Abstract:
A throttle body and an air control system that integrates the electronic engine control modules, sensors, actuators, and associated wiring on a throttle body is disclosed. In one version of the invention, there is provided a throttle body including a throttle body wall defining an airflow passage in the throttle body, a movable throttle plate that substantially conforms to the interior dimensions of the air flow passage, an engine control device (such as a sensor or an actuator) attached to the throttle body wall, and engine control electronics mounted to the throttle body wall in spaced apart relationship with the engine control device, the engine control electronics being electrically connected with the engine control device. In another version of the invention, there is provided an air control system including a throttle body having a wall defining a first airflow passage in the throttle body, a movable throttle plate substantially conforming to the interior dimensions of the first airflow passage, an air intake manifold having a wall defining a second airflow passage, the air intake manifold being attached to the throttle body such that the first airflow passage and the second airflow passage are placed in fluid communication, an engine control device mounted to the air intake manifold, and engine control electronics mounted to the throttle body wall, the engine control electronics being electrically connected with the engine control device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/130,860 filed Apr. 22, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to an internal combustion engine having at least one electronic engine control module and an air control system including a throttle body, and more particularly to an air control system that integrates the electronic engine control modules, sensors, actuators, and associated wiring on a throttle body. 
     2. Description of the Related Art 
     A typical internal combustion engine includes a throttle body mounted to an air intake manifold. The throttle body includes at least one fluid passageway, and the air intake manifold also includes at least one fluid passageway. The throttle body may be sealably and removably fastened to the air intake manifold such that the fluid passageways are placed in sealed communication with each other. 
     When sealably fastened together, air may be inducted from the atmosphere through the throttle body fluid passageway, then into the air intake manifold fluid passageway, and then into the engine. 
     Most modern internal combustion engines, such as those found in current-model automobiles, also include one or more electronic control modules which process data from various sensors and provide control signals to various engine sub-system and components in order to maintain optimum engine performance. For example, the electronic engine control module may receive data from a throttle position sensor, a mass air flow sensor, and the like, and send control signals to the throttle plate actuator, idle speed bypass solenoid valve, and the like. The complex circuitry of the electronic engine control module may be temperature sensitive and thus may be mounted in a cooler portion of the engine compartment, typically against or within the firewall to provide the desired reliability of the electronics. A lengthy and complex wiring harness is necessary to communicate between the control unit and its associated sensors, control elements, and engine components. 
     Thus, it would be desirable, therefore, to find an approach which enhances the cooling of such electronic engine control modules, and which also eliminates the need for a lengthy wiring harness. 
     SUMMARY OF THE INVENTION 
     The present invention provides a throttle body and an air control system for use in an internal combustion engine. The invention permits proximate mounting of heat sensitive engine control electronics on or near the engine. By placing temperature sensitive components on or near the engine, wiring harnesses are simplified, reduced in length or eliminated completely. 
     In one version of the invention, there is provided a throttle body including a throttle body wall defining an airflow passage in the throttle body, a movable throttle plate that substantially conforms to the interior dimensions of the air flow passage, an engine control device (such as a sensor or an actuator) attached to the throttle body wall, and engine control electronics mounted to the throttle body wall in spaced apart relationship with the engine control device, the engine control electronics being electrically connected with the engine control device. 
     In another version of the invention, there is provided an air control system including a throttle body having a wall defining a first airflow passage in the throttle body, a movable throttle plate substantially conforming to the interior dimensions of the first airflow passage, an air intake manifold having a wall defining a second airflow passage, the air intake manifold being attached to the throttle body such that the first airflow passage and the second airflow passage are placed in fluid communication, an engine control device mounted to the air intake manifold, and engine control electronics mounted to the throttle body wall, the engine control electronics being electrically connected with the engine control device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features, aspects, objects, and advantages of the present invention will become better understood upon consideration of the following detailed description, appended claims and accompanying drawings where: 
     FIG. 1 is a schematic representation of a conventional internal combustion engine; 
     FIG. 2 is a schematic representation of a throttle body with integrated electronics according to an embodiment of the present invention; 
     FIG. 3 is a schematic representation of another embodiment of a throttle body with integrated electronics according to the present invention; 
     FIG. 4 is a bottom view of a sensor shown in FIG. 3 taken along line  4 — 4  with the throttle body wall removed for clarity; 
     FIG. 4A is a bottom perspective view of another sensor suitable for use with the present invention; 
     FIG. 5 is a side view of a portion the throttle body in FIG. 3 taken along line  5 — 5  with the sensor removed for clarity; 
     FIG. 6 is a cross-sectional view of the throttle body of FIG. 5 taken along line  6 — 6 ; and 
     FIG. 7 is a schematic representation of an embodiment of an internal combustion engine air control system with integrated electronics according to the present invention. 
