CN212434741U

CN212434741U - Power battery pack structure

Info

Publication number: CN212434741U
Application number: CN202021218049.1U
Authority: CN
Inventors: 王海东; 于福成; 杨聪; 赵立志; 王博文
Original assignee: Svolt Energy Technology Co Ltd
Current assignee: Svolt Energy Technology Co Ltd
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2021-01-29
Anticipated expiration: 2030-06-28

Abstract

The utility model provides a power battery package structure, which comprises a housin, this casing includes that mutual lock is formed with the last casing and the lower casing assembly who accepts the chamber, it has BDU and a plurality of battery module to accept in accepting the chamber, the battery module includes a plurality of battery core bodies that tie together through tightening the piece, high-pressure interface and low pressure collection interface on each battery module all are located same one side, and gather the interface in the low pressure, it is connected with pencil or copper bar to correspond on high-pressure interface and the BDU, the same one side of casing is arranged in to pencil and copper bar equipartition, and the trend of pencil is along the direction of height of accepting the chamber straggly to arrange, the copper bar has at least one on the direction of height of accepting the chamber and buckles and be the setting of undulation. The utility model discloses a power battery package structure can shorten the connection length of pencil length and copper bar to but reduction in production cost and the risk of electric leakage short circuit still can improve the energy density of battery package simultaneously.

Description

Power battery pack structure

Technical Field

The utility model relates to a power battery technical field, in particular to power battery package structure.

Background

With the vigorous development of the new energy automobile industry, the safety, reliability and endurance of the power battery gradually become the concern of people. The development of a power source, namely a battery, of a new energy vehicle is important for the popularization of the new energy vehicle, and a power battery is usually arranged in a battery pack and is installed and fixed on a vehicle body of an automobile through the battery pack. In the aspect of the structure of the power battery pack, it is essential that the shell structure is stable and reliable, and certain protection performance in the aspects of mechanical impact, vibration, extrusion collision, durability, dust prevention, water prevention, corrosion resistance and the like needs to be provided. The structure failure can cause high-voltage electric shock danger and endanger the life safety of passengers. In the aspect of functions, the stability of electric energy output and storage and the monitoring of the battery state are very critical. The voltage, the pressure difference, the temperature difference and the like of the battery directly influence the functional safety of the battery pack.

However, the wiring harness in most of the conventional power battery packs is messy, the arrangement of electric elements is not reasonable enough, and the leakage short circuit is easily caused, so that the service life is influenced. In addition, the structure of the prior art is also unreasonable in terms of protection of the battery pack, so that the battery pack is easily subjected to mechanical damage, such as impact, collision, extrusion, vibration, and the like.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention is directed to a power battery pack structure, so that the wiring harness can be arranged neatly and beautifully, and the connection length of the wiring harness and the copper bar can be shortened.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

a power battery pack structure, comprising:

the casing, the casing includes that mutual lock is formed with last casing and the lower casing assembly who accepts the chamber, in it has been accepted BDU and a plurality of battery module to accept the intracavity, the battery module includes a plurality of battery core bodies that tie up together through tightening the piece, each high pressure interface and low pressure on the battery module gather the interface and all are located same one side, and in the interface is gathered to the low pressure high pressure interface with correspond on the BDU and be connected with pencil or copper bar, the pencil with the copper bar equipartition is arranged in same one side of casing, just the trend of pencil is followed the direction of height who accepts the chamber is fallen by mistake and is arranged, the copper bar is followed it buckles and is the setting of undulation form to have at least one department on the direction of height who accepts the chamber.

Further, the BDU comprises a split anode BDU and a split cathode BDU, and the anode BDU and the cathode BDU are arranged on the same side of the battery module with the high-voltage interface side by side.

Furthermore, the pencil including connect in low pressure pencil on the interface is gathered to the low pressure, with connect in high-pressure pencil on the BDU, the copper bar include with high-pressure interface connection's high-pressure copper bar and with the high-pressure copper bar that the BDU is connected.

Further, the lower shell assembly comprises a supporting bracket for supporting the battery module, and a liquid cooling piece connected with the supporting bracket and the battery module, wherein the liquid cooling piece is located below the supporting bracket, and a bottom protection plate connected with the supporting bracket is arranged at the bottom of the liquid cooling piece.

