JP6251818B2 - Vehicle fuel tank structure - Google Patents

Description

  The present invention relates to a fuel tank structure for a vehicle that can accurately detect the remaining amount of fuel.

2. Description of the Related Art Conventionally, there is a type in which a liquid level detection sensor provided in a fuel tank is provided with a float arm so as to be rotatable and the fuel level is detected by moving the float up and down via the float arm.
By the way, fuel tanks have various shapes specific to the vehicle depending on the capacity and mounting position on the vehicle, and the movable range of the float and float arm is determined according to the fuel tank shape, its mounting direction and the fuel level. Thus, the mounting position of the liquid level detection sensor main body is designed.
For example, as shown in Patent Document 1 below, a fuel tank of a small vehicle disposed in a space such as below a passenger seat often has a shape that is slender and slanted forward and backward.

Therefore, in the following Patent Document 1, in order to increase the swing angle when the float is moved up and down in the fuel tank, the swing arm is secured by moving the float arm to which the float is attached in the front-rear direction. ing.
However, since the float draws a pendulum trajectory centering on a connection point where the float arm is connected to the liquid level detection sensor main body, it is necessary to make the float arm long and bent in order for the float to move up and down.
However, if the float arm is lengthened in this way, it may be necessary to review the shape of the fuel tank and the layout of the liquid level detection sensor so that the space for moving the float in the tank can be made longer and larger. .
Therefore, in the detection of the remaining amount of the fuel tank by such a liquid level detection sensor, it has been desired that the remaining amount can be accurately detected by increasing the swing angle of the float arm even when the float arm is kept as short as possible.

Japanese Patent No. 5352008 (FIGS. 1-5, 13)

  The present invention has been made in view of the above prior art, and in a fuel tank mounted on a vehicle with at least an upper surface inclined, the float angle of the float arm can be increased without being restricted by the shape of the float arm. An object of the present invention is to provide a fuel tank structure for a vehicle that can accurately detect the remaining amount of fuel in the fuel tank.

  In order to solve the above-described problems, the present invention provides a vehicle in which a fuel tank is mounted on a vehicle with at least an upper surface inclined, and a liquid level detection device is attached to the inside of the fuel tank to detect the remaining amount of fuel. In the fuel tank structure, a liquid level detection sensor constituting the liquid level detection device, and a float arm having one end side pivotably connected to the liquid level detection sensor and a float attached to the other end side, The float arm is attached to the liquid level detection sensor so as to be able to swing up and down according to the liquid level in the fuel tank, and the liquid level detection sensor swings the float arm swinging up and down. The fuel tank is configured to output an electrical signal corresponding to the liquid level according to the angular position, and the fuel tank is provided with a bulging portion having its upper surface bulged and formed on the inner surface of the bulging portion. Recessed The part is a fuel tank structure for a vehicle, characterized in that before the level of the liquid surface detection highest liquid level to be detected by the sensor is set.

  In a preferred embodiment of the present invention, the liquid level detection sensor may detect a vertical position of the float, and the float arm may be formed linearly.

  In a preferred embodiment of the present invention, a fuel filler port of the fuel tank is disposed higher than the bulging portion, and the highest liquid level is defined by a horizontal plane including a position of a lower end opening of the fuel filler port, The protruding part can swell up to the horizontal plane.

  In a preferred embodiment of the present invention, the liquid level detection device is attached to a fuel pump unit attached to the fuel tank, and the fuel pump unit is arranged with its center closer to one side with respect to the vehicle left-right center, The liquid level detection device is arranged on the other side.

  In a preferred embodiment of the present invention, the fuel tank is disposed between the lower part of the passenger seat and the upper part of the rear wheel, and the lower surface of the fuel tank is provided with the rear wheel at the time of swinging. An upwardly-facing dent to avoid interference is provided extending forward and backward at the left and right center of the vehicle of the fuel tank, and the position at the lowest liquid level of the float is set above the dent in a side view. You can also.

  In a preferred embodiment of the present invention, a recess is formed in the seat bottom plate of the riding seat facing the upper surface of the fuel tank so as to escape interference with the bulging portion.

  In a preferred embodiment of the present invention, the bulge portion of the fuel tank is disposed only on the side of the left and right sides of the vehicle where the float of the liquid level detection device is located, and is a recess in the seat bottom plate. May be formed symmetrically on both the left and right sides.