    
    
     It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. 
     Like reference numerals will be used to refer to like or similar parts from Figure to Figure in the following description of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     A throttle body in accordance with the present invention may be used with a conventional internal combustion engine  10  as shown schematically in FIG.  1 . The engine  10  comprises a plurality of cylinders, one cylinder of which is shown in FIG.  1 . The engine  10  is controlled by main engine control electronics  12 , which may include any of a number of engine controllers known to those skilled in the engine art. The engine  10  includes combustion chamber  30  and cylinder walls  32  with piston  36  positioned therein and connected to a crankshaft  40 . The combustion chamber  30  is shown communicating with an intake manifold  44  and an exhaust manifold  48  via respective intake valve  52  and exhaust valve  54 . The intake manifold  44  is shown communicating with throttle body  58  via throttle plate  62 . 
     Primary air control is governed by the throttle plate  62 . The throttle plate  62  is controlled by a throttle controller  63  which may be a mechanical system including vacuum solenoids or an electronic throttle controller known to those skilled in the art. The throttle position of the throttle plate  62  is measured by a throttle position sensor  64  which outputs a throttle position signal TPS. The engine control electronics  12  provide a signal ETCPOS to the throttle controller  63  so that airflow is inducted into engine  10  around throttle plate  62 . When a vehicle is equipped with cruise control, the throttle position of the throttle plate  62  may also be controlled by an electronic throttle control  163  which receives signals from the engine control electronics  12 . A speed sensor  120  provides speed signals to the engine control electronics  12  to facilitate operation of the electronic throttle control  163 . The electronic throttle control  163  may a motor driven actuator that moves the throttle plate  62  electronically, and would be known to those skilled in the art. A throttle plate bypass passageway  94  provides a fluid communication path between a position upstream of the throttle plate  62  and a position downstream of the throttle plate  62 . Air flow through the throttle plate bypass passageway  94  is controlled by a idle air control solenoid  97 . The engine control electronics  12  provide the necessary signals to control the idle air control solenoid  97 . 
     Fuel is delivered to a fuel injector  66  by a conventional fuel system including fuel tank  67 , fuel pump (not shown), and fuel rail  68 . A canister purge system including a canister purge solenoid  168  for periodically purging fuel vapors from the fuel tank  67  to the intake manifold  44  is controlled by a canister purge signal CANP from the engine control electronics  12 . A conventional ignition system  88  provides ignition spark to combustion chamber  30  via spark plug  92  in response to spark advance signal SA from the engine control electronics  12 . A catalytic type exhaust gas oxygen sensor  16  is shown coupled to exhaust manifold  48  upstream of a catalytic converter  20 . The exhaust gas oxygen sensor  16  provides a signal EGO to the engine control electronics  12  which convert signal EGO into a two-state signal. A high voltage state of converted signal EGO indicates exhaust gases are rich of a desired air/fuel ratio and a low voltage state of converted signal EGO indicates exhaust gases are lean of the desired air/fuel ratio. Typically, the desired air/fuel ratio is selected as stoichiometry which falls within the peak efficiency window of the catalytic converter  20 . A differential pressure (exhaust to intake) sensor  148  is shown coupled to exhaust manifold  48  upstream of a catalytic converter  20 . The differential pressure sensor  148  provide a pressure feedback signal DPFE to the engine control electronics  12 . 
