U.S. patent application number 14/190555 was filed with the patent office on 2015-04-02 for bending die having surface microstructures and bending punch thereof.
This patent application is currently assigned to National Kaohsiung First University of Science and Technology. The applicant listed for this patent is National Kaohsiung First University of Science and Technology. Invention is credited to Chun-Chih KUO, Bor-Tsuen LIN.
Application Number | 20150089990 14/190555 |
Document ID | / |
Family ID | 52738766 |
Filed Date | 2015-04-02 |
United States Patent
Application |
20150089990 |
Kind Code |
A1 |
LIN; Bor-Tsuen ; et
al. |
April 2, 2015 |
BENDING DIE HAVING SURFACE MICROSTRUCTURES AND BENDING PUNCH
THEREOF
Abstract
Provided are a bending die having surface microstructures and a
bending punch thereof applicable to stamping processing to bend a
blank to form a shape. The bending die includes a lower die, an
upper die, and a workpiece placing piece. The lower die includes a
die, and the die includes a forming surface. The upper die includes
a bending punch, the bending punch stamps a blank placed on the die
in a back and forth stroke, and the bending punch includes a
working portion coming into contact with the blank during stamping.
The workpiece placing piece is disposed between the upper die and
the lower die and used to position or/and press the blank placed on
the die. A plurality of microstructures are disposed on the forming
surface and/or on the surface of the working portion.
Inventors: |
LIN; Bor-Tsuen; (Kaohsiung
City, TW) ; KUO; Chun-Chih; (Kaohsiung City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
National Kaohsiung First University of Science and
Technology |
Kaohsiung City |
|
TW |
|
|
Assignee: |
National Kaohsiung First University
of Science and Technology
Kaohsiung City
TW
|
Family ID: |
52738766 |
Appl. No.: |
14/190555 |
Filed: |
February 26, 2014 |
Current U.S.
Class: |
72/412 ;
72/476 |
Current CPC
Class: |
B21D 5/0209
20130101 |
Class at
Publication: |
72/412 ;
72/476 |
International
Class: |
B21D 35/00 20060101
B21D035/00; B21D 22/02 20060101 B21D022/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2013 |
CN |
201310457253.7 |
Claims
1. A bending die having surface microstructures, applicable to
stamping processing to bend a blank to form a shape, the bending
die comprising: a lower die, disposed on a die base, the lower die
comprising a die, and the die comprising a forming surface; an
upper die, comprising a bending punch, the bending punch stamping a
blank placed on the die in a back and forth stroke, and the bending
punch comprising a working portion coming into contact with the
blank during stamping; and a workpiece placing piece, disposed
between the upper die and the lower die, and used to position or
press the blank placed on the die; wherein a plurality of
microstructures are disposed on the forming surface and/or on the
surface of the working portion, wherein the plurality of the
microstructures are in the pattern of a plurality of grooves or a
plurality of concaves or a combination of a plurality of grooves
and a plurality of concaves, wherein the plurality of grooves of
the microstructures are arranged intersecting each other or
parallel to each other.
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. The bending die according to claim 2, wherein the
microstructures are arranged at intervals.
7. (canceled)
8. The bending die according to claim 2, wherein the surfaces of
the concave microstructures are approximately circular, elliptic,
square or irregular.
9. The bending die according to claim 1, wherein the cross-sections
of the microstructures are approximately square, V-shaped or
arc-shaped.
10. A bending punch, comprising a working portion in contact with a
blank, and surfaces around the working portion comprising a
plurality of microstructures, wherein the plurality of the
microstructures are in the pattern of a plurality of grooves or a
plurality of concaves or a combination of a plurality of grooves
and a plurality of concaves, wherein the plurality of grooves of
the microstructures are arranged intersecting each other or
parallel to each other.
11. (canceled)
12. The bending punch according to claim 10, wherein the
microstructures are arranged at intervals.
13. (canceled)
14. The bending punch according to claim 10, wherein the surfaces
of the concave microstructures are approximately circular,
elliptic, square or irregular.
