A mounting structure for a fixed end of a steel plate spring

Abstract

The utility model relates to a kind of steel plate spring fixed end mounting structure, it is set between frame and leaf spring, including casting leaf spring seat, leaf spring bush inner tube, pin shaft, locking nut and locking bolt, casting leaf spring seat is connected fixedly upwards with frame, the eye of ear of leaf spring end portion is provided with leaf spring bush inner tube, the eye of ear of leaf spring end portion is aligned after casting leaf spring seat lower part, pin shaft is arranged between leaf spring bush inner tube and casting leaf spring seat lower part;Pin shaft is ladder cylinder, pin shaft small diameter end is connected with locking nut by thread, for limiting pin shaft axial movement, locking bolt is arranged in the lower of casting leaf spring seat corresponding to pin shaft large diameter end, for limiting pin shaft radial movement, anti-rotation plane is set between pin shaft large diameter end and casting leaf spring seat, for limiting pin shaft circumferential rotation.The utility model's pin shaft one end is axially fastened, the other end is radially fastened, there is no gap in axial and radial, avoid the abnormal sound and abrasion generated by pin shaft movement.

Description

Technical Field

[0001] This utility model relates to the field of vehicle suspension system technology, and in particular to a mounting structure for the fixed end of a leaf spring. Background Technology

[0002] Leaf springs, also known as steel leaf springs, are the most widely used elastic element in automotive suspensions. Leaf springs have lugs at both ends. The fixed end of the leaf spring is the end that connects to the vehicle frame. A cast leaf spring seat is installed on the frame, and the frame is connected to the fixed end of the leaf spring through the cast leaf spring seat. Specifically, the inner tube of the leaf spring bushing passes through the lug. After the lug is aligned with the cast leaf spring seat, a through-pin is inserted between the inner tube of the leaf spring bushing and the cast leaf spring seat, thus installing the fixed end of the leaf spring within the cast leaf spring seat.

[0003] To prevent the pin from falling off, a locking nut is used to secure one end of the pin, restricting its circumferential movement. However, the other end of the pin is only fitted to the cast leaf spring seat through a hole diameter tolerance. There is a gap in the hole diameter fit. When the leaf spring is under force, it causes the pin to jump up and down, and the radial force on the pin is too large. After fatigue, wear, abnormal noise, and breakage are likely to occur, affecting the ride comfort and safety. Summary of the Invention

[0004] To address the problem of easy runout and wear at the end of the pin in conventional installation structures, this utility model provides a fixed end installation structure for a leaf spring. By axially tightening one end of the pin and radially tightening the other end, there is no clearance in either the axial or radial direction, achieving stable installation of the pin. This effectively prevents fatigue fracture of the pin caused by radial clearance after fatigue and durability, thus improving the overall vehicle safety.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A leaf spring fixed end mounting structure is provided between the vehicle frame and the leaf spring, including a cast leaf spring seat, a leaf spring bushing inner tube, a pin, a lock nut, and a lock bolt. The cast leaf spring seat is fixedly connected to the vehicle frame upwards. The leaf spring bushing inner tube passes through the lug at the end of the leaf spring. After the lug at the end of the leaf spring is aligned with the lower part of the cast leaf spring seat, the pin passes between the leaf spring bushing inner tube and the lower part of the cast leaf spring seat, which facilitates the connection between the cast leaf spring seat and the leaf spring. The pin is a stepped cylinder. The small diameter end of the pin is threaded with a locking nut to restrict axial movement of the pin and prevent it from coming out. A locking bolt is installed below the casting leaf spring seat corresponding to the large diameter end of the pin to restrict radial movement of the pin and ensure that there is no gap between the pin and the bolt. An anti-rotation plane is provided between the large diameter end of the pin and the casting leaf spring seat to restrict circumferential rotation of the pin. The inner tube of the leaf spring bushing is tightly pressed between one shoulder of the pin and one side of the casting leaf spring seat, and there is a gap between the other shoulder of the pin and the side wall of the casting leaf spring seat.

[0006] Furthermore, the upper part of the cast leaf spring seat is bolted to the frame, which facilitates the assembly and disassembly of the cast leaf spring seat. The lower part of the cast leaf spring seat is an inverted "U" shape. The two sides of the lower part of the cast leaf spring seat have different thicknesses. Small and large through holes are respectively opened on the two sides of the lower part of the cast leaf spring seat. The small and large through holes are arranged on the same axis, which makes it easy for the pin to pass straight through the small and large through holes. The diameter of the small through hole is smaller than that of the large through hole, which makes it easy to match the size of the pin.

