Method for forming a wheel rim

Abstract

The present application belongs to the field of walking mechanism technology, and particularly relates to a forming method of a wheel rim, wherein the central spoke plate is formed by stamping, and the outer ring body is bent by spinning, the forming process is selected reasonably, and the wheel body can be processed with high efficiency and high quality by using fewer processing steps. The wheel rim of the processed product has strong deformation resistance, thereby meeting the use requirements in a harsh environment.

Description

Technical Field

[0001] This invention belongs to the field of walking mechanism technology, and specifically relates to a method for forming wheel spokes and rims. Background Technology

[0002] Track rollers in tracked walking mechanisms support the load of the machinery and guide and limit the tracks. During steering, the track rollers force the tracks to deflect and slide, effectively preventing track slippage. Engineering or agricultural machinery often operates in harsh environments, with track rollers frequently traveling on muddy and gravel roads, making their rims highly susceptible to damage. For example, in a spin-formed harvester track roller disclosed in Chinese Patent CN205675151U, the inner wheel body 100 and outer wheel body 400 are respectively provided with flanges on their outer end faces. This increases the strength of the wheel body to maintain the roundness of the rim. However, in actual application, the outer section of the wheel body deforms under the pressure of road stones, causing the track roller to become out of round, leading to difficulty in steering and severe track wear. Summary of the Invention

[0003] The purpose of this invention is to provide a method for forming spoked wheel rims with high strength and long service life.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A method for forming a spoked wheel rim includes the following steps:

[0006] A. Blanking: A circular blank is punched out from the raw material plate;

[0007] B. One-time forming: The annular area on the inner side of the blank is formed into a basin-shaped frustum cone with a larger upper part and a smaller lower part to form the spokes. The annular area on the outer side of the spokes is bent downward to form a conical ring with a smaller upper part and a larger lower part to form the one-time forming position of the wheel rim. One-time forming is stamping.

[0008] C. Secondary forming: The wheel rim in step B continues to bend from the primary forming position to the end position where the wheel rim is a cylindrical tube. The wheel rim core at the end position is arranged with the spoke hole core as the core. This step is done by spinning and bending with a spinning wheel.

[0009] Compared with existing technologies, this invention has the following technical advantages: the center spoke is formed by stamping, and the outer rim is formed by spinning and bending. The forming process is reasonable, and the wheel body can be processed efficiently and with high quality using fewer processing steps. The resulting wheel rim has strong resistance to deformation, thus meeting the needs of use in harsh environments. Attached Figure Description

[0010] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings within them:

[0011] Figure 1 This is the front view of the blank obtained after blanking;

[0012] Figure 2 yes Figure 1 AA section view in the middle;

[0013] Figure 3 This is a front view of the blank obtained from a single molding process;

[0014] Figure 4 yes Figure 3 BB section view in the middle;

[0015] Figure 5 This is the front view of the blank obtained from the secondary forming process;

[0016] Figure 6 yes Figure 5 CC section view in the middle;

[0017] Figure 7 This is a cross-sectional view of the wheel rim when a thin edge is formed during step D;

[0018] Figure 8 This is a cross-sectional schematic diagram of the finished wheel obtained in Example 2;

[0019] Figure 9 This is a schematic diagram of the upper and lower molds not yet closed in step C;

[0020] Figure 10 This is a schematic diagram of the pre-formed wheel contacting the rim in step C1;

[0021] Figure 11 This is a schematic diagram of step C1 when the preforming wheel is in the forming position;

[0022] Figure 12 This is a schematic diagram of the contact between the forming wheel and the rim in step C2;

[0023] Figure 13 This is a schematic diagram of step C2 when the forming wheel is in the forming position;

[0024] Figure 14 This is a cross-sectional schematic diagram of the finished wheel obtained in Example 3. Detailed Implementation

[0025] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. For ease of description, the following description follows the vertical direction of the accompanying drawings; however, in practical applications, the drawings can be placed horizontally or upside down as needed.

