Fuel supply device

Abstract

To promptly heat fuel in a fuel chamber part in a fuel supply device that heats fuel to be supplied to an injector.SOLUTION: A fuel supply device includes: an injector 40 that supplies fuel to be burned in a fuel chamber of an engine; a fuel chamber part 50 that is connected to an upstream side of the injector 40 and stores fuel to be supplied to the injector 40; and a first heater part 62 disposed in the fuel chamber part 50 and heating the fuel stored in the fuel chamber part 50. A fuel feed passage for feeding the fuel into the fuel chamber part 50 is connected to the fuel chamber part 50. The fuel feed passage includes a second heater part 55 that heats the fuel in a flow passage of the fuel feed passage.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a fuel supply system. [Background technology]

[0002] Traditionally, efforts have been made to mitigate or reduce the impact of climate change, and research and development into reducing carbon dioxide emissions has been carried out to achieve this. For example, Patent Document 1 discloses a structure in which a fuel chamber is provided upstream of an injector and the fuel stored in the fuel chamber is heated by a heater in order to ensure startability at low temperatures in an internal combustion engine that is operated with fuel containing alcohol fuel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4834728 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the above-mentioned conventional technology is applied to reduce carbon dioxide emissions, if the outside air temperature is low and the fuel temperature and intake air temperature are very low, it may be necessary to heat the fuel even after the engine has started. However, simply increasing the output of the heater in the fuel chamber in response to the increase in fuel after the engine has started poses the problem that a high-output heater is required and that the fuel is easily vaporized due to localized heating of the fuel.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to efficiently heat fuel in a fuel chamber in a fuel supply device that heats fuel to be supplied to an injector. [Means for solving the problem]

[0006] As a means for solving the above problems, a first aspect of the present invention includes an injector (40) that supplies fuel to be burned in a combustion chamber of an engine (10), a fuel chamber section (50) that is connected upstream of the injector (40) and that stores the fuel to be supplied to the injector (40), and a first heater section (62) that is disposed in the fuel chamber section (50) and that heats the fuel stored in the fuel chamber section (50), a fuel feed path (44) that sends the fuel into the fuel chamber section (50) is connected to the fuel chamber section (50), and the fuel feed path (44) is provided with a second heater section (55) that heats the fuel in a flow path of the fuel feed path (44). According to this configuration, by providing a second heater separate from the first heater of the fuel chamber in the fuel feed path connected to the fuel chamber, it is possible to preheat the fuel in the flow path leading to the fuel chamber. This allows heating over a wide area while preventing localized heater temperatures from rising too high, making it possible to respond to an increase in the amount of fuel supplied after startup while suppressing the generation of vapor.

[0007] In a second aspect of the present invention, in the first aspect, at least a portion of the fuel feed path (44) where the second heater section (55) is arranged is configured with a metal pipe (56) that forms a fuel flow path in the second heater section (55) on the inner peripheral side, and the second heater section (55) heats the fuel from the outer peripheral side of the metal pipe (56) through the metal pipe (56). According to this configuration, the fuel in the flow path can be heated without affecting the flow of fuel in the flow path by heating the fuel through the metal pipe from the outer periphery of the metal pipe that forms the flow path of the fuel feed path 44. The metal pipe is preferably made of a metal with high thermal conductivity, such as a copper alloy.

[0008] A third aspect of the present invention is the heating element of the second aspect, wherein the second heater portion (55) is covered from the outside with a material having a lower thermal conductivity than the metal pipe (56). According to this configuration, the heat from the second heater section can be prevented from diffusing into the atmosphere, so that the fuel can be heated effectively.

[0009] A fourth aspect of the present invention is the second or third aspect, wherein the second heater portion (55) has an electric heating wire (58) disposed on the outer periphery of the metal pipe (56). According to this configuration, by using the heating wire 58 as the heat source for the second heater section 55, the second heater section 55 can be operated to heat the fuel from the preheating stage before starting the engine, as compared to a configuration in which the second heater section 55 uses engine waste heat as a heat source. The power supplied to the heating wire 58 is supplied from, for example, the on-board battery, but it is also possible to use a mobile battery or power from outside the vehicle.

[0010] In a fifth aspect of the present invention, in the second aspect, the second heater portion (155) is provided with at least one of a configuration in which a heat medium (Ga) is circulated and a configuration in which a heat conductor is disposed on the outer circumferential side of the metal pipe (56) as a heat source that receives waste heat from the engine (10). With this configuration, by using a heat medium or heat conductor that receives engine waste heat as the heat source for the second heater, the fuel can be heated using the heat from the waste heat heater after the engine has sufficiently warmed up, which reduces the energy consumption for heating the fuel throughout the fuel supply device.