  In a preferred embodiment of the present invention, the seat bottom plate is provided with a tool fixing portion for holding the vehicle maintenance tool, and the recess portion of the seat bottom plate is attached to the tool fixing portion and the fuel tank. The fuel pump unit is formed so as to be positioned between the portion facing the fuel pump unit, and the mounting position of the fuel pump unit to the fuel tank is formed on a mounting seat surface lower than the upper surface of the adjacent fuel tank. The

  According to the present invention, in a fuel tank liquid level detection device mounted on a vehicle in a state where at least the upper surface is inclined, a bulging portion is formed on the upper surface of the fuel tank, and the fuel tank formed by the bulging portion Since the inside of the recess on the inner surface is the position of the float of the liquid level detection device when the fuel is at the maximum liquid level level, the state of the highest liquid level of the fuel is detected by the float that has moved upward This makes it possible to increase the swing angle of the float arm without being restricted by the shape of the float arm, and to accurately detect the remaining amount of fuel.

  In one embodiment of the present invention, since the float is located in the bulging portion of the fuel tank at the highest liquid level, the float arm is linearly moved with the liquid level detection sensor of the liquid level detection device detecting the vertical position of the float. Even if it is formed in a shape, the maximum liquid level can be detected, and the liquid level detecting device can be made compact.

  According to one embodiment of the present invention, the fuel filler port of the fuel tank is disposed higher than the bulge portion, and the maximum liquid level height is defined by the position of the lower end opening of the fuel filler port. It is possible to easily design the float position and the height of the bulge portion of the fuel tank.

  Furthermore, according to one embodiment of the present invention, the center of the fuel pump unit is moved closer to one side of the fuel tank and the liquid level detection device is arranged closer to the other end. Thus, the space for arranging the liquid level detection device can be secured.

  Further, according to an embodiment of the present invention, the lower surface of the fuel tank is formed with an upward recess to avoid interference with the rear wheel, and the position of the float at the lowest liquid level of the actual fuel tank is at the bottom. Even when it is displaced from the upper part of the dent, the bulge is provided on the upper surface of the fuel tank and the maximum liquid level can be detected, so the liquid level detection range is from the lowest liquid level to the highest liquid level. Can take.

  According to one embodiment of the present invention, the bulge portion that escapes the bulge portion of the fuel tank is formed in the seat bottom plate where the space between the fuel tank and the seat bottom plate is reduced by forming the bulge portion in the fuel tank. By doing so, it is possible to secure a gap with the bulging portion of the fuel tank, to suppress an increase in the seat seating height, and to maintain the vehicle footing.

  According to one embodiment of the present invention, according to the invention of claim 7, in addition to the effect of the invention of claim 6, it is a case where the bulging portion is formed only on the side where the float is located. In addition, since the recessed portions of the seat bottom plate are formed symmetrically on the left and right sides, the right and left balance of the rigidity of the seat bottom plate can be achieved, and the uncomfortable feeling of sitting comfort can be reduced.

  According to one embodiment of the present invention, since the recessed portion of the seat bottom plate is disposed between the tool fixing portion of the seat bottom plate and the portion facing the fuel pump unit, the tool fixing portion is not provided even if the recessed portion is provided. It is provided at the rear of the recess and can be secured without sacrificing the installation space for the maintenance tool.Furthermore, the fuel tank is attached to an attachment seat that is one step lower than the upper surface of the adjacent fuel tank, so that the fuel pump unit can be expanded upward. It is possible to avoid the protruding portion from interfering with the sheet bottom plate or the like.

1 is a left side view schematically showing a vehicle body cover and a riding seat of a motorcycle according to an embodiment of the present invention. FIG. 2 is a side cross-sectional view of the vicinity of the left and right center line X of the motorcycle around the fuel tank and the riding seat of FIG. 1. FIG. 3 is a front cross-sectional view of the vicinity of a fuel tank and a riding seat as viewed in the direction of arrows III-III in FIG. 2 corresponds to a cross section taken along the line II-II in FIG. FIG. 3 is a left side view of the fuel tank according to the present embodiment, and shows a tilted posture mounted on a motorcycle shown in FIG. 2. FIG. 5 is a top view of the fuel tank as viewed in the direction of arrows VV in FIG. 4. 4 corresponds to a view taken along the arrow IV-IV in FIG. FIG. 3 is a left side view of the riding seat according to the present embodiment, and shows a posture attached to the motorcycle shown in FIG. 2. FIG. 7 is a bottom view of the riding seat as viewed in the direction of arrows VII-VII in FIG. 6. 6 corresponds to the view taken along the line VI-VI in FIG.

A vehicle fuel tank structure according to an embodiment of the present invention will be described with reference to FIGS.
The directions such as front and rear, left and right, up and down in the claims and in the description of the present specification are in accordance with the direction of the vehicle including the fuel tank structure of the present embodiment. In the present embodiment, the vehicle is a small vehicle such as a straddle-type vehicle having an internal combustion engine mounted on a body frame and provided with the fuel tank structure of the vehicle of the present embodiment, and specifically, a motorcycle.
In the figure, arrow FR indicates the front of the vehicle, LH indicates the left side of the vehicle, RH indicates the right side of the vehicle, and UP indicates the upper side of the vehicle.

