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 transfers rotational drive from the electric motor to the throttle plate. Biasing structure biases the gear assembly 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 gear assembly, against the bias biasing structure, thereby causing rotation of the shaft to move the throttle plate from the closed position to an open position. A position sensor assembly determines a position of the plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/001,387 filed May 21, 2014. The disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD 
     The invention relates generally to an electronic throttle body assembly for controlling air flow into the engine of a vehicle. 
     BACKGROUND 
     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. 
     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. 
     Accordingly, there exists a need for a throttle body or valve assembly which accommodates of the above mentioned requirements. 
     SUMMARY 
     The present invention is a throttle body assembly which accommodates various packaging configurations, and is adaptable for both gasoline and diesel applications. 
     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. 
     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 
       The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1A  is a top view of a throttle body assembly, according to an embodiment of the present invention; 
         FIG. 1B  is a bottom view of a throttle body assembly of  FIG. 1A ; 
         FIG. 2  is a bottom view of a throttle body assembly with the cover removed, according to another embodiment; 
         FIG. 3  is a side view of a throttle body assembly, according to a second embodiment of the present invention; 
         FIG. 4  is a front view of a throttle body assembly, according to a second embodiment of the present invention; 
         FIG. 5A  is a top view of a throttle body assembly, according to a second embodiment of the present invention; and 
         FIG. 5B  is a partial perspective view of a throttle body assembly, according to a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     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. 
     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. 
     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 . 
     Biasing structure is also located in the gearbox housing. In the embodiment, the biasing structure is a return spring assembly. The biasing structure biases the shaft  16  to cause the throttle plate  20  to close the throttle bore  14 . 
     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. 
     The lead frame is in electrical communication with a printed circuit board (PCB), 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. 
       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. 
     The throttle body assembly  10  comprises a position sensor assembly that includes a sensor element that is disposed with respect to the position sensor so as to be in an electrically inductive relationship therewith. In this configuration, the position sensor detects movement and position of the sensor element, which is compared to reference data to determine the position of the throttle plate  20 . Thus, as the throttle plate  14  is moved between an open position and closed position, the sensor element moves with the gear assembly. Accordingly, movement and position of the sensor element is directly related to movement and position of the throttle plate  20 . 
     In operation, the spring assembly biases the gear assembly, 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 gear assembly is rotated. To rotate the gear assembly, the bias applied to the gear assembly by the spring assembly is overcome. The amount of rotation of the gear assembly is in proportion to the amount of current applied to the motor  38 , which must overcome the force applied to the gear assembly by the spring assembly. As noted above, the sensor element and the position sensor detect the position of the gear assembly and thus the plate  20  during the operation of the throttle body assembly  10 . 
     As the gear assembly 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 gear assembly is detected by the sensor, such that the valve plate  20  may be placed in a desired position. 
     The throttle body assembly  10  also has been configured to have other dimensions that provide advantageous packing. With reference to  FIGS. 3-5B , a second embodiment of the assembly is shown, with like numbers referring to like elements. However, in this embodiment, the throttle bore  14  is of a different overall height, which corresponds to the height of several mounting bosses  120 . Also, it is shown that the distance  110  from the axis  16   a  of the shaft  16  to the upper edge  112   a  of the gear box housing  114  and the lower edge  112   b  of the gearbox housing  114  is less than 32 millimeters, which still allows for left-hand and right-hand configurations. The measurement of the distance  110  is taken along a line that is substantially perpendicular with the upper surface  130  and lower surface  132  of the bore  14 . With reference to  FIG. 4 , the gearbox housing  114  has a peripheral edge  118 , which is the furthest distance away from the axis  16   a  of the shaft  16  compared to any other area of the gearbox  114 . The distance  116  from the axis  16   a  of the shaft  16  to the peripheral edge  118  of the gearbox housing  114  is less than 75 millimeters. Each of the measurements for this distance  116  is taken at an angle  134  that is fifteen degrees from horizontal. 
     The housing  12  includes several mounting bosses  120 , shown in  FIGS. 5A and 5B , where in one embodiment, the mounting bosses  120  are of a height  122  of 20 millimeters, which in the embodiment shown in  FIGS. 4-5B  corresponds to the height of the central bore  14 , with the bore  14  having a diameter of about 40 millimeters. In another embodiment, the height  122  is about 33 millimeters, and the diameter of the bore  14  is about 54 millimeters. The height  122  of each boss  120  is chosen to be suitable where the central bore  14  has a centerline which is straight and has a consistent diameter, or suitable where the central bore  14  is a progressive bore  14  having a centerline which varies (i.e., not straight), while having a consistent diameter. In either embodiment, the surfaces  130 , 132  are double flat flange surfaces, making the assembly  10  more suitable for mounting. 
     Another advantage the throttle body assembly  10  provides with regard to packaging is the lateral distance of the bore  14  relative to the gear box housing  114 . In  FIGS. 5A and 5B , it is shown that the distance  124  from the inside edge  126  of the gear box housing  114  to the innermost edge  128  of the bore  14  is minimized, and in this embodiment, the distance  124  is about 16 millimeters. 
     With the embodiment, different motor performance is available with the same or different geartrains. The throttle body assembly  10  can be tuned to the application by swapping only the motor  38  and the gear assembly. 
     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.