Leaning vehicle

Abstract

Provided is a leaning vehicle 1 comprising: a vehicle body 2 that tilts in a vehicle left direction when turning left and tilts in a vehicle right direction when turning right; and an EGR cooler 51 for cooling exhaust gas. The EGR cooler is mounted on the vehicle body 2, and is provided in the middle of an EGR path 50 for recirculating a portion of exhaust gas, generated in an engine unit 3, from an exhaust path 30 to an intake path 20. The EGR cooler has: an exhaust-side port 52a into which exhaust gas flows from the exhaust path 30; and an intake-side port 52b from which exhaust gas flows out toward the intake path 20. The exhaust-side port 52a and the intake-side port 52b of the EGR cooler 51 are separated from each other in a vehicle body left-right direction so that when the vehicle body 2 tilts in the vehicle body left-right direction and the leaning vehicle 1 is turning, condensed water W in the EGR cooler 51 generated by the cooling of the exhaust gas receives a combined force S of gravity G and a centrifugal force C so as to be discharged from the exhaust-side port 52a of the EGR cooler 51 and flow toward the exhaust path 30. A lower end of the exhaust-side port 52a is positioned below the intake-side port 52b in the vehicle body up-down direction.

Description

Lean vehicle

[0001] The present invention relates to a lean vehicle having an EGR cooler.

[0002] Conventionally, an EGR (Exhaust Gas Recirculation) path that recirculates a portion of exhaust gas generated in an engine unit from the exhaust path to the intake path may be provided with an EGR cooler to cool the exhaust gas. For example, Patent Document 1 (JP-A-2005-102626) describes a motorcycle in which an EGR cooler is integrally formed with a gearbox housing. In the EGR cooler of Patent Document 1, the exhaust-side port through which the exhaust gas flows is located lower than the intake-side port through which the exhaust gas flows. As a result, it is estimated that condensed water generated in the EGR cooler when the exhaust gas is cooled in the EGR cooler is discharged from the exhaust-side port and flows toward the exhaust path.

[0003] German Patent Application Publication No. 102018120800

[0004] Here, for lean vehicles such as motorcycles, taking into consideration the characteristics unique to lean vehicles, a specific configuration is required for directing condensed water generated in the EGR cooler toward the exhaust path, which is different from the configuration in Patent Document 1. Furthermore, lean vehicles may have unique configurations different from automobiles, such as the following (A) to (F): (A) The body leans to the left when turning left, and to the right when turning right. (B) The vehicle width (length in the left-right direction of the vehicle body) is short. (C) At least one of the tank, dummy tank, seat, and storage box is located at the center of the body in the left-right direction of the vehicle. (D) The vehicle can stand upright while tilted in the left-right direction of the vehicle using a side stand. (E) The vehicle has two frame parts along the front-rear direction of the vehicle, with a short distance between them due to its short width. (F) The vehicle has two cover parts along the front-rear direction of the vehicle, with a short distance between them due to its short width.

[0005] The present invention aims to provide a lean vehicle that takes into consideration the effects on the EGR cooler of characteristics unique to lean vehicles, such as (A) the body tilting when cornering, (B) a short vehicle width, (C) at least one of the tank, dummy tank, seat, and storage box being located in the center of the body in the left-right direction of the vehicle, (D) the side stand being used to allow the vehicle to stand while tilted in the left-right direction of the vehicle, (E) having two frame parts that are closely spaced apart in the left-right direction of the vehicle and aligned in the fore-and-aft direction of the vehicle, and (F) having two cover parts that are closely spaced apart in the left-right direction of the vehicle and aligned in the fore-and-aft direction of the vehicle, and that has a configuration different from that of Patent Document 1, allowing condensed water generated in the EGR cooler to flow toward the exhaust path.

[0006] (1) A lean vehicle according to one embodiment of the present invention has the following configuration: a vehicle body that tilts leftward when turning left and tilts rightward when turning right, and an EGR cooler that is mounted on the vehicle body and is provided midway through an EGR path that recirculates a portion of exhaust gas generated in an engine unit from an exhaust path to an intake path, the EGR cooler having an exhaust side port through which the exhaust gas flows in from the exhaust path and an intake side port through which the exhaust gas flows out toward the intake path, the EGR cooler being configured so that when the lean vehicle is upright, a lower end of the exhaust side port is located lower than the intake side port in the vertical direction of the vehicle, and so that even when the vehicle body is tilted in the horizontal direction of the vehicle, the positional relationship between the exhaust side port and the intake side port in the vertical direction of the vehicle is maintained relative to the vehicle body that is tilted in the horizontal direction of the vehicle, the EGR cooler cooling the exhaust gas and causing condensed water produced by the cooling of the exhaust gas to be discharged from the exhaust side port and flow toward the exhaust path, When the vehicle body tilts in the left-right direction of the vehicle and the lean vehicle turns, the condensed water in the EGR cooler is discharged from the exhaust side port under the combined force of gravity and centrifugal force and flows toward the exhaust path.The exhaust side port and the intake side port of the EGR cooler are spaced apart in the left-right direction of the vehicle body based on the vehicle body tilting in the left-right direction of the vehicle, and the lower end of the exhaust side port is located lower than the intake side port in the up-down direction of the vehicle body.

[0007] According to this configuration, the exhaust-side port and the intake-side port of the EGR cooler are spaced apart in the vehicle body transverse direction, and the lower end of the exhaust-side port is located lower than the intake-side port in the vehicle vertical direction, so that when the lean-air vehicle turns with the vehicle body tilted in the vehicle transverse direction, the condensed water in the EGR cooler flows toward the exhaust path under the combined force of gravity and centrifugal force. As a result, when the lean-air vehicle turns with the vehicle body tilted in the vehicle transverse direction, the combined force of centrifugal force and gravity acts on the condensed water in the EGR cooler. The direction of this combined force is downward in the vehicle body vertical direction, regardless of the vehicle body tilt angle. Therefore, this combined force can be used to flow the condensed water generated in the EGR cooler toward the exhaust path. In other words, according to this configuration, the condensed water generated in the EGR cooler can be flowed toward the exhaust path, taking into account the effect on the EGR cooler of the unique characteristic of lean-air vehicles, in which the condensed water in the EGR cooler is subjected to the above-mentioned combined force in the vehicle body vertical direction when the vehicle body tilts during a turn. Moreover, with a configuration different from that of Patent Document 1, condensed water generated in the EGR cooler can be made to flow toward the exhaust path.

[0008] (2) In addition to the configuration of (1) above, a lean vehicle according to one embodiment of the present invention may have the following configuration: A side stand for supporting the lean vehicle with the vehicle body tilted in the left-right direction of the vehicle, wherein a lower end of the exhaust-side opening is positioned lower than the intake-side opening in the vertical direction of the vehicle body so that the condensed water in the EGR cooler flows toward the exhaust path by gravity when the lean vehicle is supporting itself with the vehicle body tilted in the left-right direction of the vehicle on the side stand.

[0009] With this configuration, when the lean vehicle is left and right tilted using the side stand, the condensed water in the EGR cooler can be caused to flow toward the exhaust path by gravity. In other words, the impact on the EGR cooler of the unique characteristic of a lean vehicle, in which the vehicle is left and right tilted using the side stand, is taken into consideration, and the configuration is different from that of Patent Document 1, allowing the condensed water generated in the EGR cooler to flow toward the exhaust path.

[0010] (3) In addition to the configuration of (2) above, a lean vehicle according to one embodiment of the present invention may have the following configuration: the side stand is located to the left of the vehicle body in the left-right direction of the vehicle body, and the exhaust side port is located to the left of the intake side port in the left-right direction of the vehicle body, or the side stand is located to the right of the vehicle body in the left-right direction of the vehicle body, and the exhaust side port is located to the right of the intake side port in the left-right direction of the vehicle body.

[0011] With this configuration, when the lean vehicle is left-right tilted using the side stand, the tilt of the vehicle body caused by the side stand can be used to ensure that the lower end of the exhaust side port of the EGR cooler is lower than the intake side port. In other words, by taking advantage of the unique characteristic of a lean vehicle, where the vehicle body can stand upright while tilted using the side stand, condensed water generated in the EGR cooler can be directed toward the exhaust path.

[0012] (4) A lean vehicle according to one embodiment of the present invention may have the following configuration in addition to any one of the configurations (1) to (3) above: At least a portion of the EGR cooler is located between the left and right ends of the vehicle body in the left-right direction of the vehicle body, and the center of the EGR cooler is located to the left or right of the center of the vehicle body.

