Subframe for vehicle

Abstract

The present invention relates to a vehicle subframe and comprises a frame portion formed by stacking a plurality of composite material portions, a cover portion coupled to the frame portion, a retaining portion disposed between the composite material portions and maintaining the shape, and a bushing portion mounted on the frame portion and coupled to the vehicle body, thereby enabling lightweighting while maintaining strength.

Description

Technology Field

[0001] The present invention relates to a vehicle subframe, and more specifically, to a vehicle subframe that reduces self-weight and improves workability by eliminating the welding process. Background Technology

[0002] Generally, passenger vehicles primarily use monocoque bodies instead of frame bodies due to their lighter weight and superior productivity. A monocoque body is a structure in which a separate frame is eliminated, allowing the powertrain, including the engine, to be mounted directly to the vehicle body.

[0003] Therefore, in a monocoque body, the vehicle body itself functions as the frame, allowing for the separate mounting of suspension and chassis components; however, a subframe is installed at the bottom of the vehicle to prevent vibrations from the powertrain (composed of an integrated engine, transmission, and differential gear) from being directly transmitted to the vehicle body and to disperse impact in the event of a collision.

[0004] Conventional subframes are constructed by welding metal plates to form closed sections in a box shape. This results in significant structural loads and limited freedom of form. Therefore, there is a need to improve this.

[0005] The background technology of the present invention is disclosed in Korean Published Patent Application No. 1998-0035861 (published on August 5, 1998, Title of Invention: Mounting Structure of Front Subframe and Lower Arm). The problem to be solved

[0006] The present invention was devised to improve the aforementioned problems and aims to provide a vehicle subframe that reduces self-weight and improves workability by eliminating the welding process. means of solving the problem

[0007] A vehicle subframe according to the present invention is characterized by comprising: a frame portion formed by laminating a plurality of composite material portions; a cover portion coupled to the frame portion; a retaining portion disposed between the composite material portions and maintaining a shape; and a bushing portion mounted on the frame portion and coupled to the vehicle body.

[0008] The above frame portion is characterized by including a pair of opposing side frame portions; and one or more connecting frame portions connecting the side frame portions.

[0009] The above frame portion comprises one or more first composite material portions; and one or more second composite material portions laminated with the first composite material portions; wherein the first composite material portions and the second composite material portions are integrated by press molding.

[0010] The first composite material part is characterized by being disposed between the second composite material parts.

[0011] The first composite material part is carbon fiber reinforced plastic, and the second composite material part is glass fiber reinforced plastic.

[0012] The above frame part is characterized by further including a third composite material part that is integrated with the second composite material part by press molding to reinforce rigidity.

[0013] The bushing portion is characterized by including: a bushing pipe portion penetrating the frame portion; and a bushing extension portion extending laterally from the bushing pipe portion and inserted into the frame portion. Effects of the invention

[0014] The vehicle subframe according to the present invention is formed from a composite material, so the welding process is eliminated, and lightweighting can be achieved while maintaining strength.

[0015] A vehicle subframe according to the present invention may be integrated by press molding, wherein one or more first composite material parts made of carbon fiber reinforced plastic and one or more second composite material parts made of glass fiber reinforced plastic are laminated.

[0016] A vehicle subframe according to the present invention can be press-formed by adding a third composite material part to the strength reinforcement area. Brief explanation of the drawing

[0017] FIG. 1 is a perspective view schematically showing a vehicle subframe according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a vehicle subframe according to one embodiment of the present invention. FIG. 3 is a schematic planar perspective view of a frame portion according to one embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing a frame portion according to one embodiment of the present invention. FIG. 5 is a diagram schematically illustrating the manufacturing process of a frame part according to one embodiment of the present invention. FIG. 6 is a diagram schematically showing a manufacturing process in which a third composite material part is added to a frame part according to one embodiment of the present invention. FIG. 7 is a schematic diagram showing the state in which an installation part is temporarily fixed to a fastening part formed in a frame part according to one embodiment of the present invention. FIG. 8 is a schematic diagram showing an installation part according to one embodiment of the present invention. FIG. 9 is a cross-sectional view schematically showing a bushing portion according to one embodiment of the present invention. Specific details for implementing the invention

[0018] Hereinafter, an embodiment of a vehicle subframe according to the present invention will be described with reference to the attached drawings. In this process, the thickness of lines or the size of components depicted in the drawings may be exaggerated for clarity and convenience of explanation. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intention or convention of the user or operator. Therefore, the definitions of these terms should be based on the content throughout this specification.

