Composite front wall sound insulation pad

Abstract

The utility model discloses a composite front wall sound insulation pad, and relates to the technical field of new energy automobiles, the composite front wall sound insulation pad comprises a pad main body, the pad main body is formed by compounding and bonding a blocking layer, a reflecting layer and a sound absorption layer, the blocking layer is a hard polyethylene glycol terephthalate / polypropylene blend fiber surface layer, and a compact structure blocks high-frequency noise of an engine compartment and improves the sound absorption effect. The reflecting layer is a polyethylene / polyamide / polyethylene composite film middle layer and is used for inhibiting structural noise generated by metal plate vibration, a polyamide film is rigidly supported to form a quality-spring system and reflect low-frequency sound waves, the sound absorbing layer is a polyethylene glycol terephthalate / wool composite cotton felt bottom layer, wool fibers are of a natural pore structure and absorb medium-frequency sound waves, and the sound absorbing effect is good. Through collaborative design of the hard barrier layer, the elastic reflecting layer and the porous sound absorption layer, full-band noise control is realized.

Description

Technical Field

[0001] This utility model relates to the field of new energy vehicle technology, and in particular to a composite front sound insulation pad. Background Technology

[0002] The front bulkhead is an important component of the car body. It is located between the engine compartment and the passenger compartment and plays a role in isolating engine exhaust, high temperature and noise. The front bulkhead sound insulation pad is a core component for noise, vibration and acoustic roughness control of new energy vehicles, and it addresses unique challenges such as high-frequency noise of motors, structural vibration and cavity resonance.

[0003] However, when the drive motor and reducer are running at high speed, they generate electromagnetic vibration and mechanical meshing noise, with a typical frequency range of 2000-5000Hz and a sound pressure level of 85-95dB. This noise can easily penetrate traditional sound insulation materials and form a "sharp howl", which seriously affects the comfort of driving and riding. Utility Model Content

[0004] The purpose of this utility model is to solve the problems existing in the prior art by proposing a composite front sound insulation pad.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a composite front sound insulation pad, comprising a pad body, the pad body being composed of a barrier layer, a reflective layer and a sound-absorbing layer bonded together, the barrier layer being bonded to the upper side of the reflective layer, the sound-absorbing layer being bonded to the lower side of the reflective layer, a crease being provided in the middle of the pad body to make it a mirror symmetrical structure, and both sides of the pad body being hot-pressed to form folded edges, with protrusions provided at the bends of the folded edges.

[0006] Preferably, both ends of one side of the pad body are hot-pressed with recessed areas, and the depth of the recessed areas is equal to the thickness of the pad body.

[0007] Preferably, an installation area is hot-pressed in the opposite direction at the edge of the recessed area, and the depth of the installation area is equal to the depth of the recessed area.

[0008] Preferably, the middle part of the recessed area and the middle part of the pad body are both hot-pressed with a second rounded corner groove, and the opening direction of the recessed area and the second rounded corner groove is the same.

[0009] Preferably, a first rounded corner groove is hot-pressed in the middle of the recessed area, and the opening direction of the first rounded corner groove is opposite to the opening direction of the recessed area.

[0010] Preferably, the first rounded corner groove and the second rounded corner groove have the same depth, and the first rounded corner groove and the second rounded corner groove are distributed perpendicular to each other.

[0011] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0012] 1. In this utility model, the barrier layer is a rigid polyethylene terephthalate / polypropylene blended fiber surface layer, with a dense structure to block high-frequency noise from the engine compartment; the reflective layer is a polyethylene / polyamide / polyethylene composite film intermediate layer, which suppresses structural noise generated by sheet metal vibration; the rigid support of the polyamide film forms a "mass-spring" system to reflect low-frequency sound waves; and the sound-absorbing layer is a polyethylene terephthalate / wool composite cotton felt bottom layer, with the natural porous structure of wool fibers absorbing mid-frequency sound waves. Through the synergistic design of the rigid barrier layer, elastic reflective layer, and porous sound-absorbing layer, noise control across the entire frequency band is achieved.

[0013] 2. In this utility model, the crease divides the pad body into two symmetrical parts. When installed in the mounting areas at both ends, the pad body can better fit the front part of the car. The pad body has a recessed area with the same opening direction and a second rounded corner groove, as well as a mounting area with the same opening direction and a first rounded corner groove, which enhances the structural strength of the pad body. The first rounded corner groove and the second rounded corner groove are perpendicular to each other. Under the action of the folded edges on both sides, the pad body's resistance to deformation is enhanced. Attached Figure Description

[0014] Figure 1 This utility model provides a first three-dimensional structural schematic diagram of a composite front sound insulation pad;

[0015] Figure 2 This utility model provides a schematic diagram of the second three-dimensional structure of a composite front sound insulation pad;

[0016] Figure 3 A cross-sectional view of a composite front sound insulation pad is provided for this utility model.

