Cold extrusion forming process and die for thin-wall pure aluminum camera shell

Abstract

According to the cold extrusion forming process and die for the thin-wall pure aluminum camera shell, a 1060 pure aluminum plate serves as a blank, surface pretreatment, first extrusion, annealing, surface retreatment and second extrusion are conducted in sequence, and finally a small amount of machining is conducted to obtain a finished product. According to different extrusion procedures, dies matched with the method are divided into a floating radial extrusion die and a floating combined extrusion die, and each of the floating radial extrusion die and the floating combined extrusion die comprises an upper die assembly, a middle floating die assembly and a lower die assembly; the floating radial extrusion die forms a radial extrusion cavity in the die assembly process, first-order extrusion is completed, and a radial extrusion forging stock is obtained; and the floating combined extrusion die forms a combined extrusion cavity in the die assembly process, two-order extrusion is completed, and a combined extrusion forging stock is obtained. Radial extrusion and combined extrusion share the same press frame, the die cost is remarkably reduced, and the die is suitable for large-scale production of thin-wall pure aluminum camera shells in multiple scenes such as vehicle-mounted scenes and security and protection scenes.

Description

Technical Field

[0001] The invention belongs to the technical field of metal plastic processing, and in particular relates to a cold extrusion forming process and a die for a thin-walled pure aluminum camera housing. Background Art

[0002] With the rapid development of intelligent driving, security surveillance, industrial automation, and consumer electronics, various camera types (including but not limited to automotive front-view and surround-view cameras, security domes, industrial cameras, and sports cameras) are evolving towards miniaturization, lightweighting, and high power density. These camera housings must not only possess excellent structural strength and strong pressure-retaining airtightness (high-end cameras are filled with dry nitrogen or argon to prevent lens mold and sensor oxidation), but must also maintain excellent performance in complex operating environments such as high temperature, vibration, rain, and snow.

[0003] A common camera housing structure is as follows Figure 1 As shown, the camera housing 100 is primarily composed of four parts: a large wing structure 101 with two mounting holes 106 and a central positioning hole 107; a small wing structure 102 with one mounting hole 106 and one positioning hole 107; a housing body 103 with snap-fit ​​features for storing PCBs; and a cylindrical structure 104 with a sealing ring groove and a wiring harness hole 105. The large wing structure 101 and the small wing structure 102 are positioned on opposite sides of the housing body 103. The cylindrical structure 104 protrudes from the back of the housing body 103. The wiring harness hole 105 on the cylindrical structure 104 extends through the cylindrical structure 104 and communicates with the inner cavity of the housing body 103.

[0004] Currently, the following methods can be used to form the camera housing: 1. Injection molding has the following defects: (1) The heat dissipation performance of the plastic shell cannot meet the requirements. When the power of the camera of an assisted intelligent driving car is high, a lot of heat will be generated. When the plastic parts wrap the lens and PCB board, it is easy to cause the temperature of the camera component to be too high, and the PCB board circuit is prone to problems; (2) Plastic parts will creep when they are subjected to strong air pressure for a long time, and their functionality will be reduced and cannot meet the requirements.

[0005] 2. Due to the characteristics of pressure casting itself, when the wall thickness of the part shell is 1.2mm, 30% of the cast parts cannot pass the airtight pressure holding performance test requirements, and there will be appearance defects in the thin-walled state, and the yield rate is only about 70%.

[0006] 3. Machining: Using block materials for machining, the material utilization rate is only 11.4%, and the processing time is 30 minutes. The machining efficiency is low, which is not conducive to reducing costs and cannot meet the needs of large-scale supply. In addition, the streamlines of the material itself will cause streamline fractures during the cutting process, which has a significant impact on the fatigue performance of the part itself.

[0007] Therefore, there is an urgent need for a camera housing forming process and supporting mold that has high material utilization, low machining allowance, can form thin walls in one near-net shape, and ensures airtightness. Summary of the Invention

[0008] The purpose of the present invention is to address the defects of the existing forming process and provide a cold extrusion forming process and mold for a thin-walled pure aluminum camera housing. With a small amount of mechanical processing, a high-precision thin-walled pure aluminum camera housing can be obtained, which significantly reduces production costs and improves processing efficiency, and is suitable for a variety of application scenarios.

[0009] In order to achieve the above-mentioned object, the first technical solution adopted by the present invention is: a cold extrusion forming process of a thin-walled pure aluminum camera housing, comprising the following steps: Step 1: Prepare a rectangular plate-shaped blank made of 1060 pure aluminum; Step 2: Surface pretreatment: After the obtained blank is subjected to quartz sand blasting treatment, it is subjected to phosphorus saponification film treatment; Step 3, Extrusion 1: The processed billet is subjected to radial extrusion forming to extrude the plate-shaped billet into a radially extruded forging billet with a large wing structure, a small wing structure, and a shell wall portion, wherein the large wing structure and the small wing structure of the radially extruded forging billet are connected to the outer side of the formed shell wall portion; Step 4, annealing: keeping the radial extrusion forging blank at 410°C ± 10°C for 4 hours, cooling it to 150°C in the furnace, and then taking it out of the furnace and air cooling it; Step 5: Surface re-treatment: polish the annealed radial extrusion forging blank to remove the burrs on the end surface, and perform sand blasting and phosphorus saponification film treatment; Step 6, Extrusion 2: Composite extrusion is performed on the radial extrusion forging blank after surface treatment. Based on the structure of the radial extrusion forging blank, a shell body with a square inner hole and a cylindrical structure are further formed to obtain a composite extrusion forging blank. Step 7: Machining: Machining the obtained composite extrusion forging billet to obtain a finished thin-walled pure aluminum camera housing.

[0010] Furthermore, in step seven, the machining locations are the snap-fit ​​features around the outer wall of the shell body, the two mounting holes and one positioning hole of the large wing structure, the one mounting hole and one positioning hole of the small wing structure, the sealing ring groove and the wiring harness through-hole features of the cylindrical structure.

