Pouch Molding Apparatus

A pouch molding apparatus includes a die plate, a first stripper, a punch part, and a second stripper. The die plate has a flat plate shape so that a pouch film is seated on an upper portion thereof and has a molding hole having a shape passing through top and bottom surfaces of the die plate. The first stripper is configured to press and fix the pouch film to an upper side of the die plate and has a punch hole at a position at a position corresponding to the molding hole. The punch part is drawn in and out of the punch hole of the first stripper and the molding hole of the die plate to mold the pouch film. The second stripper protrudes from a bottom surface of the first stripper along a circumference of the punch hole in order to press and fix the pouch film.

TECHNICAL FIELD

The present disclosure relates to a pouch molding apparatus, and more particularly, to a pouch molding apparatus, in which a second stripper uniformly and strongly presses a pouch film around a cup part molding position of the pouch film to minimize an occurrence of wrinkles around the cup part, prevent cracks or fractures, which may occur due to the wrinkles, and improve molding quality, thereby achieving space efficiency of the cup part and maximizing energy density.

BACKGROUND ART

A secondary battery refers to a battery that is chargeable and dischargeable, unlike a primary battery that is not charged, and examples of the secondary battery may include a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery, and a lithium ion polymer battery. Such a secondary battery is being applied to be used in small-sized products such as digital cameras, notebooks, mobile phones, PDAs, E-bikes, and the like as well as large-sized products requiring high power such as electric vehicles and hybrid vehicles, power storage devices for storing surplus power or renewable energy, and backup power storage devices.

Such a secondary battery is classified into a pouch-type secondary battery and a can type secondary battery according to a material of a battery case accommodating an electrode assembly. In the pouch-type secondary battery, the electrode assembly is accommodated in a pouch made of a flexible polymer material having a variable shape. In addition, in the can type secondary battery, an electrode assembly is accommodated in a case made of a metal or plastic material having a predetermined shape.

A pouch, which is a case of the pouch type secondary battery, is manufactured by forming a cup part by performing press processing on a pouch film having flexibility. In addition, when the cup part is formed, an electrode assembly is accommodated in an accommodation space of the cup part, and then, a side of the cup part is sealed to manufacture a secondary battery.

In the press processing, draw-molding is performed by inserting a pouch film into a molding device such as a press equipment and applying a pressure to the pouch film by using a punch to draw the pouch film. The pouch molding apparatus may be divided into a stripper area for fixing the pouch and a punch area. Ideally, after fixing the pouch by applying a uniform surface pressure on the stripper area, the pouch film is molded by applying a pressure through a punch. However, since flatness of a pressing surface on the stripper area is uneven, or surface pressure is applied through the wide pressing surface, the pouch film may not be strongly held around the cup part in which stretching of the pouch film occurs.

FIG.1is a view illustrating a state in which wrinkles or cracks occur in a pouch according to the related art.FIG.2is a view illustrating a state in which wrinkles are concentrically formed in a cup part according to the related art. As a result, as illustrated inFIGS.1and2, an insertion of the pouch film may non-uniformly occur, and as a result, as illustrated in (a) and (b) ofFIG.1, wrinkles W may occur around a pouch molding part.

Particularly, referring toFIG.2, the wrinkles are concentrically formed at a corner of the cup part of the pouch in which stretching of the pouch film is concentrated, and the wrinkles may cause cracks (C) due to an impact during movement of logistics (see (c) ofFIG.1), which are directly related to battery performance and safety. Therefore, development of a pouch molding apparatus for solving the above problems is required.

DISCLOSURE OF THE INVENTION

Technical Problem

The present disclosure solves the above problem, and an object of the present disclosure is to provide a pouch molding apparatus, in which a second stripper uniformly and strongly presses a pouch film around a cup part molding position of the pouch film to minimize an occurrence of wrinkles around the cup part, prevent cracks or fractures, which may occur due to the wrinkles, and improve molding quality, thereby achieving space efficiency of the cup part and maximizing energy density.

