Description:FIELD OF THE INVENTION
[001] The present invention relates to a saddle-type vehicle. More particularly, the present invention relates to a saddle-type vehicle having an improved fuel injection system for regulating fuel pressure.

BACKGROUND OF THE INVENTION
[002] Saddle-type vehicles, more particularly two-wheeled vehicles, are widely used for transportation due to their compact size, agility, and fuel efficiency. The fuel injection system of the two-wheeled vehicle plays a significant role in determining the engine stability and fuel efficiency.
[003] In existing vehicles, a fuel supply hose is required to connect a fuel tank with fuel injectors of an engine to supply the fuel required for combustion process of the engine to drive the vehicle. The fuel supply hose is usually connected to a fuel pump connected to the fuel tank. Once the engine is started, the fuel pump is actuated by an electric current from a battery and is controlled by an engine control module to provide requisite amount of fuel to the fuel injectors. In existing vehicles, generally two types of fuel injection systems are used i.e., a return-type fuel injection system and a non-return type fuel injection system. Owing to the advantages of consistent fuel pressure delivery, reduced fuel consumption, optimized fuel-air mixing and effective heat dissipation of the fuel, the return-type fuel injection system is preferred over the non-return type fuel injection system.
[004] However, it has been observed that the existing return-type fuel injection systems are prone to the problems of pressure fluctuations which occur within the fuel system of the vehicle during the fuel injection process. These pressure fluctuations are usually caused by opening and closing of a fuel injection valve, which is controlled by the engine control module or an electronic control unit (ECU) of the vehicle based on various sensors inputs. Upon the opening of the fuel injection valve, the fuel is injected into the combustion chamber of the engine causing a sudden increase in fuel pressure within the fuel system. As the fuel injection valve closes, the pressure drops rapidly, resulting in a decrease in the fuel pressure. Such variations in fuel pressure causes a pulsation effect which negatively impacts the fuel delivery and engine performance. Further, it has also been observed that due to improper fuel routing configuration of the fuel supply hoses, said pulsation effect is generated by resonating and amplifying the fuel pressure fluctuations. Such pulsation effect interferes with the precise control of fuel injection and leads to issues like uneven fuel distribution among cylinders, poor fuel combustion, reduced power output, increased emissions, and decreased fuel efficiency. Moreover, the pulsation effect also impact the stability and durability of fuel system components, such as fuel supply hoses, connectors, and seals etc.
[005] Further, it has been observed that the fuel supply hoses are generally made of plastic material and thus prone to issues like limited elasticity, durability, temperature range, compatibility with fuel additives, and higher manufacturing costs. These problems can affect fuel control, performance, and the overall reliability of the fuel system. The plastic hoses become more elastic when the temperature of the fuel increases and are subjected to squeeze or flex due to pressure fluctuations which impacts the flow of the fuel.
[006] Furthermore, it has also been observed that routing/disposing long fuel hoses in two-wheeled vehicles, especially motorcycles, causes a great challenge and complexities. Space limitations, tight clearances, and the safety requirements which mandates to avoid interference of the fuel hoses with other components, such as the engine assembly located just below the fuel tank, makes it more difficult to effectively route the fuel hoses.
[007] Owing to improper routing configuration of the fuel hoses of the existing fuel systems, the fuel hoses may kink, flex, or strike against sharp bends resulting into hose damage, leaks, or decreased fuel flow. Further, it has been observed that the length of the fuel hose plays a significant role in the occurrence of the pulsation effect, particularly when the vehicle accelerates. Rapid acceleration of a throttle unit causes an abrupt rise in fuel demand, which causes a spike in fuel flow inside the long fuel hoses. This quick flow creates pressure pulsations or oscillations generating a negative effect on the fuel stability and control and further impacts the engine performance, fuel economy, and overall ride quality, which is undesired.
[008] In view of the foregoing, there is a need to provide a saddle-type vehicle having an improved fuel system which solves at least one of the aforesaid problems.

