KR102437845B1 - Method of manufacturing battery cell cover and the battery cover thereof - Google Patents

Abstract

The present invention provides a method for manufacturing a battery cell cover coupled to a battery cell, the step of injecting an injection molding product into a mold at a predetermined injection pressure ( _PM ), the injection molding product is filled in a cavity in the mold, A battery cell comprising a step of discharging gas or air in the cavity to a predetermined discharge pressure (Pa ) with _a time difference of A method of manufacturing a cover is provided.

Description

Method of manufacturing a battery cell cover and a battery cell cover comprising the same

The present invention relates to a method of manufacturing a battery cell cover and to a battery cell cover including the same.

As is well known, an electric vehicle (EV) mainly refers to a vehicle that obtains power by driving an AC or DC motor using the power of a battery.

In general, batteries used in electric vehicles are modularized. A positive plate, a negative plate, and a separator are installed inside a cell case, and a storage battery filled with electrolyte is provided, and is charged to a rated capacity by a generator and consumes electricity. Repeats the electrochemical action that is discharged according to the increase of As such, since the battery is a key device in the electric vehicle, it is sealed with a cover to protect it from external impact and is maintained to have watertightness. Also, a battery cell cover is used for the purpose of avoiding cell-to-cell contact and stacking cells. The manufacture of such a battery cell cover is formed of a plastic material and is also manufactured through a molding die. Therefore, in order to manufacture a relatively thin battery cell cover, there is a disadvantage in that it is difficult for the plastic injection material to spread evenly into the space inside the mold. For this reason, it is difficult to expect good quality molding results.

Republic of Korea Patent Publication No. 10-2014-0048372 (2014. 04. 24)

The present invention has been devised to solve the above technical problem, and an embodiment of the present invention is a thin film battery applied to a battery module for an electric vehicle through a thin film injection process manufactured through a mold for molding a plastic or synthetic resin injection product. An object of the present invention is to provide a cell cover.

An embodiment of the present invention provides a method of manufacturing a battery cell cover that can fundamentally prevent the occurrence of defective or unmolded parts such as burrs by providing specific process conditions during injection molding of a thin film battery cell cover. intended to provide

And, one embodiment of the present invention is to provide a battery cell cover that can reduce the volume and weight of the battery module for the electric vehicle by lightening the battery cell cover coupled to the battery cell included in the battery module of the electric vehicle. The purpose.

In addition, an embodiment of the present invention is to provide a thin-film battery cell cover produced by a mold that depressurizes the space between the upper and lower molds so that the plastic or synthetic resin injection product is uniformly filled into the space between the upper and lower molds of the mold. do.

In addition, an embodiment of the present invention aims to provide a battery cell cover manufactured by a mold that is formed so that the mold is symmetrical with respect to the injection hole so that a pair of battery cell covers can be manufactured.

In addition, an embodiment of the present invention aims to provide a mold that depressurizes the space between the upper and lower molds so that the plastic or synthetic resin injection product is uniformly filled into the space between the upper and lower molds of the mold.

In addition, an embodiment of the present invention aims to provide a mold for manufacturing a pair of battery cell covers by forming a mold to be symmetrical about an injection hole.

Another object of the present invention is to provide a method of depressurizing the space between the upper and lower molds so that the plastic or synthetic resin injection product is uniformly filled into the space between the upper and lower molds of a mold.

In addition, an embodiment of the present invention aims to provide a method of manufacturing a pair of battery cell covers by forming a mold to be symmetrical about an injection hole.

A method for manufacturing a battery cell cover according to the present invention,

A method of manufacturing a battery cell cover coupled to a battery cell, the method comprising:

injecting the injection material into the mold at a predetermined injection pressure (P _M );

discharging the gas or air in the cavity to a predetermined discharge pressure (P _M ) with a predetermined time difference while the injection product is filled in a cavity in the mold; and

The injection product filled in the mold is cured,

and separating the cured product from which the injection product is cured.

In one embodiment of the present invention, the gas or air may be removed simultaneously or sequentially.

In one embodiment of the present invention, the time difference between the process in which the injection-molded product is injected and the process in which the gas or air is discharged may be within a range of 0.01 to 0.05 seconds.

