Torsion beam
By designing a curved connection structure between the wheel bracket, spring disc and longitudinal arm in the torsion beam, the problem of stress concentration in the existing torsion beam is easily cracked, and the effect of reducing weld stress concentration and improving service life is achieved.
Patent Information
- Application Number
- CN202421409791.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-19
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-06-19
AI Technical Summary
In the existing torsion beams, the overlapping points between the wheel bracket, spring and longitudinal arm are prone to stress concentration, resulting in cracks in the welds and affecting driving safety.
By designing the connecting part of the wheel bracket, the spring disc and the longitudinal arm to bend in the third direction, the stress is changed from a single area in the vertical direction to a multi-area in the horizontal direction to a stress-concentration of the weld.
It effectively reduces the risk of cracks caused by stress on welds, improves the service life of the torsion beam, and ensures driving safety.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present application relates to the technical field of vehicle structures, and in particular to a torsion beam. [Background technology]
[0002] The suspension system is an important component of a car and has a great influence on the car's ride smoothness and handling stability. Among them, the suspension system can balance the up and down bounce of the left and right wheels through the torsion beam to reduce the shaking of the vehicle and keep the vehicle stable. Its working principle is to install the wheels on the vehicle support of the torsion beam. When one side of the wheel bounces up and down, the torsion beam will bounce accordingly, thereby driving the other side of the wheel to bounce accordingly, reducing the tilt or shaking of the entire body of the car; and, because the torsion beam has a certain torsional stiffness, it can play the same role as the anti-roll bar to increase the vehicle's roll stiffness and improve the vehicle's roll stability.
[0003] The torsion beam structure includes a longitudinal arm, a wheel bracket for mounting a wheel, and a spring plate for mounting a shock absorbing spring. The wheel bracket and the spring plate are overlapped on the longitudinal arm and welded. However, in the prior art, the overlap points of the wheel bracket, the spring and the longitudinal arm are located on the concentric circles of the longitudinal arm cross section. During the driving process of the vehicle, due to the up and down jumping of the wheel or the compression of the shock absorbing spring, the stress lever formed makes the larger stress concentrate on the same concentric circle of the overlap part in the vertical direction. The weld at the overlap part is prone to cracks, affecting driving safety. [Contents of the utility model]
[0004] In view of this, the present application provides a torsion beam, which, through the special structure of the wheel bracket and the spring plate, disperses the force of the weld at the overlapping part of the two and the longitudinal arm into multiple areas of force, reduces the influence of stress on the weld, reduces cracks in the weld, increases the service life of the torsion beam, and ensures driving safety.
[0005] The present application provides a torsion beam, the torsion beam comprising a cross beam, a longitudinal arm, a spring plate and a wheel bracket, the two ends of the cross beam are respectively overlapped with the two longitudinal arms, the cross beam extends along a first direction, and the longitudinal arms extend along a second direction;
[0006] The wheel bracket is provided with a first connecting part and a second connecting part, and the first connecting part and / or the second connecting part are connected to the longitudinal arm after being bent along the second direction away from the center of the wheel bracket; the spring disk is provided with a fourth connecting part and a fifth connecting part, and the fourth connecting part and / or the fifth connecting part are connected to the longitudinal arm after being bent along the second direction away from the center of the spring disk.
[0007] In some embodiments, a bending angle of the first connection portion and / or the second connection portion is between 19° and 67°.
[0008] In some embodiments, the circumferential connection length between the first connection portion, the second connection portion and the longitudinal arm is 80 mm to 120 mm.
[0009] In some embodiments, a bending angle of the fourth connecting portion and / or the fifth connecting portion is between 23° and 29°.
[0010] In some embodiments, the circumferential connection length between the fourth connection portion, the fifth connection portion and the longitudinal arm is 69 mm to 89 mm.
[0011] In some embodiments, the torsion beam further includes a reinforcement, a portion of which is connected to the longitudinal arm; another portion of the reinforcement is connected to the cross beam, and a connection portion between the reinforcement and the cross beam is bent along a third direction.
[0012] In some embodiments, the bending angle of the connection portion between the reinforcement and the crossbeam is 15° to 25°.
