Patent Publication Number: US-2023149845-A1

Title: Air cleaner

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on Japanese Patent Application No. 2021-185549 filed on Nov. 15, 2021, the contents of which are incorporated herein by way of reference. 
     TECHNICAL FIELD 
     The present invention relates to an air cleaner. 
     BACKGROUND 
     As a straddle-type vehicle, there is known a straddle-type vehicle in which an air cleaner is disposed behind an engine (for example, see Patent Literature 1). In the air cleaner disclosed in Patent Literature 1, an inlet tube is attached to a rear surface of an air cleaner case, and an outlet tube is attached to a front surface of the air cleaner case. Air is taken into the air cleaner case from the inlet tube, and the air is filtered by a filter disposed in the air cleaner. Then, the clean air enters the outlet tube from the air cleaner, and the clean air is sent out to a throttle body through the outlet tube. 
     Patent Literature 1: Japanese Patent No. 4121392 
     However, the air cleaner described in Patent Document 1 is disposed in a narrow space inside a vehicle body frame below a seat. Therefore, the position for arranging the intake air temperature sensor with respect to the air cleaner is also limited. When the intake air temperature sensor is arranged at a position deviated from the air flow in the air cleaner, there is a possibility that an accurate intake air temperature cannot be detected by the intake air temperature sensor. 
     The present invention bas been made in view of the above circumstances, and an object thereof is to provide an air cleaner capable of improving the detection accuracy of an intake air temperature sensor. 
     SUMMARY 
     An air cleaner according to an aspect of the present invention is configured to be disposed inside a vehicle body frame, and includes: an air cleaner case in which an intake chamber is formed; an intake air temperature sensor configured to detect an intake air temperature in the intake chamber; an inlet tube configured to take in air to the intake chamber; and an outlet tube configured to send out air from the intake chamber. The outlet tube has an upstream portion protruding into the intake chamber, and the upstream portion of the outlet tube has a peripheral wall formed with a through hole, thereby solving the above-described problem. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a left side view of a straddle-type vehicle according to the present embodiment. 
         FIG.  2    is a left side view of the periphery of an engine according to the present embodiment. 
         FIG.  3    is a top view of the periphery of the engine according to the present embodiment. 
         FIG.  4    is a side view of an air cleaner according to the present embodiment. 
         FIG.  5    is a top view of the air cleaner of the present embodiment. 
         FIG.  6    is a cross-sectional view of the air cleaner of  FIG.  5    taken along a line A-A. 
         FIG.  7    is a cross-sectional perspective view of the air cleaner of  FIG.  5    taken along a line B-B. 
         FIG.  8    is a top view of the air cleaner of  FIG.  5    from which an upper case is removed. 
         FIG.  9    is a diagram showing an air flow in the air cleaner according to the present embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     An air cleaner according to an aspect of the present invention is disposed inside a vehicle body frame. An intake chamber is formed in an air cleaner case of the air cleaner, and an intake air temperature of the intake chamber is detected by an intake air temperature sensor. Air is taken into the intake chamber through an inlet tube, and air is sent out from the intake chamber through an outlet tube. The outlet tube has an upstream portion protruding into the intake chamber. The upstream portion of the outlet tube has a peripheral wall formed with a through hole. The main air flow is formed from the inlet tube to the outlet tube. Air flows out from the through hole of the outlet tube, and air flow is also created at positions deviated from the main air flow. Even if the intake air temperature sensor is disposed at a position deviated from the main air flow, the detection accuracy of the intake air temperature sensor can be improved. 
     Embodiments 
     Hereinafter, a present embodiment will be described in detail with reference to the accompanying drawings.  FIG.  1    is a left side view of a straddle-type vehicle according to the present embodiment in addition, in the drawings to be described later, an arrow FR indicates a vehicle front side, an arrow RE indicates a vehicle rear side, an arrow L indicates a vehicle left side, and an arrow R indicates a vehicle right side. 
