Aluminum profile hot extrusion cooling forming device and forming method

Abstract

The application relates to the field of aluminum profile extrusion forming, and particularly discloses an aluminum profile hot extrusion cooling forming device and a forming method, which comprises a machine body, a cooling box, a die and a die cushion, an air passage is arranged at one end of the die cushion close to the die, a main cooling flow channel is arranged in the die cushion wall and communicated with the air passage, a nozzle matched with the main cooling flow channel and connected with a cooling source is arranged on the machine body, and a transition mechanism for isolating and protecting the aluminum profile is arranged between the machine body and the cooling box; and a guide mechanism for guiding the air passage to spray gas is arranged on the machine body. The application has the effects of cooling the die cushion and the lower die under the premise of ensuring the working strength and efficiently cooling the upper die in the gap of replacing the blank of the machine body.

Description

TECHNICAL FIELD

[0001] The application relates to the field of aluminum profile extrusion molding, and in particular to an aluminum profile hot extrusion cooling molding device and a molding method. BACKGROUND

[0002] Aluminum profile hot extrusion is a core forming process of obtaining a profile with a required cross-sectional shape by forcing a heated aluminum alloy ingot (blank) through a specific shape of a die orifice under high pressure.

[0003] The aluminum profile hot extrusion molding process is generally as follows: the blank is heated to a range of 450-520 DEG C (the specific temperature depends on the blank model), the die is also heated to 400-520 DEG C, then the die is installed at a corresponding position of the machine body, the blank is placed in the extrusion cylinder, the blank is formed into an extrusion product corresponding to the die through the pushing force of the extrusion shaft, and finally the extrusion product is transported to a cooling box for water cooling or air cooling. During the extrusion process, the die work zone temperature rises sharply due to the severe friction generated when the blank passes through the die. The die is continuously affected by high temperature and high pressure during the process, the die blank has a large elastic deformation, and thus the extrusion product has a large error. Therefore, when producing high-quality aluminum profiles, the die usually needs to be cooled to keep the die temperature within a corresponding temperature range.

[0004] The patent CN119281851A of the related art proposes an aluminum profile extrusion molding die cooling mechanism, which comprises a front die (upper die) and a rear die (lower die), the rear die comprises an inner module, an outer module and a spacer block, the inner module is provided with a welding chamber and a work zone, the inner module is connected with a water cooling mechanism, the water cooling mechanism comprises a first cooling channel, the first cooling channel is arranged at the rear side of the welding chamber and annularly arranged outside the work zone, the spacer block is connected with an air cooling mechanism, the air cooling mechanism comprises a second cooling channel, and the air cooling mechanism forms an air temperature insulation layer in the spacer block through the second cooling channel.

[0005] According to the related art in the above, the inventors believe that the following defects exist: the water cooling mechanism is arranged in the lower die to improve the heat dissipation performance of the rear lower die, but since the work zone is one of the weakest links of the die, the opening of the channel in the lower die will reduce the strength of the lower die and easily cause the work zone to break. SUMMARY

[0006] In order to improve the problem that the die is difficult to cool under the premise of ensuring the strength of the die, the application provides an aluminum profile hot extrusion cooling molding device and a molding method.

[0007] The aluminum profile hot extrusion cooling molding device and the molding method provided by the application adopt the following technical solutions:

[0008] The utility model provides an aluminium profile hot extrusion cooling forming device, including body, cooling box, mould and mould pad, the mould pad is opened with the air passage in the end close to the mould, the mould pad peripheral wall is opened with the main cooling flow channel of communicating with the air passage, the body is provided with the nozzle of communicating with the main cooling flow channel and is connected with the cooling source, the body is still provided with: transition mechanism, sets up between the body and the cooling box, is used for the isolation protection to aluminium profile, the guiding mechanism is used for guiding the guiding mechanism of the air passage spouts gas.

[0009] Optionally, the guiding mechanism includes a flow guide cylinder fixed to the mould pad, the flow guide cylinder covers the air passage, a gap is left between the end of the flow guide cylinder away from the mould and the mould pad, and a flow guide groove is left between the side of the flow guide cylinder close to the axis of the mould pad and the mould pad.

