Bag forming device containing a vacuum pad

Abstract

A bag forming apparatus comprising: a die part with a forming groove; a stamping member arranged to face the forming groove and configured to move relative to the forming groove and to press a bag film arranged on the stamping member into the forming groove; a forming pad arranged to move relative to the punch member within the forming groove and to control the depth of the forming groove; and a vacuum pad that applies vacuum pressure to the forming groove to be in close contact with the bag film, wherein the vacuum pad is arranged in at least one corner region of the forming pad.

Description

TECHNICAL FIELD

[0001] The present disclosure in this patent document relates generally to a bag forming apparatus including a vacuum pad. BACKGROUND

[0002] In contrast to primary batteries, secondary batteries have the advantage that they can be charged and discharged and are therefore receiving considerable attention as energy sources for various mobile devices and electric vehicles.

[0003] Such secondary batteries may include battery cells in which an electrode assembly formed by stacking a positive electrode plate, a negative electrode plate, and a separator, or by winding them in a roll, is housed in a casing. A plurality of battery cells may be stacked in a specific direction and housed in a battery module or battery pack.

[0004] Depending on the type of housing in which the electrode assembly is housed, the battery cells can be divided into pouch-like, prismatic or cylindrical battery cells.

[0005] In this case, the casing of the pouch-type battery cell can be manufactured using a deep-drawing process, in which an outer pouch material is pressed against a groove of a prefabricated mold with a punch to form an elongated shape. This allows a shell part to be formed in which the electrode assembly is housed.

[0006] However, if the bag film is extended beyond a certain depth in the groove of the mold, problems such as cracks or wrinkles in the bag body or tearing due to limitations in the external material attachment may occur. SUMMARY

[0007] The present disclosure may be implemented in some embodiments to provide a bag forming apparatus capable of significantly reducing the tearing or breakage of a bag film.

[0008] According to one aspect of the present disclosure, a bag forming apparatus capable of significantly increasing the stretch amount of a bag film can be provided.

[0009] According to one aspect of the present disclosure, a bag forming apparatus for producing a bag casing for improving energy efficiency may be provided.

[0010] In some embodiments of the present disclosure, a bag forming apparatus includes a die portion having a forming groove; a punch portion arranged to face the forming groove and configured to move relative to the forming groove and press a bag film arranged on the die portion into the forming groove; a forming pad arranged to move relative to the punch portion in the forming groove and to control the depth of the forming groove; and a vacuum pad that applies vacuum pressure to the forming groove to be in close contact with the bag film. The vacuum pad is arranged in at least one corner region of the forming pad.

[0011] The forming pad may have a plurality of edge portions and at least one corner portion provided between the plurality of edge portions and arranged in the corner region, and the vacuum pad may be arranged adjacent to the at least one corner portion.

[0012] The forming pad can divide the forming groove into a first space into which the bag film is inserted and a second space into which the bag film is not inserted. The vacuum pad can apply vacuum pressure to the first space so that it is in close contact with a corner area of the bag film that corresponds to a corner area of the vacuum pad.

[0013] The vacuum pad and the forming pad may each have an upper surface facing the stamping part and on which the bag film sits, and the upper surface of the vacuum pad may be arranged parallel to the upper surface of the forming pad or lower than the upper surface of the forming pad.

[0014] The vacuum pad can be inserted into the forming pad to be exposed to the forming groove through the upper surface of the forming pad.

[0015] The bag forming device may further include a vacuum device located outside the forming groove and generating a vacuum pressure, as well as a vacuum line connecting the vacuum device and the vacuum pad and supplying the vacuum pressure to the vacuum pad. The vacuum line may penetrate at least one of a bottom forming surface and a side forming surface of the die part forming the forming groove and may be connected to the vacuum device.

[0016] The forming pad may be provided to move so as to change a relative distance to the punch part while being raised and lowered in the forming groove, and the vacuum pad may be provided to be in close contact with a corner portion of the bag film corresponding to the corner portion of the forming pad.

[0017] The forming pad may be provided to extend the corner portion of the bag film while moving in a direction in which the relative distance to the punch part increases in a state where the corner portion of the bag film and the vacuum pad are in close contact.

