Aluminum alloy bicycle die casting heat treatment device and heat treatment method

Abstract

The application discloses an aluminum alloy bicycle die casting heat treatment device, which comprises a solid solution furnace, a cooling device, an aging furnace and a conveying frame, the conveying frame is used for placing aluminum alloy die castings and conveying the aluminum alloy die castings between the solid solution furnace, the cooling device and the aging furnace, and the conveying frame comprises a bottom frame, a supporting frame and supporting rods, the supporting frame comprises side frames, a center frame, connecting rods and positioning seats, one end of the connecting rod is rotatably installed on the side frame, and the opposite end is rotatably installed on the center frame. The application also discloses a heat treatment method of the aluminum alloy bicycle die castings. Compared with the prior art, the application effectively improves the heating speed and the cooling speed of the aluminum alloy bicycle die castings during heat treatment, and simultaneously improves the consistency of the heating and cooling speeds of multiple aluminum alloy die castings, thereby effectively improving the mechanical processing performance of the aluminum alloy die castings and improving the heat treatment effect.

Description

Technical Field

[0001] This invention relates to the field of bicycle die-casting parts manufacturing technology, and in particular to a heat treatment apparatus and method for aluminum alloy bicycle die-casting parts. Background Technology

[0002] Die casting is a type of pressure casting of parts. It is a process that uses a pressure casting machine equipped with a casting mold. The heated metal such as copper, zinc, aluminum or aluminum alloy is poured into the feed port of the die casting machine and then die-cast to produce copper, zinc, aluminum or aluminum alloy parts with shapes and sizes limited by the mold.

[0003] Heat treatment of aluminum alloy castings generally consists of two stages: solution treatment (quenching) and aging treatment. Solution treatment involves heating the aluminum alloy casting to a certain temperature and holding it at that temperature for a period of time, allowing the excess phase to fully dissolve into the solid solution, followed by rapid cooling to obtain a supersaturated solid solution. This process improves mechanical properties and enhances corrosion resistance. Aging treatment uses a higher aging temperature and a longer holding time to achieve maximum hardness and tensile strength, thus ensuring dimensional stability.

[0004] In existing heat treatment processes for aluminum alloy die castings, the heat treatment effect is adjusted only by changing the temperature and holding time of solution treatment and aging treatment, resulting in unsatisfactory heat treatment effects. Summary of the Invention

[0005] The purpose of this invention is to provide a heat treatment device and method for aluminum alloy bicycle die castings, which effectively improves the heating and cooling rates of aluminum alloy bicycle die castings during heat treatment, and at the same time improves the consistency of heating and cooling rates of multiple aluminum alloy die castings, thereby effectively improving the machinability of aluminum alloy die castings and enhancing the heat treatment effect.

[0006] To achieve the above objectives, in one respect, the present invention discloses a heat treatment apparatus for aluminum alloy bicycle die-cast parts, comprising:

[0007] Solution treatment furnace, used for solution treatment of aluminum alloy die castings;

[0008] A cooling device is used to rapidly cool aluminum alloy die castings after solution treatment, thereby achieving quenching of the aluminum alloy die castings.

[0009] An aging furnace is used to artificially age quenched aluminum alloy die castings.

[0010] The transport frame includes a bottom frame, a support frame, and support rods. It is used to place aluminum alloy die-cast parts and to transport them between solution furnaces, cooling devices, and aging furnaces. Two parallel limiting rods are provided on the bottom frame, and a baffle is provided on one side of the bottom frame, perpendicular to the bottom frame. The transport frame includes several parallel support frames, each comprising a side frame, a center frame, connecting rods, and positioning seats. Symmetrically arranged side frames are provided on both sides of the center frame. The side frames are connected to the center frame via connecting rods. One end of the connecting rod is rotatably mounted on the side frame, and the opposite end is rotatably mounted on the center frame. The center frame passes through the baffle, and the support rods pass through the support frames. The side frames are fixedly mounted on the support rods, and the bottom of the support rods is slidably connected to the limiting rods. The positioning seats are located on the connecting rods.

[0011] As a further description of the above technical solution:

[0012] The positioning seat is rotatably mounted on the connecting rod.

