Saddle-type vehicle

Abstract

The present invention provides a saddle-type vehicle that can construct an intake system, including a supercharger used in an internal combustion engine, with a small number of parts. [Solution] A saddle-type vehicle comprising an engine, a supercharger 50 that compresses and supplies air to the engine, and a surge tank 60 into which supercharged intake air is introduced from the supercharger 50, wherein the vehicle comprises a first intake passage (discharge passage) T1 extending from the supercharger 50 and connected to the surge tank 60, and a second intake passage T2 provided separately from the first intake passage T1 and connected to the surge tank 60 without going through the supercharger 50.

Description

Technical Field

[0001] The present invention relates to a saddle-type vehicle.

Background Art

[0002] Conventionally, a turbocharger that utilizes the exhaust energy of an engine and a supercharger that utilizes a part of the driving force of an engine are known as superchargers used for an engine (internal combustion engine) of a vehicle. In recent years, an electric charger that uses an electric motor to drive a supercharger is known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a saddle-type vehicle such as a motorcycle, the component arrangement space is limited compared to a four-wheeled vehicle. When the number of components is increased, the supporting members also increase, so there is a problem that the component arrangement space is further suppressed.

[0005] Therefore, the present invention provides a saddle-type vehicle capable of configuring an intake system including a supercharger used for an internal combustion engine with a small number of components.

Means for Solving the Problems

[0006] As a means of solving the above problems, a first aspect of the present invention is a saddle-type vehicle (1) comprising an internal combustion engine (E), a supercharger (50) that compresses and supplies air to the internal combustion engine (E), and a surge tank (60) into which supercharged intake air is introduced from the supercharger (50), the vehicle comprising a first intake passage (T1) extending from the supercharger (50) and connected to the surge tank (60), and a second intake passage (T2) provided separately from the first intake passage (T1) and connected to the surge tank (60) without going through the supercharger (50). In this configuration, in addition to the first intake passage for turbocharged intake extending from the turbocharger, there is a second intake passage for naturally aspirated air that connects to the surge tank without going through the turbocharger, so that both turbocharged and naturally aspirated air are introduced into a common surge tank. By receiving both intake systems into a common surge tank, the number of parts in the intake system, including the turbocharger, can be reduced, and intake capacity can be secured by the surge tank even in naturally aspirated air, thereby improving intake efficiency (the ratio of the amount of intake air to the change in volume inside the cylinder).

[0007] A second aspect of the present invention, in the first aspect described above, comprises a head portion (6) supporting a front wheel suspension component (3A) at the front of the vehicle body (5B), and a pair of left and right frame portions (7) branching off from the head portion (6) and extending to the rear, wherein the surge tank (60) is positioned between the left and right frame portions (7) in a top view. This configuration allows the surge tank to be positioned between the left and right frame sections, ensuring sufficient capacity while minimizing the overall size increase of the vehicle compared to when the surge tank is positioned outside the left and right frame sections.

[0008] A third aspect of the present invention is that, in the first or second aspect described above, the surge tank (60) comprises a first connection part (62) for connecting the first intake passage (T1) and a second connection part (64) for connecting the second intake passage (T2), wherein both the first connection part (62) and the second connection part (64) are arranged on one side in the left-right direction with respect to the left-right center (CL) of the vehicle body. This configuration allows the connection points of the first and second intake passages in the surge tank to be located together on one side of the vehicle body, making both connection points accessible from that side, thereby improving manufacturability and maintainability.

[0009] A fourth aspect of the present invention is that, in any one of the first to third aspects described above, the first intake passage (T1) and the second intake passage (T2) are arranged such that their central axes (C8, C9) extending inward from the surge tank (60) intersect each other at an acute angle in a top view. This configuration, by arranging the central axes of the first and second intake passages to form acute angles with each other, prevents the supercharged intake air and naturally aspirated air introduced into the surge tank from each intake passage from flowing in opposite directions. This suppresses the generation of turbulence within the surge tank and prevents backflow of intake air from one of the first and second intake passages to the other, thereby improving intake efficiency.

[0010] A fifth aspect of the present invention is that, in any one of the first to fourth aspects described above, the surge tank (60) comprises a first connecting portion (62) for connecting the first intake passage (T1) and a second connecting portion (64) for connecting the second intake passage (T2), wherein the second connecting portion (64) is positioned above the first connecting portion (62), and the intake passage member (47) forming at least a part of the second intake passage (T2) comprises an outer positioning portion (47a) positioned on the outside in the vehicle width direction of the frame portion (7) of the vehicle body (5B), and an inner positioning portion (47b) that is connected to the rear of the outer positioning portion (47a), straddles the top of the frame portion (7) and reaches the inside in the vehicle width direction, and is connected to the second connecting portion (64). With this configuration, the intake passage member that forms a second intake passage without a supercharger is extended from the outside in the vehicle width direction of the frame to the inside in the vehicle width direction, straddling the top of the frame, thereby securing the length of the second intake passage that guides naturally occurring air, and increasing the degree of freedom in setting the intake characteristics.

[0011] A sixth aspect of the present invention is that, in any one of the first to fifth aspects described above, the internal combustion engine (E) comprises a plurality of cylinders, the surge tank (60) is provided with a plurality of funnels (33F, 34F) connected to each cylinder of the internal combustion engine (E), the supercharger (50) comprises a discharge port (53a) for discharging the drawn-in air, and the intake ports (33fa, 34fa) of the plurality of funnels (33F, 34F) open while avoiding the extension region (T1ex) of the first intake passage (T1) into the inside of the surge tank (60). With this configuration, by opening the intake port of the funnel while avoiding the extended region of the first intake passage extending from the turbocharger's discharge port, it becomes difficult for the turbocharged intake air discharged from the first intake passage to the surge tank to be directly introduced into the intake port of the funnel. This allows the turbocharged intake air to diffuse well within the surge tank, making it easier to equalize the introduction of intake air to multiple funnels and enabling stable combustion of the internal combustion engine.

