Forming process for light-weight heat-preservation top cover of heavy truck

Abstract

The invention relates to the technical field of truck top covers, and discloses a heavy truck light-weight heat preservation top cover forming process which comprises the following steps: S1, inner plate mold pressing; s2, interior trim manufacturing; s3, outer plate mold pressing; s4, manufacturing a foaming layer: putting the outer plate into a foaming mold, closing a foaming upper mold and a foaming lower mold of the foaming mold, forming a first cavity between the foaming upper mold and the outer plate, injecting first polystyrene foam into the first cavity, and foaming the first polystyrene foam in the first cavity to form the integrated foaming layer adhered to the inner side of the outer plate; s5, gluing is carried out; and S6, paint spraying. According to the forming process for the light-weight heat-preservation top cover of the heavy truck, the outer plate is placed in the foaming mold to serve as the bottom mold, the integrated foaming layer is formed on the inner side of the outer plate in a foaming mode, the heat preservation performance of the assembled light-weight heat-preservation top cover of the heavy truck is greatly improved, the inner plate is made of a high-strength SMC material, and therefore the heat preservation performance of the light-weight heat-preservation top cover of the heavy truck is greatly improved. And the outer plate is made of glass fiber reinforced low-density thermosetting plastic, so that the weight of the top cover is reduced.

Description

Technical Field

[0001] The present invention relates to the field of truck cab roofs, and more specifically, to a forming process for a lightweight thermal insulation cab roof of a heavy truck. Background Art

[0002] It is an inevitable trend for domestic commercial vehicles to enter the international market and participate in international competition. In recent years, the top five domestic commercial vehicle enterprises have successively exported heavy truck products to the Russian, African, and South American markets. From the feedback of the foreign markets, more and more deficiencies in product design have been found, such as: insufficient thermal insulation of the cab in extremely low-temperature environments, insufficient corrosion resistance of specific components in coastal and desert areas, insufficient integration of product design, and less consideration of modular design. The cab roof of a heavy truck is an important part of the heavy truck. It can not only protect the cab and the goods, but also provide functions such as sunshade, heat insulation, and thermal insulation.

[0003] The inner panel of the existing cab roof of a heavy truck is provided with a plurality of reinforcing ribs. The thermal insulation layer is usually formed by splicing and bonding a plurality of foam cakes (modules made of foam or other materials with good thermal insulation performance) to avoid the reinforcing ribs. However, there are splicing seams between adjacent foam cakes, resulting in poor thermal insulation effect of the cab roof and being unable to be applied to extremely low-temperature environments. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects existing in the prior art and provide a forming process for a lightweight thermal insulation cab roof of a heavy truck, in which an integral foam layer is formed by foaming a first foaming glue as the thermal insulation layer.

[0005] To achieve the above purpose, the technical solution of the present invention provides a forming process for a lightweight thermal insulation cab roof of a heavy truck, including the following steps: S1. Inner panel molding: Put the inner panel molding material into an inner panel molding machine and mold the inner panel. S2. Interior decoration production: Put the inner panel into a hot press, sequentially put interior decoration materials on the inner panel, and form the interior decoration by hot pressing and foaming on the inner side of the inner panel. The inner panel and the interior decoration form a first composite body. S3. Outer panel molding: Put the outer panel molding material into an outer panel molding machine and mold the outer panel. S4. Foam layer production: Put the outer panel into a foam mold, close the foam upper mold and the foam lower mold of the foam mold. A first cavity is formed between the foam upper mold and the outer panel. Inject a first foaming glue into the first cavity. The first foaming glue foams in the first cavity to form the integral foam layer adhered to the inner side of the outer panel. The outer panel and the foam layer form a second composite body. S5. Gluing: Bond the second composite to the inner side of the first composite with structural adhesive to form a third composite. S6. Painting: Spray paint on the outer surface of the third composite.

[0006] By using the forming process of the lightweight heat-insulating roof cover for heavy trucks of the present invention, by placing the outer panel in the foaming mold as the bottom mold and foaming on the inner side of the outer panel to form an integral foaming layer, the heat-insulating performance of the lightweight heat-insulating roof cover for heavy trucks formed by assembly is greatly improved. Moreover, the integral foaming layer has higher strength compared with the spliced heat-insulating structure. The foaming layer formed by the first foaming adhesive can also better adapt to the shape of the outer panel, which is beneficial to improving the overall strength of the lightweight heat-insulating roof cover for heavy trucks. In addition, the efficiency of forming the foaming layer by foaming is faster, which improves the production efficiency of the lightweight heat-insulating roof cover for heavy trucks.

