JP2001073760A - Egr structure of engine - Google Patents

Egr structure of engine

Info

Publication number
JP2001073760A
JP2001073760A JP25172399A JP25172399A JP2001073760A JP 2001073760 A JP2001073760 A JP 2001073760A JP 25172399 A JP25172399 A JP 25172399A JP 25172399 A JP25172399 A JP 25172399A JP 2001073760 A JP2001073760 A JP 2001073760A
Authority
JP
Japan
Prior art keywords
pipe
egr
curved portion
flange
main body
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
JP25172399A
Other languages
Japanese (ja)
Inventor
Toshinori Nagai
利典 永井
Akihiro Ishimatsu
昭浩 石松
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.)
Suzuki Motor Corp
Original Assignee
Suzuki Motor 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 Suzuki Motor Corp filed Critical Suzuki Motor Corp
Priority to JP25172399A priority Critical patent/JP2001073760A/en
Publication of JP2001073760A publication Critical patent/JP2001073760A/en
Pending legal-status Critical Current

Links

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 Silencers (AREA)
  • Exhaust-Gas Circulating Devices (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide the EGR construction that restrains stress concentration of welding part of EGR pipe. SOLUTION: This structure forms U-shaped bent part 10, nearly U-shaped (180 deg. bent) at connecting part of both ends of pipe 7c of EGR pipe. The U-shaped bent part 10 is so constructed that one end of bent part 10a is connected almost vertically to one end of pipe 7a and the other end of bent part 10b is connected to the other end of pipe 7b extending longitudinally, with rigidity kept low. U-shaped bent part 10 is placed at both ends of pipe 7c so as to curtail rigidity. Due to bending of part 10, stress given rise to at welding parts 8, 9 is restrained, and the strength of the welding parts 8, 9 is relatively increased. Thus, current quality of EGR pipe holds good with coming exhaust gas regulations.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、車両用のエンジン
などに用いられるＥＧＲ構造に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EGR structure used for a vehicle engine or the like.

【０００２】[0002]

【従来の技術】従来、エンジンに接続されるエキゾース
トマニホールドの本体部には、燃焼ガスの窒素酸化物
（ＮＯX ）の低減のために、他端部が吸気系に接続され
るＥＧＲパイプ（排気ガス再循環装置のパイプ）の一端
部が接続されている。このような構造の一例として、図
９及び図１０に示すようなエンジンのＥＧＲ構造があ
る。図９及び図１０において、４気筒のエンジン（図示
省略）に接続されるエキゾーストマニホールド１は、エ
ンジンの４つの排気ポート（図示省略）にそれぞれ接続
される４本の枝管２と、４本の枝管２を集合的に接続し
かつ図示しない排気管が接続される集合管部３と、４本
の枝管２の開口側に溶接され前記エンジンに対する固定
のために用いられるフランジ４と、から大略構成されて
いる。４本の枝管２及び集合管部３からエキゾーストマ
ニホールド本体部５が構成されている。４本の枝管２と
フランジ４とは略直交するように構成されている。Conventionally, the main body portion of the exhaust manifold connected to the engine, in order to reduce the nitrogen oxides in the combustion gases (NO X), EGR pipe (exhaust the other end is connected to the intake system One end of a gas recirculation device pipe) is connected. As one example of such a structure, there is an EGR structure of an engine as shown in FIGS. 9 and 10, an exhaust manifold 1 connected to a four-cylinder engine (not shown) has four branch pipes 2 connected to four exhaust ports (not shown) of the engine and four exhaust pipes, respectively. A collecting pipe section 3 to which branch pipes 2 are collectively connected and an exhaust pipe (not shown) is connected, and a flange 4 welded to the opening sides of the four branch pipes 2 and used for fixing to the engine. It is roughly configured. An exhaust manifold main body 5 is composed of the four branch pipes 2 and the collecting pipe 3. The four branch pipes 2 and the flange 4 are configured to be substantially orthogonal.

【０００３】フランジ４には吸気系に連通する孔６が形
成されている。そして、前記４本の枝管２のうち１つの
枝管（以下、符号２Ａで示す）の側部の孔（図示省略）
に一端部を挿通させ、他端部を前記孔６に挿通させて略
Ｌ字形のＥＧＲパイプ７が設けられている。ＥＧＲパイ
プ７はその一端部（以下、パイプ一端部という。）７ａ
及び他端部（以下、パイプ他端部という。）７ｂをそれ
ぞれ前記１つの枝管２Ａ及びフランジ４に溶接させるこ
とにより保持されている。[0003] A hole 6 communicating with the intake system is formed in the flange 4. A hole (not shown) in a side portion of one of the four branch pipes 2 (hereinafter, denoted by reference numeral 2A).
A substantially L-shaped EGR pipe 7 is provided, with one end of the EGR pipe 7 being inserted through and the other end being inserted through the hole 6. The EGR pipe 7 has one end thereof (hereinafter, referred to as one end of the pipe) 7a.
And the other end (hereinafter, referred to as the other end of the pipe) 7b are welded to the one branch pipe 2A and the flange 4, respectively.

