JPH10309641A - Method to improve fatigue strength by repeated pressure at branch hole part on member for high pressure fluid and branch hole part of member for high pressure fluid provided by this method - Google Patents
Method to improve fatigue strength by repeated pressure at branch hole part on member for high pressure fluid and branch hole part of member for high pressure fluid provided by this methodInfo
- Publication number
- JPH10309641A JPH10309641A JP10066246A JP6624698A JPH10309641A JP H10309641 A JPH10309641 A JP H10309641A JP 10066246 A JP10066246 A JP 10066246A JP 6624698 A JP6624698 A JP 6624698A JP H10309641 A JPH10309641 A JP H10309641A
- Authority
- JP
- Japan
- Prior art keywords
- branch hole
- pressure fluid
- hollow portion
- forming
- high pressure
- 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
- Branch Pipes, Bends, And The Like (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
ン用燃料噴射システムを構成する燃料噴射系部品、例え
ば燃料噴射ポンプ、燃料噴射ノズル、燃料噴射管、およ
び燃料蓄圧システム用のコモンレール、噴射ポンプ、噴
射ノズル、噴射管、フィードバックパイプなどや圧力容
器などの高圧流体用部材の分岐孔部での繰返し圧力によ
る疲労強度を向上させる方法および該方法により得られ
た高圧流体用部材の分岐孔部に関するものである。The present invention relates to a fuel injection system component constituting a fuel injection system for a diesel engine, such as a fuel injection pump, a fuel injection nozzle, a fuel injection pipe, and a common rail, an injection pump, and an injection for a fuel pressure accumulating system. The present invention relates to a method for improving the fatigue strength of a high pressure fluid member such as a nozzle, an injection pipe, a feedback pipe, a pressure pipe or the like for a high pressure fluid member due to repetitive pressure at a branch hole portion, and a branch hole portion of a high pressure fluid member obtained by the method. is there.
【0002】[0002]
【従来の技術】従来、この種の高圧流体用部材の中空部
と分岐孔部材の流路とを連通するために、高圧流体用部
材の肉厚部に形成された分岐孔により構成される分岐孔
部は、断面円形の内周面からなる中空部に分岐孔を穿設
して分岐孔部材の流路と連通せしめるものであった。2. Description of the Related Art Conventionally, a branch formed by a branch hole formed in a thick portion of a high-pressure fluid member in order to communicate a hollow portion of such a high-pressure fluid member with a flow path of a branch hole member. In the hole, a branch hole was formed in a hollow portion having an inner peripheral surface having a circular cross section to allow communication with the flow path of the branch hole member.
【0003】[0003]
【発明が解決しようとする課題】しかしながら、断面真
円形の高圧流体用部材の断面真円形の中空部に単に分岐
孔を穿設して、分岐孔部材の流路と連通させる構成で
は、高圧流体用部材の中空部に高い繰返し内圧が作用し
たとき、高圧流体用部材の中空部における分岐孔の出口
の開口端部に最も大きな引張応力が発生し、該開口端部
が起点となって繰返し圧力による金属疲労に基づく亀裂
が生じ易く、流体の洩れを招く可能性があった。However, in a structure in which a branch hole is simply formed in a hollow part having a perfect circular cross section of a member for high pressure fluid having a perfect circular cross section to communicate with a flow path of the branch hole member, a high pressure fluid is required. When a high internal pressure acts on the hollow portion of the high-pressure fluid member, the largest tensile stress is generated at the open end of the outlet of the branch hole in the hollow portion of the high-pressure fluid member. Cracks are likely to occur due to metal fatigue, which may lead to fluid leakage.
【0004】このような繰返し圧力による疲労強度を向
上する方法として、分岐孔の出口位置を含む前記中空部
の内周面に環状の溝を形成したり、あるいは前記分岐孔
の出口においてポケットを形成することが試みられてい
たが、前者の場合は、分岐孔の出口を含む環状の溝の形
成を正確に実施するには機械的加工を採用せざるを得ず
その作業に極めて手間がかかり、近年の大量生産方式に
は全く不適当であるとともに、機械加工を要する箇所の
みならず他の内周面に傷や損傷などを与える可能性があ
り、また後者の場合は前記ポケットの形成を電気化学的
に実施するため前記大量生産方式には合致するものの、
実際には高圧流体用部材の中空部における分岐孔の出口
の開口端部に引張応力が集中するためにかかる処理を実
施しても疲労強度の向上にはあまり効果がなかった。[0004] As a method of improving the fatigue strength due to such repetitive pressure, an annular groove is formed on the inner peripheral surface of the hollow portion including the exit position of the branch hole, or a pocket is formed at the exit of the branch hole. However, in the former case, it is necessary to employ mechanical processing to accurately form the annular groove including the outlet of the branch hole, and the work is extremely troublesome, It is completely unsuitable for recent mass production systems, and may cause scratches or damages not only on parts requiring machining but also on other inner peripheral surfaces. Although it conforms to the above-mentioned mass production method because it is performed chemically,
Actually, since the tensile stress concentrates on the opening end of the outlet of the branch hole in the hollow portion of the high-pressure fluid member, even if such a process is performed, the effect of improving the fatigue strength is not so significant.
【0005】本発明は、従来の高圧流体用部材の分岐孔
部の有する前記問題を解決するためになされたものであ
り、高圧流体用部材の中空部側における分岐孔の出口の
開口端部に発生する最大引張応力値を下げて内圧疲労強
度をより向上させることが可能な、高圧流体用部材にお
ける分岐孔部での繰返し圧力による疲労強度を向上させ
る方法および該方法により得られた高圧流体用部材の分
岐孔部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 to solve the above-described problem of the branch hole of the conventional high-pressure fluid member. A method for improving fatigue strength due to repetitive pressure at a branch hole in a member for high-pressure fluid, which is capable of further improving internal pressure fatigue strength by lowering the maximum tensile stress value to be generated, and for high-pressure fluid obtained by the method. It is an object to provide a branch hole of a member.
