JP2013166287A - Heat sealing device and heat sealing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat-seal a specific section of an enveloping film without excessively heating a storage element in a heat sealing device for heat-sealing the enveloping film covering the storage element.SOLUTION: A heat sealing device 1 for heat-sealing a side surface of a workpiece W includes: a stage member 2 on which the workpiece is placed; an extrusion member 3 that is provided above the stage member and can extrude and secure the workpiece placed on the stage member by relative descent of the extrusion member 3 with respect to the stage member; a lifting means 15 for making the extrusion member relatively lift and move with respect to the stage member; and heating means 16, 17, 18, 19, 25, 26 for heating the side surface of the workpiece secured by the stage member and the extrusion member.

Description

  The present invention relates to a heat fusion apparatus and a heat fusion method, and more particularly to a heat fusion apparatus and a heat fusion method for heat-sealing the exterior film in order to seal an electricity storage element with the exterior film.

  In recent years, in power storage devices such as lithium ion secondary batteries and lithium ion capacitors used as power sources for portable devices and automobiles, a positive electrode plate and a negative electrode plate are wound or alternately stacked via a separator as shown in FIG. As shown, a power storage element 51 is configured, and many of them are sealed in an exterior container 52 made of an exterior film together with an electrolytic solution.

In an electricity storage device 50 shown in FIG. 9, an electricity storage element 51 is disposed between one exterior film 53 and the other exterior film 54, and an electrolyte is injected between the films. (Outer peripheral edge shown in cross hatching in FIG. 9) is heat-sealed to be joined and sealed.
In the electricity storage device 50 shown in FIG. 9, the outer container 52 formed by heat fusion has a square shape in plan view, and is a positive electrode electrically connected to the positive electrode of the electricity storage element 51 from one side. The lead terminal 56 is drawn out, and the negative electrode lead terminal 57 electrically connected to the negative electrode of the power storage element 51 is drawn out from the opposite side.

By the way, in the manufacturing process of the electricity storage device 50 as described above, when the outer film 53 and the sealant portion 55 of the other outer film 54 are heat-sealed, conventionally, with respect to the stacked outer film 53 and outer film 54, The whole device is sandwiched from above and below by a plate-like heater member (not shown) and heated to a predetermined temperature (for example, 160 ° C. to 170 ° C.). As a result, the sealant portion 55 around the power storage element 51 reached the fusion temperature (for example, 150 ° C.), and the exterior films 53 and 54 were heat-sealed in the sealant portion 55, and the power storage element 51 was sealed.
In addition, about the manufacturing method of the electrical storage device which heat-seals such an exterior film, it is disclosed by patent document 1, for example.

Japanese Patent Laid-Open No. 2001-266952

  However, in the method of sandwiching and heat-sealing the entire device from above and below with the plate-shaped heater member to the overlying exterior films 53 and 54 as described above, the storage element 51 is directly heated by the heater member. However, since the temperature becomes high, for example, the deterioration temperature of lithium used as an electrode material is reached, and there is a problem of adversely affecting product performance.

  The present invention has been made in view of the above-described problems of the prior art, and in a heat-sealing apparatus for heat-sealing an exterior film that covers an electricity storage element, the exterior without overheating the electricity storage element. Provided are a heat fusion apparatus and a heat fusion method capable of thermally fusing a predetermined portion of a film.

In order to solve the above-described problems, a thermal fusion apparatus according to the present invention is a thermal fusion apparatus that thermally fuses a side surface of a workpiece, and includes a stage member on which the workpiece is placed, and the stage member. A pressing member provided above and capable of pressing and fixing a workpiece placed on the stage member by lowering relative to the stage member, and the pressing member moving up and down relatively with respect to the stage member And elevating means for heating, and heating means for heating the side surface of the work fixed by the stage member and the pressing member.
The heating means preferably includes a heating member capable of generating heat to a predetermined temperature, and an advance / retreat means for advancing and contacting the heating member with respect to a side surface of the workpiece.
The workpiece is square in a plan view, and the heating member has an L-shaped contact surface corresponding to two continuous side surfaces of the workpiece, and the two heating members diagonally sandwich the workpiece. It is desirable to be arranged in.