【０００４】そして、ＥＧＲパイプ７は、主に良好な流
通、成形性を確保するために、フランジ４やエキゾース
トマニホールド本体部５とは異なる材質で製造されるこ
とが多い。例えば、ＥＧＲパイプ７はＳＵＳ３０４、フ
ランジ４はＳＵＳ４３０、エキゾーストマニホールド本
体部５はＳＵＳ４３０で製造される。The EGR pipe 7 is often made of a material different from that of the flange 4 and the exhaust manifold body 5 in order to mainly ensure good flow and formability. For example, the EGR pipe 7 is made of SUS304, the flange 4 is made of SUS430, and the exhaust manifold body 5 is made of SUS430.

【０００５】ところで、上述したように材質が異なるこ
とによる熱膨張の差及び形状の相違等による剛性バラン
スの差により、従来、例えば図１０に示すように、ＥＧ
Ｒパイプ７のパイプ一端部７ａとこのパイプ一端部７ａ
が接続される１つの枝管２Ａ（エキゾーストマニホール
ド本体部５）との溶接部（以下、本体部側溶接部とい
う。）８、及びＥＧＲパイプ７のパイプ他端部７ｂとこ
のパイプ他端部７ｂが接続されるフランジ４との溶接部
（以下、フランジ側溶接部という。）９に応力が集中し
ていた。なお、本体部側溶接部８の方がフランジ側溶接
部９に比して表面温度が高いことから、その分、応力集
中が大きいものになっていた。By the way, as described above, conventionally, for example, as shown in FIG. 10, due to a difference in rigidity balance due to a difference in thermal expansion and a difference in shape due to a difference in material, as shown in FIG.
One end 7a of the R pipe 7 and one end 7a of the pipe
Is connected to one branch pipe 2A (exhaust manifold main body 5) (hereinafter, referred to as main body side welded part) 8, the other end 7b of the EGR pipe 7, and the other end 7b of the pipe. The stress was concentrated on a welded portion 9 (hereinafter, referred to as a flange-side welded portion) with the flange 4 to which is connected. Since the surface temperature of the main body side welded portion 8 is higher than that of the flange side welded portion 9, the stress concentration is correspondingly higher.

【０００６】上述した溶接部（本体部側溶接部８及びフ
ランジ側溶接部９）への応力集中の低減を図るために、
ＥＧＲパイプ７を、フランジ４やエキゾーストマニホー
ルド本体部５と同一材質とすることが行われている。例
えば図９及び図１０に示す構造において、上述したよう
にＥＧＲパイプ７：ＳＵＳ３０４、フランジ４及びエキ
ゾーストマニホールド本体部５：ＳＵＳ４３０とした
（以下、タイプ材質が異なるタイプという）場合に比し
て、ＥＧＲパイプ７をフランジ４及びエキゾーストマニ
ホールド本体部５と同一材質のＳＵＳ４３０とした（以
下、タイプI という）場合、溶接部（本体部側溶接部８
及びフランジ側溶接部９）の応力集中を４０％程、低減
可能である（後述の表１参照）。[0006] In order to reduce the concentration of stress on the above-mentioned welded portions (main body side welded portion 8 and flange side welded portion 9),
The EGR pipe 7 is made of the same material as the flange 4 and the exhaust manifold body 5. For example, in the structure shown in FIGS. 9 and 10, the EGR pipe 7 is made of SUS304, the flange 4 and the exhaust manifold body 5 is made of SUS430 as described above (hereinafter, referred to as a type having a different type material). When the pipe 7 is made of SUS430 made of the same material as the flange 4 and the exhaust manifold main body 5 (hereinafter referred to as type I), the welded portion (main body side welded portion 8)
In addition, the stress concentration in the flange side welded portion 9) can be reduced by about 40% (see Table 1 described later).

【０００７】[0007]

【発明が解決しようとする課題】ところで、今後の排ガ
ス規制に対処する上でエキゾーストマニホールド本体部
５の表面温度はより高いものとなり、仮にＥＧＲパイプ
７をフランジ４及びエキゾーストマニホールド本体部５
と同一材質で作製しても、溶接部（本体部側溶接部８及
びフランジ側溶接部９）に大きな応力集中の発生を招く
虞があった。The surface temperature of the exhaust manifold body 5 becomes higher in order to cope with future exhaust gas regulations, and the EGR pipe 7 is temporarily connected to the flange 4 and the exhaust manifold body 5.
Even if it is made of the same material as above, there is a possibility that large stress concentration may occur in the welded portions (the main body side welded portion 8 and the flange side welded portion 9).

【０００８】本発明は、上記事情に鑑みてなされたもの
で、ＥＧＲパイプの溶接部の応力集中を抑制できるエン
ジンのＥＧＲ構造を提供することを目的とする。The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an EGR structure of an engine capable of suppressing stress concentration at a welded portion of an EGR pipe.