[0026] Example 1

[0027] The spoke and rim structure obtained in this embodiment is shown in the attached figure. Figure 5 ,6 As shown, the spokes are generally flat and shallow annular plates, and the outer edge 111 of the spokes, which is cylindrical, is arranged in a folded-overlapping manner with the rim 12.

[0028] The wheel spoke rim forming method of this embodiment specifically includes the following steps:

[0029] A. Blanking: A circular blank 10 is punched out from the raw material plate.

[0030] As attached Figure 1 As shown, the blank plate 10 has radially aligned weight-reducing holes 115 spaced apart in the circumferential direction. In this embodiment, to ensure the integrity of the wheel rim 12 and its walking performance, the inner annular plate region including the weight-reducing holes 115 is used to form the wheel spokes, and the annular plate region outside the annular plate region is used to form the wheel rim 12. In other embodiments, the wheel spokes and wheel rim may not have weight-reducing holes, in which case the resulting blank plate 10 is an annular plate with a connecting hole 114 in the middle.

[0031] B. One-time forming: The annular area on the inner side of the blank plate 10 is formed into a basin shape that is larger at the top and smaller at the bottom, forming the spoke plate 11. The annular area on the outer side of the spoke plate 11 is bent downward to form a conical annulus that is smaller at the top and larger at the bottom, forming the one-time forming position of the wheel rim 12. The one-time forming is stamping. In this step, the spoke plate 11 is basically formed, and the wheel rim 12 needs to be further spun to the forming position.

[0032] C. Secondary forming: The wheel rim 12 in step B continues to bend from the primary forming position to the end position where the wheel rim 12 is a cylindrical tube. The core of the wheel rim 12 at the end position is arranged with the core of the spoke 11 hole. This step is done by spinning and bending with a spinning wheel.

[0033] Details are as attached Figure 9 As shown, during the spinning bending process, an upper die 20 and a lower die 30 are provided, with their rotation axes arranged concentrically. The upper die 20 and the lower die 30 include an upper boss 21 and a lower recess 31 arranged opposite to each other. The blank plate 10 is placed in the lower recess 31 with the upper part larger than the lower part. After the upper die 20 and the lower die 30 are closed, the upper boss 21 and the lower recess 31 press and push the spoke plate 11 respectively. Under the premise of ensuring the reliable fixation of the spoke plate 11, it is convenient for the spinning bending wheel pair to freely extend to the side of the pressing and pushing mating surface of the upper boss 21 and the lower recess 31 for spinning bending.

[0034] To facilitate the spinning and bending of the wheel rim 12 to the forming position, the cone surface of the wheel rim 12 in the primary forming position is arranged at an angle to the horizontal plane. To prevent the plate at the junction of the wheel rim 12 and the outer edge 111 of the spokes from being too thin after stamping, affecting the reliability of the connection between the wheel rim 12 and the spokes 11, the angle between the cone surface of the wheel rim 12 and the horizontal plane should not be too large. Conversely, if the angle between the wheel rim 12 and the outer edge 111 of the spokes is too small, it will be difficult to further bend the wheel rim 12 in subsequent steps, and sheet metal accumulation during spinning and bending can easily lead to a low yield. Therefore, in this embodiment, the angle between the cone surface of the wheel rim 12 in the primary forming position and the horizontal plane is α, where 0 < α < 30°, and specifically, 10 ≤ α ≤ 15°. Thus, as shown in the attached... Figure 4 As shown, the axial and radial differences between the overhang edge of the one-piece molded wheel rim 12 and the overhang edge of the molded wheel rim 12 are large. The one-piece molded wheel rim 12 needs to be spun and bent at nearly 90°. In order to ensure the yield of the spun and bent wheel rim 12, in this embodiment, the spun forming of the wheel rim 12 specifically includes two steps.

