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CN-121972531-A - Bayonet bronze rod backward extrusion production process for high-speed rail change

CN121972531ACN 121972531 ACN121972531 ACN 121972531ACN-121972531-A

Abstract

The invention relates to the technical field of extrusion control, and discloses a beryllium bronze rod backward extrusion production process for high-speed rail change, which comprises the steps of obtaining static parameters in advance, collecting real-time sensing data, calculating basic extrusion speed based on surface temperature and optimal deformation temperature, combining adjacent period temperature difference to obtain transient thermal strain rate, reversely calculating a dynamic target speed instruction by using a cut-off protection punishment mechanism to inhibit grain boundary microcracks, calculating fluid acceleration and transient inertial pressure compensation components according to the ratio of speed instruction variable to the sectional area of a pipe cylinder, mapping the speed to the actual flow rate of a pipeline, calculating shearing heat, integrating to obtain dynamic power viscosity, combining environmental heat loss to compensate the viscosity to obtain effective dynamic viscosity, calculating along-path viscous pressure loss based on the effective dynamic viscosity, superposing basic pressure and inertial pressure to obtain a total target pressure instruction, finally introducing a backflow prevention mechanism to solve a throttling flow equation, and outputting a target opening degree signal of a servo valve.

Inventors

  • CHEN LIHAI
  • ZHU JIANZHONG

Assignees

  • 江阴市科裕特铜材有限公司

Dates

Publication Date
20260505
Application Date
20260330

Claims (9)

