JP4260449B2

JP4260449B2 - Common rail

Info

Publication number: JP4260449B2
Application number: JP2002275516A
Authority: JP
Inventors: 隆一草薙
Original assignee: Usui Co Ltd
Current assignee: Usui Co Ltd
Priority date: 2002-09-20
Filing date: 2002-09-20
Publication date: 2009-04-30
Anticipated expiration: 2022-09-20
Also published as: JP2004108338A

Description

【０００１】
【発明の属する技術分野】
本発明は、一般にディーゼル内燃機関あるいはガソリン内燃機関の蓄圧式燃料噴射システムにおけるコモンレールに関するものである。
【０００２】
【従来の技術】
この種のコモンレールは、内部に加圧燃料を蓄える流通路を備えた長尺円筒状の本管レールからなるものが多いが、図３および図４に示すように、短尺円筒状の本管レールで構成されたものもある。このタイプのコモンレールは、略平らなあるいは球面状（図示せず）の天井壁１１を有しかつ側壁の複数箇所にボス部１２を有する短尺の円筒体からなる本管レール１０と、この本管レール１０に螺合された底壁１３とからなり、円筒体１０内に偏平状空間をなす流通路１４が形成され、前記各ボス部１２に、本管レール１０の流通路１４に通じかつ外方に開口する受圧座面１６を有する分岐孔１５が穿設され、各ボス部の外周に形成された雄ねじ１２−１に供給パイプやインジェクションパイプ（図示せず）が螺合されるごとくなし、本管レール１０の底壁１３側の他端に固定用ブラケット１７が一体に設けられた構造となしている。
【０００３】
【発明が解決しようとする課題】
しかし、図３および図４に示す従来のコモンレールは、専用素材を型鍛造により製造し流路、分岐継ぎ手部、ブラケット部等を機械加工して製品となすため、以下に記載する問題点があった。
すなわち、型鍛造による一体成形により専用素材を作製するため、高強度で高価な金型を必要とし、さらにこの専用素材を機械加工にて仕上げるため加工時間が長くかかること、成形性を良くするため素材を高温に加熱する必要があり、加熱に要するエネルギーを必要とすること、熱間加工のため強固な酸化スケールが発生し、ショットブラストや酸洗等の後処理が必要であること、製造コストが高くつくこと等の問題があった。
【０００４】
本発明は従来技術の有する前記問題点を解決するためになされたもので、型鍛造等による一体成形方式に替えて、コモンレール全体を別部材で構成しかつそれらを接合にて一体に組立てる方式を採用することにより、製造コストが安価につく高品質のコモンレールを提供しようとするものである。
【０００５】
【課題を解決するための手段】
本発明に係るコモンレールは、厚肉の管体からなる短尺の胴体部と、該胴体部の両端開口部に内嵌されかつ好ましくはかしめた状態をもって相互に接合されたキャップと、胴体部の一端に外嵌された状態をもって相互に接合された固定用フランジと、胴体部に穿設した貫孔に嵌挿されかつ相互に接合された分岐枝管もしくは分岐継手金具からなる分岐接続体とから構成され、前記胴体部は前記分岐継手金具が当該胴体部の長手方向に２個以上が取付けられない程度に短尺であることを特徴とするものである。また、前記厚肉の管体からなる短尺の胴体部は、先端側端部を絞って細径としてもよい。
【０００６】
本発明における胴体部には、厚肉鋼管の切断品を用いることができ、またキャップや固定用フランジには鋼板のプレス品等安価な部品を用いることができる。
【０００７】
また、各部品を相互に接合して一体に組立てる場合の接合手段としては、ろう付けまたは拡散接合等の手段を用いる。ろう付けには、銅ろう、銀ろう、ニッケルろう等の各種ろう材を使用することができる。なお、耐食性や耐久性を得るため、接合後コモンレール全体を亜鉛等でメッキあるいは塗装処理を施してもよい。
【０００８】
本発明において、厚肉の管体からなる短尺の胴体部の一端側を絞って細径としたのは、キャップの面積を小さくして接合部に生ずる内圧による応力を低減するためである。
【０００９】
【発明の実施の形態】
図１は本発明に係るコモンレールの一実施例を示す縦断面図、図２は同上コモンレールの他の実施例を示す縦断面図であり、１は胴体部、２、２Ｓはキャップ、３は分岐枝管、４は分岐継手金具（ニップル）、５は固定用フランジである。
【００１０】
コモンレールの本体である胴体部１は、内部を流通路１−１となして管内径φ８ｍｍ程度以上の圧力配管用炭素鋼鋼管あるいはステンレス鋼管等の厚肉鋼管材（肉厚３〜１０ｍｍ程度）からなるものである。そして、流通路１−１に通じて円周方向にわたる周壁部に間隔を保持して複数箇所での貫孔１−２を有している。貫孔１−２は、同一円周上もしくは軸方向に位置をずらして（図示せず）設ける。
【００１１】
キャップ２は、胴体部１の流通路１−１の両開口端部に内嵌し得る外径を有する。このキャップ２は、胴体部１を開口端をかしめて固定した後、胴体部１との接触部分を相互に接合して構成する。
【００１２】
分岐枝管３および分岐継手金具４は、それぞれ貫孔１−２に管径そのままの接続端部３−１、４−１を嵌挿した状態をもって胴体部１に相互に接合して接続構成するものであって、その際、前記貫孔１−２に分岐枝管３、分岐継手金具４のそれぞれの接続端部３−１、４−１を胴体部１の内周壁面より流通路１−１内部まで突出させた状態をもって相互に接合して構成する。
【００１３】
固定用フランジ５は、胴体部１に外嵌し得る内径を有し、胴体部１の基端側端部に外嵌した状態をもって胴体部１に相互に接合して接続構成する。５−１は取付けボルト孔である。
【００１４】
また、図２に示すコモンレールは、胴体部の一端側を絞って細径部１−３を形成したもので、その細径部１−３には小径のキャップ２Ｓを接合して構成する。
【００１５】
前記キャップ２、２Ｓ、固定用フランジ５、分岐接続体としての枝管３および分岐継手金具４は、胴体部１と同種鋼材もしくは各種鋼材からなるものである。３−２、４−２は流路、４−３は受圧座面、４−４は供給パイプやインジェクションパイプ（図示せず）を螺合して接続するための雄ねじである。
【００１６】
また、本願発明における胴体部１とキャップ２、２Ｓ、固定用フランジ５の接合手段および、枝管１２や分岐継手金具１４からなる分岐接続体の接合手段としては、銅接合、ニッケル接合などの炉中接合が好ましい。また、胴体部１の内外面や、貫孔１−２と分岐枝管３や分岐継手金具４からなる分岐接続体の表面を高精度に仕上げ前処理により活性化させた後、好ましくはさらにニッケルや銅などのめっき被膜を施した後、拡散温度に十分な時間保持して拡散接合する方法も可能である。
【００１７】
【発明の効果】
以上説明したごとく、本発明に係るコモンレールは、型鍛造等による一体成形方式に替えて、コモンレール全体を別部材で構成しかつそれらを接合にて一体に組立てるので、高強度で高価な金型を全く不要とし、また切削加工等の機械加工時間を大巾に短縮でき、さらに構成部品には厚肉鋼管の切断品や鋼板のプレス品等安価な部品を用いることができるので、従来品のように素材を高温に加熱する必要がなく、したがって加熱に要するエネルギーが不要となり、酸化スケール除去のためのショットブラストや酸洗等の後処理も不要となることにより、製造コストも安価につく等の効果を奏する。
【図面の簡単な説明】
【図１】本発明に係るコモンレールの一実施例を示す縦断面図である。
