Aluminum alloy shell extrusion die and forming method for electric vehicles

Abstract

The present invention relates to the technical field of aluminum alloy extrusion dies, and specifically discloses an aluminum alloy shell extrusion die and a molding method for electric vehicles, wherein the extrusion die comprises an upper die, a middle die and a pre-pressing mechanism, wherein the upper die is provided with a diversion cavity and a die core, the middle die comprises a welding chamber and an outer cavity, the die core extends into the outer cavity to form a main cavity; the pre-pressing mechanism comprises a connecting plate, a locking frame, a pre-pressing core, a pre-pressing spring and a pre-pressing guide column, the connecting plate is fixedly connected to the bottom of the middle die, and the pre-pressing guide column is fixedly arranged on the surface of the connecting plate; the locking frame is locked with the connecting plate through a locking block, the pre-pressing spring is arranged between the locking frame and the pre-pressing core, and the pre-pressing core has a pre-pressing head matching the main cavity. The present invention can ensure that the front and rear parts of the extruded aluminum material have uniform dimensions, stable quality, and improved yield rate.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy extrusion dies, and in particular to an aluminum alloy shell extrusion die and a molding method dedicated to electric vehicles. Background Art

[0002] Extrusion dies are widely used in the molding of building profiles. With the promotion of aluminum alloy applications in the industrial field, more and more industrial structures and parts are formed by aluminum alloy extrusion. Different from traditional building profiles, industrial profiles have more complex structures and higher dimensional requirements. After extrusion molding, the profiles are prone to bending due to uneven stress and other reasons, and cannot meet the process requirements.

[0003] The aluminum alloy shell for electric vehicles is used to protect the battery and other components inside the vehicle. In order to improve its strength, a box structure is generally provided. In order to save space, a triangular structure is provided on one side of the box structure, which cooperates with the box structure to further improve the structural strength while leaving a space for accommodation through the inner inclined surface. The front end of the box structure is provided with a connection part connected to other parts of the electric vehicle, and the thickness of the connection part is generally 3 times that of other areas. The existing aluminum alloy shell for electric vehicles is generally formed by casting, but the casting efficiency is low, the strength is low, and the production cost is high. Therefore, some manufacturers began to consider using extrusion molding. However, the above structure is an asymmetric frame structure. During the extrusion molding process, it is easy to cause extrusion defects due to different flow rates in various parts. Especially in the early stage of extrusion, the front end of the extruded profile is particularly deformed due to the failure of the welding chamber and the working belt of the extrusion die to establish a stable pressure. The above deformation will also affect the subsequent extrusion, resulting in the front end of the extruded aluminum material being bent and unable to meet the industrial requirements. The product yield is low, the dimensional accuracy cannot be guaranteed, and the unqualified parts can only be cut and re-cast as waste, wasting energy. Summary of the invention

[0004] In order to solve the defects of the prior art, the present invention provides an aluminum alloy shell extrusion die and a forming method for electric vehicles, which can ensure that the front and rear parts of the extruded aluminum material have uniform dimensions, stable quality, and improved yield rate.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides an aluminum alloy shell extrusion die for electric vehicles, comprising an upper die, a middle die and a pre-stressing mechanism, wherein the upper die is provided with a diversion cavity and a die core, the middle die comprises a welding chamber and an outer cavity, the die core extends into the outer cavity to form a main cavity; the pre-stressing mechanism comprises a connecting plate, a locking frame, a pre-stressing core, a pre-stressing spring and a pre-stressing guide column, the connecting plate is fixedly connected to the bottom of the middle die, the pre-stressing guide column is fixedly arranged on the surface of the connecting plate, the locking frame and the pre-stressing core are sequentially arranged on the pre-stressing guide column and can slide along the pre-stressing guide column; the locking frame is locked with the connecting plate by a locking block, the pre-stressing spring is arranged between the locking frame and the pre-stressing core, the pre-stressing core has a pre-stressing head matching the main cavity, and the pre-stressing head can extend into the main cavity; the locking block is connected with the unlocking block, and when the pre-stressing core moves to a predetermined position, it can push the unlocking block, drive the locking block to swing, and unlock the locking frame from the connecting plate.

