Abstract:
A vehicle, such as a motorcycle, includes an engine having at least one intake port. An air intake assembly introduces air into the intake port. In one arrangement, the air intake assembly includes a stationary funnel and a movable funnel positioned on the inlet side of the fixed funnel and selectively cooperates with the stationary funnel to deliver air to the intake port of the engine. A seal member creates at least a substantial seal between the fixed funnel and the movable funnel when the funnels are in cooperation with one another. A retention mechanism inhibits the seal member from disengaging with the funnel onto which the seal member is positioned. In one arrangement, the movable funnel is formed with one or more projections and the seal member is formed with one or more recesses that accommodate the projections. The projection may be a flange or a boss, among other possibilities, and the recess is configured to accommodate the specific projection.

Description:
RELATED APPLICATIONS 
     This application is related to, and claims priority from, Japanese Patent Application Nos. 2006-253673, filed Sep. 20, 2006, and 2006-111560, filed Apr. 14, 2006, each entitled “VEHICLE.” The entireties of these applications are hereby incorporated by reference herein and made a part of the present specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a vehicle, and more particularly to a vehicle having a variable length air intake arrangement for introducing air to an intake port of an engine. 
     2. Description of the Related Art 
     Some vehicles incorporate a variable length air intake system. For example, a variable length air intake system shown in Japanese Patent Publication No. 63-182229 includes a stationary intake pipe for introducing air to an intake port of an engine, a movable pipe movably disposed on the air inlet side of the stationary pipe. A rotary arm is positioned on one side of the movable pipe and is attached to the movable pipe. A rotary shaft is positioned on the same side of the movable pipe and is coupled to the rotary arm. A motor is also positioned on the same side of the movable pipe as the rotary arm and shaft, and is configured to drive the rotary arm. In this intake system, the rotary arm is moved rotationally about the rotary shaft by the driving force of the motor, so that the movable pipe attached to the rotary arm can move relative to the stationary pipe to vary a length of the intake system. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention involves the realization that, because the structure disclosed in Japanese Patent Publication No. 63-182229 is not provided with a seal arrangement to seal the gap between the movable intake pipe and the stationary intake pipe, it is difficult to restrict air leakage through the gap between the movable intake pipe and the stationary intake pipe. Accordingly, it is difficult to supply a desired amount of air to the intake port. 
     One aspect of one or more preferred embodiments of the present invention is to provide a vehicle in which air leakage through the gap between a movable intake pipe, or funnel, and a stationary intake pipe, or funnel, can be restricted. More generally, an aspect of one or more preferred embodiments is to provide a seal arrangement for an air intake arrangement having a stationary portion and a movable portion. 
     An aspect of a preferred embodiment involves a vehicle including an engine having at least one intake port. At least one stationary funnel introduces air to the intake port of the engine. A movable funnel selectively cooperates with the stationary funnel to introduce air to the intake port of the engine. A seal member creates at least a substantial seal between the stationary funnel and the movable funnel when the stationary funnel and the movable funnel cooperate with one another. A retention mechanism retains the seal member to one of the stationary funnel and the movable funnel to inhibit disengagement of the seal member from the stationary funnel or the movable funnel. 
     With the vehicle as described in the above paragraph, in which a seal member is disposed between the stationary funnel and the movable funnel, air leakage through the gap between the movable funnel and the stationary funnel can be inhibited or eliminated when the movable funnel is in cooperation with the stationary funnel. With such a construction, a desired amount of air can be supplied to the intake port. In addition, the retention mechanism for retaining the seal member with either one of the stationary funnel and the movable funnel is also provided. Thus, the seal member can be prevented from disengaging from the stationary funnel or the movable funnel. With such a construction, it is possible to inhibit or prevent the seal member from falling off from the stationary funnel or the movable funnel and possibly entering the inside of the engine, thereby preventing damage to the engine. 
     Yet another aspect of a preferred embodiment involves the vehicle described above, wherein the retention mechanism includes a first engagement defined by one of the stationary funnel and the movable funnel, and a second engagement surface defined by the seal member. The first engagement surface engages the second engagement surface to inhibit disengagement of the seal member from the one of the stationary funnel and the movable funnel. With such a construction, it is not necessary to provide a separate member for preventing the seal member from falling off from the stationary funnel or the movable funnel, and accordingly the number of parts can be reduced. 
     Still another aspect of a preferred embodiment involves the vehicle described above, wherein, the first engagement surface of the one of the stationary funnel and the movable funnel is defined by at least one projection. The seal member includes at least one recess that defines the second engagement surface. With such an arrangement, the first engagement surface and the second engagement surface can be easily engaged with one another, and hence the seal member can be easily prevented from falling off of the one of the stationary funnel and the movable funnel. 
     Another aspect of a preferred embodiment involves the vehicle described above, wherein the retention mechanism includes a first engagement surface and a second engagement surface. The first engagement surface is defined by the movable funnel. With such a construction, the first engagement surface is not formed in the stationary funnel, and hence the surface of the stationary funnel can be formed to be smooth. Thus, the passage of air to be supplied to the stationary funnel can be made smooth when the movable funnel is spaced apart from the stationary funnel (when the engine is rotating at a high speed). As a result, the air supplied to the engine can be supplied smoothly, thereby avoiding a decrease in engine output. 
     Yet another aspect of a preferred embodiment involves the vehicle described above, wherein the at least one projection comprises a flange extending from a side surface of the movable funnel. The at least one recess comprises an annular recess that accommodates the flange. With such an arrangement, the first engagement surface and the second engagement surface can be tightly engaged with one another by inserting the flange into the annular recess. Thus, the seal member can be more reliably prevented from falling off of the movable funnel. 
     Still another aspect of a preferred embodiment involves the vehicle described above, wherein the at least one projection comprises a boss extending from a side surface of the movable funnel. The at least one recess accommodates the boss. With such a construction, the first engagement surface and the second engagement surface can be tightly engaged with one another by inserting the boss into the recess. Thus, the seal member can be more reliably prevented from falling off from the movable funnel. 
