JP2008137487A - Fuel oil feed pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a slip property of a seal seating surface at an oil feed port made of metal. <P>SOLUTION: In the fuel oil feed pipe 1, a lubrication coating film 4 obtained by curing a resin material incorporated with a solid lubricant, is formed on a seal seating surface 111 of the oil feed port 11 made of metal for pressing a seal ring 21 of an oil feed port cap 2. The solid lubricant contained in the lubrication coating film 4 preferably utilizes each singly (1) a powder material of a fluorine resin, or (2) a powder material of molybdenum disulfide, or preferably utilize a powder material obtained by mixing the fluorine resin and molybdenum disulfide. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel oil supply pipe provided with a metal oil supply port (filar neck) with improved slipperiness of a seal seat surface that presses a seal ring (O-ring) of an oil supply port cap.

  A fuel supply pipe of an automobile or the like includes an integral or separate fuel supply port and a fuel supply pipe body. In recent years, resin-made fuel fillers are also seen, but metal fillers are still the mainstream. Such a fuel supply pipe closes the fuel supply port by tightening a screw-type fuel supply cap, for example. The fuel filler cap presses the seal ring against the seal seating surface of the fuel filler opening to achieve airtightness and liquid tightness (hereinafter referred to as sealability) at the fuel filler opening of the fuel filler pipe. The seal ring of the filler cap is not pressed against the seal seat surface, but is gradually pressed against the seal seat as the filler cap is tightened to the filler port. From this point, if the seal ring does not idle with respect to the seal seat surface, it becomes difficult to tighten the oil filler cap to the oil filler opening. This is a problem of the slipperiness of the seal ring with respect to the seal seat surface. Conventionally, a lubricating coating is formed on the surface of the seal ring (Patent Document 1), or the seal ring is halogenated (chlorinated) (Patent Document 2) to improve the surface slipperiness of the seal ring. Was.

JP2003-073609 JP 2004-060819 A

  As a method of spinning the seal ring against the seal seat surface, forming a lubricating coating on the surface of the seal ring or halogenating the seal ring causes the seal ring to run idle even for the filler cap. In this case, however, the mounting stability of the seal ring with respect to the filler cap may be impaired. Further, such treatment of the seal ring causes a problem of increasing the inherently inexpensive seal ring, and is not preferable as a member for an automobile that is strongly required to reduce the cost. From this, it is preferable to idle the seal ring with respect to the seal seat surface by improving the slipperiness of the seal seat surface if possible. Here, it is conceivable that only the fuel filler port is made of resin, but from the viewpoint of reducing the manufacturing cost, it is desirable to improve the slipperiness of the seal seat surface at the metal filler port if possible. Therefore, in order to improve the slipperiness of the seal seat surface at the metal filler opening, it was studied.

  As a result of the study, the fuel oil pipe that has been developed with a lubrication coating formed by curing a resin material containing a solid lubricant on the seal seat of the metal oil filler port that presses the seal ring of the filler cap is developed. is there. The metal filler opening may be made of either an electric sewing tube or a seamless tube, regardless of whether it is made of iron or stainless steel. As will be described later, the lubricating coating provides a rust-proofing action. Therefore, if the lubrication pipe body is also made of metal, it can be lubricated on the surface of a part or all of the metal filling port including the seal seat surface. A lubricating coating film may be formed on part or all of the surface of the fuel supply pipe including the mouth.

  The resin material is preferably a thermosetting resin, and specific examples include polyamideimide resin, epoxy resin, polyimide resin, and the like. Among the examples described above, the polyamideimide resin is particularly excellent in mechanical strength and is preferable as the resin material of the present invention. The solid lubricant contained in the lubricating coating may be (1) a fluororesin powder or (2) a molybdenum disulfide powder, or (3) a fluororesin and disulfide. A powdery material mixed with molybdenum may be used. Each powdery material may have a particle size of 10 μm or less or 30% or less of the film thickness of the formed lubricating coating film.

  The fuel supply pipe of the present invention improves the slipperiness of the seal seat surface by forming a lubricating coating film containing a solid lubricant on the seal seat surface in the metal fuel filler opening, and seal ring against the seal seat surface To make it idle. The lubricating coating film may be formed by curing a resin material containing a solid lubricant. For example, when the resin material is a thermosetting resin, if the resin material is applied to the seal seat surface and heated, a lubricating coating film having a certain thickness can be easily formed. The lubricating coating formed by the resin material is a fine unevenness of the seal seat surface in the metal filler opening (for example, a weld bead in the case where the metal filler opening is formed by machining an electric sewing tube) A smooth surface is formed by covering and covering small scratches (for example, scratches that may occur during press molding in the case of a metal filler opening, etc.). And the frictional resistance of the said smooth surface is reduced by the function of the solid lubricant contained, and the slipperiness of the seal seat surface is improved.

