Aluminum profile hot extrusion cooling forming device and forming method

Abstract

The invention relates to the field of aluminum profile extrusion forming, and particularly discloses an aluminum profile hot extrusion cooling forming device and method.The aluminum profile hot extrusion cooling forming device comprises a machine body, a cooling box, a mold and a mold cushion, a vent groove is formed in the end, close to the mold, of the mold cushion, and a main cooling runner communicating with the vent groove is formed in the circumferential wall of the mold cushion; the machine body is provided with a nozzle which is matched with the main cooling flow channel and is connected with a cooling source, and the machine body is further provided with a transition mechanism which is arranged between the machine body and the cooling box and is used for carrying out isolation protection on an aluminum profile; and the guide mechanism is used for guiding gas sprayed out of the vent groove. The cooling device has the effects that the die cushion and the lower die are cooled on the premise that the strength of a working belt is ensured, and the upper die is also efficiently cooled in the gap of blank replacement of the machine body.

Description

Technical Field

[0001] This application relates to the field of aluminum profile extrusion forming, and in particular to an aluminum profile hot extrusion cooling forming apparatus and forming method. Background Technology

[0002] Hot extrusion of aluminum profiles is a core forming process in which heated aluminum alloy ingots (billets) are forced through a die orifice of a specific shape under high pressure to obtain profiles with the desired cross-sectional shape.

[0003] The hot extrusion process for aluminum profiles typically involves heating the billet to 450-520℃ (the specific temperature depends on the billet type), heating the die to 400-520℃, installing the die in the appropriate position on the machine body, placing the billet inside the extrusion cylinder, and using the thrust of the extrusion shaft to form an extruded product corresponding to the die. Finally, the extruded product is transported to a cooling box for water or air cooling. During the extrusion process, the billet experiences intense friction as it passes through the die, causing a rapid increase in the temperature of the die's working zone. The die is continuously subjected to high temperature and high pressure, resulting in significant elasticity of the billet and consequently, larger errors in the extruded product. Therefore, in producing high-quality aluminum profiles, it is usually necessary to cool the die to maintain its temperature within a specific range.

[0004] The related patent CN119281851A proposes a cooling mechanism for an aluminum profile extrusion molding die, including a front die (upper die) and a rear die (lower die). The rear die includes an inner module, an outer module, and a spacer block. The inner module is provided with a welding chamber and a working belt. The inner module is connected to a water cooling mechanism, which includes a first cooling channel located on the rear side of the welding chamber and surrounding the outside of the working belt. The spacer block is connected to an air cooling mechanism, which includes a second cooling channel. The air cooling mechanism forms an air insulation layer within the spacer block through the second cooling channel.

[0005] Regarding the aforementioned technologies, the inventors believe that the following defects exist: while improving the heat dissipation performance of the lower mold by setting a water cooling mechanism inside the lower mold, the working belt is one of the weakest links in the mold. Opening a channel inside the lower mold will reduce the strength of the lower mold and easily lead to the breakage of the working belt. Summary of the Invention

[0006] To address the problem of difficulty in cooling the mold while ensuring its strength, this application provides an aluminum profile hot extrusion cooling forming apparatus and forming method.

[0007] The technical solution provided in this application for an aluminum profile hot extrusion cooling forming apparatus and forming method is as follows: A hot extrusion cooling forming apparatus for aluminum profiles includes a machine body, a cooling box, a mold, and a mold pad. A venting groove is formed at one end of the mold pad near the mold. A main cooling channel communicating with the venting groove is formed on the peripheral wall of the mold pad. The machine body is provided with nozzles adapted to the main cooling channel and connected to a cooling source. The machine body also includes: a transition mechanism, located between the machine body and the cooling box, for isolating and protecting the aluminum profile; and a guiding mechanism for guiding the gas ejected from the venting groove.

[0008] Optionally, the guiding mechanism includes a guide tube fixed to the mold pad, the guide tube covering the ventilation groove, a gap between the end of the guide tube away from the mold and the mold pad, and a guide groove between the side of the guide tube near the axis of the mold pad and the mold pad.

