Patent Grant
8375901
The present invention relates to internal combustion engines; more particularly, to devices for controlling systems in an internal combustion engine; and most particularly, to a valve plate cover with integrated lead frame of a lifter manifold assembly for variable activation and deactivation of valves in an internal combustion engine.
In conventional prior art four-stroke internal combustion engines, the mutual angular relationships of the crankshaft and the opening and closing of the combustion valves are mechanically fixed; that is, the valves are opened and closed fully and identically with every two revolutions of the crankshaft by a camshaft rotationally driven by the crankshaft with an axis of rotation parallel to the axis of rotation of the crankshaft. In engine operation, a fuel/air mixture is drawn into each cylinder in a predetermined sequence, the mixture is ignited by the sparking plug, and the burned residue is discharged.
It is known that for much of the operating life of a multiple-cylinder engine, the load can be met by a functionally smaller engine having fewer firing cylinders, and that at times of low demand, fuel efficiency can be improved if one or more cylinders of a larger engine are withdrawn from firing service. It is known in the art to accomplish this by de-activating the valve trains leading to pre-selected cylinders (for example, one bank of intake and exhaust valves in a V-style engine) in any of various ways, such as by providing deactivating hydraulic valve lifters (DHVLs), deactivating roller finger followers (DRFFs), or deactivating hydraulic lash adjusters (DHLAs) which may be switched on and off electrically or hydraulically. (As used hereinafter, SVDD should be taken to mean generically any switchable valve deactivating device.)
It is known in the prior art to controllably distribute oil to SVDDs to operate the SVDDs via a hydraulic manifold mounted to the top of the engine block and connected to an oil riser in the engine block. Such a manifold is known in the art as a Lifter Oil Manifold Assembly (LOMA). A typical LOMA is disclosed in U.S. Pat. No. 6,817,325, issued Nov. 16, 2004, which is incorporated herein by reference.
Current technology in the automotive industry utilizes separately mounted Oil Control Valves (OCVs) in a manifold device. In the assembly of this device, all OCVs are linked and wired, to a single connector via a rigid wiring harness typically called a lead frame. Such a lead frame may be an overmolded set of wires forming a rigid harness. Rivets are typically used to attach the OCV terminals to the lead frame terminals. In other cases the OCV terminals may be welded to the lead frame terminals. In the prior art, the lead frame is a separate component in the LOMA and requires separate components and processes for attachment to a valve plate cover, which is undesirable from an economical point of view.
What is needed in the art is a LOMA that includes a decreased number of components, enables a simplified assembly process, and provides a positive connection from the OCVs to the electrical circuit.
It is a principal object of the present invention to provide a valve plate cover with an integral lead frame and an integral electrical connector and, therefore, an improved LOMA for controlling the hydraulic locking and unlocking of hydraulically-switched deactivating devices in an internal combustion engine.
It is a further object of the invention to simplify the assembly and to reduce assembly costs of an internal combustion engine having variable valve activation via a plurality of SVDDs.
Briefly described, an improved LOMA in accordance with the invention for managing pressurized oil delivered to the SVDDs includes a lead frame and an electrical connector integrated into a composite valve plate cover that is used to seal the valve plate (manifold) oil galleries thereby eliminating the lead frame and its attachment components as separate components of a typical prior art LOMA. To form the valve plate cover/lead frame unit, the wiring that connects all of the OCVs with an electrical connector is overmolded into the composite valve plate cover as is the electrical connector. The OCVs, which are plugged directly into sockets included in the valve plates, include terminals that intersect with M-slots or a similar type of electrical connections integral to the valve plate cover/lead frame unit in accordance with the invention. When the valve plate cover/lead frame unit is attached to the valve plate, as for example, by welding, the terminals of the OCVs are positively held in their mating interface integrated into the cover/lead frame unit.
By forming the valve plate cover/lead frame unit in accordance with the invention, the number of components in a LOMA is decreased and the assembly of a LOMA is simplified compared to a prior art LOMA. Furthermore, a positive electrical connection from the OCVs to the electrical circuit is enabled.
