A rear subframe for a small passenger car

Abstract

This utility model discloses a rear subframe for a small passenger vehicle, including a front crossbeam, a rear crossbeam, and longitudinal beams. There are two longitudinal beams connected between the front and rear crossbeams. The front and rear crossbeams are circular tubular structures, while the longitudinal beams are square tubular structures composed of an upper and lower shell. Each longitudinal beam has at least one arc-shaped arch. The middle sections of both the front and rear crossbeams have recessed sections. Vertical mounting sleeves are connected to both ends of the front and rear crossbeams. Transverse mounting sleeves are provided on the longitudinal beams. Longitudinal mounting sleeves are mounted on the recessed sections of the front crossbeams via fixed brackets. Front and rear connecting brackets are provided at the bottom of the lower shell of the longitudinal beams. The advantages of this utility model include: simple structure, light weight, avoidance of welding stress concentration, high structural strength, achieving a dual improvement in lightweight and high strength, and the ability to withstand complex alternating loads.

Description

Technical Field

[0001] This utility model relates to the field of automotive parts, specifically to a rear subframe for a small passenger vehicle. Background Technology

[0002] The rear subframe (also known as the rear bracket or rear suspension mount) is a key structural component of a vehicle's chassis system. It typically functions as a separate, rigid metal frame mounted under or at the rear of the vehicle's body-in-white. Its main functions include: support and connection: providing robust mounting points and support for the rear suspension system (such as control arms, linkages, shock absorbers, and springs). Load transfer: effectively transferring and distributing dynamic and static loads from the wheels, including road impacts, driving forces, braking forces, and the vehicle's own weight, over a larger area of ​​the vehicle body. Vibration and noise isolation: through bushings that flexibly connect to the body, it helps isolate and attenuate vibrations and noise generated by road unevenness and the powertrain (for rear-wheel drive / four-wheel drive vehicles), improving ride comfort (NVH performance).

[0003] Existing traditional automotive rear subframe designs primarily employ the following structures and processes, but they face significant challenges in meeting increasingly stringent performance requirements. Current rear subframe structures mainly include casting and welding. Casting, using high-pressure casting, is typically made of aluminum alloy. Its advantage lies in achieving highly integrated complex geometries, reducing the number of parts and assembly steps. However, the casting process itself has limitations: wall thickness cannot be too thin to avoid defects, limiting lightweight potential; defects such as porosity and shrinkage cavities may occur inside the casting, affecting strength and reliability; and mold costs are high. Welded subframes have relatively complex structures with numerous welds, resulting in greater overall weight, which is detrimental to vehicle lightweighting. Welds are also potential fatigue failure points, affecting long-term durability. Design freedom is limited, making it difficult to achieve optimal force flow paths and stiffness distribution. Summary of the Invention

[0004] To address the shortcomings of the existing technology, this utility model provides a rear subframe for a small passenger vehicle, which has a reasonable structural design, high structural strength, and light weight.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A rear subframe for a small passenger vehicle includes a front crossbeam, a rear crossbeam, and longitudinal beams, wherein there are two longitudinal beams connected between the front and rear crossbeams. The front and rear crossbeams are cylindrical tubes, and the longitudinal beams are square tubes formed by an upper and lower shell. Each longitudinal beam has at least one arc-shaped arch. The front and rear crossbeams have a recessed portion in the middle. Vertical mounting sleeves are connected to both ends of the front and rear crossbeams. A first damping bushing is installed inside the vertical mounting sleeve. A transverse mounting sleeve is installed on the longitudinal beam, and a second damping bushing is installed inside the transverse mounting sleeve. A longitudinal mounting sleeve is installed on the recessed portion of the front crossbeam via a fixed bracket, and a third damping bushing is installed inside the longitudinal mounting sleeve. A front connecting bracket and a rear connecting bracket are installed at the bottom of the lower shell of the longitudinal beam.

[0007] Furthermore, connecting lugs are provided on the rear sides of both ends of the rear crossbeam, and the connecting lugs are welded to the connection between the vertical mounting sleeve and the rear crossbeam.

[0008] Furthermore, the front connecting bracket is welded to the bottom front side of the lower housing of the longitudinal beam and the bottom of the front crossbeam, and the rear connecting bracket is located at the bottom rear side of the lower housing of the longitudinal beam.

[0009] Furthermore, the top surface of the upper shell of the longitudinal beam and the bottom surface of the lower shell of the longitudinal beam both have recesses along the length direction.

[0010] The advantages of this utility model include: simple structure, light weight, avoidance of welding stress concentration, high structural strength, achieving a dual improvement in lightweight and high strength, and being able to withstand complex alternating loads. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model;

[0012] Figure 2 yes Figure 1 A schematic diagram of the structure viewed from below. Detailed Implementation

[0013] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0014] One such Figure 1-2The rear subframe of the small passenger vehicle shown includes a front crossbeam 1, a rear crossbeam 2, and longitudinal beams 3. There are two longitudinal beams 3, which connect the front crossbeam 1 and the rear crossbeam 2. The front crossbeam 1 and the rear crossbeam 2 are cylindrical tubes, with both ends flattened into elliptical tubes. Vertical mounting sleeves 4 connect to both ends of the front crossbeam 1 and the rear crossbeam 2. The elliptical tube structure has a wider opening, a larger seam, and a larger welding range with the vertical mounting sleeves 4, resulting in stronger connection stability. A first shock-absorbing bushing 5 is installed inside the vertical mounting sleeve 4 for connecting to the vehicle body.

