Vehicle interior panel for use over airbag and method of manufacturing same

Abstract

The invention relates to a vehicle interior trim panel for use over an airbag and a method of manufacturing the same. The vehicle interior trim panel includes a reinforcement layer overmolded with a molding material during a substrate molding operation. The base molding tool includes an extendable and retractable slide configured to clamp opposite edge portions of the reinforcement layer to a clamping surface of the tool to secure the reinforcement layer in a cavity of the molding tool to prevent undesired movement of the layer when subjected to high pressure and high viscosity molding material while filling the mold cavity. Opposite edge portions of the reinforcement layer are disposed along separate blocks of the layer and / or along one or more openings formed through the layer.

Description

Technical Field

[0001] The present disclosure generally relates to vehicle interior panels, and more particularly to vehicle interior panels configured for use above a deployable airbag. Background Art

[0002] Vehicle interior panels that conceal an airbag module from view are often constructed to separate along tear seams to form one or more airbag doors that pivot away from the peripheral portion of the panel during a crash event to allow the deployed airbag to pass through the panel and into the vehicle passenger compartment. Several devices have been proposed for ensuring that the airbag door does not detach from the panel during airbag deployment, including hinge reinforcements.

[0003] Co-owned U.S. Patent No. 9,010,799 to Hagl describes a hinge reinforcement that can be molded into the substrate of such a panel by supporting the hinge reinforcement in a mold cavity using pins that extend through openings formed in the hinge reinforcement material. One practical problem with the Hagl process is the unwanted movement of the hinge reinforcement during the molding process. High injection pressures and flow gradients within the mold cavity can cause the hinge reinforcement to move out of position away from the support pins and, in some cases, to wrinkle or fold back on itself, reducing the bond strength between the molding material and the hinge reinforcement material. Summary of the Invention

[0004] An embodiment of a method of manufacturing a vehicle interior panel for use above an airbag includes filling a mold cavity of a molding tool with a molding material to form a panel substrate while opposing edge portions of a flexible reinforcement layer are clamped in the molding tool. A portion of the reinforcement layer is overmolded with the molding material and embedded in the airbag door region of the panel.

[0005] An embodiment of the method includes the features of the previously listed embodiment, and the flexible reinforcement layer includes separate first and second pieces, each piece providing one of the opposing edge portions. A portion of the first piece is embedded in a first airbag door of the panel, and a portion of the second piece is embedded in a second airbag door of the panel that is opposite the first airbag door.

[0006] An embodiment of the method includes the features of any of the previously listed embodiments, and the molding tool includes a slider. The embodiment includes clamping the opposing edge portions of the reinforcement layer between the slider and a clamping surface of the molding tool prior to the step of filling the mold cavity. The slider defines a portion of the molding surface that bounds the mold cavity.

[0007] An embodiment of the method includes the features of the previously listed embodiments, and the slider is configured to prevent undercutting of the molding material.

[0008] One embodiment of the method includes the features of any of the previously listed embodiments, and the molding tool includes a slider. This embodiment includes positioning the opposing edge portions between the head of the slider and the clamping surface of the molding tool when the molding tool is in the open state and the slider is in the extended position. This embodiment further includes clamping the opposing edge portions between the head of the slider and the clamping surface of the molding tool by moving the slider to the retracted position before the filling step.

[0009] One embodiment of the method includes the features of the previously listed embodiments, and before and after the positioning step, the distance between the edge portions is less than the width of the head of the slider, such that the edge portions are in sliding contact with the head of the slider during the positioning step and before the clamping step.

[0010] One embodiment of the method includes the features of either of the two previously listed embodiments, and the clamping side of the head of the slider tapers away from the cavity side of the head of the slider.

[0011] One embodiment of the method includes the features of any of the previously listed embodiments, and the edge portions are defined along an opening formed through the reinforcement layer.

[0012] One embodiment of the method includes the features of any of the previously listed embodiments, and the edge portions are defined along a slit formed through the reinforcement layer.

[0013] One embodiment of the method includes the features of any of the previously listed embodiments, and the edge portions are defined along an opening formed through the reinforcement layer, the reinforcement layer including a slit and an orifice positioned along the slit.

[0014] One embodiment of the method includes the features of any of the previously listed embodiments, and the reinforcement layer is provided as a single piece.

[0015] One embodiment of the method includes the features of any of the previously listed embodiments, and the entire length of each edge portion is clamped in the molding tool during the filling step.

[0016] One embodiment of the method includes the features of any of the previously listed embodiments, and each edge portion extends away from the dorsal side of the airbag door area of the panel and is free of molding material.

