Waterproof fender rear sealing plate part for automobile and manufacturing method of waterproof fender rear sealing plate part

Abstract

The invention relates to a waterproof fender rear sealing plate part for an automobile and a manufacturing method of the waterproof fender rear sealing plate part. The manufacturing method comprises the following steps that (1) a TPU thin film is fixed to an upper mold body of a mold, and the TPU thin film is fixed to a lower mold body of the mold through vacuum adsorption; (2) after the mold is heated, pouring a raw material obtained by mixing polyol and isocyanate into a mold cavity; (3) the mold is closed, the raw materials are foamed, cured and formed in the mold cavity, and a semi-finished product part is obtained; and (4) punching the semi-finished product part to obtain the waterproof fender rear sealing plate part for the automobile. And (3) after the mold is closed for 20-40 seconds, vacuum adsorption of the lower mold to the TPU film is stopped, and after 40-60 seconds, an upper mold puncture needle is started to puncture for multiple times. Compared with the prior art, the waterproof performance of the part can be improved, and the situation that the part is mildewed is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of automobile accessories, and in particular to a waterproof fender rear cover part for an automobile and a manufacturing method thereof. Background Art

[0002] Fender parts are mainly made by mixing polyether and isocyanate and then aging at high temperature. They are mainly installed under the A-pillar of the car, and their main functions are sound insulation, filling, and noise reduction. On rainy days, rainwater is discharged from near the tires through the drainage grooves on both sides of the front windshield, which will cause the fender parts to be soaked in rainwater. After absorbing water, the weight of the parts increases, causing the parts to fall off, the sound insulation effect to deteriorate, and the parts to mold. At present, most of the parts that can be produced in China with this material are made of polyurethane foaming technology. The parts are open-cell foaming, and there are many continuous bubbles inside the parts, and the waterproof performance is very poor. In addition, the installation method of most of these parts is interference fit, and the parts need to be manually inserted into the corresponding position, which is inconvenient to install. Summary of the invention

[0003] The purpose of the present invention is to provide a waterproof fender rear cover part for automobiles and a manufacturing method thereof, so as to improve the waterproof performance of the part.

[0004] The purpose of the present invention can be achieved by the following technical solution: A method for manufacturing a waterproof fender rear cover part for an automobile, comprising the following steps:

[0005] (1) Fixing the TPU film on the upper mold and fixing the TPU film on the lower mold by vacuum adsorption;

[0006] (2) After the mold is heated, the raw material of the mixture of polyol and isocyanate is poured into the mold cavity;

[0007] (3) Clamping the mold to allow the raw materials to foam, mature, and form in the mold cavity to obtain semi-finished parts;

[0008] (4) punching the semi-finished parts to obtain the waterproof fender rear cover parts for automobiles;

[0009] Step (3) After 20-40 seconds of mold closing, the vacuum adsorption of the TPU film by the lower mold is stopped, and after 40-60 seconds, the piercing needle of the upper mold is started to pierce multiple times.

[0010] Preferably, in step (1), the cut TPU film is fixed to the upper mold of the mold by positioning pins.

[0011] Preferably, in step (1), the cut TPU film is laid flat on the lower mold of the mold, the pressing frame is lowered to fix it, and the vacuum adsorption switch is turned on. The TPU film of the lower mold of the mold is adsorbed into the mold cavity of the lower mold of the mold through the vacuum adsorption hole of the lower mold.

[0012] Further preferably, the vacuum adsorption holes are arranged at the vertices, corners and grooves of the lower mold of the mold.

[0013] In the present invention, the vacuum adsorption holes are arranged at the parts of the mold lower mold with complex characteristic structures, such as vertices, corners and grooves where the film is not easy to fit with the lower mold.

[0014] Further preferably, the vacuum adsorption hole diameter is 0.8-1.2 mm, preferably 1.0 mm.

[0015] Further preferably, the interval between adjacent vacuum adsorption holes is 5-100 mm.