[0011] A sixth aspect of the present invention is the fifth aspect, wherein the second heater section (155) circulates the heat transfer medium (Ga) on an outer circumferential side of the metal pipe (56), and supply of the heat transfer medium to the second heater section (155) is controlled by a waste heat control valve (59a1). According to this configuration, the supply of heat medium to the second heater section is controlled by the waste heat control valve, so that the heating temperature of the fuel in the waste heat heater can be adjusted.

[0012] In a seventh aspect of the present invention, in the fifth or sixth aspect, the heat medium is exhaust gas (Ga) of the engine (10), and the exhaust gas (Ga) is extracted from an exhaust path of the engine (10) downstream of an exhaust gas purification catalyst (14b) and introduced into the second heater section (155). According to this configuration, by extracting exhaust gas from downstream of the exhaust gas purification catalyst and introducing it into the second heater section, it is possible to use relatively clean exhaust gas compared to using exhaust gas upstream of the exhaust gas purification catalyst. Also, since heat is not removed from the upstream exhaust gas, it is possible to eliminate delay in activation of the exhaust gas purification catalyst. Furthermore, since exhaust gas heated by the exhaust gas purification catalyst is used, the second heater can be used at a relatively early stage after engine start. [Effects of the Invention]

[0013] According to the present invention, in a fuel supply device that heats fuel to be supplied to an injector, the fuel in the fuel chamber can be efficiently heated. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a right side view of a motorcycle according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of a main part of FIG. [Figure 3] FIG. 2 is a top view of the vicinity of an intake passage part of the motorcycle. [Figure 4] FIG. 2 is a configuration diagram of a fuel supply device of the motorcycle. [Figure 5] FIG. 3 is an explanatory diagram showing a configuration of a second heater device in the first embodiment of the fuel supply device. [Figure 6] FIG. 10 is an explanatory diagram showing a configuration of a second heater device in a second embodiment of the fuel supply device. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, directions such as front, rear, left, and right are the same as directions in the vehicle described below unless otherwise specified. In addition, in the drawings used in the following description, an arrow FR indicating the front of the vehicle, an arrow LH indicating the left side of the vehicle, an arrow UP indicating the top of the vehicle, and a line CL indicating the center of the vehicle body to the left and right are shown in appropriate positions.

[0016] <Entire vehicle> As shown in Fig. 1, this embodiment is applied to a motorcycle 1, which is a saddle-ride type vehicle. A front wheel 2 of the motorcycle 1 is supported at the lower ends of a pair of left and right front forks 3. The upper parts of the left and right front forks 3 are supported by a head pipe 21 at the front end of a body frame 20 via a steering stem 4. A steering bar handle 6 is attached to the upper part of the steering stem 4.

[0017] The rear wheel 7 of the motorcycle 1 is supported at the rear end of a swing arm 8. The front end of the swing arm 8 is supported by a pivot frame 23 located at the midpoint between the front and rear of the body frame 20. Note that the term "midpoint" used in this embodiment refers not only to the center between both ends of an object, but also to the inner range between both ends of an object. The rear wheel 7 is connected to the power unit PU of the motorcycle 1 via a chain-type transmission mechanism located, for example, on the left rear side of the body.

[0018] The power unit PU is an integrated unit that includes an engine (internal combustion engine) 10, which is the prime mover of the motorcycle 1, and a clutch and transmission (neither of which are shown) that connect and disconnect and change the speed of the output of the engine 10, and is fixedly supported on the body frame 20. The engine 10 has a cylinder 12 standing upright above the front of a crankcase 11. An intake passage part 32 is connected to the rear of the cylinder 12. An exhaust pipe 14 is connected to the front of the cylinder 12. The exhaust pipe 14 runs from the front of the engine 10 downward, is routed, for example, to the right rear, and is connected to an exhaust muffler 14a located on the right rear of the vehicle body.

[0019] A fuel tank 15 that stores fuel to be supplied to the engine 10 is disposed above the engine 10. A seat 16 on which the driver and a passenger sit is disposed behind the fuel tank 15. A pair of left and right main steps 17 on which the driver places his / her feet, and a pair of left and right pillion steps 18 on which the passenger places his / her feet are disposed on both sides of the lower body of the vehicle.

