U.S. patent application number 13/206011 was filed with the patent office on 2012-03-01 for manufacturing method for diffuser.
This patent application is currently assigned to IIDZKA SEISAKUSHO CO., LTD.. Invention is credited to Satoshi IIZUKA, Soichiro SHIBATA.
Application Number | 20120047983 13/206011 |
Document ID | / |
Family ID | 45695342 |
Filed Date | 2012-03-01 |
United States Patent
Application |
20120047983 |
Kind Code |
A1 |
IIZUKA; Satoshi ; et
al. |
March 1, 2012 |
MANUFACTURING METHOD FOR DIFFUSER
Abstract
A manufacturing method for a diffuser comprises a first process
of forming a first molded component, by gradually forging a
cylindrical solid material having fiber flow extending in an axial
direction from an axial direction thereof, the first molded
component including a flange section having a central hole section,
and a bottomed cylindrical section having a communication hole
leading to one end, in the axial direction, of the flange, and
communicating with the hole section, and having fiber flow that is
flowing substantially in the axial direction without being cut, and
a second process of forming a second molded component, by split
molding a peripheral groove using split dies at the outer periphery
of the bottomed cylindrical section of the first molded component,
including a flange having a central hole section, and a bottomed
cylindrical section having a communication hole leading to one end,
in the axial direction, of the flange, and communicating with the
hole section, and having the peripheral groove formed without
cutting fiber flow. The embodiment provides a manufacturing method
for a diffuser that can be produced with high yield and at low
cost, while doing away with locations where fiber flow is cut and
that has no gas leakage.
Inventors: |
IIZUKA; Satoshi; (Nara City,
JP) ; SHIBATA; Soichiro; (Nara City, JP) |
Assignee: |
IIDZKA SEISAKUSHO CO., LTD.
Yamatotakada City
JP
|
Family ID: |
45695342 |
Appl. No.: |
13/206011 |
Filed: |
August 9, 2011 |
Current U.S.
Class: |
72/352 |
Current CPC
Class: |
B21J 1/025 20130101;
B21K 21/08 20130101; B60R 21/261 20130101 |
Class at
Publication: |
72/352 |
International
Class: |
B21D 22/00 20060101
B21D022/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 27, 2010 |
JP |
2010-206091 |
Claims
1. A manufacturing method for a diffuser comprising a flange with a
central hole section and an outer engagement section, and a
bottomed cylindrical section having a communicating hole that leads
to one end, in an axial direction, of the flange and communicates
with the hole section, with a peripheral groove formed on an outer
peripheral section of the bottomed cylindrical section, and a
plurality of expulsion ports that communicate with an airbag
extending radially to the bottom section of the communication hole,
comprising: a first process of forming a first molded component, by
gradually forging a cylindrical solid material from an axial
direction thereof using the cylindrical solid material having fiber
flow extending in an axial direction in order to prevent material
loss, the first molded component including a flange section having
a central hole section, and a bottomed cylindrical section having a
communication hole leading to one end, in the axial direction, of
the flange, and communicating with the hole section, and having
fiber flow that is not cut and flowing substantially in the axial
direction; and a second process of forming a second molded
component, by split molding a peripheral groove using split dies at
the outer periphery of the bottomed cylindrical section of the
first molded component, the second molded component including a
flange having a central hole section, and a bottomed cylindrical
section having a communication hole leading to one end, in the
axial direction, of the flange, and communicating with the hole
section, and having the peripheral groove formed without cutting
fiber flow.
2. A manufacturing method for a diffuser comprising a flange with a
central hole section and an outer engagement hole section, and a
bottomed cylindrical section having a communicating hole that leads
to one end, in an axial direction, of the flange and communicates
with the hole section, with a peripheral groove formed on an outer
peripheral section of the bottomed cylindrical section, and a
plurality of expulsion ports that communicate with an airbag
extending radially to the bottom section of the communication hole,
comprising: an advance process of forming an intermediate molded
component, by gradually forging a cylindrical solid material that
has fiber flow extending in an axial direction using a multistage
former or press, the intermediate molded component including a
flange, and a cylindrical section of a smaller diameter than a step
section that extends axially outward from a central section at one
end, in the axial direction, of the flange, via the step section,
and having fiber flow flowing in substantially the axial direction
without being cut; a first process of forming a first molded
component by press forming the intermediate component from the
axial direction using a press unit, the first molded component
comprising a flange having a central hole section, and a bottomed
cylindrical section of smaller diameter than the outer diameter of
a step section having a communication hole that extends axially
outwards from a central section of one end of the flange in the
axial direction and communicates with the hole section, with fiber
flow flowing in a substantially axial direction without being cut;
and a second process of forming a second molded component by a
split mold upset process so as to expand only a tip end of the
bottomed cylindrical section in a state where a boundary division
of the step section and the bottomed cylindrical section of the
first molded component is restrained by split dies, the second
molded component including a flange having a central hole section,
and a bottomed cylindrical section having a peripheral groove and
extending axially outward at the same diameter as the outer
diameter of the step section from the center section of one end, in
the axial direction, of the flange, at a middle of the axial length
of the outer periphery of the bottomed cylindrical section, and
having the peripheral groove formed without cutting fiber flow.
