INTAKE SYSTEM

Abstract

Intake system (50) which receives air through at least one air inlet duct (53, 54) extending from an air filter housing (51), wherein the inlet system (50) comprises at least one vortex generator (55) which causes a flow of the intake air in the air intake duct (53, 54) to rotate about an axis (53a, 54a) of the air intake duct (53, 54), wherein the air inlet duct (53, 54) has a distal end portion provided with an inlet opening (53b, 54b) which receives inlet air into the air inlet duct (53, 54), and the vortex generator (55) is arranged at the inlet opening (53b, 54b), characterized in that the intake system (50) is mounted in the saddle-seat vehicle (10), the saddle-seat vehicle (10) has a radiator cover plate (40) which covers a radiator (37) from one side, the radiator cover plate (40) has a region which covers the inlet opening (53b, 54b), and the vortex generator (55) is formed integrally with the radiator cover plate (40).

Description

[0001] The present invention relates to an intake system.

[0002] A known intake system includes an air cleaner housing and an air intake duct extending from the air cleaner housing toward a vehicle front. The system causes air drawn in from an opening in the front surface of the air intake duct to flow through the air intake duct toward a rear of the vehicle (see, for example, JP 2000-87815 A). The technique of JP 2000-87815 A can draw air into the air cleaner housing using the flow of the airstream.

[0003] WO 2019 / 096 739 A1 discloses an intake system according to the preamble of independent claim 1. EP 2 832 985 A1 discloses an air cleaning device for a vehicle.

[0004] However, it is desired that the intake efficiency of such an intake system be improved.

[0005] It is an object of the present invention to improve intake efficiency in an intake system.

[0006] These and other objects are achieved by the subject matter of the independent claims. The dependent claims develop the central idea of ​​the invention in a particularly advantageous manner.

[0007] An intake system that takes in air through an air intake duct extending from the air cleaner housing includes a vortex generator that causes the flow of intake air in the air intake duct to rotate about an axis of the air intake duct.

[0008] The intake efficiency in the intake system can be improved. Fig. 1 is a side view of a saddle-seat vehicle according to an embodiment of the present invention; Fig. 2 is a front view of the saddle seat vehicle viewed from a front side; Fig. 3 is a cross-sectional view of the saddle seat vehicle taken along the center portion thereof in a vehicle width direction; Fig. 4 is a front view of the intake system viewed from the front; Fig. 5 is a top view of the intake system with a cover portion removed; Fig. 6 is a cross-sectional view taken along the line VI-VI of Fig. 1 was created; Fig. 7 is a left side view of the front portion of the saddle seat vehicle with a second tank fairing removed; Fig. 8 is a perspective view of a wind guide and an air cleaner case viewed from a left front side; Fig. 9 is a cross-sectional view taken along the line IX-IX of Fig. 2 was created; Fig. 10 is a left view of a radiator to which a grille is attached; Fig. 11 is a plan view illustrating a support structure of a canister; Fig. 12 is a left side view of the surroundings of a vortex generating element of a second embodiment (not falling within the scope of the independent claim). Fig. 13 is a cross-sectional view taken along the line XIII-XIII of Fig. 12 was created; and Fig. 14 is a schematic view of the internal structure of the air cleaner case viewed from the left side.

[0009] An embodiment of the present invention will be described below with reference to the drawings. Unless otherwise stated, the directions mentioned in the description, including front-rear, left-right, and top-bottom, are the same as those with respect to a vehicle body. Reference symbols FR, UP, and LH shown in the drawings indicate a front of the vehicle body, a top of the vehicle body, and a left side of the vehicle body, respectively.

[0010] Fig. 1 is a side view of a saddle seat vehicle 10 according to an embodiment of the present invention.

[0011] The saddle seat vehicle 10 is a vehicle including a vehicle body frame 11, a power unit 12 supported on the vehicle body frame 11, a front fork 14 supporting a front wheel 13 in a steerable manner, a swing arm 16 supporting a rear wheel 15, and a seat 17 for a rider.

[0012] The saddle-seat vehicle 10 is a vehicle on which the driver sits astride the seat 17. The seat 17 is provided above a rear part of the vehicle body frame 11.

[0013] The vehicle body frame 11 includes a steering head tube 18 provided at a front end portion of the vehicle body frame 11, a front frame 19 located at a rear side of the steering head tube 18, and a rear frame 20 located at a rear side of the front frame 19. A front end portion of the front frame 19 is connected to the steering head tube 18.

[0014] The seat 17 is attached to the rear frame 20.

[0015] The front fork 14 is mounted on the steering head tube 18 such that it can be steered left and right. The front wheel 13 is rotatably mounted on an axle 13a located at a lower end portion of the front fork 14. A handlebar 21 for steering, which the rider grasps, is located at the upper end portion of the front fork 14.

[0016] The swing arm 16 is supported on a pivot shaft 22, which is mounted on the vehicle body frame 11. The pivot shaft 22 is a shaft extending horizontally in a vehicle width direction. The pivot shaft 22 passes through a front end portion of the swing arm 16. The swing arm 16 swings up and down around the pivot shaft 22.

[0017] The rear wheel 15 is held on an axle 15a which is arranged at a lower end region of the swing arm 16.

[0018] The drive unit 12 is arranged between the front wheel 13 and the rear wheel 15 and is held on the vehicle body frame 11.

[0019] The drive unit 12 is an internal combustion engine. The drive unit 12 has a crankcase 23 and a cylinder 24 that houses a reciprocating piston. An exhaust device 25 is connected to an exhaust port of the cylinder 24.

[0020] An output of the drive unit 12 is transmitted to the rear wheel 15 via a drive force transmission member that connects the drive unit 12 and the rear wheel 15.

[0021] The saddle seat vehicle 10 further comprises a front fender 26 covering the front wheel 13 from above, a rear fender 27 covering the rear wheel 15 from above, footrests 28 on which the driver rests his or her feet, and a fuel tank 29 storing fuel to be used by the drive unit 12.

[0022] The front fender 26 is attached to the front fork 14. The rear fender 27 and footrests 28 are provided on a lower side relative to the seat 17. The fuel tank 29 is mounted on the vehicle body frame 11.

[0023] The front frame 19 includes a pair of left and right main frames 31 extending downward and rearward from an upper part of the steering head tube 18, a pair of left and right lower frames 32 extending downward and rearward from the lower part of the steering head tube 18, a pair of left and right swing frames 33 each extending from a rear end portion of the corresponding main frame 31, and a connecting plate 34 connecting the main frames 31 to the lower frames 32 at a rear side of the steering head tube 18.

[0024] The rear frame 20 includes a pair of left and right seat frames 35 extending upward and rearward from a rear end portion of the corresponding main frame 31, and a pair of left and right sub-frames 36 extending upward and rearward from an upper end portion of the associated swing frame 33, each of which is connected to a rear end portion of the seat frame 35.

[0025] The drive unit 12 is arranged between the main frame 31 and the lower frame 32 and the pivot frame 33.

[0026] The cylinder 24 extends upwards from an upper surface of the front part of the crankcase 23.

[0027] The fuel tank 29 is arranged above the main frame 31 between the seat 17 and the steering head tube 18 in a forward and rearward direction of the vehicle. The fuel tank 29 is held to the main frame 31.

[0028] A radiator 37, through which cooling water of the power unit 12 flows, is arranged in front of the cylinder 24 and the lower frame 32 and attached to the lower frame 32. The radiator 37 is a plate-shaped portion and is arranged such that a plate thickness direction coincides with the front-and-rear direction of the vehicle.