SUMMARY OF THE INVENTION
[009] In one aspect of the invention, a saddle-type vehicle is disclosed. The saddle-type vehicle includes an internal combustion engine, a fuel pump, and an external fuel filter. The internal combustion engine includes a cylinder head configured to receive at least one fuel injector for injecting fuel inside the internal combustion engine. The fuel pump being configured to supply the fuel at a predetermined fuel pressure to the at least one fuel injector. The external fuel filter is located in proximity to the outlet of the fuel pump and above the cylinder head of the internal combustion engine. The external fuel filter has at least one inlet port configured to be fluidly connected to the outlet of the fuel pump through a first fuel hose. The at least one outlet port being configured to be fluidly connected to the at least one fuel injector through a second fuel hose. The outlet port is connected to at least one fuel return outlet for returning the fuel from the second fuel hose to the fuel pump through a third fuel hose. Each of the first, second and third fuel hoses extends non-linearly between a first end and a second end and comprises one or more curved bent portions. The one or more curved bent portions being configured to enroute the fuel to regulate the predetermined fuel pressure.
[010] In an embodiment, the fuel pump is disposed above the internal combustion engine.
[011] In an embodiment, each of the first, second and third fuel hoses being formed of a multi-layered rubber material.
[012] In an embodiment, each of the first, second and the third fuel hoses has a durometer rating ranging between 60 to 80.
[013] In an embodiment, the one or more curved bent portions of any of the first, second and third fuel hoses are configured to form at least one L-shaped curved section or a parabolic shaped curved section with each of the first ends.
[014] In an embodiment, the one or more curved bent portions of any of the first, second and third fuel hoses are configured to form at least one parabolic shaped curved section with each of the second ends.
[015] In an embodiment, each of the parabolic shaped curved sections being configured to enroute a portion of the first fuel hose and the third fuel hose away from the cylinder head of the internal combustion engine.
[016] In an embodiment, the first end of the first fuel hose being connected to the outlet of the fluid pump and the second end of the first fuel hose being connected to the at least one inlet port of the external fuel filter.
[017] In an embodiment, the first end of the second fuel hose being connected to the at least one outlet port of the external fuel filter and the second end of the second fuel hose being connected to the at least one fuel injector.
[018] In an embodiment, the first end of the third fuel hose being connected to a fuel returning port of the fuel pump and the second end of the third hose being connected to the at least one fuel return outlet being in connection with the at least one outlet port of the external fuel filter.
[019] In an embodiment, each of the first ends and the second ends of the first, second and third fuel hoses being configured to receive one or more locking means or couplers.
[020] In an embodiment, the saddle-type vehicle includes a headtube; a main tube extending rearwardly and downwardly from the headtube in a front-rear direction of the vehicle; and a down tube extending downwardly and rearwardly from the head tube in a front-rear direction of the vehicle.
[021] In an embodiment, the internal combustion engine is supportably mounted on the downtube.
[022] In an embodiment, the saddle-type vehicle includes a fuel tank that is supportably mounted on the main tube and being disposed behind the head tube in the front-rear direction of the vehicle. The fuel tank being fluidly connected with the fuel pump.
[023] In an embodiment, the saddle-type vehicle includes a control unit being operably connected with each of the internal combustion engine, the fuel pump and the at least one fuel injector. The control unit being configured to control the flow of the fuel being injected to the internal combustion engine.
[024] In an embodiment, the saddle-type vehicle includes one or more pressure regulators being operably connected with the at least one fuel injector and the control unit.
[025] In an embodiment, the one or more pressure regulators being configured to return the fuel through the third fuel hose when the fuel pressure exceeds more than the predetermined fuel pressure.

