A leaf spring mounting structure for a balance suspension and a vehicle

Abstract

The application relates to a plate spring mounting structure of a balance suspension and an automobile, and belongs to the technical field of chassis suspension in the automobile industry. The plate spring mounting structure of the balance suspension comprises a balance shaft support assembly provided with a balance bearing hub, a plate spring assembly provided with a center hole, and a pressing connecting piece. The plate spring assembly is installed between a cover plate and the balance bearing hub, the tensile stress surface of the plate spring assembly at the center hole is partially attached to the balance bearing hub, and the compressive stress surface of the plate spring assembly is attached to the cover plate. The pressing connecting piece is matched with the cover plate to press the plate spring assembly and drive the plate spring assembly to be bent and deformed under the support of the balance bearing hub, so that the bending compressive stress and the bending tensile stress are respectively generated on the tensile stress surface and the compressive stress surface at the center hole of the plate spring assembly. The pre-bending of the plate spring assembly is realized by matching the pressing connecting piece with the balance bearing hub, the plate spring assembly stress is preloaded, the working stress of the tensile surface of the plate spring is reduced, and the early fracture of the plate spring clamping area, especially the center hole, is avoided.

Description

Technical Field

[0001] This invention relates to the field of chassis suspension technology in the automotive industry, specifically to a leaf spring mounting structure for a balanced suspension and an automobile. Background Technology

[0002] Heavy-duty vehicles operate under relatively harsh conditions, and while the performance requirements for vehicles are becoming increasingly stringent, it is also necessary to ensure the service life of the vehicles and avoid the loss of time and property due to frequent replacement of parts. Therefore, the reliability and service life of the balance shaft assembly are particularly important for heavy-duty vehicles.

[0003] In related technologies, the leaf springs in a balance suspension are installed in the balance bearing hub. After being clamped by U-bolts and a cover plate, the leaf springs can withstand the loads applied by the axle. The side of the leaf spring that contacts the balance bearing hub is the tension surface (generating tensile stress under load). A center hole (through straight hole) is provided in the middle of the leaf spring for positioning and installation. However, since the leaf spring assembly installation requires a center hole on each individual leaf spring, stress concentration occurs at the edge of the center hole. When the leaf spring is under load, even if the tightening torque of the U-bolts is sufficient, the leaf spring still experiences deformation and stress in the U-bolt clamping area. Furthermore, due to the stress concentration near the tensile stress surface of the center hole, the tensile stress surface of the leaf spring is more sensitive to defects similar to the center hole, ultimately leading to frequent leaf spring breakage at the center hole. Although existing technologies reduce the stress at the center hole of the leaf spring by increasing the length of the cover plate and the span of the U-bolts, increasing the span of the U-bolts increases the useless length of the leaf spring, increases the weight of the cover plate, and also creates placement difficulties. Another way to reduce stress at the center hole of the leaf spring is to increase the thickness of the leaf spring root, but this will increase the weight of the leaf spring and the cost. Summary of the Invention

[0004] In related technologies, stress concentration occurs at the edge of the central hole of the leaf spring in the balance suspension during operation, leading to frequent breakage of the leaf spring at the central hole.

[0005] In a first aspect, embodiments of this application provide a leaf spring mounting structure for a balance suspension, comprising: a cover plate, a balance shaft bracket assembly, a leaf spring assembly, and a clamping connector; wherein...

[0006] Balance shaft bracket assembly, on which balance bearing hub is mounted;

[0007] A leaf spring assembly has a central hole in its middle. The leaf spring assembly is installed between the cover plate and the balance bearing hub. The tensile stress surface of the leaf spring assembly at its central hole is in contact with the balance bearing hub, and the compressive stress surface of the leaf spring assembly is in contact with the cover plate.

[0008] The clamping connector, in conjunction with the cover plate, clamps the leaf spring assembly, causing the leaf spring assembly to bend and deform under the support of the balance bearing hub, so that bending compressive stress and bending tensile stress are generated on the tensile stress surface and compressive stress surface at the center hole of the leaf spring assembly, respectively.

[0009] In conjunction with the first aspect, in one embodiment, the cover plate is made of an elastic material;

[0010] The middle part of the clamping connector is attached to the cover plate, and both ends of the clamping connector are detachably connected to the balance shaft bracket assembly. The clamping connector can clamp the cover plate so that the deformation of the cover plate causes the leaf spring assembly to bend and deform.

