Saddle-ridden vehicle

Abstract

A motorcycle (1) comprises: an engine (E) provided with a cylinder block (42a) that protrudes obliquely forward and upward from a crankcase (41); an air cleaner (60) that filters intake air to the engine (E); a supercharger (70) that is provided with an electric motor (75) serving as a drive source, takes in air from the air cleaner (60), compresses the air, and supplies the compressed air to the engine (E); and a surge tank (80) into which supercharged intake air is introduced from the supercharger (70). The surge tank (80) is disposed above the cylinder block (42a). The supercharger (70) is disposed above the surge tank (80). The air cleaner (60) is disposed behind the supercharger (70).

Description

Straddle-type vehicle

[0001] The present invention relates to a straddle-type vehicle. The present invention claims priority based on Japanese Patent Application No. 2024-205952 filed in Japan on November 27, 2024, and incorporates the content herein by reference.

[0002] Patent Document 1 discloses a configuration in a motorcycle with a supercharger, where the supercharger and air cleaner are arranged behind the cylinder block. Further, a surge tank is arranged above and behind the cylinder block and above the supercharger.

[0003] International Publication No. 2011 / 077898

[0004] In the motorcycle with a supercharger disclosed in Patent Document 1, it is necessary to obtain the driving force of the supercharger from the engine's rotating shaft (crankshaft), and the degree of freedom in arranging the supercharger may be impaired. Depending on the location of the supercharger, pressure loss may occur in the intake system, potentially reducing energy efficiency and responsiveness.

[0005] The present application aims to improve energy efficiency and responsiveness in order to solve the above problems.

[0006] As a means of solving the above problems, an aspect of the present invention has the following configuration: (1) A saddle-type vehicle (1) according to an aspect of the present invention comprises an engine (E) having a cylinder block (42a) protruding diagonally forward and upward from a crankcase (41), an air cleaner (60) that filters the intake air to the engine (E), a supercharger (70) that has an electric motor (75) as a drive source and takes in air from the air cleaner (60), compresses the air, and supplies it to the engine (E), and a surge tank (80) into which supercharged intake air is introduced from the supercharger (70), wherein the surge tank (80) is positioned above or rear above the cylinder block (42a), the supercharger (70) is positioned above the surge tank (80), and the air cleaner (60) is positioned in front of or behind the supercharger (70). This configuration, by electrifying the supercharger, eliminates the need to obtain power for the supercharger from the engine's exhaust system or drive shaft, thereby increasing the flexibility of the supercharger's placement. This increased flexibility allows for closer placement of the surge tank, supercharger, and air cleaner. Consequently, pressure loss in the intake system can be reduced, improving energy efficiency and responsiveness.

[0007] (2) In the saddle-type vehicle (1) described in (1) above, the surge tank (80) is positioned above the cylinder block (42a), the air cleaner (60) is positioned behind the supercharger (70), and at least a portion of the surge tank (80) is positioned in a region (SA) enclosed by a first straight line (L1) passing over the upper end of the rear wheel (4) and extending in the longitudinal direction, a second straight line (L2) passing over the upper end of the engine (E) and extending in the longitudinal direction, a third straight line (L3) passing over the front end of the engine (E) and extending in the vertical direction, and a fourth straight line (L4) passing over the rear end of the engine (E) and extending in the vertical direction, and at least a portion of the surge tank (80) and the supercharger (70) may be positioned behind the third straight line (L3) and in front of the fourth straight line (L4) in the side view. With this configuration, the surge tank and turbocharger can be compactly arranged together within the area enclosed by straight lines in a side view, as well as within the area between the third and fourth straight lines.

[0008] (3) In the saddle-type vehicle (1) described in (1) above, the surge tank (80) is positioned above the cylinder block (42a), the air cleaner (60) is positioned in front of the supercharger (70), and at least a portion of the surge tank (80) is positioned in a region (SA) enclosed by a first straight line (L1) passing over the upper end of the rear wheel (4) and extending in the longitudinal direction, a second straight line (L2) passing over the upper end of the engine (E) and extending in the longitudinal direction, a third straight line (L3) passing over the front end of the engine (E) and extending in the vertical direction, and a fourth straight line (L4) passing over the rear end of the engine (E) and extending in the vertical direction, and at least a portion of each of the surge tank (80) and the air cleaner (60) may be positioned behind the third straight line (L3) and in front of the fourth straight line (L4) in the side view. With this configuration, the surge tank and air cleaner can be compactly arranged together within the area enclosed by straight lines in a side view, as well as within the area sandwiched between the third and fourth straight lines.

[0009] (4) In the saddle-type vehicle (1) described in any of (1) to (3) above, the vehicle body (20) further comprises a head pipe (21) supporting the front wheel suspension component (10) at the front of the vehicle body (20), and a pair of left and right main frames (22) branching off from the head pipe (21) and extending to the rear, and at least a part of each of the surge tank (80), the supercharger (70), and the air cleaner (60) may be arranged between the left and right main frames (22) in a top view. With this configuration, the surge tank, supercharger, and air cleaner can be compactly arranged together between the left and right main frames in a top view.

[0010] (5) In the saddle-type vehicle (1) described in (4) above, the surge tank (80), the supercharger (70), and the air cleaner (60) may be located behind the head pipe (21). With this configuration, the head pipe can protect the surge tank, supercharger, and air cleaner from external factors from the front of the vehicle.

[0011] (6) In the saddle-type vehicle (1) described in (4) or (5) above, at least a portion of the surge tank (80) may overlap with the main frame (22) in a side view. With this configuration, the main frame can protect the surge tank from external factors from the side of the vehicle.

[0012] According to the present invention, energy efficiency and responsiveness can be improved.