     As shown in  FIG.  1   , a straddle-type vehicle  1  is formed by mounting various components such as an engine  40  and an electrical system on a diamond-type vehicle body frame  10  formed of a pipe and a sheet metal. The vehicle body frame  10  includes a pair of main frames  12  that are branched off from a head pipe  11  to the left and right and extend rearward, and a pair of down frames  13  that are branched off from the head pipe  11  to the left and right and extend downward. A rear portion of the engine  40  is supported by the pair of main frames  12 , and a front portion of the engine  40  is supported by the pair of down frames  13 . By supporting the engine  40  with the vehicle body frame  10 , the rigidity of an entire vehicle is secured. 
     A front side portion of the main frame  12  is a tank rail  14  located above the engine  40 , and a fuel tank  31  is supported from below by the tank rail  14 . A rear side portion of the main frame  12  is a body frame  15  located behind the engine  40 , and a swing arm  25  is swingably supported by a lower half portion of the body frame  15 . Seat rails  21  each including an upper rail  22  and a lower rail  23  are attached to an upper half portion of the body frame  15 . A rider seat  32  and a pillion seat  33  are supported on an upper portion of the upper rail  22  at the rear of the fuel tank  31 . 
     A pair of front forks  34  is steerably supported by the head pipe  11  via a steering shaft (not shown). A front wheel  35  is rotatably supported by lower portions of the front forks  34 , and an upper portion of the front wheel  35  is covered with a front fender (not shown). The swing arm  25  extends rearward from the body frame  15 . A rear wheel  36  is rotatably supported at the rear end of the swing arm  25 , and the upper side of the rear wheel  36  is covered with a rear fender (not shown). The engine  40  is coupled to the rear wheel  36  via a chain drive type transmission mechanism, and power from the engine  40  is transmitted to the rear wheel  36  via the transmission mechanism. 
     An air cleaner  50  is disposed behind the engine  40 . Behind the engine  40 , the space for arranging the air cleaner is limited due to the frame width of the main frame  12  and the rail width of the seat rails  21 , and it is difficult to secure the capacity of the air cleaner  50  for securing the required output of the engine  40 . The intake air temperature in the air cleaner  50  is detected by the intake air temperature sensor. The detection accuracy is reduced when the intake air temperature sensor is arranged at a position deviated from the main air flow to satisfy the capacity of the air cleaner  50  and smooth air flow. Therefore, in the present embodiment, the air flow is also created at positions deviated from the main air flow of the air cleaner  50  to improve the detection accuracy of the intake air temperature sensor. 
     A peripheral configuration of the engine and the air cleaner will be described with reference to  FIGS.  2  to  8   .  FIG.  2    is a left side view of the periphery of the engine according to the present embodiment.  FIG.  3    is a top view of the periphery of the engine according to the present embodiment.  FIG.  4    is a side view of the air cleaner according to the present embodiment.  FIG.  5    is a top view of the air cleaner according to the present embodiment.  FIG.  6    is a cross-sectional view of the air cleaner of  FIG.  5    taken along a line A-A.  FIG.  7    is a cross-sectional perspective view of the air cleaner of  FIG.  5    taken along a line B-B.  FIG.  8    is a top view of the air cleaner of  FIG.  5    from which an upper case is removed. 
     As shown in  FIGS.  2  and  3   , the engine  40  is a two-cylinder engine, and includes a crankcase  41  having an upper-lower divided structure. A cylinder  42 , a cylinder head  43 , and a cylinder head cover  44  are attached to an upper portion of the crankcase  41 . A magneto cover  45  that covers a magneto (not shown) from a side is attached to a left side surface of the crankcase  41 . A sprocket cover  46  that covers a drive sprocket (not shown) from the side is attached to the rear of the magneto cover  45 . A clutch cover  47  that covers a clutch (not shown) from the side is attached to a right side surface of the crankcase  41 . 