FIG. 1 is a left side view of a motorcycle 1 having a vehicle fuel tank structure according to an embodiment of the present invention, in which a vehicle body cover 29 and a riding seat 8 are simply illustrated by two-dot chain lines.
As shown in FIG. 1, a body frame 2 of a motorcycle 1 as a vehicle is connected to a head pipe 20, a pair of left and right main frames 21 extending obliquely downward and rearward from the head pipe 20, and a lower rear end of the main frame 21. A pair of left and right center frames 22 extending downward, a pair of left and right seat rails 23 connected to the upper rear end of the main frame 21 and extending obliquely upward and rearward, and a center portion of the center frame 22 (rear position of the internal combustion engine 3) ), And a pair of left and right side frames 24 that are stretched over the rear portion of the seat rail 23.
A front fork 11 that supports the front wheel 10 is supported by a head pipe 20 so as to be steerable, and a steering handle 12 is connected to an upper portion of the front fork 11. A swing arm 14 that supports the rear wheel 13 is supported on the center frame 22 via a pivot bolt 15 so as to be swingable up and down.

The internal combustion engine 3 is a water-cooled single-cylinder four-stroke cycle internal combustion engine. As shown in FIG. 1, the crankshaft 31 is oriented in the vehicle width direction, and a power unit including a transmission is provided in the crankcase 30. It is supported by a support bracket 21a of the main frame 21 and a plurality of support brackets 22a of the center frame 22 (only the bottom end portion is shown).
The power of the internal combustion engine 3 is transmitted to the rear wheel 13 via a rear wheel drive sprocket 16 and a rear wheel drive chain 17 fitted to an output shaft 32 parallel to the crankshaft 31.
A radiator 33 is disposed in front of the internal combustion engine 3 to cool the cooling water.

  Referring also to FIG. 2, a rear cushion 18 is interposed between the front side of the seat rail 23 and the swing arm 14. Between the left and right seat rails 23, a pipe-like second cross member 25B is provided adjacent to the rear cushion mounting portion 23a. An air cleaner 50 or the like is attached in front of the second cross member 25B, and a fuel tank 6 is attached in the rear of the second cross member 25B.

As shown in FIG. 1, a reinforcing pipe 26 is bridged between the second cross member 25 </ b> B and the middle of the side frame 24.
27 is a main stand, and 28 is a side stand.
As shown in FIGS. 1 and 2, a riding seat 8 is attached from above the air cleaner 50 to above the fuel tank 6.
The vehicle body frame 2, the fuel tank 6, the air cleaner 50, and the like are covered with a vehicle body cover 29 schematically shown by a two-dot chain line in FIG.

As shown in FIG. 1, the first cross member 25 </ b> A is bridged over the upper rear ends of the left and right main frames 21 so as to be close to the front end of the air cleaner 50. As shown in FIG. 2, the first cross member 25 </ b> A has a left and right central portion that supports the front end portion 81 of the seat bottom plate 80 of the riding seat 8 and allows the rear portion of the riding seat 8 to swing up and down. A dynamic support bracket 25Aa is provided.
A third cross member 25C is bridged between the left and right seat rails 23 so as to straddle the upper part of a fuel pump unit 7 (described later) of the fuel tank 6. A left and right connecting portion 25D is provided behind the rear end of the fuel tank 6.

The air cleaner 50 is located below the driver seat portion 8a at the front portion of the passenger seat 8. The air cleaner 50 includes a dirty chamber 52 having an intake duct 51 in the upper portion, a clean chamber 54 in communication with a connecting tube 53 at the lower portion, and a cleaner element 55 between the dirty chamber 52 and the clean chamber 54.
The connecting tube 53 extends forward and is connected to an intake port (not shown) on the rear surface of the internal combustion engine 3 via a throttle body and an intake pipe (not shown). A fuel injection device (not shown) is attached to the intake pipe and injects fuel from the fuel tank 6 toward the intake port.
Further, as shown in FIG. 1, an exhaust pipe 58 extending from the front surface of the internal combustion engine 3 passes through a lower portion of the internal combustion engine 3 to a muffler 59 at the rear of the vehicle body.