[0020] The body frame 20 comprises a head pipe 21, a main frame 22 extending rearward and downward from the upper part of the head pipe 21, a pivot frame 23 extending rearward and downward from the lower rear end of the main frame 22 at a steeper incline than the main frame 22, a down frame 27 extending rearward and downward from the lower part of the head pipe 21 at a steeper incline than the main frame 22, seat rails 25 extending rearward from the rear of the main frame 22, and a support frame 26 extending upward and rearward from the middle part of the pivot frame 23 in the vertical direction to support the seat rails 25.

[0021] The engine 10 can be operated using not only gasoline but also ethanol or a blend of gasoline and ethanol (hereinafter collectively referred to as ethanol fuel). In other words, the motorcycle 1 is a flexible fuel motorcycle (FFM) that can run on multiple types of fuel. The cylinder 12 of the engine 10 has, in order from the crankcase 11 side, a cylinder body 12a, a cylinder head 12b, and a head cover 12c.

[0022] 2, the downstream end of an intake passage part 32 including a throttle body 33 is connected to the rear part (intake side) of the cylinder head 12b. In the figure, reference numeral 34 denotes an air cleaner box to which the upstream end of the intake passage part 32 is connected, reference numeral 35 denotes a connecting tube that connects the throttle body 33 and the air cleaner box 34, and reference numeral 36 denotes an intake pipe member that connects the throttle body 33 and the cylinder head 12b. The connecting tube 35 and the intake pipe member 36 are included in the intake passage part 32.

[0023] <Fuel supply device> As shown in FIG. 4, motorcycle 1 includes fuel tank 15, fuel pump 42, injector (fuel injection valve) 40, and the like, which constitutes a fuel supply device 40A. Fuel in the fuel tank 15 is drawn into, for example, a fuel pump 42 disposed within the fuel tank 15 and discharged downstream. The fuel pump 42 is immersed in the fuel in the fuel tank 15, thereby drawing in the fuel within the fuel tank 15. For example, the fuel pump 42 includes a pump body that pumps out the fuel, and a primary filter that filters the fuel on the suction side (upstream side) of the pump body (neither of which is shown).

[0024] A downstream path (fuel feed path 44) extending from the discharge portion 43 of the fuel pump 42 to the injector 40 is provided with a check valve and a pressure regulator, neither of which is shown. The check valve allows fuel to flow from the fuel pump 42 side to the downstream side (the injector 40 side) and restricts fuel flow in the opposite direction. By providing a check valve on the discharge side of the fuel pump 42, the pressurized state (residual pressure) of the fuel downstream of the check valve is maintained when the engine 10 is stopped (when the fuel pump 42 is stopped) due to parking or the like. Therefore, when the engine 10 is restarted, the fuel can be pressurized to the pressure required for fuel injection with little pump drive.

[0025] The pressure regulator adjusts the pressure of the fuel discharged from the fuel pump 42 to a predetermined pressure. The fuel whose pressure is adjusted by the pressure regulator is supplied to the injector 40 via a feed hose 48 extending to the outside of the fuel tank 15. The check valve and the pressure regulator may be integrated with the fuel pump 42 or may be separate entities.

[0026] 5, the fuel discharged from the fuel pump 42 is supplied into the chamber T3 of the fuel chamber 50 connected to the injector 40. A first heater 62 faces the chamber T3 and is capable of heating the fuel stored in the chamber T3. The injector 40 is controlled by an ECU (Electronic Control Unit) and injects fuel into the intake passage part 32 in response to the output of a throttle sensor or the like.

[0027] For example, the ECU performs feedback control of the fuel injection amount based on the output of an exhaust gas sensor (O2 sensor) (not shown) to achieve theoretical air-fuel consumption operation. In this embodiment, by providing a chamber T3 for temporarily storing the mixed fuel, even when a fuel with a different fuel composition is refueled, the fuel before and after refueling are mixed gently. This prevents the fuel supplied to the injector 40 from suddenly changing to a different type of fuel from the fuel before refueling, making it easier to follow the feedback control.

[0028] 2 and 3, the intake passage part 32 including the throttle body 33 is disposed so as to be biased to one side (the right side in this embodiment) with respect to the vehicle body left-right center CL. A port opening 37 is provided at the rear of the cylinder head 12b, forming an opening (external opening) of the intake port to the outside of the cylinder. The front end (downstream end) of an intake pipe member 36 is fixed to the port opening 37. The front end (downstream end) of a throttle body 33 is connected to the rear end (upstream end) of the intake pipe member 36. The front end (downstream end) of a connecting tube 35 is connected to the rear end (upstream end) of the throttle body 33. The intake passage formed by the entire intake passage part 32 is designated by the symbol TA (see FIG. 1).

