Title of invention: A battery pack incorporating a battery module and a rigid beam and adopting a reverse assembly method
technical field
[One]
The present invention relates to a battery pack, and more particularly, to a battery pack structure capable of increasing mechanical rigidity and space utilization.
[2]
This application is a priority claim application for Korean Patent Application No. 10-2019-0096282 filed on August 07, 2019, and all contents disclosed in the specification and drawings of the application are incorporated herein by reference.
background
[3]
A secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged. It is used as a power source for hybrid vehicles (HEVs).
[4]
The types of secondary batteries currently widely used include a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, and the like. The operating voltage of the unit secondary battery cell, that is, the unit battery cell, is about 2.5V to 4.2V. Therefore, when higher output voltage and energy capacity are required, a battery module is configured by connecting a plurality of battery cells in series, or two or more battery modules are connected in series or parallel and other components are added to form a battery pack. make up For example, a battery module may refer to a device in which a plurality of secondary cells are connected in series or parallel, and a battery pack may refer to a component in which battery modules are connected in series or in parallel to increase capacity and output.
[5]
The battery pack may further include a cooling device for properly maintaining the temperature of the battery modules including the battery modules, a control device for monitoring the operating state of the battery modules, and a pack case for packaging them. .
[6]
On the other hand, in the case of a battery pack for an electric vehicle, the installation space of the battery pack is limited according to the overall length and width of the electric vehicle. It is important to have enough
[7]
However, in the conventional assembly structure of the battery pack, as shown in FIG. 1 , the battery modules 2 are arranged between the cross beams 3 on the top surface of the pack tray 1 corresponding to the bottom surface of the pack case, and the pack tray The assembly structure fixed by bolting to (1) is common. Here, the cross beam 3 refers to a structure that is welded or integrally formed on the pack tray 1 in order to increase the rigidity of the pack case. The cross beam 3 can act to prevent deformation such as distortion of the pack case during external impact, and thus has been widely used in pack cases in recent years.
[8]
In general, each battery module (2) can be fixed to the pack tray (1) by a total of four long bolts at the front and rear corners, and a heat sink for cooling at the lower portion of each battery module (2) (4) is further arranged. In addition, although not shown, inter-bus bars for electrical connection between the battery modules 2 are attached to each battery module using bolts.
[9]
However, recently, several problems have been pointed out with respect to the assembly structure of the conventional battery pack. Among them, ① the energy density of the battery pack decreases due to the occurrence of an unnecessary gap between the battery module and the cross beam and space occupation of the cross beams. ② Decrease in space utilization rate under the pack case due to the fastening structure between the pack tray and a number of bolts used for fixing the battery module. This complexity) and the complexity of the assembly process are pointed out a lot.
[10]
Therefore, the development of a battery pack to which an assembly structure capable of solving the above problems is applied has become an issue.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[11]
The present invention was devised to solve the above problems, and is to provide a battery pack capable of improving energy density, mechanical rigidity, and mounting space efficiency of a battery module and other components.
[12]
Other objects and advantages of the present invention may be understood by the following description, and will become more clearly understood by the examples of the present invention. Further, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the claims.
means of solving the problem
[13]
According to an aspect of the present invention, there is provided a battery pack comprising a plurality of battery modules and a pack case in which the battery modules can be fixedly installed therein,
[14]
The pack case includes a pack tray positioned under the battery modules, and a pack cover that is coupled to the pack tray to cover the battery modules, each of the battery modules includes battery cells arranged in one direction; A battery pack having a module case for accommodating battery cells in an internal space, and a rigid beam disposed between the battery cells inside the module case, and fixedly coupled to the pack cover may be provided.
[15]
The rigid beam of each battery module and the pack cover may be integrally connected by a first fastening member vertically fastened from the outside of the pack cover.
[16]
The rigid beam is positioned in the middle in the arrangement order of the battery cells, and both sides thereof may be provided to face one surface of the neighboring battery cells to prevent volume expansion of the battery cells.