Technical Solution

A pouch molding apparatus according to the present disclosure may include: a die plate which has a flat plate shape so that a pouch film is seated on an upper portion thereof and in which a cup part molding hole having a shape passing through top and bottom surfaces thereof is formed; a first stripper which is configured to press and fix the pouch film from an upper side of the die plate and in which a punch hole having a shape passing through top and bottom surfaces thereof is formed at a position corresponding to the cup part molding hole; a punch part drawn in and out of the punch hole of the first stripper and the cup part molding hole of the die plate to mold the pouch film; and a second stripper provided to protrude from a bottom surface of the first stripper and provided along a circumference of the punch hole to press and fix the pouch film.

The second stripper may be formed in a ring shape having an inner circumference and an outer circumference, wherein the inner circumference may be greater than a circumference of the punch hole.

In the second stripper, a friction coating layer may be formed on a surface facing the die plate.

The friction coating layer may include silicon.

The first stripper may be formed along a circumference of the punch hole, wherein an insertion hole having a shape that is recessed upward from a lower portion of the first stripper may be formed in the first stripper.

The insertion groove may have a horizontal cross-section having a shape corresponding to that of a horizontal cross-section of the second stripper, and the second stripper may be provided to protrude from a bottom surface of the first stripper, wherein the second stripper is provided to be drawn in or out of the insertion groove so as to be vertically movable.

The pouch molding apparatus may further include: an upper plate provided above the first stripper; and a lower plate provided below the die plate, wherein the upper plate and the lower plate may be coupled to each other at an edge by a coupling member having a length in a vertical direction.

The pouch molding apparatus may further include: a stripper back plate provided between the first stripper and the upper plate to fix at least one of the first stripper or the second stripper; and a die back plate provided between the lower plate and the die plate to support the die plate from a lower side.

The first stripper may be formed along a circumference of the punch hole, wherein a through-hole passing through top and bottom surfaces of the first stripper may be formed in the first stripper, and the second stripper may be fixed to the stripper back plate by a fixing member provided to pass through the through-hole.

The fixing member may be provided in a stopper manner in which a length is changed, but is not changed to a predetermined length or less or the predetermined length or more, but is fixed.

In the second stripper, pouch film pressing force may be adjusted by a pressing force adjusting member provided to pass through the through-hole.

The pressing force adjusting member may include a spring having elasticity in a longitudinal direction.

The pressing force adjusting member may be provided to have one side that is in contact with the second stripper and the other side coupled to the stripper back plate.

The pressing force adjusting member may be provided to have one side that is in contact with the second stripper and the other side coupled to the upper plate.

The punch part may include: a punch body; and a punch which is provided below the punch body and on which a pressing surface configured to press the pouch film is formed.

The first stripper may be formed along a circumference of the punch hole, wherein a through-hole passing through top and bottom surfaces of the first stripper is formed in the first stripper, and the second stripper may be fixed to the upper plate by a fixing member provided to pass through the through-hole.

In the second stripper, pouch film pressing force may be adjusted by a pressing force adjusting member provided to pass through the through-hole, and the pressing force adjusting member may be provided to have one side that is in contact with the second stripper and the other side coupled to the upper plate.

Advantageous Effects

The pouch molding apparatus according to the present disclosure may include the die plate which has the flat plate shape so that the pouch film is seated on the upper portion thereof and in which the cup part molding hole having the shape passing through the top and bottom surfaces thereof is formed, the first stripper which is configured to press and fix the pouch film from the upper side of the die plate and in which the punch hole having the shape passing through the top and bottom surfaces thereof is formed at the position corresponding to the cup part molding hole, the punch part drawn in and out of the punch hole of the first stripper and the cup part molding hole of the die plate to mold the pouch film, and the second stripper provided to protrude from the bottom surface of the first stripper and provided along the circumference of the punch hole to press and fix the pouch film. Therefore, the second stripper may uniformly and strongly press the pouch film around the cup part molding position of the pouch film to minimize the occurrence of the wrinkles around the cup part, prevent the cracks or fractures, which may occur due to the wrinkles, and improve the molding quality, thereby achieving the space efficiency of the cup part and maximizing the energy density.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily carry out the various embodiments of the present invention. However, the present invention may be implemented in several different forms and is not limited or restricted by the following examples.