15. The bending punch according to claim 10, wherein the
cross-sections of the microstructures are approximately square,
V-shaped or arc-shaped.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of China Patent
Application No. 201310457253.7, filed on Sep. 30, 2013, which is
hereby incorporated by reference for all purposes as if fully set
forth herein
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a bending die having
surface microstructures and a bending punch thereof, and more
particularly to a bending die in which microstructures are disposed
on a surface of a working portion of a bending punch and on a
forming surface of a die and a bending punch thereof.
[0004] 2. Related Art
[0005] In the recent decade, with the rapid development of the
electronics industry, the sales of commodities like consumer
electronic products such as mobile phones and notebook computers
increase significantly. These commodities tend to become small in
volume, light in weight, high in strength, and high in heat
dissipation performance in recent years, which require that the
components thereof also need to be made of metal and in miniature
sizes. However, component production adopting semiconductor or
unconventional processes is subject to disadvantages such as high
equipment cost, limited materials used in processes, small
depth-to-width ratios of products, and difficulties in making
components of 3D shapes.
[0006] Metal forming processing is a key technology for mass
production of metal parts in conventional manufacturing, which has
advantages such as high production efficiency, material saving,
high precision, near net shape production, desirable mechanical
properties of finished products, unlimited material applications,
and simplified design of parts, and meets the conceptual
requirements for environmental friendliness of green industries, so
that the applications of metal forming in component
microfabrication have drawn more and more attention, which is
called metal micro-forming.
[0007] Bending processing in metal forming processing refers to
that metal sheets are bent and plastically deformed into demanded
shapes and angles through processing of bending tools. When
external forces are removed, the bent, permanent deformations are
still kept. FIG. 1A to FIG. 1C are schematic views of a common
bending die of a V-shaped bending type and a stamping process
thereof. For a bending die 10, a blank 11 (for example, a metal
sheet) is first placed on a forming surface 121 of a die 12 and
then a bending punch 13 is performed a back and forth stroke
towards a die 12 to stamp the blank 11, so that after the blank 11
is pressed and bent, the bottom surface of the blank 11 is shaped
by the forming surface 121, and the top surface of the blank 11 is
shaped by the bending punch 13, so as to obtain a demanded V-shaped
shape finished product or semi-finished product.
[0008] In addition, FIG. 2A to FIG. 2C are schematic views of a
common bending die of an L-shaped bending type and a stamping
process thereof For a bending die 10', a blank 1 first is placed on
a forming surface 121' of a die 12' a blank holder 14 is positioned
and held the blank 11' and then a bending punch 13' is performed a
back and forth stroke towards the die 12' to stamp the blank 11',
so that after the blank 11 is pressed and bent, the bottom surface
of the blank 11' is shaped by the forming surface 121', and the top
surface is shaped by one side of the bending punch 13', so as to
obtain a demanded L-shaped finished product or semi-finished
product.
[0009] Further, FIG. 3A to FIG. 3C are schematic views of a common
bending die of a U-shaped bending type and a stamping process
thereof. For a bending die 10'', a blank 11'' first is placed on a
forming surface 121'' of a die 12'', and then a bending punch 13''
is performed a back and forth stroke towards the die 12'' to stamp
the blank 11'', so that after the blank 11'' is pressed and bent,
the lateral surface of the blank 11'' is shaped by the forming
surface 121, the bottom surface of the blank 11'' is shaped by a
blank protrusion plate 15 of a protrusion mechanism (not shown),
and the top surface is shaped by the bending punch 13'', so as to
obtain a demanded U-shaped shape finished product or semi-finished
product.
[0010] After the bending dies 10, 10', and 10'' are performed
bending and stamping processing on a blank, without causing a crack
on the bending corner of the blanks 11, 11', and 11'', after the
blanks 11, 11', and 11'' are removed from the bending dies 10, 10',
and 10'', a deformation phenomenon of springback inevitably occurs
to the bending, causing a change in the size of the finished
product and in consequence unable to meet the standards. Therefore,
it is usually necessary to perform techniques such as secondary
shaping and processing to make the bending angle accurate.