[0007] Preferably, the material of the inner panel is high-strength SMC material, and the thickness of the inner panel is 2.5 - 4.0 mm. With such a design, water vapor in the cab is less likely to liquefy on the inner surface of the inner panel to form condensed water, thereby reducing the adverse effects of condensed water on the vehicle body, wiring harness, and electrical components.

[0008] Preferably, the inner panel includes a top inner panel block bonded to the foaming layer, a front-side inner panel block bonded to the foaming layer, a rear-side inner panel block bonded to the foaming layer, a left-side inner panel block bonded to the foaming layer, and a right-side inner panel block bonded to the foaming layer. With such a design, it is beneficial to reduce the difficulty of manufacturing the inner panel by molding.

[0009] Preferably, the front-side inner panel block, the rear-side inner panel block, the left-side inner panel block, and the right-side inner panel block all overlap with the top inner panel block, the front-side inner panel block and the rear-side inner panel block both overlap with the left-side inner panel block, and the front-side inner panel block and the rear-side inner panel block both overlap with the right-side inner panel block. With such a design, it is beneficial to improve the integrity and stability of the inner panel.

[0010] Preferably, the material of the outer panel is glass fiber-reinforced low-density thermosetting plastic, and the thickness of the outer panel is 2.0 - 2.5 mm. With such a design, it is beneficial to reduce the weight of the outer panel, thereby reducing the weight of the roof cover.

[0011] Preferably, the interior decoration includes glass wool, the first non-woven fabric, a foam layer, the second non-woven fabric, and a fabric from the outside to the inside in sequence. The interior decoration includes a top interior decoration connected to the top inner panel block and a rear-side interior decoration connected to the rear-side inner panel block. With such a design, it is beneficial to reduce the impact of external noise on the driver and improve the comfort of the cab.

[0012] Preferably, the foam layer includes a thin foam area and a thick foam area. The thin foam area has a plurality of first air bubbles, and the thick foam area has a plurality of second air bubbles. The average volume of the first air bubbles is greater than that of the second air bubbles. Such a design is beneficial to improving the heat preservation and noise reduction effects of the thin foam area.

[0013] Preferably, the foaming layer 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 that of the second cavities. Such a design is beneficial to improving the heat preservation effect of the thin foaming area.

[0014] Preferably, the first foaming adhesive is polyurethane foaming adhesive. Such a design is beneficial to improving the heat preservation effect of the foaming layer and enhancing the connection stability between the foaming layer and the outer panel.

[0015] Preferably, the structural adhesive is polyurethane structural adhesive. Such a design is beneficial to ensuring the bonding stability and reliability between the inner panel and the foaming layer.

[0016] The beneficial effects of the present invention are as follows: 1. By using the forming process of the lightweight heat-insulating top cover of a heavy-duty truck described in the present invention, by placing the outer panel in a foaming mold as the bottom mold and foaming inside the outer panel to form an integrated foaming layer, the heat preservation performance of the lightweight heat-insulating top cover of the heavy-duty truck formed by assembly is greatly improved. Moreover, the integrated foaming layer has higher strength compared with the spliced heat-insulating structure. The foaming layer formed by the first foaming adhesive can also better adapt to the shape of the outer panel, which is beneficial to improving the overall strength of the lightweight heat-insulating top cover of the heavy-duty truck. In addition, the efficiency of forming the foaming layer by foaming is faster, improving the production efficiency of the lightweight heat-insulating top cover of the heavy-duty truck; 2. By using high-strength SMC material to mold the inner panel and using glass fiber-reinforced low-density thermosetting plastic to mold the outer panel, on the basis of meeting the strength composite requirements of the assembled top cover, the weight of the top cover is reduced, which helps to improve the fuel economy of the truck; 3. By using polyurethane foaming adhesive to foam and form the foaming layer, the foaming layer can have better heat preservation effect. And by controlling the air pressure and temperature changes during the foaming process of the foaming layer, larger cavities can be formed in the thin foaming area, which can improve the heat preservation effect of the thin foaming area. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the overall structural schematic diagram of the lightweight heat-insulating top cover of a heavy-duty truck; Figure 2 is the three-dimensional structural split schematic diagram of the lightweight heat-insulating top cover of a heavy-duty truck; Figure 3It is a schematic side sectional view of a lightweight thermal insulation top cover for heavy trucks; Figure 4 It is Figure 3 an enlarged view of the structure at position A in Figure 5 It is Figure 3 an enlarged view of the structure at position B in Figure 6 It is an exploded three-dimensional view of the inner panel; Figure 7 It is an exploded three-dimensional view of the interior trim; Figure 8 It is the first three-dimensional structure schematic diagram of the rear interior hot press (after the rear inner panel is segmented and placed on the hot pressing lower die); Figure 9 It is the second three-dimensional structure schematic diagram of the rear interior hot press.