4 and 5, the fuel tank 6 is composed of a tank upper half 6A and a tank lower half 6B. The upper and lower mating surfaces are configured so that flanges 60a and 60b around each half face each other. 60 is seam welded and formed as an integral fuel tank 6 with a cavity inside.
The fuel tank 6 is provided with a total of four fuel tank mounting portions 61 in the front, rear, left, and right directions. By the fuel tank mounting portions 61, the fuel tank 6 is attached to the seat rail 23 in a space between the left and right seat rails 23. The flange portion 60b is placed, arranged in a posture inclined forward and substantially along the seat rail 23, and fastened to the left and right seat rails 23.
A pump unit insertion hole 62 for inserting and mounting the fuel pump unit 7 from above and a pump unit mounting seat surface 63 as a mounting seat surface are provided on the front upper surface of the fuel tank 6, and a fuel filler opening is provided on the rear upper surface. 64 is provided.
The pump unit mounting seat 63 is set at a position lower than the fuel tank upper surface 67 adjacent thereto.

As shown in FIG. 2, the fuel tank 6 has a shape that is long in the front-rear direction (see FIG. 5) that is mounted on the motorcycle 1 while being tilted forward. The fuel pump unit 7 is inserted into the fuel tank 6 from above into a pump unit insertion hole 62 provided on the front upper surface side of the fuel tank 6, and is attached to a pump unit mounting seat 63 around the pump unit insertion hole 62. It is concluded.
The fuel pump unit 7 includes a fuel filter 71 at the lower part of the pump main body 70 inserted into the fuel tank 6, and the fuel sucked into the pump main body 70 through the fuel filter 71 is supplied to the fuel from the pump unit insertion hole 62. The fuel is supplied from the discharge pipe 72 protruding to the upper part of the tank 6 to the above-described fuel injection device via the fuel supply pipe 73 (see FIGS. 1 and 3).
As shown in FIG. 3, in the direction opposite to the discharge pipe 72, a harness 74 for signal wiring such as an electric wiring for driving the fuel pump unit 7 and an electric signal output from the liquid level detection sensor 90 is provided. Is connected.

Referring also to FIG. 3, the pump unit insertion hole 62, the pump unit mounting seat surface 63, and the fuel pump unit 7 are on the left side with respect to the vehicle body left-right center line X.
A sensor support portion 75 that supports the liquid level detection sensor 90 of the liquid level detection device 9 extends obliquely from the lower right of the pump body 70 toward the upper right rear. As shown in FIG. 2, the liquid level detection sensor 90 is supported at the tip of the sensor support portion 75.
The liquid level detection sensor 90 is rotatably provided with a rotation shaft 91 whose axis Y is perpendicular to the vehicle body left-right center line X and oriented horizontally rightward. The pivot shaft 91 is connected and fixed to one end of a linearly formed float arm 92, and the float arm 92 is supported by the liquid level detection sensor 90 together with the pivot shaft 91 so as to be swingable. A float 93 is attached to the other end side of the float arm 92.

Therefore, when the float 93 moves in the vertical direction in the fuel tank 6 in accordance with the fuel level, the float arm 92 rotates the pivot shaft 91 of the liquid level detection sensor 90, while the vehicle body centerline. The right side rear side of the liquid level detection sensor 90 is swung up and down along a plane parallel to X and perpendicular to the axis Y of the rotation shaft 91, and the swing angle position of the float arm 92 with respect to the liquid level detection sensor 90 is It is set according to the liquid level.
The liquid level detection sensor 90 is detected by the detection element with the swing angle position of the float arm 92 as the rotation angle position of the rotation shaft 91, whereby the liquid level detection sensor 90 corresponds to the liquid level height, that is, the remaining fuel level. The electric signal is output, and the fuel remaining amount is displayed on a fuel meter (not shown).
2 and 3, the positions of the float arm 92 and the float 93 when the fuel reaches the maximum liquid level Lh (see FIGS. 2 and 4) are indicated by a two-dot chain line and become the minimum liquid level. The position at the time of hitting is indicated by a solid line.

As shown in FIG. 2 and also referring to FIG. 4, the fuel tank upper surface 67 is provided with a fuel filler port 64 higher than the bulging portion 65, and the rear portion of the riding seat 8 is connected to the first portion. The rocking support bracket 25Aa on the cross member 25A is rotated and raised with the fulcrum as a fulcrum, so that the oiling operation can be performed. A lower end opening 64 a that opens to the fuel tank 6 is formed at the lower end of the fuel filler port 64.
The maximum liquid level Lh of the fuel in the fuel tank 6 is defined by a horizontal plane Lh including the position of the lower end opening 64a of the fuel filler port 64, and the bulging portion 65 of the fuel tank 6 swells up to the horizontal plane Lh. .
Since the fuel filler port 64 of the fuel tank 6 is arranged higher than the bulging portion 65 and the maximum liquid level Lh is defined at the position of the lower end opening 64a of the fuel filler port 64, the float 93 of the maximum liquid level Lh The setting of the position and the height of the bulging portion 65 of the fuel tank 6 becomes easy, and the design of the fuel tank 6 is easy.

