CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of the
priority of Korean Patent Application No. 10-2018-0146357,
filed on November 23, 2018, which is hereby incorporated by
reference in its entirety.
10 BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a pouch forming device
and method and a facility for producing a secondary battery,
which comprises the pouch forming device, and more particularly,
15 to a pouch forming device and method, in which,, when a pouch
is formed, an elongation gradually increases to prevent cracks
from occurring, and a facility for producing a secondary battery,
which comprises the pouch forming device.
20 Description of the Related Art
[0003] In general, secondary batteries are chargeable and
dischargeable unlike primary batteries that are not chargeable
and are widely used in electronic devices such as mobile phones,
notebook computers, camcorders, and the like, electric vehicles,
25 or the like.
1
[0004] Such a secondary battery comprises an electrode
assembly comprising an electrode tab, an electrode lead coupled
to the electrode tab, and a battery case accommodating the
electrode assembly in a state in which a front end of the
5 electrode lead is withdrawn to the outside.
[0005] The battery case comprises an accommodation part
accommodating the electrode assembly and a sealing part formed
along an edge surface of the accommodation part to seal the
accommodation part. A device for forming the battery case
10 comprises a die on which a battery film is disposed, a stripper
fixing the battery film disposed on the die, and a punch pressing
a surface of the battery film disposed on the die to form the
electrode assembly accommodation part in the battery film.
[0006] However, in the above-described device for forming the
15 battery case, when the battery film is formed, cracks may occur
at a local portion, i.e. , a vertex portion of the accommodation
part.
[Prior Art Document]
[Patent Document]
20 Korean Patent Publication No. 10-2008-0081845
SUMMARY OF THE IWENTION
[0007] An aspect of the present invention provides a pouch
forming device and method, in which, when a pouch film is pressed
25 to form an accommodation part accommodating an electrode
?
assembly, a stripper fixing the pouch film gradually decreases
in pressing force, and thus, the pouch film gradually increases
in elongation to stably form the accommodation part and also
prevent cracks from occurring at a local portion, i.e., a vertex
5 portion of the accommodation part, and a facility for producing
a secondary battery, which comprises the pouch forming device.
[0008] According to an aspect of the present invention, there
is provided a pouch forming device comprising: a die member
provided with a die on which a pouch film is disposed on a top
10 surface thereof, in which a forming part is formed, and a die
holder to which the die is fixed; a stripper member provided
with a stripper that is vertically movably disposed on an upper
portion of the die member to press and fix the pouch film disposed
on the die when descending and a first driving piece allowing
15 the stripper to vertically move; a punch member provided with
a punch plate comprising a punch that is vertically movable
disposed on the upper portion of the die member and is inserted
into the forming part when descending to form an electrode
assembly accommodation part in the pouch film and a second
20 driving piece allowing the punch plate to vertically move; and
a control member controlling the first driving piece to allow
the stripper to ascend when the punch is inserted into the
forming part to press the pouch film so as to decrease in pressing
force applied to the pouch film.
25 [0009] The control member may control the first driving piece
3
to allow the stripper to gradually ascend so as to gradually
decrease in pressing force of the pouch film.
[0010] The control member may allow the stripper to ascend so
as to be separated from the pouch film when the punch is
5 completely inserted into the forming part so that the pressing
force applied to the pouch film is completely removed.
[0011] The control member may comprise a detection sensor
detecting insertion of the punch into the forming part and a
controller controlling the driving piece according to a signal
10 the detection sensor to allow the stripper to gradually ascend.
[0012] The first driving piece may comprise a plurality of
moving rods connected to the stripper by passing through a top
surface of the punch plate to allow the stripper to vertically
move, a connection bar to which the plurality of moving rods
15 disposed on an upper portion of the punch plate are fixed and
which allows the plurality of moving rods to vertically move
at the same time, and a cylinder allowing the connection bar
to vertically move.
[0013] The control member may further control the second
20 driving piece to reduce a descending speed of the punch plate
on which the punch is disposed when the punch is inserted into
the forming part to press the pouch film.
[0014] The control member may control the second driving piece
to gradually reduce the descending speed of the punch plate on
25 which the punch is disposed.
A
[0015] The control member may control the first driving piece
and the second driving piece at the same time to allow the
stripper to gradually ascend and gradually reduce the
descending speed of the punch plate.
5 [0016] According to another aspect of the present invention,
there is provided a pouch forming method comprising; a
disposition step of disposing a pouch film on a top surface of
a die member provided with a forming part; a pressing step of
pressing the pouch film disposed on the top surface of the die
10 member through a stripper member so that an edge surface of the
pouch film is fixed; a forming step of inserting a punch into
the forming part to form an electrode assembly accommodation
part in a surface of the pouch film; and a control step of
gradually reducing pressing force of the stripper member to
15 gradually decrease in pressing force applied to the pouch film
when the punch is inserted into the forming part to press the
pouch film.
