U.S. patent application number 09/035750 was filed with the patent office on 2001-12-13 for resin container and a manufacturing method thereof.
Invention is credited to ISHIMARU, HIROKAZU, KIDO, KATSUYUKI, KITO, MAKOTO, SERINO, YOICHI, TERADA, MASAKI.
Application Number | 20010051236 09/035750 |
Document ID | / |
Family ID | 27564460 |
Filed Date | 2001-12-13 |
United States Patent
Application |
20010051236 |
Kind Code |
A1 |
KIDO, KATSUYUKI ; et
al. |
December 13, 2001 |
RESIN CONTAINER AND A MANUFACTURING METHOD THEREOF
Abstract
In a state where a gas barrier sheet (10) having a gas barrier
layer is held between a heat plate (12) and a pressing plate, the
gas barrier sheet is disposed between two molds together with a sub
tank (44) and a separator (46) constituting attachment parts, the
molds are then closed and a resin is injection-molded forming a
resin layer (36). A method for manufacturing a resin container by
melt-adhering an intermediate molded product (38) and another
intermediate molded product (38) constituting a pair therewith by
heating with a heat plate (12) thereafter, and a resin container
manufactured by this manufacturing method.
Inventors: |
KIDO, KATSUYUKI; (SETO-SHI,
JP) ; ISHIMARU, HIROKAZU; (TOYOTA-SHI, JP) ;
TERADA, MASAKI; (TOYOTA-SHI, JP) ; SERINO,
YOICHI; (TOYOTA-SHI, JP) ; KITO, MAKOTO;
(AICHI-GUN, JP) |
Correspondence
Address: |
PILLSBURY MADISON & SUTRO
1100 NEW YORK AVENUE N W
NINTH FLOOR
WASHINGTON
DC
200053918
|
Family ID: |
27564460 |
Appl. No.: |
09/035750 |
Filed: |
March 6, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09035750 |
Mar 6, 1998 |
|
|
|
PCT/JP97/02329 |
Jul 4, 1997 |
|
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Current U.S.
Class: |
428/34.1 |
Current CPC
Class: |
B60K 2015/03032
20130101; B29C 65/58 20130101; Y10T 428/1352 20150115; B29C 66/1142
20130101; B60K 15/03177 20130101; B29C 51/267 20130101; B29C
66/81422 20130101; B29C 66/545 20130101; B29C 66/543 20130101; B29C
66/72341 20130101; B29C 45/006 20130101; B29C 65/203 20130101; B29C
66/81821 20130101; B29C 2793/00 20130101; B29C 66/54 20130101; B29C
66/81419 20130101; B29L 2009/00 20130101; B60K 2015/0777 20130101;
B29C 66/542 20130101; B60K 2015/03467 20130101; B29C 66/1312
20130101; Y10T 428/13 20150115; B29C 66/14 20130101; B29K 2995/0067
20130101; B29C 66/71 20130101; B29C 66/83221 20130101; B29C 66/5432
20130101; B29L 2031/7172 20130101; B29C 66/81427 20130101; B29C
65/02 20130101; B29C 65/2023 20130101; B29C 66/71 20130101; B29K
2023/065 20130101; B29C 66/71 20130101; B29K 2077/00 20130101 |
Class at
Publication: |
428/34.1 |
International
Class: |
B32B 001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 1996 |
JP |
8-178379 |
Feb 21, 1997 |
JP |
9-37976 |
Feb 27, 1997 |
JP |
9-44229 |
Apr 22, 1997 |
JP |
9-104503 |
Feb 21, 1997 |
JP |
9-37974 |
Feb 21, 1997 |
JP |
9-37977 |
Apr 18, 1997 |
JP |
9-102014 |
Claims
What is claimed:
1. A resin container formed by superposing peripheral edge portions
of at least two intermediate molded products, each of the
intermediate molded products comprising at least two layers
including a sheet member and a resin layer, in which the sheet
members of the at least two intermediate molded products are melted
and adhered to each other and the resin layers of the intermediate
molded products are melted and adhered to each other.
2. A method for manufacturing a resin container comprising an
intermediate molded product forming step of forming concave
intermediate molded products, each of the intermediate molded
products comprising at least two layers including a sheet member
and a resin layer, a sheet material melt-adhering step of
superposing the peripheral edge portions of the intermediate formed
products to melt and adhere the sheet members to each other, and a
resin layer melt-adhering step of melt-adhering the resin layers of
the intermediate molded products to each other.
3. A method for manufacturing a resin container according to claim
2, wherein the resin layers are respectively provided outside of
said sheet members in said intermediate molded product forming
step, and the pressure inside the sheet members which have been
bag-shaped in said resin layer member melt-adhering step is reduced
so as to be lower than outside the bag-shaped sheet members so as
to melt-adhere said resin layers of said intermediate molded
products to each other.
4. A method for manufacturing a resin container according to claim
3, wherein a communicating portion for communicating between the
inside of said resin layers and the outside thereof is provided in
the joining portion of said resin layers to each other, and said
method further comprising a gas exhaust step for exhausting gas
between said sheet members and said resin layers.
5. A method for manufacturing a resin container according to claim
4, wherein said sheet member is melt-adhered to said resin layer at
the temperature at which said resin layers of said intermediate
molded products are melt-adhered to each other.
6. A resin container according to claim 1, wherein a
non-melt-adhered portion of said sheet member and said resin layer
is provided on the peripheral portion of said resin layer.
7. A resin container according to claim 6, wherein a member which
is not melt-adhered to said resin layer is provided in said
non-melt-adhered portion.
8. A method for manufacturing a resin container according to claim
2, wherein a non-melt-adhered portion of said sheet member and said
resin layer is provided in the peripheral portion of said resin
layer.
9. A method for manufacturing a resin container according to claim
8, wherein a cooling portion is provided in a portion of a mold
corresponding to the peripheral portion of said resin layer and
used for said intermediate molded product forming step.
10. A resin container according to claim 1, wherein engaging
portions which are engaged with each other are provided in the
portions of said sheet members where said sheet members are to be
melt-adhered to each other.
11. A method for manufacturing a resin container according to claim
2, wherein engaging portions which are engaged with each other are
provided in the portions of said sheet members where said sheet
members are bonded to each other and after said sheet members are
engaged with each other, said sheet members are melt-adhered to
each other.
12. A method for manufacturing a resin container according to claim
2, wherein a reinforcing layer which is not melted by injected
resin is provided at least on an area of said sheet member opposite
a resin injecting hole.
13. A resin container according to claim 1, wherein an engaging
portion between said resin layer and said sheet member is contained
in the bonding end portion between said resin layer and said sheet
member.
14. A method for manufacturing a resin container according to claim
6, wherein the bonding end portions between said resin layers and
said sheet members are engaged with each other in said
melt-adhering step.
15. A resin container according to claim 1, wherein the distance of
the bonding portion between the respective sheet members and the
resin layers is different from the distance of the bonding portion
between said sheet members.
16. A method for manufacturing a resin container according to claim
3, wherein welding is performed so that the distance of the bonding
portion between the respective sheet members and the resin layers
is different from the distance of the bonding portion between said
sheet members in said sheet member welding step.
17. A resin container according to claim 1, wherein said
intermediate molded products are divided into an upper intermediate
molded product and a lower intermediate molded product, and the
sheet member of the upper intermediate molded product has better
moldability and less permeability than the sheet member of the
lower intermediate molded product.