[0011] The application further provides a second technical scheme: a cold extrusion forming die for a thin-wall pure aluminum camera shell, comprising: an upper die assembly, an intermediate floating die assembly and a lower die assembly; the upper die assembly, the intermediate floating die assembly and the lower die assembly are sequentially stacked and are slidably connected through a guide column-guide sleeve structure; the upper die assembly and the intermediate floating die assembly are connected through an equal-height screw, and an elastic element is further arranged between the upper die assembly and the intermediate floating die assembly; A male die capable of extending the upper concave die during the die closing process is arranged in the upper die assembly, and the upper concave die is arranged at the lower part of the intermediate floating die assembly. The lower die assembly is provided with a lower concave die and a ejector assembly for ejecting the forging blank from the lower concave die. According to different extrusion processes, the cold extrusion die comprises a floating radial extrusion die and a floating composite extrusion die, which are respectively used for the 1st extrusion and the 2nd extrusion. In the floating radial extrusion die, a radial extrusion cavity is formed by the male die, the upper concave die and the lower concave die during the die closing process, the outlet of the cavity is the flow space between the male die and the upper concave die and the lower concave die, and the radial extrusion cavity is used for forming a radial extrusion forging blank with a large wing structure, a small wing structure and a shell wall part connected with the two wing structures. In the floating composite extrusion die, a column forming hole is further arranged in the lower concave die cavity of the lower concave die, which is used for the material to flow into the column forming hole along the axial direction to form a cylindrical structure of the finished product part; a No. 3 ejector capable of being inserted into the lower end of the column forming hole is further arranged in the ejector assembly; a composite extrusion cavity is formed by the male die, the upper concave die, the lower concave die and the No. 3 ejector during the die closing process, the outlet of the cavity is the flow space between the male die, the upper concave die, the lower concave die and the No. 3 ejector, which is used for further forming a shell body with a square inner hole and a cylindrical structure on the basis of the radial extrusion forging blank to obtain a composite extrusion forging blank.

[0012] Further, the upper die assembly comprises an upper die plate, a male die sleeve, a male die, an elastic element and a first guide sleeve; the male die is press-fitted in the male die sleeve and extends downward out of the male die sleeve, the upper end surface of the male die sleeve is fastened and connected with the lower surface of the upper die plate through bolts; the first guide sleeve is arranged at the four corners of the upper die plate and can form a sliding pair with the first guide column of the lower die assembly; the elastic element comprises a ring-shaped elastic element and a nitrogen spring, the ring-shaped elastic element is sleeved on the lower part of the male die sleeve, and the nitrogen spring is fixed on the lower surface of the upper die plate.

[0013] Furthermore, the intermediate floating mold assembly includes an intermediate floating template, an upper die, an upper die middle ring, an upper die outer ring, a second guide pin, and contour screws; the upper die middle ring is shrink-fitted into the upper die outer ring, and the upper die is press-fitted into the upper die middle ring; the second guide pin is pressed into the lower end of the upper die outer ring and slidably cooperates with the second guide sleeve of the lower mold assembly; the contour screws limit the intermediate floating template and the upper template to control the maximum opening distance; The outer ring of the upper die is fastened to the lower surface of the intermediate floating die plate by bolts, and the punch passes through the intermediate floating die plate and is inserted into the die hole of the upper die; The four corners of the intermediate floating template are provided with first guide sleeves for forming a sliding pair with the first guide column of the lower die assembly.

[0014] Furthermore, the lower die assembly includes a lower template, a lower concave die outer ring, a lower concave die middle ring, a lower concave die, a die base and an ejector assembly; the lower concave die middle ring is heat-shrink-fitted into the lower concave die outer ring, and the lower concave die is press-fitted into the lower concave die middle ring; the die base is located below the lower concave die and the lower concave die middle ring, and is provided with a cavity for accommodating the ejector assembly and allowing the ejector assembly to move up and down, and the ejector in the ejector assembly passes upward out of the die base; the ejector assembly is driven by a lower ejector rod to eject the forging blank, and the ejector rod is arranged through the lower template; The four corners of the lower template are equipped with first guide pillars, which are slidably matched with the first guide sleeves of the middle floating mold assembly.

[0015] Furthermore, the ejector assembly includes an ejector fixing plate and an ejector pad stacked up together, wherein two ejector groups are installed on the ejector fixing plate, each ejector group includes multiple ejectors, and the two ejector groups are respectively used to push the wing structures on both sides of the radial extrusion forging billet or the compound extrusion forging billet formed on the lower die.

[0016] Furthermore, a guide pin is provided on the ejector fixing plate, and the upper end of the guide pin is slidably engaged with the guide hole in the mold base.

[0017] Furthermore, the floating composite extrusion die also includes a No. 3 ejector for pushing the cylindrical structure at the lower end of the composite extrusion forging blank formed on the lower die.

[0018] The key points of the technical solution of the present invention are: 1. The present invention combines floating radial extrusion and floating composite extrusion to achieve reasonable distribution of material flow in material extrusion sequence 1 and extrusion sequence 2. Floating radial extrusion is first performed to distribute the material, and then floating composite extrusion is performed to finally form the cylindrical part and the shell part of the material, which is beneficial to the plastic forming of the metal and increases the life of the mold.

[0019] 2. Changing the metal flow pattern during forging by using a two-step extrusion process: This part is characterized by the wing wall thickness (e.g., 3mm) being significantly thicker than the shell wall thickness (e.g., 1.2mm). Forming in one step would prevent material from flowing through, creating through cracks at the flow point and compromising the shell's sealing and pressure-maintaining performance. A two-step forming process, where the thick-walled wing structure is formed first and the thin-walled shell portion is formed next, can avoid the problem of through cracks.

[0020] 3. The concave cavity and cylindrical part of the product are formed through floating composite extrusion.