BRIEF DESCRIPTION OF THE DRAWINGS
[026] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1(a) illustrates a schematic view of an exemplary vehicle having a return-type fuel injection system, in accordance with an embodiment of the present invention.
Figure 1(b) is a bottom perspective view of a front-portion of the vehicle illustrating a fuel routing configuration of the return-type fuel injection system, in accordance with an embodiment of the present invention.
Figure 2(a) is a top perspective view illustrating internal components of the fuel tank of the vehicle, in accordance with an embodiment of the present invention.
Figure 2(b) is a bottom view of the fuel tank illustrating the fuel routing configuration of the return-type fuel injection system of the vehicle, in accordance with an embodiment of the present invention.
Figure 2(c) is a bottom perspective view of the fuel tank illustrating the fuel routing configuration of the return-type fuel injection system of the vehicle, in accordance with an embodiment of the present invention.
Figures 3(a)-3(b) illustrate the fuel hoses connected with the external fuel filter, in accordance with an embodiment of the present invention.
Figure 4 illustrates the configuration of the first fuel hose of the return-type fuel injection system, in accordance with an embodiment of the present invention.
Figure 5(a) illustrates the configuration of the second fuel hose of the return-type fuel injection system, in accordance with an embodiment of the present invention.
Figure 5(b) illustrates the configuration of the second fuel hose with a coupler and connector, in accordance with an embodiment of the present invention.
Figure 6 illustrates the configuration of the third fuel hose of the return-type fuel injection system, in accordance with an embodiment of the present invention.
Figure 7 is a bottom perspective view of the fuel tank illustrating the configuration of the return-type fuel injection system, in accordance with an embodiment of the present invention.
Figure 8 illustrates the fuel routing configuration of the return-type fuel injection system along with an air filter assembly of the vehicle, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[027] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.
[028] The present invention relates to a saddle-type vehicle having a return-type fuel injection system. The present invention provides an improved fuel routing configuration to reduce a pulsation effect of the fuel.
[029] Figure 1(a) illustrates a schematic view of a saddle-type vehicle 10, in accordance with an embodiment of the present invention. Figure 1(b) is a bottom perspective view of a front-portion of the vehicle illustrating a fuel routing configuration of the return-type fuel injection system, in accordance with an embodiment of the present invention.
[030] In the present invention, a longitudinal axis refers to a front to rear axis relative to a vehicle, defining a vehicle longitudinal direction while a lateral axis refers to a side to side, or left to right axis relative to the vehicle, defining a vehicle width direction. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Arrows provided in the top right corner of the figure 1a depicts direction with respect to the vehicle, wherein an arrow F denotes a front direction, an arrow R indicates a rearward direction, an arrow Up denotes an upward direction, an arrow Dw denotes a downward direction of the vehicle.
[031] As shown, the exemplary vehicle is a two wheeled vehicle 10. The vehicle 10 includes a frame structure configured to support and mount various parts/ components of the vehicle 10. The frame structure is extending in the front-rear direction of the vehicle 10. The frame structure includes a head tube 20, a main tube (not shown), a down tube 22 and a pair of seat rails (not shown). The vehicle 10 includes a headlamp unit 12 disposed in a front zone of the vehicle 10. The headlamp unit 12 is supportably mounted on the head tube 20 of the vehicle 10. The vehicle 10 includes a front wheel 16 and a rear wheel 90. The front wheel 16 is supportably mounted on the head tube 20 through one or more front shock absorbers 13. A handlebar 18 is rotatably and supportably mounted on the head tube 20 and is attached to the one or more front shock absorbers 13 to turn the front wheel 16 in the left-right direction of the vehicle 10. The vehicle 10 includes a front fender 14 supportably mounted on the one or more front shock absorbers 13. The front fender 14 is configured to cover at least an upper surface of the front wheel 16. The pair of seat rails of the frame structure is configured to receive a vehicle seat 92. The rear wheel 90 is supportably mounted on the pair of seat rails through one or more rear shock absorbers 94. A rear fender 96 is mounted on a rear end of the pair of seat rails. The rear fender 96 is configured to cover an upper portion of the rear wheel 90. The vehicle 10 includes an internal combustion engine 25 supportably mounted on the down tube 22. The internal combustion engine 25 has a cylinder head 25a. The cylinder head 25a includes a combustion chamber configured to receive one or more fuel injectors (not shown) for injecting a fuel inside the internal combustion engine 25 for combustion process. The one or more fuel injectors are configured to deliver the pressurized fuel into the combustion chamber of the internal combustion engine in a precise and controlled manner. The fuel injector is an electronically controlled valve that opens and closes at specific intervals and delivers a predetermined amount of fuel into the combustion chamber of the internal combustion engine 25. The handlebar 18 is configured to receive an accelerator device for providing a throttle input to the internal combustion engine 25. Basis the throttle input, the fuel injector is operated to inject the required fuel amount inside the combustion chamber.
[032] A fuel tank 30 is located above the cylinder head 25a of the internal combustion engine 25 and behind the head tube 20. The fuel tank 30 is supportably mounted on the main tube of the vehicle 10. The vehicle 10 includes a fuel pump 40 being fluidly connected with the fuel tank 30. The fuel pump 40 is configured to pressurize the fuel received from the fuel tank 30 and supply the pressurized fuel having a predetermined fuel pressure to the fuel injector of the internal combustion engine 25. Power from the internal combustion engine 25 is transmitted to the rear wheel 90 through a transmission assembly (not shown) so as to drive and rotate the rear wheel 90. The vehicle 10 includes a return-type fuel injection system. The return-type fuel injection system includes the fuel tank 30, the fuel pump 40, an external fuel filter 50, a carbon canister 60 (shown in Figure 2(b)), the fuel injector, one or more pressure regulators, a plurality of fuel hoses i.e., a first hose 100, a second hose 200, a third hose 300 and a control unit (not shown). The control unit may be the electronic control unit (ECU) of the vehicle 10 or an engine control module. The control unit is operably connected with each of the fuel pump 40, the fuel injector, one or more pressure regulators and the internal combustion engine 25 through one or more sensors/actuators. The control unit is configured to control the supply of the fuel by controlling and/or operating the fuel injector. Each of the plurality of fuel hoses 100, 200, 300 includes one or more bent portions 100c, 200c, 300c (shown in Figure 3(a)) being configured to enroute the fuel to regulate the predetermined fuel pressure. Each of the first, second and third hoses 100, 200, 300 being formed of a multilayered rubber material. In a non-limiting example, the first, second and third fuel hoses 100, 200, 300 are being formed of four layered rubber material hoses of circular cross section. Each of the first, second and third fuel hoses 100, 200, 300 has a durometer rating ranging between 60 to 80.
