Lightweight thermal insulation roof forming process for heavy truck

Abstract

The present application relates to truck roof technical field, disclose a heavy truck light weight heat preservation roof forming process, including the following steps: S1, inner plate die pressing;S2, interior decoration making;S3, outer plate die pressing;S4, foam layer making: the outer plate is put into the foaming mold, and the foaming upper die of the foaming mold is combined with the foaming lower die, and the first cavity is formed between the foaming upper die and the outer plate, and the first foaming glue is injected into the first cavity, and the first foaming glue foams in the first cavity, and the integral foaming layer adhered to the inner side of the outer plate is formed;S5, gluing;S6, paint spraying. Through the use of the heavy truck light weight heat preservation roof forming process, by placing the outer plate in the foaming mold as the bottom die, the integral foaming layer is formed on the inner side of the outer plate, the heat preservation performance of the heavy truck light weight heat preservation roof formed by assembly is greatly improved, and the inner plate is made of high-strength SMC material, and the outer plate is made of glass fiber reinforced low-density thermosetting plastic, so that the weight of the roof is reduced.

Description

Technical Field

[0001] This invention relates to the field of truck roofs, and more specifically, to a molding process for lightweight insulated roofs for heavy-duty trucks. Background Technology

[0002] It is an inevitable trend for domestic commercial vehicles to enter the international market and participate in international competition. However, issues such as insufficient insulation of the cab in extreme low-temperature environments, inadequate corrosion resistance of certain components in coastal desert regions, insufficient integration in product design, and limited consideration of modular design mean that heavy-duty truck roofs are an important component. They not only protect the cab and cargo but also provide sunshade, insulation, and heat insulation functions.

[0003] The inner panel of the roof of existing heavy trucks is equipped with multiple reinforcing ribs. The insulation layer is usually made of multiple foam blocks (modules made of foam or other materials with good insulation performance) spliced ​​and glued together to avoid the reinforcing ribs. However, there are splicing seams between adjacent foam blocks, resulting in poor insulation effect of the roof and making it unsuitable for extreme low temperature environments. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects in the prior art and provide a molding process for a lightweight thermal insulation top cover for heavy-duty trucks, in which an integral foam layer is formed by foaming a first foaming adhesive as the insulation layer.

[0005] To achieve the above objectives, the technical solution of the present invention provides a molding process for a lightweight insulated top cover for heavy-duty trucks, comprising the following steps:

[0006] S1. Inner panel molding: The inner panel molding material is placed into the inner panel molding machine and the inner panel is molded to manufacture the inner panel;

[0007] S2. Interior trim fabrication: The inner panel is placed in a hot press, and interior trim materials are placed on the inner panel in sequence. The interior trim is formed by hot pressing and foaming on the inner side of the inner panel. The inner panel and the interior trim form a first composite.

[0008] S3. Outer Panel Molding: The outer panel molding material is placed into the outer panel molding machine and the outer panel is molded to manufacture the outer panel.

[0009] S4. Foaming layer fabrication: The outer panel is placed in a foaming mold, and the upper and lower foaming molds of the foaming mold are closed. A first cavity is formed between the upper foaming mold and the outer panel. A first foaming adhesive is injected into the first cavity, and the first foaming adhesive foams in the first cavity to form an integral foaming layer that adheres to the inner side of the outer panel. The outer panel and the foaming layer constitute a second composite.

[0010] S5. Adhesion: The second composite is bonded to the inside of the first composite using structural adhesive to form a third composite.

[0011] S6. Spray painting: Apply paint to the outer surface of the third composite.

[0012] By using the lightweight thermal insulation roof molding process for heavy-duty trucks described in this invention, an integral foam layer is formed by placing the outer panel in a foaming mold as the bottom mold and foaming it on the inner side of the outer panel. This greatly improves the thermal insulation performance of the assembled lightweight thermal insulation roof for heavy-duty trucks. Moreover, the integral foam layer has higher strength than the spliced ​​insulation structure. The foam layer formed by the first foaming adhesive can also better adapt to the shape of the outer panel, which is conducive to improving the overall strength of the lightweight thermal insulation roof for heavy-duty trucks. In addition, the foaming process is faster, which improves the production efficiency of the lightweight thermal insulation roof for heavy-duty trucks.