[0017] One embodiment of the method includes the features of any of the previously listed embodiments and further includes, prior to the filling step: positioning a flexible reinforcement layer between a first tool part and a second tool part of a molding tool, wherein the molding tool is in an open state, wherein the slider is in an extended position and the opposing edge portions are aligned with the slider; moving the reinforcement layer and the first tool part relative to each other until the edge portions are located between the head of the slider and the clamping surface of the first tool part; retracting the slider towards the clamping surface to a retracted position such that the edge portions are clamped between the head of the slider and the clamping surface; moving the first tool part and the second tool part towards each other to change the molding tool to a closed state to form a mold cavity; and removing the panel substrate from the molding tool after the filling step.

[0018] One embodiment of the method includes the features of the previously listed embodiments and the distance between the edge portions before and after step (b) is less than the width of the head of the slider such that the edge portions: bend away from the first tool part during step (b), bend towards the first tool part during step (c), and bend towards the first tool part during step (e).

[0019] One embodiment of an automotive interior panel for use above an airbag includes a panel substrate formed of a molding material and a flexible reinforcement layer. A portion of the reinforcement layer is overmolded with the molding material and embedded in the airbag door region of the panel. The opposing edge portions of the flexible reinforcement layer are free of molding material.

[0020] One embodiment of an automotive interior panel includes the features of the previously listed embodiments and the entire length of each edge portion is free of molding material.

[0021] One embodiment of an automotive interior panel includes the features of any of the previously listed embodiments and includes an H-shaped tear seam that defines an area range of the airbag door region.

[0022] One embodiment of an automotive interior panel includes the features of any of the previously listed embodiments and the opposing edge portions extend along the back sides of the opposing airbag doors of the panel.

[0023] One embodiment of an automotive interior panel includes the features of any of the previously listed embodiments and another portion of the reinforcement layer is overmolded with the molding material and embedded in the walls of the chute of the panel substrate.

[0024] One embodiment of an automotive interior panel includes the features of any of the previously listed embodiments and is manufactured according to the method of any of the previously listed embodiments.

[0025] Except in the case of feature incompatibilities, any number of the individual features of the above-described embodiments and any other embodiments reflected in the following claims, drawings, or description can be combined in any combination to define the invention claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Exemplary embodiments will be described below with reference to the following drawings, in which like numbers represent like elements, and in which:

[0027] Figure 1 is a perspective view of a portion of the interior of a vehicle including an interior vehicle panel for use above an airbag;

[0028] Figure 2 is Figure 1 a cross-sectional view of the trim panel of

[0029] Figure 3 is a schematic cross-sectional view depicting opposite edge portions of a flexible reinforcement layer aligned with a slider of a molding tool;

[0030] Figure 4 depicts Figure 3 the reinforcement layer of

[0031] Figure 5 moving past the head of the slider; Figure 4 the reinforcement layer of

[0032] Figure 6 depicts molding material filling Figure 5 the cavity of the molding tool of

[0033] Figure 7 depicts Figure 6 the molding tool of

[0034] Figure 8 changing to an open state and the slider moving to an extended position; Figure 7 the molding tool of

[0035] Figure 9 is a perspective view depicting the reinforcement layer positioned between the slider and a portion of the molding tool as in Figure 4 ;

[0036] Figure 10 is a perspective view depicting opposite edge portions of an opening in a one-piece reinforcement layer aligned with a slider of a molding tool;

[0037] Figure 11 depicts Figure 10 the reinforcement layer of after moving past the head of the slider;

[0038] Figure 12 is an isometric view depicting opposite edge portions of an opening in a one-piece reinforcement layer aligned with corresponding sliders of a molding tool;

[0039] Figure 13 is Figure 2 an enlarged view of one of the openings in the reinforcement layer of;

[0040] Figure 14 depicting the Figure 12 reinforcement layer after moving past the head of the corresponding slider; and

[0041] Figure 15 depicting the Figure 14 slider after moving to the retracted position. DETAILED DESCRIPTION

[0042] A vehicle interior panel for use above an airbag and related methods are described below. The panel includes an embedded reinforcement layer that can be overmolded with molding material during a substrate molding operation. The molding tool can be equipped with sliders configured to secure the reinforcement layer within the cavity of the molding tool in a manner that prevents undesired movement of the layer when subjected to high pressure and high viscosity molding material during injection.