18. A method for manufacturing a resin container according to claim
2, wherein an extension portion extending from the point where said
resin layer bonds with the other intermediate molded product to the
point where said sheet member bonds with the other intermediate
molded product is provided in said intermediate molded product
molding step.
19. A method for manufacturing a resin container according to claim
2, wherein in said intermediate formed product forming step, a gap
inside a cavity near said resin injecting hole is made wider than a
gap in the other portion within the cavity.
20. A resin container according to claim 1, wherein in an engaging
portion between an attached part and said sheet member, said part
is formed as a concave shape.
21. A method for manufacturing a resin container according to claim
2, wherein in the engaging portion between the attached part and
said sheet member said attached part is made concave and the resin
layer is formed in said intermediate molded product molding
process.
Description
BACKGROUND ART
[0001] Conventionally, the disclosures in Japanese Patent
Application Laid-Open (JP-A) No. 5-229015 for resin containers such
as fuel tanks and the like mounted in automotive vehicles and
methods for manufacturing the same have been known.
[0002] As shown in FIG. 36, in the method for manufacturing a resin
container, firstly, a molten resin 122 in a high temperature state
is extruded onto a convex metal mold 146 so as to conform to the
measurements of the metal mold. Next, a vacuum is created in the
suction holes 134 provided on an inner wall 132 of a concave metal
mold 130 which corresponds to the shape of the convex metal mold
146 by a vacuum apparatus 140, and a film (a sheet member) 142 made
of the same material as that of the resin 122 and having a gas
barrier layer which prevents gasoline from permeating through is
heated so as to adhere to the innerwall 132 of the concave metal
mold 130. Then, the convex metal mold 146 and the concave metal
mold 130 are die matched and heat compressed, and thereafter the
molds are opened. The concave metal mold 130 holding an
intermediate concave molded product formed in the above manner and
kept in a high temperature state, and the other metal mold holding
an intermediate concave molded product formed in the same manner
and kept in a high temperature state are combined with each other
and then are thermally compressed. Accordingly, the joint portions
of the intermediate products adhere to each other in the high
temperature state, so that the bonding strength is improved.
[0003] However, in the resin containers and the method for
manufacturing the same mentioned above, when the seal members 142
are not securely die matched with each other in the bonding
portions of the intermediate molded products, the level of gasoline
permeability in the bonding portions is increased so that the gas
permeation preventing performance is deteriorated. Accordingly, it
has not been easy to obtain a resin container guaranteeing gas
permeation prevention in the bonding portions.
[0004] In this case, the related art concerning the present
invention includes Japanese Patent Application Laid-Open (JP-A) No.
63-260424 which discloses a fuel tank having a multi-layered resin
structure, Japanese Patent Application Laid-Open (JP-A) Nos.
6-278223 and 6-278224 which disclose a fuel tank in which the
peripheral portions of two concave resin containers is subjected to
melt-adhesion, and Japanese Patent Application Laid-Open (JP-A) No.
58-202112 which discloses a fuel tank in which the peripheral
portions of two containers comprising a resin layer and a metal
foil are melted to adhere to each other.
[0005] Accordingly, the present invention takes the above facts
into consideration and an object of the present invention is to
provide a resin container and a method for manufacturing the same
which can improve the gas permeation preventing performance in the
bonding portions of intermediate molded products.
DISCLOSURE OF THE INVENTION
[0006] The present invention provides a resin container formed by
superposing peripheral edge portions of at least two intermediate
molded products, each of the intermediate molded products
comprising at least two layers including a sheet member and a resin
layer, in which the sheet members of the at least two intermediate
molded products are melted and adhered to each other and the resin
layers of the intermediate molded products are melted and adhered
to each other. Accordingly, since the sheet members are securely
adhered to each other in the bonding portion in which the
peripheral edge portions of two intermediate molded products are
superposed on each other, the gas permeation preventing performance
in the bonding portion between the intermediate molded products can
be improved.
[0007] Further, the present invention comprises an intermediate
molded product forming step of forming concave intermediate molded
products, each of the intermediate molded products comprising at
least two layers including a sheet member and a resin layer, a
sheet material melt-adhering step of superposing the peripheral
edge portions of the intermediate formed products to melt and
adhere the sheet members to each other, and a resin layer
melt-adhering step of melt-adhering the resin layers of the
intermediate molded products to each other. Accordingly, the resin
container in which the gas permeation preventing performance in the
bonding portion between the intermediate molded products is
improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1A is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a first embodiment of the
present invention.
[0009] FIG. 1B is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a first embodiment of the
present invention.
[0010] FIG. 1C is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a first embodiment of the
present invention.
[0011] FIG. 1D is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a first embodiment of the
present invention.
[0012] FIG. 1E is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a first embodiment of the
present invention.
[0013] FIG. 1F is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a first embodiment of the
present invention.
[0014] FIG. 2 is a cross sectional view of an apparatus and a
container in cases where the pressure inside a saccate gas barrier
sheet is reduced by a resin layer welding process of a method for
manufacturing a resin container in accordance with a first
embodiment of the present invention.
[0015] FIG. 3 is an enlarged partial cross sectional view of a gas
barrier sheet used in a method for manufacturing a resin container
in accordance with a first embodiment of the present invention.
[0016] FIG. 4 is an enlarged cross sectional view of an attached
part (a cut off valve) in a method for manufacturing a resin
container in accordance with a first embodiment of the present
invention.
[0017] FIG. 5 is an enlarged cross sectional view of an attached
part (a pipe) in a method for manufacturing a resin container in
accordance with a first embodiment of the present invention.
[0018] FIG. 6 is an enlarged partial cross sectional view of a gas
barrier sheet and a resin layer in a state where the gas barrier
sheet and the resin layer are welded together in a method for
manufacturing a resin container in accordance with a first
embodiment of the present invention.
[0019] FIG. 7 is an enlarged cross sectional view of a bonded
portion of a heat plate, a gas barrier sheet, and a resin layer
near the heat plate in a method for manufacturing a resin container
in accordance with a first embodiment of the present invention.
[0020] FIG. 8 is a perspective view of a resin container
manufactured by a method for manufacturing a resin container in
accordance with a first embodiment of the present invention.
[0021] FIG. 9 is a cross sectional view of an apparatus and a
container which shows a gas discharge process of a method for
manufacturing a resin container in accordance with a second
embodiment of the present invention.
[0022] FIG. 10 is a cross sectional view of an apparatus and a
container which shows a state after a gas discharge step is
completed in a method for manufacturing a resin container in
accordance with a second embodiment of the present invention.
[0023] FIG. 11 is a schematical cross sectional view of a container
manufactured by a method for manufacturing a resin container in
accordance with a second embodiment of the present invention.
[0024] FIG. 12 is an enlarged cross sectional view of a bonded
portion of a heat plate, a gas barrier sheet, and a resin layer
near the heat plate in a method for manufacturing a resin container
in accordance with a third embodiment of the present invention.
[0025] FIG. 13 is an enlarged cross sectional view of a bonded
portion of a heat plate, a gas barrier sheet, and a resin layer
near the heat plate in a method for manufacturing a resin container
in accordance with a modified embodiment of the third embodiment of
the present invention.