[0006] As an improvement of the above scheme, the main mold cavity includes a rectangular frame molding cavity, a triangular frame molding cavity and a connecting end molding cavity, wherein the triangular frame molding cavity is arranged on one side of the rectangular frame molding cavity, and the connecting end molding cavity is located at the end of the rectangular frame molding cavity; both the rectangular frame molding cavity and the triangular frame molding cavity are provided with a partition molding cavity; the width of the connecting end molding cavity is more than twice that of the rectangular frame molding cavity and the triangular frame molding cavity.

[0007] As an improvement of the above-mentioned solution, a hinge seat is also provided on the connecting plate, and the locking block is arranged on the hinge seat, including a tension rod and a locking protrusion. The locking protrusion is arranged on one side of the tension rod, and the locking protrusion has a locking surface. When the tension rod is parallel to the pre-stressing guide column, the locking surface abuts against the bottom surface of the locking frame.

[0008] As an improvement of the above scheme, the unlocking block is arranged at the front end of the tension rod and has an unlocking inclined surface extending toward the pre-stressing core; when the pre-stressing core moves to a predetermined position, it contacts the unlocking inclined surface, pushing the tension rod to swing outward, and the locking protrusion disengages from the connecting plate.

[0009] As an improvement of the above solution, a guide plate is provided at the bottom of the pre-stressing core, a guide sleeve is provided on the guide plate, the guide sleeve is sleeved on the pre-stressing guide column, and the end of the pre-stressing guide column is an open end.

[0010] As an improvement of the above solution, the center of the connecting plate and the locking frame are both provided with an avoidance hole allowing the pre-pressing head to pass through.

[0011] As an improvement of the above solution, the connecting plate is provided with connecting holes, and the connecting holes are used for fixed connection with the middle mold by bolts.

[0012] Accordingly, an embodiment of the present invention further provides an extrusion molding method for an aluminum alloy shell for electric vehicles, characterized in that the aluminum alloy shell extrusion die for electric vehicles as described above is used, and the method comprises the following steps:

[0013] S1. The upper die, the middle die and the pre-pressing mechanism are assembled into a complete die and installed in an extruder; the pre-pressing head of the pre-pressing mechanism is located in the main cavity of the die;

[0014] S2, start the extruder, the semi-solid aluminum enters the main cavity and contacts the surface of the pre-pressing head, and gradually increases the pressure while pushing the pre-pressing head; the pre-pressing spring stores elastic potential energy;

[0015] S3, the semi-solid aluminum pushes the pre-pressing head to the main cavity outlet, the pre-pressing core pushes the unlocking block, and the locking block unlocks the locking frame; the locking frame accelerates in the direction away from the connecting plate under the tension of the spring, and finally pushes the pre-pressing core away from the pre-pressing guide column;

[0016] S4. The extruder continues to work to complete the extrusion molding of the aluminum alloy shell for electric vehicles.

[0017] Implementing the embodiments of the present invention has the following beneficial effects:

[0018] The above extrusion die and forming method can make the main cavity of aluminum material uniformly filled and form the same pressure in the initial stage of aluminum material extrusion, so that the working belts of different forming areas can quickly play the function of controlling the extrusion speed of aluminum material in the corresponding area, ensure the uniform size of the front and rear parts of the extruded aluminum material, stable quality, and improve the yield rate. The above structure can be directly applied to the existing extruder without high-cost modification, which is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of an aluminum alloy shell extrusion die for electric vehicles of the present invention;

[0020] Figure 2 is a cross-sectional view of an upper mold and a middle mold of the present invention;

[0021] Figure 3 It is a structural schematic diagram of the diversion cavity of the upper mold of the present invention;

[0022] Figure 4 It is a structural schematic diagram of the assembly state of the upper mold and the middle mold of the present invention;

[0023] Figure 5 It is a structural schematic diagram of the main cavity of the present invention;

[0024] Figure 6 It is a structural schematic diagram of the pre-pressing mechanism of the present invention;

[0025] Figure 7 is a structural schematic diagram of the pre-pressing mechanism of the present invention from another perspective;

[0026] Figure 8 yes Figure 6 A magnified view of part A;

[0027] Fig. 9 It is a structural schematic diagram of the extrusion die of the present invention in an initial extrusion state;

[0028] Fig.10 It is a schematic structural diagram of the extrusion die of the present invention when the pre-compression core begins to contact the unlocking block during the extrusion process. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby stated that the directional terms such as up, down, left, right, front, back, inside, outside, etc. that appear or will appear in the text of the present invention are only based on the accompanying drawings of the present invention, and are not specific limitations of the present invention.

