JP2003056428A - Connecting structure for common rail and injection pipe assembly, and forming method of the same - Google Patents
Connecting structure for common rail and injection pipe assembly, and forming method of the sameInfo
- Publication number
- JP2003056428A JP2003056428A JP2001243753A JP2001243753A JP2003056428A JP 2003056428 A JP2003056428 A JP 2003056428A JP 2001243753 A JP2001243753 A JP 2001243753A JP 2001243753 A JP2001243753 A JP 2001243753A JP 2003056428 A JP2003056428 A JP 2003056428A
- Authority
- JP
- Japan
- Prior art keywords
- hole
- common rail
- injection pipe
- inner diameter
- reduced
- 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.)
- Granted
Links
Landscapes
- Fuel-Injection Apparatus (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、ディーゼルエンジ
ンのコモンレール式燃料噴射装置におけるコモンレール
とインジェクションパイプアッシーとの接続構造及びそ
の形成方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure for a common rail and an injection pipe assembly in a common rail fuel injection device for a diesel engine and a method for forming the same.
【0002】[0002]
【従来の技術】ディーゼルエンジンのコモンレール式燃
料噴射装置において、コモンレールにはインジェクタを
接続するためのパイプ(以下、インジェクションパイプ
という。)が接続される。2. Description of the Related Art In a common rail fuel injection system for a diesel engine, a pipe for connecting an injector (hereinafter referred to as an injection pipe) is connected to the common rail.
【0003】図5〜図7は、上記接続構造の第1従来例
を示している。図5に示すように、コモンレール51の
中心部には、レール長方向に延びるコモンレール穴52
が形成され、コモンレール穴52に交差開口してレール
長直角方向に延びる分岐穴53(オリフィス孔)とシー
ル面54とが形成されていることを示している。インジ
ェクションパイプ61の端部には小筒状のカラー62が
圧入固定され、カラー62の先端には凸球面状のシール
面64が形成されている。インジェクションパイプ61
の周りには大筒状のユニオン71が通されている。そし
て、インジェクションパイプ61、カラー62及びユニ
オン71とが、予めインジェクションパイプアッシー6
0としてアッセンブリ化されている。5 to 7 show a first conventional example of the connection structure. As shown in FIG. 5, a common rail hole 52 extending in the rail length direction is provided at the center of the common rail 51.
Is formed, and a branch hole 53 (orifice hole) that intersects the common rail hole 52 and extends in the direction perpendicular to the rail length and a sealing surface 54 are formed. A small tubular collar 62 is press-fitted and fixed to the end of the injection pipe 61, and a convex spherical sealing surface 64 is formed at the tip of the collar 62. Injection pipe 61
A large cylindrical union 71 is passed around the. Then, the injection pipe 61, the collar 62, and the union 71 are preliminarily formed in the injection pipe assembly 6
Assembled as 0.
【0004】図5に図示したインジェクションパイプア
ッシー60がコモンレール51に螺合している状態の断
面図を図6に示す。燃料ポンプにより加圧してコモンレ
ール51に送られた燃料は、コモンレール穴52から分
岐穴53に導入され、カラー62内の通孔を経てインジ
ェクションパイプ61からインジェクタに送られる。そ
の際、コモンレール穴52内は、燃料ポンプから送られ
る加圧燃料により発生する圧力変動を伴った超高圧(2
0←→約200MPa)になる。そのため、分岐穴53
周辺部の詳細図の図7に示すように、コモンレール穴5
2に対する分岐穴53の交差開口縁部57に、変動を伴
った引張歪みが繰り返し発生する。すると、交差開口縁
部57に金属疲労による亀裂58が発生し易く、品質が
不安定となる。この亀裂を防止するために、コモンレー
ル51の浸炭焼入れ等の硬化処理や、交差開口縁部57
の電解バリ取り加工による曲面化や、材料変更等による
強度アップが図られているが、これらの方法では、大幅
なコストアップや重量増になってしまう。FIG. 6 is a sectional view showing a state in which the injection pipe assembly 60 shown in FIG. 5 is screwed onto the common rail 51. The fuel pressurized by the fuel pump and sent to the common rail 51 is introduced from the common rail hole 52 into the branch hole 53, and is sent from the injection pipe 61 to the injector through the through hole in the collar 62. At that time, the inside of the common rail hole 52 has an ultra high pressure (2) accompanied by pressure fluctuation generated by the pressurized fuel sent from the fuel pump.
0 ← → about 200 MPa). Therefore, the branch hole 53
As shown in FIG. 7 of the detailed view of the peripheral portion, the common rail hole 5
At the intersection opening edge 57 of the branch hole 53 with respect to 2, tensile strain accompanied by fluctuation is repeatedly generated. Then, a crack 58 due to metal fatigue is likely to occur at the cross opening edge portion 57, and the quality becomes unstable. In order to prevent this crack, hardening treatment such as carburizing and quenching of the common rail 51 and the cross opening edge portion 57 are performed.