[0018] The punch part may be provided to bring the bag film into close contact with the forming pad while moving in a direction in which a relative distance from the forming pad decreases in a state where the corner portion of the bag film is expanded. The vacuum pad may be provided to continuously generate a vacuum pressure so that it is in close contact with the corner portion of the bag film.

[0019] In some embodiments of the present disclosure, a bag forming apparatus includes a die portion having a forming groove and a bag film disposed thereon; a punch portion configured to move relative to the forming groove to be at least partially inserted into the forming groove; a forming pad configured to be raised and lowered within the forming groove and dividing the forming groove into a first space into which the forming groove is inserted and formed and a second space into which the forming groove is not inserted, and providing a bottom surface of the first space; and a vacuum pad that applies vacuum pressure to the first space so that the bag film is inserted into the first space and adheres thereto. The vacuum pad is disposed at a corner portion of the forming pad so that the bag film adheres to the corner portion of the forming pad.The forming pad is provided to extend the bag film while moving in a direction in which the depth of the first space increases in a state where the bag film adheres to the corner portion of the forming pad.

[0020] Forming a bag includes a first forming process in which a bag film is tightly adhered to a forming pad disposed within a forming groove, and the bag film is stretched by lowering the forming pad; and a second forming process in which a punch part arranged to oppose an upper part of the forming pad is lowered into the forming groove and presses the bag film against the forming pad. The first forming process includes a first process of pressing the bag film against a corner portion of the forming pad by a vacuum pad disposed at the corner portion of the forming pad and generating a vacuum pressure; and a second process in which the forming pad moves away from the punch part to extend a corner portion of the bag film corresponding to the corner portion of the forming pad.

[0021] In the above, the solution according to the present disclosure is described, but this is only exemplary, and it should be understood that other configurations not mentioned are also included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Certain aspects, features and advantages of the present disclosure are explained in the following detailed description with reference to the accompanying drawings. Fig. 1 is a schematic diagram of a bag forming apparatus according to an embodiment. Fig. 2 is a schematic exploded perspective view of a bag forming apparatus according to an embodiment. Fig. 3 is a plan view of a molding pad according to one embodiment. Fig. 4 and Fig. 5 are schematic diagrams illustrating the forming of a bag film using a vacuum pad according to one embodiment. Fig. 6 is a schematic diagram showing the forming of a bag film using a stamping member according to an embodiment. DETAILED DESCRIPTION

[0023] Features of the present disclosure disclosed in this patent specification are described by way of embodiments with reference to the accompanying drawings.

[0024] Before describing embodiments in detail, it should be clarified that the terms or words used in the following descriptions and claims should not be construed as being limited to their common or dictionary meaning, but should be interpreted with a meaning and concept consistent with the technical idea of the present disclosure, based on the principle that the inventor can appropriately define the concept of the terms to best explain his invention.

[0025] The same reference numbers or symbols in the respective drawings indicate parts or components that perform essentially the same function.

[0026] In the following description, singular terms include plural terms unless the context clearly dictates otherwise. Terms such as "including," "configuring," and the like are intended to denote the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the description and are not intended to preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0027] In addition, in the following description, terms such as top, upper part, lower part, bottom, side, front, back and the like are expressed based on the direction shown in the drawing, and it should be noted in advance that if the direction of the object is changed, they may be expressed differently.

[0028] Furthermore, in the descriptions and claims below, terms with ordinal numbers such as "first," "second," and the like may be used to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from one another, and the meaning of the term should not be interpreted in a restricted manner based on the use of these ordinal numbers. For example, components combined with these ordinal numbers should not be interpreted as having a limited order of use or arrangement based on number. If necessary, the respective ordinal numbers may be used interchangeably.

[0029] Hereinafter, a bag forming apparatus according to an embodiment will be described with reference to the drawings.

[0030] Fig. 1 is a schematic representation of a bag forming apparatus according to an embodiment, and Fig. 2 is a schematic exploded perspective view of a bag forming apparatus according to an embodiment. Although a bag film P used in the present disclosure is also depicted in the drawings for convenience, the bag forming apparatus of the present disclosure does not need to include the bag film P.

