KR20080051982A - Mold for secondary battery - Google Patents

Abstract

A mold for a secondary battery is provided to minimize the consumption of resin capable of fixing a protection circuit board to a bare cell, and to reduce a resin molding time to the minimum. A mold(100) for a secondary battery includes: a battery receiving part(200) which moves straight on one plane in one direction and in which a bare cell and a protection circuit board have a space therebetween and are accommodated with being electrically connected to each other; a core part(300) which is fixed to face an external input/output terminal formed on the protection circuit board and is formed to come in contact with the terminal face according to the movement of the battery receiving part; a runner(400) of which at least a part forms a certain angle relative to the one plane and in which injected resin flows; and a gate(500) which is connected to the runner and guides the resin to the space.

Description

Secondary Battery Mold {MOLD FOR SECONDARY BATTERY}

1 is a perspective plan view of a conventional secondary battery mold,

2 is an enlarged cross-sectional view of a portion A of FIG. 1;

3 is a perspective view of a secondary battery in which a packing process is completed;

4 is a schematic perspective view of a secondary battery mold according to an embodiment of the present invention;

5 is a plan view of the secondary battery mold shown in FIG.

FIG. 6 is an enlarged cross-sectional view of part B of FIG. 5.

Explanation of symbols on the main parts of the drawings

10: bare cell 30: protection circuit board

100: mold 200: battery storage portion

250: Moving guide 300: Coabu

320: core body 400: runner

410: common runner portion 420: sub runner portion

500: gate

The present invention relates to a secondary battery mold, and more particularly, to a secondary battery mold capable of minimizing waste of resin and shortening molding time in pack battery manufacture.

In general, a secondary battery, particularly a lithium ion secondary battery, has a protective circuit board electrically connected to a negative terminal and a positive terminal of a bare cell in order to prevent overcharge, overdischarge, and overcurrent. In addition, in order to increase the mechanical bonding strength between the bare cell and the protective circuit board, the bare cell and the protective circuit board are accommodated together in the outer cover of the upper cover and the lower cover and shipped as a product.

Recently, in order to reduce the number of parts and improve productivity, a method of filling a gap between the bare cell and the protective circuit board using a mold or covering the bare cell and the entire protective circuit board with a resin is also used.

1 and 2, the conventional mold 900 includes a battery storing part 920, a core part 930, a runner 940, and a gate 950.

The battery storage unit 920 has a space in which the bare cell 10 and the protection circuit board 30 have a predetermined gap and can be stored in an electrically connected state. Referring to FIG. 2, a hot melt resin is filled in the gap between the bare cell 10 and the protective circuit board 30. The resin is formed on the back surface of the protective circuit board 30, that is, bare of the protective circuit board 30. It can cover up to the opposite side of the face opposite to the cell 10. However, in this case, the external input / output terminal 35 of the protective circuit board 30 may be exposed to the outside for connection with the external circuit.

Although not shown, the external input / output terminals of the protective circuit board are formed to protrude from the surface of the substrate, and the protective circuit board is formed on the mold in order to protect the surface of the external input / output terminal 35 of the protective circuit board 30 from being covered with resin. From the beginning, the terminal surface of the protective circuit board may be directly contacted with one inner surface of the mold. However, a gap tends to occur between one inner surface of the mold and the surface of the external input / output terminals of the substrate during operation, and there is a risk that the resin is covered on the terminal surface.

In order to solve this problem, as shown in FIG. 2, the protection circuit board 30 is once installed in the battery storage unit 920, and a portion of the mold facing the terminal 35 surface is disposed on the terminal 35 surface. Can be used to move toward Here, a part of the mold is called a core part 930, and a main body on which the core part 930 is mounted is called a core body 932. The core portion 930 and the core body 932 may be integrally formed.

Referring to FIG. 2, a through hole is formed in a portion of the battery storage unit 920 corresponding to the external input / output terminal 35, and a pillar-shaped core part 930 is inserted into the through hole to advance the core part 930. By contacting the front end surface of the external input and output terminal 35, it is possible to protect the resin from being covered on the surface of the external input and output terminal 35 during molding.

Meanwhile, referring to FIG. 1, a runner 940 is formed between the two battery storage units 920 along with the long side surfaces of the battery storage units 920 to bare cells 10. The runner 940 is a passage through which hot melt resin is injected.