Further, as shown in FIG. 3, the fuel pump unit 7 is attached to the fuel tank 6 toward the left side with respect to the vehicle body left-right center line X as the vehicle left-right center, and the liquid level detection device 9 is The fuel pump unit 7 is supported by the sensor support portion 75 of the pump main body 70 so as to be arranged on the right side with respect to the left-right center line X.
Since the center of the fuel pump unit 7 is arranged closer to the left side of the fuel tank 6 and the liquid level detection device 9 is arranged closer to the right side of the fuel tank 6, the fuel pump unit 7 is disposed in the limited fuel tank 6. A space for arranging the tank 6 and the liquid level detection device 9 is secured.

As the float 93 is arranged closer to the right side in the fuel tank 6, as shown in FIGS. 4 and 5, the fuel tank 6 has a surrounding fuel tank upper surface 67 on the right side of the fuel tank upper surface 67. A bulging portion 65 that is further bulged is provided, and the position of the float 93 when the fuel reaches the maximum liquid level Lh is set inside the recess 66 formed on the inner surface of the bulging portion 65. (See FIG. 2).
Therefore, even if the fuel tank 6 is mounted on the motorcycle 1 with the upper surface inclined, when the fuel reaches the maximum liquid level Lh, the fuel tank 6 moves upward and the recess 66 on the rear surface of the bulging portion 65 is moved. The float 93 that reaches the inside of the engine can detect the state of the maximum liquid level Lh of the fuel, and the swing angle of the float arm 92 can be increased without being restricted by the shape of the float arm 92, so that the remaining fuel level can be detected accurately. Can be done well.

  Further, even if the float arm 92 is formed in a straight line so as to detect the vertical position of the float 93, the liquid level detection sensor 90 is positioned within the bulging portion of the fuel tank 6 so that the highest liquid is detected. The liquid level can be detected at the surface level Lh, and the liquid level detecting device 9 can have a compact structure.

Further, as shown in FIG. 1, the fuel tank 6 is disposed below the riding seat 8 and above the rear wheel 13. In FIG. 1, the fuel tank 6 is schematically shown by a two-dot chain line 13 '. As shown, the rear wheel 13 may approach the fuel tank 6 by swinging up and down.
Therefore, in order to avoid interference with the fuel tank 6 of the rear wheel 13 when swinging up and down, the fuel tank 6 is provided with a concave portion 68 that extends upward and backward in the center of the left and right (see FIG. 2, see FIGS. 3, 4, and 5).

  As described above, since the concave portion 68 directed upward is formed on the lower surface of the fuel tank 6 in order to avoid interference with the rear wheel 13, the actual position of the float 93 at the lowest liquid level of the fuel tank 6 is determined. In the present embodiment, the position of the float 93 at the lowest liquid level is seen in a side view so that it can be detected from the lowest liquid level to the highest liquid level Lh even when displaced from the bottom and above the recess 68. Is set above the recess 68. On the other hand, since the bulging portion 65 is provided on the upper surface of the fuel tank 6 and the highest liquid level Lh can be detected, the liquid level detection range can be taken from the lowest liquid level to the highest liquid level Lh.

As described above with reference to FIG. 2, the riding seat 8 has the front end portion 81 of the seat bottom plate 80 attached to the first cross member 25 </ b> A with the swing support bracket 25 </ b> Aa as a fulcrum. As shown in FIGS. 6 and 7, three pairs of left and right support pads 82 </ b> C, 82 </ b> T, and 82 </ b> D are provided in order from the front on the rear rear surface of the seat bottom plate 80.
The support pad 82C is placed on the third cross member 25C, the support pad 82T is placed on the seat support portion 69 (see FIG. 5) of the flange portion 60a of the fuel tank 6, and the support pad 82D is placed on the left and right connecting portion 25D. The load is supported.
A U-shaped seat lock bar 83 is erected from the seat bottom plate 80 downward in the middle and slightly forward of the left and right support pads 82D, and is provided on the vehicle body frame 2 in the vicinity of the left and right connecting portions 25D (not shown). The riding seat 8 is fixed by engaging with the locking mechanism.

  2 and 6, the riding seat 8 is formed by providing a cushion material 84 on the seat bottom plate 80 and covering the surface with a covering material 85. The lower part of the driver's seat part 8a at the front part is formed with a front recessed part 86 that is directed upward substantially avoiding the air cleaner 50 below the driver's seat part 8a, and then supported at the rear part according to the third cross member 25C. A pad 82C is attached, and at the rear part thereof, an upwardly recessed portion 87 is provided so as to face the upper surface of the fuel tank 6 and escape interference with the bulging portion 65 of the fuel tank 6.

