JP4260042B2 - Foam molding - Google Patents

Description

  The present invention includes a synthetic resin base material in which an opening is formed, a synthetic resin lid member that is disposed on the surface side of the base material and covers the opening, and the surfaces of the base material and the lid member. The present invention relates to a foam molded article comprising a foam that is foam-molded on the side and laminated on the base material and the lid member.

  Examples of the foam-molded product include an automotive instrument panel 70 in which an airbag device 90 is provided on the back side as shown in FIG. 6 and FIG. 7 showing a 7-7 cross section thereof. The illustrated instrument panel 70 is an invisible type in which the airbag door is not visible from the outer surface, and a base 71 made of synthetic resin in which an opening 72 functioning as an airbag insertion hole is formed, and the base 71 A synthetic resin lid member 75 disposed on the front surface side and covering the opening 72, and foam-molded on the surface side of the base material 71 and the lid member 75 to be formed on the surface of the base material 71 and the lid member 75. It consists of the laminated foam 81 and the skin material 85 which covers the said foam 81, and is provided in the passenger | crew seat front in a motor vehicle. FIG. 8 shows the base 71 and the lid member 75.

  In the illustrated example, the lid member 75 is formed with a frame portion 77 for holding the airbag device 90 on the back side of a main body portion (which constitutes the airbag door) 76 that covers the opening 72 of the base material 71. The frame portion 77 is inserted into the opening 72 of the base material 71 and protrudes to the back side of the base material 71. The main body 76 is formed with a thinned portion 79 having a reduced strength by a notch or a notch. The cleaving portion 79 includes a double Y shape as shown, an H shape, and the like. The lid member 75 has a peripheral edge of the opening 72 of the base 71 between a locking claw 78 formed to protrude on the outer surface of the frame portion 77 and the back surface of the main body portion 76 outside the frame portion 77. It is attached to the base material 71 by sandwiching. Note that the lid member 75 does not include the frame portion 77, and a locking claw is formed on the back side of the main body portion 76 to lock the back surface of the main body portion 76 outside the frame portion 77. There is also a type in which the nail sandwiches the periphery of the opening 72 of the base 71. The airbag device 90 stores a folded airbag and an inflator (both not shown) for inflating the airbag.

  When the impact due to the collision is applied to the automobile, the instrument panel 70 operates the inflator to inflate the airbag, and the body portion 76 of the lid member 75 is pushed from the back side by the inflating airbag. The portion 76 breaks at the position of the cleavage portion 79 and is pushed open into the vehicle interior, and the airbag is inflated and deployed into the vehicle interior through the pushed-open portion.

  The instrument panel 70 is manufactured by setting the base material 71 after the lid member 75 is assembled to the opening 72 to a foaming mold together with the skin material 85, and a polyurethane foam raw material in the foaming mold. The foam 81 is foam-molded between the surface of the base material 71 and the lid member 75 and the skin material 85 by injecting a foam raw material such as the above. At that time, the peripheral edge of the opening 72 of the base 71 is formed by pressing the main body 76 of the lid member 75 against the base 71 by the foaming pressure when the foam is foamed. This is done by bringing the peripheral edge of the body portion 76 of the lid member 75 into close contact with the surface of the lid member 75.

However, the lid member 75 is made of a synthetic resin having a predetermined rigidity, for example, a TPO resin (olefin-based thermoplastic elastomer), for the purpose of preventing damage to the lid member due to the pressure during inflation of the airbag. In the pressing by the foaming pressure at the time of the foam molding, the peripheral edge of the main body 76 of the lid member 75 is hardly completely adhered to the entire outer periphery of the opening 72, and a seal failure is likely to occur partially. Further, the base material 71 and the lid member 75 may have the opening portion due to variations in size and shape at the time of molding the respective members, or due to variations in the assembly position when the lid member 75 is assembled to the opening portion 72. A seal failure is likely to occur at the periphery of 72. When the sealing failure occurs, the foam leaks from the defective sealing portion into the opening 72, and a part of the foam 81 formed between the base material 71 and the skin material 85 at the periphery of the opening 72. The surface of the foam 81 is indented on the surface of the foam material, and the surface of the instrument panel 70 corresponding to the periphery of the opening 72 is thereby indented. The appearance of 70 may be impaired.
JP 2001-88646 A

  The present invention has been made in view of the above points, and a foam that has a good seal between a base material and a lid member assembled to the opening of the base material and is foam-molded on the surfaces of the base material and the lid member. It is an object of the present invention to provide a foam molded product that can prevent leakage from the periphery of the opening and has a good appearance.