[0007] Furthermore, the inner tube of the leaf spring bushing is centrally located within the lug at the end of the leaf spring, and the length of the inner tube is greater than the length of the lug. There is a gap between the two ends of the lug and the lower sides of the cast leaf spring seat. This avoids contact wear between the leaf spring and the cast leaf spring seat.

[0008] Furthermore, after the small perforation, the inner tube of the leaf spring bushing, and the large perforation are connected, the pin is inserted between the small perforation, the inner tube of the leaf spring bushing, and the large perforation.

[0009] Furthermore, the pin includes an integrally formed small-diameter section, a large-diameter section, and an anti-rotation section, with the diameters of the small-diameter section, the large-diameter section, and the anti-rotation section increasing sequentially. One end of the small diameter section has a thread to form a threaded section. After the threaded section passes through the small through hole, it is connected to the locking nut. The small diameter section passes through the inner tube of the leaf spring bushing and its length is greater than that of the inner tube of the leaf spring bushing. The large diameter section passes through the large through hole and its length is greater than that of the large through hole. The inner tube of the leaf spring bushing is tightly pressed against the lower side of the casting leaf spring seat and the shoulder between the small diameter section and the large diameter section.

[0010] Furthermore, the anti-rotation section has an anti-rotation plane on its periphery, the anti-rotation plane is horizontal, and the anti-rotation plane abuts against the casting leaf spring seat; there is a gap a between one side of the anti-rotation section and the other side of the lower part of the casting leaf spring seat.

[0011] Furthermore, a notch is provided on the other side of the lower part of the casting leaf spring seat. The notch is a narrow slit that connects upward to the large through hole and penetrates downward through the casting leaf spring seat. The notch divides the casting leaf spring seat into a left section and a right section. The locking bolt is arranged between the left section and the right section. The locking bolt is arranged below the large through hole and clamps the large diameter section of the pin.

[0012] The beneficial effects of this utility model through the above technical solution are: This utility model features a reasonable structural design. After the pin passes between the inner tube of the leaf spring bushing and the cast leaf spring seat, a locking nut can be used to axially lock the pin on the thin side, preventing axial movement. The anti-rotation plane of the pin engages with the thick side of the cast leaf spring seat, effectively preventing circumferential rotation of the pin. One shoulder of the pin can axially press against the inner tube of the leaf spring bushing, limiting its movement. The other shoulder of the pin has a clearance fit with the thick side of the cast leaf spring seat, with an axial clearance 'a' to avoid direct contact and reduce friction. A locking bolt can reduce the size of the large through hole, clamping the pin and preventing radial movement. This ensures reliable pin installation, prevents pin movement, and thus reduces friction and eliminates noise. Attached Figure Description

[0013] Figure 1 This is an overall front view of a steel leaf spring fixed end mounting structure according to this utility model.

[0014] Figure 2 This utility model relates to a mounting structure for the fixed end of a leaf spring. Figure 1 Front view of the casting leaf spring seat.

[0015] Figure 3 This utility model relates to a mounting structure for the fixed end of a leaf spring. Figure 1 Side sectional view of the casting leaf spring seat.

[0016] Figure 4 This is an overall side sectional view of a steel leaf spring fixing end mounting structure according to this utility model.

[0017] Figure 5 This is a schematic diagram of a pin shaft for a steel leaf spring fixing end mounting structure according to this utility model.

[0018] The attached diagram is labeled as follows: 1. Frame, 2. Leaf spring, 21. Coil, 3. Cast leaf spring seat, 4. Leaf spring bushing inner tube, 5. Pin, 51. Small diameter section, 52. Large diameter section, 53. Anti-rotation section, 54. Threaded section, 6. Locking nut, 7. Locking bolt, 8. Round hole, 9. Thick side, 10. Thin side, 11. Small perforation, 12. Large perforation, 13. Anti-rotation plane, 14. Notch, 15. Left section, 16. Right section, 17. Hole. Detailed Implementation

