WO1997010950A1

WO1997010950A1 - Energy absorbent interior trim for vehicle

Info

Publication number: WO1997010950A1
Application number: PCT/US1996/015044
Authority: WO
Inventors: Wayne C. Salisbury; Jeffrey H. Anderson
Original assignee: Textron Automotive Company Inc.
Priority date: 1995-09-20
Filing date: 1996-09-19
Publication date: 1997-03-27

Abstract

An energy absorbent headliner (10) assembly for a vehicle includes a layer of expanded, reticulated or open cell plastic material and a covering layer of reinforcing fiber either impregnated and/or saturated with a heat-activated liquid hardening compound/binder shaped to provide integrally formed, laterally spaced energy absorbing segments (24, 26) for protecting a passenger against side impacts.

Description

ENERGY ABSORBENT INTERIOR TRIM FOR VEHICLE

TECHNICAL FIELD This invention relates to headliners for a vehicle and more particularly to headliners made from layers of foam and fibers.

BACKGROUND OF THE INVENTION

In order to meet anticipated governmental requirements for added head impact protection, the automobile industry is modifying existing energy management foams and devices currently used for knee and side impact requirements to provide additional head impact protection above the belt line in the interior of a vehicle. Examples of such products are set forth in United States Patent Nos. 5,226,672 and 5,462,308 in which net or membrane type systems are used to cover a persons head following vehicle impact. An earlier proposal shown in United States Patent No. 3,953,049 discloses a inflatable bag type protector. Additionally, it is known to provide a block of energy absorbing material between a separately formed headliner and the vehicle frame.

Presently, interior trim molding used to cover most above belt line locations in a vehicle in the vicinity of a headliner therein do not respond to impact loading so as to absorb energy. Future Federal Safety Regulations are expected to require that such trim moldings be configured to absorb energy on impact to offer better impact protection to the occupants of the vehicle in the event of an accident. Overhead parts of a vehicle body between the front, mid and rear pillar posts of a vehicle are covered at the present time by headliners that do not have significant energy absorbent capabilities. While such arrangements have an aesthetic appeal they do not provide controlled energy absorption of kinetic energy through energy absorption.

While suitable for their intended purpose the prior art arrangements require excessive tooling, assembly labor and thus involve significant cost. They do not provide structure that includes integral portions thereon that are easily connected to vehicle bodies at overhead locations without the need for separate fasteners thereby to provide ease of assembly and precise location of an energy absorbing arrangement prior to installation of a decorative cover member while also having a layered configuration that will enable the energy absorbing component to be precast in a single mold operation.

SUMMARY OF THE INVENTION AND ADVANTAGES

The present invention involves making use of an improved process for forming a headliner having a decorative cover material and an energy management core with a preformed energy absorbing segment thereon that defines a connecting feature therein that can be fastened to a vehicle body while providing an improved energy absorbent structure to protect against head impact at overhead locations between the front, mid and rear pillar locations of a vehicle.

The resulting headliner requires no additional tooling than that presently used to manufacture headliners and does not require additional assembly labor to provide head impact protection features at an overhead location within the passenger compartment of a vehicle. It can also decrease the total thickness required to achieve certification under new standards since the headliner will include segments thereon that become part of the total energy management system within the passenger compartment.

The present invention addresses the problem of providing a connection of an energy absorbing component in a headliner assembly having a body member and a separate decorative cover member to a body member such as an overhead rail extending between the front and rear pillars of the vehicle. In the present invention the connection is provided by a preformed energy absorbing component that includes interposed layers of expanded, reticulated or open cell foam and reinforcing fiber that are impregnated with a reinforcing binder such that the are impregnated with a reinforcing binder such that the fibers will provide a high strength cover and the foam will provide an energy absorbing core that are molded in a single mold with the decorative cover to form a shaped configuration that can be secured in place without the need for fasteners while including an outer decorative cover.

In accordance with the present invention the headliner includes a ratio of thickness of a resin impregnated flexible foam layer and the thickness of the resin impregnated fiber material associated with the decorative cover thereon providing a premolded headliner that has a connection feature that will be joined to the vehicle body member to provide head impact energy absorption protection and a decorative outer appearance.

An object of the present invention is to provide a headliner for a vehicle providing energy absorption between a vehicle body member and a trim cover by use of a precast composite structure that includes layers of composite material that can be cast in a single mold to form a shaped configuration that can be secured in place without the need for fasteners while including an outer decorative cover and while providing energy absorption head impact protection.

