Heat treatment method of aluminum alloy wheel

Abstract

The invention discloses a heat treatment method for aluminum alloy wheels, which comprises the following steps: S1, mounting a plurality of wheels on a heat treatment frame, and respectively clamping the wheels into limiting notches corresponding to a pair of support rods in a radial vertical posture, so that the wheels are arranged at intervals; s2, stacking and fixing the heat treatment frames clamped with the wheels, and transferring the heat treatment frames to a solid solution furnace; s3, the whole stack of heat treatment frames are pushed into a solid solution furnace for heating and heat preservation, and solid solution treatment is completed; s4, the whole stack of heat treatment frames subjected to solid solution treatment are transferred out of the solid solution furnace and are integrally subjected to quenching cooling in the vertical direction; and S5, the wheel is taken down from the heat treatment frame, and aging treatment is conducted.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy wheel manufacturing technology, and more specifically, to a heat treatment method for aluminum alloy wheels. Background Technology

[0002] Aluminum alloy wheels play a crucial role in automotive lightweighting, and their mechanical properties are primarily achieved through solution treatment and aging. However, deformation during heat treatment is a key challenge restricting product precision and yield. Traditional mass heat treatment often involves horizontally stacking wheels on ordinary racks or pallets. This method has inherent drawbacks: the close contact between wheels severely hinders hot air circulation and the flow of quenching media, leading to uneven heating and cooling of the inner and outer walls, spokes, and rims, generating significant thermal stress; the wheels have extremely low strength at high temperatures, and when placed horizontally, their own weight easily causes plastic deformation such as spoke sagging, rim ellipticization, or planar warping. Therefore, the industry urgently needs a heat treatment method that can fundamentally improve the thermal and stress conditions, thereby suppressing deformation. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a heat treatment method for aluminum alloy wheels.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention discloses a heat treatment method for aluminum alloy wheels, comprising the following steps:

[0006] S1. Multiple wheels are installed in a heat treatment frame. The heat treatment frame includes frames arranged opposite each other, a connecting block connecting the two frames, and several support members installed in the lower frame. The support members include a pair of parallel support rods. The upper part of the support rods has several evenly distributed limiting notches for holding the wheel rims. The wheels are respectively inserted into the limiting notches corresponding to the pair of support rods in a radially vertical posture, so that the wheels are arranged at intervals.

[0007] S2. Stack and secure the heat treatment frames with the wheels clamped on, and transfer them to the solution furnace;

[0008] S3. Push the entire stack of heat treatment frames into the solution furnace for heating and heat preservation to complete the solution treatment;

[0009] S4. Transfer the entire stack of heat treatment frames that have completed solution treatment out of the solution furnace and perform vertical quenching and cooling as a whole;

[0010] S5. Remove the wheel from the heat treatment frame and perform aging treatment.

[0011] Furthermore, the support rod is provided with a laterally adjustable abutment block. In step S1, the position of the abutment block is adjusted according to the width of the wheel rim so that it contacts the wheel to form a clamp.

[0012] Furthermore, in step S2, the alignment and fixation between the upper and lower heat treatment frames are achieved through the cooperation of the positioning posts and positioning holes set on the heat treatment frame.

[0013] Furthermore, in step S3, convection heating is used in the solution furnace, and the dominant airflow direction is parallel to the vertical direction of the wheel.

[0014] Furthermore, in step S4, the quenching is either vertical immersion quenching or vertical spray quenching, and the dominant direction of the quenching medium flow is parallel to the wheel axle.

[0015] Furthermore, in step S4, the furnace door of the solution furnace is opened, and the time from when the heat treatment frame is transferred out of the solution furnace to when the quenching medium begins to contact the wheel does not exceed 15 seconds.

[0016] Furthermore, in step S1, the difference in wheel rim width between the wheels clamped on the same heat treatment frame is less than 2 mm.