In order to clearly explain the present disclosure, detailed descriptions of portions that are irrelevant to the description or related known technologies that may unnecessarily obscure the gist of the present disclosure have been omitted, and in the present specification, reference symbols are added to components in each drawing. In this case, the same or similar reference numerals are assigned to the same or similar elements throughout the specification.

Also, terms or words used in this specification and claims should not be restrictively interpreted as ordinary meanings or dictionary-based meanings, but should be interpreted as meanings and concepts conforming to the scope of the present disclosure on the basis of the principle that an inventor can properly define the concept of a term to describe and explain his or her invention in the best ways.

FIG.3is a perspective view of a pouch molding apparatus according to Embodiment 1 of the present invention.FIG.4is a side view of the pouch molding apparatus according to Embodiment 1 of the present invention.FIG.5is an exploded perspective view illustrating some constituents of the pouch molding apparatus according to Embodiment 1 of the present invention.FIG.6is a bottom perspective view illustrating a first stripper of the pouch molding apparatus according to Embodiment 1 of the present invention.FIG.7is a bottom perspective view illustrating first and second strippers of the pouch molding apparatus according to Embodiment 1 of the present invention.FIG.8is a side view illustrating the first stripper and a stripper back plate in the pouch molding apparatus according to Embodiment 1 of the present invention.FIG.9is a transparent perspective view illustrating the first stripper and the stripper back plate of some of the constituents of the pouch molding apparatus according to Embodiment 1 of the present invention.

Referring toFIGS.3to5, a pouch molding apparatus10according to the present embodiment includes a die plate100, a first stripper200, a punch part300, and a second stripper400.

First, the die plate100is formed in a flat plate shape so that a pouch film is seated thereon, and a cup part molding hole100apassing through top and bottom surfaces is formed in the die plate100. That is, in a state in which the pouch film is seated on an upper portion of the die plate100, the punch part300to be described later passes through a cup part molding hole100ato mold a cup part of a pouch. Thus, the die plate100serves to support or fix the pouch film from a lower side. The die plate100may be formed in a flat plate shape to support or fix the pouch film so that a uniform surface pressure is applied to the pouch film seated on the die plate100.

The first stripper200presses the pouch film from the upper side of the die plate100to fix the pouch film, and a punch hole200apassing through the top and bottom surfaces is formed at a position corresponding to the cup part molding hole100a. That is, the pouch film may be supported by the die plate100from a lower side and be pressed and fixed by the first stripper200from an upper side. It is unnecessary that the pouch film is seated on the upper portion of the die plate100, and the first stripper200presses and fixes the pouch film from the upper side of the die plate100. On the contrary, the pouch film may be seated on the upper portion of the first stripper200, and the die plate100may press and fix the pouch film from the upper side of the first stripper200.

The punch part300is drawn in and out of the punch hole200aof the first stripper200and the cup part molding hole100aof the die plate100to mold the pouch film. Here, the punch part300is first inserted into the punch hole200aof the first stripper200and then inserted into the cup part molding hole100aof the die plate100to press the pouch film, thereby molding the cup part. When the cup part is completely molded, the punch part300may be drawn out of the cup part molding hole100aof the die plate100and then drawn out of the punch hole200aof the first stripper200.

The second stripper400is provided to protrude from a bottom surface of the first stripper200and is provided along a circumference of the punch hole200ato press and fix the pouch film. As a result, the second stripper400may uniformly and strongly press the pouch film around a cup part molding position of the pouch film to minimize an occurrence of wrinkles around the cup part, prevent cracks or fractures, which may occur due to the wrinkles, and improve molding quality, thereby achieving space efficiency of the cup part and maximizing energy density.

Hereinafter, each of the components of the pouch molding apparatus10according to the present embodiment will be described in more detail.