Description
RELATED APPLICATION
[0001] This application claims priority to Japanese Patent
Application No. 2010-206091, filed on Aug. 27, 2010, the entire
content of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a manufacturing method for
a diffuser of an inflator for an airbag used to expand an airbag of
a vehicle.
BACKGROUND ART
[0003] Conventionally, a diffuser such as shown in the cross
sectional diagram of FIG. 8 has been used as a diffuser of an
inflator for this type of air bag. Fiber flow is an important
factor, and so in the cross section hatching has been omitted.
[0004] As shown in FIG. 8, this diffuser 6A has a flange 61 with a
central hole section 61a and an outer engagement section 61b, and a
bottomed cylindrical section 63 having a communicating hole 63a
that leads to one end, in an axial direction, of the flange 61 and
communicates with the hole section 61a, with a peripheral groove
63b formed on an outer peripheral section of the bottomed
cylindrical section 63, and a plurality of exhaust ports 64b that
communicate with an airbag extending radially to the bottom section
of the communication hole 63a. An outer end surface of the flange
61 is then attached to an opening section of a high pressure gas
container 10 by welding, while an airbag 11 is engaged in the outer
peripheral portion of the bottomed cylindrical section 63, and
attached by mechanical fastening by means of the peripheral groove
63b.
[0005] As a method for manufacturing the above described diffuser,
first, in order to increase yield and reduce cost, using
cylindrical solid material (wire rod cut to a specified length)
extending in the axial direction of fiber flow, a first molded
component 3A comprising as shown in FIG. 9 a flange 31 having a
central hole section 31a and a bottomed cylindrical section 33 that
leads to one end, in the axial direction, of the flange 31 and has
a communication hole 33a communicating with the central hole
section 31a, is formed by gradually forging this cylindrical solid
material in the axial direction using a former or press, and then a
second intermediate molded component 4A is formed by forming a
peripheral groove 43b by a cutting operation on the outer periphery
of the bottomed cylindrical section 33 of the first molded
component 3A, as shown in FIG. 10. After that, as shown in FIG. 8,
a cutting operation of an outer end engagement section 61b for
engaging with an outer end surface of a flange 41 of the second
molded component 4A, and a cutting operation of a small diameter
communication hole 64a that communicates with a bottom section of
the communication hole 43a of the bottomed cylindrical section 43
and a plurality of expulsion holes 64b that communicate with the
small diameter communication hole 64a, are carried out.
[0006] However, according to the above described manufacturing
method for a diffuser, while it is possible on the one hand to
improve yield and reduce cost, when forming the outer groove 43b on
the outer periphery of the bottomed cylindrical section 33 of the
first molded component 3, formation of the peripheral groove 43b is
carried out using a cutting operation, which means that fiber flow
extending in the axial direction is cut midway, as shown in FIG.
10. As a result, as shown in FIG. 8, when having attached the
diffuser 6A to the high-pressure gas container 10 by welding, there
is a problem that high-pressure gas leaks out from the peripheral
groove section 63b where fiber flow is cut at a very small
proportion of one in several ten-thousands components.
[0007] The cause of this gas leakage is a phenomenon where very
small amounts of high pressure gas escape with an extremely low
probability along fiber flow and non-ferrous inclusions within the
steel formed with strengthening processing by cold forging of the
material (steel). As a result, leakage of a very small amount of
high pressure gas from sections of the peripheral groove 63b where
the fiber flow has bee cut occurs at a very small proportion, e.g.,
one of ten-thousands of diffuser due to the above described
phenomenon. With respect to this problem, after manufacture of the
diffuser total inspection of the diffuser to be used is carried out
to see whether or not gas leaks have occurred in sections where the
fiber flow of the peripheral groove 63b has been cut, and only
those in which gas leaks have not occurred are used. As a result,
inspection is time consuming and this in turn pushes up costs. The
occurrence of fiber flow arises naturally with cold forging, and
non-ferrous inclusions in the material have been considerably
improved at the time of steel making at a steel producer, but the
actual situation is that they have not been completely
eliminated.
