Abstract:
An intake system for a motorcycle having an engine. The intake system includes an air box having a first opening for receiving intake air and a second opening for supplying the intake air from the air box to a throttle assembly of the engine. A filter element is disposed within the air box for separating debris from the intake air. A valve is disposed within the air box between the filter element and the second opening. The valve is movable to provide a variable restriction to intake air flow through the air box.

Description:
BACKGROUND 
     The present invention relates to a device and method for controlling the intake of air into an engine. More specifically, the invention relates to a device and method for controlling an intake state of an air box to selectively affect the operation of a motorcycle engine under predetermined conditions. 
     SUMMARY 
     In one embodiment, the invention provides an intake system for a motorcycle having an engine. The intake system includes an air box having a first opening for receiving intake air and a second opening for supplying the intake air from the air box to a throttle assembly of the engine. A filter element is disposed within the air box for separating debris from the intake air. A valve is disposed within the air box between the filter element and the second opening. The valve is movable to provide a variable restriction to intake air flow through the air box. 
     In another embodiment, the invention provides a motorcycle including an engine, an air box, and a throttle assembly. The air box has an inlet for receiving intake air and an outlet. The throttle assembly is positioned to receive intake air from the outlet and direct the intake air into the engine for combustion. A filter element is positioned in the air box. A valve is positioned in the air box between the filter element and the outlet. 
     In yet another embodiment, the invention provides a method of operating an engine of a motorcycle having a throttle assembly, an air box, and an engine controller. The throttle assembly controls the rate of intake air into the engine. The air box directs intake air into the throttle body and cleans the intake air with a filter element. The method includes running the engine, opening the throttle assembly to a substantially full throttle position, and restricting the flow of intake air into the engine by moving a valve that is positioned in the air box from a first position to a second position. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a motorcycle embodying the present invention; 
         FIG. 2  is a side view of the motorcycle of  FIG. 1 ; 
         FIG. 3  is an opposite side view of the motorcycle of  FIG. 1 ; 
         FIG. 4  is an exploded perspective view of an air box assembly of the motorcycle of  FIG. 1 ; 
         FIG. 5  is a perspective view of the air box assembly of  FIG. 4  with a valve in an open position and an upper housing removed for clarity; 
         FIG. 6  is a view similar to  FIG. 5  with the valve in a closed position; 
         FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 5 ; 
         FIG. 8  is a cross-sectional view taken along line  8 - 8  of  FIG. 6 ; and 
         FIG. 9  is a schematic diagram illustrating the function of an active intake system. 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     DETAILED DESCRIPTION 
     A motorcycle  20  including an active intake system  24  is illustrated in  FIGS. 1-3 . The motorcycle  20  includes a front wheel  26 , a rear wheel  28 , and an engine  32 . The engine  32  provides power to the rear wheel  28  through a transmission  112 . The engine  32  includes two cylinders  34   a ,  34   b  for combusting an air-fuel mixture. The crankshaft rotational speed (or simply “engine speed”) is controlled by a throttle control  38 , which is coupled either mechanically or electro-mechanically to a throttle assembly  42  ( FIG. 3 ). The throttle control  38  is a grip control that is rotated by a rider&#39;s right hand. 
     As understood by one skilled in the art, the throttle assembly  42  includes an intake funnel and a throttle body defining a flow passage and a throttle plate (not shown) within the flow passage. The throttle plate is movable between a substantially closed (i.e., “idle”) position and a substantially fully open (i.e., “full throttle”) position in response to the throttle control  38  being rotated from an at-rest position to a full throttle position. 
     As shown in  FIG. 4 , the active intake system  24  includes an air box assembly, referred to hereinafter as the air box  46 . The air box  46  includes an upper housing  48 , a lower housing  50 , and a front fascia  52 . The upper housing  48  and the lower housing  50  are coupled together by fasteners  56 . Additional fasteners  58  are used to couple the front fascia  52  to the upper housing  48  and lower housing  50 . 
     With continued reference to  FIG. 4 , the upper housing  48  and the lower housing  50  combine to define a flow passage through the air box  46 . The front fascia  52  includes an inlet opening  62  for receiving intake air into the air box  46 . The lower housing  50  includes an outlet opening  64  for supplying the intake air to the throttle assembly  42 . A filter element  66  is positioned adjacent the inlet opening  62  to separate debris from the intake air. The filter element  66  is held in place by the upper housing  48  and the lower housing  50 . The lower housing  50  includes a receiving channel  68  for receiving an outer rim  70  of the filter element  66 . The filter element  66  is securely positioned by the receiving channel  68  of the lower housing  50 . 