Referring toFIGS.5and7, the second stripper400may be formed in a ring shape having an inner circumference and an outer circumference, and the inner circumference may be formed to be greater than a circumference of the punch hole200a. Since the second stripper400is provided along the circumference of the punch hole200a, when the inner circumference is formed to be less than the circumference of the punch hole200a, the second stripper400may interfere with the punch part300passing through the punch hole200aof the first stripper200, and thus, movement of the second stripper400may occur, or punching of the punch part300may not properly performed to deteriorate the molding quality of the pouch cup part. Thus, the inner circumference of the second stripper400is formed to be greater than the circumference of the punch hole200a, and thus, the second stripper400may not interfere with the punch part300and may press uniformly and effectively the pouch film.

A friction coating layer may be formed on a surface of the second stripper400, which face the die plate100. Since the pouch film is seated on the die plate100, the surface facing the die plate100in the second stripper400may be understood as the same as the pressure surface on which the second stripper400presses the pouch film. As described above, the friction coating layer is formed on the surface of the second stripper400, which faces the die plate100, and thus, the frictional force between the second stripper400and the pouch film may increase. As a result, since the second stripper400more uniformly and strongly press the pouch film, an occurrence of wrinkles around the cup part molding position may be suppressed.

The friction coating layer may include a material capable of increasing in frictional force between the second stripper400and the pouch film and may preferably include silicone. However, it is not necessarily limited to silicon. For example, a material having no concern of physically and chemically reacting with the pouch film and having frictional coefficient greater than that of the second stripper400may be selected as the friction coating layer. In addition to the material having a large frictional coefficient in addition to a specific material, the frictional coefficient may increase by varying in shape or roughness of the surface.

Referring toFIGS.5and6, the first stripper200may be formed along the circumference of the punch hole200aand may have an insertion groove200bhaving a shape that is recessed upward from the lower side. The shape recessed upward from the lower side may be understood as the same as a shape recessed from one surface to the other surface of the first stripper200having a thickness. However, here, the one surface may be a surface of the first stripper200, which is provided with the second stripper400, and the other surface may be a surface that is opposite to the one side of the first stripper200. As described above, the insertion groove200bis formed in the first stripper200. Thus, as described below, the second stripper400may be drawn in or out of the insertion groove200b, and thus, pressing force of the second stripper400may be appropriately adjusted.

Continuously, referring toFIGS.6to8, the insertion groove200bmay be formed to have a horizontal cross-section having a shape corresponding to that of a horizontal cross-section of the second stripper400, and the second stripper400may be provided to protrude from the bottom surface of the first stripper200and may be drawn in or out of the insertion groove200bso as to be vertically movable. The insertion groove200bmay provide a space in which the second stripper400is drawn in or out of the first stripper200, and for this, the insertion groove200bmay have a shape corresponding to the horizontal cross-section of the second stripper400. Here, that the insertion groove200bhas the shape corresponding to the horizontal cross-section of the second stripper400may mean that the insertion groove200bhas a shape in which the insertion groove200bhas the same size as the horizontal cross-section of the second stripper400, but has a width that is as large as a size of an offset. If the size of the width of the insertion groove200bis the same as the size of the width of the second stripper400, the second stripper400may not be inserted into the insertion groove (200b), or even if the second stripper400is inserted into the insertion groove200b, movement may not be smooth due to an interference by a pressure, and as a result, it is impossible to apply appropriate pressing force. Conversely, if the width of the insertion groove200bis excessively larger than the width of the second stripper400, when the second stripper400presses the pouch film while the second stripper400is inserted into the insertion groove200b, movement in a lateral direction may occur, and thus, it is impossible to apply appropriate pressing force. Therefore, it is preferable that the size of the offset is an appropriate with at which the second stripper400is easily inserted into the insertion groove200b, and after the insertion, movement of the second stripper400does not occur in the insertion groove200b. In fact, the size of the offset may be experimentally determined according to the width of the second stripper400to be manufactured.

As described above, the second stripper400may be provided in a state of protruding from the bottom surface of the first stripper200and may be partially inserted into the insertion groove200bas the second stripper400presses the pouch film. As a result, the pouch film may be appropriately pressed to suppress the occurrence of the wrinkles, and also, the shape of the second stripper400may not remain around the cup part molding position to improve the molding quality.