SUMMARY OF THE INVENTION
[0008] The present invention therefore provides a manufacturing
method for a diffuser that can be produced with high yield and at
low cost, while doing away with locations where fiber flow is cut
and that has no gas leakage.
[0009] An invention of a first aspect of this application is a
manufacturing method for a diffuser including a flange with a
central hole section and an outer engagement section, and a
bottomed cylindrical section having a communicating hole that leads
to one end, in an axial direction, of the flange and communicates
with the hole section, with a peripheral groove formed on an outer
peripheral section of the bottomed cylindrical section, and a
plurality of expulsion ports that communicate with an airbag
extending radially to the bottom section of the communication hole,
comprising:
[0010] a first process of forming a first molded component using a
cylindrical solid material having fiber flow extending in an axial
direction in order to prevent material loss, and by gradually
forging a cylindrical solid material from an axial direction
thereof, the first molded component including a flange section
having a central hole section, and a bottomed cylindrical section
having a communication hole leading to one end, in the axial
direction, of the flange, and communicating with the hole section,
and having fiber flow that is not cut and flowing substantially in
the axial direction; and [0011] a second process of forming a
second molded component by split molding a peripheral groove using
split dies at the outer periphery of the bottomed cylindrical
section of the first molded component, the second molded component
including a flange having a central hole section and a bottomed
cylindrical section having a communication hole leading to one end,
in the axial direction, of the flange, and communicating with the
hole section, and having the peripheral groove formed without
cutting fiber flow.
[0012] An invention of a second aspect of this application is a
manufacturing method for a diffuser including a flange with a
central hole section and an outer engagement section, and a
bottomed cylindrical section having a communicating hole that leads
to one end, in an axial direction, of the flange and communicates
with the hole section, with a peripheral groove formed on an outer
peripheral section of the bottomed cylindrical section, and a
plurality of expulsion ports that communicate with an airbag
extending radially to the bottom section of the communication hole,
comprising:
[0013] a advance process of forming an intermediate component,
formed by gradually forging a cylindrical solid material that has
fiber flow extending in an axial direction using a multistage
former or press, the intermediate component including a flange and
a cylindrical section that extends axially outward from a central
section at one end, in the axial direction, of the flange, via a
step section and having a smaller diameter than the step section,
and having fiber flow flowing in substantially the axial direction
without being cut;
[0014] a first process of forming a first molded component by press
forming the intermediate component from the axial direction using a
press unit, the first molded component including a flange having a
central hole section, and a bottomed cylindrical section of smaller
diameter than the outer diameter of a step section, the first
molded component having a communication hole that extends axially
outwards from a central section of one end of the flange in the
axial direction and communicates with the hole section, with fiber
flow flowing in a substantially axial direction without being cut;
and [0015] a second process of forming a second molded component by
a split mold upset process so as to extend only tip end of the
bottomed cylindrical section in a state where a boundary division
of the step section and the bottomed cylindrical component of the
first molded component is restrained by split dies, the second
molded component including a flange having a central hole section,
and a bottomed cylindrical section extending axially outward at the
same diameter as the outer diameter of the step section from the
center section of one end, in the axial direction, of the flange,
and having a peripheral groove at the middle in the axial length of
the bottomed cylindrical section, the peripheral groove being
formed without cutting the fiber flow.
[0016] According to the manufacturing method for a diffuser of the
first aspect of this application, it is possible to gradually forge
shape a solid cylindrical material that has fiber flow extending in
an axial direction from the axial direction thereof, and so it is
possible to achieve high yield and low cost, and moreover in the
second process, since the second molded component has the
peripheral groove formed on an outer periphery of the bottomed
cylindrical section without cutting the fiber flow by split forging
a peripheral groove using the split dies on an outer periphery of
the bottomed cylinder, fiber flow is not cut accompanying
peripheral groove formation, and it is possible to prevent gas
leaking from locations where the peripheral groove is formed when
attaching a high pressure gas container to an outer surface of the
flange In this way, after manufacture of a diffuser it is not
necessary to test whether or not gas leaks occur at the peripheral
groove section, meaning it is possible to omit the time taken for
testing, and also, since it is also possible to guarantee the gas
leak free with the manufacturing process it is safe to use, and it
is possible to reduce cost.