[0010] Optionally, the groove wall of the side of the flow guide groove close to the axis of the mould pad is in a stepped shape.

[0011] Optionally, the end of the flow guide cylinder close to the mould is in a flared shape.

[0012] Optionally, a booster ring is fixed to the end of the flow guide cylinder away from the mould.

[0013] Optionally, a plurality of auxiliary grooves are formed in the inner circumferential wall of the mould pad.

[0014] Optionally, a secondary cooling flow channel is formed in the peripheral wall of the mould pad and communicates with the main cooling flow channel, and the main cooling flow channel converges into the secondary cooling flow channel at an acute angle.

[0015] Optionally, the transition mechanism includes an isolation cover and a control assembly, the two ends of the isolation cover communicate with the discharge opening of the cooling box and the body respectively, and the control assembly is used to adjust the connection state of the isolation cover and the body.

[0016] An aluminium profile hot extrusion cooling forming method includes the following steps:

[0017] S1, heating of the billet and the mould: heating the billet above its recrystallization temperature and synchronously heating the mould;

[0018] S2, assembly of the mould and the mould pad: sequentially assembling the mould pad and the mould to the body;

[0019] S3, hot extrusion: placing the billet in the extrusion cylinder of the body, extruding the billet by the extrusion shaft of the body, and forming the billet into an extrusion product;

[0020] S4, quenching of the extrusion product: primary cooling and intensive cooling of the extrusion product;

[0021] S5, replacing material: after one blank extrusion is finished, the new blank is placed in the extrusion cylinder of the machine body.

[0022] In summary, the present application includes at least one of the following beneficial technical effects:

[0023] 1. When the machine body is in the process of extruding the blank, the guide mechanism guides the nitrogen in the air slot to the lower die, so that the nitrogen is sequentially heat-exchanged with the outlet belt, the rear air knife and the working belt, that is, the lower die is sequentially subjected to low-to-high gradient cooling from the end close to the die pad to the end away from the die pad, avoiding the brittle working belt from being directly subjected to strong cooling and causing breakage, and then the nitrogen flows out along the extruded product into the transition mechanism due to the blockage of the working belt and the extruded product, so that the transition mechanism forms a positive pressure and is filled with nitrogen to protect and pre-cool the extruded product, and since no modification is made on the die, the strength of the die is ensured;

[0024] 2. The nitrogen entering the air slot is blocked by the guide cylinder, so that the nitrogen is uniformly distributed to each part of the air slot and sprayed out of the gap between the guide cylinder and the die pad. Due to the influence of the Coanda effect, the high-speed sprayed nitrogen adheres to the wall of the guide cylinder, forming a thin nitrogen layer, and enters the outlet belt through the guide groove. Due to the effect of the chamfers on the lower die, the phenomenon of turbulent flow of nitrogen is effectively reduced, and thus most of the nitrogen flowing to the working belt moves along the inner wall of the lower die, so as to sufficiently and uniformly cool the lower die;

[0025] 3. When the machine body is in the process of replacing the blank, the die is in a through state due to the absence of the blank, at this time the secondary cooling flow channel passes in high-pressure high-speed airflow, which is preliminarily mixed with liquid nitrogen in the primary cooling flow channel, and then the mixed gas flow enters the air slot, is uniformly mixed and uniformly distributed to each part of the air slot, and is sprayed out of the gap between the guide cylinder and the die pad. At this time, due to the influence of the high-pressure air flow, the flow rate of the mixed gas flow is large, and the high-speed mixed gas flow introduces, accelerates and amplifies the air outside the machine body to form a stable and powerful cooling airflow, thereby effectively cooling the lower die and the upper die. Since most of the cooling airflow is air and nitrogen is less, and after uniform mixing, the temperature difference between the cooling airflow and the die core with higher temperature is reduced, that is, the upper die is cooled by increasing the flow rate and the cooling airflow with appropriate temperature to avoid the upper die, especially the die core, from generating a large stress due to direct contact with low-temperature nitrogen;

