the lock pin 12 is driven by the intake valve. A lock mechanism 14 having a lever 13 that is pressed toward the gear 9 is provided.

ＥＧＲ駆動歯車８には、低圧ＥＧＲ調整弁５の開度が所定開度より小さく、低圧ＥＧＲ装置１を用いて少量のＥＧＲガスをエンジン２に戻す「低濃度制御状態」の時に、吸気弁駆動歯車９に設けられた吸気弁入力ギヤ歯１５に対して非係合となり、ＥＧＲ駆動歯車８の回転力を吸気弁駆動歯車９に非伝達とするギヤ歯除去部１６が設けられる。
また、ＥＧＲ駆動歯車８には、低圧ＥＧＲ調整弁５の開度が所定開度より大きく、低圧ＥＧＲ装置１を用いて多量のＥＧＲガスをエンジン２へ戻す「高濃度制御状態」の時に、吸気弁入力ギヤ歯１５に噛合して、ＥＧＲ駆動歯車８の回転力を吸気弁駆動歯車９に伝２達し、吸気弁６の開度を可変するＥＧＲ出力ギヤ歯１７が設けられる。 The EGR drive gear 8 has an intake valve drive when the low-pressure EGR adjustment valve 5 has an opening smaller than a predetermined opening and a small amount of EGR gas is returned to the engine 2 using the low-pressure EGR device 1. A gear tooth removal unit 16 is provided that is disengaged from the intake valve input gear teeth 15 provided on the gear 9 and that does not transmit the rotational force of the EGR drive gear 8 to the intake valve drive gear 9.
Further, the EGR drive gear 8 has a low-pressure EGR adjustment valve 5 whose opening degree is larger than a predetermined opening degree, and in the “high concentration control state” in which a large amount of EGR gas is returned to the engine 2 using the low-pressure EGR device 1, EGR output gear teeth 17 are provided which mesh with the valve input gear teeth 15 to transmit the rotational force of the EGR drive gear 8 to the intake valve drive gear 9 and vary the opening degree of the intake valve 6.

さらに、ＥＧＲ駆動歯車８には、ＥＧＲ出力ギヤ歯１７が吸気弁入力ギヤ歯１５に噛合する状態の時のみレバー１３を押圧操作してロックピン１２を凹部１１から外す押圧カム１８が設けられる。
なお、電動モータ７は、歯車減速機１９を介してＥＧＲ駆動歯車８を回転駆動するように設けられており、ＥＧＲ駆動歯車８には、ＥＧＲ出力ギヤ歯１７および押圧カム１８とは別に、歯車減速機１９に噛合するＥＧＲ入力ギヤ歯２０が設けられている。 Further, the EGR drive gear 8 is provided with a pressing cam 18 that presses the lever 13 and removes the lock pin 12 from the recess 11 only when the EGR output gear teeth 17 are engaged with the intake valve input gear teeth 15.
The electric motor 7 is provided so as to rotationally drive the EGR drive gear 8 via a gear reducer 19, and the EGR drive gear 8 includes a gear separately from the EGR output gear teeth 17 and the pressing cam 18. EGR input gear teeth 20 that mesh with the speed reducer 19 are provided.

次に、低圧ＥＧＲ装置１の具体的な一例を、図１〜図６を参照して説明する。なお、本実施例において、上記［発明を実施するための形態］と同一符号は、同一機能物を示すものである。
〔エンジン吸排気システムの概略説明〕
先ず、図５、図６を参照してエンジン２の吸排気システムを説明する。
この実施例に示すエンジン２は、車両駆動用のディーゼルエンジンであり、吸気を気筒に導く吸気通路３と、気筒内で発生した排気ガスを大気中に排出する排気通路２２とを備える。 Next, a specific example of the low pressure EGR device 1 will be described with reference to FIGS. In the present embodiment, the same reference numerals as those in the [DETAILED DESCRIPTION OF THE INVENTION] denote the same functional objects.
[Outline of engine intake and exhaust system]
First, the intake / exhaust system of the engine 2 will be described with reference to FIGS.
An engine 2 shown in this embodiment is a diesel engine for driving a vehicle, and includes an intake passage 3 that guides intake air to a cylinder and an exhaust passage 22 that exhausts exhaust gas generated in the cylinder into the atmosphere.

吸気通路３は、吸気管、インテークマニホールドおよび吸気ポートの各内部通路によって構成される。
吸気管は、外気の取入口からインテークマニホールドまで吸気通路３を形成する通路部材であり、その吸気管には、エンジン２に吸い込まれる吸気中に含まれる塵や埃を除去するエアクリーナ２３、吸気量を測定する吸気センサ、ターボチャージャのコンプレッサ２４（吸気羽根車）、このコンプレッサ２４によって圧縮されて高圧になり温度上昇した吸気を強制冷却するインタークーラ２５、気筒内に吸引される吸気量の調整を行なうスロットルバルブ２６などが設けられている。
インテークマニホールドは、吸気管から供給される吸気をエンジン２の各気筒内に分配する分配管であり、その内部には流量センサの精度に悪影響を与える吸気脈動や吸気干渉を防ぐためのサージタンク２７が設けられている。
吸気ポートは、エンジン２のシリンダヘッドにおいて気筒毎に形成されて、インテークマニホールドにより分配された吸気を気筒内に導く。 The intake passage 3 is constituted by internal passages of an intake pipe, an intake manifold, and an intake port.
The intake pipe is a passage member that forms an intake passage 3 from the outside air intake port to the intake manifold. The intake pipe includes an air cleaner 23 that removes dust and dirt contained in the intake air sucked into the engine 2, and an intake air amount. An intake sensor that measures the intake air, a compressor 24 (intake impeller) of a turbocharger, an intercooler 25 that forcibly cools the intake air that has been compressed by the compressor 24 and has increased in temperature, and adjustment of the amount of intake air that is sucked into the cylinder A throttle valve 26 to perform is provided.
The intake manifold is a distribution pipe that distributes the intake air supplied from the intake pipe to each cylinder of the engine 2, and a surge tank 27 for preventing intake pulsation and intake interference that adversely affects the accuracy of the flow sensor. Is provided.
The intake port is formed for each cylinder in the cylinder head of the engine 2 and guides the intake air distributed by the intake manifold into the cylinder.

排気通路２２は、排気ポート、エキゾーストマニホールドおよび排気管の各内部通路によって構成される。
排気ポートは、吸気ポートと同様、エンジン２のシリンダヘッドにおいて気筒毎に形成されて、気筒内で発生した排気ガスをエキゾーストマニホールドへ導く。
エキゾーストマニホールドは、各排気ポートから排出される排気ガスの集合管であり、エキゾーストマニホールドの排気出口と排気管との接合部には、ターボチャージャの排気タービン２８（排気羽根車）が配置されている。
排気管は、排気タービン２８を通過した排気ガスを大気に向けて放出する通路部材であり、その排気管には、排気ガス中に含まれるパティキュレートを捕集するＤＰＦ２９（ディーゼル・パティキュレート・フィルタの略）、このＤＰＦ２９の排気上流および排気下流の排気温度を検出する排気温度センサ３０、ＤＰＦ２９の排気上流および排気下流の圧力差を検出する差圧センサ等が設けられている。 The exhaust passage 22 includes internal passages of an exhaust port, an exhaust manifold, and an exhaust pipe.
Like the intake port, the exhaust port is formed for each cylinder in the cylinder head of the engine 2 and guides exhaust gas generated in the cylinder to the exhaust manifold.
The exhaust manifold is a collecting pipe for exhaust gas discharged from each exhaust port, and an exhaust turbine 28 (exhaust impeller) of a turbocharger is disposed at a joint portion between the exhaust outlet of the exhaust manifold and the exhaust pipe. .
The exhaust pipe is a passage member that discharges exhaust gas that has passed through the exhaust turbine 28 toward the atmosphere. The exhaust pipe includes a DPF 29 (diesel particulate filter) that collects particulates contained in the exhaust gas. An exhaust temperature sensor 30 for detecting the exhaust temperature upstream and downstream of the DPF 29, a differential pressure sensor for detecting a pressure difference between the upstream and downstream of the DPF 29, and the like.