[0011] In conjunction with the first aspect, in one embodiment, the clamping connector includes: at least two U-bolts, the two U-bolts being spaced apart on the cover plate, the two ends of the U-bolts being detachably connected to the balance shaft bracket assembly, the two U-bolts being able to clamp the cover plate so that the cover plate deforms and causes the leaf spring assembly to abut against the balance bearing hub and undergo bending deformation.

[0012] In conjunction with the first aspect, in one embodiment, the support surface of the balance bearing hub that is in contact with the leaf spring assembly is a curved surface. Part of the support surface of the balance bearing hub is always in contact with the tensile stress surface of the leaf spring assembly, and another part is in contact with the tensile stress surface of the leaf spring assembly after bending deformation.

[0013] In conjunction with the first aspect, in one embodiment, the support surface of the balance bearing hub includes a first curved surface located in the middle and second curved surfaces on both sides. The first curved surface is fitted with the tensile stress surface of the leaf spring assembly, and when the middle tangent of the first curved surface is parallel to the ground, any point on the first curved surface is higher than the second curved surface.

[0014] In conjunction with the first aspect, in one embodiment, a positioning hole is provided on the first curved surface; the leaf spring assembly includes: multiple leaf spring components and a central bolt, the leaf spring component has a central hole in the middle for the central bolt to pass through, the multiple leaf spring components are connected by the central bolt, and one end of the central bolt passes through the positioning hole.

[0015] In conjunction with the first aspect, in one embodiment, the central hole of the leaf spring is a stepped hole, and the diameter of the central hole near the tensile stress surface of the leaf spring assembly is larger than the diameter near the compressive stress surface.

[0016] In conjunction with the first aspect, in one embodiment, the transition region between the central hole and the tensile stress surface is provided with a rounded corner.

[0017] In conjunction with the first aspect, in one embodiment, the tensile stress surface of the leaf spring assembly is provided with a thin washer, the thickness of the thin washer in the middle being greater than the thickness of its two ends.

[0018] Secondly, embodiments of this application provide an automobile comprising: a leaf spring mounting structure as described in any of the preceding claims.

[0019] The beneficial effects of the technical solutions provided in this application include at least the following:

[0020] This application achieves pre-bending of the leaf spring assembly by clamping the connecting piece and cooperating with the balance bearing hub. By pre-applying assembly stress to the leaf spring, the working stress on the tension surface of the leaf spring is reduced, thus preventing early fracture in the clamping area of ​​the leaf spring, especially at the center hole. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a front view of the leaf spring mounting structure of the balance suspension in the installation state in the embodiments of this application;

[0023] Figure 2 This is a front view of the leaf spring mounting structure of the balance suspension in the embodiments of this application before installation;

[0024] Figure 3 This is a cross-sectional view of the balance shaft bracket assembly in an embodiment of this application;

[0025] Figure 4 This is a partial cross-sectional view of the balance bearing hub in an embodiment of this application;

[0026] Figure 5 This is a front view of the leaf spring assembly in an embodiment of this application;

[0027] Figure 6 This is a cross-sectional view of the leaf spring assembly in an embodiment of this application.

[0028] In the figure: 1. Cover plate; 2. Balance shaft bracket assembly; 3. Balance bearing hub; 31. First curved surface; 311. Positioning hole; 32. Second curved surface; 4. Leaf spring assembly; 41. Tensile stress surface; 42. Compressive stress surface; 43. Leaf spring component; 44. Center bolt; 45. Center hole; 5. Clamping connector; 51. U-bolt; 6. Thin washer. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0030] In related technologies, stress concentration occurs at the edge of the central hole of the leaf spring in the balance suspension during operation, leading to frequent breakage of the leaf spring at the central hole.

[0031] Firstly, such as Figure 1 As shown, this application provides an embodiment in which the leaf spring mounting structure of the balance suspension includes: a cover plate 1, a balance shaft bracket assembly 2, a leaf spring assembly 4, and a clamping connector 5; wherein,

[0032] A balance shaft support assembly 2 is provided with a balance bearing hub 3; a leaf spring assembly 4 has a central hole 45 in its middle, the leaf spring assembly 4 is installed between the cover plate 1 and the balance bearing hub 3, the tensile stress surface 41 of the leaf spring assembly 4 at its central hole 45 is in partial contact with the balance bearing hub 3, and the compressive stress surface 42 of the leaf spring assembly 4 is in contact with the cover plate 1; a clamping connector 5 cooperates with the cover plate 1 to clamp the leaf spring assembly 4, causing the leaf spring assembly 4 to bend and deform under the support of the balance bearing hub 3, so that bending compressive stress and bending tensile stress are generated on the tensile stress surface 41 and the compressive stress surface 42 at the central hole 45 of the leaf spring assembly 4, respectively.

