JP2004210003A

JP2004210003A - Fuel feed pipe

Info

Publication number: JP2004210003A
Application number: JP2002378486A
Authority: JP
Inventors: Hiroshi Goto; 宏後藤; Haruyoshi Ikagawa; 晴義五百川; Takushi Kawamura; ▲琢▼志河村
Original assignee: Asteer Co Ltd
Current assignee: Asteer Co Ltd
Priority date: 2002-12-26
Filing date: 2002-12-26
Publication date: 2004-07-29

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel feed pipe having enhanced rust preventative performance structured so that even a part exposed to the outside is unlikely to be exfoliated caused by the sputtering of sand and grit etc. and that a gap in the joining part of members is applied with a coating exerting high rust preventative performance. <P>SOLUTION: The fuel feed pipe 1 to lead liquid fuel from a filler neck 3 to a fuel tank includes a conduit pipe 2 made of stainless steel, in which a coating film 6 composed of a powder coating is formed on the surface of the conduit pipe in a thickness of 30-150 μm. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、フィラネックから燃料タンクへと液体燃料を導く燃料給油管に関する。
【０００２】
【従来の技術】
自動車の各部品には、常に耐久性の向上が要求される。特に米国では、10年・10万マイル保証から近年15年・15万マイル保証へ、非常に厳しい要求に変わりつつある。こうした厳しい耐久性の要求には、とりわけ防錆性能の向上が必要となる。ところが、従来一般的な燃料給油管は、燃料給油管を構成する主部材(フィラパイプ)が亜鉛メッキ鋼管製に通常塗装により塗膜を形成しただけだったので、前記要求(防錆性能の向上)に応えられない状況になりつつある。このため、鉄よりも耐食性に優れたステンレスを用いた燃料給油管も実用化されはじめている。例えば、特許文献１は、ステンレス鋼の燃料給油管表面にカチオン電着塗装を施して、防錆性能を向上させようとしている。
【０００３】
【特許文献１】
特開2002-242779号公報（２〜４頁、図１）
【０００４】
【発明が解決しようとする課題】
ステンレス鋼の燃料給油管表面に施す電着塗装は、密着性が悪く、剥がれやすく、塗装が剥がれると当然にその部位から錆が進展していく問題が発生する。燃料給油管には車体外部に露出している部分があり、走行中、前記露出部分が砂礫等の飛散を受けて更に塗装が剥がれやすい。こうしたことから、プロテクタと呼ぶ保護部材で燃料給油管を覆い、砂礫等の飛散から燃料給油管を保護することもあるが、部材数の増加を招く問題となる。
【０００５】
また、電着塗装の弱点として、部材相互の接合部(例えば、特許文献１におけるブリーザパイプと燃料給油管本体)の隙間に塗料がつきにくい又はついても塗膜が薄くなり、他の部位に比べて相対的に錆びやすい問題がある。これは、接合部の接合態様の種類を問わず、電着塗装特有の問題として起きる。
【０００６】
このほか、通常電着塗装は塗料液中に燃料給油管を浸して実施するが、燃料給油管内に塗料が侵入すると、前記塗料が燃料に溶けこんで、エンジンに悪影響を与える恐れがある。このため、電着塗装実施前には、燃料給油管の開口部を予めマスキングしておく必要があった。しかし、マスキングを施した燃料給油管は、内部に空気を密封する結果、塗料液に対して沈みにくくなり、煩わしさが増大する。このように、電着塗装は塗装前の準備が必要だったり、塗装作業中の煩わしさが存在した。
【０００７】
以上から、防錆性能の向上を主眼とし、第１に外部に露出した部分でも砂礫等の飛散による剥離を招きにくく、第２に部材相互の接合部の隙間でも高い防錆性能を発揮できる塗装を施した燃料給油管を開発するため、検討した。
【０００８】
【課題を解決するための手段】
