Methods of joining components in vehicle assemblies

Methods of joining components to form vehicle assemblies, such as engine assemblies, are provided. The methods include arranging a first component having a first channel defined therein in a mold, arranging a second component having a second channel defined therein in the mold, and aligning the first and second channel to define a pin-receiving channel. At least one polymeric composite pin is inserted into the pin-receiving channel thereby joining the first and second components, wherein an adhesive is disposed adjacent to at least a portion of the polymeric composite pin.

FIELD

The present disclosure relates to methods of joining components to form vehicle assemblies, such as engine assemblies, by using at least one polymeric composite pin to join the components together.

BACKGROUND

Traditionally, engine components for automotive applications have been made of metals, such as steel and iron. Metals components are robust, typically having good ductility, durability, strength and impact resistance. While metals have performed as acceptable engine components, they have a distinct disadvantage in being heavy and reducing gravimetric efficiency, performance and power of a vehicle thereby reducing fuel economy of the vehicle.

Weight reduction for increased fuel economy in vehicles has spurred the use of various lightweight metal components, such as aluminum and magnesium alloys as well as use of light-weight reinforced composite materials. While use of such lightweight materials can serve to reduce overall weight and generally may improve fuel efficiency, issues can arise when using such materials in an engine assembly due to high operating temperatures associated with the engine assembly. For example, the lightweight metal components can also have relatively high linear coefficients of thermal expansion, as compared to traditional steel or ceramic materials. In engine assemblies, the use of such lightweight metals can cause uneven thermal expansion under certain thermal operating conditions relative to adjacent components having lower linear coefficients of thermal expansion, like steel or ceramic materials, resulting in separation of components and decreased performance. Additionally, lightweight reinforced composite materials may have strength limitations, such as diminished tensile strength, and they can degrade after continuous exposure to high temperatures. Thus, lightweight engine assemblies having increased durability under high temperature operating conditions along with enhanced methods of heat transfer (e.g., heating and cooling) for such engine assemblies are needed to further improve efficiency of operation and fuel economy. However, manufacturing such lightweight engine assemblies which have a combination of lightweight materials and traditional materials can be challenging, particularly, with respect to fastening polymeric composite components with metal components.

Typically, primary engine assembly components, such as a cylinder head, cylinder housing, and crank housing, are joined together via a plurality of threaded metal fasteners (e.g., bolts). However, use of such traditional threaded metal fasteners can prove problematic when one or more of the engine components comprises a polymeric composite material. More specifically, the polymeric composite material usually comprises an arrangement of fibers and forming a channel, particularly a threaded channel, for receiving at least one of the threaded metal fastener can cause the fibers to break and/or fray in the polymeric composite resulting in compromised structural integrity of the polymeric composite component. Additionally, traditional metal fasteners and polymeric composite components when used together can undergo uneven thermal expansion under certain thermal operating conditions due to the difference in linear coefficients of thermal expansion between the materials. As known in the art, uneven thermal expansion can cause spin loss and thus diminish performance and fuel efficiency of the engine assembly. Therefore, methods of joining a combination of material components, particularly polymeric composite components, to form lightweight engine assemblies without diminishing structural integrity of the components are needed.

SUMMARY

In certain aspects, the present disclosure provides a method for joining components to form an assembly for a vehicle. The method may comprise arranging a first component in a mold, wherein the first component defines a first channel therein; arranging a second component in the mold, wherein the second component defines a second channel therein; substantially aligning the first channel with the second channel to define a pin-receiving channel capable of receiving a polymeric composite pin; and inserting at least one polymeric composite pin comprising a polymer and a plurality of reinforcing fibers into the pin-receiving channel thereby joining the first component with the second component. An adhesive may be disposed adjacent to at least a portion of the at least one polymeric composite pin.

In other aspects, the present disclosure provides a method for joining components in an engine assembly. The method may comprise arranging at least a first component in a mold, wherein the first component defines a first channel therein; arranging a second component in the mold, wherein the second component defines a second channel; substantially aligning the first channel with the second channel to define a pin-receiving channel; and inserting at least one polymeric composite pin comprising a polymer and a plurality of reinforcing fibers into the pin-receiving channel thereby joining the first component with the second component. An adhesive may be disposed adjacent to at least a portion of the at least one polymeric composite pin. The first component and the second component may be selected from the group consisting of a cylinder head, a cylinder housing, a crank housing, turbocharger, air conditioner, water pump, exhaust manifold, intake manifold, cam cover, engine cover and oil pan. At least one of the first component and the second component may comprise a polymeric composite material.

DETAILED DESCRIPTION

It should be understood for any recitation of a method, composition, device, or system that “comprises” certain steps, ingredients, or features, that in certain alternative variations, it is also contemplated that such a method, composition, device, or system may also “consist essentially of” the enumerated steps, ingredients, or features, so that any other steps, ingredients, or features that would materially alter the basic and novel characteristics of the invention are excluded therefrom.