[0016] More preferably, in the relatively flat part of the lower mold, the interval between adjacent vacuum adsorption holes is 50-100 mm, and in the part with more features, the interval between adjacent vacuum adsorption holes is 5-15 mm.

[0017] Further preferably, the adsorption pressure is 0.02Mpa-0.06Mpa.

[0018] Preferably, the mold heating temperature in step (2) is 60°C-65°C.

[0019] Preferably, the weight ratio of polyol (POLY) to isocyanate (ISO) in the raw materials of step (2) is 100:(40-45).

[0020] Preferably, in step (2), the temperature of the raw material is 30±5° C., the pouring flow rate is 60-120 g / s, and the pouring time is 2-3 s.

[0021] Preferably, in step (2), a polyol having a temperature of 30±5°C and a pouring pressure of 100bar-200bar and an isocyanate having a temperature of 30±5°C and a pouring pressure of 100bar-200bar are mixed to obtain a raw material, the pouring flow rate of the raw material is 60-120g / s, and the pouring time is 2-3s.

[0022] Preferably, the mold clamping pressure in step (3) is 0.3-0.4Mpa.

[0023] Preferably, the foaming and aging time in step (3) is 120-145 seconds. After aging, the mold is opened, the part is formed, and a semi-finished part is obtained.

[0024] In the present invention, the foaming and maturation stage includes the initiation stage (milky stage) of the raw materials and the stage when the raw materials transform from semi-solid to solid, wherein the initiation stage is 7-13 seconds.

[0025] Preferably, in step (3), 30 seconds after the mold is closed, the vacuum adsorption of the TPU film by the lower mold is stopped, and 50 seconds later, the piercing needle of the upper mold starts to pierce 2-4 times, preferably 3 times.

[0026] Preferably, the depth of the upper mold puncture needle telescopic puncture in step (3) is 8-12 mm, preferably 10 mm.

[0027] In the present invention, the upper die piercing needle needs to ensure that the piercing depth does not penetrate the entire part.

[0028] Preferably, the single puncture time of the upper mold puncture needle in step (3) is 0.4-0.6s, preferably 0.5s.

[0029] Preferably, the time interval between each puncture of the upper mold by the puncture needle in step (3) is 1-3s, preferably 2s.

[0030] Preferably, in step (4), the semi-finished part is placed in a punching die, and the die is punched after holding the pressure for 4s-8s.

[0031] Preferably, a control component is used in the manufacturing process of the waterproof automobile fender rear cover part.

[0032] Further preferably, the control component controls the mold, a driving member for driving the upper mold puncture needle to extend and retract, and a vacuum adsorption device for vacuum adsorption and fixing the TPU film.

[0033] Further preferably, the control component includes a PLC controller.

[0034] A waterproof fender rear cover part for automobiles is manufactured by the above manufacturing method and comprises a PU foaming layer and a TPU film coated on the surface of the PU foaming layer.

[0035] Preferably, the density of the PU foam layer is 58.5-71.5 kg / m 3 (i.e. 65±10% kg / m 3 ).

[0036] Preferably, the TPU film has a thickness of 0.2-0.3 mm and a surface density of 24-36 g / m 2 (i.e. 30±20% g / m 2 ).

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention reduces the density of the parts and reduces the cost by adding the TPU film, while maintaining the flame retardant effect of the parts.

[0039] 2. The present invention can improve the appearance of parts. After a layer of film is attached to the surface of the parts, defects such as process pores on the surface of the parts can be effectively covered.

[0040] 3. After traditional polyurethane fender foam parts absorb water, the parts are prone to mildew; after the surface of the parts is covered with a layer of TPU film, the possibility of mildew of the parts is greatly reduced.

[0041] 4. The parts of the present invention are easy to install, which reduces the friction coefficient and makes it more convenient for workers to install them in place.

[0042] 5. Compared with traditional polyurethane fender foam parts, the waterproof performance of the parts is greatly improved after the surface of the parts is covered with a layer of TPU film. The water absorption rate of traditional polyurethane fenders is about 20%, and the water absorption rate of the fenders covered with the TPU film of the present invention is about 2%.