[0031] With reference to Fig. 1 and Fig. 2, a bag forming apparatus according to one embodiment may include a die part 10 having a forming groove S, a punch part 20 positioned to face the die part 10 and move relative to the forming groove S while inserting a bag film P into the forming groove S, a forming support part 30 including a forming pad 31 positioned in the forming groove S and capable of supporting the punch part 20, and a vacuum generating part 35 generating a vacuum in the forming groove S.

[0032] Furthermore, according to one embodiment, the bag forming apparatus may include a vacuum device 38 connected to the vacuum generating part 35, and a control part 50 connected to at least one of the die part 10, the forming pad 31, or the vacuum generating part 35 for controlling the vacuum generating part. Furthermore, according to one embodiment, a stripper 40 may be provided for securing the bag film P to a mounting surface 13.

[0033] The pouch film P may be an outer material constituting the casing of a secondary battery, such as a battery cell. The pouch film P may be formed into a predetermined shape corresponding to a forming groove S to form a shell portion in which an electrode assembly can be accommodated. As the depth of the shell portion increases during forming of the pouch film P, a larger electrode assembly can be accommodated in the pouch casing, thereby increasing the energy efficiency of the battery cell. However, as the depth of the shell portion increases, the elongation amount of the pouch film P, which is an outer material of the casing, increases, resulting in cracks, so there is a limit to increasing the elongation amount of the pouch film P.According to an embodiment of the present disclosure, during the stretch forming of the bag film P, the stretch amount of the bag film P can be further increased, whereby a housing for a battery cell with a larger capacity can be provided.

[0034] The die part 10 may include forming inner surfaces 11 and 12 forming a forming groove S, and a fastening surface 13 arranged around the forming groove S and onto which the bag film P is fastened. In Fig. 2, a plurality of forming grooves S are shown so that a plurality of tray parts can be formed with one bag film P, but this is only for convenience, and the present disclosure is not limited thereto. In detail, even if at least one forming groove S is formed, it should be considered that they all belong to the present disclosure.

[0035] The forming groove S may refer to a space formed by the lower forming surface 11 and the side forming surface 12 by the inward sinking of the die part 10. The bag film P may be formed by being introduced into the forming groove S by the punch part 20 or the vacuum generating part 35 described later.

[0036] The mounting surface 13 may refer to the upper surface of the die part 10, which extends from the lateral forming surface 12 to the edge of the forming groove S. A stripper 40 may be arranged so that it is opposite the mounting surface 13.

[0037] The scraper 40 can press the bag film P against the mounting surface 13 so that at least a part of the bag film P facing the forming pad 31 can be inserted into the forming groove S and fixed.

[0038] The punch part 20 is arranged to face the forming groove S and to move in a direction in which the relative distance to the forming groove S changes. The punch part 20 has a shape corresponding to the forming groove S and to move so that at least a part of it is inserted into the forming groove S (see Fig. 6).

[0039] The punch part 20 can press the bag film P arranged on the die part 10 into the forming groove S so that at least a part of the bag film P can be introduced into the forming groove S.

[0040] The forming support part 30 may include a forming pad 31 disposed in the forming groove S and movable relative to the punch part 20, and a pad support part 32 supporting the forming pad 31.

[0041] The forming pad 31 can assist the bag film P in forming. For example, the bag film P can be placed on the upper surface (the surface facing the stamping part 20) of the forming pad 31 to achieve forming. The upper surface of the forming pad 31 can form the lower surface of a first space S1, which will be described later.

[0042] For example, the shape of the upper surface of the forming pad 31 can determine the shape of the tray part when forming the bag film P. In the drawing, the forming pad 31 is shown as a rectangular solid shape parallel to the lower forming surface 11, but the shape can be formed in various ways depending on the desired shape of the tray part.

[0043] The forming pad 31 can support the stamp part 20 so that the bag film P is pressurized when the stamp part 20 is inserted into the forming groove S (see Fig. 6). In addition, a vacuum pad 36 to be described later may be arranged on the forming pad 31 so that the bag film P is intensively pressed against the corner portion 31c (see Fig. 3) of the shaping pad 31 can be pressed. This will be described later.

[0044] In addition, the forming pad 31 may divide the forming groove S into a first space S1 and a second space S2 (see Fig. 5). At least parts of the bag film P and the punch part 20 can be inserted into the first space S1 of the forming groove S, so that the forming of the bag film P can be performed. A pad support part 32 and a vacuum line 37 to be described later can be arranged in the second space S2. In this case, the insertion may mean that the bag film P can be arranged in the first space S1.