In a vehicle, such as an automobile, an engine is a power source that produces torque for propulsion. The engine is an assembly of parts, including cylinder liners, pistons, crankshafts, combustion chambers, and the like. In a four stroke internal combustion engine each piston has an intake stroke, a compression stroke, a power stroke, and an exhaust stroke. During the intake stroke, a piston moves downward and an inlet valve is opened to permit a gaseous air mixture to fill a combustion chamber. During the compression stroke, intake and exhaust valves are closed and the piston moves upward to compress the gaseous air mixture. During the power stroke, the gaseous air mixture in the combustion chamber is ignited by a spark plug and the rapidly expanding combustion gases drive the piston downward. During the exhaust stroke, the exhaust valve is opened and the piston moves upward to discharge the combustion gases (exhaust gases). Overall, during internal combustion, the engine components may be subjected to varying amounts of stresses as well as varying temperatures due to the exothermic combustion reactions occurring in the engine block.

As discussed above, as weight of engine components increases, power, fuel economy, and efficiency may decrease. Thus, it is desirable to include various lightweight components, such as lightweight metals and lightweight composite materials, in engine assemblies instead of the traditional steel and/or iron components to decrease weight of the engine but also to maintain structural integrity of the engine.

Thus, methods for joining components to form assemblies for vehicles, such as engine assemblies, are provided herein which include use of a combination of components formed of lightweight materials and traditional materials. Advantageously, the methods described herein can join together a combination of material components, particularly polymeric composite components, to form lightweight engine assemblies without diminishing structural integrity of the individual components. Further, such methods may result in vehicle assemblies (e.g., engine assemblies) with improvements in noise, vibration and harshness. While the methods described herein are particularly suitable for manufacturing components of an automobile or other vehicle, they may also be used in a variety of other industries and applications, including aerospace components, consumer goods, office equipment and furniture, construction, industrial equipment and machinery, farm equipment, or heavy machinery, by way of non-limiting example. Non-limiting examples of vehicles that can be manufactured by the current technology include automobiles, tractors, buses, motorcycles, boats, mobile homes, campers, aircrafts (manned and unmanned), and tanks. Other exemplary structures that have frames that can be manufactured by the current technology include buildings, such as houses, offices, sheds, warehouses, and devices.

In particular, methods for joining components to form an assembly for a vehicle are provided herein. For example, as best shown inFIG. 1a, the method may comprise arranging at least a first component32, e.g., in a mold30, wherein the first component32defines a first channel33therein which extends from a first exterior surface34to an opposing second exterior surface36of the first component32. The method further comprises arranging a second component38, e.g., in the mold30, wherein the second component38defines a second channel35therein which extends from a third exterior surface40to an opposing fourth exterior surface42of the second component38, as shown inFIG. 1b. The components may be held together, e.g., by a jig (not shown). Alternatively, it is contemplated herein, that instead of completely extending from an exterior surface (e.g., exterior surface34) to an opposing exterior surface (e.g., exterior surface40), the first channel33, the second channel35, etc, may extend partially from an exterior surface (e.g., exterior surfaces34,36) or may extend partially from an opposing exterior surface (e.g., exterior surfaces40,42), so long as the first channel and the second channel may be aligned to form a pin-receiving channel. The first channel33may be substantially aligned with the second channel35to define a pin-receiving channel37, as shown inFIG. 1c, where the second exterior surface36of the first component32is adjacent to the third exterior surface40of the second component38. The pin-receiving channel37may be capable of receiving a polymeric composite pin. The method further comprises inserting at least one polymeric composite pin39into the pin receiving channel thereby joining the first component32with the second component38to form assembly40, as shown inFIG. 1d. Additionally or alternatively, an adhesive41may be disposed adjacent to at least a portion of the at least one polymeric composite pin39. Any suitable polymer-based adhesive may be used. Non-limiting examples of the adhesive include epoxy, polyurethane, silicones (e.g., polydimethylsiloxane (PDMS), cyanoacrylate, polyvinylacetate. The adhesive41may be applied to at least a portion of the surface29of the first component32and/or the second component38, which define the pin-receiving channel37prior to insertion of the polymeric composite pin39. Preferably, the adhesive41is applied to substantially the entire surface31of the first component32and the second component38, which define of the pin-receiving channel37. Additionally or alternatively, the adhesive41may be applied to the exterior surface of the polymeric composite pin39prior to insertion into the pin-receiving channel37. Advantageously, when the polymeric composite pin39and the first component32and/or the second component38are a different material (e.g., metal) than the polymeric composite pin39such that there is a difference in coefficients of thermal expansion between the polymeric composite pin39and the first component32and/or second component38, the adhesive41can prevent separation between the polymeric composite pin39, the first component32and/or the second component38in the event of uneven thermal expansion. In certain other variations, the present disclosure contemplates a polymeric composite pin39as described herein.

