U.S. patent application number 13/157341 was filed with the patent office on 2011-09-29 for passenger side airbag door for instrument panel and its manufacturing method.
Invention is credited to Haijun Chen, Yunju Chen, Jianfeng Hou, Shaihua Zhou.
Application Number | 20110233805 13/157341 |
Document ID | / |
Family ID | 39447352 |
Filed Date | 2011-09-29 |
United States Patent
Application |
20110233805 |
Kind Code |
A1 |
Chen; Yunju ; et
al. |
September 29, 2011 |
PASSENGER SIDE AIRBAG DOOR FOR INSTRUMENT PANEL AND ITS
MANUFACTURING METHOD
Abstract
The present invention relates to an airbag door for instrument
panel and its manufacturing method. A passenger side airbag (PAB)
door for instrument panel includes a substrate with airbag opening,
skin layer and foam layer, a PAB door reinforcement board which
covers the airbag opening is connected to the instrument panel
substrate. This PAB door reinforcement board is a cellulosic
composite material board which is soaked by thermoplastic plastic
or thermoplastic elastomer, formed through thermoforming. In
present invention, the turnover and movable portion of the airbag
door is lighten greatly. The airbag door with the light composite
material can prevent the windshields from being broken effectively
when the airbag deploys sufficiently and impacts against the
windshields.
Inventors: |
Chen; Yunju; (Shanghai,
CN) ; Chen; Haijun; (Shanghai, CN) ; Hou;
Jianfeng; (Shanghai, CN) ; Zhou; Shaihua;
(Shanghai, CN) |
Family ID: |
39447352 |
Appl. No.: |
13/157341 |
Filed: |
June 10, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12332457 |
Dec 11, 2008 |
7980587 |
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13157341 |
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Current U.S.
Class: |
264/46.8 |
Current CPC
Class: |
B29C 44/1228 20130101;
B60R 21/2165 20130101; Y10T 29/49622 20150115 |
Class at
Publication: |
264/46.8 |
International
Class: |
B29C 51/14 20060101
B29C051/14 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 11, 2007 |
CN |
200710172039.1 |
Claims
1. A method of manufacturing a passenger side airbag door for an
instrument panel having an airbag comprising the steps of:
thermoforming an airbag reinforcement board to maintain a stable
shape and mechanical properties; assembling the airbag
reinforcement board and a clamp plate onto an instrument panel
substrate; disposing a skin layer and the assembled instrument
panel substrate, airbag reinforcement board, and clamp plate into a
mold; and pouring a foaming layer into the mold to form the
passenger side airbag door.
2. The method as set forth in claim 1 wherein the assembly step is
further defined as sandwiching an end portion of the airbag
reinforcement board between the clamp plate and the instrument
panel substrate to secure the end portion of airbag reinforcement
board to the instrument panel substrate.
3. The method as set forth in claim 1 further including the step of
disposing an airbag tape on at least a body portion of the airbag
reinforcement board and the instrument panel substrate to secure
the body portion of the airbag reinforcement board to the
instrument panel substrate.
4. The method as set forth in claim 1 further including the step of
soaking a cellulosic material with one of a thermoplastic plastic
or thermoplastic elastomer to form a raw material.
5. The method as set forth in claim 4 wherein the cellulosic
material is at least one of glass fiber, bast fiber, cotton fiber
and bamboo fiber.
6. The method as set forth in claim 4 wherein the thermoplastic
plastic includes polypropylene.
7. The method as set forth in claim 4 wherein the thermoplastic
elastomer is a mixture of at least one of
acrylonitrile-butadiene-styrene and polycarbonate (ABS/PC),
thermoplastic polyolefin (TPO), and acrylonitrile-butadiene-styrene
(ABS).
8. The method as set forth in claim 1 further including the step of
combining a surface of the airbag reinforcement board with a layer
of compacted material.
9. The method as set forth in claim 1 wherein the thermoforming
step further includes the step of heating the airbag reinforcement
board to a temperature in the range of 160-200.degree. C.
10. The method as set forth in claim 1 further including the steps
of: defining an airbag opening in the substrate; and disposing the
airbag reinforcement board continuously over the airbag opening to
receive the impact of the airbag when deployed.
11. The method as set forth in claim 1 wherein the thermoforming
step is further defined as pressing the airbag reinforcement board
to form a certain shape and maintain the shape.