The present invention includes a synthetic resin base material in which an opening is formed, a synthetic resin lid member that is disposed on the surface side of the base material and covers the opening, and the surfaces of the base material and the lid member. In a foam-molded product comprising a foam that is foam-molded on the side and laminated on the base material and the lid member, the lid member includes a main body that covers the opening on the surface side of the base material, and the main body A lip that protrudes from the entire periphery of the outer peripheral edge of the portion and abuts against the surface of the outer peripheral edge of the opening of the base material, the lip being an extension line m of the contact surface of the main body with the base material On the other hand, it is formed to be inclined in the direction S to be the base material side, and a groove is formed on the surface of the base material side of the lip over the entire circumference of the outer peripheral edge of the main body portion , When the main body portion of the lid member is disposed on the surface of the base material so as to cover the opening portion, Flop is deformed in contact with the surface of the outer peripheral edge of the opening of the base, the distal end side of the groove is characterized in that close contact with the surface of the outer peripheral edge of the opening of the substrate.

  In this invention, the lid member is formed so as to protrude from the entire circumference of the outer peripheral edge of the main body portion by covering the main body portion covering the opening portion of the base material on the surface side of the base material. A lip that is in contact with the surface, and a groove is formed on the base-side surface of the base of the lip over the entire circumference of the outer peripheral edge of the main body. The rigidity is reduced by the groove, whereby the flexibility of the lip is increased and the lip is easily deformed along the surface of the outer peripheral edge of the opening of the base material, and the lip is formed on the surface of the outer peripheral edge of the opening. It becomes easy to adhere firmly. Further, when the lip is pressed against the surface of the outer peripheral edge of the opening of the base material by the foaming pressure when the foam is foam-molded on the surface side of the base material and the lid member, the lip is Therefore, it becomes easy to closely contact the surface of the outer peripheral edge of the opening of the base material, and the sealing performance of the peripheral edge of the opening is improved. In particular, since the groove is provided at the base of the lip, the flexibility of the lip is improved even at the outer peripheral corner portion of the main body portion of the lid member, and the lip base side is lifted at the corner portion. It becomes easy to reliably adhere to the surface of the outer peripheral edge of the opening without warping.

  On the other hand, unlike the present invention, when a groove is not formed at the base of the lip, as shown in FIG. 9, at the corner portion (position indicated by symbol C in FIG. 8) in the main body portion 76A of the lid member 75A. The flexibility of the lip 78A is impaired, and the base side of the lip 78A is lifted from the surface of the outer peripheral edge of the opening of the base material 71. As shown in FIG. It tends to be warped in a direction away from the surface of the outer peripheral edge of the part, and leakage of the foam 81 from the corner part to the opening part 72 cannot be sufficiently prevented.

  Furthermore, in this invention, a hollow passage is formed between the surface of the outer peripheral edge of the opening of the substrate and the base of the lip by the groove formed on the surface of the base at the base of the lip, In addition, since the hollow passage is formed so as to surround the opening of the base material, the foam may enter between the lip and the base material from the front end side of the lip during foam molding of the foam. However, the ingress foam will be guided along the outer periphery of the opening through the hollow passage surrounding the opening. Then, the reaction hardening of the foam is terminated while being guided in the hollow passage, and the foam cannot be further accessed to the opening and the foam is more reliably leaked from the opening. Can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail. 1 is a partial cross-sectional view of a foam molded product according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view showing a portion A of the foam molded product of FIG. 1, and FIG. 4 is an exploded perspective view of the base member and the lid member, FIG. 4 is a cross-sectional view showing the lip portion of the lid member in the foam molded product of the embodiment, and FIG. 5 is a foam molding die when foam molding the foam molded product of the embodiment. FIG.

  The foamed molded article 10 shown in FIGS. 1 and 2 is an automobile instrument panel in which an airbag device 90 is provided on the back side, and has the same appearance as that in FIG. The foam molded product 10 includes a base material 11, a lid member 21 and a skin material 41.