[0026] 4. Nitrogen flows back along the extrusion product due to the blocking of the working belt and the extrusion product, and the auxiliary groove enlarges the space between the die pad and the extrusion product. When the nitrogen returns to the die pad after cooling the working belt, the nitrogen flow is slow and the adhesion between the nitrogen and the extrusion product is small. The auxiliary groove effectively increases the space for the nitrogen to exit the die pad, so that the nitrogen can pass through the die pad until the nitrogen enters the isolation cover, so that the extrusion product is protected by nitrogen before entering the cooling box for strong cooling. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic diagram of the overall structure of the embodiment of the present application;

[0028] Figure 2 is a schematic diagram of the cross-sectional structure of the present application for showing the body, the cooling box, the upper die, the lower die, the die pad and the transition mechanism;

[0029] Figure 3 is a schematic diagram of the overall structure of the present application for showing the die, the die pad and the nozzle;

[0030] Figure 4 is a schematic diagram of the cross-sectional structure of the present application for showing Figure 3 ;

[0031] Figure 5 is an enlarged schematic diagram of part A in Figure 4 ;

[0032] Figure 6 is a plan view of the cross-sectional structure of the present application based on Figure 4 ;

[0033] Figure 7 is a schematic diagram of the structure of the present application for showing the transition mechanism.

[0034] Reference signs: 11, body; 12, cooling box; 2, die; 21, upper die; 211, die core; 22, lower die; 221, welding chamber; 222, working belt; 223, rear air knife; 224, outlet belt; 3, die pad; 31, air passage; 32, main cooling flow channel; 33, nozzle; 34, auxiliary groove; 35, auxiliary cooling flow channel; 4, transition mechanism; 41, isolation cover; 42, control assembly; 421, baffle; 422, hydraulic cylinder; 5, guide mechanism; 51, flow guide cylinder; 511, booster ring; 52, flow guide groove. DETAILED DESCRIPTION

[0035] The present application will be further described below in conjunction with the accompanying drawings. Figures 1-7

[0036] Embodiment one

[0037] The embodiment of the present application discloses an aluminum profile hot extrusion cooling forming device. Referring to​Figures 1-5 The aluminum profile hot extrusion cooling forming device comprises a body 11, a cooling box 12, a die 2 and a die pad 3. The die 2 is divided into an upper die 21 and a lower die 22 in the direction of the billet extrusion. The upper die 21 comprises a die core 211. The lower die 22 comprises, in sequence along the direction of the billet extrusion, a welding chamber 221, a working zone 222, a rear air knife 223 and an outlet zone 224. The die core 211 extends to the rear air knife 223. The die pad 3 is provided with a ventilation groove 31 at one end close to the die 2. The peripheral wall of the die pad 3 is provided with a main cooling flow channel 32 connected with the ventilation groove 31. The body 11 is provided with a nozzle 33 matched with the main cooling flow channel 32 and connected with a cooling source. The cooling source can be a liquid nitrogen tank storing liquid nitrogen. The application of liquid nitrogen cooling in the aluminum profile hot extrusion is relatively mature, and the damage to the die 2 and the die pad 3 is small, which will not be described in detail here. The cooling box 12 can be a water cooling box or an air cooling box. The water cooling box can be a spray type water cooling box or an immersion type water cooling box, which is selected according to the requirements of the billet. The body 11 is provided with a plurality of temperature sensors. In this application, infrared thermometers are arranged at the inlet and outlet ends of the body 11 to monitor the temperature of the material entering and leaving the body 11 in real time. A plurality of thermocouple thermometers are also arranged in the body 11. Each of the upper die 21, the lower die 22 and the die pad 3 corresponds to at least one thermocouple thermometer. The nozzle 33 and each temperature sensor on the body 11 are electrically connected with the control system built in the body 11, so as to control the opening and closing and flow of the nozzle 33 through the temperature control of the die 2, the die pad 3 and the billet. The body 11 is further provided with a transition mechanism 4 arranged between the body 11 and the cooling box 12 for isolating and protecting the aluminum profile, and a guide mechanism 5 for guiding the gas sprayed from the ventilation groove 31.