[033] The vehicle 10 includes a panel member 80 having an air cleaner assembly. The panel member 80 is disposed below the fuel tank 30 and the vehicle seat 92.
[034] Figure 2(a) is a perspective top view illustrating internal components of the fuel tank 30 of the vehicle 10, in accordance with an embodiment of the present invention. As shown, the fuel tank 30 is extending between a first end 30a and a second end 30b. The second end 30b may include mounting holes for securing a rear portion of the fuel tank 30 with the frame structure of the vehicle 10. The fuel tank 30 includes an upper internal wall 31 and a bottom outer wall 39 (shown in Figure 2(c)). The upper internal wall 31 is configured to receive cover members for forming a fuel storage cavity of the fuel tank 30. The fuel tank 30 includes one or more sensors or a fuel metering device 34 configured to measure the fuel level inside the fuel tank 30 and provides feedback to the fuel gauge or an odometer / instrumental cluster and thus allowing the rider to monitor the amount of fuel remaining inside the fuel tank 30. In a non-limiting example, the fuel tank 30 is configured to receive the fuel pump 40 inside the fuel storage cavity. The fuel pump 40 is an electrically driven pump and includes one or more motors, and/or actuator units. The fuel pump 40 having an inlet being in fluid communication with the fuel storage cavity of the fuel tank 30 for receiving the fuel.
[035] Figure 2(b) is a bottom view of the fuel tank 30 illustrating the fuel routing configuration of the return-type fuel injection system of the vehicle 10, in accordance with an embodiment of the present invention. Figure 2(c) is a bottom perspective view of the fuel tank 30 illustrating the fuel routing configuration of the return-type fuel injection system of the vehicle 10, in accordance with an embodiment of the present invention. As shown, the bottom outer wall 39 of the fuel tank 30 includes a mounting portion 39a. The mounting portion 39a being configured to receive a portion of the main tube of the frame structure for supportably mounting the fuel tank 30 on the vehicle 10 (shown in Figure 1).
[036] In an embodiment, the fuel pump 40 includes an integrated internal fuel filter for filtering out the fuel received from the fuel tank 30 before supplying it to the external fuel filter 50 of the vehicle 10. The external fuel filter 50 is configured to filter the fuel entering the fuel injector by filtering out impurities, such as dirt, debris, rust particles, and sediments remaining in the fuel even after passing through the internal fuel filter of the fuel pump 40. The fuel pump 40 includes a mounting flange 44 for attaching the fuel pump 40 with the bottom outer wall 39 of the fuel tank 30. The fuel pump 40 is having a connection port 45, an outlet 48 and a fuel returning port 49 disposed on the mounting flange 44. The fuel returning port 49 is configured to return the fuel back to the fuel storage cavity of the fuel tank 30. The outlet 48 of the fuel pump 40 is configured to discharge the pressurized fuel. The connection port 45 establishes an electrical connection between the fuel pump 40 and a battery (not shown) of the vehicle 10 for driving the fuel pump 40 and is in further communication with the control unit of the vehicle 10 (shown in Figure 1).
[037] In an embodiment, the outlet 48 of the fuel pump 40 is located in proximity to the bottom outer wall 39 of the fuel tank 30 and above the cylinder head 25a of the internal combustion engine 25 of the vehicle 10.
[038] In an embodiment, the external fuel filter 50 is configured to be fluidly connected to the outlet 48 of the fuel pump 40 through the first fuel hose 100. The external fuel filter 50 is configured to be fluidly connected to the one or more fuel injectors through the second fuel hose 200. The external fuel filter 50 is configured to be connected to the fuel returning port 49 of the fuel pump 40 through the third fuel hose 300.
[039] In an embodiment, the vehicle 10 includes the carbon canister 60 disposed in vicinity of the bottom outer wall 39 of the fuel tank 30. The carbon canister 60 is located above the cylinder head 25a of the internal combustion engine 25 and relatively opposite to the location of the external fuel filter 50. The carbon canister 60 is mounted on the bottom outer wall 39 of the fuel tank 30 through attachment means. The attachment means include a mounting bracket (not shown) being fixedly attached to the bottom outer wall 39 of the fuel tank 30. The carbon canister 60 is in fluid communication with the fuel tank 30 and having a purge control valve 70 configured to capture and store fuel vapours generated inside the fuel tank 30. In a non-limiting example, the carbon canister 60 is a sealed container having an activated charcoal or another type of adsorbent material. The carbon canister 30 is connected to the fuel tank 30 through one or more hoses or pipes. The fuel vapours generated in the fuel tank 30 due to fuel evaporation or change in temperature are captured by the carbon canister 60 and prevented to be released directly into the atmosphere. In operation, when the internal combustion engine 25 is in running condition, the carbon canister 60 purges the collected fuel vapours by allowing them to be sucked into an intake manifold 86 (shown in Figure 8) of the internal combustion engine 25. The vacuum created during the suction stroke of the internal combustion engine 25 enables the flow of the fuel vapours from the carbon canister 60 into the combustion chamber of the internal combustion engine 25 so that the fuel vapors may get burned along with the air-fuel mixture during the combustion process.
[040] Figures 3(a)-3(b) illustrate the fuel hoses connected with the external fuel filter 50, in accordance with an embodiment of the present invention. The external fuel filter 50 includes an inlet port 51 and an outlet port 58. The inlet port 51 is configured to be fluidly connected to the outlet 48 of the fuel pump 40 for receiving the pressurized fuel. The outlet port 58 being configured to be fluidly connected to the one or more fuel injectors for supplying the filtered fuel. The outlet port 58 being configured to receive a fuel return outlet 59. In a non-limiting example, the outlet port 58 includes an integrated fuel return outlet 59.
[041] As shown, each of the first fuel hose 100, second fuel hose 200 and third fuel fuel hose 300 includes a first end 100a, 200a, 300a and a second end 100b, 200b, 300b. Each of the first fuel hose 100, second fuel hose 200 and third fuel fuel hose 300 extends non-linearly between the first end 100a, 200a, 300a and the second end 100b, 200b, 300b. Each of the first fuel hose 100, second fuel hose 200 and third fuel fuel hose 300 includes the one or more curved bent portions 100c, 200c, 300c. The one or more curved bent portions 100c, 200c, 300c being configured to enroute the fuel to regulate the predetermined fuel pressure of the fuel being subjected to the one or more fuel injectors.