[0009] Optionally, the groove wall on the side of the guide groove near the axis of the mold pad is stepped.

[0010] Optionally, the end of the guide tube near the mold is flared.

[0011] Optionally, a pressure-boosting ring is fixedly connected to the end of the guide tube away from the mold.

[0012] Optionally, the inner peripheral wall of the mold pad has multiple auxiliary grooves.

[0013] Optionally, a secondary cooling channel is formed on the peripheral wall of the mold pad, which is connected to the main cooling channel, and the main cooling channel merges into the secondary cooling channel at an acute angle.

[0014] Optionally, the transition mechanism includes an isolation cover and a control component. The two ends of the isolation cover are respectively connected to the outlet of the cooling box and the discharge port of the machine body. The control component is used to adjust the connection state between the isolation cover and the machine body.

[0015] A method for hot extrusion and cooling forming of aluminum profiles includes the following steps: S1. Heating of billet and mold: Heating the billet to above its recrystallization temperature and simultaneously heating the mold; S2. Mold and mold pad assembly: Assemble the mold pad and mold onto the machine body in sequence; S3. Hot extrusion: The billet is placed in the extrusion cylinder of the machine body, and the extrusion shaft of the machine body extrudes the billet to form an extruded product; S4. Quenching of extruded products: Initial cooling and strong cooling of extruded products; S5. Material Change: After one billet is extruded, a new billet is placed in the extrusion cylinder of the machine body.

[0016] In summary, this application includes at least one of the following beneficial technical effects: 1. When the machine body is in the process of extruding and molding the billet, the guiding mechanism guides the nitrogen in the ventilation groove to the lower die, so that the nitrogen exchanges heat with the outlet belt, the rear air blade and the working belt in sequence. That is, the lower die is cooled in a gradient from low to high from the end closer to the die pad to the end farther away from the die pad, so as to avoid the fragile working belt being directly subjected to strong cooling and breaking. Then, due to the obstruction of the working belt and the extruded product, the nitrogen flows out along the extruded product to the transition mechanism, so that the transition mechanism forms a positive pressure and is filled with nitrogen to protect the extruded product with nitrogen and pre-cool it. Since no modification is made to the die, the strength of the die is ensured. 2. Nitrogen gas entering the venting groove is blocked by the guide tube, allowing it to be distributed more evenly throughout the venting groove. It is then ejected from the gap between the guide tube and the mold pad. Due to the Coanda effect, the high-speed ejected nitrogen gas adheres tightly to the wall of the guide tube, forming a thin nitrogen layer. It then enters the outlet zone through the guide groove. Furthermore, the chamfers on the lower mold effectively reduce turbulence, causing most of the nitrogen gas flowing towards the working zone to move along the inner wall of the lower mold, thus providing sufficient and even cooling for the lower mold. 3. When the machine body is in the process of changing blanks, the mold is in a through state because there is no blank. At this time, high-pressure, high-speed airflow enters the secondary cooling channel. This airflow mixes initially with the liquid nitrogen in the main cooling channel. Then, the mixed airflow enters the venting groove, mixes evenly, and is evenly distributed throughout the venting groove. It is then ejected from the gap between the guide tube and the mold pad. At this time, due to the influence of the high-pressure airflow, the flow velocity of the mixed airflow is relatively high. This high-speed mixed airflow, through Bernoulli's principle, introduces, accelerates, and amplifies the air outside the machine body to form a stable and powerful cooling airflow, which effectively cools the lower and upper molds. Furthermore, since the cooling airflow is mostly air with a small amount of nitrogen, and after uniform mixing, the temperature difference between the cooling airflow and the high-temperature mold core is reduced. That is, by increasing the flow velocity and using a suitable temperature cooling airflow, the upper mold is cooled to avoid the upper mold, especially the mold core, from generating huge stress due to direct contact with low-temperature nitrogen. 4. Due to the obstruction between the working belt and the extruded product, the nitrogen gas flows back along the extruded product. Because the auxiliary groove expands the space between the die pad and the extruded product, when the nitrogen gas returns to the die pad after cooling the working belt, the nitrogen gas flow rate is slower and the degree of contact between the nitrogen gas and the extruded product is smaller. The auxiliary groove effectively increases the space for the nitrogen gas to exit the die pad, making it easier for the nitrogen gas to pass through the die pad until the nitrogen gas enters the isolation cover, so that the extruded product is protected by nitrogen gas before entering the cooling box for strong cooling. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2This is a cross-sectional structural diagram used in this application to show the body, cooling box, upper mold, lower mold, mold pad and transition mechanism; Figure 3 This is a schematic diagram of the overall structure of the mold, mold pad, and nozzle used in this application; Figure 4 This application is for demonstration purposes. Figure 3 A schematic diagram of the cross-sectional structure; Figure 5 yes Figure 4 An enlarged schematic diagram of part A in the middle; Figure 6 Based on Figure 4 A schematic diagram of the planar sectional structure; Figure 7 This is a structural schematic diagram used in this application to illustrate the transition mechanism.

