Molding of foam resin having a hollow member

A molding of foam resin such as an instrument panel of a motor vehicle which carries an air duct or similar hollow member therewith. The molding has a substrate composed of a plurality of resin layers at least one of which is made of foam resin. Flanges extend outward from the hollow member and are buried in the foam resin layer of the substrate to securely mount the hollow member on the substrate.

BACKGROUND OF THE INVENTION 
The present invention relates to an instrument panel of a motor vehicle or 
similar molding of foam resin having a layer of foam resin and, more 
particularly, to a molding of foam resin which carries an air duct or 
similar hollow member integrally therewith. 
In general, an instrument panel of a motor vehicle has a laminate structure 
which is made up of a substrate, a covering, and a padding layer 
intervening between the substrate and the covering and made of foam 
polyurethane or similar foam resin. While the substrate has traditionally 
been implemented by hard resin such as ABS resin, a current trend in the 
art is toward a substrate which is also made of foam resin for the ease of 
fabrication. In this kind of instrument panel, the substrate and padding 
layer are formed together as a single molding of foam resin. 
A hollow member such as an air duct which forms a part of an air 
conditioning conduitwork has to be mounted on an instrument panel and has 
to be surely fixed in place thereon. With an instrument panel having a 
substrate made of foam resin as stated above, it is extremely difficult to 
securely mount an air duct or similar part on the outer periphery of the 
panel. It has been customary, therefore, to bury such a part in the foam 
resin layer. 
FIG. 3 indicates a prior art configuration of a molding of foam resin in 
which a hollow member is buried, together with a procedure for fabricating 
the molding. As shown, the molding is composed of a covering 1, a 
substrate 2 made of foam resin and provided on the back of the covering 1, 
and a hollow member 3 fully embedded in the substrate or foam resin layer 
2. To fabricate this kind of molding, the covering 1 is laid on the 
working surface of a lower mold 4, then the hollow member 3 is placed on 
the upper surface of the covering 1 with the intermediary of a suitable 
support member 5, and then an upper mold 6 is closed. Subsequently, an 
undiluted solution of foam resin is introduced in the space defined 
between the covering 1 and the upper mold 6 and is caused to foam and 
solidify. The hollow member 3 is surely fixed in place in the molding 
because it is fully embedded in the foam resin layer 2 and because it is 
bonded to the foam resin layer 2 by the foam resin which contacts the 
surfaces of the part 3 before solidification. Since the molding is 
fabricated with the hollow member 3 being buried therein, an extra step of 
mounting the part 3 after the fabrication is not necessary. 
However, a problem with the molding of the type shown in FIG. 3 is that the 
foaming pressure of the foam resin directly acts on the hollow member 3 
during the course of formation of the foam resin layer 2, tending to 
deform the hollow member 3 such as an air duct. The deformation of the 
hollow member 3 due to the foaming pressure may be eliminated by filling 
the member 3 with air, water or similar fluid, then molding the foam resin 
layer 2, and then discharging the fluid from the part 3. This, however, 
cannot be practiced unless the fluid is introduced in and then discharged 
from the hollow member 3 by extra steps, resulting in an increase in the 
number of fabricating steps. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide a molding of 
foam resin to which a hollow member can be securely mounted during the 
formation of a foam resin layer without being deformed by the foaming 
pressure of foam resin. 
A molding of foam resin of the present invention comprises a substrate 
constituted by a plurality of resin layers at least one of which is formed 
of foam resin, and a hollow member having outwardly extending flanges. The 
flanges of the hollow member are buried in the layer of foam resin.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1 of the drawings, an instrument panel 10 representative 
of a preferred embodiment of the present invention is shown. As shown, the 
panel 10 has a covering 12 made of soft resin, and a substrate 14 provided 
on the back of the covering 12 and formed of foam polyurethane or similar 
foam resin. The soft resin implementing the covering 12 is prepared by 
adding polyvinyl chloride to ABS resin. The substrate 14 is composed of a 
primary foam resin layer 16 bonded to the back of the covering 12, and a 
secondary foam resin layer 18 bonded to the primary layer 16 except for a 
part thereof. In the instrument panel 10, therefore, the substrate 14 is 
implemented as a molding of foam resin only. The primary foam resin layer 
16 has a substantially uniform thickness. 
The primary foam resin layer 16 is provided with a recess 20 in a part 
thereof where the secondary foam resin layer 18 is absent. A hollow member 
in the form of an air duct 22 is disposed in the recess 20. The duct 22 is 
constituted by a pair of shaped sheet members 24 and 26 which are elongate 
in a direction perpendicular to the sheet surface of FIG. 1. Opposite side 
edges of the sheet members 24 and 26 are put together and bonded to form a 
substantially rectangular cross-section. The sheet members 24 and 26 are 
configured such that the bonded portions thereof are positioned at a pair 
of diagonally opposite corners of the rectangular major portion. The 
bonded portions, therefore, constitute a pair of flanges 28 and 30 
extending outward from the rectangular major portion. The flanges 28 and 
30 are held between the primary and secondary foam resin layers 16 and 18, 
whereby the duct 22 is fixed to the substrate 14. In this configuration, 
the instrument panel 10 carries the duct 22 integrally therewith. 
The instrument panel 10 with the duct 22 is fabricated as follows. As shown 
in FIG. 2A, the covering 12 is molded by using one or both of an upper 
mold 32 and a lower mold 34 and by sucking the covering 12 by vacuum. When 
the upper mold 32 is used, it is removed from the covering 12 after the 
step shown in FIG. 2A. Then, as shown in FIG. 2B, an exclusive upper mold 
36 for molding the primary foam resin layer 16 is set above and at a 
predetermined distance from the covering 12 and then lowered toward the 
lower mold 34. In this condition, an undiluted solution of foam resin is 
injected into the space between the covering 12 and the exclusive mold 36. 