     Another aspect of a preferred embodiment involves the vehicle described above, wherein the stationary funnel, the movable funnel and the seal member are generally cylindrical in shape. The at least one recess is formed to extend at a predetermined angle with respect to a radial direction of the seal member and the boss extends in substantially the same direction as the at least one recess. With such an arrangement, even when the seal member expands radially, the expanding direction of the seal member is at the predetermined angle with respect to the extending direction of the boss and the recess, and hence the boss can be prevented from disengaging from the recess. In addition, since the boss extends in a direction at the predetermined angle with respect to the radial direction of the seal member, enlargement of the boss in the radial direction of the seal member can be avoided while the area of engagement between the boss and the recess can be increased. 
     Yet another aspect of a preferred embodiment involves the vehicle described above, wherein the recess is a through hole that extends completely through a wall thickness of the seal member. With this construction, it is easy to check whether or not the second projection is inserted into the second recess by visual inspection of the outside of the assembly. 
     Still another aspect of a preferred embodiment involves the vehicle described above, wherein the engine has a plurality of intake ports and each of the intake ports is provided with a stationary funnel and a movable funnel. A plurality of the movable funnels are formed integral with one another and the boss extends in a direction substantially perpendicular to a direction in which the plurality of the movable funnels are aligned relative to one another. With this construction, in the case where the plurality of the movable funnels are integrally molded using a split mold, the split line of the mold extends perpendicularly to the direction in which the plurality of the movable funnels are disposed adjacently. This allows the split line of the mold to extend in the same direction as the extending direction of the boss. Thus, the boss can be easily formed to extend in the desired direction. 
     Another aspect of a preferred embodiment involves the vehicle described above, wherein the seal member is preferably secured to either one of the stationary funnel and the movable funnel. With this construction, the seal member can be easily prevented from falling off from the stationary funnel or the movable funnel. 
     Yet another aspect of a preferred embodiment involves the vehicle described above, wherein the seal member is elastically deformable and includes a first portion having a first axial length and a second portion having a second axial length that is less than the first axial length. With such an arrangement, the seal member can be easily stretched at the second portion. Thus, the seal member can be easily attached to either the stationary funnel or the movable funnel. 
     Still another aspect of a preferred embodiment involves the vehicle described above, wherein the first engagement surface is defined by a projection and the second engagement surface is defined by a recess. Preferably, the seal member is elastically deformable and includes a first portion having a first axial length and a second portion having a second axial length that is less than the first axial length. The recess is formed in the first axial portion. With this construction, the recess can be easily formed in the seal member. 
     Another aspect of a preferred embodiment involves the vehicle described above, wherein a plurality of the movable funnels are formed integrally via a shaft. The seal member is elastically deformable and includes a first portion and a second portion having an axial length that is less than the axial length of the first portion. The shaft of the movable funnels is radially aligned with the second portion of the seal member. 
     Yet another aspect of a preferred embodiment involves the vehicle described above, wherein the seal member comprises a seal portion for contact with one of the stationary funnel and the movable funnel in multiple directions. With this construction, air leakage through the gap between the movable funnel and the stationary funnel can be reduced or eliminated when the movable funnel cooperates with the stationary funnel. 
     Still another aspect of a preferred embodiment involves the vehicle described above, wherein the seal portion includes a first seal portion extending in a direction perpendicular to an axial direction of the seal member and a second seal portion extending in the axial direction of the seal member. With this construction, the gap between the movable funnel and the stationary funnel can be sealed in two ways, that is, in the axial direction of the seal member and in a direction perpendicular to the axial direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages of the present invention are described below with drawings of preferred embodiments of the invention, which are intended to illustrate, but not to limit, the present invention. The drawings contain twenty-seven (27) figures. 
         FIG. 1  is a side view showing a motorcycle having certain features, aspects and advantages of an embodiment of the present invention. 
         FIG. 2  is a plan view of an air intake arrangement and the surrounding area of the motorcycle of  FIG. 1 . 
         FIG. 3  is a side view of the air intake arrangement and the surrounding area of the motorcycle of  FIG. 1 . 
         FIG. 4  is a cross sectional view of an attachment of an air filter to an air cleaner box of the motorcycle of  FIG. 1 . 
         FIG. 5  is a rear view of the air intake arrangement and the surrounding area of the motorcycle of  FIG. 1 . The air intake arrangement includes a plurality of stationary funnels and a plurality of movable funnels. 
         FIG. 6  is a perspective view of the air intake arrangement of  FIG. 5  with the movable funnels separated from the stationary funnels. 
         FIG. 7  is a side view of the air intake arrangement of  FIG. 5  illustrating a funnel moving mechanism. 
         FIG. 8  is a side view of a parallel linkage of the funnel moving mechanism of  FIG. 7 . 
         FIG. 9  is a perspective view of the air intake arrangement of  FIG. 5  with the movable funnels contacting the stationary funnels. 
         FIG. 10  is a side view of the funnel moving mechanism with the movable funnels in their contacting positions. 
         FIG. 11  is a side view of the parallel linkage with the movable funnels in their contacting positions. 
         FIG. 12  is a plan view of the detailed structure of the air intake arrangement and surrounding area of the motorcycle of  FIG. 1   
         FIG. 13  is a rear view of stationary funnels of the motorcycle of  FIG. 1 . 
         FIG. 14  is a cross sectional view of the attachment structure of the stationary funnels shown in  FIG. 13  to a throttle body. 
         FIG. 15  is a cross sectional view of the attachment structure of the stationary funnels shown in  FIG. 13  to the throttle body, with the components separated from one another. 
         FIG. 16  is an enlarged cross sectional view of the surrounding area of a guide member of the motorcycle of  FIG. 1 . 
         FIG. 17  is a rear view of the movable funnels of the motorcycle of  FIG. 1 . 
         FIG. 18  is a perspective view of a seal member of the air intake arrangement of the motorcycle of  FIG. 1 . 