[0035] C1. Pre-bending: The central area of ​​the clamping and positioning spoke 11 is used to spin-bend the overhang of the wheel rim 12 so that the cross section of the wheel rim 12 is a downward-opening semi-parabolic shape.

[0036] Pre-forming wheels 40 are provided on the sides of the upper mold 20 and the lower mold 30. The wheel core of the pre-forming wheel 40 is arranged parallel to the shaft core of the upper boss 21 and the lower concave platform 31, and the distance between them is adjustable. While the pre-forming wheel 40 rotates around its own axis, it moves closer to the upper mold 20 and the lower mold 20. After contacting the wheel rim 12 and bending it to the set position, the pre-forming wheel 40 moves away from the upper mold 20 and the lower mold 30 to complete the pre-bending process.

[0037] The outer peripheral surface of the preformed wheel 40 includes a preformed surface 42 with an inwardly concave arc shape. The upper edge of the preformed surface 42 is higher than the outer edge of the wheel rim 12 in the primary forming position, and the lower edge of the preformed surface 42 is lower than the lower edge of the wheel rim 12 in the pre-bending forming position. In this way, when the preformed wheel 40 approaches the upper mold 20 and the lower mold 30, the outer edge of the wheel rim 12 contacts the preformed surface 42 first, and then the preformed wheel 40 further approaches the upper mold 20 and the lower mold 30, so that the wheel rim 12 can always bend downward to the pre-bending position under the guidance of the preformed surface 42. The lower edge of the preformed surface 42 is higher than or flush with the lower end of the forming wheel rim 12. In this embodiment, the base platform 33 of the lower recess 31 restricts the lower end of the forming wheel rim 12. In other words, the lower edge of the preformed surface 42 is not lower than the base platform 33 of the lower boss, to avoid interference between the preformed wheel 40 and the lower mold 30 during operation, which could cause mold damage. (See attached...) Figure 11As shown, the cross-section of the pre-bent rim 12 is an arc shape with an opening facing downwards. The overhanging end of the pre-bent rim 12 is arranged adjacent to the base surface 33 of the recessed platform 31. The lower edge of the pre-bent rim 12 is cylindrically annular, and the radial distance between the pre-bent rim 12 and the outer peripheral surface 32 of the recessed platform is less than or equal to half the axial dimension of the rim 12. (See attached diagram) Figure 11 As shown, the axial difference between the overhanging edge of the pre-bent wheel rim 12 and the overhanging edge of the formed wheel rim 12 can be greatly reduced, and the radial difference between the overhanging edge of the pre-bent wheel rim 12 and the overhanging edge of the formed wheel rim 12 is reduced by nearly half. In this embodiment, the axial distance between the overhanging edge of the pre-bent wheel rim 12 and the overhanging edge of the formed wheel rim 12 is less than 1 / 3 of the axial dimension of the overhanging edge of the formed wheel rim 12.

[0038] In this embodiment, the upper end of the preformed surface 42 is connected to a clearance surface 41. The clearance surface 41 can enhance the strength of the upper section of the preformed wheel 40, thereby reliably maintaining the profile of the upper section of the preformed surface 42. (See attached...) Figure 10 As shown, the upper section of the preformed surface 42 protrudes outward. If the avoidance surface 41 is not provided, the upper section of the preformed surface 42 is cantilevered with a small axial dimension. During spinning, this section preferentially contacts and interacts with the rim 12, making the upper section of the preformed surface 42 highly susceptible to deformation during spinning, thus deforming its profile. Therefore, in this embodiment, to reliably maintain the profile of the preformed surface 42, an avoidance surface 41 is connected to the upper end of the preformed surface 42, and the lower end of the avoidance surface 41 is higher than the outer edge of the rim 12 in the primary forming position. See attached figure for details. Figure 10 As shown, the junction of the preformed surface 42 and the clearance surface 41 is located outside the outer edge 111 of the spoke. The clearance surface 41 is a cylindrical surface that coincides with the core of the preformed wheel 40. When the preformed wheel 40 is in the forming position, the clearance surface 41 is arranged separately from the wheel rim 12.

