Composite structure front wall inner side sound insulation pad for electric automobile and manufacturing method of composite structure front wall inner side sound insulation pad

Abstract

The invention relates to a composite structure front wall inner side sound insulation pad for an electric automobile and a manufacturing method of the composite structure front wall inner side sound insulation pad, the sound insulation pad comprises an EVA layer and a PET layer, the surface density of the EVA layer is 2000-4000 g / m < 2 >, and the surface density of the PET layer is 550-2000 g / m < 2 >; the manufacturing method comprises the following steps: (1) respectively putting the EVA layer and the PET layer into a drying oven for heating; (2) putting the EVA layer and the PET layer which are heated into a mold at the same time, and closing the mold for compounding; and (3) punching the composite layer of the EVA layer and the PET layer, maintaining the pressure, cooling and molding. Compared with the prior art, the sound insulation pad has the advantages that the sound absorption performance is improved on the basis that the sound insulation performance is met, and especially on an electric automobile, the mechanism can more effectively eliminate noise generated by the automobile.

Description

Technical Field

[0001] The invention relates to the technical field of automobile sound insulation pads, and in particular to a composite structure front inner wall sound insulation pad for electric vehicles and a manufacturing method thereof. Background Art

[0002] The sound insulation pad on the inside of the front enclosure is an important part of the interior of the car, mainly located in the partition area between the engine compartment and the cockpit of the car. Its main function is to reduce the transmission of engine noise and vibration and improve the comfort of the passengers in the car. Specifically, the sound insulation pad on the inside of the front enclosure is composed of a variety of materials, including sound-absorbing materials, sound-insulating materials, shock-absorbing materials and heat-insulating materials. These materials can effectively absorb and isolate the noise and vibration generated by the engine, preventing them from being transmitted into the cockpit and affecting the auditory perception of the driver and passengers. The conventional front enclosure material is made of a thick layer + PU foam layer. The thick layer is responsible for the sound insulation effect, and the PU foam layer is responsible for the sound absorption effect. In actual effect, the PU foam layer is more effective in low-frequency bands for sound absorption, and the effect will be attenuated in high-frequency bands. Summary of the invention

[0003] The purpose of the present invention is to provide a composite structure front inner wall sound insulation pad for electric vehicles and a manufacturing method thereof, which can more effectively eliminate the noise generated by the vehicle.

[0004] The purpose of the present invention can be achieved by the following technical scheme: A composite structure front inner wall sound insulation pad for electric vehicles, comprising an EVA (ethylene-vinyl acetate copolymer) layer and a PET (polyethylene terephthalate) layer, wherein the surface density of the EVA layer is 2000-4000g / m 2 , the surface density of the PET layer is 550-2000g / m 2 .

[0005] Preferably, the PET layer is formed by combing ordinary PET and low melting point PET.

[0006] Further preferably, the diameter range of the common PET fiber is 10-20 dtex.

[0007] Further preferably, the diameter range of the low melting point PET fiber is 2-5 dtex.

[0008] Further preferably, the melting point of the inner layer of the low-melting-point PET is 230-250°C, preferably 240°C, and the melting point of the outer layer is 100-120°C, preferably 110°C.

[0009] Further preferably, the low melting point PET accounts for 20-50% of the total mass of the ordinary PET and the low melting point PET.

[0010] Preferably, the EVA layer has a thickness of 1-3 mm, and the PET layer has a thickness of 2-20 mm.

[0011] Preferably, the EVA layer is directly connected to the PET layer without an adhesive layer in between.

[0012] A method for manufacturing the composite structure front inner wall sound insulation pad for electric vehicles comprises the following steps:

[0013] (1) placing the EVA layer and the PET layer in an oven for heating respectively;

[0014] (2) placing the heated EVA layer and PET layer into the mold at the same time, and closing the mold for compounding;

[0015] (3) After punching, the composite layer of the EVA layer and the PET layer is pressurized and cooled to form.

[0016] Preferably, the upper and lower molds of the mold are both forming molds and are connected to a chiller, and cylinder punching structures are provided on both sides of the mold.

[0017] Preferably, in step (1), the EVA layer is heated at a temperature of 160-200° C. and a heating time of 30-60 seconds.

[0018] Preferably, in step (1), the heating temperature of the PET layer is 180-240° C., and the heating time is 80-120 seconds.

[0019] Preferably, during punching in step (3), the oil cylinder punching structure drives the blade to perform side composite forming punching on the composite layer.

[0020] Preferably, in step (3), the pressure is maintained for 40-60 seconds after punching. When the time is up, the punching structures of the oil cylinders on both sides are retracted and the mold is opened.

[0021] Further preferably, after the mold is opened, the cooled and formed parts are trimmed to obtain the composite structure front inner sound insulation pad for the electric vehicle.