In certain variations, as shown inFIG. 2a, the method may further comprise arranging a third component44, e.g., in the mold30, along with the first component32and the second component38. The third component44defines a third channel47, which may extend from a fifth exterior surface46to an opposing sixth exterior surface48of the third component44. The first channel33may be substantially aligned with the second channel35and the third channel47to define a pin-receiving channel43, as shown inFIG. 2b, where the second exterior surface36of the first component32is adjacent to the third exterior surface40of the second component38and the fourth exterior surface42of the second component38is adjacent to the fifth exterior surface46of the third component44. Alternatively, the third component44may be arranged (not shown) to be adjacent to the first component32such that the sixth exterior surface48of the third component44is adjacent to the first exterior surface34of the first component32. The polymeric composite pin39may be inserted into the pin-receiving channel43thereby joining the first component32, the second component38and the third component44to form joined assembly80, as shown inFIG. 2c. The method may further comprise applying an adhesive41to at least a portion of a surface31of the first component32, the second component38, and the third component44, which define the pin-receiving channel43prior to insertion of the polymeric composite pin39. As will be appreciated by one skilled in the art, the methods described herein contemplate arranging more than three components to form a vehicle assembly as well as arranging a plurality of polymeric composite pins as described herein. For, example, a plurality of components, e.g., at least about four components, at least about five components, at least about six components, at least about seven components, at least about eight components, at least about nine components or at least about ten components, with respective channels defined therein may be arranged and joined together via a plurality of polymeric composite pins by the methods described herein.

In certain variations, a polymeric composite pin39amay further comprise a cap portion45disposed at least at one terminal surface of the polymeric composite pin39a, as shown in alternative joined assembly60inFIG. 3. The cap portion45is particularly advantageous when the first component32defines a first channel having a smaller surface area for applying the adhesive41to bond with the polymeric composite pin39aand to further improve the bond between the polymeric composite pin39awith the first component32, the cap portion45is present thereby improving the overall joining of the first component32with the second component38. In such instances, as shown inFIG. 3, adhesive41is only present on a surface of the second component38such that adhesive41is disposed between the polymeric composite pin39aand the second component38. Further, the cap portion45is also advantageous if the first component32and the second component38are formed of different materials (e.g., metal, polymeric composite) having different coefficients of thermal expansion. In such instance, the cap portion45can prevent separation between the first component32and the second component38in the event of uneven thermal expansion. Alternatively, the polymeric composite pin39amay comprise a cap portion disposed at two terminal surfaces of the polymeric composite pin39a(not shown). In certain variations, the present disclosure contemplates a polymeric composite pin39aas described herein comprising at least one cap portion45as described herein.

In certain other variations, as shown inFIGS. 4aand 4b, a polymeric composite pin50can comprise an outer pin portion51and an inner pin portion53. The outer pin portion51has an aperture52defined therein for receiving the inner pin portion53. In such instances, the inserting of the least one polymeric composite pin into the pin receiving channel may comprise inserting the outer pin portion51into the pin-receiving channel and inserting the inner pin portion53into the aperture defined in the outer pin portion to join the first component32and second component38to form joined assembly70, as shown inFIG. 5. An adhesive41may be adjacent to outer pin portion51and the inner pin portion53. In certain variations, the adhesive41may be applied to at least a portion of a surface55of the outer pin portion51, which defines the aperture52, and/or at least a portion of a surface57of the inner pin portion53such that adhesive41is adjacent to the outer pin portion51and the inner pin portion53. Additionally or alternatively, the adhesive41may be applied to at least a surface the first component32and the second component38, which define the pin-receiving channel. As shown inFIGS. 4aand 4b, the outer pin portion51and the inner pin portion53may include cap portions59and61at two terminal ends of the polymeric composite pin50. Alternatively, only outer pin portion51or inner pin portion53may include a cap portion (not shown). In certain variations, the present disclosures contemplates a polymeric composite pin50as described herein comprising an outer pin portion51as described herein and an inner pin portion53as described herein.

Additionally or alternatively, the method may further comprise applying a preload to the various components (e.g., the first component, the second component, the third component, etc.). For example, a preload may be applied after the first component and the second component are arranged and aligned to form the pin-receiving channel. Once the preload is applied, the at least one polymeric composite pin may be inserted and adhered to join the components together.

The pin described herein is a polymeric composite material, which comprises a polymer and a plurality of reinforcing fibers. Examples of suitable polymers include, but are not limited to a thermoset, a thermoplastic resin, elastomer and combination thereof. Preferable polymers include, but are not limited to epoxies, phenolics, vinylesters, bismaleimides, polyether ether ketone (PEEK), polyamides, polyimides and polyamideimides. Examples of suitable reinforcing fibers include, but are not limited to carbon fibers, glass fibers, aramid fibers, polyethylene fibers, organic fibers, metallic fibers, and combinations thereof. In particular, the reinforcing fibers are glass fibers and/or carbon fibers. The reinforcing fibers may be continuous fibers or discontinuous fibers. In particular, the reinforcing fibers are continuous fibers. Advantageously, the polymeric composite pin described herein may have a tensile strength of about 100 MPa to about 4000 MPa, about 500 MPa to about 3000 MPa or about 1000 MPa to about 2000 MPa.