[0030] like Figure 1-Figure 7 As shown, a specific embodiment of the present invention provides an aluminum alloy shell extrusion die for electric vehicles, including an upper die 1, a middle die 2 and a pre-pressing mechanism 3, wherein the upper die 1 is provided with a diversion cavity 11 and a die core 12, the middle die 2 includes a welding chamber 21 and an outer cavity 22, the die core 12 extends into the outer cavity 22 to form a main cavity 23; the pre-pressing mechanism 3 includes a connecting plate 31, a locking frame 32, a pre-pressing core 33, a pre-pressing spring 34 and a pre-pressing guide column 35, the connecting plate 31 is fixedly connected to the bottom of the middle die 2, the pre-pressing guide column 35 is fixedly arranged on the surface of the connecting plate 31, the locking frame 32 and the pre-pressing core 33 are fixedly connected to the bottom of the middle die 2, the pre-pressing guide column 35 is fixedly arranged on the surface of the connecting plate 31, and the locking frame 32 and the pre-pressing core 33 are fixedly connected to the bottom of the middle die 2. 3 are sequentially arranged on the pre-stressing guide pillar 35 and can slide along the pre-stressing guide pillar 35; the locking frame 32 is locked with the connecting plate 31 through the locking block 36, and the pre-stressing spring 34 is arranged between the locking frame 32 and the pre-stressing core 33. The pre-stressing core 33 has a pre-stressing head 331 matching the main cavity 23, and the pre-stressing head 331 can extend into the main cavity 23; the locking block 36 is connected with the unlocking block 37. When the pre-stressing core 33 moves to a predetermined position, it can push the unlocking block 37 to drive the locking block 36 to swing, so that the locking frame 32 is unlocked from the connecting plate 31.

[0031] Among them, Figure 5As shown, the main cavity 23 includes a rectangular frame molding cavity 231, a triangular frame molding cavity 232 and a connecting end molding cavity 233, wherein the triangular frame molding cavity 232 is arranged on one side of the rectangular frame molding cavity 231, and the connecting end molding cavity 233 is located at the end of the rectangular frame molding cavity 231; both the rectangular frame molding cavity 231 and the triangular frame molding cavity 232 are provided with a partition molding cavity 234; the width of the connecting end molding cavity 233 is more than twice that of the rectangular frame molding cavity 231 and the triangular frame molding cavity 232.

[0032] Combination Figure 8 As shown, in order to reliably fix or unlock the locking frame 32, a hinge seat 38 is also provided on the connecting plate 31, and the locking block 36 is arranged on the hinge seat 38, including a tension rod 361 and a locking protrusion 362. The locking protrusion 362 is arranged on one side of the tension rod 361, and the locking protrusion 362 has a locking surface 363. When the tension rod 361 is parallel to the pre-stressing guide column 35, the locking surface 363 abuts against the bottom surface of the locking frame 32.

[0033] The unlocking block 37 is arranged at the front end of the tension rod 361 and has an unlocking inclined surface 371 extending toward the pre-stressing core 33; when the pre-stressing core 33 moves to a predetermined position, it contacts the unlocking inclined surface 371, pushing the tension rod 361 to swing outward, and the locking protrusion 362 disengages from the locking frame 32.

[0034] A guide plate 332 is provided at the bottom of the pre-pressing core 33, and a guide sleeve 333 is provided on the guide plate 332. The guide sleeve 333 is sleeved on the pre-pressing guide pillar 35, and the end of the pre-pressing guide pillar 35 is an open end. The center of the connecting plate 31 and the locking frame 32 are both provided with an avoidance hole 39 that allows the pre-pressing head 331 to pass through. The connecting plate 31 is provided with a connecting hole 311, and the connecting hole 311 is used to be fixedly connected to the middle mold 2 by bolts.