  1. 1. The back extrusion production process of the beryllium bronze rod for the high-speed rail change is characterized by comprising the following steps of: Acquiring static basic data and real-time sensing data, and calculating a basic initial extrusion speed according to the deviation between the acquired surface temperature and the optimal deformation temperature; extracting the surface temperature of adjacent periods, and carrying out differential calculation to obtain a transient thermal strain rate by combining the thermal expansion coefficients of the material lines; Comparing the transient thermal strain rate with a preset threshold value, and correcting the basic initial extrusion speed by utilizing a cut-off protection punishment mechanism to obtain a dynamic target extrusion speed instruction; Calculating fluid acceleration according to the change amount of the dynamic target extrusion speed command and the sectional area ratio of the tube cylinder, and obtaining a transient inertia pressure compensation component; Mapping the speed instruction into the real flow velocity of the pipeline to calculate the shearing heat generation rate, and carrying out integral operation to obtain dynamic viscosity; Calculating the volumetric heat loss rate by combining the real-time oil temperature and the ambient temperature, and compensating the dynamic viscosity by utilizing the loss rate and the idle speed heat source constant to obtain the effective dynamic viscosity; calculating along-path viscous pressure loss according to the effective dynamic viscosity and the real flow velocity, and superposing basic pressure, transient inertia pressure compensation components and the along-path viscous pressure loss to obtain a total target pressure instruction; and introducing the minimum effective pressure difference for preventing backflow, substituting the total target pressure instruction and the speed instruction into a throttling flow equation, and solving and outputting a target opening degree signal of the servo valve.
  2. 2. The process for producing the beryllium bronze rod for high-speed rail change by backward extrusion according to claim 1, wherein the steps of obtaining static basic data and collecting real-time sensing data, calculating a basic initial extrusion speed according to the deviation of the obtained surface temperature and the optimal deformation temperature comprise the following steps: Obtaining data comprising an optimal superplastic deformation temperature of the beryllium bronze alloy, a temperature sensitivity attenuation coefficient, a thermal expansion coefficient of the beryllium bronze alloy wire, a safe thermal strain rate dead zone threshold, a critical thermal strain rate limit threshold, a hydraulic oil standard density, an initial dynamic viscosity, a viscosity-temperature sensitivity association constant, a maximum physical extrusion speed of equipment, an effective length of an oil supply pipeline, an inner diameter of the oil supply pipeline, an internal cross-sectional area of the oil supply pipeline, an effective cross-sectional area of a master cylinder, a pressure required by basic rigidity, an idle speed reference heating rate, a servo valve port flow coefficient, a maximum flow cross-sectional area of a servo valve, a sampling period, a comprehensive convection heat exchange coefficient, an environment heat exchange coupling weight and a minimum effective pressure difference; Infrared temperature sensors are deployed on the inner wall of an extrusion cylinder of the reverse extrusion machine and the outlet of a die, high-frequency dynamic pressure sensors are deployed on a main extrusion hydraulic cylinder and an oil supply pipeline, hydraulic oil temperature sensors are deployed on the inner side of an oil tank of the oil supply pipeline or a hydraulic pump station, and environmental temperature sensors are deployed on the outer sides of workshops and the hydraulic pump station; the method for calculating the basic initial extrusion speed comprises the steps of subtracting the optimal superplastic deformation temperature of the beryllium bronze alloy from the real-time temperature of the surface of the beryllium bronze rod at the outlet of the extrusion die to obtain a temperature difference value, dividing the temperature difference value by the optimal superplastic deformation temperature of the beryllium bronze alloy to obtain a temperature deviation rate, multiplying the temperature deviation rate by a temperature sensitivity attenuation coefficient to obtain a negative value, carrying out exponential operation on the obtained negative value serving as an index term of a natural logarithm, and multiplying the result of the exponential operation by the maximum physical extrusion speed of equipment to obtain the basic initial extrusion speed.
  3. 3. The process for producing the beryllium bronze rod for high-speed rail change according to claim 2, wherein the steps of extracting the surface temperature of the adjacent period, combining the thermal expansion coefficients of the material lines, and calculating the difference to obtain the transient thermal strain rate comprise the following steps: The method for calculating the transient thermal strain rate comprises the steps of subtracting the real-time temperature of the surface of the beryllium bronze alloy in the previous sampling period from the real-time temperature of the surface of the beryllium bronze alloy in the current sampling period to obtain a temperature variation, dividing the temperature variation by the sampling period to obtain a temperature variation rate, and multiplying the temperature variation rate by the coefficient of thermal expansion of the beryllium bronze alloy wire to obtain the transient thermal strain rate.
  4. 4. The process for backward extrusion production of beryllium bronze rods for high-speed rail change according to claim 3, wherein comparing the transient thermal strain rate with a preset threshold value, correcting the basic initial extrusion speed by using a cut-off protection penalty mechanism to obtain a dynamic target extrusion speed command comprises: The method for calculating the dynamic target extrusion speed instruction comprises the steps of obtaining an absolute value of transient thermal strain rate, subtracting a dead zone threshold value of the safe thermal strain rate from the absolute value when the absolute value is larger than the dead zone threshold value of the safe thermal strain rate, obtaining a thermal strain rate overrun value, otherwise taking the thermal strain rate overrun value as zero, subtracting the dead zone threshold value of the safe thermal strain rate from a limit thermal strain rate limit threshold value, obtaining a critical margin value, dividing the thermal strain rate overrun value by the critical margin value, performing square operation on the obtained quotient value, obtaining a punishment item by subtracting the punishment item from a value, obtaining a correction coefficient, taking zero as a final correction coefficient if the obtained correction coefficient is calculated to be smaller than zero, and finally multiplying the basic initial extrusion speed and the final correction coefficient to obtain the dynamic target extrusion speed instruction.