         FIG. 19  is a plan view of the seal member of  FIG. 18 . 
         FIG. 20  is a perspective view of the structure of the movable funnels of the motorcycle of  FIG. 1 . 
         FIG. 21  is a cross sectional view of the detailed structure of the seal member of the motorcycle of  FIG. 1 . 
         FIG. 22  is a cross sectional view of the detailed structure of the seal member of  FIG. 21 , with the movable funnel in contact with the stationary funnel. 
         FIG. 23  is a perspective view of a modification of the seal member of  FIG. 21 . 
         FIG. 24  is a plan view of the seal member shown in  FIG. 23 . 
         FIG. 25  is a perspective view of the structure of movable funnels configured for use with the seal member of  FIG. 23 . 
         FIG. 26  is a partial cross sectional view of the detailed structure of the seal member shown in  FIG. 23 . 
         FIG. 27  is a side view of the detailed structure of the seal member shown in  FIG. 23 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is a side view of a motorcycle having certain features, aspects and advantages of an embodiment of the present invention.  FIGS. 2 to 22  illustrate the detailed structure of a funnel and a seal member of the motorcycle shown in  FIG. 1 . In the description herein, a motorcycle is taken as an example of the vehicle of the present invention; however, the air intake arrangement may be applied to other vehicles as well. In the drawings, “FWD” indicates the forward or running direction of the motorcycle. The structure of the motorcycle is described with reference to  FIGS. 1 to 22 . 
     As shown in  FIG. 1 , the motorcycle of the first embodiment has a head pipe  1  and a main frame  2  with its front end connected to the head pipe  1 . As shown in  FIG. 2 , the main frame  2  is branched to extend leftward and rightward with respect to the forward direction of the vehicle body (FWD direction indicated by the arrow). The main frame  2  is provided with an air intake passage  2   a  for introducing air into an air cleaner box  24  described below. As shown in  FIG. 1 , the main frame  2  is formed to extend rearward and downward. A seat rail  3  extends rearward and upward and is connected to the main frame  2 . A steering mechanism  4  is attached to the head pipe  1  for rotational movement. Handlebars  5  are attached to an upper portion of the steering mechanism  4 . A clutch lever  6  is attached to the handlebars  5 . A front fork  7  is attached to a lower part of the steering mechanism  4 . A front wheel  8  is rotatably mounted at the lower end of the front fork  7 . 
     The front end of a swing arm  10  is attached to the rear end of the main frame  2  via a pivot shaft  9 . A rear wheel  11  is rotatably mounted at the rear end of the swing arm  10 . A fuel tank  12  is disposed above the main frame  2 , and a seat  13  is disposed above the seat rail  3 . An engine  14  is mounted below the main frame  2 . 
     As shown in  FIG. 3 , the engine  14  includes a piston  15 , a cylinder  16 , a cylinder head  17  and a throttle body  18 . The piston  15  is fitted in the cylinder  16 , and the cylinder head  17  closes one opening of the cylinder  16 . The cylinder head  17  is formed with an intake port  17   a  and an exhaust port  17   b . The intake port  17   a  is provided to supply a mixture of air and fuel to a combustion chamber  16   a  of the cylinder  16 . The exhaust port  17   b  is provided to exhaust a residual gas from the combustion chamber  16   a  of the cylinder  16  after combustion. The intake port  17   a  and the exhaust port  17   b  are provided with an intake valve  19   a  and an exhaust valve  19   b , respectively. The throttle body  18  is attached to an opening of the intake port  17   a . An injector  20  for injecting fuel into the intake port  17   a  is attached to the throttle body  18 . An exhaust pipe  21  is attached to an opening of the exhaust port  17   b , and a muffler  22  (see  FIG. 1 ) is connected to the exhaust pipe  21 . Although only one cylinder  16  is shown in  FIG. 3 , four cylinders  16  are actually provided at predetermined intervals in the width direction of the vehicle body. That is, the engine  14  of the first embodiment is a four-cylinder type. However, other numbers of cylinders may be provided as well. 
     As shown in  FIG. 1 , the front side of the vehicle body is covered by a front cowl  23 , which includes an upper cowl  23   a  and a lower cowl  23   b . As shown in  FIGS. 1 and 2 , an air cleaner box  24  for receiving air supplied from the air intake passage  2   a  of the main frame  2  is disposed between the left and right branches of the main frame  2 . As shown in  FIGS. 2 and 3 , an air filter  25  is disposed in the air cleaner box  24  to filter air supplied from the air intake passage  2   a  of the main frame  2 . As shown in  FIG. 3 , the air filter  25  is secured by being interposed between an upper box portion  24   a  and a lower box portion  24   b  of the air cleaner box  24 . Specifically, the front part of the air filter  25  is secured by being interposed by a pressing portion  24   c  of the upper box portion  24   a  and a support portion  24   d  of the lower box portion  24   b . As shown in  FIGS. 2 and 4 , the longitudinal center of the air filter  25  is screwed with a screw  60 , or other fastener, (see  FIG. 4 ) to a screw hole  24   e  (see  FIG. 4 ) of the upper box portion  24   a  and a screw hole  24   f  of the lower box portion  24   b . As shown in  FIG. 3 , a contacting portion  25   a  at the rear portion of the air filter  25  is secured by being interposed between a guide member  31  to be described later and the lower box portion  24   b.    
     As shown in  FIGS. 3 and 5 , a stationary funnel  26  and a movable funnel  27  are provided in the air cleaner box  24 . Preferably, the stationary funnel  26  and the movable funnel  27  are constructed from a resin-based material, such as a plastic. However, other suitable materials may also be used. As shown in  FIG. 3 , an injector  28  is attached to an upper portion of the air cleaner box  24 . The injector  28  is provided to inject fuel into the intake port  17   a , together with the injector  20 , when the engine  14  is rotating at a high speed. The injector  28  is disposed above the movable funnel  27 . A funnel moving mechanism  29  is screwed to a rear portion of the air cleaner box  24  from the outside. 