[17]
and a base plate positioned below the battery cells to support the battery cells, wherein the base plate has a hollow structure and a flow path through which a refrigerant may flow may be provided therein.
[18]
The pack cover has a cooling pipe embedded therein along an edge region, the base plate has a cooling water port that communicates with the flow path and extends in a vertical direction, and the cooling water port is directly connected to the cooling pipe in a vertical direction. can be
[19]
The pack cover may include a concave and convex portion forcibly fitted to an edge of the pack tray and a cooling pipe mounting portion extending from the concave and convex portion in an inner direction of the pack cover and into which the cooling pipe is inserted.
[20]
Each of the battery modules has electrode terminals protruding horizontally from one side of the module case, and the pack cover has at least one terminal connection part on an inner top surface of the pack, and an electrode terminal of any one of the battery modules. The electrode terminal of the other battery module may be electrically connected by the terminal connection part.
[21]
The terminal connecting portion includes an insulating bracket fixedly coupled to the inner surface of the pack cover; and an inter-bus bar mounted on the bracket and conducting electricity with the electrode terminal.
[22]
The electrode terminal and the terminal connection part may be integrally connected by a second fastening member vertically inserted into the electrode terminal and the terminal connection part.
[23]
The module case further includes a terminal support for supporting a lower portion of the electrode terminal, and each of the battery modules includes the terminal support, the electrode terminal, and the terminal connection portion integrally connected by a second fastening member to the pack cover can be fixed to
[24]
The plurality of battery modules may be arranged in two rows, and electrode terminals may be arranged to face each other with respect to the center of the pack case.
[25]
According to another aspect of the present invention, a vehicle including the above-described battery pack may be provided. The vehicle may include an electric vehicle (EV) or a hybrid vehicle (HEV).
Effects of the Invention
[26]
According to one aspect of the present invention, a battery pack capable of improving energy density, mechanical rigidity, and mounting space efficiency of a battery module and other components may be provided.
[27]
According to another aspect of the present invention, it is possible to simultaneously electrically connect and mechanically fix the battery modules by using the top cover.
[28]
According to another aspect of the present invention, by utilizing the base plate of the top cover and the module case as the cooling water circulation space, it is possible to simplify the configuration of the cooling device and improve the installation space efficiency.
[29]
Other effects of the present invention can be understood by the following description, and will be more clearly understood by the examples of the present invention.
Brief description of the drawing
[30]
1 is a view schematically showing an assembly example of a battery pack according to the prior art.
[31]
2 is a schematic perspective view of a battery pack according to an embodiment of the present invention.
[32]
3 is a partially exploded perspective view of the battery pack of FIG. 2 ;
[33]
4 is a schematic perspective view of a battery module according to an embodiment of the present invention.
[34]
FIG. 5 is a cross-sectional view taken along II′ of FIG. 2 .
[35]
6 is a cross-sectional view taken along line II-II' of FIG. 2 .
[36]
7 is a cross-sectional view taken along line III-III' of FIG. 2 .
[37]
FIG. 8 is an enlarged view of area A of FIG. 7 .
[38]
9 is a reference diagram for explaining an assembly sequence of a battery pack according to an embodiment of the present invention.
Modes for carrying out the invention
[39]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention. Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only some of the most preferred embodiments of the present invention and do not represent all the technical spirit of the present invention. It should be understood that there may be equivalents and variations.
[40]
2 is a schematic perspective view of a battery pack according to an embodiment of the present invention, FIG. 3 is a partially exploded perspective view of the battery pack of FIG. 2 , and FIG. 4 is a schematic perspective view of a battery module according to an embodiment of the present invention.
[41]
Referring to these drawings, the battery pack 10 according to an embodiment of the present invention includes a plurality of battery modules 100 and a pack case 200 accommodating the battery modules 100 . The pack case 200 includes a pack tray 210 that provides a place in which a plurality of battery modules 100 can be mounted, and a pack that is coupled to the pack tray 210 to cover the entire battery module 100 . and a cover 220 .