SUMMARY OF THE INVENTION
[0011] The object of the present invention is to provide a bending
die having surface microstructures and a bending punch thereof, in
which microstructures are disposed on a forming surface of a die
and/or a surface of a working portion of a corresponding punch
thereof, so as to reduce the springback amount of a sheet metal
blank after stamping and bending.
[0012] To achieve the above object, the present invention provides
a bending die having surface microstructures, applicable to
stamping processing to bend a blank to form a shape. The bending
die comprises an upper die, a lower die, and a workpiece placing
piece. The lower die comprises a die, and the die comprises a
forming surface. The upper die comprises a bending punch, the
bending punch stamps a blank placed on the die in a back and forth
stroke, and the bending punch comprises a working portion coming
into contact with the blank during stamping. The workpiece placing
piece is disposed between the upper die and the lower die, and used
to position or press the blank placed on the die. A plurality of
microstructures are disposed on the forming surface of the die
and/or on the surface of the working portion of the bending punch.
The microstructures are intersecting grooves disposed inclined
relative to the stamping direction, parallel grooves disposed
perpendicular to the stamping direction, and slots or concaves in
various shapes.
[0013] In an embodiment, the forming surface at least has a wall
surface turning position, and the plurality of microstructures is
disposed on the wall surface turning position and/or a neighboring
wall surface region thereof.
[0014] In an embodiment, the surface of the working portion at
least has a turning portion, and the plurality of microstructures
is disposed on the turning portion and/or a neighboring surface
region thereof.
[0015] In an embodiment, an included angle is provided between two
adjacent wall surfaces of the wall surface turning position, or a
fillet, a concave angle or an oblique angle is provided between two
adjacent wall surfaces of the wall surface turning position.
[0016] In an embodiment, the microstructures are arranged at
intervals, the shapes of the cross-sections of the intersecting
grooves of the microstructures are approximately column-shaped,
V-shaped or arc-shaped.
[0017] The present invention is characterized in that a plurality
of microstructures disposed on the surface of a working portion of
a bending punch, and/or on the surface of a working portion of a
bending punch and a forming surface of a corresponding die of the
present invention can reduce the force of friction between a
processed blank and a bending die during bending, so as to make a
sheet metal blank to completely reach plastic deformation during
bending and forming, reduce cases of uneven stress distribution on
the sheet metal blank, and reduce the springback amount of the
sheet metal blank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will become more fully understood from
the detailed description given herein below for illustration only,
and thus are not !imitative of the present invention, and
wherein:
[0019] FIG. 1A to FIG. 1C are schematic views of a bending die of a
V-shaped bending type and a stamping process thereof in the prior
art;
[0020] FIG. 2A to FIG. 2C are schematic views of a bending die of
an L-shaped bending type and a stamping process thereof in the
prior art;
[0021] FIG. 3A to FIG. 3C are schematic views of a bending die of a
U-shaped bending type and a stamping process thereof in the prior
art;
[0022] FIG. 4A is a schematic view before a bending punch performs
a bending work on a blank according to an embodiment of the present
invention;
[0023] FIG. 4B is a schematic partial view of a bending punch of a
bending die in FIG. 4A performs a bending work on a sheet metal
blank;
[0024] FIG. 5 is a schematic sectional view of the positions of
microstructures on the surface of a working portion of a bending
punch and a forming surface of a die in the U-shaped bending die
according to an embodiment of the present invention;
[0025] FIG. 6 is a schematic sectional perspective view of the
microstructures on the surface of a working portion of a bending
punch and a forming surface of a die according to the embodiment in
FIG. 5, where the microstructures of the punch are intersecting
groove arrangement, and the microstructures of the die are oblique
parallel arrangement;
[0026] FIG. 7 is a schematic view of the microstructures of a die
when the form in the embodiment of the microstructures of the