[0021] The beneficial effects of the present invention are: the process of the present invention can utilize the near-net-shape characteristics of the material to form a thin-walled pure aluminum camera back shell part with very high precision with a small amount of machining. The material utilization rate can reach 72%, and the component's requirements for airtightness and pressure maintenance performance can be maintained stably for a long time. The part itself has complete streamlines and good mechanical properties, which significantly reduces production costs and improves processing efficiency, and can meet the stringent requirements of multiple scenarios such as automotive, security, and industrial cameras. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of the camera housing processed by the present invention; Figure 2 This is a flow chart of the cold extrusion process described in Example 1; Figure 3 This is a cross-sectional view of the structure of the floating radial extrusion die used for extrusion sequence 1 in the cold extrusion forming die described in Example 2; Figure 4 This is a state diagram of the floating radial extrusion die for extrusion sequence 1 in the cold extrusion forming die described in Example 2 after the extrusion sequence 1 is completed; Figure 5 This is an axonometric view of the floating radial extrusion die used for extrusion sequence 1 in the cold extrusion forming die described in Example 2; Figure 6 Schematic diagram of the structure of the male die of the floating radial extrusion die in Example 2; Figure 7 Schematic diagram of the structure of the upper die of the floating radial extrusion die in Example 2; Figure 8 Schematic diagram of the structure of the lower concave die of the floating radial extrusion die in Example 2; Figure 9 Schematic diagram of the structure of the ejector assembly of the floating radial extrusion die in Example 2; Figure 10 Schematic diagram of the structure of ejector No. 1 of the floating radial extrusion die in Example 2; Figure 11 Schematic diagram of the structure of ejector No. 2 of the floating radial extrusion die in Example 2; Figure 12 Structure diagram of the die holder of the floating radial extrusion die in Example 2; Figure 13 Sectional view of the floating compound extrusion die for extrusion of the 2nd sequence in the cold extrusion forming die described in Example 3; Figure 14 Sectional view of the floating compound extrusion die for extrusion of the 2nd sequence in the cold extrusion forming die described in Example 3 from another perspective; Figure 15 Axonometric view of the floating compound extrusion die for extrusion of the 2nd sequence in the cold extrusion forming die described in Example 3; Figure 16 Structure diagram of the male die of the floating compound extrusion die in Example 3; Figure 17 Structure diagram of the upper female die of the floating compound extrusion die in Example 3; Figure 18 Structure diagram of the lower female die of the floating compound extrusion die in Example 3; Figure 19 Structure diagram of the ejector assembly of the floating compound extrusion die in Example 3; Figure 20 Structure diagram of the No. 3 ejector of the floating compound extrusion die in Example 3; Figure 21 Structure diagram of the die holder of the floating compound extrusion die in Example 3; Markings in the figure: 1, upper die plate, 2, upper backing plate, 3, male die sleeve, 4, male die, 401, male die groove, 5, annular elastic member, 6, intermediate floating die plate, 7, upper female die backing plate, 8, upper female die, 801, upper female die hole, 802, upper female die groove, 9, upper female die middle ring, 10, upper female die outer ring, 11, lower female die, 1101, lower female die cavity, 1102, lower female die groove, 1103, column forming hole, 12, lower female die middle ring, 13, lower female die outer ring, 14, No. 2 ejector, 15, No. 1 ejector, 16, ejector fixing plate, 17, ejector backing plate, 18, die holder, 19, die holder backing plate, 20, outer ring gasket, 21, ejector rod nut, 22, ejector rod, 23, lower die plate, 24, first guide column, 25, guide pin, 26, second guide sleeve, 27, second guide column, 28, first guide sleeve, 29, equal-height screw, 30, nitrogen gas spring, 31, nitrogen gas spring fixing seat, 32, No. 3 ejector; 100, camera housing, 101, large wing structure, 102, small wing structure, 103, housing body, 104, cylindrical structure, 105, wire harness via hole, 106, mounting hole, 107, positioning hole; 200, blank, 300, radial extrusion forged blank, 400, compound extrusion forged blank. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and examples, but they are not intended to limit the invention in any way.

[0024] Example 1 A cold extrusion forming process for a thin-walled pure aluminum camera housing comprises the following process steps: sheet metal blanking → sand blasting → film treatment → extrusion sequence 1 (radial extrusion forming) → annealing → deburring → sand blasting → film treatment → extrusion sequence 2 (compound extrusion forming) → machining.

[0025] The main steps in the above process can be found in the attached Figure 2 The specific steps are as follows: 1. Plate punching and blanking: The plate is 1060 pure aluminum plate, the plate specifications (width × height × length) are (26.9 ± 0.05) mm × (6.6 ± 0.03) mm × (1500 ± 10) mm, the specifications of the blank after punching are (26.9 ± 0.05) mm × (6.6 ± 0.05) mm × (29.9 ± 0.05) mm, the chamfers are 4 × R2.8 mm, and the weight is (14.2 ± 0.2) g; 2. Surface pretreatment: The blank is sandblasted with 120-mesh quartz sand for 10 minutes, followed by phosphorus saponification film treatment; 3. Extrusion process 1: Under the action of 70 tons forming force + 30 tons clamping force, the processed billet is subjected to radial extrusion forming, and the plate-shaped billet is extruded into a radial extrusion forging billet with a large wing structure, a small wing structure and a shell wall. The large wing structure and the small wing structure of the radial extrusion forging billet are connected to the outer side of the formed shell wall; 4. Annealing: keep the radial extrusion forging blank at 410°C ± 10°C for 4 hours, cool it to 150°C in the furnace, and then take it out of the furnace for air cooling; 5. Surface re-treatment: polish the annealed radial extrusion forging blank to remove the burrs on the end surface, and perform sandblasting with 120 mesh quartz sand for 10 minutes, followed by phosphorus saponification film treatment; 6. Extrusion process 2: Under the action of 60 tons of forming force + 30 tons of clamping force, the processed radial extrusion forging billet is subjected to composite extrusion. Under the premise that the large wing structure and the small wing structure remain in the formed state, the material mainly flows upward and downward along the axial direction, further forming the shell body with a square inner cavity and the cylindrical structure to obtain the composite extrusion forging billet; 7. Machining: The obtained composite extrusion forging billet is machined to the finished product requirements. The main processing parts are the four-sided snap-fit ​​features on the outer wall of the shell body, the two mounting holes and one positioning hole of the large wing structure, the one mounting hole and one positioning hole of the small wing structure, the sealing ring groove of the cylindrical structure and the wiring harness through-hole features.