【0006】[0006]
【課題を解決するための手段】上記課題を達成するため
本発明の第1の実施態様は、中空部を有する高圧流体用
部材に、該中空部に連通する分岐孔を形成するに際し、
前記高圧流体用部材を外部より内方に押圧して前記中空
部側内周面を変形せしめて圧縮応力が残留した変形部を
形成し、ついで該変形部に前記中空部に開口する分岐孔
を穿設して少なくとも該分岐孔周縁に前記圧縮残留応力
を存在せしめてなることを特徴とするものである。According to a first aspect of the present invention, there is provided a high-pressure fluid member having a hollow portion, wherein a branch hole communicating with the hollow portion is formed.
The high-pressure fluid member is pressed inward from the outside to deform the inner peripheral surface of the hollow portion side to form a deformed portion in which a compressive stress remains, and then the deformed portion has a branch hole opened to the hollow portion. It is characterized in that the compression residual stress is formed at least in the periphery of the branch hole by drilling.
【0007】本発明の第2の実施態様は、中空部を有す
る高圧流体用部材に、該中空部に連通する分岐孔を形成
するに際し、前記高圧流体用部材にその内周面に開口す
る分岐孔を穿設し、ついで該高圧流体用部材の分岐孔部
を外部より内方に押圧して前記中空部側内周面を変形せ
しめて少なくとも該分岐孔周縁の一部に圧縮応力を残留
させてなることを特徴とするものである。According to a second embodiment of the present invention, when a branch hole communicating with the hollow portion is formed in a member for high pressure fluid having a hollow portion, a branch opening on the inner peripheral surface of the member for high pressure fluid is provided. A hole is formed, and then the branch hole of the high-pressure fluid member is pressed inward from the outside to deform the hollow-portion-side inner peripheral surface so that a compressive stress remains at least at a part of the peripheral edge of the branch hole. It is characterized by becoming.
【0008】本発明の第3の実施態様は、中空部を有す
る高圧流体用部材に、該中空部に連通する分岐孔を形成
するに際し、前記高圧流体用部材を外部より内方に押圧
して前記中空部側内周面を変形せしめて圧縮応力が残留
した変形部を形成すると同時に、該変形部に前記中空部
に開口する分岐孔を打抜き、該分岐孔周縁に前記圧縮残
留応力を存在せしめてなることを特徴とするものであ
る。According to a third embodiment of the present invention, when a branch hole communicating with the hollow portion is formed in the high-pressure fluid member having a hollow portion, the high-pressure fluid member is pressed inward from the outside. The inner peripheral surface of the hollow portion side is deformed to form a deformed portion in which the compressive stress remains, and at the same time, a branch hole opened in the hollow portion is punched in the deformed portion, and the compressive residual stress is present at the peripheral edge of the branch hole. It is characterized by becoming.
【0009】本発明の第4の実施態様は、中空部を有す
る高圧流体用部材に、該中空部に連通する分岐孔を形成
するに際し、該分岐孔を設ける箇所からやや偏心して前
記高圧流体用部材を外部より内方に押圧し、該分岐孔周
縁部に圧縮残留応力を存在せしめてなることを特徴とす
るものである。According to a fourth embodiment of the present invention, when a branch hole communicating with the hollow portion is formed in a member for high pressure fluid having a hollow portion, the member is slightly eccentric from a position where the branch hole is provided. It is characterized in that the member is pressed inward from the outside so that residual compressive stress is present at the periphery of the branch hole.
【0010】本発明の第5の実施態様は、中空部を有す
る高圧流体用部材に、該中空部に連通する分岐孔を形成
するに際し、該分岐孔を設ける箇所からやや偏心して前
記高圧流体用部材を外部より内方に少なくとも直径方向
の2箇所押圧し、該分岐孔周縁部の少なくとも直径方向
の2箇所に圧縮残留応力を存在せしめてなることを特徴
とするものである。According to a fifth embodiment of the present invention, when a branch hole communicating with the hollow portion is formed in the high-pressure fluid member having the hollow portion, the branch member is slightly eccentric from the position where the branch hole is provided. The structure is characterized in that the member is pressed inward from the outside at least at two places in the diametrical direction, and compressive residual stress is present at least at two places in the diametrical direction on the peripheral edge of the branch hole.
【0011】本発明の第6の実施態様は、中空部を有す
る高圧流体用部材に、該中空部に連通する分岐孔を形成
するに際し、前記高圧流体用部材を外部より内方に押圧
して前記中空部側内周面を変形せしめて該分岐孔を設け
る領域より広範囲に圧縮応力が残留した変形部を形成
し、該変形部の中央部に分岐孔を穿設してなることを特
徴とするものである。In a sixth embodiment of the present invention, when a branch hole communicating with the hollow portion is formed in a high-pressure fluid member having a hollow portion, the high-pressure fluid member is pressed inward from the outside. The hollow part side inner peripheral surface is deformed to form a deformed part in which compressive stress remains in a wider area than the area where the branch hole is provided, and a branch hole is formed in the center of the deformed part. Is what you do.
【0012】本発明の第7の実施態様は、中空部を有す
る高圧流体用部材に、前記中空部に連通する分岐孔を穿
設した分岐孔部であって、該分岐孔内周縁部に圧縮残留
応力を有することを特徴とするものである。A seventh embodiment of the present invention is directed to a high-pressure fluid member having a hollow portion, wherein a branch hole communicating with the hollow portion is formed in the high-pressure fluid member. It is characterized by having residual stress.