Polymeric composites can be formed by using strips of the composite precursor material, such as a fiber-based material (e.g., cloth or graphite tape). The composite may be formed with one or more layers, where each layer can be formed from contacting and/or overlapping strips of the fiber-based material. In particular, the polymeric composite pin39may comprise one or more layers, where each layer can be formed from contacting and/or overlapping reinforcing fibers to form an interwoven preform of reinforcing fibers. The reinforcing fibers may be formed into a shape of a rod or a tube to form the polymeric composite pin. For example, a detailed view of a polymeric composite pin300is shown inFIG. 6awhere reinforcing fibers301(e.g., carbon fibers, glass fibers) are woven or braided to form the polymeric composite pin300. Alternatively, a polymeric composite pin310can comprise braided reinforcing fibers311in the shape of a tube or rod with a hollow interior, as shownFIG. 6b. It should be noted that other weaving patterns are also contemplated and not limited to the patterns shown inFIGS. 6a-6b, which are merely example embodiments. Alternatively, the polymeric composite pin can be formed of reinforcing fibers arranged in a unidirectional manner where substantially all of the reinforcing fibers are arranged in one directional length to form the pin.

The fiber-based substrate material (e.g., reinforcing fibers) may also comprise a resin (e.g., a polymer). The resin can be solidified (e.g., cured or reacted) and thus can serve to bond single or multiple layers together in the polymeric composite. Various methods are typically employed for introducing resin to impregnated fiber-based substrate composite material systems: wet winding (or layup), pre-impregnating (referred to as “pre-preg”), pultrusion, and resin transfer molding. For wet winding, a dry fiber reinforcement material can be wetted with the resin as it is used, usually by submersion through a bath. For pre-impregnating (pre-preg), the resin is wetted into the fiber-based material in advance, and usually includes a step of partially curing the resin to have a viscous or tacky consistency (also known as a B-stage partial cure), and then winding up the pre-preg fiber-based material for later use. Pre-preg composite material systems tend to use thermoset resin systems, which can be cured or reacted by elevated temperatures with cure times or reaction time ranging from about 1 minute to about 2 hours (depending on the cure or reaction temperatures). However, some pre-preg materials may employ resins that cure or react with actinic radiation (e.g., ultraviolet radiation (UV)). For pultrusion, resin may be applied to the fiber reinforcement material and the reinforcement material with the resin may be pulled through a heated or a cooled die to form the desired shape (e.g., the polymeric composite pin). For resin transfer molding, dry fiber reinforcement material may be placed into a mold and resin may be infused into the mold under pressure (e.g., about 10 psi to about 2000 psi). Injection molding techniques known in the art may also be used to introduce resin into the reinforcement material, particularly where the reinforcement material comprise discontinuous fibers. For example, a precursor comprising a resin and the reinforcement material may be injected or infused into a defined space or mold followed by solidification of the precursor to form the polymeric composite material. The term “injection molding” also includes reaction injection molding using at thermoset resin.

The polymeric composite pin may have a substantially round cross-section. As understood herein, “substantially round” may include circular and oval cross-sections and the dimensions of the cross-section may deviate in some aspects. The polymeric composite pin may have a diameter of about 50 μm to about 5,000 μm, about 100 μm to about 3,000 μm, about 100 μm to about 1,000 μm, about 100 μm to about 500 μm. Additionally or alternatively, the polymeric composite pin may have a substantially rectangular cross-section. As understood herein, “substantially rectangular” may include square cross-sections and the dimensions of the cross-section may deviate in some aspects. Other cross-sections of the polymeric composite pin contemplated herein include, but are not limited to triangular cross-section, pentagonal cross-section, hexagonal cross-section, octagonal cross-section, and the like.

The first component, the second component, and the third component may be metal (e.g. steel, iron, magnesium alloy, aluminum alloy, metal composite), ceramic (e.g., alumina, silicon carbide, ceramic composite) or a polymeric composite material as described herein. In particular, at least one of the first component, the second component, and the third component comprise a polymeric composite material as described herein. In certain aspects, the first component is a metal material as described herein or a ceramic material as described herein and the second component and/or the third components are a polymeric composite material as described herein.

The first, second and third components may be any suitable component of a vehicle assembly. Non-limiting examples of first, second and third components include a cylinder head, a housing (e.g., a cylinder housing, a crank housing), a liner defining a cylindrical region for receiving a piston, a piston, a crankshaft, a connecting rod, a bulkhead, a turbocharger, air conditioner, water pump, exhaust manifold, intake manifold, cam cover, engine cover and oil pan, and combinations thereof. In certain variations, the first component and the second component are selected from the group consisting of a cylinder head and a housing. The housing may be a cylinder housing or a crank housing. In other certain variations, the first component may be a cylinder head, the second component may be a cylinder housing and the third component may be a crank housing.

The methods described herein may be used to fasten various components of a vehicle assembly (e.g., engine assembly). For example, as best shown inFIG. 7, the methods described herein may be used to join together the components of an engine assembly1(e.g., for use in a vehicle). The engine assembly1includes a liner2, which defines an open void cylindrical region7. The liner2may be any suitable material, such as but not limited to metal (e.g. steel, iron, magnesium alloy, aluminum alloy, metal composite) or ceramic (e.g., alumina, silicon carbide, ceramic composite). In certain variations, the liner2is a metal material. The liner2generally may be cylindrically shaped and have hollow interior. The liner2has an interior surface3, an opposing exterior surface4, a first terminal surface5and an opposing second terminal surface6. The engine assembly1also includes a housing8disposed around at least a portion of the exterior surface4of the liner2. The housing8may also be adjacent to the second terminal surface6of the liner2. The housing8has an interior surface9, an opposing exterior surface10, a third terminal surface11, and an opposing fourth terminal surface12. The housing8may be a lightweight metal (e.g., aluminum alloy, magnesium alloy), a ceramic material (e.g., alumina, silicon carbide) or a polymeric composite material. A layer of polymeric composite (e.g., comprising discontinuous fibers) (not shown) may also be present between the exterior surface4of the liner2and the interior surface9of the housing8.