[0017] The control step may comprise a first control process
of outputting ah insertion signal when the punch is inserted
20 into the forming part and a second control process of gradually
reducing the pressing force applied to the pouch film when the
insertion signal is outputted.
[0018] The control step may further comprise a third control
process of gradually reducing a descending speed of the punch
25 when the insertion signal is outputted to gradually decrease
5
in pressing force applied to the pouch film through the punch.
[0019] According to another aspect of the present invention,
there is provided a facility for producing a secondary battery,
the facility comprising a pouch forming device that forms a
5 pouch film to manufacture a pouch in which an electrode assembly
accommodation part is formed, wherein the pouch forming device
comprises: a die member provided with a die on which a pouch
film is disposed on a top surface thereoff in which a forming
part is formed, and a die holder to which the die is fixed; a
10 stripper member provided with a stripper that is vertically
movably disposed on an upper portion of the die member to press
and fix the pouch film disposed on the die when descending and
a first driving piece allowing the stripper to vertically move;
a punch member provided with a punch plate comprising a punch
15 that is vertically movable disposed on the upper portion of the
die member and is inserted into the forming part when descending
to form an electrode assembly accommodation part in the pouch
film and a second driving piece allowing the punch plate to
vertically move; and a control member controlling the first
20 driving piece to allow the stripper to ascend when the punch
is inserted into the forming part to press the pouch film so
as to decrease in pressing force applied to the pouch film.
[0020] The control member may control the second driving piece
to gradually reduce a descending speed of the pouch plate on
25 which the punch is disposed when the punch is inserted into the
6
forming part to press the pouch film.
[0021] According to an aspect of the present invention, there
is provided- a pouch forming device comprising: a die member
provided with a die on which a pouch film is disposed on a top
5 surface thereof, in which a forming part is formed, and a die
holder to which the die is fixed; a stripper member provided
with a stripper that is vertically movably disposed on an upper
portion of the die member to press and fix the pouch film disposed
on the die when descending and a first driving piece allowing
10 the stripper to vertically move; a punch member provided with
a punch plate comprising a punch that is vertically movable
disposed on the upper portion of the die member and is inserted
into the forming part when descending to form an electrode
assembly accommodation part in the pouch film and a second
15 driving piece allowing the punch plate to vertically move; and
a control member controlling the second driving piece to reduce
a descending speed of the punch plate on which the punch is
disposed when the punch is inserted into the forming part to
press the pouch film.
20 [0022] The control member may control the second driving piece
to gradually reduce the descending speed of the punch plate on
which the punch is disposed.
BRIEF DESCRIPTION OF THE DRAWIHGS
25 [0023] The above and other aspects, features and other
7
advantages of the present invention will be more clearly
understood from the following detailed description taken in
conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic side view of a pouch forming device
5 according to a first embodiment of the present invention;
FIG. 2 is an exploded perspective view of the pouch forming
device according to the first embodiment of the present
invention;
FIG. 3 is an assembled perspective view of the pouch
10 forming device according to the first embodiment of the present
invention;
FIG. 4 is a front view of the pouch forming device
according to the first embodiment of the present invention;
FIG. 5 is a side view of the pouch forming device according
15 to the first embodiment of the present invention;
FIG. 6 is a cross-sectional view taken along line A-A of
FIG. 3;
FIG. 7 is a flowchart illustrating a pouch forming method
according to the first embodiment of the present invention;
20 FIG. 8 is a graph illustrating a relationship between
pressing force and a forming depth of a stripper member in the
pouch forming method according to the first embodiment of the
present invention;
FIG. 9 is a graph illustrating a relationship between a
25 descending speed and a forming depth of a punch member in the
8
pouch forming method according to the first embodiment of the
present invention;
FIG. 10 is-a view illustrating a sealing device of a
facility for producing a secondary battery according to a second
5 embodiment of the present invention;
FIG. 11 is a table showing an experimental example of the
pouch forming device according to the first embodiment of the
present invention;
FIG. 12 is a perspective view of a pouch manufactured
10 according to a comparative example in the experimental example
of the pouch forming device according to the first embodiment
of the present Invention; and
FIG. 13 Is a perspective view of a pouch manufactured
according to a manufacturing example in th experimental example
15 of the pouch forming device according to the first embodiment
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] Hereinafter, embodiments of the present invention will
20 be described in detail with reference to the accompanying
drawings in such a manner that the technical idea of the present
invention may easily be carried out by a person with ordinary
skill in the art to which the invention pertains. The present
invention mayf however, be embodied in different forms and
25 should not be construed as limited to the embodiments set forth
9
herein. In the drawings, anything unnecessary for describing
the present invention will be omitted for clarity, and also like
reference numerals in the drawings denote like elements.