[042] In an embodiment, the first end 100a of the first fuel hose 100 is configured to be attached to the outlet 48 of the fuel pump 40 (shown in Figure 2(a) through a locking means (A). In a non-limiting example, the locking means (A) may be a lock ring, fastening ring, clamp ring etc. The second end 100b of the first fuel hose 100 being configured to be secured to the inlet port 51 of the external fuel filter 50 through the locking means (A). The first end 200a of the second fuel hose 200 being configured to be attached to the outlet port 58 of the external fuel filter 50 through the locking means (A). The second end 200b of the second fuel hose 200 being configured to be secured to the one or more fuel injectors disposed inside the internal combustion engine 25. The first end 300a of the third fuel hose 300 being configured to be connected to the fuel returning port 49 of the fuel pump 40 for returning the fuel back to the fuel tank 30 (shown in Figure 2(b). The second end 300b of the third hose 300 being configured to be connected to the fuel return outlet 59 being in connection with the outlet port 58 of the external fuel filter 50. In an embodiment, the curved bent portions 100c, 300c of the first fuel hose 100, third fuel hose 300 being configured to receive a clamp ring (C) to secure both the hoses adjacently.
[043] In an embodiment, an end portion of the outlet port 58 of the external fuel filter 50 being configured to receive a connector tube 250 through a coupler (B). The connector tube 250 includes a first end and a second end. In a non-limiting example, the connector tube 250 is a L-shaped tubular member configured to fluidly connect the outlet port 58 of the external fuel filter 50 with the first end 200a of the second hose 200. The coupler (B) tightly secures the first end of the connector tube 250 with the outlet port 58 of the external fuel filter 50. The second end of the connector tube 250 being configured to receive the first end 200a of the second fuel hose 200 through the locking means (A).
[044] Figure 4 illustrates the configuration of the first fuel hose 100 of the return-type fuel injection system, in accordance with an embodiment of the present invention. As shown, the first fuel hose 100 includes curved bent portions 100c. One of the curved bent portions 100c of the first fuel hose 100 being configured to form at least one L-shaped curved section (P1) with the first end 100a of the first fuel hose 100. Another curved bent portions 100c being configured to form a parabolic shaped curved section (P2) with the second end 100b of the first fuel hose 100. The first end 100a and the second end 100b being configured to receive grooves 110, 120 respectively. The grooves 110, 120 being configured to receive the locking means(A) (shown in Figure 3(b)) to secure the first end 100a with the outlet 48 of the fuel pump 40 and the second end 100b with the inlet port 51 of the external fuel filter 50.
[045] In an embodiment, the parabolic shaped curved section (P2) of the first hose 100 being formed by two corresponding curved bent portions 100c having a predetermined distance (D1) between two adjacent portions of first fuel hose 100. The predetermined distance (D1) depends upon the fuel routing requirements of the first hose 100 and the space availability between the corresponding parts of the vehicle 10. The first hose 100 is configured to receive a protective outer sheath 150.
[046] Figure 5(a) illustrates the configuration of the second fuel hose 200 of the return-type fuel injection system, in accordance with an embodiment of the present invention. Figure 5(b) illustrates the configuration of the second fuel hose 200 with the coupler (B) and the connector tube 250, in accordance with an embodiment of the present invention. The second fuel hose 200 having the first end 200a and the second end 200b. The second fuel hose 200 extends non-linearly between the first end 200a and the second end 200b. The second fuel hose 200 includes the one or more bent portions 200c. The first end 200a being configured to receive grooves 210. The grooves 210 being configured to receive the tightening clamp or locking ring to secure the first end 200a with the outlet port 58 of the external fuel filter 50. Similarly, the second end 200b being configured to receive grooves 220 for receiving the locking means (A) for securing the second end 200b of the second fuel hose 200 with the one or more fuel injectors. As shown, the second fuel hose 200 includes plurality of curved bent portions 200c forming the parabolic shaped curved sections (P2) with each of the first end 200a and the second end 200b.
[047] Figure 6 illustrates the configuration of the third fuel hose 300 of the return-type fuel injection system, in accordance with an embodiment of the present invention. The third fuel hose 300 is a fuel returning hose. As shown, the third fuel hose 300 includes curved bent portions 300c. One of the curved bent portions 300c of the third fuel hose 300 being configured to form at least one L-shaped curved section (P1) with the first end 300a of the third fuel hose 300. Another curved bent portions 300c being configured to form a parabolic shaped curved section (P2) with the second end 300b of the first fuel hose 100. The first end 300a and the second end 300b being configured to receive grooves 310, 320 respectively. The grooves 310, 320 being configured to receive the locking means (A) to secure the first end 300a to the fuel returning port 49 of the fuel pump 40 and the second end 300b with the fuel return outlet 59 connected with the outlet port 58 of the external fuel filter 50. A portion of the parabolic shaped curved section (P2) of the third fuel hose 300 being configured to receive a protective outer sheath 350.
[048] Referring to Figures 4, 6 the parabolic shaped curved sections (P2) being configured to enroute a portion of the first fuel hose 100 and the third fuel hose 300 away from the cylinder head 25a (shown in Figure 1(b)) of the internal combustion engine 25. Such configuration provides a technical effect of reducing the temperature range of the fuel flowing through the portions of the first fuel hose 100 and the third fuel hose 300 being distant from the engine cylinder head 25a and further increases the safety of the first fuel hose 100 and the third fuel hose 300. Such configuration also improves the life of the first fuel hose 100 and the third fuel hose 300 as the exposure to engine heat is reduced through the curved bent portions 100c, 300c forming out the parabolic shaped curved sections (P2).
[049] Referring to Figures 1-6, when the vehicle is in running condition, the pressurized fuel flows from the fuel pump 40 to the external fuel filter 50 through the first fuel hose 100 with a predetermined fuel pressure. The predetermined fuel pressure depends upon the size of the internal combustion engine 25 and the throttle input received from the rider through the accelerator device. The fuel filtered by the external fuel filter 50 is supplied to the fuel injector through the second fuel hose 200. The pressure regulators connected to the fuel injector, or the fuel rails are operated by the control unit to regulate and/or maintain the predetermined fuel pressure basis the throttle input and other feedback received from the sensors. The pressure regulators allow the fuel having the fuel pressure being lower than predetermined fuel pressure to pass through the second fuel hose 200. When the fuel pressure exceeds the predetermined fuel pressure, the pressure regulators are operated to return the fuel back to the fuel pump 40 through the third fuel hose 300. The curved bent portions 100c, 200c, 300c of the first, second and third fuel hoses 100, 200, 300 provide smooth and uninterrupted flow of the fuel, regulating the predetermined fuel pressure thereof.
