air cleaner

Abstract

To smoothly flow air in an air filter by suppressing the adhesion of water to the air filter.SOLUTION: An air cleaner (50) is disposed inside a vehicle body frame. The air cleaner is provided with an air cleaner case (51) formed with an intake chamber (56), an air filter (57) disposed in the intake chamber, an inlet tube (62) taking air into the intake chamber, and an outlet tube (82) sending the air out from the intake chamber. The inlet tube extends in a fore-and-aft direction. In a side view, a bottom wall of the inlet tube is curved downward to form a recessed curved portion (71) below a discharge port (64) of the inlet tube, and a draining hole (72) is formed in the recessed curved portion.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an air cleaner. [Background technology]

[0002] A straddle-type vehicle having an air cleaner disposed behind the engine is known (see, for example, Patent Document 1). The air cleaner described in Patent Document 1 has an inlet tube attached to the rear surface of an air cleaner case and an outlet tube attached to the front surface of the air cleaner case. Air is taken into the air cleaner case through the inlet tube and filtered by an air filter disposed inside the air cleaner. Clean air then enters the outlet tube from the air cleaner and is sent out to the throttle body through the outlet tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4121392 Summary of the Invention [Problem to be solved by the invention]

[0004] The air cleaner described in Patent Document 1 is located below the seat, with the inlet tube's intake opening opening inside the vehicle frame. To improve airflow, the opening area of ​​the inlet tube's intake opening needs to be large, but if water seeps into the air cleaner through the intake opening and wets the air filter, the airflow may deteriorate. While it is possible to prevent water from entering by bending the inlet tube, this has the disadvantage of increasing intake resistance due to the sharp bend in the inlet tube in the narrow space inside the vehicle frame.

[0005] The present invention has been made in view of the above points, and an object of the present invention is to provide an air cleaner that can suppress adhesion of water to the air filter and allow air to flow smoothly. [Means for solving the problem]

[0006] An air cleaner according to one aspect of the present invention is an air cleaner disposed inside a vehicle body frame, and includes an air cleaner case having an intake chamber formed therein, an air filter disposed in the intake chamber, an inlet tube for taking air into the intake chamber, and an outlet tube for sending air out of the intake chamber, wherein the inlet tube extends in a front-rear direction, a bottom wall of the inlet tube is curved downward in a side view to form a concave curved portion below the outlet port of the inlet tube, and a drain hole is formed in the concave curved portion. The lower edge of the intake port of the inlet tube is located below the drain hole, and a convex portion is formed by protruding the bottom wall of the inlet tube upward between the lower edge of the intake port and the drain hole. This solves the above problem. [Effects of the Invention]

[0007] In one aspect of the air cleaner of the present invention, the bottom wall of the inlet tube is curved downward to form a concave portion below the inlet tube's outlet, making it difficult for water that enters the inlet tube to hit the concave portion and head toward the air filter in the intake chamber. The concave portion makes it easier for water inside the inlet tube to collect at the drain hole, allowing it to be drained from the inlet tube through the drain hole. Furthermore, the concave portion of the inlet tube does not impede the flow of air from the inlet tube toward the air filter. Therefore, even if the opening area of ​​the inlet tube's intake port is increased, water adhesion to the air filter is suppressed, allowing air to flow smoothly through the air cleaner. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a left side view of a saddle-ride type vehicle according to an embodiment of the present invention; [Figure 2] FIG. 2 is a left side view of the engine and its surroundings according to the present embodiment. [Figure 3] FIG. 2 is a top view of the engine and its surroundings according to the present embodiment. [Figure 4] FIG. 2 is a side view of the air cleaner of the present embodiment. [Figure 5] FIG. 2 is a top view of the air cleaner of the present embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the air cleaner of FIG. 5 taken along line AA. [Figure 7] 6 is a cross-sectional view of the air cleaner of FIG. 5 taken along line BB. [Figure 8] FIG. 4 is a cross-sectional view of the engine periphery taken along line CC in FIG. 3. [Figure 9] 3 is a diagram showing the flow of air and water in the air cleaner of the present embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] An air cleaner according to one aspect of the present invention is disposed inside a vehicle frame. An air cleaner case of the air cleaner defines an intake chamber, and an air filter is disposed in the intake chamber. Air is taken into the intake chamber through an inlet tube and discharged from the intake chamber through an outlet tube. The inlet tube extends in the front-to-rear direction, and a concave portion is formed by curving downward at the bottom wall of the inlet tube in a side view. The concave portion is located below the outlet of the inlet tube, so that water that has entered the inlet tube strikes the concave portion and is less likely to flow toward the air filter in the intake chamber. A drain hole is formed in the concave portion, and the concave portion makes it easier for water in the inlet tube to collect at the drain hole, allowing the water to be drained from the inlet tube through the drain hole. Furthermore, the concave portion of the inlet tube does not impede the flow of air from the inlet tube toward the air filter. Therefore, even if the opening area of ​​the inlet tube's intake port is increased, water adhesion to the air filter is suppressed, allowing air to flow smoothly through the air cleaner. [Example]

