Integrated compression molding multilayer composite material cab top cover assembly and preparation method thereof

Abstract

The invention relates to the technical field of heavy-duty car cabs, in particular to an integrated compression molding multi-layer composite material cab top cover assembly and a preparation method thereof.The cab top cover assembly comprises a top cover body, the top cover body is formed through integrated compression molding and provided with a self-sealing cavity, and the self-sealing cavity is filled with filling foam; the inner wall of the top cover body is tightly attached to the surface of the filling foam, resin runners distributed in a staggered mode are formed in the surface of the filling foam, integrated ribs are arranged on the inner wall of the top cover body at the positions of the resin runners, and the ribs are embedded into the corresponding resin runners. The forming efficiency can be improved, and the dual purposes of comprehensive performance improvement and lightweight design of the heavy-duty car cab top cover assembly are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of heavy-duty vehicle cabs, and in particular to an integrated compression-molded multi-layer composite material cab roof assembly and a preparation method thereof. Background Art

[0002] The cab of a heavy-duty vehicle is a control room on a heavy-duty vehicle for the driver to operate and drive, usually located in the front part of the vehicle.

[0003] The heavy-duty truck cab roof is an important part of the heavy-duty truck cab. It is mainly used to protect the driver and passengers, and it also reduces wind resistance and saves fuel. The roof is usually designed to be 500-820mm high, and the four sides are curved, which can expand the cab space, provide a more comfortable environment, and have a good wind resistance reduction effect.

[0004] The existing cab roof products generally rely on traditional materials and technologies in design and manufacturing, mainly using single metal materials such as steel plates or aluminum alloys, or composite materials, which are combined through welding processes between outer panels and frames or bonding technologies between inner and outer panels. Although such manufacturing methods guarantee the basic functions of the roof to a certain extent, they inevitably bring a series of performance limitations. For example, the roof assembly made by the above method has poor thermal insulation effect, poor overall structural strength and rigidity, and NVH performance (noise, vibration and acoustic roughness performance) is not outstanding enough. The existing molding methods cannot meet the design requirements of lightweight roof products. At the same time, the molding accuracy and consistency of the roof assembly lead to assembly difficulties, affecting the overall rigidity and sealing. Summary of the invention

[0005] In view of the technical problems of poor comprehensive performance, difficult assembly, and difficulty in meeting lightweight design requirements of existing cab roof assemblies, the present invention provides an integrated compression-molded multi-layer composite cab roof assembly and a preparation method thereof, which improves molding efficiency and achieves the dual goals of improving the comprehensive performance of the heavy-duty vehicle cab roof assembly and lightweight design.

[0006] The technical solution of the present invention is as follows: In the first aspect, the present invention provides an integrated compression-molded multilayer composite cab roof assembly, including a roof body, which is molded in an integrated manner and has a self-enclosed cavity, the self-enclosed cavity is filled with filling foam, the inner wall of the roof body is tightly fitted with the surface of the filling foam, the surface of the filling foam is provided with staggered resin flow channels, the inner wall of the roof body at the resin flow channel portion is provided with integrated ribs, and the ribs are embedded in the corresponding resin flow channels. The roof body is molded by injecting unsaturated resin, the unsaturated resin flows rapidly along the resin flow channel on the surface of the filling foam in the mold, fills the gap in the mold to form the roof body, and the resin at the resin flow channel portion forms ribs embedded in the resin flow channel on the surface of the filling foam.

[0007] Furthermore, the rear of the top cover body is provided with a mounting part and a positioning part. The mounting part includes a metal insert embedded in the filling foam, and the positioning part includes a positioning cavity formed by the concave surface of the filling foam. A metal insert flush with the top cover body is provided at the opening of the positioning cavity. The function is that the metal insert is pre-positioned and embedded in the filling foam in advance to provide a mounting point for the interior and exterior parts and the bracket installed on the top cover assembly. Some metal inserts are designed with threaded holes for bolt assembly connection; a metal insert is provided at the opening of the positioning cavity. After the filling foam is formed, the metal insert is pre-positioned and embedded, and the resin is introduced. After the top cover body is formed, a special open-tail rivet installation structure is formed through reprocessing. This structure enhances the sealing and installation firmness, and improves the assembly efficiency and precision. At the same time, the positioning part helps to position the filling foam as a whole according to the positioning characteristics of the top cover body after it is placed in the mold.

[0008] Furthermore, the outer surface of the filling foam is covered with a glass fiber felt, which is fixed to the filling foam by staples, so as to improve the overall strength of the filling foam.

[0009] Furthermore, the filling foam is a polyurethane foam material.