[050] In a non-limiting example, each of the first, second and third fuel hoses 100, 200, 300 has an inner ranging between 6.5 and 8.0 mm and the outer diameter ranging between 12.5 and 13.5 mm. The predetermined fuel pressure is 3.5 bar. To reduce the pulsation effect of the fuel, the fuel pressure is regulated by the pressure regulators and only the fuel having the fuel pressure corresponding to the predetermined fuel pressure of 3.5 bar is allowed to be passed to the fuel injector through the fuel hose 200 while the fuel having the fuel pressure more than 3.5 bar is returned back to the fuel pump 40 from the outlet port 58 of the external fuel filter 50 through the third fuel hose 300.
[051] In an embodiment, the curved bent portions 100c 200c, 300c of each of the first fuel hose 100, the second fuel hose 200 and the third fuel hose 300 being configured to provide an uninterrupted and/or unrestricted flow of the fuel being flowed through the fuel hoses 100, 200, 300. Each of the curved bent portions 100c, 200c, 300c being configured with reduced elasticity to withstand against the variation in the fuel pressure without getting flexed due to variation of the throttle input being provided to the internal combustion engine 25. During the running condition of the internal combustion engine 25, the curved bent portions 100c, 200c, 300c securely hold the first, second and third fuel hoses 100, 200, 300 in their original positions and thus minimizes the possibility of excessive movement or displacement caused by vibrations and further optimize the stability and proper functioning of the fuel delivery system. When the fuel is delivered consistently at a regulated pre-determined fuel pressure, a better fuel-air mixture is supplied to the internal combustion engine 25 and due to which the combustion of the fuel is optimized resulting into the increased fuel efficiency, engine stability and performance and reduced engine emissions.
[052] In an embodiment, the fuel routing configuration of the first, second and third fuel hoses 100,200, 300 having the one or more curved bent portions 100c, 200c, 300c tends to reduce the pulsation effect of the fuel which reduces a mechanical stress being exerted on components like fuel hoses 100, 200, 300, couplers (B) and the fuel injectors etc., which effectively increases engine durability and its lifespan. Further, reduction in pulsation effect of the fuel allows the control unit to effectively and accurately regulate fuel injection timing which improves the control of the control unit over the fuel combustion process and further increases overall stability and power delivery of the internal combustion engine 25.In an embodiment, the first, second and third fuel hoses 100, 200, 300 are disposed in proximity to the adjacently positioned the fuel pump 40, the external fuel filter 50, the carbon canister 60 and the fuel injector. Such routing configuration requires a shorter length of the fuel hoses 100, 200, 300 for operably connecting the fuel pump 40, the external fuel filter 50, the carbon canister 60 and the fuel injector with each other, which minimizes the pulsation effect of the fuel. Further, the one or more curved bent portions 100c, 200c, 300c route the fuel hose away from the surrounding moving parts which reduces the vibration and the mechanical stress being exerted on the fuel hoses 100, 200, 300 thereof. Further, the fuel routing configuration provides an adequate clearance through the curved bent portions 100c, 200c, 300c which facilitates a user to effectively service, replace the fuel hoses 100, 200, 300 or other components of the fuel injection system. Such fuel routing configuration also enables detecting or easily identifying the cracks, leaks or damages sustained by the fuel hoses 100, 200, 300, if any.
[053] In a non-limiting example, the one or more curved bent portions 100c, 200c, 300c have a bent angle of 90 degree or greater than 90 degree allowing the flowing fuel to bend in a controlled manner to reduce the risk of kinks or collapsing that could disrupt the fuel flow. Such configuration ensures the efficient and uninterrupted delivery of fuel within the fuel system and improves the overall fuel system stability.
[054] Figure 7 is a bottom perspective view of the fuel tank 30 illustrating the configuration of the return-type fuel injection system, in accordance with an embodiment of the present invention. Figure 8 illustrates the fuel routing configuration of the return-type fuel injection system along with an air filter assembly of the vehicle 10, in accordance with an embodiment of the present invention. As shown, an air cleaner assembly 82 is disposed below a rear portion of the fuel tank 30. The air cleaner assembly 82 has an air outlet 83 connected to the intake manifold 86 of the internal combustion engine 25. The air outlet 83 being configured to supply a filtered air to the intake manifold 86. The carbon canister 60 is connected to the fuel tank 30 through a fuel line (L1). The carbon canister 60 is connected to the purge control valve 70 through a fuel line (L2). The purge control valve 70 is connected to the intake manifold 86. When the internal combustion engine 25 runs, the vacuum created due to suction stroke of the internal combustion engine 25 enables the flow of the fuel vapors from the carbon canister 60 to the intake manifold 86 to get mixed up with the fuel-air mixture for the combustion process.
[001] Advantageously, the present invention provides a saddle-type vehicle having an improved fuel routing configuration for return-type fuel injection system. The fuel routing configuration is a simple and effective configuration for the return-type fuel injection system. The configuration of the fuel hoses having the curved bent portions enable the smooth and uninterrupted and/or unrestricted flow of the fuel to the fuel injector and return fuel back to the fuel tank with a regulated fuel pressure. The present invention provides the fuel hoses formed with the multi-layered material. Such configuration tends to reduce the pulsation effect of the fuel and achieve a consistent fuel flow with optimized fuel combustion which leads to an increased fuel efficiency, engine stability, performance and durability and further reduces engine emissions. Further, the configuration of the hoses by routing away a portion of the hose from the internal combustion engine helps in achieving or maintaining the requisite/desired fuel temperature range and further increases the life of the hoses and mitigates the accidental risks thereof. The fuel routing configuration of the return-type fuel injection system provides placing the fuel pump and the external fuel filter above and in proximity to the cylinder head of the internal combustion engine for operably connecting the fuel pump, the external fuel filter and the fuel injector through the fuel hoses with the one or more curved bent portions. Such fuel routing configuration requires a shorter length of the fuel hoses which reduces the pulsation effect of the fuel. The one or more curved bent portions of the fuel hoses provides an adequate clearance from surrounding parts which reduces the mechanical stress being exerted on the fuel hoses, connectors, and the fuel injectors. Further, such routing configuration facilitates an effective servicing of the fuel hoses and enables detecting cracks, leaks or damage sustained by the fuel hoses, if any.
[002] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