[0010] This embodiment will be described in detail below with reference to the accompanying drawings. Fig. 1 is a left side view of a saddle-ride type vehicle according to this embodiment. In the following drawings, arrow FR indicates the front of the vehicle, arrow RE indicates the rear of the vehicle, arrow L indicates the left side of the vehicle, and arrow R indicates the right side of the vehicle.

[0011] As shown in Fig. 1, the saddle-type vehicle 1 is configured by mounting an engine 40, an electrical system, and other various components on a diamond-shaped body frame 10 formed from pipes and sheet metal. The body frame 10 has a pair of main frames 12 that branch off to the left and right from a head pipe 11 and extend rearward, and a pair of down frames 13 that branch off to the left and right from the head pipe 11 and extend downward. The pair of main frames 12 support the rear of the engine 40, and the pair of down frames 13 support the front of the engine 40. Supporting the engine 40 on the body frame 10 ensures the rigidity of the entire vehicle.

[0012] The front portion of the main frame 12 forms a tank rail 14 located above the engine 40, and a fuel tank 31 is supported from below by the tank rail 14. The rear portion of the main frame 12 forms a body frame 15 located behind the engine 40, and a swing arm 25 is swingably supported on the lower half of the body frame 15. A seat rail 21 consisting of an upper rail 22 and a lower rail 23 is attached to the upper half of the body frame 15. A rider seat 32 and a pillion seat 33 are supported on the upper portion of the upper rail 22 behind the fuel tank 31.

[0013] A pair of front forks 34 are steerably supported on the head pipe 11 via a steering shaft (not shown). A front wheel 35 is rotatably supported on the lower part of the front forks 34, and an upper part of the front wheel 35 is covered by a front fender (not shown). A swing arm 25 extends rearward from the body frame 15. A rear wheel 36 is rotatably supported on the rear end of the swing arm 25, and an upper part of the rear wheel 36 is covered by a rear fender (not shown). An engine 40 is connected to the rear wheel 36 via a chain drive transmission mechanism, and power from the engine 40 is transmitted to the rear wheel 36 via the transmission mechanism.

[0014] An air cleaner 50 is disposed behind the engine 40, and an inlet tube 62 of the air cleaner 50 extends rearward. In order to improve the air flow through the air cleaner 50 by enlarging the intake port of the inlet tube 62, it is necessary to prevent water from entering the air cleaner 50 so that the air filter 57 (see FIG. 6) does not get wet. In the narrow space behind the engine 40, it is difficult to orient the intake port upward or to the side to prevent water from entering from the rear of the vehicle. Therefore, the air cleaner 50 of this embodiment uses an inlet tube 62 that can capture and drain water heading toward the air filter 57 without impeding the air flow.

[0015] The peripheral configuration of the engine and the air cleaner will be described with reference to Figures 2 to 8. Figure 2 is a left side view of the engine periphery of this embodiment. Figure 3 is a top view of the engine periphery of this embodiment. Figure 4 is a side view of the air cleaner of this embodiment. Figure 5 is a top view of the air cleaner of this embodiment. Figure 6 is a cross-sectional view of the air cleaner of Figure 5 taken along line AA. Figure 7 is a cross-sectional view of the air cleaner of Figure 5 taken along line BB. Figure 8 is a cross-sectional view of the engine periphery of Figure 3 taken along line CC.

