Semi-solid die-casting device and method for environment-friendly ultrathin-wall high-strength aluminum alloy profile

Abstract

The invention discloses a semi-solid die-casting device and method for an environment-friendly ultra-thin-wall high-strength aluminum alloy profile, and relates to the technical field of metal die-casting devices. A pressure sensor is arranged in the injection head; the multi-stage supercharging mechanism comprises a three-stage nested piston mechanism and an oil way control mechanism. The multi-stage pressurizing mechanism is arranged to drive the first-stage piston, the second-stage piston and the third-stage piston to slide in the axial direction of the injection cylinder body, the slurry injection speed and pressure are gradually increased, the thrust of the pistons is dynamically adjusted through the oil way control mechanism, stepless continuous adjustment of the pressure is achieved, and the slurry filling effect is improved; by arranging the slurry rheological property control mechanism, slurry stirring and injection are integrated, a traditional conveying pump is replaced with propelling force of an injection piston, the slurry is always in a closed environment in the process from preparation to injection, and solid-phase particle refining, solid-phase rate regulation and control and high-pressure filling are synchronously completed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal die casting devices, in particular to a semi-solid die casting device and method for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles. BACKGROUND

[0002] In the field of aluminum alloy profile forming, semi-solid die casting technology has become an important process for manufacturing ultra-thin-wall high-strength structural parts due to its ability to improve product density and mechanical properties. The rheological properties of semi-solid metal slurry (solid-liquid coexistence state) are key to the quality of the forming, among which the morphology of solid-phase particles, the stability of solid-phase rate, and the viscosity of the slurry play a decisive role. In traditional processes, the preparation and injection of semi-solid slurry are usually carried out by separate equipment, that is, the slurry is prepared by a stirring device, then transferred to the injection mechanism of the die casting machine through a conveying pipeline, and finally filled by the injection cylinder. However, this mode has many problems, such as the aggregation of solid-phase particles in the transmission process, large viscosity fluctuations, and especially the difficulty in meeting the stringent requirements of ultra-thin-wall profiles with small wall thickness on the flowability of the slurry. For example, the Chinese patent with publication number CN106424630A discloses a complex thin-walled aluminum alloy part ultrasonic-assisted semi-solid die casting forming device and method. It includes a die casting machine, a die casting mold, an ultrasonic vibration system, and a cooling system. The die casting mold is installed on the die casting machine, the injection assembly is connected to the die casting mold through the static mold fixing plate, the ultrasonic vibration system is installed on the movable mold of the die casting mold, and the ultrasonic vibration system directly acts on the movable mold to assist in semi-solid die casting forming. The movable mold is provided with a cooling system connected to the ultrasonic vibration system. This invention can effectively reduce the degree of solid-phase aggregation, improve the flowability and filling capacity of semi-solid metal, refine the grain, improve the density of the casting, and further improve the mechanical properties and thermal conductivity of the aluminum alloy casting, providing a new forming method for complex thin-walled aluminum alloy casting manufacturing.

[0003] Although the above-mentioned device improves the flowability and filling capacity of semi-solid metal, it still has the following technical problems: when facing semi-solid metal slurry with high viscosity and ultra-thin-wall aluminum alloy profile cavities with narrow and long flow paths, the injection mechanism is difficult to provide high enough pressure that can be dynamically adjusted according to different stages of the filling process, which may result in air entrapment, insufficient pouring, and other defects, and cannot meet the die casting requirements of ultra-thin-wall aluminum alloy profiles. SUMMARY

[0004] The present application aims to provide a semi-solid die casting device and method for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles, which can effectively solve the problems raised in the background art.

[0005] In order to achieve the above object, the present application provides the following technical scheme: the semi-solid die casting device of the environment-friendly ultra-thin wall high-strength aluminum alloy profile, which comprises a multi-stage pressurizing mechanism connected with a pressure head; a pressure sensor is arranged in the pressure head; the multi-stage pressurizing mechanism comprises a three-stage nested piston mechanism and an oil path control mechanism; wherein the three-stage nested piston mechanism comprises a pressure cylinder body, a first-stage piston, a guide sleeve, a second-stage piston and a third-stage piston; the pressure cylinder body is connected with a die casting machine frame through flanges at both ends; the first-stage piston is connected in the pressure cylinder body in the axial direction; the guide sleeve is coaxially arranged on the first-stage piston, and the outer wall of the guide sleeve is in contact with the inner wall of the pressure cylinder body; the second-stage piston is coaxially inserted into the first-stage piston; one end of the third-stage piston is coaxially inserted into the second-stage piston, and the other end of the third-stage piston extends outward and is coaxially connected with the pressure head; a plurality of first flow-through holes are formed in the first-stage piston, a second flow-through hole is formed in the second-stage piston, and a third flow-through hole is formed in the third-stage piston; the slurry passes through the first flow-through hole, the second flow-through hole and the third flow-through hole in sequence and is communicated with the pressure head; one end of the oil path control mechanism is connected with the inside of the pressure cylinder body, the other end of the oil path control mechanism is connected with a hydraulic pump station, and the oil path control mechanism is used for controlling the axial sliding of the first-stage piston, the second-stage piston and the third-stage piston along the pressure cylinder body.

[0006] Preferably, the first-stage piston comprises a first piston rod and a first piston head; one end of the first piston rod is coaxially connected with the first piston head, and the first piston head is coaxially connected in the pressure cylinder body; one side of the first piston head and the pressure cylinder body form a first-stage pressurizing cavity. A displacement sensor is arranged between the first piston rod and the pressure cylinder body, and is used for detecting the displacement of the first piston head.