【０００９】[0009]

【課題を解決するための手段】請求項１記載の発明は、
エキゾーストマニホールドの本体部に略直交して設けら
れ前記本体部をエンジンに固定するために用いられるフ
ランジと、一端部が前記本体部に挿通して溶接され他端
部が前記フランジに形成した吸気系に連通する孔に挿通
して前記フランジに溶接されるＥＧＲパイプとを有し、
前記ＥＧＲパイプは、その一端部及び他端部が互いに略
直交するように連接され、かつ当該連接部に剛性が低く
なるように曲部を形成したことを特徴とする。請求項２
記載の発明は、請求項１記載の構成において、曲部は、
一端側が前記一端部に略直交して連接し他端側が前記他
端部に長手状に延びるように連接する略Ｕ字形をなすＵ
字形曲部であることを特徴とする。請求項３記載の発明
は、請求項１記載の構成において、曲部は、一端側が前
記一端部に略直交して連接する略Ｕ字形のＵ字形曲部本
体と、該Ｕ字形曲部本体の他端側及び前記他端部に略直
交して連接する曲部延長部とからなることを特徴とす
る。請求項４記載の発明は、請求項１記載の構成におい
て、曲部は、略円環状をなす円環曲部であることを特徴
とする。請求項５記載の発明は、請求項１記載の構成に
おいて、曲部は、略Ｖ字形をなすＶ字形曲部であること
を特徴とする。According to the first aspect of the present invention,
A flange provided substantially orthogonal to the main body of the exhaust manifold and used for fixing the main body to the engine; and an intake system having one end inserted into the main body and welded and the other end formed on the flange. An EGR pipe that is inserted into a hole communicating with the EGR pipe and welded to the flange,
The EGR pipe is characterized in that one end and the other end thereof are connected so as to be substantially orthogonal to each other, and a curved portion is formed at the connection portion so as to reduce rigidity. Claim 2
According to the invention described in the first aspect, the curved portion includes:
A substantially U-shaped one end is connected substantially orthogonally to the one end and the other end is connected to the other end so as to extend longitudinally.
It is a character-shaped curved part. According to a third aspect of the present invention, in the configuration according to the first aspect, the curved portion has a substantially U-shaped U-shaped curved portion main body having one end connected to the one end portion substantially perpendicularly, and the U-shaped curved portion main body. It is characterized by comprising a second end portion and a curved portion extending portion which is connected to the other end portion substantially perpendicularly. According to a fourth aspect of the present invention, in the configuration of the first aspect, the curved portion is a substantially circular annular curved portion. According to a fifth aspect of the present invention, in the configuration of the first aspect, the curved portion is a V-shaped curved portion having a substantially V shape.

【００１０】[0010]

【発明の実施の形態】以下、本発明の第１実施の形態の
エンジンのＥＧＲ構造を図１及び図２に基づき、図９を
参照して説明する。図１において、エンジンに接続され
るエキゾーストマニホールド１は、エンジンの排気ポー
トに接続される複数の枝管２と、複数の枝管２を集合的
に接続し、かつ図示しない排気管が接続される集合管部
３（図９参照）と、４本の枝管２の開口側に溶接され前
記エンジンに対する固定のために用いられるフランジ４
と、から大略構成されている。４本の枝管２及び集合管
部３からエキゾーストマニホールド本体部５が構成され
ている。４本の枝管２（１つの枝管２Ａ）とフランジ４
とは略直交している。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an EGR structure of an engine according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 and with reference to FIG. In FIG. 1, an exhaust manifold 1 connected to an engine is connected to a plurality of branch pipes 2 connected to an exhaust port of the engine, the plurality of branch pipes 2 collectively, and an exhaust pipe (not shown) is connected. A collecting pipe portion 3 (see FIG. 9) and a flange 4 welded to the opening sides of the four branch pipes 2 and used for fixing to the engine.
, And is roughly composed of An exhaust manifold main body 5 is composed of the four branch pipes 2 and the collecting pipe 3. Four branch pipes 2 (one branch pipe 2A) and flange 4
Is substantially orthogonal to.

【００１１】フランジ４には吸気系に連通する孔６が形
成されている。そして、１つの枝管２Ａの側部の孔（図
示省略）にパイプ一端部７ａを挿通させ、パイプ他端部
７ｂを前記孔６に挿通させてＥＧＲパイプ７が設けられ
ている。ＥＧＲパイプ７はそのパイプ一端部７ａ及びパ
イプ他端部７ｂをそれぞれ前記１つの枝管２Ａ及びフラ
ンジ４に溶接させることにより保持されている。The flange 4 has a hole 6 communicating with the intake system. An EGR pipe 7 is provided by inserting a pipe end 7a into a hole (not shown) on the side of one branch pipe 2A and inserting the pipe end 7b into the hole 6. The EGR pipe 7 is held by welding one end 7a and the other end 7b of the pipe to the one branch pipe 2A and the flange 4, respectively.