     The engine control electronics  12  shown in FIG. 1 include a conventional microcomputer having: a microprocessor unit  102 , input/output ports  104 , read only memory  106 , random access memory  108 , and a conventional data bus. The engine control electronics  12  are shown receiving various signals from sensors mounted to the engine  10 , in addition to those signals previously discussed, including measurements of: inducted mass air flow MAF from mass air flow sensor  110  coupled to throttle body  58 ; intake manifold absolute pressure MAP from intake manifold absolute pressure sensor  144  coupled to the intake manifold  44 ; engine coolant temperature ECT from engine coolant temperature sensor  112  coupled to cooling sleeve  114 ; intake air temperature ACT from intake air temperature sensor  113  coupled to throttle body  58 ; and a crankshaft position signal CPS from crankshaft position sensor  118  coupled to crankshaft  40 . 
     It can be seen from FIG. 1 that the engine control electronics  12  communicate with a large number of engine mounted control devices including actuators (e.g., idle air control solenoid  97 , canister purge solenoid  168 , and any vacuum solenoids); sensors (e.g., mass air flow sensor  110 , engine coolant temperature sensor  112 , intake air temperature sensor  113 , crankshaft position sensor  118 , throttle position sensor  64 , exhaust gas oxygen sensor  16 , intake manifold absolute pressure sensor  144 , and differential pressure (exhaust to intake) sensor  148 ); and other control modules (e.g., electronic throttle control  163  and throttle controller  63 ). Accordingly, as used herein, “engine control device” refers to operating condition sensors, actuators, and control modules other than the main engine controller. 
     As detailed above, one disadvantage of the type of vehicle electrical system shown in FIG. 1 is that a lengthy and complex wiring harness is necessary to connect the engine control electronics  12  (which are typically located against or within the firewall) and the engine mounted control devices including the actuators, the sensors, and the other control modules. The present invention provides one solution to this vehicle electrical system problem by providing a throttle body that includes additional electromechanical functions such as integration of the wiring harness, engine controls, sensors, actuators, and mechanical attachments. The integration of the throttle body with the other functions enables reduction of wiring and connectors and thereby provides for superior electrical performance and improved testability of the engine control subsystem. 
     Turning to FIG. 2, there is generally indicated at  158  a throttle body with integrated electronics in accordance with the present invention. The throttle body  158  includes a throttle body wall  159  (which may comprise a metallic or polymeric material) that defines an airflow passage  160 . The airflow passage  160  of the throttle body  158  is in fluid communication with the intake manifold  44  via the throttle plate  62 . The throttle plate  62  is controlled by the throttle controller  63  which may be a mechanical system including vacuum solenoids or an electronic throttle controller known to those skilled in the art. The throttle position of the throttle plate  62  is measured by the throttle position sensor  64  which outputs a throttle position signal TPS. 
     Engine control electronics  121  are mounted to the throttle body wall  159 . The engine control electronics  121  communicate with a large number of engine mounted control devices including actuators (e.g., idle air control solenoid  97  in FIG.  2 ); sensors (e.g., mass air flow sensor  110 , intake air temperature sensor  113 , throttle position sensor  64 , and intake manifold absolute pressure sensor  144  in FIG.  2 ); and other control modules (e.g., electronic throttle control  163  and throttle controller  63  in FIG.  2 ). While FIG. 2 shows the engine control electronics  121  communicating with certain actuators, sensors, and control modules, it should be understood that the engine control electronics  121  can communicate with any number of engine mounted control devices, including without limitation those shown in FIG.  1 . 
     The engine control electronics  121  include an engine controller  123  and a wiring board  124  which is in electrical communication with the controller  123 . The engine controller  123  may be selected from any of a number of engine controllers known to those skilled in the engine art. The wiring board  124  may be any of a number of circuit carrying structures, including without limitation rigid circuit boards, flexible circuit boards, combination rigid/flexible circuit boards, and etched tri-layered metal. In the throttle body  158  of FIG. 2, the engine mounted control devices (which may include actuators, sensors, and control modules) are interconnected using the wiring board  124 . The engine mounted control devices can be interconnected to the wiring board  124  using a metallurgical interface (e.g., soldering, wire bonding, welding, or the like), mechanical interfaces (e.g., press fit, conductor to conductor), or polymeric interfaces (e.g., adhesives with conductive fillers, z-axis adhesives, z-axis interposers). If a heat sink is required for the engine control electronics  121 , the heat sink may comprise the throttle body itself or a discrete heat sink  125  (formed from known heat sink materials) which is in molded with the throttle body wall  159 . 