[0018] Reference numerals: 11. Body; 12. Cooling box; 2. Mold; 21. Upper mold; 211. Mold core; 22. Lower mold; 221. Welding chamber; 222. Working belt; 223. Rear air cutter; 224. Exit belt; 3. Mold pad; 31. Vent groove; 32. Main cooling channel; 33. Nozzle; 34. Auxiliary groove; 35. Secondary cooling channel; 4. Transition mechanism; 41. Isolation cover; 42. Control component; 421. Baffle; 422. Hydraulic cylinder; 5. Guide mechanism; 51. Guide tube; 511. Pressure boosting ring; 52. Guide groove. Detailed Implementation

[0019] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail.

[0020] Example 1

[0021] This application discloses an apparatus for hot extrusion cooling forming of aluminum profiles. (Refer to...) Figures 1-5The aluminum profile hot extrusion cooling forming device includes a machine body 11, a cooling box 12, a mold 2, and a mold pad 3. The mold 2 is divided into an upper mold 21 and a lower mold 22 in the direction of billet extrusion. The upper mold 21 includes a mold core 211. The lower mold 22 consists of a welding chamber 221, a working belt 222, a rear air cutter 223, and an exit belt 224 along the direction of billet extrusion. The mold core 211 extends to the rear air cutter 223. The mold pad 3 has a ventilation groove 31 at one end near the mold 2. The mold pad 3 has a main cooling channel 32 connected to the ventilation groove 31 on its peripheral wall. The machine body 11 is equipped with a nozzle 33 that is adapted to the main cooling channel 32 and connected to a cooling source. The cooling source can be a liquid nitrogen tank containing liquid nitrogen. Liquid nitrogen cooling is a mature application method in aluminum profile hot extrusion and causes less damage to the mold 2 and the mold pad 3. It will not be elaborated further here. The cooling box 12 can be a water-cooled box or an air-cooled box. The water-cooled box can be either a spray-type water-cooled box or an immersion-type water-cooled box, depending on the requirements of the billet. Multiple temperature sensors are installed on the machine body 11. In this application, infrared thermometers are installed at both the inlet and outlet ends of the machine body 11 to monitor the temperature of the material entering and leaving the machine body 11 in real time. Multiple thermocouple thermometers are also installed inside the machine body 11. At least one thermocouple thermometer corresponds to each of the upper mold 21, lower mold 22, and mold pad 3. The nozzle 33 and all temperature sensors on the machine body 11 are electrically connected to the built-in control system of the machine body 11, thereby controlling the opening and closing of the nozzle 33 and the flow rate through the temperature of the mold 2, mold pad 3, and billet. The machine body 11 also includes: a transition mechanism 4, located between the machine body 11 and the cooling box 12, used for isolating and protecting the aluminum profile; and a guide mechanism 5, used to guide the gas ejected from the ventilation groove 31.