[0013] Preferably, the inner panel is made of high-strength SMC material, and its thickness is 2.5-4.0 mm. This design makes it less likely for water vapor in the driver's cab to condense on the inner surface of the inner panel, thereby reducing the adverse effects of condensation on the vehicle body, wiring harness, and electrical components.

[0014] Preferably, the inner panel includes a top inner panel segment bonded to the foam layer, a front inner panel segment bonded to the foam layer, a rear inner panel segment bonded to the foam layer, a left inner panel segment bonded to the foam layer, and a right inner panel segment bonded to the foam layer. This design helps reduce the difficulty of molding the inner panel.

[0015] Preferably, the front inner panel segment, the rear inner panel segment, the left inner panel segment, and the right inner panel segment all overlap with the top inner panel segment; the front inner panel segment and the rear inner panel segment both overlap with the left inner panel segment; and the front inner panel segment and the rear inner panel segment both overlap with the right inner panel segment. This design helps to improve the integrity and stability of the inner panels.

[0016] Preferably, the outer panel is made of glass fiber reinforced low-density thermosetting plastic, and its thickness is 2.0-2.5 mm. This design helps to reduce the weight of the outer panel, thereby reducing the weight of the top cover.

[0017] Preferably, the interior trim, from the outside in, comprises glass wool, a first non-woven fabric, a foam layer, a second non-woven fabric, and a fabric layer. The interior trim includes a top trim piece connected to the top inner panel section and a rear trim piece connected to the rear inner panel section. This design helps reduce the impact of external noise on the driver and improves the comfort of the cab.

[0018] Preferably, the foam layer includes a thin foam region and a thick foam region. The thin foam region contains a plurality of first air bubbles, and the thick foam region contains a plurality of second air bubbles. The average volume of the first air bubbles is greater than the average volume of the second air bubbles. This design helps to improve the heat insulation and noise reduction effect of the thin foam region.

[0019] Preferably, the foamed layer includes a thin foamed area and a thick foamed area. The thin foamed area has multiple first cavities, and the thick foamed area has multiple second cavities. The average volume of the first cavities is greater than the average volume of the second cavities. This design helps to improve the thermal insulation effect of the thin foamed area.

[0020] Preferably, the first foaming adhesive is polyurethane foam. This design helps to improve the thermal insulation effect of the foam layer and enhance the stability of the connection between the foam layer and the outer panel.

[0021] Preferably, the structural adhesive is a polyurethane structural adhesive. This design helps ensure the stability and reliability of the bond between the inner panel and the foam layer.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. By using the lightweight thermal insulation top cover molding process for heavy-duty trucks described in this invention, the outer panel is placed in a foaming mold as the bottom mold, and an integral foam layer is formed on the inner side of the outer panel. This greatly improves the thermal insulation performance of the assembled lightweight thermal insulation top cover for heavy-duty trucks. Moreover, the integral foam layer has higher strength than the spliced ​​insulation structure. The foam layer formed by the first foaming adhesive can also better adapt to the shape of the outer panel, which is conducive to improving the overall strength of the lightweight thermal insulation top cover for heavy-duty trucks. In addition, the efficiency of forming the foam layer by foaming is faster, which improves the production efficiency of the lightweight thermal insulation top cover for heavy-duty trucks.

[0024] 2. By using high-strength SMC material to mold the inner panel and glass fiber reinforced low-density thermosetting plastic to mold the outer panel, the weight of the top cover is reduced while ensuring the strength and composite requirements of the assembled top cover, which helps to improve the fuel economy of the truck.

[0025] 3. By using polyurethane foam to form a foam layer, the foam layer can have a better thermal insulation effect. Furthermore, by controlling the air pressure and temperature changes during the foaming process, a larger cavity can be formed in the thin foam area, which can improve the thermal insulation effect of the thin foam area. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a lightweight insulated top cover for heavy-duty trucks;

[0027] Figure 2 This is a schematic diagram showing the disassembled three-dimensional structure of a lightweight insulated top cover for heavy-duty trucks;

[0028] Figure 3 This is a side sectional view of a lightweight insulated roof cover for heavy-duty trucks;

[0029] Figure 4 yes Figure 3 Enlarged view of the structure at point A in the middle;

[0030] Figure 5 yes Figure 3 Enlarged view of the structure at point B;

[0031] Figure 6 This is an exploded view of the inner panel's 3D structure;

[0032] Figure 7 It is an exploded view of the interior's 3D structure;

[0033] Figure 8 This is a schematic diagram of the first three-dimensional structure of the rear interior hot press (after the rear interior panels are placed in sections on the hot press lower mold).