[0039] C2. Overlapping: Maintain the positioning and clamping posture of the central area of ​​the spoke 11, and spin-bend the entire rim 12 to form a cylindrical tube shape.

[0040] The upper mold 20 and the lower mold 30 are provided with forming wheels 50 on the side. The wheel core of the forming wheel 50 is arranged parallel to the shaft core of the mating surface of the upper boss 21 and the lower concave platform 31 and the spacing is adjustable. The forming surface 51 of the forming wheel 50 is a cylindrical surface with the core parallel to the wheel core of the forming wheel 50.

[0041] The shaft of the forming wheel 50 is driven to move towards the upper mold 20 and lower mold 30 to the forming position, and the pre-bent wheel rim 12 and the outer edge 111 of the spokes are spun and formed. When the forming wheel 50 is in the forming position, the forming surface 51 and the outer peripheral walls of the upper boss 21 and the lower concave platform 31 form a space to accommodate the wheel rim 12 and the outer edge 111 of the spokes. The finished wheel rim 10 processed in this embodiment is shown in the attached figure. Figure 6As shown, the outer edge 111 of the spoke is cylindrical. Therefore, the outer peripheral surfaces of the upper boss 21 and the lower concave platform 31 are cylindrical surfaces that coincide with the core of the column and the shaft core of the upper boss 21. The outer peripheral surface 22 of the upper boss constitutes the inner forming surface of the outer edge 111 of the spoke, and the outer peripheral surface 32 of the lower concave platform constitutes the inner forming surface of the wheel rim 12. The radial difference between the outer peripheral surface 22 of the upper boss and the outer peripheral surface 32 of the lower concave platform is the thickness d of the blank 10. When the upper boss 21 and the lower concave platform 31 are in the mold-closed state, the distance between the base surface 23 of the upper boss and the base surface 33 of the lower concave platform matches the axial dimension of the wheel rim.

[0042] In this embodiment, the inner edge 112 of the spoke is a planar ring-shaped platform perpendicular to its axial direction. The inner edge 112 is connected to the outer edge 111 of the spoke via a conical ring 113. In other embodiments, the inner edge 112 can also be connected to the outer edge 111 of the spoke via a stepped conical ring 113. In step C, the central platform of the recessed platform 31 matches the inner edge 112 of the spoke, and the upper boss 21 and the lower recessed platform 31 clamp the conical ring or stepped conical ring 113 segment of the spoke 11. All other areas of the spoke 11, except for the outer edge 111, are stamped in step B, i.e., in a one-time forming process. This simplifies the processing flow and improves processing efficiency.

[0043] In addition, to ensure the flowability of the sheet metal at the rim 12 during secondary molding, the outer edge 111 of the spoke 11 is a conical ring with a larger upper edge and a smaller lower edge after the first molding is completed. The angle between the outer edge 111 of the spoke 11 at the first molding position and the plumb line is β, where 0 < β ≤ 25°. In step C, the outer edge 111 of the spoke 11 is bent and closed to the end position along with the rim 12. In this embodiment, the angle β between the outer edge 111 of the spoke 11 at the end position and the plumb line is 0.

[0044] Example 2

[0045] The difference between this embodiment and Embodiment 1 is that after step C is completed, step D is also included: flanging: the inner edge of the rim 12 is flared to form a flanged edge 121.

[0046] Details are as attached Figure 7 , 8 As shown, a thin edge 122 is first cut along the circumference of the rim 12 to form its outer surface, and then the thin edge 122 is folded inward to form a flange 121. This reduces the weight of the rim 10 while increasing the strength of the rim 12.

