JP2002130076A - High-pressure fuel injection pipe having connection head part - Google Patents
High-pressure fuel injection pipe having connection head partInfo
- Publication number
- JP2002130076A JP2002130076A JP2000325917A JP2000325917A JP2002130076A JP 2002130076 A JP2002130076 A JP 2002130076A JP 2000325917 A JP2000325917 A JP 2000325917A JP 2000325917 A JP2000325917 A JP 2000325917A JP 2002130076 A JP2002130076 A JP 2002130076A
- Authority
- JP
- Japan
- Prior art keywords
- connection
- washer
- head
- injection pipe
- head part
- 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
Links
Landscapes
- Fuel-Injection Apparatus (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えばディーゼル
内燃機関における燃料の供給路などとして配設多用され
る管径４ｍ／ｍ乃至２０ｍ／ｍ、肉厚１ｍ／ｍ乃至８ｍ
／ｍ程度の比較的細径からなる厚肉鋼管による接続頭部
を有する高圧燃料噴射管に関するものである。The present invention relates to a pipe diameter of 4 m / m to 20 m / m, a wall thickness of 1 m / m to 8 m, which is frequently used as a fuel supply path in a diesel internal combustion engine, for example.
The present invention relates to a high-pressure fuel injection pipe having a connection head made of a thick steel pipe having a relatively small diameter of about / m.
【０００２】[0002]
【従来の技術】従来、この種の接続頭部を有する高圧燃
料噴射管としては、図７、図８に例示するように、厚肉
鋼管１１の端部に設けてなる外側周面をシート面１３と
する截頭円錐状の接続頭部１２が外方からのパンチ部材
による軸芯方向への押圧による挫屈加工によって成形さ
れるのに関連して、該押圧による挫屈加工に伴う周壁の
外側への拡がりによって、該頭部内周面に深くかつ大き
な環状の鋭角なしわ１５あるいはポケットを生ぜしめて
構成され、また接続頭部１２の首下部には、接続頭部１
２を相手シール面に取付けるために有効な軸力を付与す
るのに必要な部品として、あるいは振動がかかった時の
補強として長さが５ｍｍ以下のワッシャ（接続座金）１
４、あるいは長さが５ｍｍ以下の鍔１５−１のついたス
リーブ（接続座金）１５が嵌着されていた。また従来の
ワッシャ１４、スリーブ１５の硬度は４００Ｈｖ未満で
あった。2. Description of the Related Art Conventionally, as a high-pressure fuel injection pipe having a connection head of this kind, as shown in FIGS. 7 and 8, an outer peripheral surface provided at an end of a thick steel pipe 11 has a sheet surface. In connection with the frusto-conical connection head 12 being formed by buckling processing by pressing from the outside in the axial direction by the punch member, the peripheral wall accompanying the buckling processing by the pressing is formed. Due to the outward expansion, a deep and large annular acute wrinkle 15 or pocket is formed on the inner peripheral surface of the head.
A washer (connection washer) having a length of 5 mm or less as a part necessary for applying an effective axial force to attach the second member 2 to the mating seal surface, or as a reinforcement when vibration is applied.
4, or a sleeve (connection washer) 15 having a flange 15-1 having a length of 5 mm or less was fitted. The hardness of the conventional washer 14 and sleeve 15 was less than 400 Hv.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、このよ
うな従来の接続頭部を有する高圧燃料噴射管は、前記頭
部内側に生じた深くかつ大きな環状の鋭角なしわ１５あ
るいはポケットによって、配設使用時の高圧流体に起因
して該しわ部あるいはポケット部が疲労破壊の起点とな
るという問題があった。また、このような高圧燃料噴射
管の場合、シールのために必要な軸力は大きく、この軸
力を付与するための締付けトルクは、頭部の挫屈成形部
への大きな捩り力を与えることになり、この状態で使用
されると、捩り力を初期応力とし、繰返し内圧による変
動応力として（さらには振動が発生する応力が加算さ
れ）挫屈成形部のしわあるいはクラックから破損するこ
とがあった。かかる対策として、挫屈成形により頭部成
形部の内側に発生する皺あるいはクラックを小さくして
応力を低減させる方法が考えられるが、管接続時のナッ
ト締付けによりワッシャ１４あるいはスリーブ１５が塑
性変形することで、ナットを締付けても軸力が上昇しな
いという問題があった。さらにこの方法では、頭部成形
部が変形しシール軸力の低下を招くという問題がある。However, such a conventional high-pressure fuel injection pipe having a connection head is disposed and used by a deep and large annular acute wrinkle 15 or pocket formed inside the head. There is a problem that the wrinkles or pockets become the starting point of fatigue failure due to the high pressure fluid at the time. In addition, in the case of such a high-pressure fuel injection pipe, the axial force required for sealing is large, and the tightening torque for applying this axial force applies a large torsional force to the buckled molded portion of the head. When used in this state, the torsional force is used as the initial stress, and as a fluctuating stress due to repeated internal pressure (furthermore, the stress that generates vibration is added), the buckled molded part may be damaged from wrinkles or cracks. Was. As a countermeasure, a method of reducing stress by reducing wrinkles or cracks generated inside the head forming portion by buckling molding can be considered, but the washer 14 or the sleeve 15 is plastically deformed by tightening the nut at the time of pipe connection. Thus, there is a problem that the axial force does not increase even when the nut is tightened. Further, in this method, there is a problem that the head forming portion is deformed and the sealing axial force is reduced.