上述した吸気ポートおよび排気ポートが形成されるシリンダヘッドには、各気筒毎に、吸気ポートの出口端（吸気ポートと気筒内との境界部）を開閉する吸気バルブと、排気ポートの入口端（気筒内と排気ポートとの境界部）を開閉する排気バルブとが設けられている。
エンジン２の各気筒は、吸入、圧縮、爆発、排気の各行程を順次繰り返すものである。そして、吸気の開始時（ピストンの下降に伴う気筒内容積の増加時）に吸気バルブが開かれ、吸気の終了時（ピストンの下降終了に伴う気筒内容積の増加終了時）に吸気バルブが閉じられる。このエンジン２の吸気作動により、吸気通路３には外気取入口からエンジン２の気筒内に向かう吸気の流れが生じる。
同様に、排気の開始時（ピストンの上昇に伴う気筒内容積の減少時）に排気バルブが開かれ、排気の終了時（ピストンの上昇終了に伴う気筒内容積の減少終了時）に排気バルブが閉じられる。このエンジン２の排気作動により、排気通路２２にはエンジン２の気筒内から大気放出部（排気出口）に向かう排気ガスの流れが生じる。 In the cylinder head in which the intake port and the exhaust port are formed as described above, an intake valve that opens and closes an outlet end of the intake port (a boundary portion between the intake port and the cylinder) and an inlet end of the exhaust port (for each cylinder) An exhaust valve that opens and closes a boundary portion between the cylinder and the exhaust port is provided.
Each cylinder of the engine 2 sequentially repeats the strokes of suction, compression, explosion, and exhaust. Then, the intake valve is opened at the start of intake (when the cylinder internal volume increases as the piston descends), and the intake valve closes at the end of intake (when the cylinder internal volume increases after the piston descends). It is done. By the intake operation of the engine 2, an intake air flow is generated in the intake passage 3 from the outside air intake into the cylinder of the engine 2.
Similarly, the exhaust valve is opened at the start of exhaust (when the cylinder internal volume decreases as the piston moves up), and the exhaust valve is opened at the end of exhaust (when the cylinder internal volume decreases after the piston increases). Closed. As a result of the exhaust operation of the engine 2, an exhaust gas flow is generated in the exhaust passage 22 from the cylinder of the engine 2 toward the atmospheric discharge portion (exhaust outlet).

ここで、図５に示すエンジン２の吸排気システムには、高圧ＥＧＲ装置３１と、本発明が適用される低圧ＥＧＲ装置１とが設けられている。
高圧ＥＧＲ装置３１は、排気圧の高い排気通路２２の排気上流側と、吸気負圧の大きい吸気通路３の吸気下流側とを接続して、多量のＥＧＲガスをエンジン２へ戻すことを得意とする排気ガス再循環装置であり、排気ガスの一部をＥＧＲガスとして吸気通路３の吸気下流側に戻す高圧ＥＧＲ流路３２を備えている。ここで、この実施例の高圧ＥＧＲ流路３２は、排気通路２２側がエキゾーストマニホールドに接続され、吸気通路３側がインテークマニホールドのサージタンク２７に接続されるものである。 Here, the intake and exhaust system of the engine 2 shown in FIG. 5 is provided with a high pressure EGR device 31 and a low pressure EGR device 1 to which the present invention is applied.
The high pressure EGR device 31 is good at returning a large amount of EGR gas to the engine 2 by connecting the exhaust upstream side of the exhaust passage 22 having a high exhaust pressure and the intake downstream side of the intake passage 3 having a large intake negative pressure. The exhaust gas recirculation device is provided with a high pressure EGR flow path 32 for returning a part of the exhaust gas as EGR gas to the intake downstream side of the intake passage 3. Here, the high pressure EGR flow path 32 of this embodiment has an exhaust passage 22 side connected to the exhaust manifold and an intake passage 3 side connected to a surge tank 27 of the intake manifold.

高圧ＥＧＲ流路３２の途中には、高圧ＥＧＲ流路３２の開度を調整することでＥＧＲガスの流量調整を行なう高圧ＥＧＲ調整弁３３と、吸気側に戻されるＥＧＲガスの冷却を行なう高圧ＥＧＲクーラ３４と、吸気側に戻されるＥＧＲガスを高圧ＥＧＲクーラ３４から迂回させる高圧クーラバイパス３５と、高圧ＥＧＲクーラ３４と高圧クーラバイパス３５の切り替えを行なう高圧ＥＧＲクーラ切替弁３６とが設けられている。
なお、高圧ＥＧＲ調整弁３３、高圧ＥＧＲクーラ３４、高圧クーラバイパス３５および高圧ＥＧＲクーラ切替弁３６を、予め高圧ＥＧＲモジュールとして一体的に設けて車両に搭載することが望ましいが、限定されるものではない。 In the middle of the high pressure EGR flow path 32, a high pressure EGR adjustment valve 33 that adjusts the flow rate of the EGR gas by adjusting the opening of the high pressure EGR flow path 32, and a high pressure EGR that cools the EGR gas returned to the intake side. A cooler 34, a high-pressure cooler bypass 35 that bypasses the EGR gas returned to the intake side from the high-pressure EGR cooler 34, and a high-pressure EGR cooler switching valve 36 that switches between the high-pressure EGR cooler 34 and the high-pressure cooler bypass 35 are provided. .
It is desirable that the high-pressure EGR adjustment valve 33, the high-pressure EGR cooler 34, the high-pressure cooler bypass 35, and the high-pressure EGR cooler switching valve 36 are integrally provided in advance as a high-pressure EGR module and mounted on the vehicle. Absent.

低圧ＥＧＲ装置１は、排気圧の低い排気通路２２の排気下流側と、吸気負圧の小さい吸気通路３の吸気上流側とを接続して、少量のＥＧＲガスをエンジン２に戻すことを得意とする排気ガス再循環装置であり、排気ガスの一部をＥＧＲガスとして吸気通路３の吸気上流側に戻す低圧ＥＧＲ流路４を備えている。ここで、この実施例の低圧ＥＧＲ流路４は、排気通路２２側がＤＰＦ２９より排気下流側の排気管に接続され、吸気通路３側がターボチャージャのコンプレッサ２４より吸気上流側の吸気管に接続されるものである。   The low pressure EGR device 1 is good at returning a small amount of EGR gas to the engine 2 by connecting the exhaust downstream side of the exhaust passage 22 having a low exhaust pressure and the intake upstream side of the intake passage 3 having a low intake negative pressure. The exhaust gas recirculation device is provided with a low pressure EGR flow path 4 for returning a part of the exhaust gas to the intake upstream side of the intake passage 3 as EGR gas. Here, in the low pressure EGR flow path 4 of this embodiment, the exhaust passage 22 side is connected to the exhaust pipe downstream of the DPF 29, and the intake passage 3 side is connected to the intake pipe upstream of the compressor 24 of the turbocharger. Is.

低圧ＥＧＲ流路４の途中には、低圧ＥＧＲ流路４の開度を調整することでＥＧＲガスの流量調整を行なう低圧ＥＧＲ調整弁５と、吸気側に戻されるＥＧＲガスの冷却を行なう低圧ＥＧＲクーラ３７とが設けられている。
一方、吸気管における低圧ＥＧＲ流路４の接続部分より吸気上流側には、低圧ＥＧＲ流路４の接続部分に吸気負圧を発生させるための吸気弁６（吸気負圧発生用バルブ）が設けられている。この吸気弁６は、吸気通路３を最大に絞った状態であっても、吸気通路３の一部を開放するように設けられるものである。具体的には、吸気弁６が吸気通路３を最大に絞った状態であっても、吸気通路３の例えば１０％ほどを開放するように設けられるものである（図４の破線Ｙの最小開度参照）。
なお、低圧ＥＧＲ調整弁５、吸気弁６、低圧ＥＧＲクーラ３７を、予め低圧ＥＧＲモジュールとして一体的に設けて車両に搭載することが望ましいが、限定されるものではない。 In the middle of the low pressure EGR flow path 4, a low pressure EGR adjustment valve 5 that adjusts the flow rate of the EGR gas by adjusting the opening degree of the low pressure EGR flow path 4, and a low pressure EGR that cools the EGR gas returned to the intake side. A cooler 37 is provided.
On the other hand, an intake valve 6 (an intake negative pressure generating valve) for generating intake negative pressure at the connection portion of the low pressure EGR flow path 4 is provided upstream of the connection portion of the low pressure EGR flow path 4 in the intake pipe. It has been. The intake valve 6 is provided so as to open a part of the intake passage 3 even when the intake passage 3 is squeezed to the maximum. Specifically, even if the intake valve 6 is in a state where the intake passage 3 is squeezed to the maximum, for example, about 10% of the intake passage 3 is opened (the minimum opening of the broken line Y in FIG. 4). See degree).
It is desirable that the low-pressure EGR adjustment valve 5, the intake valve 6, and the low-pressure EGR cooler 37 are integrally provided in advance as a low-pressure EGR module, but are not limited thereto.