  That is, by forming the bulging portion 65 in the fuel tank 6, the bulging portion 65 of the fuel tank 6 escapes to the seat bottom plate 80 where the gap between the fuel tank 6 and the seat bottom plate 80 becomes small if it is left as it is. By forming the recessed portion 87, a gap with the bulging portion 65 of the fuel tank 6 can be secured, and the seat seating height can be suppressed from being increased, and the vehicle footing can be maintained.

The bulging portion 65 of the fuel tank 6 is arranged only on the right side of the left and right of the vehicle center (the vehicle body left-right center line X) where the float 93 of the liquid level detection device 9 is located. In FIG. 7, as shown in FIG. 7, the recessed portions 87 of the seat bottom plate 80 are formed symmetrically on both the left and right sides.
Even in the case where the bulging portion 65 is formed only on the right side where the float 93 is formed as in the present embodiment, by forming the recessed portions 87 of the seat bottom plate 80 symmetrically on both the left and right sides, The right and left balance of the rigidity of the seat bottom plate 80 can be balanced, and the bending of the cushion material 84 can also be balanced left and right, so that the uncomfortable feeling of sitting comfort can be reduced or prevented.

A rear recess 88 facing the fuel filler port 64 of the fuel tank 6 and facing upward is formed on the rear side of the recess 87 of the seat bottom plate 80, and support pads 82T are provided on the left and right thereof. A tool fixing portion 89 that holds the maintenance tool 19 of the motorcycle 1 is provided on the lower surface between the recess portion 88 and the lower portion 88.
That is, the recess 87 of the seat bottom plate 80 is formed so as to be positioned between the tool fixing portion 89 and the portion facing the fuel pump unit 7 attached to the fuel tank 6. Even if provided, the tool fixing portion 89 is provided behind the recessed portion 87, and the mounting space for the maintenance tool 19 can be secured without sacrificing.

Further, as described above, the pump unit mounting seat surface 63 is formed one step lower than the adjacent fuel tank upper surface 67 and is the mounting position of the fuel pump unit 7 to the fuel tank 6, so that the fuel pump unit 7 It is avoided that the bulging portion upward, for example, the discharge pipe 72, the harness 74, and the mounting portion thereof interfere with the seat bottom plate 80, the third cross member 25C, and the like.
The rear depression 88 is a boundary 8c between the driver's seat 8a and the passenger's seat 8b, and contributes to raising the cushion material 84 at the boundary 8c and reinforcing the seat middle. ing.

Hereinafter, the characteristic configuration of the liquid level detection structure of the fuel tank 6 of the motorcycle 1 of the present embodiment and the operation and effect thereof will be described together.
That is, the fuel tank 6 is mounted on the motorcycle 1 with the upper surface inclined, and the liquid level detection device 9 is mounted inside the fuel tank 6 to detect the remaining fuel level. In the detection structure, a liquid level detection sensor 90 constituting the liquid level detection device 9 and a float arm 92 having one end side pivotably connected to the liquid level detection sensor 90 and a float 93 attached to the other end side are provided. I have. In the present embodiment, the float arm 92 is attached to the liquid level detection sensor 90 so as to be able to swing up and down in accordance with the liquid level in the fuel tank 6. The liquid level detection sensor 90 outputs an electrical signal corresponding to the liquid level according to the swing angle position of the float arm 92 that swings up and down. The fuel tank 6 is provided with a bulging portion 65 whose upper surface is bulged, and the highest liquid level to be detected by the liquid level detecting sensor 90 is in a recess 66 formed on the inner surface of the bulging portion 65. Level Lh is set.
For this reason, the float 93 moved upward allows the liquid level detection sensor 90 to detect the state of the maximum liquid level Lh of the fuel, and the swing angle of the float arm 92 can be increased without being restricted by the shape of the float arm 92. The remaining amount of fuel can be detected with high accuracy.

  Further, since the liquid level detection sensor 90 detects the vertical position of the float 93 and the float arm 92 is formed in a straight line, the float 93 is in the bulging portion 65 of the fuel tank 6 at the maximum liquid level Lh. Will be located. This makes it possible to detect the maximum liquid level Lh even if the liquid level detection sensor 90 of the liquid level detection device 9 detects the vertical position of the float 93 and the float arm 92 is formed linearly. And the liquid level detection apparatus 9 can be made into a compact structure.

  Further, the fuel filler port 64 of the fuel tank 6 is disposed higher than the bulging portion 65, the highest liquid level Lh level is defined by a horizontal plane Lh including the position of the lower end opening 64a of the fuel filler port 64, and the bulging portion 65 is the same. It bulges up to the horizontal plane Lh. This makes it possible to easily design the float 93 position at the maximum liquid level Lh and the height of the bulging portion 65 of the fuel tank 6.