A further feature of the present invention is to provide the aforesaid headliner for a vehicle providing energy absorption between a body member and a trim cover by a preformed composite structure that includes layers of polymeric foam and layers of fiber reinforcement impregnated by a heat-accelerated binder and a cover layer that provides a decorative appearance and the precast composite structure having laterally spaced energy absorbent segments that provide head impact protection.

A still further feature of the invention is to provide the aforesaid headliner for a vehicle providing energy absorption between a body member and a trim cover wherein the polymeric foam material is formed from expanded, reticulated or open cell plastic material such as polyether, polyolefin, polyester, polyurethane or any combination thereof and the reinforcing fibers are glass fibers or synthetic fibers such as Kevlar® or any other suitable like reinforcing fiber and wherein the reinforcing layers and foam layers are impregnated with a heat-accelerated liquid hardening compound/binder which enters and fills the cells of the foam coating the cell walls and also impregnating interstices in the reinforcing fiber layer.

A still further feature of the invention is to provide the aforesaid headliner for a vehicle providing energy absorption between a body member and a trim cover wherein at least one of the foam layers has a core weight in the range of .95-2 pounds/ft³; a concentration of MDI binder in the range of 400 grams to 900 grams/meter² and a glass fiber weight of 100-400 grams/meter².

Yet another feature of the invention is to provide the aforesaid headliner for a vehicle providing energy absorption between a vehicle body member and a trim cover wherein the preformed material includes two layers of foam.

Still another feature is to provide such a headliner wherein the two layers of foam have a layer of glass fibers formed therebetween.

Still another feature is to provide such a headliner wherein the glass fibers are woven glass fibers.

Still another feature of the present invention is to provide the glass fiber thickness from air deposited laid up non-woven fibers.

Yet another object of the present invention is to provide such headliners that include a matrix having different densities of foam and resin impregnated fiber material at different parts of the matrix.

Yet another object of the present invention is to provide such headliners wherein the preformed casting includes a decorative cover bonded to a layer of resin/binder impregnated glass fibers by an adhesive layer of heat meltable material such as polyester, polyamide, polyethylene, polypropylene and other olefins which melt or forms bonds during die molding of a preformed connection feature in the headliner.

Still another object of the present invention is to provide such a headliner wherein the preformed casting includes an exterior layer selected from thermoplastic materials such as polyvinyl chloride; thermoplastic polyurethanes; thermoplastic elastomers; thermoplastic olefins and blends of the aforesaid materials all of which can be premolded at the same time as the resin/binder is activated to reinforce the foam materials and fill the interstices of the reinforcing fiber layer.

A still further feature of the invention is to provide a method for making the aforesaid headliner for a vehicle providing energy absorption between a body member and a trim cover wherein a layer of decorative cover material is placed in a single mold tool along with a layer of reinforcing fiber and a layer of a polymeric foam material of expanded, reticulated or open cell plastic material such as polyether, polyolefin, polyester, polyurethane or any combination thereof and the reinforcing fibers are glass fibers or synthetic fibers such as Kevlar® or any other suitable like reinforcing fiber and wherein the reinforcing layers and foam layers are impregnated with a heat-accelerated hardening compound/binder which enters and fills the cells of the foam coating the cell walls and also impregnating interstices in the reinforcing fiber layer while the layered material is shaped by the mold either by compression or vacuum forming to have a desired energy absorbing thickness at preselected points therein while forming a connection feature on a resultant energy absorbent headliner for securement to a vehicle body part so as to protect the vehicle body part.

THE DRAWINGS Presently preferred embodiments of the present invention are disclosed in the following description and the accompanying drawings, wherein:

Figure 1 is a fragmentary perspective view of a motor vehicle headliner constructed in accordance with the present invention;

Figure IA is a fragmentary side elevational view of a passenger compartment showing a impact segment of a headliner including the present invention; Figure 2 is a sectional view taken along the line 2-2 of Figure 1 looking in the direction of the arrows;

Figure 3 is an enlarged sectional view taken along the line 3-3 of Figure 2 looking in the direction of the arrows; and

Figure 4 is an enlarged fragmentary cross- sectional view of a another embodiment of a headliner having a preformed composite energy absorbent interior of the present invention; Figure 5 is a fragmentary view of a passenger compartment showing a front pillar covered by another embodiment of the present invention; and

Figure 6 is a perspective view of an energy absorbent trim assembly in the embodiment taken along line 6-6 of Figure 5.

DETAILED DESCRIPTION

Figure 1 illustrates the use of the subject invention on a headliner 10 of a vehicle. It is to be appreciated that the invention may also be practiced on other interior components, such as a cover for pillar posts, headliners, side doors, consoles or other interior trim parts that have a decorative covered member supported on a vehicle body part or accessory.

