JP2007177777A - Connection structure of high pressure fuel injection pipe for diesel engine - Google Patents

Connection structure of high pressure fuel injection pipe for diesel engine Download PDF

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JP2007177777A
JP2007177777A JP2005380307A JP2005380307A JP2007177777A JP 2007177777 A JP2007177777 A JP 2007177777A JP 2005380307 A JP2005380307 A JP 2005380307A JP 2005380307 A JP2005380307 A JP 2005380307A JP 2007177777 A JP2007177777 A JP 2007177777A
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fuel injection
injection pipe
pressure fuel
sleeve
head
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Yasuaki Hashimoto
康明 橋本
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Usui Kokusai Sangyo Kaisha Ltd
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Usui Kokusai Sangyo Kaisha Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

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Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure of a high pressure fuel injection pipe for Diesel engine to bear the high internal pressure and does not leak without forming the end swelling part of the high pressure fuel injection pipe which causes the fatigue crack. <P>SOLUTION: In the connection structure of the high pressure fuel injection pipe for Diesel engine which a sleeve 2-1 of different body is fitted on the connection head part of the high pressure fuel injection pipe 1 and tightened with a counter member 3 by screwing a tightening nut to be fit on the sleeve 2-1, the sleeve 2-1 as a different body is firmly fixed to the outer circumference of a head part of the high pressure fuel injection pipe by the swelling press process method or the caulking construction method in the condition where it is fit on the head of the pressure fuel injection pipe. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、ディーゼル内燃機関にあって燃料供給路としてコモンレールと燃料ポンプ及びそれぞれノズルホルダーに接続して配置される比較的厚肉、細径からなるディーゼルエンジン用高圧燃料噴射管の接続構造に関する。   The present invention relates to a connection structure for a high-pressure fuel injection pipe for a diesel engine having a relatively thick wall and a small diameter, which is disposed in a diesel internal combustion engine and connected to a common rail, a fuel pump and a nozzle holder as fuel supply paths.

従来、この種のディーゼルエンジン用高圧燃料噴射管としては、外径５〜２５ｍｍ、肉厚２〜１０ｍｍ程度の比較的厚肉、細径の鋼管が使用されてきた。ディーゼルエンジン用高圧燃料噴射管は、燃料噴射ポンプからエンジンの各気筒に設けられた燃料噴射弁に向け燃料を圧送する役目を担うもので、流速が最大で５０ｍ／ｓｅｃ、内圧１０００ｂａｒを超える高圧条件下に曝され、近年油送圧力はますます高まる傾向にある。そのため高圧に耐えて燃料の漏洩を起こさない確実強固な接続構造が望まれる。   Conventionally, as this type of high-pressure fuel injection pipe for a diesel engine, a relatively thick and thin steel pipe having an outer diameter of 5 to 25 mm and a wall thickness of about 2 to 10 mm has been used. The high-pressure fuel injection pipe for diesel engines plays the role of pumping fuel from the fuel injection pump to the fuel injection valve installed in each cylinder of the engine. The flow rate is 50 m / sec at maximum and the internal pressure exceeds 1000 bar. In recent years, oil feed pressure has been increasing. Therefore, a reliable and strong connection structure that can withstand high pressure and does not cause fuel leakage is desired.

ディーゼルエンジン用高圧燃料噴射管としては、例えば厚肉鋼管先端部をプレス加工によるズクミ成形により頭部を膨出させて、その膨出部に袋ナットを掛けて相手部材と締結したものや、図１２に示すように、高圧燃料噴射管１０先端の膨出部１０−１の直後に嵌合した円筒状のスリーブ１１に袋ナット１２を掛けて相手部材１３と螺合して締結する接続構造等が知られている。これらの接続構造では、高圧燃料噴射管１０先端の膨出部１０−１内側にはポケット１０−２と呼ばれる空洞が生じ、さらにはそのポケット１０−２の最深部には亀裂１６が高圧燃料噴射管１０の肉厚方向に発生し、また同時にポケット１０−２の内部軸方向に皺１７が発生し、それらの亀裂１６や皺１７を起点として疲労割れを引き起こし、高圧燃料噴射管の耐圧機能を低下させていた。
このため亀裂１６や皺１７の発生原因となる高圧燃料噴射管先端の膨出部の形成を避ける方法として、図１３に示すように、高圧燃料噴射管１０の先端に異なる肉厚を有するテーパー付きスリーブ１１’を嵌合させ、該テーパー付きスリーブ１１’に袋ナット１２を掛けて相手部材１３と螺合して締結する接続構造も提案されている（例えば、特許文献１参照）。
実開昭５３−９２７２２号公報 As a high-pressure fuel injection pipe for a diesel engine, for example, a thick-walled steel pipe tip is bulged by press forming and the head is bulged, and a cap nut is hung on the bulged part and fastened with a mating member. As shown in FIG. 12, the connection structure etc. which hung the bag nut 12 on the cylindrical sleeve 11 fitted just after the bulging part 10-1 of the front-end | tip of the high-pressure fuel-injection pipe 10, and screw and fasten it with the other member 13 etc. It has been known. In these connection structures, a cavity called a pocket 10-2 is formed inside the bulging portion 10-1 at the tip of the high-pressure fuel injection pipe 10, and a crack 16 is formed in the deepest portion of the pocket 10-2. It occurs in the thickness direction of the pipe 10 and simultaneously, soot 17 is generated in the direction of the internal axis of the pocket 10-2, causing fatigue cracks starting from these cracks 16 and soot 17, and the pressure resistance function of the high-pressure fuel injection pipe It was decreasing.
For this reason, as a method of avoiding the formation of the bulging portion at the tip of the high-pressure fuel injection pipe that causes the crack 16 and the flaw 17, as shown in FIG. There has also been proposed a connection structure in which a sleeve 11 ′ is fitted, a cap nut 12 is hung on the tapered sleeve 11 ′, and the mating member 13 is screwed and fastened (for example, see Patent Document 1).
Japanese Utility Model Publication No. 53-92722

しかしながら図１３に示した接続構造では、高圧燃料噴射管１０の外径表面とテーパー付きスリーブ１１’の内表面との間の気密保持、あるいはテーパー付きスリーブ１１’の外径表面と相手部材１３の受圧座面との間の気密保持に難点があり、管内を流通する油の圧力が高まるに伴って油の漏洩を起こすという問題があった。
本発明は上記問題を解決するためになされたものであって、疲労割れを引き起こす危惧のある高圧燃料噴射管先端の膨出部を形成することなく、しかも高い内圧に耐えて漏洩を引き起こすことのないディーゼルエンジン用高圧燃料噴射管の接続構造を提供することを目的とする。 However, in the connection structure shown in FIG. 13, the airtight holding between the outer diameter surface of the high-pressure fuel injection pipe 10 and the inner surface of the tapered sleeve 11 ′ or the outer diameter surface of the tapered sleeve 11 ′ and the mating member 13 is maintained. There is a problem in maintaining airtightness between the pressure receiving seat surface and there is a problem that oil leaks as the pressure of oil flowing through the pipe increases.
The present invention has been made to solve the above-described problem, and does not form a bulging portion at the tip of a high-pressure fuel injection pipe that may cause fatigue cracking, and can withstand high internal pressure and cause leakage. It aims to provide a high pressure fuel injection pipe connection structure for diesel engines.

本発明に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、高圧燃料噴射管の接続頭部に別体のスリーブが外嵌固着され、該スリーブに外嵌した締付けナットをもって相手部材と螺着して締結されたディーゼルエンジン用高圧燃料噴射管の接続構造において、前記別体のスリーブを高圧燃料噴射管の頭部に外嵌した状態でプレス膨出加工法またはかしめ工法により該高圧燃料噴射管頭部外周に固着したことを特徴とするものである。
この接続構造において、前記プレス膨出加工法により前記スリーブを高圧燃料噴射管接続頭部に固着する手段としては、前記別体のスリーブ内周面に浅く滑らかな環状凹部を形成し、該スリーブを高圧燃料噴射管の頭部に外嵌した状態で該高圧燃料噴射管の接続頭部をプレス膨出加工にて拡径して前記スリーブの環状凹部に高圧燃料噴射管接続頭部外周面を食い込ませて固着せしめる方式、あるいは前記スリーブの内周面に環状溝を形成し、該環状溝に高圧燃料噴射管接続頭部の外周面を食い込ませる方式を用いることができる。
また、前記かしめ工法により前記スリーブを高圧燃料噴射管接続頭部に固着する手段として、高圧燃料噴射管接続頭部外周に環状突起を形成し、前記スリーブを高圧燃料噴射管の頭部に外嵌した状態で該スリーブを径方向にプレスして前記環状突起をスリーブ内周面に食い込ませる方式、あるいは前記スリーブの内周面に１または複数個の環状突起を形成し、該環状突起を高圧燃料噴射管接続頭部の外周面に食い込ませる方式を用いることができる。
さらに、本発明における前記スリーブの高圧燃料噴射管接続頭部への食い込み深さｈまたは高圧燃料噴射管接続頭部外周面の前記スリーブへの食い込み深さｈとしては、当該スリーブの肉厚Ｗの１／６〜１／３が好ましい。
さらにまた、本発明の接続構造は、前記高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に圧嵌したスリーブの端部と前記相手部材受圧座面との間に隙間を有することを特徴とするものである。
あるいはまた、本発明の接続構造は、前記高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に固着したスリーブの端部が当該接続頭部外周面と相手部材の受圧座面にくさび状に食い込み圧入されていることを特徴とするものである。
また、本発明に係る前記高圧燃料噴射管接続頭部外周に固着するスリーブは、当該接続頭部外周に固着後該高圧燃料噴射管の抗張力の少なくとも２０％以上の抗張力を有するものが好ましい。
さらに、前記高圧燃料噴射管として、管内に薄肉のオーステナイト系ステンレス鋼製の内管を密嵌状に内装した二重管からなる厚肉鋼管を用い、該噴射管の接続頭部の先端部を覆うように前記ステンレス製の内管の先端部を外側に折り曲げてシート面を形成してもよい。 In the connection structure of the high pressure fuel injection pipe for a diesel engine according to the present invention, a separate sleeve is externally fixed to the connection head of the high pressure fuel injection pipe, and a fastening nut externally fitted to the sleeve is screwed to the mating member. In the connection structure of the high-pressure fuel injection pipe for a diesel engine fastened in the above-mentioned manner, the head of the high-pressure fuel injection pipe is formed by a press bulging method or a caulking method with the separate sleeve fitted on the head of the high-pressure fuel injection pipe. It is characterized by being fixed to the outer periphery of the part.
In this connection structure, as a means for fixing the sleeve to the high pressure fuel injection pipe connection head by the press bulging method, a shallow and smooth annular recess is formed on the inner peripheral surface of the separate sleeve, and the sleeve is The connecting head of the high-pressure fuel injection pipe is expanded by press bulging while being fitted on the head of the high-pressure fuel injection pipe, and the outer peripheral surface of the high-pressure fuel injection pipe connecting head is bitten into the annular recess of the sleeve. A system in which the outer peripheral surface of the high pressure fuel injection pipe connecting head is bitten into the annular groove can be used.
Further, as a means for fixing the sleeve to the high pressure fuel injection pipe connection head by the caulking method, an annular protrusion is formed on the outer periphery of the high pressure fuel injection pipe connection head, and the sleeve is fitted on the head of the high pressure fuel injection pipe. In this state, the sleeve is pressed in the radial direction to cause the annular protrusion to bite into the inner peripheral surface of the sleeve, or one or a plurality of annular protrusions are formed on the inner peripheral surface of the sleeve. A method of biting into the outer peripheral surface of the jet pipe connecting head can be used.
Furthermore, the biting depth h of the sleeve into the high-pressure fuel injection pipe connection head or the biting depth h of the outer peripheral surface of the high-pressure fuel injection pipe connection head into the sleeve according to the present invention is the thickness W of the sleeve. 1/6 to 1/3 is preferable.
Furthermore, in the connection structure of the present invention, in a state where the high pressure fuel injection pipe connection head and the mating member are fastened by a tightening nut, the end of the sleeve press-fitted to the high pressure fuel injection pipe connection head and the counterpart A gap is provided between the member pressure-receiving seat surface.
Alternatively, in the connection structure of the present invention, in a state where the high pressure fuel injection pipe connection head and the mating member are fastened by a tightening nut, an end portion of a sleeve fixed to the high pressure fuel injection pipe connection head is the connection head. It is characterized in that it is wedged and pressed into the outer peripheral surface of the part and the pressure receiving seat surface of the mating member.
The sleeve fixed to the outer periphery of the high pressure fuel injection pipe connection head according to the present invention preferably has a tensile strength of at least 20% of the tensile strength of the high pressure fuel injection pipe after being fixed to the outer periphery of the connection head.
Further, as the high-pressure fuel injection pipe, a thick-walled steel pipe made of a double pipe in which a thin-walled austenitic stainless steel inner pipe is tightly fitted in the pipe is used, and the tip of the connecting head of the injection pipe is used. The sheet surface may be formed by bending the tip of the stainless steel inner tube outward so as to cover the sheet.