[0026] FIG. 14A is an enlarged cross sectional view which shows a
state before sheet member engaging portions are engaged in a method
for manufacturing a resin container in accordance with a fourth
embodiment of the present invention.
[0027] FIG. 14B is an enlarged cross sectional view which shows a
state after sheet member engaging portions are engaged in a method
for manufacturing a resin container in accordance with a fourth
embodiment of the present invention.
[0028] FIG. 15 is an exploded perspective view of a container
manufactured by a method for manufacturing a resin container in
accordance with a fourth embodiment of the present invention.
[0029] FIG. 16A is an enlarged cross sectional view which shows a
state before sheet member engaging portions are engaged in a method
for manufacturing a resin container in accordance with a modified
embodiment of the fourth embodiment of the present invention.
[0030] FIG. 16B is an enlarged cross sectional view which shows a
state after sheet member engaging portions are engaged in a method
for manufacturing a resin container in accordance with a modified
embodiment of the fourth embodiment of the present invention.
[0031] FIG. 17A is an enlarged cross sectional view which shows a
state before sheet member engaging portions are engaged in a method
for manufacturing a resin container in accordance with a further
modified embodiment of the fourth embodiment of the present
invention.
[0032] FIG. 17B is an enlarged cross sectional view which shows a
state after sheet member engaging portions are engaged in a method
for manufacturing a resin container in accordance with a further
modified embodiment of the fourth embodiment of the present
invention.
[0033] FIG. 18 is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a fifth embodiment of the
present invention.
[0034] FIG. 19 is an enlarged partial cross sectional view of a
bonded portion of a gas barrier sheet and a resin layer in a method
for manufacturing a resin container in accordance with a sixth
embodiment of the present invention.
[0035] FIG. 20A is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a sixth embodiment of the
present invention.
[0036] FIG. 20B is a cross sectional view of an apparatus and a
container which shows one step of a method for manufacturing a
resin container in accordance with a sixth embodiment of the
present invention.
[0037] FIG. 21A is an enlarged cross sectional view which shows a
state before a bonding portion of a gas barrier sheet is welded in
a method for manufacturing a resin container in accordance with a
sixth embodiment of the present invention.
[0038] FIG. 21B is an enlarged cross sectional view which shows a
state after a bonding portion of a gas barrier sheet is welded in a
method for manufacturing a resin container in accordance with a
sixth embodiment of the present invention.
[0039] FIG. 22 is a schematical cross sectional view which shows a
container manufactured by a method for manufacturing a resin
container in accordance with a sixth embodiment of the present
invention.
[0040] FIG. 23A is a schematical cross sectional view which shows a
heat plate used for a method for manufacturing a resin container in
accordance with a modified embodiment of the sixth embodiment of
the present invention.
[0041] FIG. 23B is a schematical cross sectional view which shows a
heat plate used for a method for manufacturing a resin container in
accordance with a further modified embodiment of the sixth
embodiment of the present invention.
[0042] FIG. 24 is an enlarged cross sectional view of a bonded
portion of a heat plate, a gas barrier sheet, and a resin layer
near the heat plate in a method for manufacturing a resin container
in accordance with a seventh embodiment of the present
invention.
[0043] FIG. 25 is a cross sectional view along a line 25-25 in FIG.
24.
[0044] FIG. 26 is a cross sectional view of an apparatus and a
container which shows a portion near a resin injecting heat plate
in a method for manufacturing a resin container in accordance with
an eighth embodiment of the present invention.
[0045] FIG. 27 is a cross sectional view of an apparatus and a
container which shows a part engaging portion in a method for
manufacturing a resin container in accordance with a ninth
embodiment of the present invention.
[0046] FIG. 28 is a partial cross sectional view of a jig and a
container which shows a shape correcting step of a method for
manufacturing a resin container in accordance with a modified
embodiment of the present invention.
[0047] FIG. 29 is a partial cross sectional view of a jig and a
container which shows a shape correcting step of a method for
manufacturing a resin container in accordance with a modified
embodiment of the present invention.
[0048] FIG. 30 is a cross sectional view of an apparatus and a
container which shows a gas barrier layer forming step of a method
for manufacturing a resin container in accordance with a modified
embodiment of the present invention.
[0049] FIG. 31 is a cross sectional view of an apparatus and a
container which shows a resin layer forming step of a method for
manufacturing a resin container in accordance with a modified
embodiment of the present invention.
[0050] FIG. 32 is a cross sectional view of an apparatus and a
container which shows an attachment part forming step of a method
for manufacturing a resin container in accordance with a modified
embodiment of the present invention.
[0051] FIG. 33 is a cross sectional view of an apparatus and a
container which shows a resin layer forming step of a method for
manufacturing a resin container in accordance with a modified
embodiment of the present invention.
[0052] FIG. 34A is an enlarged cross sectional view which shows a
state before bonding portions of a resin layer and a gas barrier
sheet are welded in a method for manufacturing a resin container in
accordance with a modified embodiment of the present invention.
[0053] FIG. 34B is an enlarged cross sectional view which shows a
state after bonding portions of a resin layer and a gas barrier
sheet are welded in a method for manufacturing a resin container in
accordance with a modified embodiment of the present invention.
[0054] FIG. 35A is an enlarged cross sectional view which shows a
state before bonding portions of a resin layer and a gas barrier
sheet are welded in a method for manufacturing a resin container in
accordance with a modified embodiment of the present invention.
[0055] FIG. 35B is an enlarged cross sectional view which shows a
state after bonding portions of a resin layer and a gas barrier
sheet are welded in a method for manufacturing a resin container in
accordance with a modified embodiment of the present invention.
[0056] FIG. 36 is a schematic cross sectional view which shows a
part of a method for manufacturing a resin container in accordance
with a conventional embodiment.
BEST MODE FOR CARRYING OUT THE INVENTION
[0057] A first embodiment of a method for manufacturing a resin
container (for example, a fuel tank for an automotive vehicle) in
accordance with the present invention will be described in detail
with reference to FIG. 1 through FIG. 8.
[0058] Firstly, as shown in FIG. 1A, the peripheral edges of a gas
barrier sheet 10 serving as a sheet member are held between heater
containing heat plates 12 and pressing plates 14. In this case, as
shown in FIG. 3, the gas barrier sheet 10 is structured so that a
gas barrier layer 10A having a gas permeation preventing properties
is held between resin layers 10B made of the same resin as that of
a base resin. The gas barrier layer 10A is also called as an
anti-gas permeation layer and is made of an ethylene vinyl alcohol
(EVOH) layer or a nylon (TRADE MARK) layer. The resin layer 10B is
made of a high density polyethylene (HDPE) which is the same type
of resin (for example, polyethylene resin) as that of the base
resin. Examples of the gas barrier sheet 10 having the above
structure include DAIAMILON MF, manufactured by Mitsubishi
Plastics, Inc., and examples of the HDPE include F6040V
manufactured by Nihon Poly olefin Inc. The anti-gas permeability of
the gas barrier sheet 10 is improved by the gas barrier layer 10A,
and the adhesiveness between the gas barrier sheet 10 and the base
resin is improved by the resin layer 10B.