[0013] As a further description of the above technical solution:

[0014] A locking block is connected to one end of the center frame, and the locking block is connected to the center frame via a threaded rod.

[0015] As a further description of the above technical solution:

[0016] The locking block has a handle.

[0017] On the other hand, the present invention also discloses a heat treatment method based on the above-mentioned heat treatment device for aluminum alloy bicycle die castings, comprising the following steps:

[0018] S1. Place the aluminum alloy die casting on the transport rack and send the aluminum alloy die casting into the solution furnace for solution treatment.

[0019] S2. In the solution treatment furnace, the supporting frame of the transport rack is opened. When the aluminum alloy die casting is solution treated, it is heated to a temperature 30-120℃ lower than the solidus melting temperature of the die casting alloy, and the holding time is 3.0~10.0 min / mm of the maximum cross-sectional thickness t mm.

[0020] S3. After the solution treatment is completed, the transport frame is pushed out of the solution furnace. After the support frame on the transport frame is adjusted to the retracted state, it is pushed into the cooling device for quenching.

[0021] S4. The support frame of the transport frame is opened in the cooling device, and the aluminum alloy die casting is rapidly cooled in the cooling device by spraying cooling medium to achieve quenching.

[0022] S5. After quenching, push the transport frame out of the cooling device, adjust the supporting frame on the transport frame to the retracted state, and push it into the aging furnace for aging treatment.

[0023] S6. The support frame of the transport rack is opened in the aging furnace, and the aluminum alloy die casting is aged in the aging furnace.

[0024] S7. Aging treatment is completed. The transport frame is removed. The heat treatment process of the aluminum alloy die casting is completed.

[0025] As a further description of the above technical solution:

[0026] In step S4, after the aluminum alloy die-casting is cooled by spraying a cooling medium, it is dried in a cooling device by using an air knife.

[0027] As a further description of the above technical solution:

[0028] In step S6, when the aluminum alloy die casting is aged in the aging furnace, it first undergoes multiple short-term artificial aging processes. After each short-term artificial aging process, the part is removed from the furnace and air-cooled. After the last short-term artificial aging process, a long-term artificial aging process is performed.

[0029] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0030] 1. In this invention, when the transport frame conveys the aluminum alloy die castings into the solution furnace, cooling device, and aging furnace, it pushes the central frame and drives the side frames to move horizontally along the limiting rod via the connecting rod, thereby opening the supporting frame. This increases the spacing between the aluminum alloy die castings on the positioning seat. Whether the aluminum alloy die castings are heated inside the solution furnace or aging furnace, or cooled in the cooling device, each aluminum alloy die casting can have more sufficient contact with the heating or cooling medium. This effectively improves the heating and cooling rates of the aluminum alloy die castings, as well as the consistency of the heating / cooling speeds of multiple aluminum alloy die castings, thereby effectively improving the machinability of the aluminum alloy die castings and enhancing the heat treatment effect.

[0031] 2. In this invention, when the aluminum alloy die-casting is heated and cooled, the supporting frame is in an open state, allowing the die-castings to be dispersed for better contact with the heating / cooling medium, thus improving the heating and cooling rates. However, at this time, the spacing between the die-castings on the transport frame is large, and they are distributed along the edges, causing instability in the frame's center of gravity. This makes the frame prone to tipping over during movement, and the die-castings are susceptible to contact with external objects, resulting in collisions and damage. Therefore, during transport, the central frame can be pulled in the opposite direction, causing the supporting frame to retract and bringing the two positioning seats closer together. This retracts the die-castings onto the transport frame, placing them closer together and in the center, preventing the frame from tipping over. Furthermore, the bottom frame of the transport frame can be effectively utilized to protect the die-castings from external objects, preventing collision damage.

[0032] 3. In this invention, when the supporting frame changes from a contracted state to an open state, the connecting rod changes from an inclined state to a state perpendicular to the central frame. The connecting rod reduces the obstruction of several parallel through holes at the bottom of the positioning seat, allowing the aluminum alloy die-casting on the positioning seat to better contact the heating / cooling medium, effectively improving the heating and cooling speed of the aluminum alloy die-casting. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a side view structural diagram of the transport frame in a heat treatment device for die-cast aluminum alloy bicycle parts.

