Saddle-type multi-characteristic fuel vehicle

Abstract

The purpose of the present invention is to provide a saddle-type multi-characteristic fuel vehicle capable of realizing a fuel characteristic variation adjustment function with a simple structure, while suppressing or preventing effects on the degree of freedom in design of a fuel pump and that of the structure for mounting the fuel pump in a fuel tank for the saddle-type multi-characteristic fuel vehicle. By supporting a partition wall member on an inner surface of the fuel tank for the saddle-type multi-characteristic fuel vehicle, a receiving fuel storage chamber and a fuel characteristic variation adjustment chamber are defined inside the fuel tank for the saddle-type multi-characteristic fuel vehicle. A communication part that communicates the receiving fuel storage chamber with the fuel characteristic variation adjustment chamber is formed in the partition wall member. The communication part has such a shape that the mixing speed of a receiving fuel and an existing fuel is adjusted by making it difficult for the receiving fuel to enter the fuel characteristic variation adjustment chamber from the receiving fuel storage chamber.

Description

Saddle-type multi-property fuel vehicle

[0001] The present invention relates to a straddle-type multi-characteristic fuel vehicle, and more particularly to a straddle-type multi-characteristic fuel vehicle equipped with an internal combustion engine capable of burning a plurality of types of fuels with different characteristics.

[0002] 2. Description of the Related Art Saddle-type multi-characteristic fuel vehicles are known in the art, and are equipped with an internal combustion engine capable of burning a plurality of types of fuel with different characteristics.

[0003] JP 2014-51894 A JP 2008-280031 A JP 2009-209909 A

[0004] In a straddle-type multi-characteristic fuel vehicle, when new fuel is received in the fuel tank, the received fuel mixes with the fuel already in the fuel tank, which can change the characteristics of the fuel supplied to the internal combustion engine (hereinafter simply referred to as "fuel characteristics"). Therefore, in a straddle-type multi-characteristic fuel vehicle, methods have been studied to suppress abrupt changes in fuel characteristics and to make the changes more gradual (see, for example, Patent Documents 1 to 3).

[0005] Patent Document 1 discloses a fuel pump unit that minimizes the impact of changes in fuel composition on fuel injection control, is compact, and is easy to install. Specifically, the fuel pump unit includes a case, a partition wall, an intake port, and a fuel pump. The case includes a discharge port through which fuel is discharged and a return port through which excess fuel returns. The partition wall divides the interior space of the case into a return fuel chamber and a main fuel chamber. The return fuel chamber is provided with a return port. The main fuel chamber is connected to the outside of the case. The intake port is located within the return fuel chamber. The fuel pump draws fuel through the intake port and discharges it through the discharge port. Patent Document 2 discloses the provision of a sub-tank that functions as a fuel storage section separated from the fuel tank. This allows for gentle mixing of the two fuels, even when a fuel with a different fuel composition is supplied. Patent Document 3 discloses a fuel supply device that allows combustion at a preferred air-fuel ratio when a multi-fuel internal combustion engine is cold started. Specifically, it is equipped with a connecting pipe extending from a fuel injection device that injects fuel into the air supplied to the internal combustion engine, and the volume of the connecting pipe is equal to or greater than the amount of fuel consumed from the time the internal combustion engine starts until the temperature rises to a level at which the oxygen sensor can be measured.

[0006] An object of the present invention is to provide a saddle-type multi-characteristic fuel vehicle that can achieve a fuel characteristic change adjustment function with a simple structure while suppressing or preventing any impact on the design freedom of the fuel pump and the mounting structure of the fuel pump inside the fuel tank of the saddle-type multi-characteristic fuel vehicle.

[0007] The inventors have studied ways to achieve the above object, and have found that it is possible to divide the interior of a saddle-type multi-characteristic fuel vehicle fuel tank into a receiving fuel storage chamber and a fuel property change adjusting chamber by supporting a partition wall member on the inner surface of the fuel tank, form a communication section in the partition wall member that connects the receiving fuel storage chamber and the fuel property change adjusting chamber, and appropriately design the shape of the communication section to make it difficult for the receiving fuel to enter the fuel property change adjusting chamber from the receiving fuel storage chamber, thereby adjusting the mixing rate of the receiving fuel and the existing fuel. The present invention was completed based on this finding.