本発明に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、該高圧燃料噴射管の先端部にポケットがほとんど存在しないので亀裂や皺の発生が皆無となり、亀裂や皺を起点とする内圧疲労割れを引き起こす危惧が無くなり、高い気密性と優れた疲労強度が得られる。
また、本発明の接続構造において、前記スリーブを高圧燃料噴射管接続頭部に固着する手段として、高圧燃料噴射管の接続頭部内径をプレス膨出加工にて拡径してスリーブの環状凹部に高圧燃料噴射管接続頭部外周面を食い込ませて固着せしめる方式、あるいは前記スリーブの内周面に環状溝を形成し、該環状溝に高圧燃料噴射管接続頭部の外周面を食い込ませるプレス膨出加工方式、あるいは高圧燃料噴射管接続頭部外周に環状突起を形成し、かしめ工法によりスリーブを径方向にプレスしてスリーブ内周面に前記環状突起を食い込ませる方式、あるいは前記スリーブの内周面に１または複数個の環状突起を形成し、該環状突起を高圧燃料噴射管接続頭部の外周面に食い込ませる方式を採用することにより、噴射管接続頭部にポケットをほとんど形成することなくスリーブを強固に固着することができるので、気密性と内圧疲労強度の優れたディーゼルエンジン用高圧燃料噴射管の接続構造が得られる。 The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the present invention has no pockets at the tip of the high-pressure fuel injection pipe, so that no cracks or soot are generated, and internal pressure fatigue cracks starting from the cracks and soot There is no fear of causing odor, and high airtightness and excellent fatigue strength are obtained.
Further, in the connection structure of the present invention, as means for fixing the sleeve to the high pressure fuel injection pipe connection head, the inner diameter of the connection head of the high pressure fuel injection pipe is expanded by press bulging to form an annular recess of the sleeve. A system in which the outer peripheral surface of the high pressure fuel injection pipe connection head is bitten and fixed, or an annular groove is formed in the inner peripheral surface of the sleeve, and the outer peripheral surface of the high pressure fuel injection pipe connection head is bitten into the annular groove. A method of forming an annular protrusion on the outer periphery of the head of the high pressure fuel injection pipe connection and pressing the sleeve in the radial direction by a caulking method, or an inner periphery of the sleeve By adopting a system in which one or a plurality of annular projections are formed on the surface and the annular projections are bitten into the outer peripheral surface of the high pressure fuel injection pipe connection head, a pocket is formed on the injection pipe connection head. Since the sleeve without command form can be firmly fixed, excellent connection structure of a high-pressure fuel injection pipes for diesel engines of tightness and pressure fatigue strength can be obtained.

本発明に係るディーゼルエンジン用高圧燃料噴射管の接続構造としては、内周面に浅く滑らかな環状凹部を有する筒形スリーブを高圧燃料噴射管の頭部に外嵌した状態で該高圧燃料噴射管の接続頭部をプレス膨出加工にて拡径して前記スリーブの環状凹部に高圧燃料噴射管接続頭部外周面を食い込ませて固着した構成となしたもの、あるいは異なる肉厚を有するテーパ面付きスリーブの内周面に環状溝を形成し、該スリーブを高圧燃料噴射管の頭部に外嵌した状態で該高圧燃料噴射管の接続頭部をプレス膨出加工にて拡径して前記環状溝高圧燃料噴射管接続頭部の外周面を食い込ませて固着した構成としたもの、または高圧燃料噴射管接続頭部外周に環状突起を形成し、異なる肉厚を有するテーパ面付きスリーブを高圧燃料噴射管の頭部に外嵌した状態で径方向にプレスしてスリーブ内周面を高圧燃料噴射管接続頭部外周に食い込ませて固着した構成としたもの、あるいは異なる肉厚を有するテーパ付きスリーブの内周面に環状突起を形成し、該スリーブを高圧燃料噴射管の頭部に外嵌した状態で径方向にプレスして前記環状突起を高圧燃料噴射管接続頭部の外周面に食い込ませて固着した構成としたもの、さらに高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に固着したスリーブの端部と前記相手部材受圧座面との間に隙間を設けた構成としたもの、または高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に固着したスリーブの端部が当該接続頭部外周面と相手部材の受圧座面にくさび状に食い込み圧入されている構成となしたものである。   As a connection structure for a high-pressure fuel injection pipe for a diesel engine according to the present invention, the high-pressure fuel injection pipe is fitted in a state where a cylindrical sleeve having a shallow annular recess that is shallow on the inner peripheral surface is fitted over the head of the high-pressure fuel injection pipe. The diameter of the connecting head is expanded by press bulging and the outer peripheral surface of the high pressure fuel injection pipe connecting head is bitten into the annular recess of the sleeve, or a tapered surface having a different thickness An annular groove is formed on the inner peripheral surface of the attached sleeve, and the connecting head of the high pressure fuel injection pipe is expanded in diameter by press bulging while the sleeve is externally fitted to the head of the high pressure fuel injection pipe. The outer peripheral surface of the annular groove high-pressure fuel injection pipe connection head is inserted and fixed, or an annular protrusion is formed on the outer periphery of the high-pressure fuel injection pipe connection head, and a sleeve with a tapered surface having a different thickness is high pressure. Outside the head of the fuel injection pipe In such a state, the sleeve is pressed in the radial direction so that the inner peripheral surface of the sleeve bites into the outer periphery of the connection head of the high-pressure fuel injection pipe, or an annular protrusion is formed on the inner peripheral surface of the tapered sleeve having a different thickness. Formed and pressed in the radial direction in a state in which the sleeve is externally fitted to the head of the high-pressure fuel injection pipe, and the annular protrusion is bitten into the outer peripheral surface of the high-pressure fuel injection pipe connection head, Further, in a state where the high pressure fuel injection pipe connection head and the mating member are fastened by a tightening nut, a gap is provided between the end of the sleeve fixed to the high pressure fuel injection pipe connection head and the mating member pressure receiving seat surface. Or the end of the sleeve fixed to the high pressure fuel injection pipe connection head is the connection head in a state where the high pressure fuel injection pipe connection head and the mating member are fastened by a tightening nut. The pressure receiving seat surface of the peripheral surface and the mating member is obtained without the configuration being pressed bite in a wedge shape.

本発明において、前記スリーブの高圧燃料噴射管接続頭部への食い込み深さｈまたは高圧燃料噴射管接続頭部外周面の前記スリーブへの食い込み深さｈを、当該スリーブの肉厚Ｗの１／６〜１／３としたのは、１／６未満ではスリーブの固着強度が十分に得られず、他方、１／３を超えるとスリーブ自体の肉厚が薄くなり強度が低下するためである。   In the present invention, the biting depth h of the sleeve into the high pressure fuel injection pipe connecting head or the biting depth h of the outer peripheral surface of the high pressure fuel injection pipe connecting head into the sleeve is 1 / th of the wall thickness W of the sleeve. The reason why the thickness is set to 6 to 1/3 is that when the sleeve is less than 1/6, sufficient fixing strength of the sleeve cannot be obtained, and when it exceeds 1/3, the thickness of the sleeve itself is reduced and the strength is lowered.

また、高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に固着したスリーブの端部と前記相手部材受圧座面との間に隙間を設けることとしたのは、高圧燃料噴射管と相手部材との繰返し脱着の際スリーブで相手側シート面を傷付け、または変形させることによる洩れを防ぐためである。   Further, in a state where the high pressure fuel injection pipe connection head and the mating member are fastened by a tightening nut, a gap is formed between the end of the sleeve fixed to the high pressure fuel injection pipe connection head and the mating member pressure receiving seat surface. The reason for this is to prevent leakage due to damage or deformation of the mating sheet surface by the sleeve when the high pressure fuel injection pipe and the mating member are repeatedly detached.

また、高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に固着したスリーブの端部が当該接続頭部外周面と相手部材の受圧座面にくさび状に食い込み圧入させることとしたのは、スリーブ先端のくさび効果によって締付けを増すごとにスリーブが食い込み気密性をより向上させることと、スリーブの固着をより強化するためである。   Further, in a state where the high pressure fuel injection pipe connection head and the mating member are fastened by a tightening nut, the end of the sleeve fixed to the high pressure fuel injection pipe connection head is the connection head outer peripheral surface and the pressure receiving seat of the mating member. The reason why the surface is wedged and press-fitted into the surface is that the sleeve bites into the sleeve as the tightening effect is increased due to the wedge effect at the tip of the sleeve, and that the sleeve is more firmly fixed.

本発明の高圧燃料噴射管接続頭部外周に固着するスリーブの材質として、当該高圧燃料噴射管の抗張力の少なくとも２０％以上の抗張力を有することとしたのは、抗張力が２０％未満では噴射管接続頭部の変形（へたり）より先にスリーブが変形（へたり）すると、気密に必要な締付け力を得ることができないためである。   The material of the sleeve fixed to the outer periphery of the high pressure fuel injection pipe connection head according to the present invention has a tensile strength of at least 20% or more of the tensile strength of the high pressure fuel injection pipe when the tensile strength is less than 20%. This is because if the sleeve is deformed (sagging) before the head is deformed (sagging), the necessary tightening force cannot be obtained in an airtight manner.

