Title of Invention: Battery pack including hold-down bracket with protrusion structure
technical field
[One]
This application claims the benefit of priority based on Korean Patent Application No. 2019-0116903 dated September 23, 2019, and all contents disclosed in the literature of the Korean patent application are incorporated as a part of this specification.
[2]
The present invention relates to a hold-down bracket having a protrusion structure, and specifically, when the battery module assembly is coupled to the base plate, the hold-down bracket is pressed as much as the height of the protrusion structure, so that the battery module assembly is more stably fixed to the base plate It is about a battery pack with a structure that can do this.
background
[3]
As exhaust gas from automobiles that use fuel such as gasoline or diesel is pointed out as a cause of fine dust and air pollution, secondary batteries are attracting attention as an alternative raw material.
[4]
According to this trend, an electric vehicle and a hybrid electric vehicle using a battery and a conventional combustion engine together have been developed and commercialized.
[5]
As a power source of the electric vehicle, a nickel-metal hydride secondary battery has been conventionally used, but recently a lithium ion secondary battery having high output and high capacity is used as a main power source.
[6]
In particular, an electric vehicle requires a high-output and large-capacity power source. In a lithium secondary battery, unit battery cells are interconnected in series or parallel to form a battery module, and a plurality of battery modules are interconnected to provide desired output and capacity characteristics. It is possible to manufacture a battery pack having
[7]
In order to fix the battery pack to a device such as an electric vehicle, after the battery module assembly is mounted on the base plate, the base plate may be fixed to the device. At this time, a hold-down bracket can be used. The hold-down bracket has a problem in that the bolting part is loosened by vibration and shock generated during operation of the device. There is a problem in that the force for fixing the battery module is not uniformly applied due to the occurrence of a tolerance.
[8]
In this regard, Patent Document 1 discloses a battery module assembly in which an outward protrusion is formed at the lower end of one or both sides of the battery module; a base plate on which the battery module assembly is mounted; and a hold-down bracket having a structure in which one side surrounds the outward protrusion of the battery module and the other side is coupled to the base plate in order to fix each battery module of the battery module assembly in position to the base plate. As a result, stable fixing of the battery module assembly and the hold-down bracket can be made, but there is a problem in that strong coupling between the battery module assembly and the base plate cannot be achieved.
[9]
Patent Document 2 relates to a fixing structure of a battery stack mounted on a vehicle to a lower frame, which is installed on a lower frame of a hollow cross-section and fixed to the lower frame so that the flanges of opposite sides are pressed in common from the upper portion and a fixing frame for fixing the fixing frame to the hollow part of the lower frame with bolts so as to press the flanges of the opposite sides with pressing pieces formed on both sides of the fixing frame.
[10]
However, Patent Document 2 has a structure in which a cell holder including a battery cell is stably fixed in the vertical direction by simply pressing the flange portion of the cell holder with a pressing piece and fastening the fixture to fix it.
[11]
Therefore, in the case of using the hold-down bracket for coupling the battery module assembly and the base place, the coupling between the hold-down bracket and the battery module assembly becomes stable, and the coupling force between the hold-down bracket and the base plate is increased. There is a high need for a battery pack having a structure that can be used.
[12]
(Prior art literature)
[13]
(Patent Document 1) Republic of Korea Patent Publication No. 1769577 (2017.08.11)
[14]
(Patent Document 2) Japanese Patent Publication No. 5618747 (2014.09.26)
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[15]
The present invention is to solve the above problems, and by forming a protrusion structure protruding in the direction of the base plate to the hold-down bracket for fixing the battery module assembly to the base plate, the coupling force between the hold-down bracket and the base plate can be increased. And, as a result, an object of the present invention is to provide a battery pack capable of stably fixing the battery module assembly on the base plate.
means of solving the problem
[16]
A battery pack according to the present invention for achieving this object is a battery module assembly including two or more battery modules in which one or more battery cells are adjacently arranged in a cartridge, the battery module assembly is mounted on the upper part a base plate, and a hold-down bracket for fixing the battery module assembly to the base plate, wherein the cartridge includes a step portion having a lower portion protruding outward, and the hold-down bracket is an upper end portion covering an upper surface of the step portion of the cartridge , a lower end coupled to the base plate, and a middle portion connecting the upper end and the lower end, and the lower end may have a structure in which a protrusion structure protruding in the direction of the base plate is formed.