検討の結果開発したものが、フィラネックから燃料タンクへと液体燃料を導く燃料給油管において、燃料給油管を構成する主部材は素材がステンレス鋼であり、この主部材の表面に粉体塗装による塗膜を形成した燃料給油管である。主部材は、素材がフェライト系ステンレス鋼が好ましい。ここで、「主部材」とは、フィラネック及び燃料タンクを結ぶ導管を指すが、フィラネック、燃料タンクへの接続部又はブリーザパイプを導管と一体にして本発明の適用対象たる燃料給油管としてもよい。
【０００９】
本発明に用いる粉体塗装は、(1)各種溶剤や水等を全く含まない、(2)塗膜の厚さを自由に設定でき、特に電着塗装に比べて厚い塗装が容易、(3)塗料の損失が少ない、等の利点がある。特に、電着塗装が１度の塗装で通常10〜20μmの塗膜しか形成できないのに対し、粉体塗装では１度の塗装で数倍の厚みを有する塗膜を容易に形成できる利点がある。塗装条件の設定によっては、より厚い塗膜を形成することもできる。
【００１０】
そこで、本発明の燃料給油管の粉体塗装による塗膜は、30〜150μmの範囲で形成することとした。30μmは最低限の厚みで電着塗装よりも十分に大きな厚みであり、150μmは粉体塗装により１度に形成できる塗膜の一般的な上限である。これから、本発明の燃料給油管の粉体塗装による塗膜は、40〜80μmの厚みであるとより好ましい。そして、こうした厚い塗膜は、部材相互の接続部における隙間をも被覆し、燃料給油管全体の防錆性能を向上させる。
【００１１】
本発明の粉体塗装に用いる塗料は、燃料給油管の防錆性能を向上させる厚みのある塗膜を形成できれば自由であるが、ステンレス鋼からなる燃料給油管に適した粉体塗装による塗膜は、ポリエステル系塗料、エポキシ系塗料、アクリル系塗料、ポリエステル及びエポキシのハイブリッド系塗料、又は変成EVA系塗料のいずれかを用いて形成する塗膜である。特に、燃料給油管の塗膜としてはエポキシ系塗料が最適である。
【００１２】
【発明の実施の形態】
以下、本発明の実施形態について図を参照しながら説明する。図１は本発明を適用した燃料給油管１を表した断面図、図２は図１中Ａ矢視部拡大図であり、図３は図１中Ｂ矢視部拡大図である。本発明の粉体塗装を施す対象の燃料給油管の構造は問わず、また導管だけでなく、本例に見られるように、導管にフィラネック３、ブリーザパイプ８や燃料タンクの接続部(図示略)等を一体にして全体に略均一の塗膜６を形成できる。これから、同じ粉体塗装設備を種々の燃料給油管に利用でき、設備コストを低減できる。
【００１３】
本例は、図１に見られるように、主部材がフェライト系ステンレス(SUS436)製導管２に、フィラネック３及びブリーザパイプ８を取り付けた構成の燃料給油管１である。フィラネック３は、前記導管２と同種のフェライト系ステンレス(SUS436)製とし、両者の嵌合部位４をシーム溶接(又はロウ付け)する(図中太線でシーム溶接した部分を表している)。ここで、前記嵌合部位４における導管２端縁には、溶接されない隙間５が残っている。粉体塗装は、図２に見られるように、こうした隙間５を略均一で比較的厚い(40〜80μm、好ましくは60μm前後)塗膜６で前記隙間５を塞ぐことができる。
【００１４】
また、本例は、導管２及びフィラネック３を接続して一体に粉体塗装しているため、図３に見られるように、給油口(開口部)７の縁部を回り込んで塗膜６が続くことになる。電着塗装では、こうした給油口の縁部等、部材端縁(エッジ)に塗膜を形成しようとすると、どうしても薄くなって剥離しやすく、防錆性能を発揮させることができなかった。しかし、粉体塗装はこうした部材端縁にも十分塗料を行き渡らせ、比較的厚い(40〜80μm、好ましくは60μm前後)塗膜６を形成できるので、塗膜６が剥離することがなく、防錆性能を十分に発揮できる。
【００１５】
本発明の燃料給油管１は、(1)導管２、フィラネック３及びブリーザパイプ８を接続した後、例えば(2)フィラネック３の給油口７に吊下補助具(図示略)を嵌合してマスキングし、導管２及びブリーザパイプ８の開放端を別途マスキングしてから、(3)前記吊下補助具を介してフィラネック３及び導管２を一体に吊り下げ、(4)粉体塗料をフィラネック３及び導管２の表面に吹き付けて、(5)その後焼き付けする手順で粉体塗装を施す。マスキングに対して外部圧が加わるわけではないので、単純に粉体塗料が内部に侵入しないようにするだけの簡易なマスキングでよい利点がある。
【００１６】
【実施例】
次に、導管にブリーザパイプを取り付けた燃料給油管の素材及び塗装種類の組み合わせについて、防錆を主とした比較試験を実施した。実施例は、SUS436(フェライト系ステンレス鋼)製の導管及びブリーザパイプ表面に粉体塗装を施している。これに対し、比較例１は鉄製の導管及びブリーザパイプ表面に粉体塗装を施し、比較例２はSUS436製導管及びブリーザパイプ表面にカチオン電着塗装を施している。いずれも、導管に対するブリーザパイプの取り付けは、燃料給油管に一般的なロウ付けを用いている。
【００１７】
比較項目は、経時的な外観(全体外観、リングスポット、ロウ付け部分)の発錆の程度と、気密性(検圧、100kPaを１分間加えたときの導管内外の漏れを検定)とであり、両者の比較から総合判定を試みた。試験結果を表１に示す。
【００１８】
【表１】