[0043] Figure 1 is a perspective view of the front portion of a vehicle passenger compartment equipped with a vehicle interior panel 10. An inflatable airbag is mounted behind the panel 10, and the panel has a tear seam 12 along which the panel separates during airbag inflation and deployment. The tear seam 12 is defined along one or more lines along which the panel 10 is intentionally weakened. This weakening can be in the form of perforations, locally thinned material, notches, or other stress concentrators included in one or more layers of the panel. The illustrated panel 10 is a dashboard or instrument panel, and the tear seam 12 is H-shaped, and the area of the H shape defines an airbag door region 14.

[0044] Figure 2 is a cross-sectional view of the panel 10 taken along a central plane A of the airbag door region 14, the central plane A being the Figure 1 x-z plane in Figure 2 that passes through and is parallel to the crossbars of the H shape of the tear seam 12. During airbag deployment, the airbag inflation force causes the panel 10 to separate along the tear seam 12, and a pair of opposing airbag doors 16a, 16b pivot or otherwise move outwardly away from the peripheral portion of the panel along corresponding hinges 18a, 18b, as Figure 2as shown by the dashed line in. Although illustrated in the context of the instrument panel 10 and the H-shaped tear seam 12, the structures and methods described below are applicable to other vehicle interior panels (e.g., door panels, steering wheel panels, pillar panels, seat panels, etc.) and to other tear seam shapes (e.g., U-shaped, Y-shaped, X-shaped, asymmetric shapes, etc.). The crossbar of the H shape does not need to be perpendicular to the uprights of the H shape.

[0045] The illustrated panel 10 is a multi-layer panel that includes a panel substrate 20, a decorative cover 22, and a flexible reinforcement layer 24. The panel substrate 20 can be formed from a polymer-based material (e.g., glass-filled polypropylene, TPO, TPE) in a molding operation and provides the overall shape and structure of the finished panel 10. The decorative cover 22 provides the outer surface of the panel 10 that faces the interior of the vehicle cabin when installed in the vehicle. The illustrated decorative cover 22 is a two-layer component that includes a decorative outer layer 26 (e.g., a polymer film or leather) and an intermediate layer 28 (e.g., foam or spacer fabric) between the substrate 20 and the outer layer.

[0046] The tear seam 12 in this example includes notches formed along the back side of the substrate 20. Although not shown here, the decorative cover 22 may also include stress concentrators along the tear seam 12. Alternatively or in addition, the substrate 20 may include perforations or through openings along the opposite edges 30a, 30b of the airbag doors 16a, 16b, and the opposite edges 30a, 30b are positioned along the central plane A of the airbag door area 14. The opposite edges 30a, 30b are the leading edges of the airbag doors 16a, 16b during airbag deployment and are positioned along the side of each airbag door opposite the respective hinge 18a, 18b. This is only one example of a vehicle interior panel 10 for use above an airbag. In other configurations, the panel 10 is a plug-in airbag module or a bottom airbag module attached to the outside or inside of a surrounding panel along an airbag deployment opening that aligns with the airbag door area 14. The decorative cover 22 is optional and may be a single layer or a backfilled outer layer in other examples.

[0047] The panel base 20 includes a body 32 and a chute 34. The body 32 provides the profile of the panel that lies beneath and directly supports the decorative cover 22. The chute 34 is formed by one or more walls extending away from the backside of the body 32 and at least partially surrounds the airbag door area 14. The illustrated chute 34 is integrally molded with the body 32 as a single piece and is configured to constrain and guide the deployed airbag toward the deployment opening when the tear seam 12 splits and the airbag doors 16a, 16b open. The illustrated panel base 20 also includes a network of reinforcing ribs 36 along the backside of the airbag door area 14 and the airbag doors 16a, 16b. The ribs 36 can be overmolded onto the reinforcement layer 24 in the same molding operation as the body 32 and the chute 34.

[0048] The reinforcement layer 24 is at least partially embedded in the airbag door area 14 of the panel 10, and more specifically, in the material of the panel base 20. The reinforcement layer 24 serves as a tether and is intended to prevent the airbag doors 16a, 16b from separating from the remainder of the panel 10 during airbag deployment, i.e., the reinforcement layer 24 strengthens the hinges 18a, 18b. The reinforcement layer 24 can be of any suitable material and construction and can be referred to as a flexible reinforcement layer, which indicates that the force required to bend the sheet layer 24 out of plane is negligible compared to the force required to bend the base 20 in which the sheet layer 24 is embedded.