[0013] This is a left side view of a motorcycle according to the first embodiment. This is a perspective view showing the arrangement of a surge tank, supercharger, and air cleaner, including the engine and body frame according to the first embodiment. This is a top view showing the arrangement as indicated by arrow III in Figure 2. This is a front view showing the arrangement as indicated by arrow IV in Figure 2. This is a left side view showing the arrangement as indicated by arrow V in Figure 2. This is an explanatory diagram showing an overview of the intake system of a motorcycle according to the first embodiment. This is a perspective view showing the arrangement of a surge tank, supercharger, and air cleaner according to the second embodiment. This is a top view showing the arrangement as indicated by arrow VIII in Figure 7. This is a front view showing the arrangement as indicated by arrow IX in Figure 7. This is a left side view showing the arrangement as indicated by arrow X in Figure 7. This is a left side view showing the arrangement of a surge tank, supercharger, and air cleaner according to the third embodiment. This is a left side view showing the arrangement of a surge tank, supercharger, and air cleaner according to the fourth embodiment.

[0014] Embodiments of the present invention will be described below with reference to the drawings. In the following description, a motorcycle will be used as an example of a saddle-type vehicle. In the following description, it will be assumed that the motorcycle is stationary, upright with no tilt to the left or right and a steering angle of 0 degrees, and is in an unloaded state of 1G on a horizontal plane. Unless otherwise specified, the directions of front, rear, left, and right in the following description will be the same as the directions of a motorcycle. Hereinafter, a motorcycle may be simply referred to as "vehicle". In the figures used in the following description, arrows FR indicating the front of the vehicle, LH indicating the left side of the vehicle, UP indicating the top of the vehicle, and CL indicating the left-right center of the vehicle body are shown where appropriate.

[0015] <First Embodiment> <Motorcycle> Figure 1 is a left side view of a motorcycle 1 according to the first embodiment. Referring to Figure 1, the motorcycle 1 comprises a front wheel 3 steered by a handle 2 and a rear wheel 4 driven by a power unit PU including an engine E.

[0016] The front suspension components 10, including the front wheel 3, are steerably supported by a head pipe 21 located at the front end of the vehicle frame 20 (vehicle body). The handlebars 2 and the front suspension components 10 are steerably supported by the head pipe 21. The front suspension components 10 include a pair of left and right front forks 11, and a top bridge 12 and a bottom bridge 13 connecting the upper parts of the left and right front forks 11. A bar-type handlebar 2 is mounted on the top bridge 12. A power unit PU is located in the front-to-rear center of the vehicle frame 20.

[0017] Motorcycle 1 is equipped with a telescopic front fork 11 as its front suspension. However, the configuration of the front suspension is not limited to this. For example, the front suspension may be of other types, such as a link type using a swing arm. The front end of the vehicle frame 20 may be equipped with a head section with a configuration that replaces the head pipe 21, depending on the type of front suspension. The configuration of the front suspension can be changed according to the design specifications.

[0018] For example, the vehicle frame 20 is formed by integrally joining multiple types of steel materials by welding or the like. The vehicle frame 20 includes a head pipe 21, a main frame 22, a down frame 23, a front stay 24, a first side stay 25, a second side stay 26, a pivot frame 27, a seat rail 28, and a rear stay 29.

[0019] Figure 2 is a perspective view showing the arrangement of a surge tank 80, supercharger 70, and air cleaner 60, including the engine E and vehicle frame 20 according to the first embodiment. Figure 3 is a top view showing the arrangement as indicated by arrow III in Figure 2. Figure 4 is a front view showing the arrangement as indicated by arrow IV in Figure 2. Figure 5 is a left side view showing the arrangement as indicated by arrow V in Figure 2. Referring together to Figures 1 to 5, the head pipe 21 is formed in a cylindrical shape that is inclined backward with respect to the vertical direction. In both the top view and the front view, the head pipe 21 is positioned on the left-right centerline CL of the vehicle body. In a side view, the head pipe 21 is inclined such that the upper end of the head pipe 21 is located rearward and the lower end of the head pipe 21 is located forward.

[0020] The main frame 22 connects the head pipe 21 and the pivot frame 27. The main frame 22 is provided in pairs, one on each side, so as to branch off from the head pipe 21 to the left and right and extend rearward. In a top view, the main frame 22 extends diagonally outward from the rear of the head pipe 21 in the vehicle width direction (left-right direction), then curves rearward, extending toward the pivot frame 27 with the distance in the vehicle width direction gradually increasing. In a side view, the main frame 22 comprises a front portion 22a that extends diagonally downward and rearward from the top of the head pipe 21, and a rear portion 22b that curves rearward from the rear end of the front portion 22a and extends downward toward the upper end of the pivot frame 27 with a gentler slope than the front portion 22a.

[0021] The down frame 23 connects the head pipe 21 and the engine E. In a side view, the down frame 23 is provided in pairs on the left and right so as to extend diagonally downward and rearward from the lower part of the head pipe 21 at a steeper angle than the front part 22a of the main frame 22. In a top view, the down frame 23 extends diagonally from the head pipe 21 at a steeper angle than the main frame 22 towards the rear and outward in the vehicle width direction, then curves rearward and extends inward in the vehicle width direction toward the underside of the cylinder 42. In a side view, the down frame 23 extends diagonally downward and rearward from the lower part of the head pipe 21 at a steeper angle than the main frame 22 toward the underside of the cylinder 42. The lower ends of the left and right down frames 23 are connected to the lower part of the cylinder block 42a via hangers or the like.

[0022] The front stays 24 are provided in pairs, one on each side, extending rearward from the lower part of the head pipe 21. The front part of the front stays 24 is connected to the upper end of the down frame 23. The rear end of the front stays 24 is connected to the upper and lower intermediate part of the front portion 22a of the main frame 22.

[0023] The first side stays 25 are provided in pairs, left and right, extending diagonally upward and rearward from the upper and lower middle portion of the down frame 23. In a top view, the first side stays 25 extend rearward and inward in the vehicle width direction from the curved portion 23c on the outer end side in the vehicle width direction of the down frame 23 toward the front portion 22a of the main frame 22. The upper end of the first side stays 25 is connected to the front portion 22a of the main frame 22 below the connection point between the main frame 22 and the front stay 24.