The engine assembly1may further include a cylinder head13having a fifth terminal surface14and an opposing sixth terminal surface15. At least a portion of the sixth terminal surface15may be adjacent to the first terminal surface5of the liner2. The cylinder head13may be any suitable material, metal (e.g. steel, iron, magnesium alloy, aluminum alloy, metal composite), ceramic (e.g., alumina, silicon carbide, ceramic composite) or a polymeric composite material as described herein. In certain variations, the cylinder head13is a metal material. The liner2may be held in place by its contact with the cylinder head13and housing8. A coolant channel16may be defined between at least a portion of the exterior surface4of the liner2, an interior surface9of the housing8and the sixth terminal surface15of the cylinder head13. If more than one liner is present, there may be a continuous coolant channel16adjacent to each liner or there may be discrete coolant channels corresponding to each liner. The coolant channel16is capable of receiving a suitable heat transfer fluid for cooling a vehicle assembly (e.g., engine assembly). Examples of suitable heat transfer fluids include, but are not limited to air, water, oil, ethylene glycol, propylene glycol, glycerol, methanol, and combinations thereof. The air may be supplied from an air conditioning system or produced from movement of the vehicle. The heat transfer fluid may be supplied by at least one pump (not shown) from at least one supply reservoir or supply channel (not shown) to at least one inlet (not shown) in the coolant channel16. The pump and supply reservoir may be present adjacent to the engine assembly. Optionally, the heat transfer fluid may flow through a cooler (not shown) to further reduce the temperature of the heat transfer fluid or the heat transfer fluid may flow through a heater (not shown) to increase the temperature of the heat transfer fluid. One of ordinary skill in the art appreciates that the heat transfer fluid may be supplied to one or more coolant channels as necessary.

The cylinder head13, housing8and/or liner2are joined together via the methods described herein by at least one polymeric composite pin39as described herein. For example, a plurality of polymeric composite pins39may join together the cylinder head13(e.g., a first component) and the housing8(e.g., a second component). Additionally or alternatively, a suitable sealant (not shown) and/or gasket (not shown) may be present between at least a portion of the sixth terminal surface15of the cylinder head13, at least a portion of the first terminal surface5of the liner2, and/or a least a portion of the third terminal surface11of the housing8.

The cylindrical region7defined by the liner2may receive a piston18. The piston18is connected to a crankshaft20via a connecting rod19. The piston18, connecting rod19, and the crankshaft20may be any suitable material, e.g., metal, ceramic, polymeric composite, and combinations thereof. As will be appreciated by those of skill in the art, the engine assembly1shown inFIG. 7depicts a single piston18and single cylindrical region7and associated componentry, but may in fact include a plurality of pistons, cylindrical regions7, plurality of polymeric composite pins39and associated components described above.

In various embodiments, the housing8comprises a cylinder housing portion8aand crank housing portion8b. The cylinder housing portion8aand the crank housing portion8bmay be integrally formed, as shown inFIG. 7. Alternatively, as shown inFIG. 8, the cylinder housing portion8aand the cranking housing portion8bmay be distinct components joined together via an adhesive (not shown) or with a plurality of polymeric composite pins39in engine assembly100. When present as distinct components, the cylinder housing portion8aand the crank housing portion8bmay be the same or different material. With reference toFIG. 8, the cylinder housing portion8ahas a seventh terminal surface21and an opposing eighth terminal surface22. The crank housing portion8bhas a ninth terminal surface23and an opposing tenth terminal surface24. The ninth terminal surface23of the crank housing portion is adjacent to the second terminal surface6of the liner2and the eighth terminal surface22of the cylinder housing portion8a. The seventh terminal surface21of the cylinder housing portion8amay be adjacent to the sixth terminal surface15of the cylinder head13. The cylinder head13, cylinder housing portion8a, the crank housing portion8b, and/or liner2may be coupled together by any suitable fasteners as described herein. For example, a plurality of polymeric composite pins39may join together the cylinder head13(e.g., first component), the cylinder housing portion8a(e.g., second component), and the crank housing portion8b(e.g., third component). Additionally or alternatively, a suitable sealant (not shown) and/or gasket (not shown) may be present between at least a portion of the sixth terminal surface15of the cylinder head13, at least a portion of the first terminal surface5of the liner2, and/or a least a portion of the seventh terminal surface21of the cylinder housing portion8a.