     A throttle body  48  is connected to a rear surface of the cylinder head  43 , and the air cleaner  50  is connected to an upstream side (rear side) of the throttle body  48 . The air cleaner  50  is disposed behind 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  are the pair of body frames  15 , and a front end portion of the air cleaner  50  is located inside the pair of body frames  15 . The upper half portion of the body frame  15  is inclined obliquely downward toward the rear, and an air cleaner case  51  behind the body frame  15  is also inclined obliquely downward. 
     An upper bracket  16  and a lower bracket  17  are formed at a rear edge of the upper half portion of the body frame  15 . The upper rail  22  of the seat rail  21  is connected to the upper bracket  16 , and the lower rail  23  of the seat rail  21  is connected to the lower bracket  17 . The upper rail  22  extends rearward across a side of an upper half portion of the air cleaner case  51 , and the lower rail  23  extends obliquely rearward across a side of a lower half portion of the air cleaner case  51 . Front sides of the upper rail  22  and the lower rail  23  are coupled to each other via a bridge pipe  24 , and rear sides of the upper rail  22  and the lower rail  23  are coupled to each other at a vehicle rear portion. 
     A front portion of the air cleaner case  51  protrudes upward from the upper rail  22 , and a protruding portion of the front portion is accommodated in a space inside the rider seat  32  (see  FIG.  1   ). A rear portion of the air cleaner case  51  protrudes downward from the lower rail  23 , and a protruding portion of the rear portion serves as an expansion portion  65  that expands an intake chamber  56  (see  FIG.  6   ) in the air cleaner case  51 . The expansion portion  65  of the air cleaner case  51  is located above the swing arm  25  (see  FIG.  1   ), and the expansion portion  65  extends rearward so as to avoid a swing range of the swing arm  25 . A volume of the air cleaner case  51  is expanded by using a lower space of the seat rail  21 . 
     A battery case  38  and a battery  37  are disposed above the expansion 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 having an open upper surface, and a rectangular parallelepiped battery  37  is held inside the battery case  38 . In a top view, the pair of inlet tubes  62  of the air cleaner  50  are curved, and the battery  37  is located between the pair of inlet tubes  62 . A space for arranging the battery  37  is secured by using a space above the expansion portion  65  of the air cleaner  50 . 
     As shown in  FIGS.  4  to  6   , the air cleaner case  51  of the air cleaner  50  includes an upper case  52  and a lower case  53  which are divided in an upper-lower direction, and a filter cover  54  attached to a rear surface of the upper case  52 . The upper case  52  and the lower case  53  extend obliquely downward from the front to the rear, and the filter cover  54  bulges in a dome shape on a rear side of the upper case  52 . Internal spaces of the upper case  52  and the lower case  53  and an internal space of the filter cover  54  are connected to each other through an opening  55  formed in the rear surface of the upper case  52 , and an intake chamber  56  is formed inside the air cleaner case  51 . 
     An air filter  57  is disposed in the opening  55  in the rear surface of the upper case  52 , and the air filter  57  is covered by the filter cover  54  from behind. The air filter  57  is inclined along an upper surface of the upper case  52  such that an upper portion of the air filter  57  is located closer to the vehicle front side than a lower portion. By the air filter  57 , the intake chamber  56  is divided into a dirty side  58  and a clean side  59 . That is, the dirty side  58  is formed by the filter cover  54  on the upstream side of the air filter  57 , and the clean side  59  is formed by the upper case  52  and the lower case  53  downstream of the air filter  57 . 
     A pair of inlet tubes  62  are attached to 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 vehicle rear side, and air is taken into the dirty side  58  from the rear of the vehicle by the pair of inlet tubes  62 . A suction port  63  of each inlet tube  62  is directed toward the rear of the vehicle, and a discharge port  64  of the inlet tube  62  is directed inward in the vehicle width direction. The pair of inlet tubes  62  are located inside the pair of seat rails  21  (see  FIG.  3   ), and an interval between the pair of inlet tubes  62  is substantially equal to a lateral width of the expansion portion  65 . 
