A method for manufacturing a fiber-woven composite subframe and a subframe

Abstract

A method for preparing a fiber-woven composite subframe and the subframe itself are disclosed. The subframe includes an annular composite frame and metal connectors mounted on the frame for assembly with a vehicle. The preparation method comprises: first, processing a foam core material into a support template for the subframe frame shape, and placing metal inserts with connecting holes on the support template; second, weaving a reinforcing frame composed of fiber material around the support template and metal inserts using a three-dimensional weaving method; third, injecting resin into the reinforcing frame and curing it to form the composite frame of the subframe, and connecting the metal connectors to the metal inserts before or after resin injection. The subframe formed by this invention exhibits significant weight reduction, meeting the requirements for lightweight design, and possesses high load-bearing capacity, outstanding damage tolerance, and overall integrity, thus solving the industry requirements for high strength, fatigue resistance, integrity, and lightweight automotive subframes.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a subframe and a subframe, specifically to a method for manufacturing a fiber-woven composite material subframe and a subframe. Background Technology

[0002] The subframe structure of a car chassis is among the most complex and harshest operating parts in the entire vehicle, and its lightweighting has the most significant impact on improving the overall vehicle stability. To meet the current lightweighting requirements of vehicles, especially new energy vehicles, the automotive industry has already adopted the application of composite materials in car subframes, but almost all of these are based on composite sheet layups, which can cause significant delamination damage when subjected to impact. Summary of the Invention

[0003] This invention addresses the problem of easy damage to composite material subframes formed by layup methods under current lightweight requirements. It proposes a method for preparing fiber braided composite material subframes and a subframe that can meet the industry requirements of high strength, fatigue resistance, integrity, and lightweight, and also has outstanding damage tolerance and integrity.

[0004] The technical means adopted by this invention to solve the above problems is as follows: a method for preparing a fiber-woven composite material subframe. The first step involves processing a foam core material into a support template for the subframe frame, and setting metal inserts on the support template, with connecting holes on the metal inserts. The second step involves weaving a reinforcing frame composed of fiber material around the support template and metal inserts using a three-dimensional weaving method. The third step involves injecting resin into the reinforcing frame and curing it to form the composite material frame of the subframe, with metal connectors attached to the metal inserts before or after resin injection. The combination of machined foam core material and three-dimensionally woven fiber material forms a lightweight subframe body, resulting in significant weight reduction and strong load-bearing capacity.

[0005] Furthermore, in the first step, the foam core material is processed into two support templates with openings, and the two support templates are combined into a ring. Dividing it into two support templates facilitates subsequent three-dimensional weaving operations.

[0006] Furthermore, in the first step, the foam core material is processed into a support template using CNC machining technology, and recesses for placing metal inserts are opened on the support template.

[0007] Furthermore, in the first step, the metal insert is bonded to the recess using an adhesive.

[0008] Furthermore, in the second step, fiber material is woven around the two support templates to form two woven frames, while the connection holes of the metal inserts are connected to the outside.

[0009] Furthermore, in the second step, two independent annular sleeves are woven using a three-dimensional weaving method. One annular sleeve is fitted onto each end of the two woven frames, and the two annular sleeves connect the two support templates to form an annular reinforcing frame.

[0010] Furthermore, in the second step, during the three-dimensional weaving process, the X and Y directions are woven using methods such as 1´1, 2´2, 4´4, etc., while the Z direction uses fibers to stitch the layers together.

[0011] Furthermore, in the third step, the metal connector is first connected to the metal insert, and the mounting holes of the metal connector are sealed before resin is injected into the reinforcing frame. The resin further improves the bonding strength between the metal connector and the metal insert.

[0012] Furthermore, in the third step, after the metal connector is connected to the metal insert, the entire reinforcing frame is placed in a mold and heated. Resin-impregnated fibers are injected into the mold, and after cooling and curing, the subframe frame structure is formed.

[0013] Furthermore, the metal connectors and metal inserts are locked together by bolts.

[0014] A fiber-woven composite material subframe includes an annular composite material frame and metal connectors disposed on the frame for assembly and connection with a vehicle. The frame is formed by first processing a support template with foam core material, then three-dimensionally weaving a reinforcing frame on the surface of the support template, and finally injecting resin into the reinforcing frame. Metal inserts are provided inside the support template, and the metal connectors are connected and fixed by the metal inserts.