[0029] <Injector> 2, 4 and 5, an injector 40 is attached to the upper front side of the intake pipe member . The injector 40 includes a cylindrical injector body, a valve portion housed in the injector body, and an electromagnetic drive portion (none of which are shown) that drives the valve portion. In the drawing, line C1 indicates the central axis of the injector 40, and symbol 40b indicates an injection port provided at one axial end of the injector 40. The injector body defines a fuel flow path through which fuel flows. The valve portion closes the fuel flow path by the biasing force of the return spring, thereby closing the injector 40. The electromagnetic drive unit drives the valve unit against the biasing force of the return spring to open the fuel flow path and open the injector 40. This causes fuel to be injected from the injection port 40b of the injector 40 into the intake passage TA.

[0030] A fuel chamber 50 that stores fuel to be supplied to the injector 40 and a first heater device 60 that heats (increases the temperature of) the fuel in the fuel chamber 50 are connected to an extension portion of the injector 40 on the opposite side (upstream side) from the injection port 40b in its longitudinal direction (longitudinal direction of the injector body). The fuel chamber 50 and the first heater device 60 form a heating portion that raises the temperature of the fuel to be supplied to the injector 40.

[0031] 5, the fuel chamber 50 includes a chamber case 51. The chamber case 51 is cylindrical and opens upstream of the injector 40, forming a chamber T3 as an internal space. Line C2 in the figure indicates the central axis of the fuel chamber 50. In the example of FIG. 5, the fuel chamber 50 and the injector 40 are arranged coaxially with each other.

[0032] A feed nozzle 53 for connecting a feed hose 48 protrudes from the outer peripheral wall 52 of the chamber case 51. The feed nozzle 53 and the feed hose 48 are included in the fuel feed path 44. The fuel feed path 44 extends from the discharge portion of the fuel pump 42 and enables pressurized fuel to be supplied into the chamber T3 via the feed nozzle 53. The feed nozzle 53 in FIG. 5 is disposed in an axially intermediate portion (not limited to the center) of the outer peripheral wall 52 and extends along the radial direction of the outer peripheral wall 52. A second heater unit 55, which will be described later, is provided around the feed nozzle 53 of the fuel feed path 44.

[0033] Within the chamber T3, a circulation flow is promoted by the upward flow of fuel heated around the first heater 62 and the downward flow of fuel supplied from the feed nozzle 53, and the heated fuel is guided to the lower end side (injector 40 side) of the chamber T3. The circulation flow of fuel within the chamber T3 suppresses unevenness in fuel temperature and also suppresses the generation of vapor on the surface of the first heater 62, improving heat transfer. The feed nozzle 53 is not limited to being located at the axially intermediate portion of the outer peripheral wall 52, but may be located further upstream (upper end side) in the axial direction of the outer peripheral wall 52. In this case, the vertical flow within the chamber T3 is further promoted.

[0034] The upstream end of the injector body is connected to the downstream end of the chamber case 51. A main body (heater main body) 61 including a circuit and the like of a first heater device 60 is attached to the end of the chamber case 51 opposite to the injector body. The first heater device 60 has a rod-shaped first heater portion 62 that protrudes into the chamber T3 from a heater main body portion 61. The first heater portion 62 is disposed coaxially with the chamber case 51, for example.

[0035] The fuel supplied from the feed hose 48 is supplied to and stored in the chamber T3, and is heated by the heat generated by the first heater 62. The fuel in the chamber T3 is stirred by natural convection generated by the heating of the first heater 62. For convenience of explanation, FIG. 5 shows an example in which the fuel chamber 50 is arranged with its longitudinal direction (axial direction) aligned vertically.

[0036] The fuel heated to a specified temperature reaches the injector body of the injector 40, and is injected into the intake passage TA from the injection port 40b by driving the valve portion. In the ethanol fuel engine 10, in order to improve cold startability and reduce harmful components contained in the exhaust gas, it is effective to inject heated fuel into the intake passage TA to promote vaporization of the injected fuel.

[0037] Here, the operation of the first heater device 60 will be described. When the vehicle is parked and the engine 10 is stopped, the engine 10 is cold, and the fuel in the fuel supply device 40A is also cold. In order to promote evaporation of the fuel to be injected into the intake passage TA, it is necessary to heat the fuel using the first heater device 60 before starting the engine 10. A suitable timing for the first heater device 60 to start heating the fuel is, for example, when the main switch of the vehicle is turned on while the engine 10 is stopped and the vehicle is parked and stopped.

