A fiber composite chassis beam with pre-tensioned fiber bundles

Abstract

The application discloses a fiber composite chassis beam with pre-tensioned fiber bundle, and relates to the technical field of automobile chassis structure and composite material automobile body part. The chassis beam comprises a beam body, a pre-tensioned fiber bundle, a metal pressure-bearing component and a battery accommodating bin. The beam body is a fiber-reinforced composite material beam body. The pre-tensioned fiber bundle is embedded in the beam body along the length direction of the beam body, and the two ends of the pre-tensioned fiber bundle are anchored in the end area of the beam body, and the pre-tensioned fiber bundle maintains the pre-tension stress along the length direction in the beam body. The metal pressure-bearing component is arranged at the motor suspension point or the suspension connecting point of the beam body, and is used for dispersing the local compression load and the shear load at the connecting point. The battery accommodating bin is arranged in the middle area of the beam body, and forms an integrated load-bearing structure with the beam body. The application is beneficial to reducing the crushing and delamination risks of the connecting area of the composite material beam body, and reducing the use of the independent externally-hung battery support.

Description

Technical Field

[0001] This invention relates to the technical field of automobile chassis structure and composite material body components, specifically to a fiber composite chassis beam with pre-tensioned fiber bundles. Background Technology

[0002] In new energy vehicles, the battery pack, drive motor, and suspension system all require support and connection from the chassis structure. Traditional chassis beams are mostly made of steel or aluminum alloy, which, while offering good load-bearing capacity, result in significant overall weight, hindering vehicle weight reduction. In recent years, fiber-reinforced composite materials have been used in chassis structures to reduce component weight and improve structural rigidity. However, composite materials are inherently sensitive to localized compression, shear, and concentrated loads at bolted connections, making them prone to delamination, crushing, or localized damage at stress points such as motor mounts and suspension connection points.

[0003] Existing composite chassis structures typically require additional metal supports, battery brackets, or localized reinforcements, resulting in a large number of parts, complex assembly relationships, and an increased chassis height and vehicle center of gravity. While some composite beams can reduce weight, their connection points still rely primarily on bolts, bushings, or localized reinforcements for load-bearing, making it easy for concentrated loads to be directly transferred to the interlayer areas of the composite material. Some prestressed composite components also focus primarily on the bending resistance of the beam itself, failing to simultaneously address the localized load-bearing requirements of motor mounting points and suspension connection points, as well as the integrated layout of the battery housing structure. For cross-model platforms, the battery pack, suspension points, and powertrain arrangements differ between models, and traditional solutions require separate designs for mounting brackets and reinforcement structures, resulting in poor versatility. Therefore, a chassis beam structure that can combine the lightweight advantages of fiber composites, the tensile strength advantages of pre-tensioned fiber bundles, and the localized load-bearing advantages of metal components is needed. Summary of the Invention

[0004] The purpose of this invention is to provide a fiber composite chassis beam with pre-tensioned fiber bundles to improve the problems of existing composite chassis beams that are prone to local crushing, delamination or stress concentration at motor mounting points, suspension connection points and other locations, as well as the large number of battery mounting structural parts.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a fiber composite chassis beam with pre-tensioned fiber bundles, comprising a beam body, pre-tensioned fiber bundles, a metal pressure-bearing component, and a battery housing; the beam body is a fiber-reinforced composite material beam; the pre-tensioned fiber bundles are embedded in the beam body along its length, with both ends of the pre-tensioned fiber bundles anchored to the end regions of the beam body, and the pre-tensioned fiber bundles maintain pre-tensioned stress along the length of the beam body within the beam body; the metal pressure-bearing component is disposed at the motor suspension point or suspension connection point of the beam body and contacts and engages with the corresponding connection area of ​​the beam body to disperse local compressive and shear loads at the connection point; the battery housing is disposed in the middle region of the beam body and forms an integrated load-bearing structure with the beam body.