[0035] Figure 2 This is a top-view structural diagram of the transport frame in a heat treatment device for die-cast aluminum alloy bicycle parts.

[0036] Figure 3 This is a schematic diagram showing the state changes of a transport frame in a heat treatment device for die-cast aluminum alloy bicycle parts.

[0037] Legend:

[0038] 1. Transport frame; 11. Bottom frame; 111. Limiting rod; 12. Support frame; 121. Side frame; 122. Center frame; 123. Connecting rod; 124. Positioning seat; 13. Support rod; 14. Baffle; 15. Locking block; 151. Threaded rod; 152. Handle. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0041] Please see Figure 1-3 On one hand, the present invention discloses a heat treatment apparatus for die-cast aluminum alloy bicycle parts, including...

[0042] Solution treatment furnace, used for solution treatment of aluminum alloy die castings;

[0043] A cooling device is used to rapidly cool aluminum alloy die castings after solution treatment, thereby achieving quenching of the aluminum alloy die castings.

[0044] An aging furnace is used to artificially age quenched aluminum alloy die castings.

[0045] The transport frame 1 includes a bottom frame 11, a support frame 12, and support rods 13. The transport frame 1 is used to place aluminum alloy die-cast parts and to transport them between a solution furnace, a cooling device, and an aging furnace. Two parallel limiting rods 111 are provided on the bottom frame 11, and a baffle 14 is provided on one side of the bottom frame 11, perpendicular to the bottom frame 11. The transport frame 1 includes several parallel support frames 12, each including a side frame 121, a center frame 122, a connecting rod 123, and a positioning seat 12. 4. Symmetrically arranged side frames 121 are provided on both sides of the central frame 122. The side frames 121 are connected to the central frame 122 through the connecting rod 123. One end of the connecting rod 123 is rotatably mounted on the side frame 121, and the other end is rotatably mounted on the central frame 122. The central frame 122 passes through the baffle 14, and the support rod 13 passes through the supporting frame 12. The side frames 121 are fixedly mounted on the support rod 13. The bottom of the support rod 13 is slidably connected to the limiting rod 111, and the positioning seat 124 is set on the connecting rod 123.

[0046] The positioning seat 124 is rotatably mounted on the connecting rod 123 to reduce the inertia of the aluminum alloy die-casting on the positioning seat 124 during the process of supporting the frame 12 being opened, and to prevent the aluminum alloy die-casting from detaching from the positioning seat 124.

[0047] One end of the central frame 122 is connected to the locking block 15. The locking block 15 is connected to the central frame 122 through the threaded rod 151. The locking block 15 can be adjusted by rotating the threaded rod 151 to adjust the distance between the locking block 15 and the baffle 14 when the supporting frame 12 is fully opened, thereby controlling the opening angle of the supporting frame 12 and making it easier to control the supporting frame 12 to be opened in place.

[0048] The locking block 15 is provided with a handle 152 to facilitate pushing the locking block 15.

[0049] On the other hand, the present invention also discloses a heat treatment method based on the above-mentioned heat treatment device for aluminum alloy bicycle die castings, comprising the following steps:

[0050] S1. Place the aluminum alloy die casting on the transport frame 1, and send the aluminum alloy die casting into the solution furnace for solution treatment through the transport frame 1.

[0051] S2. Inside the solution furnace, expand the support frame 12 of the transport frame 1. See the attached diagram for the expanded state. Figure 2 When solution treatment is performed on aluminum alloy die castings, the temperature is heated to a range of 30-120℃ below the solidus melting temperature of the die casting alloy, and the holding time is 3.0~10.0 min / mm of the maximum cross-sectional thickness t mm.

[0052] S3. After the solution treatment is completed, remove the transport frame 1 from the solution furnace. After adjusting the support frame 12 on the transport frame 1 to the contracted state (see Appendix for the contracted state),... Figure 3 It is then pushed into the cooling device for quenching;

[0053] S4. The supporting frame 12 of the transport frame 1 is opened in the cooling device, and the aluminum alloy die casting is rapidly cooled in the cooling device by spraying cooling medium to achieve quenching.

[0054] S5. After quenching, push the transport frame 1 out of the cooling device, adjust the support frame 12 on the transport frame 1 to the retracted state, and push it into the aging furnace for aging treatment.