In one embodiment of the present invention, the time for which the gas or air is discharged may be in the range of 0.25 to 0.35 seconds.

In one embodiment of the present invention, the pressure (pressure) for injecting the injection molding may have a range of 250 to 500bar.

In an embodiment of the present invention, the pressure at which the gas or air is discharged may have a range of 150 to 250 bar.

In one embodiment of the present invention, the filling speed of the injection mold in the mold may be proportional to the injection pressure ( _PM ).

In one embodiment of the present invention, the discharge rate (V) of the gas or air may be proportional to the discharge pressure (Pa).

Here, in one embodiment of the present invention, the discharge rate (V) may satisfy the following relation (1),

--------------------------------------------- (1)

--------------------------------------------- (One)

*V : gas or air exhaust velocity

: 금형 내의 주입 압력*

: Injection pressure in the mold

: 가스 또는 공기의 배출 압력*

: Exhaust pressure of gas or air

*d: diameter of the exit path of the mold

*k: proportional constant.

In an embodiment of the present invention, the injection amount (Q) of the injection product may satisfy the following relational expression,

------------------------------------------------ (2)

------------------------------------------------ (2 )

*Q: Injection volume of the injection

*V : gas or air exhaust velocity

*d: Diameter of the exit path of the mold.

In one embodiment of the present invention, the step of discharging the gas or air by a cutting process to at least a portion of the injection-molded product before curing after the step of discharging the gas or air; may further include.

Meanwhile, the present invention may provide a battery cell cover manufactured by the method for manufacturing the battery cell cover.

In one embodiment of the present invention, the battery cell cover may have a thin film thickness (t) in the range of 0.15 to 0.2mm.

The method for manufacturing a battery cell cover and the battery cell cover including the same according to the present invention provide a thin film battery cell cover applied to a battery module for an electric vehicle through a thin film injection process manufactured through a mold for molding a plastic or synthetic resin injection product can do.

In addition, an embodiment of the present invention provides specific process conditions during injection molding of a thin-film battery cell cover to produce a battery cell cover that can fundamentally prevent the occurrence of defective or unmolded parts such as burrs. method can be provided.

In addition, an embodiment of the present invention can provide a battery cell cover capable of reducing the volume and weight of a battery module for an electric vehicle by lightening the battery cell cover coupled to the battery cell included in the battery module of the electric vehicle. have.

In addition, an embodiment of the present invention can provide a thin-film battery cell cover produced by a mold that depressurizes the space between the upper and lower molds so that the plastic or synthetic resin injection product is uniformly filled into the space between the upper and lower molds of the mold.

In addition, an embodiment of the present invention can provide a battery cell cover manufactured by a mold in which a pair of battery cell covers can be manufactured by forming a mold to be symmetrical about an injection hole.

In addition, an embodiment of the present invention may provide a mold that depressurizes the space between the upper and lower molds so that the plastic or synthetic resin injection product is uniformly filled into the space between the upper and lower molds of the mold.

In addition, an embodiment of the present invention may provide a mold for manufacturing a pair of battery cell covers by forming the mold to be symmetrical about the injection hole.

In addition, an embodiment of the present invention may provide a method of depressurizing the space between the upper and lower molds so that the plastic or synthetic resin injection product is uniformly filled into the space between the upper and lower molds of the mold.

In addition, an embodiment of the present invention may provide a method of manufacturing a pair of battery cell covers by forming a mold to be symmetrical about an injection hole.

1 is a flowchart illustrating a method of manufacturing a battery cell cover according to an embodiment of the present invention;
2 is a perspective view of a battery cell cover in an injection-molded state according to an embodiment of the present invention according to an embodiment of the present invention;
Figure 3 (a) is a side view of the battery cell cover according to an embodiment of the present invention, Figure 3 (b) is a cut-away perspective view of the battery cell cover according to an embodiment of the present invention,
Figure 4 (a) is an exploded perspective view of a battery cell cover including an adhesive film according to an embodiment of the present invention, Figure 3 (b) is a portion of the battery cell cover to which the adhesive film is attached according to an embodiment of the present invention; is an enlarged view,
5 is a perspective view of a mold according to an embodiment of the present invention;
6 is a cutaway view of a mold according to an embodiment of the present invention;
7 and 8 are photographs showing comparison of molding results of a battery cell cover according to an embodiment of the present invention;
9 is a flowchart illustrating a method of manufacturing a battery cell cover according to an embodiment of the present invention.