[0006] Furthermore, the main beam body includes an upper wall, a lower wall, and a side wall connecting the upper and lower walls, wherein the upper wall, lower wall, and side wall form a hollow beam cavity. The pre-tensioned fiber bundles include at least one set of upper fiber bundles and at least one set of lower fiber bundles, wherein the upper fiber bundles are embedded near the upper wall, and the lower fiber bundles are embedded near the lower wall; the upper fiber bundles and / or lower fiber bundles are arranged at intervals along the width direction of the main beam body, or arranged in layers along the thickness direction of the main beam body.

[0007] Furthermore, the ends of the pre-tensioned fiber bundles are provided with end anchoring sections, which are formed by the end bundles, diffusion or thickening of the pre-tensioned fiber bundles and are covered or embedded in the end area of ​​the main beam body.

[0008] Furthermore, the metal pressure-bearing assembly includes a metal support, a pressure-bearing platform, and connecting holes. The pressure-bearing platform is located on the outside of the main beam body or embedded in the connection area of ​​the main beam body, and the connecting holes penetrate or are disposed on the metal support. The pressure-bearing platform is a planar pressure-bearing structure, and the contact area between the pressure-bearing platform and the main beam body is larger than the orifice area of ​​a single connecting hole; in a specific embodiment, the contact area between the pressure-bearing platform and the main beam body is not less than 30mm × 30mm. Through this structure, the local load at the motor suspension point or suspension connection point can be distributed and transferred to the main beam body after being transmitted through the metal pressure-bearing assembly.

[0009] Furthermore, the metal pressure-bearing component is an aluminum alloy pressure-bearing component, a steel pressure-bearing component, or a magnesium alloy pressure-bearing component. The metal pressure-bearing component is at least partially embedded in the connection area of ​​the main beam body, or is fitted to the outside of the main beam body and connected to the main beam body by composite material covering or adhesive bonding.

[0010] Furthermore, the battery housing is formed by an inward recess or enclosure of the main beam body, and no independent external battery bracket is provided between the battery housing and the main beam body. The battery housing is provided with fixing anchor points for connecting the battery pack, which are one or more of the following: fixing bosses, pre-embedded nuts, threaded inserts, or connecting holes. Reinforcing ribs are integrally formed on the bottom or side walls of the battery housing, and these reinforcing ribs are arranged along the length, width, or intersection directions of the main beam body. A buffer pad may also be provided on the bottom or side walls of the battery housing for elastic support or vibration isolation of the battery pack.

[0011] Furthermore, the pre-tensioned fiber bundles are one or more combinations of carbon fiber bundles, glass fiber bundles, basalt fiber bundles, or aramid fiber bundles. The matrix material of the main beam body is a thermosetting resin matrix or a thermoplastic resin matrix, wherein the thermoplastic resin matrix includes polypropylene, polyamide, or polyetheretherketone.

[0012] Compared with the prior art, the present invention provides a fiber composite chassis beam with pre-tensioned fiber bundles, which has the following beneficial effects:

[0013] This invention embeds pre-tensioned fiber bundles along the length of the main beam body and anchors their ends to the end regions of the main beam body. This allows the pre-tensioned fiber bundles to maintain pre-tension within the main beam body and participate in bearing tensile loads when the beam is bent. Simultaneously, metal bearing components are installed at the motor mounting points or suspension connection points. These metal bearing components bear and distribute local compressive loads, shear loads, and local loads generated by bolted connections at the connection points, reducing the risk of crushing and delamination when the composite material directly bears concentrated loads. The battery compartment forms an integrated load-bearing structure with the main beam body, reducing the need for independent external brackets and making the chassis structure more compact. Furthermore, the battery compartment area can share the load with the main beam body, avoiding complete reliance on external brackets for battery installation. This structure combines the advantages of lightweight composite materials, the tensile strength of pre-tensioned fiber bundles, and the local load-bearing capacity of metal components, making it suitable for adjustments based on beam cross-section, fiber bundle quantity, and connection point location in different vehicle platforms. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0015] Figure 1 This is a schematic diagram of the overall structure of the chassis beam of the present invention;

[0016] Figure 2This is a schematic diagram of the integrated structure of the battery storage compartment and the main beam body in this invention;

[0017] Figure 3 This is a schematic diagram of the cross-sectional distribution of the pre-tensioned fiber bundle and the metal pressure-bearing component in this invention;

[0018] Figure 4 This is a schematic diagram showing the connection relationship between the pre-tensioned fiber bundle and the end anchoring section in this invention.