[0024] The second side stays 26 are provided in pairs on the left and right so as to extend upward and rearward from the upper and lower middle portion of the down frame 23 with a gentler slope than the first side stays 25. In a top view, the second side stays 26 extend from below the first side stays 25 towards the rear end of the front portion 22a of the main frame 22 with a gentler slope than the first side stays 25, at the curved portion 23c on the outer end side in the vehicle width direction of the down frame 23. The rear end of the second side stays 26 is connected to the curved portion 22c on the rear end side of the front portion 22a of the main frame 22.

[0025] The pivot frames 27 are provided in pairs, one on each side, extending downward from the rear end of the main frame 22. The upper parts of the left and right pivot frames 27 are connected by a cross pipe 30 that extends in the vehicle width direction. The lower ends of the left and right pivot frames 27 are connected to the lower rear part of the crankcase 41 via hangers or the like.

[0026] A pair of seat rails 28 are provided on the left and right sides, extending diagonally upward and rearward from the upper end of the pivot frame 27. The front ends of the seat rails 28 are connected to the pivot frame 27 above and rearward from the connection point between the main frame 22 and the pivot frame 27. The rear ends of the left and right seat rails 28 are connected to each other via a first cross member 32 that extends in the vehicle width direction.

[0027] The rear stays 29 connect the upper part of the pivot frame 27 to the rear part of the seat rail 28. A pair of rear stays 29 are provided on the left and right so as to extend diagonally upward and rearward from the upper part of the pivot frame 27. The front ends of the rear stays 29 are connected to the pivot frame 27 below the connection point between the seat rail 28 and the pivot frame 27 and above the pivot axis 31. The front ends of the left and right rear stays 29 are connected to each other via a second cross member 33 that extends in the vehicle width direction.

[0028] The power unit PU is located below the main frame 22. The power unit PU is located in the space enclosed by the left and right main frames 22, the left and right down frames 23, and the left and right pivot frames 27. In a side view, the power unit PU is provided extending from below the front portion 22a to below the rear portion 22b of the main frame 22. The power unit PU is supported by the vehicle frame 20 by a plurality of hangers. The power unit PU comprises an engine E, a transmission 45, and a generator 46.

[0029] Engine E is, for example, a multi-cylinder engine. However, engine E may also be a single-cylinder engine. The type of engine E is not limited to the above and can be changed according to the design specifications. Engine E comprises a crankshaft 40 extending in the vehicle width direction, a crankcase 41 housing the crankshaft 40, and a cylinder 42 rising diagonally forward and upward from the top of the crankcase 41. The cylinder 42 is integrally connected to the top of the crankcase 41. An oil pan 43 is connected to the bottom of the crankcase 41.

[0030] The transmission 45 is located at the rear of the crankcase 41. The rear of the crankcase 41 also serves as the transmission case, housing the clutch and transmission. The transmission 45 is equipped with an output shaft (not shown) for taking power from the engine E to the outside.

[0031] The generator 46 generates electricity using the rotation of the engine E. The generator 46 is connected to the left end of the crankshaft 40 in the vehicle width direction. A cover member 47 is attached to the left side of the crankcase 41, covering the generator 46 from the outside in the vehicle width direction. Although not shown in the figures, the generator 46 comprises a stator fixed to the cover member 47 and an outer rotor provided on the crankshaft 40.

[0032] The front ends of the swingarms 35 are pivotably supported on the left and right pivot frames 27 via pivot shafts 31. A link mechanism, including a link member 36, is provided between the front lower part of the swingarms 35 and the lower part of the pivot frames 27. A rear suspension 37 is provided between the link member 36 and the cross pipe 30. The axle of the rear wheel 4 is supported at the rear of the swingarms 35. The output shaft of the transmission 45 and the axle of the rear wheel 4 are connected via a power transmission mechanism 38 (for example, a chain-type transmission mechanism) including a drive chain.

[0033] A storage box 5 is mounted on the main frame 22. Behind the storage box 5 is a seat 6 for the occupant to sit on. The seat 6 is mounted on a seat rail 28 so that it can be opened and closed. Below the seat 6 is a fuel tank 7.

[0034] The cylinder 42 comprises a cylinder block 42a connected to the upper front end of the crankcase 41 and protruding diagonally forward and upward from the crankcase 41, a cylinder head 42b connected to the front end of the cylinder block 42a, and a head cover 42c connected to the front end of the cylinder head 42b.

[0035] The upper end of the exhaust pipe 48, which discharges exhaust from engine E, is connected to the lower (front) part of the cylinder head 42b. The muffler 49 is connected to the downstream (rear) end of the exhaust pipe 48. The muffler 49 is inclined upward and rearward on the right side of the rear wheel 4.

[0036] In Figure 1, reference numeral 50 indicates the left step on which the occupant places their foot. In front of the left step 50 is a change pedal 51 for operating the transmission (gearbox 45). In Figure 1, reference numeral 52 indicates the front fender and reference numeral 53 indicates the rear fender.

[0037] The motorcycle 1 includes an air cleaner 60 that filters the intake air to the engine E, an electric motor 75 as a power source, a supercharger 70 (electric supercharger) that takes in air from the air cleaner 60, compresses the air and supplies it to the engine E, and a surge tank 80 into which supercharged intake air is introduced from the supercharger 70.

[0038] <Intake System> Figure 6 is an explanatory diagram showing an overview of the intake system of a motorcycle 1 according to the first embodiment. Referring to Figure 6, the overview of the intake system of the engine E in the motorcycle 1 will be explained. As shown in Figure 6, the intake system comprises an air cleaner 60, a supercharger 70, and a surge tank 80. The air cleaner 60 is connected to the supercharger 70 via a suction pipe 65 that forms an intake passage T. The supercharger 70 is connected to the surge tank 80 via a discharge pipe 74 (first intake pipe) that forms a discharge passage (first intake passage) T1. The surge tank 80 is connected to the intake port of the engine E via a throttle body 55. The air cleaner 60 is connected to the surge tank 80 via a second intake pipe 66 that forms a second intake passage T2. Intake air that does not pass through the supercharger 70 can be supplied to the surge tank 80 via the second intake passage T2.

