KR102575052B1 - Manufacturing method of battery pack housing for electric vehicles for injection molding - Google Patents

Abstract

The present invention is a method for manufacturing a battery pack housing for an electric vehicle using an injection mold, comprising: manufacturing a rigid reinforcing material insert to have a long bar shape of a bundled fiber material; A rigid reinforcing material insert water cutting step of cutting the rigid reinforcing material insert into a predetermined length in the form of a long bar manufactured through the rigid reinforcing material insert water manufacturing step; In order to make a box-shaped rectangular parallelepiped with the plurality of stiffener inserts cut through the stiffener insert water cutting step, the front end of the stiffener insert and the other adjacent stiffener insert are inserted into each corner or middle part, respectively, while the rigid stiffener insert is inserted. An insert water connection fixture manufacturing step of manufacturing an insert water connection fixture for continuously maintaining a fixed coupling state of the insert water; A rigid reinforcement cuboid frame manufacturing step of manufacturing a box-shaped rigid reinforcement cuboid frame with a plurality of insert water connection fixtures manufactured through the insert water connection fixture manufacturing step and a plurality of rigid reinforcement inserts cut to the predetermined length; Place the rigid reinforcement cuboid frame fabricated through the step of manufacturing the rigid reinforcement cuboid frame at the molding center between the upper mold and the lower mold of the injection mold, and form bosses or core protrusions at the parts of the plurality of insert water connection fixtures to form the rigid reinforcement cuboid frame in the mold. A step of fixing the central portion of the rigid reinforcement cuboid frame forming to fix the mounting position of the; And through the step of fixing the molding center of the rigid reinforcement cuboid frame, the rigid reinforcement cuboid frame can be fixed to the molding center between the upper mold and the lower mold when the injection mold is opened, and the rigid reinforcement cuboid frame can be retracted to the product exterior when the mold is closed. It relates to a method for manufacturing an electric vehicle battery pack housing for injection molding comprising a reverse slide injection molding step of performing injection molding in a reverse slide method that minimizes exposure.
The present invention has excellent light weight and excellent mechanical properties such as flexural stiffness and energy absorption, and is an insert injection molding method using a rigid reinforcing material insert structure, which is a fiber-reinforced composite material in the form of a long bar, in advance. By combining the structure with the injection mold and locating it in the center of the molding thickness, self-stiffness can be increased, and the mechanical strength performance can be maximized while the rigidity reliability of the molded product is maintained, and the unified rigid reinforcing insert structure can be inserted more quickly. This has the effect of further increasing productivity.

Description

Manufacturing method of battery pack housing for electric vehicles for injection molding {Manufacturing method of battery pack housing for electric vehicles for injection molding}

The present invention relates to a method for manufacturing an electric vehicle battery pack housing for injection molding, and more particularly, has excellent light weight, excellent mechanical properties such as bending stiffness and energy absorption, and stiffness, which is a fiber-reinforced composite material in the form of a long bar. It relates to a method for manufacturing an electric vehicle battery pack housing for injection molding using a reinforcing insert structure and an insert water connector for fixing the same.

In general, due to the strengthening of international environmental regulations on automobile exhaust gas, the possibility of oil depletion, and the continuing high oil price, the global automobile market is turning its eyes from internal combustion engine vehicles to electric vehicles. In particular, electric vehicles (EVs) are emerging as an effective means of reducing global greenhouse gas emissions and a viable alternative for a sustainable environment. Meanwhile, sales of electric vehicles (EVs) and hybrid vehicles (HEVs) are significantly increasing as consumers' preference for low-cost vehicles increases due to the burden of rising fuel costs. Accordingly, developed countries are strongly promoting electric vehicle distribution policies.

Therefore, the capacity and efficiency of the battery, which is a key part for operating an electric vehicle, has become the most important factor for an electric vehicle, and the driving distance according to its performance has become a major issue. As a result, automobile manufacturers and consumers are interested in batteries this is rising

Lead-acid batteries have been mainly used for electric vehicles in the past, but since lead-acid batteries are used as a power source for vehicles, lead-acid batteries have a low charge capacity compared to weight and volume, and lithium Series batteries are mainly used.