[0019] In the figure: 1. Main beam body; 11. Upper wall; 12. Lower wall; 13. Side wall; 14. Hollow beam cavity; 2. Pre-tensioned fiber bundle; 21. End anchorage section; 3. Metal pressure-bearing component; 31. Metal support; 32. Pressure-bearing platform; 33. Connection hole; 4. Battery housing. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] like Figures 1 to 4 As shown, a fiber composite chassis beam with pre-tensioned fiber bundles includes a main beam body 1, pre-tensioned fiber bundles 2, a metal pressure-bearing component 3, and a battery housing 4. The main beam body 1 is a fiber-reinforced composite material beam, which can be configured as a hollow beam or a partially solid beam depending on the vehicle model requirements. In this embodiment, the main beam body 1 includes an upper wall 11, a lower wall 12, and a side wall 13, which together form a hollow beam cavity 14 to reduce the beam weight while ensuring cross-sectional stiffness.

[0023] The pre-tensioned fiber bundle 2 is embedded within the main beam body 1 along its length. End anchorage sections 21 are provided at both ends of the pre-tensioned fiber bundle 2, which cover or are embedded in the end regions of the main beam body 1. During manufacturing, the pre-tensioned fiber bundle 2 can be first subjected to tension, and then molded together with the resin matrix and other reinforcing fibers. After molding, the pre-tensioned fiber bundle 2 maintains pre-tension along its length within the main beam body 1, enabling it to participate in bearing tensile loads when the chassis beam is subjected to bending.

[0024] The end anchoring section 21 can be formed by thickening the ends of the pre-tensioned fiber bundles 2 after bundling, or it can be formed by spreading the ends of the pre-tensioned fiber bundles 2 in the end region of the main beam 1 and then curing them together with the resin matrix. Through this end anchoring section 21, the bonding area between the pre-tensioned fiber bundles 2 and the end region of the main beam 1 can be increased, reducing the possibility of slippage or stress concentration at the ends of the pre-tensioned fiber bundles 2.

[0025] In one embodiment, the pre-tensioned fiber bundle 2 includes an upper fiber bundle and a lower fiber bundle. The upper fiber bundle is located near the upper wall 11, and the lower fiber bundle is located near the lower wall 12. When the chassis beam is subjected to bending loads during vehicle operation, the upper and lower fiber bundles are located in different stress areas of the beam cross-section, which helps to improve the bending resistance of the main beam 1. The pre-tensioned fiber bundle 2 can be a carbon fiber bundle, glass fiber bundle, basalt fiber bundle, or aramid fiber bundle, or a mixture of various fibers.

[0026] The metal pressure-bearing assembly 3 is installed at the motor mounting point or suspension connection point of the main beam body 1. The metal pressure-bearing assembly 3 includes a metal support 31, a pressure-bearing platform 32, and a connecting hole 33. The connecting hole 33 is used to mate with the motor mounting component, suspension connection component, or body connection component. The pressure-bearing platform 32 is a planar pressure-bearing structure with a large contact area with the main beam body 1. In this embodiment, the contact area of ​​the pressure-bearing platform 32 is greater than or equal to 30mm × 30mm, so as to distribute the local load at the connection point to a larger area of ​​the main beam body 1.

[0027] The metal bearing component 3 can be made of aluminum alloy, steel, or magnesium alloy. The metal bearing component 3 can be either an embedded structure or an external structure. When an embedded structure is used, the bearing platform 32 is at least partially embedded in the connection area of ​​the main beam 1 and is fixed by the composite material layer of the main beam 1. When an external structure is used, the bearing platform 32 is attached to the outside of the main beam 1 and connected to the main beam 1 through an adhesive layer or an external composite material layer. Both structures allow the metal bearing component 3 to first bear the compressive and shear loads near the connection point, and then distribute the load to the main beam 1, reducing localized damage caused by direct compression of the composite material by bolts or supports.