[0013] In some embodiments, the crossbeam includes a middle section, a first transition section and a first overlapping section, a second transition section and a second overlapping section; the first overlapping section, the first transition section, the middle section, the second transition section and the second overlapping section are connected in sequence, and the crossbeam is connected to the longitudinal arm through the first overlapping section and the second overlapping section.
[0014] Both sides of the middle section are recessed inwards, and a convex portion is provided on the middle section, and the convex portion extends along the length direction of the middle section.
[0015] In some embodiments, the protrusion height of the protrusion is 4 mm to 6 mm, and the protrusion length of the protrusion is 200 mm to 800 mm.
[0016] In some embodiments, the overlapping length of the first overlapping section, the second overlapping section and the longitudinal arm is 330 mm to 350 mm, and the overlapping width is 50 mm to 60 mm.
[0017] After adopting the above scheme, this application has at least the following beneficial effects:
[0018] The torsion beam provided by the present application has at least a portion of the structure of the connection portion between the wheel bracket, the spring plate and the longitudinal arm bent along a third direction in a direction away from the center of the two, so that the stress of the connection portion between the two and the longitudinal arm is transformed from a single-region stress in the vertical direction to a multi-region stress in the horizontal direction, thereby reducing the influence of stress on the weld of the connection portion, thereby reducing the risk of cracks in the weld due to stress during use, thereby increasing the service life of the torsion beam and ensuring driving safety.
Brief Description of the Drawings
[0019] Figure 1 A schematic diagram of the structure of the torsion beam provided for this application;
[0020] Figure 2 A partial structural schematic diagram of a torsion beam provided for this application;
[0021] Figure 3 A schematic structural diagram of a crossbeam of a torsion beam provided in this application;
[0022] Figure 4 A cross-sectional view of the middle section of the torsion beam provided for this application;
[0023] Figure 5 This is a schematic structural diagram of the torsion beam provided in this application from another angle.
[0024] Figure ID:
[0025] 1. Cross beam; 11. Middle section; 12. First transition section; 13. First overlapping section; 14. Second transition section; 15. Second overlapping section; 16. Protrusion; 17. Outer wall; 18. Inner wall; 2. Longitudinal arm; 3. Spring disk; 31. Fourth connecting part; 32. Fifth connecting part; 33-sixth connecting part; 4. Wheel bracket; 41. First connecting part; 42. Second connecting part; 43. Third connecting part; 5. Reinforcement member. [Specific implementation method]
[0026] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0027] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0028] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.
[0029] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.
[0030] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described at the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.
[0031] The suspension system is an important component of a car and has a great influence on the car's ride smoothness and handling stability. Among them, the suspension system can balance the up and down bounce of the left and right wheels through the torsion beam to reduce the shaking of the vehicle and keep the vehicle stable. Its working principle is to install the wheels on the vehicle support of the torsion beam. When one side of the wheel bounces up and down, the torsion beam will bounce accordingly, thereby driving the other side of the wheel to bounce accordingly, reducing the tilt or shaking of the entire body of the car; and, because the torsion beam has a certain torsional stiffness, it can play the same role as the anti-roll bar to increase the vehicle's roll stiffness and improve the vehicle's roll stability.
[0032] The torsion beam structure includes a longitudinal arm, a wheel bracket for mounting a wheel, and a spring plate for mounting a shock absorbing spring. The wheel bracket and the spring plate are overlapped on the longitudinal arm and welded. However, in the prior art, the overlap points of the wheel bracket, the spring and the longitudinal arm are located on the concentric circles of the longitudinal arm cross section. During the driving of the vehicle, due to the up and down jumping of the wheel or the compression of the shock absorbing spring, the stress lever formed causes the greater stress to be concentrated on the same point of the overlap part in the vertical direction. The weld at the overlap part is prone to cracks, affecting driving safety.
