A manufacturing method of a composite die integrated forming lathe bed

Abstract

The application discloses a composite casting integrated forming lathe bed manufacturing method and relates to the technical field of lathe manufacturing. The method comprises the following steps: obtaining the dynamic stiffness requirement and the thermal deformation compensation parameter of a target machine tool; constructing a three-dimensional digital model of a multi-material composite casting based on a topological configuration and an installation reference surface; dividing the three-dimensional digital model into a high-damping mineral casting inner core area and a high-strength cast iron shell area; generating an inner core-shell thermal stress collaborative control time sequence diagram; performing integrated pouring operation according to the thermal stress collaborative control time sequence diagram; triggering the metal liquid filling of the high-strength cast iron shell area when the high-damping mineral casting inner core area is in a semi-solidified state; performing gradient temperature control annealing treatment on the blank formed by integrated pouring; performing in-situ finishing based on the installation reference surface, milling out double-mountain-shaped guide rail surfaces and motor seat joint surfaces, and obtaining a composite casting integrated forming lathe bed; and the application reduces the composite interface residual stress and forming defects and improves the bed body interface bonding strength.

Description

Technical Field

[0001] This invention relates to the field of lathe manufacturing technology, specifically to a method for manufacturing a lathe bed using an integrated composite casting mold. Background Technology

[0002] As the core basic load-bearing component of a machine tool, the lathe bed's structural rigidity, damping and vibration reduction performance, dimensional stability, and guide rail accuracy directly determine the machine tool's cutting accuracy, vibration resistance, and long-term service life. Currently, the mainstream manufacturing methods for lathe beds in the industry are divided into two categories: integral casting of single cast iron and assembly of composite materials in separate bonding parts. Among them, the traditional all-cast iron bed has the advantages of high strength, good wear resistance of guide rails, and mature processing technology. However, the low damping coefficient of cast iron material makes it prone to vibration and resonance problems during cutting, making it difficult to adapt to high-precision, high-speed precision cutting conditions. After long-term service, it is prone to defects such as slight deformation and accuracy decay.

[0003] Existing composite bed machines made from mineral castings mostly employ a modular assembly method, where parts are formed separately and then bonded and bolted together. While this method leverages the high damping, low deformation, and strong vibration absorption of mineral castings to improve the bed's vibration reduction performance, the modular assembly structure has significant technical shortcomings: First, gaps exist at the assembly interface, and the adhesive layer strength is limited, making it prone to interface loosening and stiffness reduction under high-speed cutting impact, resulting in poor overall structural consistency. Second, the modular forming process cannot achieve coordinated matching of thermal stress. The thermal expansion coefficients and curing shrinkage characteristics of the cast iron structure and the mineral casting structure differ significantly, easily generating residual stress at the interface during service and processing, leading to problems such as guide rail surface deformation and flatness deviations. Third, traditional composite forming processes lack precise thermal timing control and interface strengthening structures, resulting in low interface bonding strength and easy peeling, making it difficult to guarantee yield and structural stability. Furthermore, existing composite bed machining processes often employ multiple clamping and segmented machining methods, which easily generate accumulated clamping errors during processing and do not dynamically compensate for fluctuations in thermal stress and cutting load during processing, limiting the straightness of the guide rail surface and the parallelism accuracy of the mating surfaces. Summary of the Invention

[0004] To solve the above-mentioned technical problems, a method for manufacturing a lathe bed using an integrated composite casting mold is provided. This technical solution solves the aforementioned problems.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for manufacturing a lathe bed using a composite casting mold integrated molding process includes: Obtain the dynamic stiffness requirements and thermal deformation compensation parameters of the target machine tool; analyze the dynamic stiffness requirements to obtain the topological configuration of the internal stiffeners and the mounting reference surface of the external guide rails; A three-dimensional digital model of a multi-material composite mold is constructed based on the aforementioned topological configuration and the aforementioned mounting reference plane; the three-dimensional digital model is divided into a high-damping mineral casting inner core area and a high-strength cast iron outer shell area; The solidification exothermic peak temperature is determined based on the volume ratio of the inner core region of the high-damping mineral casting; the cooling and solidification rate of the high-strength cast iron outer shell region is matched with the solidification exothermic peak temperature to generate a timing diagram of the coordinated control of thermal stress between the inner core and outer shell. The integrated casting operation is performed according to the thermal stress coordinated control timing diagram; when the core area of ​​the high-damping mineral casting is in a semi-solid state, the molten metal filling of the high-strength cast iron outer shell area is triggered, so that the two-phase interface forms a metallurgical mechanical interlocking structure. Gradient temperature-controlled annealing is performed on the integrally cast blank to release the residual thermal stress at the interface between the inner core area of ​​the high-damping mineral casting and the outer shell area of ​​the high-strength cast iron. Based on the aforementioned mounting reference surface, in-situ precision machining is performed to mill the double-mountain-shaped guide rail surface and the motor base mating surface, thereby obtaining the composite mold integral casting lathe bed.

[0006] Optionally, dividing the three-dimensional digital model into a high-damping mineral casting inner core area and a high-strength cast iron outer shell area includes: Extract the main load-bearing section that bears the cutting load from the three-dimensional digital model; Determine the bending section modulus of the main load-bearing section, and configure the corresponding allowable deflection threshold and matching safety factor; When the bending section modulus is not higher than the safety factor corresponding to the allowable deflection threshold, the outer side of the main load-bearing section is set as the high-strength cast iron shell area; The non-primary load-bearing cavity filling area inside the three-dimensional digital model is set as the inner core area of ​​the high-damping mineral casting.

[0007] Optionally, the generation of the core-shell thermal stress coordinated control timing diagram includes: Establish the kinetic equation for the resin polymerization reaction in the core region of the high-damping mineral casting; Solve the kinetic equation of the resin polymerization reaction to obtain the core curing shrinkage curve; Based on the core curing shrinkage rate curve, the liquid feeding pressure window suitable for the high-strength cast iron outer shell region is obtained. The working period of the liquid compensation pressure window is matched with the time period of the inner core curing shrinkage rate curve to generate the thermal stress collaborative control timing diagram.

[0008] Optionally, the process of triggering the molten metal filling of the high-strength cast iron shell region includes: The rate of change of dielectric constant in the core region of the high-damping mineral casting was continuously collected. When the rate of change of dielectric constant is within the preset gel state range, it is determined that the core region of the high-damping mineral casting has reached a semi-solidified state. Open the valve of the high-strength cast iron gating channel to inject molten metal into the mold cavity in a segmented pressurization manner; Multiple arrays of piezoelectric ceramic actuators and heat flux density sensors are arranged inside the mold cavity wall of the high-strength cast iron shell area; The local heat flux density change rate at the interface between the inner core area of ​​the high-damping mineral casting and the outer shell area of ​​the high-strength cast iron is continuously collected. Based on the local heat flux density change rate, the instantaneous shrinkage stress gradient at the interface of the core region of the high-damping mineral casting is calculated. A compensation drive signal opposite in phase to the instantaneous contraction stress gradient is generated to drive the piezoelectric ceramic actuator to output a vibration displacement with a set amplitude. The surface of the inner core area of ​​the high-damping mineral casting is subjected to pressure holding treatment by superimposing the vibration displacement with the hydrostatic pressure of the molten metal until the inner core area of ​​the high-damping mineral casting is completely solidified.