さらに、前記高圧燃料噴射管として、管内に薄肉のオーステナイト系ステンレス鋼製の内管を密嵌状に内装した二重管からなる厚肉鋼管を用い、該噴射管の接続頭部の先端部を覆うように前記ステンレス製の内管の先端部を外側に折り曲げてシート面を形成することにより、気密が強固に維持されるのみならず、燃料との接液部分には鉄系材料等の露出部が存在せず、その優れた防錆能が得られる。   Further, as the high-pressure fuel injection pipe, a thick-walled steel pipe made of a double pipe in which a thin-walled austenitic stainless steel inner pipe is tightly fitted in the pipe is used, and the tip of the connecting head of the injection pipe is used. By folding the tip of the stainless steel inner tube outward to form a sheet surface, not only the airtightness is firmly maintained, but also the exposed parts such as iron-based materials are exposed to the fuel contact part There is no part, and the excellent antirust ability is obtained.

本発明に係るディーゼルエンジン用高圧燃料噴射管の接続構造を得るためのスリーブの具体的固着手段として、例えばプレス膨出加工法を採用する場合は、高圧燃料噴射管接続頭部に当該接続頭部の先端部をのぞかせた状態で、内周面に浅く滑らかな環状凹部を形成した筒形スリーブを外嵌して下型にチャッキングしてセットし、次いで前記接続頭部の先端を上型（パンチ）にて管軸方向に押圧プレス加工して、当該接続頭部を拡径して膨出させて前記スリーブの環状凹部に高圧燃料噴射管接続頭部外周面を食い込ませて当該スリーブを高圧燃料噴射管接続頭部に固着する。しかる後、前記筒形スリーブ端部より突出している高圧燃料噴射管接続頭部の先端部をプレス加工や切削加工等により相手部材のシート面（受圧座面）に対応するシート面（押圧座面）を形成し、高圧燃料噴射管の接続頭部のシート面（押圧座面）に相手部材のシート面（受圧座面）を当接係合させるとともに、予め高圧燃料噴射管に組込んだ締付けナットを前記筒形スリーブに螺着し締付けて締結する。かかる構成の接続構造は、前記高圧燃料噴射管接続頭部に固着したスリーブの端部と前記相手部材受圧座面との間に隙間を有している。
なお、本固着手段においては、前記スリーブ環状凹部に噴射管接続頭部を膨出させて食い込ませて固定する工程と、噴射管接続頭部先端を押圧面としてのシート面形成するために行うプレス工程を同時に行ってもよいことはいうまでもない。 As a specific fixing means of the sleeve for obtaining the connection structure of the high-pressure fuel injection pipe for diesel engines according to the present invention, for example, when the press bulging method is adopted, the connection head is connected to the high-pressure fuel injection pipe connection head. In a state where the front end portion of the connecting head is viewed, a cylindrical sleeve having a shallow and smooth annular recess formed on the inner peripheral surface is externally fitted and chucked and set on the lower die, and then the tip of the connecting head is placed on the upper die ( Punch) in the direction of the pipe axis, the diameter of the connecting head is expanded and bulged, and the outer peripheral surface of the high pressure fuel injection pipe connecting head is bitten into the annular recess of the sleeve so that the sleeve is pressurized. Adheres to the fuel injection pipe connection head. After that, a sheet surface (pressing seat surface) corresponding to the sheet surface (pressure receiving seat surface) of the mating member is formed by pressing or cutting the tip of the high pressure fuel injection pipe connecting head protruding from the end of the cylindrical sleeve. ), And the seat surface (pressing seat surface) of the mating member is brought into contact with and engaged with the seat surface (pressing seat surface) of the connection head of the high pressure fuel injection pipe, and tightened in advance into the high pressure fuel injection pipe A nut is screwed onto the cylindrical sleeve and fastened. The connection structure having such a configuration has a gap between the end of the sleeve fixed to the connection head of the high-pressure fuel injection pipe and the mating member pressure-receiving seat surface.
The fixing means includes a step of expanding and biting the injection pipe connection head into the sleeve annular recess, and a press performed to form a sheet surface as a pressing surface at the tip of the injection pipe connection head. Needless to say, the steps may be performed simultaneously.

また、スリーブの内周面に環状溝を形成し、該環状溝に高圧燃料噴射管接続頭部の外周面を食い込ませるプレス膨出加工方式を採用する場合は、例えば高圧燃料噴射管接続頭部に当該接続頭部の先端部をのぞかせた状態で前記スリーブを外嵌して下型にてチャッキングしてセットし、次いで前記接続頭部の先端を上型（パンチ）にて管軸方向にプレス加工して、当該接続頭部を拡径して膨出させて前記スリーブの環状溝に高圧燃料噴射管接続頭部外周面を食い込ませて当該スリーブを高圧燃料噴射管接続頭部に固着する。しかる後、前記スリーブ端部より突出している高圧燃料噴射管接続頭部の先端部をプレス加工や切削加工等により相手部材のシート面（受圧座面）に対応するシート面（押圧座面）を形成し、高圧燃料噴射管の接続頭部のシート面（押圧座面）に相手部材のシート面（受圧座面）を当接係合させるとともに、予め高圧燃料噴射管に組込んだ締付けナットを前記筒形スリーブに螺着し締付けて締結する。かかる構成の接続構造も前記のものと同様、前記高圧燃料噴射管接続頭部に固着したスリーブの端部と前記相手部材受圧座面との間に隙間を有している。
なお、本固着手段においても前記と同様、スリーブ環状溝に噴射管接続頭部を膨出させて食い込ませて固定する工程と、噴射管接続頭部先端をシート面形成するために行うプレス工程を同時に行ってもよいことはいうまでもない。 Further, when a press bulging method is employed in which an annular groove is formed in the inner peripheral surface of the sleeve and the outer peripheral surface of the high pressure fuel injection pipe connection head is bitten into the annular groove, for example, the high pressure fuel injection pipe connection head With the tip of the connecting head being looked into, the sleeve is externally fitted and chucked with the lower die and set, and then the tip of the connecting head is placed in the tube axis direction with the upper die (punch) The connecting head is expanded to expand the diameter of the connecting head, and the outer peripheral surface of the high-pressure fuel injection pipe connection head is bitten into the annular groove of the sleeve, thereby fixing the sleeve to the high-pressure fuel injection pipe connection head. . After that, a sheet surface (pressing seat surface) corresponding to the sheet surface (pressure receiving seat surface) of the mating member is formed by pressing or cutting the tip of the high pressure fuel injection pipe connecting head protruding from the sleeve end. A clamping nut that is formed in advance and brought into contact with and engages the seat surface (pressure receiving seat surface) of the mating member with the seat surface (pressing seat surface) of the connection head of the high-pressure fuel injection pipe; The tubular sleeve is screwed and fastened to be fastened. Similarly to the above-described connection structure, the connection structure has a gap between the end of the sleeve fixed to the connection head of the high-pressure fuel injection pipe and the counterpart member pressure-receiving seat surface.
As in the above, the fixing means also includes a step of bulging and fixing the injection pipe connection head in the sleeve annular groove, and a pressing step performed to form the injection pipe connection head tip at the sheet surface. Needless to say, it may be performed simultaneously.

さらに、高圧燃料噴射管接続頭部外周に環状突起を形成し、この環状突起をスリーブ内周面に食い込ませるカシメ工法を採用する場合は、高圧燃料噴射管接続頭部外周に形成した環状突起を囲むようにスリーブを該高圧燃料噴射管接続頭部に当該接続頭部の先端部をのぞかせた状態で外嵌し、この状態で該スリーブの断面形状に応じて形成した横型にて径方向に押圧しながら該横型を回転させて前記環状突起をスリーブの内周面に食い込ませて当該スリーブを高圧燃料噴射管接続頭部に固着する。しかる後、前記スリーブ端部より突出している高圧燃料噴射管接続頭部の先端部をプレス加工や切削加工等により相手部材のシート面（受圧座面）に対応するシート面（押圧座面）を形成し、高圧燃料噴射管の接続頭部のシート面（押圧座面）に相手部材のシート面（受圧座面）を当接係合させるとともに、予め高圧燃料噴射管に組込んだ締付けナットを前記筒形スリーブを介して螺着し締付けて締結する。かかる構成の接続構造も前記のものと同様、前記高圧燃料噴射管接続頭部に固着したスリーブの端部と前記相手部材受圧座面との間に隙間を有している。   Furthermore, when a caulking method is adopted in which an annular protrusion is formed on the outer periphery of the high pressure fuel injection pipe connection head and this annular protrusion is bitten into the inner peripheral surface of the sleeve, the annular protrusion formed on the outer periphery of the high pressure fuel injection pipe connection head is The sleeve is externally fitted in a state where the tip of the connecting head is looked over the connecting head of the high-pressure fuel injection pipe, and in this state, the sleeve is pressed in a radial direction by a horizontal mold formed according to the cross-sectional shape of the sleeve. While rotating the horizontal mold, the annular protrusion is caused to bite into the inner peripheral surface of the sleeve, and the sleeve is fixed to the high pressure fuel injection pipe connecting head. After that, a sheet surface (pressing seat surface) corresponding to the sheet surface (pressure receiving seat surface) of the mating member is formed by pressing or cutting the tip of the high pressure fuel injection pipe connecting head protruding from the sleeve end. A clamping nut that is formed in advance and brought into contact with and engages the seat surface (pressure receiving seat surface) of the mating member with the seat surface (pressing seat surface) of the connection head of the high-pressure fuel injection pipe; It is screwed and tightened through the cylindrical sleeve. Similarly to the above-described connection structure, the connection structure has a gap between the end of the sleeve fixed to the connection head of the high-pressure fuel injection pipe and the counterpart member pressure-receiving seat surface.

さらにまた、スリーブの内周面に１または複数個の環状突起を形成し、この環状突起を高圧燃料噴射管接続頭部の外周面に食い込ませるカシメ工法を採用する場合は、内周面に１または複数個の環状突起を形成したスリーブを高圧燃料噴射管接続頭部に当該接続頭部の先端部をのぞかせた状態で外嵌し、この状態で該スリーブの断面形状に応じて形成した横型にて当該スリーブを径方向に押圧しながら該横型を回転させて前記環状突起を高圧燃料噴射管の接続頭部に食い込ませて当該スリーブを高圧燃料噴射管接続頭部に固着する。しかる後、前記スリーブ端部より突出している高圧燃料噴射管接続頭部の先端部をプレス加工や切削加工等により相手部材のシート面（受圧座面）に対応するシート面（押圧座面）を形成し、高圧燃料噴射管の接続頭部のシート面（押圧座面）に相手部材のシート面（受圧座面）を当接係合させるとともに、予め高圧燃料噴射管に組込んだ締付けナットを前記筒形スリーブを介して螺着し締付けて締結する。かかる構成の接続構造も前記のものと同様、前記高圧燃料噴射管接続頭部に固着したスリーブの端部と前記相手部材受圧座面との間に隙間を有している。   Furthermore, when a caulking method is employed in which one or a plurality of annular protrusions are formed on the inner peripheral surface of the sleeve and the annular protrusions bite into the outer peripheral surface of the high-pressure fuel injection pipe connection head, 1 is applied to the inner peripheral surface. Alternatively, a sleeve in which a plurality of annular protrusions are formed is externally fitted in a state where the tip of the connection head is looked into the connection head of the high-pressure fuel injection pipe, and in this state, a horizontal shape formed according to the cross-sectional shape of the sleeve is formed. Then, while pressing the sleeve in the radial direction, the horizontal mold is rotated so that the annular protrusion bites into the connection head of the high pressure fuel injection pipe, and the sleeve is fixed to the connection head of the high pressure fuel injection pipe. After that, a sheet surface (pressing seat surface) corresponding to the sheet surface (pressure receiving seat surface) of the mating member is formed by pressing or cutting the tip of the high pressure fuel injection pipe connecting head protruding from the sleeve end. A clamping nut that is formed in advance and brought into contact with and engages the seat surface (pressure receiving seat surface) of the mating member with the seat surface (pressing seat surface) of the connection head of the high-pressure fuel injection pipe; It is screwed and tightened through the cylindrical sleeve. Similarly to the above-described connection structure, the connection structure has a gap between the end of the sleeve fixed to the connection head of the high-pressure fuel injection pipe and the counterpart member pressure-receiving seat surface.