[0018] In the figure: 100, inner panel; 110, top inner panel segment; 120, front side inner panel segment; 130, rear side inner panel segment; 140, left side inner panel segment; 150, right side inner panel segment; 200, interior trim; 210, top interior trim; 220, rear side interior trim; 300, outer panel; 400, foaming layer; 500, structural adhesive; 610, hot pressing upper die; 611, first glue injection port; 612, second glue injection port; 613, first glue injection hole; 614, second glue injection hole; 620, hot pressing lower die. Detailed implementation mode

[0019] Now, the subject matter described herein will 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 thus implement the subject matter described herein. The functions and arrangements of the elements discussed can be changed without departing from the scope of protection of the content of this specification. Each example can omit, substitute, or add various processes or components as needed. Additionally, the features described relative to some examples can also be combined in other examples.

[0020] To better understand the present invention, the following will be combined with Figures 1-9 to describe in detail the forming process of the lightweight thermal insulation top cover for heavy trucks of the present invention.

[0021] Example 1: As Figures 1-5 shown, the forming process of the lightweight thermal insulation top cover for heavy trucks includes the following steps: S1. Inner panel 100 molding: Put the inner panel molding material into the inner panel molding press and mold the inner panel 100; S2. Interior 200 manufacturing: Place the inner panel 100 into a hot press, sequentially place interior materials on the inner panel 100, and form the interior 200 by hot pressing and foaming on the inner side of the inner panel 100. The inner panel 100 and the interior 200 form the first composite body; S3. Outer panel 300 molding: Place the outer panel molding material into an outer panel molding press and mold the outer panel 300; S4. Foaming layer 400 manufacturing: Place the outer panel 300 into a foaming mold. The upper foaming mold and the lower foaming mold of the foaming mold are closed. A first cavity is formed between the upper foaming mold and the outer panel 300. Inject a first foaming glue into the first cavity. The first foaming glue foams in the first cavity to form an integral foaming layer 400 adhered to the inner side of the outer panel 300. The outer panel 300 and the foaming layer 400 form the second composite body; S5. Gluing: Bond the second composite body to the inner side of the first composite body through a structural adhesive 500 to form a third composite body; S6. Painting: Spray paint on the outer surface of the third composite body.

[0022] It should be noted that the foaming layer 400 formed in S4 is integral, that is, the foaming layer 400 is a continuous integral foaming material, thus avoiding the problem of insufficient heat preservation effect caused by the formation of splicing seams due to the splicing and bonding of multiple foam cakes. The integrity and strength of the integral foaming layer 400 are better than those of the spliced heat preservation structure, and the production efficiency of the integral foaming layer 400 is high. The spliced heat preservation structure takes more time when bonding the foam cakes; The third composite body formed in S5 includes an outer panel 300, a foaming layer 400, an inner panel 100, and an interior 200 from outside to inside in sequence; In S6, the paint is sprayed on the outer surface of the outer panel 300. Before painting, it is necessary to detect the third composite body in terms of structural strength, thermal conductivity, appearance quality, dimensional shape, etc. to ensure that the quality of the third composite body meets the requirements, so as to ensure that the quality of the formed lightweight heat-insulating top cover of the heavy truck after painting meets the requirements.