[0059] Next, as shown in FIG. 1B, with the gas barrier sheet 10
covering the outer side (the outer side of the container once it
has been formed into a container shape) of attachment parts such as
a cut off valve 16, the gas barrier sheet 10 and the attachment
parts such as the cut off valve 16 and the like are set on a base
resin (hereinafter, referred to as resin layer 36) forming lower
mold 18. In this case, the gas barrier sheet 10 can be easily
adhered to the surface of the lower mold 18 by reducing the
pressure between the lower mold 18 and the gas barrier sheet 10. In
this state, an upper mold 20 is set onto the lower mold 18 in such
a way that a cavity 22 is formed between the gas barrier sheet 10
and the inner surface of the upper mold 20.
[0060] As shown in FIG. 8, FIG. 4, and FIG. 5, the cut off valve 16
is a pipe for expelling the gas which builds up in the top of the
inside of the fuel tank when fuel is fed through an inlet pipe 30
into the fuel tank which is a resin container 28 comprising a lower
part 24 and an upper part 26. This pipe closes when the fuel fills
up to the valve position and remains open when the fuel level is
below the valve position. In this case, the gas expelled from the
cut off valve 16 is expelled to the outside through a pipe 33
passing through a fuel pump mounting opening 32.
[0061] Accordingly, since the structure is made in such a way that
the gas barrier sheet 10 covers parts such as the cut off valve 16
and the like, no hole is pierced on the barrier sheet 10, and the
gas permeation preventing performance is improved in regions where
parts such as the cut off valve 16 and the like are disposed.
[0062] Next, as shown in FIG. 1C, a resin layer 36 is injection
molded onto the outer side of the gas barrier sheet 10. Namely, the
resin layer 36 is molded by pouring a molten resin into the cavity
22 through a hole 40 in the upper mold 20 and then cooling and
solidifying it. After the resin layer 36 has solidified, the
pressing plate 14 is removed and an intermediate molded product 38
having a concave shape and open peripheral edges is formed
(intermediate molded product molding process). In the case of hot
stamping, a heated base resin sheet is disposed on the gas barrier
sheet, and a resin layer is formed by stamping with a press.
[0063] As shown in FIG. 6, both in cases where the resin layer 36
is formed by injection molding as well as in cases where it is
formed by hot stamping, since the outer side resin layer (the HDPE
layer) 10B of the gas barrier sheet 10 is softened to a gel state
from the heat of the resin layer 36, an interlinked molecular chain
between the resin layer 36 and the outer resin layer of the gas
barrier sheet 10 is formed in a molten layer 37, so that the resin
layer 36 and the gas barrier sheet 10 become closely adhered as a
single body.
[0064] As shown in FIG. 7, by piercing a hole 42 in the heat plate
12 so as to introduce the molten resin to the gas barrier sheet 10
through the hole 40, the portion of the gas barrier sheet 10 in
contact with the heat plate 12 is held on the heat plate 12,
thereby preventing the portion of the gas barrier sheet 10 in
contact with the heat plate 12 from creasing. Since the portion of
the gas barrier sheet 10 in contact with the heat plate 12
corresponds to the bonding portion between the gas barrier sheets
10, the welding reliability between the gas barrier sheets 10 is
improved due to no creases in this portion being generated.
[0065] In this case, as shown in FIG. 1D, a sub tank 44 and a
separator 46 attachment parts are integrally formed on the fuel
tank lower part 24. Since the sub tank 44 and the separator 46 are
made of HDPE and do not include EVOH, they are integrally formed
with the resin layer 36 when the resin layer 36 is formed.
[0066] Next, as shown in FIG. 1D, the intermediate molded product
38 is combined with at least one other intermediate molded product
38 able to be combined therewith in a state where the peripheral
edges of the opening thereof and the peripheral edges of the gas
barrier sheet 10 (sheet member melt-adhering step) are aligned. In
this case, the pressing plate 14 has already been removed from the
intermediate molded product 38 in this state.
[0067] Next, as shown in FIG. 1D, by heating the heat plates 12 of
each of the combined intermediate molded products 38 to about
240.degree. C. and softening to a gel state the gas barrier sheet
10 and the resin layer 36 portions of the combined intermediate
molded products 38 which are in contact with the heat plate 12, the
gas barrier sheets 10 of the respective combined intermediate
molded products 38 are melt-adhered to each other so as to form a
gas barrier sheet bag.
[0068] Next, as shown in FIG. 1E, in a state where the resin layer
portions in contact with the respective heat plates 12 are
softened, the respective heat plates 12 of the combined
intermediate molded products 38 is pulled out together with the gas
barrier sheet 10 portion disposed therebetween.
[0069] Next, as shown in FIG. 1F, the combined intermediate molded
products 38 are pressed together by moving a pair of molds, 50
(upper mold) and 52 (lower mold), of the welding press adjacent to
each other so as to weld the peripheral edges of the resin layers
36 of the combined intermediate molded products 38 to each other
(resin welding step).
[0070] At this time, since the welding of the peripheral edges of
the resin layers 36 must be performed in a state where the portion
in contact with the heat plate of the resin layer 36 is softened to
a gel state, it must be performed immediately after pulling out the
heat plate.
[0071] Further, the heat plate 12 is constructed in such a manner
as to be able to be separated in several peripheral directions so
as to be pulled apart in at least two directions (for example, four
directions) with respect to the intermediate molded product 38.
[0072] Further, in order that the portions of the gas barrier
sheets 10 between the heat plates 12 can be pulled out together
with the heat plates 12 after being cut away from the bag portion,
a fixed cutter 12A for cutting the portions of the gas barrier
sheets 10 between the heat plates 12 away from the bag portion is
formed on the inner peripheral end of the heat plate 12 (refer to
FIG. 7), and is structured so that when the gas barrier sheet 10 is
held between the pair of heat plates 12, the portions of the gas
barrier sheets 10 between the opposing fixed cutters 12A are
constricted so that the gas barrier sheets 10 can be easily cut by
pulling out the heat plates 12 at the constricted portion.
[0073] Further, since the gas barrier sheets 10 of each of the
intermediate molded products 38 are put under higher pressure where
the fixed cutters 12A are positioned than in other regions, the
molten resin layer 10B between the gas barrier layers 10A flows out
and the two gas barrier layers 10 cut through to join each other.
The molecules of the two gas barrier layers 10 are thus linked
together in a chain and the gas barrier layers 10A are sealed to
each other in an air tight manner. Accordingly, as the gas barrier
sheets 10 are sealed to each other in an air tight manner, a
bag-like gas barrier sheet 10 is formed.
[0074] Further, between the processes shown in FIG. 1E and FIG. 1F
of the resin melt-adhering steps, because the sealed portions of
the gas barrier sheets are hanging slackly the pressure is reduced
inside the bag-like gas barrier sheet 10, so that the slack part of
the gas barrier sheet 10 dose not come between the facing edges of
the resin layers, but instead protrudes inside the resin container
(fuel tank), as is shown in FIG. 1F.
[0075] The pressure reduction pipe used at this time can be an
attachment pipe of the resin container (the fuel tank) 28, and this
is passed through one of the openings necessarily formed in the
resin container such as the fuel pump mounting opening 32, the
inlet pipe opening 30, and the like so as to lead to the outside of
the container. The pressure reduction pump is connected to this,
and the pressure inside the container can be reduced.
[0076] Next, the operations of the method for manufacturing the
resin container in accordance with the first embodiment will be
explained.