  The liquid level detection device 9 is attached to a fuel pump unit 7 attached to the fuel tank 6, and the fuel pump unit 7 is disposed on the left side that is one side with respect to the left-right center line X of the vehicle body. Since the surface detecting device 9 is arranged on the right side which is the other side, the space for arranging the liquid level detecting device 9 in the space in the fuel tank 6 can be secured.

  A fuel tank 6 is disposed between the lower side of the passenger seat 8 and the upper side of the rear wheel 13, and the lower surface of the fuel tank 6 is positioned above to avoid interference with the rear wheel 13 during swinging. A facing recess 68 is provided to extend in the front-rear direction at the left and right center of the fuel tank 6, and the position of the float 93 at the lowest liquid level is set above the recess 68 in a side view. Thereby, in this embodiment, even when the position of the float 93 at the time of the lowest liquid level of the actual fuel tank 6 is shifted from the bottom and above the recess 68, the bulging portion 65 is formed on the upper surface of the fuel tank 6. Since the maximum liquid level Lh can be detected, the liquid level detection range can be taken from the lowest liquid level to the highest liquid level Lh.

  In addition, a recess 87 is formed in the seat bottom plate 80 of the riding seat 8 facing the upper surface of the fuel tank 6 so as to escape interference with the bulging portion 65 of the fuel tank 6. Thus, in the present embodiment, when the bulging portion 65 is formed in the fuel tank 6, the space between the fuel tank 6 and the seat bottom plate 80 is reduced, and the bulging portion 65 of the fuel tank 6 is provided on the seat bottom plate 80. By forming the recessed portion 87 that escapes, a gap with the bulging portion 65 of the fuel tank 6 can be secured, and an increase in seat seating height can be suppressed, and the footing property of the motorcycle 1 is maintained.

  Further, the bulging portion 65 of the fuel tank 6 is arranged only on the side of the left and right center line X where the float 93 of the liquid level detecting device 9 is located, and the recessed portion 87 of the seat bottom plate 80 is located on both the left and right sides. It is formed symmetrically. Thus, even when the bulging portion 65 is formed only on the side where the float 93 is located, the recess 87 of the sheet bottom plate 80 is formed symmetrically on both the left and right sides, so that the sheet bottom plate 80 The right / left balance of rigidity can be achieved, and the uncomfortable feeling of sitting comfort can be reduced.

  The seat bottom plate 80 is provided with a tool fixing portion 89 that holds the maintenance tool 19 of the motorcycle 1, and the recessed portion 87 of the seat bottom plate 80 includes a tool fixing portion 89 and a fuel pump attached to the fuel tank 6. It is formed so as to be located between the portion facing the unit 7 and the mounting position of the fuel pump unit 7 to the fuel tank 6 is formed on the pump unit mounting seat surface 63 which is lowered by one step from the upper surface 67 of the adjacent fuel tank. Has been. Thereby, even if the recess 87 is provided, the tool fixing portion 89 is provided behind the recess 87, and can be secured without sacrificing the installation space of the maintenance tool 19, and further lowered by one step from the upper surface 67 of the adjacent fuel tank By attaching the fuel tank 6 to the pump unit mounting seat 63, it is possible to prevent the upward bulging portion of the fuel pump unit 7 from interfering with the seat bottom plate 80 and the like.

As mentioned above, although the fuel tank structure of the vehicle according to one embodiment of the present invention has been described, the aspect of the present invention is not limited to the above-described embodiment, and may be implemented in various aspects within the scope of the gist of the present invention. Of course.
For example, the vehicle of the present invention is not limited to the motorcycle according to the embodiment, and may be a small vehicle in which the fuel tank is mounted on the vehicle with at least an upper surface inclined. The internal combustion engine of the vehicle is not limited to the water-cooled single-cylinder four-stroke cycle internal combustion engine of the embodiment, and may be any internal combustion engine that needs to have a fuel tank.
In addition, the arrangement of the left and right of each device has been described specifically for illustration, for convenience of explanation, but the arrangement may be reversed to that shown in the above embodiment, and is included in the present invention. .

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 3 ... Internal combustion engine, 6 ... Fuel tank, 6A ... Tank upper half, 6B ... Tank lower half, 7 ... Fuel pump unit, 8 ... Riding seat, 9 ... Liquid level Detection device, 13 ... rear wheel, 14 ... swing arm, 19 ... maintenance tool, 21 ... main frame, 23 ... seat rail, 23a ... rear cushion mounting part, 24 ... side frame, 31 ... crankshaft, 50 ... air cleaner, 60 ... Upper and lower mating surfaces, 60a ... Flange portion, 60b ... Flange portion, 62 ... Pump unit insertion hole, 63 ... Pump unit mounting seat surface, 64 ... Fuel filling port, 64a ... Lower end opening, 65 ... Expansion portion, 66 ... Recess portion, 67 ... upper surface of fuel tank, 68 ... recess, 70 ... pump body, 71 ... fuel filter, 72 ... discharge pipe, 75 ... sensor support, 80 ... seat bottom plate, 81 ... front end, 87 ... recess, 89 ... tool Fixed part, 90 ... Liquid level detection sensor, 91 ... Rotating shaft, 92 ... Flow Toamu, 93 ... float, X ... vehicle body left-right center line, the axis of the Y ... pivot shaft 91, Lh ... highest liquid surface

