JP2000344166A - Filler opening seal structure in fuel tank for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the versatility of a fuel tank for motorcycle by stopping the flowing of water into a tank body regard less of the accuracy in relative position of a cover covering at least the circumference of a filler opening and the tank body in the fuel tank for motorcycle which is composed of the tank body mounted on a car body frame with the filler opening on the top and a cap with breather pass to block up the filler opening possible to open and close, and at least the circumference of the filler opening is covered. SOLUTION: Annular seal member 50 is attached closely around the edge of a cap 32 so that the outer circumference of an annular chamber to be formed between a tank body 31 and the cap 32 through a breather pass can be sealed. The annular seal member 50 is fixed on the upper surface of the tank body 31 surrounding a filler opening 35. The connecting route 52 leading the annular chamber 51 to the outside is prepared extending downward from the annular chamber along the upper surface of the tank body 31. It is prepared on the seal member 50 itself and at least one side between the seal member 50 and the tank body 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tank body mounted on a vehicle body frame having a filler port on an upper surface, and a breather passage for guiding breather gas from the tank body so that the filler port can be opened and closed. The present invention relates to a motorcycle fuel tank including a cap that closes and at least the periphery of the filler port is covered with a cover, and particularly to an improvement in a seal structure of the filler port.

[0002]

2. Description of the Related Art Conventionally, such a fuel tank has been already known, for example, from Japanese Patent Application Laid-Open No. Hei 7-112682. In this fuel tank, a cover for covering the periphery of a fuel filler for mounting an instrument, a tank body and An annular seal member surrounding the oil supply port is interposed between the seal members, and a communication passage leading to a breather passage provided in the cap is provided in the seal member so as to extend substantially horizontally.

[0003]

SUMMARY OF THE INVENTION In the above prior art,
Since the cover is attached to the tank body, it is easy to make the relative positions of the tank body and the cover highly accurate, and it is possible to prevent water from entering around the seal member when left in the rain or when the car is washed. However, there is also a motorcycle in which the tank body is mounted on the body frame such that the tank body is substantially covered with a cover that covers the body frame and is fixed to the body frame so that the cap of the fuel tank projects from the cover. If such a conventional seal structure is applied to such a motorcycle, it is difficult to make the relative positions of the tank body and the cover highly accurate, and it is possible to prevent water from entering around the seal member when left in the rain or when the car is washed. I can't. In this case, if the pressure in the tank body is reduced by cooling the tank body or the like, there is a possibility that water around the seal member may enter the tank body through the communication passage of the seal member.

The present invention has been made in view of such circumstances, and prevents water from entering the tank main body regardless of the relative positional accuracy of the cover and the tank main body at least surrounding the fuel filler opening. An object of the present invention is to provide a fuel filler seal structure for a motorcycle fuel tank with improved versatility.

[0005]

In order to achieve the above object, the present invention is directed to a tank body mounted on a vehicle body frame having an oil supply port on an upper surface, and a breather gas from the tank body. A cap having a leading breather passage to close and close the refueling port so as to be openable and closable, wherein at least a fuel tank for a motorcycle in which a periphery of the refueling port is covered with a cover, wherein a tank body and the cap communicate with the breather passage. An annular sealing member that seals the entire periphery of the cap so as to seal the outer peripheral side of the annular chamber formed therebetween, is fixed to the upper surface of the tank body around the oil supply port, and the sealing member Itself, and at least one between the seal member and the tank body,
A communication path for communicating the annular chamber to the outside is provided so as to extend downward from the annular chamber along the upper surface of the tank body.

According to such a configuration, the communication passage for communicating the annular chamber leading to the breather passage of the cap to the outside becomes lower as it goes from the inner end opening to the outer end opening. Sometimes, even if water infiltrates the seal member from outside the cover, the water does not rise to the annular chamber side in the communication passage, and water does not enter the tank body regardless of the relative positional accuracy of the cover and the tank body. It is possible to prevent intrusion. Further, the present invention can be applied to a plurality of types of motorcycles having different relative relationships between the cover and the tank body.