【図２】同上コモンレールの他の実施例を示す縦断面図である。
【図３】従来のコモンレールの一例を示す平面図である。
【図４】図３のＡーＡ線上の縦断面図である。
【符号の説明】
１胴体部
２、２Ｓキャップ
３分岐枝管
４分岐継手金具（ニップル）
５固定用フランジ[0001]
BACKGROUND OF THE INVENTION
The present invention generally relates to a common rail in an accumulator fuel injection system of a diesel internal combustion engine or a gasoline internal combustion engine.
[0002]
[Prior art]
This type of common rail is often composed of a long cylindrical main rail provided with a flow passage for storing pressurized fuel therein. However, as shown in FIGS. 3 and 4, a short cylindrical main rail is used. Some of them consisted of This type of common rail includes a main rail 10 having a short cylindrical body having a substantially flat or spherical (not shown) ceiling wall 11 and bosses 12 at a plurality of locations on the side wall, and the main rail. A flow path 14 is formed in the cylindrical body 10 to form a flat space. The boss portion 12 communicates with the flow path 14 of the main rail 10 and is externally formed. A branch hole 15 having a pressure-receiving seating surface 16 that opens in the direction is formed so that a supply pipe or an injection pipe (not shown) is screwed into a male screw 12-1 formed on the outer periphery of each boss portion. A fixing bracket 17 is integrally provided at the other end of the main rail 10 on the bottom wall 13 side.
[0003]
[Problems to be solved by the invention]
However, the conventional common rail shown in FIG. 3 and FIG. 4 has a problem described below because a dedicated material is manufactured by die forging and a flow path, a branch joint portion, a bracket portion, etc. are machined into a product. It was.
In other words, to produce a dedicated material by integral molding by die forging, a high-strength and expensive mold is required, and furthermore, this dedicated material is machined to take longer processing time and improve moldability The material needs to be heated to a high temperature, requires energy required for heating, a strong oxide scale is generated due to hot working, and post-treatment such as shot blasting and pickling is necessary, manufacturing cost There were problems such as being expensive.
[0004]
The present invention was made to solve the above-described problems of the prior art, and instead of an integral molding method such as die forging, the entire common rail is configured as a separate member and assembled integrally by joining them. By adopting it, we intend to provide a high-quality common rail that is inexpensive to manufacture.
[0005]
[Means for Solving the Problems]
A common rail according to the present invention includes a short body portion made of a thick tube, a cap that is fitted into both end openings of the body portion and preferably joined to each other in a crimped state, and one end of the body portion A fixing flange that is joined to each other in a state of being externally fitted to the body, and a branch connection body that includes a branch branch pipe or a branch joint fitting that is inserted into a through hole formed in the body portion and joined to each other. is, the body portion is characterized in short der Rukoto to the extent that the branch connection fitting is not more than two are mounted in the longitudinal direction of the body portion. Further, the short body portion formed of the thick tube body may have a small diameter by narrowing the end portion on the front end side.