Although it has been attempted to make the curved surface by electrolytic deburring of No. 2 and increase the strength by changing the material, these methods result in a significant increase in cost and weight.
【0005】図8〜図10は上記接続構造の第2従来例
を示している(特開平11−287166号公報)。こ
の第2従来例では、第1従来例で述べた前記分岐穴53
の代わりに内径が2mm以上の分岐穴83が形成されて
いる。さらに、インジェクションパイプ91の先端部の
シール面94の先端には、カラーの先端部を絞る方法で
形成することにより、外径が分岐穴83の内径より小さ
く縮径し、内部の通孔の内径も縮径した、細管状の第1
絞り部を形成している。この第1絞り部よりなる突き出
し部95を分岐穴83に遊挿する。突き出し部95の内
部に形成された通孔96は内径が0.7〜1.0mmで
あり、オリフィス孔となっている。この構造では、第1
従来例のように、コモンレール51に直接にオリフィス
孔の役割を果たす細管状の分岐穴ではなく、内径が2m
m以上の分岐穴83をあけるので加工が容易化される。8 to 10 show a second conventional example of the above-mentioned connection structure (Japanese Patent Laid-Open No. 11-287166). In the second conventional example, the branch hole 53 described in the first conventional example.
Instead, a branch hole 83 having an inner diameter of 2 mm or more is formed. Furthermore, the outer diameter is reduced to be smaller than the inner diameter of the branch hole 83 by forming the tip of the collar at the tip of the sealing surface 94 at the tip of the injection pipe 91, and the inner diameter of the inner through hole is reduced. The thin tubular first with a reduced diameter
It forms a narrowed portion. The protruding portion 95 formed of the first throttle portion is loosely inserted into the branch hole 83. The through hole 96 formed inside the protruding portion 95 has an inner diameter of 0.7 to 1.0 mm and serves as an orifice hole. In this structure, the first
Unlike the conventional example, the inner diameter is 2 m instead of the thin tubular branch hole that directly functions as an orifice hole in the common rail 51.
Since the branch holes 83 having a length of m or more are formed, the processing is facilitated.
【0006】[0006]
【発明が解決しようとする課題】コモンレール内のさら
なる圧力変動の減少という性能上の要求から、オリフィ
ス孔の内径を、さらに0.4〜0.7mm程度に小さく
する必要性を要求されている。Due to the performance requirement of further reduction of pressure fluctuation in the common rail, it is necessary to further reduce the inner diameter of the orifice hole to about 0.4 to 0.7 mm.
【0007】しかしながら、第1従来例のコモンレール
51の分岐穴53をオリフィス孔とする方法又は第2従
来例のインジェクションパイプ91の先端部のシール面
94の先端に、カラーの先端部を絞る方法で形成するこ
とにより、外径が分岐穴83の内径より小さく縮径し、
内部の通孔の内径も縮径しオリフィス孔とし、細管状の
第1絞り部の突き出し部95を形成する方法では、目的
である内径を0.4〜0.7mm程度に小さくするに
は、高度な技術が必要であり困難である。However, either the branch hole 53 of the common rail 51 of the first conventional example is used as an orifice hole or the tip of the collar is squeezed to the tip of the sealing surface 94 of the injection pipe 91 of the second conventional example. By forming, the outer diameter is reduced to be smaller than the inner diameter of the branch hole 83,
In the method in which the inner diameter of the internal through hole is also reduced to form the orifice hole and the protruding portion 95 of the thin tubular first throttle portion is formed, in order to reduce the target inner diameter to about 0.4 to 0.7 mm, Difficult and requires advanced technology.
【0008】本発明の目的は、上記課題を解決し、亀裂
の発生を防止して品質の安定化を図ることができるとと
もに、加工の容易化とコストダウンとを図ることであ
る。さらに、コモンレール内の圧力変動を減少すること
ができるコモンレールとインジェクションパイプアッシ
ーとの接続構造及びその形成方法を提供することにあ
る。An object of the present invention is to solve the above problems, to prevent cracks from occurring and to stabilize quality, and to facilitate processing and reduce cost. Another object of the present invention is to provide a connection structure for a common rail and an injection pipe assembly that can reduce pressure fluctuations in the common rail, and a method for forming the connection structure.