In certain aspects, the housing8is a polymeric composite material as described herein. In such instances, the housing8may comprise a suitable polymer and plurality of suitable reinforcing fibers. Examples of suitable polymers include, but are not limited to a thermoset resin, a thermoplastic resin, elastomer, and combination thereof. Preferable polymers include, but are not limited to epoxies, phenolics, vinylesters, bismaleimides, polyether ether ketone (PEEK), polyamides, polyimides and polyamideimides. Examples of suitable reinforcing fibers include, but are not limited to carbon fibers, glass fibers, aramid fibers, polyethylene fibers, ceramic fibers, organic fibers, metallic fibers, and combinations thereof. In particular, the reinforcing fibers are glass fibers and/or carbon fibers. The reinforcing fibers may be discontinuous fibers or continuous fibers. In particular, the reinforcing fibers are continuous fibers.

In order to heat and/or cool the engine assembly1, the housing8(e.g., polymeric composite) can further include a plurality of microchannels25, as shown inFIG. 7, for receiving a heat transfer fluid as described herein. The heat transfer fluid may be supplied by at least one pump (not shown) from at least one supply reservoir or supply channel (not shown) to at least one inlet (not shown) in the microchannels205in the vehicle assembly. The pump and supply reservoir may be present adjacent to the engine assembly. The heat transfer fluid may be at supplied at a suitable temperature to cool and/or heat the vehicle assembly, e.g., about 10° C. to about 120° C., about 20° C. to about 100° C. or about 20° C. to about 90° C. Optionally, the heat transfer fluid may flow through a cooler (not shown) to further reduce the temperature of the heat transfer fluid or the heat transfer fluid may flow through a heater (not shown) to increase the temperature of the heat transfer fluid.

The microchannels25may have a substantially round cross-section. As understood herein, “substantially round” may include circular and oval cross-sections and the dimensions of the cross-section may deviate in some aspects. The microchannels25may have a diameter of less than about 8,000 μm. Additionally or alternatively, the microchannels25have a diameter of about 0.1 μm to about 8,000 μm, 0.1 μm to about 5,000 μm, 0.1 μm to about 1,000 μm, about 1 μm to about 500 μm or about 1 μm to about 200 μm. Additionally or alternatively, the microchannels25may have a substantially rectangular cross-section. As understood herein, “substantially rectangular” may include square cross-sections and the dimensions of the cross-section may deviate in some aspects. Preferably, at least a portion of the microchannels25are interconnected, which may prevent blockages. The microchannels25may be oriented in any suitable direction, for example, axially, radially, spiral, branched, intersecting, criss-crossing and combinations thereof.

In certain other aspects, the present teaching also contemplates a process of using sacrificial fibers to form the microchannels25in the polymeric composite (e.g., housing8). As shown inFIG. 9a, a composite woven preform200comprises interwoven first reinforcing fibers201(e.g., carbon fibers, glass fibers) and second reinforcing fibers202(e.g., carbon fibers, glass fibers) to form a three dimensional woven structure. The first reinforcing fibers201and the second reinforcing fibers202can be the same or different fibers. Sacrificial fibers203can be woven into the composite woven preform200along with the first reinforcing fibers201, as shown inFIG. 9b. The first reinforcing fibers201and the sacrificial fibers203can be directed through the second reinforcing fibers202sinusoidally. It should be noted that other weaving patterns are also contemplated and not limited to the patterns shown inFIGS. 9a-9e, which are merely example embodiments. The sacrificial fibers203comprises a material, which can withstand weaving with the first reinforcing fibers201and/or the second reinforcing fibers202as well as solidification of the polymeric composite (e.g., resin infusion and curing or reacting), but is capable of volatilizing, melting dissolving or etching under conditions which do not substantially volatilize, melt, dissolve or etch other components of the polymeric composite (e.g., reinforcing fibers). Examples of suitable sacrificial fiber materials include, but are not limited to metals and polymers. Non-limiting metals may include solders, which comprise lead, tin, zinc, aluminum, suitable alloys and the like. Non-limiting polymers may include polyvinyl acetate, polylactic acid, polyethylene, polystyrene. Additionally or alternatively, the sacrificial fibers may further be treated with a catalyst or chemically modified to alter melting or degradation behavior.

Following incorporation of the sacrificial fibers203, a resin204is infused into the composite woven preform200, which is then solidified (e.g., reacted or cured) under suitable conditions, as shown inFIGS. 9cand 9d, respectively, to form polymeric composite210. After solidifying (e.g., reacting or curing), the polymeric composite210may be further treated (e.g., heated) to volatilize, melt, or degrade the sacrificial fibers203or the sacrificial fibers203may be dissolved to produce degradants. For example, the sacrificial fibers may be heated to a temperature (e.g., about 150° C. to about 200° C.) that substantially vaporizes or melts the sacrificial fibers but does not substantially degrade the reinforcing fibers and/or the cured resin. Any suitable solvent, such as, but not limited to acetone, may be applied to the sacrificial fibers to dissolve them, optionally with agitation, so long as the solvent does not substantially degrade or dissolve the reinforcing fibers and/or the cured resin. Alternatively, the sacrificial fibers may be etched using a suitable acid (e.g., hydrochloric acid, sulfuric acid, nitric acid, and the like). The degradants may be removed to form microchannels205(seeFIG. 9e) in the polymeric composite210, e.g., by applying a vacuum to the polymeric composite or introducing a gas to the polymeric composite to expel the degradants out of the polymeric composite. It also contemplated herein that the microchannels may be present in a non-polymeric composite housing, for example, in a metal housing or a ceramic housing.