ここで、高圧ＥＧＲクーラ３４および低圧ＥＧＲクーラ３７は、エンジン２を循環冷却するエンジン冷却水と、高温のＥＧＲガスとの熱交換を行なって高温のＥＧＲガスを冷却する水冷式ガス冷却器であり、エンジン冷却水とＥＧＲガスとの熱交換を行なう熱交換器を備えるものである。
また、高圧ＥＧＲ装置３１における高圧ＥＧＲ調整弁３３と高圧ＥＧＲクーラ切替弁３６、および低圧ＥＧＲ装置１における低圧ＥＧＲ調整弁５と吸気弁６は、ＥＣＵによってバルブの開度（切替を含む）が制御されるものである。 Here, the high-pressure EGR cooler 34 and the low-pressure EGR cooler 37 are water-cooled gas coolers that perform heat exchange between engine cooling water that circulates and cools the engine 2 and high-temperature EGR gas to cool high-temperature EGR gas. A heat exchanger for exchanging heat between the engine coolant and the EGR gas is provided.
The high pressure EGR adjustment valve 33 and the high pressure EGR cooler switching valve 36 in the high pressure EGR device 31 and the low pressure EGR adjustment valve 5 and the intake valve 6 in the low pressure EGR device 1 are controlled by the ECU in terms of valve opening (including switching). It is what is done.

ＥＣＵは、制御処理、演算処理を行うＣＰＵ、各種プログラムおよびデータを保存する記憶装置（ＲＯＭやＲＡＭ等のメモリ）、入力回路、出力回路等の機能を含んで構成される周知構造のマイクロコンピュータを搭載するエンジン制御用の電子制御装置である。
このＥＣＵは、記憶装置に格納された制御プログラムと、種々のセンサ信号（乗員の操作信号、各種検出センサ信号等）とに基づいて、エンジン２の運転制御（燃料噴射制御など）を行なうものであり、このＥＣＵの記憶装置には、高圧ＥＧＲ装置３１および低圧ＥＧＲ装置１の運転制御を行なうＥＧＲ制御プログラムが搭載されている。 The ECU includes a microcomputer having a well-known structure that includes functions of a CPU that performs control processing and arithmetic processing, a storage device (memory such as ROM and RAM) that stores various programs and data, an input circuit, and an output circuit. This is an electronic control device for engine control.
This ECU performs operation control (fuel injection control, etc.) of the engine 2 based on a control program stored in the storage device and various sensor signals (occupant operation signals, various detection sensor signals, etc.). In addition, an EGR control program for controlling the operation of the high-pressure EGR device 31 and the low-pressure EGR device 1 is installed in the storage device of the ECU.

このＥＧＲ制御プログラムは、エンジン２の暖気状態（例えば、エンジン冷却水の温度）に基づいて高圧ＥＧＲクーラ切替弁３６の切り替えを行なう高圧ＥＧＲクーラ切替プログラムと、エンジン回転数とエンジン負荷（エンジントルク）に応じて高圧ＥＧＲ調整弁３３、低圧ＥＧＲ調整弁５および吸気弁６の開度制御を行なう高圧／低圧ＥＧＲ量制御プログラムとを備えている。   The EGR control program includes a high-pressure EGR cooler switching program for switching the high-pressure EGR cooler switching valve 36 based on the warm-up state of the engine 2 (for example, the temperature of engine cooling water), the engine speed and the engine load (engine torque). And a high-pressure / low-pressure EGR amount control program for controlling the opening degree of the high-pressure EGR adjustment valve 33, the low-pressure EGR adjustment valve 5, and the intake valve 6.

高圧／低圧ＥＧＲ量制御プログラムを図６を参照して説明する。
高圧／低圧ＥＧＲ量制御プログラムは、
（ｉ）図６に示す破線α以下における運転領域（エンジン回転数とエンジントルクの関係によるエンジン運転領域）の時に、低圧ＥＧＲ装置１を停止させ、高圧ＥＧＲ装置３１の高圧ＥＧＲ調整弁３３の開度制御のみによってＥＧＲ制御を行い（具体的には、低圧ＥＧＲ流路４を低圧ＥＧＲ調整弁５によって閉塞させ、高圧ＥＧＲ調整弁３３をエンジン回転数とエンジントルクの関係に応じた開度に制御する）、
（ｉｉ）図６に示す破線αと破線βの間の運転領域の時に、高圧ＥＧＲ装置３１の高圧ＥＧＲ調整弁３３の開度制御と、低圧ＥＧＲ装置１の低圧ＥＧＲ調整弁５の開度制御の両方によってＥＧＲ制御を行い（具体的には、高圧ＥＧＲ調整弁３３をエンジン回転数とエンジントルクの関係に応じた開度に制御するとともに、低圧ＥＧＲ調整弁５および吸気弁６をエンジン回転数とエンジントルクの関係に応じた開度に制御する）、
（ｉｉｉ）図６に示す破線β以上における運転領域の時に、高圧ＥＧＲ装置３１を停止させ、低圧ＥＧＲ装置１の低圧ＥＧＲ調整弁５の開度制御のみによってＥＧＲ制御を行う（具体的には、高圧ＥＧＲ流路３２を高圧ＥＧＲ調整弁３３によって閉塞させ、低圧ＥＧＲ調整弁５および吸気弁６をエンジン回転数とエンジントルクの関係に応じた開度に制御する）制御プログラムである。 The high pressure / low pressure EGR amount control program will be described with reference to FIG.
The high pressure / low pressure EGR amount control program is
(I) In the operation region below the broken line α shown in FIG. 6 (engine operation region based on the relationship between the engine speed and the engine torque), the low pressure EGR device 1 is stopped and the high pressure EGR adjustment valve 33 of the high pressure EGR device 31 is opened. EGR control is performed only by degree control (specifically, the low pressure EGR flow path 4 is closed by the low pressure EGR adjustment valve 5, and the high pressure EGR adjustment valve 33 is controlled to an opening degree corresponding to the relationship between the engine speed and the engine torque. )
(Ii) Opening control of the high pressure EGR adjustment valve 33 of the high pressure EGR device 31 and opening control of the low pressure EGR adjustment valve 5 of the low pressure EGR device 1 in the operation region between the broken line α and the broken line β shown in FIG. (Specifically, the high pressure EGR adjustment valve 33 is controlled to an opening degree corresponding to the relationship between the engine speed and the engine torque, and the low pressure EGR adjustment valve 5 and the intake valve 6 are controlled to the engine speed). And the opening according to the relationship between the engine torque)
(Iii) In the operation region above the broken line β shown in FIG. 6, the high pressure EGR device 31 is stopped and the EGR control is performed only by the opening degree control of the low pressure EGR adjustment valve 5 of the low pressure EGR device 1 (specifically, The high-pressure EGR flow path 32 is closed by the high-pressure EGR adjustment valve 33, and the low-pressure EGR adjustment valve 5 and the intake valve 6 are controlled to an opening degree according to the relationship between the engine speed and the engine torque.

〔実施例１の特徴技術〕
低圧ＥＧＲ装置１は、低排気圧範囲のＥＧＲガスを、低吸気負圧発生範囲に戻すものであるため、少量のＥＧＲガスをエンジン２に戻すことを得意とする。しかるに、低圧ＥＧＲ装置１を用いて多量のＥＧＲガスをエンジン２へ戻したい運転領域が存在しても、低吸気負圧発生範囲にＥＧＲガスを戻す構造の低圧ＥＧＲ装置１では多量のＥＧＲガスをエンジン２へ戻すことが困難である。
そこで、この実施例１では、低圧ＥＧＲ装置１がＥＧＲガスを戻す部位の吸気通路３に大きな吸気負圧を発生させるための吸気弁６を設け、低圧ＥＧＲ装置１において大きなＥＧＲ量を得たい運転領域では、吸気弁６を閉じる方向（吸気負圧が発生する方向）に開度制御し、低圧ＥＧＲ装置１において多量のＥＧＲ量をコントロールすることを可能にしている。 [Characteristics of Example 1]
The low pressure EGR device 1 is good at returning a small amount of EGR gas to the engine 2 because it returns EGR gas in the low exhaust pressure range to the low intake negative pressure generation range. However, even if there is an operation region in which a large amount of EGR gas is desired to be returned to the engine 2 using the low pressure EGR device 1, the low pressure EGR device 1 having a structure for returning the EGR gas to the low intake negative pressure generation range is capable of supplying a large amount of EGR gas. It is difficult to return to the engine 2.
Therefore, in the first embodiment, an intake valve 6 for generating a large intake negative pressure is provided in the intake passage 3 where the low-pressure EGR device 1 returns EGR gas, and the low-pressure EGR device 1 is intended to obtain a large EGR amount. In the region, the opening degree is controlled in the direction in which the intake valve 6 is closed (the direction in which the intake negative pressure is generated), so that a large amount of EGR can be controlled in the low pressure EGR device 1.