[0025] [Pouch]
5 [0026] Referring to FIGS. 10, 12, and 13, a pouch 10A is
configured to accommodate an electrode assembly and comprises
an electrode assembly accommodation part 11 accommodating the
electrode assembly 20 and a sealing part 12 sealing the
electrode assembly accommodation part 11.
10 [0027] The pouch 10A having the above-described structure is
formed by using a pouch forming device according to the present
Invention. That is, the pouch forming device according to the
present invention presses one surface of a pouch film having
a predetermined area to form the electrode assembly
15 accommodation part 11 and bends the other surface of the pouch
film to overlap the electrode assembly accommodation part,
thereby manufacturing the pouch 10A.
[0028] Here, in the pouch forming device according to the
present invention, when the pouch film is pressed to form the
20 electrode assembly accommodation part, the pressing force for
fixing the pouch film may gradually decrease. Thus, when the
electrode assembly accommodation part is formed, elongation may
gradually increase to form the electrode assembly accommodation
part without an occurrence of cracks at a local portion, i.e.,
25 an edge or vertex portion of the electrode assembly
10
accommodation part.
[0029] Hereinafter, the pouch forming device according to the
present invention will be described in detail with reference
to the accompanying drawings.
5 [0030] [Pouch forming device according to first embodiment of
the present invention]
[0031] As illustrated in FIGS. 1 to 6f a pouch forming device
100 according to a first embodiment of the present invention
comprises a die member 110 on which a pouch film 10 is disposed,
10 a stripper member 120 pressing the pouch film 10 disposed on
the die member 110 to fix the pouch film 10, a punch member 130
pressing the pouch film 10 disposed on the die member 110 to
form an electrode assembly accommodation part,, and a control
member 140 reducing pressing force of the stripper member 120
15 when the punch member 130 presses the pouch film 10 to increase
in elongation of the pouch film 10.
[0032] Die member
[0033] As illustrated in FIG. 2, the die member 110 is
configured"t6 dispose the pouch film 10 thereon. The die member
20 110 comprises a die 111 on which the pouch film 10 is disposed
and a die holder. 112 to which the die 111 is fixed.
[0034] Here, the die 111 has an area less than that of the die
holder 112. A forming part Ilia for forming the electrode
assembly accommodation part in the pouch film 10 is formed in
25 a top surface of the die 111.
11
[0035] The die 111 comprises an upper die 111A and a lower die
111B, which are vertically stacked. The upper die 111A is
provided with the forming part Ilia, which vertically passes
through the upper die 111A, in a top surface thereof, and the
5 lower die 111B is disposed on the upper die 111A to finish a
lower portion of the forming part Ilia. In the die 111 having
the above-described structure, the plurality of upper dies 111A,
in which the forming parts having various sizes, shapes, and
thicknesses are formed, may be replaced from the lower die 111B
10 to enhance compatibility.
[0036] Siirlpper meaaber
[0037] The stripper member 120 is configured to fix the pouch
film disposed on the die member. The stripper member 120
comprises a stripper 121 vertically movably disposed on an upper
15 portion of the die member 110 and pressing the pouch film 10
to fix the pouch film 10 disposed on the die 111 when descending
and a first driving piece 122 allowing the stripper 121 to
vertically move.
[0038] The stripper "121 has a size corresponding to that of
20 the top surface of the die 111. A through-hole 121a vertically
passing through the stripper 121 and having the same size as
the forming part Ilia is formed in a top surface of the stripper
121.
[0039] The first driving piece 122 comprises a plurality of
25 moving rods 122a allowing the stripper 121 to vertically move,
12
a connection bar 122b allowing the plurality of moving rods to
vertically move at the same time, and a cylinder 122c allowing
the connection bar 122b to vertically move.
[0040] Here, the plurality of moving rods 122a are uniformly
5 connected to along an edge of the top surface of the stripper
121 so that the stripper 121 vertically descends or ascends with
respect to the die 110. Particularly, the plurality of moving
rods 122a pass through a top surface of a punch plate of the
punch member 130 and are connected to the stripper 121. Thus,
10 the moving rods 122a vertically move by the punch plate to allow
the stripper 121 to stably vertically descend or ascend.
[0041] The connection bar 122b is configured to allow the
plurality of moving rods to move at the same time. The
connection bar 122b has a long rectangular shape,, and the
15 plurality of moving rods 122a are connected to a bottom surface
of the connection bar 122b.
