Integrally-formed motor sound insulation pad manufacturing method and sound insulation pad

Abstract

The embodiment of the invention provides a manufacturing method of an integrally-formed motor sound insulation pad and the sound insulation pad. The manufacturing method comprises the following steps that a cut EVA composite sheet is softened; the softened EVA composite sheet is put into a plastic suction mold for plastic suction to form a sound insulation pad blank; after plastic uptake is completed, cooling is conducted for a set time so that the sound insulation pad blank can be shaped; the shaped sound insulation pad blank body is taken out, the taken-out sound insulation pad blank body is composed of three parts which are sequentially connected, and a folding area is formed between every two adjacent parts; the sound insulation pad blank body is put into a foaming mold, and a PP resin reinforcing gasket is arranged at the position, where the mounting hole needs to be formed, of the sound insulation pad blank body; and foaming in a foaming mold to form a semi-finished sound insulation pad, wherein the semi-finished sound insulation pad can be folded along the folding area on the sound insulation pad blank. The produced sound insulation pad is integrally formed, few molds are used, and the later maintenance cost of the molds is reduced.

Description

[Technical field]

[0001] The embodiments of the present application relate to the technical field of motor sound insulation pads, and in particular to a method for manufacturing an integrated motor sound insulation pad and a sound insulation pad. [Background technology]

[0002] With the development and popularization of new energy vehicles, the vehicle noise problem generated by the drive motor system has also attracted much attention. The main problem is the obvious high-frequency noise generated when the vehicle accelerates and decelerates, which seriously affects the comfort of the vehicle and the subjective feelings of the driver and passengers. In order to provide a better driving experience, it is necessary to develop a sound insulation pad with a simple manufacturing process and good high-frequency noise absorption effect.

[0003] At present, the design of motor sound insulation pads is in the exploratory stage. Most of the existing electric vehicle sound insulation pads use non-woven fabric + polyurethane + non-woven fabric, hard felt + polyurethane or polyurethane + non-woven fabric + glass fiber + non-woven fabric, fixed by male and female buckles or expansion buckles. Since the motor body is cylindrical, the sound insulation pad wrapped on the motor is usually divided into several parts, such as upper and lower sound insulation pads or front sound insulation pads and rear sound insulation pads. The sound insulation pads of these parts are made of the same material, but the appearance is different. During production, the same process requires 2 sets of molds, that is, the number of molds is twice the number of sound insulation pads, the mold cost is high, and the mold maintenance cost is high in the later stage. [Summary of the invention]

[0004] The embodiment of the present application proposes a method for manufacturing an integrated motor sound insulation pad and a sound insulation pad, which relates to the technical field of motor sound insulation pads. By designing an integrated sound insulation pad, the number of molds can be reduced, thereby reducing the cost of subsequent mold maintenance.

[0005] In a first aspect, an embodiment of the present application provides a method for manufacturing an integrated motor sound insulation pad, comprising the following steps:

[0006] Softening the cut EVA composite sheet;

[0007] Put the softened EVA composite sheet into a blister mold for blister forming a sound insulation pad embryo;

[0008] After the blister is formed, cooling is performed for a set time to allow the sound insulation pad embryo to be shaped;

[0009] The sound insulation pad embryo body after shaping is taken out, wherein the sound insulation pad embryo body is composed of three parts connected in sequence, and a folding area is provided between two adjacent parts;

[0010] The sound insulation pad embryo is placed in a foaming mold, and a PP resin reinforcing gasket is arranged at a position where a mounting hole is required to be opened on the sound insulation pad embryo;

[0011] Foaming in a foaming mold to form a semi-finished sound insulation pad, wherein the semi-finished sound insulation pad can be folded along a folding area on the sound insulation pad embryo;

[0012] The semi-finished sound insulation pad is placed on the water-cut fetal membrane to cut the boundaries and installation holes to obtain the finished sound insulation pad.