  5. 5. The process for producing the beryllium bronze rod for high-speed rail transfer according to claim 4, wherein the calculating the fluid acceleration according to the ratio of the variable quantity of the dynamic target extrusion speed command to the sectional area of the tube cylinder to obtain the transient inertia pressure compensation component comprises the following steps: The method for calculating the transient inertia pressure compensation component comprises the steps of subtracting a dynamic target extrusion speed command of the previous cycle from a dynamic target extrusion speed command of the current cycle to obtain a speed variation, dividing the speed variation by a sampling cycle to obtain a command acceleration, dividing the effective cross-sectional area of a master cylinder by the internal cross-sectional area of an oil supply pipeline to obtain a cross-sectional area proportion, and continuously multiplying the command acceleration, the cross-sectional area proportion, the effective length of the oil supply pipeline and the standard density of hydraulic oil to obtain the rigid liquid column transient inertia pressure compensation component.
  6. 6. The process for producing beryllium bronze rod for high-speed rail transfer according to claim 5, wherein the step of mapping the speed command to the actual flow rate of the pipeline to calculate the shear heat generation rate and performing integral operation to obtain the dynamic viscosity comprises the steps of: The method for calculating the shear heat generation rate comprises the steps of multiplying a dynamic target extrusion speed instruction by the effective cross-sectional area of a master cylinder, dividing the product of the inner diameter of an oil supply pipeline and the inner cross-sectional area of the oil supply pipeline to obtain the real shear rate of the pipeline, squaring the real shear rate of the pipeline, and multiplying the square operation of the real shear rate of the pipeline by the initial dynamic viscosity of hydraulic oil under a standard working condition to obtain the real shear heat generation rate of the pipeline fluid; The method for calculating the dynamic viscosity comprises the steps of carrying out time integral operation on the real shearing heat generation rate of the pipeline fluid in a continuous time interval from the system starting time to the current time to obtain an accumulated heat generation amount, multiplying the accumulated heat generation amount by a viscosity-temperature sensitive association constant, taking a negative value as an index term of natural logarithm to carry out index operation, and multiplying the index operation result by the initial dynamic viscosity of hydraulic oil under a standard working condition to obtain the dynamic viscosity influenced by shearing heat generation.
  7. 7. The back extrusion production process of the beryllium bronze rod for high-speed rail change according to claim 6, wherein the calculation of the volumetric heat loss rate by combining the real-time oil temperature and the ambient temperature and the compensation of the dynamic viscosity by using the loss rate and the idle heat source constant to obtain the effective dynamic viscosity comprises the following steps: The method for calculating the volumetric heat loss rate comprises the steps of subtracting the measured workshop environment temperature from the real-time oil temperature of hydraulic oil to obtain a temperature difference, multiplying the comprehensive convection heat exchange coefficient by four, dividing the comprehensive convection heat exchange coefficient by the inner diameter of an oil supply pipeline, and multiplying the comprehensive convection heat exchange coefficient by the temperature difference to obtain the volumetric heat loss rate; The method for calculating the effective dynamic viscosity comprises the steps of adding the real shearing heat generation rate of the pipeline fluid to the idling reference heat generation rate to obtain a heat generation denominator, dividing the volumetric heat loss rate by the heat generation denominator, multiplying the volumetric heat loss rate by the environmental heat exchange coupling weight to obtain a calibration proportion value, adding a first numerical value to the calibration proportion value to obtain a comprehensive compensation coefficient, and multiplying the comprehensive compensation coefficient by the dynamic viscosity to obtain the effective dynamic viscosity after environmental heat drift calibration.
  8. 8. The back extrusion production process of the beryllium bronze rod for high-speed rail transfer, as set forth in claim 7, is characterized in that the calculating the along-path viscous pressure loss according to the effective dynamic viscosity and the real flow rate, the superposing the basic pressure, the transient inertia pressure compensation component and the along-path viscous pressure loss to obtain the total target pressure command, and the calculating the total target pressure command comprises the following steps: multiplying the effective dynamic viscosity by the effective length of the oil supply pipeline, multiplying the effective dynamic viscosity by thirty-two, dividing the effective length by the square of the inner diameter of the oil supply pipeline to obtain an on-way resistance coefficient, multiplying the dynamic target extrusion speed command by the effective cross-sectional area of the master cylinder, dividing the effective cross-sectional area of the oil supply pipeline to obtain the real flow rate of the pipeline, and multiplying the on-way resistance coefficient by the real flow rate of the pipeline to obtain the real-time viscous pressure loss; the method for calculating the total target pressure command is to add the pressure required by the basic rigidity, the transient inertia pressure compensation component and the real-time viscous pressure loss to obtain the total target pressure command.
  9. 9. The process for producing the beryllium bronze rod for high-speed rail change according to claim 8, wherein the introducing the minimum effective pressure difference for preventing backflow, substituting the total target pressure command and the speed command into the throttling flow equation, solving and outputting the target opening degree signal of the servo valve comprises the following steps: The method for calculating the servo valve target opening degree control signal instruction comprises the steps of subtracting a total target pressure instruction from constant oil supply source absolute pressure provided by a pump station to obtain an actual calculation differential pressure, comparing the actual calculation differential pressure with a safe anti-backflow minimum effective differential pressure, taking the maximum value of the actual calculation differential pressure and the safe anti-backflow minimum effective differential pressure as an effective driving differential pressure, multiplying the effective driving differential pressure by two and dividing the effective driving differential pressure by the standard density of hydraulic oil, performing square operation on the obtained quotient to obtain a flow rate conversion factor, multiplying the servo valve flow coefficient and the maximum flow cross section area of the servo valve by the flow rate conversion factor to obtain a denominator, multiplying the effective cross section area of a master cylinder by a dynamic target extrusion speed instruction to obtain a numerator, dividing the numerator by the denominator, solving to obtain a servo valve target opening degree control signal instruction, and outputting the servo valve target opening degree control signal instruction to an executing mechanism.