【０００４】本発明は前記従来技術の有する前記問題点
に鑑みてなされたもので、頭部加工に伴い頭部内部に生
じる環状の鋭角なしわあるいはクラックを小さくするた
めに挫屈成形部の強度を高め、シール部面圧を高めるこ
とによって該頭部内側での疲労破壊の危惧をなくすこと
ができる高圧燃料噴射管を提供することを目的とするも
のである。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has been developed in order to reduce the sharp wrinkles or cracks formed in the inside of the head due to the processing of the head. It is an object of the present invention to provide a high-pressure fuel injection pipe which can eliminate the fear of fatigue fracture inside the head by increasing the surface pressure of the seal portion.
【０００５】[0005]
【課題を解決するための手段】本発明は上記目的を達成
するため、比較的細径からなる厚肉鋼管の接続端部に、
外側周面を相手座部への截頭円錐状もしくは截頭円弧状
のシート面とする接続頭部を設け、比較的細径からなる
厚肉鋼管の接続端部に、外側周面を相手座部への截頭円
錐状もしくは截頭円弧状のシート面とする接続頭部を設
け、該接続頭部の首下部外周面を覆い、接続頭部側に面
取り仰角θが２０度〜４０度、面取り深さ１が０．１ｄ
以上０．６ｄ（ｄ：管径）以下、軸方向長さＬが０．５
ｄ〜１．５ｄの接続座金を設け、かつ該接続座金と噴射
管を密着させた高圧燃料噴射管を要旨とし、また前記接
続座金の硬度は４００Ｈｖ以上、接続頭部の頭部径は管
径ｄの１２５％以上〜２００％以下とすることを特徴と
するものである。ここで接続座金とは、ワッシャまたは
スリーブワッシャのことである。According to the present invention, in order to achieve the above object, a connecting end of a thick steel pipe having a relatively small diameter is provided.
A connecting head having an outer peripheral surface as a frusto-conical or truncated arc seat surface to the mating seat is provided, and the outer peripheral surface is mated to the mating end of a thick-walled steel pipe having a relatively small diameter. A connecting head having a frusto-conical or truncated arc-shaped sheet surface is provided on the connecting portion, the outer peripheral surface of the lower part of the neck of the connecting head is covered, and the chamfering elevation angle θ is 20 to 40 degrees on the connecting head side, Chamfer depth 1 is 0.1d
Not less than 0.6d (d: pipe diameter) and the axial length L is 0.5
A high-pressure fuel injection pipe having a connection washer of d to 1.5d, and the connection washer and the injection pipe being in close contact with each other. The hardness of the connection washer is 400 Hv or more, and the head diameter of the connection head is the pipe diameter. d is 125% or more and 200% or less. Here, the connection washer is a washer or a sleeve washer.