一方、前記高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に固着したスリーブの端部が当該接続頭部外周面と相手部材の受圧座面にくさび状に食い込み圧入された構造の接続構造（高圧燃料噴射管接続頭部に固着したスリーブの端部と前記相手部材受圧座面との間に隙間を有しない接続構造）の場合は、高圧燃料噴射管接続頭部に当該接続頭部の先端部をのぞかせた状態で、例えば内周面に浅く滑らかな環状凹部を形成した筒形スリーブを外嵌して下型にてチャッキングしてセットし、次いで前記接続頭部の先端を前記筒形スリーブと共に上型（パンチ）にて管軸方向に押圧プレス加工して、当該接続頭部を拡径して膨出させて前記スリーブの環状凹部に高圧燃料噴射管接続頭部外周面を食い込ませて当該スリーブを高圧燃料噴射管接続頭部に固着すると同時に、当該接続頭部の先端部を相手部材のシート面（受圧座面）に対応するシート面（押圧座面）に形成すると共にスリーブの先端部をくさび状断面に加工する。しかる後、高圧燃料噴射管の接続頭部のシート面（押圧座面）に相手部材のシート面（受圧座面）を当接係合させるとともに、予め高圧燃料噴射管に組込んだ締付けナットを前記筒形スリーブを介して螺着し締付けて締結する。この時、くさび状断面のスリーブ先端部が当該接続頭部外周面と相手部材の受圧座面にくさび状に食い込み圧入されて、気密性がより高められると共にスリーブの固着がより強化される。
なお、この接続構造の場合、スリーブ先端部を断面くさび状に形成する手段としては、プレス加工以外に、スリーブを高圧燃料噴射管接続頭部に固着した後、この接続頭部とスリーブ先端部を切削加工することによっても形成することができる。
［実施例］ On the other hand, in a state where the high pressure fuel injection pipe connection head and the mating member are fastened by a tightening nut, the end of the sleeve fixed to the high pressure fuel injection pipe connection head is the pressure receiving pressure of the connection head outer peripheral surface and the mating member. In the case of a connection structure of a structure in which the seat surface is wedged and press-fitted (a connection structure having no gap between the end of the sleeve fixed to the connection head of the high-pressure fuel injection pipe and the counterpart member pressure-receiving seat surface) In the state where the tip of the connecting head is looked over the connecting head of the high-pressure fuel injection pipe, for example, a cylindrical sleeve having a shallow and smooth annular recess formed on the inner peripheral surface is externally fitted and chucked by the lower mold. Then, the tip of the connection head is pressed together with the cylindrical sleeve in the direction of the tube axis with an upper die (punch), and the connection head is expanded and bulged so that the sleeve High pressure fuel injection pipe connected to annular recess At the same time, the sleeve is fixed to the high pressure fuel injection pipe connecting head by biting the outer peripheral surface of the portion, and at the same time, the front end of the connecting head is the seat surface (pressing seat surface) corresponding to the seat surface (pressure receiving seat surface) of the counterpart member And the sleeve tip is processed into a wedge-shaped cross section. Thereafter, the seat surface (pressure-receiving seat surface) of the mating member is brought into contact with and engaged with the seat surface (pressing seat surface) of the connection head of the high-pressure fuel injection pipe, and a tightening nut previously incorporated in the high-pressure fuel injection pipe is installed. It is screwed and tightened through the cylindrical sleeve. At this time, the front end of the sleeve having a wedge-shaped cross-section is wedged and pressed into the outer peripheral surface of the connection head and the pressure-receiving seat surface of the mating member, so that airtightness is further improved and the fixing of the sleeve is further strengthened.
In the case of this connection structure, as a means for forming the sleeve tip portion in a wedge shape, in addition to pressing, the sleeve is fixed to the high pressure fuel injection pipe connection head, and then the connection head and the sleeve tip are connected. It can also be formed by cutting.
[Example]

図１〜図７はそれぞれ本発明に係るディーゼルエンジン用高圧燃料噴射管の接続構造の第１〜第７実施例を示す断面図、図８〜図１１は同上のディーゼルエンジン用高圧燃料噴射管の接続構造におけるスリーブの固着手段を例示したもので、図８は図１に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの固着方法の一例を示す断面図、図９は図２に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの固着方法の一例を示す断面図、図１０は同じく図２に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの他の固着方法を示す断面図、図１１は図３、図４に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの固着方法の一例を示す断面図で、１は高圧燃料噴射管、１ｉは内管、２−１〜２−５はスリーブ、３は相手部材、４は締結用ナットをそれぞれ示す。   1 to 7 are sectional views showing first to seventh embodiments of the connection structure of a high-pressure fuel injection pipe for a diesel engine according to the present invention, respectively, and FIGS. FIG. 8 is a sectional view showing an example of a sleeve fixing method corresponding to the connecting structure of the high-pressure fuel injection pipe for a diesel engine shown in FIG. 1, and FIG. Sectional drawing which shows an example of the adhering method of the sleeve corresponding to the connection structure of the high-pressure fuel injection pipe for diesel engines shown in FIG. 10, FIG. 10 is the other sleeve corresponding to the connection structure of the high-pressure fuel injection pipe for diesel engines shown in FIG. FIG. 11 is a sectional view showing an example of a fixing method of a sleeve corresponding to the connection structure of the high-pressure fuel injection pipe for a diesel engine shown in FIGS. High-pressure fuel injection pipe, 1i inner tube, 2-1 to 2-5 respectively sleeves, 3 mating member, 4 a fastening nut.

高圧燃料噴射管１に用いる鋼管は、特に限定するものではないが、外径が５〜１２ｍｍ、肉厚が１．５〜５ｍｍ程度の比較的厚肉で細径の鋼管である。中でも肉厚が外径の１５％以上である厚肉鋼管が好んで用いられる。鋼種としては、高圧配管用炭素鋼管（ＪＩＳ−ＳＴＳ、抗張力（引張強さ）；３７０〜４８０Ｎ／ｍｍ２）、熱交換器用炭素鋼管（ＪＩＳ−ＳＴＢ、抗張力（引張強さ）；３４０〜５１０Ｎ／ｍｍ２）、熱交換器用合金鋼管（ＪＩＳ−ＳＴＢＡ、抗張力（引張強さ）；３８０〜４１０Ｎ／ｍｍ２）等が用いられる。 The steel pipe used for the high-pressure fuel injection pipe 1 is not particularly limited, but is a relatively thick and thin steel pipe having an outer diameter of 5 to 12 mm and a wall thickness of about 1.5 to 5 mm. Among these, a thick steel pipe having a wall thickness of 15% or more of the outer diameter is preferably used. As steel types, carbon steel pipes for high pressure piping (JIS-STS, tensile strength (tensile strength); 370 to 480 N / mm 2 ), carbon steel pipes for heat exchangers (JIS-STB, tensile strength (tensile strength); 340 to 510 N / mm 2 ), alloy steel pipe for heat exchanger (JIS-STBA, tensile strength (tensile strength); 380 to 410 N / mm 2 ), and the like.

また、高圧燃料噴射管１に外嵌固着するスリーブ２−１〜２−５としては、当該高圧燃料噴射管の抗張力の少なくとも２０％以上高い抗張力を有するものが望ましい。具体的には、高張力鋼を用いるか、または一般構造用炭素鋼管（ＪＩＳ−ＳＴＫ、抗張力；２９０Ｎ／ｍｍ２以上）を焼入れ焼戻し等の熱処理により抗張力を高めて使用する。 The sleeves 2-1 to 2-5 that are externally fitted and fixed to the high-pressure fuel injection pipe 1 desirably have a tensile strength that is at least 20% higher than the tensile strength of the high-pressure fuel injection pipe. Specifically, high-strength steel is used, or a general structural carbon steel pipe (JIS-STK, tensile strength: 290 N / mm 2 or more) is used with its tensile strength increased by heat treatment such as quenching and tempering.