A battery is basically a device made to make chemical energy compatible with electrical energy, and the use of a secondary battery that can be charged and discharged together has become a basic premise due to the characteristics of a vehicle.

A lithium ion battery used in an electric vehicle is a battery having a sufficient capacity by combining a plurality of battery cell units to form a module in which a plurality of battery cell units are closely coupled to each other to secure stable capacity. form a battery pack. In an electric vehicle battery including such a module type, a case or a housing is used to stably accommodate and mechanically protect the total weight due to an increase in overall weight, and a considerably high level of rigidity of the housing is required.

In addition, since the electric vehicle battery is exposed to vibrations and shocks according to the vehicle driving environment such as road surface conditions, a rigid design for the housing is required to cope with these vibrations and shocks, and sufficient rigidity against vibrations and shocks is not secured. If not, deformation problems such as bending of the housing itself may occur, and due to such deformation, poor fixation of parts inside the housing, damage, and battery function problems may occur.

In addition, in the worst case, the battery housing may be damaged due to an impact or accident while driving, which may cause problems such as damage to the battery cell itself or other internal parts, and short circuit of the power connection. In this case, the battery accumulates a lot of energy in a small space and Since it is an electrical and chemical object that is present, a problem in which the vehicle itself and its occupants are exposed to danger may occur due to fire or explosion caused by a sudden burst of energy.

In order to solve the problems related to the existing electric vehicle battery housing, various technologies for housing material selection, housing structure, and manufacturing method have been proposed.

Existing battery packs for electric vehicles include a lithium-ion battery module that supplies power to the vehicle, a heating and cooling device for temperature management of the battery module, wiring for transmitting electricity from the battery, and various electrical devices and BMS necessary for battery control. An outer case made in the form of a container to contain, a bracket to fix the battery module, a bracket to fix the air conditioner, a bracket to fix the wiring, a bracket to fix the electric device required for battery control, a bracket to fix the BMS, an outer case at least A cover made to cover a part from the outside, a cover covering an electric device, a cover covering a low current fuse, and the like are provided.

In addition, a conduction device for grounding is applied to the housing that includes a case and a cover to form an exterior. In addition, the bracket that secures the battery module has a considerable weight compared to other parts due to the nature of the module in which a number of lithium-ion cells are combined, so a bracket that reinforces mechanical strength due to shock and vibration is added to this part.

Sheet metal parts use thin steel sheets due to the nature of their manufacturing method, and it is difficult to guarantee their mechanical strength, so the required strength is satisfied by bending or additionally welding the area requiring reinforcement. In addition, as for the assembly method, a screw and nut fastening type is mainly used, and parts selection for strengthening fastening force is applied.

Looking more closely at the battery case or housing, in general, a battery pack for an electric vehicle includes a battery housing and battery cells accommodated in the battery housing. A battery housing for an electric vehicle includes a mount device for mounting and exchanging batteries, and serves to protect battery cells stored therein from the outside. In addition, sealing between the case and cover constituting the housing is important for waterproof protection according to the external environment.

In order to solve these problems in the conventional electric vehicle battery housing, the rigidity of the housing is guaranteed by press molding using a metal material of sufficient thickness or by a method such as die casting, and internal members are added to improve mechanical strength. method was used

The method of using a steel material in the prior art has an advantage in terms of assemblability because the material itself has excellent mechanical strength and does not pose a big problem in the application of the welding method. However, since the material belongs to heavy metal, it is difficult to satisfy the requirements for light weight as a vehicle battery housing.

Another method is to use an aluminum material. In this method, the battery housing is usually made in the form of sheet metal processing, and at this time, welding of some sections is unavoidably required, which increases the cost of the welding process. In order to solve this problem, a method using a press mold or a die casting mold is also a technology suitable for mass production, but this also has problems in that the initial investment cost is generated and the flexibility of the design is limited. In addition, aluminum material itself is easy to lighten compared to steel material, but mechanical strength is lowered, so it is necessary to make and use an alloy, and the mechanical thickness dimension also needs to be increased.