[0022] When the machine body 11 is in the process of extruding and molding the billet, the liquid nitrogen sprayed from the nozzle 33 enters the main cooling channel 32. The nozzle 33 can spray liquid nitrogen continuously, intermittently, or in a pulse, preferably in an intermittent or pulse manner. The high temperature of the mold pad 3 quickly vaporizes the liquid nitrogen and increases the air pressure in the main cooling channel 32, so that the venting groove 31 is mainly filled with low-temperature nitrogen. At the same time, the nitrogen in the venting groove 31 is guided to the lower mold 22 by the guide mechanism 5, so that the nitrogen exchanges heat with the outlet belt 224, the rear air cutter 223, and the working belt 222 in sequence. That is, the lower mold 22 is cooled in a gradient from low to high from the end closer to the mold pad 3 to the end farther away from the mold pad 3, so as to avoid the relatively fragile working belt 222 being directly subjected to strong cooling and breaking. During this process, the mold pad 3 and the lower mold 22 are cooled well, especially the working strip 222, which is difficult to cool, is also cooled precisely. No modification is required on the mold 2, which effectively ensures the strength of the working strip 222, reduces elasticity, and thus ensures the stability of the profile and improves the accuracy of the profile.

[0023] Then, due to the obstruction of the working belt 222 and the extruded product, the nitrogen gas flows out along the extruded product into the transition mechanism 4, creating positive pressure and filling the transition mechanism 4 with nitrogen. During this process, the nitrogen gas has already exchanged heat with the die pad 3 and the die 2, resulting in a relatively high nitrogen temperature. Although it still cools the extruded product, the degree of cooling is limited. Because the temperature of the extruded product rises sharply during the extrusion molding process, causing its temperature to far exceed its critical quenching temperature, the nitrogen gas at this point pre-cools the extruded product before quenching. The pre-cooling is relatively minor, and an infrared thermometer maintains the temperature of the extruded product above the critical quenching temperature. Simultaneously, the nitrogen gas in the transition mechanism 4 effectively reduces the degree of oxidation of the extruded product before quenching.

[0024] When the machine body 11 is in the process of changing to a new blank, the mold 2 is in a through state because there is no blank. At this time, the nitrogen gas reaches the working zone 222 and continues to move forward and flows out from the upper mold 21, thereby cooling the upper mold 21. Moreover, during the entire operation of the machine body 11, the cooling time of the working zone 222, the rear empty blade 223, and the exit zone 224 in the lower mold 22 is relatively long, while the cooling time of the welding chamber 221 and the upper mold 21 is relatively short. This is to avoid the welding chamber 221 being too cold, which would cause uneven metal flow and result in defects such as linear or striped unwelded interfaces inside the aluminum profile and stripes on the surface.

[0025] Reference Figure 4 , Figure 5 and Figure 6 The guiding mechanism 5 includes a guide tube 51 fixed to the mold pad 3. The guide tube 51 and the mold pad 3 are manufactured separately and connected to each other by welding. The guide tube 51 covers the ventilation groove 31. There is a gap of 0.4-0.8mm between the end of the guide tube 51 away from the mold 2 and the mold pad 3. The specific thickness depends on the actual working conditions. There is a guide groove 52 between the side of the guide tube 51 near the axis of the mold pad 3 and the mold pad 3. The end of the guide tube 51 near the mold 2 is flared and the surface of the guide tube 51 is a smooth curved surface. There are chamfers between each level in the outlet band 224, at the junction of the outlet band 224 and the rear cutter 223, and at the edge of the outlet band 224. The guide tube 51 is also closely attached to the outlet band 224 and the surface of the two is a continuous curved transition.