  In this way, the upper surface of the workpiece placed on the stage member is fixed by the pressing member, and the heating member is brought into contact with the side surface requiring heat fusion to heat the workpiece, thereby heating only the side surface of the workpiece. Therefore, the inside of the workpiece (for example, the electricity storage element) is not excessively heated, and thus the adverse effect on the inside of the workpiece (the electricity storage element) can be suppressed.

In addition, it is desirable to include a cooling unit that cools at least one of the stage member and the pressing member to a predetermined temperature. Specifically, the cooling unit includes a container that houses the stage member or the pressing member, and the container It is desirable to have cooling gas supply means for supplying cooling gas at a predetermined temperature.
As described above, by heating at least one of the stage member and the pressing member to a predetermined temperature, heating of the work (for example, the power storage element) can be effectively suppressed.

In addition, it is desirable that a radiation fin is provided on at least one side surface of the stage member and the pressing member.
By comprising in this way, the heat | fever conducted from a workpiece | work can be discharge | released from a radiation fin, and a workpiece | work can be cooled more effectively.

Moreover, in order to solve the above-described problem, a heat fusion method according to the present invention is a heat fusion method of thermally fusing a side surface side of a work, and the step of placing the work on a stage member; A step of lowering the pressing member relative to the stage member from above the stage member, pressing and fixing the workpiece placed on the stage member; and a workpiece fixed by the stage member and the pressing member And heating the side surface.
In the step of heating the side surface of the workpiece, it is preferable to execute a step of advancing and abutting a heating member that generates heat to a predetermined temperature on the side surface of the workpiece.

  By such steps, only the side surface of the workpiece can be heated and heat-sealed, and the inside of the workpiece (for example, the electricity storage element) is not excessively heated, so that adverse effects on the inside of the workpiece (the electricity storage element) are suppressed. be able to.

Further, it is desirable to execute a cooling step of cooling at least one of the stage member and the pressing member to a predetermined temperature at least during the step of heating the side surface of the workpiece fixed by the stage member and the pressing member. .
As described above, by heating at least one of the stage member and the pressing member to a predetermined temperature, heating of the work (for example, the power storage element) can be effectively suppressed.

  According to the present invention, in the heat-sealing apparatus for heat-sealing the exterior film covering the power storage element, the heat-sealing apparatus capable of heat-sealing a predetermined portion of the exterior film without excessively heating the power storage element. And a heat-sealing method can be obtained.

FIG. 1 is a cross-sectional view showing a schematic configuration of an embodiment of a heat fusion apparatus according to the present invention. FIG. 2 is a perspective view showing a main part of the heat sealing apparatus of FIG. FIG. 3 is a flow showing the flow of operation of the heat sealing apparatus of FIG. FIG. 4 is a perspective view showing an operation state of the heat-sealing apparatus corresponding to the flow of FIG. FIG. 5 is a perspective view showing an operation state of the heat-sealing apparatus corresponding to the flow of FIG. FIG. 6 is a perspective view showing an operation state of the heat-sealing apparatus corresponding to the flow of FIG. FIG. 7 is a perspective view showing an operation state of the heat-sealing apparatus corresponding to the flow of FIG. FIG. 8 is a perspective view showing an operation state of the heat-sealing apparatus corresponding to the flow of FIG. FIG. 9 is a perspective view for explaining the configuration of an electricity storage device that covers an electricity storage element with an exterior film.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of an embodiment of a heat fusion apparatus according to the present invention. FIG. 2 is a perspective view showing a main part of the heat sealing apparatus of FIG.
The heat fusion apparatus 1 is used in a manufacturing process of an electricity storage device such as a lithium ion secondary battery or a lithium ion capacitor, for example, and heat-bonds a required joint portion (hereinafter referred to as a sealant portion) of a film that covers an electricity storage element. A device for wearing and sealing the electricity storage element.

The thermal fusion apparatus 1 includes a cylindrical stage member 2 on which an electricity storage device (hereinafter referred to as a workpiece W) in a state where the sealant portion of the exterior film is not thermally fused, and a stage on the upper surface of the stage member 2. A pressing member 3 is provided so as to be movable up and down above the workpiece W placed on the surface 2a, and can press and fix the workpiece W against the stage surface 2a.
The stage member 2 is formed hollow, for example, with aluminum in order to improve the heat radiation effect and weight reduction, and a plurality of heat radiation fins 2b are provided on the side peripheral surface thereof.