[0012] A seventh aspect of the present invention is, in the sixth aspect described above, a throttle device (35) and a fuel injector (35a) are provided between the funnel (33F) and the cylinder (33) of the internal combustion engine (E), and the throttle device (35) is positioned between the first intake passage (T1) and the fuel injector (35a) in the longitudinal direction of the vehicle. With this configuration, by arranging the throttle device between the first intake passage and the fuel injector in the longitudinal direction of the vehicle, it becomes easier to secure space for the first intake passage and the fuel injector compared to when the first intake passage and the fuel injector are arranged on the same side of the throttle device. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a saddle-type vehicle in which the intake system, including a supercharger used in an internal combustion engine, can be constructed with a small number of parts. [Brief explanation of the drawing]

[0014] [Figure 1]Right side view of a motorcycle in an embodiment of the present invention. [Figure 2] Top view of the above motorcycle. [Figure 3] Front view of the above motorcycle. [Figure 4] Right side view of the periphery of the front frame of the above motorcycle. [Figure 5] Right side view in a state where the air cleaner device and the top cover are removed from FIG. 4. [Figure 6] Right side view showing the front frame by a dashed line with respect to FIG. 5. [Figure 7] Cross-sectional view along a plane orthogonal to the vehicle width direction in the vicinity of the supercharger inside the above front frame. [Figure 8] Top view in a state where the top cover around the above front frame is removed. [Figure 9] Top view in a state where some parts are removed with respect to FIG. 8. <00000八十六> [Figure 10] Cross-sectional view along a horizontal plane at the center axis height of the above supercharger. [Figure 11] Cross-sectional view along a plane orthogonal to the vehicle longitudinal direction in the vicinity of the bulge of the surge tank connecting the above supercharger. [Figure 12] Cross-sectional view of FIG. 7 as viewed from the opposite side in the vehicle width direction. [Figure 13] Top view showing the angle formed by the first intake passage and the second intake passage with respect to FIG. 9. [Figure 14] Explanatory view showing an overview of the intake system of the above motorcycle.

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the directions such as front, rear, left, and right are the same as those in the vehicle described below unless otherwise specified. Also, in the drawings used in the following description, at appropriate positions, an arrow FR indicating the vehicle front, an arrow LH indicating the vehicle left, an arrow UP indicating the vehicle upper, and a line CL indicating the vehicle left-right center are shown. In this embodiment, "intermediate" means not only the center between the two ends of the object, but also the area inside the space between the two ends of the object. In the following description, it is assumed that the saddle-type vehicle is stationary in an upright position with no tilt to the left or right and a steering angle of 0 degrees, and furthermore, it is in an unloaded state of 1G on a horizontal plane.

[0016] <Entire vehicle> Figures 1 to 3 show motorcycle 1 as an example of a saddle-type vehicle. Figure 1 is a right side view of motorcycle 1, Figure 2 is a top view (plan view) of motorcycle 1, and Figure 3 is a front view (front perspective) of motorcycle 1. As shown in Figures 1 to 3, the motorcycle 1 comprises a front wheel 2 steered by a handle 2a and a rear wheel 12 driven by a power unit PU including a V-type engine (internal combustion engine) E.

[0017] The front suspension component 3A, which supports the front wheel 2, is steerably supported by the head pipe (head section) 6 located at the front end of the vehicle frame 5. The handlebars 2a and the front suspension component 3A are steerably supported by the head pipe 6. The head pipe 6 is cylindrical in shape and tilted backward with respect to the vertical. The front suspension component 3A comprises a pair of left and right front forks 3, and a top bridge 4a and a bottom bridge 4b ​​connecting the upper parts of the left and right front forks 3. A bar-type handlebar 2a is mounted on the top bridge 4a.

[0018] The motorcycle 1 of this embodiment is equipped with a telescopic front fork 3 as the front suspension, but is not limited to this configuration. 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 5 may be equipped with a head section with a configuration that replaces the head pipe 6, depending on the type of front suspension.

[0019] A power unit PU is mounted in the front-to-rear center of the vehicle frame 5. For example, the front end of a swing arm 11 is supported at the rear of the power unit PU so as to be able to swing up and down around a pivot axis 8a. For example, a rear suspension (not shown) is configured between the front of the swing arm 11 and the rear of the power unit PU.

[0020] For example, the vehicle frame 5 is formed by integrally joining multiple types of steel materials by welding or other means. The vehicle frame 5 comprises a pair of left and right main frames 7 that extend from the head pipe 6 downward and rearward to the left and right, and a pair of left and right seat rails 9 whose front ends are joined to the rear ends of the left and right main frames 7, and which extend downward and rearward from the front ends.

[0021] For example, the vehicle frame 5 is divided into a front frame 14, which includes the head pipe 6 and left and right main frames 7, and a rear frame 19, which includes left and right seat rails 9. The rear end of the front frame 14 and the front end of the rear frame 19 are connected to each other by fastening members such as bolts B1 and B2 that run along the vehicle width direction (vehicle left-right direction). The front frame 14 and the rear frame 19, including the body of the power unit PU, constitute an integrated vehicle body 5B.

[0022] In this embodiment, the vehicle body 5B refers to a portion of the entire vehicle body that is substantially integrated and does not include any movable parts (such as suspension). The vehicle body 5B may include components other than the vehicle frame 5. For example, the pivot portion 8 that supports the front end of the swing arm 11 in this embodiment is provided at the rear end of the body of the power unit PU. For example, the vehicle body 5B may include an integrated vehicle frame from the front wheel suspension portion (head portion) to the rear wheel suspension portion (pivot portion). Furthermore, the vehicle body 5B may include an integrated vehicle frame up to the seat rail 9.