[0033] In view of this, the present application provides a torsion beam, please refer to Figure 1 to Figure 5 The torsion beam comprises a cross beam 1, a longitudinal arm 2, a spring plate 3 and a wheel bracket 4, the two ends of the cross beam 1 are respectively overlapped with the longitudinal arm 2, the cross beam 1 extends along a first direction, and the longitudinal arm 2 extends along a second direction;
[0034] The wheel bracket 4 is provided with a first connecting portion 41 and a second connecting portion 42, and the first connecting portion 41 and / or the second connecting portion 42 are connected to the longitudinal arm 2 after being bent along the second direction away from the center of the wheel bracket 4; the spring disk 3 is provided with a fourth connecting portion 31 and a fifth connecting portion 32, and the fourth connecting portion 31 and / or the fifth connecting portion 32 are connected to the longitudinal arm 2 after being bent along the second direction away from the center of the spring disk 3.
[0035] In the above scheme, in the torsion beam provided by the present application, at least part of the structure of the connection part between the wheel bracket 4, the spring plate 3 and the longitudinal arm 2 is bent along the third direction in a direction away from the center of the two, so that the stress of the connection part between the two and the longitudinal arm 2 is transformed from a single-region stress in the vertical direction to a multi-region stress in the horizontal direction, thereby reducing the influence of stress on the weld of the connection part, so as to reduce the risk of cracks in the weld due to stress during use, thereby increasing the service life of the torsion beam and ensuring driving safety.
[0036] It should be noted that the connection method of each component in this application is welding connection.
[0037] In some embodiments, the beam 1 extends along a first direction, and includes a middle section 11, a first transition section 12 and a first lap section 13, a second transition section 14 and a second lap section 15. The first lap section 13, the first transition section 12, the middle section 11, the second transition section 14 and the second lap section 15 are connected in sequence and form an integrally formed structure.
[0038] The crossbeam 1 is connected to the longitudinal arm 2 through a first overlap section 13 and a second overlap section 15. The overlap lengths of the first overlap section 13, the second overlap section 15 and the longitudinal arm 2 are 330mm to 350mm, and the overlap widths are 50mm to 60mm. Optionally, the overlap lengths may be 330mm, 332mm, 334mm, 336mm, 337mm, 340mm, 342mm, 344mm, 346mm, 348mm and 350mm, etc., and the overlap widths may be 50mm, 51mm, 52mm, 53mm, 54mm, 55mm, 56mm, 57mm, 58mm, 59mm and 60mm, etc., or other values within the range. The selection may be based on actual needs and is not limited here. It can be understood that when the overlapping length and width of the first overlapping section 13, the second overlapping section 15 and the longitudinal arm 2 are within the above range, the weld connection length between the cross beam 1 and the longitudinal arm 2 is longer, and the two are more stable.
[0039] It should be noted that the overlap length of the crossbeam 1 and the longitudinal arm in the present application refers to the length of the arc edge where the crossbeam 1 overlaps the longitudinal arm in the vertical direction, and the overlap width between the crossbeam 1 and the longitudinal arm refers to the length where the crossbeam 1 overlaps the longitudinal arm in the horizontal direction.
[0040] Among them, the bottom of the middle section 11 is concave toward the top to form a U-shaped structure, that is, the U-shaped structure includes an outer wall 17 and an inner wall 18, and the inner wall 18 and the outer wall 17 are enclosed to form a closed structure; at the same time, the outer wall 17 of the U-shaped structure is concave toward the inner wall 18, so that part of the outer wall 17 is fitted with the inner wall 18. It can be understood that after the two sides of the middle section 11 are concave inward, the durability of the beam 1 during the torsion process when the torsion beam is subjected to force can be improved, and the rebound of the middle section 11 after high-pressure forming can be suppressed, thereby ensuring the consistency of the stamping size with the preset parameters.
[0041] Further, the middle section 11 is provided with a raised portion 16, which extends along the length direction of the middle section 11, and the raised height of the raised portion 16 is 4mm to 6mm, and the raised length of the raised portion 16 is 200mm to 800mm. Optionally, the raised height of the raised portion 16 can be 4mm, 4.4mm, 4.8mm, 5.2mm, 5.6mm, 5.8mm and 6mm, etc., and the raised length of the raised portion 16 can be 200mm, 300mm, 400mm, 500mm, 600mm, 700mm and 800mm, etc., or other values within the range, which can be selected according to actual needs and are not limited here. It can be understood that when the raised height and length of the raised portion 16 are within the above range, the shear center of the middle section 11 becomes higher, and the roll center also becomes higher, which can improve the torsional stiffness and lateral stiffness of the torsion beam, thereby improving the handling stability of the vehicle.