[0038] The heating of the fuel by the first heater device 60 starts, for example, when the first heater device 60 is turned on. The control unit of the first heater device 60 activates a timer when the first heater device 60 is turned on, and turns off the first heater device 60 after a specified time has elapsed. Thereafter, the engine 10 can be started (starter driven). At this time, an indicator lamp may be turned on to notify the user that the engine can be started.

[0039] The duration for which the heater is on may be varied depending on, for example, the ambient temperature or the engine temperature. The temperature detection can be performed using information detected by, for example, an existing intake air temperature sensor, oil temperature sensor, etc. Alternatively, a temperature sensor can be installed in the fuel chamber 50 to directly detect the temperature of the fuel in the chamber T3. In addition to (or instead of) the duration for which the heater is on, the output of the first heater device 60 may be varied. In this embodiment, the heater is turned off once a predetermined condition is met after the fuel has started to be heated (for example, the passage of a predetermined time), but the heater may be kept on to continue heating the fuel while the vehicle is running in order to promote vaporization of the fuel. Note that in this embodiment, the fuel chamber 50 is easily exposed to the heated airflow that flows around the engine 10, which contributes to reducing the amount of electricity consumed when the heater is kept on.

[0040] In the ethanol fuel engine 10, when the outside air temperature is low, the fuel preheat time tends to be long. 5, a second heater section 55 is provided in a portion of fuel feed path 44 on the fuel chamber section 50 side (near feed nozzle 53). Second heater section 55 is configured as a second heater device (sub-heater) 54 separate from first heater device (main heater) 60. Second heater section 55 includes a first pipe (inner piping) 56 extending in the longitudinal direction of feed nozzle 53, an electric heating wire (heat source) 58 disposed on the outer periphery of first pipe 56, and a second pipe (outer piping) 57 covering the outer peripheries of first pipe 56 and electric heating wire 58.

[0041] The first pipe 56 is attached, for example, by fitting around the feed nozzle 53, and extends in the extension direction of the feed nozzle 53. The first pipe 56 extends upstream of the feed nozzle 53, and the feed hose 48 is connected to its upstream end. The inner circumferential space of the first pipe 56 forms part of the flow path of the fuel feed passage 44. The inner circumferential surface of the first pipe 56 is exposed to the flow path formed by the first pipe 56. The first pipe 56 is made of a metal material with high thermal conductivity, such as a copper alloy, and facilitates the transfer of heat from the heating wire 58 to the fuel in the first pipe 56. The inner circumferential surface of the first pipe 56 faces the inside of the flow path and comes into contact with the fuel in the flow path to heat it.

[0042] The heating wire 58 is a heating wire such as a nichrome wire, and is wound spirally around the outer periphery of the first pipe 56, for example. The heating wire 58 can be connected to, for example, a battery, which is an on-board power source. The heating wire 58 constitutes an electric heater that can heat the fuel in the flow path via the first pipe 56. The power supply to the heating wire 58 is electrically controlled by a control device 58a. For example, when the ignition switch is turned on from off, the control device 58a closes a power supply circuit (not shown) for a specified time (for example, 10 seconds) to enable power supply to the heating wire 58. The heating wire 58 generates heat when power is supplied, and heats the fuel in the first pipe 56. The fuel in the first pipe 56 is gradually heated by utilizing the length of the first pipe 56.

[0043] The second pipe 57 is disposed on the outer periphery of the first pipe 56 with a gap therebetween. The second pipe 57 is made of a metal material with low thermal conductivity, such as stainless steel, to suppress heat generation on the outer surface. It is preferable to cover the outer periphery of the second pipe 57 with a material with lower thermal conductivity than a metal pipe, such as rubber or resin. The second pipe 57 itself may be a pipe made of a material with low thermal conductivity, such as rubber or resin. A configuration in which the second pipe 57 is not provided and a covering of rubber, resin, or the like (not limited to a pipe shape) is provided on the outside of the heating wire (heat source) 58 may also be used. The heating wire 58 is disposed between the first pipe 56 and the second pipe 57. In addition to the heating wire 58, a heat insulating material (such as a material or solvent with low thermal conductivity) may be enclosed between the first pipe 56 and the second pipe 57.

[0044] The second heater unit 55, which has a double-pipe structure, efficiently heats the fuel just before it reaches the fuel chamber unit 50. The second heater device 54 preheats the fuel in the introduction path to the fuel chamber unit 50 when the outside air temperature is low, etc. As a result, the fuel can be heated in the fuel chamber unit 50 with less power consumption and in a shorter time.