[17]
In a state before the battery module assembly and the base plate are coupled, only the protrusion structure of the lower end may be in contact with the base plate.
[18]
The maximum height of the protrusion structure may be greater than the difference in height obtained by subtracting the height difference between the lower surface of the upper end and the lower surface of the lower end of the hold-down bracket from the height of the step portion of the cartridge.
[19]
The protrusion structure may be formed at both ends of the lower end, respectively, and at least one or more may be formed in the remaining portions except for the both ends.
[20]
In one embodiment, the protrusion structure may be formed on the outer periphery of the lower end, in another embodiment, the protrusion structure may be formed on the center of the lower end.
[21]
A through hole for fixing the hold-down bracket and the base plate may be formed between the protrusion structure and the protrusion structure.
[22]
A fastening member may be inserted and coupled to the through hole.
[23]
The fastening member may be a bolt or a screw.
[24]
The hold-down bracket may couple one battery module to the base plate, or the hold-down bracket may couple a plurality of battery modules to the base plate.
[25]
The hold-down bracket may at least partially include an elastic material.
[26]
A groove may be formed in the step portion of the cartridge, and an indentation portion accommodated in the groove may be formed in the hold-down bracket.
[27]
The present invention provides a device including the battery pack as a power source, wherein the device is any one selected from the group consisting of an electric two-wheeled vehicle, an electric cart, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device can be
[28]
Since the structure of the device and its manufacturing method are known in the art, a detailed description thereof will be omitted herein.
Brief description of the drawing
[29]
1 is a perspective view of a battery pack according to an embodiment of the present invention.
[30]
FIG. 2 is a partially enlarged front view of FIG. 1 .
[31]
3 is a perspective view and a side view of a hold-down bracket according to an embodiment.
[32]
4 is a perspective view and a side view of a hold-down bracket according to another embodiment.
[33]
FIG. 5 is a partial cross-sectional view taken along line AA′ of FIG. 2 , before coupling of the hold-down bracket; FIG.
[34]
6 is a partial cross-sectional view taken along line AA' of FIG. 2, after the hold-down bracket is coupled.
[35]
Fig. 7 is a partial cross-sectional view taken along line BB' in Fig. 2;
Modes for carrying out the invention
[36]
Hereinafter, embodiments in which those skilled in the art can easily practice the present invention will be described in detail with reference to the accompanying drawings. However, in the detailed description of the principle of operation of the preferred embodiment of the present invention, if it is determined that a detailed description of a related well-known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.
[37]
In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions. Throughout the specification, when it is said that a part is connected to another part, it includes not only a case in which it is directly connected, but also a case in which it is indirectly connected with another element interposed therebetween. In addition, the inclusion of any component does not exclude other components unless otherwise stated, but means that other components may be further included.
[38]
In addition, limitations described in the dependent claims of the present specification may be applied in the same or similar form to all embodiments described in the present specification.
[39]
The present invention will be described along with detailed examples according to the drawings.
[40]
1 is a perspective view of a battery pack according to an embodiment of the present invention.
[41]
Referring to FIG. 1 , the battery pack according to the present invention includes a battery module assembly 100 , a base plate 200 on which the battery module assembly 100 is mounted, and the battery module assembly 100 , the base plate 200 . It includes a hold-down bracket 300 for fixing to the.
[42]
The battery module assembly 100 is composed of a plurality of battery modules 110 , and the battery module 110 has a stacked structure in which the battery cells 10 are embedded in the cartridge 20 .
