fuel tank

Abstract

This design aims to maintain the separator's capacity while suppressing the enlargement of the tank's upper section. [Solution] The saddle-type vehicle is equipped with an evaporative system. The fuel tank of this saddle-type vehicle is provided with a tank panel (41) having a liquid fuel storage space (44), an inlet pipe (46) attached to the top of the tank panel, a gas-liquid separation separator (51) installed inside the tank panel, and a breather pipe (57) for discharging fuel gas from the separator. The separator is formed to surround the inlet pipe.

Description

Technical Field

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[0001] The present invention relates to a fuel tank.

Background Art

[0002] In the evaporative emission control system of a saddle-type vehicle, fuel gas vaporized in the fuel tank is sent to a canister through a breather pipe. The canister is filled with an adsorbent made of activated carbon, and the fuel gas sent from the breather pipe is adsorbed by the canister. As this type of evaporative emission control system, there is known one that suppresses the inflow of liquid fuel into the canister when the vehicle overturns in order to prevent deterioration of the adsorbent (see, for example, Patent Document 1). In this evaporative emission control system, a roll-over valve is provided in the path between the breather pipe and the canister, and when the vehicle overturns, the roll-over valve closes to suppress the flow of liquid fuel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Inside the fuel tank, a separator for gas-liquid separation is installed above the liquid level of the liquid fuel. A breather pipe is connected to the bottom surface of the separator. If the capacity of the separator is small, it becomes easy for liquid fuel to flow from the separator into the breather pipe. Although it is desirable to ensure a large capacity of the separator, there is a problem that the upper part of the fuel tank becomes enlarged due to the enlargement of the separator.

[0005] The present invention has been made in view of this point, and an object thereof is to provide a fuel tank capable of securing the capacity of the separator while suppressing the enlargement of the upper part of the tank. [Means for solving the problem]

[0006] A fuel tank according to one aspect of the present invention is a fuel tank for a saddle-type vehicle equipped with an evaporator system, comprising a tank panel having a liquid fuel storage space formed therein, an inlet pipe attached to the upper part of the tank panel, a gas-liquid separator installed inside the tank panel, and a breather pipe for discharging fuel gas from the separator, wherein the separator is formed to surround the inlet pipe, thereby solving the above problem. [Effects of the Invention]

[0007] According to one embodiment of the present invention, the volume of the separator is secured by utilizing the space around the inlet pipe. The separator can be compactly installed on top of the fuel tank without expanding the top of the fuel tank. [Brief explanation of the drawing]

[0008] [Figure 1] This is a left side view of the saddle-type vehicle of this embodiment. [Figure 2] This is a right side view of the fuel tank in this embodiment. [Figure 3] This is a top view of the fuel tank with the upper panel removed in this embodiment. [Figure 4] This is a bottom view of the fuel tank with the lower panel removed in this embodiment. [Figure 5] This is a schematic cross-sectional view of the area near the separator when the vehicle is stopped in this embodiment. [Modes for carrying out the invention]

[0009] An evaporative system is installed in a saddle-type vehicle according to one embodiment of the present invention. A storage space for liquid fuel is formed in the tank panel of the fuel tank of this saddle-type vehicle, and an inlet pipe is attached to the top of the tank panel. A gas-liquid separator is installed inside the tank panel, and the fuel gas in the separator is discharged through a breather pipe. The separator is formed to surround the inlet pipe, and the volume of the separator is secured by utilizing the space around the inlet pipe. The separator can be compactly installed on top of the fuel tank without expanding the top of the fuel tank. [Examples]

[0010] The saddle-type vehicle of this embodiment will be described below with reference to the attached drawings. Figure 1 is a left side view of the saddle-type vehicle of this embodiment. In the following figures, arrow Fr indicates the front of the vehicle, arrow Re indicates the rear of the vehicle, arrow L indicates the left side of the vehicle, and arrow R indicates the right side of the vehicle.