[0013] According to this configuration, because a lean vehicle has a short vehicle width (length in the left-right direction of the vehicle body), at least a portion of the EGR cooler is located between the left and right ends of the vehicle body in the left-right direction, and the center of the EGR cooler is located to the left or right of the center of the vehicle body. This makes it easy to position a portion of the EGR cooler in a position that protrudes from the left or right end of the vehicle body or in a position close to the left or right end of the vehicle body. As a result, heat rising from the EGR cooler is less likely to be trapped in, for example, a space below a tank, dummy tank, seat, or storage box located in the center of the vehicle body in the left-right direction, or a space between two frame parts or two cover parts that are close to each other in the front-rear direction of the vehicle. Furthermore, because heat is less likely to be trapped in these spaces, the cooling performance of the EGR cooler can be improved. In other words, the impact on the EGR cooler of the unique characteristics of lean vehicles, such as a short vehicle width, and at least one of the tank, dummy tank, seat, and storage box being located at the center of the vehicle in the left-right direction of the vehicle, and / or having two frame parts or two cover parts with a short distance between them in the left-right direction of the vehicle and aligned in the fore-and-aft direction of the vehicle, is taken into consideration, and the configuration is different from that of Patent Document 1, allowing condensed water generated in the EGR cooler to flow toward the exhaust path.

[0014] (5) In addition to the configuration of (4) above, a lean-fuel vehicle according to one embodiment of the present invention may have the following configuration: In the left-right direction of the vehicle body, the center of the EGR cooler is located between the left end and the right end of the vehicle body.

[0015] With this configuration, at least a portion of the EGR cooler is positioned between the left and right ends of the vehicle body in the left-right direction, and the amount of protrusion of the EGR cooler in the left-right direction of the vehicle body can be reduced compared to when the center of the EGR cooler is located to the left of the left end of the vehicle body or to the right of the right end of the vehicle body.

[0016] (6) A lean vehicle according to one embodiment of the present invention may have the following configuration in addition to the configuration described in (4) or (5) above: The lean vehicle includes at least one of a tank, a dummy tank, a seat, and a storage box, and at least a portion of the EGR cooler is located below at least one of the tank, the dummy tank, the seat, and the storage box in the vertical direction of the vehicle body.

[0017] With this configuration, heat rising from the EGR cooler is less likely to accumulate in the space below the tank, dummy tank, seat, or storage box compared to when the center of the EGR cooler is located at the center of the vehicle body in the left-right direction. In other words, while taking into consideration the influence of the EGR cooler on the unique configuration of a lean vehicle, which has a short vehicle width and at least one of the tank, dummy tank, seat, and storage box located at the center of the vehicle body in the left-right direction, a configuration different from that of Patent Document 1 can allow condensed water generated in the EGR cooler to flow toward the exhaust path.

[0018] (7) A lean vehicle according to one embodiment of the present invention may have the following configuration in addition to any of the configurations (4) to (6) above: Two frame sections located on the left and right sides of the vehicle body in the left-right direction of the vehicle body and extending along the front-rear direction of the vehicle, and at least a portion of the EGR cooler is located below a space between the two frame sections in the up-down direction of the vehicle body.

[0019] Generally, lean-air vehicles have a short width and two frame sections that are closely spaced in the vehicle's left-right direction and aligned in the vehicle's fore-and-aft direction, which tends to trap heat in the space between the two frame sections. With this configuration, compared to when the center of the EGR cooler is located at the center of the vehicle, heat rising from the EGR cooler is less likely to be trapped in the space between the two frame sections that are closely spaced in the vehicle's left-and-right direction and aligned in the vehicle's fore-and-aft direction. In other words, while taking into consideration the effect of the EGR cooler on the unique configuration of lean-air vehicles, which have a short width and therefore tend to trap heat between the two frame sections that are closely spaced in the vehicle's left-and-aft direction, a configuration different from that of Patent Document 1 allows condensed water generated in the EGR cooler to flow toward the exhaust path.

[0020] (8) A lean vehicle according to one embodiment of the present invention may have the following configuration in addition to any of the configurations (4) to (7) above: Two cover portions located on the left and right sides of the vehicle body in the left-right direction of the vehicle body and extending along the front-rear direction of the vehicle, and at least a portion of the EGR cooler is located below a space between the two cover portions in the up-down direction of the vehicle body.

[0021] Generally, lean-air vehicles with a short width have two cover parts that are closely spaced apart in the left-right direction of the vehicle body and aligned in the front-rear direction of the vehicle, and have the characteristic that heat tends to accumulate in the space between the two cover parts. With this configuration, compared to when the center of the EGR cooler is located at the center of the vehicle body in the left-right direction of the vehicle body, heat rising from the EGR cooler is less likely to accumulate in the space between the two cover parts that are closely spaced apart in the left-right direction and aligned in the front-rear direction of the vehicle. In other words, while taking into account the effect of the EGR cooler on the unique configuration of lean-air vehicles, which have a short width and therefore tend to accumulate heat in the space between the two cover parts that are closely spaced apart in the left-right direction of the vehicle body, a configuration different from that of Patent Document 1 can allow condensed water generated in the EGR cooler to flow toward the exhaust path.

[0022] In the present invention and embodiments, the term "path" refers to a space through which an object such as gas flows. This definition applies to the EGR path, the intake path, and the exhaust path in the present invention and embodiments.

[0023] In the present invention and embodiments, the vehicle up-down direction is the direction perpendicular to a horizontal plane when the lean vehicle is placed upright on the horizontal plane. In the present invention and embodiments, the vehicle front-rear direction is the direction parallel to the traveling direction of the lean vehicle when the lean vehicle travels straight. In the present invention and embodiments, the vehicle left direction is the direction perpendicular to the vehicle up-down direction and the vehicle front-rear direction, and is the left direction from the perspective of a rider riding the lean vehicle. The vehicle right direction is defined in the same way as above. The vehicle left-right direction is the left direction or the right direction of the vehicle.

[0024] In the present invention and embodiments, the lean vehicle may be, for example, a motorcycle or a three-wheeled motor vehicle having one or two front wheels. In the present invention and embodiments, the drive source of the lean vehicle may be an engine alone, or may be both an engine and an electric motor. The electric motor as a drive source does not include a starter motor used only to start the engine.

[0025] In the present invention and its embodiments, the vehicle body includes at least the body frame, handlebars, seat, and suspension. Furthermore, when a lean vehicle includes front and rear wheels, the vehicle body includes the front and rear wheels. In the present invention and its embodiments, the vehicle body tilting to the left of the vehicle means that the vehicle body tilts to the left of the vehicle relative to the vertical direction of the vehicle. In other words, it means that the upper part of the vehicle body tilts so that it is positioned further left than the lower part. The definition of the vehicle body tilting to the right of the vehicle is the same as above.

[0026] In the present invention and embodiments, the vehicle body up-down direction refers to the up-down direction of the vehicle body. In other words, the vehicle body up-down direction is a direction fixed to the vehicle body. When a lean vehicle is upright on a horizontal plane, the vehicle body up-down direction coincides with the vehicle up-down direction. When a lean vehicle is tilted in the vehicle left-right direction, the vehicle body up-down direction is a direction inclined with respect to the vehicle up-down direction by the tilt angle of the lean vehicle. In the present invention and embodiments, the vehicle body left-right direction is a direction perpendicular to the vehicle body up-down direction and the vehicle fore-aft direction. In other words, the vehicle body left-right direction is a direction fixed to the vehicle body. When a lean vehicle is upright on a horizontal plane, the vehicle body left-right direction coincides with the vehicle left-right direction. When a lean vehicle is tilted in the vehicle left-right direction, the vehicle body left-right direction is a direction inclined with respect to the vehicle left-right direction by the lean vehicle's tilt angle.

[0027] In the present invention and embodiments, the lean vehicle has a vehicle body and an engine unit. In the present invention and embodiments, the engine unit includes at least an engine, an EGR cooler, an intake pipe for introducing air into the engine, and an exhaust pipe through which exhaust gas is discharged from the engine. In the present invention and embodiments, the engine may be a four-stroke engine. The engine may be a multi-cylinder engine having multiple combustion chambers. The engine may be a parallel multi-cylinder engine having multiple combustion chambers arranged in the left-right direction of the vehicle body. The engine may be a V-engine configured in a V-shape when viewed in the left-right direction of the vehicle body. The engine may be a single-cylinder engine having one combustion chamber. In the present invention and embodiments, the engine unit has an intake path and an exhaust path.

[0028] In the present invention and embodiments, the intake path is directly connected to at least one combustion chamber of the engine. Air supplied to the at least one combustion chamber flows through the intake path. A portion of the intake path is formed inside the engine. A rear portion of the engine may form a portion of the intake path. A portion of the intake path is disposed outside the engine and formed by the above-mentioned intake pipe or the like. The intake path has at least one downstream end in the air flow direction. The number of at least one downstream ends of the intake path may be the same as or greater than the number of combustion chambers. One or two downstream ends of the intake path may be provided for one combustion chamber. When the intake path has multiple downstream ends, the portion of the intake path including the multiple downstream ends may have a branch shape that divides the air flow.