[0008] (1) A saddle-type multi-characteristic fuel vehicle according to one embodiment of the present invention comprises: an internal combustion engine capable of burning a plurality of types of fuel having different characteristics; a saddle-type multi-characteristic fuel vehicle fuel tank configured to store fuel to be supplied to the internal combustion engine and having a filler port for receiving fuel from the outside and a mounting hole; an injector configured to supply fuel to the internal combustion engine; and a fuel pump provided on a mounting member, the mounting member being mounted to the mounting hole to be positioned within the saddle-type multi-characteristic fuel vehicle fuel tank, the fuel pump configured to draw fuel from within the saddle-type multi-characteristic fuel vehicle fuel tank and pressurize the fuel toward the injector, wherein the saddle-type multi-characteristic fuel vehicle fuel tank comprises a partition wall member, the partition wall member comprising: a fuel tank for a saddle-type multi-characteristic fuel vehicle, the fuel tank being supported on an inner surface of the saddle-type multi-characteristic fuel vehicle so as to be arranged in the order of the fuel filler opening, the fuel fill space, the partition wall member, the fuel characteristic change adjustment space, and the primary filter from the fuel filler opening toward a primary filter provided at the suction port of the fuel pump, thereby defining within the saddle-type multi-characteristic fuel vehicle fuel tank a receiving fuel storage chamber which communicates with the fuel filler opening and forms the fuel fill space, and a fuel characteristic change adjustment chamber which houses at least a portion of the primary filter and forms the fuel characteristic change adjustment space, The fuel pump has a communication section that communicates the received fuel storage chamber with the fuel property change adjustment chamber, and the communication section passes fuel from the received fuel storage chamber to the fuel property change adjustment chamber at a rate per unit time that is equal to or greater than the maximum fuel supply rate per unit time that can be supplied from the fuel pump to the internal combustion engine when the internal combustion engine is operating.The communication section has a shape that makes it difficult for the received fuel supplied from the fuel filler port to enter the fuel property change adjustment chamber from the received fuel storage chamber, thereby adjusting the mixing rate of the received fuel and the existing fuel.Therefore, the fuel property change adjustment chamber is configured to adjust the mixing rate of the received fuel and the existing fuel by making it difficult for the received fuel to enter from the received fuel storage chamber.

[0009] A saddle-type vehicle is driven by a passenger sitting astride a seat. Therefore, saddle-type vehicles are smaller in size than typical automobiles with cabins. Saddle-type vehicles are required to be maneuverable, lightweight, and easy to use. Therefore, miniaturization of the external dimensions is an important factor for saddle-type vehicles. Generally, when it comes to fuel pumps and their mounting structures within a fuel tank for a saddle-type multi-characteristic fuel vehicle, high requirements are placed on the size and shape of the fuel pump to facilitate insertion of the fuel pump into the fuel tank, and modifications tend to limit design flexibility. In the saddle-type multi-characteristic fuel vehicle (1), a fuel characteristic change adjustment chamber can be formed using a partition wall member. Therefore, there is no need to modify the fuel pump or the mounting structure within the fuel tank for a saddle-type multi-characteristic fuel vehicle, nor is there any need to modify the sealing structure associated with such modifications. Therefore, the saddle-type multi-characteristic fuel vehicle of (1) can achieve the function of adjusting fuel characteristic changes with a simple structure while minimizing or preventing any impact on the design flexibility of the fuel pump and the mounting structure of the fuel pump inside the fuel tank for the saddle-type multi-characteristic fuel vehicle. The high design flexibility of the fuel pump and the mounting structure of the fuel pump inside the fuel tank for the saddle-type multi-characteristic fuel vehicle can contribute to the miniaturization of the fuel tank for the saddle-type multi-characteristic fuel vehicle.