[0015] The longitudinal beam 3 is a square tube structure composed of an upper shell 31 and a lower shell 32. The upper shell 31 and the lower shell 32 are connected as a whole by seam welding, which greatly reduces the overall weight of the rear subframe. Both the top surface of the upper shell 31 and the bottom surface of the lower shell 32 have recesses 34 along their length, which improves structural rigidity. The longitudinal beam 3 has at least one arc-shaped arch 33, which arches upwards, creating clearance space and altering the direction of force transmission on the longitudinal beam, thereby weakening the effect of front-to-back forces and ensuring the structural strength and durability of each longitudinal beam 3.

[0016] The middle of the front crossbeam 1 and the rear crossbeam 2 has a recessed part 11, which can also change the direction of force transmission, thereby weakening the effect of the force in the left and right directions.

[0017] A transverse mounting sleeve 6 is provided on the longitudinal beam 3, and a second shock-absorbing bushing 7 is provided inside the transverse mounting sleeve 6, serving as the rear suspension mounting point of the electric drive device; a longitudinal mounting sleeve 9 is provided on the recessed part 11 of the front crossbeam 1 via a fixed bracket 8, and a third shock-absorbing bushing 10 is provided inside the longitudinal mounting sleeve 9, serving as the front suspension mounting point of the electric drive device.

[0018] The bottom of the lower housing 32 of the longitudinal beam is provided with a front connecting bracket 12 and a rear connecting bracket 13. The front connecting bracket 12 is welded to the bottom front side of the lower housing 32 of the longitudinal beam and the bottom of the front crossbeam 1, and the rear connecting bracket 13 is located at the bottom rear side of the lower housing 32 of the longitudinal beam. Both the front connecting bracket 12 and the rear connecting bracket 13 are horizontally arranged U-shaped structures, and the edges of the U-shaped structures are flanged. The front connecting bracket 12 and the rear connecting bracket 13 have mounting holes on their connecting sides, and are hinged to the front and rear arms of the multi-link through the mounting holes.

[0019] The rear beam 2 has connecting lugs 14 on the rear side of both ends, and the connecting lugs 14 are welded to the connection between the vertical mounting sleeve 4 and the rear beam 2.

[0020] The technical solutions provided by the embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of this utility model. The description of the above embodiments is only for helping to understand the principles of the embodiments of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A rear subframe of a small passenger car, comprising a front cross beam (1), a rear cross beam (2), longitudinal beams (3), wherein the number of the longitudinal beams (3) is two, and the two longitudinal beams (3) are connected between the front cross beam (1) and the rear cross beam (2), characterized in that: The front crossbeam (1) and rear crossbeam (2) are circular tube structures, and the longitudinal beam (3) is a square tube structure composed of an upper shell (31) and a lower shell (32). The longitudinal beam (3) has at least one arc-shaped arch (33). The middle of the front crossbeam (1) and the rear crossbeam (2) has a recessed part (11). The two ends of the front crossbeam (1) and the two ends of the rear crossbeam (2) are connected to vertical mounting sleeves (4). The vertical mounting sleeves (4) are provided with... The first shock absorber bushing (5) is provided on the longitudinal beam (3), the transverse mounting sleeve (6) is provided in the transverse mounting sleeve (6), the second shock absorber bushing (7) is provided in the transverse mounting sleeve (6), the longitudinal mounting sleeve (9) is provided on the recessed part (11) of the front crossbeam (1) through the fixed bracket (8), the third shock absorber bushing (10) is provided in the longitudinal mounting sleeve (9), and the bottom of the lower housing (32) of the longitudinal beam is provided with a front connecting bracket (12) and a rear connecting bracket (13).

2. The rear subframe of a small passenger car according to claim 1, characterized by: The rear beam (2) is provided with connecting lugs (14) at both ends of the rear side, and the connecting lugs (14) are welded to the connection between the vertical mounting sleeve (4) and the rear beam (2).

3. The rear subframe of a small passenger vehicle according to claim 1, characterized in that: The front connecting bracket (12) is welded to the bottom of the front side of the lower housing (32) of the longitudinal beam and the bottom of the front crossbeam (1), and the rear connecting bracket (13) is located at the bottom of the rear side of the lower housing (32) of the longitudinal beam.

4. The rear subframe of a small passenger vehicle according to claim 1, characterized in that: The top surface of the upper shell (31) of the longitudinal beam and the bottom surface of the lower shell (32) of the longitudinal beam both have recesses (34) along the length direction.

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