[0045] The first space S1 is a space into which the bag film P is inserted and in which the stretching or forming of the bag film P takes place, and may be referred to as an “upper space”, and the second space S2 is a space into which the bag film P is not inserted and in which the pad supporting part 32 can be arranged, and may be referred to as a “lower space”.

[0046] In this case, “dividing the forming groove S into the first space S1 and the second space S2” does not necessarily mean a strict physical separation or blocking of the two spaces, but may also mean a functional division of the forming groove S into a space into which the bag film P is inserted and a space into which the bag film P is not inserted.

[0047] For example, the space formed by the upper surface of the forming pad 31 and the side forming surface 12 may be referred to as the first space S1, and the space formed by the lower surface of the forming pad 31, the lower forming surface 11 and the side forming surface 12 may be referred to as the second space S2.

[0048] In addition, the forming pad 31 is provided so that it can be raised and lowered in the forming groove S by the pad support part 32 described below, so that the depth of the forming groove S, more specifically, the depth of the first space S1 into which the bag film P is inserted and formed, can be adjusted.

[0049] The pad support part 32 may be arranged in the second space S2 of the molding groove S to support the molding pad 31. For example, the pad support part 32 may support the molding pad 31 by connecting one side to the lower surface (the surface facing the lower molding surface 11) of the molding pad 31 and the other side to the lower molding surface 11.

[0050] Furthermore, the pad support part 32 can move the forming pad 31 relative to the punch part 20. More specifically, the pad support part 32 can raise and lower the forming pad 31 in the forming groove S.

[0051] When the forming pad 31 is raised and lowered, the depth of the first space S1 and the depth of the second space S2 of the forming groove S can be changed. Specifically, when the pad support part 32 lowers the forming pad 31, the depth of the first space S1 can increase and the depth of the second space S2 can decrease. Conversely, when the pad support part 32 raises the forming pad 31, the depth of the first space S1 can decrease and the depth of the second space S2 can increase by the amount of the decrease.

[0052] In this way, the pad support part 32 can enable the forming pad 31 to change the depth of the forming groove S (more precisely, the first space S1 in which forming takes place). The pad support part 32 can control the stroke distance or stroke speed of the forming pad 31 through the control element 50.

[0053] In addition, the forming pad 31 can be arranged parallel to the mounting surface 13 of the die part 10 before the forming of the bag film P and, for example, such that the depth of the second space S2 approximately corresponds to the depth of the forming groove S (see Fig. 4). As described below, the bag film P in this state can be pressed against the corner portion 31c of the forming pad 31 by the vacuum pad 36. However, the present disclosure is not limited to this.

[0054] Furthermore, the pad support part 32 can elastically support the molding pad 31 by including an elastic body. For example, the pad support part 32 can support the molding pad 31 with an elastic material such as a spring. However, the present disclosure is not limited to this, and any structure that can support the molding pad 31 is within the scope of the present disclosure.

[0055] The vacuum generating part 35 can apply a vacuum pressure to the forming groove S to form the bag film P. The vacuum generating part 35 can include a vacuum pad 36 arranged on the forming pad 31 and capable of being in close contact with the bag film P, and a vacuum line 37 connecting the vacuum pad 36 and the vacuum device 38.

[0056] The vacuum pad 36 is arranged to be exposed to the upper surface of the forming pad 31 and to exert vacuum pressure on the forming groove S, particularly on the first space S1 of the forming groove S. In this case, “exposed” may refer to a structure in which the vacuum pad 36 is positioned to be in close contact with the bag film P.

[0057] For example, the vacuum pad 36 may be inserted into the forming pad 31 such that its upper surface is parallel to the upper surface of the forming pad 31, and the lower surface of the vacuum pad 36 may be connected to the vacuum line 37 described later to receive vacuum pressure. Specifically, the structure can be deformed as long as it is a structure in which the bag film P can be in close contact with the vacuum pad 36 due to the vacuum pressure of the vacuum pad 36.