Hereinafter, a method of manufacturing a battery cell cover according to the present invention and an embodiment of a battery cell cover including the same will be described in detail with reference to the accompanying drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated on different drawings. In addition, in describing the embodiment of the present invention, if it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment of the present invention, the detailed description thereof will be omitted.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, or order of the elements are not limited by the terms. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

2 is a perspective view of a battery cell cover in an injection-molded state according to an embodiment of the present invention. Here, the battery cell cover in the injection-molded state means the cover-injected product 1 and specifies that it is a member different from the battery cell cover 100 . Accordingly, the cover injection product 1 is in a state of an uncured liquid injection molding product, and the battery cell cover 100 may mean a member cut in part for use as the battery cell cover 100 after curing. However, hereinafter, the liquid and the injection molded product will be described separately based on the shape without distinction of the state after curing.

Referring first to FIG. 2 , the cover injection 1 may include a battery cell cover 100 and a cutout 10 . Here, the battery cell covers 100 and 100 ′ may be positioned between the batteries to prevent direct contact between the batteries in a structure in which batteries are stacked. Furthermore, the area of the main covers 110 and 110', which is the main area of the battery cell covers 100 and 100', may correspond to the area of the coupling surface of the battery to be coupled to be in the above position. Accordingly, the battery cell covers 100 and 100 ′ may have at least one surface bent from the end toward the battery. For example, when the battery cell covers 100 and 100 ′ have a quadrangular shape as illustrated in FIG. 2 , the bent portions 120 and 120 ′ may be formed from two surfaces and a portion of one surface. In particular, since the bent portions 120 and 120 ′ extend from the main buckets 110 and 110 ′ as an inclined surface, they can be formed thinner than other portions of the battery cell covers 100 and 100 ′. The inclined surface is gradually narrowed in the extending direction, and may be formed as the thinnest part of the battery cell covers 100 and 100'.

And, according to the example of FIG. 2 , in the manufacture of the battery cell covers 100 and 100 ′, two battery cell covers 100 and 100 ′ may be formed by injecting an injection product once. Of course, since the number of manufacturing may be changed depending on the mold, it is not limited to the example of FIG.

Meanwhile, the cut portion 10 may include a first cut portion 11 and a second cut portion 12 . The first cut part 11 is a part that is hardened in the path that moves along the injection hole of the mold when the injection product is injected, and the second cutting part 12 is the injection product passed through the injection hole and is guided toward the battery cell cover 100. It can be a hardened part in the section.

Accordingly, in the case of FIG. 2 , the first cut portion 11 may correspond to a length in the vertical direction of the upper mold when the injection hole is formed in the upper mold among the upper and lower molds of the mold. Of course, when it is necessary to inject the injection product in an inclined manner, when the extension direction of the injection hole formed in the upper die is formed to be inclined, the first cut portion 11 may correspond to an inclined length.

In addition, the injection-molded product passing through the injection hole may be moved to the space where the battery cell cover 100 is to be formed by the second cutting part 12 . In the process of moving, the injection-molded product may be guided in the direction of movement by the mold. The content in which the injection-molded product is guided will be described in detail with reference to FIG. 2 .

3 is a side view and a cut-away perspective view of the battery cell cover 100 according to an embodiment of the present invention, FIG. 3 (a) is a side view of the battery cell cover 100 according to an embodiment of the present invention, b) is a cut-away perspective view of the battery cell cover 100 according to an embodiment of the present invention.

Referring to FIG. 3A , the cover injection product 1 may be divided into a battery cell cover 100 and a cut part 10 , and the two components may be separated and separated by a cut line 13 . The cutting line 13 means a point separated by the cutting means.

Through this cutting process, the battery cell cover 100 is manufactured. After the injection molding is hardened, in order to have a uniform shape of the battery cell cover 100, the injection molding is required to be completely filled in the mold. Here, the complete filling means that the injection material is injected into the inner space of the mold formed by the upper and lower molds of the mold and buffered. The injection product is injected and may be sucked into the discharge hole side by the suction means.