図１に示す第１実施例に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、内周面に浅く滑らかな環状凹部２−１ａを有する筒形スリーブ２−１を高圧燃料噴射管１の頭部に外嵌した状態で該高圧燃料噴射管１の接続頭部１−１内径をプレス膨出加工にて拡径して前記スリーブ２−１の環状凹部２−１ａに高圧燃料噴射管接続頭部外周面を食い込ませて固着し、高圧燃料噴射管１の接続頭部１−１のシート面（押圧座面）１−１ａに相手部材３のシート面（受圧座面）３ａを当接係合させるとともに、予め高圧燃料噴射管１に組込んだ締付けナット４を相手部材３に螺着し締付けると、締付けナット４の内底面４ａが前記筒形スリーブ２−１の下端２−１ｂに係止することによって当該筒形スリーブ２−１を介して高圧燃料噴射管１の接続頭部１−１のシート面１−１ａと相手部材３のシート面３ａとが圧接して接続構成されたものである。この接続構造の場合は、高圧燃料噴射管接続頭部１−１と相手部材３とを締付けナット４により締結した状態において、高圧燃料噴射管接続頭部１−１に固着した筒形スリーブ２−１の端部と相手部材３のシート面３ａとの間に隙間５を有している。かかる接続構造における高圧燃料噴射管接続頭部１−１の前記筒形スリーブ２−１への食い込み深さｈは、当該スリーブの肉厚Ｗの１／６〜１／３となっている。また、この接続構造の場合は、前記プレス膨出加工により前記スリーブ２−１の環状凹部２−１ａに高圧燃料噴射管接続頭部外周面が食い込むと同時に、筒形スリーブ２−１の先端部において該高圧燃料噴射管１の外周面に膨出部１−１ｂが形成され、締付けナット４の締付けに伴い筒形スリーブ２−１の先端部が前記高圧燃料噴射管１の外周面の膨出部１−１ｂに当接して当該高圧燃料噴射管１の外周面に強く食い込むため、高圧燃料噴射管１は相手部材３に強固に接続される。   The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the first embodiment shown in FIG. 1 includes a cylindrical sleeve 2-1 having a shallow annular recess 2-1a on the inner peripheral surface and a head of the high-pressure fuel injection pipe 1. The inner diameter of the connection head 1-1 of the high-pressure fuel injection pipe 1 is expanded by press bulging while being fitted on the outer portion, and the connection head of the high-pressure fuel injection pipe is inserted into the annular recess 2-1a of the sleeve 2-1. The outer peripheral surface of the part is bitten and fixed, and the seat surface (pressure receiving seat surface) 3a of the mating member 3 is brought into contact with the seat surface (pressing seat surface) 1-1a of the connection head 1-1 of the high pressure fuel injection pipe 1. When the fastening nut 4 previously assembled in the high-pressure fuel injection pipe 1 is screwed and fastened to the mating member 3, the inner bottom surface 4a of the fastening nut 4 is engaged with the lower end 2-1b of the cylindrical sleeve 2-1. By stopping the high pressure fuel injection pipe 1 through the cylindrical sleeve 2-1. A seat surface 3a of the seat surface 1-1a and the mating member 3 connection head 1-1 is one that was connected constituted by welding. In the case of this connection structure, in the state where the high pressure fuel injection pipe connection head 1-1 and the counterpart member 3 are fastened by the tightening nut 4, the cylindrical sleeve 2 fixed to the high pressure fuel injection pipe connection head 1-1. 1 has a gap 5 between the end portion of 1 and the sheet surface 3 a of the mating member 3. The depth h of biting into the cylindrical sleeve 2-1 of the high pressure fuel injection pipe connecting head 1-1 in such a connection structure is 1/6 to 1/3 of the wall thickness W of the sleeve. In the case of this connection structure, the outer peripheral surface of the high-pressure fuel injection pipe connection head bites into the annular recess 2-1a of the sleeve 2-1 by the press bulging process, and at the same time, the tip of the cylindrical sleeve 2-1 , A bulging portion 1-1 b is formed on the outer peripheral surface of the high-pressure fuel injection pipe 1, and the tip of the cylindrical sleeve 2-1 bulges on the outer peripheral surface of the high-pressure fuel injection pipe 1 as the tightening nut 4 is tightened. The high pressure fuel injection pipe 1 is firmly connected to the counterpart member 3 because it abuts against the portion 1-1b and bites into the outer peripheral surface of the high pressure fuel injection pipe 1 strongly.

図２に示す第２実施例に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、外周面に肉厚と向きの異なる凸状のテーパ面２−２ｂ、２−２ｃを有し、かつ内周面に環状溝２−２ａを有するテーパ面付きスリーブ２−２を前記図１に示す接続構造と同様、高圧燃料噴射管１の頭部に外嵌した状態で該高圧燃料噴射管１の接続頭部１−１内径をプレス膨出加工にて拡径して前記スリーブ２−２の環状溝２−２ａに高圧燃料噴射管接続頭部１−１の外周面を膨出させて食い込ませて固着し、高圧燃料噴射管１の接続頭部１−１のシート面１−１ａに相手部材３のシート面３ａを当接係合させるとともに、予め高圧燃料噴射管１に組込んだ締付けナット４を相手部材３に螺着し締付けると、締付けナット４の内底面４ａが前記テーパ面付きスリーブ２−２の下端側テーパ面２−２ｂに係止することによって当該テーパ面付きスリーブ２−２を介して高圧燃料噴射管１の接続頭部１−１のシート面１−１ａと相手部材３のシート面３−１ａとが圧接して接続構成されたものである。この接続構造の場合も前記図１に示す接続構造と同様、高圧燃料噴射管接続頭部１−１と相手部材３とを締付けナット４により締結した状態において、高圧燃料噴射管接続頭部１−１に固着したテーパ面付きスリーブ２−２の上端側テーパ面２−２ｃと相手部材３のシート面３ａとの間に隙間５を有している。また、かかる接続構造においても高圧燃料噴射管接続頭部１−１の前記テーパ面付きスリーブ２−２への食い込み深さｈは、当該スリーブの肉厚Ｗの１／６〜１／３となっている。さらに、前記図１に示す接続構造と同様、前記プレス膨出加工により筒形スリーブ２−１の先端部において該高圧燃料噴射管１の外周面に形成される膨出部１−１ｂの作用により、筒形スリーブ２−１の先端部が高圧燃料噴射管１の外周面に強く食い込むため、高圧燃料噴射管１は相手部材３に強固に接続される。   The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the second embodiment shown in FIG. 2 has convex taper surfaces 2-2b and 2-2c having different thicknesses and directions on the outer peripheral surface, and the inner periphery. As in the connection structure shown in FIG. 1, the sleeve 2-2 with the tapered surface having the annular groove 2-2a on the surface is fitted on the head of the high-pressure fuel injection pipe 1, and the connection head of the high-pressure fuel injection pipe 1 is attached. The inner diameter of the portion 1-1 is expanded by press bulging, and the outer peripheral surface of the high-pressure fuel injection pipe connecting head 1-1 is bulged into the annular groove 2-2a of the sleeve 2-2 and fixed. Then, the seat surface 3a of the mating member 3 is brought into contact with and engaged with the seat surface 1-1a of the connection head 1-1 of the high-pressure fuel injection pipe 1, and the tightening nut 4 previously incorporated in the high-pressure fuel injection pipe 1 is provided. When screwed into the mating member 3 and tightened, the inner bottom surface 4a of the tightening nut 4 is formed into the taper-surfaced slot. The seat surface 1-1a of the connection head 1-1 of the high-pressure fuel injection pipe 1 and the mating member via the sleeve 2-2 with the tapered surface by engaging with the lower tapered surface 2-2b of the bush 2-2. 3 sheet surface 3-1 a is pressed and connected. In the case of this connection structure, similarly to the connection structure shown in FIG. 1, the high pressure fuel injection pipe connection head 1-1 in a state where the high pressure fuel injection pipe connection head 1-1 and the counterpart member 3 are fastened by the tightening nut 4. A gap 5 is provided between the upper end side taper surface 2-2c of the sleeve with taper surface 2-2 fixed to 1 and the sheet surface 3a of the mating member 3. In this connection structure, the depth h of the high pressure fuel injection pipe connection head 1-1 into the tapered sleeve 2-2 is 1/6 to 1/3 of the wall thickness W of the sleeve. ing. Further, similarly to the connection structure shown in FIG. 1, the bulging portion 1-1b formed on the outer peripheral surface of the high-pressure fuel injection pipe 1 at the tip of the cylindrical sleeve 2-1 by the press bulging process is used. Since the tip of the cylindrical sleeve 2-1 strongly bites into the outer peripheral surface of the high pressure fuel injection pipe 1, the high pressure fuel injection pipe 1 is firmly connected to the counterpart member 3.

図３に示す第３実施例に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、外周面に肉厚と向きの異なる凸状のテーパ面２−３ｂ、２−３ｃを有し、かつ内周面に環状突起２−３ａを有するテーパ面付きスリーブ２−３を高圧燃料噴射管１の頭部に外嵌した状態で当該スリーブを径方向内方に押圧して環状突起２−３ａを高圧燃料噴射管接続頭部１−１の外周面を食い込ませて固着し、高圧燃料噴射管１の接続頭部１−１のシート面１−１ａに相手部材３のシート面３ａを当接係合させるとともに、予め高圧燃料噴射管１に組込んだ締付けナット４を相手部材３に螺着し締付けると、締付けナット４の押圧面４ａが前記テーパ面付きスリーブ２−３の下端側テーパ面２−３ｂに係止することによって当該テーパ面付きスリーブ２−３を介して高圧燃料噴射管１の接続頭部１−１のシート面１−１ａと相手部材３のシート面３−１ａとが圧接して接続構成されたものである。この接続構造の場合も前記の接続構造と同様、高圧燃料噴射管接続頭部１−１と相手部材３とを締付けナット４により締結した状態において、高圧燃料噴射管接続頭部１−１に固着したテーパ面付きスリーブ２−３の上端側テーパ面２−３ｃと相手部材３のシート面３ａとの間に隙間５を有している。また、かかる接続構造においても高圧燃料噴射管接続頭部１−１の前記テーパ面付きスリーブ２−３への食い込み深さｈは、当該スリーブの肉厚Ｗの１／６〜１／３となっている。   The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the third embodiment shown in FIG. 3 has convex tapered surfaces 2-3b and 2-3c having different thicknesses and directions on the outer peripheral surface, and the inner periphery. A sleeve 2-3 with a tapered surface having an annular projection 2-3a on the surface is externally fitted to the head of the high-pressure fuel injection pipe 1, and the sleeve is pressed radially inward to thereby cause the annular projection 2-3a to be high-pressure fuel. The outer peripheral surface of the injection pipe connecting head 1-1 is bitten and fixed, and the seat surface 1-1a of the connection head 1-1 of the high-pressure fuel injection pipe 1 is brought into contact with and engaged with the seat surface 3a of the counterpart member 3. At the same time, when the tightening nut 4 previously assembled in the high-pressure fuel injection pipe 1 is screwed to the mating member 3 and tightened, the pressing surface 4a of the tightening nut 4 becomes the lower end side tapered surface 2-3b of the tapered surface sleeve 2-3. The sleeve 2-3 with the tapered surface Those in which the seat surface 3-1a of the seat surface 1-1a and the mating member 3 of the connecting head 1-1 high-pressure fuel injection pipe 1 connected configured in pressure contact with. In the case of this connection structure as well, the high pressure fuel injection pipe connection head 1-1 and the mating member 3 are fastened to the high pressure fuel injection pipe connection head 1-1 in a state where the clamping member 4 is fastened. A gap 5 is provided between the tapered surface 2-3c on the upper end side of the sleeve 2-3 with the tapered surface and the sheet surface 3a of the mating member 3. In this connection structure, the depth h of the high pressure fuel injection pipe connection head 1-1 into the tapered sleeve 2-3 is 1/6 to 1/3 of the wall thickness W of the sleeve. ing.