[0019] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings: like Figures 1-5As shown in the figure, a leaf spring fixed end mounting structure is arranged between a frame 1 and a leaf spring 2, and is used for connecting and fixing the fixed end of the leaf spring 2 and the frame 1. The mounting structure comprises a cast leaf spring seat 3, a leaf spring bushing inner tube 4, a pin shaft 5, a locking nut 6 and a locking bolt 7. The cast leaf spring seat 3 is configured to be mounted to the frame 1. Specifically, the cast leaf spring seat 3 is connected and fixed to the frame 1 upward, that is, the upper part of the cast leaf spring seat 3 is fixedly connected to the frame 1 by bolts. Four circular holes 8 are uniformly formed in the upper part of the cast leaf spring seat 3, one bolt is arranged in each circular hole 8, and after the bolt passes through the circular hole 8, it is connected to the frame 1, so that the cast leaf spring seat 3 can be mounted and fixed on the frame 1.

[0020] The lower part of the cast leaf spring seat 3 is in an inverted "凵" shape, and the thickness of the two sides of the lower part of the cast leaf spring seat 3 are different. Here, the two sides of the lower part of the cast leaf spring seat 3 are respectively defined as a thick side 9 and a thin side 10 to distinguish the thickness of the two sides, and the thickness of the thick side 9 is greater than that of the thin side 10.

[0021] The leaf spring bushing inner tube 4 is penetrated in an eye 21 at the end of the leaf spring 2, and the leaf spring bushing inner tube 4 is arranged centrally in the eye 21 at the end of the leaf spring 2. The length of the leaf spring bushing inner tube 4 is greater than that of the eye 21, so that both ends of the leaf spring bushing inner tube 4 extend out of the eye 21, and the extending distances are the same.

[0022] After the eye 21 at the end of the leaf spring 2 is aligned with the lower part of the cast leaf spring seat 3, the pin shaft 5 is penetrated between the leaf spring bushing inner tube 4 and the lower part of the cast leaf spring seat 3. Since the leaf spring bushing inner tube 4 in the eye 21 is a circular tube, it is convenient for the penetration of the pin shaft 5. In order to allow the penetration of the pin shaft 5 at the lower part of the cast leaf spring seat 3, a small through hole 11 and a large through hole 12 are respectively formed on both sides of the lower part of the cast leaf spring seat 3. The diameter of the small through hole 11 is smaller than that of the large through hole 12, wherein the small through hole 11 is arranged on the thin side 10, the large through hole 12 is arranged on the thick side 9, and the small through hole 11 and the large through hole 12 are arranged on the same axis, so that the pin shaft 5 can be penetrated in a straight line.

[0023] Specifically, after the small through hole 11, the leaf spring bushing inner tube 4 and the large through hole 12 are correspondingly communicated, the pin shaft 5 is penetrated between the small through hole 11, the leaf spring bushing inner tube 4 and the large through hole 12. At this time, there are gaps between the two ends of the eye 21 and the two sides of the lower part of the cast leaf spring seat 3, and the gaps at the two ends are equal, that is, the distance between one end of the eye 21 and the thin side 10 is equal to the distance between the other end of the eye 21 and the thick side 9. Therefore, the fixed end of the entire leaf spring 2 does not contact the cast leaf spring seat 3, which avoids contact wear between the two.

[0024] In this embodiment, the pin 5 is a three-tiered cylinder. Specifically, the pin 5 includes an integrally formed small-diameter section 51, a large-diameter section 52, and an anti-rotation section 53, with the diameters of the small-diameter section 51, the large-diameter section 52, and the anti-rotation section 53 increasing sequentially. One end of the small-diameter section 51 has a thread to form a threaded section 54. The small-diameter section 51 passes through the inner tube 4 of the leaf spring bushing, and its length is greater than that of the inner tube 4 of the leaf spring bushing. The outer diameter of the small-diameter section 51 matches the inner diameter of the inner tube 4 of the leaf spring bushing. The large-diameter section 52 passes through the large through hole 12, and its length is greater than that of the large through hole 12. The diameter of the large-diameter section 52 matches the diameter of the large through hole 12.

