Land vehicles – Tank or boiler – Saddle type; vehicle frame straddling
Reexamination Certificate
1997-12-15
2001-04-10
Hurley, Kevin (Department: 3619)
Land vehicles
Tank or boiler
Saddle type; vehicle frame straddling
C280S834000
Reexamination Certificate
active
06213514
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel tank system of a motor bicycle wherein its tank main body is integrally molded out of a synthetic resin so as to freely form a shape of the tank, increase a capacity of the tank, and to facilitate a process of manufacturing the tank itself.
2. Description of the Related Art
For example, in the case where a fuel supply port of the aforesaid tank main body made of a synthetic resin is provided with a flat surface recessed type tank cap that is referred to as an aircraft type tank cap, there has been employed a structure in which the fuel supply port of the tank main body is provided with a metallic receiving pan portion, and a tank cap is fixed onto the receiving pan portion by means of a bolt.
While driving in rainy weather or during refueling, water or fuel may gather on the surface of the receiving pan portion. For this reason, there is a need for a drain pipe to discharge water or fuel from the surface of the receiving pan portion. Conventionally, a metallic pipe has been used as the drain pipe. The metallic pipe typically passes through so as to provide a connection between the receiving pan portion and a relay joint, which is provided in the tank main body itself. The relay joint is attached in an inconspicuous place such as the inside of a portion where the tank main body rides on a vehicle-body frame, and is also connected so that a hose extends to the outside therefrom.
However, tank main bodies that are made of a synthetic resin have a number of disadvantages. Specifically, when the tank main body swells due to contact with a fuel, it then becomes slightly deformed (e.g., mainly enlarged) in its whole dimensional shape. For this reason, there is a possibility that a spacial dimension between the receiving pan portion of the fuel supply port and the relay joint varies. In such a case, a metallic drain pipe having no expandability is not adaptable to a dimensional deformation between the receiving pan portion and the relay joint. Because the metallic drain pipe is not adaptable, an unreasonable force is applied to a connective section of the drain pipe. As a result, there is a possibility of causing deterioration in seal performance. Further, because the metallic drain pipe is not capable of being formed into a complicated or curved shape a drain discharge direction cannot be easily selected.
Moreover, if the tank main body is made of metal, then during assembling (e.g., a welding process) the drain pipe is simultaneously assembled into the interior of the tank main body. If the tank main body is made of a synthetic resin, however, the following process is required. After the tank main body is molded, a worker inserts a hand through the fuel supply port and into the interior of the tank main body to assemble the relay joint and the drain pipe therein. Then, the receiving pan portion is attached to the fuel supply port. As a result, assembling workability or performance of the tank main body is worsened depending upon where the relay joint is positioned.
As also described above, the tank main body swells due to contact with a fuel. For this reason, a fixed portion of the tank main body must be attached so as to be relatively movable with respect to the vehicle-body frame. This is so because the fixed portion must be floatingly fixed to the vehicle-body frame in order to achieve a vibration-proof tank main body.
To give a general example of a conventional fuel tank system, a front portion of the tank main body made of a synthetic resin has been provided with two right and left front portion fixing members while a rear portion thereof is provided with one rear portion fixing member. The front portion fixing member is formed like a plate that is parallel to a central surface of the vehicle body (i.e., in a longitudinal direction), and the front portion fixing member is fastened to the vehicle-body frame by means of a fixed bolt that penetrates along a vehicle width direction. On the other hand, the rear portion fixing member is formed like a substantially horizontal plate, and the rear portion fixing member is fastened to the vehicle-body frame by means of a fixed bolt that penetrates along a vertical (i.e., up and down) direction.
For example, a fixed bolt insertion hole of the rear portion fixing member is formed like a slot. Even if a dimension of the tank main body varies due to swelling, the rear portion fixing member is relatively slidable with respect to the fixed bolt so that a dimensional deformation of the tank main body can be absorbed. Further, rubber cushions or the like are interposed between three respective front and rear fixing members and the fixed bolt. As a result, vibration of the vehicle body may be prevented from being transmitted directly to the tank main body.
As described above, the front portion fixing member supporting the front portion of the tank main body has been formed like a plate that is parallel to the central surface of the vehicle body. For this reason, if the tank main body expands to a large scale size, then a high load acts along a direction of shearing the cushion rubber. Moreover, during rough road driving conditions or the like, a great push-up reactive force from a front fork may be applied to the tank main body via the front portion fixing member. Therefore, the rubber cushions may be crushed. As a result, it has been difficult to obtain a sufficient vibration-proof effect with respect to reactive forces in the vertical direction.
In addition, if the tank main body expands to a large scale size, then a dimensional deformation becomes large when the tank main body swells as a result of being spread in various directions. For this reason, even if only one of fixing members is fixed so as to be relatively movable with respect to the vehicle frame, it is impossible to absorb a dimensional deformation of the whole tank main body. For this reason, there is a high possibility that an unreasonable deformation stress is applied to the tank main body.
Further, there is a motor bicycle in which the tank main body made of a synthetic resin is covered with a frame cover made of a synthetic resin in order to protect the tank main body and to freely make a design having an attractive appearance. In this type of motor bicycle, if a structure is employed such that the frame cover is fixed directly to the tank main body, an unreasonable force may be applied to the frame cover due to a dimensional deformation, which may be caused by swelling of the tank main body. For this reason, the frame cover may become warped or damaged.
In view of the above circumstances, the following conventional fixing structure has been employed. Specifically, the frame cover is fixed to other members (e.g., vehicle-body frame or the like) positioned at the vicinity of the tank main body without being fixed directly to the tank main body. Or, only one portion of the frame cover is fixed to the tank main body, and other portions of the frame cover are fixed to the tank main body through the use of a surface fastener or the like so that a positioning correction can be easily made.
In the case where a relatively small tank main body is covered by a one-piece type frame cover, there is no problem even if the aforesaid fixing structure is employed. However, if the tank main body is enlarged to a large scale size, it is difficult to perform integral molding of the frame cover, and the frame cover must be constructed by being divided into a plurality of cover members and then joining these cover members together. For this reason, with the aforesaid fixing structure, a shift, unevenness or the like may occur between each of the plurality of cover members or between the cover members and the tank main body itself. As a result, the visible appearance around the fuel tank system may be remarkably deteriorated.
In a general fuel tank system of a motor bicycle, the tank main body has a shape of a reverse U-letter shaped longitudinal section (e.g., substantially the shape of a horseshoe), and
Natsume Tetsuji
Tokunaga Katsuhiko
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Fischer Andrew J.
Hurley Kevin
Suzuki Kaisha Toshiba
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