Further, the stage member 2 is accommodated in a box-like container 4, and the partition plate 5 is provided in the horizontal direction in the container, so that the stage surface 2a on the upper surface is always exposed upward, and the part below it is indoors. It is in a state of being arranged in the space R1.
The stage member 2 is provided so as to be movable up and down with respect to the partition plate 5 in the container 4, and a bottom portion is supported by a spring 6.

Further, an inlet 4a for introducing cooling air (cooling gas) having a predetermined temperature supplied from the cooling air supply unit 7 into the indoor space R1 is provided on the side surface of the container 4.
With this configuration, when cooling air is introduced into the indoor space R1, the indoor temperature is lowered, and the stage member 2 is effectively cooled.
Further, since the partition plate 5 is provided, the side surface W1 of the workpiece W is prevented from being exposed to the cooling air introduced from the introduction port 4a.
The cooling means for cooling the stage member 2 includes a cooling air supply unit 7 (cooling gas supply means) and the container 4.

The pressing member 3 has the same material and shape as the stage member 2, and the pressing surface 3 a is arranged facing the lower stage member 2.
Further, a plurality of heat radiating fins 3b are provided on the side peripheral surface of the pressing member 3 formed in a columnar shape in order to enhance the heat radiating effect.
The pressing member 3 is housed in a box-shaped container 10 and the partition plate 11 is provided in the horizontal direction in the container, so that the pressing surface 3a (lower surface) is always exposed, and the portion above it is in the indoor space R2. It is in an arranged state. The pressing member 3 is provided so as to be movable up and down with respect to the partition plate 11 in the container 10, and the upper portion is supported by a spring 12.

Further, an inlet 10a for introducing cooling air having a predetermined temperature supplied from the cooling air supply unit 7 into the indoor space R2 is provided on the side surface of the container 10.
With this configuration, when cooling air is introduced into the indoor space R2, the indoor temperature is lowered, and the pressing member 3 is effectively cooled.
Further, since the partition plate 11 is provided, the side surface W1 of the workpiece W is prevented from being exposed to the cooling air introduced from the introduction port 10a.
The cooling means for cooling the pressing member 3 includes a cooling air supply unit 7 (cooling gas supply means) and a container 10.

In addition, the container 10 that accommodates the pressing member 3 is held up and down by an elevating mechanism 15 (elevating means), and the pressing member 3 presses the workpiece W placed on the stage member 2 by moving down ( Press).
Since the lower part of the stage member 2 is supported by the spring 6 and the upper part of the pressing member 3 is supported by the spring 12 as described above, the stage surface 2a of the stage member 2 and the pressing surface 3a of the pressing member 3 are The adhesion to the workpiece W is improved.

  As shown in FIG. 2, two positioning pins 30 are provided so as to protrude upward at diagonal positions on the upper end of the container 4 that accommodates the stage member 2. These positioning pins 30 engage with the lower end of the container 10 when the work W is placed on the stage surface 2a of the stage member 2 and when the container 10 is lowered. Is provided in order to prevent misalignment.

  In addition, the heat fusion apparatus 1 is an L-shaped plate (having an L-shaped contact surface) that is pressed against the side surface W1 of the work W placed on the stage 2 while being heated. 16, 17 (heating member) are provided. The heating plates 16 and 17 are respectively configured to press down two continuous side surfaces of the workpiece W having a square shape in plan view, and are arranged diagonally across the stage 2 (work W) as shown in FIG. Yes.

The heating plates 16 and 17 are provided so as to be able to advance and retreat in the horizontal direction with respect to the stage 2 by means of press drive portions 18 and 19 (advance / retreat means), respectively. For example, as illustrated in FIG. 2, the pressing drive units 18 and 19 are configured by sliders 22 and 23 moving along rails 20 and 21, respectively.
For this reason, the L-shaped heating plates 16 and 17 are moved forward by the driving of the press driving units 18 and 19 with respect to the workpiece W placed on the stage 2, and all the side surfaces W1 (four sides) of the workpiece W are moved forward. Is pressed by the heating plates 16 and 17.