As another method, high-strength plastic materials are being developed to satisfy both light weight and mechanical strength. To replace metal battery housings with plastics, existing product structures and methods using engineering plastics have limitations in stiffness, However, in order to compensate for this, a method of injecting and injecting a rigid reinforcing material has been reviewed.

In the case of the existing rigid reinforcement bar insert input calculation, it was possible to apply rigid reinforcement only to some shapes of the product due to structural characteristics, and when arranging a large number of rigid reinforcement materials, the cycle time was reduced due to the increase in insert input time. There is a problem in that productivity is lowered due to excessive enhancement.

In addition, there is a problem in that it is practically difficult to implement a mold structure for locating a rigid reinforcing material in the center of an injection molding machine in the process of actual product production after insert injection is completed.

(KR) Republic of Korea Patent Registration No. 10-2281771 (2021.07.26., notice)

The present invention is to solve the above problems, and an object of the present invention is to provide a method for manufacturing an electric vehicle battery pack housing for injection molding that has excellent mechanical properties such as bending stiffness and energy absorption while being excellent in light weight.

In addition, it is an insert injection molding method using a rigid reinforcing material insert structure, which is a fiber-reinforced composite material in the form of a long bar. It combines the rigid reinforcing material insert structure with the mold in advance and places it in the center of the molding thickness to increase its own rigidity. Its purpose is to provide a method for manufacturing an electric vehicle battery pack housing for injection molding that can maximize the performance of mechanical strength while maintaining the rigidity and reliability of molded parts, and can increase productivity by inserting a unified rigid reinforcing material insert structure more quickly. there is

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention, in the method for manufacturing a battery pack housing for an electric vehicle using an injection mold 40,

A rigid reinforcing material insert product manufacturing step of manufacturing the rigid reinforcing material insert 10 to have a long bar shape of a bundled fiber material (S100);

A rigid reinforcing material insert water cutting step (S110) of cutting the rigid reinforcing material insert (10) in the form of a long bar manufactured through the rigid reinforcing material insert manufacturing step (S100) to a predetermined length;

Through the stiffener insert water cutting step (S110), in order to make a box-shaped rectangular parallelepiped with the plurality of rigid reinforcing material inserts 10 cut, another stiffener insert 10 is adjacent to the front end of each corner or middle portion. An insert water connection fixture manufacturing step of manufacturing an insert water connection fixture 20 for continuously maintaining the fixed coupling state of the rigid reinforcement insert water 10 while the front ends of the water reinforcement insert water 10 are inserted (S120);

Through the insert water connection fixture manufacturing step (S120), the plurality of insert water connection fixtures 20 manufactured and the plurality of rigid reinforcing material inserts 10 cut to the predetermined length are box-shaped rigid reinforcement rectangular parallelepiped frames 30 ) Rigid reinforcing material rectangular parallelepiped frame manufacturing step (S130);

Through the rigid reinforcement cuboid frame manufacturing step (S130), the rigid reinforcement cuboid frame 30 manufactured is placed in the molding center 43 between the upper mold 41 and the lower mold 42 of the injection mold 40, Forming at least one of the boss 44 or the core part protrusion 45 at the part of the insert water connection fixture 20 to firmly fix the mounting position of the rigid reinforcing material rectangular parallelepiped frame 30 in the mold. (S140); and

Through the rigid reinforcement cuboid frame molding center fixing step (S140), the rigid reinforcement cuboid frame 30 is placed in the molding center 43 between the upper mold 41 and the lower mold 42 at the time of mold opening of the injection mold 40. It is characterized by a reverse slide injection molding step (S150) in which injection molding is performed in a reverse slide method that can be fixedly mounted and is retracted backward when the mold is closed to minimize exposure of the rigid reinforcement rectangular parallelepiped frame 30 to the exterior of the product 50. there is.