Furthermore, the support bracket comprises a frame surrounded by a plurality of boundary beams, a plurality of cross beams and longitudinal beams which are connected with the cross beams in a crossing manner are arranged in the frame, the battery modules are fixedly connected to the cross beams and the longitudinal beams side by side, and a containing space for containing the BDU, the wiring harness and the copper bar is formed between the longitudinal beams and the boundary beams of the support bracket.

Furthermore, a plurality of first fixing points and second fixing points for forming connection of the upper shell and the lower shell assembly are arranged on the upper shell and the lower shell assembly, and equipotential connection of the upper shell and the lower shell assembly can be formed due to connection of the first fixing points.

Furthermore, a support member is arranged at the second fixing point, and a cushion pad is arranged at the joint of the support member and the upper shell.

Furthermore, the supporting member comprises a base capable of being screwed on the supporting bracket, a mounting seat capable of being screwed on the upper shell, and a supporting part connected between the base and the mounting seat, and the cushion pad is arranged between the mounting seat and the upper shell.

Furthermore, a vehicle body mounting hole used for being connected with the whole vehicle is formed in the supporting bracket, and an accessory mounting hole used for being connected with an external accessory is formed in the supporting bracket.

Furthermore, the liquid cooling piece is integrally arranged on the liquid cooling plate below the supporting bracket, and a liquid inlet and a liquid outlet for liquid to enter and exit are integrated on the liquid cooling plate.

Compared with the prior art, the utility model discloses following advantage has:

(1) power battery package structure, gather the same one side that the interface equipartition was arranged in the casing through the high-pressure interface and the low pressure that set up each battery module, and the trend of pencil is arranged along the direction of height mistake of acceping the chamber, the copper bar has at least one department of buckling and is the undulation setting on the direction of height of acceping the chamber, so that arranging of electric pencil and arranging of copper bar, and can shorten the connection length of pencil length and copper bar, thereby can reduce manufacturing cost and the risk of electric leakage short circuit, still can the space of maximum utilization power battery package simultaneously, improve the energy density of battery package, and better result of use has.

(2) Through the split type arrangement of BDU to be favorable to further make full use of the space of whole battery package, and further shorten the length of pencil, with reduction in production cost.

(3) The support bracket of the frame-type that sets up firstly provides the mounted position for battery module and liquid cooling spare and end backplate, secondly compares in prior art and has cancelled lower housing bottom plate, does benefit to power battery package lightweight design to can improve the mode of whole battery package.

(4) The crossbeam and the longeron of setting to can improve the intensity and the rigidity of support bracket, inject an accommodation space between longeron and support bracket boundary beam simultaneously, so that the arrangement of BDU and pencil and copper bar.

(5) Through last casing and the first fixed point and the second fixed point that lower casing assembly set up to be favorable to improving the reliability of last casing and lower casing coupling, in addition, the equipotential of casing and support bracket can be gone up to first fixed point connection through setting up.

(6) The buffering piece can weaken the impact on the upper shell and can also play a role in sealing, so that the air tightness of the whole battery pack can be improved. In addition, through the arranged supporting piece, the Z-direction impact resistance strength of the whole battery pack is improved, and the deformation resistance of the upper shell can be improved.

(7) The base, the supporting part and the mounting seat are arranged to be beneficial to the connection of the supporting part with the supporting bracket and the upper shell respectively, and the structure is simple and convenient to process and manufacture.

(8) The vehicle body mounting hole and the accessory mounting hole are arranged so as to be conveniently used for being connected with a vehicle body and being convenient for fixing external accessories of the whole vehicle.

(9) The liquid cooling piece is integrally arranged on the liquid cooling plate below the supporting bracket, so that the heat dissipation area is large, the cooling effect is better, the number of pipelines and quick insertion can be reduced, and the liquid leakage risk can be reduced.