しかし、吸気弁６は、（ｉ）低圧ＥＧＲ装置１を用いて少量のＥＧＲガスをエンジン２へ戻す「低濃度制御状態」の時に、負圧を発生させないように最大開度で固定され、低圧ＥＧＲ調整弁５のみを開度制御する必要があり、（ｉｉ）低圧ＥＧＲ装置１を用いて多量のＥＧＲガスをエンジン２へ戻す「高濃度制御状態」の時は、低圧ＥＧＲ調整弁５の開度の増加とともに、負圧を増加させるべく吸気弁６の開度を小さくする必要がある。   However, the intake valve 6 is fixed at the maximum opening so as not to generate negative pressure in the “low concentration control state” in which a small amount of EGR gas is returned to the engine 2 using the low pressure EGR device 1. Only the EGR adjustment valve 5 needs to be controlled in opening degree. (Ii) In the “high concentration control state” in which a large amount of EGR gas is returned to the engine 2 using the low pressure EGR device 1, the low pressure EGR adjustment valve 5 is opened. As the degree increases, it is necessary to reduce the opening of the intake valve 6 in order to increase the negative pressure.

このように、低圧ＥＧＲ調整弁５と吸気弁６は、それぞれが別の運転要因に基づいて独立して操作される。
このため、従来技術では、低圧ＥＧＲ調整弁５を駆動するための専用のアクチュエータＪ１（符号は図８参照）と、吸気弁６を駆動するための専用のアクチュエータＪ２（符号は図８参照）とが必要となり、コストアップ、体格アップ、重量アップの要因になっていた。 Thus, the low pressure EGR adjustment valve 5 and the intake valve 6 are independently operated based on different operating factors.
For this reason, in the prior art, a dedicated actuator J1 for driving the low-pressure EGR adjustment valve 5 (see FIG. 8 for the sign) and a dedicated actuator J2 for driving the intake valve 6 (see FIG. 8 for the sign) Was required, which was a factor in increasing costs, building up, and increasing weight.

そこで、この実施例１の低圧ＥＧＲ装置１は、上記に示す従来技術の不具合を解決するために、以下に示す技術を採用している。この解決技術を、図１〜図４を参照して説明する。なお、図４の実線Ｘは低圧ＥＧＲ調整弁５の回転角と開度（Ｑ）の関係を示し、図４の破線Ｙは低圧ＥＧＲ調整弁５の回転角に対する吸気弁６の開度（Ｑ）の関係を示すものである。   Therefore, the low-pressure EGR device 1 according to the first embodiment employs the following technique in order to solve the problems of the prior art described above. This solution technology will be described with reference to FIGS. 4 indicates the relationship between the rotation angle of the low pressure EGR adjustment valve 5 and the opening degree (Q), and the broken line Y in FIG. 4 indicates the opening degree (Q of the intake valve 6 relative to the rotation angle of the low pressure EGR adjustment valve 5. ).

低圧ＥＧＲ装置１は、低圧ＥＧＲ調整弁５を回転駆動する電動モータ７と、低圧ＥＧＲ調整弁５を駆動するＥＧＲ駆動歯車８と、吸気弁６を駆動する吸気弁駆動歯車９とを備える。
電動モータ７は、通電により回転動力を発生する周知のものであり、この実施例では通電による回転角度制御が可能なＤＣモータを用いるものである。また、この実施例１の電動モータ７は、歯車減速機１９を介してＥＧＲ駆動歯車８を回転駆動するように設けられており、ＥＧＲ駆動歯車８には、後述するＥＧＲ出力ギヤ歯１７および押圧カム１８とは別に、歯車減速機１９に噛合するＥＧＲ入力ギヤ歯２０が設けられている。 The low pressure EGR device 1 includes an electric motor 7 that rotationally drives the low pressure EGR adjustment valve 5, an EGR drive gear 8 that drives the low pressure EGR adjustment valve 5, and an intake valve drive gear 9 that drives the intake valve 6.
The electric motor 7 is a known motor that generates rotational power when energized. In this embodiment, a DC motor capable of controlling the rotation angle by energization is used. The electric motor 7 according to the first embodiment is provided so as to rotationally drive an EGR drive gear 8 via a gear reducer 19. The EGR drive gear 8 includes an EGR output gear tooth 17 and a pressing force described later. Apart from the cam 18, EGR input gear teeth 20 that mesh with the gear reducer 19 are provided.

この歯車減速機１９を具体的に説明する。歯車減速機１９は、電動モータ７の出力軸に設けられた小径のピニオンギヤ４１に噛合する大径ギヤ４２と、この大径ギヤ４２と一体的に回転する小径ギヤ４３とからなり、この小径ギヤ４３がＥＧＲ入力ギヤ歯２０に噛合するように設けられている。なお、大径ギヤ４２および小径ギヤ４３は一体成形されたものであり、その支持シャフト４４は、低圧ＥＧＲ流路４の一部を成す通路形成部材Ｈ（ハウジング）に取り付けられた軸受部４５によって回転自在に支持されるものである。   The gear reducer 19 will be specifically described. The gear reducer 19 includes a large-diameter gear 42 that meshes with a small-diameter pinion gear 41 provided on the output shaft of the electric motor 7, and a small-diameter gear 43 that rotates integrally with the large-diameter gear 42. 43 is provided so as to mesh with the EGR input gear teeth 20. The large-diameter gear 42 and the small-diameter gear 43 are integrally formed, and the support shaft 44 is supported by a bearing portion 45 attached to a passage forming member H (housing) that forms part of the low-pressure EGR flow path 4. It is supported rotatably.

ＥＧＲ駆動歯車８は、低圧ＥＧＲ調整弁５が設けられたＥＧＲ弁支持シャフト５１の端部に固定されたものであり、低圧ＥＧＲ調整弁５と一体に回転するものである。このＥＧＲ弁支持シャフト５１は、低圧ＥＧＲ調整弁５の両側に配置された軸受部５２、５３により回転自在に支持される。
ここで、ＥＧＲ駆動歯車８は、耐摩耗性に優れた材料（例えば、ナイロン系樹脂など）により成形されたものであり、ＥＧＲ駆動歯車８の一部には、通路形成部材Ｈに挿入配置される挿入筒部が設けられ、その挿入筒部がＥＧＲ弁支持シャフト５１の一方の軸受部５３を兼ねるように設けられている。 The EGR drive gear 8 is fixed to the end portion of the EGR valve support shaft 51 provided with the low pressure EGR adjustment valve 5, and rotates integrally with the low pressure EGR adjustment valve 5. The EGR valve support shaft 51 is rotatably supported by bearing portions 52 and 53 disposed on both sides of the low pressure EGR adjustment valve 5.
Here, the EGR drive gear 8 is formed of a material having excellent wear resistance (for example, nylon resin), and is inserted into the passage forming member H in a part of the EGR drive gear 8. The insertion cylinder portion is provided so that the insertion cylinder portion also serves as one bearing portion 53 of the EGR valve support shaft 51.

吸気弁駆動歯車９は、吸気弁６が設けられた吸気弁支持シャフト５４の端部に固定されたものであり、吸気弁６と一体に回転するものである。この吸気弁支持シャフト５４も、ＥＧＲ弁支持シャフト５１と同様、吸気弁６の両側に配置された軸受部５５、５６により回転自在に支持される。
ここで、吸気弁駆動歯車９は、耐摩耗性に優れた材料（例えば、ナイロン系樹脂など）により成形されたものであり、吸気弁駆動歯車９の一部には、通路形成部材Ｈに挿入配置される挿入筒部が設けられ、その挿入筒部が吸気弁支持シャフト５４の一方の軸受部５６を兼ねるように設けられている。 The intake valve drive gear 9 is fixed to the end of the intake valve support shaft 54 provided with the intake valve 6, and rotates integrally with the intake valve 6. Similarly to the EGR valve support shaft 51, the intake valve support shaft 54 is also rotatably supported by bearing portions 55 and 56 disposed on both sides of the intake valve 6.
Here, the intake valve drive gear 9 is formed of a material having excellent wear resistance (for example, nylon resin), and a part of the intake valve drive gear 9 is inserted into the passage forming member H. An insertion cylinder portion to be disposed is provided, and the insertion cylinder portion is provided so as to serve also as one bearing portion 56 of the intake valve support shaft 54.