[0028] The battery compartment 4 is located in the central region of the main beam 1 and forms an integral load-bearing structure with the main beam 1. The battery compartment 4 can be formed by an inward recess from the center of the main beam 1, or it can be formed by a partial wall of the main beam 1. Unlike external battery brackets, the battery compartment 4 in this embodiment does not require a separate bracket to connect to the main beam 1, which reduces the number of parts and allows the battery to be installed closer to the load-bearing area of ​​the chassis beam.

[0029] The battery compartment 4 can be equipped with fixing anchor points for connecting the battery pack. These anchor points can be integrally formed fixing bosses on the bottom or side wall of the battery compartment 4, or they can be pre-embedded nuts, threaded inserts, or battery pack connection holes. During battery pack installation, the battery pack can be fixed to the fixing anchor points using bolts, pressure plates, or connectors, thus forming a reliable connection between the battery pack and the main beam 1. The bottom or side wall of the battery compartment 4 can also be equipped with a buffer pad. This buffer pad can be made of rubber, polyurethane, or elastic gaskets to provide elastic support between the battery pack and the battery compartment 4, reducing the impact of vehicle vibrations on the battery pack installation position.

[0030] Reinforcing ribs can be integrally formed on the bottom or side walls of the battery housing 4 to improve the local stiffness of the battery housing 4 area. The reinforcing ribs can be arranged along the length, width, or intersection of the main beam 1 and integrally formed with the bottom or side walls of the battery housing 4.

[0031] The matrix material of the main beam 1 can be a thermosetting resin matrix or a thermoplastic resin matrix. The thermoplastic resin matrix can be polypropylene, polyamide, or polyetheretherketone. The reinforcing fibers can be carbon fiber, glass fiber, basalt fiber, or aramid fiber. For passenger cars, SUVs, off-road vehicles, or commercial vehicles, the cross-sectional dimensions of the main beam 1, the number of pre-tensioned fiber bundles 2, and the arrangement of the metal load-bearing components 3 can be adjusted according to the wheelbase, load, and suspension point location.

[0032] The chassis beam in this embodiment can be manufactured through compression molding, pultrusion, RTM, injection molding, or other composite material molding processes. During manufacturing, pre-tensioned fiber bundles 2 are first fixed to both ends of the mold and tension is applied. Then, the metal pressure-bearing component 3 is placed at the suspension connection point of the mold, and a core mold for forming the battery housing 4 is placed simultaneously. Subsequently, a resin matrix is ​​added into the mold, allowing the resin to impregnate the reinforcing fibers and cover the metal pressure-bearing component 3. After the resin cures or cools, the mold is removed, resulting in a fiber composite chassis beam that integrates the main beam body 1, pre-tensioned fiber bundles 2, metal pressure-bearing component 3, and battery housing 4.

[0033] In one specific embodiment, the main beam 1 is made of polypropylene thermoplastic resin-based composite material reinforced with a hybrid of carbon fiber and glass fiber, and the pre-tensioned fiber bundles 2 are made of high-strength carbon fiber bundles. The metal pressure-bearing component 3 is made of aluminum alloy, and the contact area between the pressure-bearing platform 32 and the main beam 1 is set to be no less than 30mm × 30mm. The battery housing 4 is formed during the molding process using a detachable mandrel. This structure can be used in new energy passenger vehicle chassis, and the beam length, cross-sectional dimensions, and mounting point positions can be adjusted according to different vehicle models.

[0034] The above are merely preferred embodiments of the present invention. Those skilled in the art can make adjustments to the cross-sectional shape of the main beam 1, the number of pre-tensioned fiber bundles 2, the material of the metal pressure-bearing component 3, and the size of the battery housing 4 without departing from the structural concept of the present invention, and all such adjustments should fall within the protection scope of the present invention.