[0017] Furthermore, the quenching medium is a water-based medium with the temperature controlled between 50℃ and 70℃.

[0018] The beneficial effects of this invention are: vertical placement combined with parallel airflow / liquid flow allows each wheel to obtain a nearly uniform heating and cooling environment as an independent unit, which greatly improves the uniformity and stability of wheel structure properties between the same batch and different batches, significantly reduces deformation and has low dispersion; the whole-stack processing maintains the efficiency of mass production; and the frame stacking and positioning design ensures the safety and stability of the transfer and processing process. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a structure of the aluminum alloy wheel heat treatment frame in this embodiment;

[0020] Figure 2 This is a front view of the aluminum alloy wheel heat treatment frame in this embodiment;

[0021] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0022] Figure 4 This is a cross-sectional view of the heat treatment frame for the aluminum alloy wheel in this embodiment;

[0023] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0024] Figure 6 This is a schematic diagram of one usage state of the aluminum alloy wheel heat treatment frame in this embodiment.

[0025] Reference numerals in the attached drawings: 1. Frame; 2. Connecting block; 3. Support component; 4. Support rod; 5. Limiting notch; 6. Positioning hole; 7. Mounting groove; 8. Receiving groove; 9. Moving block; 10. Abutting block; 11. Connecting rod; 12. Limiting block; 13. Limiting seat; 14. Limiting ring; 15. Adjusting sleeve; 16. Positioning post; 17. Fixing rod; 18. Moving groove; 19. Fixing groove two; 20. Fixing groove one; 21. Locking block; 22. Spacer block. Detailed Implementation

[0026] 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.

[0027] A heat-treated aluminum alloy wheel frame, such as Figures 1-5 As shown, the heat treatment frame includes two frames 1, arranged vertically opposite each other. Several connecting blocks 2 connect the two frames 1, with the connecting blocks 2 vertically positioned and their upper and lower ends connected to the upper and lower frames 1 respectively. The heat treatment frame also includes several support members 3, mounted on the lower frame 1. Each support member 3 includes two support rods 4, arranged parallel to each other. The two ends of each support rod 4 are fixed to the inner wall of the frame 1. Several limiting notches 5 are provided on the upper part of each support rod 4, evenly distributed along its length. The ends of the two support rods 4 with the limiting notches 5 are positioned opposite each other. An aluminum alloy wheel rests on the two support rods 4, which support the wheel, allowing it to be installed radially and vertically. This vertical installation ensures more uniform heating of the inner and outer walls and spokes of the wheel during heat treatment, reducing temperature differences and thus minimizing heat treatment deformation.

[0028] By setting a limiting notch 5, each wheel is placed in the corresponding limiting notch 5, thus separating the wheels and preventing them from being in contact during heat treatment, which would affect the heat treatment effect.

[0029] The support rod 4 includes several spacers 22, which are located between two adjacent limiting notches 5. Each spacer 22 has a receiving groove 8 at its lower part. The support rod 4 has an installation groove 7 inside, which is arranged along the length of the support rod 4. Several movable blocks 9 are arranged within the installation groove 7, and abutment blocks 10 are mounted on the upper part of each movable block 9. The abutment blocks 10 are located within the receiving groove 8 and can move along the installation groove 7. Connecting rods 11 connect the movable blocks 9. The support rod also includes an adjustment component, which can adjust the position of the movable blocks 9 within the installation groove 7 via the connecting rods 11. This allows a portion of the abutment block 10 to move from the receiving groove 8 to the limiting notch 5, thereby abutting against the side of the wheel. The other side of the wheel abuts against the side wall of the support rod 4 located at the limiting notch 5. Together, they clamp the wheel, effectively limiting its position. By adjusting the length of the abutment block 10 extending from the receiving groove 8, abutment processing for wheels of different widths can be achieved.