【0013】すなわち、本発明は高圧流体用部材の中空
部における分岐孔部材の流路と連通する分岐孔の出口の
開口端部周辺に圧縮残留応力を存在させることにより、
高圧流体用部材の中空部の高い内圧を、場合によっては
分岐孔部材の接続に際して前記高圧流体用部材の肉厚部
にかかる径方向の力により分岐孔の下端内周縁部に発生
する引張応力をも前記圧縮残留応力にて相殺して、分岐
孔の下端内周縁部に発生する最大引張応力値を下げるも
ので、高圧流体用部材の中空部における分岐孔の出口の
開口端部周辺に圧縮残留応力を発生させる方法として、
前記第1〜第7の実施態様に示す方法を用いたものであ
る。That is, according to the present invention, by providing a compressive residual stress around the opening end of the outlet of the branch hole communicating with the flow path of the branch hole member in the hollow portion of the high-pressure fluid member,
A high internal pressure in the hollow portion of the high-pressure fluid member, and in some cases, a tensile stress generated at the lower peripheral edge of the lower end of the branch hole due to a radial force applied to the thick portion of the high-pressure fluid member when connecting the branch hole member. Is also offset by the compressive residual stress, thereby lowering the maximum tensile stress value generated at the inner peripheral edge of the lower end of the branch hole. The residual compressive residual around the opening end of the outlet of the branch hole in the hollow portion of the high-pressure fluid member. As a method of generating stress,
This is a method using the method described in the first to seventh embodiments.
【0014】ここで、高圧流体用部材に対し外部より押
圧力を付与する方法としては、例えば高圧流体用部材を
下型に固定した状態で、前記高圧流体用部材の外部より
径方向に内方に向けてポンチまたはロッドを用いて加圧
する方法を用いることができる。Here, as a method of applying a pressing force to the high-pressure fluid member from the outside, for example, with the high-pressure fluid member fixed to the lower mold, a radially inward direction from the outside of the high-pressure fluid member is provided. And pressurizing using a punch or a rod.
【0015】上記のごとく、本発明では高圧流体用部材
の中空部側の分岐孔部における分岐孔の開口端部周辺に
圧縮残留応力を存在させることにより、分岐孔の下端内
周縁部における引張応力の発生を前記圧縮残留応力によ
り相殺して効果的に抑制することができ、高圧流体用部
材の分岐孔部における内圧疲労強度を向上できることと
なる。As described above, in the present invention, the compressive residual stress exists around the opening end of the branch hole in the branch hole on the hollow side of the high-pressure fluid member, so that the tensile stress at the lower end inner peripheral edge of the branch hole is formed. Can be effectively suppressed by being offset by the compressive residual stress, and the internal pressure fatigue strength at the branch hole of the high-pressure fluid member can be improved.
【0016】[0016]
【発明の実施の形態】図1は本発明に係る分岐孔を有す
る高圧流体用部材の一実施例の一部拡大横断面図、図2
は本発明に係る疲労強度を向上させる方法の一実施例を
説明する横断面図で、(a)は押圧力付与後の分岐孔を
穿設する前の図、(b)は分岐孔を穿設した後の図、図
3は本発明に係る疲労強度を向上させる方法の他の実施
例を説明する横断面図で、(a)は分岐孔を穿設した後
の図、(b)は分岐孔を穿設した後押圧力を付与した状
態の図、図4は図1の縦断面図、図5〜図8は本発明に
係る疲労強度を向上させる方法の別の実施例を説明する
図で、図5は分岐孔を設ける箇所からやや偏心して押圧
力を付与する方法を示す概略平面図、図6は分岐孔を設
ける箇所からやや偏心して直径方向の2箇所に押圧力を
付与する方法を示す概略平面図、図7は分岐孔を設ける
領域より広範囲に圧縮応力が発生するごとく押圧力を付
与する方法を示す概略平面図、図8は分岐孔を設ける領
域より広範囲に圧縮応力が発生するごとく押圧力を付与
する方法の他の実施例を示す概略平面図、図9は本発明
に係る高圧流体用部材の他の実施例を示す縦断面図であ
って、1は高圧流体用部材であって、ディーゼルエンジ
ン用燃料噴射システムを構成する燃料噴射系部品、例え
ば燃料噴射ポンプ、燃料噴射ノズル、燃料噴射管、およ
び燃料蓄圧システム用のコモンレール、噴射ポンプ、噴
射ノズル、噴射管、フィードバックパイプ等や圧力容器
等からなるものである。1 is a partially enlarged cross-sectional view of an embodiment of a high-pressure fluid member having a branch hole according to the present invention.
FIGS. 1A and 1B are cross-sectional views illustrating an embodiment of a method for improving fatigue strength according to the present invention, in which FIG. 1A is a view before a branch hole is formed after a pressing force is applied, and FIG. FIG. 3 is a cross-sectional view illustrating another embodiment of the method for improving fatigue strength according to the present invention, in which FIG. 3A is a view after a branch hole is drilled, and FIG. FIG. 4 is a longitudinal sectional view of FIG. 1, and FIG. 5 to FIG. 8 illustrate another embodiment of a method for improving fatigue strength according to the present invention. FIG. 5 is a schematic plan view showing a method of applying a pressing force with a slight eccentricity from a location where a branch hole is provided, and FIG. 6 is a diagram illustrating a method of applying a pressing force to two diametrical locations with a slight eccentricity from a location where a branch hole is provided. FIG. 7 is a schematic plan view showing a method, and FIG. 7 shows a method of applying a pressing force such that a compressive stress is generated in a wider area than a region where a branch hole is provided. FIG. 8 is a schematic plan view showing another embodiment of a method for applying a pressing force such that a compressive stress is generated in a wider area than a region where a branch hole is provided, and FIG. 9 is a view showing a member for high-pressure fluid according to the present invention. FIG. 4 is a longitudinal sectional view showing another embodiment, wherein 1 is a high-pressure fluid member, and a fuel injection system component constituting a fuel injection system for a diesel engine, for example, a fuel injection pump, a fuel injection nozzle, a fuel injection pipe, And a common rail for a fuel pressure accumulator system, an injection pump, an injection nozzle, an injection pipe, a feedback pipe, a pressure vessel, and the like.