[0023] The power unit PU is located from below the front frame 14 to the front lower part of the rear frame 19. The power unit PU integrates a V-type multi-cylinder engine E with the crank axis aligned in the left-right direction, and a transmission (not shown) that changes the speed of the engine E's driving force and outputs it. Engine E comprises a crankcase 32 housing a crankshaft (not shown), and front and rear cylinders 33 and 34 that stand upright above the crankcase 32 and are arranged in a V-shape when viewed from the side. The rear of the crankcase 32 is a transmission case housing the transmission.

[0024] The front cylinder 33 protrudes diagonally upward and forward of the crankcase 32, extending its cylinder axis C3 diagonally. The rear cylinder 34 protrudes diagonally upward and rear of the crankcase 32, extending its cylinder axis C4 diagonally. For example, engine E is a three-cylinder engine having two cylinders in the front cylinder 33 and one cylinder in the rear cylinder 34, but is not limited to this. For example, engine E may be a two-cylinder engine having one cylinder each in the front and rear cylinders 33 and 34, a four-cylinder engine having two cylinders each in the front and rear cylinders 33 and 34, a five-cylinder engine having three cylinders in the front cylinder 33 and two cylinders in the rear cylinder 34, or a six-cylinder engine having three cylinders each in the front and rear cylinders 33 and 34.

[0025] Two front intake ports (not shown) for two cylinders are formed on the rear upper surface of the cylinder head of the front cylinder 33. One rear intake port (not shown) for one cylinder is formed on the upper front surface of the cylinder head of the rear cylinder 34. Hereinafter, the triangular region sandwiched between the rear upper surface of the front cylinder 33 and the front upper surface of the rear cylinder 34 in a side view will be referred to as the inter-cylinder region R1.

[0026] Multiple throttle bodies 35, 36 (see Figures 7 and 12) are connected to the front and rear intake ports to adjust the intake air volume for each cylinder. Each of the multiple throttle bodies 35, 36 is independently provided for each cylinder. The multiple throttle bodies 35, 36 are arranged so that they are entirely located in the inter-cylinder region R1 above the crankcase 32. The multiple throttle bodies 35, 36 may partially extend above the inter-cylinder region R1. The downstream end (lower end) of each throttle body 35, 36 is connected to the front and rear intake ports, respectively.

[0027] The intake port of the front cylinder 33 and the throttle body 35 connected thereto form a linear intake passage that is inclined so that the upper part is located further rearward in a side view (see Figures 7 and 12). Although not shown, the intake port of the rear cylinder 34 and the throttle body 36 connected thereto form a linear intake passage that is inclined so that the upper part is located further forward in a side view. The upper ends (upstream ends) of each throttle body 35, 36 are connected to a surge tank 60, which will be described later, located above the inter-cylinder region R1.

[0028] Two front exhaust ports (not shown) for two cylinders are formed on the front lower surface of the cylinder head of the front cylinder 33. One rear exhaust port (not shown) for one cylinder is formed on the rear lower surface of the cylinder head of the rear cylinder 34. Multiple exhaust pipes 37 and 38 are connected to the front and rear exhaust ports to guide the exhaust from each cylinder. The multiple exhaust pipes 37 and 38 are routed below the crankcase 32, converge as appropriate, and are connected to an exhaust muffler 39 located on the rear side of the vehicle body.

[0029] Figures 4 to 6 are side views of the area around the front frame 14 of motorcycle 1. Referring to Figures 4 to 6, a fuel tank (not shown) for storing fuel for engine E is located above the surge tank 60. The fuel tank is positioned to cover the surge tank 60 from above. In front of the surge tank 60 are a canister 22 and various electrical components 23. Reference numeral 23a in the figures indicates the ABS modulator. The fuel tank, surge tank 60, canister 22, and electrical components 23 are covered by a container-shaped top cover 24 that opens downwards. A seat 25 for the occupant is located behind the top cover 24 and above the rear frame 19. A rear seat cowl 26 is attached to the rear of the rear frame 19.

[0030] <Front frame 14> Figures 8 to 10 are plan views of the area around the front frame 14 of motorcycle 1. Referring to Figures 4 to 6 and Figures 8 to 10, the front frame 14 comprises a head pipe 6 that is tilted backward with respect to the vertical direction of the vehicle, and a pair of left and right main frames 7 that branch off from the head pipe 6 to the left and right and extend rearward. Each main frame 7 includes an upper pipe 15 extending rearward from the top of the head pipe 6, a lower pipe 16 extending rearward from the bottom of the head pipe 6, and a connecting pipe 17 spanning between the upper pipe 15 and the lower pipe 16.

[0031] The upper pipe 15 extends from the top of the head pipe 6, sloping downwards towards the rear. The upper pipe 15 includes a first extension 15a that extends diagonally outward towards the rear and in the left-right direction, and a second extension 15b that curves rearward from the rear end of the first extension 15a and extends along the side of the vehicle body (the side perpendicular to the vehicle width direction). Reference numeral 15c in the figure indicates the curved portion between the first extension 15a and the second extension 15b. The rear end of the upper pipe 15 is located near the front upper surface of the rear cylinder 34 and is fixed to the rear cylinder 34 by bolts B1 or the like that run along the left-right direction. The rear end of the upper pipe 15 is close to the upper front end of the rear frame 19, and these are connected via a connecting plate 19a.