[0058] In addition, the upper surface of the vacuum pad 36 can be positioned at a height approximately parallel to or lower than the upper surface of the forming pad 31. If the upper surface of the vacuum pad 36 protrudes higher than the upper surface of the forming pad 31, the corresponding part may be deformed or broken by the punch part 20 described later (see Fig. 6). In order to improve the adhesion between the vacuum pad 36 and the bag film P, it is also advantageous that the upper surface of the vacuum pad 36 is arranged approximately parallel to the upper surface of the forming pad 31.

[0059] Meanwhile, the "vacuum pressure" in the present disclosure may mean that the vacuum pad 36 creates a pressure lower than the ambient atmospheric pressure, so that the air around the upper surface of the vacuum pad 36 is drawn into the vacuum pad 36, and may include a negative pressure. For example, the vacuum pad 36 may create a vacuum pressure in the forming groove S, so that the bag film P is drawn into the vacuum pad 36 and adheres thereto.

[0060] More specifically, the vacuum pad 36 can adhere to the bag film P while sucking it in. As will be explained later in Fig. 4 and Fig. 5, when the bag film P adheres to the vacuum pad 36 arranged near the corner portion 31c of the forming pad 31, the corner portion of the bag film P may be greatly stretched when the forming pad 31 is lowered.

[0061] In addition, the vacuum pad 36 may contain an elastic material that can improve adhesion to the bag film P. The vacuum pad 36 may, for example, contain a rubber formed from ethylene propylene diene monomer (EPDM).

[0062] The vacuum line 37 may be arranged outside the forming groove S to connect the vacuum device 38, which generates the vacuum pressure, to the vacuum pad 36. The vacuum line 37 may be arranged in the second space S2 to prevent deterioration of the bag film P. For example, one side of the vacuum line 37 may be connected to the vacuum pad 36 arranged on the forming pad 31, and the other side may be connected to the vacuum device 38 arranged outside the forming groove S by penetrating the bottom forming surface 11 or the side forming surface 12. Furthermore, the vacuum line 37 may be arranged to penetrate the forming pad 31, as shown in the drawing, but the present disclosure is not limited thereto.

[0063] The connection structure of the vacuum line 37 and the vacuum device 38 of the present disclosure is an example and can be changed in various ways as long as it applies a vacuum pressure to the vacuum pad 36.

[0064] Fig. 3 is a plan view of a molding pad 31 according to an embodiment, and is a drawing of the upper surface of the molding pad 31 and a partially enlarged drawing of a corner portion of the molding pad 31.

[0065] As in Fig. 3, the forming pad 31 may have an approximately quadrangular shape corresponding to the shape of the forming groove S, and may include four edge portions 31b and four corner portions 31c. The corner portion 31c may be arranged in the corner region of the forming pad 31 (see the partially enlarged drawing of Fig. 3).

[0066] In the present disclosure, a region adjacent to the edge portion 31b and the corner portion 31c may be referred to as a peripheral region of the molding pad 31, and a region other than the peripheral region may be referred to as a central region of the molding pad 31.

[0067] More specifically, the molding pad 31 may include a central region in which the edge portion 31b and the corner portion 31c are not disposed, and a peripheral region in which the edge portion 31b and the corner portion 31c are disposed. The peripheral region may include a corner region (see the partial enlargement of Fig. 3) in which the corner portion 31c is arranged, and an edge region in which only the edge portion 31b is arranged without the corner portion 31c.

[0068] The bag forming process can be carried out by bringing the upper surface of the forming pad 31 into close contact with the bag film P by the stamp part 20 (see Fig. 6), and during this process, the stretching of the bag film P can be intensively carried out in a region corresponding to the peripheral region of the forming pad 31. More specifically, among the surrounding regions, the corner region (see the partial enlargement of Fig. 3) in which the corner portion 31c is arranged, may cause more intense stretching of the bag film P, which may cause cracks or breaks in the bag film P.

[0069] Accordingly, in the present disclosure, the occurrence of cracks or breaks in the corner portion of the bag film P during the secondary stretching by the punch part 20 can be significantly reduced by first intensively stretching the corner portion of the bag film P corresponding to the corner portion of the forming pad 31 by the vacuum pad 36 before the forming process by the punch part 20.

[0070] According to one embodiment, the vacuum pad 36 can be arranged in the corner region of the forming pad 31 (see the partial enlargement of Fig. 3). The vacuum pad 36 can be arranged next to the corner section 31c in the corner area.