【0017】上記高圧流体用部材1の内部にはほぼ円形
の内周面からなる中空部1−1を有し、分岐孔部材(図
示せず)の流路と前記中空部1−1を連通するための分
岐孔1−2が該高圧流体用部材の肉厚部を貫通して穿設
され、該分岐孔1−2の出口をほぼ中心としてその開口
端部周辺において中空部1−1側をほぼ円形で、かつ少
なくともほぼ偏平状となるよう突出せしめて圧縮残留応
力が発生した分岐孔部2が形成されている。The high-pressure fluid member 1 has a hollow part 1-1 having a substantially circular inner peripheral surface inside the high-pressure fluid member 1, and communicates a flow path of a branch hole member (not shown) with the hollow part 1-1. Hole 1-2 is formed through the thick portion of the high-pressure fluid member, and the hollow portion 1-1 is formed around the opening end of the branch hole 1-2 substantially at the center. Are projected so as to be substantially circular and at least substantially flat, thereby forming a branch hole 2 in which compressive residual stress is generated.
【0018】次に、本発明による高圧流体用部材1にお
ける分岐孔部2での繰返し圧力による疲労強度を向上さ
せる方法を図2に基づいて説明する。Next, a method for improving the fatigue strength of the high-pressure fluid member 1 according to the present invention due to the repeated pressure in the branch hole 2 will be described with reference to FIG.
【0019】図2に示す工程によれば、本発明に係る高
圧流体用部材1は内部にボーリングなどの機械加工によ
って中空部1−1が形成され、比較的厚肉の肉厚部を有
するものである。そして該肉厚部を外部より径方向に内
方に向かってポンチまたはロッドなどを用いてプレス方
式で押圧して前記中空部1−1側をほぼ円形でかつ少な
くともほぼ偏平状になるよう突出せしめて圧縮残留応力
が発生した分岐孔部2を形成する(図2(a)参照)。According to the process shown in FIG. 2, the high-pressure fluid member 1 according to the present invention has a hollow portion 1-1 formed therein by machining such as boring and has a relatively thick wall portion. It is. Then, the thick portion is pressed radially inward from the outside by a press method using a punch or a rod, and the hollow portion 1-1 is projected so as to be substantially circular and at least substantially flat. As a result, the branch hole portion 2 in which the compressive residual stress is generated is formed (see FIG. 2A).
【0020】この時の押圧力としては、特に限定するも
のではないが、少なくとも高圧流体用部材1の中空部1
−1の内周面が僅かに偏平化する程度は必要である。こ
のポンチ等のプレス方式による押圧力により、中空部1
−1の内周面が僅かに偏平化するとともに、その押圧力
を加えた時に塑性変形部と弾性変形部を生じ、押圧力を
除去した時の戻り量の差により生じた変形のために分岐
孔部2の周辺に圧縮残留応力が発生する。Although the pressing force at this time is not particularly limited, at least the hollow portion 1 of the high-pressure fluid member 1 is used.
It is necessary that the inner peripheral surface of -1 be slightly flattened. The pressing force of the pressing method such as a punch causes the hollow portion 1
The inner peripheral surface of -1 is slightly flattened, and when the pressing force is applied, a plastically deformed portion and an elastically deformed portion are generated. When the pressing force is removed, a branch is generated due to a difference in return amount. A compressive residual stress is generated around the hole 2.
【0021】次に、形成された分岐孔部2のほぼ中央部
に出口を有するように分岐孔1−2を例えばドリル等に
て切削して穿設する(図2(b)参照)。Next, the branch hole 1-2 is cut and drilled by, for example, a drill or the like so as to have an outlet at a substantially central portion of the formed branch hole portion 2 (see FIG. 2B).
【0022】上記の実施例では、まずポンチなどによる
プレス方式によって前記高圧流体用部材の肉厚部を外部
より径方向に内方に向けて押圧することにより、のちに
形成される分岐孔1−2部分に対応する高圧流体用部材
1の中空部1−1側をほぼ円形で、かつ少なくともほぼ
偏平状になるよう突出せしめて分岐孔部2を形成し、圧
縮残留応力を発生させる。次に該分岐孔部2のほぼ中央
部に出口を有するよう分岐孔1−2を、前記高圧流体用
部材1の肉厚部を貫通するよう穿設したため、高圧流体
用部材の中空部1−1の高い内圧を、場合によっては分
岐孔部材の接続に際して前記高圧流体用部材1の肉厚部
にかかる径方向の力により分岐孔1−2の下端内周縁部
に発生する引張応力をも前記圧縮残留応力にて相殺し
て、該分岐孔1−2の下端内周縁部に発生する最大引張
応力値を大幅に下げるものである。In the above embodiment, first, the thick portion of the high-pressure fluid member is pressed radially inward from the outside by a pressing method using a punch or the like, so that a branch hole 1-to be formed later is formed. The hollow portion 1-1 of the high-pressure fluid member 1 corresponding to the two portions is made to protrude so as to be substantially circular and at least substantially flat, thereby forming a branch hole portion 2 to generate compressive residual stress. Next, since the branch hole 1-2 is formed so as to penetrate through the thick portion of the high-pressure fluid member 1 so as to have an outlet at a substantially central portion of the branch hole portion 2, the hollow portion 1- of the high-pressure fluid member is formed. In some cases, the tensile stress generated at the inner peripheral edge of the lower end of the branch hole 1-2 by the radial force applied to the thick portion of the high-pressure fluid member 1 when the branch hole member is connected is also increased. The maximum tensile stress value generated at the inner peripheral edge of the lower end of the branch hole 1-2 is largely reduced by being offset by the compressive residual stress.