【０００６】すなわち、本発明では接続頭部の首下部外
周面を覆う密着形の接続座金に面取り部を設けたことに
より、この面取り部が成形部外径を拘束し、内径側に材
料を張り出させることにより挫屈成形で生じる該頭部内
側の環状凹み溝部（ポケット部）にできる鋭角なしわあ
るいはクラックを小さくすることができることとなり、
該頭部内部での応力集中による疲労破壊の起点となる可
能性を減少させることができる。また、この接続座金を
高硬度としたことにより、当該高硬度の接続座金に軸力
が作用した場合の変形が小さくなり、さらに接続頭部最
大径部を前記接続座金の面取り部側端面に被せた構造と
したことにより、過大な締付けトルクで生じる軸力を接
続頭部最大径部と接続座金の面取り部側端面との間で吸
収できることにより、当該接続座金の拡がりを抑制でき
るので、締付けトルク過大による該接続座金の変形を防
止できる。That is, according to the present invention, a chamfered portion is provided on a contact type washer that covers the outer peripheral surface of the lower portion of the neck of the connection head, so that the chamfered portion restrains the outer diameter of the formed portion and stretches the material on the inner diameter side. It is possible to reduce sharp wrinkles or cracks formed in the annular concave groove portion (pocket portion) on the inner side of the head caused by buckling molding by causing it to come out,
It is possible to reduce the possibility of starting fatigue fracture due to stress concentration inside the head. In addition, since the connection washer has a high hardness, deformation when an axial force acts on the high-hardness connection washer is reduced, and the maximum diameter portion of the connection head is covered on the chamfered portion side end surface of the connection washer. With this structure, the axial force generated by excessive tightening torque can be absorbed between the maximum diameter portion of the connection head and the end face on the chamfered portion side of the connection washer, so that the expansion of the connection washer can be suppressed. It is possible to prevent the connection washer from being deformed due to excessively large size.
【０００７】本発明において、接続座金の面取り仰角θ
を２０度〜４０度に限定したのは、２０度未満では鋭角
なしわあるいはクラックが小さくできず、他方、４０度
を越えるとワッシャーやスリーブが潰れて広がるためで
ある。また、面取り深さ１を０．１ｄ以上０．６ｄ
（ｄ：管径）以下と限定したのは、０．１ｄ未満ではし
わやクラックを小さくできず、他方、０．６ｄを越える
と挫屈成形時に内径側に材料を張り出させる作用に乏し
く、かつ当該接続座金の拡がりを抑制できないためであ
る。さらに接続座金の軸方向長さＬを０．５ｄ〜１．５
ｄに限定したのは、０．５ｄ未満では接続座金および該
接続座金に密着した噴射管によるナット締付け時のトル
クにより発生する捩りエネルギーを吸収する体積が少な
くて吸収エネルギーが少なくなり、ポケット部の剪断面
に作用する剪断エネルギーが大きくなり、他方、１．５
ｄを超えても接続座金および当該座金に密着した噴射管
による捩りエネルギー吸収効果に差がなく、かつ接続座
金やナットが大型となって重くなる上、コストアップと
なるためである。また、同接続座金の硬度を４００Ｈｖ
以上と限定したのは、接続座金の広がりを抑制するため
である。さらに、同接続頭部の挫屈成形頭部径を管径ｄ
の１２５％以上〜２００％以下としたのは、管径ｄの１
２５％未満では頭部が塑性変形し軸力が得られず、他
方、管径ｄの２００％を超えると、鋭角なしわあるいは
クラックが発生するためである。In the present invention, the angle of elevation of the chamfer of the connection washer θ
Is limited to 20 to 40 degrees because if it is less than 20 degrees, sharp wrinkles or cracks cannot be reduced, and if it exceeds 40 degrees, the washer or the sleeve is crushed and spread. Further, the chamfering depth 1 is set to 0.1d or more and 0.6d or more.
(D: pipe diameter) The reason for limiting the diameter to less than 0.1d is that wrinkles and cracks cannot be reduced below 0.1d. In addition, it is because the spread of the connection washer cannot be suppressed. Further, the axial length L of the connection washer is set to 0.5d to 1.5d.
The reason for limiting to d is that if it is less than 0.5 d, the volume of absorbing the torsional energy generated by the torque at the time of tightening the nut by the connection washer and the injection pipe in close contact with the connection washer is small, the absorbed energy is reduced, and the pocket portion has The shear energy acting on the shear plane increases, while 1.5
Even if d is exceeded, there is no difference in the torsional energy absorbing effect of the connection washer and the injection pipe closely contacting the washer, and the connection washer and the nut become large and heavy, and the cost increases. In addition, the hardness of the connection washer is 400 Hv.
The reason why the above is limited is to suppress the spread of the connection washer. Further, the diameter of the buckled forming head of the connection head is changed to the pipe diameter d.
125% or more and 200% or less of
If it is less than 25%, the head is plastically deformed and no axial force can be obtained, while if it exceeds 200% of the pipe diameter d, sharp wrinkles or cracks occur.
