Battery cover

Abstract

The invention provides a battery cover capable of reducing noise leaking from an engine room to the outside of a vehicle. A battery cover disposed in an engine room includes a cover wall portion covering a side surface of a battery, the cover wall portion is provided with a sound-absorbing surface portion having a first sound-absorbing layer and a second sound-absorbing layer laminated in a thickness direction, the first sound-absorbing layer being formed of a sound-absorbing material for a first frequency band, the second sound-absorbing layer being formed of a sound-absorbing material for a second frequency band, and the second sound-absorbing layer being formed of a sound-absorbing material for a third frequency band. The second sound-absorbing layer is formed of a sound-absorbing material for a second frequency band lower than the first frequency band.

Description

Technical Field

[0001] The present invention relates to the technical field of a battery cover mounted on a battery mounted on a vehicle such as an automobile. Background Art

[0002] Some vehicles such as automobiles have a battery cover mounted on a battery installed in an engine compartment (for example, see Patent Document 1). The battery arranged in the engine compartment together with the engine may deteriorate or malfunction due to temperature changes caused by heat generated by the engine, but by installing the battery cover as described above, the influence of ambient temperature changes on the battery is suppressed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-231885 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in recent years, restrictions on vehicle noise have also been increasing. In particular, vehicles with an engine (internal combustion engine) as a driving source tend to have louder sounds from the driving source than vehicles with only an electric motor driven by electricity as a driving source (electric vehicles), so it is desirable to reduce the noise leaking from the engine room to the outside of the vehicle.

[0008] Therefore, an object of the present invention is to reduce the noise leaking from the engine room to the outside of the vehicle.

[0009] Technical solutions to technical problems

[0010] The battery cover of the present invention is arranged in the engine room, and includes a cover wall portion covering the side of the battery. A sound absorbing surface portion is provided on the cover wall portion, and the sound absorbing surface portion has a first sound absorbing layer and a second sound absorbing layer stacked in the thickness direction. The first sound absorbing layer is formed by a sound absorbing material for a first frequency band, and the second sound absorbing layer is formed by a sound absorbing material for a second frequency band lower than the first frequency band.

[0011] Thus, sounds of different frequency bands are absorbed by the first sound absorbing layer and the second sound absorbing layer.

[0012] Effects of the Invention

[0013] According to the present invention, since the first sound absorbing layer and the second sound absorbing layer absorb sounds of different frequency bands, the battery cover absorbs sounds of a wide frequency range, thereby reducing noise leaking from the engine room to the outside of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 and Figure 2 and Figure 3 Together, the embodiments of the battery cover of the present invention are shown. Figure 1 It is a schematic plan view showing the engine room.

[0015] Figure 2 It is a three-dimensional diagram of the battery cover.

[0016] Figure 3 is a cross-sectional view of the battery cover. DETAILED DESCRIPTION

[0017] The following describes the method for implementing the battery cover of the present invention in conjunction with the accompanying drawings.

[0018] In the following description, the vehicle's forward direction is set to the front, and the front and rear, up and down, left and right directions are indicated. However, the front and rear, up and down, left and right directions shown below are for the convenience of description, and the implementation of the present invention is not limited to these directions.

[0019] <General Structure of Engine Room>

[0020] First, a schematic configuration of an engine room of a vehicle in which a battery cover is mounted will be described.

[0021] For example, an engine room 101 is formed at the front side of the vehicle compartment of the vehicle 100 (see Figure 1 ). An engine 110, a battery 120, and a battery cover 1 are arranged in the engine room 101. An openable and closable engine cover (not shown) is provided on the upper side of the engine room 101.

[0022] The engine 110 is disposed in the substantially central portion of the engine room 101 and serves as a power source for the vehicle 100. The vehicle 100 may be a vehicle that runs solely on power utilizing fuel (gasoline), or may be a hybrid vehicle that includes a drive motor in addition to the engine 110 and runs on at least one of power based on fuel or power based on electricity.

[0023] The battery 120 is located in the engine room 101, for example, behind the left side of the engine 110. The battery 120 is used as a power source for each part operated by electricity in the vehicle 100. The battery 120 is formed into a rectangular box shape, and the battery cover 1 is mounted to cover each side.

[0024] <Battery cover configuration>

[0025] Next, the structure of the battery cover 1 will be described (see Figure 2 and Figure 3 ).

