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Steel Plate Material Method For Producing Same And Device For Producing Same And Method For Producing Press Molded Article Using Said Steel Plate Material
Abstract: This steel plate material (11) is plate shaped and is used in the production of a press molded article having an open cross section containing a bent section. The steel plate material (11) is provided with a band shaped thick region (12) that is singular across all regions and has an increased thickness and thin regions (13A 13B) having a thinner thickness than that of the thick region (12) and that neighbor the thick region (12) on both sides. Of the obverse surface (11a) and reverse surface (11b) of the steel plate material (11) a thickness step (12a) is formed along one side among the two sides of the thick region (12) at the obverse surface (11a) and a thickness step (12b) is formed along the other side among the two sides of the thick region (12) at the reverse surface (11b). By means of using the steel plate material (11) in the production of a press molded article it is possible to optimize the strength of the press molded article and it is possible to suppress production cost.
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Notices, Deadlines & Correspondence
Notices, Deadlines & Correspondence
Patent Information
Application #
Filing Date
14 April 2016
Publication Number
36/2016
Publication Type
INA
Invention Field
MECHANICAL ENGINEERING
Status
Email
Parent Application
Patent Number
Legal Status
Grant Date
2023-11-16
Renewal Date
Applicants
NIPPON STEEL & SUMITOMO METAL CORPORATION
6 1 Marunouchi 2 chome Chiyoda ku Tokyo
1008071
Inventors
1. ITO Yasuhiro
c/o Nippon Steel & Sumitomo Metal Corporation 6 1 Marunouchi 2 chome Chiyoda ku Tokyo
1008071
2. NAKAZAWA Yoshiaki
c/o Nippon Steel & Sumitomo Metal Corporation 6 1 Marunouchi 2 chome Chiyoda ku Tokyo
1008071
Specification
DESCRIPTION
TITLE OF NVENTION:
BLANK STEEL PLATE, PRODUCTION METHOD AND PRODUCTION
DEVICE THEREFOR, AND PRODUCTION METHOD FOR PRESS-FORMED
PRODUCT USING BLANK STEEL PLATE
TECHNICAL FIELD
[OOOl]
The present invention relates to a press-formed product suitable for structural
members that form a car body of an automobile, in particular relates to a blank steel
plate used for producing the press-formed product, and aproduction method and a
production device therefor. Furthennore, the present invention relates to a
production method for a press-formed product using the blank steel plate.
BACI 1.2
(due to work hardening)
Structural members for which the press-formed product 1 according to the
present embodiment is used include a bumper reinforcement, a door impact beam, a
front side member, a rear side member, a center pillar outer reinforcement, a floor
cross member, bulkhead, a rocker reinforcement, and the like. The overall length of
the press-formed product 1 is from about 1000 mm, as in a bumper reinforcement, a
front slde member, a rear side member, or the like, to about 100 mm as in a cubic
bulkhead.
[0061]
A bumper reinforcement, a door impact beam, and a center pillar outer
reinforcement are structural members that are assumed to be subjected to collapse by
three-point bending occurring when a car body has a collision on the side face
thereof (hereafter, referred to as three-point bending collapse). When the pressformed
products 1, for example, illustrated in FIG. 1A and FIG. lC, namely the
press-formed products 1 having thickened ridge portions disposed on the outside of a
car body are applied to such structural members, it is possible to enhance
performances in the three-point bending collapse.
[0062]
A front side member and a rear side member are structural members that are
assumed to be subjected to collapse in an axis direction (longitudinal direction)
occurring when a car body has a collision from the front or rear thereof (hereafter,
refel~edto as axial collapse). When the press-formed product 1, for example,
illustrated in FIG. ID, namely the press-formed product 1 having a thickened ridge
portion, among the ridge portions that curve at one, or two or more spots, positioned
inside the curve is applied to this structural member, it is possible to enhance
performances in the axial collapse.
[0063]
The press-formed products 1 according to the present embodiment are
produced using partially thickened blanks to be described later. When a partially
thickened blank is formed by press working, a high-tensile steel plate having a
tensile strength of 440 MPa or more can be used as a starting material. Therefore,
the press-fonned products 1 produced using partially thickened blanks according to
the present embodiment have high strengths.
[0064]
The partially thickened blank according to the present embodiment is made up
of a homogeneous steel plate and has no weld zones seen in the TWB. Therefore,
the press-formed products 1 produced using partially thickened blanks according to
the present embodiment have no weld zones, and thus there is no risk of rupture in a
weld zone at the time of collision.
[0065]
In the press-formed products 1 according to the present embodiment, microstructures
in the thickened portions of the ridge portions (see the bold lines in FIG.
1A to FIG. ID, and FIG. 2A and FIG. 2B) are work-hardening micro-structures made
by press working. This is for the following reason. The thickened portions of the
ridge portions are equivalent to thick areas of a partially thickened blank to be
described later. The thick areas are caused to develop large distortions and
subjected to work hardening by press working at the time of forming the partially
thickened blank. For this reason, the micro-structures in the thickened portions of
the ridge portions are the inheritance of work-hardening micro-structures in the thick
areas of the partially thickened blank, so as to have work-hardening micro-structures.
[0066]
Note that, in the case of a technique in which a TWB, a TRB, or the like is
employed as a blank steel plate, thickened areas of the TWB or TRB are not
subjected to work hardening, and thus the thickened portions of a press-formed
product fonned using the TWB or TRB do not have work-hardening micro-structures,
Also in the case of a technique in which ridge portions of the press-formed product
are subjected to buildup welding, the thickened portions subjected to the buildup
welding do not have work-hardening micro-structures.
[0067]
As will be described later, when a press-formed product 1 is produced by cold
or warm press working using a partially thickened blank according to the present
embodiment, the work-hardening micro-structures in the thick areas of the partially
thickened blank are effectively canied on by the thickened portions of the ridge
portions of the press-formed product 1. For this reason, the synergetic effect of
thickening and work hardening to the ridge portions makes the press-formed product
1 more excellent in flexural rigidity, torsional rigidity, performances in three-point
bending collapse, performances in axial collapse, and the like.
[0068]
[Blank Steel Plate (Partially Thickened Blank)]
FIG. 3A and FIG. 3B are diagrams schematically illustrating an example of
the blank steel plate according to the present embodiment. Of these drawings, FIG.
3A is a perspective view of the whole of the blank steel plate. FIG. 3B is a cross
sectional view illustrating the vicinity of a thick area in a magnified manner. A
partially thickened blank 11, which is the blank steel plate illustrated in FIG. 3A and
FIG. 3B, is an example of a partially thickened blank that is used for producing the
press-formed product 1 in the first example illustrated in FIG. 1A. The pressfanned
product 1 in the first example is hat-shaped, and the vertical wall portions 3
and the flange portions 4 are symmetrically disposed across the top panel portion 2.