[0035] Accordingly, an embodiment of the present invention further provides an extrusion molding method for an aluminum alloy shell for electric vehicles, which uses the aluminum alloy shell extrusion die for electric vehicles as described above, and comprises the following steps:

[0036] S1, the upper mold 1, the middle mold 2 and the pre-pressing mechanism 3 are assembled into a complete mold and installed in an extruder; the pre-pressing head 331 of the pre-pressing mechanism 3 is located in the main mold cavity 23 of the mold;

[0037] At this time, the tension rod 361 is kept perpendicular to the connecting plate 31 , and the locking surface 363 of the locking protrusion 362 abuts against the bottom surface of the connecting plate 31 , and cooperates with the pre-compression guide column 35 to fix the locking frame 32 on the connecting plate 31 .

[0038] S2, start the extruder, such as Fig. 9 As shown, the semi-solid aluminum 100 enters the main cavity 23 and contacts the surface of the pre-pressing head 331, and gradually increases the pressure while pushing the pre-pressing head 331; the pre-pressing spring 34 stores elastic potential energy; when the semi-solid aluminum contacts the surface of the pre-pressing head 331, the part with a faster flow rate will first fill the main cavity 23. Since the flow of the semi-solid aluminum in the main cavity 23 is blocked, it will slowly accumulate in the main cavity 23. In addition, since the surface of the pre-pressing head 331 is a plane, it can ensure that the aluminum material can be extruded synchronously under the same pressure. Working belts 235 are provided on both sides of the main cavity 23. Under the guidance of the working belts 235, the semi-solid aluminum establishes a stable extrusion rate to avoid the excessive extrusion rate due to the excessive width of the connecting end molding cavity 233 of the main cavity 23, causing a shortage of material in this area, while the width of the partition molding cavity 234 is narrow and the two ends are in contact with the triangular frame molding cavity 232 or the rectangular frame molding cavity 231, and the flow rate is too slow, resulting in excessive molding pressure and bending defects after extrusion.

[0039] S3, such as Fig.10 As shown, the semi-solid aluminum pushes the pre-stressing head 331 to the outlet of the main cavity 23, and the pre-stressing core 33 pushes the unlocking block 37, and the locking block 36 unlocks the locking frame 32; the locking frame 32 accelerates in the direction away from the connecting plate 31 under the action of the spring tension, and finally pushes the pre-stressing core 33 to disengage from the pre-stressing guide column 35.

[0040] The action here is particularly important, because when the aluminum material passes through the exit of the main cavity 23, if the above-mentioned pre-stressing core 33 still exists, the newly formed aluminum material will be crushed. The locking frame 32 is designed as a hollow frame in the middle to control its mass. The mass of the locking frame 32 is about one-sixth of the mass of the pre-stressing core 33. Although the spring accumulates a large amount of energy in the previous step, when the locking frame 32 is unlocked and accelerates in the direction away from the connecting plate 31, and finally pushes the pre-stressing core 33 away from the pre-stressing guide column 35, according to the law of conservation of momentum, the speed of the locking frame 32 and the pre-stressing core 33 is only one-seventh of the maximum speed of the locking frame 32, which not only ensures that the locking frame 32 and the pre-stressing core 33 can autonomously detach from the pre-stressing guide column 35, but also prevents the locking frame 32 and the pre-stressing core 33 from flying out at a faster speed and causing damage to the on-site operators or equipment.

[0041] S4. The extruder continues to work to complete the extrusion molding of the aluminum alloy shell for electric vehicles.

[0042] By using the above extrusion die and forming method, the aluminum material can be uniformly filled in the main cavity 23 and form the same pressure at the initial stage of extrusion, so that the working belts of different forming areas can quickly establish the function of controlling the extrusion speed of the aluminum material in the corresponding area, and ensure that the front and rear parts of the extruded aluminum material have uniform dimensions, stable quality, and improved yield. The above structure can be directly applied to the existing extruder without high-cost modification, which is easy to promote.