     Referring now to FIG. 3, there is generally indicated at  258  another embodiment of a throttle body with integrated electronics in accordance with the present invention. The throttle body  258  includes a throttle body wall  159  (which may comprise a metallic or polymeric material) that defines an airflow passage  160 . The airflow passage  160  of the throttle body  258  is in fluid communication with the intake manifold  44  via the throttle plate  62 . The throttle plate  62  is controlled by the throttle controller  63  which may be a mechanical system including vacuum solenoids or an electronic throttle controller known to those skilled in the art. The throttle position of the throttle plate  62  is measured by the throttle position sensor  64  which outputs a throttle position signal TPS. 
     Engine control electronics  121  are mounted to the throttle body wall  159 . The engine control electronics  121  communicate with a large number of engine mounted control devices including actuators (e.g., idle air control solenoid  97  in FIG.  3 ); sensors (e.g., intake air temperature sensor  113 , throttle position sensor  64 , and intake manifold absolute pressure sensor  144  in FIG.  3 ); and other control modules (e.g., electronic throttle control  163  and throttle controller  63  in FIG.  3 ). While FIG. 3 shows the engine control electronics  121  communicating with certain actuators, sensors, and control modules, it should be understood that the engine control electronics  121  can communicate with any number of engine mounted control devices, including without limitation those shown in FIG.  1 . The engine control electronics  121  include an engine controller  123  and a wiring board  124  which is in electrical communication with the controller  123 . The engine controller  123  may be selected from any of a number of engine controllers known to those skilled in the engine art. In the throttle body  258  of FIG. 3, the engine mounted control devices (which may include actuators, sensors, and control modules) are interconnected using the wiring board  124 . 
     Still referring to FIG. 3, there is shown a mass air flow sensor  210  that is mounted in the throttle body wall  159  of the throttle body  258 . The mass air flow sensor  210  includes a twist lock feature that is used to create a mechanical connection with the throttle body wall  159  of the throttle body  258  and to create an electrical connection with the wiring board  124 . The components of the mass air flow sensor  210  are shown in FIGS. 3 and 4. The mass air flow sensor  210  has a mounting head  216  that includes a raised portion  212  and a circumferential flange  217  that extends outward from the lower end of the raised portion  212 . The underside  217   a  of the mounting head  216  has downwardly extending fingers  214  that terminate in outwardly and laterally extending tabs  214   a . Typically, the mounting head is formed from plastic. Air flow sensor elements  215  are affixed to the underside  217   a  of the mounting head  216  and are electrically connected with sensor leads  213 . The sensor leads  213  may be in molded or plated leads. Of course, a different number of sensor leads and sensor elements may be used in the mass air flow sensor  210 . A flexible O-ring  211  is also attached to the underside  217   a  of the mounting head  216  and may be formed from elastomeric materials known in the art. 
     Referring now to FIGS. 4,  5  and  6 , the means for mechanical installing the mass air flow sensor  210  on the throttle body wall  159  of the throttle body  258  are shown. First, looking at FIGS. 5 and 6, it can be seen that the section of the throttle body wall  159  where the mass air flow sensor  210  is installed has a substantially circular bore  363  which has diametrically opposed recessed areas  359 . Below the surface of the throttle body wall  159 , there is a groove  360  in the inner surface  361  of the circular bore  363 . During installation of the mass air flow sensor  210 , the downwardly extending fingers  214  of the mounting head  216  are aligned with the diametrically opposed recessed areas  359  of the circular bore  363  and the mass air flow sensor  210  is moved toward the throttle body wall  159 . When the O-ring  211  of the mass air flow sensor  210  contacts the throttle body wall  159 , the mass flow sensor is rotated in either of directions “A” shown in FIG.  4 . As a result, the laterally extending tabs  214   a  of the downwardly extending fingers  214  engage the inner surface of the groove  360  in the throttle body wall  159 . The mass air flow sensor  210  may then be rotated until the downwardly extending fingers  214  contact stop  362  in the groove  360  in the throttle body wall  159 . By proper configuration of the downwardly extending fingers  214 , the O-ring  211  and the groove  360 , the mass air flow sensor  210  is both secured and sealed to the throttle body wall  159  by a simple twisting motion during installation. The twist lock feature provides the mechanical force to hold the sensor in place and seal the sensor. 