     A pair of outlet tubes  82  are attached to a front wall  81  of the lower case  53 . The pair of outlet tubes  82  penetrate the front wall  81  of the lower case  53  and extend in a front-rear direction, and air is sent out from the clean side  59  to the engine  40  (see  FIG.  1   ) by the pair of outlet tubes  82 . A suction port  83  of each outlet tube  82  is directed toward the rear of the vehicle, and a discharge port  84  of the outlet tube  82  is directed toward the front of the vehicle. The pair of outlet tubes  82  are located inside the pair of main frames  12  (see  FIG.  3   ), and the pair of outlet tubes  82  are connected to the pair of the throttle bodies  48  (see  FIG.  2   ). 
     The inlet tubes  62  and the outlet tubes  82  are attached to an upper side of the air cleaner case  51 . As described above, the inlet tubes  62  are attached to the filter cover  54 , the outlet tubes  82  are 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-rear direction via the air filter  57  in a side view. Since the discharge port  64  of each inlet tube  62  and the suction port  83  of each outlet tube  82  are located at substantially the same height, air easily flows directly from the inlet tube  62  to the outlet tube  82 . 
     During low rotation of the engine  40  and steady traveling, the main air flow from the discharge port  64  of the inlet tube  62  toward the suction port  83  of each outlet tube  82  is formed. The pair of outlet tubes  82  each has an upstream portion  91  protruding into the intake chamber  56 . The upstream portion  91  has a peripheral wall formed with a through hole  92 . In the air cleaner case  51 , an air flow from the through hole  92  toward the suction port  83  of the outlet tube  82  is formed in addition to the main air flow. The upper wall of the upper case  52  is attached with an intake air temperature sensor  95  that detects the intake air temperature of the air flowing out from the through hole  92 . The detection result of the intake air temperature sensor  95  is used to control the fuel injection amount. 
     The upper wall of the upper case  52  protrudes upward from the upper rail  22  (see  FIG.  2   ), The upper wall of the upper case  52  is partially recessed, and the intake air temperature sensor  95  is disposed in the recess of the upper case  52  so as to face obliquely upward. The proximal end side of the intake air temperature sensor  95  is exposed to the outside of the case, and a detection portion  96  on the distal end side of the intake air temperature sensor  95  is inside the case. The upper surface of the upper rail  22  is provided with an attachment bracket  18  (see  FIG.  2   ) for the fuel tank  31 , and the intake air temperature sensor  95  is positioned below the attachment bracket  18 . In this way, the intake air temperature sensor  95  is disposed in the upper case  52  using the space below the attachment bracket  18 . 
     In addition, a breather nipple  85  is formed at a front portion of the upper case  52 , and a breather hose (not shown) extending from the engine  40  is connected to the breather nipple  85 . A secondary air nipple  87  is formed at a front portion of the lower case  53 , and a secondary air hose (not shown) extending to an exhaust system is connected to the secondary air nipple  87 . A drain plug  88  is provided at a bottom portion of the lower case  53 , and water in the air cleaner case  51  is discharged from the drain plug  88 . 
     As shown in  FIGS.  7  and  8   , the pair of outlet tubes  82  is attached to the front wall  81  of the lower case  53  so as to be spaced apart from each other in the left-right direction. Upstream portions  91  (rear sides) of the pair of outlet tubes  82  extend toward the air filter  57 , and downstream portions  93  (front sides) of the pair of outlet tubes  82  are connected to the throttle body  48  (see  FIG.  3   ). Lengths of the pair of outlet tubes  82  are different, and the outlet tube  82  on the left side is formed longer than the outlet tube  82  on the right side. The output characteristics of the engine  40  are adjusted by the difference in length between the pair of outlet tubes  82 . 