[0013] Optionally, the blister mold has two dividing strips, which divide the blister mold into a first blister area, a second blister area and a third blister area; the three parts of the sound insulation pad embryo are respectively formed by blistering the first blister area, the second blister area and the third blister area, and the EVA composite sheet at the corresponding position of the dividing strips forms a folding area.

[0014] Optionally, the lower mold of the foaming mold is provided with a first foaming area, a second foaming area and a third foaming area corresponding to the first blister area, the second blister area and the third blister area; the three parts of the sound insulation pad embryo body taken out from the blister mold are respectively placed in the corresponding first foaming area, the second foaming area and the third foaming area; the foaming material is injected into the first foaming area, the second foaming area and the third foaming area; the upper mold of the foaming mold is combined with the lower mold of the foaming mold for foaming;

[0015] Optionally, the EVA composite sheet manufacturing method is as follows:

[0016] Put the powdered EVA raw material into a container, add additives into the container and stir evenly, and heat the container until the EVA raw material becomes gelatinous;

[0017] The gelatinous EVA raw material is extruded onto the roller to form the required EVA sheet thickness. After cooling for a period of time, the EVA sheet is sent to the gluing equipment for gluing;

[0018] A layer of non-woven fabric is applied to the EVA composite sheet after the glue is applied, and then the EVA composite sheet is cut into pieces as needed.

[0019] Optionally, the cut EVA composite sheet is placed in a baking oven for baking to soften the composite sheet, and the baking temperature is 295° C.-310° C.;

[0020] Optionally, the softened EVA composite sheet is sent to the blister mold via a conveyor belt, and after being laid out, it is blister molded to form the sound insulation pad embryo.

[0021] Optionally, the blister adopts negative pressure adsorption with a pressure of 0.4-0.6Mpa.

[0022] Optionally, the thickness of the finished sound insulation pad is not less than 20 mm, and the temperature of the foaming mold is maintained at 55° C.-65° C. during foaming.

[0023] In a second aspect, an embodiment of the present application provides an integrated motor sound insulation pad, which is made by the above-mentioned manufacturing method.

[0024] Optionally, the position of the mounting hole corresponds to the position of a pipeline installed on the motor, and the pipeline is installed on the motor through the mounting hole.

[0025] The present application can reduce the number of molds in the production process and the maintenance cost of the molds in the later stage by designing the sound insulation pad as an integrated molding; the process of producing the sound insulation pad is simple, and only two simple steps are required, namely, vacuum forming + foaming molding; the vacuum forming efficiency is high, and no upper and lower molds are required to close the mold, and no press is required, so it occupies less space, is simpler to operate, and is safer; PP resin reinforcement sheets are used at the sound insulation installation holes to ensure the size and shape of the installation holes during installation.

Brief Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A flow chart of a method for manufacturing an integrated motor sound insulation pad proposed in this application;

[0028] Figure 2 This is a schematic diagram of the structure of the EVA composite sheet in this application;

[0029] Figure 3 This is a schematic diagram of the structure of the finished sound insulation pad in this application;

[0030] Figure 4 It is a schematic diagram of the installation structure of the bolt and the bolt fixing seat, the PP resin reinforcing gasket, the EVA layer, and the non-woven fabric layer.

[0031] Description of reference numerals:

[0032] 1- non-woven fabric layer, 2- EVA layer, 3- PU foam layer, 4- PP resin reinforcement gasket, 5- bolt fixing seat, 6- finished sound insulation pad, 7- bolt, 8- folding area. [Specific implementation method]

[0033] In order to better understand the technical solution of this specification, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0034] It should be clear that the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit this specification. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0036] The technical solution protected by the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0037] See also Figure 1 , a method for manufacturing an integrated motor sound insulation pad provided in an embodiment of the present application, comprising the following steps:

[0038] The cut EVA composite sheet is softened; wherein the EVA composite sheet manufacturing method is as follows:

[0039] Put the powdered EVA raw material into a container, add additives into the container and stir evenly, and heat the container until the EVA raw material becomes gelatinous;