[0029] Fig. 2 is a front view of the saddle seat vehicle 10 viewed from a front side.

[0030] With reference to Fig. 1 and Fig. 2, the saddle seat vehicle 10 includes, as a vehicle body panel, a front panel 38 that covers the steering head pipe 18 from the front side, a tank panel 39 that covers the fuel tank 29 from the front side, a pair of left and right radiator panel shrouds 40 that each cover the radiator 37 from the outside in the vehicle width direction, and a pair of left and right side panels 41 that each cover a part of the vehicle body under the seat 17 from the outside in the vehicle width direction.

[0031] The tank cover 39 includes a first tank cover 42 covering the fuel tank 29 from the front and a pair of left and right second tank covers 43 arranged behind the first tank cover 42 and in front of the fuel tank 29.

[0032] The first tank cowl 42 includes an upper surface portion 42a disposed between the fuel tank 29 and the steering head pipe 18, and covers the front end portions of the main frames 31 from above. The upper surface portion 42a is located at a central region in the vehicle width direction. The first tank cowl 42 also includes a pair of left and right lower extensions 42b extending downward from the left and right sides of the upper surface portion 42a, respectively.

[0033] The second tank covers 43 are provided separately from the first tank cover 42. Each of the second tank covers 43 is arranged between the corresponding lower extension 42b and the front edge of the fuel tank 29 as viewed from a vehicle side, and covers the front end portion of the vehicle from the outside in the vehicle width direction.

[0034] The radiator 37 is arranged under the tank cover 39. The radiator 37 spans the front wheel 13 from side to side and runs in the vehicle width direction as viewed from the front.

[0035] The saddle seat vehicle 10 has a grille 44 that covers the front of the radiator 37 from the front.

[0036] Fig. 3 is a cross-sectional view of the saddle seat vehicle 10 taken along the center portion thereof in the vehicle width direction.

[0037] With reference to Fig. 1 and Fig. 3, the fuel tank 29 has a step 29a formed by receding upward from the front lower surface of the fuel tank 29 in a step shape.

[0038] The saddle seat vehicle 10 has an intake system 50 that supplies intake air to the cylinder 24.

[0039] Fig. 4 is a front view of the intake system 50 viewed from the front.

[0040] With reference to Fig. 3 and Fig. 4, the intake system 50 includes an air cleaner housing 51 that cleans the intake air, a pair of left and right throttle valve devices 52 that regulate the amount of intake air supplied to the cylinder 24, a pair of left and right air intake ducts 53 and 54 that send the intake air to the air cleaner housing 51, and vortex generators 55 that swirl the intake air streams in the air intake ducts 53 and 54. Each vortex generator 55 is arranged on the corresponding radiator shroud 40. The throttle valve devices 52 are in Fig. 4 not shown.

[0041] Each throttle device 52 has an upstream end connected to the air cleaner housing 51 and a downstream end connected to an inlet port located at the rear of the cylinder 24.

[0042] The air cleaner housing 51 is formed in a hollow housing in which a housing body 57 and a cover portion 58 are coupled, which are provided separately in the top-down direction. The air cleaner housing 51 has an air filter 59 therein, which cleans the intake air.

[0043] The air cleaner housing 51 is arranged between the steering head pipe 18 and the fuel tank 29 in the front and rear directions of the vehicle. The air cleaner housing 51 is arranged between the left and right main frames 31 in the vehicle width direction. The rear portion of the air cleaner housing 51 is arranged at the step 29a of the fuel tank 29 and is covered with the front portion of the fuel tank 29 from above.

[0044] Fig. Figure 5 is a top view of the intake system 50 with the cover portion 58 removed.

[0045] The housing body 57 includes a box-shaped portion 60 with an open upper surface and a flange portion 61 extending from the upper edge of the box-shaped portion 60 toward the front, left, right, and rear sides. The flange portion 61 is plate-shaped to surround the box-shaped portion 60 from the periphery thereof.

[0046] The cover portion 58 is attached to the housing body 57 by securing the edge of the cover portion 58 to the edge of the flange portion 61.

[0047] The air inlet ducts 53 and 54 are connected to the box-shaped area 60.

[0048] The air cleaner 59 is a plate-shaped member that seals an opening 60a in the upper surface of the box-shaped portion 60 and is attached to the opening 60a.

[0049] The air filter 59 divides the space in the air filter housing 51 in an upward and downward direction.

[0050] The space of the box-shaped portion 60 under the air cleaner 59 is a dirt side 51a into which the intake air that has not passed through the air cleaner 59 flows ( Fig. 3). In the interior of the air filter housing 51, the space above the air filter 59 is a clean side 51b, into which the intake air, which has passed through the air filter 59, flows ( Fig. 3).

[0051] In plan view, the box-shaped portion 60 is formed in a substantially triangular shape that tapers toward the front of the vehicle. That is, the dirt side 51a is a chamber with a substantially triangular shape.

[0052] In plan view, the box-shaped portion 60 has left and right side walls 60b and 60c which are inclined so that the distance therebetween increases towards the rear.

[0053] The air cleaner housing 51 has a pair of left and right supply passages 62, each connected to a corresponding one of the throttle devices 52.

[0054] Each supply channel 62 extends downward from the rear portion of the clean side 51b through the rear portion of the flange portion 61. Each supply channel 62 has a lower end, which is a downstream end connected to the corresponding throttle valve device 52.

[0055] Fig. 6 is a cross-sectional view taken along the line VI-VI of Fig. 1 was created.

[0056] With reference to Fig. 4 to 6, the air intake duct 53 extends outward from the air cleaner case 51 on one (the left) of the left and right sides in the vehicle width direction. Specifically, the air intake duct 53 extends outward in the vehicle width direction from a front end portion of the left side wall 60b of the case body 57.

[0057] The side wall 60b is provided with a duct connection opening 60d to which the air intake duct 53 is fitted and connected. The air intake duct 53 passes through the duct connection opening 60d to enter the air cleaner housing 51.

[0058] The air inlet duct 53 includes: an outer duct portion 63 extending outward from the air cleaner housing 51; and an inner duct portion 64 connected to the outer duct portion 63 and extending within the air cleaner housing 51.

[0059] The outer channel portion 63 extends outward in the vehicle width direction from the channel connection opening 60d.

[0060] The inner duct portion 64 extends rearwardly and upwardly from the duct connection opening 60d in the dirt side 51a. The inner duct portion 64 has an upper end, which is a downstream end 64a, opening toward the air cleaner 59 disposed thereabove.

[0061] The air inlet duct 53 has a first duct element 65 connected to the duct connection opening 60d and a second duct element 66 connected to the first duct element 65.

[0062] The first channel element 65 forms the inner channel area 64.

[0063] The first channel element 65 has a forward end portion 65a extending outward in the vehicle width direction from the channel connection opening 60d. The second channel element 66 is aligned with the inner periphery of an end portion 65a of the first channel element 65 and extends outward in the vehicle width direction from the end portion 65a. Thus, the outer channel portion 63 is formed by the end portion 65a of the first channel element 65 and the second channel element 66.

[0064] The air inlet duct 53 is a tube with a circular cross-section.

[0065] In the outer duct region 63, an axis 53a of the air intake duct 53 extends linearly in the vehicle width direction. Outside the air filter housing 51, the axis 53a of the air intake duct 53 extends in the vehicle width direction, and thus, the view from the vehicle side is a view along an axial direction of the air intake duct 53.

[0066] The air intake duct 53 has an upstream end, which is an inlet opening 53b opening outward in the vehicle width direction. The inlet opening 53b is the outer end of the outer duct portion 63 in the vehicle width direction.