[0071] In this case, the term "located adjacent" may mean that the distance d (hereinafter referred to as "shortest distance between the corner portion 31c and the vacuum pad 36") between the corner portion 31c of the forming pad 31 and the nearest part of the vacuum pad 36 maintains a predetermined range.

[0072] For example, the shortest distance between the corner portion 31c and the vacuum pad 36 may be 1 mm to 10 mm. However, this value is only an example to facilitate understanding, and since this value may vary depending on the shape and size of the forming pad 31 and the vacuum pad 36, the size of the bag film P, or the like, the present disclosure is not limited thereto.

[0073] Furthermore, "the vacuum pad 36 is arranged adjacent to the corner portion 31c" may mean that it is arranged adjacent to the two edge portions 31b that form the corner portion 31c. As shown in the partial enlargement (corner portion) of Fig. 3, it may be arranged, for example, near both the upper and right-side edge portions 31b based on the drawing of the vacuum pad 36.

[0074] In another embodiment, not shown in the drawing, this may be the corner region of the vacuum pad 36. For example, it may be provided in a mold in which a vacuum pad 36 is arranged between the forming pad 31 and the forming side surface 12. It goes without saying that any structure for locally applying vacuum pressure to the corner region of the bag film P is within the scope of the present disclosure.

[0075] Meanwhile, the central region, peripheral region, corner region, and edge region of the above-described forming pad 31 may be virtual regions to explain the arrangement position of the vacuum pad 36. Thus, the present disclosure is not specifically limited to a structure for intensively applying vacuum pressure to the corner region of the bag film P.

[0076] The following is based on reference to Fig. 4 to 6, a bag forming process using the bag forming apparatus of the present disclosure is described.

[0077] Fig. 4 and Fig. 5 are schematic drawings showing the forming of a bag film using a vacuum pad according to one embodiment, and Fig. 6 is a schematic drawing showing the forming of a bag film using a stamping member according to an embodiment.

[0078] The bag forming apparatus according to the present disclosure can produce a bag film P through a first forming process and a second forming process. The first forming process is carried out in the Fig. 4 and Fig. 5, and the second forming process is explained in Fig. 6 explained.

[0079] Referring to Fig. 4, the bag forming apparatus of the present disclosure applies vacuum pressure to a forming groove S via a vacuum generating part 35. The vacuum pad 36 disposed in the corner portion of the forming pad 31 can be in close contact with the bag film P while sucking the corner portion of the bag film P. More specifically, the vacuum pad 36 is included in the present disclosure if it has a structure that can be in close contact with the peripheral portion, particularly the corner portion, rather than with the central portion of the bag film P.

[0080] As in Fig. 5, the forming pad 31 can be lowered from the forming groove S to the lower forming surface 11 while the vacuum pad 36 is in close contact with the bag film P, so that the relative distance to the punch part 20 increases. For example, with the lowering of the forming pad 31, the depth of the forming groove S, more precisely the depth of the first space S1 in which the forming of the bag film P takes place, can be changed.

[0081] In this way, the forming pad 31 can be lowered while the vacuum cup 36 is in close contact with the corner region of the bag film P. Among the central region and the peripheral region of the bag film P, the peripheral region, more specifically the corner region, can be greatly stretched.

[0082] More specifically, the first forming process may include a process of pressing the bag film P against the forming pad 31 disposed within the forming groove S and lowering the forming pad 31 to at least partially expand the bag film P. In addition, the first forming process may include a process of pressing the bag film P against the corner portion of the forming pad 31 by the vacuum pad 36 and a process of expanding the bag film P while the forming pad 31 moves (lowers) away from the die part 20.

[0083] More precisely, the first process can be a process (see Fig. 4), in which the peripheral area of the forming pad 31, more precisely the corner area of the bag film P corresponding to the corner area of the forming pad 31, is pressed against the corner area of the forming pad 31 by the vacuum pad 36. In addition, the second process may be a process (see Fig. 5), in which the forming pad 31 is lowered so that the corner region of the bag film P corresponding to the corner region of the forming pad 31 is extended.

[0084] Through this series of processes, the corner area under the peripheral areas of the bag film P can be intensively stretched.