12. The method as set forth in claim 1 further including the step
of laminating a membrane on the airbag reinforcement board to form
a compact joint surface with the foam layer, so that foam layer
will not peel off from the airbag reinforcement board door during
the deployment of the airbag.
13. The method as set forth in claim 4 further including the step
of trimming the raw material to form a raw material sheet.
14. The method as set forth in claim 13 further including the step
of holding the raw material sheet in a heating device to make the
temperature of the surface and the interlayer of the raw material
sheet uniform.
15. The method as set forth in claim 13 further including the steps
of: placing the raw material sheet in a thermoforming tool; and
applying a pressure to the raw material sheet to form the airbag
reinforcement board.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a divisional application which claims priority to
U.S. patent application Ser. No. 12/332,457, filed Dec. 11, 2008
entitled "Passenger Side Airbag Door For Instrument Panel And Its
Manufacturing Method" which claims priority to Chinese patent
application No. 200710172039.1, titled "Passenger-Side Airbag Door
For Instrument Panel And Its Manufacturing Method", all of which
are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an airbag door for
instrument panel and its manufacturing method, and more
particularly to an airbag door for covering the passenger side
airbag of instrument panel and its manufacturing method.
DESCRIPTION OF THE PRIOR ART
[0003] At present, to most automotive Instrument Panel (I/P) with
Passenger side Airbag (PAB) of U-shape opening, it is common to use
an airbag door with metal reinforcement board. Generally, the metal
reinforcement board is mounted onto the I/P substrate by riveting,
snapping or insert molding, to reinforce the I/P locally. When
vehicle crash happens, the PAB will deploy and the metal
reinforcement board will help to keep the integrity of the PAB
door, prevent the PAB door from cracking, breaking into fragments,
or undesirable deformation. PAB door with metal reinforcement board
is widely used because of it's high reliability and stability.
[0004] However, the main shortcoming of metal reinforcement board
is its heavy weight. The weight of movable portion of it can be
over 250 grams, not counting the weight of I/P skin and foam.
Depending on I/P's structure, in most cases, the PAB door can still
keep a certain distance from the front windshield and will not hit
the windshield when PAB deploys. But as the design of the
automobile cockpits is confined by other factors, that PAB door
will inevitably hit the windshield when PAB deploys, the
highly-weighted PAB door with metal reinforcement board will be
very likely to crash the windshield and break it, generating glass
fragments, which will potentially hurt the passengers.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a passenger
side airbag door for instrument panel and its manufacturing method,
lowering the weight of the turnover and movable portion of the PAB
door while satisfying the appearance, the total performance
requirements and the manufacturability of I/P. Thus, even the PAB
door hits the front windshield when PAB is fully deployed, the
windshield will not be breaked.
[0006] To achieve the object mentioned above, a passenger side
airbag door for instrument panel of the present invention is
disclosed.
[0007] A passenger side airbag door for instrument panel includes a
substrate with airbag opening, skin layer and foam layer, a PAB
door reinforcement board which covers the airbag opening is
connected to the instrument panel substrate. This PAB door
reinforcement board is a cellulosic composite material board which
is soaked by thermoplastic plastic or thermoplastic elastomer.
[0008] The present invention further provides a method of
manufacturing a passenger side airbag door for instrument panel
described above. The method includes the steps of: firstly, forming
an airbag reinforcement board through thermoforming; secondly,
assembling airbag reinforcement board together with a clamp plate
onto the substrate; and then putting the skin layer and the
substrate with airbag reinforcement board and clamp plate
preinstalled into the mold; pouring in foaming material and forming
the product.
[0009] The present invention uses the airbag reinforcement board
made of a cellulosic composite material which is soaked by
thermoplastic plastic or thermoplastic elastomer. Since the
composite material is greatly lighter than the metal piece, so the
turnover and movable portion of the airbag door is lighten greatly.
After hot press molding, the glass fiber sheet material which is
soaked by polypropylene has a stable shape and stable mechanical
properties to meet the burst requirements of the airbag door. The
airbag door with the light composite material can prevent the
windshields from being broken effectively when the airbag deploys
sufficiently and impacts against the windshields.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cross-sectional view of a passenger side airbag
door for instrument panel in accordance with the present
invention.
[0011] FIG. 2 is a schematic view showing that the passenger side
airbag door for instrument panel is assembled at an airbag
opening.
[0012] FIG. 3 is a schematic view of a heating process when
manufacturing the PAB door reinforcement board.