Note that FIG. 3B illustrates the appearance from the center to one end portion of the
partially thickened blank in the width direction thereof. The appearance as far as
the other end portion is symmetrically identical and will not be illustrated.
[0069]
The partially thickened blank 11 according to the present embodiment
includes belt-shaped thick areas 12 having an increased thickness and thin areas 13A
and 13B that are adjacent to the both sides of the thick areas 12 and having a
thickness smaller than that of the thick areas. As illustrated in FIG. 3B, the thick
areas 12 are provided at positions corresponding to the ridge portions 7, which are
the thickened portions of the press-formed product 1 (see the bold lines in FIG. 1A).
The thin areas 13A and 13B are provided at positions corresponding to the top panel
portion 2, the vertical wall portions 3, and the flange portions 4 of the press-formed
product 1.
[0070]
In the partially thickened blank 11, on one of a fkont surface 1 la and back
face l lb (the front surface 1 la in FIG. 3B), a step height 12a in thickness is formed
along one side portion of the both side portions of the thick area 12. In addition, on
the other of the front surface 1 la and the back face 1 lb (the back face 1 lb in FIG.
3B), a step height 12b in thickness is formed along the other side portion of the both
side portions of the thick area 12.
[0071]
Such a partially thickened blank 11 is produced by press working using a
simple press device to be described later. A starting material used in this
production is a single steel plate. Therefore, the partially thickened blank 11 does
not have a weld zone as in the TWB but is homogeneous across its entirety.
[0072]
In the partially thickened blank 11, the hardness at the thickness centers of the
thick areas 12 is higher than the hardness at the thickness centers of the thin areas
13A and 13B. As will be illustrated later, this is because the thick areas 12 are
caused to develop large distortions and are subjected to work hardening by press
working at the time of forming the partially thickened blank.
[0073]
In addition, the increase in the thickness of the thick areas 12 with respect to
the thickness of the thin areas 13A and 13B is 20% or more.
[0074]
[Producing Blank Steel Plate (Partially Thickened Blank)]
FIG. 4A to FIG. 4D are cross sectional views schematically illustrating an
example of a forming process of a blank steel plate according to the present
embodiment. Of these drawings, FIG. 4A illustrates the state at the start of forming.
FIG. 4B illustrates the state at the initial stage of forming. FIG. 4C illustrates the
state at the middle stage of forming. FIG. 4D illustrates the state at the end of
forming. The forming process illustrated in FIG. 4A to FIG. 4D is an example of
the case of forming the partially thickened blank 11 illustrated in FIG. 3A and FIG.
3B (to be used for producing the press-formed product 1 in the first example
illustrated in FIG. 1A). Note that FIG. 4A to FIG. 4D illustrate the appearance from
the center to one end portion of the steel plate in the width direction thereof. The
appearance as far as the other end portion is symmetrically identical and will not be
illustrated.
[0075]
A production device for forming the partially thickened blank 11 (hereafter,
referred to as a "blank production device") subjects a starting material 15, which is a
steel plate having a constant thickness, to press working. The thickness of the
starting material 15 is the same as that of the thin areas 13A and 13B of the partially
thickened blank 1 1.
[0076]
As illustrated in FIG. 4A to FIG. 4D, the blank production device includes a
punch 21 and a blank holder 22 as an upper press die and includes a die 23 and a pad
24 as a lower press die. The blank holder 22 is disposed adjacent to the punch 21.
The die 23 is disposed facing the blank holder 22 and facing a part of the punch 21.
The pad 24 is disposed adjacent to the die 23 and facing the punch 21.
[0077]
The punch 21 and the blank holder 22 can be moved up and down
independently of each other. The pad 24 is urged toward the punch 21, and the pad
24 is moved down with a press by the descent of the punch 21 and is moved up with
the release of the press by the ascent of the punch 21. The die 23 is i~nrnobilized.
[0078]
The interval between the blank holder 22 and the pad 24 in the horizontal
direction is set to be the same as the width of the thick areas 12 of the partially
thickened blank 11. The term "the width of the thick areas 12" described here refers
to, as illustrated in FIG. 3B, the width from the step height 12a formed on the one
side portion of the thick area 12 to the step height 12b formed on the other side
portion.
[0079]
In addition, on the upper face of the die 23, namely the surface that faces the
blank holder 22, a projecting portion 23a is provided. The projecting portion 23a is
disposed closer to the center in the horizontal direction than an end portion of the
starting material 15.
[0080]
Using the blank production device having such a configuration, the partially
thickened blank 11 is produced through the following processes. First, the starting
material 15 is prepared. The type of a steel plate for the starting material 15 is not
specially limited, and a high-tensile steel plate having a tensile strength of 440 MPa
or more may be used.
[0081]
In the state before fonning, the punch 21 and the blank holder 22 of the upper
press die is at a top dead center, being retracted upward from the pad 24 and the die
23 of the lower press die. In this state, the upper face of the pad 24 is disposed at a
position higher than the upper face of the die 23. Then, the starting material 15 is
placed on the pad 24.
[0082]
From this state, fonning by press working is started. First, the punch 21 and
the blank holder 22 are moved down together, and the lower faces of the punch 21
and the blank holder 22 come into contact with the starting material 15. This makes,
as illustrated in FIG. 4A, an area 17A, which is a part of the starting material 15,
sandwiched between the punch 21 and the pad 24 and locked. The area 17A at the
center of the starting material 15 in the width direction thereof corresponds to the
area of the top panel portion 2 of the press-fonned product 1 illustrated in FIG. lA,
namely the thin area 13A at the center of the partially thickened blank 11 in the
width direction thereof illustrated in FIG. 3A.
[0083]
Subsequently, the descent of the punch 21 is stopped, and only the descent of
the blank holder 22 is continued. Then, the end portion of the starting material 15 is
pushed by the blank holder 22. This causes, as illustrated in FIG. 4B, the starting
material 15 is bent from the side portion of the area 17A locked by the punch 21 and
the pad 24.
[0084]
The push of the starting material 15 by the descent of the blank holder 22 is
further continued. Then, as illustrated in FIG. 4C, an area 17B in an end portion of
the starting material 15 is sandwiched between the blank holder 22 and the die 23
and locked. The blank holder 22 reaches a bottom dead center in this state. The
area 17B in the end portion of the starting material 15 corresponds to the area of the
vertical wall portion 3 and the flange portion 4 of the press-formed product 1
illustrated in FIG. lA, namely the thin area 13B in an end portion of the partially
thickened blank 11 illustrated in FIG. 3A.