[0033] It should be noted that the tensile stress surface 41 of the leaf spring assembly 4 refers to the leaf spring surface that undergoes tensile deformation when subjected to an external load (axle load). The side opposite the tensile stress surface 41 is called the compressive stress surface 42 (which will undergo compressive deformation). Specifically, the tensile stress surface of the balance suspension leaf spring refers to the side of the leaf spring that contacts the axle support surface when the vehicle is static, and the surface that undergoes tensile deformation under the load applied by the axle. It is generally a concave arc surface.

[0034] It is worth noting that in the above embodiment, the pre-bending of the leaf spring assembly 4 is achieved by the cooperation of the clamping connector 5 and the balance bearing hub 3. By pre-applying assembly stress to the leaf spring, the working stress on the tension surface of the leaf spring is reduced, thus avoiding early fracture in the clamping area of ​​the leaf spring, especially at the center hole.

[0035] In some preferred embodiments, the clamping connector 5 includes at least two U-bolts 51, which are spaced apart on the cover plate 1. The two ends of the U-bolts 51 are detachably connected to the balance shaft bracket assembly 2. The two U-bolts 51 can clamp the cover plate 1 so that the cover plate 1 deforms and causes the leaf spring assembly 4 to abut against the balance bearing hub 3 and bend.

[0036] Furthermore, the two U-bolts 51 are symmetrically arranged along the length of the leaf spring assembly 4 with their central hole 45 as the center.

[0037] It is worth noting that, such as Figure 2 As shown, in its free state, the tensile stress surface 41 (concave arc surface) of the leaf spring assembly 4 is in contact with the area of ​​the balance bearing hub 3 near the central hole 45. A pre-existing gap is left near the clamping point of the U-bolt 51. After assembly, under the pre-tightening force of the U-bolt 51, the tensile stress surface 41 of the leaf spring is in contact with the middle and edge of the mounting support surface of the balance bearing hub 3. The clamping area of ​​the leaf spring, including the tensile stress surface 41 near the central hole 45, generates pre-applied assembly stress, thereby reducing the tensile stress near the tensile surface in the area near the central hole of the leaf spring.

[0038] Specifically, the cover plate 1 is made of elastic material; the middle part of the clamping connector 5 is attached to the cover plate 1, and both ends of the clamping connector 5 are detachably connected to the balance shaft bracket assembly 2. The clamping connector 5 can clamp the cover plate 1 so that the cover plate 1 deforms and drives the leaf spring assembly 4 to bend and deform.

[0039] Furthermore, the middle part of the cover plate 1 is recessed, and its length extends to both sides to the U-bolt clamping point. The bottom surface of the cover plate 1 and the contact point with the leaf spring assembly 4 (the U-bolt clamping point) are planar structures.

[0040] Understandably, the material of cover plate 1 possesses a certain degree of toughness, allowing it to adapt to small bending deformations. The two U-bolts 51 apply a clamping force to cover plate 1, causing deformation on both sides of the central hole 45 of cover plate 1 and leaf spring assembly 4.

[0041] In some alternative implementations, such as Figure 3 As shown, the support surface of the balance bearing hub 3 that is in contact with the leaf spring assembly 4 is a curved surface. Part of the support surface of the balance bearing hub 3 is always in contact with the tensile stress surface 41 of the leaf spring assembly 4, and the other part is in contact with the tensile stress surface 41 of the leaf spring assembly 4 after bending deformation.

[0042] Preferably, the support surface of the balance bearing hub 3 includes a first curved surface 31 located in the middle and second curved surfaces 32 on both sides. The first curved surface 31 is fitted with the tensile stress surface 41 of the leaf spring assembly 4, and when the tangent in the middle of the first curved surface 31 is parallel to the ground, any point on the first curved surface 31 is higher than the second curved surface 32.