Drawings

The accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation. In the drawings:

fig. 1 is a schematic overall structure diagram of a power battery pack structure according to an embodiment of the present invention;

fig. 2 is an exploded view of a power battery pack structure according to an embodiment of the present invention;

fig. 3 is a schematic view of the overall arrangement structure of the power battery pack structure according to the embodiment of the present invention;

fig. 4 is a schematic structural diagram of a part of a thermal management system according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a lower housing assembly according to an embodiment of the present invention;

FIG. 6 is a cross-sectional view A-A of FIG. 5;

FIG. 7 is a front view of a support bracket according to an embodiment of the present invention;

FIG. 8 is a schematic view of another embodiment of a support bracket;

description of reference numerals:

1-upper housing, 11-first fixing point, 12-second fixing point, 121-aluminum bracket, 122-buffer foam, 2-support bracket, 21-vehicle body mounting hole, 22-cross beam, 23-longitudinal beam, 24-module mounting hole, 25-accessory mounting hole, 26-first mounting beam, 27-second mounting beam, 28-liquid cooling plate, 29-bottom guard plate, 3-explosion-proof air valve, 4-two-core high-voltage connector, 5-low-voltage connector, 6-four-core high-voltage connector, 7-water inlet connector, 8-water outlet connector, 9-one-core high-voltage connector, 10-battery module, 20-BDU, 30-high-voltage copper bar, 40-BMS mainboard, 50-BMS slave plate, 60-high-voltage wire harness, 61-high-voltage interface, 70-low voltage wiring harness, 71-low voltage collection interface.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

This embodiment relates to a power battery package structure, it mainly includes the casing, the battery module, BDU, high-pressure copper bar, BMS mainboard and BMS slave plate etc, wherein, the casing includes that mutual lock is formed with last casing and the lower casing assembly who accepts the chamber, it has BDU to accept in accepting the chamber, and a plurality of battery module, this battery module includes a plurality of battery core bodies that tie together through lacing piece, high-pressure interface and low pressure collection interface on each battery module all are located same one side, and gather the interface in the low pressure, correspond on high-pressure interface and the BDU and be connected with pencil and copper bar, the same one side of casing is arranged in to pencil and copper bar equipartition, and the trend of pencil is along the direction of height arrangement who accepts the chamber, the copper bar has at least one department along the direction of height who accepts the chamber and buckles and be the undulation and set up. The utility model discloses a power battery package structure can be convenient for arranging of electric pencil and arranging of copper bar to can shorten the length of pencil length and the connection length of copper bar, thereby can reduce manufacturing cost and the risk of electric leakage short circuit, still can improve the energy density of battery package simultaneously.

Based on the above idea of designing the overall structure, an exemplary structure of this embodiment is as shown in fig. 1 to fig. 3, and this power battery pack structure includes the casing, and this casing includes casing 1 and lower casing assembly, by fig. 2 combine fig. 3 and fig. 4 to show, a plurality of battery module 10 are fixed on casing assembly down, and high-voltage interface 61 and low-voltage collection interface 71 on each battery module 10 all lie in same side, collect interface 71 in the low-voltage, correspond on high-voltage interface 61 and BDU20 and be connected with pencil or copper bar, and pencil and copper bar equipartition are arranged in same side of casing. In addition, a BMS board 40 and two BMS slave boards 50 coupled to the BMS board 40 are attached to the upper side of the battery module 10. The wiring harness includes a low voltage wiring harness 70 connected to a low voltage collecting port 71, and the low voltage wiring harness 70 is connected to the BMS board 40 and the BMS board 50, respectively, and is collectively disposed on a low voltage connector 5 of a lower housing assembly, which will be referred to as a support bracket 2 as described below.

The copper bar comprises a high-voltage copper bar 30 connected with the high-voltage interface 61 and a high-voltage copper bar 30 connected with the BDU20 part, as shown in fig. 2 and 3, the high-voltage copper bar 30 connected with the high-voltage interface 61 and the high-voltage copper bar connected with the BDU20 are respectively and correspondingly connected to the two-core high-voltage connector 4 and the one-core high-voltage connector 9 on the lower shell assembly, and in addition, a high-voltage wiring harness connected with the BDU20 is connected to the four-core high-voltage connector 6. Wherein the four-core high-voltage connector 6 and the two-core high-voltage connector 4 and the low-voltage connector 5 are arranged on the same end face, and the one-core high-voltage connector 9 is arranged on the adjacent end face. It should be noted that the connections between the high-voltage wire harness 60, the low-voltage wire harness 70 and the high-voltage copper bar 30 and the electrical components can be implemented by the prior art.

As shown in fig. 2, the BDU20 in this embodiment includes a positive BDU and a negative BDU that are separated, and the positive BDU and the negative BDU are disposed side by side on the same side of the battery module 10 having the high voltage interface 61, as shown in fig. 2, one of the positive BDU and the other is the negative BDU, and the positive and negative electrodes of the BDU20 are arranged in a split manner, so as to facilitate further fully utilizing the space of the entire battery pack, and further shorten the length of the wire harness, so as to reduce the production cost. In addition, an explosion-proof air valve 3 is arranged on the upper shell 1, so that when the temperature difference or air pressure change in the power battery pack causes the pressure difference between the inner cavity of the power battery pack and the outside, the explosion-proof air valve can allow air to pass through to balance the pressure difference between the inside and the outside, and can realize air permeability and water impermeability and meet the standard IP67, so that the power battery pack has a pressure balancing function.

It should be noted that, the aforementioned fastening member is a tie commonly used in the art, that is, the battery module 10 of this embodiment is a module structure formed by binding and fastening a plurality of battery cores together by the tie, wherein the battery cores are vertically disposed, and the plurality of battery cores are fixed by the tie after being stacked transversely, so that the design is such that the battery module 10 of this embodiment can reduce the structural members of the module portion by about 15% compared with the conventional standard module, thereby reducing the cost and reducing the failure risk of the structural members.

The lower casing assembly of the present embodiment includes a frame-type support bracket 2 for supporting the battery module 10, and a liquid cooling member connected to the support bracket 2 and the battery module 10 and located below the support bracket 2, wherein a bottom protection plate 29 connected to the support bracket 2 is disposed at the bottom of the liquid cooling member. This casing assembly structure so sets up down, compares in prior art, has cancelled lower casing bottom plate, does benefit to power battery package lightweight design to can improve the mode of whole battery package.

In order to facilitate better connection between the lower casing assembly and the upper casing 1, as shown in fig. 2 and 3 in conjunction with fig. 5 and 6, a plurality of first fixing points 11 and a plurality of second fixing points 12 for forming connection between the upper casing 1 and the lower casing assembly, that is, the supporting bracket 2, are respectively disposed on the upper casing 1 and the lower casing assembly, and equipotential connection between the upper casing 1 and the lower casing assembly can be formed due to connection between the first fixing points 11. The first fixing points 11 are a plurality of fixing points arranged on the edges of the upper shell 1 and the supporting bracket 2, bolts are screwed at the first fixing points 11, and the upper shell 1 and the supporting bracket 2 are connected by adopting the bolts, so that the equipotential connection of the upper shell 1 and the supporting bracket 2 can be realized.

The second fixing points 12 are five ones disposed at the middle portions of the upper case 1 and the support bracket 2, so as to improve the Z-direction impact strength of the entire battery pack, and a support member is disposed at the second fixing points 12, as shown in fig. 5 and 6, the support member is an aluminum bracket 121 having an i-shaped longitudinal section, and the support member, that is, the aluminum bracket 121 includes a base capable of being screwed to the support bracket 2, a mounting seat capable of being screwed to the upper case 1, and a support portion connected between the base and the mounting seat, the cushion pad is disposed between the mounting seat and the upper case 1, and the support portion may be a column, plate, or frame structure.

As shown in fig. 6, the base of the aluminum bracket 121 in this embodiment is screwed to the cross member 22 of the support bracket 2, the mount is screwed to the upper case 1 via an external connector, and the support is preferably a cylindrical structure. This aluminium support 121 structure is simpler, and the manufacturing of being convenient for, and can improve battery package Z to shock-resistant intensity through the support piece that sets up to and can improve the ability that upper housing 1 resisted the deformation.

In order to improve the air tightness of the whole battery pack, as shown in fig. 6, a buffer member is disposed at the joint of the supporting member and the upper case 1, and the buffer member is preferably made of a buffer foam 122, although other materials, such as rubber or sponge, may be used, and the sealing effect of the joint is slightly poor. The foam can weaken the impact on the upper shell 1 and play a role in sealing, thereby being beneficial to improving the air tightness of the whole battery pack.

The support bracket 2 of this embodiment is as shown in fig. 7 and 8, and it adopts the processing technology of aluminium alloy (the material chooses for use Al6061-T6) tailor-welding, and this support bracket 2 includes the frame that encloses by a plurality of boundary beam, is equipped with a plurality of crossbeams 22 in the frame and with crossbeam 22 cross connection's longeron 23, each battery module links firmly on crossbeam 22 and longeron 23 side by side, and in longeron 23 with it defines the accommodation space who holds BDU20 and pencil and copper bar to hold between the 2 boundary beams of support bracket. As shown in fig. 7, module mounting holes 24 for mounting the battery modules 10 are provided in the side and cross members 22 and the longitudinal members 23, and each battery module 10 is fixed in the module mounting hole 24 by eight bolts in this embodiment, so that the fixing strength can be improved. The transverse beams 22 and the longitudinal beams 23 are arranged, so that the battery modules 10 are arranged on the support bracket 2 side by side, and meanwhile, an installation foundation is provided for the aluminum support 121, and in addition, the rigidity and the strength of the power battery pack can be improved by the arranged transverse beams 22 and the arranged longitudinal beams 23 which are connected in a cross mode, and the mode of the power battery pack is improved. In addition, the edge beam of the support bracket 2 is provided with a mounting hole for connecting the below-described middle liquid cooling plate 28 and the bottom protection plate 29, so as to provide a mounting position for the liquid cooling plate 28 and the bottom protection plate 29.

With reference to fig. 7, in the present embodiment, vehicle body mounting holes 21 for connecting with the entire vehicle are disposed on two opposite sides of the support bracket 2, and mounting holes for connecting with external accessories are disposed on the support bracket 2, so as to connect the power battery pack with the vehicle body and fix the external accessories of the entire vehicle. In this embodiment, the power battery pack is installed below the bottom plate of the entire vehicle, and the power battery pack is screwed and fixed through 16 installation points, that is, through a screw member penetrating through 16 vehicle body installation holes 21.

As shown in fig. 8, the edge beam of the support bracket 2 includes first and second mounting beams 26 and 27 for mounting high-pressure and low-pressure inserts and liquid-cooled pipes, and the first and second mounting beams 26 and 27 are formed by high-pressure casting. Wherein the first mounting beam 26 is used for mounting the one-core high-voltage connector 9 and the second mounting beam 27 is used for mounting the low-voltage connector 5, the two-core high-voltage connector 4 and the four-core high-voltage connector 6, as well as the water inlet connection 7 and the water outlet connection 8 described below. Through adopting the high pressure casting shaping, adopt integrative extrusion mode and go out corresponding connector mounting hole position through machining through comparing, weld again after the high pressure casting and can avoid the boundary beam die cavity to lead to the risk that whole package gas tightness reduces because of boundary beam die cavity gas leakage with the inside intercommunication that forms of battery package.

The power battery pack structure of this embodiment has a thermal management system therein, and it includes liquid cooling spare and pipeline assembly, and wherein, liquid cooling spare is located the liquid cooling board 28 of support bracket 2 below as an organic whole for the liquid cooling spare, and integrates on the liquid cooling board 28 to have inlet and outlet that supplies liquid business turn over. Specifically, as shown in fig. 2 and 4, the liquid cooling member, that is, the liquid cooling plate 28, has a liquid inlet and a liquid outlet, wherein the liquid inlet is connected to a water inlet joint 7, the liquid outlet is connected to a water outlet joint 8, and a water temperature sensor is integrated at the water inlet joint 7 for detecting water temperature. In addition, the whole size of the liquid cooling plate 28 is adapted to the support bracket 2, so that the liquid cooling plate has a larger heat dissipation area, the cooling effect is better, meanwhile, the number of pipelines and quick insertion can be reduced, the liquid leakage risk can be reduced, and the pipeline assembly is simple in structure, small in flow resistance, light in weight and small in occupied space. In addition, the pipeline in this embodiment adopts the nylon material, and ageing properties and mechanical properties are better, and it is safe and reliable to use. The heat management system adopts the integrated cold plate arrangement, and can adjust and control the temperature of the power battery pack, so that the power battery pack can be always kept in a proper temperature range in the operation process.

In order to facilitate the installation of the liquid cooling piece, the joint of the support bracket 2 and the liquid cooling piece is coated with sealing structural adhesive. With such an arrangement, the adhesive liquid cooling plate 28 can be used on one hand, and the bottom of the power battery pack can be sealed on the other hand. In order to facilitate the bonding connection between the liquid cooling member and the battery module 10, a heat-conducting structural adhesive is coated between the battery module 10 and the liquid cooling member, preferably, a 3M structural adhesive is used in this embodiment, so as to facilitate the heat conduction of the battery module 10.

In addition, the bottom protection plate 29 is used for protecting the liquid cooling plate 28, the material is an aluminum plate material AL5182, the process is sheet metal stamping, the bottom protection plate 29 is connected to the support bracket 2 through a screw joint, in the embodiment, PVC with a certain thickness is coated on the bottom protection plate 29, and therefore the corrosion resistance of the bottom of the battery pack can be improved.

The power battery package structure of this embodiment can discover through as before the description, not only has better mechanical security and protection security to arrange pencil and copper bar through the unilateral, and the trend of pencil and copper bar is arranged along Z to the straggly, can effectively shorten the connection length of pencil and copper bar, thereby can reduce manufacturing cost and reduce the risk of electric leakage short circuit, still do benefit to the energy density who improves the power battery package simultaneously, and have better result of use.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power battery package structure characterized by comprising:

the casing, the casing includes that mutual lock is formed with last casing (1) and the lower casing assembly who accepts the chamber, in it has BDU (20) and a plurality of battery module (10) to accept in the chamber, battery module (10) are including binding a plurality of battery core bodies that are in the same place through tightening the piece, each high pressure interface (61) and low pressure collection interface (71) on battery module (10) all are located same one side, and in interface (71) are gathered to the low pressure high pressure interface (61) with correspond on BDU (20) and be connected with pencil or copper bar, the pencil with the copper bar equipartition is arranged in the same one side of casing, just the trend of pencil is followed the direction of height of accepting the chamber is straggly arranged, the copper bar is followed it buckles and is the undulation form setting to have at least one department on the direction of height of accepting the chamber.

2. The power battery pack structure of claim 1, wherein: the BDU (20) comprises a positive BDU and a negative BDU which are separated, and the positive BDU and the negative BDU are arranged on the same side of the battery module (10) with the high-voltage interface (61) in parallel.

3. The power battery pack structure of claim 1, wherein: the pencil including connect in low pressure pencil (70) on low pressure collection interface (71), and connect in high-pressure pencil (60) on BDU (20), the copper bar include with high-pressure copper bar (30) that high-pressure interface (61) are connected and with high-pressure copper bar (30) that BDU (20) are connected.

4. The power battery pack structure of claim 1, wherein: the lower shell assembly comprises a supporting bracket (2) for supporting the battery module (10), and a liquid cooling piece connected with the supporting bracket (2) and the battery module (10), wherein the liquid cooling piece is positioned below the supporting bracket (2), and a bottom protection plate (29) connected with the supporting bracket (2) is arranged at the bottom of the liquid cooling piece.

5. The power battery pack structure of claim 4, wherein: the support bracket (2) comprises a frame surrounded by a plurality of boundary beams, a plurality of cross beams (22) and longitudinal beams (23) which are connected with the cross beams (22) in a crossing manner are arranged in the frame, the battery modules (10) are fixedly connected to the cross beams (22) and the longitudinal beams (23) side by side, and a containing space for containing the BDU (20) and the wiring harness and the copper bar is defined between the longitudinal beams (23) and the boundary beams of the support bracket (2).

6. The power battery pack structure of claim 4, wherein: the upper shell (1) and the lower shell assembly are respectively provided with a plurality of first fixing points (11) and second fixing points (12) for connecting the upper shell (1) and the lower shell assembly, and the equipotential connection of the upper shell (1) and the lower shell assembly can be formed due to the connection of the first fixing points (11).

7. The power battery pack structure of claim 6, wherein: a support piece is arranged at the second fixing point (12), and a cushion pad is arranged at the joint of the support piece and the upper shell (1).

8. The power battery pack structure of claim 7, wherein: the supporting piece comprises a base capable of being screwed on the supporting bracket (2), a mounting seat capable of being screwed on the upper shell (1) and a supporting part connected between the base and the mounting seat, and the buffer cushion is arranged between the mounting seat and the upper shell (1).

9. The power battery pack structure of claim 4, wherein: the automobile body mounting hole (21) used for being connected with the whole automobile is formed in the supporting bracket (2), and the accessory mounting hole (25) used for being connected with an external accessory is formed in the supporting bracket (2).

10. The power battery pack structure according to any one of claims 4 to 9, wherein: the liquid cooling piece is integrally arranged on a liquid cooling plate (28) below the supporting bracket (2), and a liquid inlet and a liquid outlet for liquid to enter and exit are integrated on the liquid cooling plate (28).