[0025] After the pin 5 is installed, the inner tube 4 of the leaf spring bushing is tightly pressed against one shoulder of the pin 5 and one side of the cast leaf spring seat 3. That is, the inner tube 4 of the leaf spring bushing is tightly pressed against the shoulder between the thin side 10 of the lower part of the cast leaf spring seat 3 and the shoulder between the small diameter section 51 and the large diameter section 52. In this way, the pin 5 can no longer move towards the thin side 10 due to the obstruction of the inner tube 4 of the leaf spring bushing. At this time, there is a gap between the other shoulder of the pin 5 and the side wall of the cast leaf spring seat 3. That is, there is a gap a between one side of the anti-rotation section 53 and the thick side 9 of the lower part of the cast leaf spring seat 3. The value of a is between 0.5mm and 1mm, so the end face of the anti-rotation section 53 does not contact the surface of the thick side 9.

[0026] In both of the above states, to prevent the pin 5 from retracting and moving axially toward the thicker side 9, a locking nut 6 is threaded onto the small diameter end of the pin 5. The locking nut 6 is used to restrict the axial movement of the pin 5. Specifically, the threaded section 54 of the pin 5 passes through the small through hole 11 and is connected to the locking nut 6. After tightening the locking nut 6, the entire pin 5 is fixed on the cast leaf spring seat 3 and cannot move axially.

[0027] When tightening the locking nut 6, to prevent the pin 5 from rotating circumferentially, an anti-rotation plane 13 is provided between the large-diameter end of the pin 5 and the cast leaf spring seat 3. That is, the anti-rotation section 53 has an anti-rotation plane 13 on its circumference. The anti-rotation plane 13 is a horizontal plane, and thus the outer contour surface of the anti-rotation section 53 is composed of a horizontal plane and an arc surface. The anti-rotation plane 13 abuts tightly against the cast leaf spring seat 3, and the two are in planar contact, thereby restricting the circumferential rotation of the pin 5.

[0028] In addition, a locking bolt 7 is provided below the casting leaf spring seat 3 corresponding to the large diameter end of the pin 5. The locking bolt 7 is a bolt and nut structure. The axial direction of the locking bolt 7 is perpendicular to the axial direction of the pin 5. The locking bolt 7 is used to restrict the radial movement of the pin 5.

[0029] Specifically, a notch 14 is provided on the other side of the lower part of the casting leaf spring seat 3, that is, the thick side 9. The notch 14 is a narrow slit, which connects upward to the large through hole 12 and penetrates downward through the casting leaf spring seat 3. The notch 14 divides the thick side 9 of the casting leaf spring seat 3 into a left section 15 and a right section 16. Both the left section 15 and the right section 16 have holes 17 for inserting locking bolts 7. The locking bolts 7 are arranged in the holes 17 between the left section 15 and the right section 16, and are positioned below the large through hole 12. After tightening the locking bolts 7, the notch 14 gradually becomes smaller, the large through hole 12 contracts and clamps the pin 5, and the locking bolts 7 can clamp the large diameter section 52 of the pin 5, preventing the pin 5 from moving radially within the large through hole 12.

[0030] During installation, the following steps are taken: First, install the inner tube 4 of the leaf spring bushing into the lug 21 at the end of the leaf spring 2, ensuring that the inner tube 4 is centered. Then, align the inner tube 4 with the small perforation 11 and the large perforation 12 simultaneously, and insert a pin 5 between them. When inserting the pin 5, ensure that the anti-rotation plane 13 faces directly upwards, ensuring that it forms a clamping action with the thick side 9 after insertion, restricting the circumferential rotation of the pin 5. Next, install a locking nut 6 at the end of the small diameter section 51 of the pin 5 and tighten it to prevent axial movement. The pin 5 can also axially press the inner tube 4 of the leaf spring bushing. Finally, install a fixing bolt 7 between the left section 15 and the right section 16 to ensure that the large perforation 12 can reliably clamp the pin 5, preventing radial movement.

[0031] In this invention, the inner tube 4 of the leaf spring bushing and the cast leaf spring seat 3 are connected by a through-pin 5. The pin 5 has a three-step structure. The cast leaf spring seat 3 has a large through hole 12 on its thick side 9, and a notch 14 is added to the thick side 9 for fastening with locking bolts 7. At the same time, the small diameter section 51 of the pin 5 is locked with a locking nut 6, thus ensuring that both ends of the pin 5 and the cast leaf spring seat 3 are tightly secured. This ensures that the pin 5 will not wear or make abnormal noise when subjected to radial force, improving the overall vehicle comfort and safety.

[0032] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the patent claims of this utility model should be included within the scope of the patent application of this utility model.