[43]
The battery cells 10 are coupled to form a series connection and/or parallel connection to fit a desired capacity and output within the battery module 110 , and form a series connection and/or parallel connection between individual battery modules 110 . and the battery module assembly 100 is formed.
[44]
Since the battery module assembly 100 can be mounted on a target device in a state coupled to the base plate 200 , a hold-down bracket ( 300) can be used.
[45]
The cartridge 20 includes a step portion 21 in which a lower portion coupled to the hold-down bracket 300 protrudes outward, and the hold-down bracket 300 surrounds the cartridge so as to cover the upper surface of the step portion 21 is mounted
[46]
On the other hand, a stepped portion may be formed in both lower portions of the cartridge 20, and the hold-down bracket may be mounted to surround each of the stepped portions formed in the lower both sides. Therefore, it is possible to stably secure the fixing of the battery module assembly to the base plate.
[47]
Figure 2 is a partially enlarged front view of Figure 1, Figure 3 is a perspective view and a side view of a hold-down bracket according to an embodiment.
[48]
2 and 3, the hold-down bracket 300 includes an upper end 310 covering the upper surface of the stepped portion 21 of the cartridge 20, a lower end 330 coupled to the base plate, and an upper end 310 and a lower end. and a middle portion 320 connecting the 330 .
[49]
A protrusion structure 331 protruding toward the base plate is formed at the lower end 330 .
[50]
The protrusion structure 331 may have a vertical cross section of a U-shape or a V-shape, and may have a pointed end of the protrusion, or a blunt shape.
[51]
The protrusion structure 331 is formed at both ends of the lower end 330, and at least one bar is formed in the remaining portions except for both ends, and FIGS. 2 and 3 show one protrusion structure 331 at each of both ends. ) is formed, and two protrusion structures 331 are formed inside the remaining portion, showing a state in which all four protrusion structures 331 are formed.
[52]
In a state before the battery module assembly 100 and the base plate 200 are coupled, only the protrusion structure 331 of the lower end 330 is in contact with the base plate 200, and the lower end 330 except for the protrusion structure 331. The remaining portion of the plane maintains a state in which the surface opposite to the base plate 200 is spaced apart from the base plate 200 in a planar shape.
[53]
As shown in FIG. 3 , the protrusion structure 331 may be a structure formed on the outer periphery 335 of the lower end 330 , and otherwise, the protrusion structure may be formed in the central portion 336 of the lower end. A through hole 332 for fixing the hold-down bracket 300 and the base plate 200 is formed between the protrusion structure 331 and the protrusion structure 331 .
[54]
Since a fastening member such as a bolt or screw passes through the through hole 332 and the base plate of the hold-down bracket and is coupled with the nut, the lower end floating by the protrusion structure 331 can be further pushed toward the base plate to be fastened. The coupling force between the bolt and the nut may be improved.
[55]
FIG. 2 shows a state in which one battery module 110 is coupled to the base plate 200 through the hold-down bracket 300, but by extending the length of the hold-down bracket 300, a plurality of battery modules are mounted on the base. Of course, it can be coupled to the plate.
[56]
4 is a perspective view and a side view of a hold-down bracket according to another embodiment.
[57]
4, the hold-down bracket 400 is an upper portion 410 covering the upper surface of the stepped portion of the cartridge, a lower portion 430 coupled to the base plate, and a middle portion connecting the upper portion 410 and the lower portion 430 ( 420).
[58]
A protrusion structure 431 protruding toward the base plate is formed at the lower end 430 .
[59]
The protrusion structure 431 may have a vertical cross-section in a U-shape or V-shape, and may have a pointed end of the protrusion, or a blunt shape.
[60]
The hold-down bracket 400 shown in FIG. 4 has one protrusion structure 431 formed at each of both ends of the lower end 430, like the hold-down bracket 300 shown in FIG. A state in which two protrusion structures 431 are formed and all four protrusion structures 431 are formed is shown.
[61]
The number and shape of the protrusion structure may be selectively applied in an appropriate number and shape in consideration of the length of the hold-down bracket and the height of the stepped part of the cartridge.