[0026] The outer contour of the obtained thin-walled pure aluminum camera shell is 27mm×30mm×9.3mm. The thickness of the shell body is uniformly 1.2mm on all sides and at the bottom. The thickness of the two wing structures is 3mm. The transition radius of the connecting part between the wing structure and the shell body is R0.2-R0.3mm.

[0027] The present invention can utilize the near-net-shape characteristic of the material to form a camera rear shell part with very high precision with a small amount of machining. The material utilization rate can reach 72%, and the component's requirements for airtightness and pressure retention performance can be maintained stably for a long time. The part itself has complete streamlines and good mechanical properties, which significantly reduces production costs and improves processing efficiency.

[0028] Example 2 A cold extrusion forming die for a thin-walled pure aluminum camera housing, specifically a floating radial extrusion die used in the extrusion step 1 during the implementation of Example 1.

[0029] like Figures 3-12 As shown, the floating radial extrusion die adopts a three-layer structure of an upper die assembly-a middle floating die assembly-a lower die assembly.

[0030] 1. Upper mold assembly The upper die assembly includes: an upper die plate 1 , an upper backing plate 2 , a punch sleeve 3 , a punch 4 , an annular elastic member 5 , a first guide sleeve 28 , a nitrogen spring 30 and a nitrogen spring fixing seat 31 .

[0031] like Figure 3 As shown, the upper end of the punch 4 is forcibly installed in the punch sleeve 3, and the upper end surface of the punch 4 is pressed against the lower surface of the upper pad 2 in the punch sleeve 3; the punch sleeve 3 is in an inverted "convex" shape as a whole, and an annular elastic member 5 is installed at its lower end, and in the initial state, the lower end surface of the annular elastic member 5 exceeds the lower end surface of the punch sleeve 3; the upper end of the punch sleeve 3 is connected to the upper template 1 by a universal hexagon socket bolt; four first guide sleeves 28 are installed in the four corners of the upper template 1; there are four nitrogen springs 30, which are arranged in groups of two, and the two groups are arranged opposite to each other. The nitrogen springs 30 and the nitrogen spring fixing seat 31 are connected to the lower surface of the upper template 1 by ordinary hexagon socket bolts.

[0032] 2. Intermediate floating mold assembly The middle floating mold assembly includes: a middle floating template 6, an upper die pad 7, an upper die 8, an upper die middle ring 9, an upper die outer ring 10, a first guide sleeve 28 and a second guide column 27.

[0033] like Figure 3 、 5As shown, the upper die middle ring 9 is installed in the upper die outer ring 10 in the form of a shrink fit, and the upper die 8 is forcibly installed in the upper die middle ring 9. The upper die middle ring 9 and the upper die 8 are at the same height and lower than the height of the upper die outer ring 10. The lower end surfaces of the upper die middle ring 9 and the upper die 8 are flush with the lower end surface of the upper die outer ring 10. Therefore, the upper end surfaces of the upper die middle ring 9 and the upper die 8 and the inner wall of the upper die outer ring 10 form a groove for installing the upper die pad 7, and the upper die pad 7 is placed in the groove; Two second guide pillars 27 are provided, both of which are strongly pressed into the guide pillar holes on the lower end surface of the upper die outer ring 10 and extend downward; the intermediate floating template 6 is located above the upper die outer ring 10, and the intermediate floating template 6 and the upper die outer ring 10 are connected by hexagon socket bolts; a first guide sleeve 28 is installed in each of the four corners of the intermediate floating template 6, so the intermediate floating template 6 is equipped with a total of 4 first guide sleeves 28, and these 4 first guide sleeves 28 are aligned up and down with the 4 first guide sleeves 28 at the four corners of the upper template 1, and concentricity is ensured.

[0034] The intermediate floating mold assembly and the upper mold assembly are connected in position using four contour screws 29, which connect the upper mold plate 1 and the intermediate floating mold plate 6. Once connected, the lower ends of the annular elastic member 5 and nitrogen spring 30 engage with the intermediate floating mold plate 6. The upper punch 4 passes through the intermediate floating mold plate 6 and the upper die backing plate 6 and is inserted into the upper die 8. In the initial state of the mold, the lower end of the upper punch 4 is located within the upper die 8. During mold closing, the upper punch 4 moves downward and extends out of the upper die 8 to extrude the billet into shape.

[0035] like Figure 7 As shown, the center of the upper die 8 is provided with a square upper die hole 801 with chamfered corners. The upper die hole 801 is a through hole extending vertically to accommodate the upper punch 4. Therefore, its size and shape are consistent with the size and shape of the lower end of the upper punch 4, allowing the upper punch 4 to move up and down along the inner wall of the upper die hole 801. An upper groove 802 for forming the large wing structure and the small wing structure is provided on opposite sides of the lower end of the upper die hole 801.

[0036] 3. Lower mold assembly like Figure 3 As shown, the lower die assembly includes: a lower die 11, a lower die middle ring 12, a lower die outer ring 13, a No. 2 ejector 14, a No. 1 ejector 15, an ejector fixing plate 16, an ejector pad 17, a die base 18, a die base pad 19, an outer ring washer 20, a ejector nut 21, a ejector 22, a lower die plate 23, a first guide column 24, a guide pin 25, and a second guide sleeve 26.

[0037] The lower die center ring 12 is shrink-fitted into the lower die outer ring 13. The lower die 11 is forcefully pressed into the lower die center ring 12. The lower die 11, lower die center ring 12, and lower die outer ring 13 are of equal height, so that their upper and lower end surfaces remain flush after assembly. The second guide sleeve 26 is forcefully fitted into the upper end surface of the lower die outer ring 13 to form a sliding fit with the second guide post 27.