This suction depressurizes the inner space of the mold to induce the injection to move into the depressurized space, and through suction, it is possible to overcome the disadvantage that it is difficult to move the inside of the narrow mold due to the viscosity of the liquid injection product. . In addition, it can be expected to shorten the molding time by promoting the movement. A part of the injection-molded material may be introduced into the suction hole formed in the mold by the above-described suction, and the injected injection-molded material may be hardened and cured in the form of the suction units 101 and 101 ′.

Furthermore, the suction parts 101 and 101 ′ may be detached from the battery cell cover 100 . Here, the drop-off may be removed from the mold after the injection product is cured, and included in a separation process in which the battery cell cover 100 and the cut part 10 are separated based on the cut line 13 , and may be cut. That is, before the battery cell cover 100 is positioned between the batteries, the suction units 101 and 101 ′ may be removed from the battery cell cover 100 .

Meanwhile, referring to FIG. 3( b ), the direction in which the injection-molded product is guided in the mold to the battery cell cover 100 is shown in the second cut part 12 . The second cut portion 12 includes a first guide portion 14 and a second guide portion 15 formed by guiding the injection molded product. The first guide part 14 is a structure formed by a guide structure formed in the mold, and may extend in the direction of the battery cell cover 100 from the rear end side of the injection hole based on the flow of the injection product. Here, the plurality of first guide portions 14 may extend in the direction of the battery cell cover 100 and may extend apart from each other. In addition, the second guide portion spaced apart from each other may be a groove portion formed by the guide structure protruding from the mold. The liquid injection product may preferentially flow toward the relatively low first guide part 15 .

In this flow, the location of the injection-molded material entering the battery cell cover 100 is spaced apart from each other at a predetermined distance. Through this process, the battery cell cover 100 may be formed.

4 is an exploded perspective view and an enlarged view of the battery cell cover 100 including the adhesive films 150 and 150' according to an embodiment of the present invention. An exploded perspective view of the battery cell cover 100 including the adhesive films 150 and 150 ′, FIG. 4 (b) is a battery cell cover to which the adhesive films 150 and 150 ′ are attached according to an embodiment of the present invention ( 100, 100') is a partially enlarged view.

Referring to FIGS. 4A and 4B , the battery cell cover 100 may further include adhesive films 150 and 150 ′. For example, when five or four battery cells are stacked to form one pack, the battery cell cover 100 may be positioned between the five or four battery cells and adhered thereto. At this time, the adhesive films 150 and 150 ′ coated with an adhesive material may be coupled to the battery cell cover 100 for adhesion. The adhesive films 150 and 150 ′ may be adhered to the portion where the battery cells are stacked, that is, the surface of the main cover 100 of the battery cell cover 100 .

Further, in the adhesive films 150 and 150' that are in contact with the surface, air may be interposed on the adhesive surface. can be formed. The air that is likely to be interposed through the through holes 151 and 151 ′ may be discharged to the outside through the through holes 151 and 151 ′. That is, since the through holes 151 and 151' are formed, it can be expected to facilitate storage of the battery case 100 including the adhesive films 150 and 150' and to increase the adhesive force of the adhesive films 150 and 150'.

5 is a perspective view of a mold 200 according to an embodiment of the present invention.

Referring to FIG. 5 , the mold 200 may include an upper mold 210 and a lower mold 220 . The upper mold 210 may be formed by passing an injection hole 211 through which the injection material can be injected into the upper mold 210, and the upper surface of the cover injection product 1 which is formed after the injection product is injected into the mold 200. It may include a pattern of any possible shape.

In addition, the lower mold 220 has a plurality of first injection material guide portions 224, which are inclined portions that can guide the injection material moving downward by its own weight and suction, and a second injection material guide portion spaced apart from the first injection material guide portion ( 225) may be formed.

Here, the first injection material guide portion 224 may be formed in a engraved shape from the lower mold 220 , and the injection product cured at this point may form a part of the second cut portion 12 . When the injection material fills the cavity 201 inside the mold 200 from the second cut portion 12 side to the battery cell cover 100 side, according to the example of FIG. 4 , two first injection products formed in two different directions The guide part 224 may promote that the injection-molded product may be uniformly injected in the cavity 201 of the mold 200 during the filling.