[0010] In a second aspect, the present invention provides a method for preparing an integrally molded multi-layer composite cab roof assembly, comprising the following steps: S1, the foaming mold is closed to form a closed cavity with the shape of the top cover body, and after vacuuming, the foaming material is injected into the foaming mold, and the mold is demolded under pressure. The foaming material is integrally formed in the mold to obtain a filling foam; S2, a staggered distribution of resin flow channels is provided on the surface of the filling foam; S3, placing the filling foam in an RTM mold having the shape of the main body of the top cover, closing the mold and evacuating the mold, injecting the unsaturated resin into the RTM mold, maintaining the pressure and demoulding, and the unsaturated resin is integrally formed in the mold to obtain a finished product.

[0011] Furthermore, in step S1, before the foaming mold is closed, a metal insert and a metal insert sheet are placed in the foaming mold, and the positions of the metal insert and the metal insert sheet in the mold correspond to the installation position and the positioning position of the top cover body.

[0012] Furthermore, in step S1, the obtained filling foam is post-processed, and the post-processing includes surface grinding, removing burrs and removing the surface glaze layer.

[0013] Furthermore, after the filling foam is post-processed, a glass fiber mat is laid on the surface of the filling foam and fixed with a stapler.

[0014] Furthermore, in step S2, the resin flow channels are distributed in a grid-like manner. Furthermore, the cross-section of the resin flow channels is U-shaped.

[0015] The beneficial effects of the present invention are: (1) The filling foam of the present invention adopts a vacuum injection one-piece molding foaming process to achieve component integration and modularization, so that the top cover structure has higher precision, better overall performance, and is more conducive to lightweight design.

[0016] (2) The top cover assembly provided by the present invention is integrally formed in a mold, which improves the precision and performance of the top cover assembly, makes the overall structure compact, and enhances product consistency.

[0017] (3) The cab roof assembly provided by the present invention is a "sandwich" structure consisting of a roof main body covered with filling foam, which is conducive to lightweight design.

[0018] (4) The outer surface of the filling foam of the present invention is designed with a resin flow channel structure that is interconnected in series. During molding, unsaturated resin is injected into the filling foam through the resin flow channel to form staggered ribs, thereby increasing the overall rigidity of the top cover assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a process flow chart of a specific implementation mode of the present invention.

[0021] Figure 2 It is a schematic diagram of the three-dimensional structure of the top cover assembly made according to a specific implementation method of the present invention.

[0022] Figure 3 Specific implementation mode of the present invention Figure 1 Middle AA section view.

[0023] Figure 4 Specific implementation mode of the present invention Figure 2 A magnified view of the part within the middle circle B.

[0024] Figure 5 It is a schematic diagram of the structure of laying glass fiber felt on the surface of the filled foam according to a specific embodiment of the present invention.

[0025] Figure 6 It is a schematic diagram of the resin flow channel structure of the foam surface filled according to a specific embodiment of the present invention.

[0026] Figure 7 Specific implementation mode of the present invention Figure 6 Middle DD section view.

[0027] Figure 8 Specific implementation mode of the present invention Figure 1 Middle CC section.

[0028] In the figure, 1-top cover body, 2-filling foam, 3-metal insert, 4-metal insert, 5-positioning cavity, 6-resin flow channel, 7-glass fiber felt. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] Example 1 Combination Figure 1-Figure 8 The present invention provides a method for preparing an integrated compression-molded multi-layer composite cab roof assembly, comprising the following steps: S1. Select a foaming mold in the shape of a top cover body 1. Place all embedded parts on the foaming mold before foaming. The embedded parts include metal inserts 3 and metal inserts 4. The positions of the metal inserts 3 and metal inserts 4 in the mold correspond to the installation position and positioning position of the top cover body 1. After the foaming mold is pre-vacuumed, a low-density polyurethane foam material is injected into the foaming mold to ensure that the corner features of the top and side junctions are uniformly formed; after the product is molded and demolded, it is polished, the flash is removed, and the surface glaze layer is removed, so that the resin and the foam can be better combined and infiltrated to obtain the filling foam 2. The one-piece molding of the filling foam 2 improves the accuracy and performance of the top cover structure, makes the top cover structure more compact, improves the overall performance and reduces the weight; S2. A resin flow channel 6 is provided on the surface of the filling foam 2 in a grid-like staggered distribution. The slotted cross-section of the resin flow channel 6 is U-shaped. The design of the interconnected grid-like resin flow channels 6 reduces pressure loss and heat loss, accelerates the flow speed of the unsaturated resin during the mold closing process, and facilitates the unsaturated resin to quickly fill the entire cavity, thereby improving the molding quality. At the same time, the resin in the flow channel is embedded in the filling foam 2, and after the unsaturated resin is injected, staggered ribs are formed, thereby increasing the overall rigidity of the top cover assembly. Finally, a glass fiber felt 7 is laid on the inner and outer surfaces of the formed filling foam 2, and then the glass fiber felt 7 is stapled to the filling foam 2. S3, placing the filling foam 2 in the RTM mold with the shape of the top cover body 1, the thickness of the outer wall of the top cover body 1 structure, the thickness of the inner wall of the structure and the filling foam 2 can be designed with variable thickness according to the stress characteristics and performance requirements of the top cover assembly, and the thickness design can be achieved by changing the mold size. After RTM mold closing and vacuuming, the unsaturated resin is injected into the RTM mold, and the mold is demolded under pressure. The unsaturated resin is integrally formed in the mold to form a top cover body 1 with a self-enclosed structure, and a finished product with a "sandwich" structure is obtained. The present invention adopts a vacuum-introduced resin RTM integral molding process, which can achieve multiple The one-step molding of each feature can produce a component, which has great advantages in time cost, labor cost and space cost. This transformation from multi-part assembly to "one-step molding" manufacturing can not only significantly reduce manufacturing costs, realize the integration and modularization of parts, improve production and assembly efficiency, and reduce labor costs, but also has significant technical advantages; at the same time, the integrated design of the multi-layer composite roof assembly can further reduce the number of parts, significantly improve the overall accuracy and product consistency of the heavy-duty vehicle cab roof assembly, and achieve the dual goals of comprehensive performance improvement and lightweight design of the heavy-duty vehicle cab roof assembly.