1 and 2, one side of the runner 940 and one side of the battery storage unit 920 are connected by the gate 950. The gate 950 guides the resin flowing through the runner 940 to fill the gap between the protective circuit board 30 and the bare cell 10. Thus, the high temperature and high pressure resin injected through the runner 940 is filled and solidified in the gap in the battery storage unit 920 through the gate 950, so that the bare cell 10 and the protective circuit board 30 are mechanically formed. It can be firmly fixed.

However, since the resin remaining in the runner 940 and the gate 950 easily hardens to block the passage, the runner 940 and the gate 950 are formed separately from other parts in the mold, and the runner 940 after use. And the gate 950 are often removed from the mold and discarded.

As shown in FIG. 1, the conventional mold 900 includes two battery compartments 920, a runner 940 arranged side by side between the two battery compartments, and a gate that communicates the runner and the battery compartment. 950 is fixed, and the core part 930 has the structure which makes linear motion.

That is, since the runner 940 is formed long, the amount of resin discarded is larger than the amount of resin filled in the gap in the battery storage unit 920 due to the disposal of the runner 940 and the gate 950. have. That is, there is a problem that an expensive resin is excessively wasted.

In addition, since the runner 940 is formed long, it takes a long time for the resin injected into the runner 940 to reach the battery storage portion 920, and therefore, it takes not only a long time to charge the resin, but also in some cases. In some cases, the process may be completed while the resin is not completely filled in the gap in the battery storage unit 920, and there is a problem that a large amount of resin molding defects occur in the secondary battery.

SUMMARY OF THE INVENTION The present invention has been made to overcome this problem, and has an object of minimizing the waste of resin for fixing the protective circuit board to the bare cell and shortening the molding time by the resin in the shortest time.

The secondary battery mold according to the present invention for this purpose,

A battery storage unit capable of linearly moving in one direction on one plane and having a bare cell and a protective circuit board accommodated in a state in which the bare cell and the protection circuit board are electrically connected; A core part installed and fixed to face an external input / output terminal formed on the protective circuit board, the core part being configured to reach the terminal surface according to the movement of the battery storage part; A runner having at least one portion formed at an angle with respect to the one plane and in which resin is injected; And a gate connected to the runner to guide the resin into the gap.

In this case, the battery housing may be equipped with a movement guide that can be moved linearly.

In addition, the runner may be fixed, and the gate may be formed to be detachable from the battery storage unit.

In addition, four battery compartments, the core portion, and the gate may be formed in each of one runner.

In this case, the runner may include a common runner portion having a common resin injection hole, and a sub runner portion divided into at least two branches from the common runner portion.

The common runner part may be formed to be perpendicular to the one plane.

In addition, the sub runner portion may be formed to be parallel to the one plane.

In this case, the sub runner part may be divided into two branches from the common runner part, and the two sub runner parts may be formed to form 180 °.

In addition, one gate may be connected to each of the two sub-runner parts divided into two branches.

In addition, the sub runner part may be formed side by side between the two core parts.

On the other hand, a portion of the battery compartment corresponding to the core portion is formed with a through hole, it may be formed so that the core portion of the pillar shape is fitted into the through hole.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings such that those skilled in the art may easily implement the present invention.

First, before looking at the structure of a mold for a secondary battery according to the present invention, a brief look at the structure of the secondary battery.

3 and 6, the secondary battery includes a bare cell 10, a protection circuit board 30, and a molding resin part 40. Such secondary batteries are also called pack batteries.

The bare cell 10 includes an electrode assembly, a can 11 accommodating the electrode assembly, and a cap assembly coupled to the can. In the electrode assembly, a positive electrode and a negative electrode and a separator interposed between these two electrodes are wound, and the positive and negative electrode tabs are drawn out from the positive and negative electrodes, respectively. The can 11 is a metal container having a substantially rectangular parallelepiped shape in a rectangular secondary battery, and is formed by a processing method such as deep drawing. The cap assembly includes a cap plate coupled to an upper portion of the can, an electrode terminal 13 installed through a terminal hole, and a gasket for insulating the cap plate on an outer surface thereof, an insulating plate installed below the cap plate, It is formed under the insulating plate and comprises a terminal plate that is energized with the electrode terminal. The negative electrode of the electrode assembly is electrically connected to the electrode terminal 13 through the negative electrode tab and the terminal plate, and the positive electrode is electrically connected to the cap plate or the can through the positive electrode tab. Of course, the polarity may be changed.

