Multi-area independent temperature control system and method for aluminum alloy precision forging forming die

Abstract

The invention provides an aluminum alloy precision forging forming die multi-area independent temperature control system and method, the system comprises a forming die assembly, a force thermal decoupling support base, a fluid temperature control supply station and a main control unit, the forming die assembly comprises a plurality of heat conduction inserts separated by heat insulation isolation layers; a rigid bearing loop and a dynamic thermal control loop which are parallel to each other are integrated on the force thermal decoupling supporting base, the dynamic thermal control loop drives the high-thermal-conductivity telescopic thermal bridge and the interface flexible dielectric layer to ascend and descend through a displacement actuator, and in a non-forging state, the thermal bridge supports the heat conduction insert and maintains a safety gap with the rigid bearing stand column; in the forging impact stage, the heat conduction insert moves downwards to eliminate the safety gap, the rigid bearing stand column bears the forming load, the main control unit adjusts the output force of the actuator according to temperature feedback, and the contact thermal resistance is adjusted and controlled in real time by changing the interface contact pressure. The problem that a precise temperature control assembly is difficult to bear forging impact is solved, and quick and precise response of multi-area independent heat flow is achieved.

Description

Technical Field

[0001] This invention relates to the field of metal forming and manufacturing technology, specifically to a multi-zone independent temperature control system and method for aluminum alloy precision forging forming molds. Background Technology

[0002] Precision forging of aluminum alloys is a key process for manufacturing lightweight, high-performance structural components in the aerospace and automotive industries. Its forming quality, dimensional accuracy, and microstructure are closely related to the temperature field evolution during forging. Fluctuations in die temperature directly affect the fluidity and filling behavior of the billet; therefore, the die temperature control system is a core equipment unit for ensuring the stability of the forging process and the consistency of the products.

[0003] In existing industrial applications, temperature control of forging dies primarily employs pre-embedded fluid pipelines. This method typically involves machining complex heating or cooling channels within the die steel, and then circulating heat exchange media such as heat transfer oil, water, or steam into these channels via a circulating pump station. During production, the system mainly relies on the convective heat transfer mechanism between the fluid and the channel walls to regulate the average temperature of the die substrate, maintaining the die's thermal equilibrium under continuous production cycles and preventing overheating during annealing or undercooling that could lead to filling difficulties.

[0004] However, existing technologies present a significant structural contradiction between achieving high dynamic response temperature control and withstanding extreme forming loads. To meet the stringent requirements of complex aluminum alloy components for local temperature fields, it is often necessary to introduce active heat flow control devices with fast response speeds and high adjustment precision. These devices typically include piezoelectric ceramics, high thermal conductivity materials, or precision mechanical adjustment mechanisms, and their physical characteristics are characterized by high brittleness or low compressive strength. The inherent characteristic of forging processes is the presence of enormous instantaneous impact loads and intense mechanical vibrations. This extreme working environment far exceeds the mechanical load-bearing limits of precision temperature control devices. Existing mold structure designs often cannot provide effective mechanical isolation protection for the internally integrated precision temperature control components while transmitting forming forces. This results in highly sensitive temperature control elements being prone to physical breakage or failure due to overload pressure during forging impacts, forcing the industry to rely on traditional fluid flow channel solutions that are structurally robust but have slow thermal response, making it difficult to overcome the temperature control bottleneck in the precision forming of complex components. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a multi-zone independent temperature control system and method for aluminum alloy precision forging molds, aiming to solve the technical problem that existing forging mold temperature control components cannot simultaneously achieve high-sensitivity thermal regulation and high-strength load-bearing protection.

[0006] To achieve the above objectives, the present invention provides a multi-zone independent temperature control system for aluminum alloy precision forging forming molds. The system mainly consists of forming mold components, a force-thermal decoupling support base, a fluid temperature control supply station, and a main control unit.

[0007] The forming die assembly, serving as the forming end in direct contact with the aluminum alloy blank, includes an external constraint frame, multiple heat-conducting inserts, and an insulating layer filling the spaces between adjacent heat-conducting inserts. The external constraint frame forms a mounting cavity to position and lock each heat-conducting insert. The heat-conducting inserts are physically divided according to the workpiece forming geometry, and the insulating layer blocks lateral heat conduction between each heat-conducting insert, thereby achieving independence of the thermal boundary conditions of each forming region. The vertical height of the insulating layer is less than the vertical height of the heat-conducting inserts, preventing the insulating layer from directly bearing the forging load.

[0008] The mechanical-thermal decoupling support base is located between the back of the forming mold assembly and the forging press worktable. It integrates a support structure, which adopts a rigid load-bearing circuit and a dynamic thermal control circuit arranged in parallel to achieve physical separation of forging impact load and precision temperature control function.

[0009] The rigid bearing circuit includes a bearing base plate and several rigid bearing columns fixedly mounted on the bearing base plate. The rigid bearing columns extend along the forging pressure direction and are used to provide the main rigid support during the forging impact stage.

[0010] The dynamic thermal control loop includes several variable thermal resistance actuation units arranged in the gaps between the rigid support columns. Each variable thermal resistance actuation unit includes a high thermal conductivity expansion thermal bridge, an interface flexible dielectric layer, and a displacement actuator. The displacement actuator is connected to the bottom end of the high thermal conductivity expansion thermal bridge and is used to drive the high thermal conductivity expansion thermal bridge to generate vertical lifting displacement. The interface flexible dielectric layer is disposed on the top surface of the high thermal conductivity expansion thermal bridge and is used to establish thermal conduction contact with the bottom surface of the thermally conductive insert. A circulating heat exchange channel is opened inside the high thermal conductivity expansion thermal bridge and is connected to the flow path switching valve group of the fluid temperature control supply station through a flexible pipeline. The fluid temperature control supply station switches between high-temperature and low-temperature heat exchange media according to instructions.

[0011] When the displacement actuator drives the high thermal conductivity telescopic thermal bridge into a lifting support state, the height of the top bearing surface of the rigid support column is lower than the height of the bottom surface of the thermally conductive insert, forming a safety gap between the top bearing surface and the bottom surface of the thermally conductive insert. This safety gap allows the thermally conductive insert to remain physically separated from the rigid support column in a non-forging impact state. After the thermally conductive insert is loaded and moves downward, eliminating the safety gap, the thermally conductive insert contacts the rigid support column and bears the forming load.