[0026] The battery cover 1 is formed into a square tube shape with its axial direction extending in the vertical direction, and has four cover walls 2 that cover the side surfaces of the battery 120 from four directions (see FIG. Figure 2 ).

[0027] The cover wall portion 2 includes a front face portion 3 and a rear face portion 4 that face the front-rear direction and are separated from each other, and a right face portion 5 and a left face portion 6 that face the left-right direction and are separated from each other. Front and rear ends of the right face portion 5 are respectively continuous with the right end portion of the front face portion 3 and the right end portion of the rear face portion 4, and front and rear ends of the left face portion 6 are respectively continuous with the left end portion of the front face portion 3 and the left end portion of the rear face portion 4. The battery cover 1 is mounted on the battery 120 in a state where at least a portion of the right face portion 5 faces the engine 110.

[0028] In the cover wall portion 2 , the front surface portion 3 and the right side surface portion 5 form a sound absorbing surface portion 7 , and the rear surface portion 4 and the left side surface portion 6 form a supporting surface portion 8 .

[0029] The sound absorbing surface portion 7 has, for example, a five-layer structure in which an outer member 9, a first sound absorbing layer 10, a second sound absorbing layer 11, a protective layer 12, and an inner member 13 are sequentially stacked from the outer side in the thickness direction (see Figure 3 ). An adhesive or an adhesive sheet may be provided between the stacked layers.

[0030] The outer member 9 and the inner member 13 are formed of the same material, for example, polyester nonwoven fabric. The sizes of the outer member 9 and the inner member 13 in the surface direction are set to be larger than the first sound absorbing layer 10, the second sound absorbing layer 11, and the protective layer 12, and the outer edge of the outer member 9 and the outer edge of the inner member 13 are thermally pressed. In the sound absorbing surface portion 7, the first sound absorbing layer 10, the second sound absorbing layer 11, and the protective layer 12 are held by the outer member 9 and the inner member 13 in a state of being sandwiched from both sides.

[0031] The first sound absorbing layer 10 is mainly formed of a material having sound absorbing properties for a frequency band above 1000 Hz (first frequency band), such as an aluminum film. In addition, copper, lead, silver, gold, platinum, etc. can be used as the first sound absorbing layer 10. The higher the specific gravity of the metal used, the higher the sound absorbing performance of the first sound absorbing layer 10 can be ensured.

[0032] The second sound absorbing layer 11 is formed of a material having sound absorbing properties for a frequency band lower than the first sound absorbing layer 10, for example, mainly a frequency band below 1000 Hz (second frequency band), such as polyurethane. The thickness of the second sound absorbing layer 11 is set to be thicker than the first sound absorbing layer 10, and is maintained in a compressed state in the thickness direction by the outer member 9 and the inner member 13. Since the second sound absorbing layer 11 is compressed in the thickness direction, the thickness of the cover wall portion 2 is reduced, so it is difficult to cause the battery cover 1 to be enlarged. In addition, as the second sound absorbing layer 11, in addition to polyurethane, a foam material or a rubber material can also be used.

[0033] The protective layer 12 is formed of a material having corrosion resistance to battery liquid (dilute sulfuric acid), and for example, an aluminum film similar to the first sound absorbing layer 10 is used as the protective layer 12. The thickness and size of the protective layer 12 are also set to be substantially the same as those of the first sound absorbing layer 10. In addition, copper, lead, silver, gold, platinum, etc. can be used as the protective layer 12, as with the first sound absorbing layer 10, and the protective layer 12 and the first sound absorbing layer 10 can be formed of different materials. The smaller the ionization tendency of the metal used as the protective layer 12, the higher the corrosion resistance to the battery liquid can be ensured.

[0034] The support surface portion 8 has, for example, a four-layer structure in which the outer member 9, the second sound absorbing layer 11, the protective layer 12, and the inner member 13 are stacked in order from the outer side in the thickness direction. In the support surface portion 8, the second sound absorbing layer 11 and the protective layer 12 are held in a state of being sandwiched from both sides by the outer member 9 and the inner member 13. Each layer in the support surface portion 8 is set to the same structure as that of the sound absorbing surface portion 7.

[0035] As described above, in the battery cover 1, a sound absorbing surface portion 7 having a first sound absorbing layer 10 and a second sound absorbing layer 11 stacked in the thickness direction is provided, the first sound absorbing layer 10 being formed of a sound absorbing material for a first frequency band, and the second sound absorbing layer 11 being formed of a sound absorbing material for a second frequency band lower than the first frequency band.