[62]
Unlike the hold-down bracket 300 of FIG. 3 , the hold-down bracket 400 of FIG. 4 has a protrusion structure formed in the center 436 of the lower end 430 , and is located on the same line as the through-hole 432 . .
[63]
When the protrusion structure is formed on the outer periphery 335 of the lower end as shown in FIG. 3, even if a tolerance occurs according to the height difference of the step portion of the cartridge in which the battery cell is accommodated, the distance at which the upper end of the hold-down bracket presses the step portion of the cartridge is the protrusion structure As it increases by the height of , the hold-down bracket can be coupled to the base plate more strongly. Accordingly, it is possible to prevent the cartridge constraining the battery cells from loosening by reducing the occurrence of tolerances according to the height difference of the step portion.
[64]
On the other hand, when the protrusion structure is formed in the central part 436 of the lower end as shown in FIG. 4, since the protrusion structure is compressed and the height of the protrusion structure is reduced when the bolt is fastened, the fastening depth of the bolt and the nut is increased. can improve the anti-loosening effect of
[65]
On the other hand, the hold-down bracket may at least partially include an elastic material, for example, a portion made of an elastic material may be included in the middle part, the lower part, or the protrusion structure. In this case, the elastic material part is stretched or the elastic part of the protrusion structure is pressed during the fastening process of the hold-down bracket, so that the lower end may be more closely attached to the base plate. Accordingly, as a result of maintaining a stronger coupling of the bolt and the nut, the loosening prevention effect of the bolt and the nut may be significantly improved.
[66]
In one specific example, referring to FIGS. 2 to 4 , a groove (not shown) is formed in the stepped portion of the cartridge 20, and the hold-down brackets 300 and 400 are accommodated to engage the groove. Since the indentations 311 and 411 may be formed, the battery modules may be stably fixed to the base plate even when vibration is applied to the battery pack in vertical and/or left and right directions.
[67]
5 is a partial cross-sectional view taken along line AA' of FIG. 2, before the hold-down bracket is coupled, and FIG. 6 is a partial cross-sectional view taken along line AA' of FIG. 2, after the hold-down bracket is coupled, FIG. 7 is a partial cross-sectional view taken along line BB′ in FIG. 2 .
[68]
A line AA′ in FIG. 2 is located on a portion where the protrusion structure is formed, and a line BB′ is located on a portion where the through hole is formed.
[69]
5 to 7, in the state before the hold-down bracket 300 is coupled as shown in FIG. 5, the upper end of the hold-down bracket 300 is disposed while covering the upper surface of the cartridge step 21, and the lower end ( Only the protrusion structure 331 of the entire portion of the 330 is in contact with the base plate 200 .
[70]
At this time, the maximum height of the protrusion structure 331 is greater than subtracting the height difference (a2) between the lower surface of the upper end 310 and the lower surface of the lower end 330 in the hold-down bracket from the height a1 of the step 21 of the cartridge. made in size
[71]
When the maximum height of the protrusion structure is less than the difference in height (a2) between the lower surface of the upper end 310 and the lower surface of the lower end 330 in the hold-down bracket from the height a1 of the step 21 of the cartridge, the battery module This is undesirable because it is difficult to achieve the purpose of more strongly bonding the assembly to the base plate.
[72]
As shown in FIG. 7 , the bolt and nut are fastened through the through hole, and when the hold-down bracket is coupled as shown in FIG. 6 , the protrusion structure is pressed and the protrusion structure is excluded from the lower end 330 except for the protrusion structure. The part also comes into contact with the base plate. That is, since there is a space for further pushing the lower end 330 to the base plate due to the height of the protrusion structure, the bolt and the nut are tightened more deeply, thereby preventing the bolt and the nut from loosening.