[0042] Here, a guide groove 122b-l is formed in a top surface
of the connection bar 122b in a longitudinal direction, and the
cylinder 122c is positionally adjustably connected to the guide
20 groove 122b-l. That is, even though a connection error between
the cylinder 122c and the connection bar 122b occurs, the
cylinder 122c may be stably connected to the connection bar
122b.
[0043] In the stripper member 120 having the above-described
25 structure, when the connection bar 122b descends through the
13
cylinder 122c, the stripper member 120 may be interlocked with
the connection bar 122b to allow the plurality of moving rods
122a to descend. -Thus,, while the stripper 121 descends by the
plurality of moving rods 122ar the stripper 121 may press and
5 fix the edge surface of the pouch film 10 disposed on the die
111 at the same time.
[0044] Punch member
[0045] The punch member 130 comprises a punch plate 131
comprising a punch 131a that is vertically movably disposed on
10 the upper portion of the die member 110 and inserted into the
forming part Ilia when descending to form the electrode assembly
accommodation part and a second driving piece 132 allowing the
punch plate 131 to vertically move.
[0046] In the punch member 130 having the above-described
15 structuref when the punch plate 131 descends by the second
driving piece 132, the punch 131a provided on the punch plate
131 may pass through the through-hole of the stripper 121 and
then be inserted into the forming part Ilia. Here, the punch
131a may be inserted into the forming part Ilia in the state
20 of pressing the pouch film 10 disposed on the forming part 111a
to form the electrode assembly accommodation part having the
form of the forming part in the pouch film 10.
[0047] Control member
[0048] The control member 140 may control the first driving
25 piece to allow the stripper to ascend so as to decrease in
14
pressing force applied to the pouch film when the punch is
inserted into the forming part to press the pouch film.
[0049] That is, the control member 140 may reduce the pressing
force applied to the edge surface of the pouch film 10 to induce
5 the pouch film 10 so that a portion of the edge surface of the
pouch film 10 together with the punch 131a is inserted into the
forming part Ilia. Thus, the electrode assembly accommodation
part 11 to be formed in the pouch film 10 may increase in
elongation, and therefore, the electrode assembly
10 accommodation part 11 may be formed without the occurrence of
the cracks.
[0050] For example,, the control member 140 comprises a
detection sensor 141 detecting the insertion of the punch 131a
into the forming part Ilia and a controller 142 controlling the
15 first driving piece 122 according to a signal of the detection
sensor 141 to allow the stripper 121 to gradually ascend so as
to gradually decrease in pressing force applied to the pouch
film 10 disposed on the die 111.
[0051] That is, in the control member 140, when the punch 131a
20 is inserted into the forming part Ilia, the detection sensor
141 detects.the insertion of the punch 131a to transmit a signal
to the controller 142, and the controller 142 allows the first
driving piece 122 to gradually ascend according to the signal
transmitted from the detection sensor 141. Then, while the
25 stripper 121 gradually ascends by being interlocked with the
15
first driving piece 122, the pressing force applied to the pouch
film 10 disposed on the die 111 may gradually decrease. As a
result, a portion of the edge surface of the pouch film 10 pressed
by the stripper 121 moves by the pressing force of the punch
5 131a in the direction of the forming part Ilia to significantly
enhance the elongation. Thus, the electrode assembly
accommodation part 11 may be stably formed in the pouch film
10 without the occurrence of the cracks.
[0052] That is to sayf as the pressing force of the punch 131a
10 pressing the pouch film 10 largely increases, the pressing force
of the stripper 121 fixing the pouch film 10 largely decreases.
Accordingly, the elongation of the electrode assembly
accommodation part of the pouch film 10 may significantly
increase to prevent the cracks from occurring when the electrode
15 assembly accommodation part is formed in the pouch film.
[0053] Here, the control member 140 may gradually reduce the
pressing force of the stripper 121. Thus, a quality problem
caused by excessive movement of the edge surface of the pouch
film 10 or a quality problem caused by small moving force may
20 be solved. That is, the edge surface of the pouch film may
uniformly move and be uniformly elongated to improve quality
of the electrode assembly accommodation part.
[0054] The control member 140 may allow the stripper 121 to
ascend so as to be separated from the pouch film 10 when the
25 punch 131a is completely inserted into the forming part Ilia
16
so that the pressing force applied to the pouch film 10 is
completely removed. Thus, the elongation of the edge and vertex
portion of the electrode assembly accommodation part formed in
the pouch film may be maximized to prevent the cracks from
5 occurring. Particularly, since the stripper 121 is separated
from the pouch film 10f a separate process for the ascending
of the stripper 121 may be removed to achieve process
simplification.
[0055] When the punch 131a is inserted into the forming part
10 Ilia to press the pouch film 10, the control member 140 further
controls the second driving piece 132 to reduce a descending
speed of the punch plate 131 on which the pouch 131a is disposed.
