Abstract:
Conductors supported integrally with engine structure such as air intake manifolds and the like provide interconnection between engine components without the need for separate conventional wiring harnesses. The conductors take their mechanical strength from the underlying physical object and thus can be lighter than a freestanding harness. Connectors allow traces to continue across points of mechanical interface between structural components and allow wiring of engine components to be accomplished in the same operation as their physical assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to provisional Appln. No. 60/130,860, filed Apr. 22, 1999. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to automotive electronics and in particular to a method of simplifying or eliminating wiring harnesses associated with advanced engine control and integrating engine control electronics with the vehicle engine. 
     Internal combustion engines used in automobiles and the like employ sophisticated engine control technologies making use of a variety of sensors and actuators in communication with microprocessor-based control circuitry. Engine control provided by these systems may provide increased performance, reduced emissions and higher reliability in the operation of the vehicle. 
     The microprocessor-based control circuitry may be located near the vehicle fire wall to provide a secure mounting of the circuitry away from the high temperature components of the engine and communicating with driver instrumentation in the passenger compartment. 
     The control circuitry communicates with a variety of sensors on or close to the engine including, for example, sensors for air mass flow, engine temperature, throttle position, engine speed and crankshaft position. The control circuitry, in receiving these sensor signals, produces actuator signals used to control throttle valves, fuel injectors, ignition coils and the like. 
     The sensors and actuators must be connected to the control circuitry by wiring and the wiring must be of a sufficient gauge to resist breaking under the tensile loads and flexure incident to normal service. The wires may be bound together in “harnesses” to improve their mechanical resilience and may be sheathed to better resist abrasion. 
     Wiring harnesses represent a significant cost in the manufacture of a vehicle, not only in costs of material and manufacture, but also in costs of routing and connection to the sensors and actuators. Mechanically robust harnesses add weight to the vehicle affecting vehicle mileage and emissions. The harness with its attendant branching wire sets can increase the clutter of the engine compartment adversely affecting assembly, maintenance and repair of the engine. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides an alternative to conventional wiring harnesses that use conductors supported and routed directly on engine components. These engine components guide, support and protect the conductors eliminating unneeded weight and structure incident to conventional harness systems. By eliminating separate harness structure, clutter in the engine compartment is substantially reduced. 
     The invention can also eliminate the separate assembly steps of attaching the harness to the engine components. This is done by incorporating control electronics directly on the engine structures (eliminating unnecessary points of attachment) and/or by incorporating connectors into the interfaces between engine structures so that mechanical assembly of the engine structures simultaneously accomplishes electrical connection. Engine components may be modified in design to improve their function as wiring support. 
     Specifically, then, the present invention provides interconnect circuitry system for use with a vehicle engine having control electronics communicating with engine mounted control devices. The interconnect circuitry system includes at least one structural engine component which when assembled to the vehicle engine presents a surface spanning a distance between the control electronics and at least one of the engine mounted control devices. Electrical conductors attach integrally to the surface of the structural engine component to be supported and guided thereby. 
     It is thus one object of the invention to eliminate the need for separate wiring harnesses by allowing structural engine components to provide interconnect circuitry between engine mounted control devices and control electronics. 
     The structural components may be, for example, an engine intake manifold, a valve cover, throttle body, air filter housing, or engine shrouding. 
     Thus it is another object of the invention to select engine components that naturally span the distance between common interconnected devices. 
     It is yet another object of the invention to provide for an extremely stiff and inelastic support for the conductors such as reduces the need for large gauge conductors. 
     The electrical conductors may be metal plated on the structural component and etched appropriately or may be preformed metal conductors molded into a molded polymer forming the structural component or may be adhesively or mechanically bonded to the surface of the structural component. 
     Thus it is another object of the invention to provide simple means for attaching conductors directly to an engine structure with the minimum necessary conductor and additional material. 
     At least one electrical connector may be integrally attached to the structural component electrically communicating with the electrical conductors. 
     Thus it is another object of the invention to permit multiple mechanically separable structural components to be fit together to provide interconnect circuitry between devices. It is another object of the invention to allow a structural component to form a portion of the interconnect circuitry between components. 
     It is another object of the invention to permit the devices to be easily detachable from the interconnect circuitry of the structural component for repair and the like. 
     The electrical conductors may provide exposed bonding surfaces and the invention may further include bonding solid-state circuitry to the bonding surfaces and integrally to the structural components. 
     Thus it is another object of the invention to allow the structural components to support not only conductors but also integrated circuits and other circuit components eliminating the need for separate circuit support structure (such as a circuit board) and the need for separate connections to the control circuitry. 
     The electrical connectors may be positioned at a point of attachment of the structural component with other engine parts so as to electrically connect to electrical conductors on the other engine parts when the structural component is mechanically attached to the other engine components. 
     Thus it is another object of the invention to allow the single step of mechanically attaching engine components to also provide for electrical connection of various components to each other. 