[0032] The lower pipe 16 extends from the lower part of the head pipe 6 towards the rear, sloping more steeply and downwards towards the rear than the upper pipe 15. The upper pipe 15 has a first extension 16a that extends diagonally towards the rear and outward in the left-right direction, and a second extension 16b that curves towards the rear from the rear end of the first extension 16a and extends along the side of the vehicle body (the side perpendicular to the vehicle width direction). Reference numeral 16c in the figure indicates the curved portion between the first extension 16a and the second extension 16b. The curved portion 16c of the lower pipe 16 is located forward of the curved portion 15c of the upper pipe 15. The rear end of the lower pipe 16 is located near the front lower surface of the front cylinder 33 (see Figure 1) and is fixed to the front cylinder 33 by bolts B2 or the like that running along the left-right direction.

[0033] The connecting pipe 17 comprises a first connecting pipe 17a that spans between the first extensions 15a and 16a of the upper and lower pipes 15 and 16, a second connecting pipe 17b that spans between the curved portion 15c of the upper pipe 15 and the rear end of the lower pipe 16, and a third connecting pipe 17c that spans between the curved portion 16c of the lower pipe 16 and the rear end of the upper pipe 15 and extends in the front-rear direction. The middle portion of the third connecting pipe 17c is connected to the second connecting pipe 17b by intersecting it. The third connecting pipe 17c may be composed of two members that are divided at the front and rear of the second connecting pipe 17b.

[0034] The truss structure of the main frame 7 is formed by connecting the upper and lower pipes with connecting pipes 17. In a side view, the main frame 7 has an opening region R2 enclosed by the upper pipe 15, the upper part of the first connecting pipe 17a, the upper part of the second connecting pipe 17b, and the front part of the third connecting pipe 17c. In a side view of the right main frame 7, a suction passage T to the supercharger 50, which will be described later, is located in the opening region R2.

[0035] Now, referring to Figure 14, we will describe the overview of the intake system of engine E in motorcycle 1. The intake system of this embodiment includes an air cleaner device 40, a supercharger 50, and a surge tank 60. The air cleaner device 40 is connected to the supercharger 50 via a suction pipe 45 that forms an intake passage T. The supercharger 50 is connected to the surge tank 60 via a discharge pipe (first intake pipe) 54 that forms a discharge passage (first intake passage) T1. The surge tank 60 is connected to the intake port of the engine E via throttle bodies 35, 36 and injectors 35a, 36a. The surge tank 60 is also connected to the air cleaner device 40 via a second intake pipe 47 that forms a second intake passage T2, allowing intake without going through the supercharger 50.

[0036] <Air cleaner device 40> Referring to Figures 4 to 6 and Figures 8 to 10, an air cleaner device 40 for filtering the intake air to the engine E is located on the right front of the vehicle body. The air cleaner device 40 has a flattened shape with reduced dimensions in the vehicle width direction (thickness direction). The air cleaner device 40 has a rectangular shape in side view and is provided in a size that covers the front of the front frame 14 (the part in front of the rear end of the opening area R2) from the outside in the vehicle width direction. In the vertical direction, the air cleaner device 40 is positioned at a height that overlaps with the entire head pipe 6, and in the front-to-rear direction, it straddles the head pipe 6 front to back and is positioned to overlap with the front of the main frame 7.

[0037] The air cleaner device 40 comprises a case body 41 that forms its exterior and an element 42 supported inside the case body 41. The front end of the case body 41 is an air intake port 41a that opens toward the front of the vehicle, allowing airflow from the front of the vehicle to be introduced into the case. The element 42 is supported inside the front-to-rear intermediate section of the case body 41. The internal space of the case body 41 is divided into a dirty side 42a in front of the element 42 (towards the intake port 41a) and a clean side 42b behind the element 42.

[0038] On the front inner side of the case body 41, an opposing plate 43 is supported, facing the intake port 41a from the rear. The opposing plate 43 functions as a baffle plate to prevent the airflow taken into the case body 41 from the intake port 41a from colliding with the element 42. The airflow taken into the case body 41 is filtered by passing through the element 42, and then either drawn into the supercharger 50 through the intake passage T, or introduced into the surge tank 60 through a second intake passage T2 that bypasses the supercharger 50. Even when the airflow is introduced into the surge tank 60 without going through the supercharger 50, supercharging by ram pressure is possible because the intake port 41a opens towards the front of the vehicle.

[0039] In the figure, reference numeral 44 denotes a first opening that opens inward in the vehicle width direction at the inner wall portion of the case body 41 on the inner side in the vehicle width direction and communicates with the suction passage T; reference numeral 45 denotes a suction pipe that connects the first opening 44 to the suction port 52a of the supercharger 50 and forms the suction passage T inside; reference numeral 46 denotes a second opening that opens to the rear of the vehicle at the rear end of the case body 41 and communicates with the second intake passage T2; and reference numeral 47 denotes a second intake pipe that connects the second opening 46 to the second opening 64a of the surge tank 60 and forms the second intake passage T2 inside.

[0040] <Supercharger 50> Figure 7 is a cross-sectional view of the area around the supercharger 50. Referring to Figures 4 to 10, the supercharger 50 compresses the air taken in from the air cleaner device 40 and supplies it to the engine E. The supercharger 50 is a so-called blower fan, and by the rotation of a fan body (impeller) (not shown), it draws in air from the axial direction and discharges this air in a direction perpendicular to the axial direction (tangential direction). The supercharger 50 is located in the interframe region R3 of the front frame 14, which is surrounded on three sides by the head pipe 6 and the left and right main frames 7. In the vertical direction, the supercharger 50 is positioned at a height that overlaps with the front of the head pipe 6 and the main frame 7, and in the front-rear direction, it is located behind the head pipe 6 and overlaps with the front of the main frame 7.

[0041] The supercharger 50 comprises the fan body, a blower case 51 housing the fan body, and an electric motor 55 that drives the fan body. The supercharger 50 is an electric device that is driven by the driving force of the electric motor 55, without using the exhaust energy or driving force of the engine E. The supercharger 50 is positioned with its axial direction (the axial direction of the fan body) in the direction of the vehicle width. Line C6 in the figure indicates the central axis along the axial direction of the supercharger 50. In this embodiment, the axial direction (central axis C6) of the supercharger 50 is substantially parallel to the vehicle width direction, but it may be perfectly parallel, or it may be more inclined with respect to the vehicle width direction.