In addition, a plurality of heaters 25 are embedded in the heating plates 16 and 17, and they generate heat to a predetermined temperature when a predetermined value of current is supplied from the heater driving unit 26.
Therefore, when the heating plates 16 and 17 are pressed against the side surface W1 of the workpiece W while the heater 25 generates heat, the side surface W1 of the workpiece W is heated to a predetermined temperature.
The heater 25, the heater driving unit 26, the heating plates 16 and 17, and the pressing driving units 18 and 19 constitute a heating unit.

Next, the operation of heat fusion with respect to the workpiece W in the heat fusion apparatus 1 configured as described above will be described with reference to FIGS. 3 to 8. FIG. 3 is a flow showing the flow of operation of the heat fusion apparatus 1, and FIGS. 4 to 8 are perspective views showing the operation state of the heat fusion apparatus 1 corresponding to the flow of FIG.
4 to 8, the heat sealing apparatus 1 is housed in a box-shaped housing 40, and the lifting mechanism 15 that lifts and lowers the pressing member 3 is fixed to the ceiling portion of the housing 40. Yes.
In addition, the workpiece W has a square shape in plan view, a sealant portion that is a required joint portion is positioned on the four side surfaces W1, and a lead terminal W2 connected to the electrode of the electricity storage element is drawn from one side thereof. And

First, as shown in FIG. 4, the pressing member 3 is disposed above the stage member 2, and the heating plates 16 and 17 are disposed on the side of the stage member 2.
From this state, as shown in FIG. 5, a work W (a power storage element and an electrolytic solution sandwiched between outer and upper films) is placed on the stage member 2 (step S1 in FIG. 3).

Next, as shown in FIG. 6, the lifting mechanism 15 lowers the pressing member 3, the upper and lower surfaces of the work W are sandwiched between the stage member 2 and the pressing member 3, and the upper and lower surfaces of the work W are pressed with a predetermined pressure. (Step S2 in FIG. 3).
In addition, air cooled to a predetermined temperature from the cooling air supply unit 7 is introduced into the indoor spaces R1 and R2 in the containers 4 and 10 through the inlets 4a and 10a, and the stage member 2 and the pressing member 3 are kept at a predetermined temperature. It cools (for example, 80 degrees C or less) (step S3 of FIG. 3).

  Next, as shown in FIG. 7, the heating plates 16 and 17 are advanced by the pressing drive units 18 and 19 to press the side surface W <b> 1 of the workpiece W, and the heater 25 is heated by the heater driving unit 26, thereby Is heated at a predetermined temperature (for example, 160 ° C. to 170 ° C.) (step S4 in FIG. 3). Thereby, the sealant part located on the side surface W1 side of the workpiece W reaches the fusion temperature (for example, 150 ° C.) and is thermally fused.

Further, since the upper and lower surfaces of the workpiece W are fixed by the stage member 2 and the pressing member 3 cooled to a predetermined temperature (for example, 80 ° C. or less), the temperature does not increase excessively, and the power storage element ( Adverse effects on (not shown) are suppressed.
Further, since the workpiece W is fixed, the heating plates 16 and 17 are pressed against the workpiece side surface W1 without the position of the workpiece W being displaced even when the lead terminal W2 is pulled out.

When the heating state in step S4 elapses for a predetermined time, the heating plates 16 and 17 are retracted by the pressing drive units 18 and 19, and the heating of the workpiece side surface W1 is completed (step S5 in FIG. 3).
Further, the pressing member 3 is raised by the elevating mechanism 15, the fixed state of the workpiece W is released, and the heat fusion work for the workpiece W is completed (step S6 in FIG. 3).

As described above, according to the embodiment of the heat welding apparatus according to the present invention, the upper surface of the workpiece W placed on the stage member 2 is fixed by the pressing member 3, and the side surface W1 (where heat fusion is required) The heating plates 16 and 17 are pressed against the sealant portion side and heated.
Thereby, only the side surface W1 of the workpiece W can be heated and heat-sealed, and the power storage element in the work W is not excessively heated, so that adverse effects on the power storage element can be suppressed.
Moreover, since the stage member 2 and the pressing member 3 are cooled to a predetermined temperature, heating of the workpiece W can be effectively suppressed.