[0023] By using the forming process of the lightweight heat-insulating top cover of the heavy truck of the present invention, by placing the outer panel 300 in the foaming mold as the bottom mold and foaming on the inner side of the outer panel 300 to form an integral foaming layer 400, the heat preservation performance of the formed lightweight heat-insulating top cover of the heavy truck is greatly improved. Moreover, the integral foaming layer 400 has higher strength compared with the spliced heat preservation structure. The foaming layer 400 formed by foaming the first foaming glue can also better adapt to the shape of the outer panel 300, which is beneficial to improving the overall strength of the lightweight heat-insulating top cover of the heavy truck. In addition, the efficiency of forming the foaming layer 400 by foaming is faster, improving the production efficiency of the lightweight heat-insulating top cover of the heavy truck.

[0024] Example 2: As an optimization of Embodiment 1, the material of the inner panel 100 is high-strength SMC material, and the thickness of the inner panel 100 is 2.5 - 4.0 mm.

[0025] It should be noted that the high-strength SMC material has relatively poor thermal conductivity, which can slow down the heat transfer speed. In an extremely low-temperature environment, the cooling speed of the inner panel 100 made of high-strength SMC material is slower, and the water vapor in the cab is less likely to liquefy on the inner surface of the inner panel 100 to form condensed water, reducing the impact of condensed water on the vehicle body, wiring harness, and electrical components, and is beneficial to improving the comfort of the cab; the high-strength SMC material has good mechanical properties. When subjected to external force impact, the inner panel 100 made of high-strength SMC material can effectively absorb energy and reduce the risk of deformation and damage. In addition, the high-strength SMC material has a lower density compared to traditional steel plates. Therefore, using high-strength SMC material to make the inner panel 100 is beneficial to reducing the weight of the roof.

[0026] Embodiment 3: As an optimization of Embodiment 2, as Figure 2 and Figure 6 shown, the inner panel 100 includes a top inner panel sub-block 110 bonded to the foaming layer 400, a front-side inner panel sub-block 120 bonded to the foaming layer 400, a rear-side inner panel sub-block 130 bonded to the foaming layer 400, a left-side inner panel sub-block 140 bonded to the foaming layer 400, and a right-side inner panel sub-block 150 bonded to the foaming layer 400.

[0027] It should be noted that since there are multiple installation points on the inner panel 100, if the inner panel 100 is made by one-time molding, the inner panel 100 cannot be demolded. Therefore, by splitting the inner panel 100 into five sub-blocks and performing molding manufacturing separately, the front-side inner panel sub-block 120, the rear-side inner panel sub-block 130, the left-side inner panel sub-block 140, and the right-side inner panel sub-block 150 are respectively located around the top inner panel sub-block 110 in the front, rear, left, and right directions. The inner panel molding machine in S1 includes a top inner panel molding machine, a front-side inner panel molding machine, a rear-side inner panel molding machine, a left-side inner panel molding machine, and a right-side inner panel molding machine.

[0028] The top inner panel sub-block 110, the front-side inner panel sub-block 120, the rear-side inner panel sub-block 130, the left-side inner panel sub-block 140, and the right-side inner panel sub-block 150 are respectively molded by the top inner panel molding machine, the front-side inner panel molding machine, the rear-side inner panel molding machine, the left-side inner panel molding machine, and the right-side inner panel molding machine. S1 includes the following steps: S11. The molding upper die and the molding lower die of the top inner panel molding machine are opened, and the molding upper die and the molding lower die are preheated to a preset temperature; S12. Place the cut high-strength SMC material on the molding lower die; S13. The upper molding die and the lower molding die are closed, and pressure and heat are applied to the high-strength SMC material, and it is maintained under a preset pressure for a period of time, so that the high-strength SMC material flows, fills and cures in the mold to form a shape. S14. The upper molding die and the lower molding die are opened, and the product is taken out. S15. The flash and redundant parts at the edge of the product are removed, and the surface of the product is trimmed and polished to obtain the top inner panel segment 110. S16. According to the steps S11 - S15 above, 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 and manufactured by using the front inner panel press, the so-called rear inner panel press, the left inner panel press and the right inner panel press.

[0029] Example 4: As an optimization of Example 3, as Figure 5 and Figure 6 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.

[0030] It should be noted that by setting the adjacent two segments among the five segments of the inner panel 100 to be overlapping connections, and bonding the five segments together with the structural adhesive 500, the integrity and stability of the inner panel 100 can be improved.

