Split type alloy wheel and machining process thereof

Abstract

The invention discloses a split type alloy wheel and a machining process thereof. The split type alloy wheel comprises a rim. A spoke is arranged on one side of the rim; the rim and the spoke are in butt joint through a two-step matching structure, and an inner annular welding seam and an outer annular welding seam are formed on the inner side and the outer side of the butt joint position respectively. The inner annular welding seam and the outer annular welding seam are connected through friction stir welding. By optimizing the structural design, the forming process and the full-friction-stir welding connection mode of the spoke and the rim, the lightweight level, the structural strength and the forming precision of the wheel are further improved, the strict requirements of the automobile industry for lightweight and safety are met, the advanced friction-stir welding technology is adopted to replace a traditional fusion welding mode, and the production cost is reduced. The problem that the performance of a welding joint is not uniform is solved, and the stability and consistency of the overall performance of the wheel are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field, more particularly to a split alloy wheel and a processing technology thereof. BACKGROUND

[0002] With the increasing demand for lightweight vehicles, aluminum alloy wheels gradually replace traditional steel wheels due to their light weight, high strength, and good heat dissipation performance. Existing aluminum alloy wheels are mainly divided into one-piece, two-piece, and three-piece structures. One-piece wheels are mostly made by low-pressure casting process, which has low cost but poor mechanical properties. Although forged wheels have excellent performance, they require large equipment investment and high cost. Two-piece wheels are manufactured by connecting the spokes and the rim, which are traditionally connected by bolts, resulting in heavy weight and complex structure. In recent years, welding technology, especially friction stir welding, has been introduced into wheel manufacturing, but there are still problems such as insufficient weld strength and stress concentration. SUMMARY

[0003] Therefore, the present application provides a split alloy wheel and a processing technology thereof to solve the problems in the prior art.

[0004] To solve the above technical problems, the present application adopts the following technical solutions: A split alloy wheel, comprising: a rim; a spoke arranged on one side of the rim; the rim and the spoke are connected together through a two-stage stepped matching structure, and an inner annular weld and an outer annular weld are formed on the inner and outer sides of the connection, respectively; the inner annular weld and the outer annular weld are connected by friction stir welding.

[0005] Preferably, the rim and the spoke are made of high-strength lightweight alloy.

[0006] Preferably, the rim is formed by deforming aluminum alloy strip through a spiral winding drum, friction stir welding longitudinal seam, and array ball rolling.

[0007] Preferably, the spoke is made of cast aluminum alloy material and is formed by low-temperature low-pressure casting or liquid die forging process.

[0008] Preferably, the height difference of the two-stage stepped matching structure is 2-3mm, and the roughness Ra of each stepped surface is ≤3.2μm.

[0009] A processing technology for a split alloy wheel, comprising the following steps: S1, spoke manufacturing: formed by low-temperature low-pressure casting or liquid die forging process, and machined after T6 heat treatment; S2, rim manufacturing: S21, the aluminum alloy strip is spirally rolled into a cylinder, and the longitudinal seam is welded by friction stir welding; S22, the cylinder is cut into units and is formed into a rim shape by array type ball rolling; S23, solid solution and aging heat treatment is carried out; S3, rim and spoke assembly: the rim and the spoke are assembled in a high-precision positioning mold, and self-positioning is realized by using a two-stage stepped matching structure; S4, rim and spoke welding: the outer annular weld and the inner annular weld are welded by friction stir welding; S5, subsequent processing: secondary rolling shaping is carried out to eliminate welding residual stress, and then phosphating, electrophoresis and spraying surface treatment are carried out in sequence.

[0010] Preferably, in the S1, the T6 heat treatment specific steps are: first solid solution treatment and then water cooling, and then aging treatment; wherein, the solid solution treatment is at 535 DEG C + / - 5 DEG C for 4-7 hours, and the aging treatment is at 160-165 DEG C for 4-8 hours.

[0011] Preferably, the outer annular weld welding process parameters are: welding head speed 1200-1500 r / min, welding speed 0.2-0.3 mm / r, and shoulder pressure 3-5 kN.

[0012] Preferably, the inner annular weld welding process parameters are: welding head speed 1000-1300 r / min, welding speed 0.15-0.25 mm / r, and shoulder pressure 2.5-4 kN.

[0013] Preferably, the outer annular weld and the inner annular weld both adopt a back-pulling static shoulder welding technology, and the shoulder back-pulling speed after welding is 5-8 mm / min to avoid tail hole defects.