[0043] It is worth noting that the support surface of the balance bearing hub 3 consists of three curved surfaces: a first curved surface 31 in the middle and two second curved surfaces 32 on either side. The two second curved surfaces 32 are symmetrical about the vertical plane in the middle of the balance bearing hub 3. The radii of curvature of the two second curved surfaces 32 are equal. The first curved surface 31 can be a plane or an arc surface (the center of the arc is located below the balance bearing hub, i.e., protruding upwards). The two second curved surfaces 32 can be planes (sloping surfaces) or arc surfaces (the center of the arc is located below the balance bearing hub 3, i.e., protruding upwards). A positioning hole 311 is provided in the center of the first curved surface 31 for front and rear positioning during leaf spring installation (achieved through the center bolt 44 of the leaf spring). The axis of this positioning hole is perpendicular to the first curved surface 31. When the axis of the positioning hole on the first curved surface 31 is perpendicular to the ground, the height of any point on either of the two second curved surfaces 32 is lower than the height of any point on the first curved surface 31. The two side surfaces in the middle of the balance bearing hub 3 are the leaf spring side positioning surfaces.

[0044] In some preferred embodiments, such as Figure 5 As shown, a positioning hole 311 is provided on the first curved surface 31; the leaf spring assembly 4 includes: multiple leaf spring pieces 43 and a central bolt 44. The leaf spring piece 43 has a central hole 45 in the middle for the central bolt 44 to pass through. The multiple leaf spring pieces 43 are connected by the central bolt 44, and one end of the central bolt 44 passes through the positioning hole 311.

[0045] Understandably, the leaf spring assembly 4 consists of several individual leaf spring parts 43, gaskets, a center bolt 44, and a nut. A center hole 45 is provided on the leaf spring for connection by the center bolt 44, and a gasket is installed on the tensile stress surface of the leaf spring. During assembly, in its free state, the leaf spring only contacts the first curved surface 31 in the middle of the balance bearing hub. When the U-bolt 51 is tightened to secure the nut, under the action of preload, the cover plate 1 presses the leaf spring, causing it to contact the two second curved surfaces 32. The leaf spring bends towards the tensile stress surface, increasing its arc height. After assembly, due to the reverse bending deformation of the leaf spring, bending compressive stress is generated on the tensile stress surface 41, while bending tensile stress is generated on the compressive stress surface 42. Under the action of external load, the working stress of the tensile stress surface 41 of the leaf spring is tensile stress. The bending compressive stress generated by assembly will offset part of the tensile stress generated by the external load. The actual working tensile stress borne by the tensile stress surface 41 is reduced, which is equivalent to reducing the load and combined stress of the leaf spring. This reduces the combined stress (tensile stress) in the clamping area of ​​the U-bolt 51, including the center hole 45, and improves the bearing life of the leaf spring.

[0046] In some preferred embodiments, such as Figure 6 As shown, the central hole 45 of the leaf spring 43 is a stepped hole, and the diameter of the central hole 45 near the tensile stress surface 41 of the leaf spring assembly 4 is larger than the diameter near the compressive stress surface 42.

[0047] Specifically, the single-piece leaf spring 43 has a hole diameter D1 and a depth H1 near the working tensile stress surface 41, which is formed by stamping.

[0048] Furthermore, the transition area between the central hole 45 and the tensile stress surface 41 is provided with rounded corners. Rounded corners Ra and Rb are provided in the transition area between the central hole 45 and the tensile stress surface 41, and a straight line segment (projection, i.e., a conical surface) is provided between Ra and Rb. Ra, Rb, and the straight line segment between them are determined by the punch structure and process. The bottom surface of hole D1 has a rounded corner r. The diameter of the portion of the central hole 45 near the compressive stress surface 42 is D2, which can be punched or drilled. D1 and D2 are not equal; the purpose is to avoid damaging the surface of D1 when machining D2, thus resolving the issue of misaligned holes when assembling the center bolt. This structure can improve stress concentration at the transition area between the central hole 45 and the tensile stress surface 41.

[0049] In some preferred embodiments, such as Figure 5 As shown, the tensile stress surface 41 of the leaf spring assembly 4 is provided with a thin pad 6, and the thickness of the middle part of the thin pad 6 is greater than the thickness of its two ends.

[0050] It is worth noting that, in order to ensure that only the middle part of the leaf spring assembly 4 is in contact during the initial assembly and not near the clamping point of the U-bolt 51, the clamping point of the U-bolt 51 will be in contact after the assembly is completed. The cover plate 1 will press the leaf spring assembly 4 to generate assembly stress, which can also achieve the same effect.