[0011] As shown in Figure 1, the saddle-type vehicle 1 is constructed by mounting various components such as the engine 30 and electrical systems on a vehicle frame 10. A pair of main frames 12 extend diagonally downward and rearward from the head pipe 11 of the vehicle frame 10, and the rear ends of the pair of main frames 12 form a pair of body frames 13 that are bent downward. In addition, a down frame 14 extends downward from the head pipe 11, and a pair of under loops 15 that are bent rearward are connected to the lower part of the down frame 14. The rear ends of the pair of under loops 15 are connected to the lower part of the pair of body frames 13, so that the vehicle frame 10 is formed in a cradle shape.

[0012] A steering shaft (not shown) supports a front fork 21 on the head pipe 11 so that it can be steered. A handlebar 22 is provided on the upper part of the front fork 21, and a front wheel 23 is rotatably supported on the lower part of the front fork 21. A fuel tank 40 is placed over the top of a pair of main frames 12, and the main frames 12 and fuel tank 40 are covered from the sides by a front side cover 24. A seat 25 is installed behind the fuel tank 40, and a seat frame (not shown) that supports the seat 25 from below is covered from the sides by a rear side cover 26.

[0013] A swingarm 27 is pivotably supported in the middle of the body frame 13. The swingarm 27 extends rearward from the body frame 13, and a rear wheel 28 is rotatably supported at the rear end of the swingarm 27. A cylinder assembly, consisting of a cylinder 32, a cylinder head 33, and a cylinder head cover 34, is mounted on the upper part of the crankcase 31 of the engine 30. An exhaust pipe 35 extends rearward from the front of the engine 30, passing along the side of the cylinder 32, and an up-type muffler 36 is connected to the downstream end of the exhaust pipe 35. A side stand 37 for supporting the vehicle is provided on the left side of the body frame 13.

[0014] Furthermore, a canister 38, which constitutes the evaporative system, is exposed behind the rear side cover 26. A fuel tank 40 is connected to the upstream side of the canister 38 via a breather hose 39 (see Figure 2), and an intake system is connected to the downstream side of the canister 38 via a breather hose (not shown). Fuel gas vaporized in the fuel tank 40 is sent to the canister 38 through the breather hose 39, where it is adsorbed by the adsorbent in the canister 38. When the engine is started, the fuel gas is separated from the adsorbent in the canister 38 and sent to the intake system of the engine 30 for re-combustion.

[0015] Incidentally, in saddle-type vehicles equipped with an evaporative system, a gas-liquid separator is installed inside the fuel tank. The separator is installed at the top of the tank so as not to be immersed in the liquid. If the separator has a small capacity, it can be compactly fitted at the top of the tank, but liquid fuel that enters the separator is more easily sent to the canister. On the other hand, if the separator has a large capacity, liquid fuel is less likely to be sent to the canister, but it is difficult to secure space for the separator at the top of the tank. Therefore, in this embodiment, a U-shaped separator is installed using the area around the inlet pipe at the top of the tank.

[0016] The fuel tank will be described with reference to Figures 2 to 4. Figure 2 is a right side view of the fuel tank in this embodiment. Figure 3 is a top view of the fuel tank with the upper panel removed. Figure 4 is a bottom view of the fuel tank with the lower panel removed. Note that in Figure 2, the upper and lower panels are indicated by dashed lines.

[0017] As shown in Figure 2, the tank panel 41 of the fuel tank 40 is a two-piece tank panel with an upper panel 42 and a lower panel 43 joined together. The upper panel 42 bulges upward in a dome shape, and the lower panel 43 bulges downward in a dome shape, and the upper panel 42 and the lower panel 43 form a storage space 44 for liquid fuel. The outer edges of the upper panel 42 and the lower panel 43 are seam-welded, and a flange 45 is formed at the joint between the upper panel 42 and the lower panel 43. The tank panel 41 is formed so that its vertical dimension decreases from the front to the rear.