[0009] Optionally, the method of forming a metallurgical-grade mechanical interlock structure at the two-phase interface includes: A micron-level anchoring groove array is prefabricated on the outer surface of the inner core region of the high-damping mineral casting. During the molten metal filling process in the high-strength cast iron outer shell area, the overheating of the molten metal is controlled to cause surface micro-melting of the resin on the surface of the anchoring groove array. The molten metal penetrates the surface layer and melts to form a porous structure. After the molten metal solidifies, it forms an embedded interlocking connection structure at the interface between the two phases.

[0010] Optionally, the gradient temperature-controlled annealing treatment performed on the integrally cast blank includes: Acquire the initial residual stress distribution spectrum at the interface between the two phases; A segmented cooling process strategy is formulated based on the initial residual stress distribution map. Within the glass transition temperature range corresponding to the inner core region of the high-damping mineral casting, isothermal homogenization heat treatment is performed. The temperature drop rate is controlled to be no greater than the preset critical temperature drop rate, so that the temperature of the blank slowly passes through the phase transformation temperature point of the high-strength cast iron shell region.

[0011] Optionally, the in-situ finishing based on the mounting reference surface includes: The composite mold integral casting lathe bed is clamped and fixed to the gantry machining center; The pre-set process positioning holes on the high-strength cast iron outer shell area serve as the global coordinate reference; The double-mountain-shaped guide rail surface is subjected to continuous milling in a single clamping operation using a diamond tool. The motor base mating surface is milled synchronously to make the parallelism tolerance between the double-mountain guide rail surface and the motor base mating surface less than or equal to a preset tolerance threshold.

[0012] Optionally, the step of performing continuous milling on the double-mountain guide surface using a diamond tool in a single clamping operation includes: During a single clamping and continuous milling process, the surface temperature field distribution map and spindle cutting load fluctuation curve of the double-mountain guide surface are continuously collected; The surface temperature field distribution map is time-series matched with the spindle cutting load fluctuation curve to obtain the coordinate points of stress anomaly concentration. Based on the coordinates of the stress anomaly concentration points, the feed rate and depth of cut of the diamond tool are adjusted, and the thermal error compensation module of the gantry machining center is invoked to generate a reverse displacement correction. Based on the reverse displacement correction amount, the worktable or spindle box of the gantry machining center is driven to perform position correction to compensate for the impact of abnormal stress on the machining straightness of the double-mountain guide surface.

[0013] Optionally, before performing the integrated casting operation, the method further includes: Preheat the mold cavity corresponding to the high-strength cast iron outer shell area to the preset process temperature; A high-temperature resistant release agent is sprayed onto the inner wall of the mold cavity. The high-damping mineral casting core area mold assembly with a pre-set anchoring groove array is embedded into the mold cavity and locked and sealed.

[0014] Optionally, after milling the double-mountain-shaped guide rail surface and the motor base mating surface, the method further includes: The double-mountain-shaped guide rail surface is subjected to ultrasonic induction hardening treatment; After quenching, the double-mountain-shaped guide rail surface is subjected to grinding and scraping polishing treatment; The straightness and torsion of the double-mountain-shaped guide rail surface were detected using a coordinate measuring machine.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Based on the dynamic stiffness requirements and load distribution characteristics of machine tools, this invention divides the main load-bearing area of ​​the high-strength cast iron shell into a high-damping mineral casting inner core filling area. This enables the external load-bearing structure of the bed to possess the high load-bearing and high wear-resistant characteristics of high-strength cast iron, while the internal filling structure leverages the advantages of high damping, strong vibration absorption, and low thermal deformation of mineral castings. This solves the technical shortcomings of traditional single cast iron bed with poor vibration reduction and pure mineral casting bed with weak load-bearing capacity, thereby improving the machine tool's cutting vibration resistance and machining stability. 2. This invention establishes a resin polymerization kinetic model, matches the core curing characteristics with the cast iron solidification rate, and constructs a thermal stress synergistic control sequence. Simultaneously, it utilizes a semi-cured state filling combined with a surface micro-melting anchoring structure to form a high-strength metallurgical-grade mechanical interlocking structure at the two-phase interface, replacing adhesive and splicing structures and improving the bonding strength and integrity of the heterogeneous material interface. Furthermore, it employs a gradient segmented temperature-controlled annealing process based on residual stress maps, implementing differentiated temperature control for the glass transition range of mineral castings and the phase transformation range of cast iron. This releases residual thermal stress at the two-phase interface, avoiding the problems of incomplete stress elimination and material phase transformation defects in current uniform annealing processes. This suppresses deformation and accuracy degradation during subsequent use of the machine bed, extending its service life. 3. This invention adopts a single-clamp continuous milling process, combined with dynamic monitoring of temperature field and cutting load, and micron-level position error compensation technology, to correct thermal stress concentration and cutting error in real time during the machining process, ensuring high-precision parallelism and straightness of the double-mountain guide rail surface and the motor base mating surface, eliminating the cumulative error caused by multiple clamping, and improving the machining accuracy, wear resistance and adaptability of the guide rail surface. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the steps of the present invention. Detailed Implementation