[0051] Secondly, this application provides an automobile, comprising: a leaf spring mounting structure for a balance suspension, comprising: a cover plate 1, a balance shaft bracket assembly 2, a leaf spring assembly 4, and a clamping connector 5; wherein,

[0052] A balance shaft support assembly 2 is provided with a balance bearing hub 3; a leaf spring assembly 4 has a central hole 45 in its middle, the leaf spring assembly 4 is installed between the cover plate 1 and the balance bearing hub 3, the tensile stress surface 41 of the leaf spring assembly 4 at its central hole 45 is in partial contact with the balance bearing hub 3, and the compressive stress surface 42 of the leaf spring assembly 4 is in contact with the cover plate 1; a clamping connector 5 cooperates with the cover plate 1 to clamp the leaf spring assembly 4, causing the leaf spring assembly 4 to bend and deform under the support of the balance bearing hub 3, so that bending compressive stress and bending tensile stress are generated on the tensile stress surface 41 and the compressive stress surface 42 at the central hole 45 of the leaf spring assembly 4, respectively.

[0053] It is worth noting that in the above embodiment, the pre-bending of the leaf spring assembly 4 is achieved by the cooperation of the clamping connector 5 and the balance bearing hub 3. By pre-applying assembly stress to the leaf spring, the working stress on the tension surface of the leaf spring is reduced, thus avoiding early fracture in the clamping area of ​​the leaf spring, especially at the center hole.

[0054] In some preferred embodiments, the clamping connector 5 includes at least two U-bolts 51, which are spaced apart on the cover plate 1. The two ends of the U-bolts 51 are detachably connected to the balance shaft bracket assembly 2. The two U-bolts 51 can clamp the cover plate 1 so that the cover plate 1 deforms and causes the leaf spring assembly 4 to abut against the balance bearing hub 3 and bend.

[0055] Furthermore, the two U-bolts 51 are symmetrically arranged along the length of the leaf spring assembly 4 with their central hole 45 as the center.

[0056] It is worth noting that, such as Figure 2 As shown, in its free state, the tensile stress surface 41 (concave arc surface) of the leaf spring assembly 4 is in contact with the area of ​​the balance bearing hub 3 near the central hole 45. A pre-existing gap is left near the clamping point of the U-bolt 51. After assembly, under the pre-tightening force of the U-bolt 51, the tensile stress surface 41 of the leaf spring is in contact with the middle and edge of the mounting support surface of the balance bearing hub 3. The clamping area of ​​the leaf spring, including the tensile stress surface 41 near the central hole 45, generates pre-applied assembly stress, thereby reducing the tensile stress near the tensile surface in the area near the central hole of the leaf spring.

[0057] Specifically, the cover plate 1 is made of elastic material; the middle part of the clamping connector 5 is attached to the cover plate 1, and both ends of the clamping connector 5 are detachably connected to the balance shaft bracket assembly 2. The clamping connector 5 can clamp the cover plate 1 so that the cover plate 1 deforms and drives the leaf spring assembly 4 to bend and deform.

[0058] Furthermore, the middle part of the cover plate 1 is recessed, and its length extends to both sides to the U-bolt clamping point. The bottom surface of the cover plate 1 and the contact point with the leaf spring assembly 4 (the U-bolt clamping point) are planar structures.

[0059] Understandably, the material of cover plate 1 possesses a certain degree of toughness, allowing it to adapt to small bending deformations. The two U-bolts 51 apply a clamping force to cover plate 1, causing deformation on both sides of the central hole 45 of cover plate 1 and leaf spring assembly 4.

[0060] In some alternative implementations, such as Figure 3 As shown, the support surface of the balance bearing hub 3 that is in contact with the leaf spring assembly 4 is a curved surface. Part of the support surface of the balance bearing hub 3 is always in contact with the tensile stress surface 41 of the leaf spring assembly 4, and the other part is in contact with the tensile stress surface 41 of the leaf spring assembly 4 after bending deformation.

[0061] Preferably, the support surface of the balance bearing hub 3 includes a first curved surface 31 located in the middle and second curved surfaces 32 on both sides. The first curved surface 31 is fitted with the tensile stress surface 41 of the leaf spring assembly 4, and when the tangent in the middle of the first curved surface 31 is parallel to the ground, any point on the first curved surface 31 is higher than the second curved surface 32.