As illustrated in Figure 1, the headliner 10 extends between the front pillars 12 and rear pillars 14 of the vehicle. As shown in Figure 2, the headliner 10 includes a core 16 of expanded, reticulated or open cell foam; a reinforcing layer 18 of fiber material and a decorative cover 20 all premolded together to form an integral unitary member that is impregnated with a reinforcing binder such that the fiber layer 18 will provide a high strength component and the foam core of expanded, reticulated or open cell foam will have the cell walls thereof coated by the reinforcing binder to provide an energy absorbing core. The decorative cover 20, foam core 16 and fiber layer 18 are placed in a single mold and are molded by compression forming or the like and the application of binder activating heat to form a shaped energy absorbent headliner 10 that can be secured in place without the need for fasteners while including an outer decorative cover. The amount of MDI material in the heat accelerated binder material is selected such that the headliner 10 can have sufficient flex to fit over the supporting pillars or other vehicle body parts for securing the headliner 10 in place at the preformed recesses 30, 32 therein.

In the illustrated embodiment, the headliner 10 has a greater cross-section at the sides thereof that define laterally spaced, integral side impact segments 24, 26 located above the belt line to provide side impact head protection along the full longitudinal extent from the front of the passenger compartment to the rear of the passenger compartment. Impact surfaces 27, 28 are formed on the outer decorative cover 20 along the full length of each of the impact segments 24, 26. Preformed side recesses 30, 32 are formed in the headliner 10 during the vacuum or compression form shaping step of the process of the present invention. The recesses have a shape suitable for fitting the headliner 10 on the adjacent pillars to completely cover such pillars with an energy absorbent headliner made up of the thickened sections within the premolded components of the headliner 10. The types of material suitable for such preforming are set-forth in copending United States Serial No. 08/446,027, filed May 19, 1995 and incorporated herein by reference. In one illustrative working embodiment a suitable cross-section would provide a thickness of material in the region of the impact segments 24, 26 in the range of 18mm to provide an adequate amount of energy absorbing fiber and foam core material when impregnated with the binder materials outlined in the aforesaid '027 patent. A preferred range of thickness at the impact segments 24, 26 is in the range of from 18-25mm. In such case, in order to fit geometric requirements of the headliner, the center segment 34 of the headliner 10 can have a thickness in the range of 4mm to 25mm with a preferred thickness of around 8 mm. By controlling the ratio of thickness of the foam core and the thickness of the reinforcing fiber layer the compressive strength and thus the energy management characteristics of the composite structure shown in Figure 1 may be adjusted.

As shown in Figure IA, the impact segments 24, 26 can be configured to have openings 33 therein at appropriate points therealong to accommodate headliner accessories such as hand grips and the like. Also, while the impact segments 24, 26 are shown along the sides of the headliner 10 they could be provided at the front and rear of the headliner in appropriate configurations.

The result was that certain combinations of binder, foam, and fiber thickness provided energy management properties similar to formulated energy managements foams such as set forth in United States Patent No.5,232,957. In the present invention, more conventional foam formulations such as are used in present day headliner constructions can be utilized in the formation of the foam core 16 so long a it is impregnated with suitable binder material as outlined herein. The process thus allows for the formation of energy management areas molded integrally into headliners or other interior trim parts.. The foam core 16 is reinforced by fiberglass layer 18 and the layers are impregnated with the heat accelerated binder during the single mold processing. The resultant energy absorbent headliner 10 is then secured against a vehicle body part such as a pillar of structural material, such as steel or metal by being fit thereon.

Existing tools may be utilized to form the subject assembly 10. An example of such tools is a single processing mold as shown in United States Patent No. 5,441,675 assigned to the assignee of this application and incorporated herein by reference.

Such a single mold tool allows use of a vacfor or press form process capable of molding vinyl or other thermoplastic decorative covers to be preloaded and covered by layers of foam and reinforcing fibers in a single mold. In particular, cloth, woven and nonwoven, nylon, polypropylene in the case of headliners and vinyl or vinyl blend decorative covers or decorative covers of other materials such as TPO, TPU and TPE can be used in the single mold process of the aforesaid '675 patent for other applications, including headliners. When the binder material is impregnated into the foam and fiber layers the part can be processed to result in the illustrated premolded integral energy absorbent headliner 10 of the present invention. The polymeric foam material is formed from expanded, reticulated or open cell plastic material such as polyether, polyolefin, polyester, polyurethane or any combination thereof and the reinforcing fibers are glass fibers or synthetic fibers such as Kevlar® or any other suitable like reinforcing fiber and wherein the reinforcing layers and foam layers are impregnated with a heat- activated liquid hardening compound/binder which enters and fills the cells of the foam coating the cell walls and also impregnating interstices in the reinforcing fiber layer.