[0013] FIG. 4 is a schematic view of a press-molding process when
manufacturing the PAB door reinforcement board.
[0014] FIG. 5 is a schematic view showing the PAB door
reinforcement board assembled on the instrument panel substrate
when manufacturing the PAB door.
[0015] FIG. 6 is a schematic view showing that the airbag door is
foamed and molded in a mold.
[0016] FIG. 7 is a perspective view showing that the PAB door
without skin layer which is assembled at the airbag opening.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] To further understand functions and features of the present
invention, please refer to the detailed description of the
preferred embodiment related the present invention according to
FIGS. 1-7.
[0018] FIG. 1 and FIG. 2, a passenger side airbag door for
instrument panel 1 is located at a passenger side airbag deployment
opening 2 of an instrument panel and includes an instrument panel
substrate 11 with an airbag opening, a foam layer 12, a skin layer
13 and a PAB door reinforcement board 10 which covers the airbag
opening and is connected with the instrument panel substrate 11.
One end of the PAB door reinforcement board 10 far away from
passengers is firmly pressed by a clamp plate 3 and connected with
the instrument panel substrate via welding, riveting or bolt
connection and can be folded along the clamp plate 3 when it being
opened. It is also possible that the airbag clamp plate 3 has hook
features that can go through holes on PAB door reinforcement board
10 and substrate 11, then get hooked on substrate 11 via folding
and deforming. PAB tapes 4 seal the airbag door and the substrate
at the other three ends of the PAB reinforcement board 10, thereby
preventing the foam material from leaking through PAB opening
2.
[0019] When the airbag deploys, the airbag door 1 rotates about the
hinge line of clamp plate 3 along the weaken line on the instrument
panel substrate 2 instantly and provides deployment space for the
airbag, protecting the passengers.
[0020] The present invention uses the airbag reinforcement board
made of a cellulosic composite material which is soaked by
thermoplastic plastic or thermoplastic elastomer.
[0021] The PAB door reinforcement board 10 is thermoformed with a
composite material soaked by thermoplastic plastic or thermoplastic
elastomer via hot press molding. The thermoplastic plastic can be
polypropylene (PP) or a kind of polypropylene-based blend, such as
PP/EPDM, PP/PE and so on. The thermoplastic elastomer can be
thermoplastic polyolefin (TPO), acrylonitrile-butadiene-styrene
(ABS), or a mixture of acrylonitrile-butadiene-styrene and
polycarbonate (ABS/PC). The cellulosic composite material for
reinforcement can be at least one material of glass fiber, flax
fiber, cellulose fiber or bamboo fiber.
[0022] The cellulosic composite material should have the following
key characteristics: Area density: 1300.about.1800 g/m2,
preferredly 1500 g/m2.
[0023] After being thermoformed into the airbag door, the
cellulosic composite material maintains a stable shape and stable
mechanical properties in a wide temperature range of PAB deployment
tests and insulation ones. The requirements of the wide temperature
range come of PAB deployment tests is -30.degree.
C..about.102.degree. C. The requirements of the temperature range
of PAB insulation tests is 24 hours at 130.degree. C. plus 24 hours
at 110.degree. C. or 168 hours at 102.degree. C. Maintaining the
stable shape means that the shape of the airbag door does not have
significant change which causes concavities and convexities on
surfaces of the instrument panel product in the above mentioned
temperature range. Maintaining the stable mechanical properties
mainly means that the material has certain impact resistance
performance, especially when the PAB deploys at a low temperature
of -30.degree. C., the material won't smash into small pieces and
fly off.
[0024] A preferred embodiment is a glass fiber sheet material which
has been soaked by thermoplastic plastic or thermoplastic
elastomer, such as a glass fiber sheet material soaked by
polypropylene, or called light glass fiber mat.
[0025] The glass fiber mat material is a piece of flat sheet with a
thickness of 2.about.3 mm. Glass fibers are glass rods with a
diameter of several microns. Besides universal gravitation and
intermolecular forces, there is no adhesion relationship between
any two glass fibers. After being soaked by polypropylene,
disordered glass fibers may be pressed to form a certain shape and
maintain the shape at a temperature which is higher than the
softening temperature of polypropylene.