[0062] It is worth noting that the support surface of the balance bearing hub 3 consists of three curved surfaces: a first curved surface 31 in the middle and two second curved surfaces 32 on either side. The two second curved surfaces 32 are symmetrical about the vertical plane in the middle of the balance bearing hub 3. The radii of curvature of the two second curved surfaces 32 are equal. The first curved surface 31 can be a plane or an arc surface (the center of the arc is located below the balance bearing hub, i.e., protruding upwards). The two second curved surfaces 32 can be planes (sloping surfaces) or arc surfaces (the center of the arc is located below the balance bearing hub 3, i.e., protruding upwards). A positioning hole 311 is provided in the center of the first curved surface 31 for front and rear positioning during leaf spring installation (achieved through the center bolt 44 of the leaf spring). The axis of this positioning hole is perpendicular to the first curved surface 31. When the axis of the positioning hole on the first curved surface 31 is perpendicular to the ground, the height of any point on either of the two second curved surfaces 32 is lower than the height of any point on the first curved surface 31. The two side surfaces in the middle of the balance bearing hub 3 are the leaf spring side positioning surfaces.

[0063] In some preferred embodiments, such as Figure 5 As shown, a positioning hole 311 is provided on the first curved surface 31; the leaf spring assembly 4 includes: multiple leaf spring pieces 43 and a central bolt 44. The leaf spring piece 43 has a central hole 45 in the middle for the central bolt 44 to pass through. The multiple leaf spring pieces 43 are connected by the central bolt 44, and one end of the central bolt 44 passes through the positioning hole 311.

[0064] Understandably, the leaf spring assembly 4 consists of several individual leaf spring parts 43, gaskets, a center bolt 44, and a nut. A center hole 45 is provided on the leaf spring for connection by the center bolt 44, and a gasket is installed on the tensile stress surface of the leaf spring. During assembly, in its free state, the leaf spring only contacts the first curved surface 31 in the middle of the balance bearing hub. When the U-bolt 51 is tightened to secure the nut, under the action of preload, the cover plate 1 presses the leaf spring, causing it to contact the two second curved surfaces 32. The leaf spring bends towards the tensile stress surface, increasing its arc height. After assembly, due to the reverse bending deformation of the leaf spring, bending compressive stress is generated on the tensile stress surface 41, while bending tensile stress is generated on the compressive stress surface 42. Under the action of external load, the working stress of the tensile stress surface 41 of the leaf spring is tensile stress. The bending compressive stress generated by assembly will offset part of the tensile stress generated by the external load. The actual working tensile stress borne by the tensile stress surface 41 is reduced, which is equivalent to reducing the load and combined stress of the leaf spring. This reduces the combined stress (tensile stress) in the clamping area of ​​the U-bolt 51, including the center hole 45, and improves the bearing life of the leaf spring.

[0065] In some preferred embodiments, such as Figure 6 As shown, the central hole 45 of the leaf spring 43 is a stepped hole, and the diameter of the central hole 45 near the tensile stress surface 41 of the leaf spring assembly 4 is larger than the diameter near the compressive stress surface 42.

[0066] Specifically, the single-piece leaf spring 43 has a hole diameter D1 and a depth H1 near the working tensile stress surface 41, which is formed by stamping.

[0067] Furthermore, the transition area between the central hole 45 and the tensile stress surface 41 is provided with rounded corners. Rounded corners Ra and Rb are provided in the transition area between the central hole 45 and the tensile stress surface 41, and a straight line segment (projection, i.e., a conical surface) is provided between Ra and Rb. Ra, Rb, and the straight line segment between them are determined by the punch structure and process. The bottom surface of hole D1 has a rounded corner r. The diameter of the portion of the central hole 45 near the compressive stress surface 42 is D2, which can be punched or drilled. D1 and D2 are not equal; the purpose is to avoid damaging the surface of D1 when machining D2, thus resolving the issue of misaligned holes when assembling the center bolt. This structure can improve stress concentration at the transition area between the central hole 45 and the tensile stress surface 41.

[0068] In some preferred embodiments, such as Figure 5 As shown, the tensile stress surface 41 of the leaf spring assembly 4 is provided with a thin pad 6, and the thickness of the middle part of the thin pad 6 is greater than the thickness of its two ends.