[0006]
For the body portion in the present invention, a cut product of a thick steel pipe can be used, and for the cap and the fixing flange, inexpensive parts such as a pressed product of a steel plate can be used.
[0007]
Further, as a joining means when the parts are joined to each other and assembled together, means such as brazing or diffusion joining is used. Various brazing materials such as copper brazing, silver brazing, and nickel brazing can be used for brazing. In order to obtain corrosion resistance and durability, the entire common rail may be plated or painted with zinc or the like after joining.
[0008]
In the present invention, the one end side of the short body portion made of a thick tube is narrowed to have a small diameter in order to reduce the stress due to the internal pressure generated in the joint portion by reducing the area of the cap.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
1 is a longitudinal sectional view showing an embodiment of a common rail according to the present invention, FIG. 2 is a longitudinal sectional view showing another embodiment of the common rail, and 1 is a body portion, 2S is a cap, and 3 is a branch. A branch pipe, 4 is a branch joint fitting (nipple), and 5 is a fixing flange.
[0010]
The body portion 1 which is the main body of the common rail is formed from a thick-walled steel pipe material (wall thickness of about 3 to 10 mm) such as a carbon steel pipe for pressure piping or a stainless steel pipe having a pipe inner diameter of about 8 mm or more with the inside as a flow passage 1-1. It will be. And it has the through-hole 1-2 in several places, hold | maintaining space | interval in the surrounding wall part which leads to the flow path 1-1 and extends in the circumferential direction. The through holes 1-2 are provided on the same circumference or shifted in the axial direction (not shown).
[0011]
The cap 2 has an outer diameter that can be fitted into both opening end portions of the flow passage 1-1 of the body portion 1. The cap 2 is formed by fixing the body portion 1 by caulking the opening end and then joining the contact portions with the body portion 1 to each other.
[0012]
The branch branch pipe 3 and the branch joint fitting 4 are connected and configured to be joined to the body part 1 with the connection end parts 3-1 and 4-1 having the same pipe diameter inserted into the through holes 1-2. In this case, the connecting end portions 3-1 and 4-1 of the branch branch pipe 3 and the branch joint fitting 4 are connected to the through hole 1-2 from the inner peripheral wall surface of the body portion 1 through the flow passage 1-1. 1 are formed by joining to each other with the state protruding to the inside.
[0013]
The fixing flange 5 has an inner diameter that can be externally fitted to the body part 1, and is connected to the body part 1 by being connected to the body part 1 in a state of being externally fitted to the base end side end part of the body part 1. Reference numeral 5-1 denotes a mounting bolt hole.
[0014]
Further, the common rail shown in FIG. 2 is formed by narrowing one end side of the body portion to form a small-diameter portion 1-3, and a small-diameter cap 2S is joined to the small-diameter portion 1-3.