For example, when the injection-molded material is injected into the battery cell cover 100 side, it can be filled and moved in a semicircular shape, and since the semi-circle is spaced apart by a predetermined distance and filled at a plurality of positions to start filling in a larger area, a more uniform injection-molded material is formed. injection can be facilitated.

6 is a cutaway view of the mold 200 according to an embodiment of the present invention.

Referring to FIG. 6 , a part of the upper mold 210 of the mold 200 is cut, so that the battery cell cover 100 filled or cured inside the mold 200 can be seen. According to the example of FIG. 6 , three discharge holes 250 are formed in one battery cell cover 100 , and suction parts 101 and 101 ′ are formed in the discharge holes 250 . The formation of the suction units 100 and 101 ′ in the discharge hole 250 may mean that the injection material is filled in the cavity 201 of the mold 200 .

In this way, airtightness can be maintained when the injection product of the upper mold 210 and the lower mold 220 is brought into contact before being injected. In order to maintain the airtightness, a sealing member (not shown) may be included in at least one of the upper mold 210 and the lower mold 220 to be positioned on surfaces in contact with each other. Of course, the sealing member may be supplied from the outside of the mold 200 . For example, the contact line formed after the contact of the upper die 210 and the lower die 220 may be sealed by an external sealing member to maintain airtightness.

Meanwhile, the thickness of the battery cell covers 100 and 100 ′ manufactured through the aforementioned mold 200 may be 1 mm or less, for example, 0.2 to 0.7 mm. Preferably it may be less than 0.3. In this case, 0.2mm may be a bent portion (120, 120' in FIGS. 1 and 2), and 0.7mm may be a main cover (110, 110' in FIGS. 2 and 3). And, in the case of the bent portion (120, 120' in FIGS. 2 and 3), the thickness may be different for each location, unlike the main cover (110, 110' in FIGS. 1 and 2). For example, the bent portion (120, 120' in FIGS. 2 and 3) may be formed as a cross section of an inclined shape that is formed thinner as it goes away from the main cover (110, 110' in FIGS. 2 and 3). . Furthermore, the thinner the thickness, the more difficult it is to move the injection-molded material in the cavity 201 due to the viscosity of the injection-molded material, so that it can be sucked at a higher pressure.

1 is a flowchart illustrating a method of manufacturing the battery cell covers 100 and 100' according to an embodiment of the present invention, and FIGS. 7 to 8 are the molding results of the battery cell cover according to an embodiment of the present invention. These are pictures for comparison.

First, the mold 200 may be prepared. Here, the preparation includes preparation of the sealing member described with reference to FIG. 6 as necessary. Then, after the upper die 210 and the lower die 220 of the mold 200 contact so that airtightness is maintained, the injection product formed in the upper die 210 may be injected (S100).

Here, since the cavity 201, which is the inner space of the mold 200, is in an airtight state, the air inside the cavity 201 cannot escape to the outside. therefore. The gas and/or air is discharged to the outside of the mold 200 by the discharge hole 250 that may be formed in one or more of the upper die 210 and the lower die 220 (S200). That is, gas and/or air located in the cavity 201 may be discharged. In this process, since the cavity 201 may be decompressed, the injection product may be injected into the mold 200 by the pressure difference. In particular, according to the present invention, gas may be generated when the injection product is injected into the mold 200 , and the gas may be discharged simultaneously or continuously with the air present in the mold 200 .

According to the present invention, in the step of injecting the injection molding (S100), the injection pressure for injecting the injection molding may be performed in the range of approximately 250 to 500 bar. Preferably, the injection pressure may be 300 to 400 bar, more preferably 380 bar. At this time, when the injection pressure exceeds 500 bar, burrs may occur in the final molded product. The above range may be suitable as the occurrence may increase some thickness in the final molded product.

In addition, the step of discharging the gas and/or air ( S200 ) may be performed in a range of about 0.01 to 0.05 seconds. Preferably, it may be approximately 0.03 seconds. Furthermore, the process of discharging the gas and/or air may be performed in the range of 150 to 250 bar for approximately 0.25 to 0.35 seconds, and preferably may be performed at 180 bar for 0.3 seconds. In this process delay time and execution time range, the best molding condition can be guaranteed.