[0055] S6. The supporting frame 12 of the transport frame 1 is opened in the aging furnace, and the aluminum alloy die casting is aged in the aging furnace.

[0056] S7. Aging treatment completed, transport frame 1 removed, heat treatment process of aluminum alloy die casting completed.

[0057] In step S4, after the aluminum alloy die casting is cooled by spraying cooling medium, it is dried in the cooling device by air knife to remove the cooling medium remaining on the surface of the aluminum alloy die casting due to quenching and dry the surface of the aluminum alloy die casting.

[0058] In step S6, when the aluminum alloy die casting is aged in the aging furnace, it first undergoes multiple short-term artificial aging processes. The short-term artificial aging is performed with heating to 120℃~160℃ at a heating rate ≥20℃ / min and a holding time ≤60 minutes. After each short-term artificial aging, the part is removed from the furnace and air-cooled. After the final short-term artificial aging, a long-term artificial aging is performed with heating to 140℃-220℃ and a holding time of 6-26 hours. During the aging treatment of the aluminum alloy die casting, at least five short-term artificial aging processes are performed first, followed by the long-term artificial aging. During each short-term artificial aging process, the heating rate during the heating phase is maintained to obtain a temperature field opposite to that of the quenching process, thereby generating a stress field opposite to the quenched state. This stress field counteracts the original residual stress, effectively reducing the residual stress of the quenched aluminum alloy die casting, improving its machinability, and further enhancing the heat treatment effect.

[0059] Working principle: When the aluminum alloy die casting is heat treated, the aluminum alloy die casting is placed on the positioning seat 124 of each layer of the support frame 12 of the transport frame 1, and the aluminum alloy die casting is transported between the solution furnace, cooling device and aging furnace through the transport frame 1. When the transport frame 1 conveys the aluminum alloy die-cast parts into the solution furnace, cooling device, and aging furnace, it pushes the central frame 122, which in turn drives the side frame 121 to move horizontally along the limiting rod 111 via the connecting rod 123. Specifically, the side frame 121 moves by sliding the support rod 13 on the limiting rod 111, thus opening the supporting frame 12. This increases the spacing between the aluminum alloy die-cast parts on the positioning seat 124. Whether the aluminum alloy die-cast parts are heated inside the solution furnace or aging furnace, or cooled in the cooling device, each part can have more sufficient contact with the heating or cooling medium, effectively improving the heating and cooling rates, as well as the consistency of the heating / cooling speeds of multiple parts. This effectively improves the machinability and heat treatment effect of the aluminum alloy die-cast parts. When the supporting frame changes from a contracted state to an open state, the connecting rod 123 changes from an inclined state to a state perpendicular to the central frame 122. (See Appendix) Figure 2 It can be seen that the connecting rod 123 reduces the obstruction of several parallel through holes at the bottom of the positioning seat 124, allowing the aluminum alloy die casting on the positioning seat 124 to better contact the heating / cooling medium, effectively improving the heating and cooling speed of the aluminum alloy die casting.

[0060] When aluminum alloy die-castings are heated and cooled, the supporting frame 12 is in an open state, allowing the die-castings to be dispersed for better contact with the heating / cooling medium, thus improving the heating and cooling rates. However, the large spacing between the die-castings on the transport frame 1, located at its edges, makes the frame unstable and prone to tipping over during transport. This can cause the die-castings to collide with external objects, resulting in damage. Therefore, during transport, the central frame can be pulled in the opposite direction to retract the supporting frame 12, bringing the two positioning seats 124 closer together. This retracts the die-castings onto the transport frame 1, placing them closer together and at the center. This prevents the frame from tipping over and effectively utilizes the bottom frame to protect the die-castings from external objects, preventing collision damage.