[0034] Figure 9 This is a schematic diagram of the second type of three-dimensional structure of the rear interior hot press.

[0035] In the diagram: 100, Inner panel; 110, Top inner panel segment; 120, Front inner panel segment; 130, Rear inner panel segment; 140, Left inner panel segment; 150, Right inner panel segment; 200, Interior trim; 210, Top interior trim; 220, Rear interior trim; 300, Outer panel; 400, Foam layer; 500, Structural adhesive; 610, Hot press upper mold; 611, First injection port; 612, Second injection port; 613, First injection hole; 614, Second injection hole; 620, Hot press lower mold. Detailed Implementation

[0036] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed to enable those skilled in the art to better understand and implement the subject matter described herein. Changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0037] To better understand this invention, the following is combined with... Figures 1-9 The molding process of the lightweight insulated top cover for heavy-duty trucks according to the present invention is described in detail.

[0038] Example 1:

[0039] like Figures 1-5 As shown, the molding process for a lightweight insulated roof cover for heavy-duty trucks includes the following steps:

[0040] S1. Inner panel 100 molding: The inner panel molding material is placed into the inner panel molding machine and the inner panel 100 is molded.

[0041] S2, Interior trim 200 fabrication: The inner panel 100 is placed in a hot press, and interior trim materials are placed on the inner panel 100 in sequence. The interior trim 200 is formed by hot pressing and foaming on the inner side of the inner panel 100. The inner panel 100 and the interior trim 200 form the first composite.

[0042] S3, Outer Panel 300 Molding: The outer panel molding material is placed into the outer panel molding machine and the outer panel 300 is molded.

[0043] S4. Fabrication of foam layer 400: The outer panel 300 is placed in a foaming mold, and the upper and lower foaming molds of the foaming mold are closed. A first cavity is formed between the upper foaming mold and the outer panel 300. A first foaming adhesive is injected into the first cavity, and the first foaming adhesive foams in the first cavity to form an integral foam layer 400 that adheres to the inner side of the outer panel 300. The outer panel 300 and the foam layer 400 form a second composite.

[0044] S5. Adhesion: The second composite is bonded to the inside of the first composite using structural adhesive 500 to form the third composite.

[0045] S6. Spray painting: Apply paint to the outer surface of the third composite.

[0046] It should be noted that the foam layer 400 formed in S4 is a single piece, that is, the foam layer 400 is a continuous foam material, which avoids the problem of insufficient heat insulation caused by the splicing seams formed by the splicing of multiple foam cakes. The integrity and strength of the single foam layer 400 are better than those of the spliced ​​insulation structure. Moreover, the single foam layer 400 is more efficient to produce, while the spliced ​​insulation structure requires more time to bond the foam cakes.

[0047] The third composite formed in S5 includes, from the outside to the inside, an outer panel 300, a foam layer 400, an inner panel 100, and an interior trim 200.

[0048] In S6, paint is sprayed on the outer surface of the outer panel 300. Before painting, the third composite needs to be tested in many aspects such as structural strength, thermal conductivity, appearance quality, and size and shape to ensure that the quality of the third composite meets the requirements, thereby ensuring that the lightweight thermal insulation top cover for heavy trucks formed after painting meets the quality requirements.

[0049] By using the lightweight thermal insulation roof molding process of the present invention for heavy-duty trucks, an integral foam layer 400 is formed by placing the outer panel 300 in a foaming mold as the bottom mold and foaming it on the inner side of the outer panel 300. This greatly improves the thermal insulation performance of the assembled lightweight thermal insulation roof for heavy-duty trucks. Moreover, the integral foam layer 400 has higher strength than the spliced ​​insulation structure. The foam layer 400 formed by foaming with the first foaming adhesive can also better adapt to the shape of the outer panel 300, which is conducive to improving the overall strength of the lightweight thermal insulation roof for heavy-duty trucks. In addition, the efficiency of forming the foam layer 400 by foaming is faster, which improves the production efficiency of the lightweight thermal insulation roof for heavy-duty trucks.

