Battery pack sound insulation plate capable of preventing electromagnetic excitation noise

Abstract

The invention provides a battery pack sound insulation plate for preventing electromagnetic excitation noise, the battery pack sound insulation plate has an electromagnetic shielding function, and the battery pack sound insulation plate is arranged on a battery pack upper cover plate; the battery pack upper cover plate is used for sealing an upper port of the battery pack metal shell, and the periphery of the battery pack sound insulation plate is connected with the battery pack metal shell. Alternating electromagnetism of the battery pack can be shielded, so that an alternating magnetic field of the battery pack is difficult to reach the vehicle body bottom plate and is difficult to attract and repel the vehicle body bottom plate, the vehicle body bottom plate is difficult to vibrate, and the vehicle body bottom plate is difficult to generate noise due to vibration; the purpose of sound insulation is achieved by reducing vibration noise of the vehicle body bottom plate.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular relates to a battery pack sound insulation board for preventing electromagnetic excitation noise. Background Art

[0002] As the voltage platform of electric vehicles becomes larger and larger, the performance requirements for battery pack charging and discharging power are getting higher and higher. There is an AC component (mainly carrier frequency) emitted by the electric drive controller in the DC bus of the battery pack. The alternating magnetic field formed by it repeatedly attracts and repels the steel or steel-aluminum composite structure of the body floor, causing the body floor to vibrate, thereby generating noise.

[0003] When designing the battery pack, high-voltage components and their layout have a great impact on the electromagnetic environment of the entire pack. However, during the battery pack design process, due to the space squeeze of the body, chassis and components around the battery pack, it is necessary to arrange more cells in a limited space to achieve a higher voltage platform and higher power, which makes the electromagnetic environment of the battery pack more and more complex.

[0004] Since there is a certain gap between the battery pack and the vehicle body floor, the prior art generally fills the gap with buffer foam to achieve the effect of sound absorption and insulation. However, the foam can only isolate air noise and mechanical noise, but cannot shield the electromagnetic of the battery pack, so that it cannot avoid the vibration of the vehicle body floor caused by the alternating magnetic field and the noise it brings, resulting in poor comfort for the passengers in the car. Therefore, how to design a battery pack sound insulation board that is resistant to electromagnetic excitation noise to shield the alternating magnetic field of the battery pack so that the vehicle body floor is not prone to vibration and noise has become a technical problem that technicians in this field urgently need to solve. Summary of the invention

[0005] The purpose of the present invention is to provide a battery pack sound insulation board that is resistant to electromagnetic excitation noise, so as to solve the above-mentioned technical problems in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A battery pack sound insulation board for preventing electromagnetic excitation noise, the battery pack sound insulation board having an electromagnetic shielding function, the battery pack sound insulation board being arranged on a battery pack upper cover plate; the battery pack upper cover plate is used to seal an upper port of a battery pack metal shell, and the periphery of the battery pack sound insulation board is connected to the battery pack metal shell.

[0008] Preferably, the battery pack sound insulation board is a Permalloy board.

[0009] Preferably, the battery pack sound insulation board is a composite board including a low magnetic permeability layer and a waterproof and antifouling buffer layer.

[0010] Preferably, the low magnetic permeability layer is an aluminum foil layer, and the waterproof and antifouling buffer layer is a modified polypropylene layer.

[0011] Preferably, the battery pack sound insulation board includes an upper layer and a lower layer, the upper layer is the modified polypropylene layer, and the lower layer is the aluminum foil layer.

[0012] Preferably, the battery pack sound insulation board includes an upper layer, a middle layer and a lower layer, the middle layer is the aluminum foil layer, and the upper layer and the lower layer are both the modified polypropylene layer.

[0013] Preferably, the battery pack sound insulation board includes an upper layer, a middle layer and a lower layer, the middle layer is the modified polypropylene layer, and the upper layer and the lower layer are both the aluminum foil layer.

[0014] Preferably, the thickness of the aluminum foil layer is 0.1 mm to 0.3 mm.