[0010] A saddle-type multi-characteristic fuel vehicle is a saddle-type vehicle equipped with an internal combustion engine capable of burning multiple types of fuel with different characteristics. An example of a saddle-type vehicle is a vehicle equipped with a saddle-type seat. An example of a saddle-type vehicle is a vehicle in which a rider sits astride a saddle. Examples of saddle-type vehicles include scooters, mopeds, snowmobiles, personal watercraft, and all-terrain vehicles (ATVs). A saddle-type vehicle includes, for example, at least one front wheel and at least one rear wheel. That is, a saddle-type vehicle is not limited to a two-wheeled vehicle, but may be a tricycle having a pair of front or rear wheels, or a four-wheeled vehicle having a pair of front and rear wheels, respectively. A saddle-type vehicle may be, for example, a tilting vehicle. A tilting vehicle is a vehicle equipped with a body that tilts leftward when turning left and tilts rightward when turning right. "Fuels with different characteristics" includes not only different fuel compositions but also different impurities contained in the fuels. "Fuels with different impurities" includes, for example, different amounts or types of impurities contained in the fuels. The number of combustion chambers in an internal combustion engine is not particularly limited. The number and arrangement of cylinders in an internal combustion engine are not particularly limited. "Capable of burning multiple types of fuels with different characteristics" means that the combustion system does not switch for each fuel. The fuel filler opening is provided, for example, on the top surface of the fuel tank for a saddle-type multi-characteristic fuel vehicle. The mounting hole is provided, for example, on the bottom, side, or top surface of the fuel tank for a saddle-type multi-characteristic fuel vehicle. The fuel tank for a saddle-type multi-characteristic fuel vehicle is supported, for example, on the body of the saddle-type multi-characteristic fuel vehicle. The injector may, for example, supply fuel directly to a combustion chamber provided in the internal combustion engine or to an intake passage connected to the internal combustion engine. The mounting member may be one or more. If there are multiple mounting members, the fuel pump is provided, for example, on at least one of the mounting members. When the mounting member is attached to the mounting hole, for example, the mounting member covers at least a portion of the mounting hole. The fuel pump, for example, draws in fuel that has passed through a primary filter provided at its suction port.The primary filter is provided at the fuel pump suction port so as to cover the suction port of the fuel pump, for example. "The fuel filler port, the fuel supply space, the partition wall member, the fuel characteristics change adjustment space, and the primary filter are arranged in this order from the fuel filler port toward the primary filter provided at the fuel pump suction port" means, for example, that the fuel filler port, the fuel supply space, the partition wall member, the fuel characteristics change adjustment space, and the primary filter are arranged in this order when viewed from the fuel filler port toward the primary filter. Here, the partition wall member has a communication portion. Therefore, for example, when viewed from the fuel filler port toward the primary filter, the communication portion in the partition wall member may be located between the fuel filler space and the fuel characteristics change adjustment chamber. The fuel filler space is, for example, a space in which incoming fuel supplied from the fuel filler port is stored. The fuel characteristics change adjustment space is, for example, an intake fuel storage space in which fuel drawn into the fuel pump is stored. The intake fuel storage space functions as a fuel property change adjustment space, for example, by a communication portion shaped to adjust the mixing rate of the incoming fuel and the existing fuel. The partition wall member serves to prevent the incoming fuel from entering the fuel property change adjustment chamber from the incoming fuel storage chamber. Prior art includes small chambers or baffle plates provided in the fuel tank to ensure stable fuel supply to the fuel pump in saddle-type vehicles. Such small chambers or baffle plates actively guide fuel toward the fuel pump. In other words, the function of the partition wall member in the present invention is opposite to the function of the small chambers or baffle plates in the prior art. The phrase "the partition wall member is supported on the inner surface of the fuel tank for a saddle-type multi-characteristic fuel vehicle (hereinafter sometimes simply referred to as the "tank inner surface")" includes, for example, the partition wall member being fixed to a wall or plate-like portion that forms the tank inner surface. The fixing method may be, for example, welding. The tank inner surface on which the partition wall member is supported may be, for example, the side surface, the bottom surface (bottom surface), or both the side surface and the bottom surface (bottom surface) of a fuel tank for a saddle-type multi-characteristic fuel vehicle. The shape of the partition wall member is not particularly limited. The partition wall member may have, for example, a plate shape. The partition wall member may be, for example, a plate-shaped member in which at least a portion is bent, thereby having a vertical wall extending in the up-down direction and a horizontal wall extending in the horizontal direction. The number of communication portions is not particularly limited.The partition wall member has, for example, one or more communication portions. The partition wall member does not have, for example, a function of filtering the received fuel entering the fuel property change adjustment chamber from the received fuel storage chamber (hereinafter, simply referred to as the "received fuel filtering function"). When the partition wall member has multiple communication portions, not all of the communication portions need to have the received fuel filtering function. In other words, any of the multiple communication portions may have the received fuel filtering function. Even in this case, the mixing rate of the received fuel and the existing fuel can be adjusted. The communication portion is, for example, a through-hole penetrating the partition wall member in the thickness direction. The communication portion is realized, for example, by including a notch formed by cutting out a peripheral portion of the partition wall member in the thickness direction. The communication portion may be, for example, a through-hole-like portion formed between a notch formed in the peripheral portion of the partition wall member and the inner surface of the tank supporting the peripheral portion of the partition wall member. The communication portion may be, for example, an annular gap formed between the fuel pump and the inner surface of the insertion hole formed in the partition wall member when the fuel pump is inserted into the insertion hole. In other words, "the partition wall member has a communication portion" includes the partition wall member having a portion that constitutes the communication portion. The communication portion may be formed using at least a portion of the partition wall member when the partition wall member is supported on the inner surface of the tank. The shape of the communication portion is related to the difficulty of the received fuel entering the fuel property change adjustment chamber from the received fuel storage chamber. Therefore, by appropriately designing and modifying the shape of the communication portion, the mixing rate of the received fuel and the existing fuel can be adjusted. "The shape of the communication portion that makes it difficult for the received fuel to enter the fuel property change adjustment chamber from the received fuel storage chamber, thereby adjusting the mixing rate of the received fuel and the existing fuel" includes, in addition to the shape of the communication portion itself, for example, the position of the communication portion in the partition wall member, the size (opening area) of the communication portion, the number of communication portions, etc. The primary filter includes, for example, a filter medium for filtering the fuel and a support member for supporting the filter medium. The material of the filter medium is not particularly limited as long as it has the function of filtering the fuel. The support member has, for example, the function of maintaining the filter medium in a predetermined shape. The primary filter may be flexible, for example. In this case, it is easy to arrange at least a portion of the primary filter in the fuel property change adjustment chamber.The phrase "the fuel property change adjustment chamber accommodates at least a portion of the primary filter" includes, for example, that all of the filter material constituting the primary filter is located within the fuel property change adjustment chamber (i.e., the fuel property change adjustment space). The phrase "the fuel property change adjustment chamber accommodates at least a portion of the primary filter" includes, for example, that at least a portion of the support member constituting the primary filter is located outside the fuel property change adjustment chamber (i.e., within the fuel supply space or the receiving fuel storage chamber). When the partition wall member is supported on the tank inner surface to define the receiving fuel storage chamber and the fuel property change adjustment chamber within a fuel tank for a saddle-type multi-characteristic fuel vehicle, for example, at least a portion of the fuel pump is located within the fuel property change adjustment chamber or the receiving fuel storage chamber. For example, the entire fuel pump is located within the fuel property change adjustment chamber or the receiving fuel storage chamber. As long as at least a portion of the primary filter provided at the suction port of the fuel pump is located within the fuel property change adjustment chamber, the entire fuel pump may be located within the receiving fuel storage chamber. The "maximum fuel supply amount per unit time that can be supplied from the fuel pump to the internal combustion engine while the internal combustion engine is operating" refers to, for example, the fuel supply amount when the accelerator pedal of a saddle-type multi-characteristic fuel vehicle is operated to the maximum. The received fuel is, for example, fuel newly supplied to a fuel tank for a saddle-type multi-characteristic fuel vehicle. The existing fuel is, for example, fuel present in the fuel tank for a saddle-type multi-characteristic fuel vehicle when new fuel is supplied to the fuel tank for a saddle-type multi-characteristic fuel vehicle (i.e., at the time of refueling). The existing fuel may be present only in the fuel property change adjustment chamber, or may be present in both the received fuel storage chamber and the fuel property change adjustment chamber. The received fuel has, for example, different properties from the existing fuel. The received fuel may be mixed with the existing fuel present in the received fuel storage chamber and then mixed with the existing fuel in the fuel property change adjustment chamber, i.e., the existing fuel being drawn into the fuel pump. The received fuel mixed with the existing fuel in the received fuel storage chamber has different properties from the existing fuel in the fuel property change adjustment chamber. Even if the existing fuel and the received fuel are mixed in the received fuel storage chamber, the fuel with properties different from those of the existing fuel in the fuel property change adjustment chamber will pass through the communication portion of the partition wall member and enter the fuel property change adjustment chamber from the received fuel storage chamber."Fuel passing through the communicating portion from the received-fuel storage chamber to the fuel property change adjusting chamber" includes newly supplied received fuel. The fuel property change adjusting chamber can slow the mixing rate of the received fuel and the existing fuel compared to when the received-fuel storage chamber and the fuel property change adjusting chamber are not separated by a partition wall member. "Adjusting the mixing rate of the received fuel and the existing fuel" is based on the premise that "the received fuel and the existing fuel mix." "Adjusting the mixing rate of the received fuel and the existing fuel" is different from "making it difficult for the received fuel to mix with the existing fuel." "The communicating portion passes fuel from the received-fuel storage chamber to the fuel property change adjusting chamber at an amount per unit time equal to or greater than the maximum fuel supply amount per unit time that can be supplied from the fuel pump to the internal combustion engine during operation of the internal combustion engine" includes, for example, passing fuel from the receiving-fuel storage chamber to the fuel property change adjusting chamber via the communicating portion so that the fuel property change adjusting chamber is replenished with fuel as the fuel is supplied from the injector to the internal combustion engine.