[0077] In the method for manufacturing the resin container of the
first embodiment, the attachment part 16 is covered on the outside
by the gas permeation preventing gas barrier sheet 10. Accordingly,
it is not necessary to pierce a hole in the gas barrier sheet 10
and the resin layer 36 in the location of the attachment part 16 as
is done in the conventional art. As a result of this, the gas
permeation preventing performance and the reliability of the
container in the region of the attachment part 16 is greatly
improved. Further, since the resin container 28 manufactured by the
method mentioned above is structured so that the resin layers 36
and the gas barrier sheets 10 of each of two intermediate formed
products 38 are respectively melt-adhered to each other, the gas
barrier sheets 10 do not peel apart from each other and the gas
permeation preventing performance and the reliability thereof is
high. Further, since there is no hole piercing process and no
melt-adhering step process between the attachment part and the
container as in the conventional manufacturing method, the number
of steps and the consequent manufacturing costs can be
correspondingly reduced.
[0078] Further, since the bonding portions of the gas barrier
sheets 10 and the resin layers 36 are in close contact with the
heat plate 12, the heat transfer between the heat plate 12 and the
gas barrier sheets 10 and resin layers 36 can be efficiently
performed, so that the reliability of the bonding strength and the
air tightness is increased when welding the intermediate molded
products 38 to each other. Further, since the melt-adhesion is
performed by holding the gas barrier sheets 10 of the respective
intermediate molded products 38 between the high rigid heat plates
18, warps and deformities in the bonded portion are restricted, so
that the reliability of the bonding strength and the air tightness
when welding the gas barrier sheets 10 of the respective
intermediate molded products 38 is increased.
[0079] Further, since a hole 42 has been pierced in the heat plate
12, and molten resin has been injected into this hole 42 so that
the resin layer 36 and the portion of the gas barrier sheet 10 in
contact with the heat plate 12 connect and join with each other,
the contact between the gas barrier sheet 10 and the resin layer 36
with the heat plate 12 is strengthened so that the contact portion
between the gas barrier sheet 10 and the heat plate 12 is prevented
from generating creases. Further, by strengthening the connection
between the heat plate 12 and the part of the gas barrier sheet 10
in contact with the heat plate 12, the portion (burr) of the gas
barrier sheets 10 between the heat plates 12 is securely pulled out
together with the heat plate 12 and is cut apart from the bag-like
portion at the same time as the heat plate 12 is pulled out.
[0080] Further, when the pressure is reduced inside the bag-like
gas barrier sheet during the melt-adhesion of the resin layers 36
to each other, the slack portion of the gas barrier sheet 10 is
prevented from protruding between the adhered surfaces of the resin
layers 36 after pulling out the heat plate 12. Therefore the resin
layers 36 of the intermediate molded products 38 can be securely
melt-adhered to each other and the adhering strength and the
adhering reliability of the resin layer 36 can be improved.
[0081] Moreover the thickness and quality of the material of the
gas barrier layer 10A of the gas barrier sheet 10 in the upper
section 26 of the resin container 28 may be more moldable in
comparison with the thickness or quality of the material of the gas
barrier layer 10A of the gas barrier sheet 10 in the lower section
24 of the resin container 28. In this case, the thickness and
quality of the material of the gas barrier layer 10A of the gas
barrier sheet 10 in the upper section 26 of the resin container 28
may be inferior in gas permeation preventing properties in
comparison with the thickness and material of the gas barrier layer
10A of the gas barrier sheet 10 in the lower section 24 of the
resin container 28. Accordingly, the moldability of the upper
section 26 of the resin container 28 which has larger protuberances
can be improved and together with this, the gas permeation of the
lower section 24 of the resin container 28, in which the gas
permeation is easily increased, can be restricted.
[0082] Next, the second embodiment of a method for manufacturing a
resin container in accordance with the present invention will be
explained in detail with reference to FIG. 9 through FIG. 11.
[0083] In this case, the same reference numerals will be attached
to the same elements as those of the first embodiment, and the
explanation thereof will be omitted.
[0084] As shown in FIG. 9, in the second embodiment, when the
combined intermediate molded products 38 are pressed to each other
by moving the pair of molds 59 (upper mold) and 52 (lower mold) of
the welding press in close to each other so that the peripheral
edges of the resin layers 36 of the combined intermediate molded
products 38 are melt-adhered to each other (resin melt-adhering
step), a pipe 54 serving as a connecting passage for connecting the
inside to the outside of the resin layer 36 is provided in the
joint of the resin layer 36.
[0085] Next, as shown in FIG. 10, by connecting a pressure reducing
pump (not illustrated) to the pipe 54, the gas between the gas
barrier sheet 10 and the resin layer 38 can be exhausted and the
slack part of the gas barrier sheet 10 protruding inside the resin
container (fuel tank) 28 is brought into contact with the resin
layer 38 (gas exhausting step).
[0086] At this time, the gas barrier sheet 10 can be melt-adhered
to the resin layer 38 by the temperature of the resin layer 38.
[0087] Finally, the pipe 54 for exhausting the gas is closed, the
portion of the pipe 54 projecting from the resin container (the
fuel tank) 28 is cut and removed by a cutter and the like, and as
shown in FIG. 11, the resin container (the fuel tank) 28 is removed
from the pair of molds 50 (uppermold) and 52 (lower mold) of the
melt-adhering press.
[0088] Next, the operations of the method for manufacturing the
resin container in accordance with the second embodiment will be
explained.
[0089] In the method for manufacturing the resin container in
accordance with the second embodiment, since in the gas exhausting
step (refer to FIG. 9), the gas between the gas barrier sheet 10
and the resin layer 36 is exhausted through the pipe 54 is mounted
in the joint of the resin layer 36 connecting the inside to the
outside thereof, any gas remaining between the gas barrier sheet 10
and the resin layer 36 is removed and any capacity reduction of the
resin container (the fuel tank 28) can be prevented.
[0090] Further, in the method for manufacturing the resin container
in accordance with the second embodiment, since in the gas
exhausting process (refer to FIG. 9) the gas barrier sheet 10 is
melt-adhered to the resin layer 38 by the temperature of the resin
layer 38, the gas barrier sheet 10 can be securely held. Further,
since it is not necessary to independently heat either the gas
barrier sheet 10 or the resin layer 38, productivity is
improved.
[0091] In the second embodiment the process for injection molding
is shown, however, the present invention can be applied to
injection press molding, hot flow stamping molding, and sheet flow
stamping molding.
[0092] Next, a third embodiment of a method for manufacturing a
resin container in accordance with the present invention will be
explained in detail with reference to FIG. 12 and FIG. 13.
[0093] In this case, the same reference numerals will be attached
to the same elements as those of the first embodiment, and the
explanation thereof will be omitted.
[0094] As shown in FIG. 12, in the third embodiment, a cooling
portion 64 is provided in the portion which is brought into contact
with the peripheral edge of the resin layer 36 of the upper mold 20
used for the intermediate molded product molding process, and a
heat insulating material 66 is provided between the cooling portion
64 and the upper mold 20. In this case, the cooling portion 64 is
constructed, for example, from a pipe through which a cooling water
passes.