【0009】[0009]
【課題を解決するための手段】上記目的を達成するため
に、本発明のコモンレールとインジェクションパイプア
ッシーとの接続構造は、コモンレールに内径が2mm以
上の分岐穴が形成され、インジェクションパイプ、カラ
ー及びユニオンからなるインジェクションパイプアッシ
ーのカラーの先端部に、外径が分岐穴の内径より小さく
縮径し、内部の通孔の内径も縮径した、細管状の第1絞
り部が絞り形成され、第1絞り部の先端部に、外径がさ
らに縮径し、内部の通孔の内径もさらに縮径してオリフ
ィス孔となった、微細管状の第2絞り部が絞り形成さ
れ、前記第1絞り部及び前記第2絞り部よりなる突き出
し部を前記分岐穴に遊挿することを特徴とする。In order to achieve the above object, a connecting structure of a common rail and an injection pipe assembly according to the present invention has a branch hole having an inner diameter of 2 mm or more formed in the common rail, an injection pipe, a collar and a union. At the tip of the collar of the injection pipe assembly consisting of, the outer diameter is reduced to be smaller than the inner diameter of the branch hole, and the inner diameter of the internal through hole is also reduced to form a thin tubular first throttle portion. At the tip of the narrowed portion, a fine tubular second narrowed portion is formed in which the outer diameter is further reduced and the inner diameter of the through hole is further reduced to form an orifice hole. And a protruding portion formed of the second throttle portion is loosely inserted into the branch hole.
【0010】ここで、第1絞り部、第2絞り部の第1、
第2とは、説明の便宜上付けただけのもので、2段に限
定する意味ではなく、第1絞り部と第2絞り部の間に、
その中間的な絞り部を絞り形成する場合も含む意味であ
る。Here, the first diaphragm portion, the first diaphragm portion,
The term "second" is given only for convenience of description, and does not mean that the number of stages is limited to two.
This is also meant to include the case of forming an intermediate drawn portion by drawing.
【0011】2段に絞る場合を例にとると、それぞれの
内径については、カラー内の通孔(内径2.0mm)、
第1絞り部(内径0.7〜1.0mm)及び第2絞り部
(オリフィス孔)(内径0.4〜0.7mm)の範囲で
縮径するのが好ましい。Taking the case of squeezing into two steps as an example, the inner diameters of the respective holes are the through holes (inner diameter 2.0 mm) in the collar,
It is preferable to reduce the diameter within the range of the first throttle portion (inner diameter 0.7 to 1.0 mm) and the second throttle portion (orifice hole) (inner diameter 0.4 to 0.7 mm).
【0012】分岐穴の内径を2mm以上としたのは、特
に限定はされないが、分岐穴の加工を容易にするため
と、遊挿する突き出し部が細くなりすぎないようにする
ためであり、3mm以上にすることがさらに好ましい。
分岐穴の内径の上限は、数値上は特に限定されないが、
実際的には、コモンレール穴の内径までである。また、
通孔の内径は、連続して縮径していればその境界面は、
特に限定はされないが、曲面であっても平面であっても
よい、より好ましくは、円錐形状に縮径している状態で
ある。The reason why the inner diameter of the branch hole is set to 2 mm or more is not particularly limited, but it is for facilitating the processing of the branch hole and for preventing the protruding portion for loose insertion from becoming too thin. It is more preferable to set it as above.
The upper limit of the inner diameter of the branch hole is not particularly limited numerically,
Practically up to the inner diameter of the common rail hole. Also,
If the inner diameter of the through hole is continuously reduced, the boundary surface
Although not particularly limited, it may be a curved surface or a flat surface, and more preferably a conical diameter-reduced state.
【0013】ここで、突き出し部の先端面とコモンレー
ル穴に対する分岐穴の交差開口との位置関係は、特に限
定はするものではないが、略面一にすることが好まし
い。Here, the positional relationship between the tip surface of the protruding portion and the intersection opening of the branch hole with respect to the common rail hole is not particularly limited, but it is preferable that they are substantially flush with each other.
【0014】また、本発明のコモンレールとインジェク
ションパイプアッシーの形成方法は、コモンレールに内
径が2mm以上の分岐穴を形成し、インジェクションパ
イプ、カラー及びユニオンからなるインジェクションパ
イプアッシーのカラーの先端部を絞る方法で圧縮残留歪
みが残るように塑性変形することにより、外径が分岐穴
の内径より小さく縮径し、内部の通孔の内径も縮径し
た、細管状の第1絞り部を形成し、第1絞り部の先端部
をさらに絞る方法で圧縮残留歪みが残るように塑性変形
することにより、外径がさらに縮径し、内部の通孔の内
径もさらに縮径してオリフィス孔となった、微細管状の
第2絞り部を形成し、前記第1絞り部及び前記第2絞り
部よりなる突き出し部を前記分岐穴に遊挿することを特
徴とする。The method of forming the common rail and the injection pipe assembly of the present invention is a method of forming a branch hole having an inner diameter of 2 mm or more in the common rail and squeezing the tip of the collar of the injection pipe assembly including the injection pipe, the collar and the union. By plastically deforming so that residual compression strain remains, the outer diameter is reduced to be smaller than the inner diameter of the branch hole, and the inner diameter of the internal through hole is also reduced to form a thin tubular first throttle portion. (1) By plastically deforming so that residual compression strain remains by a method of further narrowing the tip of the narrowed portion, the outer diameter is further reduced, and the inner diameter of the internal through hole is further reduced to become an orifice hole. It is characterized in that a fine tubular second throttle portion is formed, and a protruding portion composed of the first throttle portion and the second throttle portion is loosely inserted into the branch hole.