[0038] When the body 11 is in the process of extruding and forming the billet, the liquid nitrogen sprayed from the nozzle 33 enters the main cooling flow channel 32. The nozzle 33 can continuously, intermittently or pulsedly spray liquid nitrogen, preferably intermittently or pulsedly. The high temperature of the die pad 3 rapidly gasifies the liquid nitrogen and increases the gas pressure in the main cooling flow channel 32, so that the ventilation groove 31 is mainly filled with low-temperature nitrogen gas. At the same time, the nitrogen gas in the ventilation groove 31 is guided to the lower die 22 through the guide mechanism 5, so that the nitrogen gas is sequentially heat-exchanged with the outlet zone 224, the rear air knife 223 and the working zone 222. That is, the lower die 22 is sequentially subjected to gradient cooling from low to high from the end close to the die pad 3 to the end away from the die pad 3, so as to avoid the relatively fragile working zone 222 from being directly subjected to strong cooling and being broken. In this process, the die pad 3 and the lower die 22 are preferably cooled, especially the working zone 222 which is difficult to cool is also precisely cooled, without the need for modification of the die 2, effectively ensuring the strength of the working zone 222, reducing the springback amount, and further ensuring the stability of the profile and improving the precision of the profile.

[0039] Then, the nitrogen gas flows out of the extrusion product to the transition mechanism 4 due to the block of the working belt 222 and the extrusion product, so that the transition mechanism 4 is filled with the nitrogen gas with positive pressure. The nitrogen gas in this process has relatively high temperature due to the heat exchange with the die pad 3 and the die 2, so that the extrusion product is cooled to a limited extent. Since the temperature of the extrusion product is increased sharply during the extrusion forming process, the temperature of the extrusion product is far above the critical quenching temperature. At this time, the nitrogen gas pre-cools the extrusion product before quenching, and the pre-cooling is relatively light and the temperature of the extrusion product is kept above the critical quenching temperature by the infrared thermometer. At the same time, the nitrogen gas in the transition mechanism 4 effectively reduces the oxidation of the extrusion product before quenching.

[0040] When the machine body 11 is in the process of replacing the new blank, the die 2 is in the through state due to the absence of the blank. At this time, the nitrogen gas continues to flow out of the upper die 21 after reaching the working belt 222, thereby cooling the upper die 21. During the whole process of the machine body 11, the cooling time of the working belt 222, the rear air knife 223 and the outlet belt 224 in the lower die 22 is relatively long, and the cooling time of the welding chamber 221 and the upper die 21 is relatively short, so as to avoid the uneven flow of metal due to the too low temperature of the welding chamber 221, thereby causing linear or strip non-welding interface in the aluminum profile and strip defects on the surface.

[0041] With reference to Figure 4 , Figure 5 and Figure 6 , the guide mechanism 5 comprises a flow guide cylinder 51 fixed on the die pad 3. The flow guide cylinder 51 and the die pad 3 are separately manufactured and connected by welding. The flow guide cylinder 51 covers the air passage 31. A gap of 0.4-0.8 mm is left between the end of the flow guide cylinder 51 away from the die 2 and the die pad 3, and the specific thickness is determined according to the actual working condition. A flow guide groove 52 is left between the side of the flow guide cylinder 51 close to the axis of the die pad 3 and the die pad 3. The end of the flow guide cylinder 51 close to the die 2 is flared, and the surface of the flow guide cylinder 51 is smooth and curved. The edges of the outlet belt 224, the junctions between the layers of the outlet belt 224 and the rear air knife 223 are chamfered. The flow guide cylinder 51 is tightly attached to the outlet belt 224, and the surfaces of the two are continuously curved.