[0012] The variable thermal resistance actuation unit also includes a preload reset assembly, whose axial compressive stiffness is significantly less than that of the rigid bearing column. The preload reset assembly is used to maintain the mechanical contact stability of the system components when the displacement actuator is unloaded or retracted under pressure.

[0013] The second aspect of the present invention provides a control method for a multi-zone independent temperature control system for aluminum alloy precision forging molds, which realizes full-cycle thermal state management based on the above system.

[0014] The method includes coordinated control of the initial preheating stage, the forging impact stage, and the unloading recovery stage.

[0015] During the initial preheating stage, the main control unit controls the displacement actuator to extend, driving the interfacial flexible medium layer at the top of the high thermal conductivity expansion thermal bridge to protrude beyond the rigid support column. This ensures that the heat-conducting insert only contacts the interfacial flexible medium layer and maintains a safe gap with the rigid support column. At this time, a pre-tightening force is applied to reduce the interfacial contact thermal resistance, and the heat-conducting insert is rapidly heated using a high-temperature heat exchange medium.

[0016] During the forging impact stage, the passive response characteristics of the mechanical structure are utilized for protection. When the forming load is applied to the thermally conductive insert, the insert moves downward and compresses the high thermal conductivity expansion bridge and the preload reset assembly. When the vertical displacement of the thermally conductive insert equals the value of the safety clearance, the bottom surface of the insert makes mechanical contact with the top bearing surface of the rigid bearing column. The load transfer path is transferred to the rigid bearing circuit, limiting further displacement of the insert and thus protecting the displacement actuator from overload damage. Simultaneously, the accumulated elastic force of the preload reset assembly forces the interface flexible dielectric layer to tightly adhere to the thermally conductive insert, maintaining a low thermal resistance state to dissipate transient deformation heat.

[0017] During the unloading and recovery phase, after the forming load is removed, the thermally conductive insert springs back and separates from the rigid load-bearing column, and the system returns to a flexible support state. The main control unit switches to a low-temperature heat exchange medium and executes active closed-loop control based on the principle of variable thermal resistance.

[0018] The specific active control logic is as follows: The main control unit collects the real-time temperature of the thermally conductive insert through a temperature sensor and calculates the deviation between the real-time temperature and the preset target temperature trajectory. Based on the law of conservation of energy and the principle of heat conduction, the main control unit calculates the target heat flux required to eliminate the deviation based on the temperature deviation. Subsequently, combining the temperature difference data between the current high thermal conductivity expansion thermal bridge and the circulating heat exchange fluid, as well as the inherent thermal resistance of the high thermal conductivity expansion thermal bridge, the target thermal contact resistance value required for the interface flexible dielectric layer is calculated in reverse.

[0019] Based on the pre-stored contact pressure-thermal contact resistance calibration data table, the main control unit retrieves the target control pressure required to achieve the target thermal contact resistance value and controls the displacement actuator to output the corresponding driving force. The displacement actuator changes the extrusion pressure applied to the interface flexible medium layer, causing microscopic deformation of the interface flexible medium layer to change the actual contact area and filling degree, thereby adjusting the interface contact thermal resistance in real time and precisely controlling the heat flow rate between the heat-conducting insert and the heat exchange fluid, ensuring that the mold temperature follows a preset trajectory.

[0020] This invention provides a multi-zone independent temperature control system and method for precision forging dies for aluminum alloys. It offers the following advantages: 1. This invention, by setting a force-thermal decoupling support base and a safety gap, arranges the rigid load-bearing circuit and the dynamic thermal control circuit in parallel. In the non-forging state, the dynamic thermal control circuit provides flexible temperature control, while at the moment of forging impact, the safety gap eliminates the rigid contact between the heat-conducting insert and the rigid load-bearing column, and the rigid load-bearing circuit bears the main forming load. This achieves the structural stability and long-term reliable operation of the system under extreme alternating load conditions while protecting the piezoelectric ceramic actuator and precision thermal control components from damage by forging impact.

[0021] 2. This invention employs a variable thermal resistance actuation unit and an interface flexible dielectric layer. By utilizing a displacement actuator to adjust the extrusion pressure of a high thermal conductivity expansion thermal bridge on the bottom surface of the thermally conductive insert, the interface flexible dielectric layer is forced to undergo microscopic elastoplastic deformation to change the actual contact area and the degree of void filling. This linearly and dynamically adjusts the interface contact thermal resistance, achieving rapid heat flow regulation that overcomes the defects of large thermal inertia and lag in traditional fluid temperature control. This ensures high-precision real-time tracking and closed-loop control of the mold's temperature field to the target process curve during the non-steady-state forging cycle.

[0022] 3. This invention divides the mold into multiple independent heat-conducting inserts based on the workpiece's geometric characteristics and fills their sidewalls with heat-insulating layers. It also uses corresponding variable thermal resistance actuation units to perform independent heat flow control in different zones. By constructing independent boundary conditions that are thermally insulated from each other for the differentiated heat dissipation characteristics of different forming zones such as thick walls, thin walls, and deep cavities, this invention achieves refined multi-zone temperature field management that eliminates transverse thermal crosstalk inside the mold. This effectively avoids differences in metal fluidity and uneven microstructure properties caused by local temperature mismatch, ensuring the overall forming quality of complex aluminum alloy forgings. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0024] In the diagram: 100, forming mold assembly; 110, thermally conductive insert; 120, thermal insulation layer; 130, external constraint frame; 200, mechanical and thermal decoupling support base; 201, bearing base plate; 210, rigid bearing column; 211, top bearing surface; 220, variable thermal resistance actuation unit; 221, high thermal conductivity expansion thermal bridge; 221a, circulating heat exchange channel; 222, displacement actuator; 223, interface flexible medium layer; 224, thermal insulation bearing pad; 225, flexible metal bellows; 226, pre-tightening reset assembly; 300, fluid temperature control supply station; 310, high temperature constant temperature chamber; 320, low temperature constant temperature chamber; 330, flow path switching valve group; 400, main control unit; 410, stress wave sensor; 420, temperature sensor. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see the appendix Figure 1 The present invention provides a multi-zone independent temperature control system for aluminum alloy precision forging forming mold, including: forming mold assembly 100, force and heat decoupling support base 200, fluid temperature control supply station 300 and main control unit 400.