[0039] <Air Cleaner> Referring to Figures 1 to 5, the air cleaner 60 is located behind the supercharger 70. The air cleaner 60 is formed in a flattened shape, with its vertical (thickness) dimension being shorter than its horizontal and longitudinal dimensions.

[0040] The air cleaner 60 is formed in a rectangular shape that is elongated in the left-right direction when viewed from above. When viewed from above, the air cleaner 60 straddles the left-right centerline CL of the vehicle body and is installed so as to overlap with the rear of the surge tank 80. When viewed from above, the air cleaner 60 extends in the front-rear direction from the curved portion 22c at the rear end of the front portion 22a of the main frame 22 to the front-rear middle portion of the rear portion 22b. When viewed from above, the left edge of the air cleaner 60 overlaps with the rear portion 22b of the left main frame 22. When viewed from above, the right edge of the air cleaner 60 is positioned inward in the vehicle width direction from the inner edge in the vehicle width direction of the right main frame 22.

[0041] In a front view, the air cleaner 60 overlaps with the vertical center of the head pipe 21. In a front view, the entire air cleaner 60 is positioned inward from the vertical outer end of the head pipe 21. In a front view, the entire air cleaner 60 is positioned inward from the vehicle width outer ends of the left and right down frames 23.

[0042] The air cleaner 60 is formed in a rectangular shape that is long in the front-to-back direction when viewed from the side. The entire air cleaner 60 is positioned further back than the entire supercharger 70 when viewed from the side. The air cleaner 60 extends in the front-to-back direction from the front end of the crankcase 41 to the rear side of the cover member 47 of the generator 46 when viewed from the side.

[0043] The air cleaner 60 comprises a box-shaped case body 61 that forms the exterior of the air cleaner 60 itself, and an element 62 provided inside the case body 61. The case body 61 has an intake port 60a (see Figure 6) for introducing airflow into the case body 61. The intake port 60a is formed, for example, at the rear end of the case body 61, opening toward the rear of the vehicle.

[0044] The element 62 is supported inside the front-to-rear intermediate portion of the case body 61. In a side view, the element 62 may be formed in a filter shape that is tilted forward in the vertical direction. In the internal space of the case body 61, the area in front of the element 62 is the clean side 63. In the internal space of the case body 61, the area behind the element 62 (towards the intake port 60a) is the dirty side 64.

[0045] The running air introduced into the case body 61 is filtered after passing through the element 62, and then is sucked from the suction passage T into the supercharger 70 or introduced from the second intake passage T2 that does not pass through the supercharger 70 into the surge tank 80 (see FIG. 6).

[0046] On the front wall portion of the case body 61, a first opening 61a is formed that opens toward the front of the vehicle and communicates with the suction passage T. The first opening 61a of the case body 61 and the suction port 71a of the supercharger 70 are connected by a suction pipe 65 that forms the suction passage T inside. On the front side of the lower wall portion of the case body 61, a second opening 61b is formed that opens downward of the vehicle and communicates with the second intake passage T2. The second opening 61b of the case body 61 and the second opening 81b of the surge tank 80 are connected by a second intake pipe 66 that forms the second intake passage T2 inside.

[0047] <Supercharger> The supercharger 70 compresses the air taken in from the air cleaner 60 and supplies it to the engine E. The supercharger 70 is in the form of a so-called blower fan that discharges air perpendicular to the intake air. The supercharger 70 sucks air from the axial direction by the rotation of a fan body (impeller) not shown, and discharges this air in a direction (tangential direction) perpendicular to the axial direction. The supercharger 70 is cooled by air cooling or water cooling.

[0048] The supercharger 70 is disposed above the surge tank 80. In a top view, the supercharger 70 straddles the vehicle body left - right center line CL left and right and is disposed inside the outer ends in the vehicle width direction of the surge tank 80. The whole of the supercharger 70 is disposed inside the inner edges in the vehicle width direction of the left and right main frames 22 in a top view.

[0049] In a front view, the supercharger 70 overlaps the central side in the vertical direction of the head pipe 21. The whole of the supercharger 70 is disposed inside the outer ends in the vertical direction and the outer ends in the vehicle width direction of the air cleaner 60 in a front view. The whole of the supercharger 70 is disposed inside the outer ends in the vehicle width direction of the left and right down frames 23 in a front view.

[0050] In a side view, the entire supercharger 70 is positioned in front of the air cleaner 60 and behind the front end of the surge tank 80. In a side view, the entire supercharger 70 is positioned above the front portion 22a of the main frame 22.

[0051] The supercharger 70 comprises a fan body (not shown), a blower case 71 housing the fan body, and an electric motor 75 for driving the fan body. The supercharger 70 is an electric device that is driven by the driving force of the electric motor 75, without using the exhaust energy or driving force of the engine E. The axial direction of the fan body of the supercharger 70 is oriented in the direction of the vehicle width. Line C70 in the figure indicates the central axis along the axial direction of the supercharger 70. The central axis C70 of the supercharger 70 is parallel to the direction of the vehicle width. The central axis C70 of the supercharger 70 may be inclined with respect to the direction of the vehicle width.

[0052] The blower case 71 has an annular portion 72 coaxial with the fan body. The annular portion 72 has a suction port 71a that opens on one axial side (left side). In a side view, the suction port 71a is formed in a circular shape centered on the central axis C70. An electric motor 75 is integrally attached to the other axial side (right side) of the annular portion 72. The electric motor 75 is formed in a cylindrical shape coaxial with the annular portion 72. The electric motor 75 may be integrally provided with a drive control unit (not shown) for controlling the electric motor 75.