図４に示す第４実施例に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、内周面に２個の環状突起２−４ａを形成したテーパ面付きスリーブ２−４を用いた以外は前記図３に示すものと同様の構成となしたもので、外周面に肉厚と向きの異なる凸状のテーパ面２−４ｂ、２−４ｃを有し、かつ内周面に２個の環状突起２−４ａを有するテーパ面付きスリーブ２−４を高圧燃料噴射管１の頭部に外嵌した状態で当該スリーブを径方向内方に押圧して環状突起２−４ａを高圧燃料噴射管接続頭部１−１の外周面に食い込ませて固着し、高圧燃料噴射管１の接続頭部１−１のシート面１−１ａに相手部材３のシート面３ａを当接係合させた状態で、予め高圧燃料噴射管１に組込んだ締付けナット４を相手部材３に螺着し締付けることによって、高圧燃料噴射管１の接続頭部１−１のシート面１−１ａと相手部材３のシート面３−１ａとが圧接して接続構成されたものである。この接続構造の場合も前記の接続構造と同様、高圧燃料噴射管接続頭部１−１と相手部材３とを締付けナット４により締結した状態において、高圧燃料噴射管接続頭部１−１に固着したテーパ面付きスリーブ２−４の上端側テーパ面２−４ｃと相手部材３のシート面３ａとの間に隙間５を有し、かつ高圧燃料噴射管接続頭部１−１の前記テーパ面付きスリーブ２−４への食い込み深さｈは、当該スリーブの肉厚Ｗの１／６〜１／３となっている。   The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the fourth embodiment shown in FIG. 4 is the same as that described above except that the tapered sleeve 2-4 having two annular protrusions 2-4a formed on the inner peripheral surface is used. 3 has the same configuration as that shown in FIG. 3 and has convex tapered surfaces 2-4b and 2-4c having different thicknesses and directions on the outer peripheral surface, and two annular protrusions on the inner peripheral surface. The sleeve 2-4 having a tapered surface having 2-4a is externally fitted to the head of the high pressure fuel injection pipe 1, and the sleeve is pressed radially inward to connect the annular protrusion 2-4a to the high pressure fuel injection pipe connection head. In the state where the outer peripheral surface of the part 1-1 is bitten and fixed, and the seat surface 3a of the mating member 3 is in contact with and engaged with the seat surface 1-1a of the connection head 1-1 of the high-pressure fuel injection pipe 1. By tightening the tightening nut 4 previously assembled in the high pressure fuel injection pipe 1 to the mating member 3 by screwing. , In which the seat surface 3-1a of the seat surface 1-1a and the mating member 3 of the connecting head 1-1 high-pressure fuel injection pipe 1 is connected constituted by welding. In the case of this connection structure as well, the high pressure fuel injection pipe connection head 1-1 and the mating member 3 are fastened to the high pressure fuel injection pipe connection head 1-1 in a state where the clamping member 4 is fastened. A gap 5 is provided between the tapered surface 2-4c of the tapered sleeve 2-4 and the seat surface 3a of the mating member 3, and the tapered surface of the high pressure fuel injection pipe connection head 1-1 is provided. The biting depth h into the sleeve 2-4 is 1/6 to 1/3 of the thickness W of the sleeve.

図５に示す第５実施例に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、高圧燃料噴射管接続頭部１−１と相手部材３とを締付けナット４により締結した状態において、前記高圧燃料噴射管接続頭部１−１に固着した筒形スリーブ２−５の端部が当該接続頭部外周面と相手部材のシート面にくさび状に食い込み圧入されて、該筒形スリーブの端部と相手部材のシート面との間に隙間を有しない接続構造となしている以外は、前記図１に示す接続構造と同じ構成である。すなわち、内周面に浅く滑らかな環状凹部２−５ａを有する筒形スリーブ２−５を高圧燃料噴射管１の頭部に外嵌した状態で該高圧燃料噴射管１の接続頭部１−１内径をプレス膨出加工にて拡径して前記スリーブ２−５の環状凹部２−５ａに高圧燃料噴射管接続頭部外周面を食い込ませて固着すると同時に、当該スリーブの先端部を断面くさび状２−５ｃに形成した状態で、高圧燃料噴射管１の接続頭部１−１のシート面１−１ａに相手部材３のシート面３ａを当接係合させるとともに、予め高圧燃料噴射管１に組込んだ締付けナット４を相手部材３に螺着し締付けると、締付けナット４の内底面４ａが前記筒形スリーブ２−５の下端２−５ｂに係止することによって当該筒形スリーブ２−５を介して高圧燃料噴射管１の接続頭部１−１のシート面１−１ａと相手部材３のシート面３−１ａとが圧接して接続構成されたものである。この接続構造の場合は、前記したごとく高圧燃料噴射管接続頭部１−１と相手部材３とを締付けナット４により締結した状態において、筒形スリーブ２−５の先端部の断面くさび状２−５ｃの部分が前記シート面に食い込むように嵌入されるため、高圧燃料噴射管接続頭部１−１に固着した筒形スリーブ２−５の端部と相手部材３のシート面との間に隙間を有しない構造となしている。なお、かかる接続構造における高圧燃料噴射管接続頭部１−１の前記筒形スリーブ２−５への食い込み深さｈも、当該スリーブの肉厚Ｗの１／６〜１／３となっている。   The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the fifth embodiment shown in FIG. 5 is the above-described high-pressure fuel in a state where the high-pressure fuel injection pipe connection head 1-1 and the mating member 3 are fastened by the fastening nut 4. The end of the cylindrical sleeve 2-5 fixed to the jet pipe connecting head 1-1 is wedged and press-fitted into the outer peripheral surface of the connecting head and the seat surface of the mating member, and the end of the cylindrical sleeve The structure is the same as the connection structure shown in FIG. 1 except that the connection structure does not have a gap between the mating member and the sheet surface. That is, the connecting head 1-1 of the high-pressure fuel injection pipe 1 in a state where a cylindrical sleeve 2-5 having a shallow and smooth annular recess 2-5a on the inner peripheral surface is fitted on the head of the high-pressure fuel injection pipe 1. The inner diameter of the sleeve 2-5 is expanded by press bulging so that the outer peripheral surface of the high-pressure fuel injection pipe connection head bites into and adheres to the annular recess 2-5a of the sleeve 2-5. 2-5c, the seat surface 3a of the mating member 3 is brought into contact with and engaged with the seat surface 1-1a of the connection head 1-1 of the high-pressure fuel injection pipe 1, and the high-pressure fuel injection pipe 1 is previously connected. When the assembled tightening nut 4 is screwed onto the mating member 3 and tightened, the inner bottom surface 4a of the tightening nut 4 is engaged with the lower end 2-5b of the tubular sleeve 2-5, thereby the cylindrical sleeve 2-5. The connection head 1-1 of the high-pressure fuel injection pipe 1 through A seat surface 3-1a of up surface 1-1a and the mating member 3 are those that are connected constituted by welding. In the case of this connection structure, in the state in which the high pressure fuel injection pipe connection head 1-1 and the mating member 3 are fastened by the fastening nut 4 as described above, the cross-sectional wedge shape 2- Since the portion 5c is inserted so as to bite into the seat surface, there is a gap between the end of the cylindrical sleeve 2-5 fixed to the high pressure fuel injection pipe connecting head 1-1 and the seat surface of the mating member 3. It has a structure that does not have. In this connection structure, the depth h of the high pressure fuel injection pipe connection head 1-1 into the cylindrical sleeve 2-5 is also 1/6 to 1/3 of the wall thickness W of the sleeve. .

図６に示す第６実施例に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、高圧燃料噴射管接続頭部１−１と相手部材３とを締付けナット４により締結した状態において、前記高圧燃料噴射管接続頭部１−１に固着したテーパ面付きスリーブ２−６の端部が当該接続頭部外周面と相手部材のシート面にくさび状に食い込み圧入されて、該スリーブの端部と相手部材のシート面との間に隙間を有しない接続構造となしている以外は、前記図２に示す接続構造と同じ構成となしたものである。すなわち、外周面に凸状のテーパ面２−６ｂを有し、かつ内周面に環状溝２−６ａを有するテーパ面付きスリーブ２−６を高圧燃料噴射管１の頭部に外嵌した状態で該高圧燃料噴射管１の接続頭部１−１内径をプレス膨出加工にて拡径して前記スリーブ２−６の環状溝２−６ａに高圧燃料噴射管接続頭部１−１の外周面を食い込ませて固着すると同時に、当該スリーブの先端部を断面くさび状２−６ｃに形成した状態で、高圧燃料噴射管１の接続頭部１−１のシート面１−１ａに相手部材３のシート面３ａを当接係合させるとともに、予め高圧燃料噴射管１に組込んだ締付けナット４を相手部材３に螺着し締付けると、締付けナット４の内底面４ａが前記テーパ面付きスリーブ２−６の下端側テーパ面２−６ｂに係止することによって当該テーパ面付きスリーブ２−６を介して高圧燃料噴射管１の接続頭部１−１のシート面１−１ａと相手部材３のシート面３ａとが圧接すると同時に、テーパ面付きスリーブ２−６の先端部の断面くさび状２−６ｃの部分が当該シートに食い込むように嵌入されることにより、テーパ面付きスリーブ２−６の端部と相手部材３のシート面３ａとの間に隙間を有しないように接続構成されたものである。なお、かかる接続構造における高圧燃料噴射管接続頭部１−１の前記筒形スリーブ２−１への食い込み深さｈも、当該スリーブの肉厚Ｗの１／６〜１／３となっている。   The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the sixth embodiment shown in FIG. 6 is the above-described high-pressure fuel in a state where the high-pressure fuel injection pipe connection head 1-1 and the mating member 3 are fastened by the fastening nut 4. The end of the sleeve 2-6 with the tapered surface fixed to the jet pipe connecting head 1-1 is bitten and pressed into the outer peripheral surface of the connecting head and the seat surface of the mating member. The connection structure shown in FIG. 2 is the same as that shown in FIG. 2 except that the connection structure has no gap between the member and the sheet surface. In other words, a sleeve 2-6 with a tapered surface having a convex tapered surface 2-6b on the outer peripheral surface and an annular groove 2-6a on the inner peripheral surface is externally fitted to the head of the high-pressure fuel injection pipe 1 Then, the inner diameter of the connection head 1-1 of the high-pressure fuel injection pipe 1 is expanded by press bulging, and the outer periphery of the high-pressure fuel injection pipe connection head 1-1 is inserted into the annular groove 2-6a of the sleeve 2-6. At the same time that the surface is bitten and fixed, the tip of the sleeve is formed in a wedge shape 2-6c in cross section, and the mating member 3 is attached to the seat surface 1-1a of the connection head 1-1 of the high-pressure fuel injection pipe 1. When the seat surface 3a is brought into contact with and engaged, and the fastening nut 4 previously assembled in the high-pressure fuel injection pipe 1 is screwed into the mating member 3 and fastened, the inner bottom surface 4a of the fastening nut 4 becomes the sleeve 2 with the tapered surface. 6 on the lower end side taper surface 2-6b. The sheet surface 1-1a of the connection head 1-1 of the high-pressure fuel injection pipe 1 and the sheet surface 3a of the mating member 3 are in pressure contact with each other via the sleeve 2-6 with a tapered surface, and at the same time, the sleeve 2-6 with a tapered surface By inserting the wedge-shaped section 2-6c of the tip portion so as to bite into the sheet, there is no gap between the end of the sleeve 2-6 with the tapered surface and the sheet surface 3a of the mating member 3. The connection configuration is as described above. In this connection structure, the depth h of the high pressure fuel injection pipe connection head 1-1 into the cylindrical sleeve 2-1 is also 1/6 to 1/3 of the thickness W of the sleeve. .