【０００８】[0008]
【発明の実施の形態】図１は本発明に係る高圧燃料噴射
管の接続頭部の一実施例を示す縦断面図、図２は本発明
の他の実施例を示す縦断面図、図３は図１、図２に示す
スリーブワッシャを拡大して示す縦断面図、図４、図
５、図６はそれぞれ面取り部を有する断面形状の異なる
ワッシャを示す縦断面図であり、１は厚肉鋼管、２−
１、２−２は接続頭部、３ａ、３ｂはスリーブワッシ
ャ、３ｃ、３ｄ、３ｅはワッシャ、４ａ、４ｂは環状凹
溝である。FIG. 1 is a longitudinal sectional view showing one embodiment of a connecting head of a high-pressure fuel injection pipe according to the present invention, FIG. 2 is a longitudinal sectional view showing another embodiment of the present invention, and FIG. Is an enlarged longitudinal sectional view of the sleeve washer shown in FIGS. 1 and 2, and FIGS. 4, 5, and 6 are longitudinal sectional views showing washers having chamfers and different sectional shapes, and 1 is a thick wall. Steel pipe, 2-
1, 2-2 are connection heads, 3a, 3b are sleeve washers, 3c, 3d, 3e are washers, 4a, 4b are annular concave grooves.
【０００９】厚肉鋼管１は予め定寸に切断された高圧燃
料噴射管用炭素鋼鋼材よりなる管径４ｍ／ｍないし２０
ｍ／ｍ、肉厚１ｍ／ｍないし８ｍ／ｍ程度の比較的細径
厚肉管からなる。The thick steel pipe 1 has a pipe diameter of 4 m / m to 20 m, which is made of a carbon steel material for a high-pressure fuel injection pipe which has been cut to a predetermined size.
m / m, a relatively thin thick pipe having a wall thickness of about 1 m / m to 8 m / m.
【００１０】図１に示す高圧燃料噴射管は、厚肉鋼管１
の接続端部に、外側周面を相手座部への截頭円錐状のシ
ート面２−１ａとする接続頭部２−１を設け、該接続頭
部の首下部外周面を覆う開口端部に面取り部３ａ−１を
設けた密着形のスリーブワッシャ３ａを、該スリーブワ
ッシャ３ａの面取り部３ａ−１側端面に前記接続頭部２
−１の最大径部を被せた構造となしたものである。４ａ
は内側に深さが浅くかつなだらかな断面の輪郭形状の環
状凹溝である。The high-pressure fuel injection pipe shown in FIG.
A connection head 2-1 having an outer peripheral surface as a frusto-conical seat surface 2-1a to the mating seat portion is provided at a connection end of the connection head, and an open end covering an outer peripheral surface of a lower portion of a neck of the connection head. And a contact-type sleeve washer 3a provided with a chamfered portion 3a-1 on the end face of the sleeve washer 3a on the chamfered portion 3a-1 side.
This is a structure in which the maximum diameter portion of -1 is covered. 4a
Is an annular groove having a shallow depth inside and a gentle cross section.
【００１１】同じく図２に示す高圧燃料噴射管は、厚肉
鋼管１の接続端部に、外側周面を相手座部への截頭円弧
状のシート面２−２ａとする接続頭部２−２を設け、該
接続頭部の首下部外周面を覆う開口端部に面取り部３ｂ
−１を設けた密着形のスリーブワッシャ３ｂを、該スリ
ーブワッシャ３ｂの面取り部３ｂ−１側端面に前記接続
頭部２−２の最大径部を被せた構造となしたものであ
る。４ｂは前記と同様、内側に深さが浅くかつなだらか
な断面の輪郭形状の環状凹溝である。The high-pressure fuel injection pipe also shown in FIG. 2 has a connection head 2-2 at the connection end of the thick steel pipe 1, with the outer peripheral surface having a truncated arc-shaped seat surface 2-2 a to the mating seat. 2 and a chamfered portion 3b at the opening end covering the outer peripheral surface of the neck lower portion of the connection head
-1 is provided as a close contact type sleeve washer 3b in which the maximum diameter portion of the connection head 2-2 is covered on the end face on the chamfered portion 3b-1 side of the sleeve washer 3b. Reference numeral 4b denotes an annular groove having a contour shape with a shallow inside and a gentle cross section, as described above.