[0042] In some embodiments, in order to further improve the connection stability between the longitudinal arm 2 and the cross beam 1, the torsion beam further includes a reinforcement member 5, a portion of which is connected to the longitudinal arm 2; another portion of the reinforcement member 5 is connected to the cross beam 1, and the connection portion between the reinforcement member 5 and the cross beam 1 is bent along the third direction. It can be understood that after the reinforcement member 5 bent along the third direction is provided, when stress acts on the cross beam 1 and the longitudinal arm 2, at this time, the connection portion between the reinforcement member 5 and the cross beam 1, the reinforcement member 5 located at the same height bears less force, thereby having a smaller impact on the weld.
[0043] The bending angle of the connection part between the reinforcement member 5 and the cross beam 1 is 15° to 25°. Optionally, the bending angle of the connection part between the reinforcement member 5 and the cross beam 1 can be 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24° and 25°, etc., or other values within the range. It can be selected according to actual needs and is not limited here. It can be understood that the bending angle of the connection part between the reinforcement member 5 and the cross beam 1 is within the above range, which can reduce the influence of stress on the weld while extending the length of the weld and further dispersing the stress.
[0044] In some embodiments, the longitudinal arm 2 extends along the second direction and serves as a mounting component for the spring plate 3 and the wheel bracket 4. The spring plate 3 and the wheel bracket 4 are respectively welded to both sides of the longitudinal arm 2 along the first direction. Specifically:
[0045] The wheel bracket 4 is provided with a first connection part 41 and a second connection part 42. The first connection part 41 and / or the second connection part 42 are bent along the second direction away from the center of the wheel bracket 4 and then connected to the longitudinal arm 2. Optionally, only the first connection part 41 may be bent in the direction away from the center of the wheel bracket 4, or only the second connection part 42 may be bent in the direction away from the center of the wheel bracket 4. Alternatively, both the first connection part 41 and the second connection part 42 may be bent in the second direction away from the center of the wheel bracket 4. The selection may be made according to actual needs and is not limited here. It can be understood that in the wheel bracket 4 with the above-mentioned special structure, the extension mode of the weld between the first connection part 41 and / or the second connection part 42 and the longitudinal arm 2 is changed from extending around concentric circles to extending obliquely on the surface of the longitudinal arm 2, thereby dispersing the stress acting on the weld during driving, so as to reduce the risk of cracks in the weld due to stress during use, thereby increasing the service life of the torsion beam and ensuring driving safety. Preferably, in the present application, only the first connection part 41 is bent in the direction away from the center of the wheel bracket 4.
[0046] Among them, the bending angle of the first connection part 41 and / or the second connection part 42 is 19° to 67°. Optionally, the bending angle of the first connection part 41 and / or the second connection part 42 can be 19°, 25°, 31°, 37°, 43°, 49°, 55°, 61°, 65°, 67°, etc., or other values within the range. It can be selected according to actual needs and is not limited here. It can be understood that the bending angle of the first connection part 41 and / or the second connection part 42 is within the above range, which can avoid excessive stress concentration due to too small a bending angle, and the inability to effectively disperse the stress acting on the weld. It can also avoid the circumferential connection length of the first connection part 41 and / or the second connection part 42 and the longitudinal arm 2 being too short due to too large a bending angle, which affects the welding stability of the wheel bracket 4 and the longitudinal arm 2.
[0047] The circumferential connection length between the first connection part 41, the second connection part 42 and the longitudinal arm 2 is 80 mm to 120 mm. Optionally, the circumferential connection length between the first connection part 41, the second connection part 42 and the longitudinal arm 2 can be 80 mm, 90 mm, 100 mm, 110 mm and 120 mm, etc., or other values within the range. It can be selected according to actual needs and is not limited here. It can be understood that the circumferential connection length between the first connection part 41, the second connection part 42 and the longitudinal arm 2 is within the above range, which can better extend the length of the weld and disperse the stress acting on the weld, reduce the risk of cracks in the weld due to stress during use, and thus increase the service life of the torsion beam and ensure driving safety.