【0023】本発明における繰返し圧力による疲労強度
を向上させる方法は、図2に示す工程のみならず、図3
の工程によっても実施することもできる。図3によれ
ば、前記したように中空部1−1を有する高圧流体用部
材1の肉厚部を貫通するよう例えばドリル等にてまず分
岐孔1−2を穿設する(図3(a)参照)。The method for improving the fatigue strength by the repetitive pressure in the present invention is not limited to the step shown in FIG.
It can also be carried out by the step. According to FIG. 3, a branch hole 1-2 is first drilled by, for example, a drill or the like so as to penetrate the thick portion of the high-pressure fluid member 1 having the hollow portion 1-1 as described above (see FIG. )reference).
【0024】次に、前記肉厚部を外部より径方向に内方
に向かって前記と同様にプレス方式で押圧して前記分岐
孔1−2の出口がほぼ中心となるように前記中空部1−
1側をほぼ円形でかつ少なくともほぼ偏平状になるよう
突出せしめて圧縮残留応力が発生した分岐孔部2を形成
する(図3(b)および図4参照)。Next, the thick portion is pressed radially inward from the outside by a press method in the same manner as described above, so that the outlet of the branch hole 1-2 is substantially at the center. −
One side is made to protrude so as to be substantially circular and at least substantially flat, thereby forming a branch hole portion 2 in which compressive residual stress has been generated (see FIGS. 3B and 4).
【0025】図3のような方法によっても、前記と同様
に高圧流体用部材の中空部1−1の高い内圧を、場合に
よっては分岐孔部材の接続に際して前記高圧流体用部材
1の肉厚部にかかる径方向の力により分岐孔1−2の下
端内周縁部に発生する引張応力をも前記圧縮残留応力に
て相殺して、該分岐孔1−2の下端内周縁部に発生する
最大引張応力値を大幅に下げることができる。Also in the method shown in FIG. 3, the high internal pressure of the hollow portion 1-1 of the high-pressure fluid member may be increased in the same manner as described above. The tensile stress generated at the lower end inner peripheral edge of the branch hole 1-2 due to the radial force applied is also offset by the compressive residual stress, and the maximum tensile force generated at the lower end inner peripheral edge of the branch hole 1-2 is reduced. The stress value can be greatly reduced.
【0026】上記図2に示す実施例では、まずポンチな
どによるプレス方式によって前記高圧流体用部材の肉厚
部を外部より径方向に内方に向けて押圧することによっ
て分岐孔部2を形成した後、分岐孔1−2を穿設する方
法をとり、図3に示す実施例では、ドリル等にてまず分
岐孔1−2を穿設し、しかる後当該部分をプレス方式で
押圧する方法をとっているが、分岐孔1−2はポンチ等
による押圧と同時に打抜くこともできる。この場合は、
分岐孔1−2とほぼ同一径のポンチ部あるいはロッド部
と圧縮残留応力を発生させるための変形部を形成するた
めの大径のポンチ部あるいはロッド部を有するポンチあ
るいはロッドを用いることにより実施できる。In the embodiment shown in FIG. 2, the branch hole portion 2 is formed by first pressing the thick portion of the high-pressure fluid member radially inward from the outside by a pressing method using a punch or the like. Then, a method of drilling the branch hole 1-2 is adopted. In the embodiment shown in FIG. 3, a method of first drilling the branch hole 1-2 with a drill or the like, and then pressing the portion by a press method is used. However, the branch hole 1-2 can be punched out simultaneously with pressing by a punch or the like. in this case,
It can be implemented by using a punch or rod having a punch or rod having substantially the same diameter as the branch hole 1-2 and a large-diameter punch or rod for forming a deformed portion for generating compressive residual stress. .
【0027】また、ポンチ等によるプレス方式によって
前記高圧流体用部材の肉厚部を外部より径方向に内方に
向けて押圧することにより、圧縮残留応力が発生した分
岐孔部2を形成する手段としては、前記実施例の他に図
5〜図8に示す方法を用いることもできる。Means for forming a branch hole 2 in which a compressive residual stress is generated by pressing a thick portion of the high-pressure fluid member radially inward from the outside by a pressing method using a punch or the like. Alternatively, the method shown in FIGS. 5 to 8 can be used in addition to the above embodiment.
【0028】すなわち、図5は中空部1−1を有する高
圧流体用部材1に、該中空部に連通する分岐孔1−2を
形成するに際し、該分岐孔1−2を設ける箇所からやや
偏心してポンチまたはロッド等を用いてプレス方式で高
圧流体用部材1を押圧し、分岐孔1−2の周縁部の一部
(特に亀裂発生の起点となり易い部分)に圧縮残留応力
を発生させるもので、1−3はポンチまたはロッド等に
よる押圧範囲、1−4は圧縮残留応力の発生した範囲を
示す。That is, FIG. 5 shows that when the branch hole 1-2 communicating with the hollow portion is formed in the high-pressure fluid member 1 having the hollow portion 1-1, the branch hole 1-2 is slightly deviated from the place where the branch hole 1-2 is provided. The pressurized high-pressure fluid member 1 is pressed using a punch or a rod or the like to generate a compressive residual stress in a part of the peripheral portion of the branch hole 1-2 (particularly, a portion that easily becomes a starting point of crack generation). 1-3 indicates a pressing range by a punch or a rod or the like, and 1-4 indicates a range in which compressive residual stress is generated.