[0043] 6. The present invention can easily meet the requirements of customers for the surface appearance (color, glossiness, etc.) of the fender.

[0044] 7. The puncture design of the upper mold puncture needle of the present invention can ensure that the gas generated by the raw material reaction is discharged from the inside of the part in time during the part maturation stage, thereby preventing the TPU film on the surface of the part from being lifted up and forming a bulge.

[0045] 8. The present invention increases the adsorption holes at the characteristic positions of the lower mold, so that the TPU film fits better with the mold surface of the lower mold cavity, and the structural features of the parts are retained to the maximum extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a physical picture of the upper mold of the present invention (the area encircled by the square box in the figure is the puncture needle);

[0047] Figure 2 for Figure 1 A partial enlarged view of

[0048] Figure 3 The structure of the semi-finished parts of the present invention is schematically shown Figure 1 ;

[0049] Figure 4 The structure of the semi-finished parts of the present invention is schematically shown Figure 2 ;

[0050] In the figure: a-puncture needle, b-pressing edge, 1-TPU film, 2-PU foaming layer. DETAILED DESCRIPTION

[0051] 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.

[0052] Example 1

[0053] A waterproof fender rear cover part for automobile and a manufacturing method thereof, including TPU film adsorption and part molding manufacturing, the specific steps are as follows:

[0054] a. TPU film adsorption:

[0055] (1) Open the mold and fix the cut TPU film to the upper mold of the mold through positioning pins;

[0056] (2) Lay the cut TPU film flat on the lower mold of the mold, then put down the press frame to fix it;

[0057] (3) Turn on the vacuum adsorption switch, and the TPU film of the lower mold of the mold is adsorbed onto the lower mold surface of the mold through the vacuum adsorption hole of the lower mold;

[0058] Adsorption pressure: 0.02Mpa-0.06Mpa.

[0059] b. Semi-finished parts molding and manufacturing:

[0060] (1) Heat the mold to 60°C-65°C;

[0061] (2) Set the raw material ratio: POLY:ISO=100:(40-45);

[0062] (3) Set the material temperature, POLY: 30±5℃, ISO: 30±5℃;

[0063] (4) Set pouring pressure: POLY: 100bar-200bar, ISO: 100bar-200bar;

[0064] (5) Set the pouring flow rate of the foaming machine: 60-120g / s;

[0065] (7) Set the adsorption time to 30s, start timing after mold closing, and when the time is reached, the vacuum pump stops working and the adsorption action stops;

[0066] (8) Set the puncture time of the upper mold puncture needle to 50s. Start timing after the mold is closed. When the time is reached, the puncture needle a (such as Figure 1-2 Start stretching and retracting (as shown), and stop the movement after repeating 3 times;

[0067] (9) Set the pouring time to 2.5s, and pour the mixed raw materials of POLY and ISO into the mold cavity;

[0068] (10) Mold closing and molding: The mold is closed to allow the raw materials to foam, mature, and form in the mold cavity; the adsorption stops after 30 seconds, and the puncture needle starts working after 50 seconds; the mold closing pressure is 0.35 MPa;

[0069] (11) After 120 seconds of aging, the mold is opened, the part is formed, and the part is taken out.

[0070] In this embodiment, Figure 3-4 As shown, a 3-4 mm wide edge b is reserved around the removed part, and the part structure includes a TPU film 1, a PU foam layer 2 and a TPU film 1 arranged in sequence from top to bottom, so that the TPU film can still wrap the side of the part after the part is punched.

[0071] c. Punching of formed parts

[0072] (1) Set the holding time: 4s-8s;

[0073] (2) Place the semi-finished part into the corresponding mold cavity and press the punching button; after the punching is completed, the finished part is obtained.

[0074] The density of the TPU film fender parts prepared by the method of this embodiment is 65±10% kg / m 3 , significantly lower than 90±10% kg / m of conventional fender parts 3 Moreover, the TPU coated fender parts prepared by the method of this embodiment meet GB8410, the burning rate: A-0; and the surface appearance is flat and smooth.