[0043] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A special aluminum alloy shell extrusion die for electric vehicles, characterized in that: Including upper die, middle die and pre-pressing mechanism, The upper mold is provided with a diversion cavity and a mold core, the middle mold includes a welding chamber and an outer mold cavity, and the mold core extends into the outer mold cavity to form a main mold cavity; The pre-stressing mechanism comprises a connecting plate, a locking frame, a pre-stressing core, a pre-stressing spring and a pre-stressing guide column, wherein the connecting plate is fixedly connected to the bottom of the middle mold, the pre-stressing guide column is fixedly arranged on the surface of the connecting plate, and the locking frame and the pre-stressing core are arranged on the pre-stressing guide column in sequence and can slide along the pre-stressing guide column; The locking frame is locked with the connecting plate through a locking block, the pre-pressing spring is arranged between the locking frame and the pre-pressing core, the pre-pressing core has a pre-pressing head matching the main cavity, and the pre-pressing head can extend into the main cavity; The locking block is connected to the unlocking block. When the pre-pressing core moves to a predetermined position, it can push the unlocking block, drive the locking block to swing, and unlock the locking frame and the connecting plate. The connecting plate is also provided with an articulated seat, the locking block is arranged on the articulated seat, and comprises a tension rod and a locking protrusion, the locking protrusion is arranged on one side of the tension rod, and the locking protrusion has a locking surface, when the tension rod is parallel to the pre-stressing guide column, the locking surface abuts against the bottom surface of the locking frame; The unlocking block is arranged at the front end of the tension rod and has an unlocking inclined surface extending toward the pre-stressing core; when the pre-stressing core moves to a predetermined position, it contacts the unlocking inclined surface, pushes the tension rod to swing outward, and the locking protrusion is disengaged from the connecting plate.

2. The aluminum alloy shell extrusion die for electric vehicles as claimed in claim 1, characterized in that: The main mold cavity includes a rectangular frame molding cavity, a triangular frame molding cavity and a connecting end molding cavity, wherein the triangular frame molding cavity is arranged on one side of the rectangular frame molding cavity, and the connecting end molding cavity is located at the end of the rectangular frame molding cavity; both the rectangular frame molding cavity and the triangular frame molding cavity are provided with a partition molding cavity; the width of the connecting end molding cavity is greater than twice the width of the rectangular frame molding cavity, and greater than twice the width of the triangular frame molding cavity.

3. The aluminum alloy shell extrusion die for electric vehicles as claimed in claim 1, characterized in that: A guide plate is provided at the bottom of the pre-stressing core, a guide sleeve is provided on the guide plate, and the guide sleeve is sleeved on the pre-stressing guide column, and the end of the pre-stressing guide column is an open end.

4. The aluminum alloy shell extrusion die for electric vehicles as claimed in claim 1, characterized in that: The centers of the connecting plate and the locking frame are both provided with avoidance holes for allowing the pre-pressing head to pass through.

5. The aluminum alloy shell extrusion die for electric vehicles as claimed in claim 1, characterized in that: The connecting plate is provided with connecting holes, and the connecting holes are used for fixed connection with the middle mold through bolts.

6. A method for extruding an aluminum alloy shell for electric vehicles, characterized in that: Using the aluminum alloy shell extrusion die for electric vehicles as described in any one of claims 1 to 5 comprises the following steps: S1. The upper die, the middle die and the pre-pressing mechanism are assembled into a complete die and installed in an extruder; the pre-pressing head of the pre-pressing mechanism is located in the main cavity of the die; S2, start the extruder, the semi-solid aluminum enters the main cavity and contacts the surface of the pre-pressing head, and gradually increases the pressure while pushing the pre-pressing head; the pre-pressing spring stores elastic potential energy; S3, the semi-solid aluminum pushes the pre-pressing head to the main cavity outlet, the pre-pressing core pushes the unlocking block, and the locking block unlocks the locking frame; the locking frame accelerates in the direction away from the connecting plate under the action of the spring tension, and finally pushes the pre-pressing core away from the pre-pressing guide column; S4. The extruder continues to work to complete the extrusion molding of the aluminum alloy shell for electric vehicles.

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