[0027] The forming die assembly 100 serves as the forming end of the forging system, directly contacting the aluminum alloy billet. The forming die assembly 100 includes an external constraint frame 130, multiple heat-conducting inserts 110, and an insulating layer 120 filled between adjacent heat-conducting inserts 110. The external constraint frame 130 forms a mounting cavity for positioning and locking each heat-conducting insert 110. The heat-conducting inserts 110 are physically divided according to the workpiece forming geometry and are made of hot-work die steel. The insulating layer 120 is made of load-bearing ceramic matrix composite material and is disposed between the sidewalls of adjacent heat-conducting inserts 110 to block lateral heat conduction between the heat-conducting inserts 110.

[0028] The mechanical-thermal decoupling support base 200 is disposed between the back of the forming die assembly 100 and the forging press worktable. The mechanical-thermal decoupling support base 200 has a support structure corresponding to the position of each heat-conducting insert 110. The support structure includes a rigid load-bearing circuit and a dynamic thermal control circuit arranged in parallel.

[0029] The rigid load-bearing circuit includes several fixedly installed rigid load-bearing columns 210. The rigid load-bearing columns 210 extend along the forging pressure direction and are used to bear the forming load during the forging impact stage. In the unloaded state, the height of the top surface of the rigid load-bearing column 210 is lower than the height of the bottom surface of the heat-conducting insert 110, forming a height difference, which is defined as the safety clearance. .

[0030] The dynamic thermal control circuit includes several variable thermal resistance actuation units 220 arranged in the gaps of the rigid support column 210. Each variable thermal resistance actuation unit 220 includes a high thermal conductivity expansion thermal bridge 221, an interface flexible medium layer 223, and a displacement actuator 222. The high thermal conductivity expansion thermal bridge 221 has a heat exchange channel inside, which can generate displacement in the vertical direction. The interface flexible medium layer 223 is disposed on the top surface of the high thermal conductivity expansion thermal bridge 221 and is used to contact the bottom surface of the thermally conductive insert 110. The displacement actuator 222 adopts a piezoelectric ceramic actuator or a hydraulic cylinder, which is connected to the bottom end of the high thermal conductivity expansion thermal bridge 221 and is used to drive the high thermal conductivity expansion thermal bridge 221 to rise and fall, so as to adjust the interface contact pressure and contact gap.

[0031] The fluid temperature control supply station 300 includes a high-temperature constant temperature chamber 310, a low-temperature constant temperature chamber 320, and a flow path switching valve assembly 330. The high-temperature constant temperature chamber 310 stores a heat exchange medium with a preset heating temperature, and the low-temperature constant temperature chamber 320 stores a heat exchange medium with a preset cooling temperature. The flow path switching valve assembly 330 is connected to the heat exchange channels inside the high-temperature constant temperature chamber 310, the low-temperature constant temperature chamber 320, and the high thermal conductivity expansion thermal bridge 221 through pipelines, and is used to switch the circuit of the heat exchange medium supplied according to control commands.

[0032] The main control unit 400 connects the sensing and execution components of the system via signal lines. The input terminals of the main control unit 400 are connected to a stress wave sensor 410 and a temperature sensor 420. The stress wave sensor 410 is embedded inside the rigid support column 210 to detect stress wave signals generated by forging impacts, and the temperature sensor 420 is embedded inside the heat-conducting insert 110 to detect the real-time temperature of each area. The output terminals of the main control unit 400 are connected to the displacement actuator 222 and the flow path switching valve group 330, respectively, to output control signals to adjust the contact thermal resistance state and the heat source path.

[0033] The external constraint frame 130 is a closed frame structure with a hollow mounting cavity, made of high-strength alloy steel. The inner sidewall of the external constraint frame 130 is machined with a positioning reference surface. The external constraint frame 130 provides horizontal positional constraint for the components installed in the hollow mounting cavity to withstand the lateral force generated during the forging process.

[0034] Multiple heat-conducting inserts 110 are assembled and installed in the hollow mounting cavity of the external constraint frame 130. The geometric boundaries of the heat-conducting inserts 110 are determined according to the local forming characteristics of the workpiece to be forged. Corresponding to the thick-walled forming area, thin-walled forming area, and deep cavity forming area of ​​the workpiece, independent heat-conducting inserts 110 are respectively set. Each heat-conducting insert 110 has a top surface that forms the surface of the mold cavity and a bottom surface for contact with the dynamic thermal control circuit. The heat-conducting inserts 110 are made of hot work die steel. The heat-conducting inserts 110 are connected to the external constraint frame 130 through lateral steps or positioning keys. The external constraint frame 130 restricts the horizontal displacement of the heat-conducting inserts 110 and allows the heat-conducting inserts 110 to undergo elastic compressive deformation in the vertical direction under forging load.

[0035] The heat insulation layer 120 is disposed between the lateral contact interfaces of two adjacent heat-conducting inserts 110. The heat insulation layer 120 fills the lateral gap between the adjacent heat-conducting inserts 110, blocking the lateral conduction of heat between the adjacent heat-conducting inserts 110. The heat insulation layer 120 is made of zirconia ceramic plate or mica reinforced composite material. The vertical height of the heat insulation layer 120 is less than the vertical height of the heat-conducting insert 110, and the upper surface of the heat insulation layer 120 is lower than the top surface of the heat-conducting insert 110, so that the heat insulation layer 120 does not directly contact the forging workpiece and does not directly bear the forming load in the vertical direction, thereby preventing the heat insulation layer 120 from breaking due to pressure.

[0036] The external constraint frame 130 applies lateral preload to the internal heat-conducting insert 110 and the heat insulation layer 120 through interference fit or bolt fastening, maintaining the structural compactness of the forming die assembly 100 under forging load.

[0037] The rigid bearing circuit is integrated inside the force-thermal decoupling support base 200. The rigid bearing circuit includes a bearing base plate 201 and multiple rigid bearing columns 210 vertically arranged on the bearing base plate 201.