図７に示す第７実施例に係るディーゼルエンジン用高圧燃料噴射管の接続構造は、高圧燃料噴射管１として、管内に薄肉のオーステナイト系ステンレス鋼製の内管１ｉを密嵌状に内装した二重管からなる厚肉鋼管を用い、該噴射管の接続頭部１−１の先端部を覆うように前記ステンレス鋼製の内管１ｉの先端部を外側に折り曲げてシート面１−１ａを形成した以外は、前記図１に示す接続構造と同じ構成となしたものである。したがって、この接続構造の場合は、ステンレス鋼製の内管１ｉで形成されたシート面の作用により、高温高圧の燃料に対する気密が強固に維持されるのみならず、燃料との接液部分には鉄系材料の露出部が存在せず、その優れた防錆能が得られる。   The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the seventh embodiment shown in FIG. 7 is a high-pressure fuel injection pipe 1 in which a thin austenitic stainless steel inner pipe 1i is housed in a tight fit. Using a thick steel pipe made of a heavy pipe, the front end of the inner pipe 1i made of stainless steel is bent outward so as to cover the front end of the connection head 1-1 of the injection pipe to form the sheet surface 1-1a. Except for the above, the connection structure is the same as that shown in FIG. Therefore, in the case of this connection structure, not only is the air tightness against the high-temperature and high-pressure fuel maintained firmly by the action of the seat surface formed by the inner tube 1i made of stainless steel, There is no exposed portion of the iron-based material, and the excellent antirust ability is obtained.

次に、本発明に係るディーゼルエンジン用高圧燃料噴射管の接続構造を得るためのスリーブの固着方法を図８〜図１１に基づいて説明する。
まず、図８に示すスリーブの固着方法は、前記図１に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応する筒形スリーブ２−１の固着方法を例示したもので、内周面に浅く滑らかな環状凹部２−１ａを有する筒形スリーブ２−１を高圧燃料噴射管１の接続頭部１−１に当該接続頭部の先端部をのぞかせた状態で外嵌して下型６Ａにてチャッキングしてセットし、この状態で高圧燃料噴射管１の接続頭部１−１の先端を上型７Ａ（パンチ）にて管軸方向（矢印Ｐ１で示す）にプレスする。このプレス加工により、高圧燃料噴射管１の接続頭部１−１は管が管軸方向に縮むことにより外側に膨出して拡径されると同時に、当該接続頭部の外周面が前記筒形スリーブ２−１の環状凹部２−１ａに食い込んで相互に密着して該接続頭部１−１に筒形スリーブ２−１が固着される。 Next, a method for fixing a sleeve for obtaining a connection structure for a high-pressure fuel injection pipe for a diesel engine according to the present invention will be described with reference to FIGS.
First, the fixing method of the sleeve shown in FIG. 8 is an example of the fixing method of the cylindrical sleeve 2-1 corresponding to the connection structure of the high-pressure fuel injection pipe for a diesel engine shown in FIG. 1, and is shallow on the inner peripheral surface. A cylindrical sleeve 2-1 having a smooth annular recess 2-1a is externally fitted to the connecting head 1-1 of the high-pressure fuel injection pipe 1 with the tip of the connecting head being looked over by the lower die 6A. In this state, the tip of the connection head 1-1 of the high-pressure fuel injection pipe 1 is pressed by the upper die 7A (punch) in the pipe axis direction (indicated by the arrow P1). As a result of this pressing, the connection head 1-1 of the high-pressure fuel injection pipe 1 expands and expands outward as the pipe contracts in the tube axis direction, and at the same time, the outer peripheral surface of the connection head has the cylindrical shape. The cylindrical sleeve 2-1 is fixed to the connecting head 1-1 by biting into the annular recess 2-1a of the sleeve 2-1 and closely contacting each other.

図９に示すスリーブの固着方法は、前記図２に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応する筒形スリーブ２−１の固着方法を例示したもので、内周面に環状溝２−２ａを有するテーパ面付きスリーブ２−２を高圧燃料噴射管１の接続頭部１−１に当該接続頭部の先端部をのぞかせた状態で外嵌して下型６Ｂにセットし、この状態で高圧燃料噴射管１の接続頭部１−１の先端を上型７Ｂ（パンチ）にて管軸方向（矢印Ｐ１で示す）にプレスすると、高圧燃料噴射管１の接続頭部１−１は管が管軸方向に縮むことにより外側に膨出して拡径されると同時に、当該接続頭部の外周面が前記筒形スリーブ２−２の環状溝２−２ａ内に食い込んで相互に密着して該接続頭部１−１に筒形スリーブ２−１が固着される。   The sleeve fixing method shown in FIG. 9 is an example of the cylindrical sleeve 2-1 fixing method corresponding to the connection structure of the high-pressure fuel injection pipe for a diesel engine shown in FIG. -2a and a sleeve 2-2 with a tapered surface is externally fitted to the connection head 1-1 of the high-pressure fuel injection pipe 1 with the tip of the connection head being looked over, and is set in the lower die 6B. When the tip of the connection head 1-1 of the high pressure fuel injection pipe 1 is pressed in the tube axis direction (indicated by arrow P1) with the upper die 7B (punch), the connection head 1-1 of the high pressure fuel injection pipe 1 is When the tube contracts in the tube axis direction, the tube swells outward and expands in diameter, and at the same time, the outer peripheral surface of the connection head bites into the annular groove 2-2a of the cylindrical sleeve 2-2 and adheres to each other. Thus, the cylindrical sleeve 2-1 is fixed to the connection head 1-1.

図１０に示すスリーブの固着方法は、前記図２に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの他の固着方法を例示したもので、この実施例は、高圧燃料噴射管１の接続頭部１−１の外周に環状突起１−２を形成し、この環状突起１−２を囲むように内面フラットのテーパ面付きスリーブ２−２を高圧燃料噴射管１の接続頭部１−１の外周に当該接続頭部１−１の先端部をのぞかせた状態で外嵌し、その外側にセットした前記テーパ面付きスリーブ２−２の断面形状に対応するごとく形成した横型８Ａにて径方向内方（矢印Ｐ２で示す）に押圧しながら当該横型を回転させて前記環状突起１−２を縮径して高圧燃料噴射管１の接続頭部１−１の外周に食い込ませて固着させる方法である。   The sleeve fixing method shown in FIG. 10 exemplifies another fixing method of the sleeve corresponding to the connection structure of the high-pressure fuel injection pipe for a diesel engine shown in FIG. 2, and in this embodiment, the high-pressure fuel injection pipe 1 An annular protrusion 1-2 is formed on the outer periphery of the connection head 1-1, and a tapered sleeve 2-2 having a flat inner surface is connected to the connection head 1 of the high-pressure fuel injection pipe 1 so as to surround the annular protrusion 1-2. -1 is externally fitted in a state where the tip of the connection head 1-1 is looked into the outer periphery of -1, and is formed so as to correspond to the cross-sectional shape of the sleeve 2-2 with the tapered surface set on the outer side. While rotating radially inward (indicated by an arrow P2), the horizontal mold is rotated to reduce the diameter of the annular protrusion 1-2, so that the outer periphery of the connection head 1-1 of the high-pressure fuel injection pipe 1 is caught and fixed. It is a method to make it.

図１１に示すスリーブの固着方法は、前記図３、図４に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの他の固着方法を例示したもので、内周面に環状突起２−３ａを形成したテーパ面付きスリーブ２−３を高圧燃料噴射管１の接続頭部１−１に当該接続頭部の先端部をのぞかせた状態で外嵌し、その外側にセットした前記テーパ面付きスリーブ２−３の断面形状に対応するごとく形成した横型８Ｂにて径方向内方（矢印Ｐ２で示す）に押圧しながら当該横型を回転させて前記環状突起２−３ａを縮径して高圧燃料噴射管１の接続頭部１−１の外周に食い込ませて固着させる方法である。なお、前記環状突起２−３ａは複数個設けてもよいことはいうまでもない。   The sleeve fixing method shown in FIG. 11 exemplifies another fixing method of the sleeve corresponding to the connection structure of the high-pressure fuel injection pipe for a diesel engine shown in FIG. 3 and FIG. The tapered surface 2-3 is formed by fitting a sleeve 2-3 with a tapered surface to the connection head 1-1 of the high-pressure fuel injection pipe 1 in a state where the tip of the connection head is viewed, and setting the outer surface of the connection head 1-1. The horizontal mold 8B formed as corresponding to the cross-sectional shape of the attached sleeve 2-3 is rotated inward in the radial direction (indicated by the arrow P2) while rotating the horizontal mold to reduce the diameter of the annular protrusion 2-3a and increase the pressure. In this method, the fuel injection pipe 1 is stuck into the outer periphery of the connection head 1-1. Needless to say, a plurality of the annular protrusions 2-3a may be provided.

本発明のディーゼルエンジン用高圧燃料噴射管の接続構造は、スリーブを高圧燃料噴射管接続頭部に固着する手段として、高圧燃料噴射管の接続頭部内径をプレス膨出加工にて拡径してスリーブの環状凹部に高圧燃料噴射管接続頭部外周面を食い込ませて固着せしめる方式、あるいは前記スリーブの内周面に環状溝を形成し、該環状溝に高圧燃料噴射管接続頭部の外周面を食い込ませるプレス膨出加工方式、あるいは高圧燃料噴射管接続頭部外周に環状突起を形成し、かしめ工法によりスリーブを径方向にプレスしてスリーブ内周面に前記環状突起を食い込ませる方式、あるいは前記スリーブの内周面に１または複数個の環状突起を形成し、該環状突起を高圧燃料噴射管接続頭部の外周面に食い込ませる方式等を採用したことにより、噴射管接続頭部にポケットをほとんど形成することなくスリーブを強固に固着することができるので、亀裂や皺を起点とする疲労割れを引き起こすことがなくなり、高い気密性と優れた疲労強度が得られる。また、本発明はディーゼルエンジン用高圧燃料噴射管の接続構造のみならず、一般の各種高圧配管の接続構造にも十分に適用可能である。   The connection structure of the high-pressure fuel injection pipe for a diesel engine according to the present invention is such that the inner diameter of the connection head of the high-pressure fuel injection pipe is expanded by press bulging as a means for fixing the sleeve to the connection head of the high-pressure fuel injection pipe. A system in which the outer peripheral surface of the high pressure fuel injection pipe connecting head bites into the annular concave portion of the sleeve, or an annular groove is formed in the inner peripheral surface of the sleeve, and the outer peripheral surface of the high pressure fuel injection pipe connecting head is formed in the annular groove Press bulge processing method to bite in, or a method in which an annular protrusion is formed on the outer periphery of the high pressure fuel injection pipe connection head, and the sleeve is radially pressed by a caulking method to cause the annular protrusion to bite into the sleeve inner peripheral surface, or By adopting a system or the like in which one or a plurality of annular protrusions are formed on the inner peripheral surface of the sleeve and the annular protrusions are bitten into the outer peripheral surface of the high pressure fuel injection pipe connecting head. Since the sleeve without having to almost form a pocket in connection head can be firmly fixed, no longer can cause fatigue cracks originating from the cracks and wrinkles, high air-tightness and excellent fatigue strength can be obtained. Further, the present invention can be sufficiently applied not only to the connection structure of high-pressure fuel injection pipes for diesel engines but also to the connection structure of various general high-pressure pipes.

