Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Composite having voids in a component
Reexamination Certificate
2000-11-13
2004-06-15
Juska, Cheryl A. (Department: 1771)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Composite having voids in a component
C428S308400, C428S315900, C442S370000, C442S373000, C442S378000, C442S381000, C181S290000, C181S286000, C181S294000
Reexamination Certificate
active
06749929
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to a heat-insulating and soundproofing lining for the engine compartments of motor vehicles and a process for the manufacturing thereof.
2. Description of the Related Art
In the engine compartments of motor vehicles, including both passenger and commercial vehicles, soundproofing parts in the form of absorbers are increasingly being used to reduce engine noise. In general, these absorbers are designed as molded articles to reduce the exterior and interior noise of vehicles. The molded articles may be made from webs (e.g., from cotton) or from polyurethane foam, and typically have thermostabilities up to about 160° C.
In certain areas, such as exhaust manifolds or exhaust gas recirculation areas, the molded articles may be subjected to high thermal loads. Thus, these molded articles are often laminated, partially or completely, with aluminum foil to serve as heat reflectors in order to protect the underlying nonwovens. Examples of such laminated articles are described in DE-U-87 00 919. The laminating, however, often results in the a loss of soundproofing for any component beneath the aluminum laminate, because sound cannot penetrate the aluminum foil and be absorbed.
DE 36 01 204 A describes an absorbing molded article consisting of several layers of nonwoven material that has been used for noise-reducing linings in the engine compartments of motor vehicles. The absorbing molded article consists of a covering layer of plastic fibers facing the engine, an adjacent heat-insulating and soundproofing layer of an inorganic, highly heatproof, fibrous material, and an additional absorbing layer of organic fibers.
DE 38 18 301 C also describes a noise-reducing molded article for the engine compartment of a motor vehicle in which an inorganic, highly heatproof, fibrous material bonded by a binder is covered by a fibrous carbon material by means of a bonding agent containing a melamine resin at the engine side. The molded article has a good noise reduction, and it is reportedly useful as a thermal insulation up to a temperature of about 500° C. In addition, it is planned to provide the molded article with a layer of carbon fibers. This carbon fiber layer is intended to provide a certain mechanical protection for the sensitive layer of inorganic fiber material.
DE 42 11 409 A1 describes a self-supporting, heat-insulating, and soundproofing lining for a combustion engine of a motor vehicle having several layers which have been compressed under the influence of pressure and heat with the formation of regions having a definably preset compression. The lining consists of a stronger, heat-insulating and soundproofing layer of an inorganic fiber material facing the engine which is covered by a fibrous carbon material. A stronger layer of an inorganic fibrous material opposite the engine cures to form a self-supporting backing. At the side facing the body, the backing may be covered by a layer of a polyester web or polyacrylonitrile fibers.
A heat-insulating and soundproofing lining on the basis of melamine resin foams covered with temperature-resistant covering layers on one or both sides has often been used in the automobile sector. According to DIN 4102, melamine resin foams are considered to be flame resistant, and are classified under class B1. A long-term heat resistance from −40° C. to 150° C. and a long-term heat loadability of 200° C. for three weeks render this material particularly suitable for the manufacturing of linings for the engine compartments of motor vehicles. This material, however, is extremely expensive.
SUMMARY OF THE INVENTION
Thus, it is the object of the invention to provide linings for the engine compartments of motor vehicles having comparable heat-insulating and soundproofing properties at costs distinctly reduced as against the state of the art.
According to one embodiment of the present invention, the aforementioned object is achieved by a heat-insulating and soundproofing lining for an engine compartment of a motor vehicle. According to one embodiment, the lining comprises a first covering layer facing the engine. A duroplastic foam layer having a long-term thermal stability up to 180° C., a long-term thermal loadability at 200° C. of three weeks and a thickness below 5 mm, contacts the first covering layer. Next, a soundproofing layer of plastic foam, particle composite foam or web consisting of natural or synthetic fibers and mixtures thereof, needled or non-needled, is in contact with the duroplastic foam layer layer. Finally, a second covering layer is in contact with the soundproofing layer, and is opposite the engine side.
Thus, the lining parts of the invention are especially suited for the lining of built-in components, body components and the like of motor cars, heat-radiating machines and units, in particular of sound-absorbing elements for the protection against excessive thermal loads due to machine guides, catalyst components and the like, in particular within the engine compartment of motor vehicles.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention replaces, at least partially, the relatively expensive duroplastic foam material of the foam layer of a soundproofing lining with more cost-efficient materials without a deterioration in the heat-insulating and soundproofing properties of the lining. In addition, the present invention does not cause a degradation of the thermal behavior of the soundproofing lining. For example, a suitable soundproofing lining for a front engine hood reduces the sound propagation through the front engine hood. The geometry of the lining parts may depend on the interior surface of the front engine hood and the spatial conditions within the engine compartment. The fastening of the lining parts may be effected by, for example, plugging in a hole pattern on the inner surface of the front engine hood. The lining may be secured by a split rivets. According to the invention, lining parts may be installed between the body and the engine in the area of the bulkhead within the engine compartment. The lining parts may be secured at the body by coarse-thread bolts or snap fasteners (or sheet nuts).
In general, the lining of the present invention comprises several layers. These layers include a first covering layer, a duroplastic foam layer, a soundproofing layer, and a second covering layer. The layers will be discussed in greater detail, below.
The first covering layer is the layer of the liner that faces the engine. In general, this layer comprises high-temperature resistant fibrous structures on the basis of inorganic fibers are suited. Especially preferred within the meaning of the present invention are nonwovens, fabrics, or knit fabrics of the above-mentioned fibers. According to the invention, in addition to polyester webs, glass fiber mats and/or carbon fiber mats, ceramic fiber mats, or mineral fiber mats are particularly preferred. Textile glass fibers, within the meaning of the present invention, includes fibers and filament yarns from vitreous melts of sodium, potassium and other silicates produced by the jet screen (filament yarns), bar screen (filament yarn and fiber) or the jet glass processes (fibers). The nonflammability of glass fibers, the high heat resistance, brittleness and the low wear resistance thereof are distinctive. They have a very high tensile strength, a low elasticity and are rotproof.
Mineral silicate fibers are mineral fibers obtained from melts of natural silicates or mixtures thereof with silicates, such as calcium, aluminum, or magnesium silicates. Mineral silicate fibers are very fine and smooth and have a spherical cross section and an amorphous structure. The thermal conductivity of mineral silicate fibers is low, they are incombustible, and, like glass, are resistant to all normally occurring chemical influences. Since the fibers cannot be spun solely, they are employed in the form of mats or similar forms mainly for high-temperature isolating purposes already in the art.
Ceramic fibers, within the
Bopp Michael
Enkler Michael Fred
HP-Chemie Pelzer Research and Development Ltd.
Hunton & Williams LLP
Juska Cheryl A.
Salvatore Lynda
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