[42]
As will be described later in detail, the battery pack 10 according to the present invention integrates a beam frame (see FIG. 1 ) on the existing pack tray 210 into the battery module 100 , and mechanically fixes each battery module 100 . By integrating the electrical connection with the pack cover 220, there are advantages such as an increase in the space utilization rate of the pack tray 210, a simplification of the assembly process, and a reduction in the number of fastening parts.
[43]
First looking at the battery module 100 constituting the battery pack 10, the battery module 100 includes battery cells 110, a module case 120 for accommodating the battery cells 110 in an internal space, and a module. It includes electrode terminals 150a and 150b exposed to the outside of the case 120 .
[44]
In this embodiment, the battery cells 110 may be pouch-type secondary battery cells. The pouch-type battery cells 110 may be arranged in one direction with their wide surfaces facing each other in the inner space of the module case 120 . Although not shown for convenience of the drawing, each battery module 100 has a constant capacity and an output voltage by connecting the battery cells 110 in series and/or in parallel. For reference, it is also possible to replace the battery cell 110 with a cylindrical secondary battery cell or a prismatic secondary battery cell.
[45]
As shown in FIG. 4 , the module case 120 includes a base plate 121 and a top plate 122 that cover the lower and upper portions of the battery cells 110 , respectively, and the top plate according to the arrangement direction of the battery cells 110 . It may be configured to include a pair of side plates 123 disposed outside and a front cover 124 and a rear cover 125 respectively covering the front and rear of the battery cells 110 .
[46]
In particular, the base plate 121 forming the bottom surface of the module case 120 also functions as a conventional heat sink. For example, a flow path through which cooling water can flow is provided inside the base plate 121 so that the base plate 121 can directly cool the battery cells 110, and a cooling water port ( 121a) is provided at the edge of the base plate.
[47]
The cooling water port 121a may extend in a vertical direction from one edge of the base plate 121 to be directly connected to a cooling pipe 224 of the pack cover 220 to be described later. With this cooling water supply and discharge structure, cooling water may be supplied to the base plate 121 of each battery module 100 .
[48]
Most of the battery pack 10 according to the prior art has a cooling configuration in which a heat conduction pad and a heat sink are sequentially disposed under the battery module 100 , but in the present invention, the heat sink is a base plate forming the module case 120 . By integrating with (121), the effect of reducing the heat transfer path, reducing the number of parts, and saving the space for installing the cooling device was achieved compared to the prior art.
[49]
The front cover 124 and the rear cover 125 are positioned in front of the battery cells 110 to prevent components such as electrode leads of the battery cells 110 or an inter connection board (ICB) from being exposed to the outside.
[50]
The electrode terminals 150a and 150b include a positive terminal 150a and a negative terminal 150b, are located outside the top of the front cover 124, and have a wide surface in the form of a square plate so that the bolts can be inserted in the vertical direction. will be prepared
[51]
The electrode terminals 150a and 150b may be supported by being placed on the terminal support 126 . Here, the terminal support 126 is a portion protruding from the front cover 124 and is used as a lower support for the electrode terminals 150a and 150b and a bolt fastening place for the battery module.
[52]
The terminal support part 126 may be provided to extend along the width direction of the front cover 124, and a hole into which a bolt can be inserted is provided in a place where the positive terminal 150a and the negative terminal 150b are placed. can
[53]
Although not shown, the shoulder bolts may be fastened to the pack cover 220 by providing holes for inserting the shoulder bolts in other places where the electrode terminals 150a and 150b are not located.
[54]
The pair of side plates 123 may serve to press and support the battery cells 110 from the outside of the outermost battery cells 110 in the arrangement direction of the battery cells 110 .
[55]
On the other hand, as shown in FIG. 5 , the battery module 100 of the present invention further includes a rigid beam 130 inside the module case 120 . The rigid beam 130 is provided to have a predetermined thickness and an area corresponding to the wide surface of the battery cell 110 , and may preferably be located in the middle in the arrangement order of the battery cells 110 .