[0049] The flexible reinforcement layer 24 can be in the form of a fabric or a film. The fabric reinforcement layer 24 can be woven or non-woven and can have little to no bending modulus - for example, it cannot extend horizontally while supporting its own weight. The fabric can be made of or include natural and / or synthetic fibers (e.g., nylon or other polymers, glass, metal, or carbon fibers) that provide the reinforcement layer with a tensile strength greater than that of the material of the base 20. The film reinforcement layer 24 can be a polymer film or a metal foil. In a specific embodiment, the reinforcement layer 24 is a mesh including fibers (e.g., polyester or aramid) oriented in multiple planar directions and having openings into which the overmolded base material can flow. The reinforcement layer 24 can include a polymer coating on the film or fibers that is configured to enhance the bond between the reinforcement layer and the base material.

[0050] In the illustrated example, the reinforcement layer 24 includes separate first and second pieces 24a, 24b associated with the respective airbag doors 16a, 16b. Each piece 24a, 24b of the illustrated reinforcement layer 24 includes a first portion 38 embedded in the respective airbag door 16a, 16b, a second portion 40 embedded in the wall of the chute 34, a third portion 42 interconnecting the first and second portions at the respective hinge 18a, 18b, and edge portions 44a, 44b that are not embedded in the panel base 20.

[0051] The first portion 38 of each piece of the reinforcing layer 24 extends along the entire width W1 of the back side of the corresponding air bag door 16a, 16b and spans the length L1 ( Figure 1 ) at least a majority and up to about 95% of the total weight of the base 20. While in this example, the second portion 40 of each piece of the reinforcement layer 24 is embedded in the runner 34, it may be embedded in or otherwise attached to a frame or other portion of the body 32 of the base 20.

[0052] The edge portions 44a, 44b extend from and along the back side of the air bag door area 14 and are spaced from each other across a center plane A across the area and along the Figure 2 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12. The tear seam 12 is a cross-sectional view of the tear seam 12.

[0053] Figures 3 to 8 A vehicle interior panel 10 (such as a Figure 1 and Figure 2 The method may generally include filling a mold cavity of a molding tool 100 while edge portions 44a, 44b of the reinforcement layer 24 are clamped in the tool. It should be understood that Figures 3 to 8 The molding tool 100 is schematic in nature, and may include features not shown, such as cooling channels, ejector pins, vents, other slides or lifts, and / or may be part of a larger system including a molding press and other machines (e.g., a robot) that interact with the system.

[0054] Figure 3A cross-sectional view of a base molding tool 100 that includes first and second tool portions 102, 104 and a slider 106 associated with the first tool portion. At least one of the first and second tool portions 102, 104 is movable toward and away from the other to change the tool 100 between the illustrated open state and closed state, in which the opposite faces of the tool portions 102, 104 are separated in the open state and in contact under the force of a molding press in the closed state. Figure 3 The portion of the molding tool 100 depicted in corresponds to the position of the central plane A of the base panel 20 to be molded, i.e., the positions of the opposite edges 30a, 30b of the airbag doors 16a, 16b that form the finished panel base 20. The slider 106 is movable relative to the first tool portion 102 between the extended and retracted positions as Figure 3 shown. The slider movement is uniaxial in the same direction as the relative movement of the tool portions 102, 104 (back and forth movement in the Figure 3 z-direction of ). No part of the slider moves in any other direction.

[0055] The slider 106 includes a body 108, a head 110, and a neck 112 interconnecting the body and the head. The body 108 and the neck 112 are guided along the inner surface of the first tool portion 102 during slider movement. The maximum width W2 of the head 110 of the slider 106 is greater than the maximum width of the neck 112. The head 110 has a front or cavity side 114 facing the second tool portion 104 and an opposite rear or clamping side 116 facing the first tool portion 102. The clamping side 116 tapers from the maximum width W2 in a direction away from the second tool portion 104 to the narrower neck 112. The first tool portion 102 includes a clamping surface 118 shaped complementary to the clamping side 116 of the head 110 of the slider 106.

[0056] An embodiment of the method includes positioning a flexible reinforcement layer 24 between the first and second tool portions 102, 104 of the molding tool 100, where the molding tool is in the open state and the slider 106 is in the extended position, as Figure 3 shown. In this case, the reinforcement layer 24 includes separate first and second pieces 24a, 24b. The reinforcement layer 24 is positioned between the head 110 of the slider 106 and the second tool portion 104, where the edge portions 44a, 44b of the reinforcement layer are aligned with the slider 106 and face each other across a gap (i.e., face each other). The distance D across the gap and between the opposite edge portions 44a, 44b is less than the width W2 of the head 110 of the slider 106. As Figure 3As shown, the reinforcement layer 24 can be manually supported, for example, via other machinery (such as a pick-and-place machine) between the tool parts 102, 104, or on horizontally extending pins.