[0007] The invention according to claim 2 provides the above-described claim 1.
In addition to the configuration of the invention described in the above, the communication passage is formed with an orifice portion having a smaller flow area than other parts of the communication passage. Even if the pressure inside the tank body is reduced due to cooling or the like, the outer end opening of the communication passage does not become negative pressure,
Water can be more reliably prevented from entering the tank body from the communication passage.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on one embodiment of the present invention shown in the attached drawings.

1 to 8 show one embodiment of the present invention. FIG. 1 is a side view of a scooter type vehicle, FIG. 2 is a partially cutaway side view of a fuel tank, and FIG. 4 is an enlarged sectional view taken along line 3-3, FIG. 4 is a plan view of the second seal member, and FIG.
6 is an enlarged sectional view taken along line 6-6 of FIG. 2, FIG.
2 is an enlarged sectional view taken along line 7-7 of FIG. 2, and FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG.

First, in FIG. 1, a body frame F of a scooter type vehicle, which is a motorcycle, has a front frame 11 formed by casting an aluminum alloy or the like and a front frame 11 formed by casting an aluminum alloy or the like. The vehicle includes a rear frame 12 fastened to an end, and a subframe 13 formed by processing a metal pipe and fastened to a rear end of the rear frame 12.

The front frame 11 includes a head pipe section 14.
A down frame portion 15 extending rearward and downward from the head pipe portion 14; and a pair of left and right floor support frame portions 16 and 16 extending rearward from a lower end of the down frame portion 15.
And are integrally formed. Thus, the rear frame 12 is fastened to the rear ends of both floor support frame portions 16, 16.

A front fork 17 straddling the front wheel WF is slidably supported on a head pipe portion 14 provided at the front end of the front frame 11. The front fork 1
The lower end of the front fork 17 is disposed forward of the axle 18 of the front wheel WF. The other end of a link 19 having one end connected to the lower end of the front fork 17 is connected to the axle 18. A front cushion 20 is provided between the portion and an intermediate portion of the link 19. A steering handle 21 is connected to the upper end of the front fork 17.

An engine E arranged in front of the rear wheel WR
A power unit P including a continuously variable transmission M disposed on the left side of the rear wheel WR is swingably supported at an intermediate portion of the rear frame 12 in the front-rear direction via an anti-vibration link 22. The engine E is, for example, a water-cooled, single-cylinder, four-cycle engine having cylinders arranged substantially horizontally toward the front of the vehicle body. The continuously variable transmission M is, for example, a belt type.

A rear wheel WR is pivotally supported at a rear portion of the power unit P, and a rear portion of the power unit P and a rear frame 1 are provided.
A rear cushion unit 23 is provided between the two. An air cleaner 24 disposed on the upper side of the rear wheel WR is attached to a rear portion of the power unit P. The air cleaner 24 is connected to the engine E via a carburetor 25. An exhaust pipe 2 for guiding exhaust gas from the engine E;
6 extends from the engine E to the right side of the rear wheel WR, and the exhaust pipe 26 is connected to an exhaust muffler 27 arranged on the right side of the rear wheel WR. Further, a stand 28 is rotatably supported by the engine E.

On the upper surface of the intermediate portion of the rear frame 12, a storage box 29 capable of storing a helmet or the like is supported so as to be disposed above the engine E and the carburetor 25. Is the fuel tank 30
Is supported.

The body frame F has a cover 3 made of synthetic resin.
The cover 34 includes a leg shield 34a covering the front of the driver's feet, a step floor 34b connected to a lower portion of the leg shield 34a for placing the driver's feet, and a lower part of the step floor 34b. An undercover 34c that covers the leg shield 34a and the step floor 34b,
And a side cover 34d connected to the under cover 34c and covering the rear portion of the vehicle body from both sides.

Most of the storage box 29 supported on the rear frame 12 and the tank body 31 supported on the sub-frame 13 are covered with the side cover 34d, and can cover the storage box 29 from above. The seat 33 is attached to the upper part of the side cover 34d so as to be openable and closable. The fuel injection cap 32 of the fuel tank 30 is disposed so as to protrude upward from the upper portion of the side cover 34d.

In FIG. 2, the tank main body 31 is formed by connecting a lower tank half 31a and an upper tank half 31b to each other, and an oil supply port 35 is opened in a front upper surface of the upper tank half 31b. The upper surface of the upper tank half 31b at the rear side of the filler port 35 forms an inclined surface 36 which becomes lower toward the rear.