[0015] The beneficial effects of this invention are:

[0016] 1. This invention uses foam core material machined into a support template in the shape of a subframe, and then uses three-dimensional weaving to form a fiber-reinforced frame. The resulting subframe has a significant weight reduction, which can meet the requirements of lightweighting, and has high load-bearing capacity, as well as outstanding damage tolerance and integrity. Therefore, it solves the industry requirements of high strength, fatigue resistance, integrity and lightweight for automotive subframes.

[0017] 2. The composite material body structure and process involved in this invention are flexible and can be adjusted according to actual product conditions to meet the requirements of automated mass production. It also avoids the delamination risk caused by composite sheet lamination processes and improves stress concentration caused by composite material stretching and extrusion at bending points of structural components. While achieving significant weight reduction, it greatly improves the overall mechanical performance of the subframe, making it superior to existing products and competitive in the high-end new energy vehicle market.

[0018] 3. This invention can be customized to produce corresponding support template shapes and incorporate appropriate metal inserts and connectors based on actual product requirements, thus adapting to various vehicle models and exhibiting strong versatility. Furthermore, for models with minor differences, only the metal connectors need to be replaced for direct compatibility. Moreover, the subframe structure in this method is customizable, the manufacturing process is simple and feasible, and large-scale mass production is possible. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of two C-shaped support template structures made of foam core material in Example 1;

[0020] Figure 2 This is a schematic diagram of the metal insert structure in Example 1;

[0021] Figure 3 This is a schematic diagram of the structure after the metal insert is bonded to the support template in Example 1;

[0022] Figure 4 This is a schematic diagram of the three-dimensional braided reinforcing frame structure in Example 1;

[0023] Figure 5 This is a schematic diagram of the metal connector structure in Example 1;

[0024] Figure 6 This is a schematic diagram of a vehicle frame structure for an example embodiment;

[0025] In the diagram: 1. Support template, 2. Recessed hole, 3. Woven frame, 4. Sleeve, 5. Metal insert, 51. Connecting hole, 6. Metal connector, 61. Assembly hole, 7. Frame. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings. The drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Example 1

[0027] A method for preparing a fiber-woven composite subframe, such as Figure 6 As shown, the overall structure of the composite material subframe includes a ring-shaped frame 7 and a metal connector 6 provided on the surface of the frame 7. The metal connector 6 is provided with an assembly hole 61 for assembly connection with the vehicle. After the bolt passes through the assembly hole 61, the entire subframe is installed on the vehicle.

[0028] like Figures 1-5As shown, the composite material subframe includes a support template 1 made of foam core material, a three-dimensional woven frame 3, metal inserts 5, and metal connectors 6.

[0029] The specific preparation process is as follows: Step 1, as... Figures 1-3 As shown, to reduce the difficulty of subsequent operations, the foam core material is processed into two C-shaped support templates 1 with openings using CNC machining technology. The two support templates 1 are joined together at the openings to form a ring, creating the shape of the subframe frame. Multiple recesses 2 are also provided on the support templates 1, into which metal inserts 5 are bonded. Generally, only one metal insert 5 is bonded in each recess 2. Therefore, the shape of each recess 2 matches the shape of the metal insert 5 to be bonded at that location, maximizing the contact area between the metal insert 5 and the wall of the recess 2. Furthermore, for the structure where the metal insert 5 is embedded inside the support template 1, some grooves are provided to allow the adhesive to penetrate into the grooves during bonding, preventing the contact surface between the metal insert 5 and the support template 1 from being too flat. The connecting hole 51 on the metal insert 5, for contacting the metal connector 6, is designed to protrude beyond the main surface of the metal insert 5, ensuring that the connecting hole 51 remains in contact with the outside during subsequent operations.