[0015] Preferably, the modified polypropylene layer has a thickness of 5 mm to 7 mm.

[0016] Preferably, the battery pack sound insulation board is covered on the outside of the battery pack upper cover plate.

[0017] The beneficial effects of the present invention are:

[0018] The battery pack sound insulation board for preventing electromagnetic excitation noise of the present invention has an electromagnetic shielding function, and can shield the alternating magnetic field generated in the battery pack, so that the alternating magnetic field of the battery pack is difficult to reach the vehicle body bottom plate, and the alternating magnetic field is also difficult to attract and repel the vehicle body bottom plate, so that the vehicle body bottom plate is not easy to vibrate, and then the vehicle body bottom plate is not easy to generate noise due to vibration. It can be seen that the present invention achieves the purpose of sound insulation by reducing the generation of vibration noise of the vehicle body bottom plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present invention in detail in conjunction with the drawings, wherein

[0020] Figure 1 A schematic diagram of a battery pack sound insulation board for preventing electromagnetic excitation noise provided in an embodiment of the present invention.

[0021] Markings in the accompanying drawings:

[0022] 11. Upper level, 12. Lower level. DETAILED DESCRIPTION

[0023] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0024] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0025] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0026] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0027] An embodiment of the present invention provides a battery pack sound insulation board for preventing electromagnetic excitation noise, the battery pack sound insulation board has an electromagnetic shielding function, and the battery pack sound insulation board is arranged on a battery pack upper cover plate; the battery pack upper cover plate is used to seal the upper port of the battery pack metal shell, and the periphery of the battery pack sound insulation board is connected to the battery pack metal shell.

[0028] The battery pack sound insulation board for preventing electromagnetic excitation noise provided in the embodiment of the present invention has an electromagnetic shielding function, which can shield the alternating magnetic field generated in the battery pack, so that the alternating magnetic field of the battery pack is difficult to attract and repel the vehicle body floor, thereby making the vehicle body floor less likely to vibrate, and further making the vehicle body floor less likely to generate noise due to vibration, thereby achieving the purpose of sound insulation or silencing.

[0029] In one embodiment of the present invention, the battery pack sound insulation board is a Permalloy plate. With this solution, since the main components of Permalloy are nickel and iron, it has a good electromagnetic shielding function and can effectively shield the alternating magnetic field radiated by the battery pack, making it difficult for the alternating magnetic field to reach the vehicle body floor, thereby effectively reducing the vibration of the vehicle body floor due to the attraction and repulsion of the alternating magnetic field, thereby reducing the generation of vibration noise of the vehicle body floor.

[0030] In another embodiment provided by the present invention, the battery pack sound insulation board is a composite board including a low magnetic permeability layer and a waterproof and antifouling buffer layer. With this solution, the low magnetic permeability layer is used to isolate the vehicle body floor from the alternating magnetic field radiated by the battery pack, making it less likely for the vehicle body floor to produce vibration noise; at the same time, the waterproof and antifouling buffer layer can provide better waterproof, antifouling and buffering effects, thereby preventing the battery pack from being damaged and extending the service life of the battery pack and the battery pack cover. Moreover, with this solution, the problems of high cost and difficult process implementation of Permalloy plates during mass production can be avoided.

[0031] Specifically, the low magnetic permeability layer is an aluminum foil layer, and the waterproof and antifouling buffer layer is a modified polypropylene layer, so that the cost of the composite board is low and it is easy to implement in terms of technology. At the same time, the low magnetic permeability of the aluminum foil layer can play a good electromagnetic shielding function, and the modified polypropylene (MPP) layer can play a good waterproof, antifouling and buffering function.

[0032] like Figure 1 As shown, in one embodiment, the battery pack sound insulation board includes an upper layer 11 and a lower layer 12, the upper layer 11 is the modified polypropylene layer, and the lower layer 12 is the aluminum foil layer, so that the structure of the composite board is simple and easier to process and manufacture. It can be understood that the lower layer 12 is close to the battery pack upper cover plate, and the upper layer 11 is far away from the battery pack upper cover plate.