[0029] In the present invention and embodiments, the exhaust path is directly connected to at least one combustion chamber of the engine. Exhaust gas discharged from the at least one combustion chamber flows through the exhaust path. A portion of the exhaust path is formed inside the engine. A front portion of the engine may form a portion of the exhaust path. A portion of the exhaust path is disposed outside the engine and formed by the above-mentioned exhaust pipe or the like. The exhaust path has at least one upstream end in the flow direction of the exhaust gas. The number of the at least one upstream ends of the exhaust path may be the same as or greater than the number of combustion chambers. One or two upstream ends of the exhaust path may be provided for one combustion chamber. When the number of upstream ends of the exhaust path is multiple, a portion of the exhaust path including the multiple upstream ends may be formed to collect exhaust gas flowing in from the multiple upstream ends.

[0030] In the present invention and embodiments, the EGR path is directly connected to the intake path and the exhaust path. The EGR path may be connected to the exhaust path and the intake path outside the engine. The EGR path may be connected to the exhaust path and the intake path inside the engine. The EGR path may be connected to the exhaust path inside the engine and connected to the intake path outside the engine. The EGR path may be connected to the exhaust path outside the engine and connected to the intake path inside the engine. In the present invention and embodiments, the EGR path may be connected to the exhaust path at one or more points. If the engine has multiple combustion chambers, the EGR path may be connected to the exhaust path such that a portion of exhaust gas discharged from each of the multiple combustion chambers flows into the EGR path. If the engine has multiple combustion chambers, the EGR path may be connected to the exhaust path such that only a portion of exhaust gas discharged from at least one of the multiple combustion chambers flows into the EGR path. In the present invention and embodiments, the number of points at which the EGR path is connected to the intake path may be one or more. In the present invention and embodiments, the EGR path may be provided with an EGR valve that adjusts the flow rate of exhaust gas flowing through the EGR path. The EGR valve may be disposed in the EGR path between the intake path and the EGR cooler.

[0031] In the present invention and embodiments, the EGR cooler is configured to cool exhaust gases that flow into the EGR cooler from the exhaust-side port. The EGR cooler may be configured to cool the exhaust gases using a coolant (e.g., water) that cools the engine. In this case, the engine may have a coolant path dedicated to the EGR cooler. The EGR cooler may be configured to cool the exhaust gases using airflow generated by running a lean-burn vehicle, regardless of the engine cooling method. In this case, the EGR cooler includes fins that increase the contact area with the airflow and thereby improve heat exchange efficiency.

[0032] In the present invention and embodiments, "the EGR cooler is provided midway through the EGR path" means that the portion of the EGR cooler that actually cools the exhaust gas is not provided at the connection between the exhaust path or the intake path and the EGR path. The portion of the EGR cooler that actually cools the exhaust gas may be, for example, a portion of the EGR cooler that has a coolant path. In the present invention and embodiments, the EGR cooler may be separate from the engine. In this case, the EGR cooler may be supported by the engine.

[0033] In the present invention and embodiments, "the EGR cooler is configured so that condensed water generated by cooling the exhaust gas is discharged from the exhaust-side port and flows toward the exhaust path" means that the EGR cooler and the EGR path are configured so that condensed water generated in the EGR cooler by cooling the exhaust gas flows toward the exhaust-side port of the EGR cooler and is discharged from the exhaust-side port, and the condensed water discharged from the exhaust-side port flows through the EGR path toward the exhaust path. In the present invention and embodiments, "the condensed water generated by cooling the exhaust gas is discharged from the exhaust-side port and flows toward the exhaust path" includes condensed water generated in the EGR cooler by cooling the exhaust gas by the EGR cooler being discharged from the exhaust-side port and flowing into the exhaust path. The condensed water discharged from the exhaust-side port may evaporate before reaching the exhaust path.

[0034] In the present invention and embodiments, when the vehicle body is tilted in the left-right direction and the lean vehicle turns, the condensed water in the EGR cooler is discharged from the exhaust-side port under the combined force of gravity and centrifugal force and flows toward the exhaust path. This means that, in a state where the forces acting on the lean vehicle are balanced so that the lean vehicle can turn steadily, the condensed water in the EGR cooler flows toward the exhaust-side port of the EGR cooler under the combined force of gravity and centrifugal force and is discharged from the exhaust-side port, and the condensed water discharged from the outlet flows through the EGR path toward the exhaust path under the combined force of gravity and centrifugal force. This combined force is a downward force in the vertical direction of the vehicle body, regardless of the tilt angle of the vehicle body. In the present invention and embodiments, when the vehicle body tilts in the left-right direction and the lean vehicle turns, the condensed water in the EGR cooler is discharged from the exhaust-side port due to the combined force of gravity and centrifugal force and flows toward the exhaust path includes the condensed water in the EGR cooler being discharged from the exhaust-side port due to the combined force of gravity and centrifugal force and flowing into the exhaust path when the forces acting on the lean vehicle are balanced so that the lean vehicle can turn steadily. The condensed water discharged from the exhaust-side port may evaporate before reaching the exhaust path.

[0035] In the present invention and embodiments, "when a lean-in vehicle is standing on its own with the body tilted in the left-right direction of the vehicle on the side stand" may mean "when the lean-in vehicle is standing on its own with the body tilted in the left-right direction of the vehicle on the side stand" while the engine unit is operating. Alternatively, "when a lean-in vehicle is standing on its own with the body tilted in the left-right direction of the vehicle on the side stand" may mean "when the engine unit is stopped and the vehicle is standing on its own with the body tilted in the left-right direction of the vehicle on the side stand."

[0036] In the present invention and embodiments, the center of the EGR cooler in the transverse direction of the vehicle body is the center between the left and right ends of the EGR cooler in the transverse direction of the vehicle body. The left end of the EGR cooler may be, for example, the left end of a portion of the EGR cooler that actually cools exhaust gas. The portion of the EGR cooler that actually cools exhaust gas may be, for example, a portion of the EGR cooler that has a coolant path. The same applies to the definition of the right end of the EGR cooler. In the present invention and embodiments, the center of the vehicle body in the transverse direction of the vehicle body is the center between the left and right ends of the vehicle body in the transverse direction of the vehicle body. In the present invention and embodiments, when the center of the EGR cooler is located to the left or right of the center of the vehicle body in the transverse direction of the vehicle body, the center of the EGR cooler may be located between the left and right ends of the vehicle body, or may be located to the left of the left end of the vehicle body, or may be located to the right of the right end of the vehicle body in the transverse direction of the vehicle body.

[0037] In the present invention and embodiments, the tank is, for example, a fuel tank that stores fuel to be supplied to an engine unit. In the present invention and embodiments, the dummy tank is, for example, a component that has an appearance that looks like a tank but does not store fuel. The dummy tank may have a storage space therein. The dummy tank may be a cover that does not have a storage space. In the present invention and embodiments, the seat is a portion on which a rider sits. In the present invention and embodiments, the storage box stores, for example, a helmet. The storage box may be located below the seat in the vertical direction of the vehicle body. In this case, the storage box may be configured in a box shape with an open upper end in the vertical direction of the vehicle body, and the seat may be a lid that covers the opening of the storage box. In the present invention and embodiments, the center of at least one of the tank, dummy tank, seat, and storage box may be located at the center of the vehicle body in the left-right direction of the vehicle body.

[0038] In the present invention and embodiments, a lean vehicle may have two frame portions extending along the vehicle longitudinal direction on the left and right sides of the vehicle body in the vehicle transverse direction, or may have a frame portion extending along the vehicle longitudinal direction at the center of the vehicle body in the vehicle transverse direction. The left side of the vehicle body in the vehicle transverse direction refers to a portion to the left of the center of the vehicle body in the vehicle transverse direction, and the right side of the vehicle body in the vehicle transverse direction refers to a portion to the right of the center of the vehicle body in the vehicle transverse direction. The frame portions are part of a vehicle frame. The frame portions may be part of an independent member. In the present invention and embodiments, when a lean vehicle has two frame portions extending along the vehicle longitudinal direction on the left and right sides of the vehicle body in the vehicle transverse direction, the expression "the EGR cooler is located below the space between the two frame portions" means that the EGR cooler is located between the two frame portions as viewed in the vehicle vertical direction and below the overlapping portion of the two frame portions as viewed in the vehicle transverse direction. The overlapping portion of the two frame portions when viewed in the left-right direction of the vehicle body may be the same as the entire two frame portions, or may be the same as a part of either one of the two frame portions. In the present invention and embodiments, the frame portion along the vehicle longitudinal direction is not limited to the frame portion that is parallel to the vehicle longitudinal direction.