[0053] The electric motor 75 is located to the right of the center CL of the vehicle body when viewed from above. The electric motor 75 is a rotating electric machine with a central axis C70 as its drive center, and outputs rotational power to drive the fan body. The drive of the electric motor 75 (drive of the supercharger 70) is controlled by an electronic control device (not shown). The electronic control device appropriately drives the supercharger 70 according to, for example, the operating status of the engine E, the driving status of the vehicle, and the driver's acceleration request.

[0054] The suction port 71a of the blower case 71 is positioned above the front portion 22a of the main frame 22 when viewed from the side. A suction pipe 65 extends from the suction port 71a toward the rear and outward in the vehicle width direction, forming a suction passage T. The suction pipe 65 is connected from the front to the clean side 63 of the air cleaner 60.

[0055] A discharge duct 73 is formed at the front of the annular portion 72 of the blower case 71, extending tangentially downward and forward. The discharge duct 73 is cylindrical in shape. The central axis C73 of the discharge duct 73 is inclined with respect to the vertical direction. However, the central axis C73 of the discharge duct 73 may be parallel to the vertical direction. A discharge port 73a is formed at the lower end of the discharge duct 73, opening toward the front and downward of the vehicle.

[0056] Although not shown in the diagram, a first heat shield may be provided between the supercharger 70 and the air cleaner 60 to prevent the air inside the air cleaner 60 from being heated by the heat generated by the supercharger 70. Furthermore, a second heat shield may be provided between the supercharger 70 and the surge tank 80 to prevent the air inside the surge tank 80 from being heated by the heat generated by the supercharger 70. The first and second heat shields may be integrally formed from the same material.

[0057] <Surge Tank> The surge tank 80 is located above the cylinder block 42a. The surge tank 80 is formed in a box shape, with a larger volume at the rear than at the front. A throttle body 55 and an injector 56 are provided between the funnel 54 of the surge tank 80 and the cylinder 42 of the engine E.

[0058] The surge tank 80 is formed in a shape that combines a front section formed in a trapezoidal shape that is long in the front-to-rear direction and a rear section formed in a rectangular shape that is long in the front-to-rear direction, when viewed from above. When viewed from above, the surge tank 80 is positioned to straddle the left-to-right centerline CL of the vehicle body and overlap with the entire throttle body 55. When viewed from above, the surge tank 80 extends in the front-to-rear direction from the rear of the head pipe 21 to the front-to-rear middle section of the rear portion 22b of the main frame 22. When viewed from above, the rear of the surge tank 80 is positioned inward in the vehicle width direction from the inner edges in the vehicle width direction of the left and right main frames 22.

[0059] In a front view, the surge tank 80 overlaps with the head pipe 21, main frame 22, and down frame 23. In a front view, the entire surge tank 80 is positioned below the vertical center of the head pipe 21. In a front view, the entire surge tank 80 is positioned inward from the outer ends of the left and right main frames 22 in the vehicle width direction.

[0060] The surge tank 80 comprises a hollow tank body 81. In addition to ensuring intake capacity, the surge tank 80 has the function of stabilizing the pressure by diffusing the intake air introduced into the tank body 81 within the tank body 81. A discharge pipe 74 (first intake pipe) is connected to the lower end of the discharge duct 73, forming a discharge passage (first intake passage) T1 that extends in the direction of extension of the discharge duct 73.

[0061] The front upper part of the tank body 81 overlaps with the front stay 24 in a side view. A recess 83 is formed in the front lower part of the tank body 81, which is recessed upward to avoid the throttle body 55 and injector 56. The rear wall of the tank body 81 extends along the vertical direction in a side view. The upper wall of the tank body 81 extends along the front-rear direction in a side view.

[0062] A first opening 81a is formed on the front side of the upper wall of the tank body 81, opening upwards towards the vehicle. The lower end of the discharge pipe 74 is connected to the first opening 81a of the tank body 81. Supercharged intake air discharged from the supercharger 70 is introduced into the tank body 81 through the first intake passage T1 of the discharge pipe 74 and the first opening 81a of the tank body 81. After the supercharged intake air introduced into the tank body 81 diffuses and stabilizes its pressure, it is supplied to each cylinder from the funnel 54.

[0063] A second opening 81b is formed on the rear side of the upper wall of the tank body 81, opening upwards towards the vehicle. The lower end of the second intake pipe 66, which extends from the front side of the lower wall of the air cleaner 60, is connected to the second opening 81b of the tank body 81. The inside of the second intake pipe 66 forms a second intake passage T2. Air taken into the air cleaner 60 and reaching the clean side 63 can be introduced into the tank body 81 through the second intake passage T2. This air, as naturally aspirated air not pressurized by the supercharger 70, diffuses within the tank body 81 to stabilize its pressure before being supplied to each cylinder from the funnel 54.

[0064] The first opening 81a and the second opening 81b of the tank body 81 are each positioned on the upper wall of the tank body 81, closer to the left-right centerline CL of the vehicle body. Alternatively, the first opening 81a and the second opening 81b of the tank body 81 may be positioned on the upper wall of the tank body 81, offset to one side in the vehicle width direction relative to the left-right centerline CL of the vehicle body. This allows access to each opening (each connection point) from one side of the vehicle body (right or left), improving the ease of attaching and detaching the first intake pipe 74 and the second intake pipe 66 to the surge tank 80.

[0065] The discharge passage T1 formed by the discharge pipe 74 discharges supercharged intake air into the surge tank 80. The intake port of the funnel 54 is located outside the extension region of the discharge passage T1 into the surge tank 80. A recess 83 is provided between the first opening 81a of the tank body 81 and the intake port of the funnel 54. As a result, the supercharged intake air introduced into the surge tank 80 is not directly introduced into the intake port of the funnel 54, but is instead collides with the walls of the surge tank 80 and the funnel 54 and diffused well.