The insert water connector 20 used in the rigid reinforcement cuboid frame 30 includes a 3-way A-type 21 in which the ends of the rigid reinforcement insert water 10 meet and bind each other in three directions, and 3 In the direction, the ends of the stiffener inserts 10 meet each other, but two directions are the same and one direction is vertically bound, but three-way B-type 22 and four-way B-type 22 are bound in a substantially "T" shape. In the 4-way A-type 23 in which the ends of the stiffener insert 10 meet each other, but two directions are the same direction and the other two directions are bound in different directions, and the rigid stiffener insert water in 4 directions (10) Any one or more of the 4-way B-type 21, in which the ends meet each other, where 2 directions are the same direction and the other 2 directions meet each other perpendicularly and are bound in an approximate "+" shape, is used There are features that are made.

The insert water connector 20 is characterized in that the material is made of any one or more of synthetic resin, aluminum, and aluminum alloy.

As such, the present invention is excellent in light weight and excellent in mechanical properties such as bending stiffness and energy absorption, and is an insert injection molding method using a rigid reinforcing material insert structure, which is a fiber-reinforced composite material in the form of a long bar, in advance. By combining the reinforcing insert structure with the injection mold and locating it in the center of the molding thickness, its own rigidity can be increased, and the mechanical strength performance can be maximized while the rigidity reliability of the molded product is maintained. There is an effect that can be inserted quickly to further increase productivity.

The present invention is not limited to the specific preferred embodiments described above, and various modifications can be made by anyone skilled in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes are within the scope of the claims.

1 is a flowchart of a method for manufacturing an electric vehicle battery pack housing for injection molding according to an embodiment of the present invention;
2 is an enlarged perspective view showing the appearance of a rigid reinforcing material insert produced through a rigid reinforcing material insert manufacturing step and a cutting step of the electric vehicle battery pack housing manufacturing method for injection molding according to an embodiment of the present invention,
Figure 3 is an enlarged perspective view showing the appearance of the insert water connection fixture manufactured through the insert water connection fixture manufacturing step of the electric vehicle battery pack housing manufacturing method for injection molding, which is an embodiment of the present invention;
4 is a perspective view showing an embodiment of a rigid reinforcing material rectangular parallelepiped frame manufactured through the rigid reinforcing material rectangular parallelepiped frame manufacturing step of the electric vehicle battery pack housing manufacturing method for injection molding, which is an embodiment of the present invention;
Figure 5 is an enlarged perspective view of the main part of Figure 4;
6 is a perspective view showing another embodiment of a rigid reinforcing material rectangular parallelepiped frame manufactured through the rigid reinforcing material rectangular parallelepiped frame manufacturing step of the electric vehicle battery pack housing manufacturing method for injection molding, which is an embodiment of the present invention;
7 is a cross-sectional view of a state in which a ball-in main part is enlarged and used in a step of fixing a center part of a rigid reinforcement rectangular parallelepiped frame in a method of manufacturing an electric vehicle battery pack housing for injection molding, which is an embodiment of the present invention;
8 is an enlarged cross-sectional view showing a main part sequentially operating the reverse slade injection molding step of the electric vehicle battery pack housing manufacturing method for injection molding, which is an embodiment of the present invention;
9 is a perspective view showing a product manufactured through a reverse slade injection molding step of a method for manufacturing an electric vehicle battery pack housing for injection molding, which is an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Hereinafter, with reference to the accompanying drawings, an embodiment of the present invention will be described in detail so that those skilled in the art can easily practice it. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification. The scope of the present invention should not be construed as being limited by the embodiments described in the text, and the embodiments can be changed in various ways and can have various forms, so the scope of the present invention is limited to those that can realize the technical idea. It should be understood to include equivalents.

Throughout the specification of the present invention, when a part is said to be "connected" to another part, this includes not only the case of being "directly connected" but also the case of being "indirectly connected" through another member. In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

The terms used in the present invention are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator, so the definitions of these terms are meanings consistent with the technical details of the present invention. and should be interpreted as a concept.

In addition, optional terms in the following embodiments are used to distinguish one component from other components, and the components are not limited by the terms. Hereinafter, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the subject matter of the present invention will be omitted.

The method for manufacturing an electric vehicle battery pack housing for injection molding of the present invention includes a rigid reinforcing material insert manufacturing step (S100), a rigid reinforcing material insert water cutting step (S110), an insert water connection fixture manufacturing step (S120), a rigid reinforcing material It consists of a rectangular parallelepiped frame manufacturing step (S130), a rigid reinforcement rectangular parallelepiped frame molding center fixing step (S140), and a reverse slide injection molding step (S150).