【００１９】
試験結果(表１)から明らかなように、比較例１及び２はいずれも腐食又は発錆が認められる上、検圧結果が不良であったのに対し、本発明に従う実施例は腐食又は発錆がなく、検圧の結果も良好であった。これは、粉体塗装による比較的厚い塗膜が導管及びブリーザパイプ表面全域へ略均一に形成できたことにもよるが、鉄よりもステンレス鋼のほうが粉体塗装の防錆作用をよりよく発揮できることに基づく効果と考えられる。これから、本発明は燃料給油管の主部材の素材としてステンレス鋼を用い、表面に粉体塗装による塗膜を形成することに、特に防錆性能の向上の面に効果があることが分かる。
【００２０】
【発明の効果】
本発明により、第１に外部に対して露出した部分でも砂礫等の飛散による剥離を招きにくく、プロテクタを不要とし、第２に部材相互の接合部の隙間でも高い防錆性能を発揮できる塗装を施した燃料給油管を提供できる。本発明が用いる粉体塗装は、電着塗装に比較して、塗装作業自体が容易で、マスキングも簡略で済むことから、生産性を高めることができる。また、粉体塗装は溶剤(特に有機溶剤)を用いないことから、本発明の燃料給油管の製造に際して火災、中毒や汚染といった危険性が大幅に低減する利点もある。このように、本発明は、一方で防錆性能を高めた燃料給油管を製品として提供する効果と、燃料給油管の生産性を高めながら生産現場の安全性をも高める効果とを併せ持つ。
【図面の簡単な説明】
【図１】本発明を適用した燃料給油管を表した断面図である。
【図２】図１中Ａ矢視部拡大図である。
【図３】図１中Ｂ矢視部拡大図である。
【符号の説明】
１燃料給油管
２導管
３フィラネック
６塗膜
８ブリーザパイプ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel filler pipe for guiding liquid fuel from a filler neck to a fuel tank.
[0002]
[Prior art]
Each part of an automobile is required to always have improved durability. In the United States, in particular, the demand has been changing from a 10-year, 100,000-mile warranty to a 15-year, 150,000-mile warranty in recent years. Such strict durability demands particularly require improvement in rust prevention performance. However, in the conventional fuel filler pipe, the main member (filler pipe) that constitutes the fuel filler pipe was merely formed by coating normally on a galvanized steel pipe. The situation is not being met. For this reason, fuel supply pipes using stainless steel having better corrosion resistance than iron have begun to be put into practical use. For example, Patent Literature 1 attempts to improve rust prevention performance by applying cationic electrodeposition coating to the surface of a stainless steel fuel supply pipe.
[0003]
[Patent Document 1]
JP-A-2002-242779 (pages 2 to 4, FIG. 1)
[0004]
[Problems to be solved by the invention]
Electrodeposition coating applied to the surface of a stainless steel fuel filler pipe has poor adhesion and is easily peeled off, and when the coating is peeled off, rust naturally develops from the site. The fuel filler pipe has a portion that is exposed to the outside of the vehicle body, and during running, the exposed portion is liable to be scattered by gravel or the like, and the coating is more likely to be peeled off. For this reason, the fuel filler pipe may be covered with a protective member called a protector to protect the fuel filler pipe from scattering of sand and gravel, but this poses a problem of increasing the number of members.
[0005]
Also, as a weak point of electrodeposition coating, paint is difficult to adhere to the gap between the joints between members (for example, the breather pipe and the fuel supply pipe main body in Patent Document 1) or the coating film becomes thinner, and compared with other parts. Is relatively rusty. This occurs as a problem peculiar to electrodeposition coating, regardless of the type of bonding at the bonding portion.
[0006]
In addition, the electrodeposition coating is usually performed by immersing the fuel supply pipe in a coating liquid, but if the paint enters the fuel supply pipe, the paint may dissolve in the fuel and adversely affect the engine. Therefore, it is necessary to mask the opening of the fuel supply pipe before performing the electrodeposition coating. However, as a result of sealing the air inside the masked fuel supply pipe, it becomes difficult for the fuel supply pipe to sink in the coating liquid, and the burden increases. As described above, the electrodeposition coating requires preparation before painting, and there is a trouble during the painting operation.
[0007]
From the above, with a primary focus on improving rust prevention performance, firstly, it is difficult to cause peeling due to scattering of sand and gravel even in the part exposed to the outside, and secondly, a coating that can exhibit high rust prevention performance even in the gap between the joints of the members. The study was conducted to develop a fuel supply pipe with the following.
[0008]
[Means for Solving the Problems]
As a result of the study, the main component of the fuel supply pipe, which is a stainless steel, is made of stainless steel, and the surface of this main component is formed by powder coating. It is a fuel supply pipe on which a coating film is formed. The main member is preferably made of ferritic stainless steel. Here, the `` main member '' refers to a conduit connecting the filler neck and the fuel tank, and the filler neck as a fuel filler pipe to which the present invention is applied by integrating the filler neck, the connection portion to the fuel tank or the breather pipe with the conduit. Is also good.
[0009]
The powder coating used in the present invention is (1) completely free from various solvents and water, etc., (2) the thickness of the coating film can be freely set, and particularly, thick coating is easy compared with electrodeposition coating, and (3) ) There are advantages such as less paint loss. In particular, while electrodeposition coating can usually form only a coating film of 10 to 20 μm in a single coating, powder coating has the advantage that a coating film having several times the thickness can be easily formed in a single coating. . Depending on the setting of the coating conditions, a thicker coating film can be formed.