[0011] According to one aspect of the present invention, a saddle-type multi-characteristic fuel vehicle can employ the following configuration: (2) The saddle-type multi-characteristic fuel vehicle described in (1) further includes a pressure regulator provided in a fuel flow path from the fuel pump to the injector, configured to pass fuel pressurized by the fuel pump toward the injector while returning low-pressure surplus fuel into the saddle-type multi-characteristic fuel vehicle fuel tank, and the outlet through which the pressure regulator returns low-pressure surplus fuel into the saddle-type multi-characteristic fuel vehicle fuel tank is located within the fuel property change adjustment chamber.

[0012] In the saddle-type multi-characteristic fuel vehicle of (2), the fuel in the fuel property change adjustment chamber is less likely to decrease. Therefore, the fuel newly supplied to the fuel tank of the saddle-type multi-characteristic fuel vehicle (i.e., the incoming fuel) is prevented from suddenly flowing into the fuel property change adjustment chamber. As a result, the mixing rate of the incoming fuel and the existing fuel in the fuel property change adjustment chamber can be adjusted to be slower.

[0013] The location of the pressure regulator is not particularly limited. The pressure regulator may be located, for example, inside or outside the saddle-type multi-characteristic fuel vehicle fuel tank. When the pressure regulator is located in the saddle-type multi-characteristic fuel vehicle fuel tank, the pressure regulator may be located, for example, in the receiving fuel storage chamber or the fuel property change adjustment chamber. When the pressure regulator is located in the saddle-type multi-characteristic fuel vehicle fuel tank, the pressure regulator may be provided, for example, on the fuel pump or a mounting member. The "discharge port through which the pressure regulator returns low-pressure surplus fuel into the saddle-type multi-characteristic fuel vehicle fuel tank" may be provided in the pressure regulator itself. A pipe or a flow path forming member may be connected to the pressure regulator for returning low-pressure surplus fuel into the saddle-type multi-characteristic fuel vehicle fuel tank. In this case, the "discharge port through which the pressure regulator returns low-pressure surplus fuel into the saddle-type multi-characteristic fuel vehicle fuel tank" may be provided, for example, on the pipe or the flow path forming member. The fuel flow path from the fuel pump to the injector includes, for example, a flow path formed within a case of the fuel pump.