[0017] Also, according to the manufacturing method for a diffuser
of the second aspect of this application, first, as the advance
process, an intermediate component, including a flange and a
cylindrical section of a smaller diameter than a step section that
extends axially outward from one end central section in the axial
direction, of the flange, via the step section, and having fiber
flow flowing in substantially the axial direction without being
cut, is formed by gradually forging a cylindrical solid material
that has fiber flow extending in an axial direction, from the axial
direction, using a multistage former or press, next, in the first
process, a first molded component is formed by press forming the
intermediate component from the axial direction using a press unit,
the first molded component including a flange having a central hole
section, and a bottomed cylindrical section of smaller diameter
than the outer diameter of a step section having a communication
hole that extends axially outwards from a central section of one
end of the flange in the axial direction and communicates with the
hole section, and having fiber flow axially flowing without being
cut, and after that, a second molded component is formed by a split
mold upset process so as to expand only tip end of the bottomed
cylindrical section in a state where a boundary division of the
step section and the bottomed cylindrical component of the first
molded component is restrained by the split dies, the second molded
component including a flange having a central hole section, and a
bottomed cylindrical section having a peripheral groove extending
axially outward at the same diameter as the outer diameter of the
step section from the center section of one end, in the axial
direction, of the flange, and at the middle of the axial length of
the outer peripheral of the bottomed cylindrical section, and the
peripheral groove is formed without cutting fiber flow, which means
that similarly to the above described first aspect, there are no
places where fiber flow of the peripheral groove section is cut,
and it is possible to completely prevent gas leaking at places
where the peripheral groove is formed, when having attached a high
pressure gas container to an outer surface of the flange. In this
way, after manufacture of a diffuser it is not necessary to test
whether or not gas leaks occur at the peripheral groove section,
meaning it is possible to omit the time and effort for testing, and
surely guarantee the gas leak free with the manufacturing process,
and it is possible to reduce cost. Further, the intermediate
component is forge shaped inexpensively using a former, the first
molded component is formed to high precision using a press unit,
and the second molded component can be manufactured to high
precision by carrying out a split mold upset process using the
split dies, and it is possible to proactively reduce costs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be further described with
reference to the accompanying drawings wherein like reference
numerals refer to like parts in the several views, and wherein:
[0019] FIG. 1 is a cross sectional drawing of a blank for a
diffuser manufacturing method of the present invention;
[0020] FIG. 2 is a cross sectional drawing of an intermediate
molded component in which a blank is formed by cold forging;
[0021] FIG. 3 is a cross sectional drawing of a molded component
with a hole section formed in the process after that shown in FIG.
2;
[0022] FIG. 4 is a cross sectional drawing showing a molded
component that has had a peripheral groove upset molded with a
split mold in the process after FIG. 3;
[0023] FIG. 5 is a cross sectional drawing of a molded component
that has been subjected to cutting process in the process after
that shown in FIG. 4;
[0024] FIG. 6 is a cross sectional drawing of a final molded
component that has had expulsion holes cut in the process after
that shown in FIG. 5;
[0025] FIG. 7 is an outline explanatory drawing showing a usage
state of the diffuser;
[0026] FIG. 8 is a drawing for describing a diffuser manufacturing
method of related art;
[0027] FIG. 9 is a cross sectional drawing of a molded component
before forming a peripheral groove in the diffuser manufacturing
method of the related art; and
[0028] FIG. 10 is a cross sectional drawing of a molded component
that has had a peripheral groove formed by cutting in the diffuser
manufacturing method of the related art.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] A diffuser manufacturing method of the present invention
will be described in the following based on the drawings.
[0030] FIG. 1 to FIG. 7 respectively show formation explanatory
drawings for one embodiment using the diffuser manufacturing method
of the present invention, and a molded component at each step is
shown in a front elevation or a cross sectional view. Fiber flow is
an important factor the embodiment, and so in the case of cross
sectional views hatching has been omitted.
[0031] FIG. 1 shows a cylindrical solid material 1 having fiber
flow extending in an axial direction. This solid material 1 may be
a blank formed by previously cutting a wire to specified
dimensions, or may be a material formed by cutting sequentially
supplied wire using a cutting machine at the time of forging using
a former. Here fiber flow is flowing in the axial direction, as
shown in FIG. 1.
[0032] As shown in FIG. 2, the solid material 1 is gradually forge
shaped from the axial direction thereof using a die and a punch, at
each forging station of a multistage former, to form a solid
intermediate component 2 that comprises a flange 21 having a
circular outer periphery, a cylindrical section 23 extending
axially outward via a step section 22 from a central section at one
end in the axial direction of the flange 21, and a small diameter
projecting section 24. Here, fiber flow of the intermediate molded
component 2 is flowing substantially in the axial direction,
without being cut, as shown in FIG. 2.