[0045] This allows for lower output of the first heater device 60, suppression of vapor generation, and improved fuel economy by promoting fuel vaporization. The first heater device 60 mainly heats fuel for a specified time before starting the engine, but may continue to be used as appropriate after the engine has started. In this case, combustion during warm-up is improved, and drivability can also be improved after warm-up.

[0046] As described above, the fuel supply device 40A in the above embodiment includes the injector 40 that injects fuel into the intake passage TA of the engine 10, the fuel chamber section 50 that is connected upstream of the injector 40 and that stores the fuel to be supplied to the injector 40, and the first heater section 62 that is disposed within the fuel chamber section 50 and that heats the fuel stored in the fuel chamber section 50. The fuel chamber section 50 is connected to the fuel feed path 44 that sends the fuel into the fuel chamber section 50, and the fuel feed path 44 is provided with the second heater section 55 that heats the fuel in the flow path of the fuel feed path 44. According to this configuration, by providing the second heater 55, separate from the first heater 62 of the fuel chamber 50, in the fuel feed path 44 connected to the fuel chamber 50, it is possible to preheat the fuel in the flow path leading to the fuel chamber 50. This makes it possible to heat the fuel in the fuel chamber 50 in a short time and with less energy, thereby reducing the output of the first heater 62 and shortening the heating time. The present invention is not limited to engines that inject fuel into the intake passage, but may also be applied to direct injection engines that inject fuel directly into the combustion chamber.

[0047] In addition, in the fuel supply device 40A, at least the portion of the fuel feed path 44 where the second heater section 55 is arranged is composed of a metal pipe (first pipe 56) that forms the fuel flow path in the second heater section 55 on the inner side, and the second heater section 55 heats the fuel through the first pipe 56 from the outer side of the first pipe 56. According to this configuration, the fuel in the flow path can be heated without affecting the flow of fuel in the flow path by heating the fuel from the outer periphery of the metal pipe (first pipe 56) that forms the flow path of the fuel feed path 44. The metal pipe is preferably made of a metal with high thermal conductivity, such as a copper alloy.

[0048] In the fuel supply device 40A, the second heater section 55 has an electric heating wire 58 disposed on the outer periphery of the first pipe 56. According to this configuration, by using the heating wire 58 as the heat source for the second heater section 55, the second heater section 55 can be operated to heat the fuel from the preheating stage before starting the engine, as compared to a configuration in which the second heater section 55 uses engine waste heat as a heat source. The power supplied to the heating wire 58 is supplied from, for example, the on-board battery, but it is also possible to use a mobile battery or power from outside the vehicle.

[0049] Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is particularly different from the first embodiment in that the second heater section 155 uses engine waste heat as a heat source instead of the heating wire 58. Other components that are the same as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

[0050] The second heater device 154 of the second embodiment heats the fuel before it reaches the fuel chamber 50, for example, by utilizing the heat of the exhaust gas Ga of the engine 10. The second heater device 154 of the second embodiment constitutes part of a waste heat recovery system. The second heater unit 155 of the second embodiment does not include an electric heater between the inner and outer pipes, and instead uses the space between the first pipe 56 and the second pipe 57 as a flow path for the heat medium (exhaust gas Ga), and introduces and circulates a portion of the exhaust gas Ga through this flow path. As a result, the fuel in the first pipe 56 is heated by the heat of the exhaust gas Ga. The fuel in the first pipe 56 is heated gradually by utilizing the length of the first pipe 56. For example, the end of the second pipe 57 of the second embodiment is closed.

[0051] An exhaust gas introduction pipe (heat medium introduction path) 59a is connected to one end side (for example, the side closer to the fuel chamber portion 50) of the second pipe 57. One end (base end) of the exhaust gas introduction pipe 59a is connected to the middle of the exhaust pipe 14 of the engine 10, and the other end (tip end) is connected to the second pipe 57. An exhaust gas purification catalyst (three-way catalyst, catalyzer) 14b is provided in the middle of the exhaust pipe 14. One end of the exhaust gas introduction pipe 59a is connected to a position downstream of the exhaust gas purification catalyst 14b in the exhaust pipe 14. An exhaust gas discharge pipe (heat medium discharge path) 59b is connected to the other end (e.g., the side farther from the fuel chamber) of the second pipe 57. One end (base end) of the exhaust gas discharge pipe 59b is connected to the second pipe 57, and the other end (tip end) is connected to the exhaust pipe 14 near the exhaust muffler 14a.