【００１２】ＥＧＲパイプ７のパイプ一端部７ａ及びパ
イプ他端部７ｂは、当該パイプ一端部、他端部７ａ，７
ｂを連接部分（パイプ両端連接部）７ｃを介して略直交
するように形成されている。そして、パイプ両端連接部
７ｃには、略Ｕ字形をなす（１８０°曲げ形状の）Ｕ字
形曲部１０（曲部）が設けられている。Ｕ字形曲部１０
は、その一端側（曲部一端側。図１右側）１０ａが前記
パイプ一端部７ａに略直交して連接し他端側（曲部他端
側）１０ｂが前記パイプ他端部７ｂに長手状に延びるよ
うに連接し、剛性が低いものになっている。ＥＧＲパイ
プ７は一部材で構成してもよいし、断面半円状の２部材
を接合して筒状に構成してもよい。The one end 7a and the other end 7b of the EGR pipe 7 are connected to one end and the other ends 7a and 7b of the pipe.
b are formed so as to be substantially orthogonal to each other via a connecting portion (a connecting portion at both ends of the pipe) 7c. The U-shaped curved portion 10 (curved portion) having a substantially U-shape (having a 180 ° bending shape) is provided in the pipe end connecting portion 7c. U-shaped curved part 10
The one end side (the one end side of the curved portion; right side in FIG. 1) 10a is connected to the pipe one end portion 7a substantially orthogonally, and the other end side (the other end side of the curved portion) 10b is elongated in the pipe other end portion 7b. And has low rigidity. The EGR pipe 7 may be formed by one member, or may be formed by joining two members having a semicircular cross section to form a cylinder.

【００１３】上述したように構成した第１実施の形態の
エンジンのＥＧＲ構造では、パイプ両端連接部７ｃに、
剛性が低くなるようにＵ字形曲部１０を設けている。こ
のため、ＥＧＲパイプ７は例えば図２点線Ｔに示すよう
に、Ｕ字形曲部１０で撓みやすく、その分、溶接部（本
体部側溶接部８及びフランジ側溶接部９）に発生する応
力が抑制され、溶接部の強度が相対的に向上することに
なる。このため、今後の排ガス規制にも現状の材質のＥ
ＧＲパイプで適切に対処することができる。本実施の形
態では、パイプ両端連接部７ｃにＵ字形曲部１０を形成
することにより溶接部に発生する応力の抑制を図るの
で、ＥＧＲパイプ７に耐高温材料を採用しなくて済み、
その分、コストの低減を図ることができる。In the EGR structure of the engine according to the first embodiment configured as described above, the both ends connecting portion 7c of the pipe includes:
The U-shaped curved portion 10 is provided so as to reduce rigidity. For this reason, the EGR pipe 7 is easily bent at the U-shaped curved portion 10 as shown in, for example, a dotted line T in FIG. 2, and the stress generated in the welded portions (the body portion side welded portion 8 and the flange side welded portion 9) is correspondingly reduced. Thus, the strength of the weld is relatively improved. For this reason, the current material E
The GR pipe can cope appropriately. In the present embodiment, since the stress generated in the welded portion is suppressed by forming the U-shaped curved portion 10 in the connecting portion 7c at both ends of the pipe, it is not necessary to employ a high temperature resistant material for the EGR pipe 7.
The cost can be reduced accordingly.

【００１４】本発明者は、図１に示す構造で、ＥＧＲパ
イプ７をフランジ４及びエキゾーストマニホールド本体
部５と同一材質のＳＵＳ４３０とした（以下、タイプII
という）場合、表１に示すように、前記材質が異なるタ
イプ（ＥＧＲパイプ７：ＳＵＳ３０４、フランジ４及び
エキゾーストマニホールド本体部５：ＳＵＳ４３０）に
比して溶接部（本体部側溶接部８及びフランジ側溶接部
９）の応力集中比率（前記材質が異なるタイプの溶接部
に発生する応力に対して対象となるタイプの溶接部に発
生する応力の割合。以下、適宜、応力比率という。）が
約１０％となり〔すなわち、前記タイプI （応力比率：
６０％）よりも応力比率が小さくなり〕、溶接部８，９
の応力集中を大幅に低減できることを解析により確認す
ることができた。表１中、タイプI は、上述したよう
に、図９及び図１０に示す構造（パイプ両端連接部７ｃ
が直角になっている）において、ＥＧＲパイプ７をフラ
ンジ４及びエキゾーストマニホールド本体部５と同一材
質のＳＵＳ４３０としたものである。なお、タイプIII
、タイプIV、タイプV については後述する。The inventor of the present invention has the structure shown in FIG. 1 in which the EGR pipe 7 is made of SUS430 made of the same material as the flange 4 and the exhaust manifold body 5 (hereinafter referred to as type II).
In this case, as shown in Table 1, the welded portions (main body portion side welded portion 8 and flange side) are different from those of the different materials (EGR pipe 7: SUS304, flange 4, and exhaust manifold main body portion 5: SUS430) as shown in Table 1. The stress concentration ratio of the welded portion 9) (the ratio of the stress generated in the target type of welded portion to the stress generated in the type of welded portion having a different material; hereinafter referred to as the stress ratio as appropriate) is about 10. %, Ie, the above-mentioned type I (stress ratio:
60%), and the welded portions 8 and 9
It was confirmed by the analysis that the stress concentration of can be greatly reduced. In Table 1, type I is the structure shown in FIG. 9 and FIG.
Is a right angle), and the EGR pipe 7 is made of SUS430 made of the same material as the flange 4 and the exhaust manifold body 5. Type III
, Type IV and Type V will be described later.