[0039] In the present invention and its embodiments, the cover portion forms part of the vehicle's exterior. The cover portion may be an independent member, a portion of an independent member, or may be composed of multiple independent members. The cover portion may be a tank shroud that appears integrated with the tank in appearance. The cover portion may also be at least a portion of a cover called a front cowl or a side cowl. The cover portion may also be a protector that is provided to protect at least the EGR cooler. The cover portion may also be a protector that is provided to protect at least the EGR path. In the present invention and its embodiments, when a lean vehicle has two cover portions that are aligned along the front-rear direction on the left and right sides of the vehicle body in the left-right direction of the vehicle body, the expression "the EGR cooler is located below the space between the two cover portions" means that the EGR cooler is located between the two cover portions as viewed in the up-down direction of the vehicle body and below the overlapping portion of the two cover portions as viewed in the left-right direction of the vehicle body. The overlapping portion of the two cover portions when viewed in the left-right direction of the vehicle body may be the same as the entire two cover portions, or may be the same as a part of either one of the two cover portions. In the present invention and embodiments, the cover portion along the vehicle longitudinal direction is not limited to the cover portion that is parallel to the vehicle longitudinal direction.

[0040] In the present invention and embodiments, the engine cooling system may be air-cooled or liquid-cooled using a coolant other than lubricating oil, and lubricating oil cooling may be combined with an air-cooled or liquid-cooled engine.

[0041] In the present invention and embodiments, the engine may be provided with a fuel supply device that supplies fuel to a combustion chamber of the engine. The fuel supply device may be arranged to supply fuel directly to the combustion chamber. The fuel supply device may be arranged to supply fuel to an intake path.

[0042] In the present invention and its embodiments, a lean-fuel vehicle may or may not have a forced induction device that pressurizes air supplied to a combustion chamber of the engine. The forced induction device may be a turbocharger, a mechanical supercharger, or an electric supercharger. The turbocharger may be an electrically assisted turbocharger that can pressurize air using exhaust gas pressure and an electric motor, or a turbocharger that pressurizes air using exhaust gas pressure alone. The turbine wheel of the turbocharger may be disposed downstream in the exhaust gas flow direction from a position where the EGR path is connected in the exhaust path. The turbine wheel of the turbocharger may be disposed upstream in the exhaust gas flow direction from a position where the EGR path is connected in the exhaust path.

[0043] In the present invention and embodiments, a lean-fuel vehicle may have a catalyst in the exhaust path that purifies exhaust gas. For example, the catalyst may be disposed in the exhaust path downstream in the flow direction of the exhaust gas from a position where the EGR path is connected.

[0044] In this specification, "A is to the left of B in the left-right direction" refers to the following state: The entirety of A is to the left of a plane that passes through the leftmost end of B and is perpendicular to the left-right direction. The rightmost end of A may or may not be on a plane that passes through the leftmost end of B and is perpendicular to the left-right direction. A and B may or may not be lined up on a straight line parallel to the left-right direction. The above definition also applies, with appropriate terminology replaced, to the expression "A is to the right of B in the left-right direction." The above definition also applies, with appropriate terminology replaced, to the expression "A is above or below B in the up-down direction." The above definition also applies, with appropriate terminology replaced, to the expression "A is forward or rearward of B in the front-to-back direction."

[0045] In this specification, unless otherwise specified, "A is to the left of B in the left-right direction" includes both the case where A is to the left of only a portion of B in the left-right direction and the case where A is to the left of all of B in the left-right direction. "A is to the left of B in the left-right direction" refers to the following state: when viewed left-right, all of A overlaps with at least a portion of B, and the right end of all of A faces the left end of at least a portion of B in the left-right direction. Note that the above definition also applies, with appropriate terminology replaced, to the expression "A is to the right of B in the left-right direction." Furthermore, the above definition also applies, with appropriate terminology replaced, to the expression "A is above or below B in the up-down direction." Furthermore, the above definition also applies, with appropriate terminology replaced, to the expression "A is in front of or behind B in the front-to-back direction."

[0046] In the present invention and embodiments, "at least one (one) of a plurality of options" includes all possible combinations of the plurality of options. "At least one (one) of a plurality of options" may be any one of the plurality of options or all of the plurality of options. For example, "at least one of A, B, and C" may be only A, only B, only C, A and B, A and C, B and C, or A, B, and C.

[0047] In the present invention and embodiments, the words including, comprising, having, and their derivatives are used herein to encompass additional items in addition to the listed items and equivalents thereof.

[0048] Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification and claims have the same meaning as commonly understood by those skilled 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.

[0049] In this specification, the term "may" is non-exclusive. "may" means "may, but is not limited to." In this specification, "may" implicitly includes the possibility that "may not." In this specification, a configuration described as "may" at least achieves the above-mentioned effect obtained by the configuration of claim 1.

[0050] Before describing embodiments of the present invention in detail, it is to be understood that the invention is not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present invention may be practiced in embodiments other than those described below. The present invention may also be practiced in embodiments with various variations on the embodiments described below.

[0051] According to the present invention, the effects on the EGR cooler of the characteristics unique to lean vehicles, such as (A) the body tilting when cornering, (B) a short vehicle width, (C) at least one of the tank, dummy tank, seat, and storage box being located in the center of the left-right direction of the vehicle, (D) the vehicle being able to stand upright while tilted in the left-right direction of the vehicle using the side stand, (E) having two frame parts that are closely spaced apart in the left-right direction of the vehicle and aligned in the front-to-rear direction, and (F) having two cover parts that are closely spaced apart in the left-to-right direction of the vehicle, can be taken into consideration, and a lean vehicle can be provided that has a configuration different from that of Patent Document 1 and is able to flow condensed water generated in the EGR cooler toward the exhaust path.

[0052] 1A and 1B are diagrams for explaining the configuration of a lean vehicle according to a first embodiment. (a) is a diagram for explaining the configuration of lean vehicles according to the second to fifth embodiments. (b) is a diagram for explaining the arrangement of an EGR cooler in a lean vehicle according to the second embodiment. (c) is a diagram for explaining the arrangement of an EGR cooler in a lean vehicle according to a third embodiment. (d) is a diagram for explaining the arrangement of an EGR cooler in a lean vehicle according to a fourth embodiment. (e) is a diagram for explaining the arrangement of an EGR cooler in a lean vehicle according to a fifth embodiment. (a) is a diagram for explaining the configuration of a lean vehicle according to a sixth embodiment. (b) is a diagram for explaining the configuration of a lean vehicle according to a seventh embodiment. (c) is a diagram for explaining the configuration of a lean vehicle according to an eighth embodiment. (d) is a diagram for explaining the configuration of a lean vehicle according to a ninth embodiment. (a) is a diagram for explaining the configuration of a lean vehicle of a tenth embodiment, (b) is a diagram for explaining the configuration of a lean vehicle of an eleventh embodiment, (c) is a diagram for explaining the configuration of a lean vehicle of a twelfth embodiment, and (d) is a diagram for explaining the configuration of a lean vehicle of a thirteenth embodiment. (a) is a diagram for explaining the configuration of a lean vehicle of a fourteenth embodiment, (b) is a diagram for explaining a tank or a dummy tank when the lean vehicle of the fourteenth embodiment has a frame portion along the front-rear direction of the vehicle at the center in the left-right direction of the vehicle body, and (c) is a diagram for explaining a tank or a dummy tank when the lean vehicle of the fourteenth embodiment does not have a frame portion along the front-rear direction of the vehicle at the center in the left-right direction of the vehicle body. (a) is a diagram for explaining the configuration of a lean vehicle of a fifteenth embodiment, and (b) is a diagram for explaining the positional relationship between the seat and storage box and the EGR cooler when viewed in the vertical direction of the vehicle body of (a). 16A is a left side view of a lean vehicle according to a sixteenth embodiment, and FIG. 16B is a view for explaining the positional relationship between two frame parts and an EGR cooler in the lean vehicle according to the sixteenth embodiment, as viewed in the vertical direction of the vehicle body. 17A is a left side view of a lean vehicle according to a seventeenth embodiment, and FIG. 16B is a rear view of the lean vehicle according to the seventeenth embodiment.

[0053] Arrows F, Re, L, R, U, and D shown in each drawing represent the forward, backward, left, right, upward, and downward directions of the vehicle, respectively. Arrows Lb, Rb, Ub, and Ud shown in each drawing represent the left, right, upward, and downward directions of the vehicle, respectively.