[0038] like Figure 8 As shown, a concave mold cavity 1101 is provided at the center of the upper end surface of the lower die 11. A lower groove 1102 for forming the large wing structure and the lower wing structure is provided on each of the left and right sides of the lower die cavity 1101. Two ejector holes are also provided at the bottom of the two lower grooves 1102, respectively, for an ejector to pass through the ejector holes from bottom to top to eject the formed forging billet out of the lower die 11. Therefore, a passage hole for accommodating the ejector is provided below the ejector holes. After the mold is assembled, the lower mold cavity 1101 is aligned with the upper die hole 801 of the upper die 8, and the lower groove 1102 is aligned with the upper groove 802.

[0039] The ejector in this embodiment includes ejector No. 1 15 and ejector No. 2 14 . The two ejector devices have essentially the same structure, differing in that the diameters of their upper ends are different, with the upper diameter of ejector No. 1 15 being smaller than that of ejector No. 2 14 . Ejector No. 1 15 and ejector No. 2 14 penetrate upward into ejector device fixing plate 16 . Ejector No. 1 15 and ejector No. 2 14 form a group, and two groups are provided on ejector device fixing plate 16 . These two groups of ejectors are used to support the large and small wing structures on both sides of the radially extruded forging blank 300 from below after extrusion forming is completed, ejecting the radially extruded forging blank 300 from the lower die 11 . Two guide pins 25 are also provided on ejector device fixing plate 16 .

[0040] Furthermore, the No. 1 ejector 15 and the No. 2 ejector 14 are both variable diameter rods, whose lower diameter is larger than the upper diameter, so that the lower larger diameter rod can provide support for the upper smaller diameter rod during the ejection process. Still further, the lower rods of the No. 1 ejector 15 and the No. 2 ejector 14 are cut into planes, and the No. 1 ejector 15 and the No. 2 ejector 14 in the same group support each other through the flat contact, and the distance between the two ejectors is reduced, making it easier to arrange the two ejectors in a smaller space.

[0041] The ejector fixing plate 16 on which the ejector No. 1 15, the ejector No. 2 14 and the guide pin 25 are installed and the ejector pad 17 located below the ejector fixing plate 16 are fastened together using hexagon socket bolts to form an ejector assembly.

[0042] The lower end of the die base 18 is provided with a housing for mounting the ejector assembly. The depth of the housing is greater than the sum of the heights of the ejector fixing plate 16 and the ejector pad 17, so as to allow for the ejector's travel. The die base 18 is provided with through holes for ejector No. 1 15, ejector No. 2 14, and guide pins 25 to pass through. Ejector No. 1 15 and ejector No. 2 14 extend through the upper end surface of the die base and are inserted into corresponding passage holes on the lower die. This allows the ejector assembly to be pushed upward, allowing ejector No. 1 15 and ejector No. 2 14 to push upward from the ejector holes of the lower die 11 to form the wing structures on both sides of the forged blank. During this process, the upper end of the guide pins 25 slides with the guide holes in the die base 18, providing guidance for the up and down movement of the ejector assembly.

[0043] The die base 18 is supported from below on a die base backing plate 19. Both the die base 18 and die base backing plate 19 are mounted within an outer ring washer 20. The outer ring washer 20 is positioned below the lower die outer ring 13, and its inner and outer diameters are equal to those of the lower die outer ring 13. Bolts securely connect the lower die outer ring 13, the outer ring washer 20, and the lower die plate 23 below. After being secured, the lower die 11 and the lower die middle ring 12 are supported on the upper end surface of the die base 18, with the lower die plate 23 supporting the entire lower die assembly. Four first guide posts 24 are mounted at the four corners of the lower die plate 23. The upper ends of the first guide posts 24 are slidably engaged with the first guide sleeves 28 of the intermediate floating die plate 6. A push rod mounting hole is provided in the center of the lower die plate 23. After the push rod 22 is inserted into the push rod nut 21, the entire lower die plate 23 is inserted into the push rod mounting hole. The push rod nut 21 is threadedly engaged with the push rod mounting hole, and the push rod 22 and the push rod nut 21 slidably engage. The ejector mounting hole is aligned and connected with the through hole on the die base pad 19, so that the ejector 22 can move upward under the action of external force to pass through the die base pad 19 to push the ejector assembly, so that the ejector is lifted upward to eject the extruded radial extrusion forging blank 300 out of the lower die 11.

[0044] The following is a detailed description of the working process of the floating radial extrusion die in the extrusion sequence 1.

[0045] Before the first extrusion sequence begins, the first guide pin 24 and first guide sleeve 28 align the lower die assembly, intermediate floating die assembly, and upper die assembly, ensuring concentricity and a sliding fit between the upper die assembly, the intermediate floating die assembly, and the upper die assembly. Once the upper and lower surfaces of the upper die assembly and the press's movable crossbar are in contact, they are securely connected using standard hexagon socket head cap bolts. The lower die assembly is bolted to the press's lower platen, and the ejector rod 22 is connected to the press's lower ejector cylinder.

[0046] The movable crossbeam of the press moves upward to drive the upper die assembly to move, and the upper die assembly drives the middle floating die assembly to move through the equal height screws 29. When the upper die assembly and the middle floating die assembly leave the lower die assembly for a certain distance as a whole, the rectangular blank 200 is placed in the lower concave die 11 of the lower die assembly. Figure 3 shown.

[0047] The movable crossbeam of the press drives the upper die assembly and the intermediate floating die assembly to press downward. When the upper die 8 contacts the lower die 11, a radial extrusion cavity is formed by the upper die hole 801, the upper groove 802, the lower concave model cavity 1101 and the lower groove 1102. The outlet of the cavity is the flow space between the punch 4 and the upper die 8 and the lower die 11. When the upper die assembly and the intermediate floating die assembly continue to move downward as a whole, the blank flows out from the flow space, forming a radial extrusion forging blank 300 with the shape of: a middle forging blank with a large wing structure, a small wing structure and a shell wall connected to the two wing structures, which is Figure 2 A radially extruded forging blank 300 is shown.

[0048] At the onset of radial extrusion, the lower end face of the punch 4 extends out of the upper die and contacts the upper end face of the blank 200. The upper end face of the lower die 11 also contacts the lower end face of the blank 200. As the press's movable crossbeam continuously moves downward, applying pressure to the upper die assembly, the upper die assembly pushes the intermediate floating die assembly downward through layer-by-layer pressure transmission. During the radial extrusion process, the annular elastic member 5 and nitrogen spring 30 push the intermediate floating die assembly tightly against the lower die assembly. These elastic members 5 and nitrogen spring 30 provide a strong clamping force, ensuring that the material flows within the specified flow space and preventing flash.