     One stationary funnel  26  and one movable funnel  27  are provided for each cylinder  16  of the engine  14 . The stationary funnel  26  is secured to the air cleaner box  24 , and introduces filtered air in the air cleaner box  24  to the intake port  17   a . The movable funnel  27  is disposed on the inlet side of the stationary funnel  26 , and has a function of introducing filtered air in the air cleaner box  24  to the intake port  17   a , in cooperation with the stationary funnel  26 . 
     As shown in  FIGS. 6 to 11 , the movable funnel  27  is movable between the spaced position (shown in  FIGS. 6 to 8 ) at which its opening  27   a  on the stationary funnel  26  side is spaced apart from an opening  26   a  of the stationary funnel  26  on the inlet side, and the contacting position (shown in  FIGS. 9 to 11 ) at which the opening  27   a  of the movable funnel  27  is in contact with the opening  26   a  of the stationary funnel  26 . Here, as shown in  FIG. 3 , when the movable funnel  27  is in the spaced position (shown in  FIGS. 6 to 8 ), the intake pipe extending from the air cleaner box  24  to the cylinder  16  is made up of the stationary funnel  26 , the throttle body  18  and the intake port  17   a . On the other hand, when the movable funnel  27  is in the contacting position (shown in  FIGS. 9 to 11 ), the intake pipe extending from the air cleaner box  24  to the cylinder  16  is made up of the movable funnel  27 , the stationary funnel  26 , the throttle body  18  and the intake port  17   a.    
     As shown in  FIGS. 12 and 13 , two adjacent stationary funnels  26  are integrated together via a connection  26   b . That is, the first embodiment includes two parts  30 , each integrating two adjacent stationary funnels  26  together. As shown in  FIG. 12 , each part  30 , integrating two stationary funnels  26  together, has three screw insertion holes  26   c  for insertion of screws  61  (see  FIG. 14 ). As shown in  FIG. 14 , the stationary funnels  26  (part  30 ) are attached to the air cleaner box  24  and the throttle body  18  with the screws  61  inserted into the screw insertion holes  26   c . The air cleaner box  24  is also formed with screw insertion holes  24   g  for insertion of the screws  61 . An engagement portion  26   d  is formed on the inner surface of the screw insertion hole  26   c  of the stationary funnels  26  (part  30 ). With this construction, as shown in  FIG. 15 , a head  61   a  of the screw  61  can be engaged with the engagement part  26   d  before the screw  61  is attached to the throttle body  18 . Thus, the screw  61  can be prevented from slipping upward out of the screw insertion hole  26   c . As shown  FIGS. 12 and 13 , a support column  26   e  is formed integrally with the part  30  integrating two stationary funnels  26  together. As shown in  FIG. 13 , the support column  26   e  is formed with a pair of rotary shaft support holes  26   f  for supporting ends of rotary shafts  41  described below for rotational movement. 
     As shown in  FIG. 6 , a guide member  31  is attached to the support columns  26   e  of the two parts  30 . A fixation part  31   b  having a fixation hole  31   a  is provided at both ends of the guide member  31 . As shown in  FIG. 12 , the guide member  31  is screwed at the fixation holes  31   a  (see  FIG. 6 ) to the air cleaner box  24  (see  FIG. 2 ) with screws  62 . As shown in  FIGS. 6 and 12 , the fixation parts  31   b  are each formed with a cylindrical portion  31   c  projecting upward. As shown in  FIG. 16 , the cylindrical portions  31   c  formed at both ends of the guide member  31  are respectively inserted into insertion holes  26   g  of the support columns  26   e  of the part  30  via rubber members  32 . That is, the guide or positioning member  31  operates to regulate the attachment positions of the two parts  30 . With this construction, changes in the interval between the two parts  30  in the axial direction of the guide member  31  can be restricted. 
     As shown in  FIG. 3 , the guide member  31  also functions as a guide when attaching the air filter  25  to the air cleaner box  24 . Specifically, the air filter  25  can be attached to the air cleaner box  24  by holding the air filter  25  with the contacting portion  25   a  (preferably, a generally hook-shaped portion) at the rear part thereof in contact with the guide member  31  and then rotating the air filter  25  about the guide member  31  in P direction of  FIG. 3 . The guide member  31  also has a function of preventing the rear part of the air filter  25  from coming upward out of position when the air filter  25  is attached to the air cleaner box  24 . 
     In the first embodiment, as shown in  FIGS. 12 and 17 , two adjacent movable funnels  27  are integrated together via a pair of support shafts  27   b  (see  FIG. 17 ). That is, the first embodiment includes two parts  33 , each integrating two adjacent movable funnels  27  together. The support shaft  27   b  is disposed between the two movable funnels  27  of the part  33 . The support shaft  27   b  is supported by a parallel linkage  42  described below so that the movable funnels  27  (part  33 ) are translatable. That is, the movable funnels  27  preferably define a substantially straight line between the contacting position and the spaced or separated position. As shown in  FIG. 17 , the support shaft  27   b  has a small diameter portion  27   c.    
     A support shaft  27   e  having a small diameter portion  27   d  is provided on outer sides of the part  33  integrating two adjacent movable funnels  27  together. As shown in  FIG. 12 , the two parts  33 , each integrating two movable funnels  27  together, are disposed such that their respective end surfaces of the small diameter portions  27   d  of the support shafts  27   e  are opposed to each other. 
     As shown in  FIG. 8 , a split bushing  34  is mounted on the small diameter portion  27   c  of the support shaft  27   b  (see  FIG. 12 ) of the movable funnels  27  (part  33 ). The split bushing  34  has a function of allowing rotational movement of the parallel linkage  42  described below relative to the support shaft  27   b.    
     As shown in  FIG. 12 , such a split bushing  34  is also mounted on the small diameter portions  27   d  of the support shafts  27   e  between the two parts  33 , each integrating two movable funnels  27  together. Between the two parts  33  each integrating two movable funnels  27  together, only one split bushing  34  is mounted in such a manner as to cover the two small diameter portions  27   d  of the support shafts  27   e.    