[0017] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0018] Reference Figure 1 As shown, a method for manufacturing a lathe bed using a composite casting integrated molding process includes: Step 101: Obtain the dynamic stiffness requirements and thermal deformation compensation parameters of the target machine tool; analyze the dynamic stiffness requirements to obtain the topological configuration of the internal reinforcing ribs and the mounting reference surface of the external guide rails; specifically, establish a dynamic stiffness model of the machine tool based on the maximum cutting load, spindle speed range, and rated machining accuracy level of the target lathe, and quantify the stiffness requirement indicators and thermal deformation compensation parameters of each region of the bed; solve the stress and thermal deformation law of the bed as a whole through finite element dynamic simulation and thermal deformation simulation, extract the topological layout of the internal reinforcing ribs that meet the stiffness constraints of the whole machine, and simultaneously calibrate the reference plane position, flatness, and spatial attitude parameters required for the assembly of the external guide rails; the dynamic stiffness requirements mentioned here refer to the deformation resistance and vibration resistance performance indicators of the machine tool bed under dynamic cutting impact loads; the thermal deformation compensation parameters are the thermal expansion and contraction and deformation offset parameters of the bed under continuous machining temperature rise conditions; Step 102: Construct a three-dimensional digital model of a multi-material composite mold based on the topological configuration and installation reference surface; divide the three-dimensional digital model into a high-damping mineral casting inner core area and a high-strength cast iron outer shell area; specifically, using the reinforcing rib topological configuration as the internal structural skeleton and the guide rail installation reference surface as the external contour constraint, construct a three-dimensional digital model of the composite mold that perfectly matches the bed forming structure using three-dimensional modeling software; combine the bed load distribution characteristics to perform logical division of material regions in the three-dimensional digital model, designating the external load-bearing, guide rail installation, and component docking areas as the high-strength cast iron outer shell area, and the internal cavity filling and vibration reduction area as the high-damping mineral casting inner core area, realizing the zoned matching design of structural load-bearing performance and damping vibration reduction performance; the high-damping mineral casting inner core area mentioned here is a filling structure area with high damping, low thermal deformation, and strong vibration absorption characteristics; the high-strength cast iron outer shell area is an external load-bearing structure area with high hardness, high stiffness, and high wear resistance characteristics; Step 103: Determine the peak curing exothermic temperature based on the volume ratio of the core area of ​​the high-damping mineral casting; generate a timing diagram for the coordinated control of thermal stress between the core and the outer shell by matching the cooling and solidification rate of the high-strength cast iron outer shell area with the peak curing exothermic temperature; calculate the total volume of the overall molding cavity of the composite mold, and then separately calculate the total volume of the core area of ​​the high-damping mineral casting. Divide the volume of the mineral casting core by the volume of the overall mold cavity to obtain the volume ratio of the mineral casting core. This ratio directly determines the total exothermic base of resin curing. The larger the ratio, the higher the total heat released during the resin polymerization and curing process, and the higher the corresponding peak curing exothermic temperature, thus achieving accurate quantitative calibration of the curing temperature parameters; firstly, measure and calculate the total volume of the core area of ​​the high-damping mineral casting and the overall mold cavity volume of the bed using a three-dimensional digital model, and calculate the core volume ratio. The volume ratio of the zone; combined with the pre-calibrated exothermic characteristic curve of the resin curing of mineral castings, the peak exothermic temperature of curing corresponding to the current volume ratio is fitted and matched; based on the temporal variation law of the peak exothermic temperature of curing, the cooling, solidification, and crystallization rates of high-strength cast iron molten metal are reverse-engineered and matched, so that the entire process of the core resin curing exothermic temperature rise and the entire process of the outer cast iron metal solidification cooling are matched in time sequence and the temperature field is complementary and balanced; the time sequence parameters and temperature parameters of the core curing and the cooling parameters and pressure parameters of the outer shell solidification are integrated to draw a time sequence diagram of the core-outer shell thermal stress coordinated control that can directly guide the integral casting molding operation; the peak exothermic temperature of curing refers to the highest temperature node of heat released during the polymerization and curing process of the mineral casting resin; the thermal stress coordinated control time sequence diagram is a process parameter scheduling map that coordinates the curing and solidification sequence of the two phase materials. Step 104: Perform the integrated casting operation according to the thermal stress synergistic control sequence diagram; when the core area of ​​the high-damping mineral casting is in a semi-cured state, trigger the filling of the high-strength cast iron outer shell area with molten metal, so that the two-phase interface forms a metallurgical-grade mechanical interlocking structure; specifically, strictly refer to the process nodes of the thermal stress synergistic control sequence diagram, first complete the filling of the mineral casting substrate inside the mold and start the constant temperature curing; monitor the curing state of the core in real time, and when the core enters a semi-cured gel state, has a certain structural support strength and is not completely hardened, quickly complete the filling and casting of the high-strength cast iron molten metal; utilize the microstructure characteristics of the surface of the semi-cured core and the thermal effect of the high-temperature molten metal to form a tightly interlocked metallurgical-grade mechanical interlocking structure at the interface of the two, so as to achieve gapless composite molding of heterogeneous materials; the semi-cured state mentioned here refers to the intermediate curing state in which the mineral casting resin has completed the initial gelation, has a fixed shape, no flow characteristics, and still has interfacial fusion activity. Step 105: Perform gradient temperature-controlled annealing on the integrally cast blank to release residual thermal stress at the interface between the inner core area of ​​the high-damping mineral casting and the outer shell area of ​​the high-strength cast iron. Specifically, considering the difference in thermophysical properties between the cast iron and the mineral casting, a zoned gradient temperature control method is used to perform annealing heat treatment on the integral blank. Following the process logic of segmented heating, constant temperature stabilization, and gradient cooling, the residual thermal stress generated at the interface of the two phase materials due to solidification shrinkage and solidification temperature difference is gradually released, avoiding interface stress concentration and local deformation defects. The gradient temperature-controlled annealing mentioned here refers to a heat treatment process with differentiated temperature change rates based on the differences in phase transformation characteristics and solidification characteristics of the inner and outer layer materials. Step 106: Perform in-situ finishing based on the installation datum surface, milling out the double-mountain-shaped guide rail surface and the motor seat mating surface to obtain the composite mold integrated casting lathe bed; specifically, using the previously calibrated guide rail installation datum surface as a unified machining datum, perform in-situ finishing on the integrated blank, sequentially completing the milling of the double-mountain-shaped guide rail working surface and the motor seat assembly mating surface of the bed, ensuring that the dimensional accuracy and geometric tolerance of each working surface meet the standards, and finally obtaining the finished blank of the composite mold integrated casting lathe bed.

[0019] The above technical solution adopts a heterogeneous material partitioned integrated casting process, which takes into account both the overall structural rigidity and vibration damping performance of the lathe bed. The bonding strength of the composite interface is improved by the coordinated control of thermal stress timing and the interlocking structure of the interface. Combined with gradient annealing and in-situ finishing processes, the technical problems of residual stress, easy peeling of the interface, low machining accuracy and poor dimensional stability of traditional composite lathe beds are effectively solved, thereby improving the machining accuracy and service life of the lathe bed.