The rigidity reinforcing material insert manufacturing step (S100) is a step of manufacturing the rigidity reinforcing material insert 10 to have a long bar shape of a bundled fiber material.

The rigidity reinforcing material insert cutting step (S110) is, as shown in FIG. 2, the step of cutting the long bar-shaped rigidity reinforcing material insert water 10 manufactured through the rigidity reinforcing material insert manufacturing step (S100) to a certain length. am.

In the insert water connection fixture manufacturing step (S120), a box-shaped rectangular parallelepiped is made in the same shape as shown in FIG. Insert water for continuously maintaining the fixed coupling state of the stiffener insert (10) while the front end of the other stiffener insert (10) adjacent to the front end of the stiffener insert (10) is inserted into each corner or middle part This is a step of manufacturing the connection fixture 20.

The rigid reinforcement rectangular parallelepiped frame manufacturing step (S130), as shown in FIGS. 4 to 6, through the insert water connection fixture manufacturing step (S120), the plurality of insert water connection fixtures 20 manufactured and cut to the predetermined length This is a step of manufacturing a box-shaped rigid reinforcement rectangular parallelepiped frame 30 with a plurality of rigid reinforcement inserts 10.

As the insert water connector 20 used in the rigid reinforcement cuboid frame 30, as shown in Figs. Type A 21 and the ends of the stiffener insert 10 meet each other in three directions, but two directions are the same direction and one direction is vertically bound, but three-way B that is bound in an approximate “T” shape A type 22 and a 4-way A-type 23 in which the ends of the stiffener insert 10 meet each other in 4 directions, 2 directions are the same and the other 2 directions are bound in different directions, respectively; Of the four-way B-type 21 in which the ends of the stiffener inserts 10 meet each other in four directions, but two directions are the same direction and the other two directions meet each other perpendicularly and are bound in an approximate "+" shape. Any one or more than one is used.

It can be seen that the insert water connector 20 is preferably made of one or more of synthetic resin, aluminum, and aluminum alloy, or, if necessary, for rigidity.

The rigid reinforcement cuboid frame molding center fixing step (S140), as shown in FIG. 41) and the lower mold 42, but located in the center of the molding 43, by forming at least one of the boss 44 or the core part protrusion 45 at the portion of the plurality of insert water connection fixtures 20, the rigid reinforcing material cuboid in the mold This step is to firmly fix the mounting position of the frame 30.

In the reverse slide injection molding step (S150), as shown in FIG. 8, through the fixing step (S140) of the rigid reinforcing material rectangular parallelepiped frame molding center, the rigid reinforcing material rectangular parallelepiped frame 30 is upper molded at the time of mold opening of the injection mold 40. It can be fixedly installed in the molding center 43 between the mold 41 and the lower mold 42, and is injected in a reverse slide method that minimizes the exposure of the rectangular parallelepiped frame 30 of the rigid reinforcing material to the exterior of the product 50 by retracting backward when the mold is closed. This is a step of obtaining a product 50 by performing molding, as shown in FIG. 9 .

As described above, the present invention is excellent in light weight and excellent in mechanical properties such as bending stiffness and energy absorption, and is an insert injection molding method using a rigid reinforcing material insert 10, which is a fiber-reinforced composite material in the form of a long bar, In advance, the rigid reinforcing material insert (10) is coupled to the injection mold (40), but fixed to the molding center (43) between the td type (41) and the lower mold (42) through the boss (44) or part of the core protrusion (45) The injection operation proceeds in the state in which the rigidity of the molded product 50 is not only increased, but also the mechanical strength performance can be maximized while the rigidity reliability of the molded product 50 is maintained. Productivity can be further increased by inserting and fixing the sensitive part steel rectangular parallelepiped frame 30 made of the insert water connector 20 more quickly into the injection mold 40.

The present embodiment and the drawings accompanying this specification clearly represent only a part of the technical idea included in the present invention, and can be easily inferred by those skilled in the art within the scope of the technical idea included in the specification and drawings of the present invention. It is obvious that all possible modifications and specific embodiments are included in the scope of the technical idea of the present invention.