     In the first embodiment, as shown in  FIGS. 5 and 7 , a seal member  35  is mounted (secured) at the lower end of the movable funnel  27 , which is on the stationary funnel  26  side. Preferably, the seal member  35  is made from rubber or another material, or combination of materials, suitable to create a seal between two components. As shown in  FIGS. 18 and 19 , the seal member  35  is formed with four engagement holes  35   a  as through holes. Four cylindrical projections  27   f  (see  FIG. 20 ) of the movable funnel  27  are in engagement with the engagement holes  35   a . The engagement hole  35   a  is an example of a structure that defines an “engagement surface” and a “recess” of the present invention. The projection  27   f  is an example of a structure that defines an “engagement surface” and a “projection” of the present invention. The engagement surfaces are configured to create a pair of cooperating interference surfaces that contact one another to create a force tending to resist movement of the seal member  35  in a direction separating from the funnel to which the seal member  35  is secured. As shown in  FIG. 19 , the four engagement holes  35   a  of the seal member  35  are each formed to extend at a predetermined angle (α°=approximately 45°) with respect to a radial direction of the seal member  35  (R direction indicated by the arrow). As shown in  FIG. 20 , the four projections  27   f  of the movable funnel  27  are also each formed to extend at a predetermined angle (approximately 45°) with respect to the radial direction of the movable funnel  27  (seal member  35 ), as with the four engagement holes  35   a . The four projections  27   f  of the movable funnel  27  extend in a direction perpendicular to a direction in which two movable funnels  27  are disposed adjacently, or aligned. 
     In the first embodiment, as shown in  FIG. 18 , the seal member  35  is formed with a recess  35   b  on its inner peripheral surface. A flange or flange-like projection  27   g  (see  FIG. 20 ) formed at the bottom of the movable funnel  27  is in engagement with the recess  35   b . The recess  35   b  is an example of a structure defining an “engagement surface” and a “recess” of the present invention. The projection  27   g  is an example of a structure defining an “engagement portion” and a “projection” of the present invention. 
     That is, in the first embodiment, the seal member  35  can be inhibited or prevented from slipping off (falling off or becoming disengaged) from the lower end of the movable funnel  27  by engagement of the engagement holes  35   a  with the projections  27   f  and of the recess  35   b  with the projection  27   g.    
     In the first embodiment, as shown in  FIG. 21 , the seal member  35  is formed with a first seal portion  35   c  extending laterally (radially (perpendicularly with respect to its axis) and a tubular second seal portion  35   d  extending downward (axially). When the movable funnel  27  translates from the spaced position (shown in  FIG. 21 ) to the contacting position (shown in  FIG. 22 ), the first seal portion  35   c  comes into contact with the stationary funnel  26  to block the gap between the movable funnel  27  and the stationary funnel  26 . Also, the first seal portion  35   c  is elastically deformed upward so that the second seal portion  35   d  also comes into contact with the stationary funnel  26  to block the gap between the movable funnel  27  and the stationary funnel  26 . That is, the seal member  35  has a double seal structure. 
     In the first embodiment, as shown in  FIGS. 7 and 10 , the funnel moving mechanism  29  uses a parallel linkage  42  described below to translate the movable funnel  27  between the spaced position (shown in  FIGS. 6 and 7 ) and the contacting position (shown in  FIGS. 9 and 10 ). 
     In a specific structure of the funnel moving mechanism  29 , as shown in  FIGS. 6 and 12 , an end of the rotary shaft  41  is rotatably supported by the rotary shaft support hole  26   f  (see  FIG. 13 ) of the support column  26   e  provided to the stationary funnels  26  (part  30 ). 
     As shown in  FIG. 12 , a parallel linkage  42  is attached to the one and the other ends of the rotary shaft  41  so as to move rotationally together therewith. As shown in  FIGS. 6 and 8 , the parallel linkage  42  includes an upper link lever  43  attached to the upper rotary shaft  41  for rotational movement thereabout and a lower link lever  44  attached to the lower rotary shaft  41  for rotational movement thereabout. 
     As shown in  FIG. 7 , the upper link lever  43  has a fitting part  43   a  and a rotary shaft insertion hole  43   b . As shown in  FIGS. 6 and 8 , the fitting part  43   a  of the upper link lever  43  receives the upper support shaft  27   b  (small diameter portion  27   c ) of the movable funnel  27  via the split bushing  34 . With this construction, the upper link lever  43  is rotationally movable relative to the upper support shaft  27   b.    
     As shown in  FIGS. 8 and 11 , the upper rotary shaft  41  is inserted into the rotary shaft insertion hole  43   b  of the upper link lever  43  so that the upper link lever  43  moves rotationally together with the upper rotary shaft  41 . As shown in  FIG. 12 , a link lever  43   c  is disposed between the parts  33  each integrating two movable funnels  27 . The link lever  43   c  has a fitting part  43   a  (see  FIGS. 7 and 10 ) and a rotary shaft insertion hole  43   b  similar to those of the upper link lever  43 . 
     As shown in  FIG. 8 , the lower link lever  44  has a fitting part  44   a , a rotary shaft insertion hole  44   b  and two stops or stoppers  44   c  and  44   d . The fitting part  44   a  of the lower link lever  44  receives the lower support shaft  27   b  (small diameter portion  27   c ) of the movable funnel  27  via the split bushing  34 . With this construction, the lower link lever  44  is rotationally movable relative to the lower support shaft  27   b . The lower rotary shaft  41  is inserted into the rotary shaft insertion hole  44   b  of the lower link lever  44  so that the lower link lever  44  rotates together with the lower rotary shaft  41 . As shown in  FIG. 8 , the stopper  44   c  of the lower link lever  44  has a function of regulating rotational movement of the lower link lever  44  in an A direction by coming into contact with the support column  26   e  of the stationary funnel  26  when the lower link lever  44  has moved rotationally by a predetermined amount in the A direction (when the movable funnel  27  has reached the spaced position). Also, as shown in  FIG. 11 , the stopper  44   d  of the lower link lever  44  has a function of regulating rotational movement of the lower link lever  44  in a B direction by coming into contact with the support column  26   e  of the stationary funnel  26  when the lower link lever  44  has moved rotationally by a predetermined amount in the B direction (when the movable funnel  27  has reached the contacting position). 