Furthermore, according to the present invention, as shown in FIG. 9 , after the step of discharging gas and/or air ( S200 ), a process of cutting by a printing method ( S200-1 ) may be performed. That is, bubbles may be generated during the curing process of the injection molded product, and in this case, the defect rate may increase due to the increase in volume, or quality deterioration such as physical properties may occur due to the presence of impurities in these bubbles. It is possible to fundamentally prevent defects caused by the generation of air bubbles.

Thereafter, when the injection process is completed and the cavity 201 is filled with the injection-molded material, the injection-molded material may be cured. The curing time may vary from several seconds to several hours depending on the temperature and the type of the injection product (S300).

In this way, after the process of curing the injection-molded product is finished, the mold 200 is separated into an upper mold 210 and a lower mold 220, and the battery cell covers 100 and 100' to be manufactured from the cured injection-molded product are cut. can be The cutting of the battery cell covers 100 and 100' may be made for separation from the cutting part (10 in FIG. 2), and the boundary line between the battery cell covers 100 and 100' and the cutting part (10 in FIG. 13), it can be cut along the cutting line 13 . The cutting refers to the separation of the cutting part 10 and the battery cell covers 100 and 100' including the meaning of cutting using a tool (S400).

), 배출되는 상기 가스 및/또는 공기의 배출압력 값(

) 및 금형(200)의 배출로 직경(d)에 따라 배출속도(V)를 계산할 수 있고, 이를 통하여 최종 성형 가공되는 성형품의 목표 두께(t)를 설정할 수 있다.The battery cell cover manufactured as described above may satisfy the following relational expression (1). That is, the injection pressure value (

), the discharge pressure value of the gas and/or air being discharged (

) and the discharge path diameter (d) of the mold 200 can calculate the discharge rate (V), through which it is possible to set the target thickness (t) of the final molded product.

----------------------------------- 관계식(1)

----------------------------------- Relation (1)

*V : gas or air exhaust velocity

: 금형 내의 주입 압력*

: Injection pressure in the mold

: 가스 또는 공기의 배출 압력*

: Exhaust pressure of gas or air

*d: diameter of the exit path of the mold

*K: proportional constant

) 및 배출되는 상기 가스 및/또는 공기의 배출압력 값(

)과 정비례하고, 금형(200)의 배출로 직경(d)에는 반비례하는 관계를 갖을 수 있다. 따라서, 상기 관계식(1)에 따라 상기 주입압력(

), 배출압력(

) 및 금형(200)의 배출로 직경(d)을 조절하여 소망하는 최종 성형품의 두께 등을 제작 가능하도록 함으로써, 우수한 품질을 갖는 배터리 셀 커버를 제조할 수 있다. In other words, the discharge velocity (V) of the gas and/or air is the injection pressure value (

) and the discharge pressure value of the gas and/or air being discharged (

) and may have a relationship that is inversely proportional to the discharge path diameter d of the mold 200 . Therefore, according to the above relation (1), the injection pressure (

), discharge pressure (

) and by adjusting the diameter (d) of the discharge path of the mold 200 to produce a desired thickness of the final molded product, etc., it is possible to manufacture a battery cell cover having excellent quality.

In addition, according to the value of the discharge velocity V calculated as described above, the injection amount Q of the injection-molded product may be calculated through the following relational expression (2).

-----------------------------------------------관계식 (2)

-----------------------------------------------Relational expression (2 )

*Q: Injection volume of the injection

*V : gas or air exhaust velocity

*d: diameter of the exit path of the mold

) 및 배출압력(

)을 고정하여 상기 가스 및/또는 공기의 배출속도(V)를 계산한 후에 금형(200)의 단면적(A), 즉 금형(200)의 배출로 직경(d)에 대한 함수값(f(d))을 계산하여 상기 사출물의 최초 주입량(Q)을 결정할 수 있다. 이러한 주입량(Q)은 배출속도(V)와 상기 단면적(A)에 비례할 수 있다.In other words, the injection pressure (

) and discharge pressure (

After calculating the discharge velocity (V) of the gas and/or air by fixing )) to determine the initial injection amount (Q) of the injection-molded product. This injection amount (Q) may be proportional to the discharge rate (V) and the cross-sectional area (A).