[0095] Accordingly, since the temperature of the peripheral edge of
the resin layer 36 is decreased by the cooling portion 64, thereby
restricting the temperature increase of the peripheral edge of the
gas barrier sheet 10, the reliability of the gas barrier sheet 10
can be improved. Further, a non-melt-adhered portion 68 between the
resin layer 36 and the gas barrier sheet 10 is formed along the
peripheral edge of the resin layer 36.
[0096] Further, in the resin melt-adhering step, since a
non-melt-adhered welded portion 68 is formed between the gas
barrier sheet 10 and the peripheral edge of the resin layer 36, the
gas barrier sheet 10 can be bent in the non-melt-adhered portion
68. Accordingly, since the gas barrier sheet 10 is not affected by
the influence of the heat, localized elongation of the gas barrier
sheet 10 can be restricted. As a result of this, the reliability of
the gas barrier sheet 10 can be improved.
[0097] Next, operations of the method for manufacturing the resin
container in accordance with the third embodiment will be
explained.
[0098] In the method for manufacturing the resin container in
accordance with the third embodiment, since the temperature of the
peripheral edge of the resin layer 36 is decreased by the cooling
portion 64 formed in the upper mold 20, thereby restricting the
temperature increase of the peripheral edge of the gas barrier
sheet 10, the reliability of the gas barrier sheet 10 can be
improved. Further, since the non-melt-adhered portion 68 between
the resin layer 36 and the gas barrier sheet 10 is formed along the
peripheral edge of the resin layer 36, the gas barrier sheet 10 can
be bent in the non-melt-adhered portion 68 at the same time as the
slack of the gas barrier sheet 10 is pushed inside the resin
container (fuel tank) 28. Accordingly, since the gas barrier sheet
10 is not affected by the influence of the heat, localized
elongation of the gas barrier sheet 10 is restricted and the
reliability of the gas barrier sheet 10 can be improved.
[0099] As shown in FIG. 13, for example, a structure wherein a
piece of Teflon tape may be preliminarily disposed on the
peripheral edge portion of the gas barrier sheet 10 as a member
which is not melt-adhered with the resin layer 36 may be utilized.
As the Teflon tape 70 is in contact with the peripheral edge
portion of the resin layer 36, it is able not only to inhibit the
temperature of the peripheral edge of the barrier sheet 10 from
increasing but also to allow the elongation of the gas barrier
sheet 10 to be restricted due to non-melt-adhered portions in the
peripheral edges portions of the resin layer 36 and the gas barrier
sheet 10 through the Teflon tape 70.
[0100] Further, in the third embodiment, the process for injection
molding is shown, however, the present invention can be applied to
injection press molding, hot flow stamping molding, and sheet flow
stamping molding.
[0101] Next, a fourth embodiment of a method for manufacturing a
resin container in accordance with the present invention will be
explained in detail with reference to FIG. 14 through FIG. 17.
[0102] In this case, the same reference numerals will be attached
to the same elements as those of the first embodiment, and the
explanation thereof will be omitted.
[0103] As is shown in FIG. 14A, in the fourth embodiment hook
shaped engaging concave 74 and convex 76 portions are integrally
formed in advance by press molding or the like at predetermined
intervals on the connecting sections 10C of the peripheral edges of
both gas barrier sheets 10 to act as engagers, as is also shown in
FIG. 15. After these concave 74 and convex 76 engaging portions
have engaged with each other the connecting sections 10C of the
peripheral edges of both gas barrier sheets 10 are melt-adhered
together (sheet member melt-adhering step), as is shown in FIG.
14B.
[0104] Accordingly, in the resin container (fuel tank) 28
manufactured by this manufacturing method, engaging concave
portions 74 and engaging convex portions 76 are respectively formed
in the peripheral edges of the gas barrier sheets 10 at
predetermined intervals.
[0105] Next, operations of the method for manufacturing the resin
container in accordance with the fourth embodiment will be
explained.
[0106] In the method for manufacturing the resin container in
accordance with the fourth embodiment, since the connecting
portions 10C of the peripheral edge portions of both of the gas
barrier sheets 10 is melt-adhered so as to form a bag-like shape
after the engaging concave portions 74 and the engaging convex
portions 76 previously formed in necessary portions of the
connecting sections 10C of the peripheral edge portions of both of
the gas barrier sheets 10 are engaged with each other in the sheet
member melt-adhering step, the creases in the connecting sections
of the gas barrier sheets 10 generated by the slack which is
produced in the peripheral edge portions of the gas barrier sheets
10 at a time of manufacturing can be restricted. As a result of
this, the reliability of the gas barrier sheets 10 can be improved,
and in addition to this, the air tightness of the gas barrier sheet
10 is improved. Further, the melt-adhering operability of the
peripheral edge portions of the gas barrier sheets 10 is
improved.
[0107] Further, for example, as shown in FIG. 16A and FIG. 16B, the
shape of the engaging concave portions 74 and the engaging convex
parts 76 may be made in other shapes such as an arrow head shape
and the like. Moreover, as shown in FIG. 17A and FIG. 17B, the
structure may be made so that the engaging concave portion 74 and
the engaging convex portion 76 are respectively inserted or fixed
to the connecting portions 10C of the peripheral edge portions of
each of the gas barrier sheets 10 as independent members.
[0108] Further, in the fourth embodiment, the process for injection
molding is shown, however, the present invention can be applied to
injection press molding, hot flow stamping molding, and sheet flow
stamping molding.
[0109] Next, a fifth embodiment of a method for manufacturing a
resin container in accordance with the present invention will be
explained in detail with reference to FIG. 18.
[0110] In this case, the same reference numerals will be attached
to the same elements as those of the first embodiment, and the
explanation thereof will be omitted.
[0111] As shown in FIG. 18, in the fifth embodiment, a poly-amide
resin (PA) layer 78 serving as a reinforcing layer is formed on the
gas barrier sheet 10. The poly-amide resin layer 78 is formed in
advance on the portion 10A of the gas barrier sheet 10 which is
opposite the resin injecting hole 40 provided in the upper mold 20
and an area surrounding the portion 10A.
[0112] Next, operations of the method for manufacturing the resin
container in accordance with the fifth embodiment will be
explained.
[0113] In the method for manufacturing the resin container in
accordance with the fifth embodiment, when molten resin is poured
onto the gas barrier sheet 10 disposed on the lower mold 18 from
the resin injecting hole 40 provided on the upper mold 20, the
portion 10A of the gas barrier sheet 10 opposite the resin
injecting hole 40 and the area surrounding this portion are
affected by the influence of the heat from the molten resin which
is further heated by the shearing force from the resin injecting
hole 40 and the frictional force from the molten resin.
[0114] At this time, in the fifth embodiment, the gas barrier sheet
10 can be prevented from melting by the poly-amide resin layer 78
which is not melted by the injected resin and is disposed on the
portion 10A of the gas barrier sheet 10 and the area surrounding
this portion opposite the resin injecting hole 40. As a result of
this, the reliability of the gas barrier sheet 10 can be
improved.
[0115] The reinforcing layer is not limited to the poly-amide layer
78 and the other members such as metal foil and the like which are
not melted by the injected resin may be used. Further, the
reinforcing layer may be formed on the entire surface of the gas
barrier sheet 10.
[0116] Next, a sixth embodiment of a method for manufacturing a
resin container in accordance with the present invention will be
explained in detail with reference to FIG. 19 through FIG. 23.