[0016] As shown in Figures 2 and 3, the engine 40 is a two-cylinder engine and has a crankcase 41 with an upper-lower split structure. A cylinder 42, a cylinder head 43, and a cylinder head cover 44 are attached to the upper part of the crankcase 41. A magneto cover 45 that covers a magneto (not shown) from the side is attached to the left side of the crankcase 41. A sprocket cover 46 that covers a drive sprocket (not shown) from the side is attached behind the magneto cover 45. A clutch cover 47 that covers a clutch (not shown) from the side is attached to the right side of the crankcase 41.

[0017] A throttle body 48 is connected to the rear surface of the cylinder head 43, and an air cleaner 50 is connected upstream (rear side) of the throttle body 48. The air cleaner 50 is disposed rearward of the engine 40 and inside the pair of main frames 12 and the pair of seat rails 21. As described above, the rear portions of the pair of main frames 12 form the pair of body frames 15, and the front end portion of the air cleaner 50 is positioned inside the pair of body frames 15. The upper half of the body frames 15 is inclined obliquely downward toward the rear, and the air cleaner case 51 behind the body frames 15 is also inclined obliquely downward.

[0018] An upper bracket 16 and a lower bracket 17 are formed on the rear edge of the upper half of the body frame 15. An upper rail 22 of a seat rail 21 is connected to the upper bracket 16, and a lower rail 23 of the seat rail 21 is connected to the lower bracket 17. The upper rail 22 extends rearward across the side of the upper half of the air cleaner case 51, and the lower rail 23 extends diagonally rearward across the side of the lower half of the air cleaner case 51. The front sides of the upper rail 22 and the lower rail 23 are connected via a bridge pipe 24, and the rear sides of the upper rail 22 and the lower rail 23 are connected at the rear of the vehicle.

[0019] The front part of the air cleaner case 51 protrudes upward from the upper rail 22, and the protruding part at the front is housed in the space inside the rider's seat 32 (see Figure 1). The rear part of the air cleaner case 51 protrudes downward from the lower rail 23, and the protruding part at the rear forms an extension part 65 that expands the intake chamber 56 (see Figure 6) inside the air cleaner case 51. The extension part 65 of the air cleaner case 51 is positioned above the swing arm 25 (see Figure 1), and the extension part 65 extends rearward so as to avoid the swing range of the swing arm 25. The volume of the air cleaner case 51 is expanded by utilizing the space below the seat rail 21.

[0020] The battery case 38 and the battery 37 are disposed above the extension portion 65 of the air cleaner case 51. The battery case 38 is supported by the pair of seat rails 21 via a bridge 19. The battery case 38 is formed in a box shape with an open top, and the rectangular parallelepiped battery 37 is held inside the battery case 38. In top view, the pair of inlet tubes 62 of the air cleaner 50 are curved, and the battery 37 is positioned between the pair of inlet tubes 62. Space above the extension portion 65 of the air cleaner 50 is used to ensure space for arranging the battery 37.

[0021] 4 to 6, an air cleaner case 51 of the air cleaner 50 has an upper case 52 and a lower case 53 that are split vertically, and a filter cover 54 attached to the rear surface of the upper case 52. The upper case 52 and the lower case 53 extend diagonally downward from the front to the rear, and the filter cover 54 bulges out in a dome shape on the rear side of the upper case 52. An opening 55 formed in the rear surface of the upper case 52 connects the internal spaces of the upper case 52 and the lower case 53 with the internal space of the filter cover 54, forming an intake chamber 56 inside the air cleaner case 51.