[0007] Preferably, the second-stage piston comprises a second piston rod and a second piston head; one end of the second piston rod is coaxially connected with the second piston head; a first guide groove is formed in the first piston rod, and the second piston head is coaxially connected in the first guide groove; one side of the second piston head and the first guide groove form a second-stage pressurizing cavity.

[0008] Preferably, a second guide groove is formed in the second piston rod, and one end of the third-stage piston and the second guide groove form a third-stage pressurizing cavity.

[0009] Preferably, the oil path control mechanism comprises a first-stage oil inlet pipe, a second-stage oil inlet pipe, a third-stage oil inlet pipe, three electromagnetic reversing valves and a proportional overflow valve; the first-stage oil inlet pipe, the second-stage oil inlet pipe and the third-stage oil inlet pipe are fixedly arranged in the pressure cylinder body; one electromagnetic reversing valve and one proportional overflow valve are arranged on the first-stage oil inlet pipe, the second-stage oil inlet pipe and the third-stage oil inlet pipe; and the proportional overflow valve is arranged between the pressure cylinder body and the electromagnetic reversing valve. The guide sleeve, the first piston rod, the first piston head and the inner wall of the injection cylinder form a first oil pressure cavity, the first oil inlet pipe is communicated with the first oil pressure cavity; the third piston is provided with an isolation ring, the outer wall of the isolation ring is in contact with the inner wall of the injection cylinder, the isolation ring, the third piston, the second piston rod, the second piston head, the inner wall of the first piston rod, the guide sleeve and the inner wall of the injection cylinder form a second oil pressure cavity, the second oil inlet pipe is communicated with the second oil pressure cavity; the third piston, the isolation ring and the injection cylinder form a third oil pressure cavity, the third oil inlet pipe is communicated with the third oil pressure cavity.

[0010] Preferably, the injection cylinder is provided with a slurry inlet at one end close to the first piston; the slurry inlet is provided with a slurry rheological property control mechanism; the slurry rheological property control mechanism comprises a double screw stirring mechanism and a screw control mechanism; the double screw stirring mechanism is connected with the injection cylinder through the screw control mechanism; the double screw stirring mechanism is used for stirring the slurry raw materials; and the screw control mechanism is used for conveying the slurry into the injection cylinder.

[0011] Preferably, the double screw stirring mechanism comprises a stirring shell, a driving member, a feeding hopper and a pair of stirring screws; the pair of stirring screws are rotatably connected to the stirring shell about the axis thereof, the driving member is installed on the stirring shell, and the output end of the driving member is connected with the pair of stirring screws; the feeding hopper is arranged on one side of the stirring shell close to the driving member and is used for guiding the aluminum alloy raw material particles into the stirring shell.

[0012] Preferably, the screw control mechanism comprises a conical shell, a screw pushing head, a floating isolation seat and a motor; one end of the conical shell is connected with the injection cylinder, the other end of the conical shell is connected with the stirring shell, and the screw pushing head is coaxially arranged in the conical shell; the screw pushing head is a conical structure matched with the inner wall of the conical shell, and the pitch of the screw pushing head gradually decreases from the feeding end to the discharging end; the floating isolation seat is installed on the first piston head, the motor is fixedly arranged on the floating isolation seat, and the output end of the motor is coaxially connected with the screw pushing head; the check valve is arranged at a position close to the injection cylinder in the stirring shell. The screw control mechanism further comprises a guide pipe; one end of the guide pipe is fixedly arranged on the first piston head, the guide pipe is slidably connected to the injection cylinder along the axis thereof, and the wire of the motor is inserted into the guide pipe.

[0013] Preferably, the slurry rheological property control mechanism further comprises a temperature control mechanism, the temperature control mechanism comprises a pair of temperature controllers arranged on the stirring shell and a temperature controller arranged on the conical shell; the temperature of the slurry in the stirring shell and the conical shell is controlled through the temperature controllers.

[0014] The semi-solid die-casting method of the environment-friendly ultra-thin-wall high-strength aluminum alloy profile includes a semi-solid die-casting device of the environment-friendly ultra-thin-wall high-strength aluminum alloy profile, and specifically includes the following steps: Step one, three-stage propulsion: first, the first-stage piston, the second-stage piston and the third-stage piston are all in a fully retracted state; the oil supply is controlled by the oil path control mechanism to drive the first-stage piston to move forward, so that the slurry enters the flow channel, and the first-stage propulsion is completed; then, the oil supply is controlled by the oil path control mechanism to drive the second-stage piston to advance, so that the second-stage piston moves synchronously with the first-stage piston, and the second-stage relay is realized; finally, the oil supply is controlled by the oil path control mechanism to drive the third-stage piston to advance, so that the final filling is completed, and the third-stage sprint is realized. Step two, return reset: after the filling is completed, the oil return is controlled by the oil path control mechanism, so that the third-stage piston is retracted first, then the second-stage piston is retracted in sequence, and finally the first-stage piston is retracted, and finally all of them are reset to the initial position.