  In addition, since the lubricating coating is a smooth surface, the seal ring can be uniformly pressed against the seal seat surface, and the sealing performance at the oil filler port can be improved. Further, since the lubricating coating covers and conceals the seal seating surface, the corrosion resistance of the seal seating surface is improved and a rust preventive action is brought about. Since the rust preventive action by this lubricating coating is not limited to the seal seat surface, it is effective for about metal members, and as described above, a part or all of the metal filler opening including the seal seat surface. If the oil supply pipe body is also made of metal, a lubricating coating film may be formed on a part or all of the surface of the fuel oil supply pipe including the oil supply port. For example, a metal oil filler port with a lubricating coating formed on the entire surface including the seal seat surface may be connected to a metal oil supply pipe body with other rust prevention measures, or a metal oil filler. After connecting the mouth and the fuel supply pipe body, a lubricating coating film may be formed on the entire surface of the fuel supply pipe.

  The fuel supply pipe of the present invention improves the slipperiness of the seal seat surface by forming a lubricating coating on the seal seat surface at the metal filler opening, and causes the seal ring to idle with respect to the seal seat surface. (Essential effect) Moreover, the lubricating coating film which becomes a smooth surface can realize the uniform pressing of the seal ring against the seal seat surface and can improve the sealing performance at the oil filler port (ancillary effect). Further, since the lubricating coating covers and conceals the seal seat surface, the seal seat surface has an anticorrosive action (incidental effect). The rust preventive action is effective not only on the seal seat surface but also on the metal filler opening and the filler pipe main body. If a lubricating coating is formed on the entire surface of the fuel filler pipe, the entire fuel filler pipe is formed. Can have a rust-proofing effect (derived effect).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a partial cross-sectional view showing a fuel supply pipe 1 to which the present invention is applied and a fuel supply cap 2 that closes a fuel supply opening 11 of the fuel supply pipe 1, and FIG. 2 is an enlarged cross-sectional view taken along arrow A in FIG. FIG. 3 is a cross-sectional view corresponding to FIG. 1 showing a stage where the seal ring 21 of the filler cap 2 starts to contact the seal seating surface 111 of the filler port 11, and FIG. 4 shows a stage where the filler cap 2 has been tightened. FIG. 2 is a cross-sectional view corresponding to FIG. 1.

  As shown in FIG. 1, the fuel supply pipe 1 of this example is for an automobile configured by welding a metal supply pipe 11 and a metal supply pipe body 12 in the same manner as shown in FIG. The mounting flange 112 welded to 11 is bolted to the vehicle body 3. The oil filler cap 2 is a screwed type made of a resin molded product, and the male screw 221 formed on the cap body 22 is tightened to the female screw 113 formed on the oil filler 11 to close the oil filler 11. The rubber seal ring 21 is mounted in a freely rotatable state near the base of the cap body 22 that connects to the cap head 23 that presses the seal ring 21 downward. Thus, the fuel supply pipe 1 and the fuel filler cap 2 of this example are not different from the conventionally known similar configuration in appearance. This means that the present invention can be used for off-the-shelf products and has versatility.

  The feature of the present invention is that, as seen in FIG. 2, a lubricating coating film 4 containing a solid lubricant is formed on the seal seat surface 111 of the oil filler port 11 that presses the seal ring 21 of the oil filler cap 2. It is in. The lubricating coating 4 is formed by applying a resin material containing a solid lubricant such as a fluororesin powder or a molybdenum disulfide powder to the seal seat surface 111 and curing it. Examples of the resin material include a configuration in which a powder of fluororesin or molybdenum disulfide is mixed with a thermosetting resin. In this case, the resin material is sprayed, brushed or dipped into a fixed thickness (for example, about 10 μm) on the seal seat surface 111 from which oil has been sufficiently wiped off, and after natural drying or low-temperature drying, it is 200 ° C. When heated under the conditions of 30 minutes, the resin material is cured and the lubricating coating film 4 can be formed. The lubricating coating 4 of this example functions to improve the slipperiness on the seal seat surface 111, and serves to form a smooth surface of the seal seat surface 111 by covering the minute irregularities and small scratches of the seal seat surface 111. The surface 111 has a function of providing a rust prevention effect. In order to exhibit the rust prevention effect better, the seal seat surface 111 may be preliminarily treated with zinc phosphate before the resin material is deposited.

  The lubricating coating film 4 of this example is formed only on the seal seat surface 111 for the purpose of improving only the slipperiness on the seal seat surface 111 (see FIG. 1). However, since the rust prevention effect by the lubricating coating 4 is approximately effective for a metal member, the lubricating coating 4 is applied to the entire surface of the oil supply port 11 and the entire surface of the oil supply pipe body 12 although illustration is omitted. It may be formed. In this case, as described above, it is desirable to form the lubricating coating 4 after the surface of the entire fuel filler port 11 and the entire surface of the fuel filler body 12 are preliminarily treated with zinc phosphate. Since the lubricating coating film 4 can be easily formed by applying a resin material containing a solid lubricant and curing it, the lubricating coating film 4 is applied to the entire surface of the oil supply port 11 and the entire surface of the oil supply pipe body 12. It is also easy to form.