[0085]
The process thus far (hereafter, also referred to as a "first step") brings the
starting material 15 into the state where, as illustrated in FIG. 4C, the area 17A
sandwiched between the punch 21 and the pad 24, and the area 17B sandwiched
between the blank holder 22 and the die 23 are displaced to different planes that are
parallel to each other. In the space between the blank holder 22 and the pad 24, a
belt-shaped area 16, which runs to the area 17A and the area 17B and inclines with
respect to the both of them, is formed. The inclining area 16 of the starting material
15 corresponds to the areas of the ridge poltions 7, which are the thickened portions
of the press-formed product 1 illustrated in FIG. 1A (see the bold lines in FIG. lA),
namely the thick areas 12 of the partially thickened blank 11 illustrated in FIG. 3A.
[0086]
In addition, the end face of the area 17B sandwiched between the blank holder
22 and the die 23 is in contact with or leaves a slight gap with respect to the side face
of the projecting portion 23a on the die 23. FIG. 4C illustrates the state of leaving
the slight gap.
[0087]
Through the first step, the starting material 15 is segmented into the inclining
area 16 (hereafter, also referred to as a "first area") and the areas 17A and 17B
adjacent to the both side portions of the fxst area 16 and parallel to each other
(hereafter, also referred to as "second areas"). A width L of the inclining first area
16 is larger than the width of the thick areas 12 of the partially thickened blank 11
illustrated in FIG. 3A. This is because the inclining fust area 16 exists in the space
between the blank holder 22 and the pad 24 in such a manner as to incline, and the
interval of the space in the horizontal direction is set to be the same as the width of
the thick areas 12.
[OOSS]
Subsequently, the transition to a second step is made. In the second step, the
descent of the punch 21 is resumed. Then, the area 17A, which is the widthdirection-
center portion of the starting material 15 (the second area), is pushed while
being restrained in tenns of movement in the width direction thereof by being
sandwiched between the punch 21 and the pad 24. At that point, the area 17B in the
end portion of the starting material 15 (the second area) is also restrained in terms of
movement in the width direction thereof by being sandwiched between the blank
holder 22 and the die 23. For this reason, the inclining first area 16 of the starting
material 15 existing in the space between the blank holder 22 and the pad 24 is
compressed to expand, and the inclination angle thereof is gradually lessened. This
makes the thickness of the first area 16 gradually increase.
[0089]
In addition, at that point, by the end face of the second area 17B coming into
contact with the side face of the projecting portion 23a on the die 23, the movement
of the second area 17B in the width direction thereof is reliably restrained. For this
reason, even an insufficient restraint on the second area 17B by being sandwiched by
the blank holder 22 and the die 23 has no trouble.
[0090]
Subsequently, the push of the starting material 15 by the descent of the punch
21 is continued, and finally the punch 21 reaches the bottom dead center. That is,
as illustrated in FIG. 4D, in the starting inaterial 15, the area 17A sandwiched
between the punch 21 and the pad 24 (the second area) becomes flush with the area
17B sandwiched between the blank holder 22 and the die 23 (the second area). In
short, both the second areas 17A and 17B are displaced until they are flush with each
other. In this state, the upper face of the pad 24 is disposed at a position that is
slightly higher than the upper face of the die 23. The lower face of the punch 21 is
disposed at a position that is slightly higher than the lower face of the blank holder
22.
[0091]
This makes the width of the first area 16 compressed to the interval between
the blank holder 22 and the pad 24 in the horizontal direction, namely the width of
the thick areas 12 of the partially thickened blank 11 illustrated in FIG. 3A.
Furthennore, the first area 16 expands by the compression and at the same time
crushed into a flat plane by the punch 21 and the die 23 facing each other. As the
result, the thickness of the first area 16 increases, becoming thicker than the
thickness of the starting material 15 itself, namely the second areas 17A and 17B.
The thickness of the first area 16 is determined by the interval between the lower
face of the punch 21 and the upper face of the die 23, namely the position of the
punch 21 at the bottom dead center.
[0092]
As illustrated in FIG. 4D, by such press working, the partially thickened blank
11 illustrated in FIG. 3A and FIG. 3B is formed from the starting material 15. The
belt-shaped first area 16 increasing in thickness becomes the thick area 12. The
second areas 17A and 17B adjacent to the both sides of the first area 16 (thick area
12) become the thin areas 13A and 13B, which have a thickness smaller than that of
the thick areas 12.
[0093]
Here, in the first step of the above producing process for a partially thickened
blank, a preferable condition for the formation of .the inclining fxst area 16 are as
follows.
[0094]
FIG. 5 is a diagram illustrating a thickening-allowed range in the producing
process for a partially thickened blank. As illustrated in FIG. 4C, at the time of
forming the inclining fust area 16, when the width of the first area 16 is denoted by L
[mnm], the thickness of the starting material 15 (frst area 16) is denoted by t [mm],
the inclination angle of the first area 16 with respect to the horizontal second areas
17A and 17B is denoted by 0 ['I, and the yield strength of the starting material 15 is
denoted by YS [MPa], there is a correlation between them and the thickeningallowed
range.
[0095]
As illustrated in FIG. 5, if the condition represented by the following Formula
(1) is satisfied, no buckling occurs in the process in which the inclining first area 16
is compressed and formed into the thick area 12.
(Lit) x (l/cosO) 2-5.1 x 10-6x (YS)'+ 11.5 (1)
[0096]
This condition represented by Formula (1) is valid when a steel plate having a
tensile strength of 440 MPa or more is used as the startmg material 15.
[0097]
The present inventors conducted a test to form a partially thickened blank
using various steel plates having tensile strengths ranging froin 440 to 980 MPa,
while varying the width L [im], the thickness t [mm], the inclination angle 0 ["I in
the above Formula (1). On the basis of this test, the present inventors studied the
influence of a steel plate strength on the possibility of partial thickening.
[0098]
Here, the condition of failing to perform thickening working is detennined to
be a condition of bringing about a phenomenon where the inclining first area 16
buckles in a coinpression process and is thereby folded in an overlapping manner
(hereafter, referred to as "overlap buckling"). The overlap buckling remains in a
press-formed product in the end. For this reason, the press-formed product is
degraded in appearance and considered to be a defective item. In addition, the
overlap buckling may reduce fatigue characteristics or the like of the press-fonned
product.
[0099]
In the case of using a 440 MPa-class steel plate, the overlap buckling occurred
when "(Llt) x (IIcosO)", a parameter into which the geoinetrical factors of the
inclining first area 16 are combined (hereafter, also referred to as a "parameter Q"),
becomes about 10.87 or more. The condition of inalting the parameter Q about
10.87 is, for example, the case where t = 1.6 mm, L = 10 nnn, and O = 55'. In the
case where the thickness t is small, the width L is large, and the inclination angle O is
large as compared with this condition, the overlap buckling is more prone to occur.