[0033] In another embodiment, the battery pack sound insulation board includes an upper layer, a middle layer and a lower layer, the middle layer is the aluminum foil layer, and the upper layer and the lower layer are both modified polypropylene layers. With this solution, since the upper layer and the lower layer of the battery pack sound insulation board are both modified polypropylene layers, the battery pack sound insulation board has two modified polypropylene layers, so that the battery pack sound insulation board has better waterproof, anti-fouling and buffering properties, and can better protect the battery pack upper cover and the battery pack.

[0034] In another embodiment, the battery pack sound insulation board includes an upper layer, a middle layer and a lower layer, the middle layer is the modified polypropylene layer, and the upper layer and the lower layer are both the aluminum foil layers. With this solution, since the upper layer and the lower layer of the battery pack sound insulation board are both aluminum foil layers, the battery pack sound insulation board has two aluminum foil layers, so that the battery pack sound insulation board has a better electromagnetic shielding effect, and thus makes it less likely to generate vibration noise of the vehicle body bottom plate caused by electromagnetic excitation, and has a better sound-absorbing effect.

[0035] Preferably, the thickness of the aluminum foil layer is smaller than the thickness of the modified polypropylene layer, thereby effectively reducing the cost.

[0036] Specifically, the thickness of the aluminum foil layer is 0.1 mm to 0.3 mm; the thickness of the modified polypropylene layer is 5 mm to 7 mm.

[0037] In a specific embodiment, a composite board can be formed by using an aluminum foil layer with a thickness of 0.1 mm and an MPP layer with a thickness of 6 mm, a composite board can be formed by using an aluminum foil layer with a thickness of 0.15 mm and an MPP layer with a thickness of 6 mm, and a composite board can be formed by using an aluminum foil layer with a thickness of 0.2 mm and an MPP layer with a thickness of 6 mm. Preferably, a composite board can be formed by using an aluminum foil layer with a thickness of 0.2 mm and an MPP layer with a thickness of 6 mm, so as to not only reduce the cost but also have a better electromagnetic shielding effect.

[0038] Specifically, the battery pack sound insulation board is coated on the outside of the battery pack upper cover plate, so as to achieve a better electromagnetic shielding effect. It can be understood that since the periphery of the battery pack sound insulation board is connected to the battery pack metal shell, the battery pack sound insulation board can be grounded through the battery pack metal shell, so that the current generated by the battery pack sound insulation board when the magnetic field is induced can be conducted out; the battery pack is arranged in the battery pack metal shell.

[0039] It should be noted that the principle of the noise generated by the underbody is as follows: Since the copper bars inside the battery pack are generally arranged around the battery pack, the copper bars inside the battery pack can be considered to have a relatively stable constant current during the discharge process. Based on the Biot-Savart law, the current element will excite a magnetic field in space, and the magnetic field strength at a point in space is proportional to the current magnitude, and inversely proportional to the distance from the point to the current element. Since the underbody is a steel-aluminum composite material or a rigid structure, its magnetic permeability is relatively high, and there is an AC component (mainly the carrier frequency) emitted by the electric drive controller in the DC bus of the battery pack, which will form an alternating magnetic field of the carrier frequency, which is like a magnet that changes direction alternately, repeatedly attracting and repelling the underbody, causing the underbody to vibrate, thereby generating noise.