[0031] Exemplarily, for the overlap between the top inner panel segment 110 and the rear inner panel segment 130, the mutually approaching ends of the top inner panel segment 110 and the rear inner panel segment 130 are overlapped, and the overlapping contact surfaces of the overlapping parts are bonded with the structural adhesive 500. The overlapping methods between the other segments are similar to the overlapping method between the top inner panel segment 110 and the rear inner panel segment 130, and will not be elaborated here.

[0032] Example 5: As an optimization of Example 4, the material of the outer panel 300 is glass fiber reinforced low-density thermosetting plastic, and the thickness of the outer panel is 2.0 - 2.5 mm.

[0033] It should be noted that the density of the glass fiber reinforced low-density thermosetting plastic is much lower than that of the 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. The glass fiber-reinforced low-density thermosetting plastic has high tensile strength, flexural strength, and compressive strength due to the reinforcement of glass fibers. Its elastic modulus is also high, which can provide sufficient stiffness and strength to meet the load-bearing requirements of the outer panel 300; The glass fiber-reinforced low-density thermosetting plastic has 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, thus improving the durability and reliability of the lightweight thermal insulation top cover of the heavy truck; The outer panel 300 is of an integral structure and is formed by one-time molding using an outer panel molding press. The fewer installation points on the outer panel 300 will not affect the demolding of the outer panel 300. If the outer panel 300 is made of steel plate, restricted by the size of the stamping equipment and the stamping process, the outer panel 300 must be divided into multiple pieces and then spliced by the scheme of laser welding + sealant during assembly, which will affect the aesthetics of the top cover and require higher investment in molds and tooling costs. Therefore, forming the integral outer panel 300 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 block 110 described in S11 - S15 in Embodiment 3 and will not be elaborated here.

[0034] Exemplarily, the surface area of the outer panel 300 is 7.2 m 2 , when using a steel plate to manufacture the outer panel 300, the material density is 7.85×10 3 kg / m 3 , the thickness of the outer panel 300 is 0.8×10 -3 m, and the weight of the outer panel 300 is 7.2×0.8×10 -3 ×7.85×10 3 = 45.216 (kg); when using the glass fiber-reinforced low-density thermosetting plastic to manufacture the outer panel 300, the material density is 1.5×10 3 kg / m 3 , the thickness of the outer panel 300 is 2.5×10 -3 m, and the weight of the outer panel 300 is 7.2×2.5×10 -3 ×1.5×10 3 = 27 (kg); the weight of the outer panel 300 is reduced by 45.216 - 27 = 18.216 (kg).

[0035] Embodiment 6: As an optimization of Embodiment 5, such as Figure 2 , Figure 5 and Figure 7As shown in the figure, the interior trim 200 includes glass wool, a first non-woven fabric, a foam layer, a second non-woven fabric, and a fabric from the outside to the inside. The interior trim 200 includes a top interior trim 210 connected to the top inner panel segment 110 and a rear interior trim 220 connected to the rear side inner panel segment 130.

[0036] It should be noted that the interior trim 200 is composed of a composite of glass wool, a first non-woven fabric, a foam layer, a second non-woven fabric, and a fabric. After the heavy-duty truck lightweight thermal insulation roof cover is assembled on the truck, a storage box usually needs to be installed on the front side of the inner panel 100, and other components need to be 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, and the top interior trim 210 is composite on the inner side of the top inner panel segment 110, and the rear interior trim 220 is composite on the inner side of the rear side inner panel segment 130. The foam layer has a certain heat preservation and sound insulation effect, which is beneficial to reducing the influence of external noise on the driver, and the fabric can be pattern-designed, which is beneficial to improving the comfort of the cab.

[0037] Example 7: As an optimization of Example 6, the foam layer includes a thin foam area and a thick foam area. The thin foam area has a plurality of first air bubbles, and the thick foam area has 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.