List of Reference Numerals
10 – Vehicle
12 – Headlamp unit
13 – Front shock absorbers
14 – Front fender
16 – Front wheel
18 – Handlebar
20 – Head tube
22 – Down tube
25 – Internal combustion engine
25a – Cylinder head
30 – Fuel tank
30a – First end of the fuel tank
30b – Second end of the fuel tank
31 – Upper internal wall
34 – Fuel metering device
39 – Bottom outer wall
39a – Mounting portion of the bottom outer wall
40 – Fuel pump
44 – Mounting flange of the fuel pump
45 – Connection port
48 – Outlet of the fuel pump
49 – Fuel returning port
50 – External fuel filter
51 – Inlet port of the external fuel filter
58 – Outlet port of the external fuel filter
59 – Fuel return outlet
60 – Carbon canister
70 – Purge control valve
80 – Panel member
82 – Air cleaner assembly
83 – Air outlet of the air cleaner assembly
86 – Intake manifold
90 – Rear wheel
92 – Vehicle seat
94 – Rear shock absorbers
96 – Rear fender
100 – First fuel hose
100a – First end of the first fuel hose
100b – Second end of the first fuel hose
100c – Curved bent portions of the first fuel hose
110, 120 – Grooves
150 – Protective outer sheath of the first fuel hose
200 – Second fuel hose
200a – First end of the second fuel hose
200b – Second end of the second fuel hose
200c – Curved bent portions of the second fuel hose
210, 220 – Grooves
250 – Connector tube
300 – Third fuel hose
300a – First end of the third fuel hose
300b – Second end of the third fuel hose
300c – Curved bent portions of the third fuel hose
310, 320 – Grooves
350 – Protective outer sheath of the third fuel hose
A – Locking means
B – Coupler
C – Clamp ring
L1, L2, L3 – Fuel lines
P1 – L-shaped curved section
P2 – Parabolic shaped curved section
, Claims:1. A saddle-type vehicle (10) comprising:
an internal combustion engine (25) having a cylinder head (25a) configured to receive at least one fuel injector for injecting a fuel inside the internal combustion engine (25);
a fuel pump (40) being configured to supply the fuel at a predetermined fuel pressure to the at least one fuel injector, the fuel pump (40) having an outlet (48); and
an external fuel filter (50) located in proximity to the outlet (48) of the fuel pump (40) and above the cylinder head (25a) of the internal combustion engine (25), the external fuel filter (50) having at least one inlet port (51) being configured to be fluidly connected to the outlet (48) of the fuel pump (40) through a first fuel hose (100), and at least one outlet port (58) being configured to be fluidly connected to the at least one fuel injector through a second fuel hose (200), the outlet port (58) being connected to at least one fuel return outlet (59) for returning the fuel from the second fuel hose (200) to the fuel pump (40) through a third fuel hose (300); each of the first, second and third fuel hoses (100, 200, 300) extends non-linearly between a first end (100a, 200a, 300a) and a second end (100b, 200b, 300b) and comprises one or more curved bent portions (100c, 200c, 300c), the one or more curved bent portions (100c, 200c, 300c) being configured to enroute the fuel to regulate the predetermined fuel pressure.