[0047] Example 3

[0048] As attached Figure 14As shown, the difference between this embodiment and Embodiment 2 is that the outer edge 111 of the spoke is a conical ring with a larger upper edge and a smaller lower edge, so the relevant processing mold needs to be modified accordingly. In the preferred embodiment, the angle β between the outer edge 111 of the spoke at the termination position and the plumb line is less than or equal to 10°. To ensure the forming posture of the outer edge 111 of the spoke, the angle β between the outer edge 111 of the spoke at the one-time forming position and the plumb line should satisfy 10 ≤ β ≤ 25°, and the outer peripheral surface 22 of the upper boss is a conical surface that matches the outer edge 111 of the spoke, and the radial difference between the outer peripheral surface 22 of the upper boss and the outer peripheral surface 32 of the lower concave boss is greater than or equal to the thickness d of the blank 10.

Claims

1. A method for forming a spoked wheel rim, comprising the following steps: A. Blanking: A circular blank (10) is punched out from the raw material plate. B. One-time molding: The annular area on the inner side of the blank plate (10) is formed into a basin-shaped frustum cone with a larger upper part and a smaller lower part to form the spoke plate (11). The annular area on the outer side of the spoke plate (11) is bent downward to form a cone-shaped annulus with a smaller upper part and a larger lower part to form the one-time molding position of the wheel rim (12). One-time molding is stamping. C. Secondary forming: The wheel rim (12) in step B continues to bend from the first forming position to the end position where the wheel rim (12) is a cylindrical tube. The core of the wheel rim (12) at the end position is arranged with the core of the spoke plate (11) hole. This step is to use a spinning wheel to spin and bend the wheel. In step C, the wheel rim (12) spinning process includes steps C1 and C2. C1. Pre-bending: The central area of ​​the clamping positioning spoke (11) is used to spin-bend the overhang of the wheel rim (12) so that the cross section of the wheel rim (12) is a downward-opening semi-parabolic shape. C2, Overlap: Maintain the positioning and clamping posture of the center area of ​​the spokes (11), and spin-bend the entire rim (12) to form a cylindrical tube shape; In step C, an upper mold (20) and a lower mold (30) with the rotating shaft arranged concentrically are provided. The upper mold (20) and the lower mold (30) include an upper boss (21) and a lower recess (31) arranged opposite to each other. The upper boss (21) and the lower recess (31) press and top the spoke plate (11) respectively. The wheel rim (12) is freely suspended on the side of the upper boss (21) and the lower recess (31). In step C1, a pre-forming wheel (40) is provided on the side of the upper mold (20) and the lower mold (30). The wheel core of the pre-forming wheel (40) is arranged parallel to the shaft core of the upper boss (21) and the lower concave platform (31) and the spacing is adjustable. The outer peripheral surface of the preformed wheel (40) includes a preformed surface (42). The upper end of the preformed surface (42) is higher than the outer edge of the one-time formed wheel rim (12), and the lower end of the preformed surface (42) is lower than the lower end of the preformed wheel rim (12). The lower end of the preformed surface (42) is not lower than the lower end of the formed wheel rim (12). The preformed surface (42) is a concave arc surface, and the axial curvature of the preformed surface (42) decreases from top to bottom. The upper end of the preformed surface (42) is connected to the clearance surface (41), and the lower end of the clearance surface (41) is higher than the outer edge of the wheel rim (12) in the first forming position. The clearance surface (41) is a cylindrical surface that coincides with the core of the preformed wheel (40). When the preformed wheel (40) is in the forming position, the clearance surface (41) and the wheel rim (12) are arranged separately. The shaft of the preforming wheel (40) is driven to move closer to the upper mold (20) and lower mold (30) to the forming position. The overhanging end of the wheel rim (12) first contacts the preforming surface (42), and then the overhanging section of the wheel rim (12) bends downward along the guide of the preforming surface (42) to the pre-bending position. Then the shaft of the preforming wheel (40) is driven to move further away from the upper mold (20) and lower mold (30). The lower edge of the pre-bent wheel rim (12) is cylindrical in shape, and the radial distance between the pre-bent wheel rim (12) and the outer peripheral surface (32) of the concave platform is less than or equal to 1 / 2 of the axial dimension of the wheel rim (12). In step C2, a forming wheel (50) is provided on the side of the upper mold (20) and the lower mold (30). The wheel core of the forming wheel (50) is arranged parallel to the shaft core of the mating surface of the upper boss (21) and the lower concave platform (31) and the spacing is adjustable. The forming surface (51) of the forming wheel (50) is a cylindrical surface with the core parallel to the wheel core of the forming wheel (50). The shaft of the forming wheel (50) is driven to move closer to the upper mold (20) and lower mold (30) to the forming position, and the wheel rim (12) and the outer edge of the spoke plate (111) in the pre-forming position are spun and formed. When the forming wheel (50) is in the forming position, the forming surface (51) and the outer peripheral wall of the upper boss (21) and the lower concave platform (31) enclose the space that accommodates the wheel rim (12) and the outer edge of the spoke plate (111). The outer peripheral walls of the upper boss (21) and the lower concave platform (31) are cylindrical surfaces that coincide with the core of the column and the axis of the upper boss (21).