[0010]
Then, the coating film by powder coating of the fuel supply pipe of the present invention is formed in the range of 30 to 150 μm. 30 μm is a minimum thickness which is sufficiently larger than the electrodeposition coating, and 150 μm is a general upper limit of a coating film which can be formed at once by powder coating. From this, it is more preferable that the coating film by powder coating of the fuel supply pipe of the present invention has a thickness of 40 to 80 μm. Then, such a thick coating film also covers a gap at a connecting portion between members, and improves rust prevention performance of the entire fuel supply pipe.
[0011]
The paint used for the powder coating of the present invention is free as long as it can form a thick coating that improves the rust prevention performance of the fuel filler pipe, but the powder coating suitable for the fuel filler pipe made of stainless steel is used. Is a coating film formed using any of a polyester paint, an epoxy paint, an acrylic paint, a hybrid paint of polyester and epoxy, or a modified EVA paint. Particularly, an epoxy-based paint is most suitable as a coating film for the fuel filler pipe.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a fuel supply pipe 1 to which the present invention is applied, FIG. 2 is an enlarged view of an arrow A in FIG. 1, and FIG. 3 is an enlarged view of an arrow B in FIG. Regardless of the structure of the fuel supply pipe to which the powder coating of the present invention is applied, not only the pipe, but also the connecting part of the filler neck 3, the breather pipe 8 and the fuel tank (not shown) , Etc.) can be integrally formed to form a substantially uniform coating film 6 as a whole. From this, the same powder coating equipment can be used for various fuel supply pipes, and equipment costs can be reduced.
[0013]
In this example, as shown in FIG. 1, the fuel supply pipe 1 has a configuration in which a filler neck 3 and a breather pipe 8 are attached to a conduit 2 made of ferritic stainless steel (SUS436) as a main member. The filler neck 3 is made of ferritic stainless steel (SUS436) of the same type as the conduit 2, and the fitting portion 4 of both is seam-welded (or brazed) (the seam-welded portion is shown in the figure). Here, a gap 5 that is not welded remains at the end of the conduit 2 at the fitting portion 4. In the powder coating, as shown in FIG. 2, the gap 5 can be closed with a substantially uniform and relatively thick (40 to 80 μm, preferably around 60 μm) coating film 6.
[0014]
Further, in this example, since the conduit 2 and the filler neck 3 are connected and the powder coating is integrally performed, as shown in FIG. 6 will follow. In the electrodeposition coating, when a coating film is formed on an edge of a member such as an edge of a fuel filler port, the coating is inevitably thinned and easily peeled, and the rust prevention performance cannot be exhibited. However, the powder coating sufficiently spreads the paint even to the edge of such a member, and can form a relatively thick (40 to 80 μm, preferably around 60 μm) coating film 6, so that the coating film 6 does not peel off and is prevented. Rust performance can be fully exhibited.
[0015]
In the fuel filler pipe 1 of the present invention, (1) after connecting the conduit 2, the filler neck 3 and the breather pipe 8, for example, (2) fitting a suspension aid (not shown) to the filler port 7 of the filler neck 3 And the open ends of the conduit 2 and the breather pipe 8 are separately masked. (3) The filler neck 3 and the conduit 2 are suspended together via the suspending aid, and (4) the powder coating Is sprayed onto the surface of the filler neck 3 and the conduit 2, and (5) powder coating is performed in the procedure of baking. Since external pressure is not applied to the masking, there is an advantage that simple masking that simply prevents the powder coating from entering the inside is sufficient.
[0016]
【Example】
Next, a comparative test mainly on rust prevention was performed on a combination of a material and a coating type of a fuel filler pipe having a breather pipe attached to a conduit. In this embodiment, powder coating is applied to the surface of a SUS436 (ferritic stainless steel) conduit and a breather pipe. On the other hand, in Comparative Example 1, powder coating was applied to the surface of the iron pipe and the breather pipe, and in Comparative Example 2, the cationic electrodeposition coating was applied to the surface of the SUS436 pipe and the breather pipe. In any case, the attachment of the breather pipe to the conduit uses general brazing to the fuel filler pipe.
[0017]
The comparison items are the degree of rusting of the appearance over time (overall appearance, ring spot, brazing part), and airtightness (test pressure, test for leakage inside and outside the conduit when 100 kPa is applied for 1 minute). An attempt was made to make a comprehensive judgment based on a comparison between the two. Table 1 shows the test results.
[0018]
[Table 1]