Referring also to FIG. 3, the cap 32 is
The fuel supply port 35 is openably and closably closed. The cap main body 37 is made of synthetic resin, a synthetic resin lid member 38 is polymerized on the outer end of the cap main body 37, and the lid member 3
A cover member 38 and a metal protection member 39 that covers the cap main body 37 are provided so as to maintain a state in which the cap 8 is superimposed on the cap main body 37.

The cap body 37 has a cylindrical portion 37a and a flange portion 37 extending radially outward from an outer end of the cylindrical portion 37a.
b, and the lid member 38 is formed integrally with the cylindrical portion 3.
Polymerized to the outer end of 7a. The protective member 39 is formed in a dish shape so as to cover the lid member 38 and the cap main body 37 from the side of the lid member 38, and the peripheral edge of the opening end of the protective member 39 is swaged to the peripheral edge of the flange portion 37b. Be combined.

An inner cylinder 40 is rotatably accommodated in the cylindrical portion 37a of the cap main body 37 so as to be rotatable by operating a key (not shown). Sliders 41 are arranged on the cylindrical portion 37a so as to be slidable in a direction perpendicular to the axis of the inner cylinder 40. Thus, the inner cylinder 40 and the slider 4
.. Constitute a lock mechanism 42. When the inner cylinder 40 is rotated by a key, the sliders 41 slide in a locked state in which the sliders 41 engage with the tank body 31. , The sliders 41 can be switched between an unlocked state in which the engagement with the tank body 31 is released.

An outer peripheral portion of an annular first seal member 43 is held by a flange portion 37b of the cap main body 37. When the oil supply port 35 is closed by the cap 32, the first seal member 43 is closed. Contacts the periphery of In addition, a spring 44 is provided between the cylindrical portion 37a and the first seal member 43 to bias the first seal member 43 in a direction in which the first seal member 43 comes into contact with the peripheral portion of the oil filler port 36.

A breather chamber 45 formed between the cylindrical portion 37a of the cap main body 37 and the cover member 38 and a passage 46 opened to the outer surface of the cylindrical portion 37a on the inner side of the first seal member 43. In between, a first valve 47 is provided which allows the gasket in the tank body 31 to escape into the breather chamber 45 little by little and opens the valve in accordance with the increase in the pressure in the tank body 31. Further, in the cylindrical portion 37a, gas-liquid in the breather chamber 45 is separated and only the fuel oil is supplied to the tank body 3a.
There is also provided a second valve 48 for returning to the inside.

The cap main body 37 is provided with a breather passage 49 having an inner end communicating with the breather chamber 45.
The outer end of the breather passage 49 is connected to the first seal member 4.
The outer side of the contact portion with the tank body 31 of the
7b.

On the upper surface of the tank body 31,
An annular second seal member 50 is fixed around the cover member 5 by, for example, a double-sided adhesive tape, and the second seal member 50 is in close contact with the entire periphery of the opening edge of the protective member 39 in the cap 32. Thus, an annular chamber 51 is formed between the tank body 31 and the cap 32, the inner peripheral side of which is sealed by the first seal member 43 and the outer peripheral side of which is sealed by the second seal member 50.
Is open to the annular chamber 51.

In FIGS. 4 and 5, the second seal member 50 includes a ring-shaped seal main portion 50a, a lip portion 50b connected to the inner peripheral portion of the seal main portion 50a, and a circumferential direction 1 of the seal main portion 50a. And an extension 50c extending radially outward from the location, and the extension 50c is
It is formed along the inclined surface 36 on the upper surface of the tank body 31. Thus, the second portion 50c fixed to the upper surface of the tank body 31 so that the extension portion 50c extends along the inclined surface 36
The lip 50b of the seal member 50 resiliently and closely contacts the entire periphery of the opening of the protective member 39 in the cap 32.

6 to 8, a portion corresponding to the extending portion 50c is provided between the upper surface of the second seal member 50 and the tank body 31 and the extending portion 50c of the second seal member 50. The communication path 5 that allows the annular chamber 51 to communicate with the outside.
2 is provided with, for example, a rectangular cross-sectional shape, and the communication passage 50 is formed by extending the annular portion 51 from the annular chamber 51 to the upper surface Is formed so as to extend downward along.