[0038] The bearing base plate 201 serves as the basic component of the force-thermal decoupling support base 200 and is fixedly installed on the upper surface of the forging press workbench. The bearing base plate 201 is made of high-strength alloy steel, and the thickness of the bearing base plate 201 is set according to the tonnage parameters of the forging press to provide an installation reference that is not prone to bending deformation.

[0039] Multiple rigid support columns 210 are arranged in an array on the upper surface of the support base plate 201. The horizontal distribution of the rigid support columns 210 corresponds vertically to the bottom projection area of ​​the heat-conducting insert 110 in the upper forming mold assembly 100. The rigid support columns 210 and the support base plate 201 are connected by an integrated forging structure or by high-strength pre-tightening bolts to ensure the connection rigidity of the rigid support columns 210 when subjected to alternating impact loads. A dynamic thermal control circuit mounting cavity is formed between adjacent rigid support columns 210. The dynamic thermal control circuit mounting cavity is used to accommodate the variable thermal resistance actuation unit 220.

[0040] The rigid support column 210 has a top support surface 211. When the displacement actuator 222 drives the high thermal conductivity telescopic thermal bridge 221 into a lifting support state, the height of the top support surface 211 of the rigid support column 210 is lower than the height of the bottom surface of the thermally conductive insert 110. A safety gap exists between the top support surface 211 of the rigid support column 210 and the bottom surface of the thermally conductive insert 110. This ensures that the heat-conducting insert 110 remains physically separated from the rigid load-bearing column 210 when not subjected to forging load impact.

[0041] The rigid support column 210 has blind holes machined along the axial direction inside for sensor mounting. The stress wave sensor 410 is mounted at the bottom of the blind holes by interference fit or threaded locking. The stress wave sensor 410 is located on the load transmission path of the rigid support column 210 and is used to collect mechanical vibration waves and pressure pulse signals transmitted through the rigid support column 210. The signal lead of the stress wave sensor 410 is led out through the wiring channel opened inside the support base plate 201 and connected to the main control unit 400.

[0042] The top bearing surface 211 of the rigid bearing column 210 undergoes surface nitriding hardening and flat grinding treatment. The surface hardness of the top bearing surface 211 is higher than that of the bottom surface of the heat-conducting insert 110. This ensures that the top bearing surface 211 maintains geometric flatness during repeated high-pressure closing contact with the heat-conducting insert 110, preventing the safety gap from being compromised due to plastic deformation. The value has drifted.

[0043] The displacement actuator 222 is fixedly installed on the upper surface of the base plate 201 of the bearing base, located at the bottom of the receiving cavity formed by the adjacent rigid bearing columns 210. The displacement actuator 222 is a stacked piezoelectric ceramic actuator, which is connected to the main control unit 400 through a cable. It generates vertical extension and retraction displacement according to the control voltage. The pre-tightening reset assembly 226 is sleeved on the outer periphery of the displacement actuator 222 or set between the high thermal conductivity expansion thermal bridge 221 and the base plate 201 of the bearing base. The pre-tightening reset assembly 226 is constructed as a disc spring group or a wave spring, which is used to apply axial pre-tightening pressure to the displacement actuator 222 to ensure that the displacement actuator 222 maintains mechanical contact with the high thermal conductivity expansion thermal bridge 221 during dynamic unloading.

[0044] A thermally insulating bearing pad 224 is disposed between the output end face of the displacement actuator 222 and the bottom surface of the high thermal conductivity expansion thermal bridge 221. The thermally insulating bearing pad 224 is made of pressure-resistant zirconia ceramic material and is used to block heat from being conducted downward from the high thermal conductivity expansion thermal bridge 221 to the displacement actuator 222.

[0045] A high thermal conductivity expansion thermal bridge 221 is installed on the thermal insulation bearing pad 224. A lateral thermal expansion gap is reserved between the outer wall of the high thermal conductivity expansion thermal bridge 221 and the inner wall of the rigid bearing column 210. The size of the lateral thermal expansion gap is larger than the thermal expansion of the high thermal conductivity expansion thermal bridge 221 at the preset maximum operating temperature to prevent the high thermal conductivity expansion thermal bridge 221 from getting stuck with the rigid bearing column 210 when heated. The main body of the high thermal conductivity expansion thermal bridge 221 is made of chromium zirconium copper alloy and has a circulating heat exchange channel 221a machined inside. The circulating heat exchange channel 221a is designed as a labyrinth structure. A fluid inlet interface and a fluid outlet interface are provided on the lower part of the side wall of the high thermal conductivity expansion thermal bridge 221.

[0046] The fluid inlet and fluid outlet interfaces are connected to the external flow path switching valve group 330 via flexible metal bellows 225. The flexible metal bellows 225 is arranged in the lateral clearance groove of the rigid support column 210. The flexible metal bellows 225 has axial expansion and contraction elasticity to compensate for the displacement difference generated by the high thermal conductivity expansion thermal bridge 221 during vertical movement.

[0047] The interface flexible dielectric layer 223 is bonded to the top plane of the high thermal conductivity expansion thermal bridge 221. The interface flexible dielectric layer 223 is made of highly oriented pyrolytic graphite sheet or annealed soft copper foil. The hardness of the interface flexible dielectric layer 223 is lower than the hardness of the bottom surface of the thermally conductive insert 110. Under the driving force applied by the displacement actuator 222, the interface flexible dielectric layer 223 can deform to fill the micro-gaps of the contact interface.

[0048] The force-displacement triggering mechanism provided by the present invention is based on the vertical displacement characteristics of the forming mold assembly 100 and the geometric height difference between the rigid bearing column 210 and the high thermal conductivity expansion thermal bridge 221.

[0049] In the initial preheating state, the main control unit 400 controls the displacement actuator 222 to be in the extended holding state. Driven by the displacement actuator 222, the high thermal conductivity expansion thermal bridge 221 moves upward, causing the vertical height of the interfacial flexible dielectric layer 223 at the top of the high thermal conductivity expansion thermal bridge 221 to be higher than the top bearing surface 211 of the rigid bearing column 210. In this state, the high thermal conductivity expansion thermal bridge 221 contacts and provides support to the bottom surface of the thermally conductive insert 110, while a safe gap is maintained between the bottom surface of the thermally conductive insert 110 and the top bearing surface 211 of the rigid bearing column 210. .

