Lightweight sound insulation structure, sound insulation cover and motor wrapping device

Abstract

The utility model discloses a lightweight sound insulation structure, a sound insulation cover and a motor wrapping device, along the noise propagation direction, the sound insulation structure comprises a PU sound absorption layer, a middle film layer and a PET / PP composite fiber sound insulation layer, the PU sound absorption layer is bonded with the PET / PP composite fiber sound insulation layer through the middle film layer, the middle film layer comprises a PA / PE double-layer film, and the PA / PE double-layer film is bonded with the PET / PP composite fiber sound insulation layer through the middle film layer. The PU sound-absorbing layer and the PET / PP composite fiber sound-insulating layer are bonded through the middle film layer, the PU sound-absorbing layer performs polyurethane foaming on the PA film layer of the middle film layer, in the foaming process, the PA film layer can effectively prevent foam from permeating into the PET / PP composite fiber sound-insulating layer, the PU sound-absorbing layer is of a porous structure, sound absorption is effectively achieved, the PET / PP composite fiber sound-insulating layer is of a compact structure, and the sound-absorbing effect is good. Sound insulation is effectively realized, so that the lightweight sound insulation material has the advantage of reducing noise and has excellent acoustic performance.

Description

Technical Field

[0001] The utility model belongs to the field of automobiles and relates to a lightweight sound insulation structure, a sound insulation cover and a motor wrapping device. Background Art

[0002] The motor is one of the most important components of electric vehicles, but it can easily become a noise source for two reasons: (1) Under non-sinusoidal power supply conditions, the motor has high-frequency electromagnetic force components, which can easily generate electromagnetic noise, which is transmitted through radiation and structure, forming complex reverberation in the cab; (2) Electric vehicles pursue lightweight and high power density. Not only does the mass and stiffness of the motor become smaller, but the frame, rear axle, etc. are also lighter than those of traditional vehicles, making it easier to induce large vibration responses.

[0003] Motor noise reduction mainly uses sound insulation covers and mufflers. Currently, motor wrapping usually adopts EPDM / EVA+PU foam structure, and the EPDM / EVA layer is heavy, which will increase the energy consumption of the car and is not friendly to new energy vehicles. In addition, the wrapping material can only withstand high temperatures of 100 degrees, and its application range is limited. Summary of the invention

[0004] In order to overcome at least one deficiency of the prior art, the utility model provides a lightweight sound insulation structure, a sound insulation cover and a motor wrapping device.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a lightweight sound insulation structure, comprising a PU sound-absorbing layer, an intermediate film layer and a PET / PP composite fiber sound insulation layer stacked in sequence along the noise propagation direction, the PU sound-absorbing layer and the PET / PP composite fiber sound insulation layer are bonded to each other through the intermediate film layer, and the intermediate film layer is a double-layer film, including a PA film and a PE film.

[0006] Furthermore, the PA film layer is bonded to the PU sound absorbing layer, and the PE film layer is bonded to the PET / PP composite fiber sound insulation layer.

[0007] Furthermore, the thickness of the double-layer film is set to 30-100 microns, wherein the thickness of the PA film layer is set to 10-25 microns, and the gram weight of the double-layer film is set to 30-100 g / m2, wherein the gram weight of the PA film layer is set to 10-25 g / m2.

[0008] Furthermore, the gram weight of the PET / PP composite fiber sound insulation layer is set to 800-2000 g / m2, and the bulk density of the PET / PP composite fiber sound insulation layer is set to 400-700 kg / m3.

[0009] Furthermore, the thickness of the PET / PP composite fiber sound insulation layer is set to 2mm-3mm, and the ratio of PET and PP in the PET / PP composite fiber sound insulation layer is set to 55:45-80:20.

[0010] Furthermore, the density of the PU sound absorbing layer is in the range of 60-90 kg / m3.

[0011] Furthermore, the thickness of the PU sound absorbing layer is in the range of 5-20 mm.