     With reference to  FIGS. 4-6 , the active intake system  24  further includes a valve  72  positioned in the air box  46 . Specifically, the valve  72  is positioned in the flow passage between the inlet opening  62  and the outlet opening  64 . In this position, the valve  72  is downstream of the filter element  66  and upstream of the throttle assembly  42 . Therefore, the valve  72  is shielded by the filter element  66  from the debris that the filter element  66  separates from the intake air. Also, the valve  72  is positioned to vary the intake passage geometry and affect the flow of intake air through the intake passage before the intake air reaches the throttle assembly  42 . 
     The valve  72  includes a plate or body portion  76  and a rod portion  78 . The rod portion  78  includes two ends  78   a  and  78   b  extending out from the sides of the body portion  76 . The first end  78   a  is held in a grooved support  82 . The support  82  is formed integrally as part of the lower housing  50 . A second support (not shown) is formed integrally as part of the upper housing  48  and is positioned adjacent the support  82  to hold the first end  78   a  in place. In other embodiments, one or both of the supports are provided as separate pieces from the upper housing  48  and lower housing  50 , respectively. Different structures for positioning the valve  72  are also within the spirit and scope of the invention. 
     The second end  78   b  of the valve&#39;s rod portion  78  is coupled to an actuator  88 . The actuator  88  includes a flange  90 , in which a slot  92  is formed. The second end  78   b  is received within the slot  92 . A retainer  94  is placed on the second end  78   b  to keep the second end  78   b  within the slot  92 . The second end  78   b  is offset a distance (via two ninety-degree angles) from a main axis A of the rod portion  78  ( FIG. 6 ), which is also the main axis of the valve  72 . Thus, the second end  78   b  forms a crank, allowing a force at the second end  78   b  to impart a torque to rotate the valve  72  about the main axis A. In the illustrated embodiment, the actuator  88  is a solenoid configured to apply a force to the second end  78   b  via linear actuation. In other embodiments, the actuator  88  has rotational output, and the second end  78   b  may or may not be offset from the main axis A. 
     The actuator  88  is movable between a first position (shown in  FIGS. 5 and 7 ) and a second position (shown in  FIGS. 6 and 8 ). The actuator  88  is biased to the first position by a spring  98 . Accordingly, the valve  72  is biased to a first position (i.e., the open position) as shown in  FIGS. 5 and 7 . When the actuator  88  is activated, such as by an electric signal, the spring  98  is compressed and the actuator  88  moves to the second position, moving the valve  72  to a second position (i.e., the closed position) as shown in  FIGS. 6 and 8 . 
     As mentioned above, the filter element  66  shields the valve  72  from debris that is present in unfiltered intake air. Likewise, the actuator  88  is shielded from debris by the filter element  66 . The positioning of the valve  72  and the actuator  88  inside the air box  46  downstream of the filter element  66  provides protection against impact damage, clogging of the intake passage, and jamming of the moving parts. Also, the filter element  66  shields electrical components and connections associated with the actuator  88 . The filter element  66  keeps the electrical components and connections clean, extending the useful life of the actuator  88 . 
     The actuator  88  is electrically coupled to a controller, such as the motorcycle&#39;s engine control module (ECM)  102  as shown in  FIG. 9 . The ECM  102  is configured to send a signal (e.g., an electrical signal) to the actuator  88  to activate the actuator  88  from the first position ( FIGS. 5 and 7 ) to the second position ( FIGS. 6 and 8 ) to move the valve  72  from the open position to the closed position.  FIG. 9  also illustrates an engine speed sensor  104 , a throttle position sensor  106 , and a gear selection sensor  108  all coupled to the ECM  102  and configured to send signals (e.g., electrical signals) indicative of respective parameters of the motorcycle&#39;s operating condition to the ECM  102 . 
     During some operating conditions of the motorcycle engine  32 , the flow rate of intake air into the engine  32  is controlled by the throttle assembly  42  (i.e., the position of the throttle plate). Under these operating conditions, the rider twists the throttle control  38  away from the at-rest position, and the throttle plate opens an amount proportional to the rotation of the throttle control  38 . When the rider returns the throttle control  38  to the at-rest position, the throttle plate returns to the idle position. During some operating conditions, the motorcycle engine  32  may make excessive noise when the amount or flow rate of intake air is controlled solely by the throttle assembly  42 . For example, when the engine  32  is running at a low engine speed (mostly closed throttle position) and the throttle assembly  42  is quickly moved to the substantially fully-open position, the engine  3 : 2  may emit a particularly high level of noise. The engine&#39;s noise emission can be reduced by at least partially counteracting the effect of opening the throttle assembly  42 . 