[0040] The gelatinous EVA raw material is extruded onto the roller to form the required EVA sheet thickness. After cooling for a period of time, the EVA sheet is sent to the gluing equipment for gluing; the gram weight of EVA is controlled by the thickness of the roller, such as gram weight ≥3600g / ㎡, thickness ≥2mm;

[0041] A layer of non-woven fabric is applied to the EVA composite sheet after the glue is applied, and then the EVA composite sheet is cut into pieces as needed. The function of the non-woven fabric is to ensure a good appearance and strengthen the EVA to prevent the EVA from being partially thinned during the blistering process;

[0042] Put the softened EVA composite sheet into the blister mold for blister forming to form the sound insulation pad embryo; during softening, the cut EVA composite sheet can be put into a baking oven for baking to soften the composite sheet, and the baking temperature is 295℃-310℃, with 300℃ being the best. Softening the EVA composite sheet can facilitate the subsequent blister forming;

[0043] After the blister is completed, the cooling time is set to allow the sound insulation pad embryo to be shaped; for example, the cooling time can be 40s, 45s, 48s, 50s, etc.

[0044] The sound insulation pad embryo body after shaping is taken out. The sound insulation pad embryo body taken out consists of three parts connected in sequence, and there is a folding area 8 between two adjacent parts. Figure 3 As shown; such a configuration enables the obtained sound insulation pad blank to be a continuous sheet, and the sound insulation pad blank can be folded along the folding area 8 to pave the subsequent sound insulation pad finished product 6, so that the sound insulation pad finished product 6 can be folded along the folding area 8 and then wrap the motor; Figure 3 The dotted line in FIG. 1 is a folding line along the folding area 8 when the finished sound insulation pad 6 wraps the motor.

[0045] The sound insulation pad blank is placed in a foaming mold, and a PP resin reinforced gasket 4 is arranged at the position where the mounting hole needs to be opened on the sound insulation pad blank; in specific implementation, the PP resin reinforced gasket 4 can be attached to the position where the mounting hole needs to be opened by gluing, and the mounting hole is opened by passing through the PP resin reinforced gasket 4; of course, as an implementation method, a hole is opened on the PP resin reinforced gasket 4 itself, and when the PP resin reinforced gasket 4 is pasted on the sound insulation pad blank, the hole on the PP resin reinforced gasket 4 is aligned with the position of the mounting hole to be opened on the sound insulation pad blank, and when the mounting hole is opened, the hole on the PP resin reinforced gasket 4 is passed through.

[0046] By providing the PP resin reinforcing gasket 4, the strength of the mounting hole can be increased to prevent the mounting hole from being broken during use, and at the same time, the edge of the mounting hole can be prevented from being worn by the bolt when the bolt is installed.

[0047] Foaming in a foaming mold to form a semi-finished sound insulation pad, wherein the semi-finished sound insulation pad can be folded along the folding area 8 on the sound insulation pad blank;

[0048] The semi-finished sound insulation pad is placed on the water-cut fetal membrane to cut the boundaries and installation holes to obtain the finished sound insulation pad 6.

[0049] In order to realize the one-time molding of the motor sound insulation pad, the following measures are adopted: the blister mold has two dividing strips, and the two dividing strips divide the blister mold into a first blister area, a second blister area and a third blister area; the three parts of the sound insulation pad embryo are respectively formed by blistering the first blister area, the second blister area and the third blister area, and the EVA composite sheet at the corresponding position of the dividing strip forms a folding area 8.