[0052] A solenoid valve (waste heat control valve) 59a1 is provided at one end of the exhaust gas introduction pipe 59a. The solenoid valve 59a1 is open, for example, before the engine 10 is started and even after the engine is started, if the intake air temperature and fuel temperature are sufficiently low, or until the waste heat of the engine 10 has sufficiently warmed up. After the engine is started, the solenoid valve 59a1 is closed or has a throttled flow path when the intake air temperature and fuel temperature are relatively warm and the waste heat of the engine 10 has sufficiently warmed up.

[0053] A check valve 59b1 may be provided midway through the exhaust gas lead-out pipe 59b (for example, at the other end thereof) to allow the flow of exhaust gas Ga toward the exhaust pipe 14 and restrict the flow of exhaust gas Ga toward the second heater portion 155. This allows the exhaust gas Ga to flow through the second heater portion 155 by utilizing the pulsation in the exhaust pipe 14.

[0054] A space through which exhaust gas Ga flows as a heat medium is formed between the first pipe 56 and the second pipe 57. At least one of the first pipe 56 and the second pipe 57 may be provided with a guide portion such as a rib that guides the flow of the heat medium. The second heater unit 155 is not limited to a configuration in which the exhaust gas Ga is directly introduced between the inner and outer pipes, but may instead transfer engine waste heat from the exhaust gas Ga to a predetermined solvent using a heat exchanger (not shown), and introduce this solvent between the first pipe 56 and the second pipe 57 to heat the fuel in the first pipe 56. Furthermore, instead of using the heat of the exhaust gas Ga, the second heater unit 155 may instead use the heat of engine oil or, in the case of a water-cooled engine, the heat of the coolant to heat the fuel. By using the engine waste heat, the second heater device 154 does not require any additional energy such as electricity.

[0055] When the outside air temperature is low, for example, by preheating the fuel in the introduction path to the fuel chamber section 50, it is possible to heat the fuel in the fuel chamber section 50 with less power, thereby reducing the output of the first heater device 60, suppressing vapor generation, and improving fuel efficiency by promoting fuel vaporization.

[0056] The second heater device 154 of the second embodiment can heat fuel by utilizing engine waste heat without using electric power during warm-up operation after engine start and after warm-up operation. The second heater device 154 of the second embodiment may include an electric heater between the first pipe 56 and the second pipe 57, as in the first embodiment. This improves low-temperature startability. After engine start, the electric heater is turned off and engine waste heat is utilized, thereby improving combustion during warm-up operation and drivability after warm-up operation without consuming additional electric energy.

[0057] As described above, in the fuel supply device 40A of the second embodiment, by providing the second heater unit 155 in the fuel feed path 44 connected to the fuel chamber unit 50, the fuel can be preheated in the flow path leading to the fuel chamber unit 50, thereby making it possible to heat the fuel in the fuel chamber unit 50 in an energy-saving manner and in a short time, and to reduce the output of the first heater unit 62 and shorten the heating time.

[0058] In the fuel supply device 40A, the heat source of the second heater portion 155 is configured to circulate a heat medium (exhaust gas Ga) that has received waste heat from the engine 10 on the outer circumferential side of the first pipe 56. According to this configuration, by using a heat medium that receives engine waste heat as the heat source of second heater unit 155, after engine 10 has sufficiently warmed up, the fuel can be heated using the heat of the waste heat heater. Therefore, it is possible to reduce the output of first heater unit 62 and shorten the heating time while suppressing the energy consumption for fuel heating throughout fuel supply device 40A. For example, instead of (or in combination with) a configuration in which a heat medium flows around first pipe 56, a heat conductor (including a heat pipe) made of a metal member or the like that can transfer engine waste heat may be arranged.

[0059] In the fuel supply device 40A, the supply of the heat medium to the second heater portion 155 is controlled by a waste heat control valve (solenoid valve 59a1). According to this configuration, by controlling the supply of heat medium to the second heater section 155 with the waste heat control valve 59a1, the heating temperature of the fuel in the waste heat heater can be adjusted, and in particular, the generation of vapor due to overheating of the fuel can be suppressed.

[0060] In addition, in the fuel supply device 40A, the heat medium is the exhaust gas Ga of the engine 10, and the exhaust gas Ga is extracted from the exhaust path of the engine 10 downstream of the exhaust gas purification catalyst 14b and introduced into the second heater section 155. According to this configuration, by extracting the exhaust gas Ga from the downstream side of the exhaust gas purification catalyst 14b and introducing it into the second heater section 155, it is possible to utilize a relatively clean exhaust gas Ga compared to using the exhaust gas Ga upstream of the exhaust gas purification catalyst 14b. Also, since the heat of the exhaust gas Ga upstream is not taken away, it is possible to eliminate a delay in activation of the exhaust gas purification catalyst 14b. Furthermore, since the exhaust gas Ga heated by the exhaust gas purification catalyst 14b is used, it is possible to utilize the second heater at a relatively early stage after the engine starts.