[0012] Furthermore, it also includes a non-woven fabric layer, which is arranged on a side of the PET / PP composite fiber sound insulation layer away from the noise source.

[0013] The utility model also provides a sound insulation cover, which is made of the above-mentioned lightweight sound insulation material.

[0014] The utility model also provides a motor wrapping material, and the motor wrapping material comprises the above-mentioned sound insulation cover.

[0015] In summary, the utility model is beneficial in that:

[0016] 1) The PU sound-absorbing layer of the utility model is bonded to the PET / PP composite fiber sound insulation layer through an intermediate film layer. The PU sound-absorbing layer is subjected to polyurethane foaming on the PA film layer of the intermediate film layer. During the foaming process, the PA film layer can effectively prevent the foam from penetrating into the PET / PP composite fiber sound insulation layer. The PU sound-absorbing layer has a porous structure and effectively realizes sound absorption. The PET / PP composite fiber sound insulation layer has a dense structure and effectively realizes sound insulation, so that the lightweight sound insulation material has the advantage of reducing noise and has excellent acoustic performance.

[0017] 2) The PET / PP composite fiber sound insulation layer of the utility model has a relatively high melting point and can withstand a high temperature of 150°C, which enables the lightweight sound insulation material to have the advantage of high temperature resistance and makes the lightweight sound insulation material suitable for high temperature application scenarios.

[0018] 3) The PU sound-absorbing layer of the utility model can be foamed into a desired shape through a mold, so that it can better fit the object that needs sound insulation, such as the motor, and better wrap the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the lightweight sound insulation material of the present utility model.

[0020] Figure 2 This is a sound transmission loss test diagram of the present utility model.

[0021] Markings in the figure: PU sound-absorbing layer 1, intermediate film layer 2, PET / PP composite fiber sound insulation layer 3, non-woven fabric layer 4. DETAILED DESCRIPTION

[0022] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0023] For ease of understanding, the following terms are explained:

[0024] PU: Polyurethane

[0025] PA: Polyamide

[0026] PE: Polyethylene

[0027] PET: Polyester resin

[0028] PP: Polypropylene

[0029] Example:

[0030] like Figure 1-Figure 2 As shown, a lightweight sound insulation structure includes a PU sound absorbing layer 1, an intermediate film layer 2 and a PET / PP composite fiber sound insulation layer 3 which are stacked in sequence along the noise propagation direction. The PU sound absorbing layer 1 and the PET / PP composite fiber sound insulation layer 3 are bonded to each other through the intermediate film layer 2. The intermediate film layer 2 is a double-layer film including a PA film and a PE film.

[0031] The PU sound-absorbing layer 1 is a polyurethane foam layer. The PU sound-absorbing layer 1 is located on one side of the noise source, that is, the PU sound-absorbing layer 1 is close to the noise source. The noise emitted by the noise source is first transmitted to the PU sound-absorbing layer 1. The PU sound-absorbing layer 1 has a porous structure. The sound energy frequently oscillates and rubs in the porous structure, and the sound energy is weakened, thereby effectively achieving sound absorption. In addition, the PU sound-absorbing layer 1 is a porous and loose material with a relatively soft material. The PU sound-absorbing layer is set on the inner side, which is more closely fitted to objects that need sound insulation, such as motors, and has better overall wrapping.

[0032] The PU sound-absorbing layer 1 is produced by the reaction of material A and material B, wherein material A is polyether polyol, material B is isocyanate, and the weight ratio of material A to material B is 100:40-100:70.

[0033] The density of the PU sound absorbing layer 1 is set to 70 kg / m 3 .

[0034] The middle film layer 2 is composited by a PA film layer and a PE film layer. The PA film layer is bonded to the PU sound absorbing layer 1. The PE film layer is located between the PA film layer and the PET / PP composite fiber sound insulation layer 3. The PE film layer is bonded to the PET / PP composite fiber sound insulation layer, thereby achieving bonding between the PU sound absorbing layer 1 and the PET / PP composite fiber sound insulation layer 3 through the middle film layer 2.