なお、ＥＧＲ駆動歯車８に伝えられた回転トルクが吸気弁駆動歯車９に増幅されて伝達するように、ＥＧＲ駆動歯車８の歯車径が大径で、吸気弁駆動歯車９の歯車径が小径に設けられている。
また、ＥＧＲ弁支持シャフト５１および吸気弁支持シャフト５４に装着された符号５７、５８は、ＥＧＲガスが外部へ漏れるのを防ぐシール部材（Ｏリング等）である。 The gear diameter of the EGR drive gear 8 is large and the gear diameter of the intake valve drive gear 9 is small so that the rotational torque transmitted to the EGR drive gear 8 is amplified and transmitted to the intake valve drive gear 9. Is provided.
Reference numerals 57 and 58 attached to the EGR valve support shaft 51 and the intake valve support shaft 54 are seal members (O-rings or the like) that prevent EGR gas from leaking to the outside.

低圧ＥＧＲ装置１は、吸気弁６を最大開度に切り替えた状態で固定するロック機構１４を備える。このロック機構１４は、吸気弁６が最大開度の時に、吸気弁駆動歯車９に形成された凹部１１に係合するロックピン１２と、このロックピン１２を吸気弁駆動歯車９に向けて押し付けるレバー１３とを有する。   The low pressure EGR device 1 includes a lock mechanism 14 that fixes the intake valve 6 in a state where the intake valve 6 is switched to the maximum opening. The lock mechanism 14 has a lock pin 12 that engages with a recess 11 formed in the intake valve drive gear 9 and presses the lock pin 12 toward the intake valve drive gear 9 when the intake valve 6 has a maximum opening. And a lever 13.

具体的に、この実施例に用いるレバー１３は、弾性変形可能な板バネ等による長手部材であり、一端には凹部１１に係合可能なロックピン１２が結合固定されている。また、レバー１３は、ロックピン１２が凹部１１に押し付けられる方向で、且つレバー１３の中間部がＥＧＲ駆動歯車８の外周縁に押し付けられる方向（ＥＧＲ駆動歯車８の内径方向）に付勢されるように、レバー１３の他端が固定部材（例えば、通路形成部材Ｈなど）によって固定支持されている。   Specifically, the lever 13 used in this embodiment is a longitudinal member made of an elastically deformable leaf spring or the like, and a lock pin 12 that can be engaged with the recess 11 is coupled and fixed at one end. The lever 13 is biased in the direction in which the lock pin 12 is pressed against the recess 11 and in the direction in which the intermediate portion of the lever 13 is pressed against the outer peripheral edge of the EGR drive gear 8 (inner diameter direction of the EGR drive gear 8). In this way, the other end of the lever 13 is fixedly supported by a fixing member (for example, a passage forming member H).

ここで、レバー１３は、ロックピン１２が凹部１１に係合した状態（吸気弁６が最大開度に切り替えられた状態）でも、ロックピン１２が凹部１１の底に向かって若干付勢されるように設けられている。また、この実施例のロック機構１４は、レバー１３がＥＧＲ駆動歯車８を挟み付けるように、レバー１３やロックピン１２等が対向して設けられている。
このように設けられることで、吸気弁６が最大開度に切り替えられた状態において吸気弁６が強固にロックされる。これにより、吸気通路３に異常な高圧脈動が生じたとしても、その脈動により吸気弁６が振動する不具合が生じない。 Here, the lever 13 is slightly biased toward the bottom of the recess 11 even when the lock pin 12 is engaged with the recess 11 (the intake valve 6 is switched to the maximum opening). It is provided as follows. Further, the lock mechanism 14 of this embodiment is provided with the lever 13 and the lock pin 12 facing each other so that the lever 13 sandwiches the EGR drive gear 8.
By providing in this way, the intake valve 6 is firmly locked in a state where the intake valve 6 is switched to the maximum opening. Thereby, even if an abnormal high pressure pulsation occurs in the intake passage 3, there is no problem that the intake valve 6 vibrates due to the pulsation.

ＥＧＲ駆動歯車８には、低圧ＥＧＲ調整弁５の開度が所定開度（図４における開度Ｚ）より小さく、低圧ＥＧＲ装置１を用いて少量のＥＧＲガスをエンジン２へ戻す「低濃度制御状態」の時に、吸気弁駆動歯車９に設けられた吸気弁入力ギヤ歯１５に対して非係合となり、ＥＧＲ駆動歯車８の回転力を吸気弁駆動歯車９に非伝達とするギヤ歯除去部１６（吸気弁入力ギヤ歯１５と噛合不能なギヤ歯の無い平滑部）が設けられている。   In the EGR drive gear 8, the low-pressure EGR adjustment valve 5 has an opening smaller than a predetermined opening (opening Z in FIG. 4), and a small amount of EGR gas is returned to the engine 2 using the low-pressure EGR device 1. In the state, the gear tooth removal portion is disengaged from the intake valve input gear teeth 15 provided on the intake valve drive gear 9 and does not transmit the rotational force of the EGR drive gear 8 to the intake valve drive gear 9. 16 (a smooth portion having no gear teeth that cannot mesh with the intake valve input gear teeth 15) is provided.

また、ＥＧＲ駆動歯車８には、低圧ＥＧＲ調整弁５の開度が所定開度（図４における開度Ｚ）より大きく、低圧ＥＧＲ装置１を用いて多量のＥＧＲガスをエンジン２へ戻す「高濃度制御状態」の時に、吸気弁入力ギヤ歯１５に噛合して、ＥＧＲ駆動歯車８の回転力を吸気弁駆動歯車９に伝達して吸気弁６の開度を可変するＥＧＲ出力ギヤ歯１７が設けられている。   Further, the opening of the low pressure EGR adjustment valve 5 is larger than a predetermined opening (opening Z in FIG. 4) in the EGR drive gear 8, and a large amount of EGR gas is returned to the engine 2 using the low pressure EGR device 1. In the “concentration control state”, the EGR output gear teeth 17 that mesh with the intake valve input gear teeth 15 and transmit the rotational force of the EGR drive gear 8 to the intake valve drive gear 9 to vary the opening of the intake valve 6 are provided. Is provided.

さらに、ＥＧＲ駆動歯車８には、ＥＧＲ出力ギヤ歯１７が吸気弁入力ギヤ歯１５に噛合する状態の時のみ（低圧ＥＧＲ調整弁５の開度が所定開度より大きく、低圧ＥＧＲ装置１を用いて多量のＥＧＲガスをエンジン２へ戻す「高濃度制御状態」の時のみ）、レバー１３を解除側に押圧操作してロックピン１２を凹部１１から外す押圧カム１８が設けられている。   Further, the EGR drive gear 8 uses the low pressure EGR device 1 only when the EGR output gear teeth 17 are engaged with the intake valve input gear teeth 15 (the opening of the low pressure EGR adjustment valve 5 is larger than a predetermined opening). In the “high concentration control state” in which a large amount of EGR gas is returned to the engine 2), a pressing cam 18 for pressing the lever 13 to the release side and removing the lock pin 12 from the recess 11 is provided.

〔低圧ＥＧＲ装置１を用いて少量のＥＧＲガスをエンジン２に戻す低濃度制御の作動〕
エンジン２の運転状態が、エンジン負荷が大きい運転状態（例えば、エンジン２の運転状態が図６の破線β以上における運転領域の時）など、低圧ＥＧＲ装置１に「低濃度制御状態」が望まれる運転状態になると、ＥＣＵは次のように低圧ＥＧＲ装置１の作動を制御する。
（１）先ず、ＥＣＵは、吸気弁６が最大開度に切り替わった状態に設定されているか否かの判断を行なう。即ち、ＥＣＵは、低圧ＥＧＲ装置１の運転状態が「低濃度制御状態」であるか、あるいは「高濃度制御状態」であるかの判断を行なう。 [Low-concentration control operation that returns a small amount of EGR gas to the engine 2 using the low-pressure EGR device 1]
The low pressure EGR device 1 is desired to have a “low concentration control state”, such as when the engine 2 is in an operating state where the engine load is heavy (for example, when the operating state of the engine 2 is in the operating region above the broken line β in FIG. When in the operating state, the ECU controls the operation of the low-pressure EGR device 1 as follows.
(1) First, the ECU determines whether or not the intake valve 6 is set to the maximum opening degree. That is, the ECU determines whether the operating state of the low pressure EGR device 1 is the “low concentration control state” or the “high concentration control state”.