[0057] Referring Figure 4 , at least one of the reinforcement layer 24 and the first tool part 102 then moves towards the other. The illustrated movement is a translational movement in the same direction as the relative movement of the tool parts 102, 104. The reinforcement layer 24 can be translated, for example, by the same person or equipment that supports the reinforcement layer 24 in Figure 3 or by a component of the second tool part 104 towards the first tool part 102. The reinforcement layer 24 continues to move until the opposite edge portions 44a, 44b are located between the head 110 of the slider 106 and the clamping surface 118 of the first tool part. During this movement, since the distance D is less than the width W2 of the head 110 of the slider 106, the edge portions 44a, 44b are temporarily in sliding contact with the head of the slider and bend away from the first tool part 102, as shown by the dashed lines in Figure 4 . Before the movement stops, the reinforcement layer 24 can contact the surface of the first tool part 102.

[0058] Referring Figure 5 , the slider 106 then moves relative to the first tool part 102 to the retracted position. In the retracted position, the opposite edge portions 44a, 44b of the reinforcement layer 24 are clamped between the clamping surface 118 of the first tool part 102 and the clamping side 116 of the head 110 of the slider 106. This movement again causes the edge portions 44a, 44b to contact the head 110 of the slider 106, such that the clamping side 116 of the head of the slider bends the edge portions of the reinforcement layer 24 towards the first tool part 102. If necessary, once the slider 106 retracts, the previous support for the reinforcement layer can be withdrawn or removed.

[0059] Referring Figure 6 , the molding tool 100 changes to the closed state to form the mold cavity 120. The relative movement of the opposite tool parts 102, 104 towards the closed state can at least partially overlap in time with the movement of the slider 106 towards the retracted state. The mold cavity 120 is defined by the molding surfaces of the first tool part 102, the second tool part 104, and the slider 106. More specifically, the surface of the cavity side 114 of the slider 106 defines a part of the molding surface that defines the mold cavity 120. A part of the reinforcement layer 24 is located within the mold cavity 120, and the opposite edge portions 44a, 44b are excluded from the mold cavity.

[0060] Then, the molding material 122 is introduced into the mold cavity 120 and fills the mold cavity 120, thereby overmolding that portion of the reinforcing layer 24 within the mold cavity. Notably, the slider 106 and the molding tool 100 are configured such that no undercut condition is formed along the slider relative to the molding material 122. In embodiments where the reinforcing layer 24 includes a relatively soft coating (e.g., plastisol), the reinforcing layer 24 can enhance the seal formed at the interface where the first tool portion 102, the slider 106, and the reinforcing layer meet.

[0061] Although not explicitly shown herein, the first tool portion 102 can provide an additional molding surface that defines the mold cavity 120 on the opposite side of the reinforcing layer 24 to form, for example, Figure 2 a network of ribs 36 such that a portion of the cavity 120 is on two opposite faces of the reinforcing layer and the reinforcing layer is overmolded on both sides. The slider 106 can also have additional features, such as one or more protrusions to form Figure 2 a portion of the tear slit 12. As Figure 2 shown, in embodiments where the second portion 40 of each piece 24a, 24b of the reinforcing layer is to be embedded in the chute 34 of the panel substrate 20, the reinforcing layer 24 can be preformed such that the ends opposite the edge portions 44a, 44b fit into cavity portions defined in the first tool portion 102 for overmolding.

[0062] Referring to Figure 7 , after the molding material 122 has sufficiently cooled or cured, the tool portions 102, 104 move away from each other toward the open state of the molding tool 100. Additionally, the slider 106 moves backward toward the extended position. These two relative movements can overlap in time, or the tool 100 can be in the open state before the slider 106 moves toward the extended position. During at least a portion of the movement of the slider 106 toward the extended position, the molded panel substrate 20 remains in contact with the slider 106 to effectively release the edge portions 44a, 44b from the first tool portion. The slider movement can be coordinated with the movement of the mold opening pins of the molding tool 100.

[0063] Referring to Figure 8, once the head 110 of the slider 106 is sufficiently spaced from the first tool part 102 and / or the first and second tool parts 102, 104 are sufficiently spaced apart, the molded panel substrate 20 can be separated from the slider 106. This can be achieved by the continued protrusion of the ejector pins of the molding tool 100, the stripper plate, and / or the partial backward movement of the slider 106 towards the retracted position. During the separation of the panel substrate 20 from the slider 106, the opposite edge portions 44a, 44b of the reinforcement layer 24 again interfere with the head 110 of the slider and further bend towards the first tool part 102. When the edge portions 44a, 44b are on the clamping side 116 of the head 110 of the slider 106 during the molding of the panel substrate 20, due to the flexibility of the reinforcement layer 24, they easily pass over the head of the slider after molding.