[0014] According to one aspect of the present invention, a saddle-type multi-characteristic fuel vehicle can employ the following configuration: (3) In the saddle-type multi-characteristic fuel vehicle described in (1) or (2), the fuel property change adjustment chamber includes a space between one surface of the partition wall member and an inner surface of the fuel tank for the saddle-type multi-characteristic fuel vehicle, which are spaced apart and facing each other.

[0015] According to the straddle-type multi-characteristic fuel vehicle of (3), a relatively large fuel property change adjustment chamber can be provided in the fuel tank for the straddle-type multi-characteristic fuel vehicle, which allows the mixing rate of the incoming fuel and the existing fuel in the fuel property change adjustment chamber to be adjusted to be slower.

[0016] The "space between one surface of the partition wall member facing away from each other and the inner surface of the saddle-type multi-characteristic fuel vehicle fuel tank" refers to, for example, the space between the partition wall member and the lower surface (bottom surface) or side surface of the saddle-type multi-characteristic fuel vehicle fuel tank if the partition wall member has a surface facing the lower surface (bottom surface) or side surface of the saddle-type multi-characteristic fuel vehicle fuel tank. When the entire peripheral edge of the partition wall member is supported by the inner surface of the tank, for example, the fuel property change adjustment chamber can be formed to include the space within the saddle-type multi-characteristic fuel vehicle fuel tank that is closer to the lower surface (bottom surface) of the saddle-type multi-characteristic fuel vehicle fuel tank than the partition wall member. In this case, the fuel property change adjustment chamber can be made larger. This allows for the mixing rate of the incoming fuel and the existing fuel within the fuel property change adjustment chamber to be adjusted to be slower.

[0017] According to one aspect of the present invention, a saddle-type multi-characteristic fuel vehicle can employ the following configuration: (4) The saddle-type multi-characteristic fuel vehicle according to any one of (1) to (3), wherein the fuel characteristic change adjustment chamber has a volume smaller than the volume of the receiving fuel storage chamber, but is configured to accommodate both at least a portion of the fuel pump and at least a portion of the primary filter.

[0018] In the saddle-type multi-property fuel vehicle of (4), both the receiving fuel storage chamber and the fuel property change adjustment chamber can be designed to be relatively large in a balanced manner. This allows for smooth fuel reception in the receiving fuel storage chamber while adjusting the mixing rate of the receiving fuel and the existing fuel in the fuel property change adjustment chamber to be slower.

[0019] According to one aspect of the present invention, a saddle-type multi-characteristic fuel vehicle can employ the following configuration: (5) In the saddle-type multi-characteristic fuel vehicle described in any one of (1) to (4), the communication portion has a shape that allows fuel to pass from the receiving fuel storage chamber to the fuel characteristic change adjustment chamber even without suction pressure from the fuel pump.

[0020] In the straddle-type multi-characteristic fuel vehicle of (5), the communication portion allows fuel to pass through when the fuel pump is not operating. Therefore, fuel can flow from the receiving fuel storage chamber to the fuel property change adjusting chamber during refueling when the fuel pump is stopped. As a result, smooth refueling can be achieved. Furthermore, since the receiving fuel can flow quickly from the receiving fuel storage chamber to the fuel property change adjusting chamber during refueling, the volume of the fuel property change adjusting chamber can be increased.

[0021] The above and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention taken in conjunction with the accompanying drawings. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, the use of the terms "including," "comprising," or "having" and variations thereof specifies the presence of stated features, steps, operations, elements, components, and / or equivalents thereof, but may include one or more of the steps, operations, elements, components, and / or groups thereof. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms, such as those defined in commonly used dictionaries, should be interpreted to have a meaning consistent with the meaning in the context of the relevant technology and this disclosure, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein. It is understood that numerous techniques and processes are disclosed in the description of the present invention. Each of these has distinct advantages, and each can also be used with one or more, or in some cases all, of the other disclosed technologies. Therefore, for the sake of clarity, this description will refrain from unnecessarily repeating all possible combinations of individual steps. Nevertheless, the specification and claims should be read with the understanding that all such combinations are within the scope of the present invention and the claims. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without these specific details. The present disclosure is to be considered as an example of the present invention and is not intended to limit the invention to the specific embodiments illustrated in the following drawings or description.

[0022] According to the present invention, it is possible to realize a function for adjusting fuel characteristic changes with a simple structure while suppressing or preventing an impact on the design freedom of the fuel pump and the mounting structure of the fuel pump in the fuel tank for a saddle-type multi-characteristic fuel vehicle.

[0023] 1 is a conceptual diagram showing the configuration of a saddle-riding type multi-characteristic fuel vehicle according to an embodiment of the present invention; 2 is a schematic diagram illustrating variations of a partition wall member that can be employed in a saddle-riding type multi-characteristic fuel vehicle according to an embodiment of the present invention; 3 is a schematic diagram illustrating variations of a fuel pump arrangement that can be employed in a saddle-riding type multi-characteristic fuel vehicle according to an embodiment of the present invention; 4 is a schematic diagram illustrating variations of a pressure regulator outlet arrangement that can be employed in a saddle-riding type multi-characteristic fuel vehicle according to an embodiment of the present invention; and 5 is a schematic diagram illustrating variations of a primary filter arrangement that can be employed in a saddle-riding type multi-characteristic fuel vehicle according to an embodiment of the present invention.