The protection circuit board 30 is formed by forming a protection circuit on a panel made of resin. The protection circuit is a circuit for protecting the battery from overcharging or overdischarging during charging and discharging, and is electrically connected to the connection terminals 31 and 32. The connection terminals 31 and 32 are electrically connected to the external input / output terminal 35 and connected to an external electric / electronic device. One connection terminal 32 of the protective circuit board 30 may be electrically connected to the cap plate of the bare cell 10 through the lead plate 22 to be bipolar. In addition, the other connection terminal 31 can be electrically connected to the electrode terminal 13 of the bare cell through the thermal breaker or the lead plate 21 and the PTC element 25 to exhibit negative polarity. Since the PTC element 25 and the cap plate have different polarities, an insulating member 27 for preventing a short circuit is located between the two.

The molding resin part 40 is a part in which a hot melting resin is solidified by filling a space between the cap plate of the bare cell 10 and the protective circuit board 30. The molding resin portion 40 prevents the flow of battery components between the cap plate and the protective circuit board, and allows the bare cell 10 and the protective circuit board 30 to be mechanically firmly fixed.

The present invention relates to a secondary battery mold for manufacturing a pack battery by forming the molded resin portion 40.

Figure 4 is a schematic perspective view of a secondary battery mold according to an embodiment of the present invention is shown in a state in which the upper mold is lifted. FIG. 5 is a plan view of the secondary battery mold shown in FIG. 4, and FIG. 6 is an enlarged cross-sectional view of part B of FIG. 5.

4 to 6, the secondary battery mold 100 according to the exemplary embodiment of the present invention may include a battery storing unit 200, a core unit 300, a runner 400, and a gate 500. It is made, including.

The battery storage unit 200 has a space in which the bare cell 10 and the protection circuit board 30 have a predetermined gap and can be stored in an electrically connected state. The battery storage unit 200 having such a storage space may be formed by arranging long rod-shaped blocks having a predetermined thickness to match the size and shape of the secondary battery. In addition, the blocks may be moved relative to each other to manufacture a secondary battery having various sizes and shapes.

4 and 5, the battery storage unit 200 may linearly move in one direction on one plane. The battery storage unit 200 is equipped with a movement guide 250 capable of linear movement, the battery storage unit 200 may be moved in accordance with the movement of the movement guide 250. Here, the one plane may be an upper surface of the lower mold. In addition, the one direction refers to a direction parallel to the straight line connecting the terminal 35 and the core 300 of the protective circuit board.

Referring to FIG. 6, a hot melt resin is filled in the gap between the bare cell 10 and the protection circuit board 30, which is the back surface of the protection circuit board 30, that is, the bare circuit of the protection circuit board 30. It can cover up to the opposite side of the face opposite to the cell 10. However, in this case, the external input / output terminal 35 of the protective circuit board 30 may be exposed to the outside for connection with the external circuit.

In order to protect the surface of the external input / output terminal 35 of the protective circuit board 30 from being covered with resin, although not shown, the external input / output terminal of the protective circuit board is formed to protrude from the substrate surface, and the protective circuit board is formed on the mold. At the time of installation, a method may be used in which the terminal surface of the protective circuit board is directly in contact with the inner surface of the mold. However, a gap tends to occur between one inner surface of the mold and the surface of the external input / output terminals of the substrate during operation, and there is a risk that the resin is covered on the terminal surface.

In order to solve this problem, as shown in FIG. 6, once the protection circuit board 30 is installed in the battery storage unit 200, the battery storage unit (for a part of the mold facing the surface of the terminal 35) 200) may be used. Here, one part of the mold is called a core part 300, and the main body on which the core part 300 is mounted is called a core body 320. The core part 300 and the core body 320 may be integrally formed.

The core part 300 is fixedly installed so as to face the external input / output terminal 35 formed on the protection circuit board 30, and is formed to be in contact with the surface of the terminal 35 as the battery storage part 200 moves. do. In the present invention, as shown in FIG. 4 and FIG. 5, the core part 300 is fixed, and the battery storing part 200 is formed to be movable.

Referring to FIG. 6, a through hole is formed in a portion of the battery storage unit 200 corresponding to the external input / output terminal 35, and a pillar-shaped core portion 300 is formed in the through hole according to the linear movement of the battery storage unit 200. ) Is inserted, and the front end surface of the core portion 300 is in contact with the external input and output terminal 35, it is possible to protect the resin from being covered on the surface of the external input and output terminal 35 during molding.

Meanwhile, referring to FIG. 4, the runner 400 is formed such that at least one portion has a predetermined angle with respect to the one plane (the plane where the battery compartment moves). The runner 400 is a passage through which hot melt resin is injected.

In the present exemplary embodiment, four battery compartments 200, a core portion 300, and gates 500 are formed with respect to one runner 400, respectively.