[OIOO]
The present inventors conducted the same test on the other steel grades, and
the overlap buckling occurred under the following conditions.
- 590 MPa-class steel plate: the condition that the parameter Q becomes about
10.58 (e.g., t = 1.6mm,L= lOmm,andO=54")
- 980 MPa-class steel plate: the condition that the parameter Q becomes about
9.17(e.g.,t=1.6mm,L=101nm,and0=47~)
[OlOl]
Thus, the present inventors studied the relation between the parameter Q the
yield strength YS, a material property value having a high correlation with the
occurrence of buckling. Here, the yield strengths YS of various steel plates are as
follows.
- 440 MPa-class steel plate: the yield strength YS is 352 MPa
- 590 MPa-class steel plate: the yield strength YS is 424 MPa
- 980 MPa-class steel plate: the yield strength YS is 676 MPa
The present inventors found, as the result, that the overlap buckling can be
suppressed if the parameter Q and the yield strength YS satisfy the condition
represented by the above Formula (1).
[0102]
The increase of the thickness of the first area 16 with respect to the thickness
of the second areas 17A and 17B (hereafter, also referred to as a "thickening rate") is
substantially "((l/cos0) - 1) x 100" %. In a partially thickened blank, the thickening
rate thereof is the increasing rate of the thickness of the thick area 12 with respect to
the thickness of the thin areas 13A and 13B. The thickening rate is preferably 20%
or more.
[0103]
As long as the condition represented by the above Formula (1) is satisfied, the
thickening working is possible. If a desired thickening rate, hardness, and the like
cannot be obtained by one thickening working, the thickening working may be
repeated on the same first area 16 a plurality of times.
[0 1041
The projecting portion 23a provided on the upper face of the die 23, as
described above, comes into contact with the second area 17B of the starting material
15 to play a role of restraining the movement of the second area 17B in the width
direction thereof (see FIG. 4D). The projecting portion 23a has a height identical to
or smaller than the thickness of the starting material 15 (thickness of the thin areas
13A and 13B of the partially thickened blank 11). When the projecting portion 23a
is higher than the thickness of the starting material 15, the projecting portion 23a
comes into contact with the blank holder 22 when the blank holder 22 reaches the
bottom dead center. This makes sandwiching of the second area 17B by the blank
holder 22 and the die 23 insufficient, causing a wrinkle in the second area 17B. For
example, when the thickness of the starting material 15 is 1.6 mm, the height of the
projecting portion 23a may be set at 1.3 mm.
[0105]
Note that, the above blank production device illustrated in FIG. 4A to FIG.
4D has the configuration in which the punch 21 and the blank holder 22 are disposed
as the upper press die, and the die 23 and the pad 24 are disposed as the lower press
die but may have the configuration in which the disposition of the upper and lower
press dies is vertically reversed. In addition, as to the names of the upper and lower
press dies, the press die having reference numeral 21 may be referred to as a pad
instead of the punch, the press die having reference numeral 22 may be referred to as
a die instead of the blank holder, the press die having reference numeral 24 may be
referred to as a punch instead of the pad, and the press die having reference numeral
23 may be referred to as a blank holder instead of the die.
[0 1061
By the press working using the above blank production device, the above
partially thickened blank 11 can be produced. The blank production device is
simple and dispenses with a special press die and a special structure. Therefore, it
is possible to suppress manufacturing cost to produce the partially thickened blank
11. In addition, the partially thickened blank 11 is planar and includes thick areas.
For this reason, perfonning press working on the partially thickened blank 11 yields
a press-formed product the strength of which can be optimized.
[0107]
[Producing Press-formed product]
FIG. 6A and FIG. 6B are cross sectional views schematically illustrating an
example of a fonning process of the press-formed product according to the present
embodiment. Of these drawings, FIG. 6A illustrates the state at the start of forming.
FIG. 6B illustrates the state at the end of forming. The forming process illustrated
in FIG. 6A and FIG. 6B is an example of the case of forming the press-formed
product 1 in the first example illustrated in FIG. 1A using the partially thickened
blank 11 illustrated in FIG. 3A and FIG. 3B. Note that FIG. 6A and FIG. 6B
illustrate the appearance from the center in the width direction to one end portion of a
steel plate. The appearance as far as the other end portion is symmetrically
identical and will not be illustrated.
[0 1081
A production device for forming the press-fonned product 1 (hereafter, also
referred to as a "pressed body production device") is a press device that uses the
partially thickened blank 11 and performs press working such that the thick area 12
of the partially thickened blank 11 forms the ridge portions 7 (bent portions 5) of the
press-formed product 1. As illustrated in FIG. 6A and FIG. 6B, the pressed body
production device includes punch 3 1 as an upper press die, and includes a die 32 and
a pad 33 as a lower press die.
[0109]
The punch 3 1 includes an impression portion in which the shape of the pressformed
product 1 is formed and a shoulder portion 3 la that corresponds to the ridge
portion 7 (bent portion 5) of the press-formed product 1, as a part of the impression
portion. The die 32 and the pad 33 are adjacent to each other, both of which are
disposed facing the punch 3 1. The pad 33 is a press die for forming the top panel
portion 2 of the press-formed product 1 and is disposed on the center side from the
shoulder portion 3 la of the punch 3 1 in the horizontal direction. The die 32 is a
press die for forming the vertical wall portions 3 and the flange portions 4 of the
press-formed product 1.
[OllO]
The punch 3 1 can be inoved up and down. The pad 33 is urged toward the
punch 31 and is moved down with a press by the descent of the pad 33 and is moved
up with the release of the press by the ascent of the pad 33. The die 32 is
immobilized.
[Olll]
Using the pressed body production device having such a configuration, the
press-formed product 1 is produced through the following process. In the state
before forming, the punch 3 1 of the upper press die is at a top dead center, being
retracted upward from the pad 33 and the die 32 of the lower press die. In this state,
the upper face of the pad 33 is identical in height to the upper face of the die 32.
Then, the above partially thickened blank 11 is placed on the pad 33 and the die 32.
In this state, of the thin areas 13A and 13B of the partially thickened blank 11, the
thin area 13A at the center in a width direction is disposed on the pad 33, and the thin
area 13B in an end portion are disposed on the die 32. The thick area 12 of the
partially thickened blank 11 coincides with a position immediately below the
shoulder portion 31a of the punch 31.
[0112]
From this state, fonning by press working is started. First, the punch 31 is
moved down, coming into contact with the partially thickened blank 11. This
brings the state that, as illustrated in FIG. 6A, the thin area 13A at the center in the
width direction of the partially thickened blank 11 is sandwiched between the punch
3 1 and the pad 33 and locked.