[0050] Example 2:

[0051] As an optimization of Example 1, the inner panel 100 is made of high-strength SMC material and has a thickness of 2.5-4.0 mm.

[0052] It should be noted that high-strength SMC material has relatively poor thermal conductivity, which slows down the heat transfer rate. In extreme low-temperature environments, the cooling rate of the inner panel 100 made of high-strength SMC material is slower, and water vapor in the cab is less likely to condense on the inner surface of the inner panel 100, reducing the impact of condensation on the vehicle body, wiring harness, and electrical components, and improving the comfort of the cab. High-strength SMC material has good mechanical properties. When subjected to external impact, the inner panel 100 made of high-strength SMC material can effectively absorb energy, reducing the risk of deformation and damage. In addition, high-strength SMC material has a lower density than traditional steel plates. Therefore, using high-strength SMC material to make the inner panel 100 helps to reduce the weight of the roof.

[0053] Example 3:

[0054] As an optimization of Example 2, such as Figure 2 and Figure 6 As shown, the inner panel 100 includes a top inner panel segment 110 bonded to the foam layer 400, a front inner panel segment 120 bonded to the foam layer 400, a rear inner panel segment 130 bonded to the foam layer 400, a left inner panel segment 140 bonded to the foam layer 400, and a right inner panel segment 150 bonded to the foam layer 400.

[0055] It should be noted that since there are multiple mounting points on the inner panel 100, if the inner panel 100 is produced by molding in one go, the inner panel 100 cannot be demolded. Therefore, the inner panel 100 is divided into five parts and molded separately. The front inner panel part 120, the rear inner panel part 130, the left inner panel part 140 and the right inner panel part 150 are located at the front, rear, left and right sides of the top inner panel part 110, respectively. The inner panel molding machine in S1 includes the top inner panel molding machine, the front inner panel molding machine, the rear inner panel molding machine, the left inner panel molding machine and the right inner panel molding machine.

[0056] The top inner panel segment 110, the front inner panel segment 120, the rear inner panel segment 130, the left inner panel segment 140, and the right inner panel segment 150 are respectively molded using a top inner panel molding machine, a front inner panel molding machine, a rear inner panel molding machine, a left inner panel molding machine, and a right inner panel molding machine. S1 includes the following steps:

[0057] S11. The upper and lower molds of the top inner plate molding machine are opened, and the upper and lower molds are preheated to the preset temperature.

[0058] S12. Place the cut high-strength SMC material onto the molding die;

[0059] S13. The upper and lower molds are closed to pressurize and heat the high-strength SMC material and maintain it under a preset pressure for a period of time, so that the high-strength SMC material flows, fills and solidifies in the mold.

[0060] S14. The upper and lower molds of the molding die are opened, and the product is taken out.

[0061] S15. Remove the burrs and excess parts from the edges of the product, and trim and polish the surface of the product to obtain the top inner plate segment 110.

[0062] S16. Following steps S11-S15 above, use the front inner panel molding machine, the rear inner panel molding machine, the left inner panel molding machine, and the right inner panel molding machine to mold and manufacture the front inner panel segment 120, the rear inner panel segment 130, the left inner panel segment 140, and the right inner panel segment 150, respectively.

[0063] Example 4:

[0064] As an optimization of Example 3, such as Figure 5 and Figure 6 As shown, the front inner panel segment 120, the rear inner panel segment 130, the left inner panel segment 140, and the right inner panel segment 150 all overlap with the top inner panel segment 110. The front inner panel segment 120 and the rear inner panel segment 130 both overlap with the left inner panel segment 140, and the front inner panel segment 120 and the rear inner panel segment 130 both overlap with the right inner panel segment 150.

[0065] It should be noted that by setting the five sections of the inner panel 100 to be connected by overlapping, and by bonding the five sections together with structural adhesive 500, the integrity and stability of the inner panel 100 can be improved.