Particularly, the control member 140 may control the second
driving piece 132 to gradually reduce the descending speed of
15 the punch plate 131 on which the punch 131a is disposed. Thus,
the pressing force applied to the pouch film 10 through the punch
131a may gradually decrease, and thus, the pouch film 10 may
be gradually elongated so that the electrode assembly
accommodation part to be formed in the pouch film is stably
20 formed without the occurrence of the cracks.
[0056] Particularly, since the punch 131a is inserted into the
forming part Ilia, the control member 140 may control the first
driving piece 122 and the second driving piece 132 at the same
time so that the stripper gradually ascends, and simultaneously,
25 the descending speed of the punch plate gradually decreases.
17
Thus, the pouch film may be gradually elongated to stably form
the electrode assembly accommodation part to be formed in the
pouch film may be stably formed without the occurrence of the
cracks.
5 [0057] Thus, in the pouch forming device 100 according to the
first embodiment of the present invention, when the punch is
inserted into the forming part, the stripper 121 may gradually
ascend. As a result, the pressing force applied to the pouch
film 10 fixed by the stripper may gradually decrease to
10 gradually increase in elongation of the pouch film 10.
Therefore, the electrode assembly accommodation part to be
formed in the pouch film may be stably formed without the
occurrence of the cracks.
[0058] Referring to FIG. 1, the pouch forming device 100
15 according to the first embodiment of the present invention
further comprises a body member 150. The body member 150
comprises a lower body 151 and an upper body 152 which is disposed
on the lower body 151 and on which the die member 110,. the
stripper member 120, the punch member 130, and the control
20 member 140 are installed. That is, the pouch forming device
100 according to the first embodiment of the present invention
may stably install the die member 110, the stripper member 120,
the punch member 130, and the control member 140 through the
body member 150.
25 [0059] Hereinafter, a forming method using the pouch forming
18
device 100 according to the first embodiment of the present
invention will be described.
[0060] [Pouch forming method according to first embodiment of
the present invention]
5 [0061] As illustrated in FIG. 7, a pouch forming method
according to the first embodiment of the present invention
comprises a disposition step (SlO) of disposing a pouch film
10 on a top surface of a die member 110 provided with a forming
part, a pressing step (S20) of pressing the pouch film 10
10 disposed on the top surface of the die member 110 through a
stripper member 120 so that an edge surface of the pouch film
10 is fixed, a forming step (S30) of inserting a punch into the
forming part to form an electrode assembly accommodation part
in a surface of the pouch film 10, and a control step (S40) of
15 gradually reducing pressing force of the stripper member 120
to gradually decrease in pressing force applied to the pouch
film when the punch is inserted into the forming part to press
the pouch film.
[0062] In the disposition step (SlO), the pouch film 10 is
20 disposed on the top surface of the die member 110. That is,
the die member 110 comprises a die 111 in which the forming part
Ilia is formed and a die holder 112 fixing the die 111. The
pouch film 10 is disposed on the top surface of the die 111 in
which the forming part Ilia is formed.
25 [0063] In the pressing step (S20), the stripper member 120
19
presses and fixes the pouch film disposed on the die 111. That
is, the stripper member 120 comprises a stripper 121 and a first
driving piece 122 . While the stripper 121 descends by the first
driving piece 122, the stripper 121 presses and fixes an edge
5 surface of the pouch film 10 disposed on the die 111.
[0064] In the punch step (S30) , the punch member 130 presses
the pouch film 10 disposed on the forming part Ilia to form the
electrode assembly accommodation part. Here, the punch member
130 comprises a punch plate 131 provided with the punch 131a
10 and a second driving piece. That is, in the punch member 130,
when the punch plate 131 descends by the second driving piece
132 „ the punch 131a provided on the punch plate 131 is inserted
into the forming part Ilia in a state of pressing the pouch film
10 to form the electrode assembly accommodation part in the
15 pouch film 10.
[0065] The control step (S40) comprises a first control process
of outputting an insertion signal when the punch 131a is
inserted into the forming part and a second control process of
gradually reducing pressing force applied to the pouch film when
20 the insertion signal is outputted. Here, the control member
14 0 comprises a detection sensor 141 and a controller 142.
[0066] That is, in the first control process, when the punch
131a is inserted into the forming part Ilia in the state of
pressing the pouch film 10, the detection sensor 141 detects
25 the insertion of the punch 131a to transmit the insertion signal
20
to the controller 142. In the second control process, when the
controller 142 receives the insertion signal of the detection
sensor 141, the-first driving piece 122 is controlled to allow
the stripper 121 to gradually ascend. Thus, the pressing
5 applied to the pouch film 10 fixed to the stripper 121 gradually
decreases, and a portion of the edge surface of the pouch film
10 is gradually elongated in a direction of the forming part
by the pressing force of the punch 131a to enhance elongation.