bending punch and die is a curved surface according to an
embodiment of the present invention;
[0027] FIG. 8 is a schematic sectional view when the shapes of the
cross-sections of the microstructures on a bending punch and a die
are V-shaped intersecting grooves according to an embodiment of the
present invention;
[0028] FIG. 9 is a schematic sectional view when the shapes of the
cross-sections of the microstructures on a bending punch and a die
are square intersecting grooves according to an embodiment of the
present invention;
[0029] FIG. 10 is a schematic sectional view when the shapes of the
cross-sections of the microstructures on a bending punch and a die
are arc-shaped intersecting grooves according to an embodiment of
the present invention;
[0030] FIG. 11 is a schematic view when microstructures on a
bending punch are oblique parallel arrangement according to the
present invention;
[0031] FIG. 12 is a schematic view when microstructures on a
bending punch are intersecting arrangement according to the present
invention;
[0032] FIG. 13 is a schematic view when microstructures on a
bending punch are horizontal parallel arrangement according to the
present invention;
[0033] FIG. 14 is a schematic view when concave microstructures on
a bending punch are evenly distributed according to the present
invention;
[0034] FIG. 15 is a schematic view of the positions of
microstructures on the surface of a working portion of a bending
punch and a forming surface of a die of a V-shaped bending die
according to an embodiment of the present invention;
[0035] FIG. 16 is a schematic view of the positions of
microstructures on the surface of a working portion of a bending
punch and a forming surface of a die of an L-shaped bending die
according to an embodiment of the present invention; and
[0036] FIG. 17 is a schematic sectional view when the
microstructures on the surface of a working portion of a bending
punch and a forming surface of a die in FIG. 15 are V-shaped
intersecting grooves according to an embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The embodiments of the present invention will be illustrated
below with reference to the accompanying rings.
[0038] Please first refer to FIG. 4A and FIG. 4B, in which FIG. 4A
is a schematic view before a bending punch performs a bending work
on a blank according to an embodiment of the present invention, and
FIG. 4B is a schematic partial view when a bending punch of a
bending die in FIG. 4A performs a bending work on a sheet metal
blank. In this embodiment, a bending die 20 is applicable to common
stamping and processing equipment and is used to bend a blank A
(generally a metal sheet) to form a shape. The related mechanisms
and operation principles of the stamping processing equipment are
well known to persons skilled in the art, which are therefore no
longer elaborated. The bending die 20 of the present invention
includes a lower die 21, an upper die 22, and a workpiece placing
piece 23. The lower die 21 includes a die 211, and the die 211 is
disposed on a die base B and includes a forming surface 2111. The
lower die 21 also includes a blank protrusion plates 24 of
protrusion mechanisms (not shown) configured inside the forming
surface 2111 and at the bottom of the blank A, so as to shape the
blank A and release the blank A from the die. The upper die 22
includes a bending punch 221, the bending punch 221 presses the
blank A placed on the die 211 in a back and forth stroke by
adopting the power of a stamping press (not shown), and the bending
punch 221 includes a working portion 2211 coming into contact with
the blank during stamping. The workpiece placing piece 23 is
disposed between the upper die 22 and the lower die 21, and used to
position or press the blank A placed on the die 211, so that the
bending punch 221 stamps a correct processing position on the blank
A. A plurality of microstructures G1 and G2 are disposed on the
forming surface 2111 (effective forming work surface) or the
surface (effective forming work surface) of the working portion
2211 or the forming die surface 2111 and the surfaces of the
working portion 2211. The sizes and depths of these microstructures
G1 and G2 differ depending on the factors such as the hardness of
the blank A and the size of the bending die. However, those
disposed on the forming surface 2111 and/or the surface of the
working portion 2211 and capable of keeping the required strength
of the bending die and reducing the force of friction between the
blank A and the bending die during stamping and forming shall fall
within the scope of the present invention.