[0024] Hereinafter, a saddle-type multi-characteristic fuel vehicle according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the embodiment described below is merely an example. The present invention should not be construed as being limited in any way by the embodiment described below.

[0025] A saddle-type multi-characteristic fuel vehicle 10 according to an embodiment of the present invention will be described with reference to Figure 1. The saddle-type multi-characteristic fuel vehicle 10 includes an internal combustion engine 12, a saddle-type multi-characteristic fuel vehicle fuel tank 14, an injector 16, and a fuel pump 18.

[0026] The internal combustion engine 12 is capable of burning multiple types of fuel with different characteristics. The saddle-type multi-characteristic fuel vehicle fuel tank 14 is configured to store fuel to be supplied to the internal combustion engine 12. The saddle-type multi-characteristic fuel vehicle fuel tank 14 has a fuel filler opening 141 for receiving fuel from the outside and a mounting hole 142. In the example shown in FIG. 1 , the mounting hole 142 is provided in a bottom surface 143 of the saddle-type multi-characteristic fuel vehicle fuel tank 14. The injector 16 is configured to supply fuel to the internal combustion engine 12.

[0027] The fuel pump 18 is provided on the mounting member 26. The mounting member 26 is attached to the mounting hole 142, and the fuel pump 18 is positioned within the saddle-mounted multi-characteristic fuel vehicle fuel tank 14. The fuel pump 18 is configured to draw fuel from the saddle-mounted multi-characteristic fuel vehicle fuel tank 14 and pressurize the fuel toward the injector 16.

[0028] The saddle-type multi-characteristic fuel vehicle fuel tank 14 includes a partition wall member 28. The partition wall member 28 is supported on an inner surface 145 of the saddle-type multi-characteristic fuel vehicle fuel tank 14 so that the fuel filler opening 141, fuel fill space 301, partition wall member 28, fuel property change adjustment space 321, and primary filter 20 are arranged in this order from the filler opening 141 toward the primary filter 20 provided at the suction port 181 of the fuel pump 18. In the example shown in FIG. 1 , the partition wall member 28 is supported on an inner surface 146 of the saddle-type multi-characteristic fuel vehicle fuel tank 14. As a result, the partition wall member 28 defines a receiving fuel storage chamber 30 and a fuel property change adjustment chamber 32 within the saddle-type multi-characteristic fuel vehicle fuel tank 14. The receiving fuel storage chamber 30 communicates with the filler opening 141 and forms a fuel fill space 301. The fuel property change adjusting chamber 32 accommodates at least a portion of the primary filter 20 and defines a fuel property change adjusting space 321 .

[0029] The partition wall member 28 has a communication portion 281. The communication portion 281 communicates between the received fuel storage chamber 30 and the fuel property change adjusting chamber 32. The communication portion 281 allows fuel to pass from the received fuel storage chamber 30 to the fuel property change adjusting chamber 32 at an amount per unit time that is equal to or greater than the maximum fuel supply amount per unit time that can be supplied from the fuel pump 18 to the internal combustion engine 12 when the internal combustion engine 12 is operating, but has a shape that makes it difficult for the received fuel supplied from the fuel filler port 141 to enter the fuel property change adjusting chamber 32 from the received fuel storage chamber 30, thereby adjusting the mixing rate of the received fuel and the existing fuel. As a result, the fuel property change adjusting chamber 32 is configured to adjust the mixing rate of the received fuel and the existing fuel by making it difficult for the received fuel to enter from the received fuel storage chamber 30.

[0030] In the saddle-type multi-characteristic fuel vehicle 10, the partition wall member 28 can form the fuel property change adjustment chamber 32. This eliminates the need to modify the fuel pump 18 or the mounting structure of the fuel pump 18 within the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle, nor the accompanying modification of the sealing structure. Therefore, the saddle-type multi-characteristic fuel vehicle 10 can achieve a fuel property change adjustment function with a simple structure while minimizing or preventing any impact on the design freedom of the fuel pump 18 or the mounting structure of the fuel pump 18 within the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle.

[0031] 1, the fuel property change adjusting chamber 32 includes a space between one surface of the partition wall member 28, which are spaced apart from each other and the inner surface 145 (bottom surface 143) of the saddle-type multi-characteristic fuel vehicle fuel tank 14. In the example shown in Fig. 1, the fuel property change adjusting chamber 32 has a volume smaller than the volume of the receiving fuel storage chamber 30, but is configured to accommodate both at least a portion of the fuel pump 18 and at least a portion of the primary filter 20. In the example shown in Fig. 1, the communication portion 281 has a shape that allows fuel to pass from the receiving fuel storage chamber 30 to the fuel property change adjusting chamber 32 even without suction pressure from the fuel pump 18.