     The foregoing and other objects and advantages of the invention will appear from the following description. In this description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration, a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference must be made therefore to the claims for interpreting the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top perspective view of a prior art V-block engine showing engine components interconnected by discrete wiring harnesses; 
     FIG. 2 is a view similar to that of FIG. 1 with the wiring harnesses replaced by conductors integrally bonded to engine components and, in particular, to the valve covers air intake manifold and other parts of the air induction system; 
     FIG. 3 is a cross-section along line  3 — 3  of FIG. 2 showing a first embodiment of the invention in which conductors are plated to the surface of the engine components and may have attached circuitry thereon; 
     FIG. 4 is a figure similar to that of FIG. 3 showing a second embodiment of the invention in which conductors are adhesively bonded to the surface of the engine components; 
     FIG. 5 is a figure similar to FIGS. 3 and 4 showing a third embodiment of the invention where conductors are mechanically attached to the engine components; 
     FIGS. 6 a-d  are perspective views of progressive steps of a fourth embodiment of the invention of forming a lead frame for in-molding with an engine component; 
     FIG. 7 is a cross-sectional view through two engine components having in molded conductors per FIG. 6 showing interconnection of the conductors with mechanical assembly of the components in a one step assembly operation; and 
     FIG. 8 is a figure similar to FIG. 2 showing an alternative embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIG. 1, a prior art engine compartment  10  holds an engine  12  having an engine block  14  supporting ranks of pistons (not shown) within cylinders  19  beneath valve covers  16  and behind engine shrouding  15 . An intake manifold  18  of conventional design extends between a throttle  17  and the cylinders  19 . An air induction system  31  joins the throttle  17  with air filter housing  29  positioned near a front of the engine compartment  10 . Near the point of connection of the intake manifold  18  and the cylinders  19  are positioned combustion control devices  20  including for each cylinder an ignition coil for initiating a spark within the cylinder, an electronic fuel injector for injecting fuel into the cylinder, and possibly one or more valve actuators for controlling cylinder intake and/or exhaust valves. 
     Each of these combustion control devices  20  includes a wiring harness  22  which may be joined and routed to other devices, such as distributor  28 , to ultimately join with an engine control module  23  and/or a vehicle speed control module  24  mounted near a firewall  26 . The engine control module  23  and vehicle speed control module  24  may also receive inputs from various sensors including a mass flow sensor  30  positioned near an air filter housing  29 , block temperature sensors  32  on the engine block  14 , and engine speed sensors and the like (not shown). Harnesses  22  relevant to the present invention may also extend from the alternator  34  and from ancillary automotive systems including braking systems, transmission control and the like which may need to share signals with engine control module  23  and vehicle speed control module  24 . 
     Referring now to FIG. 2, certain of the harnesses  22  may be eliminated by the modification of the air induction system  31  (of FIG. 1) to a continuous air induction system  40  (of FIG. 2) and the attachment of conductors normally in the harnesses  22  directly on the surface of the continuous air induction system  40  as will now be described. 
     As shown in FIG. 2, the continuous air induction system  40  collects the functions of the intake manifold  18  and air induction system  31  to provide an essentially continuous path from the air filter housing  29  to the combustion control devices  20  passing near the firewall  26  and incorporating on its surface, the electronics of the engine control module  23  and vehicle speed control module  24 . The continuous air induction system  40  may further electrically communicate with the air filter housing  29 , engine shrouding  15 , and the valve cover  16  as will be described. 
     Generally, the continuous air induction system  40  is a continuous tube branching at a manifold portion  42  to provide air to the various cylinders. On the upper surface of the continuous air induction system  40  which may be advantageously molded from an electrically insulating polymer material, conductors  44  are held communicating with various sensor devices such as the mass air flow sensor  30  which may be mounted directly on the continuous air induction system  40  or block temperature sensor  32  communicating with the manifold portion of the continuous air induction system  40  via a short harness  33 . The conductors  44  also communicate directly-with integrated circuits  46  mounted directly on the surface of the continuous air induction system  40  as will be described below. Removable covers  45  may be placed over portions of this circuitry or the integrated circuits to provide for additional protection. 
     As will be described further below, the conductors  44  may work with integral connectors  48  providing points of connection between the conductors  44  of the main portion of the continuous air induction system  40  and conductors  44  of adjacent manifold portion  42  which may be fabricated as separate physical parts. Connectors  48  may also provide connections with other independent mechanical elements such as the valve covers  16 , shrouding  15  and the air filter housing  29  or physically separate components via harnesses  33 . The valve cover  16  may have additional circuitry and conductors  44  attached thereto so as to allow control or sensing functions to be performed from the valve covers. Shrouding  15  and air filter housing  29  may likewise include conductors  44  communicating with sensors, actuators, or circuitry held by or near these structures. 
     Referring now to FIG. 3, the continuous air induction system  40  may have a surface layer of metal  50 , for example, copper or a sandwich lamination of multiple metals, and is selectively deposited or attached as a sheet or plated and etched according to techniques well known in the art to provide for the conductors  44 . Additional non-conductive layers (not shown) can be added over the plating. The use of additional insulated layers can be used to add plated layers of conductor interconnected in a three dimensional way such as is found in multi-layer circuit boards using through-plating and the like to allow circuit paths to cross without electrical connection. This technique can also be applied to the embodiments of in-molding, bonding and adhesive bonding multiple layers onto the engine component. 