[0038] It should be noted that the hot press in S2 includes a top interior trim hot press and a rear interior trim hot press. As Figure 8 and Figure 9 shown, S2 includes the following steps: S21. The hot press upper die 610 and the hot press lower die 620 of the rear interior trim hot press are opened, and the hot press upper die 610 and the hot press lower die 620 are preheated to a preset temperature. S22. Place the rear side inner panel segment 130 on the hot press lower die 620 with the inner side facing up, and lay the glass wool and the first non-woven fabric on the rear side inner panel segment 130 in sequence. S23. The hot press upper die 610 approaches the hot press lower die 620, squeezes and heats the glass wool and the first non-woven fabric, and thermally composites the glass wool and the first non-woven fabric with the rear side inner panel segment 130 together. S24. The hot press upper die 610 moves a preset height away from the hot press lower die 620, a second cavity is formed between the hot press upper die 610 and the rear side inner panel segment 130, and a second foaming adhesive is injected into the second cavity. The second foaming adhesive foams in the second cavity to form a foam layer adhered to the first non-woven fabric. S25. The hot press upper die 610 and the hot press lower die 620 are opened, and the second non-woven fabric and the fabric are laid on the foam layer in sequence. S26. The hot pressing upper die 610 approaches the hot pressing lower die 620, extruding and heating the second non-woven fabric and the fabric, and hot pressing and laminating the second non-woven fabric and the fabric with the foam layer together. S27. The hot pressing upper die 610 and the hot pressing lower die 620 are opened, and the complex body of the rear side inner panel block 130 and the rear side interior trim 220 is taken out. S28. According to the steps S21 - S27 above, use the top interior trim hot press to laminate and form the top interior trim 210 on the inner side of the top inner panel block 110.

[0039] In this embodiment, the second foaming glue is polyurethane foaming glue. Affected by the shape of the rear side inner panel block 130, the thickness of the foam layer is uneven. The foam layer is divided into a thin foam area and a thick foam area. 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. 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 all communicated with the first glue injection port 611, and the plurality of second glue injection holes 614 are all communicated with the second glue injection port 612. A first heating area and a second heating area are arranged in the hot pressing upper die 610. The first glue injection port 611 and the first heating area both correspond to the thin foam area, and the second glue injection port 612 and the second heating area both correspond to the thick foam area. In S24, the foaming of the foam layer includes the following three steps: Step 1: Pressurize the second cavity, inject an appropriate amount of the second foaming glue into the first glue injection port 611. The second foaming glue flows into the second cavity through the first glue injection holes 613. The first heating area is heated to a first preset temperature (at this temperature, the second foaming glue can foam normally but will not completely cure), so that the second foaming glue at the position of the first heating area foams rapidly to form a thin foam area. Step 2: Release the pressure in the second cavity, inject an appropriate amount of the second foaming glue into the second glue injection port 612. The second foaming glue flows into the second cavity through the second glue injection holes 614. The second heating area is heated to the 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 3: Both the first heating area and the second heating area are heated to a second preset temperature, and the thin foam area and the thick foam area are fused and completely cured to form a foam layer.

[0040] Under the condition of pressurization, foaming forms a thin foam area. After the pressure is released, the air holes in the thin foam area become larger, which can improve the heat preservation effect and noise reduction effect of the thin foam area, thus making up for the problems of insufficient heat preservation effect and noise reduction effect caused by the relatively thin thickness of the thin foam area.

[0041] Embodiment 8: As an optimization of Embodiment 7, 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.

[0042] It should be noted that both the first cavities and the second cavities are essentially air bubbles. The thermal conductivity of air is relatively low. The average volume of the first cavities being greater than the average volume of the second cavities can improve the heat preservation effect of the thin foaming area. The foaming steps of the foaming layer 400 are similar to the three steps of foaming the foam layer in Embodiment 7 and will not be elaborated here.

[0043] Embodiment 9: As an optimization of Embodiment 8, the first foaming adhesive is a polyurethane foaming adhesive.

[0044] It should be noted that the foaming material formed after the polyurethane foaming adhesive foams has good heat preservation performance, strength, waterproof performance and durability, thus ensuring excellent heat preservation effect of the formed foaming layer 400. Moreover, the polyurethane foaming adhesive has excellent bonding ability, and the connection strength between the formed foaming layer 400 and the outer plate 300 is high and the connection is stable, which is beneficial to improving the overall strength of the lightweight heat-insulating top cover of the heavy truck.

[0045] Embodiment 10: As an optimization of Embodiment 9, the structural adhesive 500 is a polyurethane structural adhesive.

[0046] It should be noted that the adhesion performance of the polyurethane structural adhesive is good, which can ensure firm bonding between the five inner panel segments and firm bonding between each inner panel segment and the foaming layer 400. Since the material of the foaming layer 400 is polyurethane, the polyurethane structural adhesive has good compatibility with the polyurethane foaming layer 400, which helps to ensure the stability and reliability of the bonding between the inner panel 100 and the foaming layer 400.