Claims (9)

A fuel tank (6) is mounted on the vehicle (1) with at least an upper surface and a lower surface inclined in the same direction, and a liquid level detection device (9) is mounted inside the fuel tank (6) to reduce the remaining amount of fuel. In the fuel tank structure of the vehicle to be detected,
A liquid level detection sensor (90) constituting the liquid level detection device (9);
A float arm (92) having one end side pivotably connected to the liquid level detection sensor (90) and a float (93) attached to the other end side;
The float arm (92) is attached to the liquid level detection sensor (90) so as to swing up and down according to the liquid level in the fuel tank (6),
The liquid level detection sensor (90) is configured to output an electric signal corresponding to the liquid level according to the swing angle position of the float arm (92) swinging up and down,
The fuel tank (6) is provided with a bulging portion (65) having its upper surface bulged, and an oil supply port (64) to the fuel tank (6) is inclined to the upper surface of the fuel tank (6). (67) is disposed higher than the bulging portion (65), and the liquid level detection device (9) is lower than the bulging portion (65) and the upper surface (67) on which the fuel tank (6) is inclined. The bulging part (65) is located between the fuel filler port (64) and the fuel pump unit (7) and is attached to the fuel pump unit (7) attached to the bulging part (65). The maximum liquid level (Lh) to be detected by the liquid level detection sensor (90) is set inside the recess (66) formed on the inner surface,
The fuel pump unit (7) has a center disposed closer to one side with respect to the vehicle left-right center (X) of the fuel tank (6), and includes the liquid level detection device (9) and a float (93). A fuel tank structure for a vehicle, wherein the float arm (92) and the bulge portion (65) are arranged on the other side.   The vehicle fuel according to claim 1, wherein the liquid level detection sensor (90) detects a vertical position of the float (93), and the float arm (92) is formed in a straight line. Tank structure.   The maximum liquid level (Lh) is defined by a horizontal plane (Lh) including the position of the lower end opening (64a) of the fuel filler port, and the bulging portion (65) bulges up to the horizontal plane (Lh). The fuel tank structure for a vehicle according to claim 1, wherein the fuel tank structure is a vehicle.   The fuel tank (6) is disposed between the lower part of the passenger seat (8) and the upper part of the rear wheel (13), and the lower surface of the fuel tank (6) A recess (68) directed upward to avoid interference with the wheel (13) is provided extending in the front-rear direction at the left and right center of the vehicle of the fuel tank (6), and the lowest liquid of the float (93) in side view. The fuel tank structure for a vehicle according to any one of claims 1 to 3, wherein a position at a surface level is set above the recess (68).   A recess (87) is formed in the seat bottom plate (80) of the riding seat (8) facing the upper surface (67) of the fuel tank (6) so as to escape interference with the bulging portion (65). The fuel tank structure for a vehicle according to any one of claims 1, 2, 3, and 5.   The bulging portion (65) of the fuel tank (6) is disposed only on the side where the float (93) of the liquid level detection device (9) is located on the left and right of the vehicle left-right center (X), The vehicle fuel tank structure according to claim 6, wherein the recess (87) of the seat bottom plate (80) is formed symmetrically on both the left and right sides. The seat bottom plate (80) is provided with a tool fixing part (89) for holding the maintenance tool (19) of the vehicle (1),
The recess (87) of the seat bottom plate (80) is located between the tool fixing part (89) and a part facing the fuel pump unit (7) attached to the fuel tank (6). Formed into
The mounting position of the fuel pump unit (7) to the fuel tank (6) is formed on a mounting seat surface (63) that is lowered by one step from the upper surface (67) of the adjacent fuel tank. A fuel tank structure for a vehicle according to claim 6 or claim 7.   The bulge portion (65) is disposed at a rear portion of a support pad (82C) for supporting the load of the riding seat (8) of the vehicle (1). A fuel tank structure for a vehicle according to claim 1.   The said bulging part (65) is arrange | positioned in the front part of the boundary part (8c) of the driver's seat (8a) and the passenger's seat (8b) which comprise the boarding seat (8) of a vehicle (1). The fuel tank structure for a vehicle according to any one of claims 1 to 3, wherein the fuel tank structure is a vehicle.

Images