[0067] The upstream end portion of the air intake duct 53 is provided with a tapered portion 53c having an inner diameter decreasing toward the downstream side of the intake port 53b.

[0068] The air intake duct 54 on the other (right) side of the left and right sides extends outward in the vehicle width direction from the air cleaner case 51. Specifically, the air intake duct 54 extends outward in the vehicle width direction from a front end portion of the right side wall 60c of the case body 57.

[0069] The side wall 60c is provided with a duct connection opening 60e, to which the air intake duct 54 is aligned and connected. The air intake duct 53 passes through the duct connection opening 60e to enter the air cleaner housing 51.

[0070] The air inlet duct 54 includes: an outer duct portion 73 extending outward from the air cleaner housing 51; and an inner duct portion 74 connected to the outer duct portion 73 and extending within the air cleaner housing 51.

[0071] The outer channel portion 73 extends outward in the vehicle width direction from the channel connection opening 60e.

[0072] The inner channel portion 74 extends rearwardly and upwardly from the channel connection opening 60e in the dirt side 51a. The inner channel portion 74 has an upper end, which is a downstream end 74a, opening toward the air cleaner 59 disposed thereabove.

[0073] The air inlet duct 54 has a first duct element 75 connected to the duct connection opening 60e and a second duct element 76 connected to the first duct element 75.

[0074] The first channel element 75 forms the inner channel area 74.

[0075] The first channel element 75 has a forward end portion 75a extending outward in the vehicle width direction from the channel connection opening 60e. The second channel element 76 is aligned with the inner periphery of an end portion 75a of the first channel element 75 and extends outward in the vehicle width direction from the end portion 75a. Thus, the outer channel portion 73 is formed by the end portion 75a of the first channel element 75 and the second channel element 76.

[0076] The air inlet duct 54 is a tube with a circular cross-section.

[0077] In the outer duct region 73, an axis 54a of the air intake duct 54 extends linearly in the vehicle width direction.

[0078] The air intake duct 54 has an upstream end, which is an inlet opening 54b that opens outward in the vehicle width direction. The inlet opening 54b is the outer end of the outer duct portion 73 in the vehicle width direction.

[0079] The upstream end portion of the air inlet duct 54 is provided with a tapered portion 54c having an inner diameter that decreases toward the downstream side of the inlet opening 54b.

[0080] The duct connection openings 60d and 60e of the air filter housing 51 face each other. In other words, the duct connection openings 60d and 60e at least partially overlap each other when viewed from the vehicle side.

[0081] The downstream end 64a of the left inner channel portion 64 and the downstream end 74a of the right inner channel portion 74 are arranged in a staggered manner in the front and rear direction.

[0082] Fig. 7 is a left side view of the front portion of the saddle seat vehicle 10 with the second tank fairing 43 removed.

[0083] With reference to Fig. 2 and Fig. 7, the lower extension 42b of the first tank cover 42 extends in the up-and-down direction on the outside of the main frame 31 and the lower frame 32. The lower extension 42b is plate-shaped so as to cover the side of the fuel tank 29 from the front.

[0084] The lower extension 42b has a lower portion provided with a panel opening 42c opening forward.

[0085] With reference to Fig. 1 and Fig. 7 covers the second tank fairing 43 ( Fig. 1) the upper portion of the radiator cowl panel 40 from the outside in the vehicle width direction.

[0086] The upper portion of the left radiator shroud 40 serves as a wind guide 79 that guides the airflow. The radiator shroud 40 has a shroud portion 80 extending downward from the front portion of the wind guide 79. The shroud portion 80 is a plate-shaped shroud that covers the radiator 37 from the outside in the vehicle width direction.

[0087] Fig. 8 is a perspective view of the wind guide 79 and an air cleaner case 51 viewed from a left front side. Fig. 9 is a cross-sectional view taken along the line IX-IX of Fig. 2 was created.

[0088] With reference to Fig. 4 to 9, the wind guide 79 covers the front end portion of the vehicle body frame 11, the front end portion of the air cleaner case 51, the air intake duct 53 and other components from the outside in the vehicle width direction.

[0089] The wind guide 79 integrally includes: the vortex generator 55 that causes the intake air to flow through the air intake duct 53 to swirl; a lower wall 82 positioned below the vortex generator 55 and extending front and rear in the vehicle direction; a front wall 83 positioned in front of the vortex generator 55 and extending up and down; a partition wall 84 positioned in front of the front wall 83 and extending up and down; and a bracket 85 extending upward from the vortex generator 55.

[0090] The lower wall 82 is a plate-shaped portion extending inward in the vehicle width direction from the upper edge of the trim panel portion 80. Viewed from the vehicle side, the lower wall 82 slopes rearward and upward.

[0091] The vortex generator 55 lines the intake opening 53b of the air intake duct 53 from the outside in the vehicle width direction. The vortex generator 55 is arranged above the lower wall 82.

[0092] The vortex generator 55 is arranged at the intake opening 53b of the air intake duct 53. The vortex generator 55 has a bulge 86 that bulges outward in the vehicle width direction from the upper portion of the intake opening 53b of the air intake duct 53, and a guide 87 arranged below the bulge 86. Here, the upper portion of the intake opening 53b is the upper half of the intake opening 53b as viewed from the vehicle side.

[0093] The bulge 86 includes an arcuate peripheral wall 86a along the inner periphery of the upper portion of the intake opening 53b, and a side wall 86b (slope) that lines an opening formed by the peripheral wall 86a from the outer side in the vehicle width direction as viewed from the vehicle side. The side wall 86b lines the upper portion of the intake opening 53b from the outer side in the vehicle width direction.

[0094] The peripheral wall 86a extends outward in the vehicle width direction from the upper half of the intake opening 53b. The peripheral wall 86a is aligned with the upper portion of the inner periphery of the intake opening 53b. The peripheral wall 86a may be aligned with the entire periphery of the intake opening 53b.

[0095] The side wall 86b inclines outward in the vehicle width direction as it extends toward the rear from the front end of the bulge 86.

[0096] The lower surface of the rear portion of the bulge 86 is provided with another intake port 86c (hereinafter referred to as intake port 86c) opening downward. The intake port 86c allows the space inside the bulge 86 to communicate with a space on the lower outer side of the bulge 86.

[0097] The guide 87 is arranged above the lower wall 82.

[0098] The guide 87 includes: a first guide wall 87a extending forward and rearward in the vehicle direction on one side with respect to the intake port 86c; and a second guide wall 87b connecting a rear end of the first guide wall 87a to a rear end portion of the intake port 86c.

[0099] Viewed from the vehicle side, the first guide wall 87a is positioned in front of and below the inlet opening 86c and extends straight forward and backward in the vehicle direction in a rearward-upward posture.

[0100] When viewed from the vehicle side, the second guide wall 87b extends upward and rearward from the rear end of the first guide wall 87a, and has an upper end connected to the rear end portion of the intake port 86c from below.

[0101] The second guide wall 87b is arc-shaped along the inner circumference of the inlet opening 53b as viewed from the vehicle side.

[0102] The upper end portion of the second guide wall 87b has an inclination angle θ of 70° or more with respect to the first guide wall 87a as viewed from the vehicle side, and the inlet port 86c opens to the lower side so as to be horizontal to the ground as viewed from the vehicle side.

[0103] The bottom side where the inlet port 86c opens is one of the upper and lower sides with respect to the vortex generator 55.

[0104] The bracket 85 extends from the vortex generator 55 toward the top, which is the other of the top and bottom sides.