【００１２】図１、図２に示すスリーブワッシャ３ａ、
３ｂは、図３に拡大して示すごとく、開口端部の面取り
部３ａ−１、３ｂ−１の面取り仰角θを２０度〜４０
度、面取り深さｌを０．１ｄ以上０．６ｄ（ｄ：管径）
以下、軸方向長さＬを０．５ｄ〜１．５ｄとする。この
スリーブワッシャ３ａ、３ｂの硬度は４００Ｈｖ以上で
或る。一方、厚肉鋼管１の接続頭部２−１、２−２の挫
屈成形頭部径は管径ｄの１２５％以上〜２００％以下と
する。The sleeve washer 3a shown in FIGS.
3b, as shown in an enlarged manner in FIG. 3, the chamfered elevation angles θ of the chamfered portions 3a-1 and 3b-1 at the opening ends are 20 degrees to 40 degrees.
Degree, chamfering depth l is 0.1d or more and 0.6d (d: pipe diameter)
Hereinafter, the axial length L is set to 0.5d to 1.5d. The hardness of the sleeve washers 3a, 3b is 400 Hv or more. On the other hand, the buckling formed head diameter of the connection heads 2-1 and 2-2 of the thick steel pipe 1 is set to 125% to 200% of the pipe diameter d.
【００１３】また、図４、図５、図６に示す密着形のワ
ッシャ３ｃ、３ｄ、３ｃは、全体の軸方向長さＬが前記
図１、図２に示すスリーブワッシャ３ａ、３ｂより短尺
のものであるが、全体の軸方向長さＬ、開口端部の面取
り部３ｃ−１、３ｄ−１、３ｅ−１の面取り仰角θ、面
取り深さｌおよび当該ワッシャ３ｃ、３ｄ、３ｅの硬度
は、前記図１、図２に示すスリーブワッシャ３ａ、３ｂ
と同様の条件を満足するように形成する。ここで、図４
に示すワッシャ３ｃは図３に示すワッシャ３ａ、３ｂよ
り全体の軸方向長さＬが短く、図５に示すワッシャ３ｄ
は図４に示すワッシャ３ｃより全体の軸方向長さＬが長
く、図３に示すワッシャ３ａ、３ｂより短く、かつ面取
り部３ｄ−１が面取り部３ｃ−１より大きく、図６に示
すワッシャ３ｅは、全体の軸方向長さＬおよび面取り部
３ｅ−１の長さは図５に示すワッシャと同じであるが、
内周に面取り部３ｅ−１側に拡径したテーパが形成され
ている。なお、図６に示すワッシャ３ｅのテーパの傾斜
角としては特に限定するものではないが５度以下が適当
である。4, 5 and 6, the contact type washer 3c, 3d, 3c has an overall axial length L shorter than that of the sleeve washer 3a, 3b shown in FIGS. However, the overall axial length L, the chamfered elevation angles θ of the chamfers 3c-1, 3d-1, and 3e-1 at the opening ends, the chamfering depth l, and the hardness of the washers 3c, 3d, and 3e are as follows. , The sleeve washers 3a and 3b shown in FIGS.
It is formed so as to satisfy the same conditions as described above. Here, FIG.
The washer 3c shown in FIG. 5 has a shorter overall axial length L than the washers 3a and 3b shown in FIG. 3, and the washer 3d shown in FIG.
6 has a longer overall axial length L than the washer 3c shown in FIG. 4, is shorter than the washers 3a and 3b shown in FIG. 3, and the chamfer 3d-1 is larger than the chamfer 3c-1, and the washer 3e shown in FIG. The overall length L in the axial direction and the length of the chamfer 3e-1 are the same as those of the washer shown in FIG.
The inner periphery is formed with a taper whose diameter is increased toward the chamfered portion 3e-1. The inclination angle of the taper of the washer 3e shown in FIG. 6 is not particularly limited, but is suitably 5 degrees or less.
