Patent Application
20140137833
The present disclosure relates to an engine assembly, and more particularly, to an engine front or rear cover made from plastic and having a molded-in metal insert defining a bore for receiving a rotating engine component.
This section provides background information related to the present disclosure which is not necessarily prior art.
Currently, engine covers (front or rear) are produced from aluminum castings or steel stampings. The aluminum castings provide a flexibility in design, but the cost and mass of aluminum are significant and it is desirable to use a significantly lower mass component.
The present disclosure is directed to an engine front cover assembly including a plastic engine cover. A metal insert is secured within the plastic engine cover and defines a bore configured to receive a rotating engine component. A seal is located in a seal seat defined within the bore of the metal insert and configured to sealingly engage the rotating engine component. The metal insert can include a radially extending flange portion defining reinforcing ribs that are overmolded by plastic reinforcing ribs of the plastic engine cover. The flange portion can be a mesh or textured surface to provide enhanced surface area contact between the plastic front cover and the metal insert.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.
a-5c illustrate alternative surface patterns of the flange portion of the metal insert; and
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Examples of the present disclosure will now be described more fully with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
When an element or layer is referred to as being “on,” “engaged to,” “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
With reference to
Even though the plastic materials have performance characteristics approximately equivalent to aluminum, obtaining tolerances around the crank seal is very difficult. To resolve this, the crankshaft center is set as the datum point and the metal insert 18 with the shaft seal seat 24 is overmolded at the centered location creating a final dimensionally correct part that is lighter in weight than conventional steel or aluminum engine covers. Should there be additional adjustments, the metal insert 18 can be machined to requirements.
The metal insert 18 can be overmolded within the plastic engine cover 12. The plastic engine cover 12 is configured to fit over an end of an engine block 26 and can include a plurality of mounting apertures 28 for mounting the cover 12 to the engine block 26 and/or other components of the engine assembly such as the cylinder heads, and intake manifolds and oil pans, if desired. The plastic engine cover 12 can also include additional apertures 30 to receive additional pulley hubs/tensions and cam shafts. The plastic engine cover 12 can also include a plurality of intersecting reinforcing ribs 32 on at least one face 34 thereof. The reinforcing ribs 32 can intersect with annular ribs 36 that can surround the mounting apertures 28 as well as the aperture 14 and additional apertures 30, as shown in
With reference to
With reference to
The additional reinforcing ribs 50 of the metal insert 18 can have a height of 30-70% of the final overmolded rib height. The ribs 50 of the metal insert 18 can have a thickness of 30-60% of the final overmolded rib thickness, and more preferably 40-50% of the final overmolded rib thickness. The length of the reinforcing ribs can be at least 25 mm and up to approximately 75 mm long. The thickness of the planar section 44A of the flange portion 44 can be between 0.75 and 2 mm. The size of the holes in the mesh or the recesses in the waffle-like pattern can be from 0.5 to 3.2 mm, and more preferably, 1-2 mm in diameter. The insert 18 can be made from brass, aluminum, steel, magnesium, pressed metal, or other materials. The plastic front engine cover 12 can be made from high performance thermoplastic or thermoset resins enhanced with fiberglass or other filler types at levels of from 30-60%. Also, the material should be able to withstand continuous temperatures of 130° C.