[0018] As shown in FIGS. 2 and 3, an inlet pipe 46 is attached to the upper part of the upper panel 42. The inlet pipe 46 has a double structure of an outer cylinder 47 and an inner cylinder 48, and the inlet pipe 46 is formed in a bottomed cylindrical shape by combining the outer cylinder 47 and the inner cylinder 48. The outer cylinder 47 of the inlet pipe 46 is joined to the opening of the upper panel 42, and a tank cap (not shown) is attached to the upper part of the outer cylinder 47 of the inlet pipe 46. A liquid fuel inlet is formed on the bottom surface of the inner cylinder 48 of the inlet pipe 46, and liquid fuel is supplied by inserting a nozzle (not shown) into the inlet pipe 46.

[0019] A separator 51 for gas-liquid separation is installed inside the tank panel 41. Three brackets 49 provided at the lower part of the outer cylinder 47 of the inlet pipe 46 extend in the radial direction, and a separator 51 having a U-shaped upper surface view is supported from below at the tip of each bracket 49. The separator 51 has a pair of extending portions 52 that extend back and forth on both sides of the inlet pipe 46, and a connecting portion 53 that connects the rear portions of the pair of extending portions 52 behind the inlet pipe 46. That is, the open side of the U-shaped separator 51 is directed forward, and the curved side of the U-shaped separator 51 is directed backward.

[0020] The separator 51 is inclined so that the connecting portion 53 side is lower than the front portion side of the pair of extending portions 52. More specifically, the extending direction of the inlet pipe 46 is inclined with respect to the vertical direction, and the extending direction of the pair of extending portions 52 is orthogonal to the extending direction of the inlet pipe 46 in a side view. By inclining the separator 51 in accordance with the inclination of the inlet pipe 46, the separator 51 is installed compactly in the upper space of the fuel tank 40. In addition, since the separator 51 is installed using the space around the inlet pipe 46, a sufficient volume of the separator 51 is ensured.

[0021] On the front top surface of the right extension part 52, a first breathing hole 54 is formed. The first breathing hole 54 is a small-diameter hole with a diameter of 1 [mm], and air enters and exits the separator 51 through the first breathing hole 54. The first breathing hole 54 is formed at the highest position of the separator 51. Even if the liquid fuel level shakes during driving, it is difficult for the liquid fuel to enter the separator 51 from the first breathing hole 54, and the breathing function is maintained. Also, because the first breathing hole 54 is small in diameter, even if liquid fuel adheres to the top surface of the separator 51, it is difficult for the liquid fuel to enter the separator 51 from the first breathing hole 54.

[0022] As shown in FIG. 4, a second breathing hole 55 is formed on the front bottom surface of the left extension part 52, and a third breathing hole 56 is formed on the rear bottom surface of the left extension part 52. The second and third breathing holes 55 and 56 are small-diameter holes with a diameter of 1 [mm], and air enters and exits the separator 51 through the second and third breathing holes 55 and 56. Even if liquid fuel enters the separator 51, it is returned to the storage space 44 from the second and third breathing holes 55 and 56. In particular, since the liquid fuel that has entered the separator 51 flows backward due to the inclination of the separator 51, the liquid fuel that has gathered at the rear of the separator 51 is easily returned to the storage space 44 from the third breathing hole 56.

[0023] By forming the first breathing hole 54 in the right extension part 52 and the second and third breathing holes 55 and 56 in the left extension part 52, the exhaust paths of the fuel gas are provided on the left and right, and the distance from each breathing hole to a breather pipe 57 described later is shortened, improving the breathing function. Also, the first to third breathing holes 54, 55, and 56 are formed to be smaller in diameter than the breather pipe 57, and sufficient ventilation resistance for the breathing function is obtained. Sudden pressure fluctuations in the fuel tank 40 are suppressed, the discharge of the fuel gas in the fuel tank 40 is controlled, and excessive discharge of the fuel gas to the breather pipe 57 is restricted.

[0024] As shown in Figures 2 to 4, a breather pipe 57 is provided inside the fuel tank 40 to discharge fuel gas from the separator 51. The upper inlet end of the breather pipe 57 is connected to the middle of the connecting portion 53 of the separator 51 in the direction of extension, and the lower outlet end of the breather pipe 57 is connected to the lower rear side of the lower panel 43. By having the breather pipe 57 extend through the fuel tank 40 to the outside of the tank, the exposure of the breather pipe 57 is suppressed, improving the appearance of the fuel tank 40. A breather hose 39 leading to the canister 38 (see Figure 1) is connected to the lower end of the breather pipe 57.