[0050] When the forging process begins, an external forming load is applied to the thermally conductive insert 110. Since the axial compressive stiffness of the pre-tightening reset assembly 226 is significantly less than that of the rigid bearing column 210, the forming load causes the thermally conductive insert 110 to move downward and compress the pre-tightening reset assembly 226. During this process, the high thermal conductivity expansion thermal bridge 221 moves downward in sync with the thermally conductive insert 110.

[0051] When the downward vertical displacement generated by the heat-conducting insert 110 is equal to the safety clearance When the value is specified, the bottom surface of the heat-conducting insert 110 makes mechanical contact with the top bearing surface 211 of the rigid bearing column 210, and a safety clearance is provided. When the load disappears, the mechanical boundary conditions of the system change, and the load transfer path changes from the elastic support path via the high thermal conductivity expansion thermal bridge 221 to the rigid support path via the rigid bearing column 210.

[0052] After the rigid support path is closed, the rigid support column 210 bears the main forming load. The rigid support column 210 restricts the thermally conductive insert 110 from continuing to move downward. The limiting effect of the rigid support column 210 limits the compression of the high thermal conductivity expansion thermal bridge 221 and the displacement actuator 222 within the preset stroke range, preventing the displacement actuator 222 from being damaged due to overload pressure exceeding its own compressive strength limit.

[0053] In this contact state, the high thermal conductivity expansion thermal bridge 221 is held in its maximum compressed position. The rebound force of the pre-tightening reset assembly 226 ensures that the interface flexible medium layer 223 maintains a constant contact pressure at the maximum forging load, ensuring that the contact interface is in a low thermal resistance state. When the forging load is removed, the thermally conductive insert 110 returns to its original position by the elastic rebound of the external constraint frame 130 or its own, and the thermally conductive insert 110 separates from the rigid bearing column 210, creating a safety gap. Reformed.

[0054] The interface contact thermal resistance control model runs inside the main control unit 400. The interface contact thermal resistance control model is used to perform closed-loop control of the temperature of the heat-conducting insert 110 during the non-forging impact stage.

[0055] The main control unit 400's storage module pre-stores a contact pressure-thermal contact resistance calibration data table. This table records the unit area thermal resistance of the interface flexible dielectric layer 223 under different axial loads. Obtained through experimental calibration, the table reflects the nonlinear relationship between the compressive deformation and thermal conductivity of the interface flexible dielectric layer 223.

[0056] The main control unit 400 reads the real-time temperature signal output by the temperature sensor 420 through the signal acquisition channel. The main control unit 400 calculates the difference between the real-time temperature signal and the preset target process temperature curve to obtain the temperature error signal.

[0057] The main control unit 400 inputs the temperature error signal to the PID control algorithm module. Based on the proportional, integral, and derivative terms of the temperature error signal, the PID control algorithm module calculates the target heat flux value required to maintain the target temperature. The main control unit 400 calculates the target thermal contact resistance value required to achieve the target heat flux value based on Fourier's law of thermal conductivity and the temperature difference data between the high thermal conductivity expansion thermal bridge 221 and the low-temperature constant temperature chamber 320 or the high-temperature constant temperature chamber 310.

[0058] The main control unit 400 retrieves the target contact pressure value corresponding to the target thermal contact resistance value by consulting the contact pressure-thermal contact resistance calibration data table.

[0059] Based on the voltage-output force characteristic curve of the displacement actuator 222, the main control unit 400 calculates the drive voltage control amount required to generate the target contact pressure value. The main control unit 400 outputs the drive voltage control amount to the displacement actuator 222 via a power amplifier.

[0060] Under the excitation of the driving voltage control quantity, the displacement actuator 222 generates vertical elongation deformation, which pushes the high thermal conductivity expansion thermal bridge 221 upward and compresses the interfacial flexible dielectric layer 223. Under the extrusion force, the interfacial flexible dielectric layer 223 undergoes elastoplastic rheology. The elastoplastic rheology increases the actual microscopic contact area between the interfacial flexible dielectric layer 223 and the bottom surface of the thermally conductive insert 110, and fills the microscopic roughness voids at the contact interface, eliminating the low thermal conductivity gas medium in the voids, thereby adjusting the actual interfacial contact thermal resistance to the target thermal contact resistance value.

[0061] The transient heat flow control method is executed by the main control unit 400, which calculates the thermal equilibrium state of the heat-conducting insert 110 based on the lumped parameter heat capacity model.

[0062] According to the law of conservation of energy, the temperature response of the heat-conducting insert 110 follows the following first-order differential equation:

[0063] In the formula: Defined as the material density of the thermally conductive insert 110, Defined as the effective heat capacity volume of the thermally conductive insert 110 Defined as the specific heat capacity of the thermally conductive insert 110, The real-time temperature of the thermally conductive insert 110 is collected by the temperature sensor 420. For time variables, For the unsteady heat load applied externally to the heat-conducting insert 110, The heat transfer rate is the rate of heat transfer via the dynamic thermal control loop.

[0064] because The heat originates from forging deformation and friction, which is difficult to measure directly. The main control unit 400 is configured to calculate the time-dependent component of the temperature feedback from the temperature sensor 420. And based on the information known from the previous time step Numerical value, reverse estimation of the current value The value will As a feedforward compensation parameter.

[0065] thermal conductivity The thermal resistance is determined by both the inherent thermal resistance of the high thermal conductivity thermal expansion bridge 221 and the variable contact thermal resistance of the interfacial flexible dielectric layer 223, and the calculation relationship is as follows:

[0066] In the formula, To determine the temperature of the circulating heat exchange fluid, the main control unit 400 reads the on / off status of the flow path switching valve group 330: when the flow path switching valve group 330 is connected to the high-temperature constant temperature chamber 310, The value is assigned to the preheating temperature setpoint; when the flow path switching valve group 330 is connected to the low-temperature constant temperature chamber 320... The value was assigned to the cooling temperature setpoint. For the fixed thermal resistance of the high thermal conductivity expansion thermal bridge 221, The contact thermal resistance of the flexible dielectric layer 223 at the interface, The displacement actuator 222 outputs the target control pressure. The function.