[0032] Figure 2 is a schematic diagram illustrating variations of the partition wall member 28 that can be employed in the saddle-type multi-characteristic fuel vehicle 10. In Figure 2 (A1), the partition wall member 28A has a plate shape, and one end (one end in the left-right direction of the page) is bent to form a vertical wall. As a result, one end of the partition wall member 28A is supported on the bottom surface 143 of the saddle-type multi-characteristic fuel vehicle fuel tank 14, and the other end is supported on the inner surface 146 of the saddle-type multi-characteristic fuel vehicle fuel tank 14. In Figure 2 (A2), the partition wall member 28B has a flat plate shape and is disposed at an angle. As a result, the partition wall member 28B is supported on the inner surface 146 and the bottom surface 143 of the saddle-type multi-characteristic fuel vehicle fuel tank 14. In Fig. 2(B1), the partition wall member 28C has a plate shape, and both ends (both ends in the left-right direction of the drawing) are bent into vertical walls. As a result, both ends of the partition wall member 28C are supported by the bottom surface 143 of the saddle-type multi-characteristic fuel vehicle fuel tank 14. In Fig. 2(B2), the saddle-type multi-characteristic fuel vehicle fuel tank 14A has a shallow bottom surface 1431 and a deep bottom surface 1432. The partition wall member 28D is supported by the shallow bottom surface 1431. In Fig. 2(C), the partition wall member 28E has a single insertion hole 282. The fuel pump 18 is inserted into the insertion hole 282. As a result, an annular communication portion is formed between the outer surface of the fuel pump 18 and the inner surface of the insertion hole 282.

[0033] FIG. 3 is a schematic diagram illustrating variations in the arrangement of the fuel pump 18 that may be employed in the saddle-type multi-characteristic fuel vehicle 10. In FIG. 1, the fuel pump 18 is disposed vertically within the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle. However, in FIG. 3A, the fuel pump 18 is disposed horizontally within the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle. In FIG. 3B, a mounting hole 142 is provided in an upper surface 144 of the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle. The fuel pump 18 is disposed vertically within the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle. Here, "the fuel pump 18 is disposed vertically" refers to, for example, the fuel pump 18 being disposed so that the rotational axis of the motor included in the fuel pump 18 extends in the vertical direction of the vehicle. "The fuel pump 18 is disposed horizontally" refers to, for example, the fuel pump 18 being disposed so that the rotational axis of the motor included in the fuel pump 18 extends in a direction perpendicular to the vertical direction of the vehicle. In each of FIGS. 3A and 3B, the partition wall members 28A to 28E as shown in FIG. 2 may be employed.

[0034] FIG. 4 is a schematic diagram illustrating variations in the arrangement of the discharge port 23 of the pressure regulator 22 that can be employed in the saddle-type multi-characteristic fuel vehicle 10. The saddle-type multi-characteristic fuel vehicle 10 further includes a pressure regulator 22. The pressure regulator 22 is provided in the fuel flow path from the fuel pump 18 to the injector 16. The pressure regulator 22 passes fuel pressurized by the fuel pump 18 toward the injector 16. The pressure regulator 22 is configured to return low-pressure surplus fuel to the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle. The discharge port 23, through which the pressure regulator 22 returns low-pressure surplus fuel to the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle, is located within the fuel property change adjustment chamber 32. In FIG. 4A , a pipe 24 is connected to the pressure regulator 22. The discharge port 23, provided at one end of the pipe 24, is located within the fuel property change adjustment chamber 32. In Fig. 4B, the discharge port 23 provided in the pressure regulator 22 is located inside the fuel characteristic change adjustment chamber 32. In each of Fig. 4A and Fig. 4B, the partition wall members 28A to 28E as shown in Fig. 2 may be employed.

[0035] FIG. 5 is a schematic diagram illustrating variations in the arrangement of the primary filter 20 that can be employed in the saddle-type multi-characteristic fuel vehicle 10. In FIG. 5, the fuel pump 18 is located in the receiving fuel reservoir chamber 30, but the primary filter 20 is located in the fuel characteristic change adjustment chamber 32. FIG. 5A illustrates the case in which the fuel pump 18 is disposed vertically as shown in FIG. 1. FIG. 5B illustrates the case in which the fuel pump 18 is disposed horizontally as shown in FIG. 3A. FIG. 5C illustrates the case in which the fuel pump 18 is disposed vertically as shown in FIG. 3B. In each of FIGS. 5A and 5B, the partition wall member 28 is bent so that one end (the end in the left-right direction of the drawing) becomes a vertical wall. As a result, one end of the partition wall member 28 is supported on the bottom surface 143 around the mounting hole 142 of the fuel tank 14 for the saddle-type multi-characteristic fuel vehicle. The partition wall member 28 may be bent so that both ends (both ends in the left-right direction of the drawing) form vertical walls. In this case, each of the both ends of the partition wall member 28 is supported by the bottom surface 143 of the saddle-type multi-characteristic fuel vehicle fuel tank 14. In FIG. 5C , the partition wall member 28 has a recess 282, and the lower end of the fuel pump 18 is positioned within the recess 282. This allows the primary filter 20 to be closer to the bottom surface 143 of the saddle-type multi-characteristic fuel vehicle fuel tank 14 while increasing the volume of the fuel characteristic change adjustment chamber 32. In FIG. 5C , the partition wall member 28 does not necessarily have to have a recess. In FIG. 5C , one end or both ends (one end or both ends in the left-right direction of the drawing) of the partition wall member 28 may be bent so that they form vertical walls. In this case, one end or both ends of the partition wall member 28 are supported on the bottom surface 143 of the saddle-type multi-characteristic fuel vehicle fuel tank 14. In each of Figures 5A, 5B, and 5C, a step may be formed on the bottom surface of the saddle-type multi-characteristic fuel vehicle fuel tank 14, as shown in Figure 2B2.