【0015】[0015]
【発明の実施の形態】以下、本発明を具体化した実施形
態例について、図1〜図4を参照して説明する。図4は
ディーゼルエンジンのコモンレール式燃料噴射装置の概
略を示し、コモンレール1の側部には、燃料ポンプ2を
接続するためのパイプ3と、インジェクタ4を接続する
ためのインジェクションパイプアッシー20とが接続さ
れ、コモンレール1の端部には、リリーフバルブ6と圧
力センサ7とが接続される。燃料ポンプ2とインジェク
タ4は電子制御装置8により制御される。図1〜図3
は、本実施形態に係るコモンレール1とインジェクショ
ンパイプアッシー20との接合構造を示している。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments embodying the present invention will be described below with reference to FIGS. FIG. 4 shows an outline of a common rail fuel injection device for a diesel engine. A pipe 3 for connecting a fuel pump 2 and an injection pipe assembly 20 for connecting an injector 4 are connected to a side portion of the common rail 1. The relief valve 6 and the pressure sensor 7 are connected to the end of the common rail 1. The fuel pump 2 and the injector 4 are controlled by the electronic control unit 8. 1 to 3
Shows a joint structure between the common rail 1 and the injection pipe assembly 20 according to the present embodiment.
【0016】図1に示すように、金属製のコモンレール
1の中心部にはレール長方向に延びるコモンレール穴1
2が形成され、その内径は6〜11mm(例えば11m
m)である。コモンレール1の筒壁部には、内側から外
側へ順に、コモンレール穴12に交差開口してレール長
直角方向に延びる分岐穴13と、テーパー状のシール面
14と、内周に雌ネジ16が切られた取付穴15とが形
成されている。分岐穴13の内径は3.5mmであり、
この程度の大きさであれば切削加工により形成可能であ
るから、本実施形態の分岐穴13はドリル加工されてい
る。As shown in FIG. 1, a common rail hole 1 extending in the rail length direction is formed at the center of the metal common rail 1.
2 is formed, and the inner diameter is 6 to 11 mm (for example, 11 m
m). In the cylinder wall portion of the common rail 1, a branch hole 13 that cross-opens in the common rail hole 12 and extends in the direction perpendicular to the rail length in order from the inside to the outside, a tapered sealing surface 14, and a female screw 16 is cut on the inner periphery. The mounting hole 15 is formed. The inner diameter of the branch hole 13 is 3.5 mm,
The branch hole 13 of the present embodiment is drilled because it can be formed by cutting if it has this size.
【0017】インジェクションパイプ5の周りには取付
部材としての大筒状のユニオン31が通され、ユニオン
31の外周には雄ネジ32が切られるとともに六角部3
3が形成され、ユニオン31の内周には段部34が形成
されている。そして、インジェクションパイプ5とカラ
ー22とユニオン31とが、予めインジェクションパイ
プアッシー20としてアッセンブリ化されている。A large cylindrical union 31 as a mounting member is passed around the injection pipe 5, and a male screw 32 is cut on the outer periphery of the union 31 and the hexagonal portion 3 is formed.
3 is formed, and a step portion 34 is formed on the inner circumference of the union 31. Then, the injection pipe 5, the collar 22, and the union 31 are assembled into an injection pipe assembly 20 in advance.
【0018】図2にインジェクションパイプアッシー2
0をコモンレール1に接続した態様を示す。すなわち、
ユニオン31の雄ネジ32を取付穴15の雌ネジ16に
螺合し、ユニオン31の段部34をカラー22のフラン
ジ部23に係合させて、カラー22のシール面24をコ
モンレール1のシール面14に強く密着させるととも
に、突き出し部25を分岐穴13に同心状に遊挿させ
て、突き出し部25の先端面をコモンレール穴12に対
する分岐穴13の交差開口と略面一にすればよい。この
遊挿により、突き出し部25(3mm以内)と分岐穴1
3(3.5mm)との間には周状に0.25mm以上の
隙間27が生じる。The injection pipe assembly 2 is shown in FIG.
A mode in which 0 is connected to the common rail 1 is shown. That is,
The male screw 32 of the union 31 is screwed into the female screw 16 of the mounting hole 15, and the step portion 34 of the union 31 is engaged with the flange portion 23 of the collar 22 so that the sealing surface 24 of the collar 22 becomes the sealing surface of the common rail 1. The protrusion 25 may be closely attached to the branch hole 13 and may be coaxially loosely inserted in the branch hole 13 so that the tip end surface of the protrusion 25 is substantially flush with the intersection opening of the branch hole 13 with the common rail hole 12. By this loose insertion, the protruding portion 25 (within 3 mm) and the branch hole 1
3 (3.5 mm), a gap 27 of 0.25 mm or more is circumferentially formed.