[0105] The upper end portion of the bracket 85 is secured to the vehicle body with a fastener 85a. The bracket 85 has an engagement portion 85b, which is secured below the fastener 85a and into which the second tank cover 43 is engaged.

[0106] The front wall 83 extends inward in the vehicle width direction from a region near the front end portion of the first guide wall 87a. The front wall 83 connects the front end portion of the bulge 86 to the lower wall 82 in the up-down direction.

[0107] The partition wall 84 covers the front wall 83 from the front side. The partition wall 84 connects the front end portion of the bulge 86 to the front end portion of the lower wall 82 in the upward and downward direction.

[0108] The partition wall 84 has an opening 84a extending through the partition wall 84 in the front-rear direction. The partition wall 84 also has an engagement portion 84b with which the lower extension 42b of the first tank cover 42 is engaged.

[0109] The engaging portion 84b is located outside the opening 84a in the vehicle width direction. The opening 84a overlaps the front wall 83 from the front side.

[0110] The right radiator shroud 40 is substantially symmetrical to the left radiator shroud 40, and thus the specific description of the right radiator shroud 40 will not be described.

[0111] The vortex generator 55 in the right radiator shroud 40 is connected to the inlet opening 54b of the right air intake duct 54.

[0112] With reference to Fig. 4 to 9, the flow of intake air flowing through the intake system 50 is described.

[0113] The airflow of the saddle-seat vehicle 10 flows into the tank cowl 39 via the cowl opening 42c from the front. The airflow flowing into the tank cowl 39 flows through the opening 84a of the partition wall 84, moves rearward, and flows rearward and outward in the vehicle width direction along the front wall 83. Part of the airflow flows into the vortex generator 55 as intake air W ( Fig. 7).

[0114] In the left vortex generator 55, the intake air W flows upward and backward along the upper surface of the first guide wall 87a and then flows upward and backward in an arc along the upper surface of the second guide wall 87b to flow into the intake port 86c.

[0115] Since the inclination angle θ is 70° or more, the intake air W flows on the first guide wall 87a and the second guide wall 87b, thereby changing the flow direction by 70° or more as viewed from the vehicle side.

[0116] The intake air W that has flowed into the intake port 86c flows arcuately along the peripheral wall 86a and the side wall 86b in the bulge 86.

[0117] That is, the intake air W flows through the vortex generator 55 to be a vortex rotating around the axis 53a of the air intake duct 53 as viewed from the vehicle side.

[0118] In the vortex generator 55, the intake air W flows backward and then flows upward to rotate, and thus rotates counterclockwise as viewed from the vehicle side.

[0119] The side wall 86b of the bulge 86 is a slope inclined inward in the vehicle width direction along the rotation direction of the intake air W. Therefore, the intake air W flowing in the bulge 86 flows inward in the vehicle width direction along an axial direction of the air intake duct 53 while rotating counterclockwise.

[0120] Likewise, the right vortex generator 55 causes the intake air W (not shown) to be a vortex that rotates around the axis 54a of the air intake duct 54 as viewed from the vehicle side. The intake air W generated in the right vortex generator 55 rotates clockwise as viewed from the right side of the vehicle. In other words, the vortexes of the intake air W generated in the left and right vortex generators 55 rotate counterclockwise as viewed from the left side of the vehicle, as shown in Fig. 7, and thus the rotation directions of the vortices generated in the respective left and right vortex generators 55 are the same.

[0121] The intake system 50 causes the flow of intake air W in each of the air intake passages 53 and 54 to be a swirl rotating around the corresponding one of the axes 53a and 54a, thereby increasing the flow rate of the intake air W. This can improve the intake efficiency in the intake system 50.

[0122] In each of the tapered portions 53c and 54c of the air intake passages 53 and 54, the inner diameter of each of the air intake passages 53 and 54 decreases toward the downstream side. As a result, the intake air W increases its flow rate after passing through each of the tapered portions 53c and 54c.

[0123] The intake air W continues to flow in the air intake passage 53 while swirling, and flows from the downstream end 64a of the inner passage portion 64 into the dirt side 51a.

[0124] In addition, the intake air W continues to flow in the air intake passage 54 while swirling, and flows from the downstream end 74a of the inner passage portion 74 into the dirt side 51a.

[0125] The rotation direction of the vortex flowing from the downstream end 64a into the dirt side 51a is the same as that of the vortex flowing from the downstream end 74a into the dirt side 51a. This can promote the rotation of the vortexes of the intake air W.

[0126] The intake air W flows through the air cleaner 59 from the dirty side 51a to flow to the clean side 51b and flows through the supply passages 62 and the throttle valve devices 52 to flow into the cylinder 24.

[0127] With reference to Fig. 6, the tank liner 39 includes therein: a lower channel 88a between the inner surface of the second tank liner 43 and the outer end portion of the lower wall portion 82; and an upper channel 88b between the inner surface of the second tank liner 43 and the upper portion of the wind guide 79. The upper channel 88b is located above the vortex generator 55.

[0128] A portion of the airflow flowing into the tank fairing 39 from the fairing opening 42c flows through the lower channel 88a and the upper channel 88b and is discharged rearward. This allows the airflow to flow efficiently into the tank fairing 39.

[0129] Fig. 10 is a left side view of the radiator 37 to which the grille 44 is attached;.

[0130] With reference to Fig. 2, Fig. 3 and Fig. 10, the front surface of the radiator 37 is a guide surface for air (airstream) of the radiator 37.

[0131] The radiator grille 44 includes: a plate-shaped grille portion 44a that covers the front surface of the radiator 37 from the front side; and a pair of left and right wind guide plates 44b that extend outward in the vehicle width direction from the respective left and right edges of the grille portion 44a.

[0132] The grille area 44a has a rectangular shape that covers essentially the entire front surface of the radiator 37. The grille area 44a has many openings and is permeable to air.

[0133] The wind guide plate 44b is arranged over substantially the entire length of the grid area 44a in the upward and downward direction.

[0134] The wind guide plate 44b is inclined forward and outward in the vehicle width direction and runs here.

[0135] A large portion of the airflow moving from the front toward the radiator 37 flows rearward and inward in the vehicle width direction along the front slope of the wind guide plate 44b and is guided to the grille portion 44a. Therefore, the wind guide plate 44b allows the airflow to flow efficiently into the radiator 37.

[0136] With reference to Fig. 1 and Fig. 3, a canister 90 which stores vaporized fuel is arranged behind the drive unit 12 and directly under the seat 17.

[0137] The canister 90 is connected to the fuel tank 29 via lines. The vaporized fuel from the fuel tank 29 is absorbed by an adsorbent, such as activated carbon, provided in the cylindrical canister 90.

[0138] Fig. 11 is a plan view illustrating a support structure of the canister 90.

[0139] The plate-shaped fender 91 is arranged between the left and right seat frames 35. The fender 91 substantially closes the entire space between the left and right seat frames 35 in the vehicle width direction.

[0140] The fender 91 extends from the front end of the seat frame 35 to its rear end. The fender 91 covers the rear wheel 15 from above.

[0141] The front end portion of the fender 91 is provided with a shaft-shaped canister housing 91a that opens upward. The canister 90 is arranged in the canister housing 91a and fixed to the canister housing 91a. The canister 90 is arranged such that the axial direction of the canister 90 coincides with the vehicle width direction.

[0142] As described above, according to the embodiment to which the present invention is applied, the intake system 50 takes in air through the air intake ducts 53 and 54 extending from the air cleaner case 51, and includes the vortex generator 55 that causes the flow of intake air in each of the air intake ducts 53 and 54 to rotate about the corresponding one of the axes 53a and 54a of the air intake ducts 53 and 54.