[0113]
Subsequently, the descent of the punch 31 is continued. Then, the thin area
13B in the end portion of the partially thickened blank 11 is pushed by the die 32.
This causes the partially thickened blank 11 to be bent from the thick area 12. As
the result, the bent portion 5 (ridge portion 7) is formed in the thick area 12, and with
the formation of the bent portion 5, the thin area 13A sandwiched between the punch
3 1 and the pad 33 becomes the top panel portion 2.
[0114]
Furthermore, the push of the partially thickened blank 11 by the descent of the
punch 3 1 is continued, and finally the punch 3 1 reaches a bottom dead center. This
causes, as illustrated in FIG. 6B, the bent portion 6 (ridge portion 8) to be fonned in
the thin area 13B in the end portion of the partially thickened blank 11, and with the
formation of the bent portion 5, the vertical wall portions 3 and the flange portions 4
are formed.
[0115]
By such press working, the press-fonned product 1 illustrated in FIG. 1A is
formed from the above partially thickened blank 11.
[0116]
As described above, by using the above pressed body production device, and
subjecting the above partially thickened blank 11 to press working, it is possible to
produce the press-formed product 1 having a partially large thickness, and for which
the optimization of strength is possible. The pressed body production device is, as
with the above blank production device, is simple and dispenses with a special press
die and a special structure. Therefore, it is possible to suppress manufacturing costs
in producing not only the partially thickened blank 11 but also the press-formed
product 1.
[0117]
The press working by the above pressed body production device may be
performed in a cold manner or in a warm manner. Warm press working means that
the press working is performed in the state where the temperature of the partially
thickened blank 1 1 in forming start is from 200°C to less than the point Ac3. In
contrast, cold press working means that the press working is performed in the state
where the temperature of the partially thickened blank 11 in forming start is less than
about 200°C. By the cold or warm press working, the work-hardening microstructure
in the thick area 12 of the partially thickened blank 11 is effectively carried
on by the thickened portions of the ridge portions of the press-formed product 1.
In addition, in the above partially thickened blank 11, one trace of the step
heights 12a and 12b in thickness between the thick area 12 and the thin areas 13A
and 13B appear on the front surface 1 la and the back face 1 lb, respectively. Then,
in the ridge portions 7 of the press-formed product 1 produced from the partially
thickened blank 11, only one trace of the step height in thickness is left on each of
the front side and the back side. Therefore, the press-formed product 1 is excellent
in quality in the appearance as compared with a press-formed product produced from
the partially thickened blank of Patent Literature 3.
[0119]
Note that the above pressed body production device illustrated in FIG. 6A and
FIG. 6B has the configuration in which the punch 3 1 is disposed as the upper press
die and the die 32 and the pad 33 are disposed as the lower press die but may have
the configuration in which the disposition of the upper and lower press dies is
vertically reversed.
EXAMPLES
[0120]
To confirm the effects of the present invention, the present inventors
conducted the tests on the following Examples 1 and 2.
[0121]
[Example 11
In Example 1, three kinds of structural members: a comparative example; a
conventional example; and an inventive example of the present invention, were
fabricated, and a three-point bending collapse test was conducted on each structural
member.
[0122]
(1) Structural member
FIG. 7 is a schematic diagram illustrating a cross-sectional shape of a
structural member used in the three-point bending collapse test in Example 1. As
illustrated in FIG. 7, a structural member 40 used in Example 1 was fabricated by
combining a hat-shaped press-formed product 1 with a closing plate 9 and joining
thein by spot welding. The press-formed product 1 includes a top panel portion 2, a
pair of vertical wall portions 3, and a pair of flange portions 4, and includes bent
portions 5 (ridge portions 7) coupling the top panel portion 2 with the vertical wall
portions 3, bent portions 6 (ridge portions 8) coupling the vertical wall portions 3
with the flange portions 4. Three producing conditions of the press-formed product
1 were selected and determined as the comparative example, the conventional
example, and the inventive example of the present invention.
[0123]
The spot welding was performed on the flange portions 4 of the press-formed
product 1. Intervals of the spot welding were 30 mm along the longitudinal
direction of the structural member 40. As the closing plate 9, a 440 MPa-class steel
plate having a thickness of 1.8 mn was used.
[0124]
In the comparative example, a normal blank steel plate was formed into the
hat-shaped press-formed product 1 by press working. As the blank steel plate, a
440 MPa-class steel plate having a constant thickness of 1.6 mm was used. The
thickness of the press-formed product 1 in the comparative example substantially
remained the thickness of the blank steel plate across its entirety including the ridge
portions 7. The maximum hardness (Hv) at the thickness centers of the ridge
portion 7 was substantially equal to the hardness of the blank steel plate. Note that
the hardness (Hv) of the outside of the bends in the ridge portions 7 in the
comparative example was about 1.23 times the hardness of the blank steel plate due
to work hardening in the press working.
[0125]
In the conventional example, a TRB was fonned into the hat-shaped pressfonned
product 1 by press working. The TRB was formed by partially rolling a
steel plate having a constant thickness of 2.0 mm to form thinned areas, forming
thickened areas in a relative manner by the formation of these thinned areas. The
thickness of these thinned areas was about 1.6 mm. The thickness of the thickened
areas was 2.0 im. The TRB was subjected to heat treatment before the press
working to make the strength of the thickened areas equal to that of a 440 MPa-class
steel plate. The press working was performed such that the thickened areas were
fonned into the ridge portions 7.
[0126]
The thiclcnesses of the press-formed product 1 in the conventional example
were substantially kept at the thicknesses of the TRB, 2.0 inm maximum in the ridge
portions 7, and approximately 1.6 mm in the portions other than the ridge portions 7.
That is, the thickness of the ridge portions 7 was 1.25 times the thickness of the
portions other than the ridge portions 7. The maximum hardness (Hv) at the
thickness centers of the ridge portions 7 was substantially equal to the hardness of
tlie TRB. Note that the hardness (Hv) of the outside of the bends in the ridge
portions 7 in the conventional example was about 1.26 times the hardness of the TRB
due to work hardening in the press working.
[0127]
In the inventive example of the present invention, the partially thickened
blank in the above present embodiment was formed into the hat-shaped press-formed
product 1 by press working. This partially thickened blank was obtained by
preparing a 440 MPa-class steel plate having a constant thickness 1.6 mm as a
starting material, which was subjected to the partial thickening working according to
the above present embodiment. The thickness of the partially thickened thick areas
was 2.0 mm maximum. The press working was performed such that the thick areas
were formed into the ridge portions 7.
[0128]
The thicknesses of the press-formed product 1 in the inventive example of the
present invention were substantially kept at the thicknesses of the partially thickened
blank, 2.0 mm maximum in the ridge portions 7, and approximately 1.6 mm in the
portions other than the ridge portions 7. That is, the thickness of the ridge portions
7 was 1.25 times the thiclcness of the portions other than the ridge portions 7. The
maximum hardness (Hv) at the thickness centers of the ridge portions 7 was about
1.40 times the hardness of the starting material before the partial thickening working.