【0019】燃料ポンプ2により加圧してコモンレール
1に送られた燃料は、コモンレール穴12からカラー2
2の突き出し部25の通孔26に直接導入され、インジ
ェクションパイプ5からインジェクタ4に送られる。す
なわち、本実施形態では突き出し部25の通孔26が、
従来例の分岐穴53と同様に燃料を導入させる穴として
機能する。The fuel pressurized by the fuel pump 2 and sent to the common rail 1 is supplied from the common rail hole 12 to the collar 2.
It is directly introduced into the through hole 26 of the second protruding portion 25, and is sent from the injection pipe 5 to the injector 4. That is, in this embodiment, the through hole 26 of the protruding portion 25 is
Like the branch hole 53 of the conventional example, it functions as a hole for introducing fuel.
【0020】図2及び要部詳細図は図3に図示する突き
出し部25の形成方法とその内部の通孔について示す。
インジェクションパイプ5の外径は6.35mm、内径
は3mmである。インジェクションパイプ5の端部には
金属製の小筒状のカラー22が圧入固定され、その主要
部の外径は8mm、内径は2mmである。カラー22の
途中には凸球面状のシール面24が形成され、カラー2
2の先端部には第1絞り部25a及び第2絞り部25b
よりなる突き出し部25が形成されている。この突き出
し部25は、まず、カラー22の先端部を絞る方法で圧
縮残留歪みが残るように塑性変形することにより、外径
が分岐穴の内径より小さく縮径し、内部の通孔の内径
(26a)も縮径した、細管状の第1絞り部25aを形
成する。次に、第1絞り部25aの先端部をさらに絞る
方法で圧縮残留歪みが残るように塑性変形することによ
り、外径がさらに縮径し、内部の通孔の内径もさらに縮
径してオリフィス孔26bとなった、微細管状の第2絞
り部25bを形成する。最終的に、突き出し部25全体
の長さは分岐穴13の長さと略同一とする。また、突き
出し部25の外径は分岐穴13の内径より小さい3mm
以内とし、突き出し部25は分岐穴13に遊挿する。FIG. 2 and a detailed view of the main part show a method of forming the protruding portion 25 shown in FIG. 3 and a through hole therein.
The injection pipe 5 has an outer diameter of 6.35 mm and an inner diameter of 3 mm. A small tubular collar 22 made of metal is press-fitted and fixed to the end of the injection pipe 5, and the main portion has an outer diameter of 8 mm and an inner diameter of 2 mm. A convex spherical sealing surface 24 is formed in the middle of the collar 22.
The first throttle portion 25a and the second throttle portion 25b are provided at the tip of
The protruding portion 25 is formed. The protruding portion 25 is first plastically deformed by a method of squeezing the distal end portion of the collar 22 so that residual compression strain remains, so that the outer diameter is reduced to be smaller than the inner diameter of the branch hole, and the inner diameter of the inner through hole ( 26a) also forms a thin tubular first throttle portion 25a with a reduced diameter. Next, the outer diameter is further reduced and the inner diameter of the internal through hole is further reduced by plastically deforming so that residual compression strain remains by a method of further narrowing the tip of the first throttle portion 25a. The second tubular narrowed portion 25b, which has become the hole 26b, is formed. Finally, the entire length of the protruding portion 25 is made substantially the same as the length of the branch hole 13. The outer diameter of the protruding portion 25 is 3 mm smaller than the inner diameter of the branch hole 13.
The protrusion 25 is loosely inserted into the branch hole 13.
【0021】カラー22の先端部からシール面14と突
き出し部25の形成の際の2段階の絞りの際に、インジ
ェクションパイプ5からカラー22内そして突き出し部
25内に続いている通孔26は、2段に絞り、縮径して
いて、通孔の先端の第2絞り部25bの内径はオリフィ
ス孔26bとなる。通孔26の内径は、カラー22内の
通孔(内径2.0mm)、次に第1絞り部内通孔26a
(内径0.7〜1.0mm)、最後に先端である第2絞
り部内通孔(オリフィス孔)26b(内径0.4〜0.
7mm)とそれぞれ先端に向かうにつれて連続して2段
に絞り縮径している。When the sealing surface 14 and the protruding portion 25 are formed from the tip of the collar 22 in two stages of drawing, the through hole 26 continuing from the injection pipe 5 into the collar 22 and into the protruding portion 25 is The diameter is reduced in two stages and the inner diameter of the second throttle portion 25b at the tip of the through hole becomes the orifice hole 26b. The inner diameter of the through hole 26 is the through hole in the collar 22 (inner diameter 2.0 mm), and then the through hole 26a in the first throttle portion.
(Inner diameter 0.7 to 1.0 mm), and finally the second throttle portion inner through hole (orifice hole) 26b (inner diameter 0.4 to 0.
7 mm) and the diameter is continuously reduced in two steps toward the tip.
