Abstract:
A throttle body assembly includes a housing defining a throttle bore with a throttle plate in the bore and mounted on a shaft. An electric motor has a pinion gear. A gear assembly includes an intermediate gear and a sector gear and transfers rotational drive from the electric motor to the throttle plate. Biasing structure biases the sector gear and thus the shaft to cause the throttle plate to close the throttle bore defining a closed position thereof. When the motor is energized, rotation of the pinion gear causes rotation of the gear assembly, against the bias on the sector gear, thereby causing rotation of the shaft to move the throttle plate from the closed position to an open position. A positon sensor assembly determines a position of the plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/001,348 filed May 21, 2014. The disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The invention relates generally to an electronic throttle body assembly for controlling air flow into the engine of a vehicle. 
       BACKGROUND 
       [0003]    Throttle body assemblies are generally known, and are used for controlling the amount of air flow into the engine during vehicle operation. Due to the advancement of technology implemented in modern vehicles, and the increased number of options and features available, there have also been greater restrictions placed on the packaging configuration of throttle body assemblies, as well as greater limitations on the location and placement of the throttle body assembly. Requirements are also such that throttle body assemblies be adaptable for gasoline and diesel applications. 
         [0004]    Furthermore, with the different orientations of an engine possible within an engine compartment, there is also the requirement for throttle body assemblies to have right-hand and left-hand configurations. 
         [0005]    Accordingly, there exists a need for a throttle body or valve assembly which accommodates of the above mentioned requirements. 
       SUMMARY 
       [0006]    The present invention is a throttle body assembly which accommodates various packaging configurations, and is adaptable for both gasoline and diesel applications. 
         [0007]    In accordance with an embodiment, a throttle body assembly for controlling aspiration to an engine includes a housing defining a throttle bore. A throttle plate is disposed in the bore and is mounted on a shaft. A gear assembly is constructed and arranged to transfer rotational drive from an electric motor to the throttle plate. Biasing structure is constructed and arranged to bias the gear assembly and thus the shaft to cause the throttle plate to close the throttle bore defining a closed position thereof. A throttle position sensor assembly is constructed and arranged to monitor a position of a sensor element and thus the throttle plate. When the motor is energized, rotation of the gear assembly, against the bias thereon, thereby causing rotation of the shaft to move the throttle plate from the closed position to an open position. 
         [0008]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0010]      FIG. 1A  is a top view of a throttle body assembly, according to an embodiment of the present invention; 
           [0011]      FIG. 1B  is a bottom view of a throttle body assembly of  FIG. 1A ; 
           [0012]      FIG. 2  is a bottom view of a throttle body assembly with the cover removed, according to another embodiment; 
           [0013]      FIG. 3  is an enlarged perspective view of an intermediate gear associated with a sector gear of the throttle body assembly of  FIG. 6 , with the cover removed; 
           [0014]      FIG. 4  is a side view of the throttle body assembly of  FIG. 1A , with the cover removed, showing the return spring and cooperating stop pins; and 
           [0015]      FIG. 5  is a side view of a throttle body assembly, with the cover and the sensor removed, showing stops integral with the housing that engage the return spring in accordance with another embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0017]    A throttle body assembly according to an embodiment is shown, generally indicated at  10 , in  FIG. 1A  for use in controlling aspiration to an engine. The assembly  10  includes a housing  12  with an integral central bore  14 , through which air passes during operation of the assembly  10 . A rotatable shaft  16  is disposed in the central bore  14 . The shaft  16  includes a valve member  20  disposed in a slot formed as part of the shaft  16 . In the embodiment, the valve member  20  is in the form of an annular throttle plate. 
         [0018]    The shaft  16  is partially disposed in an aperture formed in the housing  12  and disposed transverse with respect to bore  14 . At least one needle bearing is disposed in aperture that supports the shaft  16  and allows for the shaft  16  to rotate relative to the housing  12 . An actuator, preferably in the form of an electric motor  38 , is disposed in a cavity formed as part of the housing  12 . A pinion gear  42  is part of a gear assembly, and is attached to the motor  38 . The gear assembly is located in a gear box housing  114 . 
         [0019]    Biasing structure  62  is also located in the gearbox housing  114 . In the embodiment, the biasing structure  62  is a return spring assembly  62 . The biasing structure  62  biases the shaft  16  to cause the throttle plate  20  to close the throttle bore  14 . 
         [0020]    A pinion gear  42  is attached to the rotatable shaft  43  of the motor  38 . The pinion gear  42  is part of a gear assembly and is in meshing relation with teeth of a first gear  45  of a plastic intermediate gear, generally indicated at  44  in  FIGS. 3-5 . The intermediate gear  44  is mounted on an intermediate shaft  46 , and the intermediate shaft  46  partially extends into an aperture formed in housing  12 . A second or middle gear  54  is formed integrally and concentrically with the intermediate gear  44 . The middle gear  54  has a smaller diameter than the first gear  45  and is spaced there-from. With reference to  FIG. 6 , when the middle gear  54  and first gear  45  are mounted on the shaft  46 , the middle gear  54  is disposed for rotation in a recess  56  in housing  12  so that the teeth of the middle gear  54  are in meshing relation with teeth  107  of a preferably plastic sector gear  58  that is fixed to the shaft  16 . The intermediate gear  44  and the sector gear  58  define a gear assembly of the throttle body assembly  10 . 