     The suction ports  83  of the pair of outlet tubes  82  are directed toward the center of the air filter  57 . The pair of outlet tubes  82  is formed with umbrella portions  94  that extend toward the suction ports  83 , and the umbrella portions  94  expands the suction ports  83  of the outlet tubes  82 . Since the lengths of the pair of outlet tubes  82  are different from each other and the umbrella portions  94  of the pair of outlet tubes  82  are shifted in the front-rear direction, a pair of umbrella portions  94  do not interfere with each other at the center of the air filter  57 . An intake air temperature sensor  95  is disposed between the pair of outlet tubes  82  in a top view. The peripheral walls of the upstream portions  91  of the pair of outlet tubes  82  are each formed with the through hole  92 . 
     In this case, among a peripheral wall on the inner side in the vehicle width direction and a peripheral wall on the outer side in the vehicle width direction of the upstream portion  91  of each outlet tube  82 , the peripheral wall on the inner side in the vehicle width direction, which is a side closer to the intake air temperature sensor  95 , is formed with the through hole  92 . The air flow from the through hole  92  is directed toward the intake air temperature sensor  95 . In addition, the intake air temperature sensor  95  has a detection portion  96  located downstream (forward) of the suction port  83  of the outlet tube  82  and upstream (rearward) of the through hole  92  in a top view. That is, the detection portion  96  of the intake air temperature sensor  95  is located between the suction port  83  and the through hole  92  of the outlet tube  82 . The main air flow from the inlet tube  62  toward the outlet tube  82  is not interfered by the intake air temperature sensor  95 . 
     In the air cleaner case  51 , an air flow from the through hole  92  toward the suction port  83  of the outlet tube  82  is formed in addition to the main air flow from the inlet tube  62  toward the outlet tube  82 , The detection portion  96  of the intake air temperature sensor  95  is positioned in the middle of the flow of the intake air from the through hole  92  toward the suction port  83 , thereby improving the detection accuracy of the intake air temperature sensor  95 . The detection portion  96  of the intake air temperature sensor  95  is closer to the suction port  83  than to the through hole  92 . Since air is more diffused in the vehicle width direction as from the through hole  92  toward the suction port  83  in the top view, the degree of freedom in layout of the intake air temperature sensor  95  is improved as approaching the suction port  83 . 
     Further, an umbrella portion  94  is formed in the vicinity of the suction port  83 , and the detection portion  96  of the intake air temperature sensor  95  is close to the umbrella portion  94 . The air flowing from the through hole  92  toward the suction port  83  is partially retained by the umbrella portion  94 . In particular, the umbrella portions  94  of the pair of outlet tubes  82  are close to each other, and the air is likely to be retained at the portion where the umbrella portions  94  are close to each other. The detection portion  96  of the intake air temperature sensor  95  is directed between the umbrella portions  94  of the pair of outlet tubes  82 . The intake air temperature of the retained air is detected by the detection portion  96  of the intake air temperature sensor  95 , thereby improving the detection accuracy of the intake air temperature sensor  95 . 
     The through holes  92  of the pair of outlet tubes  82  face each other, and the air flow from the through holes  92  is easily directed toward the detection portion  96  of the intake air temperature sensor  95 . The intake air temperature sensor  95  is attached to the upper wall of the upper case  52 , and the detection portion  96  of the intake air temperature sensor  95  is positioned above the outlet tubes  82 . Since the intake air temperature sensor  95  is provided in the upper portion of the air cleaner case  51 , the intake air temperature sensor  95  is protected from mud, water, or the like rolled up onto the wheel. Further, by using the wide space between the pair of outlet tubes  82 , the air flow from the through holes  92  toward the suction ports  83  is easily detected by the detection portion  96  of the intake air temperature sensor  95 . 
     The flow of air in the air cleaner will be described with reference to  FIG.  9   ,  FIG.  9    is a diagram showing the flow of air in the air cleaner according to the present embodiment. 