[0067] The main control unit 400 will preset the target temperature trajectory Substituting into the above differential equation, the target heat transfer rate required to eliminate the temperature deviation can be calculated. The main control unit 400 is based on the target heat transfer rate. The current real-time temperature of the thermal pad 110 and the temperature of the circulating heat exchange fluid The target contact thermal resistance value required for the interfacial flexible dielectric layer 223 is calculated using the following inverse solution formula. :

[0068] If the calculation yields If the value is positive and within the adjustable range, the main control unit 400 retrieves the contact pressure-thermal contact resistance calibration data stored in the internal memory to obtain the thermal resistance value in contact with the target. Corresponding target control pressure And control the displacement actuator 222 to output the target control pressure. .

[0069] The initialization and constant temperature preheating method is executed by the main control unit 400. The main control unit 400 establishes the initial thermal balance of the mechanical and thermal decoupled support base 200 by coordinating the states of the fluid circuit and the mechanical circuit.

[0070] After the system starts, the main control unit 400 sends a command to the flow path switching valve group 330. The flow path switching valve group 330 activates to disconnect the pipeline connection of the low-temperature constant temperature chamber 320 and open the fluid channel between the high-temperature constant temperature chamber 310 and the high thermal conductivity expansion heat bridge 221. The high-temperature circulating heat exchange fluid stored inside the high-temperature constant temperature chamber 310 is driven by an external circulation pump and enters the circulating heat exchange channel 221a inside the high thermal conductivity expansion heat bridge 221 through the flexible metal bellows 225 and the fluid inlet interface, and then flows back to the high-temperature constant temperature chamber 310 through the fluid outlet interface, forming a closed-loop heat cycle.

[0071] Simultaneously with the establishment of fluid circulation, the main control unit 400 outputs an initial driving voltage to the displacement actuator 222. The displacement actuator 222 generates axial elongation displacement, driving the high thermal conductivity expansion thermal bridge 221 to move upward in the vertical direction. The displacement actuator 222 drives the interfacial flexible dielectric layer 223 at the top of the high thermal conductivity expansion thermal bridge 221 to protrude from the top bearing surface 211 of the rigid bearing column 210.

[0072] In this state, the forging press slide moves the heat-conducting insert 110 down to a preset standby height. The bottom surface of the heat-conducting insert 110 contacts the prominent interface flexible medium layer 223, while a safe gap is maintained between the bottom surface of the heat-conducting insert 110 and the top bearing surface 211 of the rigid bearing column 210. At this time, the weight load of the heat-conducting insert 110 is supported by the high thermal conductivity expansion thermal bridge 221 and the displacement actuator 222 in series. The rigid support column 210 is in a physically separated thermal insulation state, and the rigid support column 210 blocks the heat conduction path from the heat-conducting insert 110 to the support base plate 201.

[0073] The main control unit 400 operates the interface contact thermal resistance control model. During the preheating stage, the main control unit 400 controls the displacement actuator 222 to output the rated saturation voltage, so that the displacement actuator 222 applies the maximum pre-tightening pressure to the interface flexible dielectric layer 223. The maximum pre-tightening pressure forces the interface flexible dielectric layer 223 to undergo elastoplastic deformation to fill the micro gaps at the contact interface, thereby reducing the interface contact thermal resistance to the minimum value allowed by the system, thereby improving the thermal conduction rate of the high-temperature circulating heat exchange fluid conduction insert 110.

[0074] Temperature sensor 420 collects real-time temperature data of heat-conducting insert 110 and transmits it to main control unit 400. Main control unit 400 calculates the deviation between real-time temperature data and preset target preheating temperature. When the real-time temperature data reaches the preset target preheating temperature, main control unit 400 enters constant temperature holding logic. In constant temperature holding logic, based on the small temperature fluctuations fed back by temperature sensor 420, main control unit 400 fine-tunes the driving voltage of displacement actuator 222 through PID algorithm, and uses the change in contact thermal resistance to compensate for the natural convection heat loss of heat-conducting insert 110 to the environment, maintaining the thermal state of heat-conducting insert 110 until the forging process begins.

[0075] The forging impact and passive heat compensation method utilizes the extremely short mechanical response hysteresis of the force-displacement triggering mechanism to achieve load protection and transient heat conduction during the forging impact process.

[0076] When the external forging equipment drives the heat-conducting insert 110 to move downward and contact the high-temperature workpiece, the forging impact load is applied to the upper surface of the heat-conducting insert 110. The heat-conducting insert 110 overcomes the axial support force of the pre-tightening reset assembly 226 and generates a downward vertical displacement. During this process, the high thermal conductivity expansion thermal bridge 221 retracts downward synchronously with the heat-conducting insert 110, the displacement actuator 222 is in a passively compressed state, and the pre-tightening reset assembly 226 is forcibly compressed and accumulates elastic potential energy.

[0077] When the downward displacement of the heat-conducting insert 110 is equal to the safety clearance When the preset value is reached, the bottom surface of the heat-conducting insert 110 and the top bearing surface 211 of the rigid bearing column 210 make mechanical collision contact. At this time, the rigid bearing circuit is closed, and the forging impact load is transmitted to the rigid bearing column 210 through the heat-conducting insert 110 and finally to the bearing base plate 201. The rigid bearing column 210 mechanically limits the vertical position of the heat-conducting insert 110. The rigid bearing column 210 restricts the maximum retraction displacement of the high thermal conductivity expansion thermal bridge 221 and the displacement actuator 222, thereby preventing the displacement actuator 222 from being physically damaged due to overload impact force exceeding its compressive strength.

[0078] During the impact holding phase when the rigid bearing circuit is closed, the system enters the passive thermal compensation mode. Although the electronic control circuit of the main control unit 400 may not have acted yet due to sensor response delay, the pre-tightening reset assembly 226 is in the maximum compression state. The pre-tightening reset assembly 226 releases a constant axial mechanical rebound force, which is transmitted upward through the high thermal conductivity expansion thermal bridge 221, forcing the interface flexible medium layer 223 to always be tightly attached to the bottom surface of the thermally conductive insert 110 under the vibration environment of forging impact.