（２）吸気弁６が最大開度に切り替わっていない状態であるとＥＣＵが判断した場合（低圧ＥＧＲ装置１の運転状態が「高濃度制御状態」の場合）、ＥＧＲ駆動歯車８と吸気弁駆動歯車９が噛合した状態であるため、ＥＣＵは、電動モータ７を作動させて低圧ＥＧＲ調整弁５の開度を所定開度（図４における開度Ｚ）より小さくする。すると、図２（ａ）に示すように、ＥＧＲ駆動歯車８と吸気弁駆動歯車９が非噛合状態となるとともに、ロック機構１４により吸気弁６が最大開度でロックされる。即ち、低圧ＥＧＲ装置１の運転状態が「低濃度制御状態」に切り替わる。 (2) When the ECU determines that the intake valve 6 is not switched to the maximum opening (when the operation state of the low pressure EGR device 1 is “high concentration control state”), the EGR drive gear 8 and the intake valve drive Since the gear 9 is engaged, the ECU operates the electric motor 7 to make the opening of the low pressure EGR adjustment valve 5 smaller than a predetermined opening (opening Z in FIG. 4). Then, as shown in FIG. 2A, the EGR drive gear 8 and the intake valve drive gear 9 are brought into a non-meshing state, and the intake valve 6 is locked at the maximum opening degree by the lock mechanism 14. That is, the operating state of the low pressure EGR device 1 is switched to the “low concentration control state”.

（３）吸気弁６が最大開度でロックされた状態（「低濃度制御状態」に切り替わった状態）では、ＥＧＲ駆動歯車８と吸気弁駆動歯車９が非噛合状態となり、電動モータ７の出力は低圧ＥＧＲ調整弁５に伝達されるが、吸気弁６には伝達されない状態になる。このため、ＥＣＵは、電動モータ７によって低圧ＥＧＲ調整弁５を回動制御してＥＧＲ量をコントロールすることができる。即ち、ＥＣＵは、図３（ａ）に示すように、吸気弁６を最大開度でロックした状態のままで、低圧ＥＧＲ調整弁５を回動制御することができ、低圧ＥＧＲ装置１を用いて少量のＥＧＲガスをエンジン２へ戻すことができる。 (3) In a state in which the intake valve 6 is locked at the maximum opening (a state in which the intake valve 6 is switched to the “low concentration control state”), the EGR drive gear 8 and the intake valve drive gear 9 are disengaged, and the output of the electric motor 7 Is transmitted to the low pressure EGR regulating valve 5 but is not transmitted to the intake valve 6. For this reason, the ECU can control the EGR amount by rotationally controlling the low pressure EGR adjustment valve 5 by the electric motor 7. That is, as shown in FIG. 3A, the ECU can control the rotation of the low pressure EGR adjustment valve 5 while keeping the intake valve 6 locked at the maximum opening, and uses the low pressure EGR device 1. A small amount of EGR gas can be returned to the engine 2.

〔低圧ＥＧＲ装置１を用いて多量のＥＧＲガスをエンジン２に戻す高濃度制御の作動〕
エンジン２の運転状態が、エンジン負荷が中程度の運転状態（例えば、エンジン２の運転状態が図６の破線αと破線βの間における運転領域の時）など、低圧ＥＧＲ調整弁５に「高濃度制御状態」が望まれる運転状態になると、ＥＣＵは次のように低圧ＥＧＲ装置１の作動を制御する。
（１）先ず、ＥＣＵは、吸気弁６が最大開度に切り替わった状態に設定されているか否かの判断を行なう。即ち、ＥＣＵは、低圧ＥＧＲ装置１の運転状態が「低濃度制御状態」であるか、あるいは「高濃度制御状態」であるかの判断を行なう。 [High-concentration control operation that returns a large amount of EGR gas to the engine 2 using the low-pressure EGR device 1]
When the engine 2 is in an operation state where the engine load is medium (for example, when the operation state of the engine 2 is in the operation region between the broken line α and the broken line β in FIG. 6), When the operation state in which the “density control state” is desired, the ECU controls the operation of the low-pressure EGR device 1 as follows.
(1) First, the ECU determines whether or not the intake valve 6 is set to the maximum opening degree. That is, the ECU determines whether the operating state of the low pressure EGR device 1 is the “low concentration control state” or the “high concentration control state”.

（２）吸気弁６が最大開度に切り替わっている状態であるとＥＣＵが判断した場合（低圧ＥＧＲ装置１の運転状態が「低濃度制御状態」の場合）、ＥＧＲ駆動歯車８と吸気弁駆動歯車９が噛合していない状態であるため、ＥＣＵは、電動モータ７を作動させて低圧ＥＧＲ調整弁５の開度を所定開度（図４における開度Ｚ）より大きくする。すると、図２（ｂ）に示すように、ロック機構１４による吸気弁６のロックが解除されるとともに、図２（ｃ）に示すように、ＥＧＲ駆動歯車８と吸気弁駆動歯車９が噛合状態となる。即ち、低圧ＥＧＲ装置１の運転状態が「高濃度制御状態」に切り替わる。 (2) When the ECU determines that the intake valve 6 is switched to the maximum opening degree (when the operation state of the low pressure EGR device 1 is “low concentration control state”), the EGR drive gear 8 and the intake valve drive Since the gear 9 is not engaged, the ECU operates the electric motor 7 to increase the opening of the low pressure EGR adjustment valve 5 from a predetermined opening (opening Z in FIG. 4). Then, as shown in FIG. 2 (b), the lock of the intake valve 6 by the lock mechanism 14 is released, and as shown in FIG. 2 (c), the EGR drive gear 8 and the intake valve drive gear 9 are engaged. It becomes. That is, the operation state of the low pressure EGR device 1 is switched to the “high concentration control state”.

（３）吸気弁６のロックが解除された状態（「高濃度制御状態」に切り替わった状態）では、ＥＧＲ駆動歯車８と吸気弁駆動歯車９が噛合状態であるため、ＥＣＵは、電動モータ７によって、低圧ＥＧＲ調整弁５の開度増加制御と、負圧増加制御（吸気弁６の開度減少制御）とを同時にコントロールすることができる。即ち、ＥＣＵは、図３（ｂ）に示すように、低圧ＥＧＲ調整弁５と吸気弁６を同時にコントロールすることができ、低圧ＥＧＲ装置１により多量のＥＧＲガスをコントロールすることができる。
このとき、ＥＧＲ駆動歯車８の歯車径が大径で、吸気弁駆動歯車９の歯車径が小径に設けられているため、図３（ｂ）に示すように、低圧ＥＧＲ調整弁５の開度変化が小さくても、吸気弁６が大きく開度変化することができる。 (3) Since the EGR drive gear 8 and the intake valve drive gear 9 are meshed in a state where the lock of the intake valve 6 is released (a state in which the intake valve 6 is switched to the “high concentration control state”), the ECU Thus, the opening degree increase control of the low pressure EGR adjustment valve 5 and the negative pressure increase control (opening degree reduction control of the intake valve 6) can be controlled simultaneously. That is, the ECU can simultaneously control the low pressure EGR adjustment valve 5 and the intake valve 6 as shown in FIG. 3B, and can control a large amount of EGR gas by the low pressure EGR device 1.
At this time, since the gear diameter of the EGR drive gear 8 is large and the gear diameter of the intake valve drive gear 9 is small, the opening of the low pressure EGR adjustment valve 5 is shown in FIG. Even if the change is small, the opening degree of the intake valve 6 can be greatly changed.

〔実施例１の効果〕
この実施例１の低圧ＥＧＲ装置１は、上述したように、１つの電動モータ７によって低圧ＥＧＲ調整弁５を回動操作するのみで、（ｉ）吸気弁６を最大開度に設定した状態を保ったままで、低圧ＥＧＲ調整弁５を回動操作して、少量のＥＧＲ量をエンジン２へ戻すことができるとともに、（ｉｉ）低圧ＥＧＲ調整弁５の開度調整と、吸気弁６の開度調整とを同時に回動操作して、低圧ＥＧＲ装置１を用いて多量のＥＧＲ量をエンジン２へ戻すことができる。 [Effect of Example 1]
As described above, the low pressure EGR device 1 according to the first embodiment only rotates the low pressure EGR adjustment valve 5 with one electric motor 7, and (i) the state where the intake valve 6 is set to the maximum opening degree. While maintaining this, the low pressure EGR adjustment valve 5 can be rotated to return a small amount of EGR to the engine 2, and (ii) the opening adjustment of the low pressure EGR adjustment valve 5 and the opening of the intake valve 6 A large amount of EGR can be returned to the engine 2 by using the low pressure EGR device 1 by simultaneously rotating the adjustment.