[0022] An air filter 57 is disposed in an opening 55 on the rear surface of the upper case 52, and the air filter 57 is covered from the rear by a filter cover 54. The air filter 57 is tilted along the top surface of the upper case 52 so that the top of the air filter 57 is further forward of the vehicle than the bottom. The air filter 57 divides the intake chamber 56 into a dirty side 58 and a clean side 59. In other words, the dirty side 58 is formed by the filter cover 54 upstream of the air filter 57, and the clean side 59 is formed by the upper case 52 and lower case 53 downstream of the air filter 57.

[0023] A pair of inlet tubes 62 are attached to the left and right side walls 61 of the filter cover 54. The pair of inlet tubes 62 extend from the left and right side walls 61 of the filter cover 54 toward the rear of the vehicle, and air is taken in from the rear of the vehicle to the dirty side 58 by the pair of inlet tubes 62. An intake port 63 of the inlet tube 62 faces toward the rear of the vehicle, and an exhaust port 64 of the inlet tube 62 faces inward in the vehicle width direction. The pair of inlet tubes 62 are positioned inside the pair of seat rails 21 (see FIG. 3), and the distance between the pair of inlet tubes 62 approximately matches the lateral width of the extension portion 65.

[0024] A pair of outlet tubes 82 are attached to a front wall 81 of the lower case 53. The pair of outlet tubes 82 extend longitudinally through the front wall 81 of the lower case 53, and air is sent from the clean side 59 to the engine 40 (see FIG. 1) by the pair of outlet tubes 82. An intake port 83 of the outlet tube 82 faces toward the rear of the vehicle, and an exhaust port 84 of the outlet tube 82 faces toward the front of the vehicle. The pair of outlet tubes 82 are positioned inside the pair of main frames 12 (see FIG. 3), and the pair of outlet tubes 82 are connected to a pair of intake passages of the throttle body 48.

[0025] The inlet tube 62 and the outlet tube 82 are attached to the upper side of the air cleaner case 51. As described above, the inlet tube 62 is attached to the filter cover 54, and the outlet tube 82 is attached to the front wall 81 of the lower case 53, and the filter cover 54 and the front wall 81 of the lower case 53 face each other in the front-to-rear direction with the air filter 57 interposed between them in a side view. The outlet port 64 of the inlet tube 62 and the intake port 83 of the outlet tube 82 are located at approximately the same height, which makes it easier for air to flow directly from the inlet tube 62 to the outlet tube 82.

[0026] A breather nipple 85 is formed in the front of the upper case 52, and a breather hose (not shown) extending from the engine 40 is connected to the breather nipple 85. An intake air temperature sensor 86 is attached near the breather nipple 85, and the detection result of the intake air temperature sensor 86 is used to control the amount of fuel injected into the engine 40 (see FIG. 1). A secondary air nipple 87 is formed in the front of the lower case 53, and a secondary air hose (not shown) extending to the exhaust system is connected to the secondary air nipple 87. A drain plug 88 is provided in the bottom of the lower case 53, and water inside the air cleaner case 51 is drained from the drain plug 88.

[0027] As shown in Figure 7, the bottom wall and top wall of the inlet tube 62 are curved downward. The bottom wall of the inlet tube 62 is curved downward to form a concave curved portion 71 below the outlet 64, and the top wall of the inlet tube 62 is curved downward to form a convex curved portion 73. The lowest position of the concave curved portion 71 is located below the lower edge of the outlet 64 of the inlet tube 62 (see Figure 6), and the lowest position of the convex curved portion 73 is located below the upper edge of the outlet 64 of the inlet tube 62. Air inside the inlet tube 62 flows smoothly toward the outlet 64, but water adhering to the wall surface of the inlet tube 62 has difficulty flowing toward the outlet 64.

[0028] A drain hole 72 that penetrates the bottom wall of the inlet tube 62 is formed in the concave curved portion 71, making it easy for water captured by the concave curved portion 71 to collect in the drain hole 72. A convex curved portion 73 is positioned above the drain hole 72, making it easy for water captured by the convex curved portion 73 to fall into the concave curved portion 71 and collect in the drain hole 72. Water is discharged through the drain hole 72, improving the drainage performance of the inlet tube 62. Water that has entered the inlet tube 62 is less likely to head toward the air filter 57 (see FIG. 6), which reduces water adhesion to the air filter 57 and ensures smoother airflow in the air cleaner 50.