【0029】図6は高圧流体用部材1を外部よりポンチ
またはロッド等を用いてプレス方式で中空部を有する高
圧流体用部材1に、該中空部に連通する分岐孔を形成す
るに際し、該分岐孔1−2を設ける箇所からやや偏心し
て前記高圧流体用部材1を外部より内方に少なくとも直
径方向の2箇所押圧し、該分岐孔周縁部の少なくとも直
径方向の2箇所に圧縮残留応力を発生させる方法を示し
たものである。ここで直径方向の2箇所とは、前記と同
様亀裂発生の起点となり易い部分を指す。FIG. 6 is a view showing a state in which a branch hole communicating with the hollow portion is formed in the high pressure fluid member 1 having a hollow portion by a press method using a punch or a rod. The high-pressure fluid member 1 is pressed eccentrically at least two places in the diametric direction from the outside with a slight eccentricity from the place where the hole 1-2 is provided, and compressive residual stress is generated at least at two places in the diametric direction of the peripheral edge of the branch hole. FIG. Here, the two locations in the diameter direction refer to a portion that is likely to be a starting point of crack generation as described above.
【0030】図7は高圧流体用部材1を外部よりポンチ
またはロッド等を用いてプレス方式で中空部1−1を有
する高圧流体用部材1に、該中空部に連通する分岐孔1
−2を形成するに際し、分岐孔1−2より小径のポンチ
またはロッド等を用いて該分岐孔を設ける領域より広範
囲に圧縮応力が残留した変形部を形成し、該変形部の中
央部に分岐孔を穿設する方法を示したものである。FIG. 7 shows a high pressure fluid member 1 having a hollow portion 1-1 formed by pressing a high pressure fluid member 1 from the outside using a punch or a rod or the like, and a branch hole 1 communicating with the hollow portion.
When forming -2, using a punch or rod or the like having a smaller diameter than the branch hole 1-2, a deformed portion in which compressive stress remains in a wider area than the region where the branch hole is formed is formed, and a branch is formed at the center of the deformed portion. 4 illustrates a method of forming a hole.
【0031】図8は高圧流体用部材1を外部よりポンチ
またはロッド等を用いてプレス方式で中空部1−1を有
する高圧流体用部材1に、該中空部に連通する分岐孔1
−2を形成するに際し、分岐孔1−2より大径のポンチ
またはロッド等を用いて該分岐孔を設ける領域より広範
囲に圧縮応力が残留した変形部を形成し、該変形部の中
央部に分岐孔1−2を穿設する方法を示したものであ
る。FIG. 8 shows a high pressure fluid member 1 having a hollow portion 1-1 formed by pressing the high pressure fluid member 1 from the outside using a punch or a rod or the like, and a branch hole 1 communicating with the hollow portion.
In forming -2, using a punch or rod or the like having a larger diameter than the branch hole 1-2, a deformed portion in which compressive stress remains in a wider area than the region where the branch hole is provided is formed, and a central portion of the deformed portion is formed. It shows a method of drilling a branch hole 1-2.
【0032】以上述べた実施例では分岐孔1−2を中空
部1−1の中心軸線に対してほぼ直交する方向に穿設し
た例を説明したが、本発明はこれに限らず図9に示すよ
うに分岐孔1−2を該中空部1−1の中心軸線に対して
ある角度を持って設けることもできる。この場合はポン
チなどにより所望の角度を持って高圧流体用部材1の肉
厚部を押圧すればよく、分岐孔部2の表面も前記中心軸
線に対して角度を持つことになる。In the embodiment described above, an example is described in which the branch hole 1-2 is formed in a direction substantially perpendicular to the central axis of the hollow portion 1-1. However, the present invention is not limited to this, and FIG. As shown, the branch hole 1-2 can be provided at an angle with respect to the center axis of the hollow portion 1-1. In this case, the thick portion of the high-pressure fluid member 1 may be pressed at a desired angle by a punch or the like, and the surface of the branch hole 2 also has an angle with respect to the central axis.
【0033】[0033]
【発明の効果】以上説明したごとく本発明によれば、分
岐孔の下端内周縁部における引張応力の発生を圧縮残留
応力により相殺して効果的に抑制することができ、分岐
孔部における内圧疲労強度を向上できるので、耐久性に
優れ、亀裂の発生による流体洩れをなくして確実にして
安定した機能を発揮することができるという優れた効果
を有する。また通常の製造工程に押圧力付与工程を付加
するだけで済み、かつ複雑な設備を必要とするものでは
ないから、工程増による設備コストのアップや生産性の
低下等の問題はほとんどなく、高品質の高圧流体用部材
を安価に提供できるという大きな効果を奏する。As described above, according to the present invention, the generation of tensile stress at the inner peripheral edge at the lower end of the branch hole can be effectively suppressed by canceling out the residual stress by the compressive residual stress. Since the strength can be improved, the durability is excellent, and there is an excellent effect that a fluid leak due to the generation of cracks can be eliminated and a stable function can be surely exhibited. In addition, since it is only necessary to add a pressing force applying step to the normal manufacturing process, and there is no need for complicated equipment, there is almost no problem such as an increase in equipment cost and a decrease in productivity due to an increase in the number of steps. There is a great effect that a high-pressure fluid member of high quality can be provided at low cost.
【図1】本発明に係る分岐孔を有する高圧流体用部材の
一実施例の一部拡大横断面図である。FIG. 1 is a partially enlarged cross-sectional view of one embodiment of a high-pressure fluid member having a branch hole according to the present invention.
【図2】本発明に係る疲労強度を向上させる方法の一実
施例を説明する横断面図で、(a)は押圧力付与後の分
岐孔を穿設する前の図、(b)は分岐孔を穿設した後の
図である。FIGS. 2A and 2B are cross-sectional views illustrating an embodiment of a method for improving fatigue strength according to the present invention, wherein FIG. 2A is a diagram before a branch hole is formed after a pressing force is applied, and FIG. It is a figure after drilling a hole.
【図3】本発明に係る疲労強度を向上させる方法の他の
実施例を説明する横断面図で、(a)は分岐孔を穿設し
た後の図、(b)は分岐孔を穿設した後押圧力を付与し
た状態の図である。3A and 3B are cross-sectional views illustrating another embodiment of the method for improving fatigue strength according to the present invention, in which FIG. 3A is a diagram after a branch hole is formed, and FIG. FIG. 4 is a view showing a state in which a pressing force is applied after the pressing.