[0014] The present application has the following technical effects relative to the prior art: 1) The rim and spoke welding part of the present application adopts a two-stage stepped matching structure, realizing the close cooperation and self-positioning of the spoke and the rim. In the assembly process, the three-stage stepped structure can guide the accurate butt joint of the spoke and the rim, greatly improving the assembly precision and efficiency, ensuring that the seam gap is controlled within a very small range, effectively reducing the stress concentration phenomenon, enhancing the overall structural strength of the wheel, and significantly improving the reliability and service life of the wheel.

[0015] 2) The outer annular weld and the inner annular weld of the present application both adopt friction stir welding, forming a high-strength and high-reliability connection system, which not only improves the strength and fatigue performance of the welded joint, but also makes the overall structure of the wheel more compact and further reduces the weight. In actual application, it can better adapt to various complex working conditions in the process of automobile driving, providing a strong guarantee for driving safety. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of a split alloy wheel according to the present invention; Figure 2 for Figure 1 A magnified view of part A in the middle; Figure 3 This is a schematic diagram of the wheel rim structure; Figure 4 This is a schematic diagram of the spoke structure; In the diagram: 1. Rim; 2. Spokes; 3. Inner circumferential weld; 4. Outer circumferential weld. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Reference Figures 1-4 As shown, the present invention discloses a split alloy wheel, including: a rim 1; a spoke 2 on one side of the rim 1; the rim 1 and the spoke 2 are joined together by a two-stage stepped fit structure, and an inner annular weld 3 and an outer annular weld 4 are formed on the inner and outer sides of the joint respectively; the inner annular weld 3 and the outer annular weld 4 are both connected by friction stir welding.

[0019] Both the rim 1 and the spokes 2 are made of high-strength lightweight alloy.

[0020] The rim 1 is formed by spiral winding, friction stir welding of longitudinal seams and array ball bearing rolling of wrought aluminum alloy strip; specifically, the material of the rim 1 is 6xxx series or 5xxx series wrought aluminum alloy.

[0021] Spoke 2 is made of cast aluminum alloy and formed by low-temperature low-pressure casting or liquid forging process; specifically, the material of spoke 2 is A356 or 6061 cast aluminum alloy.

[0022] The step height difference of the two-step stepped mating structure is 2-3mm, and the surface roughness Ra of each step is ≤3.2μm.

[0023] This invention also discloses a processing technology for a split alloy wheel, comprising the following steps: S1. Spoke manufacturing: formed by low-temperature and low-pressure casting or liquid forging process, and machined after T6 heat treatment to ensure that the flatness of the welded end face is ≤0.03mm and the surface roughness Ra≤1.6μm; S2, rim manufacturing: S21, spiral winding aluminum alloy strip into a cylinder, longitudinal seam using friction stir welding; S22, cutting the cylinder into units, and rolling into the shape of the rim 1 through the array ball, the thickness deviation of the formed rim is ≤0.1mm, the roundness error is ≤0.2mm; S23, solid solution and aging heat treatment; S3, rim and spoke assembly: the rim 1 and the spoke 2 are assembled in a high-precision positioning mold, and self-positioning is realized by using a two-stage stepped structure, ensuring that the joint gap is ≤0.3mm and the coaxiality is ≤0.05mm; S4, rim and spoke welding: outer ring weld 4 and inner ring weld 3 are welded using friction stir welding; S5, subsequent processing: secondary rolling shaping is performed to eliminate welding residual stress, followed by phosphating, electrophoresis and spray surface treatment.

[0024] In S1, the specific steps of T6 heat treatment are: first water cooling after solid solution treatment, and then aging treatment; wherein, the solid solution treatment: temperature control at 535℃±5℃, holding for 4-7 hours, aging treatment: 160-165℃, holding for 4-8 hours.

[0025] The welding process parameters of the outer ring weld 4 are: the welding head speed is 1200-1500r / min, the welding speed is 0.2-0.3mm / r, and the shoulder pressure is 3-5kN.

[0026] The welding process parameters of the inner ring weld 3 are: the welding head speed is 1000-1300r / min, the welding speed is 0.15-0.25mm / r, and the shoulder pressure is 2.5-4kN.

[0027] The inner ring weld 3 welding adopts a gradually changing diameter welding needle, which can better adapt to the shape and thickness changes of the weld, improving the welding quality; the front end diameter of the welding needle is 3.5-4.5mm, and the rear end diameter is 5.8-7.8mm.

[0028] Both the outer ring weld 4 and the inner ring weld 3 use a static shoulder welding technology with retraction, and the shoulder retraction speed after welding is 5-8mm / min to avoid tail hole defects.

[0029] In S5, the pressure of the secondary rolling is 8-12kN.