【００１４】つぎに、本発明に係る高圧燃料噴射管の頭
部成形方法は、厚肉鋼管の接続頭部付近に該接続頭部を
覆うほぼ円筒状の筒状部と頭部成形側内周に面取り部を
有する前記スリーブワッシャ３ａ、３ｂあるいはワッシ
ャ３ｃ、３ｄ、３ｅを頭部加工代を有して予め外嵌し、
この状態においてこれらのワッシャをおよび厚肉鋼管を
チャックに保持した状態で当該鋼管１の先端部をパンチ
部材７により軸芯方向へ押圧すると、予め厚肉鋼管に嵌
着したワッシャの前記面取り部に厚肉鋼管の頭部加工代
の部分が塑性流動し、接続頭部が成形されると同時に厚
肉鋼管がワッシャ内周に密着し、かつ該接続頭部の最大
径部がワッシャの端面に被さり、接続頭部の首下部外周
面をワッシャが覆い、厚肉鋼管の先端部に相手座部（図
示せず）への截頭円錐状あるいは截頭円弧状ののシート
面２−１ａ、２−２ａを有する接続頭部が得られる。Next, a method of forming a head of a high-pressure fuel injection pipe according to the present invention is characterized in that a substantially cylindrical tubular portion which covers the connection head near the connection head of a thick steel pipe and an inner periphery on the head formation side. The sleeve washer 3a, 3b or the washer 3c, 3d, 3e having a chamfered portion is externally fitted in advance with a head machining allowance,
In this state, when the tip of the steel pipe 1 is pressed in the axial direction by the punch member 7 while holding the washer and the thick steel pipe on the chuck, the chamfered part of the washer previously fitted to the thick steel pipe is formed. The portion of the head machining allowance of the thick-walled steel pipe plastically flows, and at the same time the connection head is formed, the thick-walled steel pipe closely adheres to the inner periphery of the washer, and the largest diameter portion of the connection head covers the end face of the washer. A washer covers the outer peripheral surface of the lower part of the neck of the connection head, and a frusto-conical or truncated arc-shaped seat surface 2-1a, 2- to the mating seat (not shown) is provided at the tip of the thick steel pipe. A connection head having 2a is obtained.
【００１５】この頭部成形方法においては、頭部成形
時、ワッシャの面取り部が成形部外径を拘束することに
より、パンチ部材の押圧による挫屈加工に伴う周壁の外
側への拡がりによって該頭部内周面にできる環状凹溝４
ａ、４ｂは深さが浅くかつなだらかな断面の輪郭形状を
有するものとなっている。また、接続頭部の最大径部が
ワッシャの端面に被さった状態となっている。In this head forming method, when forming the head, the chamfered portion of the washer restrains the outer diameter of the formed portion, so that the head expands outwardly due to buckling due to the pressing of the punch member. Annular groove 4 formed on the inner peripheral surface
Reference numerals a and 4b each have a contour shape of a shallow depth and a gentle cross section. In addition, the maximum diameter portion of the connection head is in a state of covering the end face of the washer.
【００１６】上記のごとく、本発明に係る高圧燃料噴射
管の場合は、接続頭部２−１または２−２の内周面にで
きる環状凹溝４ａまたは４ｂは深さが浅くかつなだらか
な断面の輪郭形状を有するものとなっているので、該頭
部内部での応力集中による疲労破壊の起点となる可能性
はほとんどない。As described above, in the case of the high-pressure fuel injection pipe according to the present invention, the annular groove 4a or 4b formed on the inner peripheral surface of the connection head 2-1 or 2-2 has a shallow and gentle cross section. Therefore, there is almost no possibility of becoming a starting point of fatigue failure due to stress concentration inside the head.
【００１７】また、配管接続時にナットを締付けるとス
リーブワッシャ３ａ、３ｂやワッシャ３ｃ、３ｄ、３ｅ
等の接続金具には軸力が作用すると共に、ナットとの当
り面との間の摩擦係数に応じたトルクが伝わり、この伝
わったトルクにより接続金具が捩られ、捩られた接続金
具はその捩じりエネルギーを接続金具と接続金具の内周
面に密着した噴射管の双方で吸収することになるので、
トルク制御せずに過大に締付けた場合には、その過大な
締付けトルクで生じる軸力は、接続頭部２−１または２
−２の最大径部とワッシャあるいはスリーブの面取り部
側端面との間で吸収できると共に、ワッシャ硬度あるい
はスリーブ硬度が高いことにより、当該ワッシャあるい
はスリーブの拡がりを抑制できるので、軸力によりワッ
シャあるいはスリーブが潰れて変形するようなことはな
い。したがって、締付けトルクに比例して軸力が上昇す
るので、同じ締付けトルクでの軸力の範囲が大きい方に
広がる。さらに、頭部外径を大きくすることで、軸力に
より塑性変形した頭部がワッシャあるいはスリーブ内周
に塑性変形して一部が入り込むこともない。When the nut is tightened at the time of pipe connection, sleeve washers 3a, 3b and washers 3c, 3d, 3e
In addition to the axial force acting on the connection fittings, a torque corresponding to the friction coefficient between the nut and the contact surface is transmitted, and the transmitted fittings are twisted by the transmitted torque. Since the torsion energy is absorbed by both the connection fitting and the injection pipe that is in close contact with the inner peripheral surface of the connection fitting,
If excessive tightening is performed without performing torque control, the axial force generated by the excessive tightening torque will be applied to the connection head 2-1 or 2
-2 can be absorbed between the maximum diameter portion and the end face of the washer or the sleeve on the chamfered side, and because the washer hardness or the sleeve hardness is high, the expansion of the washer or the sleeve can be suppressed. It does not collapse and deform. Therefore, since the axial force increases in proportion to the tightening torque, the range of the axial force at the same tightening torque is widened. Further, by increasing the outer diameter of the head, the head plastically deformed by the axial force is not plastically deformed into the inner periphery of the washer or the sleeve, and a part of the head does not enter.