Description

Bayonet bronze rod backward extrusion production process for high-speed rail change Technical Field The invention relates to the technical field of extrusion control, in particular to a back extrusion production process of a beryllium bronze rod for high-speed rail transfer. Background The high-speed rail transfer mechanism has extremely high requirements on the mechanical properties of key transmission parts, and beryllium bronze alloy is widely applied to the field due to the excellent mechanical properties. Backward extrusion is a core process for producing high quality beryllium bronze bars. However, beryllium bronze materials are extremely sensitive to temperature. In existing backward extrusion processes, constant extrusion speed or single variable closed loop control is typically employed. This conventional control method is difficult to cope with complex multiple physical field variations in the extrusion process. First, the squeeze interface is very prone to uneven intense frictional heating. When the local temperature suddenly changes too quickly, the crystal boundary in the material can generate extremely large transient thermal strain rate, so that microcracks are induced, and the product is scrapped. The prior art cannot dynamically limit the extrusion speed in real time and adaptively based on microscopic thermal strain rate. Secondly, if the extrusion speed is frequently and severely adjusted in order to suppress the thermal stress, rapid acceleration and deceleration of the fluid in the hydraulic circuit are directly caused. The existing control mode does not incorporate the rigid liquid column transient inertia pressure (water hammer impact) induced by the speed mutation into feedforward compensation, and the violent vibration of a pipeline is easily caused. Further, to counter the transient pressure fluctuations described above, the hydraulic servo valve must be high frequency tuned. The local high-frequency shearing work of the pipeline can lead to rapid heat generation of hydraulic oil, and the dynamic viscosity of the hydraulic oil is greatly attenuated. The prior art mostly uses static constant viscosity computing system along-path resistance such that the feedforward pressure compensates for severe distortion. In addition, the microfluidic thermal boundary layer is highly susceptible to unsteady shifts in the temperature of the plant environment. The existing pressure regulating mechanism does not consider the calibration effect of environmental heat loss on viscosity recovery, and the phenomenon of over-regulation or under-regulation compensation is very easy to occur. Therefore, a process for producing beryllium bronze rods for high-speed rail transfer by backward extrusion is needed to solve the problems of multiple deep coupling interference such as thermal strain microcracks, hydraulic inertial impact, fluid shear heat distortion, environmental thermal drift and the like. Disclosure of Invention The invention provides a back extrusion production process of a beryllium bronze rod for high-speed rail change, which promotes solving the problems in the prior art. The invention provides a back extrusion production process of a beryllium bronze rod for high-speed rail change, which comprises the following steps: Acquiring static basic data and real-time sensing data, and calculating a basic initial extrusion speed according to the deviation between the acquired surface temperature and the optimal deformation temperature; extracting the surface temperature of adjacent periods, and carrying out differential calculation to obtain a transient thermal strain rate by combining the thermal expansion coefficients of the material lines; Comparing the transient thermal strain rate with a preset threshold value, and correcting the basic initial extrusion speed by utilizing a cut-off protection punishment mechanism to obtain a dynamic target extrusion speed instruction; Calculating fluid acceleration according to the change amount of the dynamic target extrusion speed command and the sectional area ratio of the tube cylinder, and obtaining a transient inertia pressure compensation component; Mapping the speed instruction into the real flow velocity of the pipeline to calculate the shearing heat generation rate, and carrying out integral operation to obtain dynamic viscosity; Calculating the volumetric heat loss rate by combining the real-time oil temperature and the ambient temperature, and compensating the dynamic viscosity by utilizing the loss rate and the idle speed heat source constant to obtain the effective dynamic viscosity; calculating along-path viscous pressure loss according to the effective dynamic viscosity and the real flow velocity, and superposing basic pressure, transient inertia pressure compensation components and the along-path viscous pressure loss to obtain a total target pressure instruction; and introducing the minimum effective pressure difference for preventing backflow,