Claims

1. A leaf spring fixing end mounting structure, disposed between a vehicle frame (1) and a leaf spring (2), characterized in that, The spring includes a cast leaf spring seat (3), a leaf spring bushing inner tube (4), a pin (5), a locking nut (6), and a locking bolt (7). The cast leaf spring seat (3) is connected and fixed to the frame (1) upwards. The leaf spring bushing inner tube (4) is inserted into the lug (21) at the end of the leaf spring (2). After the lug (21) at the end of the leaf spring (2) is aligned with the lower part of the cast leaf spring seat (3), the pin (5) is inserted between the leaf spring bushing inner tube (4) and the lower part of the cast leaf spring seat (3). The pin (5) is a stepped cylinder. The small diameter end of the pin (5) is threaded with the locking nut (6) to restrict the axial movement of the pin (5). The casting leaf spring seat (3) corresponding to the large diameter end of the pin (5) is provided with a locking bolt (7) to restrict the radial movement of the pin (5). An anti-rotation plane (13) is provided between the large diameter end of the pin (5) and the casting leaf spring seat (3) to restrict the circumferential rotation of the pin (5). The inner tube (4) of the leaf spring bushing is tightly pressed between one shoulder of the pin (5) and one side of the casting leaf spring seat (3). There is a gap between the other shoulder of the pin (5) and the side wall of the casting leaf spring seat (3).

2. The steel leaf spring fixed end mounting structure according to claim 1, characterized in that, The upper part of the casting leaf spring seat (3) is bolted to the frame (1). The lower part of the casting leaf spring seat (3) is an inverted "U" shape. The two sides of the lower part of the casting leaf spring seat (3) have different thicknesses. Small perforations (11) and large perforations (12) are respectively opened on the two sides of the lower part of the casting leaf spring seat (3). The small perforations (11) and large perforations (12) are arranged on the same axis. The diameter of the small perforation (11) is smaller than that of the large perforation (12).

3. The steel leaf spring fixed end mounting structure according to claim 2, characterized in that, The inner tube (4) of the leaf spring bushing is centrally located in the lug (21) at the end of the leaf spring (2). The length of the inner tube (4) of the leaf spring bushing is greater than the length of the lug (21). There is a gap between the two ends of the lug (21) and the lower sides of the cast leaf spring seat (3).

4. The steel leaf spring fixed end mounting structure according to claim 2, characterized in that, After the small perforation (11), the inner tube of the leaf spring bushing (4) and the large perforation (12) are connected, the pin (5) is inserted between the small perforation (11), the inner tube of the leaf spring bushing (4) and the large perforation (12).

5. The steel leaf spring fixed end mounting structure according to claim 4, characterized in that, The pin (5) includes an integrally formed small diameter section (51), a large diameter section (52), and an anti-rotation section (53), with the diameters of the small diameter section (51), the large diameter section (52), and the anti-rotation section (53) increasing sequentially. One end of the small diameter section (51) is threaded to form a threaded section (54). The threaded section (54) passes through the small through hole (11) and is connected to the locking nut (6). The small diameter section (51) is inserted into the inner tube (4) of the leaf spring bushing. The length of the small diameter section (51) is greater than that of the inner tube (4) of the leaf spring bushing. The large diameter section (52) is inserted into the large through hole (12). The length of the large diameter section (52) is greater than that of the large through hole (12). The inner tube (4) of the leaf spring bushing is pressed against the lower side of the casting leaf spring seat (3) and the shoulder between the small diameter section (51) and the large diameter section (52).

6. The steel leaf spring fixed end mounting structure according to claim 5, characterized in that, The anti-rotation section (53) has an anti-rotation plane (13) on its periphery. The anti-rotation plane (13) is a horizontal plane and is tightly pressed against the casting leaf spring seat (3). There is a gap a between one side of the anti-rotation section (53) and the other side of the lower part of the casting leaf spring seat (3).

7. The steel leaf spring fixed end mounting structure according to claim 5, characterized in that, A notch (14) is provided on the other side of the lower part of the casting leaf spring seat (3). The notch (14) is a narrow slit. The notch (14) connects upward to the large through hole (12) and penetrates downward through the casting leaf spring seat (3). The notch (14) divides the casting leaf spring seat (3) into a left section (15) and a right section (16). The locking bolt (7) is arranged between the left section (15) and the right section (16). The locking bolt (7) is arranged below the large through hole (12) and clamps the large diameter section (52) of the pin (5).

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