[0029] At this time, the concave curved portion 71 and the convex curved portion 73 are curved with a curvature that does not interfere with the flow of air from the inlet port 63 to the outlet port 64, and the concave curved portion 71 and the convex curved portion 73 do not significantly increase the intake resistance of the inlet tube 62. Although some air flows out from the inlet tube 62 through the drain hole 72, the inner diameter of the drain hole 72 is formed small enough so as not to excessively affect the flow of air from the inlet port 63 to the outlet port 64. In addition, the inlet port 63 of the inlet tube 62 is formed larger than the outlet port 64, making it easier for air to enter the inlet tube 62 from the inlet port 63.

[0030] The lower edge of the intake port 63 of the inlet tube 62 is located below the drain hole 72. A convex portion 75 is formed between the lower edge of the intake port 63 and the drain hole 72 by protruding the bottom wall of the inlet tube 62 upward. The convex portion 75 is curved upward near the lower edge of the intake port 63, and even if the opening area of ​​the intake port 63 of the inlet tube 62 is increased, the convex portion 75 prevents water from entering near the intake port 63. When water is captured by the convex portion 75 near the intake port 63 of the inlet tube 62, some of the water moves from the convex portion 75 toward the concave portion 71 and is collected in the drain hole 72, improving the drainage performance of the inlet tube 62.

[0031] Furthermore, when the air cleaner 50 is disposed inside a pair of seat rails 21 that have height restrictions, as in this embodiment, the positions of the air filter 57 (see FIG. 6) and the outlet 64 of the inlet tube 62 cannot be shifted in the height direction. For this reason, the drain hole 72 of the inlet tube 62 is positioned below the center of the height direction of the air filter 57. Even if water that has accumulated in the concave curved portion 71 is carried by the air flow and moves toward the outlet 64 (see FIG. 6), the water is unlikely to adhere to positions higher than the center of the height direction of the air filter 57. Therefore, water does not adhere to the entire air filter 57, and the air flow is not obstructed by a wet air filter 57.

[0032] As shown in Figure 8, in a cross-sectional view perpendicular to the direction in which the inlet tube 62 extends, the inlet tube 62 has a cross-sectional shape of a right-angled trapezoid with its acute angle facing downward. The acute angle of the right-angled trapezoid is positioned on the inner side in the vehicle width direction, and the acute angle of this right-angled trapezoid forms a valley shape in the bottom wall of the concave curved portion 71. A drain hole 72 is formed in the valley bottom of the concave curved portion 71, and the valley shape of the concave curved portion 71 collects water in the drain hole 72, improving the drainage performance of the inlet tube 62. In both a side view and a cross-sectional view, the drain hole 72 is formed at the lowest position of the concave curved portion 71.

[0033] The battery 37 is located on the inner side of the inlet tube 62 in the vehicle width direction. As described above, the battery 37 is held in the box-shaped battery case 38. The flange 39 extends outward in the vehicle width direction from the outer edge of the battery case 38, and the flange 39 is located below the drain hole 72 of the inlet tube 62. The inlet tube 62 and the flange 39 face each other with a small gap between them, and the flange 39 covers the drain hole 72 of the inlet tube 62 from below. The flange 39 blocks the inflow path to the drain hole 72, preventing water from entering the inlet tube 62 through the drain hole 72.

[0034] The flow of air and water in the air cleaner will be described with reference to Figure 9. Figure 9 is a diagram showing the flow of air and water in the air cleaner of this embodiment. Figure 9(A) shows the flow of air and water in the air cleaner as seen from the side, and Figure 9(B) shows the flow of air and water in the air cleaner as seen from the rear.

[0035] 9(A), the air filter 57 is tilted so that the upper part is closer to the front of the vehicle than the lower part in a side view. The outlet 64 of the inlet tube 62 faces the center of the front surface of the air filter 57, and the intake port 83 of the outlet tube 82 faces the upper part of the back surface of the air filter 57. Because the center of the front surface and the upper part of the back surface of the tilted air filter 57 are at approximately the same height, the outlet 64 of the inlet tube 62 and the intake port 83 of the outlet tube 82 face each other with the air filter 57 in between. The intake port 63 of the inlet tube 62 is formed wide, making it easy for air to be taken in through the intake port 63.