[0042] The nitrogen gas entering into the vent groove 31 is blocked by the flow guide cylinder 51, so that the nitrogen gas is evenly distributed to each part of the vent groove 31 and is sprayed out from the gap between the flow guide cylinder 51 and the die cushion 3. The high-speed sprayed nitrogen gas adheres to the cylinder wall of the flow guide cylinder 51 due to the effect of the Coanda effect, forming a thin nitrogen gas layer, and then enters into the outlet zone 224 through the flow guide groove 52. Due to the effect of the chamfer of the lower die 22, the phenomenon of turbulent flow of the nitrogen gas is effectively reduced, and most of the nitrogen gas flowing to the working zone 222 moves along the inner wall of the lower die 22, so as to sufficiently and evenly cool the lower die 22. In this process, the nitrogen gas sprayed from the gap between the flow guide cylinder 51 and the die cushion 3 has a high flow rate but a small amount, and is mainly driven by the initial pressure of the liquid nitrogen gas and the nozzle to move, so that it is difficult to adsorb the gas outside the die cushion 3, and the conflict between the nitrogen gas sprayed from the vent groove 31 and the nitrogen gas flowing out of the die cushion 3 is small. When the nitrogen gas hits the working zone 222, although turbulent flow occurs, more nitrogen gas adheres to the product, and in this process, the nitrogen gas is supplied in an intermittent or pulse mode, which further ensures the smooth progress of the process.

[0043] In other possible embodiments, if it is found that the temperature difference between the working zone 222 and the nitrogen gas is too large and needs to be reduced without reducing the flow rate, a pre-cooling groove can be provided on the end of the die cushion 3 close to the mold 2 and connected to the main cooling flow channel 32. The pre-cooling groove is annular, the main cooling flow channel 32 is divided into two parts by the pre-cooling groove, one part of the main cooling flow channel 32 is connected to the outer peripheral wall of the pre-cooling groove, the other end is connected to the inner peripheral wall of the pre-cooling groove, and the two parts of the main cooling flow channel 32 are opposite to each other, so that the nitrogen gas and the liquid nitrogen mixture can exchange heat with the groove wall of the pre-cooling groove, so as to preliminarily reduce the temperature of the die cushion 3 and the lower die 22, and increase the temperature of the nitrogen gas entering into the vent groove 31. If further preliminary cooling of the lower die 22 is needed, in addition to increasing the number of pre-cooling grooves, the pre-cooling groove can also be provided in the die cushion 3 and the lower die 22, so that the cross section of the groove wall of the pre-cooling groove in the die cushion 3 part is a superior arc, and the cross section of the groove wall of the pre-cooling groove in the lower die 22 part is an inferior arc, that is, the nitrogen gas and / or liquid nitrogen can directly contact the lower die 22 while minimizing the modification of the lower die 22.

[0044] Referring to Figure 5 , the groove wall of the flow guide groove 52 close to the axis of the die cushion 3 is in a stepped shape, and the inner peripheral wall of the die cushion 3 is provided with a plurality of auxiliary grooves 34.

[0045] The stepped guide groove 52 wall makes it difficult for the gas to adhere to the guide groove 52 wall close to the axis of the die pad 3 when the gas is sprayed out of the vent groove 31 outlet, and mainly adheres to the guide cylinder 51 to move, further enhancing the guide effect of the guide cylinder 51. The auxiliary groove 34 expands the space between the die pad 3 and the extruded product. When the nitrogen gas returns to the die pad 3 after cooling the work belt 222, the nitrogen gas flow rate is relatively slow and the adhesion between the nitrogen gas and the extruded product is small. The auxiliary groove 34 effectively increases the space for nitrogen gas to exit the die pad 3, facilitating the nitrogen gas to pass through the die pad 3, and the auxiliary groove 34 increases the contact area between the die pad 3 and the nitrogen gas to enhance the cooling effect of the die pad 3.

[0046] Referring to Figure 4 and Figure 6 The peripheral wall of the die pad 3 is provided with a secondary cooling flow channel 35 connected with the primary cooling flow channel 32, and the secondary cooling flow channel 35 is also connected with a nozzle connected with a high-pressure gas source, which can be air directly extracted by a fan, air compressor, etc. The secondary cooling flow channel 35 is divided into a coarse flow channel part and a fine flow channel part, and the primary cooling flow channel 32 is connected to the fine flow channel part of the secondary cooling flow channel 35 at an acute angle.