  The base material 11 is made of a synthetic resin having a required rigidity, for example, a TPO resin, and is injection-molded in a predetermined shape as a base material of the instrument panel. An opening 12 for inserting an airbag when the airbag is inflated is formed in the base material 11 at a predetermined position on the passenger seat side of the instrument panel. In the illustrated example, as is better understood from FIG. 3, the opening 12 has a rectangular shape, and the outer peripheral edge 13 of the opening 12 is formed one step lower than the general surface 11a at the peripheral edge.

  The lid member 21 is made of a synthetic resin having a required rigidity, such as a TPO resin, and covers the opening 12 from the surface side of the base material 11 and covers the opening 12 so as to cover the lid body 21 and the lid member 21. The lip 26 is formed so as to protrude from the outer peripheral edge of the main body 22, and the frame 28 is erected on the back side of the main body 22. The main body 22 of the lid member 21 constitutes an airbag door. The illustrated main body 22 has a substantially rectangular plate shape that can be placed on the outer peripheral edge 13 of the opening that is one step lower than the general surface 11 a in the base material 11. The size of the main body portion 22 is a size that allows the main body portion 22 including the lip 26 portion to be placed on the outer peripheral edge 13 of the opening. The main body portion 22 is formed with a split portion 23 formed of Y-shaped notches on both sides on the back surface 22b side as a reduced strength portion. The cleavage portion 23 may be H-shaped or may be a simple cut.

  As shown in FIG. 4, a lip 26 that is thinner than the main body portion 22 and has flexibility is formed on the entire outer peripheral edge of the main body portion 22 rather than the base portion 26a of the lip. The taper is tapered on the tip 26b side, and is formed so as to protrude from the main body portion 22. The lip 26 is a contact surface of the main body portion 22 that contacts the outer peripheral edge 13 of the opening portion of the base material 11 when the main body portion 22 is disposed on the surface of the outer peripheral edge 13 of the opening portion 12 of the base material 11. It is formed so as to be inclined toward the base material side (downward) S with respect to the extension line m of 22d. A contact surface 22 d of the main body 22 is formed in parallel with the surface of the outer peripheral edge 13 of the opening 12. The inclination angle α of the lip 26 is appropriately determined depending on the rigidity of the lip 26, but is preferably in the range of 1 ° to 20 °. The lip 26 has a length u between the base portion 26a and the tip 26b and a thickness of the base portion 26a as appropriate. In the illustrated example, the length u is about 10 mm and the base portion 26a has a thickness of 0.5 to 0.5. It is about 1.0 mm.

  A groove 27 is formed in the base portion 26 a of the lip 26 in an annular shape surrounding the outer periphery of the main body portion 22 on the surface 26 c on the base material side over the entire outer peripheral edge of the main body portion 22. The size of the groove 27 is appropriate, but in the illustrated example, the depth d is about 0.1 to 0.2 mm, and the groove width w is about 0.5 mm.

  A frame portion 28 is formed on the back surface (base surface side) 22b of the main body portion 22 so as to be inserted into the opening portion 12 of the base material 11 at a position within a required distance from the outer peripheral edge of the main body portion 22. Yes. On the outer surface of the frame portion 28, there are a plurality of locking claws 29 that sandwich the outer peripheral edge 13 of the opening 12 between the contact surface 22 d with the base material outside the frame portion 28 at a required interval. Is formed. The frame portion 28 has a square shape whose cross-sectional shape is substantially similar to the opening portion, and a pair of opposing side walls of the frame portion 28 are below the locking claws 29 (in a direction away from the main body portion 22). In this position, a case locking hole 30 of the airbag device is formed. The lid member 21 has the main body portion 22, the lip 26, the frame portion 28, and the locking claw 29 integrally formed by known injection molding.

  The lid member 21 inserts the frame portion 28 into the opening 12 from the surface side of the base material 11 and forcibly pushes the locking claw 29 into the opening 12 to The outer peripheral edge 13 of the opening 12 is sandwiched between the contact surface 22d on the rear surface of the main body portion and the locking claw 29, so that the base 11 is assembled.

  The foam 31 is made of a synthetic resin foam such as polyurethane foam. As shown in FIG. 5, the base material 11 and the skin material 41 after the cover member 21 is assembled are placed in a foam mold 51. The foaming raw material such as polyurethane foaming raw material is injected into the foaming mold 51, and between the surface of the base material 11 and the lid member 21 (main body portion 22 in this embodiment) and the back surface of the skin material 41 The foamed raw material is foamed and the foam 31 is foam-molded to be laminated on the surface of the main body 22 of the base material 11 and the lid member 21.