[0036] A concave curved portion 71 is formed on the bottom wall of the inlet tube 62, and a convex curved portion 73 is formed on the top wall of the inlet tube 62. Because the concave curved portion 71 and the convex curved portion 73 are gently curved, even when air is taken in through the intake port 63 of the inlet tube 62, the curved shapes of the concave curved portion 71 and the convex curved portion 73 do not impede the flow of air. Therefore, air flows smoothly from the intake port 63 to the exhaust port 64 of the inlet tube 62. During rainy weather, water is taken in along with the air through the intake port 63 of the inlet tube 62, but the curved shapes of the concave curved portion 71 and the convex curved portion 73 capture the water.

[0037] On the bottom wall of the inlet tube 62, the upstream side of the concave curved portion 71 from the convex portion 75 to the drain hole 72 slopes downward, and the downstream side of the concave curved portion 71 from the drain hole 72 to the discharge port 64 slopes upward. When water adheres to the downward slope on the upstream side of the concave curved portion 71, the water moves downstream (front) from the downward slope toward the drain hole 72, as indicated by arrow A1. When water adheres to the upward slope on the downstream side of the concave curved portion 71, the water moves upstream (rear) from the upward slope toward the drain hole 72, as indicated by arrow A2. Furthermore, the convex portion 75 makes it difficult for water to enter the vicinity of the intake port 63 of the inlet tube 62, as indicated by arrow A3.

[0038] On the upper wall of the inlet tube 62, the upstream side of the convex curved portion 73 from the intake port 63 to the apex 74 slopes downward, and the downstream side of the convex curved portion 73 from the apex 74 to the exhaust port 64 slopes upward. When water adheres to the downward slope on the upstream side of the convex curved portion 73, the water moves downstream (front side) from the downward slope toward the apex 74 as indicated by arrow A4. When water adheres to the upward slope on the downstream side of the convex curved portion 73, the water moves upstream (rear side) from the upward slope toward the apex 74 as indicated by arrow A5. Furthermore, water flows down from the apex 74 of the convex curved portion 73 toward the concave curved portion 71 and moves toward the drain hole 72 in the concave curved portion 71.

[0039] As shown in Figure 9(B) , in a cross-sectional view perpendicular to inlet tube 62, the bottom wall of inlet tube 62 slopes downward from the outer side in the vehicle width direction toward the inner side in the vehicle width direction. In cross-sectional view, concave curved portion 71 is formed in a V-shaped valley, and water drainage hole 72 is formed at the bottom of this valley shape. Therefore, when water adheres to the slope of concave curved portion 71, the water moves from the slope toward water drainage hole 72 toward the inner side in the vehicle width direction, as shown by arrow A6. As shown by arrows A1-A6, water is collected in water drainage hole 72 by concave curved portion 71 and convex curved portion 73, and is effectively drained from inlet tube 62 through water drainage hole 72.

[0040] 9(A), the lower edge of the outlet 64 of the inlet tube 62 is located below the center of the height of the air filter 57. Therefore, even if water travels up the slope on the downstream side of the concave curved portion 71 and is discharged from the outlet 64 toward the air filter 57, the water is less likely to adhere to the air filter 57 above the center of the height, as indicated by arrow A7. In other words, the water adheres to the air filter 57 at a position that avoids the main flow of air F flowing from the outlet 64 of the inlet tube 62 toward the intake port 63 of the outlet tube 82. Therefore, the main flow of air F within the air cleaner 50 is not obstructed by a wet air filter 57.