  When tightening of the filler cap 2 to the filler port 11 is started, the seal ring 21 eventually comes into contact with the seal seat surface 111 as seen in FIG. At this time, the seal seat surface 111 on which the lubricating film is formed has improved slipperiness (the frictional resistance is reduced), so that the seal ring 21 idles with respect to the seal seat surface 111. Thereby, the filler cap 2 can be smoothly tightened to the filler port 11 without resistance, and the seal ring 21 can be pressed against the seal seat surface 111 as seen in FIG. As described above, since the seal seat surface 111 is smoothed by the lubricating coating 4, the seal ring 21 pressed until the cross-sectional shape is crushed is pressed uniformly and tightly over the entire circumference of the seal seat surface 111. Realizes high sealing performance.

  A confirmation test was conducted on the slipperiness and sealability of the fuel supply pipe that was prototyped based on the present invention. The oil filler port of the example was made of iron having the structure shown in FIG. 1 and was subjected to zinc phosphate treatment as a whole, and then a lubricating coating film was formed on the seal seat surface. The lubricating coating is a resin material obtained by mixing a fluororesin powder (3 μm: 30% of the thickness of the lubricating coating) with a polyamide-imide resin, which is a thermosetting resin, as a solid lubricant. The film was applied to the seal seat surface to a thickness of 10 μm and cured by heating. A standard ring made of fluororubber is used as the seal ring to be pressed against the seal seat surface. Conventional Example 1 is a combination of an oil filler port in which a lubricating coating film is not formed and the same seal ring as that of the example. Conventional Example 2 is a combination of an oil filler port in which a lubricating coating film is not formed and a seal ring coated with Teflon (registered trademark) (corresponding to Patent Document 1).

<Slipperiness confirmation test>
In the slipping confirmation test, the amount of tightening of the filler cap is proportional to the amount of slipping until the cap head ratchet starts to engage with the latch claws of the cap body and exceeds it. It carried out in. The test conditions were such that the tightening torque when the ratchet starts to engage with the latch pawl is a tightening torque of 2 Nm, which is a general specification requirement. The tightening amount of the filler cap means how much the seal ring can be pressed against the seal seat surface with a tightening torque of 2 Nm, and affects the sealing performance by the seal ring described later. As a result of the test, although the tightening amount of Conventional Example 1 was 1.37 mm, the tightening amount of Example was 1.61 mm, and an improvement in slipperiness corresponding to the difference of 0.24 mm was confirmed.

  A similar slip confirmation test was performed on Conventional Example 2. As a result, the tightening amount of Conventional Example 2 was 2.29 mm, which was significantly higher than the Example. If only the tightening amount is compared, it can be considered that the conventional example 2 is preferable to the embodiment. However, if the tightening amount is too large, the seal ring may be excessively crushed and may cause close contact with the seal seat surface. is there. In particular, since the seal ring of the filler cap swells due to absorption of fuel or fuel vapor, there is a high risk of close contact with the seal seat surface due to excessive crushing. From this, it can be said that the fuel refueling pipe of the present invention improves slipperiness compared to the conventional case and appropriately crushes the seal ring.

<Sealability confirmation test>
Even if the slipperiness of the seal seat surface is improved, it does not make sense to cause leakage when the seal ring is pressed.Therefore, in the embodiment, when the oil filler cap is tightened to the oil filler, there is no leakage. The sealing property confirmation test of the Example was implemented. First, as a case where fuel vapor is normally generated in the fuel supply pipe, when a gas pressure of 2 kPa (gas: air) is applied from the inside of the fuel supply port with the fuel supply cap tightened, no gas leakage was detected. In addition, when abnormal fuel vapor was generated in the fuel filler pipe, when a gas pressure of 13 kPa (gas: air) was applied from the inside of the filler port with the filler cap tightened, no gas leak was detected. From this, it was confirmed that the fuel supply pipe to which the present invention is applied has a necessary and sufficient sealing performance.

It is a fragmentary sectional view showing the fuel filler pipe to which the present invention is applied, and the filler cap which closes the filler opening of the fuel filler pipe. FIG. 2 is an enlarged sectional view taken along arrow A in FIG. 1. It is sectional drawing equivalent to FIG. 1 showing the step which the seal ring of the filler cap began to contact the seal seat surface of the filler port. FIG. 2 is a cross-sectional view corresponding to FIG. 1, illustrating a stage where the filler cap has been tightened.

Explanation of symbols

1 Fuel supply pipe
11 Refueling port
111 Seal seat 2 Oil filler cap
21 Seal ring 3 Car body 4 Lubrication coating

Claims (4)

A fuel supply pipe formed by forming a lubricating coating film obtained by curing a resin material containing a solid lubricant on a seal seating surface of a metal filler opening that presses a seal ring of a filler cap. 2. The fuel supply pipe according to claim 1, wherein the solid lubricant is a powder of fluororesin. The fuel supply pipe according to claim 1, wherein the solid lubricant is a powder of molybdenum disulfide. 2. The fuel supply pipe according to claim 1, wherein the solid lubricant is a powdered material in which a fluororesin and molybdenum disulfide are mixed.

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