In other variations, a composite precursor material may be injection molded or otherwise applied to the opposing exterior surface4of liner2, which may be followed by solidification (e.g., curing or reacting) to form the housing8.

Additionally or alternatively, the polymeric composite (e.g., housing8) may include a plurality of microspheres (not shown) for improved heat transfer. The microspheres may be ceramic or glass, and optionally, may be coated with a metal, ceramic and/or nanoparticles. Preferably, the coating has a high thermal conductivity, e.g., aluminum, copper, tin and the like. The microspheres may have a diameter of less than about 1,000 μm. Additionally or alternatively, the microspheres have a diameter of about 0.1 μm to about 1,000 μm, about 1 μm to about 500 μm or about 1 μm to about 200 μm.

Additionally or alternatively, the polymeric composite (e.g., housing8) may include at least one wire for heating the engine assembly. For example, as shown inFIG. 10, one or more wires402may be incorporated or woven into reinforcing fibers401(e.g., carbon fibers) in the polymeric composite400(e.g., housing8). The wires402may be comprise any material suitable for conducting electricity (e.g., copper, Nichrome, and the like). The wires402may be insulated from the reinforcing fibers401. For example, the wires402may include a suitable insulative coating, such as a polymer coating and/or a braided glass fiber sheath. To heat the wires402, electricity is provided by a battery or other suitable external source (not shown) and controlled by a control unit (not shown). Referring toFIG. 7, although not shown, a person of ordinary skill in the art appreciates that the wires402may be included in the housing8in addition to or instead of the plurality of microchannels25.

In a particular embodiment, the polymeric composite housing comprises one or more of: (i) a plurality of microchannels as described herein; (ii) at least one wire as described herein; and (iii) a plurality of microspheres as described herein. Additionally or alternatively, the polymeric composite housing comprises two or more of (i), (ii) and (iii) (e.g., (i) and (ii), (i) and (iii), (ii) and (iii)). Additionally or alternatively, the polymeric composite housing comprises (i), (ii) and (iii).

Referring back toFIG. 7, the engine assembly1may further include a polymeric composite layer26disposed around at least a portion of the exterior surface10of the housing8. The polymeric composite layer26may serve as a mechanical, chemical and/or thermal shield for the engine assembly. The polymeric composite layer26may comprise a suitable polymer as described herein (e.g., thermoset resin, thermoplastic resin, elastomer) and a plurality of suitable reinforcing fibers (e.g., carbon fibers, glass fibers, aramid fibers, polyethylene fibers, ceramic fibers, organic fibers, metallic fibers, and combinations thereof). In particular, the reinforcing fibers are glass fibers and/or carbon fibers. The reinforcing fibers may be discontinuous fibers. The polymeric composite layer26may be formed by injection molding. Additionally or alternatively, the polymeric composite layer26may extend around at least a portion of the cylinder head13, as shown inFIG. 11. Further, as shown inFIG. 11in an alternative vehicle assembly90, the polymeric composite layer26may extend along substantially all of the exterior surface10of the housing8. Additionally or alternatively, the polymeric composite layer26may extend around any other suitable surface of the vehicle assembly, e.g., around an oil pan, around cam cover. Additionally or alternatively, the polymeric composite layer26may extend around any peripheral systems of the vehicle assembly, e.g., water pump, air conditioner, turbocharger. Alternatively, it is contemplated herein, that instead of utilizing a polymeric composite layer26, a metal layer or ceramic layer may be used in its place. Such a polymeric composite layer26, metal layer or ceramic layer may seal the outside of the engine assembly and prevent leakage of fluid from between the various components in the engine assembly and may avoid the need for the use of gaskets for sealing the engine assembly.

In other variations, polymeric composites used herein for the housing8, the polymeric composite pin39, and/or the polymeric composite layer26may be made by any other suitable methods known in the art, e.g., pultrusion, reaction injection molding, injection molding, compression molding, prepreg molding (in autoclave or as compression molding), resin transfer molding, and vacuum assisted resin transfer molding. Further, fiber precursors may be made by any other suitable methods known in the art, e.g., braiding, weaving, stitching, knitting, prepregging, hand-layup and robotic or hand placement of tows.

In various aspects, as shown inFIGS. 12aand 12b, an engine assembly400is contemplated, which includes a cap27. The cap27may be adjacent to a third terminal surface11of the housing8and the sixth terminal surface15of the cylinder head13. The cap27may be any suitable material, such as a metal, ceramic, or polymeric composite material. In particular, the cap27is metal (e.g., steel, iron, magnesium alloy, aluminum alloy), especially when the housing8is a polymeric composite because cap27may be more machinable than the polymeric composite. The cap27may serve as a mating surface between the cylinder head13and the housing8. Preferably, the cap27and the liner2are the same material (e.g., metal) so that they may both be machined or formed together in preparation for a head gasket and/or the cylinder head13. The cap27may be joined to the housing8with a suitable adhesive or directly molded with the housing8. The cylinder head13(e.g., first component), the cap27(e.g., second component) and/or the housing8(e.g. third component) may be joined together via the methods described herein by a polymeric composite pin39. Additionally or alternatively, a second cap (not shown) similar to the cap27may be adjacent to the eighth terminal surface22of the cylinder housing portion8aand the ninth terminal surface23of the crank housing portion8b.