[0085] Referring to Fig. 6, the punch part 20 can press the peripheral portion and the central portion of the bag film P together toward the upper surface of the forming pad 31 in the second forming process while moving toward the forming groove S. Since the corner portion of the bag film P is formed by the Fig. 4 and Fig. 5 and then stretched for the second time by the punch part 20, it is possible to significantly increase the elongation of the bag film P and at the same time prevent the occurrence of cracks or breaks in the corner portion of the bag film P.

[0086] Meanwhile, according to an embodiment, the vacuum pad 36 can be continuously brought into close contact with the bag film P even when the punch part 20 is inserted into the forming groove S to be close to the upper surface of the forming pad 31. For example, the vacuum pad 36 can be continuously brought into close contact with the corner portion of the bag film P by continuously pressing the vacuum pad 36 during the entire first forming process and the second forming process described above with reference to Fig. 4 to 6, vacuum pressure or negative pressure is continuously applied.

[0087] As set forth above, a bag forming apparatus according to one embodiment can significantly reduce the occurrence of cracks or breaks in a bag film.

[0088] A bag forming apparatus according to one embodiment can significantly increase the stretch size of a bag film.

[0089] A bag forming apparatus according to one embodiment can produce a bag wrapper with improved energy efficiency.

[0090] (Aspect 1) A bag forming apparatus comprising: a die portion having a forming groove; a punch portion disposed to face the forming groove and configured to move relative to the forming groove and press a bag film disposed on the die portion into the forming groove; a forming pad disposed to move relative to the punch portion within the forming groove and control the depth of the forming groove; and a vacuum pad that applies vacuum pressure to the forming groove to be in close contact with the bag film, wherein the vacuum pad is disposed in at least one corner portion of the forming pad.

[0091] (Aspect 2) The bag forming device according to aspect 1, wherein the forming pad has a plurality of edge portions and at least one corner portion provided between the plurality of edge portions and arranged in the corner area, and the vacuum pad is arranged adjacent to the at least one corner portion.

[0092] (Aspect 3) The bag forming device according to the preceding aspects, wherein the forming pad divides the forming groove into a first space in which the bag film is arranged and a second space in which the bag film is not arranged, and the vacuum pad applies vacuum pressure to the first space to be in close contact with a corner portion of the bag film corresponding to a corner portion of the vacuum pad.

[0093] (Aspect 4) The bag forming device according to the preceding aspects, wherein the vacuum pad and the forming pad each have an upper surface facing the stamping part and on which the bag film sits, and wherein the upper surface of the vacuum pad is arranged parallel to the upper surface of the forming pad or is arranged lower than the upper surface of the forming pad.

[0094] (Aspect 5) The bag forming device according to the preceding aspects, wherein the vacuum pad is inserted into the forming pad to be exposed to the forming groove through the upper surface of the forming pad.

[0095] (Aspect 6) The bag forming apparatus according to the preceding aspects, further comprising: a vacuum device disposed outside the forming groove and generating a vacuum pressure; and a vacuum line connecting the vacuum device and the vacuum pad and supplying the vacuum pressure to the vacuum pad, wherein the vacuum line penetrates at least one of a bottom forming surface and a side forming surface of the die part forming the forming groove and is connected to the vacuum device.

[0096] (Aspect 7) The bag forming device according to the preceding aspects, wherein the forming pad is provided to move so that a relative distance to the punch part changes while being raised and lowered in the forming groove, and the vacuum pad is provided to be in close contact with a corner portion of the bag film corresponding to the corner portion of the forming pad.

[0097] (Aspect 8) The bag forming device according to the preceding aspects, wherein the forming pad is provided to extend the corner portion of the bag film while moving in a direction in which the relative distance from the stamping part increases in a state where the corner portion of the bag film and the vacuum pad are in close contact.

[0098] (Aspect 9) The bag forming device according to the preceding aspects, wherein the punch part is provided to bring the bag film into close contact with the forming pad while moving in a direction in which a relative distance from the forming pad decreases in a state where the corner portion of the bag film is expanded, and the vacuum pad is provided to continuously generate a vacuum pressure to be in close contact with the corner portion of the bag film.