[0061] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A heat treatment device for die-cast aluminum alloy bicycle parts, characterized in that, include Solution treatment furnace, used for solution treatment of aluminum alloy die castings; A cooling device is used to rapidly cool aluminum alloy die castings after solution treatment, thereby achieving quenching of the aluminum alloy die castings. An aging furnace is used to artificially age quenched aluminum alloy die castings. A transport frame (1) includes a bottom frame (11), a support frame (12), and a support rod (13). The transport frame (1) is used to place aluminum alloy die castings and to transport aluminum alloy die castings between a solution furnace, a cooling device, and an aging furnace. Two parallel limiting rods (111) are provided on the bottom frame (11). A baffle (14) is provided on one side of the bottom frame (11), and the baffle (14) is perpendicular to the bottom frame (11). The transport frame (1) includes several parallel support frames (12). Each support frame (12) includes a side frame (121), a center frame (122), a connecting rod (123), and a positioning seat (124). 22) The side frames (121) are symmetrically arranged on both sides. The side frames (121) are connected to the central frame (122) through the connecting rod (123). One end of the connecting rod (123) is rotatably mounted on the side frame (121), and the other end is rotatably mounted on the central frame (122). The central frame (122) passes through the baffle (14). The support rod (13) passes through the supporting frame (12). The side frames (121) are fixedly mounted on the support rod (13). The bottom of the support rod (13) is slidably connected to the limiting rod (111). The positioning seat (124) is set on the connecting rod (123). When the transport frame conveys the aluminum alloy die castings into the solution furnace, cooling device, and aging furnace, it pushes the central frame and drives the side frames to move horizontally along the limit rod through the connecting rod. The side frames move by sliding the support rod on the limit rod, thereby expanding the support frame and increasing the spacing between the aluminum alloy die castings on the positioning seat. When the supporting frame changes from a contracted state to an extended state, the connecting rod changes from an inclined state to a state perpendicular to the central frame. The connecting rod reduces the obstruction of several parallel through holes at the bottom of the positioning seat, allowing the aluminum alloy die casting on the positioning seat to have better contact with the heating / cooling medium, effectively improving the heating and cooling rates of the aluminum alloy die casting.

2. The heat treatment device for aluminum alloy bicycle die-casting parts according to claim 1, characterized in that, The positioning seat (124) is rotatably mounted on the connecting rod (123).

3. The heat treatment device for aluminum alloy bicycle die-casting parts according to claim 1, characterized in that, One end of the central frame (122) is connected to a locking block (15), and the locking block (15) is connected to the central frame (122) via a threaded rod (151).

4. The heat treatment device for aluminum alloy bicycle die-casting parts according to claim 3, characterized in that, The locking block (15) is provided with a handle (152).

5. A heat treatment method based on the heat treatment apparatus for aluminum alloy bicycle die castings according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Place the aluminum alloy die casting on the transport frame (1) and send the aluminum alloy die casting into the solution furnace for solution treatment through the transport frame (1); S2. In the solution furnace, the support frame (12) of the transport frame (1) is opened. When the aluminum alloy die casting is solution treated, it is heated to a temperature range of 30-120℃ lower than the solidus melting temperature of the die casting alloy. The holding time is the maximum cross-sectional thickness tmm×3.0~10.0min / mm. S3. After the solution treatment is completed, the transport frame (1) is pushed out of the solution furnace, the support frame (12) on the transport frame (1) is adjusted to the retracted state, and then pushed into the cooling device for quenching. S4. The support frame (12) of the transport frame (1) is opened in the cooling device, and the aluminum alloy die casting is rapidly cooled in the cooling device by spraying cooling medium to achieve quenching. S5. After quenching, push the transport frame (1) out of the cooling device, adjust the support frame (12) on the transport frame (1) to the retracted state, and push it into the aging furnace for aging treatment. S6. The support frame (12) of the transport frame (1) is opened in the aging furnace, and the aluminum alloy die casting is aged in the aging furnace. S7. After the aging treatment is completed, the transport frame (1) is removed, and the heat treatment process of the aluminum alloy die casting is completed.

6. The heat treatment method for an aluminum alloy bicycle die-casting part according to claim 5, characterized in that, In step S4, after the aluminum alloy die casting is cooled by spraying a cooling medium, it is dried in a cooling device by using an air knife.

7. The heat treatment method for an aluminum alloy bicycle die-casting part according to claim 5, characterized in that, In step S6, when the aluminum alloy die casting is aged in the aging furnace, it first undergoes multiple short-term artificial aging processes. After each short-term artificial aging process, the part is removed from the furnace and air-cooled. After the last short-term artificial aging process, a long-term artificial aging process is performed.

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