Note that the same was tme for the hardness (Hv) of the outside of the bends in the
ridge portions 7 in the inventive example of the present invention
(2) Condition of Three-Point Bending Collapse Test
FIG. 8 is a schematic diagram illustrating the outline of the three-point
bending collapse test. The structural member 40 was supported at two points from
the side of the closing plate 9. A support interval for the structural member 40 was
determined to be 1000 mm. In the middle of the supports for the structural member
40, an impactor 45 was caused to collide with the press-formed product 1 from the
side of the top panel portion 2 thereof so as to collapse the structural member 40.
The radius of curvature of the front end portion of the iinpactor 45 was 150 mm.
The collision speed of the impactor 45 was 64 kmlh.
[0130]
(3) Evaluation and Result of Test
For the structural members in the comparative example, the conventional
example, and the inventive example of the present invention, maximum loads in the
three-point bending collapse test were measured. The evaluation was made using
the ratio to a maximum load in the comparative example, with the maximum load in
the comparative example defined as a reference (1.00). The results are shown in
Table 2.
[0131]
[Table 21
TABLE 2
[0132]
As shown in Table 2, the maximum load ratio in the conventional example
was about 1.05. In contrast to this, the maximum load ratio in the inventive
example of the present invention was 1.12. This demonstrated that the structural
member in the inventive example of the present invention employing the technique
of the present embodiment has a high performance in the three-point bending
Category
Blank steel plate
Hardness ratio at
thickness center
Maximum thickness
of ridge portion
Maximum load ratio
collapse brought by the influences of partial thickening and significant work
hardening.
[0133]
[Example 21
Comparative
example
Normal blank
having constant
thickness
1.02
1.6 mm
(thickness ratio:
1 .OO)
1 .OO
In Example 2, three kinds of structural members: a comparative example; a
conventional example; and an inventive example of the present invention, were
Conventional
example
Partially thickened
blank
(TRB)
1.01
2.0 mm
(thickness ratio:
1.25)
1.05
fabricated, and an axial collapse test was conducted on each structural member.
[0134]
(1) Structural member
FIG. 9 is a schematic diagram illustrating a cross-sectional shape of a
structural member used in the axial collapse test in Example 2. As illustrated in
FIG. 9, a structural member 40 used in Example 2 was fabricated by combining a
pair of groove-shaped press-formed products 1, and joining them by laser welding.
Inventive example of
present invention
Partially thickened
blank
(partial thickening
working according to
present embodiment)
1.40
2.0 mm
(thickness ratio: 1.25)
1.12
Each press-formed product 1 includes a top panel portion 2, and a pair of vertical
wall portions 3, and includes bent portions 5 (ridge portions 7) coupling the top panel
portion 2 with the vertical wall portions 3. Three producing conditions of the pressfonned
product 1 were selected and determined as the comparative example, the
conventional example, and the inventive example of the present invention. The
overall length of the press-fonned product 1 was determined to be 150 mm. The
laser welding was performed between the vertical wall portions 3 of the press-formed
products 1.
[0135]
In the comparative example, a normal blank steel plate was formed into the
groove-shaped press-formed product 1 by press working. As the blank steel plate, a
440 MPa-class steel plate having a constant thickness of 1.6 mm was used. The
thickness of the press-formed product 1 in the comparative example substantially
remained the thickness of the blank steel plate across its entirety including the ridge
portions 7. The maximum hardness (Hv) at the thickness centers of the ridge
portions 7 was substantially equal to the hardness of the blank steel plate. Note that
the hardness (Hv) of the outside of the bends in the ridge portions 7 in the
comparative example was about 1.23 tiines the hardness of the blank steel plate.
[0136]
In the conventional example, a TRB was fonned into the groove-shaped
press-fonned product 1 by press working. This TRB was formed by partially
rolling a steel plate having a constant thickness of 2.0 mm to fonn thinned areas,
forming thickened areas in a relative manner by the formation of these thinned areas.
The thickness of these thinned areas was about 1.6 nnn. The thickness of the
thickened areas was 2.0 mm. The TRB was subjected to heat treatment before the
press working to make the strength of the thickened areas equal to that of a 440 MPaclass
steel plate. The press working was performed such that the thickened areas
were formed into the ridge portions 7.
[0137]
The thicknesses of the press-formed product 1 in the conventional example
were substantially kept at the thicknesses of the TRB, 2.0 mm maximum in the ridge
portions 7, and approximately 1.6 mm in the portions other than the ridge portions 7.
That is, the thickness of the ridge portions 7 was 1.25 times the thickness of the
portions other than the ridge portions 7. The maximuin hardness (Hv) at the
thickness centers of the ridge portions 7 was substantially equal to the hardness of
the TRB. Note that the hardness (Hv) of the outside of the bends in the ridge
portions 7 in the conventional example was about 1.26 times the hardness of the TRB
[0138]
In the inventive example of the present invention, the partially thickened
blank in the above present embodiment was formed into the groove-shaped pressformed
product 1 by press working. This partially thickened blank was obtained by
preparing a 440 MPa-class steel plate having a constant thickness of 1.6 mm as a
starting material, which was subjected to the partial thickening working according to
the above present embodiment. The thickness of the partially thickened thick areas
was 2.0 mm maximum. The press working was performed such that the thick areas
were formed into tLe ridge portions 7.
[0139]
The thicknesses of the press-formed product 1 in the inventive example of the
present invention were substantially kept at the thicknesses of the partially thickened
blank, 2.0 mm maximum in the ridge portions 7, and approximately 1.6 mm in the
portions other than the ridge portions 7. That is, the thickness of the ridge portions
7 was 1.25 times the thickness of the portions other than the ridge portions 7. The
maximum hardness (Hv) at the thickness centers of the ridge portions 7 was about
1.40 times the hardness of the starting material before the partial thickening working.
Note that the same was true for the hardness (Hv) of the outside of the bends in the
ridge portions 7 in the inventive example of the present invention.
[0 1401
(2) Condition of Axial Collapse Test
Of both end portions of the structural member 40 in the longitudinal direction
thereof, one end portion is immobilized. From the other of both end portions of this
structural member 40, an impactor was caused to collide with the structural member
40 so as to collapse the structural member 40 in the axis direction thereof. The
collision speed of the impactor was 10 lanlh.
[0141]
(3) Evaluation and Result of Test
For the structural members in the comparative example, the conventional
example, and the inventive example of the present invention, absorbed energies EA
of the time when the stroke of the impactor reached 100 mm in the axial collapse test
were measured. The evaluation was made using the ratio to an absorbed energy EA
in the comparative example, with the absorbed energy EA in the comparative
example defined as a reference (1.00). The results are shown in Table 3.