[0054] [First Embodiment] A lean vehicle 1 according to a first embodiment of the present invention will be described below with reference to Figure 1. The lean vehicle 1 according to the first embodiment includes a vehicle body 2 and an engine unit 3. The vehicle body 2 leans to the left when the lean vehicle 1 turns left, and leans to the right when the lean vehicle 1 turns right. The engine unit 3 is mounted on the vehicle body 2. The engine unit 3 includes an intake path 20, an exhaust path 30, an EGR path 50, and an EGR cooler 51.

[0055] The intake path 20 is a path through which air supplied to the engine unit 3 flows. The exhaust path 30 is a path through which exhaust gas generated in the engine unit 3 flows. The EGR path 50 connects the intake path 20 and the exhaust path 30. A portion of the exhaust gas flowing through the exhaust path 30 is recirculated to the intake path 20 via the EGR path 50.

[0056] The EGR cooler 51 is provided midway through the EGR path 50. The EGR cooler 51 has an in-cooler path 52 that is part of the EGR path 50. For example, the EGR cooler 51 has a coolant path (not shown) located around the in-cooler path 52, and exhaust gas in the in-cooler path 52 is cooled by the coolant flowing through the coolant path. The in-cooler path 52 has an exhaust-side opening 52a at one end in the length direction, through which exhaust gas flows in from the exhaust path 30. The in-cooler path 52 has an intake-side opening 52b at the other end in the length direction, through which exhaust gas flows out toward the intake path 20.

[0057] 1 , the EGR cooler 51 of the lean vehicle 1 of the first embodiment is configured so that, when the lean vehicle 1 is in an upright position, the lower end of the exhaust-side port 52a is located lower than the intake-side port 52b in the vehicle vertical direction. As a result, when the lean vehicle 1 is in an upright position, condensed water W generated by cooling the exhaust gas by the EGR cooler 51 is discharged from the exhaust-side port 52a by gravity G and flows toward the exhaust path 30. Furthermore, the EGR cooler 51 is configured so that the positional relationship between the exhaust-side port 52a and the intake-side port 52b in the vehicle vertical direction is maintained even if the vehicle body 2 is tilted in the left-right direction of the vehicle, for example, by being fixed to the vehicle body 2.

[0058] Furthermore, in the EGR cooler 51 of the lean vehicle 1 of the first embodiment, when the vehicle body 2 tilts in the left-right direction of the vehicle and the lean vehicle 1 turns, the exhaust-side port 52a and the intake-side port 52b of the EGR cooler 51 are spaced apart in the left-right direction of the vehicle body, and the lower end of the exhaust-side port 52a is located lower than the intake-side port 52b in the up-down direction of the vehicle body so that condensed water W in the EGR cooler 51 is discharged from the exhaust-side port 52a under the combined force S of gravity G and centrifugal force C and flows toward the exhaust path 30. Specifically, as in the lean vehicle 1A of FIG. 1 , regardless of whether the lean vehicle 1 tilts leftward or rightward, the exhaust-side port 52a of the EGR cooler 51 is located to the left of the intake-side port 52b in the left-right direction of the vehicle body, and the lower end of the exhaust-side port 52a is located lower than the intake-side port 52b in the up-down direction of the vehicle body. 1 , regardless of whether the lean vehicle 1 is tilted to the left or right, the exhaust-side port 52a of the EGR cooler 51 is located to the right of the intake-side port 52b in the vehicle left-right direction, and the lower end of the exhaust-side port 52a is located below the intake-side port 52b in the vehicle up-down direction. On the other hand, when the lean vehicle 1 is turning steadily while tilting to the left or right, the resultant force S of gravity G and centrifugal force C acting on the condensed water W is directed downward in the vehicle up-down direction, regardless of whether the lean vehicle 1 is tilted to the left or right and regardless of the angle of tilt of the lean vehicle 1 in the vehicle left-right direction. As a result, the condensed water W is discharged from the exhaust-side port 52a and flows toward the exhaust path 30, regardless of whether the lean vehicle 1 is tilted to the left or right. Furthermore, regardless of the magnitude of the tilt angle of the lean vehicle 1 in the left-right direction of the vehicle, the condensed water W is discharged from the exhaust side port 52 a and flows toward the exhaust path 30 .

[0059] According to the first embodiment, the exhaust-side port 52a and the intake-side port 52b of the EGR cooler 51 are spaced apart in the transverse direction of the vehicle body, and the lower end of the exhaust-side port 52a is located lower than the intake-side port 52b in the vertical direction of the vehicle body. As a result, when the vehicle body 2 tilts in the transverse direction of the vehicle and the lean vehicle 1 turns, a resultant force S of gravity G and centrifugal force C acts on the condensed water W in the EGR cooler 51. The direction of this resultant force S is downward in the vertical direction of the vehicle body regardless of the tilt angle of the vehicle body 2. Therefore, this resultant force S can be used to cause the condensed water W generated in the EGR cooler 51 to flow toward the exhaust path 30. Furthermore, according to the first embodiment, unlike Patent Document 1, the exhaust-side port 52a and the intake-side port 52b of the EGR cooler 51 are spaced apart in the transverse direction of the vehicle body, which reduces the restrictions on the positions of the exhaust-side port 52a and the intake-side port 52b of the EGR cooler 51.

[0060] [Second to Fifth Embodiments] Lean vehicles 1 according to second to fifth embodiments of the present invention will be described below with reference to Figures 2(a) to 2(e). The lean vehicles 1 according to the second to fifth embodiments have all the configurations of the lean vehicle 1 according to the first embodiment.

[0061] As shown in FIGS. 2A to 2E , the vehicle body 2 of the lean-head vehicle 1 of the second to fifth embodiments includes a front wheel 21, a rear wheel 22, a handlebar 23 operated by a rider, and a seat 24 on which the rider sits. The engine unit 3 of the lean-head vehicle 1 of the second to fifth embodiments includes an engine 10. The engine 10 includes a cylinder section 11 and a crankcase section 12. The cylinder section 11 defines at least one combustion chamber 9. The cylinder section 11 includes a cylinder body section 13 and a cylinder head section 14. The cylinder body section 13 defines at least one cylinder hole 15. The cylinder head section 14 is connected to the cylinder body section 13 and defines an end of the engine 10 in a direction parallel to at least one cylinder axis Cy, which is the central axis of the at least one cylinder hole 15. The cylinder axis Cy is inclined with respect to the vertical direction of the vehicle body so that an upper portion of the cylinder axis Cy in the vertical direction of the vehicle body is located forward of a lower portion in the longitudinal direction of the vehicle. The cylinder head 14 forms part of the intake path 20 and part of the exhaust path 30. An intake pipe 18, which forms part of the intake path 20, is connected to a rear surface 14b of the cylinder head 14. An exhaust pipe 19, which forms part of the exhaust path 30, is connected to a front surface 14f of the cylinder head 14. The crankcase 12 is connected to the lower end of the cylinder 11 (cylinder body 13) in the vertical direction of the vehicle body. The crankcase 12 houses a crankshaft and other components (not shown).

[0062] As shown in Figure 2(b), the EGR cooler 51 of the lean vehicle 1 of the second embodiment is located behind the cylinder section 11 in the vehicle longitudinal direction. Also, in the EGR cooler 51 of the lean vehicle 1 of the second embodiment, the exhaust-side port 52a is located to the left of the intake-side port 52b in the vehicle transverse direction, similar to the lean vehicle 1A of Figure 1. Also, the portion of the EGR path 50 of the lean vehicle 1 of the second embodiment between the portion connected to the exhaust path 30 and the exhaust-side port 52a passes through a space to the left of the cylinder section 11 in the vehicle transverse direction.

[0063] As shown in Figure 2(c), the EGR cooler 51 of the lean vehicle 1 of the third embodiment is located behind the cylinder section 11 in the vehicle longitudinal direction. Also, in the EGR cooler 51 of the lean vehicle 1 of the third embodiment, the exhaust-side port 52a is located to the right of the intake-side port 52b in the vehicle transverse direction, similar to the lean vehicle 1B of Figure 1. Also, the portion of the EGR path 50 of the lean vehicle 1 of the third embodiment between the portion connected to the exhaust path 30 and the exhaust-side port 52a passes through a space to the right of the cylinder section 11 in the vehicle transverse direction.

[0064] As shown in Figure 2(d), the EGR cooler 51 of the lean vehicle 1 of the fourth embodiment is located in front of at least one of the cylinder section 11 and the crankcase section 12 in the vehicle longitudinal direction. Also, in the EGR cooler 51 of the lean vehicle 1 of the fourth embodiment, the exhaust-side port 52a is located to the right of the intake-side port 52b in the vehicle transverse direction, similar to the lean vehicle 1B of Figure 1. Also, the portion of the EGR path 50 of the lean vehicle 1 of the fourth embodiment between the intake-side port 52b and the portion connected to the intake path 20 passes through a space to the left of the cylinder section 11 in the vehicle transverse direction.