【図4】図1の縦断面図である。FIG. 4 is a longitudinal sectional view of FIG.
【図5】本発明に係る疲労強度を向上させる方法の他の
実施例を説明する図で、分岐孔を設ける箇所からやや偏
心して押圧力を付与する方法を示す概略平面図である。FIG. 5 is a view for explaining another embodiment of the method for improving the fatigue strength according to the present invention, and is a schematic plan view showing a method for applying a pressing force with a slight eccentricity from a location where a branch hole is provided.
【図6】本発明に係る疲労強度を向上させる方法の他の
実施例を説明する図で、分岐孔を設ける箇所からやや偏
心して直径方向の2箇所に押圧力を付与する方法を示す
概略平面図である。FIG. 6 is a view for explaining another embodiment of the method for improving the fatigue strength according to the present invention, and is a schematic plan view showing a method of applying a pressing force to two diametrical locations with a slight eccentricity from a location where a branch hole is provided. FIG.
【図7】本発明に係る疲労強度を向上させる方法の他の
実施例を説明する図で、分岐孔を設ける領域より広範囲
に圧縮応力が発生するごとく押圧力を付与する方法を示
す概略平面図である。FIG. 7 is a view for explaining another embodiment of the method for improving fatigue strength according to the present invention, and is a schematic plan view showing a method for applying a pressing force so that a compressive stress is generated in a wider area than a region where a branch hole is provided. It is.
【図8】本発明に係る疲労強度を向上させる方法の他の
実施例を説明する図で、分岐孔を設ける領域より広範囲
に圧縮応力が発生するごとく押圧力を付与する方法の他
の実施例を示す概略平面図である。FIG. 8 is a view for explaining another embodiment of the method for improving fatigue strength according to the present invention, and is another embodiment of a method for applying a pressing force so that a compressive stress is generated in a wider area than a region where a branch hole is provided. FIG.
【図9】本発明に係る高圧流体用部材の他の実施例の縦
断面図である。FIG. 9 is a longitudinal sectional view of another embodiment of the high-pressure fluid member according to the present invention.
1 高圧流体用部材 1−1 中空部 1−2 分岐孔 1−3 押圧範囲 1−4 圧縮残留応力の発生した範囲 2 分岐孔部 DESCRIPTION OF SYMBOLS 1 High-pressure fluid member 1-1 Hollow part 1-2 Branch hole 1-3 Pressing range 1-4 Range where compressive residual stress occurred 2 Branch hole
Claims (7)
空部に連通する分岐孔を形成するに際し、前記高圧流体
用部材を外部より内方に押圧して前記中空部側内周面を
変形せしめて圧縮応力が残留した変形部を形成し、つい
で該変形部に前記中空部に開口する分岐孔を穿設して少
なくとも該分岐孔周縁に前記圧縮残留応力を存在せしめ
てなることを特徴とする高圧流体用部材における分岐孔
部での繰返し圧力による疲労強度を向上させる方法。When forming a branch hole communicating with the hollow portion in a member for high-pressure fluid having a hollow portion, the member for high-pressure fluid is pressed inward from the outside so that the inner peripheral surface on the hollow portion side is formed. Forming a deformed portion in which compressive stress remains by deforming, and then forming a branch hole opening in the hollow portion in the deformed portion so that the compressive residual stress is present at least on the periphery of the branch hole. A method for improving fatigue strength due to repetitive pressure at a branch hole in a high-pressure fluid member.
空部に連通する分岐孔を形成するに際し、前記高圧流体
用部材にその内周面に開口する分岐孔を穿設し、ついで
該高圧流体用部材の分岐孔部を外部より内方に押圧して
前記中空部側内周面を変形せしめて少なくとも該分岐孔
周縁の一部に圧縮応力を残留させてなることを特徴とす
る高圧流体用部材における分岐孔部での繰返し圧力によ
る疲労強度を向上させる方法。2. When forming a branch hole communicating with the hollow portion in a member for high pressure fluid having a hollow portion, a branch hole opening on an inner peripheral surface of the member for high pressure fluid is formed in the member for high pressure fluid. The high pressure fluid is characterized in that the branch hole of the high pressure fluid member is pressed inward from the outside to deform the inner peripheral surface of the hollow portion side so that a compressive stress remains on at least a part of the periphery of the branch hole. A method for improving fatigue strength due to repeated pressure at a branch hole in a fluid member.
空部に連通する分岐孔を形成するに際し、前記高圧流体
用部材を外部より内方に押圧して前記中空部側内周面を
変形せしめて圧縮応力が残留した変形部を形成すると同
時に、該変形部に前記中空部に開口する分岐孔を打抜
き、該分岐孔周縁に前記圧縮残留応力を存在せしめてな
ることを特徴とする高圧流体用部材における分岐孔部で
の繰返し圧力による疲労強度を向上させる方法。3. When forming a branch hole communicating with the hollow portion in the high-pressure fluid member having a hollow portion, the high-pressure fluid member is pressed inward from the outside to remove the hollow portion side inner peripheral surface. Forming a deformed portion in which the compressive stress remains by deforming, and punching a branch hole opened in the hollow portion in the deformed portion, so that the compressive residual stress is present around the branch hole. A method for improving fatigue strength due to repeated pressure at a branch hole in a fluid member.
空部に連通する分岐孔を形成するに際し、該分岐孔を設
ける箇所からやや偏心して前記高圧流体用部材を外部よ
り内方に押圧し、該分岐孔周縁部に圧縮残留応力を存在
せしめてなることを特徴とする高圧流体用部材における
分岐孔部での繰返し圧力による疲労強度を向上させる方
法。4. When forming a branch hole communicating with the hollow portion in the high-pressure fluid member having a hollow portion, the member for a high pressure fluid is slightly eccentrically pressed from a location where the branch hole is provided to press the high-pressure fluid member inward from the outside. A method for improving the fatigue strength of a member for high-pressure fluid due to repetitive pressure at a branch hole portion, wherein compressive residual stress is present at the periphery of the branch hole.