     As shown in  FIG.  9   , a main air flow F 1  is formed between the discharge ports  64  of the pair of inlet tubes  62  and the suction ports  83  of the outlet tubes  82  in a top view. The detection portion  96  of the intake air temperature sensor  95  is disposed downstream of (forward of) the suction ports  83  of the pair of outlet tubes  82 , and the main air flow F 1  is not hindered by the detection portion  96  of the intake air temperature sensor  95 . When the main air flow F 1  enters the pair of outlet tubes  82 , the air flows from the through holes  92  toward the suction ports  83  of the pair of outlet tubes  82 . As described above, an air flow F 2  is also formed in the air cleaner  50  at a position deviated from the main air flow F 1 . 
     The intake air temperature sensor  95  is disposed between the pair of outlet tubes  82 , and the detection portion  96  of the intake air temperature sensor  95  is positioned between the through holes  92  and the umbrella portions  94  of the pair of outlet tubes  82  in a top view. The air flow F 2  is partially blocked by the umbrella portions  94  of the pair of outlet tubes  82 , and is retained in the vicinity of the umbrella portions  94  of the pair of outlet tubes  82 . The detection portion  96  of the intake air temperature sensor  95  is directed toward the umbrella portions  94  of the pair of outlet tubes  82 , and the intake air temperature of the air retained in the vicinity of the pair of umbrella portions  94  is detected by the detection portion  96  of the intake air temperature sensor  95 , thereby improving the detection accuracy of the intake air temperature sensor  95 . 
     As described above, according to the present embodiment, the main air flow is formed from the inlet tube  62  to the outlet tube  82 . Air flows out from the through hole  92  of the outlet tube  82 , and air flow is also created at positions deviated from the main air flow. Even if the intake air temperature sensor  95  is disposed at a position deviated from the main air flow, the detection accuracy of the intake air temperature sensor  95  can be improved. 
     In the present embodiment, a two-cylinder engine is exemplified as the engine, but the type of the engine is not particularly limited. 
     In the present embodiment, the air cleaner includes a pair of inlet tubes and a pair of outlet tubes, but the numbers of inlet tubes and outlet tubes are not limited. For example, the air cleaner may include a single inlet tube and a single outlet tube, or the air cleaner may include three or more inlet tubes and three or more outlet tubes. 
     In the present embodiment, the air filter is inclined, but the air filter may also be not inclined. For example, the air filter may be disposed vertically. 
     Further, in the present embodiment, the detection portion of the intake air temperature sensor is located between the through hole and the suction port in the top view, but the detection portion of the intake air temperature sensor may be located at any position as long as the main air flow is not strongly hindered. For example, the detection portion of the intake air temperature sensor may be located upstream of the suction ports of the outlet tubes, as long as at a position where the main air flow is not strongly hindered. Moreover, the detection portion of the intake air temperature sensor may be located downstream of the through holes. 
     The umbrella portions are formed in the outlet tubes in the present embodiment, but the shape of the outlet tubes is not particularly limited as long as air can be fed from the intake chamber, For example, the outlet tubes may be not formed with umbrella portions. 
     The through holes are formed in the peripheral walls on the inner side in the vehicle width direction of the outlet tubes in the present embodiment, but the through holes may also be formed in the peripheral walls on the outer side in the vehicle width direction of the outlet tubes when the intake air temperature sensor is located on the outer side in the vehicle width direction of the outlet tubes. 
     In the present embodiment, the intake air temperature sensor is attached to the upper wall of the air cleaner case, but the intake air temperature sensor may also be attached to the bottom wall of the air cleaner case. 
     In the present embodiment, the through holes of the pair of outlet tubes face each other, but the through holes of the pair of outlet tubes may also not face each other. 
     In addition, in the present embodiment, the pair of outlet tubes is formed with different lengths, but the pair of outlet tubes may also be formed with the same length. 