[0033] Next, as shown in FIG. 3, the solid intermediate molded
component 2 that was forge shaped by the former is subjected to
press forming from an axial direction of the intermediate molded
component 2 using an upper mold and a lower mold at a first press
station of a vertical press unit (not shown), to form a high
precision first molded component 3 comprising a flange 31 having a
central hole section 31a, a bottomed cylindrical section 33 that
extends axially outward via a step section 32 from a center section
at one end, in the axial direction, of the flange 31 and has a
communication hole 33a leading to the hole 31a of the flange 31,
and a small diameter projecting section 34. Here, fiber flow of the
first molded component 3 is flowing substantially in the axial
direction, without being cut, as shown in FIG. 3.
[0034] In FIG. 4, the first molded component 3 is subjected to
forging processing so as to expand only tip end of the bottomed
cylindrical section 33 in a second press station, using the upper
mold and the lower mold provided with the split dies of a vertical
press unit, from an axial direction of the first molded component
3, with a boundary portion of the step section 32 and the bottomed
cylindrical section 33 being restrained by the split dies. In this
way, a high precision second molded component 4 comprising the
flange 41 having the central hole section 41a as shown in FIG. 4,
the bottomed cylindrical section 43 (also including the step
section 32) extending axially outwards from the central hole
section of one end in the axial direction of the flange 41 at the
same diameter as the outer diameter of the step section 32, and
being provided with the peripheral groove 41b at the middle of the
axial length of the outer periphery of the bottomed cylinder
section 33, and having a communication hole 43a leading to the
central hole section 41a of the flange 41, and the small diameter
projecting section 44, is formed. Here, fiber flow of the second
molded component 4 is flowing substantially in the axial direction,
without being cut, as shown in FIG. 4.
[0035] After that, as shown in FIG. 5, the second molded component
is shaped by cutting out an engagement section 51b for attachment
of a blocking plate etc. of a gas canister around a central hole
section 51b of an outer surface of the flange 41 using a first
cutting station of a cutting unit (not shown), and a third molded
component 5 is formed by cutting out a small diameter communication
hole 54a extending into the small diameter projecting section 54
from the bottom section of the communicating hole 53a of the
bottomed cylindrical section 53. In FIG. 5, blackened sections are
cutting locations, and reference numeral 7 indicates a holding
section for when cutting the second molded component 4.
[0036] Further, as shown in FIG. 6, a diffuser 6 is formed as a
finished product by cutting a plurality of expulsion holes 64b . .
. 64b extending in a radial direction close to the bottom section
of the small diameter communication hole 54a of the small diameter
projecting section 54 of the third molded component 5. In FIG. 6,
blackened sections are cutting locations, and reference numerals 8
and 9 indicate holding sections for when cutting the second molded
component 4.
[0037] The diffuser 6 that has been formed in this way then has an
outer end surface of the flange 61 attached to an opening section
of a high pressure gas container 10 by welding, as shown in FIG. 7,
while an airbag 11 is engaged in the outer peripheral portion of
the bottomed cylindrical section 63, and attached by mechanical
fastening by means of the peripheral groove 63a.
[0038] According to the diffuser 6 manufactured as descried above,
there are no places where fiber flow of the portion of the
peripheral groove 63b is cut, and it is possible to prevent gas
leaking from portions of the peripheral groove 63a, when attaching
a high pressure gas container 10 to an outer surface of the flange.
In this way, after manufacture of a diffuser 6 it is not necessary
to test whether or not gas leaks occur at parts of the peripheral
groove 64b, meaning that it is possible to omit the time and effort
for testing, and it is possible to reduce cost. Further, with the
above described embodiment, first the intermediate second molded
component is inexpensively mass produced by forging using a
multi-stage former, then the first and second molded components 3,
4 are press molded to high precision using a vertical press unit,
and after that the third molded component 5 and final molded
component 6 are cut using a cutting unit, which means that it is
possible to finally manufacture with high precision by combining
these steps, and it is also possible to proactively achieve cost
reduction.
[0039] As described above, the multi-stage former, the vertical
press unit and the cutting unit may be combined, but it is also
possible, for example, to continuously carry out using only a press
unit by carrying out using press forming of the intermediate molded
component 2.
[0040] Although the present invention has been fully described by
way of examples with reference to the accompanying drawings, it is
to be noted that various changes and modifications will be apparent
to those skilled in the art. Therefore, unless such changes and
modifications depart from the spirit and the scope of the present
invention, they should be construed as being included therein.
* * * * *