[0117] In this case, the same reference numerals will be attached
to the same elements as those of the first embodiment, and the
explanations thereof will be omitted.
[0118] As shown in FIG. 20A and FIG. 20B, in the sixth embodiment,
a length L1 and a length L2 of the peripheral edges portions of the
gas barrier sheets 10 of the combined intermediate molded products
38 are different from each other.
[0119] Further, since the convex portion 10A is formed on the gas
barrier sheet 10, when the resin layer 36 is formed on the outside
of the gas barrier sheet 10 by injection molding, an engaging
portion 39 between the convex portion 10A of the gas barrier sheet
10 and the concave portion 36A of the resin layer 36 is formed near
the portion held between the heat plate 12 and the pressing plate
14 of the gas barrier sheet 10, that is, in the end portion of the
bonding portion between the resin layer 36 and the gas barrier
sheet 10.
[0120] Further, as shown in FIG. 21A, the cross sectional shape of
the heat plate 12 is formed as a wedge shape. Accordingly, when the
peripheral edge of the gas barrier sheet 10 is thermally
melt-adhered, as shown in FIG. 21B, the resin layer 15 held between
the respective gas barrier layers 13 can be pressed out so that the
respective gas barrier layers 13 are melt-adhered to each other. As
a result of this, since the structure advantageous for preventing
gas permeation, that is, the gas barrier layer 13, can be made into
a seamless bag shape, the level of gas permeation can be
minimized.
[0121] It should be noted that the pressing plate 14 has already
been removed from the intermediate molded product 38, by the
stage.
[0122] Further, in the sixth embodiment, as shown in FIG. 19, since
the engaging portion 39 between the convex portion 10A of the gas
barrier sheet 10 and the concave portion 36A of the resin layer 36
is formed in an end portion 80A of a bonded portion 80 between the
resin layer 36 and the gas barrier sheet 10, when the pressure
inside the bag-shaped gas barrier sheet 10 is reduced so as to pull
in the gas barrier sheet 10, the stress generated in the gas
barrier sheet 10 acts as a tensile force (arrow F1 of FIG. 19) on
the gas barrier sheet 10 at the engaging portion 39, but does not
act as a peeling force (arrow F2 of FIG. 19) on the bonding portion
80 between the resin layer 36 and the gas barrier sheet 10.
Accordingly, the gas barrier sheet 10 can be prevented from peeling
away from the resin layer 36 or becoming liable to peel away, so
that the reliability of the gas barrier sheet 10 can be
improved.
[0123] In this case, in a portion 82 closer to the bonding portion
than the engaging portion 39 of each of the intermediate molded
products 38, the portion 82 may be previously made as a
non-melt-adhered portion so that the peeling force does not act on
the bonded portion 80 between the resin layer 36 and the gas
barrier sheet 10.
[0124] Further, as shown in FIG. 20A, in the sixth embodiment,
since the length L1 and the length L2 of the respective peripheral
edge portions of the gas barrier sheets 10 of the combined
intermediate molded products 38 are different from each other, as
shown in FIG. 19, the position of the joint 10B between the gas
barrier sheets 10 and the position of the bend 10C in the gas
barrier sheet 10 generated when the sheet is pulled in, do not
match each other. As a result of this, the stress generated when
the sheet is pulled in is not concentrated on the joint 10B between
the gas barrier sheets 10.
[0125] Accordingly, as shown in FIG. 22, in the resin container
(the fuel tank) 28 manufactured by this manufacturing method, the
engaging portion 39 engaging the convex portion 10A of the gas
barrier sheet 10 and the concave portion 36A of the resin layer 36,
is formed in the end portion of the bonding portion between the
resin layer 36 and the gas barrier sheet 10.
[0126] Next, operations of the method for manufacturing the resin
container in accordance with the sixth embodiment will be
explained.
[0127] In the resin container in accordance with the present
embodiment, since the engaging portion 39 engaging the convex
portion 10A of the gas barrier sheet 10 and the concave portion 36A
of the resin layer 36, is formed on the end portion 80A of the
bonding portion 80 between the resin layer 36 and the gas barrier
sheet 10, during the manufacturing process, when the pressure
inside the bag-shaped gas barrier sheet 10 is reduced and the gas
barrier sheet 10 is pulled in, the stress generated in the gas
barrier sheet 10 acts as a tensile force (arrow F1 of FIG. 19) on
the gas barrier sheet 10 at the engaging portion 39, but does not
act as a peeling force on the bonding portion 80 between the resin
layer 36 and the gas barrier sheet 10. Accordingly, the reliability
of the gas barrier sheet 10 can be improved.
[0128] Further, in the sixth embodiment, as shown in FIG. 20A, the
length L1 and L2 of the peripheral edge portions of the gas barrier
sheets 10 of the combined intermediate molded products 38 are
different from each other. Accordingly, as shown in FIG. 19, since
the position of the joint 10B between the gas barrier sheets 10 and
the position of the bend 10C in the gas barrier sheet 10 generated
when the sheet is pulled in, do not match each other, the stress
generated when the sheet is pulled in is not concentrated on the
joint 10B, so that the reliability of the gas barrier sheet 10 can
be further improved.
[0129] Further, in the present embodiment, as shown in FIG. 21A,
since the cross section of the heat plate 12 is made wedge shaped,
when the peripheral edge portion of the gas barrier sheet 10 are
thermally melt-adhered, as shown in FIG. 21B, the resin layer 15
held between the respective gas barrier layers 13 can be pressed
out and the respective gas barrier layers 13 can be melt-adhered to
each other, so that the amount of the gas permeation can be
minimized.
[0130] Further, in the sixth embodiment, the cross sectional shape
of the heat plate 12 is made wedge shaped, however, the cross
sectional shape of the heat plate 12 is not limited to this, and
can be made as other convex shapes FIG. 23A and FIG. 23B show
examples of a cross sectional shape having a circular convex
portion 12A so that the resin layer held between the respective gas
barrier layers can be pressed out by the convex portion 12A.
[0131] Further, in the sixth embodiment, the process for injection
molding is shown, however, the present invention can be applied to
injection press molding, hot flow stamping molding, and sheet flow
stamping molding. Further, high frequency welding can be applied as
the film welding method.
[0132] Next, a seventh embodiment of a method for manufacturing a
resin container in accordance with the present invention will be
explained in detail with reference to FIG. 24 and FIG. 25.
[0133] In this case, the same reference numerals will be attached
to the same elements as those of the first embodiment, and the
explanation thereof will be omitted.
[0134] As shown in FIG. 24, in the seventh embodiment, a notch 100
is formed in the edge portion of the heat plate 12 opposed to the
gas barrier sheet 10 along the gas barrier sheet 10, and the
opening 100A of the notch 100 disposed on the opposite side to the
bonding portion 10C on the gas barrier sheet 10 is made with a
small diameter. Further, as shown in FIG. 25, the cross section of
the notch 100 is made in a half circular shape.
[0135] Accordingly, in the intermediate molded product molding
step, an extension portion 36B is formed extending from a point 36C
where a portion of the resin layer 36 bonds with the other
intermediate molded product to the bonding portion 10C of the gas
barrier sheet 10.
[0136] Next, operations of the method for manufacturing the resin
container in accordance with the seventh embodiment will be
explained.