[56]
In the module case 120 , the battery cells 110 are arranged in close contact with each other on both sides with respect to the rigid beam 130 . A group of battery cells 110 is positioned between the rigid beam 130 and one side plate 123 , and another group of battery cells 110 is positioned between the rigid beam 130 and the other side plate 123 . A buffer pad 140 may be further interposed between the battery cells 110 and the rigid beam 130 .
[57]
In this way, the rigid beam 130 is disposed in the middle of the battery cells 110 , and the rigid beam 130 expands the battery cells 110 even when the battery cells 110 expand in volume during charging and discharging (swelling phenomenon). By serving to absorb the pressure, less pressure may act on the side plates 123 of the module case 120 by that much. Therefore, the rigid beam 130 may be effective in preventing deformation of the module case 120 .
[58]
In addition, upper ends of the rigid beams 130 of each battery module 100 may be integrally fastened with the pack cover 220 and the first fastening member B1 during the assembly process of the battery pack 10 . Long bolts may be employed as the first fastening member B1 , and the long bolts may be vertically fastened to the rigid beams 130 from the outside of the pack cover 220 . Accordingly, each of the battery modules 100 may be fixed to the pack cover 220 , and the pack cover 220 may also be supported by the rigid beams 130 to reinforce impact resistance.
[59]
By integrating the rigid beam 130 into the battery module 100 as described above, the problem caused by the beam frame, which is a structure for reinforcing the rigidity of the pack tray 210, mentioned in the background, that is, the conventional battery module 100 and the cross beam It is possible to improve the problem that the energy density of the battery pack 10 is lowered due to the occurrence of an unnecessary gap therebetween and space occupation of the cross beams.
[60]
Next, with reference to FIGS. 2, 3, and 6 to 8 , an electrical connection and a fixing structure between the battery modules 100 in the pack case 200 will be further described.
[61]
The battery modules 100 are arranged in two rows on the pack tray 210 , and the electrode terminals 150a and 150b may be arranged to face each other based on the center of the pack case 200 . Although this embodiment consists of a total of four battery modules 100 , the number of battery modules 100 may be increased or decreased as much as possible. The positive terminal of one battery module 100 may be connected to the negative terminal of another adjacent battery module 100 via the terminal connection unit 221 .
[62]
At least one terminal connection part 221 may be provided on an inner top surface of the pack cover 220 . Specifically, the terminal connection part 221 according to the present embodiment is mounted on an insulating bracket 221a fixedly coupled to the top inner surface of the pack cover 220 and the bracket 221a, and conducts electricity with the electrode terminals 150a and 150b. It includes an inter-bus bar 221b made of a possible metal material.
[63]
For example, as shown in FIG. 6 , when the upper portions of the battery modules 100 are covered with the pack cover 220 , the two battery modules 100 adjacent in the Y-axis direction have a positive terminal and a negative terminal of the pack cover 220 . ) may be in contact with one end and the other end of the terminal connection part 221 , respectively. In other words, the positive terminal of one battery module 100 and the negative terminal of the other battery module 100 come into contact with both ends of the inter-bus bar 221b of the terminal connection part 221, so that the two battery modules 100 are serially connected. can be connected In addition, of course, the two battery modules 100 facing in the X-axis direction may also connect the positive terminal and the negative terminal in the same manner as above.
[64]
For reliability of electrical connection of the battery modules 100 , the electrode terminals 150a and 150b and the terminal connection part 221 may be integrally fastened with the second fastening member B2 . The second fastening member B2 may be a bolt that is vertically inserted into the electrode terminals 150a and 150b and the terminal connection part 221 to fasten them.
[65]
At this time, the bolt is inserted from the lower portion of the terminal support 126 and fastened to the electrode terminals 150a and 150b and the terminal support 126 . Accordingly, the electrical connectivity of the battery modules 100 and the fixability with the pack cover 220 can be secured at once, so that the number of bolted locations can be reduced, thereby simplifying the assembly process. In addition, since the battery modules 100 are fixed to the pack cover 220 , a space for bolting between the battery module 100 and the pack tray 210 can be eliminated, so that the space utilization rate of the upper surface of the pack tray 210 can be improved.