[0066] In the figure, line CT1 is the central axis of the discharge passage T1 of the discharge pipe 74 (first intake pipe), and corresponds to a straight line along the extension direction of the discharge passage T1. In the figure, line CT2 is the central axis of the second intake passage T2 of the second intake pipe 66, and corresponds to a straight line along the extension direction of the second intake passage T2. In a side view, the first intake passage (discharge passage) T1 and the second intake passage T2 are spaced apart such that the distance between their respective central axes CT1 and CT2, which extend inside the surge tank 80, increases as they move towards the underside of the vehicle. In a side view, the respective central axes CT1 and CT2, which extend inside the surge tank 80, may be arranged parallel to each other. This prevents the intake air introduced into the surge tank 80 from each of the first intake passage T1 and the second intake passage T2 from facing each other. Therefore, it is possible to prevent the generation of turbulence due to airflow interference and to prevent intake air from flowing back from one of the first intake passage T1 and the second intake passage T2 to the other.

[0067] <Example of arrangement of surge tank, supercharger and air cleaner> At least a portion of the surge tank 80 is located in a region SA enclosed by a first straight line L1 passing over the upper end of the rear wheel 4 and extending in the longitudinal direction, a second straight line L2 passing over the upper end of the engine E and extending in the longitudinal direction, a third straight line L3 passing over the front end of the engine E and extending in the vertical direction, and a fourth straight line L4 passing over the rear end of the engine E and extending in the vertical direction, in a side view. The first straight line L1 corresponds to a horizontal line passing over the upper end of the tire of the rear wheel 4 in a side view. The second straight line L2 corresponds to a horizontal line passing over the upper end of the cylinder 42 of the engine E in a side view. The third straight line L3 corresponds to a vertical line passing over the front end of the cylinder 42 of the engine E in a side view. The fourth straight line L4 corresponds to a vertical line passing over the rear end of the crankcase 41 of the engine E in a side view. In the example of Figure 5, the lower end side of the surge tank 80 is located within region SA.

[0068] At least a portion of each of the surge tank 80, the supercharger 70, and the air cleaner 60 is positioned between the left and right main frames 22 in a top view. For example, it is preferable that the entirety of the surge tank 80, the supercharger 70, and the air cleaner 60 is positioned inside the outer edges of the left and right main frames 22 in the vehicle width direction in a top view, and more preferably inside the inner edges of the left and right main frames 22 in the vehicle width direction in a top view. In the example of Figure 3, the entirety of the surge tank 80, the entirety of the supercharger 70, and the entirety of the air cleaner 60 are positioned inside the outer edges of the left and right main frames 22 in the vehicle width direction in a top view.

[0069] The surge tank 80, supercharger 70, and air cleaner 60 are located behind the head pipe 21. At least a portion of each of the surge tank 80 and supercharger 70 is located behind the third straight line L3 and in front of the fourth straight line L4 in a side view. In the example of Figure 5, the entire surge tank 80, supercharger 70, and air cleaner 60 are located behind the third straight line L3 and in front of the fourth straight line L4 in a side view. Note that the front-to-rear orientation of the air cleaner 60 (the front-to-rear positional relationship between the dirty side 64 and the clean side 63) is not limited to the above and can be changed according to the design specifications.

[0070] At least a portion of the surge tank 80 overlaps with the main frame 22 in a side view. In the example shown in Figure 5, the front of the tank body 81 and the rear of the recess 83 of the surge tank 80 are positioned to overlap with the front portion 22a of the main frame 22 in a side view.

[0071] <Effects> As described above, the motorcycle 1 of the above embodiment includes an engine E having a cylinder block 42a protruding diagonally forward and upward from the crankcase 41, an air cleaner 60 that filters the intake air to the engine E, a supercharger 70 having an electric motor 75 as a drive source that takes in air from the air cleaner 60, compresses the air and supplies it to the engine E, and a surge tank 80 into which supercharged intake air is introduced from the supercharger 70. The surge tank 80 is located above the cylinder block 42a. The supercharger 70 is located above the surge tank 80. The air cleaner 60 is located behind the supercharger 70. With this configuration, by electrifying the supercharger 70, it is no longer necessary to obtain driving force for the supercharger 70 from the exhaust system or drive shaft of the engine E, and the degree of freedom in the placement of the supercharger 70 can be increased. The increased flexibility in the placement of the turbocharger 70 makes it possible to position the surge tank 80, turbocharger 70, and air cleaner 60 in close proximity to each other. This reduces pressure loss in the intake system, thereby improving energy efficiency and responsiveness. Furthermore, by positioning the turbocharger 70 above the surge tank 80, the turbocharger 70 and the surge tank 80 are linearly connected by a connecting pipe (discharge pipe 74) extending vertically, allowing for efficient introduction of supercharged intake air from the turbocharger 70 to the surge tank 80. Additionally, linearly connecting the turbocharger 70 and the surge tank 80 in the vertical direction shortens the connecting pipe, reducing weight and cost, while also suppressing supercharger pressure loss.

[0072] In the above embodiment, at least a portion of the surge tank 80 is located in a region SA enclosed by a first straight line L1 passing over the upper end of the rear wheel 4 and extending in the longitudinal direction, a second straight line L2 passing over the upper end of the engine E and extending in the longitudinal direction, a third straight line L3 passing over the front end of the engine E and extending in the vertical direction, and a fourth straight line L4 passing over the rear end of the engine E and extending in the vertical direction, in a side view. At least a portion of each of the surge tank 80 and the supercharger 70 is located behind the third straight line L3 and in front of the fourth straight line L4, in a side view. With this configuration, the surge tank 80 and the supercharger 70 can be compactly arranged together in the region SA enclosed by the straight lines L1 to L4 and the region sandwiched between the third straight line L3 and the fourth straight line L4, in a side view.

[0073] In the above embodiment, the vehicle body frame 20 includes a head pipe 21 at the front supporting the front wheel suspension components 10, and a pair of left and right main frames 22 that branch off from the head pipe 21 and extend to the rear. At least a portion of each of the surge tank 80, supercharger 70, and air cleaner 60 is positioned between the left and right main frames 22 in a top view. With this configuration, the surge tank 80, supercharger 70, and air cleaner 60 can be compactly arranged together between the left and right main frames 22 in a top view.