[0019] FIG. 1 is a perspective view schematically showing a vehicle subframe according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view schematically showing a vehicle subframe according to one embodiment of the present invention. Referring to FIG. 1 and FIG. 2, a vehicle subframe (1) according to one embodiment of the present invention includes a frame portion (10), a cover portion (20), and a bushing portion (90).

[0020] The frame portion (10) is formed by stacking multiple composite material portions. For example, the frame portion (10) can serve as the framework of a vehicle subframe (1) and can maintain rigidity while achieving product lightweighting.

[0021] The cover portion (20) is combined with the frame portion (10). For example, the cover portion (20) may be made of a resin material, and the frame portion (10) may be insert-molded. At this time, a plurality of holes may be formed in the frame portion (10) so that the cover portion (20) can be injected and then cured. As the cover portion (20), a vinyl ester synthetic resin formed by the esterification reaction of epoxy resin and acrylic acid may be used. In addition, the cover portion (20) may be capable of high-speed curing and may be made of an eco-friendly material.

[0022] A retaining member (80) is positioned between multiple composite material members and can maintain the shape. For example, the retaining member (80) may be made of a shape memory alloy and can maintain the shape of the product. Such a retaining member (80) increases the rigidity of the part and may have a panel shape with holes or a mesh shape so that the composite material members can pass through.

[0023] The bushing (90) is mounted on the frame (10) and combined with the vehicle body. For example, the bushing (90) may be made of metal and inserted into the frame (10), which is molded from a composite material, to maintain a combined state.

[0024] In addition, a vehicle subframe (1) according to one embodiment of the present invention may further include an installation part (30). The installation part (30) is combined with other parts and is insert-molded into the cover part (20). For example, a lower arm, an upper arm, etc. may be mounted on the installation part (30). The installation part (30) may be manufactured including a metal material to prevent deformation when combined with other parts, and may be insert-molded into the cover part (20) while being temporarily fixed to the frame part (10). At this time, the cover part (20) may wrap around the entire frame part (10) or be molded by selecting only the area where the installation part (30) is placed.

[0025] FIG. 3 is a schematic planar perspective view of a frame portion according to one embodiment of the present invention, and FIG. 4 is a schematic cross-sectional view of a frame portion according to one embodiment of the present invention. Referring to FIG. 3 and FIG. 4, a frame portion (10) according to one embodiment of the present invention includes a side frame portion (40) and a connecting frame portion (50).

[0026] A pair of side frame sections (40) are arranged to face each other. For example, the side frame section (40) may include a side top plate section (41) and side side plate sections (42) extending downward from both ends of the side top plate section (41). Additionally, a side reinforcement section (43) may be formed on the inner side of the side top plate section (41) and the side side plate section (42) to reinforce rigidity.

[0027] The connecting frame section (50) connects the side frame section (40). For example, two connecting frame sections (50) are connected to the side frame section (40), and the connecting frame section (50) may include a connecting top plate section (51) and connecting side plate sections (52) extending downward from both ends of the connecting top plate section (51). Additionally, a connecting reinforcement section (53) may be formed on the inner side of the connecting top plate section (51) and the connecting side plate section (52) to reinforce rigidity.

[0028] The side frame portion (40) and the connecting frame portion (50) are formed from a composite material. For example, the side frame portion (40) and the connecting frame portion (50) can be integrally formed from a composite material that can achieve lightweighting while maintaining rigidity.

[0029] FIG. 5 is a schematic diagram illustrating the manufacturing process of a frame portion according to one embodiment of the present invention, and FIG. 6 is a schematic diagram illustrating the manufacturing process of a frame portion with a third composite material portion added according to one embodiment of the present invention. Referring to FIG. 5 and FIG. 6, the frame portion (10) includes a first composite material portion (110) and a second composite material portion (120).

[0030] One or more first composite material parts (110) may be stacked. Also, one or more second composite material parts (120) may be stacked. After the first composite material parts (110) and the second composite material parts (120) are stacked, they are integrated by press molding. At this time, a retaining part (80) may be placed between the first composite material parts (110) and the second composite material parts (120). Alternatively, a retaining part (80) may be placed between multiple first composite material parts (110) or between multiple second composite material parts (120).

[0031] More specifically, the first composite material part (110) is positioned between the second composite material part (120) which is positioned vertically. At this time, carbon fiber reinforced plastic may be used as the first composite material part (110). And, glass fiber reinforced plastic may be used as the second composite material part (120).