[0041] As described above, according to this embodiment, by curving the bottom wall and top wall of the inlet tube 62 downward, water that has entered the inlet tube 62 is less likely to head toward the air filter 57 in the air intake chamber 56. Water inside the inlet tube is more likely to collect at the drain holes 72, and is drained from inside the inlet tube through the drain holes 72. In addition, the curved shape of the inlet tube 62 does not impede the flow of air from the inlet tube 62 toward the air filter 57. Therefore, even if the opening area of ​​the intake port 63 of the inlet tube 62 is increased, water adhesion to the air filter 57 is suppressed, allowing air to flow smoothly through the air cleaner 50.

[0042] In this embodiment, a two-cylinder engine is used as an example of the engine, but the type of engine is not particularly limited.

[0043] In addition, in this embodiment, the air cleaner has a pair of inlet tubes and a pair of outlet tubes, but the number of inlet tubes and outlet tubes is not limited. For example, the air cleaner may have a single inlet tube and a single outlet tube, or may have three or more inlet tubes and three or more outlet tubes.

[0044] Furthermore, in this embodiment, a convex curved portion is formed on the upper wall of the inlet tube, but as long as a concave curved portion is formed at least on the bottom wall of the inlet tube, the upper wall of the inlet tube does not necessarily have to have a convex curved portion.

[0045] In addition, in this embodiment, the inlet tube is formed in a right-angled trapezoidal shape when viewed in a cross section perpendicular to the extending direction of the inlet tube, but it is sufficient if the cross-sectional shape of the concavely curved portion of the inlet tube is formed in a valley shape when viewed in a cross section.

[0046] In addition, in this embodiment, the drain hole is formed at the lowest position of the concavely curved portion of the inlet tube when viewed from the side, but the drain hole may be formed at a position other than the lowest position as long as it is in the concavely curved portion.

[0047] Furthermore, although the air filter is disposed at an angle in this embodiment, the air filter does not have to be disposed at an angle. For example, the air filter may be disposed vertically.

[0048] In addition, in this embodiment, the drain hole is located below the height center of the air filter, but the positional relationship between the height center of the air filter and the height center of the drain hole is not particularly limited.

[0049] In addition, in this embodiment, a convex portion is formed near the intake port of the inlet tube, but the inlet tube does not necessarily have to have a convex portion.

[0050] In addition, in this embodiment, the air cleaner case is formed with an expanded portion that expands the intake chamber, but the air cleaner case does not have to be formed with an expanded portion. As long as the air cleaner case has an intake chamber, the shape of the air cleaner case is not particularly limited.

[0051] Furthermore, the air cleaner is not limited to the straddle-type vehicle shown in the drawings, and may be used in other types of straddle-type vehicles. A straddle-type vehicle is not limited to all vehicles in which a rider sits astride a seat, but also includes small scooter-type vehicles in which a rider does not sit astride a seat.

[0052] As described above, the air cleaner (50) of this embodiment is an air cleaner disposed inside the vehicle body frame (10) and includes an air cleaner case (51) having an intake chamber (56), an air filter (57) disposed in the intake chamber, an inlet tube (62) for drawing air into the intake chamber, and an outlet tube (82) for discharging air from the intake chamber. The inlet tube extends in the front-to-rear direction, and the bottom wall of the inlet tube is curved downward in side view to form a concave curved portion (71) below the inlet tube's outlet port, and a water drain hole (72) is formed in the concave curved portion. With this configuration, the bottom wall of the inlet tube is curved downward to form the concave curved portion below the inlet tube's outlet port (64). This configuration prevents water that enters the inlet tube from hitting the concave curved portion and flowing toward the air filter in the intake chamber. The concave curved portion allows water in the inlet tube to easily collect at the water drain hole, allowing water to be drained from the inlet tube through the water drain hole. Furthermore, the concave curve of the inlet tube does not impede the flow of air from the inlet tube toward the air filter, so even if the opening area of ​​the inlet tube's intake port is increased, water adhesion to the air filter is suppressed, allowing air to flow smoothly through the air cleaner.

[0053] In the air cleaner of this embodiment, the upper wall of the inlet tube is curved downward in side view to form a convex curved portion (73), and the drain holes are located below the convex curved portion. According to this configuration, by forming the convex curved portion by curving the upper wall of the inlet tube downward, water that has entered the inlet tube is less likely to flow toward the air filter in the intake chamber. Water adhering to the convex curved portion falls to the concave curved portion, and is more likely to collect in the drain holes, further improving drainage.