[0065] As shown in Figure 2(e), the EGR cooler 51 of the lean vehicle 1 of the fifth embodiment is located in front of at least one of the cylinder section 11 and the crankcase section 12 in the vehicle longitudinal direction. Also, in the EGR cooler 51 of the lean vehicle 1 of the fifth embodiment, the exhaust-side port 52a is located to the left of the intake-side port 52b in the vehicle transverse direction, similar to the lean vehicle 1A of Figure 1. Also, the portion of the EGR path 50 of the lean vehicle 1 of the fifth embodiment between the intake-side port 52b and the portion connected to the intake path 20 passes through a space to the right of the cylinder section 11 in the vehicle transverse direction.

[0066] Here, Figures 2(b) to (e) show a case where one end of the EGR path 50 is connected to a portion of the exhaust path 30 formed by the exhaust pipe 19, and the other end of the EGR path 50 is connected to a portion of the intake path 20 formed by the intake pipe 18.

[0067] [Sixth to Ninth Embodiments] Lean vehicles 1 according to sixth to ninth embodiments of the present invention will be described below with reference to Figures 3(a) to 3(d). The lean vehicles 1 according to the sixth to ninth embodiments have all of the configurations of the lean vehicle 1 according to the first embodiment. The lean vehicles 1 according to the sixth to ninth embodiments may have the same configuration as the lean vehicle 1 according to any one of the second to fifth embodiments.

[0068] 3(a) to 3(d), the lean-mounted vehicles 1 of the sixth to ninth embodiments are provided with a side stand 61. The side stand 61 enables the lean-mounted vehicles 1 of the sixth to ninth embodiments to stand on their own with the vehicle body 2 tilted in the left-right direction of the vehicle.

[0069] As shown in FIG. 3A , in the lean vehicle 1 of the sixth embodiment, the exhaust-side port 52 a of the EGR cooler 51 is located to the left of the intake-side port 52 b in the vehicle left-right direction. The side stand 61 of the lean vehicle 1 of the sixth embodiment is provided on the left side of the vehicle body 2 in the vehicle left-right direction. When the lean vehicle 1 of the sixth embodiment is supported by the side stand 61 with the vehicle body 2 tilted to the left of the vehicle, the lower end of the exhaust-side port 52 a is located lower than the intake-side port 52 b in the vehicle up-down direction. This allows condensed water in the EGR cooler 51 to flow toward the exhaust path 30 by gravity. Furthermore, in the lean vehicle 1 of the sixth embodiment, as described above, the exhaust-side port 52 a is located to the left of the intake-side port 52 b in the vehicle left-right direction, while the side stand 61 is provided on the left side of the vehicle body 2 in the vehicle left-right direction. As a result, when the lean vehicle 1 is made to stand upright using the side stand 61, the tilt of the vehicle body 2 caused by the side stand 61 can be utilized to ensure that the lower end of the exhaust side port 52a of the EGR cooler 51 is lower than the intake side port 52b.

[0070] As shown in FIG. 3B , in the EGR cooler 51 of the lean vehicle 1 of the seventh embodiment, the exhaust-side port 52 a is located to the right of the intake-side port 52 b in the vehicle left-right direction. The side stand 61 of the lean vehicle 1 of the seventh embodiment is provided on the right side of the vehicle body 2 in the vehicle left-right direction. Furthermore, when the lean vehicle 1 of the seventh embodiment is supported by the side stand 61 with the vehicle body 2 tilted to the right of the vehicle, the lower end of the exhaust-side port 52 a is located lower than the intake-side port 52 b in the vehicle up-down direction. This allows condensed water in the EGR cooler 51 to flow toward the exhaust path 30 by gravity. Furthermore, in the lean vehicle 1 of the seventh embodiment, as described above, the exhaust-side port 52 a is located to the right of the intake-side port 52 b in the vehicle left-right direction, while the side stand 61 is provided on the right side of the vehicle body 2 in the vehicle left-right direction. As a result, when the lean vehicle 1 is made to stand upright using the side stand 61, the tilt of the vehicle body 2 caused by the side stand 61 can be utilized to ensure that the lower end of the exhaust side port 52a of the EGR cooler 51 is lower than the intake side port 52b.

[0071] As shown in Figure 3(c), in the EGR cooler 51 of the lean vehicle 1 of the eighth embodiment, the exhaust-side port 52a is located to the right of the intake-side port 52b in the left-right direction of the vehicle body. The side stand 61 of the lean vehicle 1 of the eighth embodiment is provided on the left side of the vehicle body 2 in the left-right direction of the vehicle body. Furthermore, in the lean vehicle 1 of the eighth embodiment, when the vehicle body 2 is standing on the side stand 61 with the vehicle body 2 tilted to the left of the vehicle, the lower end of the exhaust-side port 52a is located lower than the intake-side port 52b in the up-down direction of the vehicle. This allows condensed water in the EGR cooler 51 to flow toward the exhaust path 30 by gravity.

[0072] As shown in FIG. 3D , in the EGR cooler 51 of the lean vehicle 1 of the ninth embodiment, the exhaust-side port 52a is located to the left of the intake-side port 52b in the left-right direction of the vehicle body. The side stand 61 of the lean vehicle 1 of the ninth embodiment is provided on the right side of the vehicle body 2 in the left-right direction of the vehicle body. Furthermore, in the lean vehicle 1 of the ninth embodiment, when the vehicle body 2 is standing on the side stand 61 with the vehicle body 2 tilted to the right of the vehicle, the lower end of the exhaust-side port 52a is located lower than the intake-side port 52b in the up-down direction of the vehicle. This allows condensed water in the EGR cooler 51 to flow toward the exhaust path 30 by gravity.

[0073] [Tenth to Thirteenth Embodiments] Lean vehicles 1 according to tenth to thirteenth embodiments of the present invention will be described below with reference to Figures 4(a) to 4(d). The lean vehicles 1 according to the tenth to thirteenth embodiments have all of the configurations of the lean vehicle 1 according to the first embodiment. The lean vehicles 1 according to the tenth to thirteenth embodiments may have the same configuration as the lean vehicle 1 according to any one of the second to fifth embodiments. The lean vehicles 1 according to the tenth to thirteenth embodiments may have the same configuration as the lean vehicle 1 according to any one of the sixth to ninth embodiments.

[0074] 4A, the EGR cooler 51 of the lean-fuel vehicle 1 of the tenth embodiment is disposed so that the exhaust-side opening 52a is located to the left of the intake-side opening 52b in the left-right direction of the vehicle body. Also, the EGR cooler 51 of the lean-fuel vehicle 1 of the tenth embodiment is disposed so that at least a portion of the EGR cooler 51 is located between the left end (line L1) and the right end (line L2) of the vehicle body 2 in the left-right direction of the vehicle body, and the center (line L3) of the EGR cooler 51 is located to the left of the center (line L4) of the vehicle body 2.

[0075] 4B, the EGR cooler 51 of the lean-fuel vehicle 1 of the eleventh embodiment is disposed so that the exhaust-side opening 52a is located to the left of the intake-side opening 52b in the left-right direction of the vehicle body. Also, the EGR cooler 51 of the lean-fuel vehicle 1 of the eleventh embodiment is disposed so that at least a portion of the EGR cooler 51 is located between the left end (line L1) and the right end (line L2) of the vehicle body 2 in the left-right direction of the vehicle body, and the center (line L3) of the EGR cooler 51 is located to the right of the center (line L4) of the vehicle body 2.

[0076] 4(c), the EGR cooler 51 of the lean-fuel vehicle 1 of the twelfth embodiment is disposed so that the exhaust-side opening 52a is located to the right of the intake-side opening 52b in the left-right direction of the vehicle body. Also, the EGR cooler 51 of the lean-fuel vehicle 1 of the twelfth embodiment is disposed so that at least a portion of the EGR cooler 51 is located between the left end (line L1) and the right end (line L2) of the vehicle body 2 in the left-right direction of the vehicle body, and the center (line L3) of the EGR cooler 51 is located to the left of the center (line L4) of the vehicle body 2.

[0077] 4(d), the EGR cooler 51 of the lean-fuel vehicle 1 of the thirteenth embodiment is disposed so that the exhaust-side opening 52a is located to the right of the intake-side opening 52b in the left-right direction of the vehicle body. Also, the EGR cooler 51 of the lean-fuel vehicle 1 of the thirteenth embodiment is disposed so that at least a portion of the EGR cooler 51 is located between the left end (line L1) and the right end (line L2) of the vehicle body 2 in the left-right direction of the vehicle body, and the center (line L3) of the EGR cooler 51 is located to the right of the center (line L4) of the vehicle body 2.