[0049] As the upper die assembly gradually moves downward until the lower surface of the punch sleeve 3 is in rigid contact with the upper surface of the intermediate floating template 6, the upper die assembly can no longer move downward. When the press reaches the set load, the radial extrusion is completed. Figure 4 shown.

[0050] After radial extrusion is complete, the movable crossbeam drives the upper die assembly upward in its return stroke. Simultaneously, the annular elastic member 5 and nitrogen spring 30 also recover upward. Once the upper die assembly reaches a certain position, the intermediate floating die assembly is driven upward again via the contour screws 29. The movable crossbeam continues to drive the upper die assembly upward. After reaching a certain distance, the press's movable crossbeam stops. At this point, the intermediate floating die assembly maintains a certain distance from the lower die assembly, facilitating removal of the radially extruded forging blank 300.

[0051] When taking out the radially extruded forging blank 300, the ejector cylinder under the press moves upward, thereby pushing the ejector rod 22 upward, and the ejector rod 22 pushes the die base pad 19 upward, and the die base pad 19 pushes the ejector device combination to drive the No. 2 ejector device 14 and the No. 1 ejector device 15 to move upward together, and the No. 2 ejector device 14 and the No. 1 ejector device 15 pass through the ejector hole of the lower die to push the radially extruded forging blank 300 in the lower die upward, thereby ejecting the radially extruded forging blank 300 out of the lower concave model cavity 1101, and finally taking the radially extruded forging blank 300 out of the lower concave die 11, completing the radial extrusion process, that is, extrusion sequence 1.

[0052] Example 3 A cold extrusion forming die for a thin-walled pure aluminum camera housing, specifically a floating composite extrusion die used in the extrusion step 2 during the implementation of Example 1.

[0053] like Figures 13-21 As shown, the floating composite extrusion die adopts a three-layer structure of an upper die assembly-a middle floating die assembly-a lower die assembly.

[0054] 1. Upper mold assembly like Figure 13 As shown, the upper die assembly includes: an upper die plate 1, an upper backing plate 2, a punch sleeve 3, a punch 4, an annular elastic member 5, a first guide sleeve 28, a nitrogen spring 30, and a nitrogen spring fixing seat 31. The structure of the upper die assembly and the connection relationship of each component are the same as those of the upper die assembly in Example 2. The difference is that the lower end surface of the punch 4 of the floating composite extrusion die in this embodiment is different from the lower end surface of the punch in Example 2, as shown in FIG. Figure 16 As shown, the lower end face of the punch 4 is provided with an inwardly concave punch groove 401. When the radially extruded forging blank 300 is subjected to floating composite extrusion, a small protrusion is formed on the radially extruded forging blank 300 at a position corresponding to the inner cavity of the shell body in the finished part. The protrusion corresponds to the cylindrical structure of the finished part, and the wiring harness through-hole of the cylindrical structure is machined at this location in subsequent machining.

[0055] 2. Intermediate floating mold assembly like Figure 13 As shown, the intermediate floating mold assembly includes: an intermediate floating mold plate 6, an upper die pad 7, an upper die 8, an upper die middle ring 9, an upper die outer ring 10, a first guide sleeve 28 and a second guide post 27. The structure of the intermediate floating mold assembly and the connection relationship of each component are the same as those of the intermediate floating mold assembly in Example 2. The difference is that, as shown in FIG. Figure 17 As shown, in this embodiment, a step structure is provided at the opening of the lower end of the upper die hole 801 of the upper die 8, which is used to form the edge of the shell body in the finished part.

[0056] 3. Lower mold assembly like Figure 3As shown, the lower die assembly includes: a lower die 11, a lower die middle ring 12, a lower die outer ring 13, a No. 2 ejector 14, a No. 1 ejector 15, an ejector fixing plate 16, an ejector pad 17, a die base 18, a die base pad 19, an outer ring washer 20, an ejector nut 21, an ejector 22, a lower die plate 23, a first guide post 24, a guide pin 25, a second guide sleeve 26, and a No. 3 ejector 32. The structure of the lower die assembly and the connection relationship between the various components are the same as those of the lower die assembly in Example 2. The difference is that: (1) If Figure 18 As shown, in the lower concave die 11, a cylindrical forming hole 1103 is provided at the bottom of the concave mold cavity 1101. The cylindrical forming hole 1103 is a through hole for material to flow into the cylindrical forming hole 1103 during the extrusion process to form the cylindrical structure of the finished part. In addition, compared to the lower concave die in Example 2, the lower grooves on both sides of the concave mold cavity in this embodiment have two ejector holes on one side and three ejector holes on the other side.

[0057] (2) If Figure 19 As shown, the ejector assembly of this embodiment also includes a No. 3 ejector 32. The installation method of the No. 3 ejector 32 is the same as that of other ejectors. The No. 3 ejector 32 is located below the columnar forming hole 1103 and is used to push the formed cylindrical structure, such as Figure 14 In addition, in the ejector group consisting of the No. 1 ejector 15 and the No. 2 ejector 14, one group includes one No. 1 ejector 15 and one No. 2 ejector 14, and the other group includes one No. 1 ejector 15 and two No. 2 ejectors 14, and the No. 1 ejector 15 is located between the two No. 2 ejectors 14.

[0058] (3) As the number and type of ejector combinations change, the arrangement of the holes on the die base 18 for ejector devices to pass through also changes, such as Figure 21 shown.

[0059] It should be noted that when a forging (radial extrusion forging blank 300, composite extrusion forging blank 400) is ejected using an ejector, traces of the ejector remain on the forging, affecting the appearance of the finished product. Therefore, in the design of the lower concave die 11 of Examples 2 and 3, the ejector holes in the lower recess 1102 are positioned at the mounting holes and locating holes on the two wing structures of the finished part. The ejector holes are slightly smaller than the mounting holes and locating holes. This allows the ejector traces to be removed after the mounting holes and locating holes are subsequently machined, without affecting the finished product's appearance.