[0017] Legend: 1. Main body of the pad; 11. Barrier layer; 12. Reflective layer; 13. Sound-absorbing layer; 2. Folded edge; 3. Recessed area; 4. Installation area; 5. First rounded corner groove; 6. Second rounded corner groove; 7. Crease. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0019] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0020] Example 1: As Figure 1 - Figure 3As shown, this utility model provides a composite front sound insulation pad, including a pad body 1. The pad body 1 is composed of a barrier layer 11, a reflective layer 12 and a sound-absorbing layer 13 bonded together. The barrier layer 11 is bonded to the upper side of the reflective layer 12, and the sound-absorbing layer 13 is bonded to the lower side of the reflective layer 12. A crease 7 is provided in the middle of the pad body 1 to make it a mirror symmetrical structure. Both sides of the pad body 1 are hot-pressed with folded edges 2, and protrusions are provided at the bends of the folded edges 2.

[0021] The specific setup and function of this embodiment are described below: Barrier layer 11 is a rigid polyethylene terephthalate / polypropylene blend fiber surface layer, using a blend of 35% polyethylene terephthalate (density 1.36 g / cm³) and 65% polypropylene (density 0.92 g / cm³) fibers. A rigid barrier is formed through needle punching and hot pressing processes, with a density of 0.3-0.5 g / cm³ and a thickness of 4-6 mm. The surface is hot-embossed to a roughness Ra≤1.6μm, increasing the sound wave contact area and reducing reflection. The sound insulation for mid-to-high frequencies (>1000Hz) reaches 25-30 dB. The dense structure blocks high-frequency noise from the engine compartment, such as motor whine, while simultaneously dissipating some sound energy through inter-fiber friction. The temperature resistance is 150℃ for short-term use, meeting the high-temperature environment of the engine compartment. The polyamide film interlayer has a melting point of 160℃ to prevent delamination between the surface layer and the intermediate layer. The reflective layer 12 is a polyethylene / polyamide / polyethylene composite film intermediate layer. The two polyethylene films have a melting point of 120℃ and are bonded to the surface layer and the bottom layer by heating and melting. The thickness of the intermediate polyamide film nylon interlayer is 0.5-1mm, and the water vapor transmission rate is <5g / (m²・24h). A butyl rubber damping layer with a loss factor >0.3 is added to the inner side of the film layer to suppress structural noise generated by sheet metal vibration. The rigid support of the polyamide film forms a "mass-spring" system, reflecting low-frequency sound waves <500Hz, and the weighted sound insulation Rw≥28dB. The polyethylene film is hot-melt bonded to ensure structural stability while blocking moisture penetration and preventing the bottom cotton felt from becoming damp and moldy. The sound-absorbing layer 13 is a polyethylene terephthalate / wool composite cotton felt bottom layer, containing 15%-30% wool fiber and low-melting-point polyethylene terephthalate fiber, with a density of 0.12-0.18 g / cm³, a thickness of 15-20 mm, and an open porosity >90%. Under halogen-free flame retardant conditions, the flame retardancy rating reaches the national standard GB8410 vertical burning test FV-0 level, with a smoke density rating SDR <15. The natural porous structure of the wool fiber absorbs mid-frequency sound waves of 500-2000Hz, resulting in a noise reduction coefficient NRC ≥0.85. The polyethylene terephthalate fiber provides structural support, preventing rebound after compression. With bio-based materials accounting for over 50%, the carbon footprint is reduced by 40% compared to traditional polyurethane foam. Through the synergistic design of rigid barrier layer 11, elastic reflective layer 12, and porous sound-absorbing layer 13, noise control across the entire frequency band is achieved.

[0022] Example 2: Figure 1 - Figure 2As shown, recessed areas 3 are hot-pressed at both ends of one side of the pad body 1. The depth of the recessed areas 3 is equal to the thickness of the pad body 1. An installation area 4 is hot-pressed in the opposite direction at the edge of the recessed areas 3. The depth of the installation area 4 is equal to the depth of the recessed areas 3. A second rounded corner groove 6 is hot-pressed in the middle of the recessed areas 3 and the middle part of the pad body 1. The opening directions of the recessed areas 3 and the second rounded corner groove 6 are the same. A first rounded corner groove 5 is hot-pressed in the middle of the recessed areas 3. The opening direction of the first rounded corner groove 5 is opposite to the opening direction of the recessed areas 3. The depths of the first rounded corner groove 5 and the second rounded corner groove 6 are the same. The first rounded corner groove 5 and the second rounded corner groove 6 are distributed perpendicularly to each other.