[0015] In summary, the technical effects and advantages of the present application are as follows: The present application has a reasonable structure, by setting up a multi-stage supercharging mechanism, driving the first-stage piston, the second-stage piston and the third-stage piston to slide along the pressure cylinder body in the axial direction, gradually increasing the slurry pressure and pressure, and dynamically adjusting the piston thrust by the oil path control mechanism, realizing stepless continuous adjustment of the pressure, improving the slurry filling effect. In the present application, by setting up a slurry rheological property control mechanism, the slurry stirring and pressure injection are combined, the slurry preparation function of the double screw is embedded in the front flow channel of the pressure injection mechanism by coaxial nesting and time sequence linkage design, the propulsion force of the pressure injection piston is used to replace the traditional conveying pump, so that the slurry is always in a closed environment from preparation to pressure injection, and the solid phase particle refinement, solid phase rate control and high pressure filling are completed synchronously, eliminating the slurry conveying delay and performance decay problem of the traditional split type equipment.

[0016] By setting up a spiral control mechanism, the motor is moved by the first-stage piston, so that the spiral propulsion head realizes rotary and linear compound motion, and the stable motion and power transmission are ensured by precise shafting design; in the stirring stage, the reverse meshing shear of the spiral propulsion head and the double screw and the segmented temperature control are relied on to realize slurry homogenization; in the stage of discharging into the first supercharging cavity, the qualified slurry is efficiently guided into the first supercharging cavity through forward pushing, reverse valve avoidance design and pre-compression, laying a foundation for subsequent pressure injection molding. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0018] Figure 1 The overall schematic diagram of the three-dimensional structure of the present application; Figure 2 The schematic diagram of the three-dimensional enlarged structure of the multi-stage supercharging mechanism of the present application; Figure 3 The schematic diagram of the three-dimensional enlarged structure of the partial section of the injection cylinder of the present application; Figure 4 The schematic diagram of the three-dimensional enlarged structure of the partial section of the three-stage nested piston mechanism of the present application; Figure 5 The schematic diagram of the three-dimensional enlarged structure of the main section of the three-stage nested piston mechanism of the present application; Figure 6 The schematic diagram of the three-dimensional structure of the overall partial section of the first perspective angle of the present application; Figure 7 The schematic diagram of the three-dimensional structure of the overall partial section of the second perspective angle of the present application; Figure 8 The schematic diagram of the enlarged structure of the A area of the present application Figure 7 Figure 9 The schematic diagram of the specific three-dimensional enlarged section of the partial structure of the spiral control mechanism of the present application; Figure 10 The schematic diagram of the method flow of the present application.

[0019] In the figure: 1, injection head; 2, multi-stage supercharging mechanism; 21, three-stage nested piston mechanism; 211, injection cylinder; 212, first-stage piston; 2121, first piston rod; 2122, first piston head; 2123, first flow-through hole; 213, guide sleeve; 214, first-stage supercharging cavity; 215, second-stage piston; 2151, second piston rod; 2152, second piston head; 2153, second flow-through hole; 216, second-stage supercharging cavity; 217, third-stage piston; 218, third flow-through hole; 219, third-stage supercharging cavity; 22, oil path control mechanism; 221, first-stage oil inlet pipe; 222, first-stage oil pressure cavity; 223, second-stage oil inlet pipe; 224, second-stage oil pressure cavity; 225, third-stage oil inlet pipe; 226, isolation ring; 227, third-stage oil pressure cavity; 228, electromagnetic reversing valve; 229, proportional overflow valve; 3, slurry rheological property control mechanism; 31, double-screw stirring mechanism; 311, stirring shell; 312, stirring screw; 313, driving member; 314, feed hopper; 32, spiral control mechanism; 321, conical shell; 322, spiral pushing head; 323, floating isolation seat; 324, motor; 325, guide pipe; 326, check valve; 33, temperature control mechanism; 331, temperature controller. DETAILED DESCRIPTION

[0020] ​With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0021] Embodiment 1: see Figures 1-4 The semi-solid die casting device for environment-friendly ultra-thin-wall high-strength aluminum alloy profiles shown in the embodiment comprises a multi-stage pressurizing mechanism 2 connected with a pressure head 1; the pressure head 1 is provided with a pressure sensor; the multi-stage pressurizing mechanism 2 comprises a three-stage nested piston mechanism 21 and an oil path control mechanism 22; the three-stage nested piston mechanism 21 comprises a pressure cylinder body 211, a first-stage piston 212, a guide sleeve 213, a second-stage piston 215 and a third-stage piston 217; the pressure cylinder body 211 is connected with a die casting machine frame through flanges at both ends; the first-stage piston 212 is slidingly connected in the pressure cylinder body 211 along an axial direction thereof; the guide sleeve 213 is coaxially sleeved on the first-stage piston 212, and an outer wall of the guide sleeve 213 abuts against an inner wall of the pressure cylinder body 211; the second-stage piston 215 is coaxially inserted into the first-stage piston 212; one end of the third-stage piston 217 is coaxially inserted into the second-stage piston 215, and the other end of the third-stage piston 217 extends outward of the pressure cylinder body 211 and is coaxially connected with the pressure head 1; a plurality of first flow-through holes 2123 are formed in the first-stage piston 212, a second flow-through hole 2153 is formed in the second-stage piston 215, and a third flow-through hole 218 is formed in the third-stage piston 217; slurry passes through the first flow-through holes 2123, the second flow-through hole 2153 and the third flow-through hole 218 in sequence and communicates with the pressure head 1; one end of the oil path control mechanism 22 is connected with the inside of the pressure cylinder body 211, the other end of the oil path control mechanism 22 is connected with a hydraulic pump station, and the oil path control mechanism 22 is used for controlling the first-stage piston 212, the second-stage piston 215 and the third-stage piston 217 to slide along the pressure cylinder body 211 in an axial direction.