[0026] Nitrogen gas entering the ventilation groove 31 is blocked by the guide tube 51, allowing it to be distributed more evenly throughout the ventilation groove 31. It is then ejected from the gap between the guide tube 51 and the mold pad 3. Due to the Coanda effect, the high-speed ejected nitrogen gas adheres tightly to the wall of the guide tube 51, forming a thin nitrogen layer. It then enters the outlet zone 224 through the guide groove 52. Furthermore, the chamfers on the lower mold 22 effectively reduce the turbulence of the nitrogen gas, causing most of the nitrogen gas flowing towards the working zone 222 to move along the inner wall of the lower mold 22, thus providing sufficient and even cooling for the lower mold 22. During this process, the nitrogen gas ejected from the gap between the guide tube 51 and the mold pad 3 has a relatively fast flow rate, but the amount of nitrogen gas is relatively small. It mainly relies on the vaporization of liquid nitrogen and the initial pressure of the nozzle to drive the movement of nitrogen gas. Therefore, it is difficult to adsorb gas outside the mold pad 3 to enter. As a result, the nitrogen gas ejected from the ventilation groove 31 and the nitrogen gas flowing out of the mold pad 3 have less conflict. When the nitrogen gas hits the working belt 222, although turbulence will occur, more nitrogen gas will stick to the pressed product. In addition, nitrogen is supplied in an intermittent or pulsed manner during this process to further ensure the smooth progress of the process.

[0027] In other feasible implementations, if it is found that the temperature difference between the working zone 222 and nitrogen is too large and it is necessary to reduce the temperature difference without reducing the flow rate, a pre-cooling tank connected to the main cooling channel 32 can be opened at one end of the mold pad 3 near the mold 2. The pre-cooling tank is annular, and the main cooling channel 32 is divided into two parts by the pre-cooling tank, so that one part of the main cooling channel 32 is connected to the outer peripheral wall of the pre-cooling tank and the other end is connected to the inner peripheral wall of the pre-cooling tank. The two parts of the main cooling channel 32 are opposite to each other so that the nitrogen and liquid nitrogen mixture can exchange heat with the tank wall of the pre-cooling tank, so as to initially reduce the temperature of the mold pad 3 and the lower mold 22 and increase the temperature entering the ventilation groove 31. To further improve the initial cooling of the lower mold 22, in addition to increasing the number of pre-cooling grooves, a pre-cooling groove can be jointly opened by the mold pad 3 and the lower mold 22. Furthermore, the groove wall section of the pre-cooling groove located in the mold pad 3 is a superior arc, and the groove wall section of the pre-cooling groove located in the lower mold 22 is a inferior arc. That is, with minimal modification to the lower mold 22, nitrogen and / or liquid nitrogen can directly contact the lower mold 22.

[0028] Reference Figure 5 The groove wall of the guide groove 52 near the axis of the mold pad 3 is stepped, and multiple auxiliary grooves 34 are opened on the inner peripheral wall of the mold pad 3.

[0029] The stepped walls of the flow channel 52, when gas is ejected from the outlet of the venting channel 31, prevent the gas from adhering to the side of the flow channel 52 closest to the axis of the mold pad 3. Instead, the gas mainly adheres to the flow guide tube 51, further enhancing the flow guiding effect of the flow guide tube 51. The auxiliary channel 34 expands the space between the mold pad 3 and the extruded product. When nitrogen returns to the mold pad 3 after cooling the working zone 222, the nitrogen flow rate is relatively slow and the adhesion between the nitrogen and the extruded product is small. The auxiliary channel 34 effectively increases the space for nitrogen to exit the mold pad 3, facilitating the exit of nitrogen from the mold pad 3. Furthermore, the auxiliary channel 34 increases the contact area between the mold pad 3 and the nitrogen, thereby enhancing the cooling effect of the mold pad 3.

[0030] Reference Figure 4 and Figure 6 The peripheral wall of the mold pad 3 is provided with a secondary cooling channel 35 that is connected to the main cooling channel 32. The secondary cooling channel 35 is also connected to a nozzle, which is connected to a high-pressure air source. This air source can be air directly drawn from a fan, air compressor, etc. The secondary cooling channel 35 is divided into a coarse channel section and a fine channel section. The main cooling channel 32 merges into the fine channel section of the secondary cooling channel 35 at an acute angle.