[0020] In some embodiments, the three-dimensional digital model is divided into a high-damping mineral casting inner core region and a high-strength cast iron outer shell region, including: Step 201: Extract the main load-bearing sections from the 3D digital model that bear the cutting load. Specifically, perform load traversal analysis on the overall structure of the machine bed through finite element mechanical simulation, and screen out the key section areas that bear tensile stress, compressive stress, shear stress, and impact load during the machine tool cutting process. Mark these high-load, high-stress sections as the main load-bearing sections. These sections are mainly concentrated in the guide rail bearing area, the end support area of ​​the machine bed, and the motor base docking area. The main load-bearing section mentioned here refers to the core stress section of the machine bed that bears the cutting load and support load of the whole machine, and is the key control area for the stiffness of the machine bed. Step 202: Determine the flexural section modulus of the main load-bearing section and configure the corresponding allowable deflection threshold and matching safety factor. First, determine the geometric profile parameters of the main load-bearing section and solve for the moment of inertia of the section. This parameter is determined by the shape of the section. Regular sections can be calculated using conventional geometric methods, while irregular sections are solved by integration using simulation software. Then, measure the vertical distance from the outermost edge of the section to the neutral axis of the section. The flexural section modulus of the main load-bearing section is obtained by the ratio of the moment of inertia of the section to this vertical distance. The overall calculation logic is that the larger the value of the moment of inertia of the section and the smaller the vertical distance from the edge of the section to the neutral axis, the larger the final flexural section modulus, and the greater the allowable deflection threshold and matching safety factor of the corresponding section. The stronger the resistance to bending deformation, the better. Based on the geometric profile parameters of the main load-bearing section, the moment of inertia of the section and the distance to the maximum neutral axis are calculated, and the bending section modulus is obtained through ratio calculation. Combining the accuracy level and ultimate load conditions of the target machine tool, the maximum allowable elastic deformation deflection of the bed is set as the allowable deflection threshold. At the same time, the corresponding structural safety factor is configured according to the mechanical design specifications to avoid the risk of plastic deformation under ultimate load and ensure the structural stability of the bed under rated working conditions and short-term overload conditions. The bending section modulus mentioned here is the core geometric parameter for measuring the bending stiffness of the section. The allowable deflection threshold is the maximum allowable elastic deformation displacement of the bed under normal working conditions. Step 203: When the bending section modulus is not higher than the safety factor corresponding to the allowable deflection threshold, the outer side of the main load-bearing section is set as a high-strength cast iron shell area; the bending section modulus calculated by actual measurement is multiplied by the preset structural safety factor to obtain the actual stiffness reserve value of the section; at the same time, the allowable bending section modulus of the section is calculated by reverse derivation based on the preset allowable deflection threshold; if the actual stiffness reserve value is less than or equal to the allowable bending section modulus, it is determined that the current section stiffness reserve is insufficient and cannot meet the load-bearing deformation constraint requirements; the calculated bending section modulus and the preset safety factor are substituted into the verification logic to complete the stiffness determination. If the stiffness deficiency determination condition is met, the outer surface area of ​​the main load-bearing section is designated as a high-strength cast iron shell area, and the high stiffness and high strength characteristics of high-strength cast iron are used to improve the overall bending and deformation resistance of the load-bearing section; the structural safety factor is selected in the range of 1.2 to 1.5 according to the machine tool accuracy level to adapt to the load-bearing requirements of lathes of different accuracy levels; Step 204: Set the non-main load-bearing cavity filling area inside the three-dimensional digital model as the high-damping mineral casting inner core area; specifically, all the redundant cavity areas inside the three-dimensional model of the bed that do not directly bear external cutting loads or support loads are designated as high-damping mineral casting inner core filling areas. Without reducing the overall structural stiffness of the bed, the high-damping characteristics of the mineral casting are used to absorb processing vibration and resonance energy.

[0021] The above technical solution precisely divides the heterogeneous material regions based on mechanical load-bearing characteristics, allowing high-rigidity cast iron materials to be concentrated in key stress areas, and high-damping mineral materials to fill redundant cavities, achieving the optimal match between stiffness, strength and vibration reduction performance, and avoiding material waste and structural performance shortcomings.

[0022] In some embodiments, generating a timing diagram for the coordinated control of inner core-outer shell thermal stress includes: Step 301: Establish the resin polymerization reaction kinetic equation for the inner core region of the high-damping mineral casting. Specifically, based on the resin matrix and curing agent ratio parameters of the mineral casting, and combined with the variation law of polymerization reaction rate and crosslinking degree at different temperatures, the resin polymerization reaction kinetic equation is fitted. This equation can characterize the mapping relationship between curing time, ambient temperature, resin polymerization degree, shrinkage rate, and heat release. The resin polymerization reaction kinetic equation mentioned here is a mathematical model describing the reaction law of the entire curing process of the mineral casting. Step 302: Solve the kinetic equation of the resin polymerization reaction to obtain the core curing shrinkage rate curve; count the total liquid volume of the initial filling of the mineral casting, and then collect the real-time volume of the mineral casting at any time during the curing process. Calculate the difference between the initial volume and the real-time volume, divide the volume difference by the initial liquid volume and convert it to a percentage to obtain the volume shrinkage rate of the mineral casting at the corresponding time. The larger the shrinkage rate, the more significant the volume shrinkage deformation caused by resin polymerization and curing at that time. Solve the kinetic equation time by time through numerical iteration to calculate the degree of polymerization of the resin corresponding to different curing times. Combine the linear correspondence between the degree of polymerization and the volume shrinkage amount, and substitute them into the volume shrinkage calculation logic one by one to obtain the volume shrinkage rate at each time node in the entire curing process. With curing time as the horizontal axis and volume shrinkage rate as the vertical axis, fit and generate the core curing shrinkage rate curve that changes with time, which intuitively reflects the volume shrinkage change law of the mineral casting core from liquid state, gel state to solid state throughout the entire process. Step 303: Based on the core solidification shrinkage rate curve, match the appropriate liquid feeding pressure window for the high-strength cast iron outer shell region; extract the solidification shrinkage volume of the mineral core at each solidification time point, and calculate the solidification shrinkage volume of the cast iron outer shell at the corresponding time point by combining the solidification characteristics of the cast iron molten metal; determine the interface stress state by comparing the volume difference between the two; if the shrinkage volume of the mineral core is greater than the shrinkage volume of the cast iron outer shell, tensile stress will be generated at the interface between the two phases, and the deformation difference needs to be compensated by feeding with molten metal; if the shrinkage volume of the mineral core is less than or equal to the shrinkage volume of the cast iron outer shell... The two phases shrink and deform in a matched manner, with no obvious residual tensile stress at the interface. The shrinkage volume data of the two-phase materials at each time point of the entire curing process are extracted, and the volume shrinkage difference is calculated at each time point. Based on the positive and negative state and the magnitude of the difference, the process pressure range that can compensate for the volume difference of the solidified and solidified heterogeneous materials and effectively offset the tensile stress at the interface is accurately determined. This stable pressure range is the liquid feeding pressure window of the high-strength cast iron shell area. The liquid feeding pressure window mentioned here refers to the process pressure range that can effectively compensate for the volume difference of the solidified and solidified heterogeneous materials and suppress interface defects. Step 304: Match the working period of the liquid feeding pressure window with the change period of the core curing shrinkage rate curve to generate a thermal stress collaborative control time sequence diagram. Specifically, extract the effective nodes of the start and end times of the feeding pressure window, and extract the key time nodes of rapid change, stable change, and tendency to stabilize of the core curing shrinkage rate. Match the two types of time nodes one by one to complete the time sequence alignment, and integrate the pressure parameters, temperature parameters, and time parameters to generate a standardized thermal stress collaborative control time sequence diagram, providing a process basis for integrated casting operations.

[0023] By using the above technical solution, the deformation law of the inner core is predicted based on the dynamic model, and the solidification and feeding sequence of the outer shell metal is matched in reverse, the deformation difference of heterogeneous materials is reduced from the root of the forming process, and the initial residual stress of the composite interface is reduced.