[0030] In S2, when welding the longitudinal seam by friction stir welding, heat is generated between the high-speed rotating stirrer and the base material, making the base material reach a plastic state, and then the stirrer realizes welding under the extrusion action, which can obtain high-quality welds, and the strength of the welded longitudinal seam joint reaches more than 90% of the strength of the base material, effectively ensuring the overall strength of the rim.

[0031] In S2, the cylinder welded by longitudinal seam is cut into units, and then is rolled and formed by arrayed balls. In the rolling process, the balls apply uniform pressure to the cylinder according to specific trajectory and pressure, so that the cylinder is gradually deformed into the shape of the rim. This forming method can precisely control the wall thickness and roundness of the rim. After forming, the wall thickness deviation of the rim is controlled within 0.1 mm, and the roundness error is controlled within 0.2 mm, which greatly improves the dimensional accuracy and surface quality of the rim. Meanwhile, the rolling process of the balls can also make the metal structure of the rim more dense, further improving the strength and fatigue performance of the rim.

[0032] Specifically, the balls with a diameter of 10-12 mm are uniformly arranged at a certain interval to uniformly press the cylinder, so that the cylinder is gradually deformed into the shape of the rim. The rolling pressure is controlled within 10-122 kN, which can ensure the dimensional accuracy and surface quality of the rim.

[0033] In S2, the solid solution treatment temperature is 535℃, and the holding time is 2 hours; the aging treatment is carried out at 165℃ for 4 hours.

[0034] The above is only a preferred embodiment of the present application, and does not limit the technical scope of the present application. Any slight modification, equivalent change and modification made according to the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A split-type alloy wheel, characterized in that, include: The rim (1) has spokes (2) on one side; the rim (1) and spokes (2) are joined together by a two-stage stepped fit structure, and an inner annular weld (3) and an outer annular weld (4) are formed on the inner and outer sides of the joint respectively; the inner annular weld (3) and the outer annular weld (4) are both connected by friction stir welding.

2. A split-type alloy wheel according to claim 1, characterized in that, Both the rim (1) and the spokes (2) are made of high-strength lightweight alloy.

3. A split-type alloy wheel according to claim 2, characterized in that, The rim (1) is formed by spiral winding, friction stirring welding of longitudinal seams and array ball bearings from deformed aluminum alloy strip.

4. A split-type alloy wheel according to claim 2, characterized in that, The spokes (2) are made of cast aluminum alloy and formed by low-temperature low-pressure casting or liquid forging.

5. A split-type alloy wheel according to claim 1, characterized in that, The step height difference of the two-stage stepped mating structure is 2-3mm, and the surface roughness Ra of each step is ≤3.2μm.

6. A processing method for a split alloy wheel as described in claim 1, characterized in that, Includes the following steps: S1. Spoke manufacturing: formed by low-temperature and low-pressure casting or liquid forging process, and machined after T6 heat treatment; S2, Rim fabrication: S21, the aluminum alloy strip is spirally rolled into a cylinder, and the longitudinal seam is welded by friction stir; S22, the cylinder is cut into units and formed into a rim (1) shape by array ball rolling; S23, solution aging heat treatment is performed; S3. Assembly of rim and spokes: The rim (1) and spokes (2) are assembled in a high-precision positioning mold, and self-positioning is achieved by using a two-stage stepped fit structure; S4. Wheel rim and spoke welding: Friction stir welding is used to weld the outer circumferential weld (4) and the inner circumferential weld (3); S5. Subsequent treatment: Secondary rolling and shaping are performed to eliminate residual welding stress, followed by phosphating, electrophoresis and spraying surface treatment in sequence.

7. The processing technology of the split alloy wheel according to claim 6, characterized in that, In S1, the specific steps of the T6 heat treatment are as follows: first, solution treatment followed by water cooling, and then aging treatment; wherein, solution treatment: 535℃±5℃, holding for 4-7 hours, aging treatment: 160-165℃, holding for 4-8 hours.

8. The processing technology of the split alloy wheel according to claim 6, characterized in that, The welding process parameters for the outer annular weld (4) are: welding head rotation speed 1200-1500r / min, welding speed 0.2-0.3mm / r, and shoulder pressure 3-5kN.

9. The processing technology of the split alloy wheel according to claim 8, characterized in that, The welding process parameters for the inner annular weld (3) are: welding head rotation speed 1000-1300r / min, welding speed 0.15-0.25mm / r, and shoulder pressure 2.5-4kN.

10. The processing technology of the split alloy wheel according to claim 9, characterized in that, Both the outer annular weld (4) and the inner annular weld (3) adopt the pullback static shoulder welding technology. After welding, the shoulder pullback speed is 5-8 mm / min to avoid welding tail hole defects.

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