[73]
In addition, as a step is formed between cartridges or a step or tolerance is formed between battery modules, there may occur a problem that the bonding force to the base plate may be partially different between the battery cells in the battery module or between the battery modules. In the case of using the hold-down bracket having a structure, the above problem can be prevented because the hold-down bracket can be pressed more strongly in the direction of the base plate.
[74]
Those of ordinary skill in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.
[75]
(Explanation of symbols)
[76]
10: battery cell
[77]
20: cartridge
[78]
21: step part
[79]
100 Battery module assembly
[80]
110: battery module
[81]
200: base plate
[82]
300, 400: hold down bracket
[83]
310, 410: upper part
[84]
311, 411: indentation
[85]
320, 420: middle part
[86]
330, 430: lower part
[87]
331, 431: projection structure
[88]
332, 432: through hole
[89]
335, 435: outer periphery
[90]
336, 436: central
[91]
a1: the height of the cartridge step
[92]
a2: difference in height between the lower surface of the upper part and the lower surface of the lower part
Industrial Applicability
[93]
As described above, in the battery pack according to the present invention, due to the protrusion structure formed on the hold-down bracket, the hold-down bracket can apply a stronger pressing force to the battery module assembly in the direction of the base plate, so that the battery module assembly and the base plate can increase the bonding strength of
[94]
In addition, if a bolt and a nut are used for coupling the battery module assembly and the base plate and an elastic material is applied to a part of the hold-down bracket, the effect of preventing loosening of the bolt and the nut can be increased.
Claims
[Claim 1]
a battery module assembly including two or more battery modules in which one or more battery cells are arranged adjacent to each other in a state embedded in the cartridge; a base plate on which the battery module assembly is mounted; and a hold-down bracket for fixing the battery module assembly to the base plate. Including, wherein the cartridge includes a stepped portion with a lower portion protruding outward, and the hold-down bracket includes an upper portion covering the upper surface of the stepped portion of the cartridge, a lower portion coupled to the base plate, and a middle portion connecting the upper portion and the lower portion The battery pack having a protrusion structure protruding toward the base plate at the lower end thereof.
[Claim 2]
The battery pack according to claim 1, wherein, in a state before the battery module assembly and the base plate are coupled, only the protrusion structure of the lower end is in contact with the base plate.
[Claim 3]
The battery pack according to claim 2, wherein the maximum height of the protrusion structure is greater than the height of the stepped portion of the cartridge minus the height difference between the lower surface of the upper end and the lower surface of the lower end of the hold-down bracket.
[Claim 4]
The battery pack according to claim 1, wherein the protrusion structure is formed at both ends of the lower end, respectively, and at least one of the protrusion structures is formed in the remaining portions except for the both ends.
[Claim 5]
The battery pack according to claim 4, wherein the protrusion structure is formed on an outer periphery of the lower end portion.
[Claim 6]
The battery pack according to claim 4, wherein the protrusion structure is formed in the center of the lower end portion.
[Claim 7]
The battery pack according to claim 4, wherein a through hole for fixing the hold-down bracket and the base plate is formed between the protrusion structure and the protrusion structure.
[Claim 8]
The battery pack according to claim 7, wherein a fastening member is inserted into the through hole to be coupled thereto.
[Claim 9]
The battery pack according to claim 8, wherein the fastening member is a bolt or screw.
[Claim 10]
The battery pack according to claim 1, wherein the hold-down bracket couples one battery module to the base plate.
[Claim 11]
The battery pack according to claim 1, wherein the hold-down bracket couples the plurality of battery modules to the base plate.
[Claim 12]
The battery pack according to claim 1, wherein the hold-down bracket at least partially includes an elastic material.
[Claim 13]
The battery pack according to claim 1, wherein a groove is formed in the step portion of the cartridge, and an indentation portion accommodated in the groove is formed in the hold-down bracket.
[Claim 14]
A device comprising the battery pack according to any one of claims 1 to 13 as a power source.
[Claim 15]
The device of claim 14 , wherein the device is any one selected from the group consisting of an electric two-wheeled vehicle, an electric cart, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a power storage device.