While the present invention is best suited for forming large area composites such as headliners, Figure 5 illustrates a passenger compartment of an automotive vehicle 34 in which a frame 36 of the vehicle is shown extending about an adjacent window 38 and including an energy absorbent trim assembly 40 constructed according to the present invention. In the illustrated arrangement of Figure 6, the trim assembly 40 is associated with the upright front or A pillar 42 of the vehicle with it being understood that the invention is suitable for side rail components of the interior trim of a vehicle including but not limited to the window frame components and the upright back or B pillar portion . of the frame and interconnecting roof structure rails that extend between the upper ends of the A and B pillar portions all of which components are well known to those skilled in the art as including structural sections that will provide desired support and rigidity to the body sections of a motor vehicle. In the illustrated embodiment, the trim assembly 40 has the same general shape and configuration as the front A pillar 42 on which it is mounted and in the illustrated embodiment the headliner 40 includes a decorative trim cover 44 that is associated with an energy absorbent center 46 that is preformed by casting in a single mold. The preformed center 46 includes a foam core 48 covered by a layer of fiber 50 both impregnated with binder as in the case of the embodiment shown in Figures 1 and 2. The preformed center 46 and cover 44 have a preformed groove 35 therein that receives a flange 37 on the pillar 42. It will be appreciated that the groove 35 and flange 37 are merely representative of a premolded interconnection feature that can be secured to a vehicle body part. In other cases the feature can have a cross-section that will vary from a channel shape as shown to a curved hole; a V-shaped hole or other interconnection that can be either molded integrally of or adhesively connected to the inner surface 56 of the cover 44. In accordance with one principle of the present invention, the energy absorbent trim assembly 40 includes a premolded composite center that has layers of polymeric foam and layers of fiber reinforcement connected by adhesive layers. More specifically as shown in Figure 3, the energy absorbent material making up either the headliner or the pillar post cover includes a foam core 48 of expanded, reticulated or open cell foam; and a reinforcing fiber layer 50 of fiber material to form an integral unitary member that is impregnated with a reinforcing binder such that the fiber layer 50 will provide a high strength component and the foam core of expanded, reticulated or open cell foam will have the cell walls thereof coated by the reinforcing binder to provide an energy absorbing center comprised of the material types previously set-forth in the embodiment of Figures 1 and 2. In the Figure 3 embodiment, the cover 44 is adhered to the fiber layer 50 by a layer 52 of adhesive. In the case of a preformed energy absorbing headliner 40 in which the cover 44 is preloaded into a single mold and preformed therein the adhesive layer can be a layer of heat meltable thermoplastic material such as polyester, polyamide, polyethylene, polypropylene and other olefins which melt or forms a bond during die molding of a preformed connection feature in the headliner. As shown in the embodiment of Figure 4, another embodiment of an energy absorbent headliner 60 is shown connected to a pillar 62. In this embodiment a center 65 is formed by a plurality of foam layers 64, 66 of different thicknesses are formed on either side of a layer of fiber 68 all of which are impregnated with a binder of the type previously described. A base support layer shown as a layer of SCRIM 70 is provided over a second layer 72 of reinforcing fiber and connected thereto by a layer of adhesive 74. In the embodiment of Figure 4, the fiber layers 68, 72 can be formed from of either woven or chopped fibers of a suitable material εuch as glass fibers, or a high strength fiber material such as carbon with the compressive characteristics of the foam in layers 64, 66 to provide a desired deformation and energy absorption protection over the pillar post configuration. The materials used in the cover and center will depend upon a particular application. However, in many cases the cover can be formed of a suitably formed thermoplastic material such as thermoplastic urethane or thermoplastic polyvinyl chloride or alloys of same backed by the foam layer 64. Alternatively, thermoplastic materials such as ABS or polycarbonates can be used for a base layer 70 for the foam material and for defining the connection groove on the core foam 10. In the aforesaid embodiments a preferred working embodiment includes a foam core have a weight in the range of .95-2 pounds/ft³; a concentration of MDI binder in the range of 400grams to 900 grams/meter² and a glass fiber weight of 100-400 grams/meter². These are merely representative of one suitable range of constituents and the invention encompasses the ranges of variation set forth in copending United States Serial No. 08/446,027.