     In addition, the air cleaner may be applied not only to the straddle-type vehicle shown in the drawings but also to other types of straddle-type vehicles. The straddle-type vehicle is not limited to general vehicles on which a rider rides in a posture of straddling a seat, and. includes a small-sized scooter-type vehicle on which a rider rides without straddling a seat, 
     As described above, the air cleaner ( 50 ) according to the present embodiment is an air cleaner configured to be disposed inside a vehicle body frame ( 10 ), and including: an air cleaner case ( 51 ) in which an intake chamber ( 56 ) is formed; an intake air temperature sensor ( 95 ) configured to detect an intake air temperature in the intake chamber; an inlet tube ( 62 ) configured to take in air to the intake chamber; and an outlet tube ( 82 ) configured to send out air from the intake chamber. The outlet tube has an upstream portion ( 91 ) protruding into the intake chamber. The upstream portion of the outlet tube has a peripheral wall formed with a through hole ( 92 ). According to this configuration, the main air flow is formed from the inlet tube to the outlet tube. Air flows out from the through hole of the outlet tube, and air flow is also created at positions deviated from the main air flow. Even if the intake air temperature sensor is disposed at a position deviated from the main air flow, the detection accuracy of the intake air temperature sensor can be improved. 
     In the air cleaner according to the present embodiment, the intake air temperature sensor has a detection portion ( 96 ) located downstream of a suction port ( 83 ) of the outlet tube in a top view. According to this configuration, it is possible to improve the detection accuracy of the intake air temperature sensor without the intake air temperature sensor blocking the main air flow. 
     In the air cleaner according to the present embodiment, the detection portion of the intake air temperature sensor is located between the through hole and the suction port in the top view. According to this configuration, an air flow is created from the through hole toward the suction port, and the detection portion of the intake air temperature sensor is positioned in the middle of the flow of the intake air, thereby improving the detection accuracy. 
     In the air cleaner of the present embodiment, the detection portion of the intake air temperature sensor is closer to the suction port than to the through hole. According to this configuration, since air is more diffused in the vehicle width direction as from the through hole toward the suction port in the top view, the degree of freedom in layout of the intake air temperature sensor is improved as approaching the suction port. 
     In the air cleaner of the present embodiment, the outlet tube is formed with an umbrella portion ( 94 ) expanding toward the suction port. According to this configuration, the air flowing out from the through hole is easily retained by the umbrella portion, thereby improving the detection accuracy of the intake air temperature sensor. 
     In the air cleaner of the present embodiment, among a peripheral wall on an inner side in a vehicle width direction and a peripheral wall on an outer side in the vehicle width direction of the upstream portion of the outlet tube, a peripheral wall on a side closer to the intake air temperature sensor is formed with a single through hole. According to this configuration, the air flow from the through hole is easily directed toward the detection portion of the intake air temperature sensor, thereby improving the detection accuracy of the intake air temperature sensor. 
     In the air cleaner of the present embodiment, the intake air temperature sensor is attached to an upper wall of the air cleaner case, and the intake air temperature sensor is positioned on a lateral side of the outlet tube in a top view, and a detection portion of the intake air temperature sensor is positioned above the outlet tube. According to this configuration, since the intake air temperature sensor is provided in the upper portion of the air cleaner case, the intake air temperature sensor is protected from mud, water, or the like rolled up onto the wheel. By using the wide space on the lateral side of the outlet tube, the air flow from the through hole is easily detected by the detection portion of the intake air temperature sensor. 
     In the air cleaner of the present embodiment, the outlet tube is a plurality of outlet tubes, and the intake air temperature sensor is positioned between the outlet tubes adjacent to each other in a top view, and the through holes of the adjacent outlet tubes face each other. According to this configuration, the air flow from the through holes of the adjacent outlet tubes is easily directed toward the intake air temperature sensor, thereby improving the detection accuracy of the intake air temperature sensor. 
     Although the present embodiment has been described, the above-described embodiment and modifications may be combined entirely or partially as another embodiment. 
     The technique of the present invention is not limited to the above-described embodiment, and various changes, substitutions, and modifications may be made without departing from the spirit of the technical concept of the present invention. The present invention may be implemented by other methods as long as the technical concept can be implemented by the methods through advance of the technique or other derivative techniques. Therefore, the claims cover all embodiments that may be included within the scope of the technical concept.