[0060] The following is a detailed description of the working process of the floating composite extrusion die for the extrusion sequence 2.

[0061] Before the second extrusion sequence begins, the first guide pin 24 and first guide sleeve 28 align the lower die assembly, intermediate floating die assembly, and upper die assembly, ensuring concentricity and a sliding fit between the upper die assembly, the intermediate floating die assembly, and the upper die assembly. Once the upper and lower surfaces of the upper die assembly and the press's movable crossbar are in contact, they are securely connected using standard hexagon socket head cap bolts. The lower die assembly is bolted to the press's lower platen, and the ejector rod 22 is connected to the press's lower ejector cylinder.

[0062] The movable crossbeam of the press moves upward, driving the upper die assembly to move. The upper die assembly drives the intermediate floating die assembly to move via the equal height screws 30. When the upper die assembly and the intermediate floating die assembly leave the lower die assembly for a certain distance as a whole, the radial extruded forging blank 300 obtained by extrusion sequence 1 is placed into the lower concave die of the lower die assembly. The movable crossbeam of the press drives the upper die assembly and the intermediate floating die assembly to press downward together. When the upper concave die 8 contacts the lower concave die 11, a composite extrusion cavity is formed. The outlet of the cavity is the flow space between the punch 4 and the upper concave die 8, the lower concave die 11, and the No. 3 ejector 32. When the upper die assembly continues to move downward (i.e., the punch 4 moves downward), the material flows out of the flow space, forming Figure 2 The shape of the composite extrusion forging blank 400 is as follows: under the premise that the large wing structure and the small wing structure of the radial extrusion forging blank are kept in the formed state, the shell body with a square inner hole and the cylindrical structure are further formed, as shown in FIG. Figure 13 、 14 shown.

[0063] At the start of composite extrusion, the square end of the punch 4 extends out of the upper die 8 and contacts the upper end face of the radially extruded forging blank 300. The upper end face of the lower die 11 contacts the lower end face of the radially extruded forging blank 300. As the movable crossbeam of the press continuously moves downward to apply pressure to the upper die assembly, the upper die 4 pushes the intermediate floating die assembly downward through layer-by-layer pressure transmission. During the composite extrusion process, the annular elastic member 5 and nitrogen spring 30 push the intermediate floating die assembly tightly against the lower die assembly. During the floating composite extrusion process, the annular elastic member 5 and nitrogen spring 30 provide a strong clamping force to ensure that the material flows within the specific flow space and does not produce flash.

[0064] The upper die assembly gradually moves downward until the lower surface of the punch sleeve 3 is in rigid contact with the upper surface of the intermediate floating template 6. The upper die assembly can no longer move downward. When the press reaches the set load, the composite extrusion is completed.

[0065] After the completion of the composite extrusion, the movable cross beam drives the upper die assembly to move back and upward, and the annular elastic member 5 and the nitrogen spring 30 also recover upwardly. When reaching a certain position, the intermediate floating die assembly is driven to move upwardly again by the equal-height screw 29. At this time, the movable cross beam continuously drives the upper die assembly to move upwardly, and when moving to a certain distance, the press movable cross beam stops moving. At this time, the intermediate floating die assembly has a certain distance from the lower die assembly, which facilitates the removal of the composite extrusion billet 400.

[0066] When the composite extrusion billet 400 is removed, the lower ejecting oil cylinder of the press moves upwardly, thereby pushing the ejector rod 22 to move upwardly. The ejector rod 22 pushes the die pad 19 to move upwardly, and the die pad 19 pushes the ejector assembly to drive the No. 2 ejector 14, the No. 1 ejector 15 and the No. 3 ejector 32 to move upwardly together. The No. 2 ejector 14, the No. 1 ejector 15 and the No. 3 ejector 32 push the composite extrusion billet 400 to move upwardly, thereby ejecting the composite extrusion billet 400 from the lower concave die cavity 1101. Finally, the composite extrusion billet 400 is removed from the lower concave die 11, and the floating composite extrusion process, i.e. the extrusion 2 sequence, is completed.

[0067] The molds of example 2 and example 3 are respectively used to complete the extrusion 1 sequence and the extrusion 2 sequence, i.e. to complete the cycle of cold extrusion forming of the part once.

[0068] The above examples are only used to illustrate the technical solutions of the present application but not to limit it. It should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced by equivalents according to the above examples. Any modification or equivalent replacement without departing from the spirit and scope of the present application is within the protection scope of the claims.

Claims

1. A cold extrusion forming process for a thin-walled pure aluminum camera housing, characterized in that: The steps include: Step 1: Prepare a rectangular plate-shaped blank made of 1060 pure aluminum; Step 2: Surface pretreatment: After the obtained blank is subjected to quartz sand blasting treatment, it is subjected to phosphorus saponification film treatment; Step 3, extrusion sequence 1: radially extruding the processed billet to form a radially extruded forging billet (300) with a large wing structure (101), a small wing structure (102) and a shell wall portion, and the large wing structure (101) and the small wing structure (102) of the radially extruded forging billet (300) are connected to the outer side of the formed shell wall portion; Step 4, annealing: keeping the radial extrusion forging billet (300) at 410°C ± 10°C for 4 hours, cooling it to 150°C in the furnace, and then taking it out of the furnace and air cooling it; Step 5, surface reprocessing: polishing the annealed radial extrusion forging blank (300) to remove burrs on the end surface, and performing sand blasting and phosphorus saponification film treatment; Step 6, extrusion sequence 2: performing composite extrusion on the radial extrusion forging blank (300) after surface reprocessing, further forming a shell body (103) with a square inner hole and a cylindrical structure (104) based on the structure of the radial extrusion forging blank to obtain a composite extrusion forging blank (400); Step seven, machining: machining the obtained composite extrusion forging billet (400) to obtain a finished thin-walled pure aluminum camera housing.