[0066] For example, for the overlap between the top inner panel segment 110 and the rear inner panel segment 130, the ends of the top inner panel segment 110 and the rear inner panel segment 130 that are close to each other overlap, and the overlapping contact surfaces of the overlapping parts are bonded with structural adhesive 500. The overlap method between other segments is similar to the overlap method between the top inner panel segment 110 and the rear inner panel segment 130 described above, and will not be repeated here.

[0067] Example 5:

[0068] As an optimization of Example 4, the outer panel 300 is made of glass fiber reinforced low-density thermosetting plastic, and the thickness of the outer panel is 2.0-2.5 mm.

[0069] It should be noted that the density of glass fiber reinforced low-density thermosetting plastic is much lower than that of steel plate. By using the outer panel 300 made of glass fiber reinforced low-density thermosetting plastic, the weight of the outer panel 300 can be significantly reduced, thereby reducing the weight of the top cover.

[0070] Glass fiber reinforced low-density thermosetting plastics have high tensile strength, flexural strength and compressive strength due to the reinforcement of glass fibers. They also have a high elastic modulus, which can provide sufficient stiffness and strength to meet the load-bearing requirements of the outer panel 300.

[0071] Fiberglass reinforced low-density thermosetting plastics have good resistance to corrosive media such as acids, alkalis, and salts. Even if the paint on the outer surface of the outer panel 300 is damaged by impact, the outer panel 300 is not easily corroded and only needs to be repainted, thereby improving the durability and reliability of the lightweight thermal insulation top cover for heavy trucks.

[0072] The outer panel 300 is a one-piece structure, formed by one-time molding using an outer panel molding machine. The few mounting points on the outer panel 300 will not affect the demolding of the outer panel 300. If steel plate is used to manufacture the outer panel 300, due to the limitations of the stamping equipment size and stamping process, the outer panel 300 must be divided into multiple pieces, and then spliced ​​together by laser welding and sealant during assembly. The aesthetics of the top cover will be affected, and the cost of molds and tooling will be higher. Therefore, forming the outer panel 300 into a one-piece structure by one-time molding is beneficial to reducing the production cost of the outer panel 300. The molding steps of the outer panel 300 are similar to the molding steps of the top inner panel segment 110 described in S11-S15 of Example 3, and will not be repeated here.

[0073] For example, the surface area of ​​the outer panel 300 is 7.2m². 2 When steel plates are used to manufacture the outer panel 300, the material density is 7.85 × 10⁻⁶. 3 kg / m³, outer plate 300 material thickness 0.8×10 -3 m, outer plate 300 weighs 7.2×0.8×10 -3 ×7.85×10 3 =45.216 (kg); When using glass fiber reinforced low-density thermosetting plastic to manufacture the outer panel 300, the material density is 1.5 × 10⁻⁶. 3 kg / m 3 , the outer plate is 300mm thick and 2.5×10 -3 m, outer plate 300 weighs 7.2×2.5×10 -3 ×1.5×10 3 =27 (kg); the weight of the outer panel 300 was reduced by 45.216-27=18.216 (kg).

[0074] Example 6:

[0075] As an optimization of Example 5, such as Figure 2 , Figure 5 and Figure 7 As shown, the interior trim 200 includes glass wool, a first non-woven fabric, a foam layer, a second non-woven fabric, and a fabric layer from the outside to the inside. The interior trim 200 includes a top interior trim 210 connected to the top inner panel block 110 and a rear interior trim 220 connected to the rear inner panel block 130.

[0076] It should be noted that the interior trim 200 is composed of glass wool, a first non-woven fabric, a foam layer, a second non-woven fabric, and a fabric composite. After the lightweight insulated roof of a heavy-duty truck is assembled on the truck, a storage box is usually installed on the front side of the inner panel 100, and other components are installed on the left and right sides of the inner panel 100. Therefore, the interior trim 200 is only provided on the top and rear of the inner panel 100. The top interior trim 210 is composited with the inner side of the top inner panel segment 110, and the rear interior trim 220 is composited with the inner side of the rear inner panel segment 130. The foam layer has a certain heat insulation and sound insulation effect, which helps to reduce the impact of external noise on the driver. In addition, the fabric can be patterned, which helps to improve the comfort of the cab.