[0042] The blower case 51 has an annular portion 52 coaxial with the fan body, and a circular suction port 52a is opened on one axial side (right side) of the annular portion 52, with the axis C6 at its center. A cylindrical electric motor 55, coaxial with the annular portion 52, is integrally mounted on the other axial side (left side) of the annular portion 52. A rectangular drive control unit 56 is integrally provided on the upper surface of the electric motor 55.

[0043] The annular portion 52 of the blower case 51 is located to the right of the vehicle body's left-right center CL in a plan view, and its suction port 52a opens to the right (outward in the vehicle width direction). An electric motor 55 is located on the left side of the blower case 51 (towards the vehicle body's left-right center CL). The electric motor 55 is a rotating electric machine with a central axis C6 as its drive center, and it outputs rotational power to drive the fan body. The electric motor 55 protrudes to the left of the vehicle body's left-right center CL. The drive of the electric motor 55, and consequently the drive of the supercharger 50, is controlled by an electronic control device (not shown). The electronic control device appropriately drives the supercharger 50 according to, for example, the operating status of the engine E, the vehicle's driving conditions, and the driver's acceleration request.

[0044] The suction port 52a of the blower case 51 is located in the opening area R2 of the right main frame 7 when viewed from the side. Referring to Figure 10, a suction passage T extends from the suction port 52a toward the outside in the vehicle width direction, and this suction passage T is connected to the clean side 42b of the air cleaner device 40 from the inside in the vehicle width direction. A discharge duct 53 is formed at the rear upper part of the annular portion 52 of the blower case 51, extending tangentially downward and rearward. The discharge duct 53 is cylindrical and positioned with its central axis C8 inclined downward and rearward with respect to the horizontal direction. A discharge port 53a is formed at the rear end of the discharge duct 53, opening toward the rear of the vehicle.

[0045] <Surge Tank 60> Figure 11 is a cross-sectional view of the area around the bulge 63 of the surge tank 60, Figure 12 is a cross-sectional view of Figure 7 seen from the opposite side in the vehicle width direction, and Figure 13 is a plan view showing the angle between the first intake passage T1 and the second intake passage T2. Referring to Figures 4 to 13, a surge tank 60 is positioned behind the turbocharger 50. The surge tank 60 has a hollow tank body 61. In addition to ensuring intake capacity, the surge tank 60 has the function of diffusing the intake air introduced into the tank body 61 within the tank body 61 to stabilize the pressure. A discharge pipe (first intake pipe) 54 is connected to the rear end of the discharge duct 53, forming a discharge passage (first intake passage) T1 that extends in the direction of extension of the discharge duct 53. The rear end of the discharge pipe 54 is connected to a first connection part 62 provided on the front wall of the surge tank 60. The first connection part 62 has a first opening 62a that opens forward. The supercharged intake air discharged from the turbocharger 50 reaches the first connection part 62 via the discharge pipe 54 and is introduced into the surge tank 60 through the first opening 62a. The supercharged intake air introduced into the surge tank 60 diffuses within the surge tank 60 to stabilize its pressure, and then is supplied to each cylinder through multiple funnels 33F and 34F.

[0046] The surge tank 60 has an overhang 63 that protrudes above the supercharger 50. The upper right part of the overhang 63 is provided with a second connection part 64 having a second opening 64a that opens to the upper right front. The rear end of the second intake pipe 47, which extends from the rear end of the air cleaner device 40, is connected to the second connection part 64. The second intake pipe 47 forms a second intake passage T2 inside. Air taken into the air cleaner device 40 and reaching the clean side 42b can be introduced into the surge tank 60 from the second intake passage T2. This air, as naturally aspirated air not pressurized by the supercharger 50, diffuses in the surge tank 60 to stabilize its pressure, and then is supplied to each cylinder from multiple funnels 33F, 34F. The second connection part 64 is provided with a control valve 48 to prevent supercharged intake air introduced from the supercharger 50 into the surge tank 60 from flowing back into the second intake passage T2.

[0047] Referring to Figure 11, both the first connection part 62 and the second connection part 64 are positioned off-center to one side (to the right in this embodiment) in the left-right direction relative to the center CL of the vehicle body. This allows access to both connection parts from the right side of the vehicle body, improving the ease of attaching and detaching the first intake pipe 54 and the second intake pipe 47 to the surge tank 60.

[0048] Referring to Figures 7 and 8, the second intake pipe 47 comprises an outer configuration portion 47a positioned on the outside in the vehicle width direction of the right main frame 7, and an inner configuration portion 47b that is connected to the rear of the outer configuration portion 47a, straddles the top of the right main frame 7, and reaches the inside in the vehicle width direction to connect to the second connection portion 64. By ensuring the length of the second intake passage T2 for natural aspiration, it is easier to increase the degree of freedom in setting the intake characteristics. The second connection portion 64 of the surge tank 60 is provided in a bulge portion 63 above the first connection portion 62, making it easier to connect the second intake passage T2 that straddles the top of the right main frame 7. By forming the bulge portion 63, the capacity of the surge tank 60 is increased, and the intake efficiency is improved.

[0049] Referring to Figure 7, the discharge passage T1 discharges supercharged intake air into the surge tank 60. The extension region of the discharge passage T1 into the surge tank 60 is indicated by the symbol T1ex. Each funnel 33F, 34F has its respective intake ports 33fa, 34fa positioned outside the extension region T1ex, or, if within the extension region T1ex, positioned so as not to face the upstream side of the extension region T1ex. When the intake ports 33fa, 34fa of each funnel 33F, 34F are within the extension region T1ex, they open so as to face the downstream side of the extension region T1ex (or at least include a component that faces the downstream side). As a result, the supercharged intake air introduced into the surge tank 60 is not directly introduced into the intake ports 33fa, 34fa of each funnel 33F, 34F, but is well diffused by colliding with the walls of the surge tank 60 and each funnel 33F, 34F.