[0032] Meanwhile, the first composite material part (110) and the second composite material part (120) can be heated by an oven and then stacked so that the first composite material part (110) is placed between the second composite material part (120). Then, after being seated on the lower mold part (210), the upper mold part (220) moves downward to press-form the first composite material part (110) and the second composite material part (120). As a result, the first composite material part (110) and the second composite material part (120) can become an integrated product.

[0033] The frame portion (10) may further include a third composite material portion (130). The third composite material portion (130) can be integrated with the second composite material portion (120) by press molding to reinforce rigidity.

[0034] For example, a continuous fiber-reinforced thermoplastic may be used as the third composite material part (130). The third composite material part (130) is inserted into the lower groove part (211) in a circular cross-sectional shape and can be molded integrally with the second composite material part (120) by pressure from the upper protrusion part (221). This third composite material part (130) can be placed in a part where a component such as a tension link is mounted to prevent damage.

[0035] FIG. 7 is a schematic diagram showing a state in which an installation part is temporarily fixed to a fastening part formed in a frame part according to an embodiment of the present invention, and FIG. 8 is a schematic diagram showing an installation part according to an embodiment of the present invention. Referring to FIG. 7 and FIG. 8, the frame part (10) according to an embodiment of the present invention may further include a fastening part (140). The fastening part (140) may be formed in one or more of the first composite material part (110) and the second composite material part (120) so that the installation part (30) can be temporarily fixed. For example, the fastening part (140) may be formed in the first composite material part (110) and the second composite material part (120) and become a fastening hole part (141) through which the installation part (30) partially penetrates (see FIG. 7a). Additionally, the fastening portion (140) may be formed in the second composite material portion (120) and may become a fastening groove portion (142) into which the installation portion (30) is partially inserted (see FIG. 7b). Furthermore, the fastening portion (140) may be formed in one or more of the first composite material portion (110) and the second composite material portion (120), and may have a hook shape or a hooking projection shape that guides the installation portion (30) to be fixed by hooking, and various shapes may be adopted to temporarily fix the installation portion (30).

[0036] Meanwhile, the frame portion (10) may further include an insert portion (150). This insert portion (150) may have a hole shape that penetrates the first composite material portion (110) and the second composite material portion (120). As a result, when the frame portion (10) is insert-molded into the cover portion (20), a portion of the resin-based cover portion (20) passes through the insert portion (150), thereby improving the bonding strength with the frame portion (10).

[0037] An installation part (30) according to one embodiment of the present invention includes an installation plate part (31) and an installation projection part (32). This installation part (30) may further include an installation support part (33). This installation part (30) may be manufactured using a metal material. For example, the installation part (30) may be manufactured from aluminum and extruded.

[0038] The mounting plate (31) is in close contact with the second composite material part (120) corresponding to the inner surface of the frame part (10), and the mounting projection (32) can penetrate the fastening hole part (141). Additionally, the mounting plate (31) can be inserted into the fastening groove (142) formed in the second composite material part (120) corresponding to the outer surface of the frame part (10). At this time, the mounting plate (31) can be joined to the contact surface of the frame part (10) through an additional joining process. One or more mounting projections (32) can be fastened to other parts.

[0039] One end of the installation support member (33) is connected to the installation plate member (31), and the other end is connected to the installation projection member (32). The installation support member (33) is positioned to have an incline to support the installation projection member (32). A cover member (20) is injected into the space formed between the installation support member (33), the installation plate member (31), and the installation projection member (32), thereby increasing the bonding strength with the cover member (20) during the insert molding process.

[0040] Meanwhile, an installation insert portion (35) may be formed in the installation plate portion (31). When the installation insert portion (35) is positioned in a straight line with the insert portion (150) formed in the frame portion (10), the cover portion (20) is injected into the installation insert portion (35) and the insert portion (150), thereby increasing the bonding strength with the cover portion (20) during the insert molding process.

[0041] FIG. 9 is a cross-sectional view schematically showing a bushing portion according to an embodiment of the present invention. Referring to FIG. 9, the bushing portion (90) according to an embodiment of the present invention includes a bushing pipe portion (91) and a bushing extension portion (92).

[0042] The bushing section (91) penetrates the frame section (10). For example, the bushing section (91) has a cylindrical shape and can be inserted into a bushing hole section (190) formed in the frame section (10).