[0025] The inlet at the upper end of the breather pipe 57 is positioned midway along the left-right direction of the separator 51. Even if either the left or right extension 52 is positioned downwards when the vehicle tips over, liquid fuel will not enter the breather pipe 57 until approximately half of the volume of the separator 51 is filled with liquid fuel. Furthermore, the upper end of the breather pipe 57 is positioned to one side (right side) in the vehicle width direction relative to the center line L1 passing through the front-rear direction of the separator 51. When the vehicle is tilted to the left by the side stand 37 (see Figure 1), liquid fuel is prevented from accumulating near the inlet of the breather pipe 57.

[0026] A linear reinforcing member 61 is provided inside the fuel tank 40 along the breather pipe 57. The upper end of the linear reinforcing member 61 is connected to the separator 51, and the lower end of the linear reinforcing member 61 is connected to the lower rear side of the lower panel 43. A connecting bracket 62 is provided at an intermediate position in the extending direction of the linear reinforcing member 61, and the intermediate part of the linear reinforcing member 61 and the intermediate part of the breather pipe 57 are connected via the connecting bracket 62. Even if the amount of overhang of the upper end relative to the lower end of the breather pipe 57 is large, the load acting on both ends of the breather pipe 57 is reduced because the breather pipe 57 is supported by the linear reinforcing member 61.

[0027] An in-tank type pump 63 is installed on the bottom surface of the lower panel 43. The pump 63 is immersed in liquid fuel and cooled by the liquid fuel. The pump 63 is located in the center of the bottom surface of the lower panel 43, and the breather pipe 57 and linear reinforcing member 61 extend to the rear of the pump 63, passing to the right side of the pump 63. Even though the pump 63 protrudes into the fuel tank 40, it does not interfere with the breather pipe 57 and linear reinforcing member 61. In addition, the fact that the breather pipe 57 and linear reinforcing member 61 extend along the right side of the fuel tank 40 improves the ease of attaching and detaching the pump 63.

[0028] Referring to Figure 5, the positions of the breather pipe and the first to third breathing holes when the vehicle is stopped will be explained. Figure 5 is a schematic cross-sectional view of the area near the separator when the vehicle is stopped in this embodiment.

[0029] As shown in Figure 5, when the vehicle is parked, it stands upright with the body tilted to the left by the side stand 37 (see Figure 1). That is, the right extension 52 is provided on the opposite side of the side stand 37 relative to the inlet pipe 46, and the left extension 52 is provided on the same side as the side stand 37 relative to the inlet pipe 46. As described above, a first breathing hole 54 is formed on the front top surface of the right extension 52, a second breathing hole 55 is formed on the front bottom surface of the left extension 52, and a third breathing hole 56 is formed on the rear bottom surface of the left extension 52. A breather pipe 57 is connected to the bottom surface of the connecting part 53.

[0030] When the vehicle body is tilted to the left, the first breathing hole 54 of the right-side extension 52 is positioned at the highest point, so the first breathing hole 54 is not submerged in liquid fuel and its breathing function is maintained. The second and third breathing holes 55 and 56 of the left-side extension 52 are positioned lower, making it easier for liquid fuel that has entered the separator 51 to be returned to the storage space 44 through the second and third breathing holes 55 and 56. In particular, because the third breathing hole 56 is positioned at the lowest point, liquid fuel tends to accumulate around the third breathing hole 56. The second and third breathing holes 55 and 56 are also positioned above the liquid level, so their breathing function is also maintained.

[0031] The upper end of the breather pipe 57 is connected to the right of the center of the separator 51, and when the vehicle is tilted, the inlet of the upper end of the breather pipe 57 is positioned higher than the third breathing hole 56. As a result, liquid fuel that has entered the separator 51 is less likely to enter the breather pipe 57 compared to the third breathing hole 56. In addition, since the first to third breathing holes 54, 55, and 56 are distributed to the left and right in the separator 51, the fuel gas is distributed throughout the separator 51 and the pressure inside the separator 51 becomes uniform, so that the fuel gas is discharged stably from the breather pipe 57.