     Bonding pads  52  may be formed in the metal  50  to which integrated circuits  55  or other electronic components may be attached by soldering, welding, brazing, conductive adhesive or other similar techniques. The continuous air induction system  40  thus serves as a printed circuit-like substrate for electrical components while the conductors  44  provide interconnections for these components. 
     The mechanical rigidity provided by the continuous air induction system  40 , which serves the additional role of conducting air, allows extremely thin layers of metal  50  to serve as conductors  44 . This reduces the unnecessary structure and weight to the effective interconnecting process over that which would be required with a harness system. The conductors  44  may be given a conformal coating of an insulating material or the like to protect them from moisture and mechanical abrasion. 
     Referring now to FIG. 4, in an alternative embodiment, the conductors  44  may be flat wire conductors or conventional wires bonded by means of adhesive  56  to the surface of the continuous air induction system  40 . Such bonding techniques are known in the art of printed wiring board manufacture and may use computer controlled wire or conductor guiding tools to lay out arbitrary paths on the surface of an insulating substrate. 
     Referring now to FIG. 5 in yet a further alternative embodiment, the continuous air induction system  40  may have integral dovetailed grooves  60  or the like into which oversized wires may be pressed for mechanical support and attachment. 
     Referring now to FIGS. 6 a-d  in yet a further embodiment, conductors  44  may be in-molded at the surface of structural components of the engine such as may be molded out of plastic or the like. Initially as shown in FIG. 6a, conductors  44  may be manufactured as plated traces or a lead frame  62  die cut from a plated metallic strip  63  of the type used for manufacturing electrical connectors or from a more ductile material such as annealed copper. The strip  63  may have a number of longitudinal slots  64  providing separate conductors joined at the ends by bridging end sections  66 . 
     As shown in FIG. 6 b , the strip  63  may be preformed in this case by giving it a slight bow to conform to an intake manifold pipe  68  and bending the ends at 90° for the attachment of conductors. 
     Thus formed, the lead frame  62  may be in-molded to an intake manifold pipe  68  so as to be wholly contained within the pipe wall except for the ends including the bridging end sections  66  and a portion of the slots  64 . The bridging end sections  66  may be cut and removed leaving only projecting ends of the conductors  44  which may be folded down to form bonding or attaching pads for connection with other conductors or circuit elements or may be fit within a connector shell  70  separately formed and attached to the projecting ends or molded during the molding of the intake manifold pipe  68 . Wiring interconnections between components joined by the intake manifold pipe  68  can thus be obtained using the intake manifold pipe  68  eliminating a separate harness. In a similar manner, sensors and electronic components such as integrated circuits and discrete devices such as transistors, resistors, diodes, capacitors and inductors, can be in-molded directly into the manifold pipe  68 . 
     Referring now to FIG. 7, the mechanical component supporting the conductors  44  need not be a single continuous part but may be fabricated in sections that are mechanically and electrically attached to each other. In this case, the connector  48  may be used to electrically join conductors  44  of adjacent mechanically assembled components, for example, using short jumper harnesses (not shown). 
     Alternatively, the connectors  48  may be constructed to connect directly to connectors of adjacent parts when the parts are assembled and without the need for a separate electrical connection step. Thus, for example, an intake manifold pipe  68  of the type shown in FIG. 6 may be attached to a second intake manifold pipe  68 ′ by means of flanges  72  and  72 ′ at one end of each of the intake manifold pipes  68  and  68 ′, respectively. Flanges  72  and  72 ′ present opposed substantially planar faces  77  generally perpendicular to the extent of the intake manifold pipe  68  and  68 ′ that may be held together by bolts  76  inserted through bolt holes  74  and  74 ′ in the flanges  72  and  72 ′ when the flanges  72  and  72 ′ abut. 
     In-molded conductors  44  and  44 ′ in intake manifold pipe  68  and  68 ′, respectively, may emerge at the planar faces  77  at projecting tabs  78  and  78 ′. Projecting tabs  78  and  78 ′ may then be given a suitable bend so that conductors  44  and  44 ′ may engage each other automatically when flanges  72  and  72 ′ are assembled. In this manner, mechanical assembly also serves the purpose of electrical assembly. 
     Referring now to FIG. 8, in an alternative embodiment shown for a 4-cylinder engine, a continuous air induction system  40  may be integrally molded with the manifold portion  42  and may carry on its surface conductors  44  and circuits  46 . Additional components of the alternator  34  and a throttle body  82  may be attached to this structure so as to provide a continuous path of electrical interconnection even though, at least for the alternator  34 , such a connection would not be necessitated for mechanical purposes. The throttle body  82  may include, for example, sensors such as a throttle plate position sensor  84  and the like and may be joined to conductors  44  on the manifold portion  42  by means of surface conductor halves  48  such as may be attached to expose portions of the conductors  44  to allow for their continuation across mechanical interface  88  between continuous air induction system  40  and throttle body  82 . A similar connector half  48 ′ may serve this function for the alternator. 
     It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.