[0077] Example 7:

[0078] As an optimization of Example 6, the foam layer includes a thin foam region and a thick foam region. The thin foam region has a plurality of first bubbles, and the thick foam region has a plurality of second bubbles. The average volume of the first bubbles is greater than the average volume of the second bubbles.

[0079] It should be noted that the hot presses in the S2 include the headliner hot press and the rear side liner hot press, such as... Figure 8 and Figure 9 As shown, S2 includes the following steps:

[0080] S21, the upper hot press mold 610 and the lower hot press mold 620 of the rear interior hot press are opened, and the upper hot press mold 610 and the lower hot press mold 620 are preheated to the preset temperature;

[0081] S22. Place the rear inner panel segment 130 on the hot press mold 620 with the inner side of the rear inner panel segment 130 facing upward, and lay the glass wool and the first non-woven fabric on the rear inner panel segment 130 in sequence.

[0082] S23. The upper hot pressing mold 610 moves closer to the lower hot pressing mold 620 to squeeze and heat the glass wool and the first non-woven fabric, and hot press the glass wool and the first non-woven fabric together with the rear inner plate segment 130.

[0083] S24. The hot pressing upper mold 610 moves a preset height away from the hot pressing lower mold 620, and a second cavity is formed between the hot pressing upper mold 610 and the rear inner plate segment 130. The second foaming adhesive is injected into the second cavity, and the second foaming adhesive foams in the second cavity to form a foam layer that adheres to the first non-woven fabric.

[0084] S25. The upper hot-pressing mold 610 and the lower hot-pressing mold 620 are opened, and the second non-woven fabric and the fabric are laid on the foam layer in sequence.

[0085] S26. The upper hot pressing mold 610 moves closer to the lower hot pressing mold 620 to squeeze and heat the second non-woven fabric and the fabric, and hot-press the second non-woven fabric and the fabric together with the foam layer.

[0086] S27. The hot-pressing upper mold 610 and hot-pressing lower mold 620 are opened to remove the composite of the rear inner panel block 130 and the rear interior trim 220.

[0087] S28. Following steps S21-S27 above, use a top interior panel hot press to composite the top interior panel 210 on the inner side of the top interior panel block 110.

[0088] In this embodiment, the second foaming adhesive is polyurethane foaming adhesive. Due to the shape of the rear inner panel block 130, the thickness of the foam layer is different, and the foam layer is divided into a thin foam area and a thick foam area. The top of the hot pressing upper mold 610 is provided with a first injection port 611 and a second injection port 612. The bottom of the hot pressing upper mold 610 is provided with a plurality of first injection holes 613 and a plurality of second injection holes 614. The plurality of first injection holes 613 are all connected to the first injection port 611, and the plurality of second injection holes 614 are all connected to the second injection port 612. The hot pressing upper mold 610 is provided with a first heating area and a second heating area. The first injection port 611 and the first heating area are both corresponding to the thin foam area, and the second injection port 612 and the second heating area are both corresponding to the thick foam area.

[0089] In S24, the foaming of the foam layer includes the following three steps:

[0090] Step 1: Pressurize the second cavity and inject an appropriate amount of second foaming adhesive into the first injection port 611. The second foaming adhesive flows into the second cavity through the first injection hole 613. The first heating zone is heated to the first preset temperature (at this temperature, the second foaming adhesive can foam normally, but will not be completely cured), so that the second foaming adhesive at the position of the first heating zone foams quickly to form a thin foam area.

[0091] Step 2: Depressurize the second cavity and inject an appropriate amount of second foaming adhesive into the second injection port 612. The second foaming adhesive flows into the second cavity through the second injection hole 614. The second heating zone is heated to the first preset temperature, so that the second foaming adhesive at the position of the second heating zone foams rapidly to form a thick foam area.

[0092] Step 3: Both the first heating zone and the second heating zone are heated to the second preset temperature, and the thin foam zone and the thick foam zone are fused and completely solidified to form a foam layer.