[0074] In the above embodiment, the surge tank 80, supercharger 70, and air cleaner 60 are located behind the head pipe 21. With this configuration, the head pipe 21 can protect the surge tank 80, supercharger 70, and air cleaner 60 from external factors from the front of the vehicle.

[0075] In the above embodiment, at least a portion of the surge tank 80 overlaps with the main frame 22 in a side view. With this configuration, the main frame 22 can protect the surge tank 80 from external factors from the side of the vehicle.

[0076] <Second Embodiment> In the first embodiment, an example was given in which the air cleaner 60 is located behind the supercharger 70, but the embodiment is not limited to this. As shown in Figures 7 to 10, the second embodiment differs from the first embodiment in that the air cleaner 60 is located in front of the supercharger 70. In the following description, components similar to those in the first embodiment are denoted by the same reference numerals and detailed descriptions are omitted.

[0077] Figure 7 is a perspective view showing the arrangement of the surge tank 80, turbocharger 70, and air cleaner 60 according to the second embodiment. Figure 8 is a top view showing the arrangement as indicated by arrow VIII in Figure 7. Figure 9 is a front view showing the arrangement as indicated by arrow IX in Figure 7. Figure 10 is a left side view showing the arrangement as indicated by arrow X in Figure 7. Referring to Figures 7 to 10 together, in the second embodiment, the arrangement of the air cleaner 60 and turbocharger 70 in a side view is reversed front to back compared to the first embodiment.

[0078] In the supercharger 70, a suction pipe 65 extends from the suction port 71a of the blower case 71, forming a suction passage T toward the outside and forward in the vehicle width direction. The suction pipe 65 is connected from the rear to the clean side 63 of the air cleaner 60. The central axis C73 of the discharge duct 73 is inclined downward and backward in the vertical direction when viewed from the side.

[0079] In the second embodiment, the connection relationship of each intake pipe to the upper wall of the tank body 81 in the surge tank 80 is reversed compared to the first embodiment. The lower end of the discharge pipe 74 (first intake pipe) extending from the discharge duct 73 is connected to the rear side of the upper wall of the tank body 81. The lower end of the second intake pipe 66 extending from the air cleaner 60 is connected to the front side of the upper wall of the tank body 81.

[0080] At least a portion of the surge tank 80 is located in a region SA enclosed by straight lines L1 to L4 in a side view. In the example of Figure 10, the lower end side of the surge tank 80 is located within region SA.

[0081] At least a portion of each of the surge tank 80 and the air cleaner 60 is positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. In the example of Figure 10, the entire surge tank 80, supercharger 70, and air cleaner 60 are positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. Note that the front-to-rear orientation of the air cleaner 60 (the front-to-rear positional relationship between the dirty side 64 and the clean side 63) is not limited to the above and can be changed according to the design specifications.

[0082] In the second embodiment, the air cleaner 60 is positioned in front of the supercharger 70. At least a portion of the surge tank 80 is positioned in a region SA enclosed by a first straight line L1 passing over the upper end of the rear wheel 4 and extending in the longitudinal direction, a second straight line L2 passing over the upper end of the engine E and extending in the longitudinal direction, a third straight line L3 passing over the front end of the engine E and extending in the vertical direction, and a fourth straight line L4 passing over the rear end of the engine E and extending in the vertical direction, in a side view. At least a portion of each of the surge tank 80 and the air cleaner 60 is positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. With this configuration, the surge tank 80 and the air cleaner 60 can be compactly arranged together in the region SA enclosed by the straight lines L1 to L4 and the region sandwiched between the third straight line L3 and the fourth straight line L4 in a side view.

[0083] <Third Embodiment> In the first embodiment, an example was given in which the surge tank 80 is located above the cylinder block 42a, but the embodiment is not limited to this. As shown in Figure 11, the third embodiment differs from the first embodiment in that the surge tank 80 is located above and behind the cylinder block 42a. In the following description, components similar to those in the first embodiment are denoted by the same reference numerals and detailed descriptions are omitted.

[0084] Figure 11 is a left side view showing the arrangement of the surge tank 80, supercharger 70, and air cleaner 60 according to the third embodiment. Referring to Figure 11, in the third embodiment, the surge tank 80 is located above and behind the cylinder block 42a. In a side view, the surge tank 80 extends in the front-rear direction from near the third straight line L3 to near the rear cross pipe 30 of the fourth straight line L4.

[0085] At least a portion of each of the surge tank 80, the supercharger 70, and the air cleaner 60 is positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. At least a portion of the surge tank 80 is positioned in the region SA enclosed by straight lines L1 to L4. In the example of Figure 11, the upper and lower middle portion of the surge tank 80 is positioned within region SA. The portion of the surge tank 80 other than the rear end, the entire supercharger 70, and the front part of the air cleaner 60 are positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. Note that the front-to-rear orientation of the air cleaner 60 (the front-to-rear positional relationship between the dirty side 64 and the clean side 63) is not limited to the above and can be changed according to the design specifications.

[0086] In the third embodiment, the surge tank 80 is positioned above and behind the cylinder block 42a. At least a portion of each of the surge tank 80, the supercharger 70, and the air cleaner 60 is positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. With this configuration, the surge tank 80, the supercharger 70, and the air cleaner 60 can be compactly arranged together in the region between the third straight line L3 and the fourth straight line L4 in a side view.

[0087] <Fourth Embodiment> In the second embodiment, an example was given in which the surge tank 80 is located above the cylinder block 42a, but the embodiment is not limited to this. As shown in Figure 12, the fourth embodiment differs from the second embodiment described above in that the surge tank 80 is located above and behind the cylinder block 42a. In the following description, components similar to those in the second embodiment described above are denoted by the same reference numerals and detailed descriptions are omitted.