[0019]
As is clear from the test results (Table 1), in each of Comparative Examples 1 and 2, corrosion or rust was observed and the test results were poor, whereas the examples according to the present invention showed corrosion or rust. There was no rust, and the result of the test was good. This is due to the fact that relatively thick coatings formed by powder coating can be formed almost uniformly on the entire surface of the conduit and breather pipe, but stainless steel exhibits better rust-preventive action of powder coating than iron. This is considered to be an effect based on what can be done. From this, it is understood that forming the coating film by powder coating on the surface using stainless steel as the material of the main member of the fuel filler pipe is particularly effective in improving rust prevention performance.
[0020]
【The invention's effect】
According to the present invention, first, a coating which can hardly cause peeling due to scattering of gravel or the like even in a portion exposed to the outside, does not require a protector, and secondly, can exhibit high rust prevention performance even in a gap between joints between members. The fuel supply pipe provided can be provided. In the powder coating used in the present invention, the coating operation itself is easier and the masking can be simplified as compared with the electrodeposition coating, so that the productivity can be improved. In addition, since powder coating does not use a solvent (particularly an organic solvent), there is also an advantage that the risk of fire, poisoning, and contamination is significantly reduced when the fuel supply pipe of the present invention is manufactured. As described above, the present invention has both the effect of providing a fuel supply pipe with improved rust prevention performance as a product and the effect of increasing the productivity of the fuel supply pipe and also improving the safety at the production site.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a fuel supply pipe to which the present invention is applied.
FIG. 2 is an enlarged view of a portion viewed from an arrow A in FIG.
FIG. 3 is an enlarged view of a portion viewed from an arrow B in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel supply pipe 2 Conduit 3 Filaneck 6 Coating film 8 Breather pipe

Claims

In a fuel filler pipe for guiding liquid fuel from a filler neck to a fuel tank, a main member constituting the fuel filler pipe is made of stainless steel, and a coating film by powder coating is formed on a surface of the main member. And fuel filler pipe.

The fuel filler pipe according to claim 1, wherein the main member is made of a ferritic stainless steel.

2. The fuel filler pipe according to claim 1, wherein the powder coating has a thickness of 30 to 150 [mu] m.

The fuel filler pipe according to claim 1, wherein the coating film formed by powder coating is formed of any one of a polyester paint, an epoxy paint, an acrylic paint, a hybrid paint of polyester and epoxy, or a modified EVA paint.