[0030] The adjustment assembly includes a limiting seat 13 and an adjusting sleeve 15. The limiting seat 13 is fixedly installed at the end of the support rod 4, and the adjusting sleeve 15 is rotatably disposed within the limiting seat 13. The limiting seat 13 can restrict the axial movement of the adjusting sleeve 15. The connecting rod 11 includes a threaded section, which is threadedly connected to the adjusting sleeve 15. By rotating the adjusting sleeve 15, the threaded engagement between the adjusting sleeve 15 and the connecting rod 11 drives the connecting rod 11 to move axially, thereby adjusting the position of the abutment block 10.

[0031] Furthermore, a limiting ring 14 is installed on the inner wall of the limiting seat 13, and an annular groove is opened on the outer wall of the adjusting sleeve 15. A part of the limiting ring 14 is located in the annular groove. The axial movement of the adjusting sleeve 15 is restricted by the limiting ring 14 without affecting the rotation of the adjusting sleeve 15.

[0032] Furthermore, one end of the connecting rod 11 extending out of the adjusting sleeve 15 is connected to a limiting block 12. The diameter of the limiting block 12 is larger than the inner diameter of the adjusting sleeve 15. The axial movement position of the connecting rod 11 is limited by the limiting block 12 to prevent the connecting rod 11 from moving excessively into the support rod 4.

[0033] like Figure 6 As shown, these processing frames can be stacked, allowing them to enter the heat treatment chamber simultaneously for heat treatment. To ensure the stability of the stacking, several positioning holes 6 are provided on the upper part of the upper frame 1, located at the four corners of the frame 1. Positioning components are provided on the lower part of the lower frame 1, which can be inserted into the positioning holes 6, thereby achieving relative fixation between the upper and lower processing frames and preventing offset between the two processing frames.

[0034] Furthermore, the positioning component includes a movable groove 18 formed on the frame 1, within which a positioning post 16 is installed. The positioning post 16 can move and rotate within the movable groove 18. The positioning component also includes a first fixing groove 20 and a second fixing groove 19, which are respectively connected to the movable groove 18. A fixing rod 17 is connected to the side of the positioning post 16. The height of the first fixing groove 20 is higher than that of the second fixing groove 19. When the fixing rod 17 is located within the first fixing groove 20, the entire positioning post 16 is located within the movable groove 18. When the fixing rod 17 is located within the second fixing groove 19, the lower end of the positioning post 16 extends out of the movable groove 18 and is inserted into the positioning hole 6 of the processing frame below. A locking block 21 is installed within the first fixing groove 20 and the second fixing groove 19. The locking block 21 can hold the fixing rod 17 placed in the first fixing groove 20 or the second fixing groove 19, preventing the positioning post 16 from deflecting.

[0035] A heat treatment method for aluminum alloy wheels includes the following steps: Step S1: Clamping, taking out the heat treatment frame, placing the wheels one by one, with the lower end of the wheel rim engaging a preset limiting notch 5, rotating the adjusting sleeve 15 at the end of the support rod, and moving the connecting rod 11 through threaded transmission, causing all moving blocks 9 and abutment blocks 10 to move synchronously. Stopping when the inner side of the abutment block 10 abuts against the side of the wheel, thus completing the fixing of the wheel.

[0036] Step S2: Stacking and Transfer. Stack the three clamped heat treatment frames. Rotate the positioning post 16 of the bottom frame so that its fixing rod 17 engages with the fixing slot 19, and the lower end of the positioning post retracts. Rotate the positioning posts of the middle and top frames so that their fixing rods 17 engage with the fixing slot 20, and the lower end of the positioning post extends out and accurately inserts into the positioning hole 6 on the bottom frame 1. Use a forklift to transfer the securely stacked three-layer frame to the solution furnace.