[0024] In some embodiments, triggering the molten metal filling of the high-strength cast iron shell region includes: Step 401: Continuously collect the dielectric constant change rate of the inner core region of the high-damping mineral casting; set a fixed signal sampling time interval, continuously collect the real-time dielectric constant value during the curing process of the mineral casting, record the dielectric constant at the current sampling moment and the dielectric constant at the previous sampling moment, calculate the difference between the dielectric constants at the two moments, divide the difference by the fixed sampling time interval, and finally obtain the dielectric constant change rate per unit time; this parameter can accurately reflect the resin gelation and curing process, is not affected by ambient temperature or external interference, and has high data stability; arrange dielectric sensing probes inside the inner core mold, continuously collect the real-time value of the dielectric constant of the medium throughout the curing process of the mineral casting, calculate the dielectric constant change rate successively according to the fixed sampling period, and accurately characterize the real-time degree of resin polymerization and curing through the dynamic change law of electrical parameters; Step 402: When the dielectric constant change rate is within the preset gel state value range, it is determined that the core area of ​​the high-damping mineral casting has reached the semi-cured state. Specifically, the dielectric constant change rate range corresponding to the semi-cured gel state of the mineral casting is calibrated in advance through experiments, and the gel initiation threshold and gel termination threshold are determined. When the change rate value collected and calculated in real time stably falls within the range, it can be determined that the core has been cured to the semi-cured state and has the conditions for interface composite molding. Step 403: Open the high-strength cast iron pouring channel valve and inject the molten metal into the mold cavity in a segmented pressurization manner; specifically, adopt a segmented gradient pressurization pouring method, complete the cavity filling and bottoming at low speed and low pressure, and gradually increase the pouring pressure and flow rate to avoid the high-speed molten metal from scouring and breaking through the semi-solidified mineral casting core structure, and ensure the stability of filling. Step 404: Arrange multiple sets of piezoelectric ceramic actuators and heat flux density sensors in the mold cavity wall of the high-strength cast iron shell area; specifically, arrange multiple sets of piezoelectric ceramic actuators and heat flux density sensors in an array in the area corresponding to the two-phase interface of the mold cavity to realize full-domain monitoring of interface thermal parameters and stress state and active vibration compensation. Step 405: Continuously collect the local heat flux density change rate at the interface between the inner core area of ​​the high-damping mineral casting and the outer shell area of ​​the high-strength cast iron; set a fixed sampling time interval, collect the heat flux density value of the two-phase interface at the current moment and the heat flux density value at the previous sampling moment in real time, calculate the heat flux density difference between the two moments, divide the difference by the fixed sampling time interval to obtain the heat flux density change rate per unit time. This parameter can directly reflect the dynamic rate of heat transfer at the two-phase interface and correspond to the real-time thermal deformation degree of the interface; collect the real-time heat transfer value of the two-phase interface in real time through the heat flux density sensor, calculate the heat flux density change rate successively according to a fixed period, and characterize the interface temperature difference heat transfer intensity and thermal deformation dynamic state. Step 406: Based on the local heat flux density change rate, calculate the instantaneous shrinkage stress gradient at the interface of the core area of ​​the high-damping mineral casting; select two adjacent monitoring points at the two-phase interface, collect the instantaneous shrinkage stress values ​​at the two points respectively, calculate the stress difference between the two points, divide the stress difference by the straight-line distance between the two monitoring points, and finally obtain the local stress gradient of the interface; the larger the stress gradient value, the more uneven the interface stress distribution, and the higher the risk of local stress concentration; calibrate the correspondence coefficient between the heat flux density change rate and the material thermal shrinkage strain in advance through experiments, first calculate the real-time thermal strain of the interface based on the real-time heat flux density change rate, and then convert the instantaneous shrinkage stress at each monitoring point through the material strain-stress constitutive relationship, select the stress values ​​of adjacent points and substitute them into the calculation logic to obtain the stress gradient of each region of the interface, and accurately locate the stress concentration defect area; Step 407: Generate a compensation drive signal that is opposite in phase to the instantaneous contraction stress gradient, and drive the piezoelectric ceramic actuator to output a vibration displacement with a set amplitude; specifically, based on the magnitude and positive / negative phase of the stress gradient, generate an electric drive signal with an opposite phase, the signal amplitude of which is positively correlated with the stress gradient value, and control the piezoelectric ceramic actuator to output a high-frequency micro-amplitude vibration that matches the amplitude, thereby offsetting the tensile stress generated by the instantaneous contraction of the interface. Step 408: By superimposing the static pressure of the molten metal with vibration displacement, pressure holding treatment is applied to the surface of the inner core area of ​​the high-damped mineral casting until the inner core area of ​​the high-damped mineral casting is completely solidified; the static pressure generated by the self-weight of the high-strength cast iron molten metal is collected, and the dynamic equivalent pressure corresponding to the vibration output of the piezoelectric ceramic is calculated. The static pressure and the dynamic equivalent pressure are directly superimposed to obtain the total pressure of the interface composite pressure holding. The interface shrinkage gap is compensated by the continuous and stable composite pressure; the dynamic pressure generated by the piezoelectric vibration and the static self-weight pressure of the molten metal are superimposed in real time to continuously apply dynamic pressure holding to the two-phase composite interface, continuously compensate for the small gaps generated by solidification shrinkage, effectively suppress the generation of interface porosity, cracks and peeling defects, until the inner core of the mineral casting is completely solidified and shaped.

[0025] The above technical solutions enable accurate determination of the core curing state and active compensation of interface stress. The dynamic pressure holding process eliminates interface stress defects in the composite molding process, thereby improving the density and integrity of the interface bonding of heterogeneous materials.

[0026] In some embodiments, forming a metallurgical-grade mechanical interlock structure at the two-phase interface includes: Step 501: Prefabricate a micron-level anchoring groove array on the outer surface of the inner core area of ​​the high-damping mineral casting; specifically, by means of mold etching and molding, a uniformly arranged micron-level groove array is prefabricated on the mating surface of the inner core forming mold of the mineral casting, so that the outer surface of the solidified mineral inner core forms a regular anchoring concave-convex structure, providing a structural basis for the penetration and interlocking of molten metal. Step 502: During the molten metal filling process in the high-strength cast iron outer shell area, the superheat of the molten metal is controlled to cause surface micro-melting of the resin on the surface of the anchoring groove array; the fixed liquidus temperature parameter of the cast iron material is obtained, and the actual pouring temperature of the molten metal is monitored in real time. The real-time superheat of the molten metal is obtained by subtracting the liquidus temperature of the cast iron from the actual pouring temperature; the superheat value directly determines the melting depth of the resin surface. If the superheat is too low, the resin will not melt sufficiently and the molten metal will not penetrate well. If the superheat is too high, the surface structure of the inner core will be burned. In this embodiment, the superheat is strictly controlled within the optimal range of 20~40℃; the pouring temperature of the molten metal is collected in real time, and the superheat value is calculated and matched in real time to maintain the superheat within the preset process range. The surface heat radiation and heat conduction of the high-temperature molten metal cause the resin on the surface of the groove of the mineral casting to undergo controllable micro-melting, forming a loose and porous rough interface structure, while ensuring that the overall structural strength of the inner core is not damaged. Step 503: The molten metal penetrates into the porous structure formed by the micro-melting of the surface layer. After the molten metal solidifies, an embedded interlocking connection structure is formed at the interface between the two phases. Specifically, the high-temperature molten metal fully penetrates into the pores and grooves generated by the micro-melting. After the molten metal cools and solidifies, the cast iron metal structure and the groove structure of the mineral casting interlock and fix each other to form an embedded mechanical interlocking interface, replacing the traditional planar bonding structure.