[0064] Figure 9 is a schematic isometric view depicting a part of the first tool part 102 of the molding tool 100. Only the necessary portions of the faces of the first tool part 102 are shown here. Figure 9 The element 126 of which represents a part of the mold cavity 120 in which the chute 34 of the panel substrate 20 is formed. The airbag door area 14 of the finished panel is thus defined at the inner periphery of this part 126 of the mold cavity provided by the first tool part 102. Although not shown here, the reinforcement layer 24 can be folded or preformed such that its ends are received by this part 126 of the mold cavity for overmolding.

[0065] The molding tool 100 and the two-piece reinforcement layer 24 are shown in Figure 4 in their relative positions - this is after the reinforcement layer has moved towards the first tool part 102 and beyond the head 110 of the slider 106 but before the slider moves to Figure 5 its retracted position. In this example, the cavity side of the head 110 of the slider 106 is illustrated as gradually decreasing from its widest point at W2 to a vertex 124, which is located at Figure 2 the boundary of the opposite edges 30a, 30b of the corresponding airbag doors 16a, 16b. When the reinforcement layer 24 moves from its initial position between the first and second tool parts towards the first part 102 of the molding tool 100, this vertex 124 of the slider 106 can also be used as an introduction end.

[0066] As shown here, the entire length L2 of the opposing edge portions 44a, 44b is positioned to be clamped between the head 110 of the slider 106 and the clamping surface 118 of the first tool portion 102. The length L2 of the reinforcement layer 24 is less than the length L3 of the slider 106. This ability to clamp and thereby fix the entire edge portions 44a, 44b of the reinforcement layer 24 ensures that the reinforcement layer remains in the desired position within the mold cavity 120 and within the finished panel substrate 20 and the finished vehicle interior panel 10. Additionally, this secure fixation of the reinforcement layer 24 within the mold cavity 120 provides a much larger panel molding process window. In other words, without clamping the reinforcement layer within the molding tool 100, process parameters such as injection pressure, melt temperature, coolant temperature, etc. must be closely monitored and cannot be changed much without causing undesired movement of the reinforcement layer 24 within the mold cavity 120. In such a case, the processing parameters cannot be adjusted to address other issues such as short shots, sink marks, or dimensional variations without causing problems with reinforcement layer movement.

[0067] Figure 10 and Figure 11 A variation of the above process is shown where the reinforcement layer 24 is a single piece having an opening 48 formed through its thickness. In this example, the opening 48 is in the form of a slit that is completely contained within the outer perimeter of the reinforcement layer 24. The length L2 of the reinforcement layer 24 is greater than the length L3 of the slider 106, and the length L4 of the slit 48 is less than the length L2 of the reinforcement layer 24 but greater than the length L3 of the slider 106. In this case, the opposing edge portions 44a, 44b are placed along the slit 48 such that when the reinforcement layer 24 is initially positioned between the first and second tool portions 102, 104 of the molding tool, the distance between the opposing edge portions 44a, 44b measured in the same direction as the width W2 of the head of the slider 106 is effectively 0. In some embodiments, the slit 48 is replaced by an orifice (e.g., a rectangular opening) formed where material has been removed from the reinforcement layer 24. The orifice may have a length L4 that is less than the length L2 of the reinforcement layer, where the edge portions 44a, 44b are spaced apart by a non-zero distance D, similar to Figure 3 .

[0068] In either case, the process can be carried out in the same manner as Figures 3 to 8 . The reinforcement layer 24 is positioned between the extended slider 106 and the second tool portion 104, where the molding tool is in the open state as in Figure 10 , where the opening 48 is aligned with the slider 106. The reinforcement layer 24 is then moved towards the first tool portion 102 until the edge portions 44a, 44b are located between the head 110 of the slider and the first tool portion, as in Figure 11As shown. As in the previous example, the opposing edge portions 44a, 44b slidably contact the head 110 of the slider 106 and bend toward the second tool portion 104 during this movement. The additional length L4 of the slit 48 relative to the length of the slider 106 allows the slit to open wide enough for the head 110 of the slider to pass through. At this time, the distance between the edge portions 44a, 44b is equal to the width W3 of the neck 112 of the slider 106. The slider 106 then retracts to bend the edge portions 44a, 44b toward the first tool portion 102 and clamp them there, the molding tool 100 is closed, and molding material is introduced into the mold cavity to form the panel substrate 20.