Claims

1. A fiber composite chassis beam with pre-tensioned fiber bundles, characterized in that: It includes the main beam (1), pre-tensioned fiber bundles (2), metal pressure-bearing components (3) and battery housing (4); The main beam body (1) is a fiber-reinforced composite material beam body; The pre-tensioned fiber bundle (2) is embedded in the beam body (1) along the length direction of the beam body (1). The two ends of the pre-tensioned fiber bundle (2) are respectively anchored to the end area of ​​the beam body (1), and the pre-tensioned fiber bundle (2) maintains the pre-tensioned stress along the length direction of the beam body (1) in the beam body (1). The metal pressure-bearing component (3) is set at the motor suspension point or suspension connection point of the main beam body (1) and contacts and cooperates with the corresponding connection area of ​​the main beam body (1) to disperse the local compressive load and shear load at the connection point. The battery compartment (4) is located in the middle area of ​​the main beam (1) and forms an integrated load-bearing structure with the main beam (1).

2. The fiber composite chassis beam with pre-tensioned fiber bundles according to claim 1, characterized in that: The main body of the beam (1) includes an upper wall (11), a lower wall (12) and a side wall (13) connecting the upper wall (11) and the lower wall (12), and the upper wall (11), the lower wall (12) and the side wall (13) form a hollow beam cavity (14).

3. A fiber composite chassis beam with pre-tensioned fiber bundles according to claim 2, characterized in that: The pre-tensioned fiber bundle (2) includes at least one set of upper fiber bundles and at least one set of lower fiber bundles. The upper fiber bundles are embedded near the upper wall (11), and the lower fiber bundles are embedded near the lower wall (12). The upper fiber bundles and / or lower fiber bundles are arranged at intervals along the width direction of the main beam body (1), or arranged in layers along the thickness direction of the main beam body (1).

4. A fiber composite chassis beam with pre-tensioned fiber bundles according to claim 1, characterized in that: The pre-tensioned fiber bundle (2) has an end anchoring section (21) at its end. The end anchoring section (21) is formed by the end of the pre-tensioned fiber bundle (2) being bundled, diffused or thickened, and is wrapped or buried in the end area of ​​the main beam body (1).

5. A fiber composite chassis beam with pre-tensioned fiber bundles according to claim 1, characterized in that: The metal pressure-bearing component (3) includes a metal support (31), a pressure-bearing platform (32) and a connecting hole (33). The pressure-bearing platform (32) is located outside the main beam body (1) or embedded in the connection area of ​​the main beam body (1). The connecting hole (33) penetrates or is provided on the metal support (31).

6. A fiber composite chassis beam with pre-tensioned fiber bundles according to claim 5, characterized in that: The pressure-bearing platform (32) is a planar pressure-bearing structure. The contact area between the pressure-bearing platform (32) and the main beam (1) is larger than the orifice area of ​​a single connecting hole (33), so that the local load at the connection point is distributed through the pressure-bearing platform (32) and then transmitted to the main beam (1).

7. A fiber composite chassis beam with pre-tensioned fiber bundles according to claim 1, characterized in that: The battery compartment (4) is formed by recessing or enclosing the middle of the main beam (1). There is no independent external battery bracket between the battery compartment (4) and the main beam (1). The battery compartment (4) is provided with a fixed anchor point for connecting the battery pack. The fixed anchor point is one or more of the following: a fixed boss, a pre-embedded nut, a threaded insert, or a battery pack connection hole.

8. A fiber composite chassis beam with pre-tensioned fiber bundles according to claim 1, characterized in that: The pre-tensioned fiber bundle (2) is one or more combinations of carbon fiber bundle, glass fiber bundle, basalt fiber bundle or aramid fiber bundle.

9. A fiber composite chassis beam with pre-tensioned fiber bundles according to claim 1, characterized in that: The matrix material of the main beam body (1) is a thermosetting resin matrix or a thermoplastic resin matrix, wherein the thermoplastic resin matrix includes polypropylene, polyamide or polyether ether ketone.

10. A fiber composite chassis beam with pre-tensioned fiber bundles according to claim 1, characterized in that: The metal pressure-bearing component (3) is an aluminum alloy pressure-bearing component, a steel pressure-bearing component or a magnesium alloy pressure-bearing component. The metal pressure-bearing component (3) is at least partially embedded in the connection area of ​​the main beam body (1), or is attached to the outside of the main beam body (1) and connected to the main beam body (1) by means of composite material covering or adhesive bonding.

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