即ち、この実施例１の低圧ＥＧＲ装置１は、低圧ＥＧＲ調整弁５と吸気弁６の両方を１つの電動モータ７で駆動可能であり、且つ低圧ＥＧＲ調整弁５に要求される特性と吸気弁６に要求される特性の両方を満足することができる。
このように、低圧ＥＧＲ調整弁５と吸気弁６の両方を１つの電動モータ７で駆動できるため、低圧ＥＧＲ装置１のコストを抑えることができるとともに、低圧ＥＧＲ装置１の小型化および軽量化を図ることができる。 That is, the low-pressure EGR device 1 of the first embodiment can drive both the low-pressure EGR adjustment valve 5 and the intake valve 6 with one electric motor 7, and the characteristics required for the low-pressure EGR adjustment valve 5 and the intake valve Both of the characteristics required for 6 can be satisfied.
Thus, since both the low pressure EGR adjustment valve 5 and the intake valve 6 can be driven by one electric motor 7, the cost of the low pressure EGR device 1 can be reduced, and the low pressure EGR device 1 can be reduced in size and weight. Can be planned.

上記実施例では、ターボチャージャを搭載するエンジン２の吸排気システムに本発明を適用する例を示したが、ターボチャージャに代えて他の吸気加給機（スーパチャージャ等）を搭載するエンジン２の吸排気システムに本発明を適用しても良いし、吸気加給機を搭載しないエンジン２の吸排気システムに本発明を適用しても良い。
なお、吸気加給機を搭載するエンジン２の吸排気システムに本発明を適用する場合、吸気通路３における低吸気負圧発生範囲は、コンプレッサの吸気上流側である。また、吸気加給機を搭載しないエンジン２の吸排気システムに本発明を適用する場合、吸気通路３における低吸気負圧発生範囲は、スロットルバルブの吸気上流側である。 In the above-described embodiment, an example in which the present invention is applied to the intake / exhaust system of the engine 2 equipped with the turbocharger has been shown. The present invention may be applied to an exhaust system, or the present invention may be applied to an intake / exhaust system of an engine 2 that is not equipped with an intake / charger.
When the present invention is applied to the intake / exhaust system of the engine 2 equipped with the intake / charger, the low intake negative pressure generation range in the intake passage 3 is on the intake upstream side of the compressor. In addition, when the present invention is applied to the intake / exhaust system of the engine 2 that is not equipped with the intake air charger, the low intake negative pressure generation range in the intake passage 3 is the intake upstream side of the throttle valve.

上記の実施例では、ディーゼルエンジンの吸排気システムに本発明を適用する例を示したが、ディーゼルエンジンとは異なる他のエンジン（ガソリンエンジン等）の吸排気システムに本発明を適用しても良い。
上記の実施例では、ロックピン１２をレバー１３とは別部材で設けて結合する例を示したが、レバー１３の先端部にロックピン１２を一体に設けても良い。具体的には、レバー１３を板バネで形成し、その先端部を曲折させてロックピン１２を形成しても良い。 In the above embodiment, the example in which the present invention is applied to the intake / exhaust system of a diesel engine has been described. However, the present invention may be applied to an intake / exhaust system of another engine (such as a gasoline engine) different from the diesel engine. .
In the above embodiment, the lock pin 12 is provided as a separate member from the lever 13 and coupled. However, the lock pin 12 may be integrally provided at the tip of the lever 13. Specifically, the lock pin 12 may be formed by forming the lever 13 with a leaf spring and bending the tip thereof.

１ 低圧ＥＧＲ装置
２ エンジン
３ 吸気通路
４ 低圧ＥＧＲ流路
５ 低圧ＥＧＲ調整弁
６ 吸気弁
７ 電動モータ（アクチュエータ）
８ ＥＧＲ駆動歯車
９ 吸気弁駆動歯車
１１ 凹部
１２ ロックピン
１３ レバー
１４ ロック機構
１５ 吸気弁入力ギヤ歯
１６ ギヤ歯除去部
１７ ＥＧＲ出力ギヤ歯
１８ 押圧カム
１９ 歯車減速機
２０ ＥＧＲ入力ギヤ歯
５１ ＥＧＲ弁支持シャフト
５３ ＥＧＲ駆動歯車に設けられた軸受部
５４ 吸気弁支持シャフト
５６ 吸気弁駆動歯車に設けられた軸受部 DESCRIPTION OF SYMBOLS 1 Low pressure EGR apparatus 2 Engine 3 Intake passage 4 Low pressure EGR flow path 5 Low pressure EGR adjustment valve 6 Intake valve 7 Electric motor (actuator)
8 EGR drive gear 9 Intake valve drive gear 11 Recess 12 Lock pin 13 Lever 14 Lock mechanism 15 Intake valve input gear tooth 16 Gear tooth removal part 17 EGR output gear tooth 18 Press cam 19 Gear reducer 20 EGR input gear tooth 51 EGR valve Support shaft 53 Bearing portion 54 provided on the EGR drive gear Intake valve support shaft 56 Bearing portion provided on the intake valve drive gear

Claims (5)