[0069] Figures 12 to 15 Depicts another variation of the above process, where the reinforcement layer 24 is a single piece having a plurality of openings 48 formed through the thickness of the reinforcement layer and completely contained within the perimeter of the reinforcement layer. Referring to Figure 12 , each opening 48 is positioned away from the central plane A of the panel substrate to be molded and includes both an orifice 50 and a slit 52, the orifice 50 being defined where material has been removed from the reinforcement layer and the slit 52 being defined through the reinforcement layer without removing material. The molding tool 100 includes a corresponding plurality of sliders 106 associated with the first tool portion 102. Each of these sliders 106 is similar to a partial longitudinal segment of the slider in the previous figures. Here, the respective lengths L3, L4 of each slider 106 and each opening 48 are Figure 10 and Figure 11 fractions of the lengths in

[0070] and are approximately equal to each other. Figure 13 Also referring to Figure 12 , the distance D between the opposing edge portions 44a, 44b of the reinforcement layer 24 is approximately equal to the width W3 of the neck 112 of each slider 106 ( Figures 3 to 8 ), and is less than the maximum width W2 of the head 110 of each slider, as in the example of

[0071] The process can be carried out in substantially the same manner as those depicted in Figures 3 to 8 and Figures 9 to 11 . The reinforcement layer 24 is initially positioned between the second tool portion (not shown) and the sliders 106, each opening 48 and its corresponding edge portions 44a, 44b are aligned with a corresponding one of the sliders, and the sliders are in Figure 12is in the extended position. The reinforcement layer 24 then moves towards the first tool part 102 until the edge parts 44a, 44b are located between the heads 110 of the respective sliders 106 and the first tool part, as Figure 14 shown. As in the previous example, the opposite edge parts 44a, 44b are in sliding contact with the heads 110 of the sliders 106 and bend towards the second tool part 104 during this movement. The additional distance D2 between the ends of each slit 52 relative to the distance D between the opposite edge parts 44a, 44b allows each edge part to temporarily separate along the slit 52 by enough for the head 110 of the slider to pass through. Thus, half of each opposite edge part 44a, 44b of the reinforcement layer 24 slides across the opposite corners of the head 110 of the slider 106 and bends away from the first tool part 102 as the layer moves past the head.

[0072] As Figure 15 shown, the slider 106 then moves to the retracted position to clamp the opposite edge parts 44a, 44b of the reinforcement layer 24 between the head 110 of the respective slider and the clamping surface of the first tool part 102. Although not shown in detail in Figures 12 to 15 , the clamping surface may be similar to the clamping surface 118 of Figures 3 to 11 , i.e., an inclined or recessed surface that is aligned with and complementary in shape to the clamping side 116 of the head 110 of each slider 106 ( Figure 14 ). In the case where the slider 106 retracts as Figure 15 shown and the molding tool 100 is in the closed state, the opposite edge parts 44a, 44b of the reinforcement layer 24 are excluded from the mold cavity, and the cavity side 114 of the head 110 of each slider 106 forms part of the molding surface that defines the mold cavity. A local thin area or through-opening is formed in the airbag door area of the finished panel by the head 110 of each slider 106. As in the previous example, when the reinforcement layer is clamped in the molding tool 100 with the slider in the retracted position, the cavity side 114 of the head 110 of each slider 106 extends beyond the reinforcement layer 24 (in the z-direction of the figure) by an amount that is less than or equal to the nominal thickness of the finished panel substrate in the airbag door area.

[0073] In some embodiments, the molding tool 100 includes a central slider 106 along the central plane A of the panel to be molded, as Figures 3 to 11 shown, and one or more additional sliders 106 located away from the central plane A. The central slider may, for example, clamp the entire length L2 of the opposite edge parts 44a, 44b of the reinforcement layer 24 to the first tool part 102 near the central plane A, as Figures 3 to 9As shown, wherein the additional slider will locally clamp an additional edge portion positioned along the through opening 48 to the first tool portion 102 at a position away from the central slider.

[0074] It should be understood that the foregoing is a description of one or more embodiments of the present invention. The present invention is not limited to the specific embodiments disclosed herein, but is only defined by the following appended claims. Additionally, the statements contained in the foregoing description relate to specific embodiments and should not be construed as limiting the scope of the present invention or the definition of the terms used in the claims, unless the term or phrase is expressly defined above. For those skilled in the art, various other embodiments and various changes and modifications to the disclosed embodiments of the present invention will become apparent. All such other embodiments, changes, and modifications are intended to fall within the scope of the appended claims.