[0143] According to this configuration, the vortex generator 55 causes the intake air W from each of the air intake passages 53 and 54 to be a vortex rotating around the corresponding one of the axes 53a and 54a of the air intake passages 53 and 54, and such a vortex flow flows into the air cleaner case 51. This increases the flow rate of the intake air W, possibly improving the intake efficiency.

[0144] The air intake ducts 53 and 54 have respective distal end portions provided with respective inlet openings 53b and 54b that take the intake air into the respective air intake ducts 53 and 54, and the vortex generator 55 is arranged at each of the inlet openings 53b and 54b.

[0145] This configuration can generate the swirling currents from positions where the intake ports 53b and 54b take in the intake air W into the respective air intake passages 53 and 54, thereby efficiently generating swirling currents in the air intake passages 53 and 54.

[0146] The interior of the air cleaner case 51 is divided by the air cleaner 59 which cleans the intake air, the air intake ducts 53 and 54 are arranged upstream of the air cleaner 59 in a left and right pair with respect to the air cleaner case 51, and the air cleaner case 51 has the duct connection openings 60d and 60e in a left and right pair facing each other, wherein each of the air intake ducts 53 and 54 is connected to the corresponding one of the left and right duct connection openings 60d and 60e.

[0147] This configuration can arrange the air intake ducts 53 and 54 at the left and right sides of the air cleaner case 51, respectively, on the upstream side of the air cleaner 59 in a well-balanced manner.

[0148] Furthermore, each of the air intake ducts 53 and 54 includes: the corresponding one of the outer duct portions 63 and 73 extending outward from the air cleaner case 51; and the corresponding one of the inner duct portions 64 and 74 extending within the air cleaner case 51, wherein the vortex generator 55 is disposed in each of the outer duct portions 63 and 73, and the inner duct portions 64 and 74 have the downstream ends 64a and 74a opened toward the air cleaner 59, respectively.

[0149] This design allows diverse flows to flow into the air intake ducts 53 and 54 at a high flow rate, flowing from the respective downstream ends 64a and 74a of the inner duct portions 64 and 74 toward the air cleaner 59. This improves intake efficiency. Furthermore, the air intake ducts 53 and 54 can be elongated, thereby reducing intake noise.

[0150] The air intake ducts 53 and 54 are provided in a left and right pair, the vortex generator 55 is provided in each of the left and right air intake ducts 53 and 54, and the left and right vortex generators 55 cause the flows of the intake air to rotate in the same direction.

[0151] According to this configuration, the rotations of the swirled intake air W flowing into the left and right air intake passages 53 and 54 are in the same direction, and this can promote rotations of the swirled intake air W to improve the intake efficiency.

[0152] The intake system 50 is mounted in the saddle seat vehicle 10, the saddle seat vehicle 10 having the radiator shroud 40 covering the radiator 37 from the side, the radiator shroud 40 having a portion covering the intake openings 53b and 54b, and the vortex generator 55 being integrally formed with the radiator shroud 40.

[0153] This configuration can provide the heat generator 55 in a simple structure using the radiator shroud 40.

[0154] The saddle-seat vehicle 10 includes a fuel tank 29 and the tank cowl 39 that cowls at least a portion of the fuel tank 29, the tank cowl 39 cowling the inlet openings 53b and 54b from the vehicle front and the outer side in the vehicle width direction and having a cowl opening 42c opening forward, the radiator cowl panel 40 includes the partition wall 84 behind the cowl opening 42c and in front of each of the inlet openings 53b and 54b, and the partition wall 84 includes the opening 84a that allows the running wind to flow rearward from the cowl assembly 42c.

[0155] This configuration allows the airflow to flow from the fairing opening 42c of the tank fairing 39 into the tank fairing 39 to flow into each of the inlet openings 53b and 54b through the opening 84a of the partition wall 84.

[0156] The air inlet channels 53 and 54 are arranged above the opening 84a.

[0157] This configuration separates the opening 84a from the air intake ducts 53 and 54 in the up and down directions. Thus, air (airflow) can be trapped in the tank cowl 39 between the opening 84a and the air intake ducts 53 and 54, increasing the amount of air flowing through the air intake ducts 53 and 54.

[0158] The intake system 50 is mounted in the saddle-seat vehicle 10. Each of the air intake ducts 53 and 54 extends outward in the vehicle width direction from the air cleaner case 51. The vortex generator 55 includes: the intake port 86c communicating with the corresponding one of the intake ports 53b and 54b; and the guide 87 extending forward from the intake port 86c. The intake port 86c opens toward the bottom, that is, one of the upper and lower sides, and the guide 87 includes: the first guide wall 87a extending forward and rearward in the vehicle width direction to a lower side with respect to the intake port 86c; and the second guide wall 87b connecting the rear end of the first guide wall 87a to the rear end portion of the intake port 86c.

[0159] This configuration changes the direction of the intake air W flowing backward along the first guide wall 87a in the up-and-down direction along the second guide wall 87b, and flowing into each of the air intake passages 53 and 54 from the intake port 86c. This can generate the flow rotating around each of the axes 53a and 54a of the air intake passages 53 and 54.

[0160] The second guide wall 87b is arc-shaped along the inner circumference of each of the air intake passages 53 and 54 as viewed along the axial direction of each of the air intake passages 53 and 54.

[0161] This configuration enables the arcuate second guide wall 87b provided along the inner circumference of each of the air intake ducts 53 and 54 to efficiently generate the flow around each of the axes 53a and 54a of the air intake ducts 53 and 54.

[0162] The vortex generator 55 has a side wall 86b which is a slope located downstream of the intake port 86c and inclined inward in a vehicle width direction along the rotation direction of the intake air W rotated by the vortex generator 55.

[0163] According to this configuration, the side wall 86b allows the swirled intake air W to efficiently move inward in the vehicle width direction along the axial direction of each of the air intake ducts 53 and 54.

[0164] The intake air W flowing along the guide 87 flows along the first guide wall 87a and the second guide wall 87b in an axial direction as viewed from each of the air intake passages 53 and 54 to change the flow direction thereof by 70° or more, thereby allowing the intake air W to flow into the intake port 86c.

[0165] This configuration allows the intake air W to flow along the first guide wall 87a and the second guide wall 87b to change the flow direction by 70° or more, thereby allowing the intake air W to flow into the intake port 86c. This can efficiently generate the swirling flow.

[0166] The saddle seat vehicle 10 has the radiator shroud 40 that covers the radiator 37 from the side, the radiator shroud 40 has a portion that covers the inlet openings 53b and 54b, and the vortex generator 55 is formed integrally with the radiator shroud 40. The saddle-seat vehicle 10 includes the fuel tank 29 and the tank cowl 39 that cowls at least a portion of the fuel tank 29, the tank cowl 39 cowling the intake ports 53b and 54b from the vehicle front and the outer side in the vehicle width direction and having the cowl opening 42c opening forward, the radiator cowl panel 40 including the partition wall 84 behind the cowl opening 42c and in front of each of the intake ports 53b and 54b, and the partition wall 84 including the opening 84a that allows the running wind to flow rearward from the cowl opening 42c.The intake port 86c opens toward the lower side, the first guide wall 87a extends forward and backward in a vehicle direction on the lower side with respect to the intake port 86c, and the second guide wall 87b extends upward from the first guide wall 87a toward the rear end portion of the intake port 86c, and the opening 84a is disposed below the intake port 86c and in front of the first guide wall 87a.

[0167] According to this configuration, the first guide wall 87a and the second guide wall 87b guide the air flowing through the opening 84a of the partition wall 84 rearward and upward to flow into the intake opening 86c in an efficient manner.