[0069] It is worth noting that, in order to ensure that only the middle part of the leaf spring assembly 4 is in contact during the initial assembly and not near the clamping point of the U-bolt 51, the clamping point of the U-bolt 51 will be in contact after the assembly is completed. The cover plate 1 will press the leaf spring assembly 4 to generate assembly stress, which can also achieve the same effect.

[0070] In summary, this application achieves pre-bending of the leaf spring assembly by clamping the connecting piece and cooperating with the balance bearing hub. By pre-applying assembly stress to the leaf spring, the working stress on the tension surface of the leaf spring is reduced, thus preventing early fracture in the clamping area of ​​the leaf spring, especially at the center hole.

[0071] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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 between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0072] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0073] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A leaf spring mounting structure for a balanced suspension, characterized in that, It comprises: a cover plate (1); a balance shaft support assembly (2) provided with a balance bearing hub (3); a leaf spring assembly (4) provided with a center hole (45) in the middle, the leaf spring assembly (4) is installed between the cover plate (1) and the balance bearing hub (3), the tensile stress surface (41) of the leaf spring assembly (4) at the center hole (45) is partially attached to the balance bearing hub (3), the compressive stress surface (42) of the leaf spring assembly (4) is attached to the cover plate (1); a compression connecting piece (5) which cooperates with the cover plate (1) to compress the leaf spring assembly (4) to drive the leaf spring assembly (4) to bend and deform under the support of the balance bearing hub (3), so as to generate bending compressive stress and bending tensile stress at the tensile stress surface (41) and the compressive stress surface (42) of the center hole (45) of the leaf spring assembly (4) respectively; the support surface of the balance bearing hub (3) attached to the leaf spring assembly (4) is a curved surface, part of the support surface of the balance bearing hub (3) is always attached to the tensile stress surface (41) of the leaf spring assembly (4), and the other part is attached to the tensile stress surface (41) of the leaf spring assembly (4) after bending deformation; the support surface of the balance bearing hub (3) comprises a first curved surface (31) in the middle and a second curved surface (32) on both sides, the first curved surface (31) is attached to the tensile stress surface (41) of the leaf spring assembly (4), and when the tangent line in the middle of the first curved surface (31) is parallel to the ground, any point on the first curved surface (31) is higher than the second curved surface (32).

2. The leaf spring mounting structure according to claim 1, wherein: the cover plate (1) is made of elastic material; the compression connecting piece (5) is attached to the cover plate (1) in the middle, the two ends of the compression connecting piece (5) are detachably connected to the balance shaft support assembly (2), and the compression connecting piece (5) can compress the cover plate (1) to make the cover plate (1) deform and drive the leaf spring assembly (4) to bend and deform.

3. The leaf spring mounting structure according to claim 2, wherein the compression connecting piece (5) comprises at least two U-shaped bolts (51), the two U-shaped bolts (51) are spaced apart on the cover plate (1), the two ends of the U-shaped bolt (51) are detachably connected to the balance shaft support assembly (2), and the two U-shaped bolts (51) can compress the cover plate (1) to make the cover plate (1) deform and drive the leaf spring assembly (4) to abut against the balance bearing hub (3) and bend and deform.

4. The leaf spring mounting structure according to claim 1, wherein: a positioning hole (311) is formed in the first curved surface (31); the leaf spring assembly (4) comprises a plurality of leaf spring pieces (43) and a center bolt (44), the leaf spring piece (43) is provided with a center hole (45) in the middle for the center bolt (44) to pass through, the plurality of leaf spring pieces (43) are connected by the center bolt (44), and one end of the center bolt (44) is arranged in the positioning hole (311).

5. The leaf spring mounting structure according to claim 4, wherein: The center hole (45) of the plate spring member (43) is a stepped hole, and the hole diameter of the center hole (45) near the tensile stress surface (41) side of the plate spring assembly (4) is larger than the hole diameter near the compressive stress surface (42) side.

6. The plate spring mounting structure according to claim 5, wherein: The center hole (45) is provided with a round corner in the transition area with the tensile stress surface (41).

7. The plate spring mounting structure according to claim 1, wherein: The tensile stress surface (41) of the plate spring assembly (4) is provided with a thin gasket (6), and the thickness of the middle part of the thin gasket (6) is larger than the thickness of the two ends.

8. An automobile characterized by comprising: The plate spring mounting structure according to any one of claims 1-7. The plate spring mounting structure according to any one of claims 1-7.

Images