[0036] (Other Embodiments) The embodiments and variations described and / or illustrated in this specification are intended to facilitate understanding of the present disclosure and are not intended to limit the scope of the present disclosure. The above-described embodiments and variations may be modified or improved without departing from the spirit of the present disclosure. This spirit encompasses equivalent elements, modifications, deletions, combinations (e.g., combinations of features across embodiments and variations), improvements, and modifications that would be recognized by a person skilled in the art based on the embodiments disclosed herein. The limitations in the claims should be interpreted broadly based on the terms used in the claims and should not be limited to the embodiments and variations described in the specification or prosecution of this application. Such embodiments and variations should be construed as non-exclusive. For example, in this specification, the terms "preferably" and "good" are non-exclusive and mean "preferably but not limited to" or "good but not limited to."

[0037] For example, the shape, size, position, etc. of the filter 20 are not limited to those shown in FIGS.

[0038] REFERENCE SIGNS LIST 10 saddle-type multi-characteristic fuel vehicle 12 internal combustion engine 14 fuel tank for saddle-type multi-characteristic fuel vehicle 141 fuel filler port 142 mounting hole 145 inner surface 16 injector 18 fuel pump 181 suction port 20 primary filter 26 mounting member 28 partition wall member 281 communicating portion 30 receiving fuel storage chamber 301 fuel supply space 32 fuel characteristic change adjustment chamber 321 fuel characteristic change adjustment space

Claims

1. A straddle-type multi-fuel vehicle, comprising: - an internal combustion engine capable of burning a plurality of types of fuels having different characteristics; - a fuel tank for a straddle-type multi-fuel vehicle configured to store the fuel supplied to the internal combustion engine, having a fuel filler port for receiving fuel from the outside, and a mounting hole; - an injector configured to supply fuel to the internal combustion engine; - a fuel pump provided on a mounting member, the mounting member being mounted in the mounting hole so as to be located inside the fuel tank for a straddle-type multi-fuel vehicle, and configured to suck fuel inside the fuel tank for a straddle-type multi-fuel vehicle and pressurize the fuel toward the injector. - The fuel tank for a straddle-type multi-fuel vehicle includes a partition wall member, and the partition wall member is supported on the inner surface of the fuel tank for a straddle-type multi-fuel vehicle in the order of the fuel filler port, a fuel supply space, the partition wall member, a fuel characteristic change adjustment space, and the primary filter toward the primary filter provided at the suction port of the fuel pump from the fuel filler port, thereby defining, inside the fuel tank for a straddle-type multi-fuel vehicle, a received fuel storage chamber communicating with the fuel filler port and forming the fuel supply space, and a fuel characteristic change adjustment chamber accommodating at least a part of the primary filter and forming the fuel characteristic change adjustment space. - The fuel tank for a straddle-type multi-fuel vehicle has a communication portion communicating the received fuel storage chamber and the fuel characteristic change adjustment chamber, and the communication portion allows fuel to pass from the received fuel storage chamber to the fuel characteristic change adjustment chamber at an amount per unit time greater than the maximum fuel supply amount per unit time that can be supplied from the fuel pump toward the internal combustion engine during operation of the internal combustion engine, and has a shape such that the received fuel supplied from the fuel filler port is made difficult to enter from the received fuel storage chamber into the fuel characteristic change adjustment chamber, thereby adjusting the mixing speed of the received fuel and the existing fuel. Accordingly, the fuel characteristic change adjustment chamber is configured such that the mixing speed of the received fuel and the existing fuel is adjusted by making it difficult for the received fuel to enter from the received fuel storage chamber.

2. The straddle-type multi-characteristic fuel vehicle according to claim 1, further comprising a pressure regulator provided in a fuel flow path from the fuel pump to the injector, configured to direct the fuel pressurized by the fuel pump toward the injector while returning low-pressure surplus fuel into the fuel tank for the straddle-type multi-characteristic fuel vehicle, and a discharge port for the pressure regulator to return the low-pressure surplus fuel into the fuel tank for the straddle-type multi-characteristic fuel vehicle is located in the fuel characteristic change adjustment chamber.

3. The straddle-type multi-characteristic fuel vehicle according to claim 1 or 2, wherein the fuel characteristic change adjustment chamber includes a space between one surface of the partition wall members facing each other at a distance and the inner surface of the fuel tank for the straddle-type multi-characteristic fuel vehicle.

4. The straddle-type multi-characteristic fuel vehicle according to any one of claims 1 to 3, wherein the fuel characteristic change adjustment chamber has a volume smaller than the volume of the received fuel storage chamber, but is configured to accommodate at least a part of the fuel pump and at least a part of the primary filter.

5. The straddle-type multi-characteristic fuel vehicle according to any one of claims 1 to 4, wherein the communication portion has a shape that allows fuel to pass from the received fuel storage chamber to the fuel characteristic change adjustment chamber even without the suction pressure by the fuel pump.

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