The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention.

10: rigid reinforcement insert water
20: insert water connector
21 : 3 way A type
22: 3 way B type
23 : 4 way A type
24 : 4 way B type
30: Rigid steel rectangular parallelepiped frame
40: injection mold
41: hieroglyph
42: lower hyung
43; molding center
44 : Boss
45: core part protrusion
50: product
100: Rigid reinforcing material insert water manufacturing step
110: rigid reinforcement insert water cutting step
120: manufacturing step of insert water connection fixture
130: rigid reinforcement rectangular parallelepiped frame production step
140: Rigid reinforcement rectangular parallelepiped frame molding center fixing step
150: reverse slade injection molding step

Claims (3)

In the method for manufacturing a battery pack housing for an electric vehicle using an injection mold 40,
A rigid reinforcing material insert product manufacturing step of manufacturing the rigid reinforcing material insert 10 to have a long bar shape of a bundled fiber material (S100);
A rigid reinforcing material insert water cutting step (S110) of cutting the rigid reinforcing material insert (10) in the form of a long bar manufactured through the rigid reinforcing material insert manufacturing step (S100) to a predetermined length;
Through the stiffener insert water cutting step (S110), in order to make a box-shaped rectangular parallelepiped with the plurality of rigid reinforcing material inserts 10 cut, another stiffener insert 10 is adjacent to the front end of each corner or middle portion. An insert water connection fixture manufacturing step of manufacturing an insert water connection fixture 20 for continuously maintaining the fixed coupling state of the rigid reinforcement insert water 10 while the front ends of the water reinforcement insert water 10 are inserted (S120);
Through the insert water connection fixture manufacturing step (S120), the plurality of insert water connection fixtures 20 manufactured and the plurality of rigid reinforcing material inserts 10 cut to the predetermined length are box-shaped rigid reinforcement rectangular parallelepiped frames 30 ) Rigid reinforcing material rectangular parallelepiped frame manufacturing step (S130);
Through the rigid reinforcement cuboid frame manufacturing step (S130), the rigid reinforcement cuboid frame 30 manufactured is placed in the molding center 43 between the upper mold 41 and the lower mold 42 of the injection mold 40, Forming at least one of the boss 44 or the core part protrusion 45 at the part of the insert water connection fixture 20 to firmly fix the mounting position of the rigid reinforcing material rectangular parallelepiped frame 30 in the mold. (S140); and
Through the rigid reinforcement cuboid frame molding center fixing step (S140), the rigid reinforcement cuboid frame 30 is placed in the molding center 43 between the upper mold 41 and the lower mold 42 at the time of mold opening of the injection mold 40. A reverse slide injection molding step (S150) in which injection molding is performed in a reverse slide method that can be fixed and mounted, and is retreated backward when the mold is closed to minimize exposure of the rigid reinforcement rectangular parallelepiped frame 30 to the exterior of the product 50. A method for manufacturing an electric vehicle battery pack housing for injection molding. According to claim 1,
The insert water connector 20 used in the rigid reinforcement cuboid frame 30 includes a 3-way A-type 21 in which the ends of the rigid reinforcement insert water 10 meet and bind each other in three directions, and 3 In the direction, the ends of the rigid reinforcing material inserts 10 meet each other, but 2 directions are the same direction and 1 direction is vertically bound but 3 way B type 22 bound in a “T” shape, and in 4 directions A 4-way A-type 23 in which the ends of the rigid reinforcing material inserts 10 meet each other, but two directions are the same direction and the other two directions are bound in different directions, and the rigid reinforcing material insert water in 4 directions ( 10) One or more of the four-way B-type 21 in which the ends meet each other, but the two directions are the same direction and the other two directions meet each other perpendicularly and are bound in a "+" shape. Method for manufacturing electric vehicle battery pack housing for injection molding. According to claim 2,
The insert water connector 20 is a method for manufacturing an electric vehicle battery pack housing for injection molding, characterized in that the material is made of any one or more than one of synthetic resin, aluminum, and aluminum alloy.