【0022】本実施形態のコモンレール1によれば、次
の作用・効果(1)(2)(3)が得られる。
(1)前記の通り、コモンレール1の分岐穴13の内径
を3mm程度に大きくするので、分岐穴13は切削加工
又はその他の方法により容易に形成することができ、設
備投資の軽減とコストダウンとを図ることができる。一
方、インジェクションパイプアッシー20は、カラー2
2に突き出し部25を形成する分だけ構造が複雑になる
が、加工は容易であるから、コモンレール1も含めたト
ータルとしては、図5〜図7に示す第1従来例より製造
が容易になり、コストメリットが大きい。According to the common rail 1 of this embodiment, the following actions / effects (1), (2) and (3) can be obtained. (1) As described above, since the inner diameter of the branch hole 13 of the common rail 1 is increased to about 3 mm, the branch hole 13 can be easily formed by cutting or another method, which reduces facility investment and reduces cost. Can be achieved. On the other hand, the injection pipe assembly 20 is a color 2
Although the structure becomes complicated by forming the protruding portion 25 on the second rail 2, the processing is easy. Therefore, as a total including the common rail 1, the manufacturing is easier than the first conventional example shown in FIGS. The cost merit is great.
【0023】(2)図3に示すように、コモンレール穴
12内の加圧燃料による超高圧は、カラー22の突き出
し部25にかかる。しかし、突き出し部25と分岐穴1
3との間に隙間27があるため、突き出し部25はその
内周面(通孔26)と外周面とに同じ圧力を受け、発生
応力が抑えられ、変動を伴った引張歪みが発生すること
もなく、亀裂の発生を防止することができる。結果とし
て、品質が安定する。従って、図5〜図7に示す第1従
来例のような浸炭焼入れ等の硬化処理や材料変更等によ
る強度アップは不要であるから、大幅なコストアップを
図ることができ、重量増の心配も無い。なお、超高圧は
コモンレール穴12に対する分岐穴13の交差開口縁部
17にもかかるが、その内径が大きいことから、従来よ
り簡単な方法(例えば流体研磨等)による曲面化等で局
部応力集中を緩和できるので、性能は保障できる。(2) As shown in FIG. 3, the super high pressure by the pressurized fuel in the common rail hole 12 is applied to the protruding portion 25 of the collar 22. However, the protrusion 25 and the branch hole 1
Since there is a gap 27 between the protruding portion 25 and the inner peripheral surface (through hole 26) and the outer peripheral surface of the protruding portion 25, the generated stress is suppressed, and a tensile strain accompanied by fluctuation is generated. Also, it is possible to prevent the occurrence of cracks. As a result, the quality is stable. Therefore, unlike the first conventional example shown in FIGS. 5 to 7, it is not necessary to increase the strength by hardening treatment such as carburizing and quenching or changing the material, so that it is possible to significantly increase the cost and increase the weight. There is no. Although the ultra-high pressure is also applied to the intersection opening edge portion 17 of the branch hole 13 with respect to the common rail hole 12, its inner diameter is large, so that local stress concentration can be prevented by forming a curved surface by a simpler method (for example, fluid polishing) than before. Since it can be relaxed, performance can be guaranteed.
【0024】(3)さらに、図2に示すように、通孔2
6は、カラー22内の通孔(内径2.0mm)から、第
1絞り部内通孔26a(内径0.7〜1.0mm)と
し、さらに第2絞り部内通孔26b(オリフィス孔、内
径0.4〜0.7mm)と2段に絞り縮径をすると、径
を0.4〜0.7mmとすることが可能となる。2段の
絞りによる通孔の縮径により、オリフィス孔を図8〜図
10に示す第2従来例より、内径の小さいものとするこ
とができる。その結果、燃料噴射により発生する圧力波
の伝播を減らすことができ、コモンレール内の圧力変動
を減少することができる。さらに、このような2段絞り
の形状をとることで、インジェクション側の通孔内の圧
力波の減衰もみられる。(3) Further, as shown in FIG.
Reference numeral 6 is a through hole (inner diameter 2.0 mm) in the collar 22 to be a first through hole 26a (inner diameter 0.7 to 1.0 mm), and a second through hole 26b (orifice hole, inside diameter 0). .4 to 0.7 mm), the diameter can be reduced to 0.4 to 0.7 mm. By reducing the diameter of the through hole by the two-stage throttle, the orifice hole can be made smaller in inner diameter than the second conventional example shown in FIGS. As a result, the propagation of the pressure wave generated by the fuel injection can be reduced, and the pressure fluctuation in the common rail can be reduced. Further, by adopting such a two-stage throttle shape, the attenuation of the pressure wave in the injection-side through hole is also observed.