[0047] When the machine body 11 is in the process of replacing the blank, the die 2 is in a through state without a blank. At this time, the secondary cooling flow channel 35 is connected with a high-pressure high-speed gas flow, which is preliminarily mixed with the liquid nitrogen in the primary cooling flow channel 32, so that the liquid nitrogen is warmed to nitrogen gas and the air flow is cooled. In this process, the amount of nitrogen gas is less than that of air. Then the mixed gas flow enters the vent groove 31 and is uniformly mixed and distributed to all parts of the vent groove 31, and is sprayed out from the gap between the guide cylinder 51 and the die pad 3. At this time, the fast air flow and the faster nitrogen gas flow make the overall flow rate of the mixed gas flow larger. The high-speed mixed gas flow introduces, accelerates and enlarges the air outside the machine body 11 to form a stable and powerful cooling gas flow by Bernoulli's principle. In this process, the auxiliary groove 34 further increases the amount of air introduced to the machine body 11, thereby effectively cooling the lower die 22 and the upper die 21. Since most of the cooling gas flow is air and nitrogen is less, and after uniform mixing, the temperature difference between the cooling gas flow and the relatively high-temperature die core 211 is reduced, that is, the upper die 21 is cooled by increasing the flow rate and the cooling gas flow at a suitable temperature to avoid the upper die 21, especially the die core 211, from being directly contacted with low-temperature nitrogen gas to generate a large stress.

[0048] Referring to Figure 4 and Figure 5, the end of the flow guide cylinder 51 away from the mold 2 is fixed with a booster ring 511, the booster ring 511 is curved towards the end close to the mold 2. When nitrogen and / or air is injected into the vent groove 31, the booster ring 511 blocks most of the nitrogen from being directly sprayed out of the gap between the flow guide cylinder 51 and the mold pad 3, so that the nitrogen fills the vent groove 31 first, and the vent groove 31 is uniformly filled with nitrogen and pressurized. When air and nitrogen are injected into the vent groove 31 at the same time, the booster ring 511 also makes the air and nitrogen uniformly mixed in the vent groove 31 and further pressurized, so that the air cylinder sprays the high-speed airflow uniformly and quickly from the gap between the flow guide cylinder 51 and the mold pad 3.

[0049] Referring to Figure 1 , Figure 2 and Figure 7 , the transition mechanism 4 includes an isolation cover 41 and a control assembly 42, the isolation cover 41 and the inner bottom wall of the cooling box 12 are provided with a plurality of conveying rollers, the two ends of the isolation cover 41 are respectively connected with the cooling box 12 and the discharge port of the machine body 11, the control assembly 42 is used for adjusting the connection state of the isolation cover 41 and the machine body 11, in the present application, the control assembly 42 is a baffle 421 slidingly connected between the machine body 11 and the isolation cover 41 in the vertical direction and a hydraulic cylinder 422 arranged on the machine body 11, the output end of the hydraulic cylinder 422 is fixedly connected with the baffle 421, the baffle 421 is divided into an upper thin plate and a lower thick plate, a passage larger than the size of the extruded product is formed in the lower thick plate, the end of the baffle 421 close to the isolation cover 41 is a plane and always abuts against the isolation cover 41, the thickness of the lower thick plate is matched with the distance between the isolation cover 41 and the machine body 11.

[0050] When the machine body 11 is in extrusion operation, the hydraulic cylinder 422 drives the baffle 421 to move to the position where the extruded product faces the passage, so as to ensure that the extruded product is smoothly conveyed from the machine body 11 to the isolation cover 41 through the passage and finally enters the cooling box 12 for strong cooling, during the process, the two ends of the lower thick plate of the baffle 421 abut against the isolation cover 41 and the machine body 11 respectively, which reduces the leakage of nitrogen and makes the nitrogen enter the isolation cover 41 smoothly, thereby providing nitrogen protection for the extruded product in the isolation cover 41 to slow down the oxidation degree of the extruded product before strong cooling. When the machine body 11 is in the process of changing the material, the hydraulic cylinder 422 drives the baffle 421 to move downward, so that one end of the upper thin plate of the baffle 421 abuts against the isolation cover 41 and the other end forms a gap with the machine body 11, thereby facilitating the high-speed airflow to be sprayed out of the gap between the flow guide cylinder 51 and the mold pad 3, and external air enters 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.