[0048] Further, the wheel bracket 4 is also provided with a third connecting portion 43, which is connected to the longitudinal arm 2 after being bent in a direction close to the center of the wheel bracket 4, wherein the bending angle of the third connecting portion 43 is 110° to 130°, that is, the angle between the third connecting portion 43 and the plane of the wheel bracket 4 is 110° to 130°, and optionally, the bending angle of the third connecting portion 43 can be specifically 110°, 113°, 116°, 119°, 122°, 125°, 128° and 130°, etc., or other values within the range, which can be selected according to actual needs and are not limited here. It can be understood that the bending angle of the third connecting portion 43 within the above range can reduce the volume of the wheel bracket 4 extending out of the longitudinal arm 2. Preferably, the bending angle of the third connecting portion 43 is 120°.
[0049] The connection length between the third connection part 43 and the longitudinal arm 2 is 90 mm to 98 mm. Optionally, the connection length between the third connection part 43 and the longitudinal arm 2 can be 90 mm, 91 mm, 92 mm, 93 mm, 94 mm, 95 mm, 96 mm, 97 mm, 98 mm, etc., or other values within the range. It can be selected according to actual needs and is not limited here. It can be understood that when the connection length between the third connection part 43 and the longitudinal arm 2 is within the above range, the connection stability between the wheel bracket 4 and the longitudinal arm 2 is further improved.
[0050] The spring disk 3 is provided with a fourth connection part 31 and a fifth connection part 32. The fourth connection part 31 and / or the fifth connection part 32 are bent along the second direction away from the center of the spring disk 3 and then connected to the longitudinal arm 2. Optionally, only the fourth connection part 31 may be bent in the direction away from the center of the spring disk 3, or only the fifth connection part 32 may be bent in the direction away from the center of the spring disk 3. Alternatively, both the fourth connection part 31 and the fifth connection part 32 may be bent in the second direction away from the center of the spring disk 3. The selection may be made according to actual needs and is not limited here. It can be understood that the special structure of the spring disk 3 mentioned above changes the extension mode of the weld between the fourth connection part 31 and / or the fifth connection part 32 and the longitudinal arm 2 from extending around a concentric circle to extending obliquely on the surface of the longitudinal arm 2, thereby dispersing the stress acting on the weld during driving, so as to reduce the risk of cracks in the weld due to stress during use, thereby increasing the service life of the torsion beam and ensuring driving safety. Preferably, in the present application, only the fourth connection part 31 is bent in the direction away from the center of the wheel bracket 4.
[0051] Among them, the bending angle of the fourth connection part 31 and / or the fifth connection part 32 is 23° to 29°. Optionally, the bending angle of the fourth connection part 31 and / or the fifth connection part 32 can be 23°, 24°, 25°, 26°, 27°, 28° and 29°, etc., or other values within the range. It can be selected according to actual needs and is not limited here. It can be understood that the bending angle of the fourth connection part 31 and / or the fifth connection part 32 is within the above range, which can avoid excessive stress concentration due to too small bending angle, and can not effectively disperse the stress acting on the weld, and can also avoid the circumferential connection length of the fourth connection part 31 and / or the fifth connection part 32 and the longitudinal arm 2 being too short due to too large bending angle, which affects the welding stability of the spring disk 3 and the longitudinal arm 2.
[0052] The circumferential connection length between the fourth connection part 31, the fifth connection part 32 and the longitudinal arm 2 is 69 mm to 89 mm. Optionally, the circumferential connection length between the fourth connection part 31, the fifth connection part 32 and the longitudinal arm 2 can be 69 mm, 72 mm, 75 mm, 78 mm, 81 mm, 84 mm, 87 and 89 mm, etc., or other values within the range. It can be selected according to actual needs and is not limited here. It can be understood that the circumferential connection length between the fourth connection part 31, the fifth connection part 32 and the longitudinal arm 2 is within the above range, which can better extend the length of the weld and disperse the stress acting on the weld, reduce the risk of cracks in the weld due to stress during use, and thus increase the service life of the torsion beam and ensure driving safety.