エンジン（２）の排気ガスの一部を、吸気通路（３）における低吸気負圧発生範囲に戻す低圧ＥＧＲ流路（４）と、
この低圧ＥＧＲ流路（４）の開度を調整することでＥＧＲガスの流量調整を行なう低圧ＥＧＲ調整弁（５）と、
前記低圧ＥＧＲ流路（４）と前記吸気通路（３）との接合部より前記吸気通路（３）の吸気上流側の開度を可変可能な吸気弁（６）とを具備する低圧ＥＧＲ装置（１）において、
（ａ）この低圧ＥＧＲ装置（１）は、
前記低圧ＥＧＲ調整弁（５）を回転駆動するアクチュエータ（７）と、前記低圧ＥＧＲ調整弁（５）を駆動するＥＧＲ駆動歯車（８）と、前記吸気弁（６）を駆動する吸気弁駆動歯車（９）とを備えるとともに、
前記吸気弁（６）が前記吸気通路（３）を全開に開く全開時に、前記吸気弁駆動歯車（９）に形成された凹部（１１）に係合するロックピン（１２）と、このロックピン（１２）を前記吸気弁駆動歯車（９）に向けて押し付けるレバー（１３）とを有するロック機構（１４）を備え、
（ｂ）前記ＥＧＲ駆動歯車（８）には、
前記低圧ＥＧＲ調整弁（５）の開度が所定開度より小さく、当該低圧ＥＧＲ装置（１）を用いて少量のＥＧＲガスを前記エンジン（２）へ戻す低濃度制御状態の時に、前記吸気弁駆動歯車（９）に設けられた吸気弁入力ギヤ歯（１５）に対して非係合となり、前記ＥＧＲ駆動歯車（８）の回転力を前記吸気弁駆動歯車（９）に非伝達とするギヤ歯除去部（１６）が設けられるとともに、
前記低圧ＥＧＲ調整弁（５）の開度が所定開度より大きく、当該低圧ＥＧＲ装置（１）を用いて多量のＥＧＲガスを前記エンジン（２）へ戻す高濃度制御状態の時に、前記吸気弁入力ギヤ歯（１５）に噛合して、前記ＥＧＲ駆動歯車（８）の回転力を前記吸気弁駆動歯車（９）に伝達し、前記吸気弁（６）の開度を可変するＥＧＲ出力ギヤ歯（１７）が設けられ、
（ｃ）さらに、前記ＥＧＲ駆動歯車（８）には、前記ＥＧＲ出力ギヤ歯（１７）が前記吸気弁入力ギヤ歯（１５）に噛合する状態の時のみ前記レバー（１３）を押圧操作して前記ロックピン（１２）を前記凹部（１１）から外す押圧カム（１８）が設けられることを特徴とする低圧ＥＧＲ装置。 A low pressure EGR flow path (4) for returning a part of the exhaust gas of the engine (2) to a low intake negative pressure generation range in the intake passage (3);
A low pressure EGR adjustment valve (5) for adjusting the flow rate of the EGR gas by adjusting the opening of the low pressure EGR flow path (4);
A low-pressure EGR device (6) comprising an intake valve (6) capable of changing the opening upstream of the intake passage (3) from the joint between the low-pressure EGR flow path (4) and the intake passage (3). In 1)
(A) This low pressure EGR device (1)
An actuator (7) that rotationally drives the low-pressure EGR adjustment valve (5), an EGR drive gear (8) that drives the low-pressure EGR adjustment valve (5), and an intake valve drive gear that drives the intake valve (6) (9)
When the intake valve (6) fully opens the intake passage (3), the lock pin (12) engaged with the recess (11) formed in the intake valve drive gear (9), and the lock pin A locking mechanism (14) having a lever (13) for pressing (12) against the intake valve drive gear (9);
(B) In the EGR drive gear (8),
When the low-pressure EGR adjustment valve (5) has an opening smaller than a predetermined opening and the low-pressure EGR device (1) is in a low concentration control state in which a small amount of EGR gas is returned to the engine (2), the intake valve A gear that is disengaged from the intake valve input gear teeth (15) provided on the drive gear (9) and does not transmit the rotational force of the EGR drive gear (8) to the intake valve drive gear (9). A tooth removal part (16) is provided;
When the opening of the low pressure EGR adjustment valve (5) is larger than a predetermined opening and the high pressure control state in which a large amount of EGR gas is returned to the engine (2) using the low pressure EGR device (1), the intake valve An EGR output gear tooth that meshes with the input gear teeth (15), transmits the rotational force of the EGR drive gear (8) to the intake valve drive gear (9), and varies the opening degree of the intake valve (6). (17) is provided,
(C) Further, the EGR drive gear (8) is operated by pressing the lever (13) only when the EGR output gear teeth (17) are engaged with the intake valve input gear teeth (15). A low-pressure EGR device characterized in that a pressing cam (18) for removing the lock pin (12) from the recess (11) is provided. 請求項１に記載の低圧ＥＧＲ装置（１）において、
前記吸気弁（６）は、前記吸気通路（３）を最大に絞った状態であっても、前記吸気通路（３）の一部を開放するように設けられていることを特徴とする低圧ＥＧＲ装置。 In the low pressure EGR device (1) according to claim 1,
The low pressure EGR is characterized in that the intake valve (6) is provided so as to open a part of the intake passage (3) even when the intake passage (3) is squeezed to the maximum. apparatus. 請求項１または請求項２に記載の低圧ＥＧＲ装置（１）において、
前記アクチュエータ（７）は、歯車減速機（１９）を介して前記ＥＧＲ駆動歯車（８）を回転駆動するように設けられ、
前記ＥＧＲ駆動歯車（８）には、前記ＥＧＲ出力ギヤ歯（１７）および前記押圧カム（１８）とは別に、前記歯車減速機（１９）に噛合するＥＧＲ入力ギヤ歯（２０）が設けられていることを特徴とする低圧ＥＧＲ装置。 In the low pressure EGR device (1) according to claim 1 or 2,
The actuator (7) is provided to rotationally drive the EGR drive gear (8) via a gear reducer (19),
In addition to the EGR output gear teeth (17) and the pressing cam (18), the EGR drive gear (8) is provided with EGR input gear teeth (20) that mesh with the gear reducer (19). A low-pressure EGR device characterized by comprising: 請求項１〜請求項３のいずれかに記載の低圧ＥＧＲ装置（１）において、
前記ＥＧＲ駆動歯車（８）は、前記吸気弁駆動歯車（９）より大径に設けられ、前記ＥＧＲ出力ギヤ歯（１７）が前記吸気弁入力ギヤ歯（１５）に噛合した状態において前記ＥＧＲ駆動歯車（８）に伝達されたトルクを増幅して前記吸気弁駆動歯車（９）に伝達することを特徴とする低圧ＥＧＲ装置。 In the low pressure EGR device (1) according to any one of claims 1 to 3,
The EGR drive gear (8) is provided with a larger diameter than the intake valve drive gear (9), and the EGR drive gear is in a state where the EGR output gear teeth (17) mesh with the intake valve input gear teeth (15). A low pressure EGR device that amplifies the torque transmitted to the gear (8) and transmits the amplified torque to the intake valve drive gear (9). 請求項１〜請求項４のいずれかに記載の低圧ＥＧＲ装置（１）において、
前記ＥＧＲ駆動歯車（８）および前記吸気弁駆動歯車（９）には、前記低圧ＥＧＲ調整弁（５）を支持するＥＧＲ弁支持シャフト（５１）、および前記吸気弁（６）を支持する吸気弁支持シャフト（５４）の軸受部（５３、５６）が、一体に設けられていることを特徴とする低圧ＥＧＲ装置。 In the low pressure EGR device (1) according to any one of claims 1 to 4,
The EGR drive gear (8) and the intake valve drive gear (9) include an EGR valve support shaft (51) that supports the low pressure EGR adjustment valve (5), and an intake valve that supports the intake valve (6). The low pressure EGR device, wherein the bearing portions (53, 56) of the support shaft (54) are integrally provided.
JP2009007534A 2009-01-16 2009-01-16 Low pressure egr device Pending JP2010163996A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2009007534A JP2010163996A (en) 2009-01-16 2009-01-16 Low pressure egr device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2009007534A JP2010163996A (en) 2009-01-16 2009-01-16 Low pressure egr device

Publications (1)

Publication Number Publication Date
JP2010163996A true JP2010163996A (en) 2010-07-29

Family

ID=42580349

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2009007534A Pending JP2010163996A (en) 2009-01-16 2009-01-16 Low pressure egr device

Country Status (1)

Country Link
JP (1) JP2010163996A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013515194A (en) * 2009-12-22 2013-05-02 ヴァレオ システム ドゥ コントロール モトゥール Control method of EGR circuit for automobile engine
WO2015029894A1 (en) * 2013-08-28 2015-03-05 いすゞ自動車株式会社 Supercharging system, internal combustion engine, and supercharging method for internal combustion engine
US9784220B2 (en) 2014-09-30 2017-10-10 Hyundai Motor Company Intake air control apparatus of engine
KR101920921B1 (en) 2017-05-24 2018-11-21 이래에이엠에스 주식회사 Integrated back pressure and egr valve module
KR20180128301A (en) * 2017-05-23 2018-12-03 이래에이엠에스 주식회사 Integrated back pressure and egr valve module

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013515194A (en) * 2009-12-22 2013-05-02 ヴァレオ システム ドゥ コントロール モトゥール Control method of EGR circuit for automobile engine
WO2015029894A1 (en) * 2013-08-28 2015-03-05 いすゞ自動車株式会社 Supercharging system, internal combustion engine, and supercharging method for internal combustion engine
JP2015045279A (en) * 2013-08-28 2015-03-12 いすゞ自動車株式会社 Turbocharger system, internal combustion engine and method for supercharging internal combustion engine
US9784220B2 (en) 2014-09-30 2017-10-10 Hyundai Motor Company Intake air control apparatus of engine
KR20180128301A (en) * 2017-05-23 2018-12-03 이래에이엠에스 주식회사 Integrated back pressure and egr valve module
KR102000758B1 (en) 2017-05-23 2019-07-17 이래에이엠에스 주식회사 Integrated back pressure and egr valve module
KR101920921B1 (en) 2017-05-24 2018-11-21 이래에이엠에스 주식회사 Integrated back pressure and egr valve module

Similar Documents

Publication Publication Date Title
JP4793454B2 (en) High pressure EGR device
JP4730447B2 (en) Low pressure EGR device
JP4935866B2 (en) Low pressure EGR device
EP2044301B1 (en) Cooling fan arrangement at a vehicle
JP4746389B2 (en) Supercharging system
JP5594433B2 (en) Intake device for an internal combustion engine with a supercharger
JP5491028B2 (en) Method for an internal combustion engine with exhaust recirculation
WO2012073365A1 (en) Apparatus for controlling internal combustion engine provided with turbocharger
JP2010090876A (en) Exhaust gas recirculation device
JP4802992B2 (en) Exhaust gas recirculation device for internal combustion engine
JP2001329879A (en) Exhaust gas recirculation system for internal combustion engine
JP2010163996A (en) Low pressure egr device
JP2010096143A (en) Device and system for controlling internal combustion engine
JP2011074841A (en) Egr device
JP4882688B2 (en) Exhaust gas recirculation device for internal combustion engine
JP4511845B2 (en) Internal combustion engine with a supercharger
JP2007127070A (en) Internal combustion engine with supercharger
KR20120015386A (en) Operation controling system of waste gate unit for turbocharger
JP2010163993A (en) High pressure egr device
JP2008280953A (en) Exhaust gas recirculation device for internal combustion engine
JP2007077899A (en) Two-stage supercharging system
JP5737161B2 (en) Control device for supercharged engine
JP2011052604A (en) Low-pressure egr device
JP2010127228A (en) Exhaust emission control device
JP2005188359A (en) Internal combustion engine with supercharger