Fiber woven composite material auxiliary frame preparation method and auxiliary frame

Abstract

The auxiliary frame comprises an annular composite frame body and a metal connecting piece which is arranged on the frame body and used for being connected with a vehicle in an assembling mode, and the manufacturing method of the auxiliary frame comprises the steps that firstly, a foam core material is machined into a supporting template in the shape of the auxiliary frame body, and a metal insert is arranged on the supporting template; a connecting hole is formed in the metal insert; secondly, a reinforcing frame defined by fiber materials is woven outside the supporting formwork and the metal insert in a three-dimensional weaving mode; and thirdly, resin is injected into the reinforcing frame to be cured to form a composite frame body of the auxiliary frame, and the metal connecting piece is connected to the metal insert before or after resin injection. The formed auxiliary frame is obvious in weight reduction, capable of meeting the requirement for light weight, high in bearing capacity and outstanding in damage tolerance capacity and integrity, and therefore the industrial requirements for high strength, fatigue resistance, integrity and light weight of the automobile auxiliary frame are met.

Description

Technical Field

[0001] The invention relates to a method for preparing a subframe and the subframe, and in particular to a method for preparing a fiber braided composite material subframe and the subframe. Background Art

[0002] The subframe structure of the automobile chassis is the part with the most complex working conditions and the worst operating environment in the whole vehicle, and its lightweighting has the most obvious effect on improving the stability of the whole vehicle. In order to meet the requirements of lightweighting of current vehicles, especially new energy vehicles, the automotive industry has already applied composite materials to automobile subframes, but most of them are mainly laminated with composite sheets, which will cause obvious delamination damage when impacted. Summary of the invention

[0003] In view of the problem that composite subframes formed by layering under lightweight requirements are easily damaged, the present invention proposes a method for preparing a fiber woven composite subframe and a subframe, which can meet the industry requirements of high strength, fatigue resistance, integrity, and lightweight of the subframe, and also has outstanding damage tolerance and integrity.

[0004] The technical means adopted by the present invention to solve the above problems are: a method for preparing a fiber woven composite material subframe, the first step is to process the foam core material into a supporting template in the shape of the subframe frame, and set a metal insert on the supporting template, and the metal insert is provided with a connecting hole; the second step is to use a three-dimensional weaving method to weave a reinforcement frame surrounded by fiber material outside the supporting template and the metal insert; the third step is to inject resin into the reinforcement frame and solidify it to form a composite material frame of the subframe, and connect the metal connector to the metal insert before or after injecting the resin. The machined foam core material is combined with the three-dimensional woven fiber material to form a lightweight subframe body, which has obvious 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. The two support templates are divided into two to facilitate the subsequent three-dimensional weaving operation.

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

[0007] Furthermore, in the first step, the metal insert is bonded in the recessed hole by an adhesive.

[0008] Furthermore, in the second step, fiber materials are woven outside the two support templates to wrap the support templates to form two woven frames, and the connection holes of the metal inserts are connected to the outside.

[0009] Furthermore, in the second step, two independent annular sleeves are woven by three-dimensional weaving, and one annular sleeve is respectively sleeved on both ends of the two weaving frames, and the two annular sleeves connect the two supporting templates into an annular reinforcement frame.

[0010] Furthermore, 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, etc. manner, and the laminated layers are sewed together with fibers in the Z direction.

[0011] Furthermore, in the third step, the metal connector is first connected to the metal insert, and the assembly hole of the metal connector is sealed before injecting resin into the reinforcement frame to further improve the bonding force 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 reinforcement frame is placed in a mold and heated, and resin is injected into the mold to impregnate the fibers, and the structure of the subframe frame is formed after cooling and curing.

[0013] Furthermore, the metal connector and the metal insert are connected and locked by bolts.

[0014] A fiber woven composite material subframe comprises an annular composite material frame and a metal connector arranged on the frame for assembly and connection with a vehicle, wherein the frame is a structure formed by first processing a foam core material into a support template, then three-dimensionally weaving a reinforcement frame on the surface of the support template, and finally injecting resin into the reinforcement frame, and a metal insert is provided in the support template, and the metal connector is connected and fixed by the metal insert.