[0015]
The caps 2 and 2S, the fixing flange 5, the branch pipe 3 as the branch connection body, and the branch joint fitting 4 are made of the same steel material as the body portion 1 or various steel materials. 3-2 and 4-2 are flow paths, 4-3 is a pressure-receiving seat surface, and 4-4 is a male screw for screwing and connecting a supply pipe and an injection pipe (not shown).
[0016]
Further, as a joining means for the body portion 1 and the caps 2 and 2S, the fixing flange 5 and a joining means for the branch connection body including the branch pipe 12 and the branch joint metal fitting 14 in the present invention, furnaces such as copper joining and nickel joining are used. Middle joining is preferred. In addition, after activating the inner and outer surfaces of the body part 1 and the surface of the branch connection body composed of the through hole 1-2 and the branch branch pipe 3 and the branch joint fitting 4 with high precision by finishing pretreatment, preferably further nickel It is also possible to perform diffusion bonding by applying a plating film such as copper or copper and holding the diffusion temperature for a sufficient time.
[0017]
【The invention's effect】
As described above, the common rail according to the present invention is constructed by using a separate member for the common rail instead of an integral molding method such as die forging. It eliminates the need for machining at all, and can greatly reduce machining time such as cutting. In addition, low-cost parts such as thick-walled steel pipe cuts and steel plate presses can be used as components. In addition, it is not necessary to heat the material to a high temperature, so that the energy required for heating is unnecessary, and post-treatment such as shot blasting and pickling for removing oxide scale is also unnecessary, resulting in low manufacturing costs. There is an effect.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a common rail according to the present invention.
FIG. 2 is a longitudinal sectional view showing another embodiment of the common rail.
FIG. 3 is a plan view showing an example of a conventional common rail.
4 is a longitudinal sectional view taken along line AA in FIG. 3. FIG.
[Explanation of symbols]
1 Body 2, 2S Cap 3 Branch branch pipe 4 Branch fitting (nipple)
5 Flange for fixing

Claims

A short body part made of a thick-walled tube, a cap joined to each other in a state of being fitted into both end openings of the body part, and a state of being fitted to one end of the body part to be joined to each other. A fixing flange and a branch connection body consisting of a branch branch pipe or a branch joint fitting inserted into a through-hole formed in the body portion and joined to each other, and the body portion includes the branch joint fitting. a common rail, wherein short der Rukoto to the extent that two or more can not be attached to the longitudinal direction of the body portion.

The common rail according to claim 1, wherein the short body portion made of the thick tube body has a narrow diameter by narrowing a tip end portion.

3. The common rail according to claim 1, wherein the caps are fitted into the opening portions at both ends of the body portion and joined to each other in a crimped state. 4.