[0047] The embodiments of the invention have been described above in conjunction with the drawings. However, the present embodiments are not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present embodiments, those of ordinary skill in the art can also make many forms without departing from the purpose of the present embodiments and the scope protected by the claims, and all of them fall within the protection scope of the present embodiments.

Claims

1. Heavy truck lightweight insulation roof forming process, characterized in that: The following steps are involved: S1, inner panel (100) molding: placing inner panel molding material into an inner panel molding machine, and molding to manufacture the inner panel (100); S2, manufacturing the interior decoration (200): placing the inner panel (100) in a hot press, placing interior decoration materials on the inner panel (100) in sequence, and compounding the inner panel (100) on the inner side of the inner panel (100) by hot pressing and foaming to form the interior decoration (200), wherein the inner panel (100) and the interior decoration (200) form a first composite body; S3, molding the outer panel (300): placing the outer panel molding material into an outer panel molding machine, and molding the outer panel (300); S4, making the foaming layer (400): placing the outer panel (300) into a foaming mold, closing the foaming upper mold and the foaming lower mold of the foaming mold, forming a first cavity between the foaming upper mold and the outer panel (300), injecting a first foaming glue into the first cavity, the first foaming glue foams in the first cavity, forming the integrated foaming layer (400) adhered to the inner side of the outer panel (300), and the outer panel (300) and the foaming layer (400) form a second composite body; S5, gluing: gluing the second composite body to the inner side of the first composite body by means of structural adhesive (500) to form a third composite body; S6. Spraying paint: spraying paint on the outer surface of the third complex.

2. The heavy truck lightweight heat-insulating roof forming process according to claim 1 is characterized in that: The material of the inner plate (100) is a high-strength SMC material, and the thickness of the inner plate (100) is 2.5-4.0 mm.

3. The heavy truck lightweight heat-insulating roof forming process according to claim 1 is characterized in that: The inner panel (100) comprises a top inner panel block (110) bonded to the foam layer (400), a front inner panel block (120) bonded to the foam layer (400), a rear inner panel block (130) bonded to the foam layer (400), a left inner panel block (140) bonded to the foam layer (400), and a right inner panel block (150) bonded to the foam layer (400).

4. The heavy truck lightweight heat-insulating roof forming process according to claim 3 is characterized in that: The front inner panel block (120), the rear inner panel block (130), the left inner panel block (140) and the right inner panel block (150) are all overlapped with the top inner panel block (110), the front inner panel block (120) and the rear inner panel block (130) are all overlapped with the left inner panel block (140), and the front inner panel block (120) and the rear inner panel block (130) are all overlapped with the right inner panel block (150).

5. The heavy truck lightweight heat-insulating roof forming process according to claim 1 is characterized in that: The material of the outer panel (300) is glass fiber reinforced low-density thermosetting plastic, and the thickness of the outer panel is 2.0-2.5 mm.

6. The heavy truck lightweight heat-insulating roof forming process according to claim 3 is characterized in that: The interior decoration (200) comprises glass wool, a first non-woven fabric, a foam layer, a second non-woven fabric and a fabric from the outside to the inside, and the interior decoration (200) comprises a top interior decoration (210) connected to the top inner panel block (110), and a rear interior decoration (220) connected to the rear inner panel block (130).

7. The heavy truck lightweight heat-insulating roof forming process according to claim 6, characterized in that: The foam layer includes a thin foam area and a thick foam area. The thin foam area has a plurality of first bubbles, and the thick foam area has a plurality of second bubbles. The average volume of the first bubbles is greater than the average volume of the second bubbles.

8. The heavy truck lightweight heat-insulating roof forming process according to claim 1, characterized in that: The foaming layer (400) comprises a thin foaming area and a thick foaming area, the thin foaming area has a plurality of first cavities, the thick foaming area has a plurality of second cavities, and the average volume of the first cavities is greater than the average volume of the second cavities.

9. The heavy truck lightweight heat-insulating roof forming process according to claim 1, characterized in that: The first foaming glue is polyurethane foaming glue.

10. The heavy truck lightweight heat-insulating roof forming process according to claim 9, characterized in that: The structural adhesive (500) is a polyurethane structural adhesive.

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