     As shown in  FIG. 9 , the lower rotary shaft  41  is provided with a support part  45  for rotational movement together therewith. The support part  45  is made up of a pair of holding pieces  45   b  each formed with a cutout  45   a.    
     With the support part  45  and the parallel linkage  42  constructed as described above, as shown in  FIGS. 7 and 8 , when the support part  45  (see  FIG. 7 ) is rotationally moved in the A direction to rotationally move the parallel linkage  42  (see  FIG. 8 ) in the A direction, the movable funnel  27  is translated away from the stationary funnel  26 . Also, as shown in  FIGS. 10 and 11 , when the support part  45  (see  FIG. 10 ) is rotationally moved in the B direction to rotationally move the parallel linkage  42  (see  FIG. 11 ) in the B direction, the movable funnel  27  is translated closer to the stationary funnel  26 . Here, as shown in  FIGS. 8 and 11 , the amount of rotational movement of the parallel linkage  42  is adjusted such that the position of the opening end of the movable funnel  27  on the side of the opening  26   a  of the stationary funnel  26  is substantially the same as viewed in the opening direction of the stationary funnel  26  (along its axis) between when the movable funnel  27  is in the spaced position (shown in  FIG. 8 ) and when it is in the contacting position (shown in  FIG. 11 ). With this construction, even when the opening  27   a  of the movable funnel  27  is spaced apart from the opening  26   a  of the stationary funnel  26  while the engine  14  is rotating at a high speed, air can flow linearly through the movable funnel  27  into the stationary funnel  26  and hence an increase in air flow resistance can be avoided. As a result, a decrease in air intake efficiency can be avoided while the engine  14  is rotating at a high speed (when the movable funnel  27  is spaced apart from the stationary funnel  26 ). 
     As shown in  FIG. 12 , the parallel linkage  42 , which includes the upper link lever  43  (see  FIG. 6 ) and the lower link lever  44 , is moved rotationally by the driving force of a motor  46  disposed outside of the air cleaner box  24  (see  FIG. 3 ). 
     Specifically, the motor  46  is disposed on the rear side of the movable funnel  27  in the running direction of the vehicle (FWD direction indicated by the arrow). As shown in  FIG. 7 , one end of a rotary lever  47  is attached to an output shaft  46   a  of the motor  46 . The other end of the rotary lever  47  is formed with an insertion hole  47   a.    
     The rotary lever  47  is disposed inside the air cleaner box  24 . A projection  48   a  provided on both sides of a movable member  48  is attached to the insertion hole  47   a  of the rotary lever  47  so as to be pivotable relative to the insertion hole  47   a . One end of a movable shaft  49  is disposed inside the movable member  48 . Only one movable shaft  49  is provided. 
     As shown in  FIG. 12 , the movable shaft  49  is disposed between the two parts  33  (movable funnels  27 ). As shown in  FIG. 7 , a support shaft  51  is provided at the other end of the movable shaft  49 . The cutout  45   a  of the support part  45 , which moves rotationally together with the rotary shaft  41 , is in engagement with the support shaft  51 . 
     When the rotary lever  47  is rotationally moved in the C direction (as shown in  FIG. 7 ) by the driving force of the motor  46 , the movable member  48  moves in the D direction, which in turn rotationally moves the parallel linkage  42  in the A direction. 
     On the other hand, when the rotary lever  47  is rotationally moved in the E direction by the driving force of the motor  46  as shown in  FIG. 10 , the movable member  48  moves in the F direction, which in turn rotationally moves the parallel linkage  42  in the B direction. 
     With reference to  FIGS. 3 ,  7  and  10 , a description is provided of how the length of the intake pipe is changed between when the engine  14  is rotating at a high speed and when it is rotating at a low speed. 
     When the engine  14  shown in  FIG. 3  is rotating at a high speed, the intake pipe is shortened so that a pulsation effect can be easily obtained. That is, the movable funnel  27  is translated to its spaced position when the engine  14  is rotating at a high speed. By utilizing the pulsation effect, the intake efficiency can be improved by adjusting the length of the intake pipe such that high-pressure pulses come closer to the vicinity of the intake valve. 
     Specifically, first of all, as shown in  FIG. 7 , the rotary lever  47  is rotationally moved in the C direction by the motor  46  of the funnel moving mechanism  29  to move the movable member  48  in the D direction. This moves the movable shaft  49  in the D direction, which in turn rotationally moves the parallel linkage  42  (see  FIG. 8 ) in the A direction. After that, the parallel linkage  42  is kept rotationally moving in the A direction until the stopper  44   c  of the lower link lever  44  comes into contact with the support column  26   e  as shown in  FIG. 8 . 
     This causes the movable funnel  27  to be moved to the spaced position with the opening end of the opening  27   a  of the movable funnel  27  kept in parallel to the opening end of the opening  26   a  of the stationary funnel  26 . As a result, when the engine  14  (see  FIG. 3 ) is rotating at a high speed, the intake pipe is made up of the stationary funnel  26 , the throttle body  18  (see  FIG. 3 ) and the intake port  17   a  (see  FIG. 3 ) and hence can be shortened. Here, when the intake pipe is shortened when the engine  14  shown in  FIG. 3  is rotating at a high speed, high-pressure pulses can easily reach the opening of the intake port  17   a  on the cylinder  16  side when the intake valve  19   a  opens, thereby improving the intake efficiency. 
     When the engine  14  shown in  FIG. 3  is rotating at a low speed, the intake pipe is lengthened so that the pulsation effect can be easily obtained. That is, the movable funnel  27  is translated to its contacting position when the engine  14  is rotating at a low speed. 