[0142]
[Table 31
TABLE 3
[0 1431
As illustrated in Table 3, the EA ratio in the conventional example was about
1.10. In contrast, the EA ratio in the inventive example of the present invention
was 1.3 1. This demonstrated that the structural member in the inventive example of
the present invention employing the technique of the present embodiment has a high
EA performance brought by the influences of partial thickening and significant work
hardening.
REFERENCE SIGNS LIST
[0144]
1 : press-formed product
Inventive example of
present invention
Partially thickened
blank
(partial thickening
working according to
present embodiment)
1.40
2.0 mm
(thickness ratio: 1.25)
1.31
Category
Blank steel plate
Hardness ratio. at
thickness center
Maximum thickness
of ridge portion
Absorbed energy EA
ratio
Comparative
example
Normal blank
having constant
thickness
1.02
1.6 mm
(thickness ratio:
1.00)
1 .OO
Conventional
example
Partially thickened
blank
(TRB)
1.01
2.0 mm
(thickness ratio:
1.25)
1.10
2: top panel portion
3: vertical wall portion
4: flange portion
5,6: bent portion
7, 8: ridge portion
9: closing plate
11: partially thickened blank (blank steel plate)
1 la: front surface
1 lb: back face
12: thick area
12a, l2b: step height
13A, 13B: thin area
15: starting material
16: first area
17A, 17B: second area
2 1 : punch
22: blank holder
23: die
23a: projecting portion
24: pad
3 1 : punch
3 la: shoulder portion
32: die
33: pad
40: stmctural member
We claim:
1. A blank steel plate that is planar and used for producing a press-formed
product having an open cross-section including a bent portion,
the blank steel plate being hoinogeneous across its entirety, and
including a belt-shaped thick area that has an increased thickness, and thin
areas that are adjacent to both sides of the thick area and have a thickness smaller
than the thickness of the thick area, wherein
on one of a front surface and a back face, a step height in thiclmess is formed
along one of both side portions of the thick area, and
on another of the front surface and the back face, a step height in thickness is
formed along another of both side portions of the thick area.
2. The blank steel plate according to Claim 1, wherein
a hardness at a thickness center of the thick area is higher than a hardness at a
thickness center of the thin area.
3. The blank steel plate according to Claim 1 or 2, wherein
an increase in the thickness of the thick area to the thickness of the thin area is
20% or more.
4. A production method for the blank steel plate described in any one of Claiins
1 to 3, comprising:
a preparing step of preparing, as a starting material, a steel plate having a
thickness that is constant and identical to the thickness of the thin area; and
a fonning process of forming the starting material into the blank steel plate by
press working, wherein
the fonning process includes:
a first step of segmenting the starting material into a belt-shaped first area that
has a width larger than a width of the thick area, and second areas that are adjacent to
both side portions of the first area, and displacing the second areas to different planes
parallel to each other while causing the first area to incline with respect to the second
areas; and
a second step of displacing the second areas to be flush with each other while
restraining the second areas in terms of movement in a width direction so as to
compress the width of the first area into the width of the thick area and increase a
thickness of the first area to the thickness of the thick area.
5. The production method for the blank steel plate according to Claim 4, wherein
in the fonning process, a press device is used, the press device including a
punch, a blank holder that is disposed adjacent to the punch, a die that is disposed
facing the blank holder and facing a part of the punch, and a pad that is disposed
adjacent to the die and facing the punch,
in the first step, the starting inaterial is pushed by the blank holder with one of
the second areas of the starting material sandwiched between the punch and the pad,
and the push is continued while another of the second areas of the starting material is
sandwiched between the blank holder and the die, so as to form the fust area that
inclines with respect to the second areas, and
in the second step, the one second area is pushed by the punch and the pad
until the one second area becomes flush with the other second area, and the first area
is compressed by the punch and the die so as to form the thick area a thickness of
which is increased from a thickness of the starting material.
6. The production method for the blank steel plate according to Claim 4 or 5,
wherein
in the fust step, a width L [mm] of the inclined first area, a thickness t [mm]
of the starting material, an inclination angle 0 ['I of the fust area with respect to the
second area, and a yield strength YS [MPa] of the starting material satisfy a
condition represented by a following Formula (1).
(Llt) x (l/cosO) 2-5.1 x x (YS)'+ 11.5 (1)
7. A production device for the blank steel plate according to any one of Claims 1
to 3, wherein
the production device for the blank steel plate uses, as a starting material, a
steel plate having a thickness that is constant and identical to the thickness of the thin
area, and forms the starting material into the blank steel plate by press working,
the production device including a punch, a blank holder that is disposed
adjacent to the punch, a die that is disposed facing the blank holder and facing a part
of the punch, and a pad that is disposed adjacent to the die and facing the punch, and
wherein
an interval between the blank holder and the pad is identical to a width of the
thick area of the blank steel plate.
8. The production device for the blank steel plate according to Claim 7, wherein
a projecting portion is provided on a surface of the die, the surface facing the
blank holder, and
the projecting portion has a height identical to or smaller than a thickness of
the starting material.
9. A production method for a press-formed product that has an open crosssection
including a bent portion, the production method comprising
using the blank steel plate according to any one of Claims 1 to 3 to subject the
blank steel plate to press working such that the thick area of the blank steel plate
forms the bent portion.
10. The production method for a press-formed product according to Claim 9,
wherein
by using a press device having: a punch that includes an impression portion in
which a shape of the press-formed product is formed and a shoulder portion
corresponding to the bent portion; and a pad and a die that are adjacent to each other
and disposed facing the punch,
press working is performed with the thick area of the blank steel plate made to
coincide with a position of the shoulder portion of the punch.
11. The production method for a press-fo&ed product according to Claim 9 or 10,
wherein the press working is performed in a cold or warm manner.
12. The production method for a press-formed product according to any one of
Claims 9 to 11, wherein a hardness at a thickness center of the bent portion is higher
than a hardness at a thickness center of a flat portion that is adjacent to the bent
portion.
13. The production method for a press-formed product according to Claim 12,
wherein the hardness of the bent portion is 1.2 times or more the hardness of the flat
portion in tenns of Vickers hardness.
14. The production method for a press-formed product according to any one of
Claims 9 to 13, wherein a thickness of the bent portion is 1.2 times or more a
thickness of a flat portion that is adjacent to the bent portion.
15. The production method for a press-formed product according to any one of
Claims 9 to 14, wherein a tensile strength of the blank steel plate is 440 MPa or more.
16. The production method for a press-formed product according to any one of
Claims 9 to 15, wherein a shape of an open cross-section of the press-formed product
is hat-shaped or groove-shaped.