[0040] The battery pack sound insulation board for preventing electromagnetic excitation noise of the present invention shields the alternating magnetic field of the battery pack, making it difficult for the magnetic field to reach the vehicle body floor. Even if the magnetic field reaches the vehicle body floor after passing through the battery pack sound insulation board, its strength will be significantly reduced, so that the strength of the magnetic field received by the vehicle body floor is also significantly reduced, making it difficult for the vehicle body floor to vibrate due to electromagnetic excitation of the magnetic field. Even if the vehicle body floor vibrates, its vibration amplitude can be reduced, thereby effectively reducing the vibration of the vehicle body floor, reducing the frequency of occurrence of vibration noise of the vehicle body floor, and reducing the noise value of the vibration noise of the vehicle body floor, thereby achieving the purpose of sound insulation, or it can be said that the purpose of silencing is achieved, that is, achieving the purpose of preventing the vehicle body floor from vibrating and generating noise under electromagnetic excitation, thereby reducing the noise received by the occupants in the car and improving the comfort of the occupants.

[0041] The present invention can reduce the vibration of the vehicle body floor caused by the alternating magnetic field generated by the electromagnetic excitation of the battery pack and the vibration noise caused by it, achieving the purpose of preventing electromagnetic excitation noise and preventing the vibration of the vehicle body floor. The present invention is a battery pack sound insulation component with electromagnetic shielding function, which can make it difficult for the alternating magnetic field generated by the copper bus inside the battery pack to act on the vehicle body floor and generate vibration and noise when the battery pack outputs high power, ensuring that the passengers in the crew cabin can have a comfortable NVH experience during the vehicle's medium and high speed driving.

[0042] By covering the upper cover plate of the battery pack with a sound insulation board, the present invention can effectively shield the alternating magnetic field of the carrier frequency formed by the AC component emitted by the electric drive controller in the DC bus when the battery pack is discharged, reduce the vibration and noise of the vehicle body bottom plate, reduce the radiation noise caused by the coupling between the sound insulation board and the floor current, and improve the NVH performance of the whole vehicle.

[0043] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A battery pack sound insulation board for preventing electromagnetic excitation noise, characterized in that: The battery pack sound insulation board has an electromagnetic shielding function, and the battery pack sound insulation board is arranged on the battery pack upper cover plate; the battery pack upper cover plate is used to cover the upper port of the battery pack metal shell, and the periphery of the battery pack sound insulation board is connected to the battery pack metal shell.

2. The battery pack sound insulation board for preventing electromagnetic excitation noise according to claim 1, characterized in that: The battery pack sound insulation board is a Permalloy board.

3. The battery pack sound insulation board for preventing electromagnetic excitation noise according to claim 1, characterized in that: The battery pack sound insulation board is a composite board including a low magnetic permeability layer and a waterproof and antifouling buffer layer.

4. The battery pack sound insulation board for preventing electromagnetic excitation noise according to claim 3 is characterized in that: The low magnetic permeability layer is an aluminum foil layer, and the waterproof and antifouling buffer layer is a modified polypropylene layer.

5. The battery pack sound insulation board for preventing electromagnetic excitation noise according to claim 4, characterized in that: The battery pack sound insulation board includes an upper layer and a lower layer, the upper layer is the modified polypropylene layer, and the lower layer is the aluminum foil layer.

6. The battery pack sound insulation board for preventing electromagnetic excitation noise according to claim 4, characterized in that: The battery pack sound insulation board includes an upper layer, a middle layer and a lower layer, the middle layer is the aluminum foil layer, and the upper layer and the lower layer are both the modified polypropylene layer.

7. The battery pack sound insulation board for preventing electromagnetic excitation noise according to claim 4, characterized in that: The battery pack sound insulation board includes an upper layer, a middle layer and a lower layer, the middle layer is the modified polypropylene layer, and the upper layer and the lower layer are both the aluminum foil layers.

8. The battery pack sound insulation board for preventing electromagnetic excitation noise according to claim 4, characterized in that: The thickness of the aluminum foil layer is 0.1 mm to 0.3 mm.

9. The battery pack sound insulation board for preventing electromagnetic excitation noise according to claim 4, characterized in that: The modified polypropylene layer has a thickness of 5 mm to 7 mm.

10. The battery pack sound insulation board for preventing electromagnetic excitation noise according to any one of claims 1 to 9, characterized in that: The battery pack sound insulation board is covered on the outside of the battery pack upper cover plate.

Images