[0043] The bush extension portion (92) extends laterally from the bush pipe portion (91) and is inserted into the frame portion (10). For example, the bush extension portion (92) may protrude along the circumferential surface of the bush pipe portion (91) and be inserted between the first composite material portion (110) and the second composite material portion (120). When the bush extension portion (92) is inserted into the first composite material portion (110) and the second composite material portion (120), the first composite material portion (110) and the second composite material portion (120) are integrated through press forming. At this time, the bush extension portion (92) is provided with a bush connection portion (93) in the shape of a hole having various sizes and numbers. As a result, the first composite material portion (110) and the second composite material portion (120) can be connected to each other through the bush connection portion (93) during the press forming process.

[0044] The manufacturing process of a vehicle subframe according to one embodiment of the present invention having the above-described structure is as follows.

[0045] A plurality of first composite material parts (110) are stacked, and the first composite material parts (110) are placed between a plurality of second composite material parts (120). At this time, glass fiber reinforced plastic is used for the second composite material parts (120), and carbon fiber reinforced plastic, which has superior rigidity to the second composite material parts (120), is used for the first composite material parts (110).

[0046] When the first composite material part (110) and the second composite material part (120) are stacked, the stacked first composite material part (110) and the second composite material part (120) are placed on the lower mold part (210). Then, the upper mold part (220) is moved downward to press-process the stacked first composite material part (110) and the second composite material part (120).

[0047] The first composite material part (110) and the second composite material part (120) are produced by press processing to produce a frame part (10) in which the side frame part (40) and the connecting frame part (50) are integrated.

[0048] When the frame part (10) is manufactured, a metal installation part (30) is temporarily fixed to the frame part (10). Then, the frame part (10) and the installation part (30) are inserted and molded into the cover part (20) to become an integrated unit.

[0049] A vehicle subframe (1) according to one embodiment of the present invention is formed from a composite material so that a welding process is omitted and lightweighting can be achieved while maintaining strength.

[0050] A vehicle subframe (1) according to one embodiment of the present invention may be integrated by press molding, wherein one or more first composite material parts (110) made of carbon fiber reinforced plastic and one or more second composite material parts (120) made of glass fiber reinforced plastic are laminated.

[0051] A vehicle subframe (1) according to one embodiment of the present invention can be press-formed by adding a third composite material part (130) to the strength reinforcement area.

[0052] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the claims below. Explanation of the symbols

[0053] 10 : Frame part 20 : Cover part 30 : Installation part 31 : Installation plate part 32: Installation projection 33: Installation support 35 : Installation insert section 40 : Side frame section 50 : Connecting frame part 80 : Retaining part 90 ; Bushibu 91 : Bushibu Officer Department 92 : Bush expansion section 110 : First composite material section 120 : 2nd Composite Material Division 130 : 3rd Composite Material Division 140 : Fastening part 150 : Insert part

Claims

Claim 1 A vehicle subframe comprising: a frame portion formed by stacking and molding a plurality of composite material portions; a cover portion coupled to the frame portion; a retaining portion disposed between the plurality of composite material portions and maintaining a shape; and a bushing portion mounted on the frame portion and coupled to a vehicle body; wherein the retaining portion has a panel shape having a hole or a mesh shape and is integrated by press molding after the plurality of composite material portions are stacked; and wherein the bushing portion includes a bushing tube portion penetrating the frame portion; a bushing expansion portion extending laterally from the bushing tube portion and inserted into the frame portion; and a bushing connection portion having a hole shape formed in the bushing expansion portion; wherein the frame portion includes one or more first composite material portions; and one or more second composite material portions stacked with the first composite material portion; wherein the first composite material portion and the second composite material portion are integrated by press molding, and wherein the first composite material portion and the second composite material portion inserted into the bushing connection portion during the press molding process are connected to each other through the bushing connection portion. Claim 2 A vehicle subframe according to claim 1, characterized in that the frame portion comprises a pair of opposing side frame portions; and one or more connecting frame portions connecting the side frame portions. Claim 3 delete Claim 4 A vehicle subframe according to claim 1, characterized in that the first composite material part is disposed between the second composite material part. Claim 5 A vehicle subframe characterized in that, in claim 4, the first composite material part is carbon fiber reinforced plastic and the second composite material part is glass fiber reinforced plastic. Claim 6 A vehicle subframe according to claim 2, further comprising a third composite material part that is integrated with the second composite material part by press forming to reinforce rigidity. Claim 7 delete

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