[0031] When the machine body 11 is in the process of changing blanks, the mold 2 is in a through state because there are no blanks. At this time, the secondary cooling channel 35 is supplied with high-pressure and high-speed airflow. This airflow is initially mixed with the liquid nitrogen in the main cooling channel 32, causing the liquid nitrogen to heat up into nitrogen gas and the airflow to cool down. During this process, the amount of nitrogen gas is less than the amount of air. Then the mixed airflow enters the ventilation groove 31, mixes evenly, and is evenly distributed throughout the ventilation groove 31. It is then ejected from the gap between the guide tube 51 and the mold pad 3. At this time, the fast airflow and the relatively fast nitrogen flow result in a large overall flow velocity of the mixed airflow. This high-speed mixed airflow introduces, accelerates, and amplifies the air outside the body 11 through Bernoulli's principle, forming a stable and powerful cooling airflow. During this process, the auxiliary groove 34 further enhances the amount of air introduced from outside the body 11, thereby effectively cooling the lower mold 22 and the upper mold 21. Since the cooling airflow is mostly air with less nitrogen, and after being evenly mixed, the temperature difference between the cooling airflow and the higher temperature mold core 211 is reduced. That is, by increasing the flow velocity and the cooling airflow at a suitable temperature, the upper mold 21 is cooled to avoid the upper mold 21, especially the mold core 211, from generating huge stress due to direct contact with low-temperature nitrogen.

[0032] Reference Figure 4 and Figure 5A pressure-boosting ring 511 is fixedly connected to the end of the guide tube 51 furthest from the mold 2. The pressure-boosting ring 511 is bent towards the end closer to the mold 2. When nitrogen and / or air are injected into the venting groove 31, the pressure-boosting ring 511 prevents most of the nitrogen from being directly ejected from the gap between the guide tube 51 and the mold pad 3, allowing the nitrogen to first fill all parts of the venting groove 31, ensuring that the venting groove 31 is evenly filled with nitrogen and pressurized. When air and nitrogen are injected into the venting groove 31 at the same time, the pressure-boosting ring 511 further mixes the air and nitrogen evenly throughout the venting groove 31 and further pressurizes it, so that the air is evenly and at high speed ejected from the gap between the guide tube 51 and the mold pad 3.

[0033] Reference Figure 1 , Figure 2 and Figure 7 The transition mechanism 4 includes an isolation cover 41 and a control component 42. The inner bottom wall of the isolation cover 41 and the cooling box 12 is provided with multiple conveying rollers. The two ends of the isolation cover 41 are respectively connected to the outlet of the cooling box 12 and the machine body 11. The control component 42 is used to adjust the connection state between the isolation cover 41 and the machine body 11. In this application, the control component 42 is a baffle 421 that slides vertically between the machine body 11 and the isolation cover 41 and a hydraulic cylinder 422 provided on the machine body 11. The output end of the hydraulic cylinder 422 is fixedly connected to the baffle 421. The baffle 421 is divided into an upper thin plate and a lower thick plate. The lower thick plate has a channel larger than the size of the extruded product. The end of the baffle 421 near the isolation cover 41 is flat and always fits against the isolation cover 41. The thickness of the lower thick plate is adapted to the distance between the isolation cover 41 and the machine body 11.

[0034] When the machine body 11 is in the extrusion operation, the hydraulic cylinder 422 drives the baffle 421 to move to the position where the extruded product is facing the channel, so as to ensure that the extruded product is smoothly transported from the machine body 11 through the channel into the isolation cover 41, and finally enters the cooling box 12 for strong cooling. During this process, the two ends of the lower thick plate of the baffle 421 are respectively in contact with the isolation cover 41 and the machine body 11, reducing nitrogen leakage and allowing nitrogen to smoothly enter the isolation cover 41, providing nitrogen protection for the extruded product in the isolation cover 41, so as to slow down the oxidation of the extruded product before strong cooling. When the machine body 11 is in the process of changing materials, the hydraulic cylinder 422 drives the baffle 421 to move down, so that one end of the upper thin plate of the baffle 421 is in contact with the isolation cover 41 and the other end forms a gap with the machine body 11. This facilitates the ejection of high-speed airflow from the gap between the guide tube 51 and the mold pad 3. At the same time, outside air enters into the mold pad 3 from the gap between the machine body 11 and the baffle 421, so as to enhance the cooling speed and uniformity of the upper mold 21 and the lower mold 22.