[0015] The beneficial effects of the present invention are: 1. The present invention uses foam core material to be machined into a supporting template in the shape of a subframe, and then uses three-dimensional weaving to form a fiber-reinforced frame. The formed subframe has significant weight reduction, can meet the requirements of lightweight, and has a high load-bearing capacity, as well as outstanding damage tolerance and integrity, thus meeting the industry requirements of high strength, fatigue resistance, integrity and lightweight for automobile subframes.

[0016] 2. The structure and process of the composite material body involved in the present invention are flexible and can be adjusted according to the actual product situation to meet the requirements of automated mass production, avoid the risk of delamination caused by the composite sheet lamination process, and improve the stress concentration caused by the stretching and extrusion of the composite material at the bending of the structural parts. While achieving significant weight reduction, it greatly improves the overall mechanical properties of the subframe, which is better than existing products and has competitiveness in the high-end new energy vehicle market.

[0017] 3. The present invention can process the corresponding support template shape and set the corresponding metal inserts and metal connectors according to the actual product requirements to adapt to various vehicle models, so it has strong versatility. At the same time, for vehicle models with smaller differences, it only needs to replace different metal connectors to be directly universal. Moreover, the structure of the subframe in this method can be designed, the production process is simple and feasible, and large-scale mass production can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of two C-shaped support templates processed with foam core material in Example 1; Figure 2 This is a schematic diagram of the metal insert structure of Example 1; Figure 3 This is a schematic diagram of the structure after the metal insert is bonded to the support template in Example 1; Figure 4 This is a schematic diagram of a three-dimensionally woven reinforcement frame structure according to the first embodiment; Figure 5 This is a schematic diagram of the structure of a metal connector in Example 1; Figure 6 This is a schematic diagram of a frame structure of an embodiment; In the figure: 1. Support template, 2. Concave hole, 3. Braided frame, 4. Sleeve, 5. Metal insert, 51. Connecting hole, 6. Metal connector, 61. Assembly hole, 7. Frame. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings. The accompanying drawings are only for illustrative purposes and are only schematic diagrams, not actual pictures, and cannot be understood as limiting the present patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; it is understandable to those skilled in the art that some well-known structures and their descriptions in the accompanying drawings may be omitted. Embodiment 1

[0020] A method for preparing a fiber braided composite material subframe, such as Figure 6 As shown, the overall structure of the composite subframe includes a ring-shaped frame 7 and a metal connector 6 arranged on the surface of the frame 7. The metal connector 6 is provided with an assembly hole 61 for assembly and connection with the vehicle. After the bolts pass through the assembly hole 61, the entire subframe is installed on the vehicle.

[0021] like Figure 1-Figure 5 As shown, the composite material subframe includes a support template 1 made of foam core material, a woven frame 3 made of three-dimensional weaving, a metal insert 5 and a metal connector 6.

[0022] The specific preparation process is as follows: the first step is Figure 1-Figure 3As shown, in order to reduce the difficulty of subsequent operations, the foam core material is processed into two C-shaped support templates 1 with openings by CNC machining technology. The two support templates 1 can be combined into a ring by fitting together at the openings to form the shape of the subframe frame. In addition, a plurality of recessed holes 2 are provided on the support template 1, and the metal insert 5 is bonded into the recessed holes 2. At this time, generally only one metal insert 5 is bonded into a recessed hole 2. Therefore, the shape of each recessed hole 2 matches the shape of the metal insert 5 to be bonded at this position, and the contact area between the metal insert 5 and the wall of the recessed hole 2 is increased as much as possible. Moreover, for the structure in which the metal insert 5 is embedded in the support template 1, some grooves are provided so that the adhesive can penetrate into the grooves during bonding, so as to avoid the contact surface between the metal insert 5 and the support template 1 being too flat, and the surface of the connection hole 51 on the metal insert 5 for contacting the metal connector 6 is designed to protrude from the large surface of the metal insert 5, so as to ensure that the connection hole 51 can maintain contact with the outside world in subsequent operations.

[0023] The second step is, Figure 4 As shown, two support templates 1 are used as the skeleton, and fiber materials are woven around the periphery of the support templates 1 in a three-dimensional weaving manner to form two independent weaving frames 3. During the weaving process, the X and Y directions can be woven in 1'1, 2'2, 4'4 and other ways, and the Z direction uses fiber materials to sew the laminated layers together, thereby overcoming the problem of easy delamination and peeling between the layers of the traditional laminated sheets, while solving the risk of stress failure caused by wrinkles and pulling at the bends of the existing composite material subframe frame, and improving the structural integrity and uniformity of mechanical properties. In addition, two independent annular sleeves 4 are woven. Then, a sleeve 4 covers each end of the two weaving frames 3, and the two sleeves 4 cover the two ends of the two weaving frames 3, respectively, to form an annular reinforcement frame. Moreover, all the connection holes 51 on the reinforcement frame are exposed to ensure the connection of the subsequent metal connector 6.