Therefore, the electrode assembly to be formed in the pouch film
10 10 may be stably formed without an occurrence of cracks.
[0067] Particularly, when the punch 131a is completely
inserted into the forming part? the control member 140
completely removes the pressing force applied to the pouch film
10 through the stripper 121. Thus, the elongation of the pouch
15 film while the punch 131a is completely inserted into the
forming part may be maximized to prevent the cracks from
occurring at an edge and a vertex of the electrode assembly
accommodation part formed in the pouch film 10.
[0068] The control step (S40) further comprises a third control
20 process of gradually reducing a descending speed of the punch
when the insertion signal is outputted through the control
member 140 to gradually decrease in pressing force applied to
the pouch film through the punch.
[0069] In the third control process, the second driving piece
25 132 may be controlled through the controller 142 to gradually
21
decrease in descending speed of the punch plate 131. Thus, the
punch 131a together with the punch plate 131 may gradually
decrease in descending speed to gradually decrease in pressing
force applied to the pouch film 10 disposed on the forming part.
5 As a result, the pouch film 10 may be gradually formed to form
the electrode assembly accommodation part 11 without the
occurrence of the cracks.
[0070] In summary, as shown in the graph of FIG. 8, in the second
control process, the pressing force of the stripper 121 and a
10 depth at which the punch 131a is inserted into the forming part
Ilia are inversely proportional to each other. That is, as the
depth of the punch 131a inserted into the forming part Ilia
increases, the pressing force of the stripper 121 may gradually
decrease to expand an elongation area of the pouch film. As
15 a result, a local elongation of the pouch may increase to prevent
the cracks from occurring.
[0071] Also, as illustrated in FIG. 9, in the third control
process, the descending speed of the punch 131a and the depth
of the punch 131a inserted into the forming part Ilia are
20 inversely proportional to each other. That is, as the depth
of the punch 131a inserted into the forming part Ilia increases,
the descending speed, i.e., the pressing force of the punch 131a
may gradually decrease to expand the elongation area of the
pouch film. As a result, a local elongation of the pouch may
25 increase to prevent the cracks from occurring.
22
[0072] Thus, in the pouch forming method according to the first
embodiment of the present invention, when the pouch film is
formed, the elongation may gradually increase to form the
electrode assembly accommodation part in the pouch film without
5 the occurrence of the cracks, thereby manufacturing the pouch
having high quality.
[0073] [Facility for producing secondary battery according to
second embodiment of the present invention]
[0074] A facility for producing a secondary battery according
10 to a second embodiment of the present invention comprises the
pouch forming device according to the foregoing first
embodiment.
[0075] That is, referring to FIGS. 1 and 10, the facility for
producing secondary battery according to the second embodiment
15 of the present invention comprises a pouch forming device
forming a pouch 10A and a sealing device 200 sealing an edge
surface of the pouch 10A in a state of accommodating an electrode
assembly 20 in the pouch 10A to produce a secondary battery 1.
[0076] Here, the pouch forming device 100 comprises a die
20 member on which a pouch film is disposed, a stripper member
pressing and fixing the pouch film disposed on the die member,
a punch member forming the pouch film disposed on the die member
to form an electrode assembly accommodation part, and a control
member reducing pressing force of the stripper member when the
25 punch member perform the forming to increase in tensile force
23
of the pouch film and to prevent cracks from occurring.
[0077] The pouch forming device 100 has the same configuration
and function - as the pouch forming device according to the
foregoing first embodiment, and thus, its detailed description
5 will be omitted.
[0078] Thusf the facility for producing the secondary battery
according to the second embodiment of the present invention may
produce the secondary battery having high quality.
[0079] [Pouch forming device according to third embodiment of
10 the present invention]
[0080] A pouch forming device according to a third embodiment
of the present invention comprises a die member on which a pouch
film is disposed, a stripper member pressing and fixing the
pouch film disposed on the die member, and a punch member forming
15 the pouch film disposed on the die member to form an electrode
assembly accommodation part. The punch member comprises a
punch plate comprising a punch that is vertically movably
disposed on an upper portion of the die member and is inserted
into the forming part when descending to form the electrode
20 assembly accommodation part in the pouch film and a second
driving piece allowing the punch plate to vertically move.
[0081] Here, the pouch forming device according to the third
embodiment of the present invention further comprises a control
member controlling the second driving piece to reduce a
25 descending speed of the punch plate provided with the punch when
24
the punch is inserted into the forming part to press the pouch
film. Thus, the descending speed of the punch may be adjusted
to gradually decrease in pressing force applied to the pouch
film. Therefore, the pouch film may be gradually elongated to
5 prevent cracks from occurring.