[0039] Please refer to FIG. 5 and FIG. 6 then, in which FIG. 5 is a
schematic view of the positions of microstructures on the surface
of a working portion of a bending punch and a forming surface of a
die in the U-shaped bending die according to an embodiment of the
present invention, and FIG. 6 is a schematic view of the
microstructures on the surface of a working portion of a bending
punch and a forming surface of a die according to the embodiment in
FIG. 5. In this embodiment, the microstructures G2 on the bending
punch 221 are intersecting arrangement, and the microstructures G1
on the die 211 are oblique parallel arrangement; however, the
present invention is not limited to this implementation aspect in
practical applications. The blank A is positioned and pressed on
the die 211 by the workpiece placing piece 23 (blank holder), the
bending punch 22) stamps downwards corresponding to the middle of
the forming surface 2111 of the die 211, and is held against the
blank protrusion plate 24 of a protrusion mechanism (not shown).
The forming surface 2111 at least has a wall surface turning
position C. The plurality of microstructures G1 on the die 211 are
disposed on the wall surface turning position and a neighboring
wall surface region C1 thereof. The surface of the working portion
2211 at least has a turning portion D, and the plurality of
microstructures G2 of the bending punch 221 are disposed on the
turning portion and a neighboring surface region D1 thereof.
[0040] Please refer to FIG. 7 then, in which FIG. 7 is a schematic
view of the microstructures of a die when the form in the
embodiment is a curved surface according to an embodiment of the
present invention. The forming surface 2111a on the die 211a is a
curved surface or an irregular surface. The above microstructure G1
may be the pattern of a plurality of concaves. Of course, the
corresponding bend punch thereof that is not shown may also have
the same features of the curved surface and concave microstructures
corresponding to the forming surface 2111a. In addition, the
microstructures G1 may be the pattern of a plurality of grooves or
the pattern of a plurality of concaves, or the pattern of a
combination a plurality of grooves and a plurality of concaves.
Moreover, the groove microstructures may be the aspects of being
arranged intersecting each other or arranged parallel to each
other. The plurality of concave (may be approximately circular,
elliptic, square, or in other geometric shapes and other irregular
shapes) microstructures are suitable to be disposed on the surface
of a forming surface with a curved surface or the surface of a
working portion of a curved surface or irregular surface; however,
the present invention is not limited thereto. In other words, by
adopting the current processing technology, it is out of the
question to process groove microstructures on a curved surface or
an irregular surface, or to process concaves of circular, elliptic,
square shapes, other geometric shapes, and other irregular shape on
a plane.
[0041] Please then refer to FIG. 8, FIG. 9, and FIG. 10, in which
FIG. 8 is a schematic sectional view when the shapes of the
cross-sections of the microstructures on a bending punch and a die
are V-shaped intersecting grooves according to an embodiment of the
present invention, FIG. 9 is a schematic view when the
microstructures on a bending punch and a die are square
intersecting grooves according to an embodiment of the present
invention, and FIG. 10 is a schematic view when the microstructures
on a bending punch and a die are arc-shaped intersecting grooves
according to an embodiment of the present invention. The shapes F
of the cross-sections of the intersecting groove microstructures of
the microstructures G1 on the die 211 or the microstructures G2 on
the bending punch 221 in the embodiment of FIG. 8 are approximately
V-shaped, the shapes F' of the cross-sections of the intersecting
groove microstructures of the microstructures G1 of the die 211 or
the microstructures G2 of the bend punch 221 are square in the
embodiment of FIG. 9, and the shapes F'' of the cross-sections of
the intersecting groove microstructures of the microstructures G1
of the die 211 or the microstructures G2 of the bend punch 221 in
the embodiment of FIG. 10 are arc-shaped.
[0042] Please continue to refer to FIG. 11, FIG. 12, FIG. 13, and
FIG. 14, in which FIG. 11 is a schematic view when a plurality of
surface microstructures G2 on the turning portion on the bending
punch 221 and the neighboring surface region Di thereof is oblique
parallel arrangement relative to the stamping direction of the
bending punch 221 according to an embodiment of the present
invention, FIG. 12 is a schematic view when a plurality of surface
microstructures G2 on the turning portion of the bending punch 221
and the neighboring surface region D1 thereof is intersecting
arrangement relative to the stamping direction of the bending punch
221 according to an embodiment of the present invention, FIG. 13 is
a schematic view when a plurality of surface microstructures G2 on
the turning portion of the bending punch 221 and the neighboring
surface region D1. thereof is the arrangement perpendicular to the
stamping direction of the bending punch 221 (that is, the
arrangement horizontal to each other) according to an embodiment of
the present invention, and FIG. 14 is a schematic view when a
plurality of surface microstructures G2 in a concave form on the
turning portion of the bending punch 221 and the neighboring
surface region D1 thereof are evenly distributed according to an
embodiment of the present invention.