[0026] The surfaces of the PAB reinforcement board 10, especially
the surface contacting the foam layer 12, should be compatible with
polyurethane foam materials and forming compact joint surface, so
that foam layer 12 will not peel off from PAB door during the PAB
deployment. There can also be a membrane laminated on the PAB door
reinforcement board 10, such as a mixture of
acrylonitrile-butadiene-styrene and polyvinyl chloride (PVC/ABS) or
thermoplastic polyurethane (TPU), via films or spraying. The
compact joint surface of the airbag door formed by polyurethane
avoid that the foam raw materials infiltrate into the airbag door,
then the foam materials will not peel off from the PAB door during
the deployment.
[0027] The thermoforming process of the PAB door reinforcement
board 10 is shown in FIGS. 3-4.
[0028] Firstly, the 1500 g/m2 airbag reinforcement board 10 plate
raw material is trimmed into raw material sheet 5 with suitable
mold size. The raw material sheet 5 is held in a heating device 6.
Heating device 6 can be an infra-red oven. Raw material sheet 5 is
vertically hung between the heating plates 60 and 61. Distance
between the heating plates 60 and 61 is about 20 cm. Allow raw
material sheet 5 to be heated up in 5 minutes and be kept at a
temperature between 160.degree. C. and 200.degree. C. for a period
of time, making the temperature of the surface and the interlayer
of the material uniform.
[0029] After being heated, remove the raw material sheet 5 from
heating device 6 and put it into lower half 70 of the thermoforming
tool 7, close the tool and apply a pressure. The upper half and
lower half of the mold match the airbag reinforcement board needs
to design. The thermoforming tool is made by steel, or hard
aluminum alloy. To improve the productivity, there can be cooling
water pipes running inside thermoforming tool 7. In this
embodiment, 30 tons pressure were applied for 1 minute, tool
temperature can be between 30.degree. C. and 70.degree. C.
[0030] After thermoforming, open thermoforming tool 7 and take out
PAB door reinforcement board 10, trim off any undesired margin of
raw material sheet 5 and get the product of airbag reinforcement
board 10.
[0031] Thermoforming is a known, widely used process to produce
automotive components such as roof trims, door panels, carpets and
sound insulation mats. Methods for heating are variable, which can
be heat plates heating, hot air heating and infra-red heating
corresponding to three heating ways of conduction, convection or
radiation. Heating method and heating time duration is variable to
suit individual need of every product and its raw material. The
temperature heated up to should within the softening temperature
and the decomposing temperature of thermoplastic plastic and
elastomer. In the embodiment, the heating temperature can be
between 160.degree. C. and 200.degree. C. After reaching the
machining temperature above mentioned, put the raw material sheet
into tool and compress before it cools down and exceeds the range
of thermoforming temperature. The compressing extent can be
controlled by compress or by the knob on the tool to limit the
height of closing the tool. In the embodiment, 30 tons pressure is
applied onto a 03.times.0.25 m2 raw material sheet and the
intensity of pressure is 4 MPa yielding a final product of about
1.3 mm thick.
[0032] The method of manufacturing the passenger side airbag door
for instrument panel is shown in FIGS. 5-7.
[0033] As described above, the PAB door reinforcement board 10 made
by light glass fiber mat is formed into a desired shape by
thermoforming molding.
[0034] As shown in FIG. 5, at first, preassemble the PAB door
reinforcement board 10 and the clamp plate 3 onto the instrument
panel substrate 11.
[0035] As shown in FIG. 6, place the skin 13 and the substrate 11
with PAB door reinforcement 10 and the clamp plate 3 preassembled
into the tool 8 and pour foam material layer 12 into it.
[0036] Finish other necessary processes such as trimming the margin
of foam layer, welding and assembling other accessories, etc. FIG.
7 is a perspective view showing a passenger side PAB door of
instrument panel covering the opening of airbag door with the skin
layer and foam layer peeled off.
[0037] The skin layer 13 can be made from powder material by slush
process, or from sheet material by vacuum forming process. The skin
layer 13 also needs to be scored at the profile line of the PAB
opening area, so that the skin layer at the profile line is thinner
than the skin layer at other places. The skin layer will be torn
into pieces along this scored line when PAB deploys. The scoring
method of the skin layer can be a mechanical scoring blade (cold
knife), a shaped, heated knife (hot knife), or laser scoring. The
substrate 11 is molded by injection molding process.
[0038] What are disclosed above are only the preferred embodiments
of the present invention and it is therefore not intended that the
present invention be limited to the particular embodiments
disclosed. It will be understood by those skilled in the art that
various equivalent changes may be made depending on the claims and
the specification of the present invention without departing from
the scope of the present invention.
* * * * *