[0053] Further, the spring disk 3 is further provided with a sixth connection portion 33, which is connected to the longitudinal arm 2 after being bent in a direction close to the center of the spring disk 3, wherein the bending angle of the sixth connection portion 33 is 100° to 104°, that is, the angle between the sixth connection portion 33 and the plane of the spring disk 3 is 100° to 104°, and optionally, the bending angle of the sixth connection portion 33 can be specifically 100°, 101°, 102°, 103°, 104°, etc., or other values within the range, which can be selected according to actual needs and are not limited here. It can be understood that the bending angle of the sixth connection portion 33 is within the above range, which can reduce the volume of the spring disk 3 extending out of the longitudinal arm 2.
[0054] The connection length between the sixth connection portion 33 and the longitudinal arm 2 is 77 mm to 81 mm. Optionally, the connection length between the sixth connection portion 33 and the longitudinal arm 2 can be 77 mm, 78 mm, 79 mm, 80 mm, 81 mm, etc., or other values within the range. It can be selected according to actual needs and is not limited here. It can be understood that when the connection length between the sixth connection portion 33 and the longitudinal arm 2 is within the above range, the connection stability between the spring plate 3 and the longitudinal arm 2 is further improved.
[0055] The above describes in detail the structure, features and effects of the present application based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present application, but the present application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of the present application, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the protection scope of the present application.
Claims
1. A torsion beam, characterized in that: The torsion beam comprises a crossbeam (1), a longitudinal arm (2), a spring plate (3) and a wheel bracket (4); the two ends of the crossbeam (1) are respectively overlapped with the two longitudinal arms (2); the crossbeam (1) extends along a first direction, and the longitudinal arms (2) extend along a second direction; The wheel bracket (4) is provided with a first connecting portion (41) and a second connecting portion (42), and the first connecting portion (41) and / or the second connecting portion (42) are connected to the longitudinal arm (2) after being bent along the second direction in a direction away from the center of the wheel bracket (4); the spring disk (3) is provided with a fourth connecting portion (31) and a fifth connecting portion (32), and the fourth connecting portion (31) and / or the fifth connecting portion (32) are connected to the longitudinal arm (2) after being bent along the second direction in a direction away from the center of the spring disk (3).
2. The torsion beam according to claim 1, characterized in that: The bending angle of the first connecting portion (41) and / or the second connecting portion (42) is 19° to 67°.
3. The torsion beam according to claim 1, characterized in that: The circumferential connection length between the first connection part (41), the second connection part (42) and the longitudinal arm (2) is 80 mm to 120 mm.
4. The torsion beam according to claim 1, characterized in that: The bending angle of the fourth connecting portion (31) and / or the fifth connecting portion (32) is 23° to 29°.
5. The torsion beam according to claim 1, characterized in that: The circumferential connection length between the fourth connection part (31), the fifth connection part (32) and the longitudinal arm (2) is 69 mm to 89 mm.
6. The torsion beam according to claim 1, characterized in that: The torsion beam further comprises a reinforcement member (5), a part of which is connected to the longitudinal arm (2); another part of which is connected to the cross beam (1), and a connection part between the reinforcement member (5) and the cross beam (1) is bent along a third direction.
7. The torsion beam according to claim 6, characterized in that: The bending angle of the connection portion between the reinforcement member (5) and the crossbeam (1) is 15° to 25°.
8. The torsion beam according to claim 1, characterized in that: The cross beam (1) comprises a middle section (11), a first transition section (12) and a first overlapping section (13), a second transition section (14) and a second overlapping section (15); the first overlapping section (13), the first transition section (12), the middle section (11), the second transition section (14) and the second overlapping section (15) are connected in sequence, and the cross beam (1) is connected to the longitudinal arm (2) via the first overlapping section (13) and the second overlapping section (15); Both sides of the middle section (11) are recessed inwards, and a convex portion (16) is provided on the middle section (11), wherein the convex portion (16) extends along the length direction of the middle section (11).
9. The torsion beam according to claim 8, characterized in that: The protrusion height of the protrusion (16) is 4 mm to 6 mm, and the protrusion length of the protrusion (16) is 200 mm to 800 mm.
10. The torsion beam according to claim 8, characterized in that: The overlapping lengths of the first overlapping section (13), the second overlapping section (15) and the longitudinal arm (2) are 330 mm to 350 mm, and the overlapping widths are 50 mm to 60 mm.