[0023] The overall effect of this embodiment is that the crease 7 divides the pad body 1 into two symmetrical parts. When the pad body 1 is installed in the mounting areas 4 at both ends, it can better fit the front part of the car. The recessed area 3 and the second rounded corner groove 6 have the same opening direction. The mounting area 4 and the first rounded corner groove 5 have the same opening direction, which enhances the structural strength of the pad body 1. The four parts have the same hot pressing depth. The first rounded corner groove 5 and the second rounded corner groove 6 are in a vertical state. Under the action of the folded edges 2 on both sides, the deformation resistance of the pad body 1 is enhanced.

[0024] The usage and working principle of this device are as follows: Barrier layer 11 is a rigid polyethylene terephthalate / polypropylene blend fiber surface layer. Its dense structure blocks high-frequency noise from the engine compartment, such as motor whine, while simultaneously dissipating some sound energy through inter-fiber friction. It has short-term temperature resistance up to 150℃, meeting the high-temperature environment of the engine compartment. The polyamide film interlayer has a melting point of 160℃ to prevent delamination between the surface layer and the intermediate layer. Reflective layer 12 is a polyethylene / polyamide / polyethylene composite film intermediate layer, suppressing structural noise generated by sheet metal vibration. The rigid support of the polyamide film forms a "mass-spring" system, reflecting low-frequency sound waves <500Hz. Sound-absorbing layer 13 is a polyethylene terephthalate / wool composite cotton felt bottom layer. The natural porous structure of wool fibers absorbs mid-frequency sound waves 500-2000Hz, with a noise reduction coefficient NRC≥0.85. The polyethylene terephthalate fibers provide structural support, preventing rebound after compression. Through the synergistic design of the rigid barrier layer 11, the elastic reflective layer 12, and the porous sound-absorbing layer 13, full-frequency noise control is achieved. The crease 7 divides the pad body 1 into two symmetrical parts. When installed in the mounting areas 4 at both ends, the pad body 1 can better fit the front part of the car. The recessed area 3 and the second rounded corner groove 6 have the same opening direction, and the mounting area 4 and the first rounded corner groove 5 have the same opening direction, which enhances the structural strength of the pad body 1. The first rounded corner groove 5 and the second rounded corner groove 6 are in a vertical state. Under the action of the folded edges 2 on both sides, the deformation resistance of the pad body 1 is enhanced.

[0025] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A composite front sound insulation pad, characterized in that, The pad body (1) is composed of a barrier layer (11), a reflective layer (12) and a sound-absorbing layer (13) bonded together. The barrier layer (11) is bonded to the upper side of the reflective layer (12), and the sound-absorbing layer (13) is bonded to the lower side of the reflective layer (12). A crease (7) is provided in the middle of the pad body (1) to make it a mirror symmetrical structure. Both sides of the pad body (1) are hot-pressed with folded edges (2), and protrusions are provided at the bends of the folded edges (2).

2. The composite front sound insulation pad according to claim 1, characterized in that: The pad body (1) has a recessed area (3) hot-pressed on both ends of one side, and the depth of the recessed area (3) is equal to the thickness of the pad body (1).

3. The composite front sound insulation pad according to claim 2, characterized in that: The edge of the recessed area (3) is hot-pressed in the opposite direction to form an installation area (4), and the depth of the installation area (4) is equal to the depth of the recessed area (3).

4. The composite front sound insulation pad according to claim 3, characterized in that: The middle part of the recessed area (3) and the middle part of the pad body (1) are both hot-pressed with a second rounded corner groove (6), and the opening direction of the recessed area (3) and the second rounded corner groove (6) is the same.

5. A composite front sound insulation pad according to claim 4, characterized in that: The middle of the recessed area (3) is hot-pressed with a first rounded corner groove (5), and the opening direction of the first rounded corner groove (5) is opposite to the opening direction of the recessed area (3).

6. A composite front sound insulation pad according to claim 5, characterized in that: The first rounded corner groove (5) and the second rounded corner groove (6) have the same depth, and the first rounded corner groove (5) and the second rounded corner groove (6) are distributed perpendicularly to each other.

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