[0078] 4(a) to 4(d), the entire EGR cooler 51 is located to the left or right of the center of the vehicle body 2 in the left-right direction of the vehicle body, but the EGR cooler 51 may have a portion located to the left of the center of the vehicle body 2 and a portion located to the right of the center of the vehicle body 2 in the left-right direction of the vehicle body. Also, while Figures 4(a) to 4(d) show a case where the center of the EGR cooler 51 is located between the left and right ends of the vehicle body 2 in the left-right direction of the vehicle body, the center of the EGR cooler 51 may be located to the left of the left end of the vehicle body 2 or to the right of the right end of the vehicle body 2 in the left-right direction of the vehicle body.

[0079] Generally, a lean-fuel vehicle 1 has a shorter width (length in the left-right direction of the vehicle body) than an automobile. In the tenth to thirteenth embodiments, at least a portion of the EGR cooler 51 of the lean-fuel vehicle 1 is located between the left and right ends of the vehicle body 2 in the left-right direction of the vehicle body, and the center of the EGR cooler 51 is located to the left or right of the center of the vehicle body 2. This makes it easy to arrange a portion of the EGR cooler 51 in a position that protrudes from the left or right end of the vehicle body 2 or in a position close to the left or right end of the vehicle body 2. This makes it difficult for heat rising from the EGR cooler 51 to be trapped in, for example, the tank 71, the dummy tank 72, the seat 24, or the space below the storage box 81, the space between the frame portion 92A and the frame portion 92B, or the space between the cover portion 101A and the cover portion 101B, as will be described in the fourteenth to eighteenth embodiments below. Furthermore, heat is less likely to be trapped in these spaces, which improves the cooling performance of the EGR cooler 51. Furthermore, in a lean vehicle 1 that is characterized by a short vehicle width and in which maintenance is usually performed from the left or right side of the vehicle body 2, maintenance of the EGR cooler 51 is easier than when the center of the EGR cooler 51 is disposed at the center of the vehicle body 2 in the left-right direction of the vehicle body.

[0080] Furthermore, when the center of the EGR cooler 51 is configured to be located between the left and right ends of the vehicle body 2 in the left-right direction of the vehicle body, the amount of protrusion of the EGR cooler 51 in the left-right direction of the vehicle body can be reduced compared to when at least a part of the EGR cooler is located between the left and right ends of the vehicle body 2 in the left-right direction of the vehicle body and the center of the EGR cooler is located to the left of the left end of the vehicle body 2 or to the right of the right end of the vehicle body 2.

[0081] [Fourteenth Embodiment] A lean vehicle 1 according to a fourteenth embodiment of the present invention will be described below with reference to Figures 5(a) to 5(c). The lean vehicle 1 according to the fourteenth embodiment has all the configurations of the lean vehicle 1 according to the first embodiment. The lean vehicle 1 according to the fourteenth embodiment also has all the configurations of the lean vehicle 1 according to any one of the tenth to thirteenth embodiments. The lean vehicle 1 according to the fourteenth embodiment may have the same configuration as the lean vehicle 1 according to any one of the second to fifth embodiments. The lean vehicle 1 according to the fourteenth embodiment may also have the same configuration as the lean vehicle 1 according to any one of the sixth to ninth embodiments.

[0082] 5A, the vehicle body 2 of the lean-fuel vehicle 1 of the fourteenth embodiment has a tank 71 for storing fuel or a dummy tank 72 that looks like a tank but does not store fuel. In the left-right direction of the vehicle body, the center of the tank 71 or the dummy tank 72 may be located at the center of the vehicle body 2. In addition, at least a portion of the EGR cooler 51 of the lean-fuel vehicle 1 of the fourteenth embodiment is located below the tank 71 or the dummy tank 72 in the up-down direction of the vehicle body.

[0083] As shown in FIG. 5B, if the vehicle body 2 has a frame portion 73 extending along the vehicle longitudinal direction and centered in the vehicle transverse direction (line L4), the tank 71 or dummy tank 72 has a recess 74a on its underside, centered in the vehicle transverse direction, for locating the frame portion 73. Also, as shown in FIG. 5C, even if the vehicle body 2 does not have a frame portion extending along the vehicle transverse direction and centered in the vehicle transverse direction, the tank 71 or dummy tank 72 has a recess 74b on its underside. Heat tends to build up in the space formed by the recesses 74a and 74b. Generally, a lean-fuel vehicle 1 has a short vehicle width (length in the vehicle transverse direction). Furthermore, the EGR cooler 51 of the lean-fuel vehicle 1 of the fourteenth embodiment is positioned such that at least a portion of the EGR cooler 51 is located between the left and right ends of the vehicle body 2 and the center of the EGR cooler 51 is located to the left or right of the center of the vehicle body 2. This makes it easy to arrange a portion of the EGR cooler 51 in a position that protrudes from the left or right end of the vehicle body 2 or in a position close to the left or right end of the vehicle body 2. This makes it difficult for heat rising from the EGR cooler 51 to accumulate in the space below the tank 71 or the dummy tank 72. And, because heat is less likely to accumulate in this space, the cooling performance of the EGR cooler 51 can be improved.

[0084] 5A to 5C show the case where the dummy tank 72 has a storage space inside, the dummy tank 72 may be a cover that does not have a storage space.

[0085] [Fifteenth Embodiment] A lean vehicle 1 according to a fifteenth embodiment of the present invention will be described below with reference to FIGS. 6(a) and 6(b). The lean vehicle 1 according to the fifteenth embodiment has all the configurations of the lean vehicle 1 according to the first embodiment. The lean vehicle 1 according to the fifteenth embodiment also has all the configurations of the lean vehicle 1 according to any one of the tenth to thirteenth embodiments. The lean vehicle 1 according to the fifteenth embodiment may have the same configuration as the lean vehicle 1 according to any one of the second to fifth embodiments. The lean vehicle 1 according to the fifteenth embodiment may have the same configuration as at least one of the lean vehicles 1 according to the sixth to ninth embodiments. The lean vehicle 1 according to the fifteenth embodiment may have the same configuration as the lean vehicle 1 according to the fourteenth embodiment.

[0086] As shown in FIGS. 6A and 6B , the vehicle body 2 of the lean vehicle 1 of the fifteenth embodiment has a storage box 81. The storage box 81 is provided below the seat 24 in the vertical direction of the vehicle body. The storage box 81 has an open upper end in the vertical direction of the vehicle body. The seat 24 functions as a lid that covers the opening at the upper end of the storage box 81. Furthermore, the centers of the seat 24 and the storage box 81 may be located at the center of the vehicle body 2 in the left-right direction of the vehicle body. Furthermore, as shown in FIGS. 6A and 6B , at least a portion of the EGR cooler 51 of the lean vehicle 1 of the fifteenth embodiment is located below the seat 24, which is located in the closed position, and the storage box 81 in the vertical direction of the vehicle body. Here, FIG. 6B illustrates a case in which at least a portion of the EGR cooler 51 is located to the left of the center of the vehicle body 2 (line L4) in the left-right direction of the vehicle body, similar to the tenth and twelfth embodiments ( FIGS. 4A and 4C ). However, similarly to the eleventh and thirteenth embodiments (FIGS. 4(b) and 4(d)), at least a portion of the EGR cooler 51 may be located to the right of the center of the vehicle body 2 in the left-right direction of the vehicle body.

[0087] In the fifteenth embodiment, the EGR cooler 51 of a lean vehicle 1 having a short vehicle width (length in the left-right direction of the vehicle body) is disposed so that at least a portion of the EGR cooler 51 is located between the left and right ends of the vehicle body 2 in the left-right direction of the vehicle body, and the center of the EGR cooler 51 is located to the left or right of the center of the vehicle body 2. This makes it easy to dispose a portion of the EGR cooler 51 in a position that protrudes from the left or right end of the vehicle body 2 or in a position close to the left or right end of the vehicle body 2. This prevents heat rising from the EGR cooler 51 from being trapped in the space below the seat 24 or the storage box 81. Since heat is less likely to be trapped in these spaces, the cooling performance of the EGR cooler 51 can be improved.

[0088] [16th Embodiment] A lean vehicle 1 according to a 16th embodiment of the present invention will be described below with reference to FIGS. 7(a) and 7(b). The lean vehicle 1 according to the 16th embodiment has all the configurations of the lean vehicle 1 according to the first embodiment. The lean vehicle 1 according to the 16th embodiment also has all the configurations of the lean vehicle 1 according to any one of the 10th to 13th embodiments. The lean vehicle 1 according to the 16th embodiment may have the same configuration as the lean vehicle 1 according to any one of the second to fifth embodiments. The lean vehicle 1 according to the 16th embodiment may have the same configuration as the lean vehicle 1 according to any one of the sixth to ninth embodiments. The lean vehicle 1 according to the 16th embodiment may have the same configuration as the lean vehicle 1 according to at least one of the fourteenth and fifteenth embodiments.