【００１８】[0018]
【発明の効果】以上説明したごとく本発明に係る高圧燃
料噴射管は、接続頭部の首下部外周面を覆う密着形の接
続座金に面取り部を設けたことにより、この面取り部が
成形部外径を拘束し、内径側に材料を張り出させること
により鋭角なしわあるいはクラックを小さくすることが
できることとなり、該頭部内部での応力集中による疲労
破壊の起点となる可能性を減少させることができる。ま
た、接続座金を高硬度としたことにより、当該高硬度の
接続座金に軸力が作用した場合の変形が小さくなる。さ
らに、接続金具の軸方向長さを長くしたことにより、そ
れに密着した噴射管長さも長くなると共にその体積も大
きくなり、体積が大きくなることによって接続金具とこ
れに密着した噴射管により吸収されるエネルギーが増加
し、接続頭部背面に伝藩される捩りエネルギーを受ける
接続頭部のポケットの最大径部から接続頭部の最大径部
に至る剪断面における剪断応力を減少することができ、
これによってポケットからの剪断面における剪断による
破損を防止することができ、信頼性が向上する。さらに
また、接続頭部最大径部を前記接続座金の面取り部側端
面に被せた構造としたことにより、過大な締付けトルク
で生じる軸力を接続頭部最大径部と接続座金の面取り部
側端面との間で吸収できることにより、当該接続座金の
拡がりを抑制できるので、より高い軸力を与えることが
できるという優れた効果を奏する。As described above, in the high-pressure fuel injection pipe according to the present invention, the chamfered portion is provided on the close contact type washer which covers the outer peripheral surface of the lower portion of the neck of the connection head. By restricting the diameter and projecting the material to the inner diameter side, sharp wrinkles or cracks can be reduced, and the possibility of becoming a starting point of fatigue fracture due to stress concentration inside the head can be reduced. it can. In addition, since the connection washer has a high hardness, deformation when an axial force acts on the high hardness connection washer is reduced. Furthermore, by increasing the length of the connection fitting in the axial direction, the length of the injection pipe that is in close contact with the connection fitting is also increased, and the volume thereof is also increased. As the volume increases, the energy absorbed by the connection fitting and the injection pipe that is in close contact with it Increases, and it is possible to reduce the shear stress in the shear plane from the maximum diameter portion of the connection head pocket to the maximum diameter portion of the connection head that receives torsional energy transmitted to the back of the connection head,
This can prevent breakage due to shearing in the shear plane from the pocket, and improve reliability. Furthermore, by adopting a structure in which the connection head maximum diameter portion is placed on the chamfered portion side end surface of the connection washer, the axial force generated by excessive tightening torque can be applied to the connection head maximum diameter portion and the connection washer chamfered portion side end surface. Since it is possible to suppress the spread of the connection washer by being able to absorb between the above and the above, there is an excellent effect that a higher axial force can be given.
【図１】本発明に係る高圧燃料噴射管の接続頭部の一実
施例を示す縦断面図である。FIG. 1 is a longitudinal sectional view showing one embodiment of a connection head of a high-pressure fuel injection pipe according to the present invention.
【図２】本発明の他の実施例を示す縦断面図である。FIG. 2 is a longitudinal sectional view showing another embodiment of the present invention.
【図３】図１、図２に示すスリーブワッシャを拡大して
示す縦断面図である。FIG. 3 is an enlarged longitudinal sectional view showing the sleeve washer shown in FIGS. 1 and 2;
【図４】本発明に係るワッシャの一例を示す縦断面図で
ある。FIG. 4 is a longitudinal sectional view showing an example of a washer according to the present invention.
【図５】本発明に係るワッシャの他の例を示す縦断面図
である。FIG. 5 is a longitudinal sectional view showing another example of the washer according to the present invention.