[0082] [Experimental Example]
[0083] Comparative Example
[0084] In Comparative Example, an electrode assembly
accommodation is formed in a pouch film by using a pouch forming
10 device comprising a die member, a stripper member, and a punch
member. That is, the pouch film is formed by using the
constituents except for the control member in the pouch forming
device according to the first embodiment of the present
invention except for the control member.
15 [0085] Manufacturing Example
[0086] In Manufacturing Example, an electrode assembly
accommodation is formed in a pouch film by using a pouch forming
device comprising a die member, a stripper member, a punch
member, and a control member. That is, the pouch film is formed
20 by using all the constituents of the pouch forming device
according to the first embodiment of the present invention.
[0087] Here, in Comparative Example and Manufacturing Example,
the same pouch film is used, and the pouch film is formed under
the same environment. Here, the same environment has following
25 conditions: a degree of vacuum: -98kPa, a pressure of the
25
stripper member: 4kg/cuf, an initial descending speed of the
punch member: 30 mm/s, a pressure inverse proportion control
rate: 95%, and a surface roughness of the punch: 0.1 s.
[0088] Elongation
5 [0089] As results obtained by measuring whether the pouch film
formed through Comparative Example and Manufacturing Example
is defective, a result table as illustrated in FIG. 11 may be
obtained.
[0090] Referring to the result table of FIG. 11, In Comparative
10 Example, it is seen that the cracks occur in the pouch film from
a point at which the punch descends by 7 mm from the uppermost
end of the forming part of the die. Also, in Manufacturing
Example, it is seen that the cracks occur In the pouch film from
a point at which the punch descends by 10 mm from the uppermost
15 end of the forming part of the die.
[0091] In summary, In Manufacturing Example, the cracks occurs
after further descending by 3 mm when compared to Comparative
Example. As the results of the above experiments, in
Manufacturing Example, it is confirmed that the elongation
20 increases when compared to Comparative Example.
[0092] Crack occurrence photograph
[0093] In Comparative Example and Manufacturing Example, FIGS .
12 and 13 shows a photograph of the pouch formed in the state
in which the punch descends by 7 mm from the uppermost end of
25 the forming part of the die.
26
[0094] As illustrated in FIG. 12, the pouch 10A manufactured
by Comparative Example comprises the electrode assembly
accommodation part 11 and the sealing part 12. Here, it is
confirmed that the cracks occur in the vertex of the electrode
5 assembly accommodation part 11.
[0095] As illustrated in FIG. 13, the pouch 10A manufactured
by Manufacturing Example comprises the electrode assembly
accommodation part 11 and the sealing part 12. Here, it is
confirmed that the electrode assembly accommodation part 11 is
10 formed up to the vertex without the occurrence of the cracks.
[0096] Thus, as the results of the above experiments, it is
confirmed that the pouch forming device according to
Manufacturing Example of the present Invention Increases in
elongation in comparison to that of the pouch forming device
15 according to Comparative Example of the present invention.
Therefore, the electrode assembly accommodation part may be
formed without the occurrence of the cracks.
[0097] According to the present invention, the pouch forming
device may comprise the die member, the stripper member, the
20 punch member, and the control member. That is, when the pouch
is formed, the stripper may gradually decrease in pressing force,
or the punch member may gradually decrease in descending speed.
Thus, when the pouch is formed, the elongation may gradually
increase, and thus, the pouch may be stably formed.
25 Particularly, when the pouch is formed, the local portion, i.e.,
27
the edge or vertex portion of the electrode assembly
accommodation part formed in the pouch may be prevented from
being cracked.
[0098] Accordingly, the scope of the present invention is
5 defined by the appended claims rather than the foregoing
description and the exemplary embodiments described therein.
Various modifications made within the meaning of an equivalent
of the claims of the invention and within the claims are to be
regarded to be in the scope of the present invention.

What Is Claimed Is:
1. A pouch forming device comprising:
a die member provided with a die on which a pouch film
is disposed on a top surface thereof, in which a forming part
5 is formed, and a die holder to which the die is fixed;
a stripper member provided with a stripper that is
vertically movably disposed on an upper portion of the die
member to press and fix the pouch film disposed on the die when
descending and a first driving piece allowing the stripper to
10 vertically move;
a punch member provided with a punch plate comprising a
punch that is vertically movable disposed on the upper portion
of the die member and is inserted into the forming part when
descending to form an electrode assembly accommodation part in
15 the pouch film and a second driving piece allowing the punch
plate to vertically move; and
a control member controlling the first driving piece to
allow the stripper to ascend when the punch is inserted into
the forming part to press the pouch film so as to decrease in
20 pressing force applied to the pouch film.