Further, in the portion near the inner end of the communication passage 52,
An orifice portion 52a having a smaller flow area than other portions of the communication passage 52 is formed.

Next, the operation of this embodiment will be described. An annular second seal member for sealing the outer peripheral side of an annular chamber 51 formed between the tank body 31 and the cap 32 through a breather passage 49 provided in the cap 32. 50
Is fixed to the upper surface of the tank main body 31 around the fuel supply port 35, and a communication passage 52 for communicating the annular chamber 51 to the outside is provided between the second seal member 50 itself and the second seal member 50 and the tank main body 31. It is provided so as to extend downward from the annular chamber 51 along the upper surface of the tank body 31. That is, the annular chamber 5 communicating with the breather passage 49 of the cap 32
Since the communication passage 52 that allows the outside 1 to go to the outside becomes lower as it goes from the inner end opening to the outer end opening, water permeates around the second seal member 50 from outside the cover 34 when left in the rain or during car washing. However, the water does not rise in the communication passage 52 toward the annular chamber 51, and the tank body 3 does not matter regardless of the relative positional accuracy of the cover 34 and the tank body 31.
1 can be prevented from entering water, and the cover 3
4 and the tank body 31 can be applied to motorcycles of a plurality of different models.

Since the orifice portion 52a having a smaller flow area than the other portion of the communication passage 52 is formed in the communication passage 52, the tank body 31 is cooled by cooling the tank body 31 or the like. Even if the internal pressure is reduced, the communication path 5
No negative pressure is applied to the outer end opening of the tank 2, and the intrusion of water from the communication path 52 into the tank body 31 can be more reliably prevented.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, in the above embodiment, the tank body 31
Has been described in a case where the present invention is applied to a motorcycle in which almost the entirety is covered by a cover 34. However, in the present invention, as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-112682 or the like, only the vicinity of an oil filler port is covered by a cover. It is also applicable to motorcycle fuel tanks of the type.

[0033]

As described above, according to the first aspect of the present invention, it is possible to prevent water from entering the tank body regardless of the relative positional accuracy of the cover and the tank body. Further, the present invention can be applied to a plurality of types of motorcycles having different relative relationships between the cover and the tank body.

According to the second aspect of the present invention, it is possible to more reliably prevent water from entering the tank body from the communication passage.

[Brief description of the drawings]

FIG. 1 is a side view of a scooter type vehicle.

FIG. 2 is a partially cutaway side view of a fuel tank.

FIG. 3 is an enlarged sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a plan view of a second seal member.

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 2;

FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 2;

FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 ... Tank main body 32 ... Cap 34 ... Cover 35 ... Oil supply port 49 ... Breather passage 50 ... Seal member 51 ... Annular chamber 52 ... Communication passage 52a ... Orifice F: Body frame

[Procedure amendment]

[Submission date] April 21, 2000 (200.4.2
1)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 2

[Correction method] Change

[Correction contents]

FIG. 2

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiaki Noda 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Inventor Hiroyuki Ito 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (reference) 3D038 CA22 CB01 CC14 CC15

Claims (2)

[Claims] 1. A tank body (31) having an oil supply port (35) on an upper surface and mounted on a body frame (F), and a breather passage (49) for guiding breather gas from the tank body (31). And a cap (32) for opening and closing the fuel supply port (35) so as to be openable and closable, wherein at least the periphery of the fuel supply port (35) is covered with a cover (34). An annular chamber that is in close contact with the entire periphery of the cap (32) so as to seal the outer peripheral side of an annular chamber (51) formed between the tank body (31) and the cap (32) through the cap (32). A seal member (50) is fixed to the upper surface of the tank body (31) around the oil supply port (35), and the seal member (50) itself and the seal member (50) are provided.
A communication passage (52) for communicating the annular chamber (51) to the outside extends downward at least at one side between the annular chamber (51) and the tank body (31) along the upper surface of the tank body (31). A fuel filler seal structure in a motorcycle fuel tank, which is provided as described above. 2. The communication path (52) is provided in the communication path (52).
2) The fuel filler port seal structure for a motorcycle fuel tank according to claim 1, wherein an orifice part (52a) having a smaller flow area than other parts is formed.