2. The cold extrusion forming process according to claim 1, characterized in that: In step seven, the machining locations are the snap-fit ​​features around the outer wall of the shell body (103), the two mounting holes (106) and one positioning hole (107) of the large wing structure (101), one mounting hole (106) and one positioning hole (107) of the small wing structure (102), and the sealing ring groove and wiring harness through hole (105) features of the cylindrical structure (104).

3. A cold extrusion die for a thin-walled pure aluminum camera housing, characterized in that: include: An upper mold assembly, an intermediate floating mold assembly, and a lower mold assembly; the upper mold assembly, the intermediate floating mold assembly, and the lower mold assembly are stacked in sequence and slidingly matched through a guide column-guide sleeve structure; the upper mold assembly and the intermediate floating mold assembly are connected through equal height screws (29), and an elastic element is also provided between the upper mold assembly and the intermediate floating mold assembly; The upper mold assembly is provided with a male mold (4) capable of extending out of the upper female mold (8) during the mold closing process, and the upper female mold (8) is arranged at the lower part of the middle floating mold assembly; The lower die assembly is provided with a lower concave die (11) and an ejector assembly for ejecting the forging blank from the lower concave die (11); According to different extrusion processes, the cold extrusion die includes a floating radial extrusion die and a floating composite extrusion die, and the floating radial extrusion die and the floating composite extrusion die are respectively used for the first sequence extrusion and the second sequence extrusion as claimed in claim 1; In the floating radial extrusion die, a radial extrusion cavity is formed by the punch (4), the upper die (8), and the lower die (11) during the die closing process, and the outlet of the cavity is a flow space between the punch (4), the upper die (8), and the lower die (11), which is used to form a radial extrusion forging blank (300) with a large wing structure (101), a small wing structure (102), and a shell wall connected to the two wing structures; In the floating composite extrusion die, a cylindrical forming hole (1103) is further provided in the concave mold cavity (1101) of the lower concave die (11), for allowing material to flow axially into the cylindrical forming hole (1103) to form a cylindrical structure (104) of a finished part; a No. 3 ejector (32) capable of being inserted into the lower end of the cylindrical forming hole (1103) is further provided in the ejector assembly; during the mold closing process, a composite extrusion cavity is formed by the punch (4), the upper concave die (8), the lower concave die (11) and the No. 3 ejector (32), the outlet of which is a flow space between the punch (4) and the upper concave die (8), the lower concave die (11) and the No. 3 ejector (32), for further forming a shell body (103) with a square inner hole and a cylindrical structure (104) on the basis of radially extruding the forging blank, thereby obtaining a composite extrusion forging blank.

4. The cold extrusion die according to claim 3, characterized in that: The upper die assembly comprises an upper die plate (1), a punch sleeve (3), a punch (4), an elastic element and a first guide sleeve (28); the punch (4) is press-fitted into the punch sleeve (3) and extends downward from the punch sleeve (3); the upper end surface of the punch sleeve (3) is fastened to the lower surface of the upper die plate (1) by bolts; the first guide sleeve (28) is mounted on the four corners of the upper die plate (1) and can form a sliding pair with the first guide column (24) of the lower die assembly; the elastic element comprises an annular elastic member (5) and a nitrogen spring (30); the annular elastic member (5) is sleeved on the lower part of the punch sleeve (3), and the nitrogen spring (30) is fixed to the lower surface of the upper die plate (1).

5. The cold extrusion die according to claim 3, characterized in that: The intermediate floating mold assembly includes an intermediate floating template (6), an upper die (8), an upper die middle ring (9), an upper die outer ring (10), a second guide post (27) and an equal height screw (29); the upper die middle ring (9) is thermally sleeved into the upper die outer ring (10), and the upper die (8) is press-fitted into the upper die middle ring (9); the second guide post (27) is pressed into the lower end of the upper die outer ring (10) and slidably fits with the second guide sleeve (26) of the lower mold assembly; the equal height screw (29) limits the intermediate floating template (6) and the upper template (1) to control the maximum opening distance; The upper die outer ring (10) is fastened to the lower surface of the intermediate floating template (6) by bolts, and the punch (4) passes through the intermediate floating template (6) and is inserted into the upper die hole (801) of the upper die (8); The four corners of the intermediate floating template (6) are provided with first guide sleeves (28) for forming a sliding pair with the first guide column (24) of the lower mold assembly.

6. The cold extrusion die according to claim 3, characterized in that: The lower die assembly comprises a lower die plate (23), a lower die outer ring (13), a lower die middle ring (12), a lower die (11), a die base (18) and a ejector assembly; the lower die middle ring (12) is heat-fitted into the lower die outer ring (13), and the lower die (11) is press-fitted into the lower die middle ring (12); the die base (18) is located below the lower die (11) and the lower die middle ring (12), and is provided with a cavity for accommodating the ejector assembly and allowing the ejector assembly to move up and down, and the ejector in the ejector assembly passes through the die base (18) upward; the ejector assembly is driven by a lower ejector rod (22) to eject the forging blank, and the ejector rod (22) is arranged to pass through the lower die plate (23); First guide posts (24) are installed at the four corners of the lower template (23), and the first guide posts (24) are in sliding engagement with the first guide sleeves (28) of the intermediate floating mold assembly.

7. The cold extrusion die according to claim 6, characterized in that: The ejector assembly comprises an ejector fixing plate (16) and an ejector pad (17) stacked up together, wherein two ejector groups are mounted on the ejector fixing plate (16), each ejector group comprising a plurality of ejectors, and the two ejector groups are respectively used to push the wing structures on both sides of the radial extrusion forging blank (300) or the composite extrusion forging blank (400) formed on the lower die (11).

8. The cold extrusion die according to claim 7, characterized in that: A guide pin (25) is also provided on the ejector fixing plate (16), and the upper end of the guide pin (25) is slidably engaged with the guide hole in the mold base (18).

9. The cold extrusion die according to claim 6 or 7, characterized in that: The floating composite extrusion die also includes a No. 3 ejector (32) for pushing the cylindrical structure (104) at the lower end of the composite extrusion forging blank (400) formed on the lower concave die (11).

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