The foam layer can be polyurethane foam or urea foam having a specific gravity in the range of .05- .2 and an initial load deflection, ILD, of 20-80 psi.

The invention has been described in an illustrative manner with respect to presently preferred embodiments, and it is to be understood that the terminology that has been used is intended to be in the nature of words of description rather than words of limitation. Obviously, many modifications and variations of the present invention in light of the above teachings nature of words of description rather than words of limitation. Obviously, many modifications and variations of the present invention in light of the above teachings may be made. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically shown and described.

Claims

What is claimed is:

1. An energy absorbent assembly for a vehicle providing energy absorption between a vehicle body member and a decorative trim cover comprising a composite structure that includes a layer of polymeric foam material with open cell walls formed from expanded, reticulated or open cell plastic material such as polyether, polyolefin, polyester, polyurethane or any combination thereof; a reinforcement layer(s) of glass or synthetic fibers; a heat accelerated liquid hardening compound/binder coating said cell walls and impregnating interstices in said the reinforcing fiber layer.

2. An energy absorbent assembly for a vehicle providing energy absorption between a body member and a trim cover as set-forth in claim 1 further comprising: said precast composite structure comprising a laminated layer of flexible polymeric foam and a layer of resin impregnated reinforcing fibers.

3. An energy absorbent assembly for a vehicle providing energy absorption between a body member and a trim cover as set forth in claim 2 wherein said foam layer is formed from either polyurethane foam or urea foam having a specific gravity in the range of .05-.2 and an initial load deflection ILD of 20-80 psi.

4. The energy absorbent assembly of claim 1 wherein a layer of reinforcing fibers is formed on opposite faces of said foam layer.

5. The energy absorbent assembly of claim 1 wherein the laminated layers include two foam layers one of which directly underlies the trim cover and the other of which is spaced from said one layer by a layer of reinforcing fibers.

6. An energy absorbent assembly for a vehicle providing energy absorption between a body member and a trim cover as set-forth in claim 5 wherein said foam layers are formed from a flexible polyurethane foam having a specific gravity in the range of .05-.2 and an ILD of 20-80 psi.

7. An energy absorbent assembly for a vehicle providing energy absorption between a body member and a trim cover as set-forth in claim 1 wherein the precast composite structure is a laminate having a separate polymeric cover; and a layer of adhesive bonding said polymeric cover to said precast composite structure.

8. An energy absorbent assembly for a vehicle providing energy absorption between a body member and a trim cover as set-forth in claim 4 wherein the composite structure is a laminate having a separate polymeric cover and having a separate scrim backing layer; and a layer of adhesive bonding said cover to said precast composite structure and a second layer of adhesive bonding said scrim backing layer to said composite structure.

9. An energy absorbent assembly for a vehicle providing energy absorption between a body member and a trim cover as set-forth in claim 7 wherein said layer of adhesive is a layer of heat meltable material such as polyester, polyamide, polyethylene, polypropylene and other olefins which melt or forms bonds during die molding of a preformed connection feature in the headliner.

10. An energy absorbent assembly for a vehicle providing energy absorption between a body member and a trim cover as set-forth in claim 8 wherein said layers of adhesive are layers of heat meltable material such as polyester, polyamide, polyethylene, polypropylene and other olefins which melt or forms bonds during die molding of a preformed connection feature in the headliner.

11. An energy absorbent headliner for a vehicle providing energy absorption between a body member and a decorative trim cover comprising a composite headliner that includes a layer of polymeric foam material with open cell walls formed from expanded, reticulated or open cell plastic material such as polyether, polyolefin, polyester, polyurethane or any combination thereof; a layer of reinforcing fibers of glass fibers or synthetic fibers; a heat accelerated liquid hardening compound/binder coating said cell walls and impregnating interstices in said the reinforcing fiber layer and an enlarged side segments thereon forming energy absorbing segments overlying the upper side rails of the vehicle.

12. An energy absorbent headliner for a vehicle providing energy absorption between a body member and a trim cover as set forth in claim 2 wherein said foam layer is formed from either polyurethane foam or urea foam having a specific gravity in the range of .05-.2 and an initial load deflection ILD of 20-80 psi.

13. The energy absorbent headliner of claim 1 wherein a layer of reinforcing fibers is formed on opposite faces of said foam layer.

14. An energy absorbent headliner for a vehicle providing energy absorption between a vehicle body member and a decorative trim cover as set forth in claim 11 further comprising a headliner having energy absorbing segments with a thickness of material in the range of 18mm to 25mm and a center thickness in the range of 4mm to 25mm.