Referring toFIG.8, the pouch molding apparatus10according to the present embodiment may further include an upper plate700and a lower plate800. The upper plate700may be provided above the first stripper200, and the lower plate800may be provided below the die plate100. Here, the upper plate700and the lower plate800may be coupled to each other at an edge by a coupling member900having a length in a vertical direction. That is, the upper plate700is provided at an upper end of the pouch molding apparatus10, and the punch part300and the configuration of the stripper back plate500described later may be coupled to be fixed. The lower plate800may be provided at the lower end of the pouch molding apparatus10to serve to support the entire pouch molding apparatus10from the lower side.

In addition, the pouch molding apparatus10may further include a stripper back plate500and a die back plate600. The stripper back plate500is provided between the first stripper200and the upper plate700to fix at least one of the first stripper200or the second stripper400. The die back plate600is provided between the lower plate800and the die plate100to support the die plate100from the lower side. As described above, the first stripper200, the second stripper400, and the die plate100may be in direct contact with the pouch film to serve to press the pouch film, and the stripper back plate500and the die back plate600may be provided above or below the stripper, and thus, the first and second strippers and the die plate100may be stably fixed to the pouch molding apparatus10.

Hereinafter, a method for fixing a second stripper400will be described in detail with reference toFIGS.6,8and9.

First, as illustrated inFIG.6, a punch hole200amay be formed along a circumference of a first stripper200, and a through-hole200cpassing through top and bottom surfaces of the first stripper200may be formed in the first stripper200. Here, as illustrated inFIGS.8and9, a second stripper400may be fixed to the stripper back plate500by a fixing member410passing through the through-hole200c. As described above, even if the second stripper400is provided below the first stripper200or inside the insertion groove200bof the first stripper200, the second stripper400may not be in direct contact with the first stripper200, but be fixed to the stripper back plate500so as to be independently movable in the vertical direction with respect to the first stripper200, thereby applying appropriate pressing force to the pouch film. Here, the through-hole200cmay be formed in plurality, and the fixing member410may also be formed in plurality. However, the number of through-holes200cmay be the same or less than the number of through-holes200cto fix the second stripper400.

The fixing member410may be provided in a stopper manner in which a length is changed, but not changed to a predetermined length or less or a predetermined length or more, but is fixed. Here, the meaning of being fixed without changed to the predetermined length or more may mean that the second stripper400is fixed to protrude from a bottom surface of the first stripper200, and also, the second stripper400is not changed to a length or more at which the second stripper400is fixed to protrude so as not to seat the pouch film between the die plate100and the first stripper200. In addition, the meaning of being fixed without changed to the predetermined length or less may mean that the second stripper400is inserted into the insertion groove200bformed in the first stripper, and also, the second stripper400is completely inserted into the insertion groove200band is not changed to a length or less at which the second stripper400does not protrude.

The second stripper400may adjust pressing force of pressing the pouch film by a pressing force adjusting member provided to pass through the through-hole200cin addition to the above fixing member410. The pressing force adjusting member420is provided separately with respect to the fixing member410, and the second stripper400applies force in a direction opposite to the direction in which the first stripper200is inserted into the insertion groove200bso that the second stripper400provides pressing force to press the pouch film. Therefore, the pressing force adjusting member420may continuously increase in pressing force of the second stripper400as the second stripper400is inserted into the insertion groove200b. One side of the pressing force adjusting member420may be provided to be in contact with the second stripper400, and the other side may be provided to be coupled to the stripper back plate500. The pressing force adjusting member420may also be formed in plurality to adjust the pressing force for each position.

The pressing force adjusting member420may include a spring having elasticity in a longitudinal direction. Since elastic force increases as the spring is pressed, when the spring is selected as the pressing force adjusting member420, the pressing force of the second stripper400may continuously increase so that the second stripper400is inserted into the insertion groove200b. The pressing force adjusting member420may further include a spring fixing member for fixing the other side of the spring to the stripper back plate500in addition to the spring.

Next, the punch part300may include a punch body320and a punch310that is provided under the punch body320and has a pressing surface for pressing the pouch film. The punch body320may be configured to fix the punch part300to the pouch molding apparatus10, and the punch310having the pressing surface may have a shape and size of a cup part to be molded as a component that directly presses the pouch film.