     Specifically, first of all, as shown in  FIG. 10 , the rotary lever  47  is rotationally moved in the E direction by the motor  46  of the funnel moving mechanism  29  to move the movable member  48  in the F direction. This moves the movable shaft  49  in the F direction, which in turn rotationally moves the parallel linkage  42  (see  FIG. 11 ) in the B direction. After that, the parallel linkage  42  is kept rotationally moving in the B direction until the stopper  44   d  of the lower link lever  44  comes into contact with the support column  26   e  as shown in  FIG. 11 . 
     This causes the movable funnel  27  to be moved to the contacting position with the opening end of the opening  27   a  of the movable funnel  27  kept in parallel to the opening end of the opening  26   a  of the stationary funnel  26 . As a result, when the engine  14  (see  FIG. 3 ) is rotating at a low speed, the intake pipe is made up of the movable funnel  27 , the stationary funnel  26 , the throttle body  18  (see  FIG. 3 ) and the intake port  17   a  (see  FIG. 3 ) and hence can be lengthened. Here, when the intake pipe is lengthened when the engine  14  shown in  FIG. 3  is rotating at a low speed, high-pressure pulses can easily reach the opening of the intake port  17   a  on the cylinder  16  side when the intake valve  19   a  opens, thereby improving the intake efficiency. 
     In the first embodiment, as described above, a seal member  35  is provided between the stationary funnel  26  and the movable funnel  27 . Thus, air leakage through the gap between the movable funnel  27  and the stationary funnel  26  can be reduced or eliminated when the movable funnel  27  is moved to the stationary funnel  26  side (in the contacting position). With this construction, a desired amount of air can be supplied to the intake port  17   a . In addition, the movable funnel  27  is formed with projections  27   f  and a projection  27   g , and the seal member  35  is formed with engagement holes  35   a  and a recess  35   b  for engagement with the projections  27   f  and  27   g , respectively, to prevent the seal member  35  from falling off from the movable funnel  27 . Thus, the seal member  35  can be prevented from falling off from the movable funnel  27  without providing a separate member specifically for that purpose. With this construction, it is possible to prevent the seal member  35  and the member for preventing the seal member  35  from falling off from the movable funnel  27  from entering the inside of the engine  14 , thereby preventing damage to the engine  14 . It will be appreciated that, although referred to as a “contacting position” between the movable funnel  27  and the stationary funnel  26 ; the funnels do not necessary come into direct contact with one another. For instance, in the illustrated arrangement, the seal member  35  provides contact between the stationary funnel  26  and the movable funnel  26 . Furthermore, alternative arrangements are possible wherein the funnels remain in contact with one another at all times, even while moving relative to one another to vary a length of the intake passage, such as by a sliding or telescoping arrangement, for example. 
     In the first embodiment, the movable funnel  27  is formed with a flange-like projection  27   g . Therefore, the projection  27   g  and the recess  35   b  can be tightly engaged with each other by inserting the projection  27   g  into the recess  35   b . Thus, the seal member  35  can be more reliably prevented from falling off from the movable funnel  27 . 
     In the first embodiment, the movable funnel  27  is formed with four cylindrical (boss-like) projections  27   f , and the seal member  35  is formed with four engagement holes  35   a  for receiving the projections  27   f  therein. Therefore, the projections  27   f  and the engagement holes  35   a  can be tightly engaged with each other by inserting the projections  27   f  into the engagement holes  35   a . Thus, the seal member  35  can be more reliably prevented from falling off from the movable funnel  27 . 
     In the first embodiment, the boss-like projections  27   f  of the movable funnel  27  are formed to extend at a predetermined angle (approximately 45°) with respect to a radial direction of the seal member  35  (R direction indicated by the arrow), and the engagement holes  35   a  of the seal member  35  are also formed to extend at a predetermined angle (α°=approximately 45°) with respect to the radial direction of the seal member  35  (R direction indicated by the arrow) correspondingly to the projections  27   f . Thus, even when the seal member  35  expands radially, the expanding direction of the seal member  35  is at the predetermined angle (α°=approximately 45°) with respect to the extending direction of the projections  27   f  and the engagement holes  35   a , and hence the projections  27   f  can be more reliably prevented from coming disengaged from the engagement holes  35   a . In addition, since the projections  27   f  are formed to extend in a direction at the predetermined angle (approximately 45°) with respect to the radial direction of the seal member  35  (R direction indicated by the arrow), enlargement of the projections  27   f  in radial directions of the seal member  35  can be avoided while the area of engagement between the projections  27   f  and the engagement holes  35   a  can be increased. 
     In the first embodiment, since the engagement holes  35   a  are formed as through holes, it is easy to check whether or not the projections  27   f  are inserted into the engagement holes  35   a  by a visual inspection from the outside. 
     In the first embodiment, two movable funnels  27  are integrated together, and the bosses, or boss-like projections  27   f , are formed to extend in a direction perpendicular to a direction in which the two movable funnels  27  are disposed adjacently or aligned with one another. Thus, in the case where the two movable funnels  27  are integrally molded using a split mold, since the split line of the mold extends perpendicularly to the direction in which the two movable funnels  27  are disposed adjacently, the split line of the mold extends in the same direction as the extending direction of the projections  27   f . With this construction, the projections  27   f  can be easily formed in a cylindrical shape (e.g., a boss-like shape). 
     In the first embodiment, the seal member  35 , which is secured to the movable funnel  27 , can smooth the passage of air to be supplied to the stationary funnel  26  when the movable funnel  27  is spaced apart from the stationary funnel  26  (when the engine  14  is rotating at a high speed). Thus, air can be smoothly supplied to the engine  14 . With this construction, a decrease in engine  14  output can be avoided. 
     In the first embodiment, the seal member  35  is formed with a first seal portion  35   c  formed to extend in a radial direction relative to the seal member  35 , and a tubular second seal portion  35   d  extends in the axial direction of the seal member  35 . Thus, air leakage through the gap between the movable funnel  27  and the stationary funnel  26  can be reduced or eliminated when the movable funnel  27  is moved to the stationary funnel  26  side (in the contacting position). 