【００１５】 [0015]

【００１６】次に、本発明の第２実施の形態のエンジン
のＥＧＲ構造を図３及び図４に基づいて説明する。図３
において、ＥＧＲパイプ７のパイプ両端連接部７ｃに
は、一端側（曲部本体一端側）１１ａがパイプ一端部７
ａに略直交して連接する略Ｕ字形のＵ字形曲部本体１１
と、該Ｕ字形曲部本体１１の他端側（曲部本体他端側）
１１ｂ及び前記パイプ他端部７ｂにそれぞれ略直交して
連接する曲部延長部１２とからなり、剛性が低くなるよ
うに構成された曲部１０Ａが形成されている。Next, an EGR structure of an engine according to a second embodiment of the present invention will be described with reference to FIGS. FIG.
In the EGR pipe 7, one end side (one end side of the curved portion main body) 11a is connected to the pipe end connecting portion 7c of the EGR pipe 7.
a U-shaped curved portion main body 11 having a substantially U-shape and connected substantially orthogonally to a
And the other end of the U-shaped curved body 11 (the other end of the curved body)
A curved portion 10A is formed, which comprises a curved portion extension portion 12 which is connected to the pipe end 11b and the other end portion 7b of the pipe so as to be substantially orthogonal to each other.

【００１７】この第２実施の形態のエンジンのＥＧＲ構
造では、ＥＧＲパイプ７のパイプ両端連接部７ｃに、Ｕ
字形曲部本体１１及び曲部延長部１２からなり、剛性が
低くなるようにされた曲部１０Ａを設けている。このた
め、ＥＧＲパイプ７は例えば図４点線Ｔに示すように、
曲部１０Ａ（Ｕ字形曲部本体１１及び曲部延長部１２）
で撓みやすく、その分、溶接部（本体部側溶接部８及び
フランジ側溶接部９）に発生する応力が抑制され、溶接
部８，９の強度が相対的に向上する。In the EGR structure of the engine according to the second embodiment, the EGR pipe 7 has U
A curved portion 10A is provided, which is composed of a character-shaped curved portion main body 11 and a curved portion extension portion 12 and has low rigidity. For this reason, the EGR pipe 7 is, for example, as shown by a dotted line T in FIG.
Curved portion 10A (U-shaped curved portion main body 11 and curved portion extension portion 12)
, The stress generated in the welded portions (the body-side welded portion 8 and the flange-side welded portion 9) is suppressed, and the strength of the welded portions 8, 9 is relatively improved.

【００１８】本発明者は、図３に示す構造で、ＥＧＲパ
イプ７をフランジ４及びエキゾーストマニホールド本体
部５と同一材質のＳＵＳ４３０とした（以下、タイプII
I という）場合、表１に示すように、溶接部（本体部側
溶接部８及びフランジ側溶接部９）の応力比率が約２０
％となり〔すなわち、前記タイプI （応力比率：６０
％）よりも応力比率が小さくなり〕、溶接部８，９の応
力集中を大幅に低減できることを解析により確認するこ
とができた。The inventor of the present invention has the structure shown in FIG. 3 in which the EGR pipe 7 is made of SUS430 made of the same material as the flange 4 and the exhaust manifold body 5 (hereinafter referred to as type II).
I), as shown in Table 1, the stress ratio of the welded portions (main body side welded portion 8 and flange side welded portion 9) is about 20%.
%, Ie, the above-mentioned type I (stress ratio: 60
%), And it was confirmed by analysis that the stress concentration at the welds 8 and 9 could be significantly reduced.

【００１９】次に、本発明の第３実施の形態のエンジン
のＥＧＲ構造を図５及び図６に基づいて説明する。図５
において、ＥＧＲパイプ７のパイプ両端連接部７ｃに
は、略円環状をなし（３６０°曲げ形状）、剛性が低く
なるようにされた円環曲部１０Ｂ（曲部）が形成されて
いる。Next, an EGR structure of an engine according to a third embodiment of the present invention will be described with reference to FIGS. FIG.
In the EGR pipe 7, an annular curved portion 10B (curved portion) having a substantially annular shape (bending shape of 360 °) and low rigidity is formed in the connecting portion 7c at both ends of the pipe of the EGR pipe 7.

【００２０】この第３実施の形態のエンジンのＥＧＲ構
造では、ＥＧＲパイプ７のパイプ両端連接部７ｃに剛性
が低くなるようにされた円環曲部１０Ｂを設けている。
このため、ＥＧＲパイプ７は例えば図６点線Ｔに示すよ
うに、円環曲部１０Ｂで撓みやすく、その分、溶接部
（本体部側溶接部８及びフランジ側溶接部９）に発生す
る応力が抑制され、溶接部８，９の強度が相対的に向上
する。In the EGR structure of the engine according to the third embodiment, an annular curved portion 10B whose rigidity is reduced is provided at the connecting portion 7c at both ends of the EGR pipe 7.
For this reason, the EGR pipe 7 is easily bent at the annular curved portion 10B as shown by, for example, a dotted line T in FIG. 6, and the stress generated in the welded portions (the main body side welded portion 8 and the flange side welded portion 9) is correspondingly reduced. The strength of the welds 8, 9 is relatively improved.