[0032] The top of the fuel tank 40 bulges upward, and an inlet pipe 46 is attached to this bulging portion at the top of the tank. An annular space is left around the inlet pipe 46, and a separator 51 is installed using part of this annular space. The separator 51 is formed in a U-shape so that it fits within the annular space, ensuring sufficient volume for the separator 51 even in the narrow space at the top of the tank. The inclination of the separator 51 is adjusted to match the inclination of the inlet pipe 46, achieving efficient use of space around the inlet pipe 46.

[0033] As described above, with the fuel tank 40 of this embodiment, the volume of the separator 51 is secured by utilizing the space around the inlet pipe 46. The separator 51 can be compactly installed on top of the fuel tank 40 without expanding the top of the fuel tank 40. Furthermore, because the separator 51 is formed in a U shape, even if either of the pair of extended parts 52 is positioned on the lower side when the vehicle rolls over, liquid fuel is prevented from entering the breather pipe 57 until approximately half of the volume of the separator 51 is filled with liquid fuel.

[0034] In this embodiment, the separator is formed in a U-shape, but the separator only needs to be formed to surround the inlet pipe. For example, the separator may be formed in an annular shape to surround the separator.

[0035] Furthermore, in this embodiment, the breather pipe is connected to the middle of the extension direction of the connecting portion, but the breather pipe only needs to be connected to the separator. For example, the breather pipe may be connected to the extension portion.

[0036] Furthermore, although the separator is tilted in this embodiment, the separator may also be installed horizontally.

[0037] In this embodiment, the separator has three breathing holes, but it may have only one breathing hole, two breathing holes, or four or more breathing holes. The diameter and shape of each breathing hole can also be changed as appropriate.

[0038] In this embodiment, a first breathing hole is formed in the left extension and second and third breathing holes are formed in the right extension; however, the first breathing hole may be formed in the right extension and the second and third breathing holes may be formed in the left extension.

[0039] Furthermore, the fuel tank of this embodiment is not limited to the above-described saddle-type vehicle, but may also be used in other types of saddle-type vehicles. Note that the term "saddle-type vehicle" is not limited to all vehicles in which the driver sits straddling a seat, but also includes scooter-type vehicles in which the driver does not straddle a seat.

[0040] As described above, the first embodiment is a fuel tank (40) of a saddle-type vehicle (1) equipped with an evaporator system, comprising a tank panel (41) having a liquid fuel storage space (44), an inlet pipe (46) attached to the top of the tank panel, a gas-liquid separator (51) installed inside the tank panel, and a breather pipe (57) for discharging fuel gas from the separator, wherein the separator is formed to surround the inlet pipe. With this configuration, the volume of the separator is secured by utilizing the space around the inlet pipe. The separator can be compactly installed on top of the fuel tank without expanding the top of the fuel tank.

[0041] In the second embodiment, the separator is formed in a U-shape having a pair of extending portions (52) that extend forward and backward on both sides of the inlet pipe, and a connecting portion (53) that connects the pair of extending portions at the rear of the inlet pipe, with a breather pipe connected to the middle of the connecting portion in the extending direction. With this configuration, even if either of the pair of extending portions is positioned on the lower side when the vehicle overturns, liquid fuel will not enter the breather pipe until approximately half of the separator's volume is filled with liquid fuel.

[0042] In the third embodiment, the separator is tilted in the second embodiment such that the connecting portion is lower than the front end portion of the pair of extended portions, and a first breathing hole (54) is formed on the front top surface of one of the extended portions of the pair. With this configuration, even if the liquid fuel level fluctuates during driving, it is difficult for the liquid fuel to enter the separator through the first breathing hole, thus maintaining the breathing function.

[0043] In the fourth embodiment, a second breathing hole (55) is formed on the front bottom surface of the other of the pair of extended parts, as in the third embodiment. With this configuration, even if liquid fuel enters the separator, it is returned to the storage space through the second breathing hole. Furthermore, the formation of first and second breathing holes in the pair of extended parts increases the number of discharge routes and shortens the distance from each breathing hole to the breather pipe, thereby improving the breathing function. In addition, when the vehicle rolls over, the speed at which liquid fuel enters the separator from the first and second breathing holes is made uniform.