[0079] In this state, the interface flexible medium layer 223 bears the contact pressure determined by the stiffness characteristics of the pre-tightening reset component 226. Due to the transient deformation heat generated by the plastic deformation of the workpiece, the temperature of the heat-conducting insert 110 rises sharply, and a significant thermal potential difference is formed between the heat-conducting insert 110 and the fluid in the circulating heat exchange channel 221a. The interface flexible medium layer 223 maintains low thermal resistance characteristics under the high-pressure bonding state maintained by the mechanical rebound force, so that the accumulated heat absorbed by the heat-conducting insert 110 can be quickly conducted to the internal circulating heat exchange channel 221a through the high thermal conductivity expansion thermal bridge 221.

[0080] The circulating heat exchange fluid in the circulating heat exchange channel 221a flows continuously, carrying away the heat generated by the transient impact from the high thermal conductivity expansion thermal bridge 221. This passive heat compensation mode relies on the physical closure characteristics of the mechanical structure to passively maintain the contact thermal resistance, ensuring that the heat conduction path always remains in a low thermal resistance connected state before the active control intervention of the main control unit 400, thereby using the thermal potential difference to naturally suppress the instantaneous temperature rise peak of the contact surface of the heat-conducting insert 110.

[0081] The unloading recovery and active control method is executed by the main control unit 400. During the process cycle interval after the forging load is removed, the main control unit 400 performs closed-loop temperature control based on the principle of variable thermal resistance.

[0082] After the forging slide moves the heat-conducting insert 110 upward and separates it from the workpiece, the external forming load is removed. The preload reset assembly 226 releases the accumulated elastic potential energy, and the preload reset assembly 226 pushes the high thermal conductivity expansion thermal bridge 221 and the heat-conducting insert 110 to produce an upward relative displacement relative to the rigid support column 210. The bottom surface of the heat-conducting insert 110 separates from the top bearing surface 211 of the rigid support column 210, and a safety clearance is established. Upon reformation, the mechanical transmission path of the system is broken, and the thermally conductive insert 110 returns to a flexible suspension state supported only by the interfacial flexible dielectric layer 223 and the highly thermally conductive expansion thermal bridge 221.

[0083] The main control unit 400 continuously monitors the displacement sensor signal installed on the slide block of the forging press. When the main control unit 400 determines that the heat-conducting insert 110 has detached from the workpiece and is in the upward stroke, the main control unit 400 sends a cooling mode command to the flow path switching valve group 330. The flow path switching valve group 330 cuts off the flow path of the high-temperature constant temperature chamber 310 and opens the circulation loop between the low-temperature constant temperature chamber 320 and the high thermal conductivity expansion thermal bridge 221. The low-temperature circulating heat exchange fluid in the low-temperature constant temperature chamber 320 enters the circulating heat exchange channel 221a, providing a constant low-temperature heat absorption boundary for the high thermal conductivity expansion thermal bridge 221.

[0084] The main control unit 400 executes the aforementioned transient heat flux control equation, and calculates the real-time temperature collected by the temperature sensor 420 and the preset target temperature trajectory. Based on the numerical deviation at the current moment, the main control unit 400 calculates the target contact thermal resistance value required to maintain the target temperature trajectory according to the numerical deviation and the PID control algorithm.

[0085] The main control unit 400 converts the target contact thermal resistance value into the target control pressure based on the contact pressure-thermal contact resistance calibration data, and adjusts the drive voltage output to the displacement actuator 222.

[0086] If the real-time temperature is higher than the preset target temperature trajectory, the main control unit 400 increases the driving voltage of the displacement actuator 222, and the pressure output by the displacement actuator 222 increases, forcing the interface flexible medium layer 223 to further fill the micro-roughness of the bottom surface of the heat-conducting insert 110, reducing the interface contact thermal resistance, thereby increasing the heat flux of the heat-conducting insert 110 to the low-temperature circulating heat exchange fluid.

[0087] If the real-time temperature is lower than or close to the preset target temperature trajectory, the main control unit 400 reduces the driving voltage of the displacement actuator 222, the pressure output by the displacement actuator 222 decreases, the interface flexible medium layer 223 elastically rebounds, reducing the effective contact area and introducing a micro-gap gas film, increasing the interface contact thermal resistance, thereby hindering the transfer of heat from the heat-conducting insert 110 to the low-temperature circulating heat exchange fluid, suppressing the temperature drop rate of the heat-conducting insert 110. The main control unit 400 continuously adjusts the interface contact thermal resistance to make the temperature change of the heat-conducting insert 110 run along the preset target temperature trajectory until the next forging cycle begins.

[0088] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-zone independent temperature control system for aluminum alloy precision forging forming dies, characterized in that, The application relates to a forming die assembly, a force-heat decoupling support base, a fluid temperature control supply station and a master control unit. The forming die assembly is a forming end of a forging system and comprises an external constraint frame, a plurality of heat-conducting inserts and heat-insulating isolation layers filled between adjacent heat-conducting inserts. The force-heat decoupling support base is arranged between the back of the forming die assembly and a workbench of a forging press, and the force-heat decoupling support base is internally provided with a support structure, which comprises a rigid bearing loop and a dynamic heat control loop arranged side by side. The rigid bearing loop comprises a plurality of fixedly arranged rigid bearing columns. The dynamic heat control loop comprises a plurality of variable heat resistance actuating units arranged in gaps between the rigid bearing columns, and each variable heat resistance actuating unit comprises a high-heat-conducting telescopic heat bridge, an interface flexible medium layer and a displacement actuator. The interface flexible medium layer is arranged on the top end surface of the high-heat-conducting telescopic heat bridge and is used for being in contact with the bottom surface of the heat-conducting insert. The master control unit is connected with the displacement actuators and a flow path switching valve group of the fluid temperature control supply station respectively and is used for outputting control signals to adjust the contact heat resistance state and the heat source passage. The external constraint frame is configured to form a mounting cavity for positioning and locking the heat-conducting inserts.