【００２１】本発明者は、図５に示す構造で、ＥＧＲパ
イプ７をフランジ４及びエキゾーストマニホールド本体
部５と同一材質のＳＵＳ４３０とした（以下、タイプIV
という）場合、表１に示すように、溶接部８，９の応力
比率が約３０％となり〔すなわち、前記タイプI （応力
比率：６０％）よりも応力比率が小さくなり〕、溶接部
８，９の応力集中を大幅に低減できることを解析により
確認することができた。The inventor of the present invention has the structure shown in FIG. 5 in which the EGR pipe 7 is made of SUS430 made of the same material as the flange 4 and the exhaust manifold body 5 (hereinafter referred to as type IV).
In this case, as shown in Table 1, the stress ratio of the welded portions 8 and 9 becomes about 30% (that is, the stress ratio becomes smaller than that of the type I (stress ratio: 60%)). It was confirmed by analysis that the stress concentration of No. 9 could be significantly reduced.

【００２２】次に、本発明の第４実施の形態のエンジン
のＥＧＲ構造を図７及び図８に基づいて説明する。図７
において、ＥＧＲパイプ７のパイプ両端連接部７ｃに
は、略Ｖ字形をなし剛性が低くなるようにされたＶ字形
曲部１０Ｃが形成されている。Next, an EGR structure of an engine according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG.
In the EGR pipe 7, a V-shaped curved portion 10C which is substantially V-shaped and has low rigidity is formed at a pipe end connecting portion 7c of the EGR pipe 7.

【００２３】この第４実施の形態のエンジンのＥＧＲ構
造では、ＥＧＲパイプ７のパイプ両端連接部７ｃに、剛
性が低くなるようにされたＶ字形曲部１０Ｃを設けてい
る。このため、ＥＧＲパイプ７は例えば図８点線Ｔに示
すように、Ｖ字形曲部１０Ｃで撓みやすく、その分、溶
接部（本体部側溶接部８及びフランジ側溶接部９）に発
生する応力が抑制され、溶接部８，９の強度が相対的に
向上する。In the EGR structure of the engine according to the fourth embodiment, a V-shaped curved portion 10C whose rigidity is reduced is provided at the pipe end connecting portion 7c of the EGR pipe 7. For this reason, the EGR pipe 7 is easily bent at the V-shaped curved portion 10C as shown in, for example, a dotted line T in FIG. 8, and the stress generated in the welded portions (the body-side welded portion 8 and the flange-side welded portion 9) is correspondingly reduced. The strength of the welds 8, 9 is relatively improved.

【００２４】本発明者は、図７に示す構造で、ＥＧＲパ
イプ７をフランジ４及びエキゾーストマニホールド本体
部５と同一材質のＳＵＳ４３０とした（以下、タイプV
という）場合、表１に示すように、溶接部８，９の応力
比率が約３５％となり〔すなわち、前記タイプI （応力
比率：６０％）よりも応力比率が小さくなり〕、溶接部
８，９の応力集中を大幅に低減できることを解析により
確認することができた。The inventor of the present invention has the structure shown in FIG. 7 in which the EGR pipe 7 is made of SUS430 made of the same material as the flange 4 and the exhaust manifold body 5 (hereinafter referred to as type V).
In this case, as shown in Table 1, the stress ratio of the welded portions 8 and 9 is about 35% (that is, the stress ratio is smaller than that of the type I (stress ratio: 60%)). It was confirmed by analysis that the stress concentration of No. 9 could be significantly reduced.

【００２５】[0025]

【発明の効果】請求項１記載の発明によれば、ＥＧＲパ
イプの一端部及び他端部を連接する部分に剛性が低くな
るように曲部を形成したことにより、ＥＧＲパイプは曲
部が撓みやすくなるので、その分、ＥＧＲパイプのエキ
ゾーストマニホールドの本体部及びフランジに対する溶
接部（ＥＧＲパイプの溶接部）に発生する応力が抑制さ
れ溶接部の応力集中が緩和される。請求項２記載の発明
によれば、ＥＧＲパイプの連接部分に剛性が低くなるよ
うにＵ字形曲部を形成しており、ＥＧＲパイプはＵ字形
曲部で撓みやすくなるので、その分、ＥＧＲパイプの溶
接部に発生する応力が抑制され溶接部の応力集中が緩和
される。According to the first aspect of the present invention, the curved portion is formed at the portion connecting the one end and the other end of the EGR pipe so as to have low rigidity. As a result, the stress generated in the welded portion (the welded portion of the EGR pipe) to the main body portion and the flange of the exhaust manifold of the EGR pipe is suppressed, and the stress concentration in the welded portion is reduced. According to the second aspect of the present invention, the U-shaped curved portion is formed at the connecting portion of the EGR pipe so as to have low rigidity, and the EGR pipe is easily bent by the U-shaped curved portion. The stress generated in the welded portion is suppressed, and the stress concentration in the welded portion is reduced.