[0089] As shown in FIGS. 7A and 7B, the body 2 of the lean vehicle 1 of the sixteenth embodiment has a body frame 90. The body frame 90 has a head pipe 91 and two frame portions 92A and 92B. The head pipe 91 is cylindrical and is disposed so that its axial direction is along the vertical direction of the vehicle body. A steering shaft connected to the handlebars 23 is inserted through the head pipe 91. The frame portions 92A and 92B are portions of the body frame 90 that extend along the longitudinal direction of the vehicle, and their front ends in the longitudinal direction of the vehicle are connected to the head pipe 91. The frame portion 92A is located on the left side of the body 2 in the transverse direction of the vehicle body. The frame portion 92B is located on the right side of the body 2 in the transverse direction of the vehicle body. The frame portions 92A and 92B are disposed with a gap between them in the transverse direction of the vehicle body.

[0090] In the vehicle body up-down direction, at least a portion of the EGR cooler 51 of the lean vehicle 1 of the fifteenth embodiment is located below the space 93 between the frame portions 92A and 92B in the vehicle body left-right direction.

[0091] In the sixteenth embodiment, the EGR cooler 51 of a lean vehicle 1 having a short vehicle width (length in the left-right direction of the vehicle body) is disposed so that at least a portion of the EGR cooler 51 is located between the left and right ends of the vehicle body 2 in the left-right direction of the vehicle body, and the center of the EGR cooler 51 is located to the left or right of the center of the vehicle body 2. This makes it easy to dispose a portion of the EGR cooler 51 in a position that protrudes from the left or right end of the vehicle body 2 or in a position close to the left or right end of the vehicle body 2. This prevents heat rising from the EGR cooler 51 from being trapped in the space 93 between the frame portions 92A and 92B. Since heat is less likely to be trapped in this space 93, the cooling performance of the EGR cooler 51 can be improved.

[0092] [17th Embodiment] A lean vehicle 1 according to a 17th embodiment of the present invention will be described below with reference to FIGS. 8(a) and 8(b). The lean vehicle 1 according to the 17th embodiment has all the configurations of the lean vehicle 1 according to the first embodiment. The lean vehicle 1 according to the 17th embodiment also has all the configurations of the lean vehicle 1 according to any one of the 10th to 13th embodiments. The lean vehicle 1 according to the 17th embodiment may have the same configuration as the lean vehicle 1 according to any one of the second to fifth embodiments. The lean vehicle 1 according to the 17th embodiment may have the same configuration as the lean vehicle 1 according to any one of the sixth to ninth embodiments. The lean vehicle 1 according to the 17th embodiment may have the same configuration as at least one of the lean vehicles 1 according to the fourteenth to sixteenth embodiments.

[0093] As shown in FIGS. 8A and 8B, the vehicle body 2 of the lean vehicle 1 of the seventeenth embodiment has two cover portions 101A and 101B. The cover portion 101A is located on the left side of the vehicle body 2 in the left-right direction of the vehicle body. The cover portion 101B is located on the right side of the vehicle body 2 in the left-right direction of the vehicle body. The cover portion 101A and the cover portion 101B are arranged with a gap between them in the left-right direction of the vehicle body. Here, the cover portion 101A and the cover portion 101B may be separate bodies. Alternatively, the cover portion 101A and the cover portion 101B may be two different parts of a single cover provided on the vehicle body 2 of the lean vehicle 1. Furthermore, in the vertical direction of the vehicle body, at least a portion of the EGR cooler 51 of the lean vehicle 1 of the seventeenth embodiment is located below the space 102 between the cover portion 101A and the cover portion 101B in the left-right direction of the vehicle body.

[0094] In the seventeenth embodiment, the EGR cooler 51 of a lean vehicle 1 having a short vehicle width (length in the left-right direction of the vehicle body) is disposed so that at least a portion of the EGR cooler 51 is located between the left and right ends of the vehicle body 2 in the left-right direction of the vehicle body, and the center of the EGR cooler 51 is located to the left or right of the center of the vehicle body 2. This makes it easy to dispose a portion of the EGR cooler 51 in a position that protrudes from the left or right end of the vehicle body 2 or in a position close to the left or right end of the vehicle body 2. This prevents heat rising from the EGR cooler 51 from being trapped in the space 102 between the cover portion 101A and the cover portion 101B. Since heat is less likely to be trapped in this space 102, the cooling performance of the EGR cooler 51 can be improved.

[0095] 1: lean vehicle, 2: vehicle body, 3: engine unit, 20: intake path, 24: seat, 30: exhaust path, 50: EGR path, 51: EGR cooler, 52: path inside cooler, 52a: exhaust side port, 52b: intake side port, 61: side stand, 71: tank, 72: dummy tank, 81: storage box, 92A, 92B: frame part, 93: space between two frame parts, 101A, 101B: cover part, 102: space between two cover parts, C: centrifugal force, G: gravity, W: condensed water

Claims

1. A lean vehicle comprising: a vehicle body that tilts to the left when turning left and to the right when turning right; and an EGR cooler mounted on the vehicle body and provided midway through an EGR path that recirculates a portion of exhaust gas generated in an engine unit from the exhaust path to the intake path, the EGR cooler having an exhaust side port into which the exhaust gas flows in from the exhaust path and an intake side port from which the exhaust gas flows out toward the intake path, the EGR cooler being configured so that when the lean vehicle is in an upright position, a lower end of the exhaust side port is located lower than the intake side port in the vertical direction of the vehicle, and so that even when the vehicle body is inclined in the horizontal direction of the vehicle, the positional relationship between the exhaust side port and the intake side port in the vertical direction of the vehicle is maintained with respect to the vehicle body inclined in the horizontal direction of the vehicle, the EGR cooler cooling the exhaust gas and allowing condensed water produced by cooling the exhaust gas to be discharged from the exhaust side port and flow toward the exhaust path, A lean vehicle characterized in that, when the vehicle body tilts in the left-right direction of the vehicle and the lean vehicle turns, the condensed water in the EGR cooler is discharged from the exhaust side port under the combined force of gravity and centrifugal force and flows toward the exhaust path, the exhaust side port and the intake side port of the EGR cooler are separated in the left-right direction of the vehicle body based on the vehicle body tilting in the left-right direction of the vehicle, and a lower end of the exhaust side port is located lower than the intake side port in the vertical direction of the vehicle body.

2. A lean vehicle as described in claim 1, further comprising a side stand for supporting the lean vehicle with the body tilted in the left-right direction of the vehicle, wherein when the lean vehicle is supporting itself with the body tilted in the left-right direction of the vehicle by means of the side stand, the lower end of the exhaust side port is positioned lower than the intake side port in the vertical direction of the vehicle body so that the condensed water in the EGR cooler flows toward the exhaust path by gravity.

3. A lean vehicle as described in claim 2, characterized in that the side stand is located to the left of the vehicle body in the left-right direction of the vehicle body, and the exhaust side port is located to the left of the intake side port in the left-right direction of the vehicle body, or the side stand is located to the right of the vehicle body in the left-right direction of the vehicle body, and the exhaust side port is located to the right of the intake side port in the left-right direction of the vehicle body.

4. A lean vehicle as described in any one of claims 1 to 3, characterized in that at least a portion of the EGR cooler is located between the left and right ends of the vehicle body in the left-right direction of the vehicle body, and the center of the EGR cooler is located to the left or right of the center of the vehicle body.

5. The lean vehicle according to claim 4, wherein the center of the EGR cooler is located between the left and right ends of the vehicle body in the left-right direction.

6. A lean vehicle as described in claim 4 or 5, characterized in that it is equipped with at least one of a tank, a dummy tank, a seat, and a storage box, and at least a portion of the EGR cooler is located below at least one of the tank, the dummy tank, the seat, and the storage box in the vertical direction of the vehicle body.

7. A lean vehicle as described in any one of claims 4 to 6, characterized in that it comprises two frame parts located on the left and right parts of the vehicle body in the left-right direction of the vehicle and aligned in the front-to-rear direction of the vehicle, and at least a portion of the EGR cooler is located below the space between the two frame parts in the up-down direction of the vehicle body.

8. A lean vehicle as described in any one of claims 4 to 7, characterized in that it is provided with two cover parts located on the left and right parts of the vehicle body in the left-right direction of the vehicle body and aligned in the front-to-rear direction of the vehicle, and at least a portion of the EGR cooler is located below the space between the two cover parts in the up-down direction of the vehicle body.

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