As the solution is caused to foam and solidify, it forms the primary foam 
resin layer 16 on the back of the covering 12. In this instance, the upper 
mold 36 provides the primary foam resin layer 16 with a pair of support 
portions 38 and 40 for supporting the flanges 28 and 30 of the duct 22, 
and the recess 20 intervening between the support portions 38 and 40. 
After the exclusive upper mold 36 has been removed, the duct assembly 22 is 
placed in the recess 20 with its flanges 28 and 30 being respectively 
positioned on the support potions 38 and 40 of the primary foam resin 
layer 16, as shown in FIG. 2C. More specifically, the support portions 38 
and 40 are configured in association with the flanges 28 and 30 of the 
duct 22. When the duct 22 is supported by the support portions 38 and 40 
as mentioned, a gap is defined between the duct 22 and the bottom of the 
recess 20. 
Thereafter, as shown in FIG. 2D, an exclusive upper mold 42 for forming the 
secondary foam resin layer 18 is so positioned as to form a predetermined 
space between itself and the primary foam resin layer 16. The mold 42 has 
a pair of projections 44 and 46. The flanges 28 and 30 of the duct 22 are 
held by the projections 44 and 46 and the support portions 38 and 40 of 
the primary foam resin layer 16. Then, an undiluted solution of foam resin 
is injected into the space between the primary foam resin layer 16 and the 
upper mold 42. The solution foams and solidifies to form the secondary 
foam resin layer 18. At this instant, the projections 44 and 46 of the 
mold 42 prevent the foam resin from entering the space defined between the 
projections 44 and 46, upper mold 42, and duct 22. Further, since the 
support portions 38 and 40 of the primary foam resin layer 16 and the 
flanges 28 and 30 of the duct 22 remain in intimate contact with each 
other, the foam resin is inhibited from entering the space between the 
duct 22 and the primary foam resin layer 16. Thereafter, the upper mold 42 
and lower mold 34 are removed to produce the instrument panel 10 having 
the duct 22, as shown in FIG. 1. 
In the instrument panel 10 fabricated by the above procedure, only the pair 
of flanges 28 and 30 of the duct 22 are buried in the interface between 
the primary and secondary foam resin layers 16 and 18. Therefore, the 
foaming pressure being developed during the formation of the secondary 
foam resin layer 18 acts on the flanges 28 and 30 only and does not act on 
the hollow major part of the duct 22. This prevents the duct 22 from being 
deformed by the foaming pressure and thereby allows a designed amount of 
air to flow through the duct 22 for the air conditioning purpose. 
The resin forming the secondary foam resin layer 18 on the primary foam 
resin layer 16 soaks into the surface of the primary layer 16, insuring 
firm bond of the primary and secondary layers 16 and 18. The flanges 28 
and 30 of the duct 22 are buried in between the primary and secondary 
layers 16 and 18. This, coupled with the fact that the resin forming the 
secondary layer 18 adheres the flanges 28 and 30 to the layers 16 and 18, 
firmly connects the duct 22 to the substrate 14 while the substrate 14 is 
produced. 
The substrate 14 is composed of the primary and secondary foam resin layers 
16 and 18, and the primary layer 16 is formed on the back of the covering 
12 first. Hence, the primary layer 16 and the covering 12 are surely 
connected together. The primary layer 16 is provided with a substantially 
uniform thickness to eliminate the deformation of the covering 12 while 
the resin forming the layer 16 solidifies. Even though the thickness of 
the secondary layer 18 may noticeably differ from one portion to another, 
the primary layer 16 prevents the layer 18 from being deformed due to the 
difference in contraction which occurs during the solidification. Hence, 
the instrument panel 10 having an irregular thickness distribution can be 
fabricated with accuracy. 
Since the primary layer 16 is formed on the covering 12 beforehand, it is 
possible to form the support portions 38 and 40 integrally therewith for 
supporting the flanges 28 and 30 of the duct 22. This eliminates the need 
for extra members for PG,10 supporting the duct 22. The position for 
burying the duct 22 is readily adjustable by selecting, for example, the 
height of the support portions 38 and 40 of the primary layer 16 
adequately. 
In the illustrative embodiment, a gap is defined between the lower end of 
the duct 22 and the bottom of the recess 20 of the primary foam resin 
layer 16. Alternatively, an arrangement may be made such that the bottom 
of the recess 20 makes contact with the lower end of the duct 22. This 
alternative configuration will cause the primary layer 16 to support the 
duct 22 over the entire lower end of the latter, thereby preventing the 
duct 22 from being dislocated during the formation of the secondary layer 
18 more positively. 
The illustrative embodiment has been shown and described by taking as an 
example the instrument panel 10 having two foam resin layers 16 and 18 and 
to which the air duct 22 of an air conditioning conduitwork is fitted. It 
is to be noted that the present invention is applicable to any other kind 
of molding of foam resin in which a hollow member is fitted on a laminate 
resin substrate at least one layer of which is made of foam resin, even if 
the other laminate layer is made of hard resin or similar material. This 
can be implemented simply by burying the flanges of the hollow member in 
the foam resin layer. 
In summary, in accordance with the present invention, a hollow member has 
flanges which are buried in a foam resin layer. Hence, when the foam resin 
layer is foamed, its foaming pressure is prevented from acting on the 
other or major part of the hollow member. This allows the hollow member to 
be fixed in place on a molding during the formation of the molding while 
freeing the hollow member from deformation, thereby realizing an 
inexpensive molding of foam resin having a hollow member of desired 
configuration therewith. 
Various modifications will become possible for those skilled in the art 
after receiving the teachings of the present disclosure without departing 
from the scope thereof.