In other variations, it is further contemplated that one or more of the vehicle assembly components described herein include one or more mechanical interlock features for coupling together the various vehicle components. For example, complementary protruding flanges, grooves, channels, locking wings of differing shapes could be used as mechanical interlock features. In particular, as shown inFIG. 13a, at least a portion of polymeric composite pin39bmay comprise one or more mechanical interlock features28afor increasing surface area of the polymeric composite pin39bfor coupling with the first component32and/or the second component38. Additionally or alternatively, as shown inFIG. 13b, at least a portion of a first component32aand/or a second component38amay comprise mechanical interlock features28bfor increasing surface area of the first component32aand/or the second component38afor coupling with the polymeric composite pin39. Additionally or alternatively, as shown inFIG. 14in alternative engine assembly600, at least a portion of the exterior surface4of the liner2may comprise one or more mechanical interlock features28for coupling with the housing8(e.g., interior surface9), particularly where the housing8is a polymeric composite material. Additionally or alternatively, the cap27and or the third terminal surface11of the housing8may include one or more mechanical interlock (not shown) features for coupling the cap27with the housing8. Additionally or alternatively, ceramic material may be present between various metal and polymeric composite components in the engine assembly for insulation purposes. It is understood herein that the various metal components described herein can be readily machined or cast.

Optionally, the first, second and/or third components may be pretreated prior to arranging the first component in the mold to further enhance assembly of the various components. Pretreating of the first component may comprise or more of the following: cleaning, abrading, etching, applying a chemical primer (e.g., methyl ethyl ketone) and forming at least one mechanical interlock feature as described above in the first component. Etching can include electroetching (electroplating) or rinsing the first component with a suitable acid as described above. Abrading can include sandblasting the surface of the first component or rubbing sandpaper over the surface of the first component followed by rinsing with a solvent (e.g., acetone).

In another particular embodiment, the present disclosure contemplates a method for joining components in an engine assembly. The method may comprise arranging a first component in a mold, wherein the first component defines therein a first channel as described herein; arranging a second component in the mold, wherein the second component defines therein a second channel as described herein; and substantially aligning the first channel with the second channel to define a pin-receiving channel as described herein. The method further comprises inserting at least one polymeric composite pin as described herein comprising a polymer as described herein (e.g., thermoplastic or thermoset resin) and a plurality reinforcing fibers as described herein (e.g., carbon fibers, glass fibers, aramid fibers, polyethylene fibers, ceramic fibers, organic fibers, metallic fibers, and combinations thereof) into the pin-receiving channel thereby joining the first component with the second component. At least one of the first component and the second component comprises a polymeric composite material as described herein. An adhesive as described herein may be disposed adjacent to at least a portion of the at least one polymeric composite pin. In certain aspects, the adhesive may be applied as described herein, e.g., to at least a portion of the surface of the first component and/or the second component, which define the pin-receiving channel, prior to insertion of the polymeric composite pin. The first component and the second component may be selected from the group consisting of a cylinder head as described herein and housing as described herein. The housing may comprise a cylinder housing and a crank housing. Further, the first component may be a metal material metal (e.g., steel, iron, magnesium alloy, aluminum alloy, metal composite) or a ceramic material (e.g., alumina, silicon carbide, ceramic composite), and the second component may be a polymeric composite material as described herein. In particular, the first component may be a metal or ceramic cylinder head and the second component may be a polymeric composite housing.

Additionally or alternatively, the at least one polymeric composite pin may further comprise a cap portion disposed on at least one terminal surface of the polymeric composite pin.

Additionally or alternatively, the at least one polymeric composite pin comprises an inner pin portion as described herein and an outer pin portion as described herein (e.g., having an aperture defined therein for receiving an inner pin portion). The inserting of the at least one polymeric composite pin as described herein into the pin-receiving channel comprises inserting the outer pin portion as described herein into the pin-receiving channel as described herein and inserting the inner pin portion as described herein into the aperture defined in the outer pin portion. The adhesive as described herein may be adjacent to the outer pin portion and inner pin portion, and the method may further comprise applying the adhesive to at least a portion of the surface of the outer pin portion which defines the aperture.

Additionally or alternatively, a third component as described herein may be arranged in the mold and joined to the first and second components as described herein.

In an alternative embodiment, another method for joining components in an engine assembly is provided. The method may comprise arranging a first component in a mold, wherein the first component defines therein a first channel as described herein; arranging a second component in the mold, wherein the second component defines therein a second channel as described herein; and/or arranging a third component as described herein in the mold, wherein the third component defines a third channel as described herein. The method may further comprise substantially aligning the first channel, the second channel and/or the third channel to define a pin-receiving channel as described herein. A polymeric composite pin may be formed in the pin-receiving channel via injection molding. For example, a fluid precursor comprising a plurality of reinforcing fibers as described herein and resin as described herein may be injected or infused into the pin-receiving channel followed by solidifying (e.g., curing or reacting) of the fluid precursor to form the polymeric composite pin thereby joining the first component, the second component, and/or the third component.