[0022] It should be noted that the injection head 1 is connected with the multi-stage supercharging mechanism 2, and the pressure sensor in the injection head 1 can monitor the pressure in the injection process in real time; when the three-stage nested piston mechanism 21 in the multi-stage supercharging mechanism 2 is working, by controlling the input and output of hydraulic oil, the first-stage piston 212, the second-stage piston 215 and the third-stage piston 217 are driven to slide along the injection cylinder body 211 in the axial direction, so that the slurry treated by stirring enters from one end of the injection cylinder body 211, first enters the first-stage supercharging cavity 214 through the first flow-through hole 2123 on the first-stage piston 212, then enters the second-stage supercharging cavity 216 through the second flow-through hole 2153 on the second-stage piston 215, and finally flows to the injection head 1 through the third flow-through hole 218 on the third-stage piston 217, so as to realize the injection action; and the injection force is detected in real time through the pressure sensor in the injection head 1, and the data is transmitted to the PLC controller, so that the piston thrust can be dynamically adjusted through the oil way control mechanism 22, so as to realize stepless continuous adjustment of the pressure; it can be understood that the pressure sensor and the PLC controller are both prior art, wherein the pressure sensor is a strain gauge type pressure sensor, which is not shown in the figure and will not be described in detail; The three-stage nested piston mechanism 21 can realize multi-stage supercharging, and the oil way control mechanism 22 can dynamically adjust the pressure according to the injection process, so as to solve the problem that the pressure of the injection mechanism in the traditional split type equipment is insufficient and difficult to dynamically adjust, meet the stringent requirements of the super-thin-walled aluminum alloy profile on the injection pressure, and reduce defects such as air entrapment and insufficient pouring; and the cooperation of the first flow-through hole 2123, the second flow-through hole 2153 and the third flow-through hole 218 provides a stable conveying path for the slurry, reduces the flow resistance of the slurry in the conveying process, avoids the stagnation or agglomeration of solid particles in the conveying path, and helps to maintain the good fluidity of the slurry.

[0023] Please refer to Figures 1-5 The first-stage piston 212 includes a first piston rod 2121 and a first piston head 2122; one end of the first piston rod 2121 is coaxially connected with the first piston head 2122, and the first piston head 2122 is coaxially and slidingly connected in the injection cylinder body 211; one side of the first piston head 2122 surrounds the first-stage supercharging cavity 214 with the injection cylinder body 211; a displacement sensor is arranged between the first piston rod 2121 and the injection cylinder body 211 and is used to detect the displacement of the first piston head 2122; the second-stage piston 215 includes a second piston rod 2151 and a second piston head 2152; one end of the second piston rod 2151 is coaxially connected with the second piston head 2152; a first guide slot is formed in the first piston rod 2121, and the second piston head 2152 is coaxially and slidingly connected in the first guide slot; one side of the second piston head 2152 surrounds the second-stage supercharging cavity 216 with the first guide slot; a second guide slot is formed in the second piston rod 2151, and one end of the third-stage piston 217 surrounds the third-stage supercharging cavity 219 with the second guide slot.

[0024] It should be noted that during operation, after the slurry enters the first-stage pressure-increasing cavity 214, the pressure in the first-stage pressure-increasing cavity 214 increases with the advancement of the first-stage piston 212, and the slurry is pushed to pass through the first flow-through hole 2123 into the second-stage pressure-increasing cavity 216 at a relatively slow speed; a lower pressure and speed are adopted to avoid turbulence due to excessive speed at the initial stage of filling, thereby reducing the occurrence of air entrapment; when the slurry enters the cavity at the initial stage, approximately 50% of the cavity is filled, and the second-stage piston 215 starts to work, thereby further increasing the pressure and speed; at this time, the difficulty of cavity filling gradually increases, and a greater pressure is required to push the slurry to continue to flow; at this time, the first-stage piston 212 and the second-stage piston 215 move synchronously, and the pushing forces of the two are superimposed to jointly overcome the gradually increasing flow resistance of the cavity, thereby ensuring the continuous filling of the slurry; at the final stage of filling, i.e., the stage of filling the last 30% of the cavity, the third-stage piston 217 is started, and the pressure and speed are further increased; this is because the far-end region of the ultra-thin-wall profile has the greatest difficulty in filling, and extremely high pressure and speed are required to ensure that the slurry fills this region before solidification; therefore, through the design of the multi-stage pressure-increasing cavity, the pressure of the slurry can be gradually increased, and appropriate pressure can be provided according to different stages of the filling process of the ultra-thin-wall aluminum alloy profile, thereby improving the cavity filling capacity of the slurry; during the working stage of the third-stage piston 217, the injection force is collected in real time through the pressure sensor, and if the detected pressure exceeds the preset threshold value, the controller will reduce the oil supply pressure through the oil path control mechanism 22 to avoid overloading of the mold; if the pressure is insufficient, the oil supply pressure is increased to ensure sufficient filling; after filling is completed, the oil path control mechanism 22 sequentially switches the control of the return oil in the order of the third-stage piston 217, the second-stage piston 215, and the first-stage piston 212, and the hydraulic oil flows back to the oil tank through the return oil path, so that the third-stage piston 217, the second-stage piston 215, and the first-stage piston 212 retreat to the initial position, preparing for the next die casting cycle; It should be noted that the diameter of the first piston head 2122 is greater than that of the second piston head 2152, and the diameter of the second piston head 2152 is greater than that of the third-stage piston 217, so that the injection specific pressure is amplified under the same oil supply pressure, and the pushing speed can be increased at the same time; Furthermore, during operation, the sliding distance of the first piston head 2122 in the injection cylinder body 211 is monitored in real time through the displacement sensor, and the displacement signal is transmitted to the control system; the control system judges the movement state of the first-stage piston 212 according to the displacement data, and then adjusts the oil supply through the oil path control mechanism 22 to ensure that the first-stage piston 212 moves according to the preset trajectory; the displacement sensor can accurately grasp the position of the first-stage piston 212, providing data support for the coordinated movement of the pistons, ensuring the accuracy of the injection process, and reducing filling defects caused by movement deviation of the pistons; it can be understood that the displacement sensor and the control system are both prior art, and the control system is a PLC control system, which is not shown in the figure and will not be described in detail.