[0022] A method for using the composite structure inner front wall sound insulation pad for electric vehicles is provided, wherein the EVA layer of the composite structure inner front wall sound insulation pad for electric vehicles faces the passenger compartment.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Compared with the existing heavy layer + foam layer parts, the sound insulation pad of the present invention improves the sound absorption performance on the basis of meeting the sound insulation performance, especially in electric vehicles, this mechanism can more effectively eliminate the noise generated by the vehicle;

[0025] 2. The present invention has good safety performance and meets the parts strength required for such situations;

[0026] 3. The invention is easy to install, and the parts fit perfectly with the corresponding vehicle model;

[0027] 4. The parts of the present invention are simple to manufacture and can be manufactured in one step. Compared with similar solutions, the cost is lower and it will not cause too much additional processes and manpower. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a test diagram of the sound insulation performance of the sound insulation pad with a thickness of 3 mm of the present invention;

[0029] Figure 2 This is a test diagram of the sound insulation performance of the sound insulation pad with a thickness of 5 mm of the present invention;

[0030] Figure 3 This is a test diagram of the sound insulation performance of the sound insulation pad of the present invention with a thickness of 20-22 mm;

[0031] Figure 4 This is a test diagram of the sound absorption performance of the sound insulation pad of the present invention with a thickness of 20-22 mm. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0033] A composite structure front wall inner sound insulation pad for electric vehicles and a manufacturing method thereof, including mold structure and parts molding manufacturing, the specific steps are as follows:

[0034] a. Mould structure

[0035] (1) Both the upper and lower molds are forming molds, and both are connected to a chiller with a temperature of 7-23°C;

[0036] (3) Cylinder punching structure is designed on both sides of the mold.

[0037] b. Parts molding and manufacturing

[0038] (1) placing the heavy layer (EVA layer) in a heating device and heating it at a temperature of 160-200°C for 30-60 seconds; placing the PET layer in a heating device and heating it at a temperature of 180-240°C for 80-120 seconds;

[0039] (2) Place the heated EVA layer and PET layer into the mold at the same time, with accurate positioning;

[0040] (3) Press the mold closing button, the mold is closed and compounded, and the oil cylinders on both sides are pushed forward to perform side compound forming and punching, and the pressure is maintained for 40-60 seconds. After the time is up, the knives on both sides are automatically retracted and the mold is automatically opened to obtain the product.

[0041] (4) The cooled and formed parts are trimmed to obtain the formed parts.

[0042] The material used in this embodiment is EVA (2600g / m 2 )+PET felt(1000g / m 2 ), the strength of the manufactured parts can meet the requirements of vehicle loading.

[0043] The sound insulation performance of the molded parts with different average surface densities and thicknesses prepared by the method of the present invention is as follows: Figure 1-Figure 2 shown.

[0044] The sound insulation and sound absorption properties of the molded parts with a thickness of 20-22 mm prepared by the method of the present invention are as follows: Figure 3-Figure 4 shown.

[0045] The present invention has the following advantages:

[0046] 1. Through the mold structure design, the double-layer material can be composite-formed and punched in one step, and the vertical structures on both sides of the front wall can also be composite-formed in one step, saving the production cost of similar solutions;

[0047] 2. The material used is EVA+PET. PET has more advantages in sound absorption than PU, especially in high-frequency bands. The sound generated by the motor of electric vehicles is more in the high-frequency band. This structure is more effective in eliminating the noise generated by the vehicle.

[0048] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A composite structure front inner wall sound insulation pad for electric vehicles, characterized in that: It comprises an EVA layer and a PET layer, wherein the surface density of the EVA layer is 2000-4000g / m 2 , the surface density of the PET layer is 550-2000g / m 2 .

2. The composite structure front wall inner side sound insulation pad for electric vehicles according to claim 1, characterized in that: The PET layer is formed by combing common PET and low-melting-point PET, the diameter of the common PET fiber is in the range of 10-20 dtex, and the diameter of the low-melting-point PET fiber is in the range of 2-5 dtex.

3. The composite structure front wall inner side sound insulation pad for electric vehicles according to claim 1, characterized in that: The thickness of the EVA layer is 1-3 mm, and the thickness of the PET layer is 2-20 mm.

4. The composite structure front wall inner side sound insulation pad for electric vehicles according to claim 1, characterized in that: The EVA layer is directly connected to the PET layer.

5. A method for manufacturing a composite structure front inner wall sound insulation pad for electric vehicles according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) placing the EVA layer and the PET layer in an oven for heating respectively; (2) placing the heated EVA layer and PET layer into the mold at the same time, and closing the mold for compounding; (3) After punching, the composite layer of the EVA layer and the PET layer is pressurized and cooled to form.

6. The method for manufacturing the composite structure front wall inner side sound insulation pad for electric vehicles according to claim 5, characterized in that: The upper and lower molds of the mold are both forming molds and are connected to a chiller, and cylinder punching structures are arranged on both sides of the mold.

7. The method for manufacturing the composite structure front inner side sound insulation pad for electric vehicles according to claim 5, characterized in that: The heating temperature of the EVA layer in step (1) is 160-200° C., and the heating time is 30-60 seconds.

8. The method for manufacturing the composite structure front inner side sound insulation pad for electric vehicles according to claim 5, characterized in that: In step (1), the heating temperature of the PET layer is 180-240° C., and the heating time is 80-120 seconds.

9. The method for manufacturing the composite structure front inner side sound insulation pad for electric vehicles according to claim 5, characterized in that: During the mold closing and compounding process of step (2), during the punching process of step (3), the oil cylinder punching structure drives the blade to perform side composite forming and punching on the composite layer.

10. The method for manufacturing the composite structure front inner side sound insulation pad for electric vehicles according to claim 5, characterized in that: Step (3) maintains pressure for 40-60 seconds after punching. When the time is up, the punching structures of the oil cylinders on both sides are withdrawn, the mold is opened, and the cooled and formed parts are trimmed to obtain the composite structure front inner sound insulation pad for the electric vehicle.

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