[0099] (Aspect 10) A bag forming apparatus comprising: a die portion having a forming groove and a bag film disposed thereon; a punch portion configured to move relative to the forming groove to be at least partially inserted into the forming groove; a forming pad configured to be raised and lowered within the forming groove and to divide the forming groove into a first space into which the bag film is inserted and formed and a second space into which the bag film is not inserted, and to provide a bottom surface of the first space;and a vacuum pad that applies vacuum pressure to the first space so that the bag film is introduced into the first space and adheres thereto, wherein the vacuum pad is arranged at a corner portion of the forming pad so that the bag film adheres to the corner portion of the forming pad, and the forming pad is provided to elongate the bag film while moving in a direction in which a depth of the first space increases in a state where the bag film adheres to the corner portion of the forming pad.

Claims

[1] A bag forming apparatus comprising: a die part with a forming groove; a stamping member arranged to face the forming groove and configured to move relative to the forming groove and to press a bag film arranged on the stamping member into the forming groove; a forming pad arranged to move relative to the punch member within the forming groove and to control the depth of the forming groove; and a vacuum pad that applies vacuum pressure to the forming groove to be in close contact with the bag film, wherein the vacuum pad is arranged in at least one corner region of the forming pad. [2] The bag forming apparatus according to any one of the preceding claims, wherein the forming pad has a plurality of edge portions and at least one corner portion provided between the plurality of edge portions and arranged in the corner region, and the vacuum pad is arranged adjacent to the at least one corner portion. [3] The bag forming apparatus according to any one of the preceding claims, wherein the forming pad divides the forming groove into a first space in which the bag film is arranged and a second space in which the bag film is not arranged, and the vacuum pad applies a vacuum pressure to the first space to be in close contact with a corner portion of the bag film corresponding to a corner portion of the vacuum pad. [4] The bag forming apparatus according to any one of the preceding claims, wherein the vacuum pad and the forming pad each have an upper surface facing the stamping part and on which the bag film rests, and the upper surface of the vacuum pad is arranged parallel to the upper surface of the forming pad or is arranged lower than the upper surface of the forming pad. [5] The bag forming apparatus according to any one of the preceding claims, wherein the vacuum pad is inserted into the forming pad to be exposed to the forming groove through the upper surface of the forming pad. [6] The bag forming apparatus according to any one of the preceding claims, further comprising: a vacuum device arranged outside the forming groove and generating a vacuum pressure; and a vacuum line that connects the vacuum device to the vacuum pad and directs the vacuum pressure to the vacuum pad, wherein the vacuum line penetrates at least one of a lower forming surface or a lateral forming surface of the die part forming the forming groove and is connected to the vacuum device [7] The bag forming apparatus according to any one of the preceding claims, wherein the forming pad is provided to move so that a relative distance to the punch part changes while being raised and lowered in the forming groove, and the vacuum pad is provided to be in close contact with a corner portion of the bag film corresponding to the corner portion of the forming pad. [8] The bag forming apparatus according to any one of the preceding claims, wherein the forming pad is provided to extend the corner portion of the bag film while moving in a direction in which the relative distance from the punch part increases in a state in which the corner portion of the bag film and the vacuum pad are in close contact. [9] The bag forming apparatus according to any one of the preceding claims, wherein the punch part is provided to bring the bag film into close contact with the forming pad while moving in a direction in which a relative distance from the forming pad decreases in a state in which the corner portion of the bag film is expanded, and the vacuum pad is provided to continuously generate vacuum pressure so as to be in close contact with the corner portion of the bag film. [10] A bag forming apparatus comprising: a die part with a forming groove and a bag film arranged thereon; a punch part provided to move relative to the forming groove to be at least partially inserted into the forming groove; a forming pad provided so as to be raised and lowered within the forming groove and dividing the forming groove into a first space into which the bag film is inserted and formed and a second space into which the bag film is not inserted, and forming a lower surface of the first space; and a vacuum pad that exerts a vacuum pressure on the first space so that the bag film is inserted into the first space and adheres there, wherein the vacuum pad is arranged at a corner region of the forming pad so that the bag film adheres to the corner region of the forming pad, and the forming pad is provided to extend the bag film while moving in a direction in which a depth of the first space increases in a state where the bag film adheres to the corner portion of the forming pad.

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