     Referring now to FIG. 3, it can be seen that the twisting motion used to install the mass air flow sensor  210  on the throttle body wall  159  also serves to establish an electrical connection between the mass air flow sensor  210  and the wiring board  124 . In FIG. 3, it can be seen that the wiring board  124  includes an electrical connector  224  that extends outwardly from the wiring board  124  and is electrically connected to the wiring board  124 . After installation of the mass air flow sensor  210  on the throttle body wall  159  as described above, at least one of the sensor leads  213  on the underside  217   a  of the mounting head  216  is placed in contact with the electrical connecter  224  of the wiring board  124 . In other words, the twist lock feature provides the mechanical force for contacting the electrical circuit, and the mass air flow sensor  210  is placed in electrical communication with the wiring board  124  and the engine controller  123 . 
     While the twist lock feature that is used to create a mechanical and an electrical connection between the mass air flow sensor  210  and the wiring board  124  has been described with reference to a mass air flow sensor, it should be understood that the mechanical electrical connection system is not limited to mass air flow sensors but may be applied to any sensor, actuator, control module or other component that must be placed in electrical communication with throttle body mounted engine control electronics. Furthermore, other equivalent means for accomplishing the twist lock installation are possible. For instance, an alternative sensor is shown in FIG.  4 A. The sensor  310  in FIG. 4A may be mounted in the throttle body wall  159  of the throttle body  258 . The mass air flow sensor  310  includes a twist lock feature that is used to create a mechanical connection with the throttle body wall  159  of the throttle body  258  and to create an electrical connection with the wiring board  124 . The mass air flow sensor  310  has a mounting head  316  that includes a raised portion  312  and a circumferential flange  317  that extends outward from the lower end of the raised portion  312 . Typically, the mounting head is formed from plastic. Air flow sensor elements  315  are affixed to the underside  317   a  of the mounting head  216  by way of a protruding disk shaped section  320 . The sensor elements  315  are electrically connected with four sensor leads  313 . The sensor leads  313  may be in molded or plated leads. Of course, a different number of sensor leads and sensor elements may be used in the mass air flow sensor  310 . A flexible O-ring  311  is also attached to the underside  317   a  of the mounting head  316  and surrounds the protruding disk shaped section  320 . The O-ring  311  may be formed from elastomeric materials known in the art. Ramp-shaped blades  314  extend laterally from opposite diametrically opposed sides of the protruding disk shaped section  320  of the mass air flow sensor  310 . 
     The means for mechanical installing the mass air flow sensor  310  on the throttle body wall  159  of the throttle body  258  is similar to that described above for the mass airflow sensor  210 . During installation of the mass airflow sensor  310  of FIG. 4A, the ramp-shaped blades  314  of the mounting head  316  are aligned with the diametrically opposed recessed areas  359  of the circular bore  363  (shown in FIG. 5) and the mass air flow sensor  310  is moved toward the throttle body wall  159 . When the O-ring  311  of the mass air flow sensor  310  contacts the throttle body wall  159 , the mass flow sensor is rotated in either of directions “B” shown in FIG.  4 A. As a result, the ramp-shaped blades  314  engage the inner surface of the groove  360  in the throttle body wall  159 . The mass air flow sensor  310  may then be rotated until the ramp-shaped blades  314  contact stop  362  in the groove  360  in the throttle body wall  159 . By proper configuration of the ramp-shaped blades  314 , the O-ring  311  and the groove  360 , the mass air flow sensor  310  is both secured and sealed to the throttle body wall  159  by a simple twisting motion during installation. The twist lock feature provides the mechanical force to hold the sensor in place and seal the sensor. 
     Referring now to FIG. 3, it can be seen that the twisting motion used to install the mass air flow sensor  310  on the throttle body wall  159  also serves to establish an electrical connection between the mass air flow sensor  310  and the electrical connector  224  of the wiring board  124 . After installation of the mass air flow sensor  310  on the throttle body wall  159  as described above, at least one of the sensor leads  313  on the underside  317   a  of the mounting head  316  is placed in contact with the electrical connecter  224  of the wiring board  124 . In other words, the twist lock feature provides the mechanical force for contacting the electrical circuit, and the mass air flow sensor  310  is placed in electrical communication with the wiring board  124  and the engine controller  123 . It should be understood that other equivalent means for accomplishing the twist lock feature will become apparent to those skilled in the art when reading this description, and therefore, are within the scope of the invention. For example, the twist lock feature may be accomplished with quarter-turn threads on the mounting head  216  of the mass air flow sensor  210  that engage threads with a stop on the throttle body  159 . 