[0035] The preparation process of the sound insulation material provided in this embodiment is as follows: firstly, the PET / PP composite fiber sound insulation layer and the intermediate film layer are hot-pressed and then the intermediate film layer is subjected to PU foaming to obtain the PU sound absorption layer 1. When the PU sound absorption layer is formed, the pre-formed PET / PP composite fiber sound insulation layer and the intermediate film layer are first placed in the mold cavity, and the PET / PP composite fiber sound insulation layer is fitted with the bottom of the cavity. Then, the liquid material is injected into the cavity. The intermediate film layer is provided to effectively prevent the liquid material from penetrating into the PET / PP composite fiber sound insulation layer 3.

[0036] The thickness of the double-layer film is set to 30-100 microns, wherein the thickness of the PA film layer is set to 10-25 microns, and the gram weight of the double-layer film is set to 30-100 g / m2, wherein the gram weight of the PA film layer is set to 10-25 g / m2. This embodiment sets the thickness and gram weight of the PA film layer and the PE film layer to enhance the strength of the middle film layer 2, thereby effectively preventing deformation and breakage of the middle film layer 2 due to stress during the foaming process of the PU sound-absorbing layer 1.

[0037] For a film containing or consisting of PE, the tear strength can be improved when its thickness is not less than 30 μm and not more than 60 μm, preferably about 40 μm, so the tear strength of the intermediate film layer 2 can be improved by increasing the thickness of the film layer.

[0038] Furthermore, the middle film layer can also play a certain acoustic role. Both the PA film layer and the PE film layer are airtight. When sound waves are transmitted to the PA film layer and the PE film layer, part of the sound waves will be bounced back into the PU sound-absorbing layer, playing a certain sound insulation role.

[0039] The ratio of PET to PP in the PET / PP composite fiber sound insulation layer 3 is set to 55:45-80:20.

[0040] PET is a high melting point substrate with a melting point of 250℃-260℃, and PP is a low melting point component with a melting point of 150℃-160℃. During the processing, it is preheated to between the melting points of the two materials, such as 200 degrees. PP melts and can be pressed into the required dense structure.

[0041] The gram weight of the PET / PP composite fiber sound insulation layer 3 is 800gsm-2000gsm, and the PET / PP composite fiber sound insulation layer 3 has two states, including a free state and a compressed state. In the free state, the thickness of the PET / PP composite fiber sound insulation layer 3 is 6mm-8mm, which can be obtained by a conventional needle punching process and has a porous loose structure. In the compressed state, the thickness of the PET / PP composite fiber sound insulation layer 3 is 2mm-3mm, which is obtained from the free state by a hot pressing process. First, the PET / PP composite fiber material needs to be preheated in an oven or a preheating furnace, the preheating temperature is 185+ / -10℃, and the preheating time is 100s. The preheated material is quickly placed in the mold, the mold temperature is 40+ / -10℃, the mold gap is 2-3mm, the mold is closed and pressed, the pressing pressure is 280T, and the holding time is 70+ / -10s.

[0042] The PET / PP composite fiber sound insulation layer 3 has a relatively high melting point and can withstand a high temperature of 150°C, which enables the lightweight sound insulation material to have the advantage of being resistant to high temperatures and to be suitable for high temperature application scenarios.

[0043] In this embodiment, the traditional heavy layer is replaced by the PET / PP composite fiber sound insulation layer 3, the gram weight of the heavy layer is more than 2000gsm, and the gram weight of the PET / PP composite fiber sound insulation layer 3 is 800gsm-2000gsm, thereby meeting the lightweight demand.