When the punch body320is fixed and does not move in the pouch molding apparatus10and moves vertically in a state in which the pouch film interposed between the die plate100and the first stripper200, the cup part may be molded on the pouch film while the punch body320and the punch310of the punch part300pass through a punch hole200aand a cup part molding hole100a. However, on the other hand, the die plate100and the first stripper200may be fixed with the pouch film interposed therebetween, and the punch part300may move to mold the cup part.

Embodiment 2 of the present invention is different from Embodiment 1 in that the pressing force adjusting member420according to Embodiment 1 is provided so that one side thereof is in contact with the second stripper400, and the other side thereof is provided to be coupled to the upper plate700. The contents that are duplicated with Embodiment 1 will be omitted as much as possible, and Embodiment 2 will be described with a focus on the differences. That is, it is obvious that the contents that are not described in Embodiment 2 may be regarded as the contents of Embodiment 1 if necessary.

FIG.10is a transparent perspective view illustrating a first stripper and a stripper back plate in a pouch molding apparatus according to Embodiment 2 of the present invention.

In a pouch molding apparatus10according to Embodiment 2 of the present invention, the pouch molding apparatus10includes a die plate100, a first stripper200, a punch part300, and a second stripper400. In addition, the pouch molding apparatus10may further include a stripper back plate500, a die back plate600, an upper plate700, and a lower plate800.

The first stripper200may be formed along a circumference of a punch hole200a, a through-hole200cpassing through top and bottom surfaces may be formed, and the second stripper400may be fixed to the striper back plate500by a fixing member410provided to pass through the through-hole200c.

In addition, in the second stripper400, pouch film pressing force may be adjusted by a pressing force adjusting member420provided through the through-hole200c. Here, the pressing force adjusting member420of the pouch molding apparatus10according to Embodiment 2 of the present invention may be provided to have one side that is in contact with the second stripper400and the other side coupled to the upper plate700.

As described above, the other side of the pressing force adjusting member420may be coupled to the upper plate700, and thus, the pressing force may be provided more stably compared to a case of being coupled to the stripper back plate420. When the pressing force adjusting member420includes a spring, a length of the spring is formed to be elongated, and thus, pressing force having more various intensities may be provided. The pressing force adjusting member420may further include a spring fixing member for fixing the other side of the spring to the stripper back plate500in addition to the spring.

Example 3 of the present invention is different from Embodiments 1 and 2 in that the first and second strippers400according to Embodiments 1 and 2 are fixed by a fixing member410, i.e., is not fixed to a stripper back plate500, but fixed to an upper plate700. The contents that are duplicated with Embodiments 1 and 2 will be omitted as much as possible, and Embodiment 3 will be described with a focus on the differences. That is, it is obvious that the contents that are not described in Embodiment 3 may be regarded as the contents of Embodiments 1 and 2 if necessary.

Therefore, the pouch molding apparatus10according to Embodiment 3 of the present invention includes a die plate100, a first stripper200, a punch part300, and a second stripper400. In addition, the pouch molding apparatus10may further include a die back plate600, an upper plate700and a lower plate800.

In the pouch molding apparatus10according to the third embodiment of the present invention, the first stripper200may be formed along a circumference of a punch hole200a, a through-hole200cpassing through top and bottom surfaces may be formed, and the second stripper400may be fixed to the upper plate700by a fixing member410provided to pass through the through-hole200c. Therefore, a structure of the pouch molding apparatus may be simplified while maintaining molding quality of the pouch.

The fixing member410may be provided in a stopper manner in which a length is changed, but not changed to a predetermined length or less or a predetermined length or more, but is fixed. In addition, the second stripper400may adjust pouch film pressing force by a pressing force adjusting member provided to pass through the through-hole200c. Here, the detailed configurations of the fixing member410and the pressing force adjusting member420and the resulting effect may be understood as the same as in Embodiment 1.

In addition, in the second stripper400, pouch film pressing force may be adjusted by a pressing force adjusting member420provided through the through-hole200c. Here, the pressing force adjusting member420may be provided to have one side that is in contact with the second stripper400and the other side coupled to the upper plate700.

DESCRIPTION OF THE SYMBOLS