[0093] Under pressure, foaming forms a thin foam zone. After depressurization, the pores in the thin foam zone become larger, which can improve the heat insulation and noise reduction effects of the thin foam zone, thereby making up for the problem of insufficient heat insulation and noise reduction effects caused by the thin foam zone being too thin.

[0094] Example 8:

[0095] As an optimization of Embodiment 7, the foam layer 400 includes a thin foam region and a thick foam region. The thin foam region has a plurality of first cavities, and the thick foam region has a plurality of second cavities. The average volume of the first cavities is greater than the average volume of the second cavities.

[0096] It should be noted that the first cavity and the second cavity are essentially air bubbles. Air has a low thermal conductivity, and the average volume of the first cavity is greater than that of the second cavity, which can improve the heat preservation effect of the thin foamed area. The foaming steps of the foam layer 400 are similar to the three steps of foaming the foam layer in Example 7, and will not be repeated here.

[0097] Example 9:

[0098] As an optimization of Example 8, the first foaming adhesive is a polyurethane foaming adhesive.

[0099] It should be noted that the foamed material formed after polyurethane foam has good thermal insulation performance, strength, waterproof performance and durability, thus ensuring the excellent thermal insulation effect of the foam layer 400. In addition, polyurethane foam has excellent adhesion ability, and the connection strength between the foam layer 400 and the outer panel 300 is high and the connection is stable, which is conducive to improving the overall strength of the lightweight thermal insulation top cover of heavy trucks.

[0100] Example 10:

[0101] As an optimization of Example 9, structural adhesive 500 is a polyurethane structural adhesive.

[0102] It should be noted that the polyurethane structural adhesive has good adhesion properties, which can ensure that the five inner panel sections are firmly bonded together, and that each inner panel section is firmly bonded to the foam layer 400. Since the foam layer 400 is made of polyurethane, the polyurethane structural adhesive and the polyurethane foam layer 400 have good compatibility, which helps to ensure the stability and reliability of the bonding between the inner panel 100 and the foam layer 400.

[0103] The embodiments of the invention have been described above with reference to the accompanying drawings. However, the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the embodiments without departing from the spirit of the embodiments and the scope of protection of the claims, and all of these forms are within the protection scope of the embodiments.