[0075] Furthermore, the present invention has the following advantages:

[0076] 1. The surface of conventional fender molds needs to be sprayed with a release agent, which is unevenly sprayed or aggregated on the mold surface before drying, which can easily cause pollution or damage to the surface of the parts, resulting in reduced high temperature resistance and aging resistance of the parts. For the fenders made by the TPU coating process of the present invention, the mold surface does not need to be sprayed with a release agent, which reduces the possibility of part contamination.

[0077] 2. The puncture time of the puncture needle and the adsorption time of the TPU film are controlled by PLC to achieve time adjustability, reduce the impact of external temperature differences or seasonal differences on part molding, and improve the qualified rate of parts.

[0078] 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 method for manufacturing a waterproof fender rear cover part for an automobile, characterized in that: The following steps are involved: (1) Fixing the TPU film on the upper mold and fixing the TPU film on the lower mold by vacuum adsorption; (2) After the mold is heated, the raw material of the mixture of polyol and isocyanate is poured into the mold cavity; (3) Clamping the mold to allow the raw materials to foam, mature, and form in the mold cavity to obtain semi-finished parts; (4) punching the semi-finished parts to obtain the waterproof fender rear cover parts for automobiles; Step (3) After 20-40 seconds of mold closing, the vacuum adsorption of the TPU film by the lower mold is stopped, and after 40-60 seconds, the piercing needle of the upper mold is started to pierce multiple times.

2. The method for manufacturing a waterproof fender rear cover part for an automobile according to claim 1, characterized in that: Step (1) fixing the cut TPU film to the upper mold of the mold by positioning pins; Step (1) lay the cut TPU film flat on the lower mold of the mold, put down the press frame, fix it, turn on the vacuum adsorption switch, and the TPU film of the lower mold of the mold is adsorbed to the mold cavity of the lower mold of the mold through the vacuum adsorption hole of the lower mold, and the adsorption pressure is 0.02Mpa-0.06Mpa.

3. The method for manufacturing a waterproof fender rear cover part for an automobile according to claim 1, characterized in that: The mold heating temperature in step (2) is 60° C.-65° C., and the weight ratio of polyol to isocyanate in the raw materials is 100:(40-45).

4. The method for manufacturing a waterproof fender rear cover part for an automobile according to claim 1, characterized in that: In step (2), the temperature of the raw material is 30±5° C., the pouring flow rate is 60-120 g / s, and the pouring time is 2-3 s.

5. The method for manufacturing a waterproof fender rear cover part for an automobile according to claim 1, characterized in that: Step (3) the mold clamping pressure is 0.3-0.4Mpa; The foaming and aging time in step (3) is 120-145s. After aging, the mold is opened, the part is formed, and a semi-finished part is obtained.

6. The method for manufacturing a waterproof fender rear cover part for an automobile according to claim 1, characterized in that: Step (3) 30 seconds after the mold is closed, the vacuum adsorption of the lower mold on the TPU film is stopped, and 50 seconds later, the piercing needle of the upper mold starts to pierce 2-4 times.

7. The method for manufacturing a waterproof fender rear cover part for an automobile according to claim 1, characterized in that: In step (3), the puncture depth of the upper mold puncture needle is 8-12 mm, the single puncture time is 0.4-0.6 s, and the time interval between each puncture is 1-3 s.

8. The method for manufacturing a waterproof fender rear cover part for an automobile according to claim 1, characterized in that: Step (4) placing the semi-finished parts in a punching die, holding the pressure for 4s-8s and then punching.

9. A waterproof fender rear cover part for automobiles, characterized in that: The invention is prepared by the method according to any one of claims 1 to 8, and comprises a PU foaming layer and a TPU film coated on the surface of the PU foaming layer.

10. The waterproof rear fender cover component for automobile according to claim 9, characterized in that: The density of the PU foam layer is 58.5-71.5 kg / m 3 The TPU film has a thickness of 0.2-0.3 mm and a surface density of 24-36 g / m 2 .

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