[0050] The lower mold of the foaming mold is provided with a first foaming area, a second foaming area and a third foaming area corresponding to the first blister area, the second blister area and the third blister area; the three parts of the sound insulation pad embryo body taken from the blister mold are respectively placed in the corresponding first foaming area, the second foaming area and the third foaming area; the foaming material is injected into the first foaming area, the second foaming area and the third foaming area; the upper mold of the foaming mold and the lower mold of the foaming mold are molded together for foaming. In the specific implementation, the foaming material uses PU foaming, and the A material used for PU foaming is: foaming agent + catalyst + polyether polyol, the foaming agent is ammonia, and the catalyst is silicone oil; B material: isocyanate, AB materials are mixed in a ratio of 100:60 and squeezed into the foaming mold at the same time through a spray gun. During foaming, the temperature of the foaming mold is maintained at 55℃-65℃, and it is best to maintain it at 60℃, so that A and B materials can foam at a certain speed and will not produce abnormal pores. The foaming time is about 180s.

[0051] As an implementation method, the softened EVA composite sheet is sent to the blister mold via a conveyor belt, and after being laid, it is blister molded to form the sound insulation pad embryo. This arrangement can avoid the high temperature of the softened EVA composite sheet from scalding the staff and improve efficiency. After the blister is completed, the shaped sound insulation pad embryo is taken out and transported to the foaming mold via a conveyor belt.

[0052] The vacuum forming process uses negative pressure adsorption, and the pressure is 0.4-0.6Mpa, preferably 0.5Mpa.

[0053] The thickness of the finished sound insulation pad 6 is not less than 20 mm, thereby meeting the NVH requirements.

[0054] The material layers of the sound insulation pad prepared by the above method are non-woven fabric layer 1, EVA layer 2, PU foam layer 3 from the outside to the inside of the motor surface. Figure 2 As shown, the locations of the local installation fixing points are the non-woven fabric layer 1, the EVA layer 2, the PP resin reinforcement pad 4, and the PU foam layer 3. Figure 4 As shown;

[0055] An embodiment of the present application also provides an integrated motor sound insulation pad, which is made by the manufacturing method described above.

[0056] The position of the mounting hole corresponds to the position of the pipeline installed on the motor, and the pipeline is installed on the motor through the mounting hole. For further fixing, a bolt fixing seat 5 can be welded on the motor, and a mounting hole matching the bolt can be opened on the sound insulation pad. For details, please refer to Figure 4As shown, when a mounting hole that cooperates with a bolt is opened on the sound insulation pad, the mounting hole can be opened along the direction from the PU foam layer 3 to the non-woven fabric layer 1 into a stepped hole including a first hole and a second hole. The aperture of the first hole is larger than the aperture of the second hole, and the aperture of the first hole is larger than the diameter of the bolt fixing seat 5. When the first hole is opened, it passes through the PU foam layer 3 but does not pass through the PP resin reinforcement gasket 4, so that when it is installed, the bolt fixing seat 5 rests on the PP resin reinforcement gasket 4; when the second hole is opened, it passes through the non-woven fabric layer 1, the EVA layer 2, and the PP resin reinforcement gasket 4. When the sound insulation pad is installed, the stud of the bolt 7 passes through the second hole to cooperate with the bolt fixing seat 5, and the head of the bolt 7 rests on the non-woven fabric layer 1.

[0057] When the sound insulation pad is installed on the motor, it is fixed with bolts 7. Although there are non-woven fabric and PP resin reinforcement gaskets 4 at the installation hole, in order to avoid excessive torque and damage to EVA, the torque of the bolts is specified to be 4-6N. The installation point of the motor sound insulation pad is shared with the installation point of the pipeline, that is, there is no need to add additional male and female buckles or expansion buckles for fixing, which saves costs.

[0058] The present application can reduce the number of molds in the production process and the maintenance cost of the molds in the later stage by designing the sound insulation pad to be an integral molding. The process of producing the sound insulation pad is simple and only requires two simple steps, namely, blister molding + foam molding. The blister molding efficiency is high, and no upper and lower molds need to be clamped, and no press is required, so it occupies less space, is simpler to operate, and is safer. A PP resin reinforcement sheet is used at the sound insulation installation hole to ensure the size and shape of the installation hole during installation. The sound insulation pad is formed by blister molding, which is an integral molding with a simple and efficient process. The sound insulation pad uses EVA + non-woven fabric material, which has better sound absorption effect and simple molding.