【図６】本発明に係るワッシャの別の例を示す縦断面図
である。FIG. 6 is a longitudinal sectional view showing another example of the washer according to the present invention.
【図７】従来の高圧燃料噴射管の接続頭部の一例を示す
縦断面図である。FIG. 7 is a longitudinal sectional view showing an example of a connection head of a conventional high-pressure fuel injection pipe.
【図８】従来の高圧燃料噴射管の接続頭部の他の例を示
す縦断面図である。FIG. 8 is a longitudinal sectional view showing another example of the connection head of the conventional high-pressure fuel injection pipe.
１ 厚肉鋼管 ２−１、２−２ 接続頭部 ３ａ、３ｂ スリーブワッシャ ３ｃ、３ｄ、３ｅ ワッシャ ４ａ、４ｂ 環状凹溝 DESCRIPTION OF SYMBOLS 1 Thick steel pipe 2-1 and 2-2 Connection head 3a, 3b Sleeve washer 3c, 3d, 3e Washer 4a, 4b Annular groove
Claims (3)
に、外側周面を相手座部への截頭円錐状もしくは截頭円
弧状のシート面とする接続頭部を設け、該接続頭部の首
下部外周面を覆い、接続頭部側に面取り仰角θが２０度
〜４０度、面取り深さ１が０．１ｄ以上０．６ｄ（ｄ：
管径）以下、軸方向長さＬが０．５ｄ〜１．５ｄの接続
座金を設け、かつ該接続座金と噴射管を密着させたこと
を特徴とする接続頭部を有する高圧燃料噴射管。1. A connecting head of a thick steel pipe having a relatively small diameter having a frusto-conical or truncated arcuate seat surface on the outer peripheral surface to a mating seat portion is provided at a connecting end of a thick steel pipe having a relatively small diameter. The outer peripheral surface of the lower part of the neck of the connection head is covered, the elevation angle θ of the chamfer is 20 degrees to 40 degrees, and the chamfer depth 1 is 0.1d or more and 0.6d (d:
A high-pressure fuel injection pipe having a connection head, wherein a connection washer having an axial length L of 0.5d to 1.5d is provided, and the connection washer is brought into close contact with the injection pipe.
することを特徴とする請求項１記載の接続頭部を有する
高圧燃料噴射管。2. The high pressure fuel injection pipe having a connection head according to claim 1, wherein the hardness of the connection washer is 400 Hv or more.
上〜２００％以下とすることを特徴とする請求項１また
は２記載の接続頭部を有する高圧燃料噴射管。3. A high-pressure fuel injection pipe having a connection head according to claim 1, wherein a diameter of the connection head is 125% to 200% of a pipe diameter d.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000325917A JP2002130076A (en) | 2000-10-25 | 2000-10-25 | High-pressure fuel injection pipe having connection head part |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000325917A JP2002130076A (en) | 2000-10-25 | 2000-10-25 | High-pressure fuel injection pipe having connection head part |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002130076A true JP2002130076A (en) | 2002-05-09 |
Family
ID=18803204
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000325917A Pending JP2002130076A (en) | 2000-10-25 | 2000-10-25 | High-pressure fuel injection pipe having connection head part |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002130076A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005002806A (en) * | 2003-06-09 | 2005-01-06 | Usui Kokusai Sangyo Kaisha Ltd | Joint structure of high pressure fuel injection pipe |
| DE10358373B4 (en) * | 2002-12-11 | 2005-10-13 | Usui Kokusai Sangyo Kaisha Ltd., Nagasawa | High pressure fuel injection pipe with connection head |
| US7568736B2 (en) | 2004-05-19 | 2009-08-04 | Usui Kokusai Sangyo Kaisha Limited | Joint structure of branch connector for common rail |
-
2000
- 2000-10-25 JP JP2000325917A patent/JP2002130076A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10358373B4 (en) * | 2002-12-11 | 2005-10-13 | Usui Kokusai Sangyo Kaisha Ltd., Nagasawa | High pressure fuel injection pipe with connection head |
| CN1325788C (en) * | 2002-12-11 | 2007-07-11 | 臼井国际产业株式会社 | High-pressure fuel jet cell with connecting head |
| JP2005002806A (en) * | 2003-06-09 | 2005-01-06 | Usui Kokusai Sangyo Kaisha Ltd | Joint structure of high pressure fuel injection pipe |
| US7568736B2 (en) | 2004-05-19 | 2009-08-04 | Usui Kokusai Sangyo Kaisha Limited | Joint structure of branch connector for common rail |
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