[0037] Step S3: Vertical homogenization and solution treatment. The entire stack of frames is pushed into a forced convection gas-fired solution treatment furnace preheated to 500℃. A high-temperature fan inside the furnace circulates the hot air primarily vertically. After heating to 540℃ at a rate of 1.5℃ / min, and based on the maximum wheel wall thickness of 25mm, it is held at that temperature for 4.5 hours. During this process, the temperature curves of all parts of the vertically spaced wheels are highly consistent.

[0038] Step S4: Rapid transfer and vertical quenching. After heat preservation, quickly open the furnace and transfer the entire stack of red-hot frames to the quenching tank within 12 seconds. The tank contains circulating, stirred water at a temperature controlled at 60±2℃. Immerse the frames vertically and uniformly into the water for a total immersion time of 3 minutes. During quenching, the water flow mainly washes along the wheel axis.

[0039] Step S5: Frame removal and aging. After quenching, remove the wheel from the frame, clean and dry it. Then, hold it in an aging furnace at 155℃ for 3 hours, and air cool it after removal from the furnace.

[0040] Testing revealed that wheels treated using this method had an average roundness error of 0.25 mm and an average flatness error of 0.30 mm. Compared to the traditional horizontal stacking heat treatment process, the deformation was reduced by approximately 65%, and the uniformity of hardness distribution (HRB standard deviation) was improved by 40%. This method fully leverages the advantages of a dedicated heat treatment frame, achieving high-quality anti-deformation heat treatment.

[0041] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A heat treatment method of an aluminum alloy wheel, characterized by, The method comprises the following steps: S1. A plurality of wheels are installed in a heat treatment frame, the heat treatment frame comprising upper and lower frames arranged opposite to each other, a connecting block connecting the two frames, and a plurality of support members installed on the lower frame, the support member comprising a pair of parallel support rods, a plurality of uniformly distributed limiting notches for clamping wheel rims being formed in the upper portions of the support rods; the wheels are clamped in the corresponding limiting notches of the pair of support rods in a radial vertical posture, so that the wheels are arranged in a spaced manner; S2. The heat treatment frame clamping the wheels is stacked and fixed, and is transported to a solid solution furnace; S3. The whole stack of heat treatment frames is pushed into the solid solution furnace for heating and holding, so that the solid solution treatment is completed; S4. The whole stack of heat treatment frames completing the solid solution is transferred out of the solid solution furnace and is subjected to vertical quenching cooling as a whole; S5. The wheels are taken off from the heat treatment frame and are subjected to aging treatment.

2. The heat treatment method of an aluminum alloy wheel according to claim 1, characterized by, The support rod is internally provided with a transversely adjustable abutting block, in step S1, the position of the abutting block is adjusted according to the width of the wheel rim, so that the abutting block is in contact with the wheel to form clamping.

3. The method of heat treating an aluminum alloy wheel of claim 1 wherein, In step S2, the alignment and fixation between the upper and lower heat treatment frames are realized through the cooperation of the positioning columns and the positioning holes arranged on the heat treatment frame.

4. The method of heat treating an aluminum alloy wheel of claim 1 wherein, In step S3, the solid solution furnace adopts convection heating, and the main direction of the airflow is parallel to the vertical direction of the wheels.

5. The method of heat treating an aluminum alloy wheel of claim 1 wherein, In step S4, the quenching is integral vertical immersion quenching or vertical direction spray quenching, and the main direction of the flow of the quenching medium is parallel to the wheel axis.

6. The method of heat treating an aluminum alloy wheel of claim 1 wherein, In step S4, the time from the opening of the furnace door of the solid solution furnace to the transfer of the heat treatment frame out of the solid solution furnace to the contact of the quenching medium with the wheels is not more than 15 seconds.

7. The method of heat treating an aluminum alloy wheel of claim 1 wherein, In step S1, the difference in the rim width of the wheels clamped on the same heat treatment frame is less than 2 mm.

8. The method of heat treating an aluminum alloy wheel of claim 1 wherein, The quenching medium is a water-based medium with a temperature controlled at 50-70°C.

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