[0027] The above technical solution, through the combination of prefabricated anchoring structure and hot micro-melting process, achieves embedded interlocking composite of heterogeneous materials, improves the interface bonding strength, and solves the defects of traditional composite bed interfaces that are prone to cracking, peeling, and loosening.

[0028] In some embodiments, gradient temperature-controlled annealing is performed on the integrally cast blank, including: Step 601: Collect the initial residual stress distribution map of the two-phase interface; specifically, use a residual stress detection device to perform full-area scanning detection on the two-phase composite interface of the integrated molding blank, obtain the magnitude, direction and concentration distribution of residual stress at different locations of the interface, and generate a visual residual stress distribution map. Step 602: Develop a segmented cooling process strategy based on the initial residual stress distribution map. Extract the maximum residual stress value of the local area of ​​the interface from the residual stress distribution map, and simultaneously calculate the average residual stress value of the entire interface. Divide the local maximum residual stress by the average residual stress of the entire interface to obtain the stress concentration coefficient. Determine the degree of stress concentration through the coefficient value. When the coefficient value is greater than 1.5, the area is determined to be a severely stress-concentrated area, requiring targeted strengthening of annealing cooling control. Extract the residual stress values ​​of each monitoring point in the map, calculate the stress concentration coefficient for each area, accurately distinguish between severely stress-concentrated areas and uniform stress areas, and set differentiated heating, isothermal, and cooling process parameters for different areas. Develop a gradient cooling annealing strategy with zoned, segmented, and temperature-zoned approaches to eliminate localized stress concentration. Step 603: Perform isothermal homogenization heat treatment within the glass transition temperature range corresponding to the inner core region of the high-damping mineral casting; specifically, raise the blank temperature to the glass transition temperature range of the mineral casting and keep it at a constant temperature to fully relax the inner core resin structure, uniformly arrange the molecular chains, release the structural stress generated by the curing of the inner core, and achieve structural homogenization. Step 604: Control the temperature drop rate to be no greater than the preset critical temperature drop rate, so that the billet temperature slowly passes through the phase transformation temperature point of the high-strength cast iron outer shell region; set a fixed cooling time interval, collect the billet temperature at the previous moment and the billet temperature at the current moment in real time, calculate the temperature difference between the two moments, divide the temperature difference by the fixed time interval, and obtain the real-time temperature drop rate of the billet; calibrate the critical temperature drop rate allowed by the process through preliminary experiments to ensure that the actual temperature drop rate during processing is always less than or equal to the critical rate; collect the billet temperature data in real time throughout the process, calculate the real-time temperature drop rate one by one, strictly control the cooling speed, and use a low-speed gradient cooling method to allow the billet temperature to slowly pass through the phase transformation temperature range of the cast iron material, avoid secondary phase transformation stress and interface peeling defects caused by rapid temperature change, and achieve stable and thorough release of residual stress. The above technical solution utilizes differentiated gradient annealing to address the differences in thermophysical properties between the inner and outer heterogeneous materials, thereby releasing residual stress at the composite interface and ensuring the stability of the bed blank's microstructure and dimensional accuracy.

[0029] In some embodiments, in-situ finishing based on the mounting reference plane includes: Step 701: Clamp and fix the bed of the composite casting lathe to the gantry machining center; specifically, after annealing and stress release, the bed blank is steadily hoisted and clamped on the worktable of the gantry machining center, and the bed is fixed by multi-point positioning and clamping to ensure that the clamping is firm, without loosening, and without additional clamping stress. Step 702: Use the pre-set process positioning holes on the high-strength cast iron shell area as the global coordinate reference; specifically, use the process positioning holes reserved in the casting stage as the unified coordinate reference to establish the whole machine machining coordinate system, so as to ensure the reference of all subsequent finishing processes is consistent and avoid reference conversion errors. Step 703: Perform continuous milling on the double-mountain guide rail surface in one clamping using a diamond tool; specifically, select a high wear-resistant and high-hardness diamond tool to complete the continuous milling and finishing of the double-mountain guide rail working surface of the bed in a single clamping state, and eliminate the cumulative error caused by multiple clamping. Step 704: Simultaneously mill the mating surface of the motor base to ensure that the parallelism tolerance between the double-mountain guide rail surface and the mating surface of the motor base is less than or equal to the preset tolerance threshold. Select multiple sets of sampling points evenly at corresponding positions on the guide rail surface and the mating surface of the motor base, measure the vertical distance between each set of sampling points, calculate the average value of the vertical distance between all sampling points, and then compare the deviation of each set of sampling point distances from the average value. Extract the maximum value among all deviation values; this maximum deviation value is the parallelism tolerance of the two mating surfaces, thus accurately determining whether the form and position accuracy meets the standard. Evenly distribute multiple sets of corresponding sampling points and complete the distance measurement. Obtain the parallelism tolerance through the above calculation method. Relying on the integrated machining method with a unified benchmark, precisely control the machining dimensions to ensure that the parallelism tolerance value meets the preset precision machining threshold requirements.

[0030] The above technical solution adopts a one-time clamping integrated precision machining process, unifies the machining datum, reduces the cumulative clamping error, and improves the dimensional accuracy and machining consistency of the key assembly surfaces of the bed and the working surfaces of the guide rails.

[0031] In some embodiments, a diamond tool is used to perform continuous milling on the double-peaked guide surface in a single clamping operation, including: Step 801: During a single clamping and continuous milling process, continuously collect the surface temperature field distribution map and spindle cutting load fluctuation curve of the double-mountain guide rail surface; specifically, during the finishing process, the temperature field distribution data and spindle cutting load fluctuation data of the guide rail machining area are collected in real time through an infrared temperature measurement array and a spindle load sensor, and the machining thermal state and cutting mechanical state are monitored throughout the process. Step 802: Match the surface temperature field distribution map with the spindle cutting load fluctuation curve in time sequence to obtain the coordinate points of stress anomaly concentration; pre-calibrate the reference cutting load and reference machining temperature for finishing, and collect the spindle load fluctuation and temperature fluctuation during the machining process in real time. Calculate the ratio of load fluctuation to reference load and the ratio of temperature fluctuation to reference temperature, and finally obtain the temperature-load correlation fluctuation coefficient through the correspondence between the two sets of ratios; if the fluctuation coefficient exceeds the preset normal range, it can be determined that there is a problem of abnormal concentration of thermal stress and cutting stress at the machining location; align the collected temperature field data and load fluctuation data with a unified timestamp, calculate the correlation fluctuation coefficient at each time step, and accurately locate the coordinate points of stress anomaly concentration where the coefficient exceeds the standard, providing a positioning basis for subsequent process adjustment and error compensation; Step 803: Based on the coordinates of the stress anomaly concentration points, adjust the feed rate and depth of cut of the diamond tool, and call the thermal error compensation module of the gantry machining center to generate the reverse displacement correction amount; specifically, adjust the cutting process parameters corresponding to the stress anomaly area to reduce cutting heat and cutting impact. The equipment calculates the position error amount based on the deviation between the real-time parameters and the reference parameters, and takes the equivalent reverse value as the reverse displacement correction amount. Step 804: Based on the reverse displacement correction amount, drive the worktable or spindle box of the gantry machining center to perform position correction to compensate for the impact of abnormal stress on the straightness of the double-mountain guide rail surface. Specifically, drive the moving parts of the equipment to complete position compensation according to the reverse displacement correction amount, offset the guide rail surface deformation deviation caused by thermal stress and cutting stress, and ensure the straightness accuracy of the guide rail surface.