[0168] The above embodiment represents only one aspect of the present invention to which the present invention is applied, but the present invention is not limited to the above embodiment.

[0169] In the above embodiment, the intake port 86c opens toward the bottom, and the guide 87 includes: the first guide wall 87a extending front and rear in the vehicle direction on a lower side with respect to the intake port 86c; and the second guide wall 87b connecting the rear end of the first guide wall 87a and the rear end portion of the intake port 86c. However, the present invention is not limited to this. For example, the intake port may open toward the top, and the guide may include: a first guide wall extending front and rear in the vehicle direction on an upper side with respect to the intake port; and a second guide wall extending downward from the first guide wall and connecting the rear end of the first guide wall to the rear end portion of the intake port.

[0170] In the above embodiments, a motorcycle was described as an example of the saddle-seat vehicle 10. However, the present invention is not limited to a motorcycle, and is equally applicable to a three-wheeled saddle-seat vehicle having two front wheels or two rear wheels and a saddle-seat vehicle having four or more wheels.

[0171] A second embodiment will be described below with reference to Fig. 12 to 14. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals and will not be described.

[0172] The second embodiment differs from the above embodiment in that a vortex generating element 255 (vortex generator) is provided which is different from vortex generator 55 in shape.

[0173] Fig. 12 is a left side view of the surroundings of the vortex generating element 255 of the second embodiment. Fig. 13 is a cross-sectional view taken along the line XIII-XIII of Fig. 12 was created.

[0174] Instead of the air filter housing 51, an air filter housing 251 is arranged between the left and right main frames 31.

[0175] Fig. 14 is a view of the schematic internal structure of the air cleaner case 251 viewed from the left side.

[0176] With reference to Fig. 12 to 14, the box-shaped air cleaner housing 251 has an air cleaner 259 therein that cleans the intake air. The air cleaner 259 divides the space in the air cleaner housing 251 in a front-to-rear direction.

[0177] In the air filter housing 251, the space in front of the air filter 259 is a dirty side 251a, into which the intake air that has not passed through the air filter 259 flows. In the air filter housing 251, the space behind the air filter 259 is a clean side 251b, into which the intake air that has passed through the air filter 259 flows.

[0178] The supply channel 262 extends downward from the clean side 251b to be connected to the throttle valve device 52.

[0179] A pair of left and right air intake ducts 253 and 254 are connected to the air cleaner housing 251.

[0180] The left air intake duct 253 extends outward in the vehicle width direction from a side wall 260b on the left side of the air cleaner case 251.

[0181] The right air intake duct 254 extends outward in the vehicle width direction from a side wall 260c on the right side of the air cleaner case 251.

[0182] The side wall 260b is provided with a duct connection opening 260d to which the air inlet duct 253 is matched and connected.

[0183] The side wall 260c is provided with a duct connection opening 260e to which the air inlet duct 254 is adapted and connected.

[0184] The duct connection openings 260d and 260e are positioned in front of and below the air filter 259 in the dirt side 251a.

[0185] The air filter 259 is plate-shaped and extends in the up-and-down direction at a position behind and above the duct connecting openings 260d and 260e.

[0186] The channel connection openings 260d and 260e face each other. In other words, viewed from the vehicle side, the channel connection openings 260d and 260e at least partially overlap each other.

[0187] The air inlet duct 253 has a downstream end 253c that opens to the dirt side 251a at the duct connection opening 260d.

[0188] The air inlet duct 254 has a downstream end 254c that opens to the dirt side 251a at the duct connection opening 260e.

[0189] The downstream ends 253c and 254c face each other.

[0190] The air intake duct 253 has an axis 253a and the air intake duct 254 has an axis 254a, the axes 253a and 254a extending in the vehicle width direction.

[0191] The air intake duct 253 has, at the distal end thereof in the outer side in the vehicle width direction, an inlet opening 253b which takes in air into the air intake duct 253.

[0192] The air intake duct 254 has an inlet opening 254b at the distal end thereof in the outer side in the vehicle width direction, which takes in air into the air intake duct 254.

[0193] The radiator cowl plate 240 covers the radiator 37 at a position below the tank cowl 39 from the outside in the vehicle width direction.

[0194] Inside the tank fairing 39, vortex generating elements 255 are provided in a left and right pair.

[0195] Each swirl generating element 255 is arranged behind the lower extension 42b of the first tank cowl 42, and is covered with the second tank cowl 43 from the outside in the vehicle width direction.

[0196] The left swirl generating element 255 lines the intake port 253b from the outside in the vehicle width direction. The right swirl generating element 255 lines the intake port 254b from the outside in the vehicle width direction.

[0197] The left swirl generating element 255 includes: a side wall 290 disposed outside the intake port 253b in the vehicle width direction; a cylinder portion 293 extending inward in the vehicle width direction from the side wall 290; a guide wall 292 extending outward in the vehicle width direction from the side wall 290; and a front wall 294 extending outward in the vehicle width direction from the front edge of the side wall 290.

[0198] The outer end of the cylinder portion 293 in the vehicle width direction is a sidewall opening 290a that penetrates the sidewall 290 in the vehicle width direction. The sidewall opening 290a communicates with the intake port 253b.

[0199] The inner end of the cylinder portion 293 in the vehicle width direction is aligned with the intake port 253b from the outer side in the vehicle width direction, thereby allowing the swirl generating element 255 to be connected to the air intake passage 253. That is, the swirl generating element 255 is arranged at the intake port 253b.

[0200] The guide wall 292 is a spiral wall provided so as to surround the side wall opening 290a as viewed from the vehicle side.

[0201] Specifically, the guide wall 292 includes: an inner guide wall 295 extending outward in the vehicle width direction along the periphery of the side wall opening 290a; and an outer guide wall 296 surrounding the inner guide wall 295 from the surroundings thereof.

[0202] The inner guide wall 295 is semi-cylindrical in shape when viewed from the vehicle side and is provided at substantially the rear half of the periphery of the side wall opening 290a. Therefore, the front surface of the inner guide wall 295 opens forward.

[0203] The outer guide wall 296 extends from a starting portion 296a, which is an upper end of the inner guide wall 295 as viewed from the vehicle side, to a position in front of and below the side wall opening 290a, then rotates counterclockwise around the inner guide wall 295 and extends to a position above the starting portion 296a.

[0204] The channel formed between the outer guide wall 296 and the inner guide wall 295 is an intake air channel 297 that guides the intake air. The intake guide channel 297 has an inlet 297a above the side wall opening 290a. The intake guide channel 297 spirals clockwise around the axis 253a of the air intake channel 253 along the circumference of the side wall opening 290a, as viewed from the vehicle side.

[0205] The front wall 294 is arranged in front of the guide wall 292. The front wall 294 has a lower portion provided with an opening 294a. The opening 294a is positioned in front of and below the side wall opening 290a and the guide wall 292.

[0206] The right vortex generating element 255 is substantially symmetrical to the left vortex generating element 255 and thus the specific description of the right vortex generating element 255 will not be described.

[0207] The cylinder portion 293 in the right swirl generating element 255 is connected to the inlet port 254b of the right air intake duct 254.

[0208] The airflow from the upper opening 42c ( Fig. 2) flows into the tank cover 39, flows through the opening 294a of the front wall 294 to flow into the vortex generating element 255. A part of the airflow flowing into the heat generating element 255 flows into the upper intake guide channel 297 as intake air W ( Fig. 12).

[0209] The intake air W passes through the intake guide duct 297, rotating around the side wall opening 290a as viewed from the vehicle side, and then flows into the side wall opening 290a.