17. The production method for a press-fonned product according to any one of
Claims 9 to 16, wherein the press-formed product is a structural member of a car
body of an automobile.
18. The production method for a press-formed product according to Claim 17:
wherein the structural member is a bumper reinforcement, a door impact beam, a
front side member, a rear side member, a center pillar outer reinforcement, a floor
cross member, a bulkhead, or a rocker reinforcement.
Documents
Application Documents
| # | Name | Date |
|---|---|---|
| 1 | 201617013111-IntimationOfGrant16-11-2023.pdf | 2023-11-16 |
| 1 | Power of Attorney [14-04-2016(online)].pdf | 2016-04-14 |
| 2 | 201617013111-PatentCertificate16-11-2023.pdf | 2023-11-16 |
| 2 | Form 5 [14-04-2016(online)].pdf | 2016-04-14 |
| 3 | Form 3 [14-04-2016(online)].pdf | 2016-04-14 |
| 3 | 201617013111-Correspondence-280120.pdf | 2020-01-29 |
| 4 | Drawing [14-04-2016(online)].pdf | 2016-04-14 |
| 4 | 201617013111-Power of Attorney-280120.pdf | 2020-01-29 |
| 5 | Description(Complete) [14-04-2016(online)].pdf | 2016-04-14 |
| 5 | 201617013111-CLAIMS [21-01-2020(online)].pdf | 2020-01-21 |
| 6 | Marked Copy [02-05-2016(online)].pdf | 2016-05-02 |
| 6 | 201617013111-DRAWING [21-01-2020(online)].pdf | 2020-01-21 |
| 7 | Form 13 [02-05-2016(online)].pdf | 2016-05-02 |
| 7 | 201617013111-FER_SER_REPLY [21-01-2020(online)].pdf | 2020-01-21 |
| 8 | Description(Complete) [02-05-2016(online)].pdf | 2016-05-02 |
| 8 | 201617013111-Information under section 8(2) (MANDATORY) [21-01-2020(online)].pdf | 2020-01-21 |
| 9 | 201617013111-PETITION UNDER RULE 137 [21-01-2020(online)].pdf | 2020-01-21 |
| 9 | 201617013111.pdf | 2016-06-07 |
| 10 | 201617013111-certified copy of translation (MANDATORY) [31-10-2019(online)].pdf | 2019-10-31 |
| 10 | abstract.jpg | 2016-07-19 |
| 11 | 201617013111-FER.pdf | 2019-08-01 |
| 11 | Other Patent Document [03-08-2016(online)].pdf | 2016-08-03 |
| 12 | 201617013111-FORM 3 [05-07-2019(online)].pdf | 2019-07-05 |
| 12 | 201617013111-OTHERS-040816.pdf | 2016-08-08 |
| 13 | 201617013111-Correspondence-040816.pdf | 2016-08-08 |
| 13 | 201617013111-Correspondence-240619.pdf | 2019-07-01 |
| 14 | 201617013111-OTHERS-240619.pdf | 2019-07-01 |
| 14 | 201617013111-Power of Attorney-090816.pdf | 2016-08-11 |
| 15 | 201617013111-AMENDED DOCUMENTS [21-06-2019(online)].pdf | 2019-06-21 |
| 15 | 201617013111-Correspondence-090816.pdf | 2016-08-11 |
| 16 | 201617013111-FORM 13 [21-06-2019(online)].pdf | 2019-06-21 |
| 16 | Form 3 [06-10-2016(online)].pdf | 2016-10-06 |
| 17 | 201617013111-RELEVANT DOCUMENTS [21-06-2019(online)].pdf | 2019-06-21 |
| 18 | Form 3 [06-10-2016(online)].pdf | 2016-10-06 |
| 18 | 201617013111-FORM 13 [21-06-2019(online)].pdf | 2019-06-21 |
| 19 | 201617013111-AMENDED DOCUMENTS [21-06-2019(online)].pdf | 2019-06-21 |
| 19 | 201617013111-Correspondence-090816.pdf | 2016-08-11 |
| 20 | 201617013111-OTHERS-240619.pdf | 2019-07-01 |
| 20 | 201617013111-Power of Attorney-090816.pdf | 2016-08-11 |
| 21 | 201617013111-Correspondence-040816.pdf | 2016-08-08 |
| 21 | 201617013111-Correspondence-240619.pdf | 2019-07-01 |
| 22 | 201617013111-FORM 3 [05-07-2019(online)].pdf | 2019-07-05 |
| 22 | 201617013111-OTHERS-040816.pdf | 2016-08-08 |
| 23 | 201617013111-FER.pdf | 2019-08-01 |
| 23 | Other Patent Document [03-08-2016(online)].pdf | 2016-08-03 |
| 24 | abstract.jpg | 2016-07-19 |
| 24 | 201617013111-certified copy of translation (MANDATORY) [31-10-2019(online)].pdf | 2019-10-31 |
| 25 | 201617013111-PETITION UNDER RULE 137 [21-01-2020(online)].pdf | 2020-01-21 |
| 25 | 201617013111.pdf | 2016-06-07 |
| 26 | 201617013111-Information under section 8(2) (MANDATORY) [21-01-2020(online)].pdf | 2020-01-21 |
| 26 | Description(Complete) [02-05-2016(online)].pdf | 2016-05-02 |
| 27 | 201617013111-FER_SER_REPLY [21-01-2020(online)].pdf | 2020-01-21 |
| 27 | Form 13 [02-05-2016(online)].pdf | 2016-05-02 |
| 28 | 201617013111-DRAWING [21-01-2020(online)].pdf | 2020-01-21 |
| 28 | Marked Copy [02-05-2016(online)].pdf | 2016-05-02 |
| 29 | 201617013111-CLAIMS [21-01-2020(online)].pdf | 2020-01-21 |
| 29 | Description(Complete) [14-04-2016(online)].pdf | 2016-04-14 |
| 30 | 201617013111-Power of Attorney-280120.pdf | 2020-01-29 |
| 30 | Drawing [14-04-2016(online)].pdf | 2016-04-14 |
| 31 | Form 3 [14-04-2016(online)].pdf | 2016-04-14 |
| 31 | 201617013111-Correspondence-280120.pdf | 2020-01-29 |
| 32 | Form 5 [14-04-2016(online)].pdf | 2016-04-14 |
| 32 | 201617013111-PatentCertificate16-11-2023.pdf | 2023-11-16 |
| 33 | Power of Attorney [14-04-2016(online)].pdf | 2016-04-14 |
| 33 | 201617013111-IntimationOfGrant16-11-2023.pdf | 2023-11-16 |
Search Strategy
| 1 | 201617013111_06-11-2018.pdf |