[0035] The implementation principle of the aluminum profile hot extrusion cooling forming device in this application embodiment is as follows: When the machine body 11 is in the process of extruding and forming the billet, the liquid nitrogen sprayed from the nozzle 33 enters the main cooling channel 32. The high temperature of the die pad 3 quickly vaporizes the liquid nitrogen and increases the air pressure in the main cooling channel 32, thereby making the ventilation groove 31 mainly contain low-temperature nitrogen. The nitrogen entering the ventilation groove 31 is blocked by the guide tube 51 and the pressure ring 511, so that the nitrogen is more evenly distributed to the ventilation after being pressurized. Nitrogen gas is ejected from various locations in the channel 31 and from the gap between the guide cylinder 51 and the mold pad 3. Due to the Coanda effect, the high-speed ejected nitrogen gas adheres tightly to the cylinder wall of the guide cylinder 51, forming a thin nitrogen layer. It then enters the outlet zone 224 through the guide channel 52, causing most of the nitrogen gas flowing towards the working zone 222 to move along the inner wall of the lower mold 22, thus providing sufficient and uniform cooling for the lower mold 22. When the nitrogen gas hits the working zone 222, although turbulence occurs, more nitrogen gas still adheres tightly to the pressed product.

[0036] Then, due to the obstruction of the working belt 222 and the extruded product, the nitrogen gas flows back along the extruded product. Since the auxiliary groove 34 expands the space between the mold pad 3 and the extruded product, when the nitrogen gas returns to the mold pad 3 after cooling the working belt 222, the nitrogen gas flow rate is relatively slow and the degree of contact between the nitrogen gas and the extruded product is relatively small. The auxiliary groove 34 effectively increases the space for the nitrogen gas to exit the mold pad 3, making it easier for the nitrogen gas to pass through the mold pad 3 until the nitrogen gas enters the isolation cover 41, so that the extruded product is protected by nitrogen gas before entering the cooling box 12 for strong cooling.

[0037] When the machine body 11 is in the process of changing to a new blank, the mold 2 is in a through state because there is no blank. At this time, the secondary cooling channel 35 is introduced with high-pressure and high-speed airflow. This airflow is initially mixed with the liquid nitrogen in the main cooling channel 32. Then the mixed airflow enters the ventilation groove 31 for uniform mixing, pressurization and uniform distribution to all parts of the ventilation groove 31, and is sprayed out from the gap between the guide tube 51 and the mold pad 3. At this time, because the high-pressure airflow velocity is much greater than the nitrogen flow velocity, the total velocity of the mixed airflow is large. This high-speed mixed airflow introduces, accelerates and amplifies the air outside the machine body 11 through Bernoulli's principle to form a stable and powerful cooling airflow. During this process, the auxiliary groove 34 no longer exhausts, but instead increases the amount of air introduced from outside the machine body 11, thereby making the total amount of airflow sprayed onto the mold 2 larger and the airflow more uniform, so as to achieve the effect of uniform and rapid cooling of the mold 2.