[0210] Specifically, the intake air W flowing through the intake guide duct 297 becomes a vortex rotating clockwise around the axis 253a of the air intake duct 253 as viewed from the vehicle side.

[0211] The swirled intake air W that has flowed into the side wall opening 290a flows inward in the vehicle width direction along an axial direction of the air intake duct 253 while rotating clockwise in the air intake duct 253 to flow into the dirt side 251a.

[0212] Likewise, the right vortex generating element 255 causes the intake air W (not shown) to be a vortex that rotates around the axis 254a of the air intake duct 254 when viewed from the vehicle side. Viewed from the right side of the vehicle, the intake air W generated in the right vortex generating element 255 rotates counterclockwise. In other words, from the left side of the vehicle, as shown in Fig. 12, the vortexes of the intake air W generated in the left and right vortex generating elements 255 are clockwise, and thus the rotation directions of the vortexes generated in the left and right vortex generating elements 255 are the same.

[0213] In the right swirl generating element 255, the swirled intake air W that has flowed into the side wall opening 290a flows inward in the vehicle width direction along an axial direction of the air intake duct 254 while rotating clockwise as viewed from the left side of the vehicle to flow into the dirt side 251a.

[0214] With reference to Fig. 13 and Fig.14, when viewed from the left side of the vehicle, the intake air W flowing into the dirt side 251a of each of the duct connection openings 260d and 260e rotates clockwise. This can promote the rotation of the intake air W. Moreover, the duct connection openings 260d and 260e face each other, and thus the intake air W from the duct connection opening 260d and the intake air W from the duct connection opening 260e are easily mixed, possibly promoting the rotation of the intake air W.

[0215] The intake air W rotates clockwise in the dirt side 251a as viewed from the left side of the vehicle, and thus is likely to flow upward and rearward along the inner surfaces of a front wall 251c and an upper wall 251d of the dirt side 251a. This allows the intake air W in the dirt side 251a to flow efficiently to the air cleaner 259.

[0216] As described above, according to the second embodiment to which the present invention is applied, the air intake ducts 253 and 254 have respective downstream ends 253c and 254c opening to the interior of the air cleaner case 251 at the respective duct connecting openings 260d and 260e.

[0217] This configuration allows the swirling intake air W rotating around each of the axes 253a and 254a to flow from each of the duct connection openings 260d and 260e into the air cleaner case 251 and flow to the air cleaner 259 along the inner surface of the air cleaner case 251. This allows the intake air W to flow efficiently in the air cleaner 259 by utilizing the swirling currents of the intake air W in the air cleaner case 251.

[0218] The above embodiments support the following designs.

[0219] (1. Design) An intake system that takes in air through at least one air intake duct extending from the air cleaner housing includes at least one vortex generator that causes a flow of intake air in the air intake duct to rotate about an axis of the air intake duct.

[0220] According to this design, the vortex generator causes the intake air from the air intake ducts to swirl around the axis of the air intake duct, and this vortex flow flows into the air cleaner housing. This increases the intake air flow rate, potentially improving intake efficiency.

[0221] (2nd configuration) The intake system according to the first configuration, wherein the air intake duct has a distal end portion provided with an inlet opening that receives the intake air into the air intake duct, and the vortex generator is arranged at the inlet opening.

[0222] This design can generate the swirl flow from a position where the intake port receives the intake air into the air intake duct, thereby efficiently generating the swirl flow in the air intake duct.

[0223] (3rd configuration) The intake system according to the first or second configuration, wherein an interior of the air cleaner case is partitioned by an air cleaner that cleans the intake air, the air intake duct having a pair of left and right air intake ducts disposed upstream of the air cleaner case with respect to the air cleaner case, and the air cleaner case having a pair of left and right duct connecting holes facing each other, each of the intake ducts being connected to a corresponding one of the left and right duct connecting holes.

[0224] This design can arrange the air intake ducts on the respective left and right of the air cleaner housing on the upstream side of the air cleaner in a well-balanced manner.

[0225] (4th configuration) The intake system according to the third configuration, wherein each of the air intake ducts has a downstream end opening to an interior of the air cleaner case at a corresponding one of the duct connecting ports.

[0226] This design allows the swirling intake air, rotating around each of the axes, to flow from each of the duct connection openings into the interior and flow to the air filter along the inner surface of the air filter housing. This allows the intake air to flow efficiently into the air filter using the swirling currents of the intake air in the air filter housing.

[0227] (5th configuration) The intake system according to the third configuration, wherein each of the air intake ducts comprises: an outer duct portion extending outward from the air cleaner housing; and an inner duct portion extending within the air cleaner housing, wherein the vortex generator is disposed in the outer duct portion, and the inner duct portion has an opening at the downstream end toward the air cleaner.

[0228] This design allows the swirling flow, which flows at a high flow rate in each of the air intake ducts, to flow from the downstream end of the inner duct area toward the air filter. This improves intake efficiency. Furthermore, the air intake ducts can be lengthened, thereby reducing intake noise.

[0229] (6th configuration) The intake system according to any one of the first to fifth configurations, wherein the air intake duct includes a pair of left and right air intake ducts, the swirl generator includes a pair of left and right swirl generators each disposed in a corresponding one of the left and right air intake ducts, and the left and right swirl generators cause the intake air to flow in the same direction.

[0230] According to this design, the rotations of the swirled intake air flowing into the left and right air intake ducts are in the same direction, and this can promote rotations of the swirled intake air to improve intake efficiency.

[0231] (7th configuration) The intake system according to the second configuration, wherein the intake system is mounted in the saddle-seat vehicle, the saddle-seat vehicle having a radiator shroud panel that covers a radiator from the side, the radiator shroud panel having a portion that covers the intake port, and the vortex generator is formed integrally with the radiator shroud panel.

[0232] This design can provide the vortex generator in a simple structure using the radiator shroud plate.

[0233] (8th configuration) The intake system according to the seventh configuration, wherein the saddle-seat vehicle includes a fuel tank and a tank cowl that cowls at least a portion of the fuel tank, the tank cowl covering the intake port from a vehicle front side and an outer side in a vehicle width direction and having a cowl opening opening forward, the radiator cowl panel including the partition wall behind the cowl opening and in front of an intake port, and the partition wall including an opening that allows the running wind to flow rearward from the cowl opening.

[0234] This design allows the airflow to flow from the tank fairing opening into the tank fairing to flow into the intake opening through the opening in the partition.

[0235] (9th design) The intake system according to the eighth design, wherein the air intake duct is arranged above the opening.

[0236] This design separates the opening from the air intake duct in the up and down direction, thereby increasing the amount of air flowing through the air intake duct.

[0237] (10th Configuration) The intake system according to the second configuration, wherein the intake system is mounted in the saddle-seat vehicle, the air intake duct extends outward in a vehicle width direction from the air cleaner case, the vortex generator comprising: an inlet port communicating with the inlet port; and a guide extending forward from the inlet port, the inlet port opening toward one side of the upper and lower sides, and the guide comprising: a first guide wall extending forward and rearward in a vehicle direction on one side with respect to the inlet port; a second guide wall connecting a rear end of the first guide wall to a rear end portion of the inlet port.

[0238] This design changes the direction of the intake air flowing up and down along the first guide wall and backward along the second guide wall, flowing into the air intake duct from the intake port. This can generate a flow that rotates around the axis of the air intake duct.

[0239] (11th Design) The intake system according to the tenth design, wherein the second guide wall is arc-shaped along an inner circumference of the air intake duct when viewed along an axial direction of the air intake duct.