[0059] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this specification should be included in the scope of protection of this specification.

Claims

1. A method for manufacturing an integrated motor sound insulation pad, characterized in that: The following steps are involved: Softening the cut EVA composite sheet; Put the softened EVA composite sheet into a blister mold for blister forming a sound insulation pad embryo; After the blister is formed, cooling is performed for a set time to allow the sound insulation pad embryo to be shaped; The sound insulation pad embryo body after shaping is taken out, wherein the sound insulation pad embryo body is composed of three parts connected in sequence, and a folding area is provided between two adjacent parts; The sound insulation pad embryo is placed in a foaming mold, and a PP resin reinforcing gasket is arranged at a position where a mounting hole is required to be opened on the sound insulation pad embryo; Foaming in a foaming mold to form a semi-finished sound insulation pad, wherein the semi-finished sound insulation pad can be folded along a folding area on the sound insulation pad embryo; The semi-finished sound insulation pad is placed on the water-cut fetal membrane to cut the boundaries and installation holes to obtain the finished sound insulation pad.

2. The method for manufacturing an integrated motor sound insulation pad according to claim 1, characterized in that: The blister mold has two dividing strips, which divide the blister mold into a first blister area, a second blister area and a third blister area; the three parts of the sound insulation pad embryo are formed by blistering the first blister area, the second blister area and the third blister area respectively, and the EVA composite sheet at the corresponding position of the dividing strips forms a folding area.

3. The method for manufacturing an integrated motor sound insulation pad according to claim 2, characterized in that: The lower mold of the foaming mold is provided with a first foaming area, a second foaming area and a third foaming area corresponding to the first blister area, the second blister area and the third blister area; the three parts of the sound insulation pad embryo taken out from the blister mold are respectively placed in the corresponding first foaming area, the second foaming area and the third foaming area; the foaming material is injected into the first foaming area, the second foaming area and the third foaming area; the upper mold of the foaming mold is combined with the lower mold of the foaming mold for foaming.

4. The method for manufacturing an integrated motor sound insulation pad according to claim 1, characterized in that: The EVA composite sheet manufacturing method is as follows: Put the powdered EVA raw material into a container, add additives into the container and stir evenly, and heat the container until the EVA raw material becomes gelatinous; The gelatinous EVA raw material is extruded onto the roller to form the required EVA sheet thickness. After cooling for a period of time, the EVA sheet is sent to the gluing equipment for gluing; A layer of non-woven fabric is applied to the EVA composite sheet after the glue is applied, and then the EVA composite sheet is cut into pieces as needed.

5. The method for manufacturing an integrated motor sound insulation pad according to claim 1, characterized in that: The cut EVA composite sheets are placed in a baking oven for baking to soften the composite sheets, and the baking temperature is 295°C-310°C.

6. The method for manufacturing an integrated motor sound insulation pad according to claim 1, characterized in that: The softened EVA composite sheet is sent to the blister mold via a conveyor belt, and after being laid out, blister molding is performed to form the sound insulation pad embryo.

7. The method for manufacturing an integrated motor sound insulation pad according to claim 1, characterized in that: The vacuum forming process uses negative pressure adsorption, and the pressure is 0.4-0.6Mpa.

8. The method for manufacturing an integrated motor sound insulation pad according to claim 1, characterized in that: The thickness of the finished sound insulation pad (6) is not less than 20 mm, and the temperature of the foaming mold is maintained at 55° C.-65° C. during foaming.

9. An integrated motor sound insulation pad, characterized in that: The sound insulation pad is made by the manufacturing method described in any one of claims 1-9.

10. The integrated motor sound insulation pad according to claim 9, characterized in that: The position of the mounting hole corresponds to the position of the pipeline installed on the motor, and the pipeline passes through the mounting hole and is installed on the motor.

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