2. The method for forming a spoked wheel rim according to claim 1, characterized in that: In step B, the angle between the conical surface of the wheel rim (12) located in the one-time forming position and the horizontal direction is α, 0<α<30°.

3. The method for forming a spoked wheel rim according to claim 1, characterized in that: In step B, after the first molding is completed, the outer edge (111) of the spoke (11) is a conical ring with a larger upper part and a smaller lower part. The angle between the outer edge (111) of the spoke in the first molding position and the plumb line is β, 0<β≤25°. In step C, the outer edge (111) of the spoke is bent and closed to the end position along with the wheel rim (12), and the angle β between the outer edge (111) of the spoke at the end position and the plumb line is less than or equal to 10°.

4. The method for forming a spoked wheel rim according to claim 1, characterized in that: In step B, after the first molding is completed, the outer edge (111) of the spoke is stamped to the end position, and the angle β between the outer edge (111) of the spoke at the end position and the plumb line is less than or equal to 10°.

5. The method for forming a spoked wheel rim according to claim 1, characterized in that: The blank (10) has weight-reducing holes (115) arranged at intervals in the circumferential direction with the same radial position. The inner annular plate region including the weight-reducing holes (115) is used to form the spokes (11), and the outer annular plate region used to form the spokes (11) is used to form the wheel rim (12).

6. The method for forming a spoked wheel rim according to claim 1, characterized in that: The inner edge (112) of the spoke is a planar ring platform perpendicular to its axis. The inner edge (112) of the spoke is connected to the outer edge (111) of the spoke through a conical ring or a stepped conical ring (113). In step C, the central platform of the lower concave platform (31) matches the inner edge (112) of the spoke, and the upper protrusion (21) and the lower concave platform (31) clamp the conical ring or stepped conical ring (113) segment of the spoke (11); The outer peripheral surface (22) of the upper boss forms the inner forming surface of the outer edge (111) of the spoke, and the outer peripheral surface (32) of the lower concave boss forms the inner forming surface of the rim (12). The minimum radial difference between the outer peripheral surface (22) of the upper boss and the outer peripheral surface (32) of the lower concave boss is the thickness d of the blank (10). When the upper boss (21) and the lower recess (31) are in the mold closing state, the distance between the base surface (23) of the upper boss and the base surface (33) of the lower recess matches the axial dimension of the wheel rim.

7. The method for forming a spoked wheel rim according to claim 1, characterized in that: It also includes step D, flanging: the inner edge of the rim (12) is flared to form a flanging (121).

8. The method for forming a spoked wheel rim according to claim 7, characterized in that: In step D, the outer surface of the rim (12) is first cut along the circumference to form a thin edge (122), and the thin edge (122) is folded inward to form a flange (121).

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