2. The pouch forming device of claim 1, wherein the control
member controls the first driving piece to allow the stripper
to gradually ascend so as to gradually decrease in pressing
25 force of the pouch film.
29
3. The pouch forming device of claim 2, wherein the control
member allows the stripper to ascend so as to be separated from
the pouch film when the punch is completely inserted into the
5 forming part so that the pressing force applied to the pouch
film is completely removed.
4. The pouch forming device of claim 2, wherein the control
member comprises a detection sensor detecting insertion of the
10 punch into the forming part and a controller controlling the
driving piece according to a signal the detection sensor to
allow the stripper to gradually ascend.
5. The pouch forming device of claim 1, wherein the first
15 driving piece comprises a plurality of moving rods connected
to the stripper by passing through a top surface of the punch
plate to allow the stripper to vertically move, a connection
bar to which the plurality of moving rods disposed on an upper
portion of the punch plate are fixed and which allows the
20 plurality of moving rods to vertically move at the same time,
and a cylinder allowing the connection bar to vertically move.
6. The pouch forming device of claim 3, wherein the control
member further controls the second driving piece to reduce a
25 descending speed of the punch plate on which the punch is
30
disposed when the punch is inserted into the forming part to
press the pouch film.
7. The pouch forming device of claim 6, wherein the control
5 member controls the second driving piece to gradually reduce
the descending speed of the punch plate on which the punch is
disposed.
8. The pouch forming device of claim 7, wherein the control
10 member controls the first driving piece and the second driving
piece at the same time to allow the stripper to gradually ascend
and gradually reduce the descending speed of the punch plate.
9. A pouch forming device comprising:
15 a die member provided with a die on which a pouch film
is disposed on a top surface thereof, in which a forming part
is formed, and a die holder to which the die is fixed;
a stripper member provided with a stripper that is
vertically movably disposed on an upper portion of the die
20 member to press and fix the pouch film disposed on the die when
descending and a first driving piece allowing the stripper to
vertically move;
a punch member provided with a punch plate comprising a
punch that is vertically movable disposed on the upper portion
25 of the die member and is inserted into the forming part when
31
descending to form an electrode assembly accommodation part in
the pouch film and a second driving piece allowing the punch
plate to vertically move; and
a control member controlling the second driving piece to
5 reduce a descending speed of the punch plate on which the punch
is disposed when the punch is inserted into the forming part
to press the pouch film.
10. The pouch forming device of claim 9, wherein the control
10 member controls the second driving piece to gradually reduce
the descending speed of the punch plate on which the punch is
disposed.
11. A pouch forming method comprising;
15 a disposition step of disposing a pouch film on a top
surface of a die member provided with a forming part;
a pressing step of pressing the pouch film disposed on
the top surface of the die member through a stripper member so
that an edge surface of the pouch film is fixed;
20 a forming step of inserting a punch into the forming part
to form an electrode assembly accommodation part in a surface
of the pouch film; and
a control step of gradually reducing pressing force of
the stripper member to gradually decrease in pressing force
25 applied to the pouch film when the punch is inserted into the
32
forming part to press the pouch film.
12. The pouch forming method of claim 11, wherein the control
step comprises a first control process of outputting an
5 insertion signal when the punch is inserted into the forming
part and a second control process of gradually reducing the
pressing force applied to the pouch film when the insertion
signal is outputted.
10 13. The pouch forming method of claim 12, wherein the control
step further comprises a third control process of gradually
reducing a descending speed of the punch when the insertion
signal is outputted to gradually decrease in pressing force
applied to the pouch film through the punch.
15
14 . A facility for producing a secondary battery, the facility
comprising a pouch forming device that forms a pouch film to
manufacture a pouch in which an electrode assembly
accommodation part is formed,
20 wherein the pouch forming device comprises:
a die member provided with a die on which a pouch film
is disposed on a top surface thereof, in which a forming part
is formed, and a die holder to which the die is fixed;
a stripper member provided with a stripper that is
25 vertically movably disposed on an upper portion of the die
33
member to press and fix the pouch film disposed on the die when
descending and a first driving piece allowing the stripper to
vertically move;
a punch member provided with a punch plate comprising a
5 punch that is vertically movable disposed on the upper portion
of the die member and is inserted into the forming part when
descending to form an electrode assembly accommodation part in
the pouch film and a second driving piece allowing the punch
plate to vertically move; and
10 a control member controlling the first driving piece to
allow the stripper to ascend when the punch is inserted into
the forming part to press the pouch film so as to'decrease in
pressing force applied to the pouch film.
15 15. The facility of claim 14, wherein the control member
controls the second driving piece to gradually reduce a
descending speed of the pouch plate on which the punch is
disposed when the punch is inserted into the forming part to
press the pouch film.