[0050] Referring to Figure 13, the line C8 in the figure is the central axis of the discharge passage T1 and corresponds to a straight line along the extension direction of the discharge passage T1. The line C9 in the figure is the central axis of the downstream side (inner arrangement portion 47b) of the second intake passage T2 and corresponds to a straight line along the extension direction of the second intake passage T2.

[0051] The first intake passage (discharge passage) T1 and the second intake passage T2 are arranged such that, in a top view, their respective central axes C8 and C9, which extend inward into the surge tank 60, intersect each other. In a top view, the angle θ between the line segment from the intersection point PC of the central axes C8 and C9 to the center of the downstream end of the first intake passage T1 (center of the first opening 62a) and the line segment from the intersection point PC of the central axes C8 and C9 to the center of the downstream end of the second intake passage T2 (center of the second opening 64a) is an acute angle. As a result, the intake air introduced into the surge tank 60 from each of the first intake passage T1 and the second intake passage T2 does not face 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.

[0052] Referring to Figures 7 and 12, throttle bodies (throttle devices) 35 and 36 and injectors (fuel injection devices) 35a and 36a are provided between each funnel 33F and 34F and the front and rear cylinders 33 and 34. The injectors 35a and 36a are positioned behind the throttle body 35 in the front cylinder 33 and in front of the throttle body 36 in the rear cylinder 34. In other words, the injectors 35a and 36a are positioned closer to the front-to-rear center of the inter-cylinder region R1.

[0053] Focusing on the components of the front cylinder 33, the throttle body 35 is positioned between the first intake passage T1 and the injector 35a in the longitudinal direction of the vehicle. In the longitudinal direction of the vehicle, the components are arranged in the following order from the front: supercharger 50, first intake passage T1, funnel 33F and throttle body 35, and injector 35a.

[0054] As described above, the motorcycle 1 in the above embodiment is a saddle-type vehicle equipped with an engine E and a supercharger 50 that compresses and supplies air to the engine E, and is equipped with a head pipe 6 that supports the front wheel suspension component 3A at the front of the vehicle body 5B, and a pair of left and right main frames 7 that branch off from the head pipe 6 to the left and right and extend to the rear, and the supercharger 50 is arranged in the interframe region R3 surrounded by the head pipe 6 and the left and right main frames 7. With this configuration, by positioning the supercharger 50 in the inter-frame region R3 surrounded on three sides by the head pipe 6 and the left and right main frames 7, the supercharger 50 is less likely to be exposed to the outside and less likely to be tampered with from the outside. In addition, it is easier to secure space for the supercharger 50, which has rotating parts, and the weight balance is improved by positioning the supercharger 50 closer to the center CL on the left and right sides of the vehicle body. Furthermore, even if the engine E has multiple cylinders arranged in the width direction of the vehicle, it is easier to equalize the intake air to each cylinder. By positioning the supercharger 50, which is a heavy object integrated with the electric motor 55, at the center CL on the left and right sides of the vehicle body, mass can be concentrated.

[0055] The above-mentioned motorcycle 1 includes throttle bodies 35 and 36 whose downstream ends are connected to cylinders 33 and 34 of the engine E, and a surge tank 60 connected to the upstream ends of the throttle bodies 35 and 36, into which supercharged intake air from the supercharger 50 is introduced, with the surge tank 60 positioned behind the supercharger 50. With this configuration, by positioning the surge tank 60 behind the supercharger 50, the supercharger 50 and the surge tank 60 are linearly connected by a connecting pipe (discharge pipe 54) extending in the front-rear direction, allowing for efficient introduction of supercharger intake air from the supercharger 50 to the surge tank 60. By linearly connecting the supercharger 50 and the surge tank 60 in the front-rear direction, the connecting pipe can be shortened, reducing weight and cost, and minimizing supercharger pressure loss. The vehicle frame 5 can also be a monocoque structure with the surge tank 60 integrated into it.

[0056] In the above-described motorcycle 1, the surge tank 60 is positioned between the left and right main frames 7 when viewed from above. With this configuration, the surge tank 60 can be placed between the left and right main frames 7, allowing the supercharger 50 and the surge tank 60 to be compactly arranged together.

[0057] In the above-described motorcycle 1, the supercharger 50 is provided with an intake port 52a that opens outward in the vehicle width direction, and the intake port 52a is located in an opening region R2 surrounded by a plurality of frame members in the main frame 7 when viewed from the side. With this configuration, by positioning the intake port 52a of the supercharger 50 in an opening region R2 surrounded by the frame members of the main frame 7 in a side view, the intake passage T can be easily connected to the intake port 52a from the outside in the vehicle width direction. By positioning the supercharger 50 itself between the left and right main frames 7, the weight balance including the supercharger 50 is improved, and even if the engine E has multiple cylinders arranged in the vehicle width direction, it becomes easier to equalize the intake air to each cylinder.

[0058] In the above-described motorcycle 1, the supercharger 50 is configured to draw in air from a suction port 52a that opens in the axial direction of the rotating body and to discharge the drawn-in air in the tangential direction of the rotating body, with the rotation axis C6 facing the vehicle width direction, and the surge tank 60 is positioned in the tangential direction of the supercharger 50. With this configuration, the supercharger 50 is a centrifugal fan that draws in air from the axial direction (vehicle width direction) of the rotating body and discharges it tangentially, and the surge tank 60 is positioned tangentially to the supercharger 50 (discharge direction, rear of the supercharger 50), allowing the supercharger 50 and the surge tank 60 to be placed close to each other and easily connected. The intake of air by the supercharger 50 can be performed from the outside in the vehicle width direction, which reduces the complexity around the head pipe 6 compared to a configuration in which intake is performed from the front of the head pipe 6.