[0025] Please refer to Figures 1-5The oil path control mechanism 22 comprises a first-stage oil inlet pipe 221, a second-stage oil inlet pipe 223, a third-stage oil inlet pipe 225, three electromagnetic reversing valves 228, and proportional overflow valves 229; the first-stage oil inlet pipe 221, the second-stage oil inlet pipe 223, and the third-stage oil inlet pipe 225 are fixedly arranged on the injection cylinder body 211, and each of the first-stage oil inlet pipe 221, the second-stage oil inlet pipe 223, and the third-stage oil inlet pipe 225 is provided with an electromagnetic reversing valve 228 and a proportional overflow valve 229, and the proportional overflow valve 229 is arranged between the injection cylinder body 211 and the electromagnetic reversing valve 228; the guide sleeve 213, the first piston rod 2121, the first piston head 2122, and the inner wall of the injection cylinder body 211 form a first-stage oil pressure cavity 222, and the first-stage oil inlet pipe 221 is in communication with the first-stage oil pressure cavity 222; the third-stage piston 217 is fixedly provided with a separation ring 226, the outer wall of the separation ring 226 abuts against the inner wall of the injection cylinder body 211, and the separation ring 226, the third-stage piston 217, the second piston rod 2151, the second piston head 2152, the inner wall of the first piston rod 2121, the guide sleeve 213, and the inner wall of the injection cylinder body 211 form a second-stage oil pressure cavity 224, and the second-stage oil inlet pipe 223 is in communication with the second-stage oil pressure cavity 224; the third-stage piston 217, the separation ring 226, and the injection cylinder body 211 form a third-stage oil pressure cavity 227, and the third-stage oil inlet pipe 225 is in communication with the third-stage oil pressure cavity 227.

[0026] It should be noted that the electromagnetic reversing valve 228 controls the on-off of each oil inlet pipe, the hydraulic oil enters the first-stage oil pressure cavity 222 through the first-stage oil inlet pipe 221 to drive the first-stage piston 212 to move, enters the second-stage oil pressure cavity 224 through the second-stage oil inlet pipe 223 to drive the second-stage piston 215 to move, enters the third-stage oil pressure cavity 227 through the third-stage oil inlet pipe 225 to drive the third-stage piston 217 to move, and the proportional overflow valve 229 adjusts the oil pressure in each oil pressure cavity; the independent oil path control enables the movement of the first-stage piston 212, the second-stage piston 215, and the third-stage piston 217 to be independently regulated, the pressure is flexibly adjusted, the pressure can be changed in real time according to different requirements of the filling process, the injection process is stable, and the product forming quality is improved.

[0027] Please refer to Figure 1 and Figure 6 The end of the injection cylinder body 211 close to the first-stage piston 212 is provided with a slurry inlet; the slurry inlet is provided with a slurry rheological property control mechanism 3; the slurry rheological property control mechanism 3 comprises a double-screw stirring mechanism 31 and a screw control mechanism 32; the double-screw stirring mechanism 31 is connected to the injection cylinder body 211 through the screw control mechanism 32; the double-screw stirring mechanism 31 is used for stirring the slurry raw materials; and the screw control mechanism 32 is used for conveying the slurry into the injection cylinder body 211.

[0028] It should be noted that the double screw stirring mechanism 31 stirs the aluminum alloy raw material to form a semi-solid slurry, and the screw control mechanism 32 stably delivers the stirred slurry into the injection cylinder 211; the slurry rheological property control mechanism 3 realizes the integration of slurry preparation and delivery, reduces the performance fluctuation of the slurry in the transmission process, ensures the stability of the solid phase rate, and is beneficial to meet the stringent requirements of the ultra-thin wall aluminum alloy profile on the fluidity of the slurry.

[0029] Please refer to Figures 6-7 It should be understood that the specific structure and installation method of the double screw stirring mechanism 31 are not limited in the present application, and only one feasible technical solution is provided below; the double screw stirring mechanism 31 includes a stirring shell 311, a driving member 313, a feed hopper 314, and a pair of stirring screws 312; the pair of stirring screws 312 are rotatably connected to the stirring shell 311 about their axes, the driving member 313 is installed on the stirring shell 311, and the output end of the driving member 313 is connected to the pair of stirring screws 312; the feed hopper 314 is arranged on one side of the stirring shell 311 close to the driving member 313 and is used to introduce aluminum alloy raw material particles into the stirring shell 311.