本発明に係るディーゼルエンジン用高圧燃料噴射管の接続構造の第１実施例を示す断面図である。It is sectional drawing which shows 1st Example of the connection structure of the high pressure fuel injection pipe for diesel engines which concerns on this invention. 同じく接続構造の第２実施例を示す断面図である。It is sectional drawing which similarly shows 2nd Example of a connection structure. 同じく接続構造の第３実施例を示す断面図である。It is sectional drawing which similarly shows 3rd Example of a connection structure. 同じく接続構造の第４実施例を示す断面図である。It is sectional drawing which similarly shows 4th Example of a connection structure. 同じく接続構造の第５実施例を示す断面図である。It is sectional drawing which similarly shows 5th Example of a connection structure. 同じく接続構造の第６実施例を示す断面図である。It is sectional drawing which similarly shows 6th Example of a connection structure. 同じく接続構造の第７実施例を示す断面図である。It is sectional drawing which similarly shows 7th Example of a connection structure. 図１に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの固着方法の一例を示す断面図である。It is sectional drawing which shows an example of the adhering method of the sleeve corresponding to the connection structure of the high pressure fuel injection pipe for diesel engines shown in FIG. 図２に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの固着方法の一例を示す断面図である。It is sectional drawing which shows an example of the adhering method of the sleeve corresponding to the connection structure of the high pressure fuel injection pipe for diesel engines shown in FIG. 図２に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの他の固着方法を示す断面図である。It is sectional drawing which shows the other adhering method of the sleeve corresponding to the connection structure of the high pressure fuel injection pipe for diesel engines shown in FIG. 図３に示すディーゼルエンジン用高圧燃料噴射管の接続構造に対応するスリーブの固着方法の一例を示す断面図である。It is sectional drawing which shows an example of the adhering method of the sleeve corresponding to the connection structure of the high pressure fuel injection pipe for diesel engines shown in FIG. 本発明の対象とする従来のディーゼルエンジン用高圧燃料噴射管の接続構造の一例を示す断面図である。It is sectional drawing which shows an example of the connection structure of the conventional high pressure fuel injection pipe for diesel engines made into the object of this invention. 同じく従来のディーゼルエンジン用高圧燃料噴射管の接続構造の他の例を示す断面図である。It is sectional drawing which similarly shows the other example of the connection structure of the conventional high pressure fuel injection pipe for diesel engines.

符号の説明Explanation of symbols

１ 高圧燃料噴射管
１ｉ 内管
１−１ａ、３ａ シート面
１−１ｂ 膨出部
２−１〜２−５ スリーブ
２−１ａ、２−５ａ 環状凹部
２−２ａ、２−６ａ 環状溝
１−２、２−３ａ、２−４ａ 環状突起
３ 相手部材
４ 締付けナット
５ 隙間
６Ａ、６Ｂ 下型
７Ａ、７Ｂ 上型
８Ａ、８Ｂ 横型

DESCRIPTION OF SYMBOLS 1 High pressure fuel injection pipe 1i Inner pipe | tube 1-1a, 3a Seat surface 1-1b Swelling part 2-1 to 2-5 Sleeve 2-1a, 2-5a Annular recessed part 2-2a, 2-6a Annular groove 1-2 2-3a, 2-4a annular projection 3 mating member 4 tightening nut 5 gap 6A, 6B lower mold 7A, 7B upper mold 8A, 8B horizontal type

Claims (10)

高圧燃料噴射管の接続頭部に別体のスリーブが外嵌固着され、該スリーブに外嵌した締付けナットをもって相手部材と螺着して締結されたディーゼルエンジン用高圧燃料噴射管の接続構造において、前記別体のスリーブを高圧燃料噴射管の頭部に外嵌した状態でプレス膨出加工法またはかしめ工法により該高圧燃料噴射管頭部外周に固着したことを特徴とするディーゼルエンジン用高圧燃料噴射管の接続構造。   In a connection structure of a high-pressure fuel injection pipe for a diesel engine, a separate sleeve is externally fixed to the connection head of the high-pressure fuel injection pipe, and is screwed to a mating member with a fastening nut externally fitted to the sleeve. A high-pressure fuel injection for a diesel engine, characterized in that the separate sleeve is fixed to the outer periphery of the high-pressure fuel injection pipe head by a press bulging method or a caulking method in a state where the separate sleeve is fitted over the head of the high-pressure fuel injection pipe. Tube connection structure. 前記プレス膨出加工法により前記スリーブを高圧燃料噴射管接続頭部に固着する手段として、前記別体のスリーブ内周面に浅く滑らかな環状凹部を形成し、該スリーブを高圧燃料噴射管の頭部に外嵌した状態で該高圧燃料噴射管の接続頭部をプレス膨出加工にて拡径して前記スリーブの環状凹部に高圧燃料噴射管接続頭部外周面を食い込ませて固着せしめる方式を用いることを特徴とする請求項１に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。   As a means for fixing the sleeve to the high pressure fuel injection pipe connecting head by the press bulging method, a shallow and smooth annular recess is formed on the inner peripheral surface of the separate sleeve, and the sleeve is connected to the head of the high pressure fuel injection pipe. A method of expanding the diameter of the connecting head of the high-pressure fuel injection pipe by press bulging with the outer periphery of the sleeve being fitted, and causing the outer circumferential surface of the connecting head of the high-pressure fuel injection pipe to bite into the annular recess of the sleeve The connection structure for a high-pressure fuel injection pipe for a diesel engine according to claim 1, wherein the connection structure is used. 前記プレス膨出加工法により前記スリーブを高圧燃料噴射管接続頭部に固着する手段として、当該スリーブの内周面に環状溝を形成し、該環状溝に高圧燃料噴射管接続頭部の外周面を食い込ませる方式を用いることを特徴とする請求項１に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。   As a means for fixing the sleeve to the high pressure fuel injection pipe connecting head by the press bulging method, an annular groove is formed in the inner peripheral surface of the sleeve, and the outer peripheral surface of the high pressure fuel injection pipe connecting head is formed in the annular groove. The connection structure for a high-pressure fuel injection pipe for a diesel engine according to claim 1, wherein a system for biting is used. 前記かしめ工法により前記スリーブを高圧燃料噴射管接続頭部に固着する手段として、高圧燃料噴射管接続頭部外周に環状突起を形成し、前記スリーブを高圧燃料噴射管の頭部に外嵌した状態で該スリーブを径方向にプレスして前記環状突起をスリーブ内周面に食い込ませる方式を用いることを特徴とする請求項１に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。   As a means for adhering the sleeve to the high pressure fuel injection pipe connection head by the caulking method, an annular protrusion is formed on the outer periphery of the high pressure fuel injection pipe connection head, and the sleeve is externally fitted to the head of the high pressure fuel injection pipe 2. The connection structure for a high-pressure fuel injection pipe for a diesel engine according to claim 1, wherein a method is used in which the sleeve is pressed in a radial direction so that the annular protrusion is bitten into the inner peripheral surface of the sleeve. 前記かしめ工法により前記スリーブを高圧燃料噴射管接続頭部に固着する手段として、当該スリーブの内周面に１または複数個の環状突起を形成し、該環状突起を高圧燃料噴射管接続頭部の外周面に食い込ませる方式を用いることを特徴とする請求項４に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。   As a means for fixing the sleeve to the high pressure fuel injection pipe connection head by the caulking method, one or a plurality of annular protrusions are formed on the inner peripheral surface of the sleeve, and the annular protrusion is formed on the high pressure fuel injection pipe connection head. The connection structure for a high-pressure fuel injection pipe for a diesel engine according to claim 4, wherein a method of biting into the outer peripheral surface is used. 前記スリーブの高圧燃料噴射管接続頭部への食い込み深さｈまたは高圧燃料噴射管接続頭部外周面の前記スリーブへの食い込み深さｈが、当該スリーブの肉厚Ｗの１／６〜１／３であることを特徴とする請求項２乃至５のいずれか１項に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。   The biting depth h of the sleeve into the high pressure fuel injection pipe connection head or the biting depth h of the outer periphery of the high pressure fuel injection pipe connection head into the sleeve is 1/6 to 1/1 of the wall thickness W of the sleeve. The connection structure for a high-pressure fuel injection pipe for a diesel engine according to any one of claims 2 to 5, wherein the connection structure is 3. 前記高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に固着したスリーブの端部と前記相手部材受圧座面との間に隙間を有することを特徴とする請求項１乃至６のいずれか１項に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。   In a state where the high pressure fuel injection pipe connection head and the mating member are fastened by a tightening nut, there is a gap between the end of the sleeve fixed to the high pressure fuel injection pipe connection head and the mating member pressure receiving seat surface. The connection structure for a high-pressure fuel injection pipe for a diesel engine according to any one of claims 1 to 6. 前記高圧燃料噴射管接続頭部と相手部材とを締付けナットにより締結した状態において、前記高圧燃料噴射管接続頭部に固着したスリーブの端部が当該接続頭部外周面と相手部材の受圧座面にくさび状に食い込み圧入されていることを特徴とする請求項１乃至６のいずれか１項に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。   In a state where the high pressure fuel injection pipe connecting head and the mating member are fastened by a tightening nut, the end of the sleeve fixed to the high pressure fuel injection pipe connecting head is the connecting head outer peripheral surface and the pressure receiving seating surface of the mating member. The connection structure for a high-pressure fuel injection pipe for a diesel engine according to any one of claims 1 to 6, wherein the connection structure is bitten and pressed into a wedge shape. 前記高圧燃料噴射管接続頭部外周に固着するスリーブは、当該接続頭部に固着後該高圧燃料噴射管の抗張力の少なくとも２０％以上の抗張力を有することを特徴とする請求項１乃至８のいずれか１項に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。   9. The sleeve according to claim 1, wherein the sleeve fixed to the outer periphery of the connection head of the high-pressure fuel injection pipe has a tensile strength that is at least 20% or more of the tensile strength of the high-pressure fuel injection pipe after being fixed to the connection head. 2. A connection structure for a high-pressure fuel injection pipe for a diesel engine according to claim 1. 前記高圧燃料噴射管として、管内に薄肉のオーステナイト系ステンレス鋼製の内管を密嵌状に内装した二重管からなる厚肉鋼管を用い、該噴射管の接続頭部の先端部を覆うように前記ステンレス鋼製の内管の先端部を外側に折り曲げてシート面を形成したことを特徴とする請求項１乃至９のいずれか１項に記載のディーゼルエンジン用高圧燃料噴射管の接続構造。

As the high-pressure fuel injection pipe, a thick-walled steel pipe made of a double pipe in which a thin-walled austenitic stainless steel inner pipe is housed in a tight fitting manner is used to cover the tip of the connecting head of the injection pipe. The connecting structure for a high-pressure fuel injection pipe for a diesel engine according to any one of claims 1 to 9, wherein a seat surface is formed by bending the tip of the inner pipe made of stainless steel outward.

JP2005380307A 2005-12-28 2005-12-28 Connection structure of high pressure fuel injection pipe for diesel engine Pending JP2007177777A (en)

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CN117028389A (en) * 2023-10-10 2023-11-10 太原理工大学 Full thread riveted shear fastener and method of use thereof

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CN117028389B (en) * 2023-10-10 2024-01-26 太原理工大学 Full thread riveted shear fastener and method of use thereof

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