       FIGS. 23 to 27  illustrate the detailed structure of a seal member and a movable funnel of a motorcycle according to a second embodiment of the present invention. As described with reference to  FIGS. 23 to 27 , the second embodiment is different from the first embodiment described above in that the seal part is formed with a portion, or portions, having a reduced axial length compared to other portions or the remainder of the seal part. 
     In the second embodiment, as in the first embodiment, a rubber seal member  85  (see  FIG. 23 ) is mounted (secured) at the lower end of the movable funnel  77  (see  FIG. 25 ). As shown in  FIGS. 23 and 24 , the seal member  85  is formed with four engagement holes  85   a  as through holes, as in the first embodiment. Four cylindrical projections  77   f  (see  FIG. 25 ) of the movable funnel  77  are in engagement with the engagement holes  85   a . The engagement hole  85   a  is an example of a structure defining an “engagement portion” and a “recess” of the present invention. The projection  77   f  is an example of a structure defining an “engagement portion” and a “projection” of the present invention. 
     As shown in  FIG. 23 , the seal member  85  is formed with a recess  85   b  on its inner peripheral surface, as in the first embodiment. A flange-like projection  77   g  (see  FIG. 25 ) formed at the bottom of the movable funnel  77  is in engagement with the recess  85   b . The recess  85   b  is an example of a structure defining an “engagement portion” and a “recess” of the present invention. The projection  77   g  is an example of a structure defining an “engagement portion” and a “projection” of the present invention. 
     As shown in  FIG. 26 , the seal member  85  is formed with a first seal portion  85   c  extending laterally (radially) and a tubular second seal portion  85   d  extending downward (axially). 
     In the second embodiment, as shown in  FIG. 23 , the seal member  85  is formed with a thick portion, or a first portion  85   e  with a first axial length and a recessed thin portion, or second portion  85   f  with a second axial length that is less than the axial length of the first portion  85   e . As shown in  FIG. 27 , a lower part of the support shafts  77   b  and  77   e  of the movable funnel  77  is disposed in the recessed part of the second portion  85   f . The support shaft  77   b  is an example of the “shaft part” of the present invention. 
     In the second embodiment, as shown in  FIGS. 25 and 26 , the movable funnel  77  is formed with a recess  77   h . As shown in  FIG. 26 , the seal member  85  is formed with a projection  85   g  for engagement with the recess  77   h . With this construction, the seal member  85  can be more reliably prevented from coming off from the movable funnel  77 . 
     The structure of the other part of the second embodiment is similar to that of the first embodiment. In the second embodiment, as described above, since the seal member  85  is formed with a second portion  85   f  that has a smaller axial length than the first portion  85   e , the seal member  85  can be easily stretched at the second or thin portion  85   f . Thus, the seal member  85  can be easily attached to the movable funnel  77 . 
     The embodiment disclosed herein is intended to be illustrative in all respects, rather than restrictive. The scope of the present invention is defined by the appended claims, rather than the foregoing description of the embodiment, and is intended to include all modifications that fall within the meaning and scope equivalent to the appended claims. For example, although the present invention is applied to a motorcycle in the first and second embodiments described above, it is not limited thereto and may also be applied to vehicles other than motorcycles. In the first and second embodiments described above, the seal member is secured to the movable funnel. However, the present invention is not limited thereto, and the seal member may be secured to the stationary funnel. 
     In the first and second embodiments described above, the movable funnel is formed with four boss-like (cylindrical) projections for securing the seal member to the movable funnel. However, the present invention is not limited thereto, and the movable funnels may be formed with three or less, or five or more projections for that purpose. 
     In the first and second embodiments described above, the seal member is provided with a first seal portion and a second seal portion. However, the present invention is not limited thereto, and the seal member may be formed with a single seal portion. 
     In the first and second embodiments described above, the present invention is applied to a vehicle incorporating a four-cylinder engine. However, the present invention is not limited thereto and may also be applied to vehicles incorporating a multi-cylinder engine other than a four-cylinder one, vehicles incorporating a single-cylinder engine, and so forth. 
     In the first and second embodiments described above, two movable funnels are integrated together. However, the present invention is not limited thereto, and three or more movable funnels may be integrated together. Alternatively, a separate movable funnel may be provided for each cylinder. 
     In the first and second embodiments described above, the boss-like projections of the movable funnel are formed to extend at approximately 45° with respect to a radial direction of the seal member, and the engagement holes of the seal member are also formed to extend at approximately 45° with respect to the radial direction of the seal member. However, the present invention is not limited thereto, and the boss-like projections of the movable funnel may be formed to extend in a radial direction of the seal member, and the engagement holes of the seal member may also be formed to extend in the radial direction of the seal member. Alternatively, the boss-like projections of the movable funnel may extend at an angle other than approximately 45° with respect to a radial direction of the seal member, and the engagement holes of the seal member may also be formed to extend at the angle other than approximately 45° with respect to the radial direction of the seal member. In this case, the boss-like projections of the movable funnel can be sufficiently prevented from coming off out of the engagement holes of the seal member, if the projections are formed to extend at approximately 30° to 60° with respect to a radial direction of the seal member and the engagement holes of the seal member are also formed to extend at approximately 30° to 60° with respect to the radial direction of the seal member. 
     In the first and second embodiments described above, the movable funnel is translatable using a parallel link. However, the present invention is not limited thereto, and the movable funnel may be not provided with a parallel link and hence not translatable, but movable throughout an arcuate path. 
     Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In particular, while the present vehicle with air intake arrangement has been described in the context of particularly preferred embodiments, the skilled artisan will appreciate, in view of the present disclosure, that certain advantages, features and aspects of the vehicle with air intake arrangement may be realized in a variety of other applications, many of which have been noted above. Additionally, it is contemplated that various aspects and features of the invention described can be practiced separately, combined together, or substituted for one another, and that a variety of combination and subcombinations of the features and aspects can be made and still fall within the scope of the invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims.