Battery module cover plate

Abstract

The utility model relates to the technical field of battery modules, and provides a battery module cover plate which comprises a cover plate body, a groove and a first air bag are arranged on the inner side of the cover plate body, and the groove is communicated with the first air bag through an inflation channel; a control seat capable of axially moving is arranged in the groove, the control seat is in sealing fit with the inner wall of the groove, and the moving stroke of the control seat is configured to drive the first air bag to expand by compressing air in the groove. Through collaborative design of the control seat and the first air bag, active inflation sealing is realized, and when the battery module shell is assembled, mechanical force of shell assembly is converted into air pressure energy in the air bag, so that the second sealing element is more tightly and uniformly attached to a sealing surface, and the battery module shell is particularly suitable for scenes with complex curved surfaces or uneven sealing surfaces; and the initial sealing reliability is obviously improved.

Description

Technical Field

[0001] This utility model relates to the field of battery module technology, and in particular to a battery module cover. Background Technology

[0002] A battery module is a modular component created by adding necessary circuitry and control units to a battery pack. The design and structure of a battery module can be customized as needed, including aspects such as size, shape, capacity, and functionality. The purpose of a battery module is to increase the density and reliability of the battery cells, while also facilitating the assembly, connection, and management of the battery pack. Within the battery module, a cover plate serves to protect it.

[0003] A search revealed a battery pack and an electric vehicle using publication number CN218632330U. The battery pack includes a lower housing, a battery module, and a cover plate. The inner cavity of the lower housing is divided into a battery cavity and a receiving cavity by a first baffle. A cooling inlet and a cooling outlet are provided on the side wall of the lower housing, allowing cooling medium to flow into the battery cavity from the cooling inlet and out from the cooling outlet. The receiving cavity is used to house the battery management unit. The battery module is placed inside the battery cavity, and the cooling medium can immerse and cool the battery module. The cover plate seals the inner cavity of the lower housing.

[0004] Existing battery module covers rely on a single sealing ring or flat pressing. After long-term vibration or thermal cycling, the cover is prone to slight local or overall deformation. At this time, the seal on the cover fails to seal with the outer shell, and the seal cannot compensate for the deformation. Utility Model Content

[0005] In view of this, the present invention proposes a battery module cover plate that can achieve active inflation sealing. When the battery module shell is assembled, its edge pushes the control seat through the inclined surface to compress the gas in the groove. The gas is injected into the first airbag through the inflation channel, which drives the second seal to actively expand and press against the sealing surface of the shell. This process converts the mechanical force of the shell assembly into the air pressure energy in the airbag, making the second seal fit more tightly and evenly with the sealing surface, and improving the initial sealing reliability.

[0006] The technical solution of this utility model is implemented as follows: This utility model provides a battery module cover plate, including a cover plate body, the inner side of which is provided with a groove and a first airbag, and the groove is connected to the first airbag through an inflation channel.

[0007] The groove is provided with an axially movable control seat, which is sealed to the inner wall of the groove, and its movement stroke is configured to drive the first airbag to inflate by compressing the gas in the groove.

[0008] A second sealing element is fixed to the outer surface of the first airbag. When the first airbag is inflated, the second sealing element is pressed against the sealing surface of the battery module housing.

[0009] The contact surface of the second seal is coated with a water-swellable sealing adhesive layer, which expands in volume when in contact with liquid to fill the gap at the sealing interface.

[0010] Based on the above technical solutions, preferably, one side of the control seat is provided with an inclined surface, which is configured such that when the battery module housing is installed into the cover plate body, the edge of the battery module housing contacts the inclined surface and drives the control seat to move into the groove.

[0011] More preferably, the control seat has an elastic element on the side facing away from the inclined surface. One end of the elastic element is fixed to the inner wall of the groove, and the other end is connected to the control seat, which is used to drive the control seat to reset when the battery module housing is disassembled.

[0012] Based on the above technical solutions, preferably, the edge of the cover plate body is provided with a first sealing element. The first sealing element is an annular structure and is in sealing contact with the battery module shell. The sealing pressure of the first sealing element is independent of the second sealing element.

[0013] Based on the above technical solutions, preferably, it also includes: a second airbag, installed on the top wall of the cover plate body, the second airbag being in sealed contact with the top of the battery module housing.

[0014] In a further preferred embodiment, the cover plate body has a cavity, a piston is installed in the cavity, the piston is sealed to the inner wall of the cavity, the inner wall of the cavity has a through hole and an air inlet, a one-way valve is installed in the air inlet, and the second airbag is connected to the cavity through the through hole.

[0015] Based on the above technical solutions, the preferred method is to use a water-swellable waterproofing adhesive strip.

[0016] Even more preferably, both the second airbag and the first airbag have an annular structure.

[0017] More preferably, the inflation channel is an inflation tube, with one end connected to the groove and the other end connected to the inflation nozzle of the first airbag.

[0018] More preferably, the inflation channel is an inflation hole, with one end connected to the groove and the other end connected to the inflation nozzle of the first airbag.

[0019] The battery module cover plate of this utility model has the following advantages over the prior art:

[0020] Through the coordinated design of the control seat and the first airbag, active inflation sealing is achieved. When the battery module shell is assembled, its edge pushes the control seat to compress the gas in the groove through the inclined surface. The gas is injected into the first airbag through the inflation channel, which drives the second seal to actively expand and press against the sealing surface of the shell. This process converts the mechanical force of the shell assembly into the air pressure energy in the airbag, making the second seal fit more tightly and evenly with the sealing surface. It is especially suitable for scenarios with complex curved surfaces or uneven sealing surfaces, and significantly improves the initial sealing reliability.

[0021] The high-pressure gas inside the first airbag has elastic buffering properties. When the outer shell deforms due to thermal cycling or vibration, the airbag can adjust the internal air pressure by expanding or slightly contracting, automatically compensating for the gap caused by deformation and maintaining a tight fit between the second seal and the outer shell. When a gap appears between the second seal and the outer shell due to the contraction of the airbag, if liquid seeps in, the adhesive layer absorbs moisture and expands in volume, filling the gap and forming a physical barrier to prevent further liquid penetration.

[0022] During installation, the outer shell squeezes the second airbag, forcing gas into the cavity, which in turn moves the piston and triggers the one-way valve to open. A small negative pressure is formed inside the outer shell for a short time. This negative pressure causes the cover plate to be attracted to the outer shell, enhancing assembly stability and reducing the risk of vibration and loosening. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a three-dimensional structural diagram of a battery module cover according to the present invention;

[0025] Figure 2 This is a three-dimensional structural diagram of a battery module cover plate according to this utility model from another perspective;

[0026] Figure 3 This is a schematic diagram of the structure of the first airbag and the second sealing element of a battery module cover plate according to the present invention.

[0027] Figure 4 This is a schematic cross-sectional view of the cover body of a battery module cover according to the present invention;

[0028] Figure 5 for Figure 4 Enlarged cross-sectional views of the middle cover plate body, the first airbag, the control seat and the piston;

[0029] Figure 6 for Figure 5 Enlarged cross-sectional view of the first airbag, the second seal, and the inflation tube.

[0030] Wherein: 100, cover plate body; 101, first sealing element; 102, groove; 103, cavity; 104, piston; 105, one-way valve; 106, through hole; 200, first airbag; 201, second sealing element; 202, water-swellable sealing adhesive layer; 203, inflation tube; 300, control seat; 301, elastic element; 400, second airbag. Detailed Implementation

[0031] The technical solutions of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0032] Example 1: As Figure 1-6 As shown, a battery module cover of this utility model includes a cover body 100. The inner side of the cover body 100 is provided with a groove 102 and a first airbag 200. The groove 102 is connected to the first airbag 200 through an inflation channel. An axially movable control seat 300 is provided in the groove 102. The control seat 300 is sealed to the inner wall of the groove 102, and its movement stroke is configured to drive the first airbag 200 to expand by compressing the gas in the groove 102. A second sealing member 201 is fixed on the outer surface of the first airbag 200. When the first airbag 200 is inflated, the second sealing member 201 is pressed against the sealing surface of the battery module shell. A water-swellable waterproof adhesive layer 202 is laminated on the contact surface of the second sealing member 201. The water-swellable waterproof adhesive layer 202 expands in volume when in contact with liquid to fill the gap of the sealing interface.

[0033] The pressure exerted by the battery module housing on the control seat 300 causes displacement of the control seat 300. The control seat 300 can then compress the gas in the groove 102 into the first airbag 200, causing the first airbag 200 to expand outward. This pushes the first airbag 200 to press the second seal 201 on the outer surface of the housing against the housing seal. The first airbag 200 allows the second seal 201 to fit more closely to the surface of the battery module housing. Even if the cover plate or battery module housing undergoes slight local or overall deformation after long-term vibration or thermal cycling, the high air pressure inside the first airbag 200 can compensate for the deformation area. If the air pressure in the first airbag 200 decreases due to a drop in external temperature and the airbag contracts, a gap will exist between the second seal 201 on the first airbag 200 and the battery module housing. In this case, the water-swellable sealing adhesive layer 202 can expand upon contact with water, filling the tiny gaps at the sealing interface. This is especially suitable for local gaps caused by vibration or thermal deformation of the cover plate, enhancing waterproof sealing.

[0034] like Figure 5 As shown, a slope is provided on one side of the control seat 300. The slope is configured such that when the battery module housing is installed into the cover plate body 100, the edge of the battery module housing contacts the slope and drives the control seat 300 to move into the groove 102. The slope on the control seat 300 can better fit the battery module housing. When the cover plate body 100 is installed on the battery module housing, the battery module housing is inserted into the cover plate body 100 and presses the slope on the control seat 300 accordingly. The control seat 300 can be pushed along the slope to compress the gas in the groove 102.

[0035] like Figure 5 As shown, an elastic element 301 is provided on the side of the control seat 300 facing away from the inclined surface. One end of the elastic element 301 is fixed to the inner wall of the groove 102, and the other end is connected to the control seat 300. It is used to drive the control seat 300 to reset when the battery module shell is disassembled. The elastic element 301 is a spring. When the control seat 300 is squeezed, it deforms. When it is not squeezed, it will drive the control seat 300 to reset.

[0036] like Figure 2 and Figure 5 As shown, the edge of the cover plate body 100 is provided with a first sealing element 101. The first sealing element 101 has an annular structure and is in sealing contact with the battery module shell. The sealing pressure of the first sealing element 101 is independent of the second sealing element 201. The first sealing element 101 achieves sealing through the assembly pre-tightening force between the cover plate body 100 and the shell, providing double sealing protection.

[0037] like Figure 2 and Figure 5As shown, the second airbag 400 is installed on the top wall of the cover plate body 100. The second airbag 400 is in sealed contact with the top of the battery module housing. A cavity 103 is provided on the cover plate body 100. A piston 104 is installed in the cavity 103. The piston 104 is sealed to the inner wall of the cavity 103. A through hole 106 and an air inlet are provided on the inner wall of the cavity 103. A one-way valve 105 is installed in the air inlet. The second airbag 400 is connected to the cavity 103 through the through hole 106.

[0038] A second airbag 400, made of silicone rubber or EPDM rubber, is provided on the top wall of the cover plate body 100. On one hand, when the top edge of the battery module housing contacts the second airbag 400, its inner diameter matches the outer diameter of the top edge of the battery module housing, forming an annular sealing contact surface. On the other hand, when the battery module housing is assembled upwards onto the cover plate body 100, the top edge of the housing contacts the second airbag 400 and applies a compressive force F, triggering the following action:

[0039] The second airbag 400 is deformed under pressure: the volume of the airbag decreases, and the internal gas is forced into the cavity 103 through the through hole 106. At this time, the air pressure P1 in the cavity 103 increases instantaneously.

[0040] Piston 104 moves: The increased air pressure P1 pushes piston 104 to move away from the airbag (i.e., towards the top surface of the cover).

[0041] During the movement of piston 104, the volume change of cavity 103 and the synergistic effect of check valve 105 are as follows:

[0042] Volume change of cavity 103: The piston 104 moves upward, which increases the volume of cavity 103. If the air intake of through hole 106 is less than the increase in volume, the air pressure P1 in cavity 103 will be temporarily lower than the air pressure P2 inside the outer shell (P1 < P2).

[0043] One-way valve 105 opening condition: When P2-P1>5kPa, the valve plate of one-way valve 105 opens, and the gas inside the housing flows into the cavity 103 through the air inlet until the air pressure is balanced (P1≈P2).

[0044] Negative pressure effect: If the piston 104 moves quickly (such as in rapid assembly), the flow rate of gas through the one-way valve 105 is limited, resulting in the gas loss ΔV inside the shell being greater than the increase in volume of cavity 103 ΔV' in a short time. As a result, the gas pressure P2 inside the shell drops briefly, forming a small negative pressure.

[0045] The negative pressure is maintained by the first seal 101 and the second seal 201 between the cover plate body 100 and the outer shell, so that the cover plate is adsorbed onto the outer shell, thereby enhancing the assembly stability.

[0046] Water-swellable waterproofing adhesive layer 202 is a water-swellable waterproofing strip.

[0047] like Figure 2 and Figure 3 As shown, both the second airbag 400 and the first airbag 200 are annular structures.

[0048] like Figure 6 As shown, the inflation channel is an inflation tube 203, one end of which is connected to the groove 102, and the other end is connected to the inflation nozzle of the first airbag 200.

[0049] Example 2: The difference between this example and Example 1 is that, as Figure 5 As shown, the inflation channel is an inflation hole, one end of which is connected to the groove 102, and the other end is connected to the inflation nozzle of the first airbag 200.

[0050] The elastic element 301 adopts an elastic block.

[0051] The working principle of the battery module cover of this utility model is as follows:

[0052] When the battery module housing is assembled upwards onto the cover plate body 100, the edge of the battery module housing contacts the inclined surface of the control seat 300. The thrust applied by the housing along the inclined surface is decomposed into an axial component, pushing the control seat 300 to move into the groove 102. The control seat 300 and the inner wall of the groove 102 are sealed together. During the movement, the gas in the groove 102 is compressed, and the gas is forced into the first airbag 200 through the inflation channel. The first airbag 200 expands due to the increased internal air pressure, pushing the second sealing member 201 on its outer surface to expand outwards, and finally pressing it against the outer peripheral sealing surface of the battery module housing to form an initial mechanical seal.

[0053] The top edge of the battery module housing contacts the second airbag 400. The housing presses the second airbag 400 upward, reducing its volume. The internal gas is forced into the cavity 103 inside the cover plate body 100 through the through hole 106. The gas pressure inside the cavity 103 increases instantaneously, pushing the piston 104 towards the top surface of the cover plate, resulting in an increase in the volume of the cavity 103. If the amount of gas entering through the through hole 106 is less than the increase in the volume of the cavity 103, the gas pressure inside the cavity 103 is briefly lower than the gas pressure inside the housing. The one-way valve 105 in the air hole opens, and the gas inside the housing flows into the cavity 103 through the air inlet. If the piston 104 moves too fast, the flow rate of the gas through the one-way valve 105 is limited, resulting in the amount of gas lost from the housing ΔV > the increase in the volume of the cavity 103 ΔV'. The gas pressure inside the housing drops briefly, forming a small negative pressure. This negative pressure is maintained by the interface between the first seal 101 and the second seal 201, causing the cover plate to be adsorbed onto the housing, enhancing assembly stability.

[0054] The first seal 101 provides a basic seal through the pre-tightening force of the cover plate and the outer shell. Its sealing pressure is independent of other components, ensuring the reliability of the initial seal. The high-pressure gas in the first airbag 200 keeps the second seal 201 pressed against the sealing surface of the outer shell. Even if the cover plate or the outer shell undergoes local or overall deformation due to vibration or thermal cycling (such as thermal expansion or contraction), the first airbag 200 can compensate for the deformation gap through internal air pressure adjustment (expansion or micro-contraction) to maintain the fit between the second seal 201 and the outer shell.

[0055] If the air pressure inside the first airbag 200 decreases due to a drop in external temperature, a small gap may appear between the second seal 201 and the sealing surface of the outer shell. In this case, if liquid seeps into the gap, the water-swellable sealing adhesive layer 202 on the contact surface of the second seal 201 absorbs the liquid and expands in volume, filling the gap and forming a double seal of physical compression and expansion filling to prevent liquid penetration.

[0056] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A battery module cover, comprising a cover body (100), characterized in that: The inner side of the cover plate body (100) is provided with a groove (102) and a first airbag (200), and the groove (102) is connected to the first airbag (200) through an inflation channel; The groove (102) is provided with an axially movable control seat (300), the control seat (300) is sealed to the inner wall of the groove (102), and its movement stroke is configured to drive the first airbag (200) to expand by compressing the gas in the groove (102); The outer surface of the first airbag (200) is fixed with a second sealing member (201). When the first airbag (200) is inflated, the second sealing member (201) is pressed against the sealing surface of the battery module housing. The second seal (201) has a water-swellable sealing adhesive layer (202) on its contact surface. The water-swellable sealing adhesive layer (202) expands in volume when in contact with liquid to fill the gap at the sealing interface.

2. The battery module cover plate as described in claim 1, characterized in that: The control base (300) has a slope on one side, which is configured such that when the battery module housing is installed into the cover plate body (100), the edge of the battery module housing contacts the slope and drives the control base (300) to move into the groove (102).

3. The battery module cover plate as described in claim 2, characterized in that: The control seat (300) has an elastic element (301) on the side facing away from the inclined surface. One end of the elastic element (301) is fixed to the inner wall of the groove (102), and the other end is connected to the control seat (300) for driving the control seat (300) to reset when the battery module housing is disassembled.

4. The battery module cover plate as described in claim 1, characterized in that: The edge of the cover plate body (100) is provided with a first sealing element (101). The first sealing element (101) has an annular structure and is in sealing contact with the battery module shell. The sealing pressure of the first sealing element (101) is independent of the second sealing element (201).

5. The battery module cover plate as described in claim 1, characterized in that: Also includes: The second airbag (400) is installed on the top wall of the cover body (100) and is in sealed contact with the top of the battery module housing.

6. The battery module cover plate as described in claim 5, characterized in that: The cover plate body (100) has a cavity (103) and a piston (104) is installed in the cavity (103). The piston (104) is sealed to the inner wall of the cavity (103). The inner wall of the cavity (103) has a through hole (106) and an air inlet. A one-way valve (105) is installed in the air inlet. The second airbag (400) is connected to the cavity (103) through the through hole (106).

7. The battery module cover plate as described in claim 1, characterized in that: The water-swellable waterproofing layer (202) is a water-swellable waterproofing strip.

8. The battery module cover plate as described in claim 5, characterized in that: Both the second airbag (400) and the first airbag (200) are annular structures.

9. The battery module cover plate as described in claim 1, characterized in that: The inflation channel is an inflation tube (203), one end of which is connected to the groove (102), and the other end is connected to the inflation nozzle of the first airbag (200).

10. The battery module cover plate as described in claim 1, characterized in that: The inflation channel is an inflation hole, one end of which is connected to the groove (102), and the other end is connected to the inflation nozzle of the first airbag (200).

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