[0088] Figure 12 is a left side view showing the arrangement of the surge tank 80, supercharger 70, and air cleaner 60 according to the fourth embodiment. Referring to Figure 12, in the fourth embodiment, the surge tank 80 is located above and behind the cylinder block 42a. In a side view, the surge tank 80 extends in the front-rear direction from near the third straight line L3 to near the cross pipe 30 at the rear of the fourth straight line L4.

[0089] At least a portion of each of the surge tank 80 and the air cleaner 60 is positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. At least a portion of the surge tank 80 is positioned in the region SA enclosed by straight lines L1 to L4. In the example in Figure 12, the upper and lower middle portion of the surge tank 80 is positioned within region SA. The portion of the surge tank 80 other than the rear end and the entire air cleaner 60 are positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. Note that the front-to-rear orientation of the air cleaner 60 (the front-to-rear positional relationship between the dirty side 64 and the clean side 63) is not limited to the above and can be changed according to the design specifications.

[0090] In the fourth embodiment, the surge tank 80 is positioned above and behind the cylinder block 42a. At least a portion of each of the surge tank 80 and the air cleaner 60 is positioned behind the third straight line L3 and in front of the fourth straight line L4 in a side view. With this configuration, the surge tank 80 and the air cleaner 60 can be compactly arranged together in the region between the third straight line L3 and the fourth straight line L4 in a side view.

[0091] <Modification> In the above embodiment, an example was given in which at least a part of the surge tank overlaps with the main frame in a side view, but the embodiment is not limited to this. For example, the entire surge tank may be positioned to avoid the main frame in a side view. The manner in which the surge tank overlaps with the main frame in a side view can be changed according to the design specifications.

[0092] In the above embodiment, an example of a multi-cylinder engine was given, but the invention is not limited to this. For example, the engine may be a single-cylinder engine. The configuration of the engine can be changed according to the design specifications.

[0093] In the above embodiments, a motorcycle was given as an example of a saddle-type vehicle, but the invention is not limited to this. For example, the present invention may be applied to saddle-type vehicles other than motorcycles. For example, saddle-type vehicles include all vehicles on which the driver straddles the vehicle body, and include 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). Furthermore, the present invention is applicable not only to motorcycles but also to four-wheeled vehicles such as automobiles (four-wheeled buggies, etc.). Furthermore, the present invention may be applied to saddle-type vehicles that include an electric motor as the prime mover. Furthermore, the present invention may be applied to various types of reciprocating engines, such as single-cylinder engines, parallel or V-type multi-cylinder engines, and longitudinally mounted engines with the crankshaft aligned along the front-rear direction of the vehicle. The configuration in the above embodiments is an example of the present invention, and various modifications are possible without departing from the gist of the invention, such as replacing the components of the embodiments with well-known components.

[0094] 1 Motorcycle (saddle-type vehicle) 10 Front suspension components 20 Body frame (body) 21 Head pipe 22 Main frame 41 Crankcase 42a Cylinder block 60 Air cleaner 70 Supercharger 75 Electric motor 80 Surge tank E Engine L1 First straight line L2 Second straight line L3 Third straight line L4 Fourth straight line SA Area

Claims

1. A saddle-type vehicle comprising: an engine (E) having a cylinder block (42a) protruding diagonally forward and upward from a crankcase (41); an air cleaner (60) for filtering intake air to the engine (E); a supercharger (70) having an electric motor (75) as a drive source, which takes in air from the air cleaner (60), compresses the air, and supplies it to the engine (E); and a surge tank (80) into which supercharged intake air is introduced from the supercharger (70), wherein the surge tank (80) is positioned above or rear-upper of the cylinder block (42a), the supercharger (70) is positioned above the surge tank (80), and the air cleaner (60) is positioned in front of or behind the supercharger (70).

2. The saddle-type vehicle according to claim 1, wherein the surge tank (80) is positioned above the cylinder block (42a), the air cleaner (60) is positioned behind the supercharger (70), at least a portion of the surge tank (80) is positioned in a region (SA) enclosed by a first straight line (L1) passing over the upper end of the rear wheel (4) and extending in the longitudinal direction, a second straight line (L2) passing over the upper end of the engine (E) and extending in the longitudinal direction, a third straight line (L3) passing over the front end of the engine (E) and extending in the vertical direction, and a fourth straight line (L4) passing over the rear end of the engine (E) and extending in the vertical direction, and at least a portion of the surge tank (80) and the supercharger (70) are positioned behind the third straight line (L3) and in front of the fourth straight line (L4) in the side view.

3. The saddle-type vehicle according to claim 1, wherein the surge tank (80) is positioned above the cylinder block (42a), the air cleaner (60) is positioned in front of the supercharger (70), at least a portion of the surge tank (80) is positioned in a region (SA) enclosed by a first straight line (L1) passing over the upper end of the rear wheel (4) and extending in the longitudinal direction, a second straight line (L2) passing over the upper end of the engine (E) and extending in the longitudinal direction, a third straight line (L3) passing over the front end of the engine (E) and extending in the vertical direction, and a fourth straight line (L4) passing over the rear end of the engine (E) and extending in the vertical direction, and at least a portion of each of the surge tank (80) and the air cleaner (60) is positioned behind the third straight line (L3) and in front of the fourth straight line (L4) in the side view.

4. A saddle-type vehicle according to any one of claims 1 to 3, further comprising a head pipe (21) supporting a front wheel suspension component (10) at the front of the vehicle body (20), and a pair of left and right main frames (22) branching off from the head pipe (21) to the left and right and extending to the rear, wherein at least a portion of each of the surge tank (80), the supercharger (70), and the air cleaner (60) is positioned between the pair of left and right main frames (22) in a top view.

5. The saddle-type vehicle according to claim 4, wherein the surge tank (80), the supercharger (70), and the air cleaner (60) are located behind the head pipe (21).

6. The saddle-type vehicle according to claim 4, wherein at least a portion of the surge tank (80) overlaps with the main frame (22) in a side view.

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