[0036] Therefore, since the first sound absorbing layer 10 and the second sound absorbing layer 11 absorb sounds of different frequency bands, the battery cover 1 absorbs sounds of a wide frequency range emitted from the engine 110 , thereby reducing noise leaking from the engine room 101 to the outside of the vehicle.

[0037] In the engine room 101, at least a portion of the sound absorbing surface 7 (right side surface 5) is located opposite to the engine 110. Therefore, the sound generated by the engine 110 easily reaches the sound absorbing surface 7, so that the battery cover 1 can ensure a good sound absorbing state.

[0038] In addition, the front surface 3 of the battery cover 1 is also set as a sound absorbing surface 7, and the cover wall portion 2 located on the side close to the engine 110 among the four cover walls 2 is set to have a structure that functions as a sound absorbing surface 7. As a result, the sound emitted from the engine 110 can easily reach any sound absorbing surface 7, so that a better sound absorbing state of the battery cover 1 can be ensured.

[0039] In addition, in the battery cover 1, the first sound absorbing layer 10 is located on the outside of the second sound absorbing layer 11. Sounds with higher frequencies (shorter wavelengths) are more easily reflected, and conversely, sounds with lower frequencies (longer wavelengths) have higher penetrability. Therefore, by adopting the structure as described above, sounds in the first frequency band are easily absorbed by the first sound absorbing layer 10 without being reflected, and sounds in the second frequency band pass through the first sound absorbing layer 10 and are absorbed by the second sound absorbing layer 11, thereby ensuring high sound absorption performance of the battery cover 1.

[0040] In addition, the protective layer 12 is provided inside the second sound absorbing layer 11. Thus, if battery liquid leaks from the battery 120, the second sound absorbing layer 11 is protected from the battery liquid by the protective layer 12, thereby preventing the second sound absorbing layer 11 from being dissolved and deteriorated by the battery liquid, thereby extending the life of the battery cover 1.

[0041] Furthermore, the protective layer 12 is formed of the same material as the first sound absorbing layer 10. Thus, since it is not necessary to prepare dedicated materials for the protective layer 12 and the first sound absorbing layer 10, respectively, the manufacturability of the battery cover 1 can be improved.

[0042] Furthermore, in the battery cover 1, an aluminum film is used as the first sound absorbing layer 10, and polyurethane is used as the second sound absorbing layer 11. Thus, the battery cover 1 can be made lighter and noise can be reduced without significantly increasing the manufacturing cost.

[0043] In addition, although the example in which the sound absorbing surface portion is formed of sound absorbing materials for two different frequency bands is shown above, the sound absorbing surface portion may be configured to have sound absorbing materials for three or more different frequency bands.

[0044] Furthermore, by changing the thickness and material combination of the first sound absorbing layer and the second sound absorbing layer, the frequency band of the sound absorbed by the sound absorbing surface portion can be set to an arbitrary value.

[0045] Explanation of symbols

[0046] 100…Vehicles

[0047] 101…Engine Room

[0048] 110…Engine

[0049] 120…Battery

[0050] 1…Battery cover

[0051] 2…Hood wall

[0052] 7…Sound-absorbing face

[0053] 8…Support your face

[0054] 10…First sound absorbing layer

[0055] 11…Second sound absorbing layer

[0056] 12…protective layer.

Claims

1. A battery cover, which is arranged in an engine room, comprising: a cover wall portion, which covers the sides of the battery, The cover wall portion is provided with a sound absorbing surface portion, wherein the sound absorbing surface portion has a first sound absorbing layer and a second sound absorbing layer stacked in a thickness direction. The first sound absorbing layer is formed of a sound absorbing material for a first frequency band, The second sound absorbing layer is formed of a sound absorbing material for a second frequency band lower than the first frequency band.

2. The battery cover according to claim 1, wherein: At least a portion of the sound absorbing surface portion is located opposite to the engine.

3. The battery cover according to claim 1 or 2, wherein: The first sound absorbing layer is located outside the second sound absorbing layer.

4. The battery cover according to claim 3, wherein: A protection layer for protecting the second sound absorbing layer from the influence of battery fluid is arranged on the inner side of the second sound absorbing layer.

5. The battery cover according to claim 4, wherein: The first sound absorbing layer and the protective layer are formed of the same material.

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