2. The saddle-type vehicle (10) as claimed in claim 1, wherein the fuel pump (40) being disposed above the internal combustion engine (25).

3. The saddle-type vehicle (10) as claimed in claim 1, wherein each of the first, second and third hoses (100, 200, 300) being formed of a multi-layered rubber material.

4. The saddle-type vehicle (10) as claimed in claim 1, wherein each of the first, second and the third hoses (100, 200, 300) have a durometer rating ranging between 60 to 80.

5. The saddle-type vehicle (10) as claimed in claim 1, wherein the one or more curved bent portions (100c, 200c, 300c) of any of the first, second and third fuel hoses (100, 200, 300) being configured to form at least one L-shaped curved section (P1) or a parabolic shaped curved section (P2) with each of the first ends (100a, 200a, 300a).

6. The saddle-type vehicle (10) as claimed in claim 1, wherein the one or more curved bent portions (100c, 200c, 300c) of any of the first, second and third fuel hoses (100, 200, 300) being configured to form at least one parabolic shaped curved section (P2) with each of the second ends (100b, 200b, 300b).

7. The saddle-type vehicle (10) as claimed in claim 6, wherein each of the parabolic shaped curved sections (P2) being configured to enroute a portion of the first fuel hose (100) and the third fuel hose (300) away from the cylinder head (25a) of the internal combustion engine (25).

8. The saddle-type vehicle (10) as claimed in claim 1, wherein the first end (100a) of the first fuel hose (100) being connected to the outlet (48) of the fluid pump (40) and the second end (100b) of the first fuel hose (100) being connected to the at least one inlet port (51) of the external fuel filter (50).

9. The saddle-type vehicle (10) as claimed in claim 1, wherein the first end (200a) of the second fuel hose (200) being connected to the at least one outlet port (58) of the external fuel filter (50) and the second end (200b) of the second fuel hose (200) being connected to the at least one fuel injector.

10. The saddle-type vehicle (10) as claimed in claim 1, wherein the first end (300a) of the third fuel hose (300) being connected to a fuel returning port (49) of the fuel pump (40) and the second end (300b) of the third hose (300) being connected to the at least one fuel return outlet (59) being in connection with the at least one outlet port (58) of the external fuel filter (50).

11. The saddle-type vehicle (10) as claimed in claim 1, wherein each of the first ends (100a, 200a, 300a) and the second ends (100b, 200b, 300b) of the first, second and third hoses (100, 200, 300) being configured to receive one or more locking means (A) or couplers (B).

12. The saddle-type vehicle (10) as claimed in claim 1, comprises:
a headtube (20);
a main tube extending rearwardly and downwardly from the headtube (20) in a front-rear direction of the vehicle (10); and
a down tube (22) extending downwardly and rearwardly from the head tube (20) in a front-rear direction of the vehicle (10).

13. The saddle-type vehicle (10) as claimed in claim 1 or claim 12, wherein the internal combustion engine (25) being supportably mounted on the downtube (22).

14. The saddle-type vehicle as claimed in claim 12, comprises a fuel tank (30) being supportably mounted on the main tube and being disposed behind the head tube (20) in the front-rear direction of the vehicle (10), the fluid tank (30) being fluidly connected with the fuel pump (40).

15. The saddle-type vehicle (10) as claimed in claim 1, comprises a control unit being operably connected with each of the internal combustion engine (25), the fuel pump (40) and the at least one fuel injector, the control unit being configured to control the flow of the fuel being injected to the internal combustion engine (25)

16. The saddle-type vehicle (10) as claimed in claim 1, comprises one or more pressure regulators being operably connected with the at least one fuel injector and the control unit.

17. The saddle-type vehicle (10) as claimed in claim 16, wherein the one or more pressure regulators being configured to return the fuel through the third fuel hose (300) when the fuel pressure exceeds more than the predetermined fuel pressure.