[0137] In the resin container in accordance with the seventh
embodiment, since the extended portion 36B of the resin layer 36
imparts tension to the bonding portion 10C of the gas barrier sheet
10 in the intermediate molded product molding step, the creases in
the connecting portion 10C of the gas barrier sheet 10 can be
restricted. Further, when the bonding portions 36C of the resin
layers 36 are melt-adhered to each other, the extension portion 36B
is easily broken at the neck portion 37 formed by the opening
portion 100A of the notch 100 and is drawn into the container
together with the gas barrier sheet 10.
[0138] Next, an eighth embodiment of a method for manufacturing a
resin container in accordance with the present invention will be
explained in detail with reference to FIG. 26.
[0139] In this case, the same reference numerals will be attached
to the same elements as those of the first embodiment, and the
explanation thereof will be omitted.
[0140] As shown in FIG. 26, in the eighth embodiment, in the
intermediate molded product forming step, a gap H1 within the
cavity 22 near the resin injecting hole 40 of the upper mold 20 is
wider than a gap H2 of the other portions.
[0141] Next, operations of the method for manufacturing the resin
container in accordance with the eighth embodiment will be
explained.
[0142] In the intermediate molded product molding step, when molten
resin is poured on the gas barrier sheet 10 disposed on the lower
mold 18 from the resin injecting hole 40 provided on the upper mold
20 (the arrow in FIG. 26 shows the flow of the molten resin), the
portion 10A of the gas barrier sheet 10 opposite the resin
injecting hole 40 and the area surrounding the portion 10A are
affected by the influence of the heat of the molten resin which is
increased by the shear force imparted by the resin injecting hole
40 and the friction force from the molten resin.
[0143] At this time, in the eighth embodiment, since the gap H1
inside the cavity 22 near the resin injecting hole 40 on the gas
barrier sheet 10 is wider than the gap H2 of the other portions,
the flow speed of the molten resin can be restricted. As a result
of this, the gas barrier sheet 10 can be prevented from being
melted and the reliability of the gas barrier sheet 10 can be
improved.
[0144] Next, a ninth embodiment of a method for manufacturing a
resin container in accordance with the present invention will be
explained in detail with reference to FIG. 27.
[0145] In this case, the same reference numerals will be attached
to the same elements as those of the first embodiment, and the
explanation thereof will be omitted.
[0146] As shown in FIG. 27, in the ninth embodiment, in an engaging
portion 110 between an attachment part, such as the cut off valve
16 and the like, and the gas barrier sheet 10 the engaging portion
110A of the attachment part is formed as a concave shape.
Accordingly, in the intermediate molded product molding process,
when the attachment part such as the cut off valve 16 or the like
is covered by the gas barrier sheet 10, the engaging portion 110A
of the attachment part is formed as a concave shape and the
engaging portion 110A of the gas barrier sheet 10 is formed as a
convex shape.
[0147] Next, operations of the method for manufacturing the resin
container in accordance with the ninth embodiment will be
explained.
[0148] In the ninth embodiment, as shown in FIG. 27, since the
engaging portion 110A of the attachment part such a cut off valve
16 is formed as a concave shape in the engaging portion 110, which
is different from in case that the engaging portion of the
attachment part such a cut off valve 16 is formed as a convex shape
as shown in FIG. 1B, in the intermediate molded product molding
process, the engaging portion 100 can reduce the heat and the
friction force imparted by the molten resin (the arrow in FIG. 27
shows the flow of the molten resin). As a result of this, fusion
due to accumulated heat between the attachment part and the gas
barrier sheet 10 is not generated in the engaging portion 100, so
that the reliability of the gas barrier sheet 10 can be
improved.
[0149] In the above, the present invention has been explained with
respect to the specified embodiments, however, the present
invention is not limited to the above embodiments, and it will be
clear to those skilled in the art that other various embodiments
are possible within the scope of the present invention. For
example, in the above, a fuel tank for an automotive vehicle is
used as an example of a resin container 22, however, the resin
container 22 is not limited to fuel tanks for automotive vehicles.
Further, the material of the gas barrier sheet 10 and the material
of the resin layer 36 are not limited to those explained above.
[0150] Further, in order to improve strength, air tightness,
appearance and the like of the bonding portion between the
peripheral edge portions of the resin layers 36 of the intermediate
molded products 38, as shown in FIG. 28, after reheating the molded
and cooled resin layer 36, or while it is still warm, the resin
layer 36 may be set to a jig 112 so as to correct the shape of the
bonding portion (the peripheral edge portion) 36C. At this time, as
shown in FIG. 29, by using a vacuum shape correcting machine 114
and the like, external force maybe applied to the resin layer 36.
Further, when the external force is given during the melt-adhering
of the peripheral edges of the resin layers 36 of the combined
intermediate molded products 38 (resin melt-adhering step), it is
more effective.
[0151] Further, as shown in FIG. 30, the gas barrier layer 10A may
be formed between the lower mold 18 and an upper mold 116 by
injection molding (the arrow in FIG. 30 shows the flow of the
molten resin), thereafter, as shown in FIG. 31, the upper mold 116
may be replaced by the upper mold 20, and the resin layer 36 may be
formed between the upper mold 20 and the gas barrier layer 10A by
injection molding (the arrow in FIG. 31 shows the flow of the
molten resin). Accordingly, productivity and moldability is
improved. Further, since the thickness and the quality of the
material of the gas barrier layer 10A can be changed in the upper
portion and the lower portion or the front portion and the rear
portion, or the like of the resin container, the optimum gas
permeation preventing performance, strength and formability can be
guaranteed. Further, by forming inner structural portions such as a
sub tank 44, a separator 46, and the like integrally with the gas
barrier layer 10A, a resin container with a seamless gas barrier
layer 10A can be efficiently produced. Further, as a method for
producing the resin container with a seamless gas barrier layer
10A, as shown in FIG. 32, a resin injecting port 118 is provided in
the lower mold 18, a resin 122 is poured into the cavity of a
middle mold 120 from the resin injecting port 118 (the arrow in
FIG. 32 shows the flow of the molten metal), so that the inner
structural portions such as the sub tank 44, the separator 46, and
the like bonded to the gas barrier layer 10A may be formed.
[0152] Further, as shown in FIG. 33, in order to improve
productivity, at the same time as the resin layer 36 is formed by
injection molding (the arrow in FIG. 33 shows the flow of the
molten resin), the inner structural portions such as the separator
46 and the like set on the lower mold 18, and a clamp 124 and the
like set on the upper mold 20 may be simultaneously melt-adhered.
At this time, by using a resin having a gas barrier capacity for
the inner structural portions such as the separator 46 and the like
which are melt-adhered to the gas barrier layer 10A, breakage of
the gas barrier layer during melt-adhering can be prevented.
[0153] Further, as shown in FIG. 34A, FIG. 34B, FIG. 35A and FIG.
35B, in order to improve productivity, at the same time as the
resin layers 36 are melt-adhered to each other, the gas barrier
sheets 10 may be melt-adhered to each other by the heat from the
resin layer 36.
Industrial Applicability
[0154] As mentioned above, the resin container and the method for
manufacturing the same in accordance with the present invention are
effective for fuel tanks for automotive vehicles and the
manufacturing thereof, and in particular, for improving the gas
permeation preventing performance in the area where the
intermediate formed products of a fuel tank for an automotive
vehicle are bonded to each other.
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