[66]
In this embodiment, the battery modules 100 are arranged in two rows inside the pack case 200, but the scope of the present invention is not necessarily limited thereto. For example, the battery modules 100 may be arranged in three or four rows or more. At this time, the electrode terminals 150a and 150b of each battery module 100 are arranged adjacent to each other, and the electrode terminals 150a and 150b, which would have covered the top with the pack cover 220 , are selectively selected by the terminal connection part 221 . Any array can be any array that can be concatenated.
[67]
Meanwhile, the pack cover 220 according to the present embodiment may include a cooling pipe 224 embedded therein along the edge region. The cooling pipe 224 may be directly connected to the cooling water port 121a provided on the base plate 121 of each battery module 100 .
[68]
Specifically, as shown in FIGS. 7 to 8 , the pack cover 220 includes an uneven portion 222 that is forcibly fitted to the edge of the pack tray 210 and the pack cover 220 in the uneven portion 222 . A cooling pipe mounting part 223 extending in an inward direction is provided. A rubber O-ring 230 for enhancing sealing properties may be further interposed between the pack cover 220 and the pack tray 210 at the coupling portion thereof.
[69]
An empty space extending along the circumferential direction of the pack cover 220 is provided in the cooling pipe mounting part 223 , and the cooling pipe 224 may be inserted into the empty space. As an alternative embodiment, as a way to eliminate the hassle of inserting the cooling pipe 224 into the cooling pipe mounting unit 223, one area of ​​the cooling pipe mounting unit 223 is formed in a hollow structure to omit the cooling pipe 224. good.
[70]
The base plate 121 of each battery module 100 includes a port assembly part 121b that further extends outward with respect to the vertical surface of the cell rear cover. The cooling water port 121a may be vertically provided in the upper direction in the port assembly part 121b.
[71]
The port assembly unit 121b is disposed directly below the cooling pipe mounting unit 223 of the pack cover 220 , and the cooling water port 121a is directly connected to the cooling pipe 224 of the pack cover 220 . Although not shown, a fixing connector and a sealing member may be further used to secure fastening and sealing properties between the cooling water port 121a and the cooling pipe 224 .
[72]
According to the configuration of the present invention as described above, the coolant is supplied to the base plate 121 of each battery module 100 while flowing along the cooling pipe 224 of the pack cover 220 in the circumferential direction of the pack cover 220 . During charging and discharging, heat from the battery cells 110 may be absorbed to maintain them at an appropriate temperature.
[73]
In particular, in the present invention, since the cooling pipe 224 is in the pack cover 220 and the cooling water port 121a of the base plate 121 is simply connected to the cooling pipe 224 by the shortest distance, the cooling water circulation It is possible to significantly reduce the number of parts such as additional connecting pipes or hoses for the In addition, since there is no connecting pipe or hose on the pack tray 210 , the battery module 100 and other electronic components can be more easily mounted.
[74]
Next, an assembly example of the battery pack 10 according to an embodiment of the present invention will be briefly described with reference to FIG. 9 .
[75]
In the battery pack 10 according to the present invention, unlike the conventional assembly method of the battery pack 10 , the battery modules 100 are assembled to be fixed to the pack cover 220 . In this respect, the battery pack 10 of the present invention can be said to be a reverse module assembly type.
[76]
First, the pack cover 220 is turned over, and the battery module 100 is placed therein. At this time, the electrode terminals 150a and 150b of each battery module 100 are vertically aligned with the terminal connection part 221 of the corresponding pack cover 220 , and the cooling water port 121a is a cooling pipe of the pack cover 220 . (224) to be inserted into.
[77]
Then, the terminal support 126 of each battery module 100, the electrode terminals 150a and 150b, and the terminal connection 221 of the pack cover 220 are integrally fastened using the second fastening member B2. Thus, electrical connectivity and mechanical fixability of each battery module 100 are secured.