[0044] In this embodiment, acoustic tests are performed on the heavy layer + PU sound absorbing layer, the lightweight sound insulation material, and the PU sound absorbing layer 1 + PET / PP composite fiber sound insulation layer 3 to detect the transmission loss of sound at different frequencies. The greater the sound transmission loss, the better the sound absorption and sound insulation effect of the material. The acoustic test of the heavy layer + PU sound absorbing layer is marked as Scheme A, the acoustic test of the lightweight sound insulation material is marked as Scheme B-1, and the acoustic test of the PU sound absorbing layer 1 + PET / PP composite fiber sound insulation layer 3 is marked as Scheme B-1LC. The following results are obtained: Figure 2 The test diagram shown, Figure 2 The vertical axis is the transmission loss in dB, and the horizontal axis is the frequency in Hz. It can be seen from the figure that in the frequency range of 1600Hz-2500Hz, the transmission loss of Scheme B-1 is significantly greater than the transmission loss of Scheme A and Scheme B-1LC. The frequency range of 1600Hz-2500Hz is the frequency range of the noise source of electric vehicles. The lightweight sound insulation material provided by the utility model effectively isolates the noise, effectively reduces the noise, and has excellent acoustic performance.

[0045] Table 1 shows the sound absorption performance results of the lightweight sound insulation material provided in this application. The sound absorption test method adopts a conventional reverberation chamber α box, and the sample size is 1.2m*1m.

[0046]

[0047]

[0048] Table 2 shows the sound insulation performance results of the lightweight sound insulation material provided in this application, and the sound insulation test method adopts an acoustic window test room.

[0049]

[0050]

[0051] It can be seen from Table 1 and Table 2 that the lightweight sound insulation material provided by the utility model can effectively isolate noise, has a good sound absorption effect, reduces noise, and has excellent acoustic performance.

[0052] Preferably, the lightweight sound insulation material further includes a non-woven fabric layer 4 , and the non-woven fabric layer 4 is arranged on the PET / PP composite fiber sound insulation layer 3 .

[0053] The present application also provides a sound insulation cover, which is made of the above-mentioned lightweight sound insulation material.

[0054] The present application also provides a motor wrapping material, including the above-mentioned sound insulation cover.

[0055] Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

Claims

1. A lightweight sound insulation structure, characterized in that: The device includes a PU sound absorbing layer, an intermediate film layer and a PET / PP composite fiber sound insulation layer which are sequentially stacked along the noise propagation direction; the PU sound absorbing layer and the PET / PP composite fiber sound insulation layer are bonded to each other through the intermediate film layer; and the intermediate film layer is a double-layer film including a PA film layer and a PE film layer.

2. A lightweight sound insulation structure according to claim 1, characterized in that: The PA film layer is bonded to the PU sound-absorbing layer, and the PE film layer is bonded to the PET / PP composite fiber sound-insulating layer.

3. A lightweight sound insulation structure according to claim 1, characterized in that: The thickness of the double-layer film is set to 30-100 microns, wherein the thickness of the PA film layer is set to 10-25 microns, and the gram weight of the double-layer film is set to 30-100 g / m2, wherein the gram weight of the PA film layer is set to 10-25 g / m2.

4. A lightweight sound insulation structure according to claim 1, characterized in that: The gram weight of the PET / PP composite fiber sound insulation layer is set to 800-2000 g / m2, and the bulk density of the PET / PP composite fiber sound insulation layer is set to 400-700 kg / m3.

5. A lightweight sound insulation structure according to claim 1, characterized in that: The thickness of the PET / PP composite fiber sound insulation layer is set to 2mm-3mm.

6. A lightweight sound insulation structure according to claim 1, characterized in that: The density of the PU sound absorbing layer is in the range of 60-90 kg / m3.

7. A lightweight sound insulation structure according to claim 1, characterized in that: The thickness of the PU sound-absorbing layer ranges from 5 to 20 mm.

8. The lightweight sound insulation structure according to claim 1, characterized in that: It also includes a non-woven fabric layer, which is arranged on a side of the PET / PP composite fiber sound insulation layer away from the noise source.

9. A soundproof enclosure, characterized in that: The soundproof cover is made of the lightweight soundproof structure according to any one of claims 1-8.

10. A motor wrapping device, characterized in that: The motor wrapping device includes the sound insulation cover according to claim 9.

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