[0032] Through the above technical solutions, dynamic monitoring and real-time compensation of thermal stress and cutting stress during the machining process can be achieved, deformation errors during the finishing process can be eliminated, and the straightness and flatness accuracy of the double-mountain guide surface can be improved. In some embodiments, the method for manufacturing a lathe bed by integral casting according to claim 1 further includes, before performing the integral casting operation: Step 901: Preheat the mold cavity corresponding to the high-strength cast iron outer shell area to the preset process temperature; specifically, before the casting operation, the mold cavity is uniformly preheated to raise the mold temperature to the preset process temperature, eliminating the rapid condensation of molten metal, excessive temperature difference stress, and cold shut defects caused by low mold temperature. Step 902: Spray a high-temperature resistant release agent onto the inner wall of the mold cavity; specifically, spray a high-temperature resistant, high-strength release agent evenly onto the inner wall of the preheated mold cavity to prevent the molten metal from sticking to the mold and to avoid oxidation defects caused by direct contact between the mold and the molten metal, thus ensuring the surface forming quality of the casting. Step 903: Embed the high-damping mineral casting core area mold assembly with pre-set anchoring groove array into the mold cavity and lock and seal it; Specifically, the pre-made mineral core mold assembly with anchoring groove array structure is accurately embedded into the main mold cavity to complete the positioning, locking and sealing treatment, to prevent liquid leakage, misalignment and material leakage during the casting process, and to ensure the molding accuracy of the composite structure.

[0033] The above technical solutions complete the pre-treatment of molds and pre-positioning of inner core components before casting, avoiding casting cold defects, sticking defects and structural misalignment defects, and providing stable mold process conditions for integrated composite molding. In some embodiments, after milling the double-mountain-shaped guide rail surface and the motor base mating surface, the method further includes: Step 1001: Perform ultrasonic induction hardening treatment on the double-mountain type guide rail surface; specifically, perform ultrasonic induction hardening process on the finished double-mountain type guide rail working surface to refine the metal structure of the guide rail surface, increase the hardness, enhance the wear resistance and anti-galling performance of the guide rail surface, and extend the service life of the guide rail. Step 1002: After quenching, the double-mountain type guide rail surface is ground and scraped. Specifically, after quenching, the quenching oxide layer and micro-deformation are removed by precision grinding, and then the micro-flatness of the guide rail surface is optimized by manual scraping and grinding to reduce surface roughness and improve the guide rail movement fitting accuracy. Step 1003: Use a coordinate measuring machine to detect the straightness and torsion of the double-mountain type guide rail surface; specifically, sampling points are evenly distributed along the length of the guide rail, a reference straight line is fitted, and the deviation value between each sampling point and the reference straight line is calculated. The maximum deviation value is the straightness error; by fitting the reference plane through multiple points in space, the plane deviation of each point is calculated to obtain the torsion value, verifying whether the finished product processing accuracy meets the standard, and ensuring the consistency of the quality of the finished bed.

[0034] The above technical solutions involve quenching and precision finishing of the guide rail surface to improve its hardness, wear resistance, and motion accuracy. Combined with high-precision testing processes, this ensures the finished product performance and accuracy of the high-end lathe bed.

[0035] Overall, firstly, this invention achieves an optimal matching design of bed stiffness, strength, and damping performance; based on the bed load distribution characteristics and mechanical simulation results, this invention divides the load-bearing area into a high-strength cast iron outer shell and a vibration-damping area into a high-damping mineral casting inner core. High-stiffness, high-wear-resistant cast iron materials are concentrated in core stress areas such as guide rail load-bearing, end supports, and motor mount connections, fully ensuring the overall load-bearing capacity, bending resistance, and assembly wear resistance of the bed; simultaneously, the high damping, low thermal deformation, and strong vibration absorption characteristics of mineral castings are used to fill the internal cavities. The redundant region can efficiently absorb vibration energy and resonant impact during machine tool cutting, significantly reducing vibration amplitude and noise during machining. This completely solves the problems of poor damping performance and easy vibration resonance in traditional all-cast iron lathe beds, significantly improving the stability of lathe machining and the surface finish of workpieces. Secondly, this invention establishes a timing matching mechanism for the temperature and shrinkage fields of two-phase materials by quantifying the exothermic solidification law of mineral castings and the solidification shrinkage characteristics of molten cast iron, matching the process timing of core solidification and outer shell solidification. Simultaneously, it combines interfacial heat flow and stress... Real-time force gradient monitoring, employing piezoelectric dynamic vibration compensation combined with molten metal hydrostatic pressure composite pressure holding method, effectively offsets the interfacial tensile stress and shrinkage gaps caused by differences in thermal properties and solidification characteristics of heterogeneous materials, eliminating forming defects such as composite interface porosity, microcracks, and delamination. Combined with a gradient temperature-controlled annealing heat treatment process adapted to heterogeneous materials, it can smoothly release residual stress in the overall lathe bed and interface, avoiding secondary stress concentration and deformation problems, and improving the overall structural density, integrity, and long-term dimensional stability of the composite bed. Furthermore, this invention constructs a metallurgical-grade mechanically interlocked composite interface through a prefabricated micron-level anchoring groove array combined with a controllable micro-melting and infiltration process of molten metal. Compared to ordinary planar adhesive composite structures, the embedded interlocking interface structure formed by this invention does not require an adhesive medium, relying on the mechanical interlocking structure of metal and mineral castings to achieve a high-strength composite connection. The interface's shear resistance, delamination resistance, and impact resistance are significantly improved, allowing it to withstand the dynamic cutting impact loads of machine tools for a long time, avoiding problems such as interface loosening, delamination, and failure after long-term service, thus extending the service life of the lathe bed and the overall stability of the equipment.