[0024] The third step is Figure 5-Figure 6 As shown, all metal connectors 6 are connected and locked to the metal insert 5, and the assembly holes 61 of the metal connectors 6 are blocked with bolts, etc., and then the entire reinforcement frame is placed in a mold for preheating, and then a low-viscosity resin is injected into the mold, and the resin is fully infiltrated into the fiber and then cooled and solidified to form a composite material subframe frame 7. In this embodiment, the metal connector 6 is installed on the metal insert 5 before the glue is injected, so that the adhesive can strengthen the combination between the metal connector 6 and the metal insert 5. Of course, the connection holes 51 of the metal insert 5 can also be blocked before the glue is injected, and the metal connector 6 can be installed after the glue injection is completed and cooled and solidified.

[0025] In the above embodiment, in order to reduce the difficulty of three-dimensional weaving, the foam core material is processed into two parts, and four independent parts are woven three-dimensionally. 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 reinforcement frame can be directly woven on the support template.

[0026] The above embodiments are only used to illustrate the present invention, rather than to limit the present invention. Technicians in the relevant technical field may make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the protection scope of the present invention, and the protection scope of the present invention should be defined by the claims.

Claims

1. A method for preparing a fiber braided composite material subframe, characterized in that: The first step is to process the foam core material into a supporting template (1) in the shape of a sub-frame frame, and to arrange a metal insert (5) on the supporting template (1), wherein the metal insert (5) is provided with a connecting hole (51); the second step is to weave a reinforcing frame surrounded by fiber material outside the supporting template (1) and the metal insert (5) by a three-dimensional weaving method; In the third step, resin is injected into the reinforcement frame and cured to form a composite material frame (7) of the subframe, and the metal connector (6) is connected to the metal insert (5) before or after the resin is injected.

2. The method for preparing a fiber braided composite material subframe according to claim 1, characterized in that: In the first step, the foam core material is processed into two support templates (1) with openings, and the two support templates (1) are combined into a ring.

3. The method for preparing a fiber braided composite material subframe according to claim 1, characterized in that: In the first step, the foam core material is processed into a support template (1) using CNC processing technology, and a recessed hole (2) for placing a metal insert (5) is opened on the support template (1).

4. The method for preparing a fiber braided composite material subframe according to claim 3, characterized in that: The metal insert (5) is bonded in the recessed hole (2) by means of an adhesive.

5. The method for preparing a fiber braided composite material subframe according to claim 1, characterized in that: In the second step, fiber materials are woven outside the two support templates (1) to wrap the support templates (1) to form two woven frames (3), and the connection holes (51) of the metal inserts (5) are connected to the outside.

6. The method for preparing a fiber braided composite material subframe according to claim 5, characterized in that: Two independent annular sleeves (4) are woven in a three-dimensional weaving manner, one annular sleeve (4) is respectively sleeved on both ends of two weaving frames (3), and the two annular sleeves (4) connect the two supporting templates (1) to form an annular reinforcement frame.

7. The method for preparing a fiber braided composite material subframe according to claim 1, characterized in that: 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, etc. manner, and the Z direction uses fibers to sew the layers of the laminate.

8. The method for preparing a fiber braided composite material subframe according to 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 injecting resin into the reinforcement frame.

9. The method for preparing a fiber braided composite material subframe according to claim 8, characterized in that: After the metal connector (6) is connected to the metal insert (5), the entire reinforcement frame is placed in a mold and heated, and resin is injected into the mold to impregnate the fibers. After cooling and solidification, the structure of the subframe frame (7) is formed.

10. A fiber braided composite material subframe, comprising an annular composite material frame (7) and a metal connector (6) disposed on the frame (7) for assembly and connection with a vehicle, characterized in that: The frame (7) is a structure formed by first processing a foam core material into a support template (1), then three-dimensionally weaving a reinforcement frame on the surface of the support template (1), and finally injecting resin into the reinforcement frame. A metal insert (5) is provided in the support template (1), and the metal connector (6) is connected and fixed via the metal insert (5).

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