[0054] In the air cleaner of this embodiment, the drain hole is located below the center of the air filter in the vertical direction. With this configuration, even if water accumulated in the concave curved portion moves toward the outlet with the air flow, the water is less likely to adhere to positions above the center of the air filter in the vertical direction. Therefore, water does not adhere to the entire air filter, and the air flow is less likely to be obstructed by a wet air filter.

[0055] In the air cleaner of this embodiment, the lower edge of the inlet tube's intake port (63) is located below the drain hole, and a convex portion (75) is formed by projecting upward from the bottom wall of the inlet tube between the lower edge of the intake port and the drain hole. With this configuration, even if the opening area of ​​the inlet tube's intake port is increased, the convex portion makes it difficult for water to penetrate deep into the intake port. In addition, the convex portion and the concave portion make it easier for water to collect at the drain hole, improving drainage.

[0056] In the air cleaner of this embodiment, the concave curved portion is formed in a valley shape in a cross section perpendicular to the extension direction of the inlet tube, and a drain hole is formed at the bottom of the valley of the concave curved portion. With this configuration, the valley shape of the concave curved portion makes it easier for water to collect in the drain hole, further improving drainage.

[0057] In the air cleaner of this embodiment, a battery (37) is located to the side of the inlet tube and is held in place by a battery case (38), and the drain hole is covered from below by a flange (39) on the outer edge of the battery case. With this configuration, the flange can prevent water from entering the inlet tube through the drain hole.

[0058] Although the present embodiment has been described, other embodiments may be made by combining the above-described embodiments and modifications in whole or in part.

[0059] Furthermore, the technology of the present invention is not limited to the above-described embodiments, and various changes, substitutions, and modifications may be made without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to technological advances or other derived technologies, it may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical idea. [Explanation of symbols]

[0060] 10: Body frame 37: Battery 38: Battery case 39: Flange 50:Air cleaner 51: Air cleaner case 56: Intake chamber 57:Air filter 62: Inlet tube 63: Inlet tube intake 64: Inlet tube outlet 71: Concave section 72: Drain hole 73: Convex curved part 75: Convex 82: Outlet tube

Claims

1. An air cleaner disposed inside a vehicle body frame, an air cleaner case in which an intake chamber is formed; an air filter disposed in the intake chamber; an inlet tube that takes air into the intake chamber; an outlet tube that sends air out from the intake chamber, the inlet tube extends in the front-rear direction, a bottom wall of the inlet tube is curved downward in a side view to form a concave curved portion below the outlet of the inlet tube, and a drain hole is formed in the concave curved portion; An air cleaner characterized in that the lower edge of the intake port of the inlet tube is located below the drain hole, and a convex portion is formed between the lower edge of the intake port and the drain hole by protruding the bottom wall of the inlet tube upward.

2. An air cleaner disposed inside a vehicle body frame, an air cleaner case in which an intake chamber is formed; an air filter disposed in the intake chamber; an inlet tube that takes air into the intake chamber; an outlet tube that sends air out from the intake chamber, the inlet tube extends in the front-rear direction, a bottom wall of the inlet tube is curved downward in a side view to form a concave curved portion below the outlet of the inlet tube, and a drain hole is formed in the concave curved portion; a battery is located on the side of the inlet tube, and the battery is held by a battery case; An air cleaner characterized in that the drain hole is covered from below by a flange on the outer edge of the battery case.

3. 3. The air cleaner according to claim 1, wherein an upper wall of the inlet tube is curved downward in a side view to form a convex curved portion, and the drain hole is located below the convex curved portion.

4. 4. The air cleaner according to claim 1, wherein the drain hole is located below the center of the air filter in the height direction.

5. 5. The air cleaner according to claim 1, wherein the concave curved portion is formed in a valley shape in a cross-sectional view perpendicular to the extension direction of the inlet tube, and the drain hole is formed at the bottom of the valley of the concave curved portion.

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