[0075] As used in this specification and the claims, the terms "for example," "e.g.," "by way of example," "such as," and "like," and the verbs "comprising," "having," "including," and their other verb forms, when used in conjunction with a list of one or more components or other items, shall each be construed as open-ended, meaning that the list should not be considered to exclude other additional components or items. Other terms shall be construed in their broadest reasonable sense unless they are used in a context that requires a different interpretation.

Claims

1. A method of manufacturing a vehicle interior panel for use above an airbag, the method comprising: filling a mold cavity of a molding tool with a molding material to form a panel substrate while opposite edge portions of a flexible reinforcement layer are clamped in the molding tool, wherein a portion of the reinforcement layer is overmolded with the molding material and embedded in an airbag door region of the panel.

2. The method according to claim 1, wherein the flexible reinforcement layer comprises separate first and second pieces, the first and second pieces each providing one of the opposite edge portions, a portion of the first piece being embedded in a first airbag door of the panel, and a portion of the second piece being embedded in a second airbag door of the panel opposite the first airbag door.

3. The method according to claim 1, wherein the molding tool comprises a slider, and the method further comprises clamping the opposite edge portions of the reinforcement layer between the slider and a clamping surface of the molding tool prior to the step of filling the mold cavity, the slider defining a portion of the molding surface that defines the mold cavity.

4. The method according to claim 3, wherein the slider is configured to prevent undercutting of the molding material.

5. The method according to claim 1, wherein the molding tool comprises a slider, and the method further comprises: positioning the opposite edge portions between a head of the slider and the clamping surface of the molding tool when the molding tool is in an open state and the slider is in an extended position; and clamping the opposite edge portions between the head of the slider and the clamping surface of the molding tool by moving the slider to a retracted position prior to the filling step.

6. The method according to claim 5, wherein the distance between the edge portions is less than the width of the head of the slider before and after the positioning step, such that the edge portions are in sliding contact with the head of the slider during the positioning step and prior to the clamping step.

7. The method according to claim 5, wherein the clamping side of the head of the slider tapers away from the cavity side of the head of the slider.

8. The method according to claim 1, wherein the edge portions are defined along an opening formed through the reinforcement layer.

9. The method according to claim 8, wherein the reinforcement layer is provided as a single piece.

10. The method according to claim 8, wherein the opening is a slit.

11. The method according to claim 8, wherein the opening comprises a slit and an orifice positioned along the slit.

12. The method according to claim 1, wherein during the filling step, the entire length of each edge portion is clamped in the molding tool.

13. The method according to claim 1, wherein each edge portion extends away from a back side of the airbag door region of the panel and is free of molding material.

14. The method according to claim 1, before the filling step, the method further comprises: (a) positioning the flexible reinforcement layer between a first tool part and a second tool part of the molding tool, wherein the molding tool is in an open state, wherein the slider is in an extended position and the opposing edge portions are aligned with the slider; (b) moving the reinforcement layer and the first tool part relative to each other until the edge portions are located between the head of the slider and the clamping surface of the first tool part; (c) retracting the slider towards the clamping surface to a retracted position such that the edge portions are clamped between the head of the slider and the clamping surface; (d) moving the first tool part and the second tool part towards each other to change the molding tool to a closed state to form the mold cavity; and (e) removing the panel substrate from the molding tool after the filling step.

15. The method according to claim 13, wherein the distance between the edge portions before and after step (b) is less than the width of the head of the slider, such that the edge portions: bend away from the first tool part during step (b), bend towards the first tool part during step (c), and bend towards the first tool part during step (e).

16. A vehicle interior panel for use above an airbag, the vehicle interior panel comprising: a panel substrate formed of a molded material; and a flexible reinforcement layer, wherein a portion of the reinforcement layer is overmolded with the molded material and embedded in the airbag door area of the panel, and wherein opposing edge portions of the flexible reinforcement layer are free of the molded material.

17. The vehicle interior panel according to claim 16, wherein the entire length of each edge portion is free of the molded material.

18. The vehicle interior panel according to claim 16, the vehicle interior panel further comprising an H-shaped tear seam having an area range defining the airbag door area.

19. The vehicle interior panel according to claim 16, wherein the opposing edge portions extend along the back sides of opposing airbag doors of the panel.

20. The vehicle interior panel according to claim 16, wherein another portion of the reinforcement layer is overmolded with the molded material and embedded in the walls of a chute of the panel substrate.

Images