     Referring now to FIG. 7, there is shown an air control system  300  for an internal combustion engine that includes an air intake manifold  344  and a throttle body  358  with integrated electronics in accordance with the present invention. The throttle body  358  includes a throttle body wall  159  (which may comprise a metallic or polymeric material) that defines an airflow passage  160 . The airflow passage  160  of the throttle body  358  is in fluid communication with the intake manifold  344  via the throttle plate  62 . The throttle plate  62  is controlled by the throttle controller  63  which may be a mechanical system including vacuum solenoids or an electronic throttle controller known to those skilled in the art. The throttle position of the throttle plate  62  is measured by the throttle position sensor  64  which outputs a throttle position signal TPS. 
     Engine control electronics  121  are mounted to the throttle body wall  159 . The engine control electronics  121  communicate with a large number of engine mounted control devices including actuators; sensors (e.g., mass air flow sensor  110 , intake air temperature sensor  113 , and throttle position sensor  64  in FIG.  7 ); and other control modules (e.g., electronic throttle control  163  and throttle controller  63  in FIG.  7 ). While FIG. 7 shows the engine control electronics  121  communicating with certain actuators, sensors, and control modules, it should be understood that the engine control electronics  121  can communicate with any number of engine mounted control devices, including without limitation those shown in FIG.  1 . The engine control electronics  121  include an engine controller  123  and a wiring board  124  which is in electrical communication with the controller  123 . The engine controller  123  may be selected from any of a number of engine controllers known to those skilled in the engine art. In the throttle body  358  of FIG. 7, the engine mounted control devices (which may include actuators, sensors, and control modules) are interconnected using the wiring board  124 . 
     Still referring to FIG. 7, it can be seen that the intake manifold  344  includes an in molded lead frame  246  that includes a first terminal end  248  and a second terminal end  247 . There is also shown an intake manifold absolute pressure sensor  244  that is mounted in a wall  249  of the intake manifold  344 . The intake manifold absolute pressure sensor  244  includes an in molded electrical connector  245  affixed to the underside of the intake manifold absolute pressure sensor  244 . The throttle body wall  159  of the throttle body  358  also includes an in molded lead frame  288  that includes a first terminal end  280  and a second terminal end  289 . The lead frame  246  and the lead frame  288  may be formed from any conductive material. It can be seen that when the throttle body  358  and the air intake manifold  344  are mechanically attached, the first terminal end  280  of the lead frame  288  and the second terminal end  247  of the lead frame  246  are placed in contact thereby forming an electrical connection that extends from the first terminal end  248  of the lead frame  246  to the second terminal end  289  of the lead frame  288 . 
     Further, when the intake manifold absolute pressure sensor  244  is installed in the wall  249  of the intake manifold  344 , the in molded electrical connector  245  affixed to the underside of the intake manifold absolute pressure sensor  244  is placed in contact with the first terminal end  247  of the lead frame  246  thereby forming an electrical connection between the intake manifold absolute pressure sensor  244  and the lead frames  246  and  288 . In addition, when the wiring board  124  is installed on the throttle body wall  159 , an electrical connector  299  affixed to the wiring board  124  is placed in contact with the second terminal end  289  of the lead frame  288  thereby forming an electrical connection between the wiring board  124  and the lead frames  246  and  288 . Thus, an electrical connection is formed between the intake manifold absolute pressure sensor  244  and the engine control electronics  121  by way of the in molded lead frames  246  and  288 . In another embodiment, the lead frames  246  and  288  may be integrally attached to the throttle body wall  159  and the wall  249  of the intake manifold  344  by plating the lead frames  246  and  288  on an outer surface of the throttle body wall  159  and an outer surface of the wall  249  of the intake manifold  344 . 
     Although the present invention has been described in considerable detail with reference to certain embodiments, one skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the scope of the appended claims should not be limited to the description of the embodiments contained herein.