In this regard, in the present invention, the molding results were confirmed after the battery cell covers 100 and 100' were manufactured under the process conditions according to Table 1 while satisfying the above-described relational conditions.

As shown in Table 1, in the case of Comparative Example 1 when the injection pressure was 220, Comparative Example 2 in this case where the discharge pressure of the gas or air was 120, and Comparative Example 3 when the discharge time was 0.15 seconds, FIG. As shown in 7, it can be confirmed that the unformed part of the battery cell cover is generated.

That is, even with the same injection pressure as in Example 1, in the case of the battery cell cover manufactured under the discharge pressure and discharge time process conditions of Comparative Examples 2 and 3, an unmolded part was generated, and in Example 1 and It can be confirmed that unmolded parts are generated in the case of the battery cell cover manufactured under the injection pressure process conditions of Comparative Example 1 even though it is manufactured under the process conditions having the same discharge pressure and discharge time. In particular, the thickness of the battery cell cover manufactured according to the preferred embodiment 1 of the present invention can be manufactured with the most excellent molding thickness in the range of about 0.15 to 0.2mm.

In some cases, in addition to the size of the cross-sectional area of the discharge path of the mold through which the injection-molded product moves, the viscosity of the injection-molded product may be adjusted. For example, the relationship between the viscosity of the injection-molded product itself or the viscosity of the injection-molded product and the thickness of the battery cell covers 100 and 100' to be manufactured may be considered.

Although representative embodiments of the present invention have been described in detail above, those of ordinary skill in the art to which the present invention pertains will understand that various modifications are possible within the limits without departing from the scope of the present invention with respect to the above-described embodiments. . Therefore, the scope of the present invention should not be limited to the described embodiments, and should be defined by the claims described below as well as the claims and equivalents.

1: cover injection 10: cut part
11: first cut portion 12: second cut portion
13: cutting line 14: first guide part
15: second guide part 100, 100': battery cell cover
101, 101': suction part 110, 110': main cover
120, 120': bent 150, 150': adhesive film
151, 151': through hole 200: mold
201: cavity (cavity) 210: upper mold
211: inlet 220: lower type
224: first injection product guide unit 225: second injection product guide unit
250: exhaust hole

Claims (13)

A method of manufacturing a battery cell cover coupled to a battery cell, the method comprising:
injecting the injection material into the mold at a predetermined injection pressure (P _M );
discharging the gas or air in the cavity to a predetermined discharge pressure (Pa) with _a predetermined time difference while filling the injection-molded material into a cavity in the mold;
discharging the gas or air by a cutting process to at least a portion of the injection-molded product before the injection-molded product is cured; and
The injection product filled in the mold is cured,
Including; separating the cured product in which the injection product is cured
The time difference is within the range of 0.01 to 0.05 seconds, the time for which the gas or air is discharged is within the range of 0.25 to 0.35 seconds,
The pressure for injecting the injection molding is in the range of 250 to 500 bar, and the pressure at which the gas or air is discharged is in the range of 150 to 250 bar.
The method of claim 1,
The method of manufacturing a battery cell cover in which the gas or air is removed simultaneously or continuously with the filling of the extrudate.
delete delete delete delete The method of claim 1,
The filling speed of the injection-molded material is proportional to the injection pressure (P _M ) Method of manufacturing a battery cell cover.
The method of claim 1,
The discharge rate (V) of the gas or air is a method of manufacturing a battery cell cover is proportional to the discharge pressure (Pa).
9. The method of claim 8,
The discharge rate (V) is a method of manufacturing a battery cell cover that satisfies the following relation (1),

----------------------------------- (One)

*V : gas or air exhaust velocity
*

: Injection pressure in the mold
*

: Exhaust pressure of gas or air
*d: diameter of the exit path of the mold
*K: proportionality constant.
The method of claim 1,
The injection amount (Q) of the injection material is a method of manufacturing a battery cell cover that satisfies the following relation,

------------------------------------------- (2)

*Q: Injection volume of the injection
*V : Exhaust rate of gas or air
*d: Diameter of the exit path of the mold.
delete delete delete

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