【００２６】請求項３記載の発明によれば、ＥＧＲパイ
プの連接部分に、剛性が低くなるようにＵ字形曲部本体
及び曲部延長部からなる曲部を形成しており、ＥＧＲパ
イプは曲部（Ｕ字形曲部本体及び曲部延長部）で撓みや
すくなるので、その分、ＥＧＲパイプの溶接部に発生す
る応力が抑制され溶接部の応力集中が緩和される。請求
項４記載の発明によれば、ＥＧＲパイプの連接部分に剛
性が低くなるように円環曲部を形成しており、ＥＧＲパ
イプは円環曲部で撓みやすくなるので、その分、ＥＧＲ
パイプの溶接部に発生する応力が抑制され溶接部の応力
集中が緩和される。請求項５記載の発明によれば、ＥＧ
Ｒパイプの連接部分に剛性が低くなるようにＶ字形曲部
を形成しており、ＥＧＲパイプはＶ字形曲部で撓みやす
くなるので、その分、ＥＧＲパイプの溶接部に発生する
応力が抑制され溶接部の応力集中が緩和される。According to the third aspect of the present invention, the connecting portion of the EGR pipe is formed with a curved portion including a U-shaped curved portion main body and a curved portion extension portion so as to have low rigidity. Since it is easy to bend at the portion (the U-shaped curved portion main body and the curved portion extension portion), the stress generated in the welded portion of the EGR pipe is suppressed and the stress concentration in the welded portion is reduced. According to the fourth aspect of the present invention, the annular curved portion is formed at the connecting portion of the EGR pipe so as to have low rigidity, and the EGR pipe is easily bent at the annular curved portion.
Stress generated in the welded portion of the pipe is suppressed, and stress concentration in the welded portion is reduced. According to the invention of claim 5, EG
A V-shaped curved portion is formed at the connecting portion of the R pipe so as to reduce rigidity, and the EGR pipe is easily bent at the V-shaped curved portion, so that the stress generated in the welded portion of the EGR pipe is correspondingly suppressed. Stress concentration at the weld is reduced.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の第１実施の形態のエンジンのＥＧＲ構
造を模式的に示す正面図である。FIG. 1 is a front view schematically showing an EGR structure of an engine according to a first embodiment of the present invention.

【図２】図１のエンジンのＥＧＲ構造の作用を模式的に
示す図である。FIG. 2 is a view schematically showing an operation of an EGR structure of the engine of FIG.

【図３】本発明の第２実施の形態のエンジンのＥＧＲ構
造を模式的に示す正面図である。FIG. 3 is a front view schematically showing an EGR structure of an engine according to a second embodiment of the present invention.

【図４】図３のエンジンのＥＧＲ構造の作用を模式的に
示す図である。FIG. 4 is a view schematically showing an operation of an EGR structure of the engine shown in FIG. 3;

【図５】本発明の第３実施の形態のエンジンのＥＧＲ構
造を模式的に示す正面図である。FIG. 5 is a front view schematically showing an EGR structure of an engine according to a third embodiment of the present invention.

【図６】図５のエンジンのＥＧＲ構造の作用を模式的に
示す図である。6 is a diagram schematically showing an operation of an EGR structure of the engine of FIG.

【図７】本発明の第４実施の形態のエンジンのＥＧＲ構
造を模式的に示す正面図である。FIG. 7 is a front view schematically showing an EGR structure of an engine according to a fourth embodiment of the present invention.

【図８】図７のエンジンのＥＧＲ構造の作用を模式的に
示す図である。FIG. 8 is a diagram schematically showing an operation of an EGR structure of the engine of FIG. 7;

【図９】従来のエンジンのＥＧＲ構造の一例を模式的に
示す正面図である。FIG. 9 is a front view schematically showing an example of an EGR structure of a conventional engine.

【図１０】図９のＥＧＲパイプ及びその接合部分を拡大
して示す図である。FIG. 10 is an enlarged view showing the EGR pipe of FIG. 9 and a joint thereof.

【符号の説明】[Explanation of symbols]

１ エキゾーストマニホールド ２Ａ １つの枝管 ４ フランジ ７ ＥＧＲパイプ ７ａ パイプ一端部 ７ｂ パイプ他端部 ７ｃ パイプ両端連接部 １０ Ｕ字形曲部（曲部） １０Ａ 曲部 １０Ｂ 円環曲部（曲部） １０Ｃ Ｖ字形曲部（曲部） １０ａ 曲部一端側（曲部の一端側） １０ｂ 曲部他端側（曲部の他端側） DESCRIPTION OF SYMBOLS 1 Exhaust manifold 2A One branch pipe 4 Flange 7 EGR pipe 7a Pipe one end 7b Pipe other end 7c Pipe both ends connecting part 10 U-shaped curved part (curved part) 10A curved part 10B annular curved part (curved part) 10C V Figure-shaped curved part (curved part) 10a One end of curved part (one end of curved part) 10b The other end of curved part (other end of curved part)

Claims (5)