  In the above-described embodiment, the stage member 2 and the pressing member 3 are cooled to a predetermined temperature by the cooling means. However, only the side surface W1 of the workpiece W is heated even if the cooling means is not provided. Since it is the structure to perform, the bad influence by the heating to the electrical storage element in the workpiece | work W can be suppressed.

  Moreover, in the said embodiment, although it was set as the structure which cools both the stage member 2 and the press member 3 with a cooling means, even if it is the structure cooled with either cooling means, it is to the electrical storage element inside the workpiece | work W. The effect of suppressing heating can be expected.

  Moreover, in the said embodiment, although it was set as the structure which drops the press member 3 from the upper direction with respect to the fixed stage member 2, and presses and fixes the workpiece | work W on a stage, it is not restricted to this, For example, it is fixed. The stage member 2 may be moved upward relative to the pressing member 3 and the workpiece W may be sandwiched and fixed with the pressing member 3 (that is, the pressing member 3 is lowered relative to the stage member 2). If any).

In the above embodiment, the cooling means is configured to introduce cooling air into the indoor spaces R1 and R2 in the containers 4 and 10 to cool the stage member 2 and the pressing member 3 to a predetermined temperature. In the heat sealing | fusion apparatus of invention, it is not limited to the structure.
For example, the cooling means may be configured to cool the stage member 2 and the pressing member 3 by circulating cooling water cooled to a predetermined temperature inside the stage member 2 and the pressing member 3, respectively. Alternatively, the stage member 2 and the pressing member 3 may be cooled to a predetermined temperature using a Peltier element or the like.

DESCRIPTION OF SYMBOLS 1 Thermal fusion apparatus 2 Stage member 2b Radiation fin 3 Pressing member 3b Radiation fin 4 Container (cooling means)
7 Cooling air supply unit (cooling gas supply means, cooling means)
10 Container (cooling means)
15 Lifting mechanism (lifting means)
16 Heating plate (heating member, heating means)
17 Heating plate (heating member, heating means)
18 Press drive (advance / retreat means, heating means)
19 Press drive (advance / retreat means, heating means)
25 Heater (heating means)
26 Heater drive (heating means)
W Work W1 Work Side

Claims (9)

A heat fusion apparatus for heat fusing the side surface of a workpiece,
A stage member for placing the workpiece;
A pressing member provided above the stage member and capable of pressing and fixing the workpiece placed on the stage member by descending relative to the stage member;
Lifting means for moving the pressing member up and down relatively with respect to the stage member;
A heat fusion apparatus, comprising: a heating unit that heats a side surface of a workpiece fixed by the stage member and the pressing member. The heating means includes
A heating member capable of generating heat at a predetermined temperature;
The heat fusion apparatus according to claim 1, further comprising advance / retreat means for advancing and contacting the heating member with respect to a side surface of the workpiece. The workpiece is a square in plan view,
The heating member has an L-shaped contact surface corresponding to two continuous side surfaces of the workpiece,
The heat fusion apparatus according to claim 2, wherein two heating members are arranged diagonally across the workpiece.   The heat fusion apparatus according to any one of claims 1 to 3, further comprising a cooling unit that cools at least one of the stage member and the pressing member to a predetermined temperature. The cooling means is
A container for accommodating the stage member or the pressing member;
The heat sealing apparatus according to claim 4, further comprising cooling gas supply means for supplying a cooling gas having a predetermined temperature into the container.   The heat fusion apparatus according to claim 4 or 5, wherein a radiation fin is provided on at least one side surface of the stage member and the pressing member. A heat fusion method for heat fusing the side surface of a workpiece,
Placing the workpiece on a stage member;
Lowering the pressing member relative to the stage member from above the stage member, and pressing and fixing the workpiece placed on the stage member;
Heating the side surface of the work fixed by the stage member and the pressing member. In the step of heating the side surface of the workpiece,
The heat fusion method according to claim 7, wherein a step of advancing and abutting a heating member that generates heat to a predetermined temperature with respect to a side surface of the workpiece is performed. During the step of heating the side surface of the workpiece fixed by at least the stage member and the pressing member,
The heat sealing method according to claim 7 or 8, wherein a cooling step of cooling at least one of the stage member and the pressing member to a predetermined temperature is executed.

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