[0030] It should be noted that the aluminum alloy raw material particles enter the stirring shell 311 from the feed hopper 314, the driving member 313 drives the pair of stirring screws 312 to rotate, and the stirring screws 312 shear and mix the raw material to form a semi-solid slurry with uniform distribution of solid phase particles. The double screw stirring can effectively refine the solid phase particles, reduce the particle agglomeration phenomenon, and improve the uniformity of the slurry, thereby providing high-quality slurry for subsequent die casting.

[0031] Please refer to Figures 6-9 The screw control mechanism 32 includes a conical shell 321, a screw pushing head 322, a floating isolation seat 323, and a motor 324; one end of the conical shell 321 is connected to the injection cylinder 211, the other end of the conical shell 321 is connected to the stirring shell 311, and the screw pushing head 322 is coaxially arranged in the conical shell 321; the screw pushing head 322 is a conical structure matched with the inner wall of the conical shell 321, and the pitch of the screw pushing head 322 gradually decreases from the feeding end to the discharging end; the floating isolation seat 323 is installed on the first piston head 2122, the motor 324 is fixedly arranged on the floating isolation seat 323, and the output end of the motor 324 is coaxially connected with the screw pushing head 322; a check valve 326 is arranged in the stirring shell 311 close to the injection cylinder 211; the screw control mechanism 32 further includes a guide pipe 325; one end of the guide pipe 325 is fixedly arranged on the first piston head 2122, the guide pipe 325 is slidably connected to the injection cylinder 211 along its axis, and the wires of the motor 324 are inserted into the guide pipe 325.

[0032] It should be noted that the motor 324 drives the screw push head 322 to rotate in the conical shell 321, and the stirred slurry is transported to the injection cylinder 211 under the action of the screw push head 322. The gradually decreasing pitch makes the slurry be compressed step by step, and the conical structure and variable pitch design enhance the pushing force and compression effect on the slurry, and the check valve 326 prevents the slurry from flowing back; the guide pipe 325 moves with the first piston head 2122 and protects the wires of the motor 324, ensuring the safety of the motor wires during the movement of the piston and improving the stability of the slurry transportation; It should be noted that the taper of the screw push head 322 is 5°-10°, and the gap between the conical surface thereof and the conical shell 321 is 0.1-0.3mm, which gradually increases from the front end to the rear end in the axial direction. The front end can ensure the sealing during injection; the rear end is slightly larger to avoid movement interference. The gap is much smaller than the diameter of the solid particles in the slurry, which can not only prevent the particles from being stuck, but also reduce the leakage of the slurry through the liquid film sealing effect; During the raw material introduction and preliminary preheating stage: the first piston 212 is retracted backward, driving the screw push head 322 to retreat, and the position between the stirring shell 311 and the conical shell 321 forms a negative pressure, which sucks the molten metal raw material into the stirring cavity in the conical shell 321. At this time, the motor 324 drives the screw push head 322 to rotate in reverse, and the convex teeth thereof mesh with the concave teeth of the pair of stirring screws 312 to form shearing; when the screw push head 322 rotates in reverse, high-frequency shearing force is generated in the tooth gap, which further breaks the blocky solid particles in the raw material. At the same time, the stirring screws 312 rotate in the opposite direction, i.e. opposite to the screw push head 322, to form cross shearing, which further refines the particles; and before the slurry is introduced into the injection cylinder 211, the rotation speed of the screw push head 322 is controlled to decrease, and the slurry flows along the axial direction through the guiding effect of the screw groove, ensuring uniform composition; After stirring is completed, the screw push head 322 is switched to the pushing mode, and the homogeneous slurry is sent into the first booster cavity 214 through the cooperation of the check valve 326 and the first piston 212. The specific process is as follows: The motor 324 drives the screw push head 322 to rotate forward, and the first piston 212 advances forward, and the axial thrust is generated by the superposition of the two, which pushes the slurry into the first booster cavity 214; the pressure of the slurry increases under the pushing of the screw push head, and the sector valve of the check valve 326 is opened, the valve rotates around the edge shaft, and avoids the center screw push head 322, at this time the screw push head 322 has stopped rotating, only through the axial movement to push; the opened check valve 326 and the conical surface of the front end of the screw push head 322 form a converging flow channel, the slurry flow rate decreases, and enters the first booster cavity 214 along the flow channel; the screw push head 322 continuously advances with the first piston 212, the volume of the first booster cavity 214 gradually decreases, the slurry is pre-compressed, the air bubbles are removed, and the pressure is stable, which prepares for the subsequent multi-stage compression.

[0033] Please refer toFigures 6-7 The slurry rheological property control mechanism 3 further comprises a temperature control mechanism 33, which comprises a pair of temperature controllers 331 arranged on the stirring shell 311 and a temperature controller 331 arranged on the conical shell 321; the temperature controllers 331 control the temperature of the slurry in the stirring shell 311 and the conical shell 321.