[0036] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A method for manufacturing a lathe bed using a composite mold integral casting process, characterized in that, include: Obtain the dynamic stiffness requirements and thermal deformation compensation parameters of the target machine tool; analyze the dynamic stiffness requirements to obtain the topological configuration of the internal stiffeners and the mounting reference surface of the external guide rails; A three-dimensional digital model of a multi-material composite mold is constructed based on the aforementioned topological configuration and the aforementioned mounting reference plane; the three-dimensional digital model is divided into a high-damping mineral casting inner core area and a high-strength cast iron outer shell area; The solidification exothermic peak temperature is determined based on the volume ratio of the inner core region of the high-damping mineral casting; the cooling and solidification rate of the high-strength cast iron outer shell region is matched with the solidification exothermic peak temperature to generate a timing diagram of the coordinated control of thermal stress between the inner core and outer shell. The integrated casting operation is performed according to the thermal stress coordinated control timing diagram; when the core area of ​​the high-damping mineral casting is in a semi-solid state, the molten metal filling of the high-strength cast iron outer shell area is triggered, so that the two-phase interface forms a metallurgical mechanical interlocking structure. Gradient temperature-controlled annealing is performed on the integrally cast blank to release the residual thermal stress at the interface between the inner core area of ​​the high-damping mineral casting and the outer shell area of ​​the high-strength cast iron. Based on the aforementioned mounting reference surface, in-situ precision machining is performed to mill the double-mountain-shaped guide rail surface and the motor base mating surface, thereby obtaining the composite mold integral casting lathe bed.

2. The method for manufacturing a lathe bed using a composite mold integral casting according to claim 1, characterized in that, The process of dividing the three-dimensional digital model into a high-damping mineral casting inner core area and a high-strength cast iron outer shell area includes: Extract the main load-bearing section that bears the cutting load from the three-dimensional digital model; Determine the bending section modulus of the main load-bearing section, and configure the corresponding allowable deflection threshold and matching safety factor; When the bending section modulus is not higher than the safety factor corresponding to the allowable deflection threshold, the outer side of the main load-bearing section is set as the high-strength cast iron shell area; The non-primary load-bearing cavity filling area inside the three-dimensional digital model is set as the inner core area of ​​the high-damping mineral casting.

3. The method for manufacturing a lathe bed using a composite mold integral casting according to claim 1, characterized in that, The generation of the core-shell thermal stress coordinated control timing diagram includes: Establish the kinetic equation for the resin polymerization reaction in the core region of the high-damping mineral casting; Solve the kinetic equation of the resin polymerization reaction to obtain the core curing shrinkage curve; Based on the core curing shrinkage rate curve, the liquid feeding pressure window suitable for the high-strength cast iron outer shell region is obtained. The working period of the liquid compensation pressure window is matched with the time period of the inner core curing shrinkage rate curve to generate the thermal stress collaborative control timing diagram.

4. The method for manufacturing a lathe bed using a composite mold integral casting as described in claim 1, characterized in that, The process of triggering the molten metal filling of the high-strength cast iron outer shell region includes: The rate of change of dielectric constant in the core region of the high-damping mineral casting was continuously collected. When the rate of change of dielectric constant is within the preset gel state range, it is determined that the core region of the high-damping mineral casting has reached a semi-solidified state. Open the valve of the high-strength cast iron gating channel to inject molten metal into the mold cavity in a segmented pressurization manner; Multiple arrays of piezoelectric ceramic actuators and heat flux density sensors are arranged inside the mold cavity wall of the high-strength cast iron shell area; The local heat flux density change rate at the interface between the inner core area of ​​the high-damping mineral casting and the outer shell area of ​​the high-strength cast iron is continuously collected. Based on the local heat flux density change rate, the instantaneous shrinkage stress gradient at the interface of the core region of the high-damping mineral casting is calculated. A compensation drive signal opposite in phase to the instantaneous contraction stress gradient is generated to drive the piezoelectric ceramic actuator to output a vibration displacement with a set amplitude. The surface of the inner core area of ​​the high-damping mineral casting is subjected to pressure holding treatment by superimposing the vibration displacement with the hydrostatic pressure of the molten metal until the inner core area of ​​the high-damping mineral casting is completely solidified.

5. The method for manufacturing a lathe bed using a composite mold integral casting according to claim 1, characterized in that, The method of forming a metallurgical-grade mechanical interlock structure at the two-phase interface includes: A micron-level anchoring groove array is prefabricated on the outer surface of the inner core region of the high-damping mineral casting. During the molten metal filling process in the high-strength cast iron outer shell area, the overheating of the molten metal is controlled to cause surface micro-melting of the resin on the surface of the anchoring groove array. The molten metal penetrates the surface layer and melts to form a porous structure. After the molten metal solidifies, it forms an embedded interlocking connection structure at the interface between the two phases.

6. The method for manufacturing a lathe bed using a composite mold integral casting according to claim 1, characterized in that, The gradient temperature-controlled annealing treatment performed on the integrally cast blank includes: Acquire the initial residual stress distribution spectrum at the interface between the two phases; A segmented cooling process strategy is formulated based on the initial residual stress distribution map. Within the glass transition temperature range corresponding to the inner core region of the high-damping mineral casting, isothermal homogenization heat treatment is performed. The temperature drop rate is controlled to be no greater than the preset critical temperature drop rate, so that the temperature of the blank slowly passes through the phase transformation temperature point of the high-strength cast iron shell region.

7. The method for manufacturing a lathe bed by integral casting using a composite mold according to claim 1, characterized in that, The in-situ finishing based on the mounting reference surface includes: The composite mold integral casting lathe bed is clamped and fixed to the gantry machining center; The pre-set process positioning holes on the high-strength cast iron outer shell area serve as the global coordinate reference; The double-mountain-shaped guide rail surface is subjected to continuous milling in a single clamping operation using a diamond tool. The motor base mating surface is milled synchronously to make the parallelism tolerance between the double-mountain guide rail surface and the motor base mating surface less than or equal to a preset tolerance threshold.

8. The method for manufacturing a lathe bed by integral casting using a composite mold according to claim 7, characterized in that, The method of performing continuous milling on the double-mountain guide surface using diamond tools in a single clamping operation includes: During a single clamping and continuous milling process, the surface temperature field distribution map and spindle cutting load fluctuation curve of the double-mountain guide surface are continuously collected; The surface temperature field distribution map is time-series matched with the spindle cutting load fluctuation curve to obtain the coordinate points of stress anomaly concentration. Based on the coordinates of the stress anomaly concentration points, the feed rate and depth of cut of the diamond tool are adjusted, and the thermal error compensation module of the gantry machining center is invoked to generate a reverse displacement correction. Based on the reverse displacement correction amount, the worktable or spindle box of the gantry machining center is driven to perform position correction to compensate for the impact of abnormal stress on the machining straightness of the double-mountain guide surface.

9. The method for manufacturing a lathe bed using a composite mold integral casting according to claim 1, characterized in that, Before performing the integrated casting operation, the following are also included: Preheat the mold cavity corresponding to the high-strength cast iron outer shell area to the preset process temperature; A high-temperature resistant release agent is sprayed onto the inner wall of the mold cavity. The high-damping mineral casting core area mold assembly with a pre-set anchoring groove array is embedded into the mold cavity and locked and sealed.

10. The method for manufacturing a lathe bed by integral casting using a composite mold according to claim 1, characterized in that, After milling the double-mountain-shaped guide rail surface and the motor base mating surface, the process also includes: The double-mountain-shaped guide rail surface is subjected to ultrasonic induction hardening treatment; After quenching, the double-mountain-shaped guide rail surface is subjected to grinding and scraping polishing treatment; The straightness and torsion of the double-mountain-shaped guide rail surface were detected using a coordinate measuring machine.

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