[0030] The second step, as Figure 4 As shown, two supporting templates 1 serve as the skeleton, and fiber material is woven around the outer periphery of the supporting templates 1 using a three-dimensional weaving method to form two independent woven frames 3. During the weaving process, the X and Y directions can be woven using 1´1, 2´2, 4´4, etc., while the Z direction is stitched together with fiber material between the layers, overcoming the problem of easy delamination between layers in traditional laminated sheets. This also solves the risk of stress failure caused by wrinkles and tension at the bending points of existing composite material subframe frames, improving the overall structural integrity and uniformity of mechanical properties. In addition, two independent annular sleeves 4 are woven. Then, one sleeve 4 covers one end of each of the two woven frames 3, and the two sleeves 4 cover both ends of the two woven frames 3 respectively, forming an annular reinforcing frame. Furthermore, all the connection holes 51 on the reinforcing frame are exposed to ensure the connection of the subsequent metal connectors 6.

[0031] The third step, as Figures 5-6As shown, all metal connectors 6 are connected and locked to the metal inserts 5, and the assembly holes 61 of the metal connectors 6 are sealed with bolts, etc. Then, the entire reinforcing frame is placed in the mold for preheating, and then low-viscosity resin is injected into the mold. After the resin fully impregnates the fibers, it cools and cures to form the composite material subframe frame 7. In this embodiment, the metal connectors 6 are installed to the metal inserts 5 before the adhesive is injected, so that the adhesive can strengthen the bond between the metal connectors 6 and the metal inserts 5. Of course, the connection holes 51 of the metal inserts 5 can also be sealed before the adhesive is injected, and the metal connectors 6 can be installed after the adhesive is injected and cooled and cured.

[0032] In the above embodiments, to reduce the difficulty of three-dimensional weaving, the foam core material is processed in two parts, and four independent parts are woven in three dimensions. If the limitations of three-dimensional weaving technology are overcome, the foam core material can also be directly processed into a ring-shaped support template, and the reinforcing frame can be woven directly on the support template.

[0033] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the protection scope of the invention, which should be defined by the claims.

Claims

1. A method for preparing a fiber-woven composite material subframe, characterized in that: The first step is to process the foam core material into a support template (1) for the subframe frame, and to set a metal insert (5) on the support template (1), and to provide a connecting hole (51) on the metal insert (5); the second step is to weave a reinforcing frame made of fiber material outside the support template (1) and the metal insert (5) using a three-dimensional weaving method. The third step is to inject resin into the reinforcing frame and cure it to form a composite material frame (7) of the subframe, and to connect the metal connector (6) to the metal insert (5) before or after the resin injection. In the first step, the foam core material is processed into two C-shaped support templates (1) with openings, and the two C-shaped support templates (1) are combined into a ring; In the second step, fiber material is woven around the two support templates (1) to form two woven frames (3), while the connecting hole (51) of the metal insert (5) is connected to the outside; Two independent annular sleeves (4) are woven using a three-dimensional weaving method. One annular sleeve (4) is fitted onto the two ends of the two weaving frames (3). The two annular sleeves (4) connect the two support templates (1) to form an annular reinforcing frame. In the second step, during the three-dimensional weaving process, the X and Y directions are woven in a 1´1, 2´2, 4´4 pattern, while the Z direction uses fibers to stitch the layers together.

2. The method for preparing a fiber-woven composite subframe as described in claim 1, characterized in that: In the first step, the foam core material is processed into a support template (1) using CNC machining technology, and a recess (2) is opened on the support template (1) to place the metal insert (5).

3. The method for preparing a fiber-woven composite subframe as described in claim 2, characterized in that: The metal insert (5) is bonded to the recess (2) with adhesive.

4. The method for preparing a fiber-woven composite subframe as described in claim 1, characterized in that: In the third step, the metal connector (6) is first connected to the metal insert (5), and the assembly hole (61) of the metal connector (6) is sealed before resin is injected into the reinforcing frame.

5. The method for preparing a fiber-woven composite subframe as described in claim 4, characterized in that: After the metal connector (6) is connected to the metal insert (5), the entire reinforcing frame is placed in the mold and heated. Resin is injected into the mold to impregnate the fiber. After cooling and curing, the subframe frame (7) is formed.

6. A fiber-woven composite subframe prepared by the method of claim 1, comprising an annular composite frame (7) and metal connectors (6) disposed on the frame (7) for assembly connection with a vehicle, characterized in that: The frame (7) is formed by first processing the foam core material into a support template (1), then three-dimensionally weaving a reinforcing frame on the surface of the support template (1), and finally injecting resin into the reinforcing frame. The support template (1) is provided with metal inserts (5), and the metal connectors (6) are connected and fixed through the metal inserts (5).

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