Claims

1. A process for forming a lightweight thermal roof cap for a heavy duty truck, characterized in that, The method comprises the following steps: S1, inner plate (100) molding: put the inner plate molding material into the inner plate molding machine to mold the inner plate (100); S2, inner decoration (200) manufacturing: put the inner plate (100) into the hot press, and sequentially put the inner decoration material on the inner plate (100), and form the inner decoration (200) on the inner side of the inner plate (100) by hot pressing and foaming, wherein the inner plate (100) and the inner decoration (200) form a first composite; S3, outer plate (300) molding: put the outer plate molding material into the outer plate molding machine to mold the outer plate (300); S4, foaming layer (400) manufacturing: put the outer plate (300) into the foaming mold, and the foaming upper mold and the foaming lower mold of the foaming mold are closed, a first cavity is formed between the foaming upper mold and the outer plate (300), the first foaming glue is injected into the first cavity, and the first foaming glue is foamed in the first cavity to form the integral foaming layer (400) adhered to the inner side of the outer plate (300), wherein the outer plate (300) and the foaming layer (400) form a second composite; S5, gluing: the second composite is adhered to the inner side of the first composite by the structural adhesive (500) to form a third composite; S6, paint spraying: the outer surface of the third composite is sprayed with paint; The inner plate (100) comprises a top inner plate sub-block (110) adhered to the foaming layer (400), a front side inner plate sub-block (120) adhered to the foaming layer (400), a rear side inner plate sub-block (130) adhered to the foaming layer (400), a left side inner plate sub-block (140) adhered to the foaming layer (400), and a right side inner plate sub-block (150) adhered to the foaming layer (400); The inner decoration (200) comprises glass wool, first non-woven fabric, foam layer, second non-woven fabric and fabric from outside to inside in sequence, the foam layer comprises thin foam area and thick foam area, the thin foam area has a plurality of first bubbles, the thick foam area has a plurality of second bubbles, and the average volume of the first bubbles is greater than the average volume of the second bubbles; S2 comprises the following steps: S21, the hot pressing upper mold (610) and the hot pressing lower mold (620) of the rear side inner decoration hot press are opened, and the hot pressing upper mold (610) and the hot pressing lower mold (620) are preheated to a preset temperature; S22, the rear side inner plate sub-block (130) is placed on the hot pressing lower mold (620), the inner side of the rear side inner plate sub-block (130) faces upward, and the glass wool and the first non-woven fabric are sequentially laid on the rear side inner plate sub-block (130); S23, the hot pressing upper mold (610) approaches the hot pressing lower mold (620), and the glass wool and the first non-woven fabric are extruded and heated to be hot-pressed and combined with the rear side inner plate sub-block (130); S24, the hot pressing upper die (610) moves away from the hot pressing lower die (620) by a preset height, the hot pressing upper die (610) and the rear side inner plate block (130) form a second cavity, the second foaming glue is injected into the second cavity, the second foaming glue foams in the second cavity, and a foam layer adhered to the first non-woven fabric is formed; The top of the hot pressing upper die (610) is provided with a first glue injection port (611) and a second glue injection port (612), and the bottom of the hot pressing upper die (610) is provided with a plurality of first glue injection holes (613) and a plurality of second glue injection holes (614). The plurality of first glue injection holes (613) are in communication with the first glue injection port (611), and the plurality of second glue injection holes (614) are in communication with the second glue injection port (612). The hot pressing upper die (610) is provided with a first heating area and a second heating area. The first glue injection port (611) and the first heating area correspond to the thin foam area, and the second glue injection port (612) and the second heating area correspond to the thick foam area. In S24, the foaming of the foam layer includes the following three steps: Step one: pressurize the second cavity, inject an appropriate amount of second foaming glue into the first glue injection port (611), and the second foaming glue flows into the second cavity through the first glue injection hole (613). The first heating area is heated to a first preset temperature, so that the second foaming glue at the position of the first heating area foams rapidly to form a thin foam area; Step two: depressurize the second cavity, inject an appropriate amount of second foaming glue into the second glue injection port (612), and the second foaming glue flows into the second cavity through the second glue injection hole (614). The second heating area is heated to a first preset temperature, so that the second foaming glue at the position of the second heating area foams rapidly to form a thick foam area; Step three: the first heating area and the second heating area are heated to a second preset temperature, the thin foam area and the thick foam area are fused and completely solidified to form a foam layer.

2. The process for forming a lightweight thermal roof for a heavy duty truck of claim 1, wherein, The material of the inner plate (100) is high-strength SMC material, and the thickness of the inner plate (100) is 2.5-4.0 mm.

3. The process for forming a lightweight thermal roof for heavy duty trucks of claim 1, wherein, The front side inner plate block (120), the rear side inner plate block (130), the left side inner plate block (140) and the right side inner plate block (150) are all overlapped with the top inner plate block (110). The front side inner plate block (120) and the rear side inner plate block (130) are both overlapped with the left side inner plate block (140), and the front side inner plate block (120) and the rear side inner plate block (130) are both overlapped with the right side inner plate block (150).

4. The process for forming a lightweight thermal roof for heavy duty trucks of claim 1, wherein, The material of the outer plate (300) is glass fiber reinforced low density thermosetting plastic, and the thickness of the outer plate is 2.0-2.5 mm.

5. The process for forming a lightweight thermal roof for heavy duty trucks of claim 1 wherein, The interior decoration (200) includes a top interior decoration (210) connected to the top inner plate block (110), and a rear side interior decoration (220) connected to the rear side inner plate block (130).

6. The process for forming a lightweight thermal roof for a heavy truck of claim 1, wherein, The foaming layer (400) includes a thin foaming area and a thick foaming area. The thin foaming area has a plurality of first cavities, and the thick foaming area has a plurality of second cavities. The average volume of the first cavities is greater than the average volume of the second cavities.

7. The heavy duty truck light weight thermal top cap forming process of claim 1, wherein, The first foaming glue is polyurethane foaming glue.

8. The process for forming a lightweight thermal roof for a heavy duty truck of claim 7, wherein, The structural adhesive (500) is a polyurethane structural adhesive.

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