         [0021]    A first end  70  the return spring  62  is in contact with a first pin  74  functioning as a first spring stop, and a second end  72  of the return spring  62  is in contact with a second pin  76  functioning as a second spring stop. Each of the pins  74 ,  76  are partially disposed in corresponding apertures formed in the housing  12 . The spring  62  biases the sector gear  58  and thus the shaft  16  to cause the throttle plate  20  to close the throttle bore  14 . In an alternate embodiment shown in  FIG. 6 , stops  75  and  77  are surfaces of the housing  12  and thus are formed integral with the housing  12 , replacing the pins  74 ,  76  of  FIG. 5 . 
         [0022]    A cover  80  is connected to the housing  12 . More specifically, the gear box housing  114 , and partially surrounds the gear assembly. The cover  80  is connected to the housing  12  using a plurality of clips  86 . Once the cover  80  is placed on the housing  12 , the clips  86  connect the cover  80  to the housing  12 . Once the cover  80  is attached to the housing  12  the terminals for the motor  38  can be accessed or viewed through an opening in the cover  80 . Once it is determined that the terminals of the motor  38  are in contact with the terminals of a lead frame, a secondary cover  88  is attached to the cover  80  to close the opening. The lead frame is part of the cover  80 , and defines motor leads which place the connector  90  in electrical communication with a sensor, the function of which will be explained below. 
         [0023]    The cover  80  also includes a connector  90  which is in electrical communication with the motor  38 , such that the connector  90  is able to be connected to a source of power. The lead frame is in electrical communication with a printed circuit board (PCB)  94 , and the electric motor  38 . The lead frame is also in electrical communication with the connector  90 . For reverse motor direction, the polarity of the motor  38  can be reversed. 
         [0024]    The leads of the leadframe include a first set of terminals which are in electrical communication with the printed circuit board (PCB)  94 , and a second set of terminals which are connected to and in electrical communication with the electric motor  38 . 
         [0025]      FIGS. 1A and 1B  show another embodiment of the cover  80  where a single cover includes all three connectors  90 ,  90 ′ and  90 ″. Thus, depending on the orientation required, the terminals are provided in the appropriate connector and the leads are configured based on the selected connector location. This ensures a common seal profile, a common cover  80  and common sealing area on the housing  12 , which reduces number of components required and thus saves cost. Also, the same cover  80  can be used for different types of sensors  94 . 
         [0026]    The throttle body assembly  10  comprises an inductive rotary position sensor assembly that includes a sensor element (not shown) that is disposed with respect to the inductive rotary position sensor  94  so as to be in an electrically inductive relationship therewith. In this configuration, the position sensor  94  detects movement and position of the sensor element, which is compared to reference data to determine the position of the throttle plate  20 . 
         [0027]    Referring to  FIG. 6 , the sensor element, preferably of aluminum, is attached to the sector gear  58 . The sector gear  58  includes an insert  96  that is welded or otherwise coupled to the end of the shaft  16 . Thus, as the throttle plate  14  is moved between an open position and closed position, the sensor element moves with the sector gear  58 . Accordingly, movement and position of the sensor element is directly related to movement and position of the throttle plate  20 . Referring to  FIGS. 4 and 6 , the position sensor  94  is disposed in an inductive relationship to the sensor element. In the configuration shown, the position sensor  94  is mounted to inside of the cover  80  of the throttle body assembly  10  using suitable attachment means. In one embodiment, the position sensor  94  is sized and contoured to fit beside the intermediate gear  44  (the position sensor  94  is adjacent the intermediate gear  44 ), which provides another advantage for packaging. In the embodiment shown in  FIG. 4 , the position sensor  94  has a flat surface adjacent the intermediate gear  44 , but it is within the scope of the invention that the position sensor  94  may have other shapes to curve around the intermediate gear  44 , or away from the intermediate gear  44 . Furthermore, the sensor  94  may be is secured into the gearbox cover  80  by heat stakes, glue, clip features, along with press-fit terminals with or without solder, or non press-fit terminals with or without solder. The position sensor  94  comprises a PCB sensor board so that as the sensor element moves, different inductive readings are observed across the sensor board  94 , which are transferred a sensor processor, which transmits signals to a monitor or control unit of the throttle body assembly  10 , or engine, through connector  90 . 
         [0028]    In operation, the spring  62  biases the sector gear  58 , and therefore the shaft  16  and throttle plate  20  towards a closed position, such that the central bore  14  is substantially closed, or blocked completely, depending upon how the assembly  10  is configured. When current is applied to the motor  38 , the pinion gear  42  is rotated, which causes the rotation of the first gear  45  of the intermediate gear  44 , the second or middle gear  54  of the intermediate gear  44 , and the sector gear  58 . To rotate the sector gear  58 , the bias applied to the sector gear  58  by the return spring  62  is overcome. The amount of rotation of the sector gear  58  is in proportion to the amount of current applied to the motor  38 , which must overcome the force applied to the sector gear  58  by the return spring  62 . Since the sector gear  58  is coupled to the shaft  16  by the insert  96 , rotation of the sector gear  58  rotates the shaft  16  to open the plate  20 . As noted above, the sensor element and the position sensor  94  detect the position of the sector gear  58  and thus the plate  20  during the operation of the throttle body assembly  10 . 
         [0029]    As the sector gear  58  is rotated, the shaft  16  is rotated as well, rotating the plate  20 , and allowing increased levels of air flow through the central bore  14 . The amount of rotation of the sector gear  58  is detected by the sensor  94 , such that the valve plate  20  may be placed in a desired position. 
         [0030]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.