Here, the runner 400 includes a common runner portion 410 having a common resin injection hole, and a sub runner portion 420 divided in two from the common runner portion 410. However, the content of the present invention is not limited thereto, and the sub-runner portion may be divided into two or more branches in the common runner portion.

Referring to FIG. 4, the common runner part 410 is formed to be perpendicular to the one plane (the plane in which the battery storage part moves). In addition, the sub runner part 420 is formed to be parallel to the one plane. In addition, the sub-runner part 420 divided into two at the common runner part 410 is 180 degrees. The sub runner part 420 is formed side by side between the two core parts 300 and the core body 320. In addition, one gate 500 is connected to both sides of each of the two sub-runner portions 420.

Referring to FIG. 6, one side of the runner 400 and one side of the battery storage unit 200 are connected by the gate 500. The gate 500 guides the resin flowing through the runner 400 to fill the gap between the protective circuit board 30 and the bare cell 10. Thus, the high temperature and high pressure resin injected through the runner 400 is filled and solidified in the gap in the battery storage unit 200 through the gate 500, so that the bare cell 10 and the protective circuit board 30 are mechanically formed. It can be firmly fixed.

4 and 5, the runner 400 is fixed, and the gate 500 is installed to be detachable from the battery storing unit 200. For example, the core part 300, the runner 400, and the gate 500 are fixed, and the battery storage part 200 is moved to form a resin formed at one side of the gap in the battery storage part 200. Incoming inlet and gate 500 may be matched. However, the content of the present invention is not limited thereto.

In the conventional mold, as shown in Fig. 1, the core part is moved while the battery compartment, the runner and the gate are fixed, and the runner is disposed on the same plane so as to be parallel to the long side of the battery compartment between the two battery compartments. Thereby, there was a problem that the length of the runner to be discarded after use was too long.

However, in the present invention, as shown in Figure 4, since the resin injection into the gap in the battery compartment 200 is made from above, it is possible to minimize the length of the runner to be discarded after use.

In addition, in the related art, only two battery storage parts may correspond to one runner, but according to the present invention, four battery storage parts 200 may correspond to one runner 400, and thus, discarded after use. The amount of runner to be made can be minimized.

In addition, as the length of the runner 400 is minimized, the time taken for the resin injected into the runner 400 to reach the battery storage unit 200 is shortened, thereby minimizing the filling time of the resin.

According to the present invention, since the resin injection is made from the upper side rather than the side of the battery compartment, the length of the runner is minimized, and the four battery compartments can correspond to one runner, thereby minimizing the amount of runner to be discarded after use. can do. Moreover, the molding time by resin can be shortened to the shortest time.

Although the present invention has been described with reference to the illustrated embodiments, it is merely exemplary, and the present invention may encompass various modifications and equivalent other embodiments that can be made by those skilled in the art. Will understand.

Claims (11)

A battery storage unit capable of linearly moving in one direction on one plane and having a bare cell and a protective circuit board accommodated in a state in which the bare cell and the protection circuit board are electrically connected; A core part installed and fixed to face an external input / output terminal formed on the protective circuit board, the core part being configured to reach the terminal surface according to the movement of the battery storage part; A runner having at least one portion formed at an angle with respect to the one plane and in which resin is injected; And And a gate connected to the runner to guide the resin into the gap. The method of claim 1, The battery storage unit is a secondary battery mold, characterized in that the movement guide is mounted to the linear movement. The method of claim 1, The runner is fixed, the gate is a secondary battery mold, characterized in that the removable battery compartment. The method of claim 1, The battery compartment, the core portion and the gate is a secondary battery mold, characterized in that formed by four for each one runner. The method of claim 4, wherein The runner includes a common runner portion having a common resin injection hole, and a sub runner portion divided into at least two branches from the common runner portion. The method of claim 5, wherein The common runner part is a secondary battery mold, characterized in that formed to be perpendicular to the one plane. The method of claim 5, wherein The sub runner part is a secondary battery mold, characterized in that formed in parallel with the one plane. The method of claim 7, wherein The sub-runner part is divided into two branches from the common runner part, and the two-runner sub runner part forms a 180 ° secondary mold. The method of claim 8, The secondary battery mold, characterized in that the gate is connected to each of the two sub-runner portion divided into two. The method of claim 8, The sub-runner part is a secondary battery mold, characterized in that formed between the two core parts side by side. The method of claim 1, The through-hole is formed in a portion corresponding to the core portion of the battery storage portion, the secondary battery mold, characterized in that the core portion can be fitted into the through-hole core.

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