JPH0529829U - Drain structure of synthetic resin fuel tank - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a material having improved fire resistance by enhancing the cooling effect of the drain plug by the fuel in the fuel tank. [Structure] A drain seat 11 provided on the bottom portion 10a of the synthetic resin fuel tank 10 is screwed with a cylindrical metal drain plug 14 having a bottom 16 and an upper opening portion 15 thereof being screwed into the fuel tank 10. Drain structure of a synthetic resin fuel tank with the same configuration.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a synthetic resin fuel tank installed in an automobile, a boiler, or the like, and more specifically to a drain structure for draining water provided at the bottom of the tank.

[0002]

[Prior Art]

 Generally, in a fuel tank for light oil, a drain for draining water is provided on the bottom surface of the tank in order to prevent the water accumulated at the bottom from being mixed with the fuel. As a conventional example thereof, as shown in FIG. 4, a polyethylene drain sheet 3 having a female screw 1a engraved in a cylindrical portion 1 and a flange 2 at the upper end is molded into a synthetic resin fuel tank 4. The drain plug 5 is sometimes attached to the bottom of the drain sheet 3 by insert molding, and a normal bolt is used as the drain plug 5 attached to the drain sheet 3 by screwing, and the drain plug 5 is attached via a packing 6. In another conventional example, as shown in FIG. 5, a metal sleeve 9 is inserted and fixed in a synthetic resin connecting pipe 8 provided in a lower range of a synthetic resin fuel container 7, and an inner end of the metal sleeve 9 is fixed. 9a is exposed from the inner end 8a of the connecting pipe 8 and protrudes into the fuel container 7, and its outer end 9b is located inside the outer end 8b of the connecting pipe 8 (JP-A-56). -63522 gazette).

[0003]

[Problems to be solved by the device]

 However, in the conventional drain structure shown in FIG. 4, when a fire resistance test was conducted based on the safety standard of passenger cars, the drain plug 5 was formed of solid metal, and therefore the drain plug 5 was flamed for a predetermined time. Upon receiving the heat, the heat from the flame is transferred from the drain plug 5 through the drain seat 3 to the synthetic resin part in contact with the drain seat 3 faster than it is transferred to the synthetic resin part near the drain plug 5. The synthetic resin of No. 1 melted, causing a gap, and fuel leaked from there. Further, in the conventional example shown in FIG. 5, since the connecting tube 8 has the metal sleeve 9 inserted therein, it is not broken or crushed during heating, and the metal sleeve 9 is cooled by the fuel in the fuel container 7. However, since the outer end 8b of the connecting pipe 8 is exposed to the outside world, when the connecting pipe 8 is directly exposed to a flame, the outer end 8b of the connecting pipe 8 softens and shrinks to form a metal. Since the outer end 9b of the sleeve 9 is closed to prevent fuel from flowing out of the fuel container 7, there is a problem that the connecting pipe 8 cannot be reused.

[0003]

[Means for solving problems]

 The present invention has been made to solve the above-mentioned conventional problems, in which the drain plug having a high heat conductivity has a hollow shape, and the cooling effect is enhanced by the fuel stored therein. The purpose of the present invention is to provide a drain with improved fire resistance by means of a drain seat provided at the bottom of a fuel tank made of synthetic resin and a metal drain plug with a bottomed cylindrical shape. The drain structure of the fuel tank is characterized in that the upper opening is screwed toward the inside of the fuel tank.

[0004]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in FIGS. 1 is a sectional view of a fuel tank to which the drain structure according to the present invention is applied when the fuel tank is opened, FIG. 2 is a sectional view of the fuel tank when the fuel tank is closed, and FIG. 3 is used for the drain structure. FIG. 3 is a perspective view of a drain plug to be used.

In the figure, 10 is a fuel tank made of synthetic resin, and a drain seat 11 made of metal is embedded in the bottom portion 10 a of the fuel tank 10 by insert molding when the fuel tank 10 is molded. The drain seat 11 is composed of a cylindrical portion 12 having an internal thread 12a engraved on the inner periphery thereof and a flange 13 provided at the lower end thereof, and is insert-molded when the synthetic resin fuel tank 10 is molded. After being embedded and fixed by, the synthetic resin in the cylindrical portion 12 is removed so that the inside and outside of the fuel tank 10 are in communication with each other.

Reference numeral 14 denotes a drain plug which can be screwed into the cylindrical portion 12 of the drain seat 11, and has a cylindrical shape with an opening 15 at one end (upper) and a bottom 16 at the other end (lower). The outer flange 17 formed approximately at the middle position of the entire length has a threaded portion 18 engraved with a male screw 18a on the outer circumference above the outer flange 17, and the outer circumference below the flange 17 has the same size as a bolt. Each of them has a rectangular head 19.

Reference numeral 20 denotes a packing, and the drain plug 14 is disposed through the packing 20 with the upper opening 15 thereof facing the fuel tank 10 side, and the screw portion 18 thereof is provided on the cylindrical portion 12 of the drain seat 11. It is fixed by screwing it inside.

Therefore, as shown in FIG. 2, the fuel F in the fuel tank 10 enters the cylindrical portion through the upper opening 15 of the drain plug 14, and the fuel F is always stored in the drain plug 14. become. In addition, since the fuel F is constantly filled inside the drain plug 14 over almost the entire length, the contact area between the fuel F and the drain plug 14 is large, and the heat exchange efficiency with the fuel F is high. In the fire resistance test in which the bottom of the fuel tank 10, particularly the vicinity of the drain plug 14, was exposed to flame, no fuel leaked from the drain seat 11 in any of 45 seconds, 2 minutes, and 150 seconds. ..

[0009]

[Effect of the device]

 As described above, the drain structure of the synthetic resin fuel tank according to the present invention is such that the drain seat provided at the bottom of the synthetic resin fuel tank has the cylindrical drain metal plug with a bottom and the upper opening thereof. Since the structure is screwed into the fuel tank, heat exchange between the drain plug and the fuel stored therein can be performed in a wide area, and the cooling effect of the drain plug can be enhanced. Therefore, even if a flame should occur, the melting of the portion of the synthetic resin fuel tank that comes into contact with the drain seat will be delayed as much as possible, ensuring sufficient time for fire extinguishing work and evacuation of passengers. There are various effects that can be done.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a fuel tank to which a drain structure according to the present invention is applied when the plug is opened.

FIG. 2 is a cross-sectional view of the fuel tank when the fuel tank is closed.

FIG. 3 is a perspective view of a drain plug used in the drain structure.

FIG. 4 is a cross-sectional view showing a main part of a fuel tank having a conventional drain structure when the plug is opened.

FIG. 5 is a sectional view showing a main part of another conventional fuel tank.

[Explanation of symbols] 10 Fuel tank made of synthetic resin 11 Drain sheet 14 Drain plug F Fuel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ogawa Takao, 3-5-1, Fujisaki, Kawasaki-ku, Kawasaki-shi, Kanagawa, Tokyo Radiator Manufacturing Co., Ltd. (72) Shuji Nakato, 3 Fujisaki, Kawasaki-ku, Kawasaki-shi, Kanagawa 5-5-1 Tokyo Radiator Manufacturing Co., Ltd. (72) Inventor Hideki Yamaji 3-5-1 Fujisaki, Kawasaki-ku, Kawasaki-shi, Kanagawa Tokyo Radiator Manufacturing Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A drain seat provided at the bottom of a synthetic resin fuel tank, a metal drain plug having a bottomed cylindrical shape, and an upper opening of the metal drain plug is screwed into the fuel tank. Drain structure of fuel tank.