[0031] Although the present invention has been described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person skilled in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, and they shall be within the scope of protection of the present invention.

Claims

1. An integrated compression molded multi-layer composite cab roof assembly, comprising a roof body, characterized in that: The top cover body is formed by one-piece compression molding and has a self-enclosed cavity, which is filled with filling foam. The inner wall of the top cover body is tightly fitted with the surface of the filling foam, and the surface of the filling foam is provided with staggered resin flow channels. The inner wall of the top cover body at the resin flow channel is provided with integrated ribs, which are embedded in the corresponding resin flow channels.

2. The one-piece compression molded multi-layer composite cab roof assembly according to claim 1, characterized in that: The tail of the top cover body is provided with a mounting piece and a positioning piece. The mounting piece includes a metal insert embedded in the filling foam. The positioning piece includes a positioning cavity formed inwardly on the surface of the filling foam. A metal insert flush with the top cover body is provided at the opening of the positioning cavity.

3. The one-piece compression molded multi-layer composite cab roof assembly according to claim 1, characterized in that: The outer surface of the filling foam is covered with glass fiber felt, and the glass fiber felt is fixed to the filling foam by staples.

4. The one-piece compression molded multi-layer composite cab roof assembly according to claim 1, characterized in that: The filling foam is polyurethane foam material.

5. A method for preparing the one-piece compression molded multi-layer composite cab roof assembly as claimed in claim 1, characterized in that: The steps include: S1, the foaming mold is closed to form a closed cavity with the shape of the top cover body, and after vacuuming, the foaming material is injected into the foaming mold, and the mold is demolded under pressure. The foaming material is integrally formed in the mold to obtain the filling foam; S2, a staggered distribution of resin flow channels is provided on the surface of the filling foam; S3, placing the filling foam in an RTM mold having the shape of the main body of the top cover, closing the mold and evacuating the mold, injecting the unsaturated resin into the RTM mold, maintaining the pressure and demoulding, and the unsaturated resin is integrally formed in the mold to obtain a finished product.

6. The method for preparing the one-piece compression molded multi-layer composite cab roof assembly according to claim 5, characterized in that: In step S1, before the foaming mold is closed, a metal insert and a metal insert sheet are placed in the foaming mold, and the positions of the metal insert and the metal insert sheet in the mold correspond to the installation position and the positioning position of the top cover body.

7. The method for preparing the one-piece compression molded multi-layer composite cab roof assembly according to claim 5, characterized in that: In step S1, the prepared filling foam is post-processed, and the post-processing includes surface grinding, removing burrs and removing the surface glaze layer.

8. The method for preparing the one-piece compression molded multi-layer composite cab roof assembly according to claim 7, characterized in that: After the filling foam is post-processed, fiberglass mat is laid on the surface of the filling foam and fixed with a stapler.

9. The method for preparing the one-piece compression molded multi-layer composite cab roof assembly according to claim 5, characterized in that: In step S2, the resin flow channels are distributed in a grid-like manner.

10. The method for preparing the one-piece compression molded multi-layer composite cab roof assembly according to claim 9, characterized in that: The cross section of the resin flow channel is U-shaped.

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