【0025】なお、本発明は前記実施形態に限定される
ものではなく、例えば以下のように、発明の趣旨から逸
脱しない範囲で適宜変更して具体化することもできる。
(1)インジェクションパイプアッシーの構成を変更
し、例えばインジェクションパイプ5の先端に突き出し
部を直接形成し、インジェクションパイプ5の外周にカ
ラーを固定すること。
(2)通孔の内径、突き出し部の外径又は分岐穴の径等
の寸法を適宜変更すること。The present invention is not limited to the above-described embodiment, but can be embodied with appropriate modifications within the scope not departing from the spirit of the invention, for example, as follows. (1) Changing the configuration of the injection pipe assembly, for example, forming a protrusion directly on the tip of the injection pipe 5 and fixing the collar on the outer periphery of the injection pipe 5. (2) Appropriately change the inner diameter of the through hole, the outer diameter of the protruding portion, or the diameter of the branch hole.
【0026】[0026]
【発明の効果】以上詳述した通り、本発明のコモンレー
ルとインジェクションパイプアッシーとの接続構造及び
その形成方法によれば、亀裂の発生を防止して品質の安
定化を図ることができるとともに、加工の容易化とコス
トダウンを図ることができる。さらに、燃料噴射により
発生するコモンレール内の圧力変動が減少するという優
れた効果が得られる。As described in detail above, according to the connection structure of the common rail and the injection pipe assembly of the present invention and the method of forming the same, it is possible to prevent the occurrence of cracks and stabilize the quality, and Can be facilitated and cost can be reduced. Further, the excellent effect that the pressure fluctuation in the common rail caused by the fuel injection is reduced can be obtained.
【図1】本発明の実施形態に係るコモンレールとインジ
ェクションパイプアッシーとの接続構造の接続前の断面
図である。FIG. 1 is a cross-sectional view of a connection structure of a common rail and an injection pipe assembly according to an embodiment of the present invention before connection.
【図2】同接続構造の接続後の断面図である。FIG. 2 is a cross-sectional view of the connection structure after connection.
【図3】図2の要部拡大断面図である。FIG. 3 is an enlarged cross-sectional view of a main part of FIG.
【図4】ディーゼルエンジンのコモンレール式燃料噴射
装置の概略図である。FIG. 4 is a schematic diagram of a common rail fuel injection device for a diesel engine.
【図5】第1従来例に係るコモンレールとインジェクシ
ョンパイプアッシーとの接続構造の接続前の断面図であ
る。FIG. 5 is a cross-sectional view of a connection structure of a common rail and an injection pipe assembly according to a first conventional example before connection.
【図6】同接続構造の接続後の断面図である。FIG. 6 is a cross-sectional view of the connection structure after connection.
【図7】図6の要部拡大断面図である。FIG. 7 is an enlarged cross-sectional view of the main parts of FIG.
【図8】第2従来例に係るコモンレールとインジェクシ
ョンパイプアッシーとの接続構造の接続前の断面図であ
る。FIG. 8 is a cross-sectional view of a connection structure of a common rail and an injection pipe assembly according to a second conventional example before connection.
【図9】同接続構造の接続後の断面図である。FIG. 9 is a cross-sectional view of the connection structure after connection.
【図10】図9の要部拡大断面図である。10 is an enlarged cross-sectional view of the main parts of FIG.
1 コモンレール 5 インジェクションパイプ 12 コモンレール穴 13 分岐穴 20 インジェクションパイプアッシー 22 カラー 25 突き出し部 26 通孔 27 隙間 31 ユニオン 1 common rail 5 injection pipes 12 Common rail hole 13 branch holes 20 injection pipe assembly 22 colors 25 protruding part 26 through holes 27 Gap 31 Union
───────────────────────────────────────────────────── フロントページの続き (72)発明者 丹羽 哲也 愛知県西尾市中畑町浜田下10番地 株式会 社オティックス内 Fターム(参考) 3G066 AA07 AB02 AC09 AD05 BA12 BA46 BA55 BA61 CB03 CB11 CD04 CD30 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Tetsuya Niwa 10 Hamadashita, Nakahata-cho, Nishio-shi, Aichi Stock Association Company Otics F term (reference) 3G066 AA07 AB02 AC09 AD05 BA12 BA46 BA55 BA61 CB03 CB11 CD04 CD30
Claims (2)
穴が形成され、 インジェクションパイプ、カラー及びユニオンからなる
インジェクションパイプアッシーのカラーの先端部に、
外径が前記分岐穴の内径より小さく縮径し、内部の通孔
の内径も縮径した、細管状の第1絞り部が絞り形成さ
れ、 前記第1絞り部の先端部に、外径がさらに縮径し、内部
の通孔の内径もさらに縮径してオリフィス孔となった、
微細管状の第2絞り部が絞り形成され、 前記第1絞り部及び前記第2絞り部よりなる突き出し部
を前記分岐穴に遊挿することを特徴とするコモンレール
とインジェクションパイプアッシーとの接続構造。1. A common rail is formed with a branch hole having an inner diameter of 2 mm or more, and a front end portion of a collar of an injection pipe assembly including an injection pipe, a collar and a union,
An outer diameter is reduced to be smaller than an inner diameter of the branch hole, and an inner diameter of an internal through hole is also reduced to form a narrow tubular first throttle portion, and an outer diameter is formed at a tip portion of the first throttle portion. The diameter was further reduced, and the inner diameter of the internal through hole was also reduced to become an orifice hole.