[0034] It should be noted that the temperature controllers 331 monitor the temperature in the stirring shell 311 and the conical shell 321 in real time, and adjust the temperature by heating or cooling, so that the temperature of the slurry in different areas is maintained within a suitable range to control the solid phase rate of the slurry; specifically, the stirring shell 311 is divided into a feeding section and a shearing section, and the conical shell 321 is a discharging section, and each of the feeding section, the shearing section and the discharging section is provided with a temperature controller 331, and the temperature is adjusted by a thermocouple and a PID controller to accurately control the solid phase rate; that is, when the slurry is stirred in the conical shell 321, the temperature control is matched: the temperature controller 331 outside the conical shell 321 is started, the temperature is fed back in real time by the thermocouple, the heating power is adjusted by the PID controller, the raw materials are preheated to a semi-molten state, and the subsequent shearing resistance is reduced; and a high-frequency induction coil is arranged at the discharge port, the solid phase rate is calculated in real time by detecting the change of the electrical conductivity of the slurry, that is, by the difference between the electrical conductivity of the solid and liquid phases, the data is fed back to the temperature control mechanism 33 to realize closed-loop control, and the solid phase rate is ensured to be stable; it can be understood that the thermocouple, the PID controller and the high-frequency induction coil are prior art and are not shown in the figure and will not be described in detail.

[0035] Accurate temperature control ensures that the viscosity of the slurry is always within a suitable range, avoiding poor flowability of the slurry due to temperature fluctuations, and is beneficial to improving the consistency of the ultra-thin-walled aluminum alloy profile forming.

[0036] Embodiment 2: The technical solution of this embodiment is different from that of Embodiment 1 in that Figures 1-10 The semi-solid die casting method of the environment-friendly ultra-thin-walled high-strength aluminum alloy profile comprises the semi-solid die casting device of the environment-friendly ultra-thin-walled high-strength aluminum alloy profile, and specifically comprises the following steps: Step one, three-stage propulsion: first, the first-stage piston 212, the second-stage piston 215 and the third-stage piston 217 are all in a fully retracted state; the oil supply is controlled by the oil path control mechanism 22 to drive the first-stage piston 212 to move forward, so that the slurry enters the flow channel, and the first-stage propulsion is completed; then, the oil supply is controlled by the oil path control mechanism 22 to drive the second-stage piston 215 to advance, so that it moves synchronously with the first-stage piston 212, and the second-stage relay is realized; finally, the oil supply is controlled by the oil path control mechanism 22 to drive the third-stage piston 217 to advance, so that the last filling is completed, and the three-stage sprint is realized. Step two, back stroke reset: after filling, the oil control mechanism 22 controls the oil return, so that the three-stage piston 217 is first retracted, then the two-stage piston 215 is retracted in turn, and finally the one-stage piston 212 is retracted, and finally all are reset to the initial position.

[0037] Finally, it should be noted that the above only for the preferred embodiments of the present application, and is not intended to limit the present application, although the foregoing detailed description of the application has been made with reference to the foregoing embodiments, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement, within the spirit and principles of the present application, any modification, equivalent replacement, improvement, etc., should be included within the scope of the present application.

Claims

1. A semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles, characterized in that: It comprises a multi-stage pressurizing mechanism (2) connected to a shot-shooting head (1); a pressure sensor is provided in the shot-shooting head (1); the multi-stage pressurizing mechanism (2) comprises: A three-stage nested piston mechanism (21), the three-stage nested piston mechanism (21) comprising an injection cylinder body (211), a first-stage piston (212), a second-stage piston (215) and a third-stage piston (217); both ends of the injection cylinder body (211) are connected to a die-casting machine frame via flanges; the first-stage piston (212) is connected to the injection cylinder body (211) by sliding along its axial direction; the second-stage piston (215) is coaxially plugged into the first-stage piston (212); one end of the third-stage piston (217) is coaxially plugged into the second-stage piston (215), and the other end of the third-stage piston (217) extends outward from the injection cylinder body (211) and is coaxially connected to the injection head (1); and an oil circuit control mechanism (22), one end of which is connected to the interior of the injection cylinder body (211), and the other end of which is connected to the hydraulic pump station, and is used to control the first-stage piston (212), the second-stage piston (215), and the third-stage piston (217) to slide axially along the injection cylinder body (211).

2. The semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles according to claim 1, characterized in that: The first-stage piston (212) is provided with a plurality of first flow holes (2123), the second-stage piston (215) is provided with a second flow hole (2153), and the third-stage piston (217) is provided with a third flow hole (218); the slurry is connected to the injection head (1) through the first flow holes (2123), the second flow holes (2153), and the third flow holes (218) in sequence.

3. The semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles according to claim 2, characterized in that: The secondary piston (215) includes a second piston rod (2151) and a second piston head (2152); the primary piston (212) includes a first piston rod (2121) and a first piston head (2122); one end of the first piston rod (2121) is coaxially connected to the first piston head (2122), and the first piston head (2122) is coaxially slidably connected to the injection cylinder body (211); one side of the first piston head (2122) and the injection cylinder body (211) form a primary pressure chamber (214); One end of the second piston rod (2151) is coaxially connected to the second piston head (2152); a first guide groove is provided in the first piston rod (2121), and the second piston head (2152) is coaxially slidably connected to the first guide groove; one side of the second piston head (2152) and the first guide groove form a secondary pressure chamber (216); A second guide groove is provided on the second piston rod (2151), and one end of the three-stage piston (217) and the second guide groove form a three-stage boosting chamber (219).

4. The semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles according to claim 3, characterized in that: A displacement sensor is provided between the first piston rod (2121) and the injection cylinder body (211), and is used to detect the displacement of the first piston head (2122).