[0051] The implementation principle of the aluminum profile hot extrusion cooling forming device is as follows: when the machine body 11 is in the process of extruding the blank, the liquid nitrogen sprayed by the nozzle 33 enters the main cooling flow channel 32, the high temperature of the die cushion 3 rapidly gasifies the liquid nitrogen and increases the air pressure in the main cooling flow channel 32, and then the low-temperature nitrogen gas in the air passage 31, the nitrogen gas entering the air passage 31 is blocked by the flow guide cylinder 51 and the booster ring 511, so that the nitrogen gas is uniformly distributed to each part of the air passage 31 after being boosted, and is sprayed out of the gap between the flow guide cylinder 51 and the die cushion 3, the high-speed sprayed nitrogen gas is tightly attached to the cylinder wall of the flow guide cylinder 51 due to the influence of the Coanda effect, a thin nitrogen gas layer is formed, and the nitrogen gas enters the outlet belt 224 through the guide groove 52, and most of the nitrogen gas flowing to the working belt 222 moves along the inner wall of the lower die 22, so that the lower die 22 is sufficiently and uniformly cooled; and when the nitrogen gas hits the working belt 222, although turbulence occurs, more nitrogen gas still adheres to the extruded product.

[0052] Then, the nitrogen gas flows back along the extruded product due to the blocking of the working belt 222 and the extruded product, and the auxiliary groove 34 enlarges the space between the die cushion 3 and the extruded product, so that when the nitrogen gas returns to the die cushion 3 after cooling the working belt 222, the nitrogen gas has a slow flow rate and a small adhesion degree to the extruded product, the auxiliary groove 34 effectively increases the space for the nitrogen gas to exit the die cushion 3, so that the nitrogen gas can pass through the die cushion 3, and the extruded product is protected by the nitrogen gas before entering the cooling box 12 for strong cooling.

[0053] When the machine body 11 is in the process of replacing a new blank, the die 2 is in a through state without the blank, at this time, the secondary cooling flow channel 35 is connected to a high-pressure high-speed airflow, the airflow is preliminarily mixed with the liquid nitrogen in the main cooling flow channel 32, then the mixed airflow is uniformly mixed, pressurized and uniformly distributed to each part of the air passage 31, and is sprayed out of the gap between the flow guide cylinder 51 and the die cushion 3, at this time, due to the fact that the flow rate of the high-pressure air is much greater than that of the nitrogen gas, the total flow rate of the mixed airflow is large, and the high-speed mixed airflow introduces, accelerates and enlarges the air outside the machine body 11 to form a stable and powerful cooling airflow, in this process, the auxiliary groove 34 no longer exhausts, but enhances the introduction amount of air outside the machine body 11, so that the total amount of the airflow sprayed to the die 2 is large and the airflow is uniform, so that the die 2 is uniformly and quickly cooled.

[0054] Embodiment two

[0055] The embodiment of the application discloses an aluminum profile hot extrusion cooling forming method, referring to Figures 1-7 The aluminum profile hot extrusion cooling forming method comprises the following steps:

[0056] S1, billet and mold 2 heating: heating the billet above its recrystallization temperature and synchronously heating the mold 2, wherein the billet heating temperature is generally 450-520℃, the specific temperature depends on the billet model, the mold 2 is 400-520℃, depending on the actual working conditions;

[0057] S2, mold 2 and mold pad 3 assembly: sequentially assembling the mold pad 3 and the mold 2 to the body 11;

[0058] S3, hot extrusion: placing the billet in the extrusion cylinder of the body 11, extruding the billet by the extrusion shaft of the body 11, and shaping the billet into an extruded product, wherein the mold pad 3 and the lower mold 22 are cooled by the nitrogen gas blown out by the vent groove 31 to reduce the elastic deformation of the mold pad 3 and the lower mold 22;