2. The aluminum alloy precision forging die multi-zone independent temperature control system of claim 1, wherein, The heat-conducting inserts are physically divided according to the forming geometric features of workpieces and are arranged correspondingly to thick wall forming areas, thin wall forming areas and deep cavity forming areas of the workpieces.

3. The aluminum alloy precision forging die multi-zone independent temperature control system of claim 1, wherein, The heat-insulating isolation layers are arranged between the lateral contact interfaces of two adjacent heat-conducting inserts and are used for blocking the horizontal conduction of heat between the heat-conducting inserts.

4. The aluminum alloy precision forging die multi-zone independent temperature control system of claim 3, wherein, The rigid bearing loop further comprises a bearing base bottom plate, the rigid bearing columns are vertically arranged above the bearing base bottom plate, the horizontal distribution positions of the rigid bearing columns vertically correspond to the bottom surface projection areas of the heat-conducting inserts in the forming die assembly. The rigid bearing columns have top end bearing surfaces, when the high-heat-conducting telescopic heat bridges are driven by the displacement actuators to be in a jacking support state, the heights of the top end bearing surfaces of the rigid bearing columns are lower than the height of the bottom surface of the heat-conducting insert, a safety gap is formed between the top end bearing surfaces and the bottom surface of the heat-conducting insert, so that the heat-conducting insert is physically separated from the rigid bearing columns when the heat-conducting insert is not impacted by a forging load. When the downward vertical displacement amount of the heat-conducting insert is equal to the value of the safety gap, the bottom surface of the heat-conducting insert is in mechanical contact with the top end bearing surface.

5. The aluminum alloy precision forging die multi-zone independent temperature control system of claim 1 wherein, The high-thermal-conductivity telescopic thermal bridge is internally provided with a circulating heat exchange flow channel, and a main body of the high-thermal-conductivity telescopic thermal bridge is made of chromium-zirconium-copper alloy; the displacement actuator is selected from a stack type piezoelectric ceramic actuator; the interface flexible medium layer is selected from a high-oriented pyrolytic graphite sheet or an annealed soft red copper foil, and a hardness of the interface flexible medium layer is lower than that of a bottom surface of the thermal conduction insert, so that the interface flexible medium layer can be deformed to fill micro voids of a contact interface under a driving force applied by the displacement actuator.

6. The aluminum alloy precision forging die multi-zone independent temperature control system of claim 5, wherein, The high-thermal-conductivity telescopic thermal bridge is internally provided with a circulating heat exchange flow channel, and a main body of the high-thermal-conductivity telescopic thermal bridge is made of chromium-zirconium-copper alloy; the displacement actuator is selected from a stack type piezoelectric ceramic actuator; the interface flexible medium layer is selected from a high-oriented pyrolytic graphite sheet or an annealed soft red copper foil, and a hardness of the interface flexible medium layer is lower than that of a bottom surface of the thermal conduction insert, so that the interface flexible medium layer can be deformed to fill micro voids of a contact interface under a driving force applied by the displacement actuator.

7. The aluminum alloy precision forging die multi-zone independent temperature control system of claim 1 wherein, The input end of the main control unit is connected with a stress wave sensor and a temperature sensor; the stress wave sensor is embedded in the rigid bearing column for detecting stress wave signals generated by forging impact; and the temperature sensor is embedded in the thermal conduction insert for detecting real-time temperatures of different regions.

8. The aluminum alloy precision forging die multi-zone independent temperature control system of claim 1 wherein, The variable thermal resistance actuating unit further comprises a pre-tightening reset assembly, which is sleeved on the outer periphery of the displacement actuator or arranged between the high-thermal-conductivity telescopic thermal bridge and the bearing base bottom plate; the axial compression stiffness of the pre-tightening reset assembly is smaller than that of the rigid bearing column, which is used to apply an axial pre-tightening pressure to the displacement actuator, and is forced to compress to accumulate elastic potential energy in the forging impact stage, and the interface flexible medium layer is forced to tightly adhere to the bottom surface of the thermal conduction insert by using the axial mechanical rebound force.

9. The aluminum alloy precision forging die multi-zone independent temperature control system of claim 1 wherein, The fluid temperature control supply station comprises a high-temperature constant temperature library, a low-temperature constant temperature library and a flow path switching valve group; the flow path switching valve group is connected with the high-temperature constant temperature library, the low-temperature constant temperature library and the heat exchange flow channel in the high-thermal-conductivity telescopic thermal bridge through pipelines, and is used to switch the heat exchange medium loop according to the control instruction of the main control unit.

10. A method of controlling a multi-zone independent temperature control system of an aluminum alloy precision forging forming die according to any one of claims 1-9, characterized in that, The method comprises the following steps: In the initial preheating state, the main control unit controls the displacement actuator to extend, drives the interface flexible medium layer on the high-thermal-conductivity telescopic thermal bridge to protrude from the rigid bearing column, makes the thermal conduction insert contact with the interface flexible medium layer and keeps a safe gap between the thermal conduction insert and the rigid bearing column; In the forging impact stage, the thermal conduction insert moves downward and compresses the high-thermal-conductivity telescopic thermal bridge under the forming load, and when the displacement amount of the thermal conduction insert is equal to the value of the safe gap, the thermal conduction insert contacts with the rigid bearing column, the displacement of the thermal conduction insert is limited by the rigid bearing column and the forming load is borne by the rigid bearing column; In the unloading recovery stage, after the forming load is removed, the thermal conduction insert is separated from the rigid bearing column, and the main control unit is connected with the loop of the low-temperature constant temperature library through the flow path switching valve group. The main control unit performs interface contact thermal resistance regulation and control by calculating the difference between the real-time temperature collected by the temperature sensor and the preset target temperature trajectory to obtain a temperature error signal; The main control unit calculates the target thermal contact resistance value required to achieve the target heat flux value according to the temperature error signal and the temperature difference data between the high thermal conductivity expansion thermal bridge and the circulating heat exchange fluid; The main control unit retrieves the target control pressure corresponding to the target thermal contact resistance value according to the pre-stored contact pressure and thermal contact resistance calibration data table, and controls the displacement actuator to output the target control pressure, so as to adjust the actual interface contact thermal resistance by changing the extrusion force between the interface flexible medium layer and the bottom surface of the heat conduction insert.

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