     When the ECM  102  receives a signal from the engine speed sensor  104  indicating that the engine speed is below a predetermined speed and also receives a signal from the throttle position sensor  106  indicating that the throttle assembly  42  is in the substantially fully-open position, the ECM  102  sends a signal to the actuator  88  to close the valve  72  as described above. When the valve  72  moves to the closed position, it at least partially restricts the flow of intake air through the air box  46 , counteracting the effect of the open throttle assembly  42  and allowing the engine  32  to build speed more gradually without generating excessive noise levels. In the closed position, the valve  72  blocks approximately 90% of the cross-sectional area of the air flow passage. As shown in  FIG. 8 , air is allowed to pass on both sides of the valve  72  when the valve  72  is in the closed position. 
     After a predetermined amount of time has passed, another signal is sent from the ECM  102  to the actuator  88  to re-open the valve  72 . In some embodiments, the ECM  102  deactivates the actuator  88  to re-open the valve  72  before the predetermined amount of time has passed if the throttle assembly is at least partially closed by an input from the throttle control  38 . In some embodiments, the ECM  102  deactivates the actuator  88  to re-open the valve  72  as soon as the engine speed reaches the predetermined speed (or a second predetermined speed). Other methods of determining when to deactivate the actuator  88  are also within the scope of the present invention. 
     The signal for re-opening the valve  72  (by de-activating the actuator  88 ) can simply be the termination of the signal that activates the actuator  88 . For example, the ECM  102  may send a positive voltage signal to the actuator  88  to close the valve  72 , and when the signal returns to zero Volts, the actuator  88  and the valve  72  are biased by the spring  98  back to the first position (the open position of the valve  72 ). Other signal conventions, including, but not limited to equal but opposite voltage signals may alternately be used to control the activation and deactivation of the actuator  88 . 
     In some embodiments, the ECM  102  activates and deactivates the actuator  88  based on signals not only from the engine speed sensor  104  and the throttle position sensor  106 , but also based on a signal from the gear selection sensor  108 . In some such embodiments, the ECM  102  recognizes a combination of engine speed below a predetermined speed, substantially fully-open throttle position, and the transmission  112  of the motorcycle  20  being in a predetermined gear or one of a plurality of predetermined gears before activating the actuator  88  to close the valve  72 . The ECM  102  deactivates the actuator  88  to re-open the valve  72  when at least one of three events occurs, the three events being: the engine speed reaching the predetermined speed, throttle position being at least partially closed, and the transmission  112  of the motorcycle  20  being shifted out of the predetermined gear(s). Signals from the engine speed sensor  104 , the throttle position sensor  106 , and/or the gear selection sensor  108  are sent to the ECM  102  to deactivate the actuator  88  when at least one of the deactivation events occurs (i.e., at least one of the activation conditions is no longer met). Alternately or in addition, the ECM  102  deactivates the actuator  88  after a predetermined time has elapsed since the closing of the valve  72  (i.e., elapsed time since the activation of the actuator  88 ). 
     In some embodiments, the ECM  102  activates the actuator  88  to close the valve  72  based on the position of the throttle assembly  42  and vehicle speed of the motorcycle  20 . In some embodiments, the ECM  102  activates the actuator  88  to close the valve  72  when it recognizes a vehicle speed within a predetermined range and substantially fully open throttle position The vehicle speed is sensed directly or calculated by the ECM  102  (e.g., based upon a known measurement of the front and/or rear wheels  26 ,  28  and signals communicated to the ECM  102  by the engine speed sensor  104  and the gear position sensor  108 ). The throttle position is sensed and communicated to the ECM  102  by the throttle position sensor  106 . The ECM  102  deactivates the actuator  88  to re-open the valve  72  after a predetermined amount of time has passed. In one embodiment, the actuator  88  is deactivated to re-open the valve  72  about two seconds after the actuator  88  is activated (i.e., about two seconds after the valve is moved from the open position to the closed position). Because the activation of the actuator  88  is dependent upon the vehicle speed and not simply the engine speed, the valve  72  is actuated to the closed position at different engine speeds based on the gear the transmission  112  is in. For example, the predetermined range of vehicle speed can be reached at a first engine speed when the transmission  112  is in a first predetermined gear and can be reached at a lower engine speed when the transmission  112  is in a higher gear. In some embodiments, the ECM  102  deactivates the actuator  88  when the throttle is at least partially closed, the vehicle speed of the motorcycle  20  is no longer within the predetermined range, and/or the transmission  112  is shifted to a different gear.