5. The semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles according to claim 3, characterized in that: The oil circuit control mechanism (22) includes a first-stage oil inlet pipe (221), a second-stage oil inlet pipe (223), a third-stage oil inlet pipe (225), three electromagnetic reversing valves (228) and a proportional relief valve (229); the first-stage oil inlet pipe (221), the second-stage oil inlet pipe (223) and the third-stage oil inlet pipe (225) are all fixedly mounted on the injection cylinder body (211); the first-stage oil inlet pipe (221), the second-stage oil inlet pipe (223) and the third-stage oil inlet pipe (225) are each provided with an electromagnetic reversing valve (228) and a proportional relief valve (229); and the proportional relief valve (229) is arranged between the injection cylinder body (211) and the electromagnetic reversing valve (228); The inner wall of the injection cylinder body (211) is coaxially fixed with a guide sleeve (213), and the guide sleeve (213) is sleeved on the first-stage piston (212); the guide sleeve (213), the first piston rod (2121), the first piston head (2122) and the inner wall of the injection cylinder body (211) form a first-stage oil pressure chamber (222), and the first-stage oil inlet pipe (221) is connected to the first-stage oil pressure chamber (222); an isolation ring (226) is fixed on the third-stage piston (217), and the outer wall of the isolation ring (226) contacts the inner wall of the injection cylinder body (211). The isolating ring (226), the third-stage piston (217), the second piston rod (2151), the second piston head (2152), the inner wall of the first piston rod (2121), the guide sleeve (213) and the inner wall of the injection cylinder body (211) form a second-stage oil pressure chamber (224), and the second-stage oil inlet pipe (223) is connected to the second-stage oil pressure chamber (224); the third-stage piston (217), the isolating ring (226) and the injection cylinder body (211) form a third-stage oil pressure chamber (227), and the third-stage oil inlet pipe (225) is connected to the third-stage oil pressure chamber (227).

6. The semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles according to claim 3, characterized in that: A slurry inlet is provided at one end of the injection cylinder body (211) close to the first-stage piston (212); the slurry inlet is provided with a slurry rheology control mechanism (3); the slurry rheology control mechanism (3) includes a twin-screw stirring mechanism (31) and a spiral control mechanism (32); the twin-screw stirring mechanism (31) is connected to the injection cylinder body (211) via the spiral control mechanism (32); the twin-screw stirring mechanism (31) is used to stir the slurry raw material; and the spiral control mechanism (32) is used to transport the slurry into the injection cylinder body (211).

7. The semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles according to claim 6, characterized in that: The twin-screw stirring mechanism (31) comprises a stirring shell (311), a driving member (313), a feed hopper (314), and a pair of stirring screws (312); the pair of stirring screws (312) are connected to the stirring shell (311) by rotating around their axes, the driving member (313) is mounted on the stirring shell (311), and the output end of the driving member (313) is connected to the pair of stirring screws (312); a feed hopper (314) is provided on one side of the stirring shell (311) close to the driving member (313), and is used to introduce aluminum alloy raw material particles into the stirring shell (311).

8. The semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles according to claim 7, characterized in that: The spiral control mechanism (32) includes a conical shell (321), a spiral push head (322), a floating isolation seat (323), and a motor (324); one end of the conical shell (321) is connected to the injection cylinder body (211), and the other end of the conical shell (321) is connected to the stirring shell (311); the spiral push head (322) is coaxially arranged in the conical shell (321); the spiral push head (322) is connected to the conical shell (321) ) has a conical structure adapted to the inner wall thereof, and the pitch of the spiral push head (322) gradually decreases from the feed end to the discharge end; a floating isolation seat (323) is installed on the first piston head (2122), the motor (324) is fixed to the floating isolation seat (323), and the output end of the motor (324) is coaxially connected to the spiral push head (322); a check valve (326) is provided in the stirring shell (311) at a position close to the injection cylinder body (211); The spiral control mechanism (32) further includes a guide tube (325); one end of the guide tube (325) is fixed to the first piston head (2122), the guide tube (325) is slidably connected to the injection cylinder body (211) along its axis, and the wire of the motor (324) is inserted into the guide tube (325).

9. The semi-solid die-casting device for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles according to claim 6, characterized in that: The slurry rheology control mechanism (3) further includes a temperature control mechanism (33), wherein the temperature control mechanism (33) includes a pair of temperature controllers (331) provided on the stirring shell (311) and a temperature controller (331) provided on the conical shell (321); the temperature of the slurry in the stirring shell (311) and the conical shell (321) is controlled by the temperature controller (331).

10. A semi-solid die-casting method for environmentally friendly ultra-thin-wall high-strength aluminum alloy profiles, characterized by: A semi-solid die-casting device for an environmentally friendly ultra-thin-wall high-strength aluminum alloy profile according to any one of claims 1 to 9, specifically comprising the following steps: Step 1, three-stage propulsion: First, the first-stage piston (212), the second-stage piston (215) and the third-stage piston (217) are all in a fully retracted state; the oil supply is controlled by the oil circuit control mechanism (22) to push the first-stage piston (212) forward, so that the slurry enters the flow channel, and the first-stage propulsion is completed; then, the oil supply is controlled by the oil circuit control mechanism (22) to drive the second-stage piston (215) to advance, so that it moves synchronously with the first-stage piston (212), and realize the second-stage relay; finally, the oil supply is controlled by the oil circuit control mechanism (22) to drive the third-stage piston (217) forward, complete the final filling, and realize the third-stage sprint; Step 2: Return stroke reset: After filling is completed, the oil circuit control mechanism (22) controls the oil return, so that the third-stage piston (217) retracts first, then the second-stage piston (215) retracts in sequence, and the last-stage piston (212) retracts, and finally all three are reset to their initial positions.

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