[78]
Next, the O-ring 230 is interposed in the concave-convex portion 222 of the pack cover 220 , and then the edge portion of the pack tray 210 is coupled to the concave-convex portion 222 in a press-fitting manner.
[79]
Then, the battery pack 10 is turned over again and the rigid beams 130 of each battery module 100 and the pack cover 220 are integrally fastened using the first fastening member B1.
[80]
The battery pack 10 according to the present invention described above may further include various devices for controlling the charging and discharging of the battery modules 100 , for example, a BMS, a current sensor, a fuse, and the like. The battery pack 10 may be applied to a vehicle such as an electric vehicle or a hybrid vehicle. Of course, the battery pack 10 may be applied to a power storage device or other IT products.
[81]
In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific preferred embodiments described above, and in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Anyone with ordinary skill in the art can implement various modifications, of course, such changes are within the scope of the claims.
[82]
On the other hand, in this specification. Although terms indicating directions such as up, down, left, and right have been used, those skilled in the art are aware that these terms are only for convenience of description and may be expressed differently depending on the viewing position of the observer or the location of the object. self-evident to
Claims
[Claim 1]
A battery pack comprising a plurality of battery modules and a pack case capable of fixing and installing the battery modules therein, wherein the pack case is mutually coupled to a pack tray positioned below the battery modules and the pack tray A pack cover for covering battery modules is provided, wherein each of the battery modules includes battery cells arranged in one direction, a module case accommodating the battery cells in an internal space, and between the battery cells in the module case. A battery pack comprising a rigid beam disposed and fixedly coupled to the pack cover.
[Claim 2]
The battery pack according to claim 1, wherein the rigid beam of each battery module and the pack cover are integrally connected by a first fastening member vertically fastened from the outside of the pack cover.
[Claim 3]
The battery pack according to claim 2, wherein the rigid beam is located in the center in the arrangement order of the battery cells, and both side surfaces are provided to face one surface of the neighboring battery cells to prevent volume expansion of the battery cells.
[Claim 4]
The battery according to claim 1, wherein the module case includes a base plate positioned under the battery cells to support the battery cells, wherein the base plate has a flow path through which a refrigerant can flow therein. pack.
[Claim 5]
5. The method of claim 4, wherein the pack cover has a cooling pipe embedded therein along an edge region, the base plate has a cooling water port communicating with the flow path and extending in a vertical direction, and the cooling water port is the cooling water port. A battery pack, characterized in that it is directly connected to the pipe in the vertical direction.
[Claim 6]
The method of claim 5, wherein the pack cover comprises a concave-convex portion forcibly fitted to the edge of the pack tray, and a cooling pipe mounting portion extending from the concave-convex portion in the inner direction of the pack cover and into which the cooling pipe is inserted. A battery pack, characterized in that.
[Claim 7]
The method according to claim 1, wherein each of the battery modules includes electrode terminals horizontally protruding from one side of the module case, and the pack cover includes at least one terminal connection part on an inner top surface of the pack cover, The battery pack, characterized in that the electrode terminal of the battery module and the other electrode terminal of the battery module are electrically connected by the terminal connection part.
[Claim 8]
According to claim 7, wherein the terminal connection portion is an insulating bracket fixedly coupled to the inner surface of the pack cover; and an inter-bus bar mounted on the bracket and conducting electricity with the electrode terminal.
[Claim 9]
The battery pack of claim 7 , wherein the electrode terminal and the terminal connection part are integrally connected by a second fastening member vertically inserted into the electrode terminal and the terminal connection part.
[Claim 10]
10. The method of claim 9, wherein the module case further comprises a terminal support for supporting the lower portion of the electrode terminal, each of the battery module is the terminal support, the electrode terminal, the terminal connection portion by the second fastening member A battery pack, characterized in that it is integrally connected and fixed to the pack cover.
[Claim 11]
The battery pack according to claim 1, wherein the plurality of battery modules are arranged in two rows, and electrode terminals are arranged to face each other with respect to the center of the pack case.
[Claim 12]
12. A motor vehicle comprising a battery pack according to any one of claims 1 to 11.