A connection structure between a common rail and an injection pipe assembly, wherein a fine tubular second throttle portion is formed by drawing, and a protruding portion composed of the first throttle portion and the second throttle portion is loosely inserted in the branch hole.
穴を形成し、 インジェクションパイプ、カラー及びユニオンからなる
インジェクションパイプアッシーのカラーの先端部を絞
る方法で圧縮残留歪みが残るように塑性変形することに
より、外径が前記分岐穴の内径より小さく縮径し、内部
の通孔の内径も縮径した、細管状の第1絞り部を形成
し、 前記第1絞り部の先端部をさらに絞る方法で圧縮残留歪
みが残るように塑性変形することにより、外径がさらに
縮径し、内部の通孔の内径もさらに縮径してオリフィス
孔となった、微細管状の第2絞り部を形成し、 前記第1絞り部及び前記第2絞り部よりなる突き出し部
を前記分岐穴に遊挿することを特徴とするコモンレール
とインジェクションパイプアッシーとの接続構造の形成
方法。2. A common rail is formed with a branch hole having an inner diameter of 2 mm or more, and the end of the collar of an injection pipe assembly including an injection pipe, a collar and a union is squeezed to plastically deform so that residual compression strain remains. In the method, the outer diameter is reduced to be smaller than the inner diameter of the branch hole, and the inner diameter of the internal through hole is also reduced to form a thin tubular first throttle portion, and the tip portion of the first throttle portion is further narrowed. By plastically deforming so that residual compressive strain remains, the outer diameter is further reduced, and the inner diameter of the internal through hole is also further reduced to form an orifice hole, forming a fine tubular second throttle portion, A method for forming a connection structure between a common rail and an injection pipe assembly, wherein a projecting portion including the first throttle portion and the second throttle portion is loosely inserted in the branch hole.
Priority Applications (1)
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JP2001243753A JP4010786B2 (en) | 2001-08-10 | 2001-08-10 | Connection structure between common rail and injection pipe assembly and method for forming the same |
Applications Claiming Priority (1)
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JP2001243753A JP4010786B2 (en) | 2001-08-10 | 2001-08-10 | Connection structure between common rail and injection pipe assembly and method for forming the same |
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JP2003056428A true JP2003056428A (en) | 2003-02-26 |
JP4010786B2 JP4010786B2 (en) | 2007-11-21 |
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ID=19073795
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JP2001243753A Expired - Fee Related JP4010786B2 (en) | 2001-08-10 | 2001-08-10 | Connection structure between common rail and injection pipe assembly and method for forming the same |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007015566A1 (en) * | 2005-08-04 | 2007-02-08 | Nippon Steel Corporation | High-pressure fuel injection accumulator distributor for automobile and method of manufacturing the same |
WO2008041374A1 (en) * | 2006-10-02 | 2008-04-10 | Bosch Corporation | Common rail and method of manufacturing common rail |
EP2154407A1 (en) * | 2008-07-25 | 2010-02-17 | J.M. Martin Tiby | Tubing configuration and sealing method for high pressure tubing on high pressure fuel system |
JP2013511637A (en) * | 2009-11-23 | 2013-04-04 | ロバート ボッシュ ゲーエムベーハー | Joint for pressure piping of common rail injection system |
-
2001
- 2001-08-10 JP JP2001243753A patent/JP4010786B2/en not_active Expired - Fee Related
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007015566A1 (en) * | 2005-08-04 | 2007-02-08 | Nippon Steel Corporation | High-pressure fuel injection accumulator distributor for automobile and method of manufacturing the same |
KR100937058B1 (en) | 2005-08-04 | 2010-01-15 | 신닛뽄세이테쯔 카부시키카이샤 | High-pressure fuel injection accumulator distributor for automobile and method of manufacturing the same |
US7900603B2 (en) | 2005-08-04 | 2011-03-08 | Nippon Steel Corporation | Automobile-use high pressure fuel injection accumulator-distributor and method of production of the same |
WO2008041374A1 (en) * | 2006-10-02 | 2008-04-10 | Bosch Corporation | Common rail and method of manufacturing common rail |
JP2008088887A (en) * | 2006-10-02 | 2008-04-17 | Bosch Corp | Common rail and its manufacturing method |
JP4484227B2 (en) * | 2006-10-02 | 2010-06-16 | ボッシュ株式会社 | Common rail |
EP2154407A1 (en) * | 2008-07-25 | 2010-02-17 | J.M. Martin Tiby | Tubing configuration and sealing method for high pressure tubing on high pressure fuel system |
JP2013511637A (en) * | 2009-11-23 | 2013-04-04 | ロバート ボッシュ ゲーエムベーハー | Joint for pressure piping of common rail injection system |
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