[0043] It should he noted that the intervals between the plurality
of surface microstructures G2 may be approximately even
distribution, and it is not required that the intervals are
completely accurate. Also, the shape of the microstructure surface
in a concave form may be circular; however, the present invention
is not limited to being circular, and may also be elliptic, square
shape and in other shapes. In addition, although the embodiments
use the microstructure G2 of the bending punch 221 as an example,
they may also be applicable to the setting of microstructures G1 on
the die 211.
[0044] FIG. 15 is a schematic view of the positions of
microstructures on the surface of a working portion of a bending
punch and a forming surface of a die of a V-shaped bending die
according to the present invention. In the embodiment in FIG. 15,
in a bending die 20, a blank A' is positioned on a die 211 with a
workpiece placing piece 23' (positioning plate). A bending punch
221' stamps downwards corresponding to the V-shaped forming surface
2111' of the die 211' to perform bending and forming on the blank
A'. A plurality of microstructures G1' of the die are disposed on
the wall surface turning position of the forming surface 2111' and
a neighboring wall surface region C1' thereof. A plurality of
microstructures G2' of the bending punch are disposed on the
turning portion and a neighboring surface region D1' thereof.
[0045] FIG. 16 is a schematic view of the positions of
microstructures on the surface of a working portion of a bending
punch and a forming surface of a die of an L-shaped bending die
according to the present invention. In the embodiment in FIG. 16,
in a bending die 20, a blank A'' is pressed and fixed on the die
211'' with a workpiece placing piece 23'' (blank holder). A bending
punch 221'' corresponds to the lateral side of an L-shaped forming
surface 2111'' of a die 211'', and stamps downwards to perform
bending and forming on the blank A''. A plurality of
microstructures G1'' are disposed on the wall surface turning
position of the forming surface 2111'' and a neighboring wall
surface region C1'' thereof A plurality of microstructures G2'' are
disposed on the turning portion and a neighboring surface region
D1'' thereof. FIG. 17 is a schematic sectional view of the
positions that the plurality of V-shaped microstructures G1'' and
the plurality of V-shaped microstructures G2'' on the turning
portion and the neighboring surface region D1'' thereof are
disposed relative to each other in a processing process.
[0046] In an embodiment, an included angle (right angle, acute
angle or obtuse angle) may be provided between two adjacent wall
surfaces of the wall surface turning position C, and a fillet, a
concave angle or an oblique angle may be provided two adjacent wall
surfaces, among other aspects.
[0047] It should be noted that, in an embodiment, the
microstructures on the forming surface and the surface of the
working portion may be disposed inclined or perpendicular to the
stamping direction, or disposed inclined or perpendicular to the
edge of the forming die surface.
[0048] In an embodiment, the microstructures are arranged at
intervals.
[0049] In conclusion, the present invention at least has the
following advantages: microstructures disposed on the surface of a
working portion of a bending punch, or the surface of a working
portion of a bending punch and a forming surface of a corresponding
die in the present invention are intersecting grooves disposed
inclined relative to the stamping direction, parallel grooves
disposed perpendicular to the stamping direction, and various shape
slots, and can reduce the force of friction between a processed
blank and a bending die during bending, so as to make a sheet metal
blank to completely reach plastic deformation during bending and
forming, reduce cases of uneven stress distribution on the sheet
metal blank, and reduce the springback amount of the sheet metal
blank.
[0050] The invention being thus described, it will be obvious that
the same may be varied in many ways. Such variations are not to be
regarded as a departure from the spirit and scope of the invention,
and all such modifications as would be obvious to one skilled in
the art are intended to be included within the scope of the
following claims.
* * * * *