An added advantage of overmolding the wires of the lead frame integral with the valve plate cover is that the lead frame wires now provide a “torcherous path” type seal and a secondary sealant operation as needed in the assembly of a prior art LOMA to prevent oil wicking along the wires to the connector terminals and from there to the atmosphere is not necessary anymore.
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one presently preferred embodiment of the invention, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
Referring to
A first pattern of passages 22 is formed in valve plate 20. Similarly, a second pattern of passages 32 is formed in an underside 42 of a body 31 of valve plate cover/lead frame unit 30. Passages 32 may be expressed as a corresponding pattern of raised sections 34 on the upper surface 44 of body 31 (also shown in
Valve plate 20 and body 31 of cover/lead frame unit 30 preferably are formed of a thermoplastic polymer having a relatively high melting temperature, for example, a glass-filled polyphthalamide (PPA) or a glass-filled nylon. Valve plate 20 and cover/lead frame unit 30 may be joined along mating surfaces preferably by fusion, such as, for example, by vibration welding or laser welding. During the welding operation, the mating surfaces liquefy, compress, and fuse in a fusion zone, forming a mechanical and hermetic seal 36 defining the oil galleries 28 in valve plate assembly 10 (as shown in
Valve plate 20 includes a plurality of sockets 24 for receiving a plurality of solenoid-actuated OCVs 26 for controlling oil flow from passages 22 and 32 to individual SVDDs (not shown) in a deactivation-equipped engine. Solenoid-activated OCVs 26 may be retained in their respective sockets 24, for example, by a separate retainer or by having individual flanges that can be thermally welded to valve plate 20. Typically, each OCV 26 controls the activation and deactivation of all SVDDs (intake and exhaust) for a given cylinder of a multi-cylinder engine via outlet ports (not visible); thus, in the typical example, four control valves 26 are required to deactivate valves for four cylinders of a bank of an eight-cylinder V-style engine. However, it is possible that a single OCV could control the operation of the SVDDs of more than one cylinder.
As shown in
Referring now to
For each OCV 26 received by valve plate 20, one M-slot 46 or similar type of connector is integrated into cover/lead frame unit 30. When an OCV 26 is plugged into a socket 24 of valve plate 20, the terminal of the OCV 26 directly intersects with one of the M-slots 46. When cover/lead frame unit 30 is welded in place, the terminals of the OCVs 26 are held positively by the mating interface of M-slots 46.
By designing cover lead/frame unit 30 as a single integral part with integrated lead frame wires 52, an integrated electrical connector 48, and integrated M-slots 46, the number of components that form valve plate assembly 10 is decreased, assembly operations of valve plate assembly 10 is simplified, and a positive connection is provided from the OCVs 26 to the electrical circuit.
A simplified process for assembling the valve plate assembly 10 includes the insertion of compression limiters into clearance holes 38. In a following step, cover/lead frame unit 30 is welded to valve plate 20. After press-in-place gaskets (not shown) are pressed into valve plate 20 in various locations, a first leak check may be performed. In a following step, the OCVs 26 are inserted into sockets 24 integral with valve plate 20. After a second leak check, the OCVs 26 are welded in place. A cap may be attached to cover oil inlet port 54 for protection of oil galleries 28 prior to assembly of valve plate assembly 20 into a LOMA.
In addition to a reduction in components and assembly process steps, the proposed design of valve plate assembly 10, and especially of cover/lead frame unit 30, offers substantial cost reduction over a prior art LOMA design.
While the invention has been described in reference to a V-type engine, it is understood that the invention is applicable to other type engines.
While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6817325 | Dinkel et al. | Nov 2004 | B2 |
| 7007641 | Kryglowski et al. | Mar 2006 | B1 |
| Number | Date | Country | |
|---|---|---|---|
| 20110139115 A1 | Jun 2011 | US |