[0240] This configuration enables the arcuate second guide wall provided along the inner circumference of each of the air intake ducts to efficiently generate the flow rotating around the axis of the air intake duct.

[0241] (12th configuration) The intake system according to the tenth or eleventh configuration, wherein the swirl generator has a slope that is disposed downstream of the intake port and slopes inward in a vehicle width direction along a rotation direction of intake air rotating by the swirl generator.

[0242] According to this design, the inclination of the swirled intake air allows it to move efficiently inward in the vehicle width direction along the axial direction.

[0243] (13th configuration) The intake system according to any one of the tenth to twelfth configurations, wherein the intake air flowing along the guide flows along the first guide wall and the second guide wall as viewed in an axial direction of the air intake duct to change a flow direction of the intake air by 70° or more, thereby allowing the intake air to flow into the intake port.

[0244] This design allows the intake air to flow along the first guide wall and the second guide wall, changing the flow direction by 70° or more, allowing the intake air to flow into the intake port. This can efficiently generate the swirling flow.

[0245] (14. Configuration) The intake system according to any one of the tenth to thirteenth configurations, wherein the saddle-seat vehicle has a radiator cowl panel that covers a radiator from one side, the radiator cowl panel having a portion that covers the intake port, the vortex generator is formed integrally with the radiator cowl panel, the saddle-seat vehicle has a fuel tank and a tank cowl that covers at least a portion of the fuel tank, the tank cowl covering intake ports from a vehicle front side and an outer side in the vehicle width direction and having a cowl opening that opens forward, the radiator cowl panel having a partition wall behind the cowl opening and in front of the intake port, the partition wall having an opening that allows the running wind to flow rearward from the cowl opening,the inlet opening opens towards the underside and the first guide wall extends forward and rearward in a vehicle direction on the underside with respect to the inlet opening, and the second guide wall extends upward from the first guide wall towards the rear end region of the inlet opening, and the opening is arranged below the inlet opening and in front of the first guide wall.

[0246] According to this configuration, the first guide wall and the second guide wall guide the airflow passing through the opening of the partition wall rearward and upward to allow the airflow to flow into the intake port efficiently. List of reference symbols: 10 saddle-seat vehicle 29 Fuel tank 37 coolers 39 Tank fairing 40 Radiator cover plate 42c panel opening 50 Inlet system 51, 251 air filter housing 53, 54 Air intake duct 53a, 54a axis 53b, 54b Inlet opening 55 Vortex Generator 59, 259 air filters 60d, 60e duct connection opening 63, 73 Outer canal area 64, 74 Inner canal area 64a, 74a Downstream end 84 Partition wall 84a Opening 86b Side wall (slope) 86c Inlet opening 87 leadership 87a First guide wall 87b Second guide wall 253, 254 Air intake duct 253a, 254a axis 253b, 254b Inlet opening 253C, 254c Downstream end 255 Vortex generating element (vortex generator) 260d, 260e duct connection opening

Claims

[1] Intake system (50) which receives air through at least one air inlet duct (53, 54) extending from an air filter housing (51), wherein the inlet system (50) comprises at least one vortex generator (55) which causes a flow of the intake air in the air intake duct (53, 54) to rotate about an axis (53a, 54a) of the air intake duct (53, 54), wherein the air inlet duct (53, 54) has a distal end portion provided with an inlet opening (53b, 54b) which receives inlet air into the air inlet duct (53, 54), and the vortex generator (55) is arranged at the inlet opening (53b, 54b), characterized by , that the intake system (50) is mounted in the saddle-seat vehicle (10), the saddle-seat vehicle (10) has a radiator cover plate (40) which covers a radiator (37) from one side, the radiator cover plate (40) has a region which covers the inlet opening (53b, 54b), and the vortex generator (55) is formed integrally with the radiator cover plate (40). [2] Intake system (50) according to claim 1, wherein an interior of the air filter housing (51) is divided by an air filter (59) which cleans the intake air, the air inlet duct (53, 54) has a pair of left and right air inlet ducts (53, 54) with respect to the air filter housing (51) which are arranged upstream of the air filter (59, 259), and the air cleaner housing (51) has a pair of left and right duct connecting openings (60d, 60e) facing each other, each of the air intake ducts (53, 54) being connected to a corresponding one of the left and right duct connecting openings (60d, 60e). [3] Intake system (50) according to claim 2, wherein each of the air inlet ducts (53, 54) comprises: an outer duct portion (63, 73) extending outwardly from the air filter housing (51); and an inner duct portion (64, 74) extending within the air filter housing (51), the vortex generator (55) is arranged in the outer channel region (63, 73), and the inner channel region (64, 74) has a downstream end (64a, 74a) which opens towards the air filter (59). [4] Inlet system (50) according to one of claims 1 to 3, wherein the air inlet duct (53, 54) has a pair of left and right air inlet ducts (53, 54), the vortex generator (55) comprises a pair of left and right vortex generators (55), each of which is arranged on a corresponding one of the left and right air intake ducts (53, 54), and the left and right vortex generators (55) cause streams of intake air to rotate in the same direction. [5] Inlet system (50) according to one of claims 1 to 4, wherein the saddle-seat vehicle (10) has a fuel tank (29) and a tank cladding (39) which covers at least a portion of the fuel tank (29), the tank cowl (39) covers the inlet opening (53b, 54b) from a vehicle front side and an outer side in a vehicle width direction and has a cowl opening (42c) opening forward, the radiator cover plate (40) has a partition wall (84) behind the cover opening (42c) and in front of the inlet opening (53b, 54b), and the partition wall (84) has an opening (84a) which allows the airflow to flow rearward from the fairing opening (42c). [6] Intake system (50) according to claim 5, wherein the air inlet duct (53, 54) is arranged above the opening (84a). [7] Intake system (50) according to one of claims 1 to 6, wherein the air intake duct (53, 54) extends outward in a vehicle width direction from the air cleaner housing (51), the vortex generator (55) comprises: another inlet opening (86c) communicating with the inlet opening (53b, 54b); and a guide (87) extending forward from the other inlet opening (86c), the other inlet opening (86c) opens to one side of the upper and lower sides, and the guide (87) comprises: a first guide wall (87a) extending forward and rearward in a vehicle direction on one side with respect to the other inlet opening (86c); and a second guide wall (87b) connecting a rear end of the first guide wall (87a) to a rear end portion of the other inlet opening (86c). [8] The intake system (50) according to claim 7, wherein the second guide wall (87b) is arcuately formed along an inner circumference of the air intake duct (53, 54) when viewed in an axial direction of the air intake duct (53, 54). [9] The intake system (50) according to claim 7 or 8, wherein the vortex generator (55) has a slope (86b) disposed downstream of the other intake port (86c) and inclined inward in a vehicle width direction along a rotation direction of the intake air rotated by the vortex generator (55). [10] The intake system (50) according to any one of claims 7 to 9, wherein the intake air flowing along the guide (87) flows along the first guide wall (87a) and the second guide wall (87b) as viewed in an axial direction of the air intake duct (53, 54) to change a flow direction of the intake air by 70° or more, thereby allowing the intake air to flow into the other intake port (86c). [11] Inlet system (50) according to claim 5 in conjunction with any one of claims 7 to 10, wherein the other inlet opening (86c) opens towards the bottom, the first guide wall (87a) extends forward and rearward in a vehicle direction on the lower side with respect to the other intake opening (86c); and the second guide wall (87b) extends from the first guide wall (87a) toward a rear end portion of the other intake opening (86c), and the opening (84a) is arranged below the other inlet opening (86c) and in front of the first guide wall (87a).

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