[0059] In the above-described motorcycle 1, the engine E has multiple cylinders, and the surge tank 60 is provided with multiple funnels 33F, 34F connected to each cylinder of the engine E. The supercharger 50 has a discharge port 53a for discharging the drawn-in air, and the discharge passage T1 extending from the discharge port 53a communicates with the inside of the surge tank 60. The intake ports 33fa, 34fa of the multiple funnels 33F, 34F open while avoiding the extension region T1ex of the discharge passage T1 into the inside of the surge tank 60. With this configuration, by opening the intake ports 33fa and 34fa of the funnels 33F and 34F while avoiding the extended region T1ex of the discharge passage T1 extending from the discharge port 53a of the supercharger 50, it becomes difficult for the supercharged intake air discharged from the discharge passage T1 into the surge tank 60 to be directly introduced into the intake ports 33fa and 34fa of the funnels 33F and 34F. Since the supercharged intake air is well diffused within the surge tank 60, it becomes easier to equalize the introduction of intake air into the multiple funnels 33F and 34F, thereby achieving stable combustion of the engine E.

[0060] In the above-mentioned motorcycle 1, the supercharger 50 is equipped with an electric motor 55 as a drive source. With this configuration, by electrifying the supercharger 50, it becomes unnecessary to obtain driving force for the supercharger 50 from the exhaust system or drive shaft of the engine E, thereby improving the flexibility of the supercharger 50's placement.

[0061] Furthermore, the motorcycle 1 in the above embodiment is a saddle-type vehicle comprising an engine E, a supercharger 50 that compresses and supplies air to the engine E, and a surge tank 60 into which supercharged intake air is introduced from the supercharger 50, and includes a first intake passage (discharge passage) T1 extending from the supercharger 50 and connected to the surge tank 60, and a second intake passage T2 provided separately from the first intake passage T1 and connected to the surge tank 60 without going through the supercharger 50. In this configuration, in addition to the first intake passage T1 for supercharged intake extending from the supercharger 50, there is a second intake passage T2 for naturally aspirated air that connects to the surge tank 60 without going through the supercharger 50, so that both supercharged and naturally aspirated air are introduced into a common surge tank 60. By receiving both intake systems into a common surge tank 60, the number of parts is reduced, and intake capacity is secured by the surge tank 60 even in naturally aspirated air, thereby improving intake efficiency (the ratio of the amount of intake air to the change in cylinder volume).

[0062] In the above-described motorcycle 1, the front of the vehicle body 5B is a head pipe 6 that supports the front wheel suspension component 3A, and a pair of left and right main frames 7 that branch off from the head pipe 6 to the left and right and extend to the rear, and the surge tank 60 is positioned between the left and right main frames 7 in a top view. With this configuration, by placing the surge tank 60 between the left and right main frames 7, it is possible to secure the capacity of the surge tank 60 while keeping the vehicle size down compared to when the surge tank 60 is placed outside the left and right main frames 7.

[0063] In the above-described motorcycle 1, the surge tank 60 includes a first connection part 62 that connects to the first intake passage T1 and a second connection part 64 that connects to the second intake passage T2, and both the first connection part 62 and the second connection part 64 are arranged on one side in the left-right direction with respect to the left-right center CL of the vehicle body. With this configuration, the connection points 62 and 64 of the first intake passage T1 and the second intake passage T2 in the surge tank 60 are arranged together on one side in the left-right direction of the vehicle body, making it possible to access both connection points 62 and 64 from one side in the left-right direction of the vehicle body, thereby improving manufacturability and maintainability.

[0064] In the above-described motorcycle 1, the first intake passage T1 and the second intake passage T2 are arranged such that their central axes C8 and C9, which extend inside the surge tank 60, intersect each other at an acute angle when viewed from above. With this configuration, by arranging the central axes C8 and C9 of the first intake passage T1 and the second intake passage T2 to form acute angles with each other, it is possible to prevent the supercharged intake air and naturally aspirated air introduced into the surge tank 60 from each intake passage T1 and T2 from flowing in opposite directions. This suppresses the generation of turbulence within the surge tank 60 and prevents backflow of intake air from one of the first intake passage T1 and the second intake passage T2 to the other, thereby improving intake efficiency.

[0065] In the above-described motorcycle 1, the surge tank 60 includes a first connection portion 62 that connects to the first intake passage T1 and a second connection portion 64 that connects to the second intake passage T2, the second connection portion 64 being positioned above the first connection portion 62, and the intake passage member (second intake pipe 47) that forms at least a part of the second intake passage T2 includes an outer arrangement portion 47a positioned on the outside in the vehicle width direction of the main frame 7 of the vehicle body 5B, and an inner arrangement portion 47b that is connected to the rear of the outer arrangement portion 47a, crosses over the main frame 7 to the inside in the vehicle width direction, and is connected to the second connection portion 64. With this configuration, the second intake pipe 47, which forms a second intake passage T2 that does not go through the supercharger 50, is extended from the outside in the vehicle width direction of the main frame 7 to the inside in the vehicle width direction, straddling the top of the main frame 7. This ensures the length of the second intake passage T2 that guides naturally aspirated air, and increases the degree of freedom in setting the intake characteristics.