【特許請求の範囲】[Claims] 【請求項１】 エキゾーストマニホールドの本体部に略
直交して設けられ前記本体部をエンジンに固定するため
に用いられるフランジと、一端部が前記本体部に挿通し
て溶接され他端部が前記フランジに形成した吸気系に連
通する孔に挿通して前記フランジに溶接されるＥＧＲパ
イプとを有し、前記ＥＧＲパイプは、その一端部及び他
端部が互いに略直交するように連接され、かつ当該連接
部に剛性が低くなるように曲部を形成したことを特徴と
するエンジンのＥＧＲ構造。A flange provided substantially perpendicular to a main body of the exhaust manifold and used for fixing the main body to an engine; one end of the flange being inserted into the main body and welded; And an EGR pipe that is inserted into a hole that communicates with the intake system and that is welded to the flange. The EGR pipe is connected so that one end and the other end thereof are substantially orthogonal to each other, and An EGR structure for an engine, wherein a curved portion is formed in the connecting portion so as to reduce rigidity. 【請求項２】 曲部は、一端側が前記一端部に略直交し
て連接し他端側が前記他端部に長手状に延びるように連
接する略Ｕ字形をなすＵ字形曲部であることを特徴とす
る請求項１記載のエンジンのＥＧＲ構造。2. The curved portion is a U-shaped curved portion having a substantially U-shaped one end connected to the one end substantially perpendicular to the one end and the other end connected to the other end in a longitudinally extending manner. The EGR structure of an engine according to claim 1, wherein: 【請求項３】 曲部は、一端側が前記一端部に略直交し
て連接する略Ｕ字形のＵ字形曲部本体と、該Ｕ字形曲部
本体の他端側及び前記他端部に略直交して連接する曲部
延長部とからなることを特徴とする請求項１記載のエン
ジンのＥＧＲ構造。3. The curved portion has a substantially U-shaped U-shaped curved portion main body having one end connected to the one end portion substantially orthogonal to the one end portion, and substantially orthogonal to the other end and the other end of the U-shaped curved portion main body. 2. An EGR structure for an engine according to claim 1, wherein the EGR structure comprises a curved portion extension portion connected to the engine. 【請求項４】 曲部は、略円環状をなす円環曲部である
ことを特徴とする請求項１記載のエンジンのＥＧＲ構
造。4. The EGR structure of an engine according to claim 1, wherein the curved portion is a substantially circular annular curved portion. 【請求項５】 曲部は、略Ｖ字形をなすＶ字形曲部であ
ることを特徴とする請求項１記載のエンジンのＥＧＲ構
造。5. The EGR structure for an engine according to claim 1, wherein the curved portion is a V-shaped curved portion having a substantially V shape.
JP25172399A 1999-09-06 1999-09-06 Egr structure of engine Pending JP2001073760A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP25172399A JP2001073760A (en) 1999-09-06 1999-09-06 Egr structure of engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP25172399A JP2001073760A (en) 1999-09-06 1999-09-06 Egr structure of engine

Publications (1)

Publication Number Publication Date
JP2001073760A true JP2001073760A (en) 2001-03-21

Family

ID=17227029

Family Applications (1)

Application Number Title Priority Date Filing Date
JP25172399A Pending JP2001073760A (en) 1999-09-06 1999-09-06 Egr structure of engine

Country Status (1)

Country Link
JP (1) JP2001073760A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012056885A1 (en) * 2010-10-28 2012-05-03 本田技研工業株式会社 Egr cooler structure
WO2013054711A1 (en) * 2011-10-12 2013-04-18 本田技研工業株式会社 Exhaust gas recirculation device for internal combustion engine

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012056885A1 (en) * 2010-10-28 2012-05-03 本田技研工業株式会社 Egr cooler structure
CN103189632A (en) * 2010-10-28 2013-07-03 本田技研工业株式会社 EGR cooler structure
US20130206120A1 (en) * 2010-10-28 2013-08-15 Honda Motor Co., Ltd. Egr cooling structure
JPWO2012056885A1 (en) * 2010-10-28 2014-03-20 本田技研工業株式会社 EGR cooler structure
JP5719376B2 (en) * 2010-10-28 2015-05-20 本田技研工業株式会社 EGR cooler structure
US9810180B2 (en) 2010-10-28 2017-11-07 Honda Motor Co., Ltd. EGR cooling structure
WO2013054711A1 (en) * 2011-10-12 2013-04-18 本田技研工業株式会社 Exhaust gas recirculation device for internal combustion engine
CN103782018A (en) * 2011-10-12 2014-05-07 本田技研工业株式会社 Exhaust gas recirculation device for internal combustion engine
US20140318511A1 (en) * 2011-10-12 2014-10-30 Honda Motor Co., Ltd. Exhaust gas recirculation device for internal combustion engine
JPWO2013054711A1 (en) * 2011-10-12 2015-03-30 本田技研工業株式会社 Exhaust gas recirculation device for internal combustion engine
US9518536B2 (en) 2011-10-12 2016-12-13 Honda Motor Co., Ltd. Exhaust gas recirculation device for internal combustion engine

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