[0044] The fifth embodiment is the fourth embodiment, wherein a third breathing hole (56) is formed on the rear bottom surface of the other extended portion. With this configuration, the liquid fuel in the separator flows to the rear, making it easier for the liquid fuel accumulated at the rear of the separator to be returned to the storage space through the third breathing hole.

[0045] The sixth embodiment is one of the third to fifth embodiments, in which a side stand (37) that allows the vehicle to tilt and stand on its own is provided on one side in the vehicle width direction, with one extension provided on the side opposite the side stand relative to the inlet pipe, and the other extension provided on the same side as the side stand. With this configuration, a first breathing hole is formed on the front top surface of the extension on the side opposite the side stand, so that the first breathing hole does not become submerged in liquid fuel even when the vehicle is tilted toward the side stand when parked. Second and third breathing holes are formed on the front bottom surface and rear bottom surface of the other extension on the same side as the side stand, so that when the vehicle is tilted toward the side stand when parked, liquid fuel that has entered the separator is returned to the storage space through the second and third breathing holes.

[0046] The seventh embodiment is one of the third to sixth embodiments, in which the extension direction of the inlet pipe is inclined with respect to the vertical direction, and in a side view, the extension direction of the pair of extension parts is perpendicular to the extension direction of the inlet pipe. With this configuration, by tilting the separator in accordance with the inclination of the inlet pipe, the separator can be compactly installed in the space above the fuel tank.

[0047] Although this embodiment has been described, other embodiments may be combinations of the above embodiment and its modifications, either entirely or partially.

[0048] Furthermore, the technology of the present invention is not limited to the embodiments described above, and may be modified, substituted, or transformed in various ways without departing from the spirit of the technical idea. Moreover, if the technical idea can be realized in a different way by advances in the technology or by other derived technologies, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea. [Explanation of Symbols]

[0049] 1: Saddle-type vehicle 37: Side stand 40: Fuel tank 41: Tank Panel 44: Storage space 46: Inlet pipe 51: Separator 52: A pair of extensions 53:Connection part 54: First breathing point 55: Second breathing point 56: The third breathing point 57: Breather pipe

Claims

1. A fuel tank for a saddle-type vehicle equipped with an evaporative system, A tank panel in which a liquid fuel storage space is formed, An inlet pipe attached to the upper part of the aforementioned tank panel, A gas-liquid separator installed inside the tank panel, The separator includes a breather pipe for discharging fuel gas from within the separator, A fuel tank characterized in that the separator is formed to surround the inlet pipe.

2. The separator is formed in a U-shape, having a pair of extending portions that extend forward and backward on both sides of the inlet pipe, and a connecting portion that connects the pair of extending portions at the rear of the inlet pipe. The fuel tank according to claim 1, characterized in that the breather pipe is connected to the intermediate portion in the extending direction of the connecting portion.

3. The separator is tilted such that the connecting portion is lower than the front end portion of the pair of extended portions. The fuel tank according to claim 2, characterized in that a first breathing hole is formed on the front top surface of either of the pair of extended portions.

4. The fuel tank according to claim 3, characterized in that a second breathing hole is formed on the front bottom surface of the other of the pair of extended portions.

5. The fuel tank according to claim 4, characterized in that a third breathing hole is formed on the rear bottom surface of the other extended portion.

6. The fuel tank according to claim 5, characterized in that a side stand for tilting the vehicle body to allow it to stand on its own is provided on one side in the vehicle width direction, the one extended portion is provided on the side opposite to the side stand with respect to the inlet pipe, and the other extended portion is provided on the same side as the side stand.

7. The extension direction of the inlet pipe is inclined with respect to the vertical direction. The fuel tank according to any one of claims 3 to 6, characterized in that, in a side view, the extending direction of the pair of extending portions is perpendicular to the extending direction of the inlet pipe.

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