[0066] In the above-described motorcycle 1, the engine E has multiple cylinders, and the surge tank 60 is provided with multiple funnels 33F, 34F connected to each cylinder of the engine E, and the supercharger 50 has an outlet 53a for discharging the drawn-in air, and the intake ports 33fa, 34fa of the multiple funnels 33F, 34F are opened to avoid the extension region T1ex in the first intake passage T1 that extends inward from the surge tank 60. With this configuration, by opening the intake ports 33fa and 34fa of the funnels 33F and 34F while avoiding the extended region T1ex of the first intake passage T1 extending from the discharge port 53a of the supercharger 50, it becomes difficult for the supercharged intake air discharged from the first intake passage T1 to the surge tank 60 to be directly introduced into the intake ports 33fa and 34fa of the funnels 33F and 34F. The supercharged intake air is diffused well within the surge tank 60, making it easier to equalize the introduction of intake air into the multiple funnels 33F and 34F, and enabling stable combustion of the engine E.

[0067] The above-described motorcycle 1 is equipped with the throttle body 35 and injector 35a between the funnel 33F and the cylinder 33, and the throttle body 35 is positioned between the first intake passage T1 and the injector 35a in the longitudinal direction of the vehicle. With this configuration, by positioning the throttle body 35 between the first intake passage T1 and the injector 35a in the longitudinal direction of the vehicle, it is possible to secure more space for the first intake passage T1 and the injector 35a compared to the case where the first intake passage T1 and the injector 35a are positioned on the same side of the throttle body 35.

[0068] It should be noted that the present invention is not limited to the embodiments described above. For example, the supercharger vehicle structure of the embodiment may be applied to saddle-type vehicles other than motorcycles. The 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) or four-wheeled vehicles (such as four-wheeled buggies). Furthermore, it includes not only scooter-type vehicles with a straddling space but also vehicles with a straddling section. It may also be applied to vehicles that include an electric motor as the prime mover. This can be applied to various types of reciprocating engines, including single-cylinder engines, multi-cylinder engines such as parallel or V-type engines, and longitudinally mounted engines with the crankshaft aligned along the vehicle's longitudinal direction. Furthermore, the configuration in the above embodiment is just one example of the present invention, and various modifications are possible without departing from the spirit of the invention, such as replacing the components of the embodiment with well-known components. [Explanation of symbols]

[0069] 1. Motorcycle (saddle-type vehicle) 3A Front wheel suspension parts 5. Vehicle frame 5B Vehicle body (vehicle body) 6. Head pipe (head section) 7. Mainframe (frame section) 15. Upper pipe (frame component) 17. Connecting pipes (frame components) 33 Front cylinder (cylinder) 34 Rear cylinder (cylinder) 33F, 34F funnel 33fa, 34fa intake port 35,36 Throttle body (throttle device) 35a, 36a Injector (fuel injection device) 47 Second intake manifold 47a Outside placement part 47b Inside placement part 50 Supercharger 52a Suction port 53a Discharge port 54 Discharge pipe (first intake pipe) 55 Electric motor 60 Surge Tank 62 First connection section 64 Second connection section C6 Rotation axis C8,C9 center axis CL vehicle body left and right center E-engine R2 opening area R3 Interframe Region T Suction passage T1 First intake passage, discharge passage T1ex extension area T2 Second intake passage

Claims

1. A saddle-type vehicle (1) comprising an internal combustion engine (E), a supercharger (50) that compresses and supplies air to the internal combustion engine (E), and a surge tank (60) into which supercharged intake air is introduced from the supercharger (50), A first intake passage (T1) extends from the supercharger (50) and is connected to the surge tank (60), A saddle-type vehicle comprising a second intake passage (T2) provided separately from the first intake passage (T1) and connected to the surge tank (60) without going through the supercharger (50).

2. The vehicle body (5B) is provided with a head section (6) at the front that supports the front wheel suspension components (3A), and a pair of left and right frame sections (7) that branch off from the head section (6) and extend to the rear. The saddle-type vehicle according to claim 1, wherein the surge tank (60) is positioned between the left and right frame sections (7) in a top view.

3. The surge tank (60) includes a first connection part (62) that connects to the first intake passage (T1) and a second connection part (64) that connects to the second intake passage (T2). The saddle-type vehicle according to claim 1, wherein both the first connecting portion (62) and the second connecting portion (64) are arranged on one side in the left-right direction with respect to the left-right center (CL) of the vehicle body.

4. The saddle-type vehicle according to claim 1, wherein the first intake passage (T1) and the second intake passage (T2) are arranged such that their central axes (C8, C9) extending inward from the surge tank (60) intersect each other at an acute angle in a top view.

5. The surge tank (60) includes a first connection part (62) that connects to the first intake passage (T1) and a second connection part (64) that connects to the second intake passage (T2). The second connecting portion (64) is positioned above the first connecting portion (62), The saddle-type vehicle according to claim 1, wherein the intake passage member (47) forming at least a part of the second intake passage (T2) comprises an outer arrangement portion (47a) positioned on the outside in the vehicle width direction of the frame portion (7) of the vehicle body (5B), and an inner arrangement portion (47b) that is connected to the rear of the outer arrangement portion (47a), straddles the top of the frame portion (7) and reaches the inside in the vehicle width direction, and is connected to the second connection portion (64).

6. The internal combustion engine (E) comprises multiple cylinders, The surge tank (60) is provided with a plurality of funnels (33F, 34F) connected to each cylinder of the internal combustion engine (E). The supercharger (50) is equipped with a discharge port (53a) for discharging the drawn-in air, The saddle-type vehicle according to claim 1, wherein the intake ports (33fa, 34fa) of the plurality of funnels (33F, 34F) open while avoiding the extension region (T1ex) in the first intake passage (T1) toward the inside of the surge tank (60).

7. A throttle device (35) and a fuel injection device (35a) are provided between the funnel (33F) and the cylinder (33) of the internal combustion engine (E). The saddle-type vehicle according to claim 6, wherein the throttle device (35) is positioned between the first intake passage (T1) and the fuel injection device (35a) in the longitudinal direction of the vehicle.

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