空部に連通する分岐孔を形成するに際し、該分岐孔を設
ける箇所からやや偏心して前記高圧流体用部材を外部よ
り内方に少なくとも直径方向の2箇所押圧し、該分岐孔
周縁部の少なくとも直径方向の2箇所に圧縮残留応力を
存在せしめてなることを特徴とする高圧流体用部材にお
ける分岐孔部での繰返し圧力による疲労強度を向上させ
る方法。5. When forming a branch hole communicating with the hollow portion in the member for high pressure fluid having a hollow portion, the member for high pressure fluid is at least slightly eccentric from a position where the branch hole is provided to inward from the outside. The fatigue strength due to the repetitive pressure at the branch hole in the high-pressure fluid member is characterized in that the member is pressed at two points in the diameter direction and compressive residual stress is present at least at two points in the diameter direction of the periphery of the branch hole. How to improve.
空部に連通する分岐孔を形成するに際し、前記高圧流体
用部材を外部より内方に押圧して前記中空部側内周面を
変形せしめて該分岐孔を設ける領域より広範囲に圧縮応
力が残留した変形部を形成し、該変形部の中央部に分岐
孔を穿設してなることを特徴とする高圧流体用部材にお
ける分岐孔部での繰返し圧力による疲労強度を向上させ
る方法。6. When forming a branch hole communicating with the hollow portion in the high-pressure fluid member having a hollow portion, the high-pressure fluid member is pressed inward from the outside to remove the hollow portion side inner peripheral surface. Forming a deformed portion in which compressive stress remains in a wider area than a region where the branch hole is formed by deforming, and forming a branch hole in a central portion of the deformed portion; Method to improve fatigue strength by repeated pressure in the part.
中空部に連通する分岐孔を穿設した分岐孔部であって、
該分岐孔内周縁部に圧縮残留応力を有することを特徴と
する高圧流体用部材の分岐孔部。7. A branch hole portion in which a branch hole communicating with the hollow portion is formed in a high-pressure fluid member having a hollow portion,
A branch hole for a high-pressure fluid member, wherein the branch hole has a compressive residual stress at an inner peripheral edge thereof.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10066246A JPH10309641A (en) | 1997-03-03 | 1998-03-02 | Method to improve fatigue strength by repeated pressure at branch hole part on member for high pressure fluid and branch hole part of member for high pressure fluid provided by this method |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9-63843 | 1997-03-03 | ||
JP6384397 | 1997-03-03 | ||
JP9-63846 | 1997-03-03 | ||
JP6384697 | 1997-03-03 | ||
JP10066246A JPH10309641A (en) | 1997-03-03 | 1998-03-02 | Method to improve fatigue strength by repeated pressure at branch hole part on member for high pressure fluid and branch hole part of member for high pressure fluid provided by this method |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH10309641A true JPH10309641A (en) | 1998-11-24 |
Family
ID=27298303
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP10066246A Pending JPH10309641A (en) | 1997-03-03 | 1998-03-02 | Method to improve fatigue strength by repeated pressure at branch hole part on member for high pressure fluid and branch hole part of member for high pressure fluid provided by this method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH10309641A (en) |
-
1998
- 1998-03-02 JP JP10066246A patent/JPH10309641A/en active Pending
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6213095B1 (en) | Common rail and method of manufacturing the same | |
US6397881B1 (en) | Method for improving fatigue strength due to repeated pressure at branch hole part in member for high pressure fluid, branch hole part of member for high pressure fluid formed by the method, and member for high pressure fluid with built-in slider having the branch hole | |
KR100251264B1 (en) | Common rail and method for manufacturing the same | |
US20030230349A1 (en) | High-pressure fuel injection pipe having connecting head portion | |
US20050146134A1 (en) | Connecting structure of branch connector in fuel pressure accumulating container | |
US6824173B2 (en) | High-pressure metal pine having connecting head and method of forming the connecting head as well as sleeve washer for the connecting head | |
US6317975B1 (en) | Method of manufacturing common rails | |
JP2006070827A (en) | High-pressure fuel injection pipe and molding method therefor | |
EP1552130B1 (en) | Piston assembly and method of manufacture | |
JPH10309641A (en) | Method to improve fatigue strength by repeated pressure at branch hole part on member for high pressure fluid and branch hole part of member for high pressure fluid provided by this method | |
US6263862B1 (en) | Common rail and method of manufacturing the same | |
JP2000033525A (en) | Inertia pressing-in method | |
KR20130064718A (en) | Cylinder device | |
JPH10318081A (en) | Common rail and its manufacture | |
JP2971334B2 (en) | Hole processing method for injection nozzle | |
JPH10318086A (en) | Common rail and its manufacture | |
JP3173301B2 (en) | Split bearing manufacturing method | |
JPH1099923A (en) | Flange joint and its manufacture | |
US7448362B2 (en) | Conduit arrangement in a control valve module for a fuel injector assembly | |
US20040177504A1 (en) | Method for the production of a forged piston for an internal combustion engine | |
WO2007070003A1 (en) | A method for manufacturing of a tubular element comprising a tube with a fixedly arranged flange | |
CN218151213U (en) | Injector body and injector body semi-finished product | |
JPH09250663A (en) | Connecting structure and connecting method of eye joint and small diameter metal pipe | |
WO2019093274A1 (en) | Pressure-resistant device, hydraulic cylinder, and method for producing pressure-resistant device | |
JPH1190578A (en) | Manufacture of steel tube with thick-walled tube end |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20040908 |