[0038] Example 2

[0039] This application discloses a method for hot extrusion and cooling forming of aluminum profiles, referring to... Figures 1-7 The hot extrusion and cooling forming of aluminum profiles includes the following steps: S1. Heating of billet and mold 2: The billet is heated to above its recrystallization temperature and the mold 2 is heated simultaneously. The billet heating temperature is usually 450-520℃, depending on the billet type. The mold 2 heating temperature is 400-520℃, depending on the actual working conditions. S2. Assembly of mold 2 and mold pad 3: Assemble mold pad 3 and mold 2 onto body 11 in sequence; S3. Hot extrusion: The billet is placed in the extrusion cylinder of the machine body 11 and the extrusion shaft of the machine body 11 extrudes the billet to form an extruded product. During this process, the die pad 3 and the lower die 22 are cooled by nitrogen gas blown out of the ventilation groove 31 to reduce the elasticity of the die pad 3 and the lower die 22. S4. Quenching of extruded products: The extruded products are subjected to initial cooling and strong cooling. The initial cooling is the process in which the nitrogen gas after cooling the lower die 22 exchanges heat with the extruded products during the return process, so that the temperature of the extruded products is cooled to above the critical quenching temperature. When the extruded products enter the cooling box 12, they are subjected to strong quenching by the cooling box 12. S5. Material Change: After a blank is extruded, a new material needs to be replaced. During this process, the mold 2 is in a break period. The ventilation channel 31 sprays high-speed nitrogen and air mixture to cool the upper mold 21 and the lower mold 22.

[0040] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A hot extrusion cooling forming apparatus for aluminum profiles, comprising a machine body (11), a cooling box (12), a mold (2), and a mold pad (3), characterized in that: The mold pad (3) has a venting groove (31) at one end near the mold (2), and the mold pad (3) has a main cooling channel (32) connected to the venting groove (31) on its peripheral wall. The machine body (11) is provided with a nozzle (33) adapted to the main cooling channel (32) and connected to a cooling source. The machine body (11) is also provided with: A transition mechanism (4) is provided between the body (11) and the cooling box (12) for isolating and protecting the aluminum profile; Guide mechanism (5), used to guide the gas ejected from the ventilation slot (31).

2. The aluminum profile hot extrusion cooling forming apparatus according to claim 1, characterized in that: The guiding mechanism (5) includes a guide tube (51) fixed to the mold pad (3), the guide tube (51) covering the ventilation groove (31), a gap between the end of the guide tube (51) away from the mold (2) and the mold pad (3), and a guide groove (52) between the side of the guide tube (51) close to the axis of the mold pad (3) and the mold pad (3).

3. The aluminum profile hot extrusion cooling forming apparatus according to claim 2, characterized in that: The groove wall of the guide groove (52) near the axis of the mold pad (3) is stepped.

4. The aluminum profile hot extrusion cooling forming apparatus according to claim 2, characterized in that: The guide tube (51) has an flared end near the mold (2).

5. The aluminum profile hot extrusion cooling forming apparatus according to claim 2, characterized in that: A pressure ring (511) is fixed to one end of the guide tube (51) away from the mold (2).

6. The aluminum profile hot extrusion cooling forming apparatus according to claim 1, characterized in that: The inner peripheral wall of the mold pad (3) has multiple auxiliary grooves (34).

7. The aluminum profile hot extrusion cooling forming apparatus according to claim 1, characterized in that: The peripheral wall of the mold pad (3) is provided with a secondary cooling channel (35) that communicates with the main cooling channel (32), and the main cooling channel (32) merges into the secondary cooling channel (35) at an acute angle.

8. The aluminum profile hot extrusion cooling forming apparatus according to claim 1, characterized in that: The transition mechanism (4) includes an isolation cover (41) and a control component (42). The two ends of the isolation cover (41) are connected to the outlet of the cooling box (12) and the machine body (11), respectively. The control component (42) is used to adjust the connection state between the isolation cover (41) and the machine body (11).

9. A method for hot extrusion and cooling forming of aluminum profiles, comprising an apparatus for hot extrusion and cooling forming of aluminum profiles according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Heating of billet and mold (2): Heating the billet to above its recrystallization temperature and simultaneously heating the mold (2); S2. Assembly of mold (2) and mold pad (3): Assemble the mold pad (3) and mold (2) onto the body (11) in sequence; S3, Hot extrusion: The billet is placed in the extrusion cylinder of the machine body (11), and the extrusion shaft of the machine body (11) extrudes the billet to form an extruded product; S4. Quenching of extruded products: Initial cooling and strong cooling of extruded products; S5, material change: After one billet is extruded, a new billet is placed in the extrusion cylinder of the machine body (11).

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