  At the time of foam molding of the foam 31, the lip 26 of the lid member 21 is pressed and brought into close contact with the surface of the outer peripheral edge 13 of the opening 12 in the base material 11 by the foaming pressure. Seal and prevent leakage of foam. At this time, since the flexibility of the lip 26 is improved by the groove 27 at the base of the lip 26 also in the corner portion 22e (shown in FIG. 3) in the main body portion 22 of the lid member 22, the lip 26 is It is deformed along the surface of the corner portion of the outer peripheral edge 13 of the opening portion 12, and adheres well to the surface of the corner portion of the outer peripheral edge 13 of the opening portion 12 so that a good sealing is performed. Furthermore, even if the foam 31 enters between the lip 26 and the surface of the outer peripheral edge 13 of the opening 12 from the tip 26b side of the lip 26, the groove 27 and the opening of the base of the lip 26 Since the hollow passage 43 is formed over the entire periphery of the opening portion 12 by the surface of the outer peripheral edge 13 of the portion 12, the ingress foam is formed in the hollow passage 43 along the outer periphery of the opening portion 12. In addition, during the induction, the foam is completely cured by reaction and loses its fluidity, so that the foam cannot reach into the opening 12 and leakage from the opening 12 occurs. Is prevented.

  The skin material 41 is made of a material impermeable to liquid, such as a synthetic resin sheet, and is integrated with the foam 31 when the foam 31 is formed in the foam mold.

  Since the foamed molded article 10 thus configured prevents the foam 31 from leaking from the opening 12, it has a good appearance with no depression at the surface position corresponding to the opening 12. Have

  In addition, this invention is not limited to the said Example, It can change in the range which does not deviate from the meaning of this invention. For example, in the above-described embodiment, the lid member has a frame portion on the back surface of the main body portion. However, the lid member may have no frame portion, and the airbag device may be fixed to the vehicle body side.

It is a fragmentary sectional view of the foaming molded product concerning one Example of this invention. It is sectional drawing which expands and shows the A section of the foaming molded article of FIG. It is a disassembled perspective view of the base material and lid member in the foaming molded product of the Example. It is sectional drawing which shows the lip | rip part of the cover member in the foaming molded article of the Example. It is a fragmentary sectional view of the foaming mold at the time of foam-molding the foam-molded article of the Example. It is a perspective view which shows a part of instrument panel. It is 7-7 sectional drawing of FIG. It is a disassembled perspective view of the base material and lid member in the conventional foaming molded article. It is a fragmentary sectional view of the foaming molded product which shows the malfunction when the lip without a groove | channel is provided in a cover member. It is a fragmentary sectional view of the foaming molded product which shows the other malfunction at the time of providing a lip without a groove in a lid member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Foam molded article 11 Base material 12 Opening part 13 Outer periphery of opening part 21 Lid member 22 Main body part 26 Lip 26a Lip base part 26b Tip of lip 27 Groove 31 Foam body 41 Skin material m Extension line of contact surface

Claims (2)

A synthetic resin base material (11) in which an opening (12) is formed, and a synthetic resin lid member (21) which is disposed on the surface side of the base material (11) and covers the opening (12). And a foamed molded article comprising a foam (31) formed by foam molding on the surface side of the base material and the lid member and laminated on the base material (11) and the lid member (21),
The lid member (21) is formed so as to protrude from the main body (22) covering the opening (12) on the surface side of the base material (11) and the entire outer periphery of the main body (22). A lip (26) that contacts the surface of the outer peripheral edge (13) of the opening (12) of the substrate;
The lip (26) is formed to be inclined in the direction S on the substrate side with respect to an extension line m of the contact surface (22d) with the substrate (11) in the main body (22). At the same time, a groove (27) is formed on the entire surface of the outer peripheral edge of the main body (22) on the surface of the lip (26) on the base material side ,
When the main body (22) of the lid member (21) is disposed on the surface of the base (11) so as to cover the opening (12), the lip (26) 12) is deformed in contact with the surface of the outer peripheral edge (13), and the front end side is closer to the surface of the outer peripheral edge (13) of the opening (12) of the base material than the groove (27). Foam molded product. The foam-molded product according to claim 1, wherein the foam-molded product is an instrument panel of an automobile, and the main body (22) of the lid member is an airbag door .

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