[0061] The present invention is not limited to the above-described embodiment. For example, the fuel supply device of the present embodiment may be applied to a saddle-ride type vehicle other than a motorcycle. The saddle-ride type vehicle includes all vehicles on which a driver straddles the vehicle body, including not only motorcycles (including motorized bicycles and scooter-type vehicles) but also three-wheeled vehicles (including vehicles with one front wheel and two rear wheels, as well as vehicles with two front wheels and one rear wheel) or four-wheeled vehicles (such as four-wheeled buggies). It may also be applied to vehicles that include an electric motor as a prime mover, such as HEVs (Hybrid Electric Vehicles). It may also be applied to vehicles other than saddle-ride type vehicles (such as passenger cars, buses, and trucks). In other words, although the vehicle in the embodiment is a flexible fuel motorcycle (FFM), it may also be a four-wheeled vehicle (flexible fuel vehicle (FFV)). Although the fuel supply device of this embodiment is applied to a vehicle, the present invention is not limited to application to vehicles and may be applied to various vehicles and moving objects such as various transportation equipment such as aircraft and ships, as well as construction machinery and industrial machinery. Furthermore, the present invention can be widely applied to equipment other than vehicles that has a fuel supply device, such as push lawn mowers and cleaning machines. The configurations in the above-described embodiments are merely examples of the present invention, and various modifications are possible within the scope of the gist of the present invention, such as replacing the components of the embodiments with well-known components. [Explanation of symbols]

[0062] 1. Motorcycles (saddle-type vehicles) 10 Engine (internal combustion engine) 14b Exhaust gas purification catalyst TA intake passage 40 injectors 44 Fuel feed path 50 Fuel chamber section 54,154 Second heater device 55,155 Second heater section 56 First Pipe (Metal Pipe) 58 Heating wire 59a1 Solenoid valve (waste heat control valve) 60 First heater device 62 Heater section Ga Exhaust gas (heat medium)

Claims

1. an injector (40) for supplying fuel for combustion in a combustion chamber of the engine (10); a fuel chamber portion (50) connected to the upstream side of the injector (40) and storing fuel to be supplied to the injector (40); a first heater section (62) disposed within the fuel chamber section (50) for heating the fuel stored within the fuel chamber section (50); A fuel feed path (44) is connected to the fuel chamber portion (50) to deliver the fuel into the fuel chamber portion (50); The fuel feed path (44) is provided with a second heater section (55) that heats the fuel in the flow path of the fuel feed path (44), At least a portion of the fuel feed path (44) where the second heater section (55) is disposed is configured with a metal pipe (56) that forms a fuel flow path in the second heater section (55) on its inner circumferential side, The second heater section (55) heats the fuel through the metal pipe (56) from the outer circumferential side of the metal pipe (56), The fuel chamber portion (50) is disposed above the injector (40), the second heater section (55) is provided at a connection between the fuel feed path (44) and the fuel chamber section (50); The fuel supply device, wherein the first heater portion (62) is disposed above the fuel chamber portion (50).

2. 2. The fuel supply device according to claim 1, wherein the second heater portion (55) is covered from the outside with a material having a lower thermal conductivity than the metal pipe (56).

3. 3. The fuel supply device according to claim 1, wherein the second heater portion (55) has an electric heating wire (58) disposed on an outer periphery of the metal pipe (56).

4. 2. The fuel supply device according to claim 1, wherein the second heater portion has at least one of a configuration in which a heat medium (Ga) is circulated and a configuration in which a heat conductor is disposed on an outer circumferential side of the metal pipe (56) as a heat source that receives waste heat from the engine (10).

5. The second heater section (155) circulates the heat medium (Ga) on the outer circumferential side of the metal pipe (56), 5. The fuel supply device according to claim 4, wherein the supply of the heat medium to the second heater section (155) is controlled by a waste heat control valve (59a1).

6. The heat medium is exhaust gas (Ga) from the engine (10), 6. The fuel supply device according to claim 4, wherein the exhaust gas (Ga) is extracted from an exhaust path of the engine (10) downstream of an exhaust gas purification catalyst (14b) and introduced into the second heater portion (155).

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