[0059] S4, extruded product quenching: primary cooling and intensive cooling of the extruded product, wherein the primary cooling is heat exchange between the nitrogen gas cooling the lower mold 22 and the extruded product during the return process, so that the temperature of the extruded product is cooled to above the critical quenching temperature, and when the extruded product enters the cooling box 12, the intensive quenching is performed by the cooling box 12;

[0060] S5, material replacement: after one billet is extruded, a new material needs to be replaced, wherein the mold 2 is in an empty window period, and the high-speed nitrogen and air mixed gas blown out by the vent groove 31 is used to cool the upper mold 21 and the lower mold 22.

[0061] The above are preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. An apparatus for hot extrusion and cooling forming of aluminum profile, comprising a machine body (11), a cooling box (12), a die (2) and a die cushion (3), characterized in that: The mold pad (3) is provided with a ventilation groove (31) near one end of the mold (2), the peripheral wall of the mold pad (3) is provided with a main cooling flow channel (32) communicated with the ventilation groove (31), the machine body (11) is provided with a nozzle (33) matched with the main cooling flow channel (32) and connected with a cooling source, and the machine body (11) is further provided with: A transition mechanism (4) is arranged between the machine body (11) and the cooling box (12) and used for isolating and protecting the aluminum profile; A guide mechanism (5) is used for guiding the gas sprayed out of the ventilation groove (31), the guide mechanism (5) comprises a flow guide cylinder (51) fixed on the mold pad (3), the flow guide cylinder (51) covers the ventilation groove (31), a gap is left between one end of the flow guide cylinder (51) away from the mold (2) and the mold pad (3), and a flow guide groove (52) is left between one side of the flow guide cylinder (51) close to the axis of the mold pad (3) and the mold pad (3). The flow guide cylinder (51) is fixed with a booster ring (511) at one end away from the mold (2), and the booster ring (511) is bent towards the end close to the mold (2).

2. The device for hot extrusion and cooling forming of aluminum profile according to claim 1, characterized in that: The groove wall of the flow guide groove (52) close to one side of the mold pad (3) is in a stepped shape.

3. The device for hot extrusion and cooling forming of aluminum profile according to claim 1, characterized in that: The flow guide cylinder (51) is in a flared shape at one end close to the mold (2).

4. The device for hot extrusion and cooling forming of aluminum profile according to claim 1, characterized in that: A plurality of auxiliary grooves (34) are formed in the inner peripheral wall of the mold pad (3).

5. The device for hot extrusion and cooling forming of aluminum profile according to claim 1, characterized in that: The peripheral wall of the mold pad (3) is provided with a secondary cooling flow channel (35) communicated with the main cooling flow channel (32), and the main cooling flow channel (32) is connected to the secondary cooling flow channel (35) at an acute angle.

6. The device for hot extrusion and cooling forming of aluminum profile according to claim 1, characterized in that: The transition mechanism (4) comprises an isolation cover (41) and a control assembly (42), the two ends of the isolation cover (41) are respectively communicated with the cooling box (12) and the discharge port of the machine body (11), and the control assembly (42) is used for adjusting the connection state of the isolation cover (41) and the machine body (11).

7. A method of hot extrusion and cooling forming of aluminum profile according to the apparatus of any one of claims 1-6, characterized in that, The method comprises the following steps: S1, heating of the blank and the mold (2): heating the blank to above the recrystallization temperature and synchronously heating the mold (2); S2, assembly of the mold (2) and the mold pad (3): sequentially assembling the mold pad (3) and the mold (2) on the machine body (11); S3, hot extrusion: placing the blank in the extrusion cylinder of the machine body (11), extruding the blank by the extrusion shaft of the machine body (11), and shaping the blank into an extruded product; S4, quenching of the extruded product: primary cooling and intensive cooling of the extruded product; S5, material replacement: after one blank is extruded, placing a new blank in the extrusion cylinder of the machine body (11).

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