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CN-121979090-A - Control method for precisely stamping fisheye terminal to prevent crystal slag

CN121979090ACN 121979090 ACN121979090 ACN 121979090ACN-121979090-A

Abstract

The application relates to a fisheye terminal crystal residue prevention precision stamping processing control method which comprises the steps of establishing a tribovoltaic potential standard response based on a die of a pre-processing micro-nano structure, collecting transient tribovoltaic potential in real time by utilizing a suspension ground potential technology, collecting dynamic differential capacitance spectrum of a lubricating oil film and analyzing molecular orientation order degree, carrying out time sequence correlation analysis on potential variation characteristics and dispersion characteristics, judging as a crystal residue microscopic nucleation stage when polarity inversion and order degree falling are detected, triggering an electrostatic micro-lubrication system, and driving charged oil mist to be adsorbed to friction hot spots in a targeted mode by utilizing a high-gradient electrostatic field induced by the micro-nano structure. The application has the advantages of realizing early warning of nucleation microcosmic crystal slag and achieving self-alignment targeted lubrication.

Inventors

  • FU PENGWEI
  • ZHU XINAI
  • Fang Peixi

Assignees

  • 上海徕木电子股份有限公司

Dates

Publication Date
20260505
Application Date
20260108

Claims (9)

  1. 1. The control method for the precise stamping processing of the fisheye terminal crystal slag is characterized by comprising the following steps of: S1, in a test stamping stage, obtaining standard response of a friction voltaic potential of a pre-processed indium-plated layer on a fish-eye terminal and a stamping die interface at the moment of plastic deformation based on a normal stamping working condition, wherein a micro-nano structure is pre-processed on the surface of a fish-eye forming insert of the stamping die, and the micro-nano structure is used for increasing the specific surface area of contact to enhance the friction voltaic effect signal-to-noise ratio of the contact interface and is used for constructing a non-uniformly distributed high-gradient electrostatic field in a friction contact area; S2, in the stamping forming stage, configuring a die-terminal electric loop into a suspension ground potential measuring mode, and collecting transient friction voltaic potential generated by a stamping die and a fisheye terminal in real time; S3, continuously applying sweep frequency signals of a preset frequency range to a die-terminal electric loop in a die closing descending stage and a bottom dead center pressure maintaining stage, so as to acquire a dynamic differential capacitance spectrum of a lubricating oil film to acquire dispersion characteristics and analyze molecular orientation order degree, wherein the die-terminal electric loop is a conductive loop formed by the stamping die and the fisheye terminal; S4, comparing the transient tribovoltaic potential with the standard response of the tribovoltaic potential in a bottom dead center pressure maintaining window before the end of a single stamping stroke, and extracting and identifying potential variation characteristics; performing association analysis on the potential variation characteristics and the dispersion characteristics acquired in the current bottom dead center pressure maintaining stage, and judging that the plating crystal lattice is broken and derived in a crystal slag microscopic nucleation stage when the potential variation characteristics corresponding to the stamping are detected to be in polarity inversion and the molecular orientation degree of order falls to a preset molecular orientation degree of order threshold; S5, triggering an electrostatic micro-lubrication system based on a discrimination result of a crystal slag microscopic nucleation stage, spraying lubricating oil mist with specific polarity charges to a forming area, and driving the lubricating oil mist to autonomously migrate along an electric field line and preferentially adsorb to a friction hot spot area with highest electric potential by utilizing a high gradient electrostatic field induced by the micro-nano structure in a friction intense area.
  2. 2. The fisheye terminal crystal slag prevention precision stamping processing control method according to claim 1 is characterized in that the fisheye terminal is provided with an elastic arm structure with gradual change thickness and an inner wall rounding feature, the standard response of the friction voltaic potential obtained in the step S1 is determined based on a specific potential waveform feature excited by a non-uniform stress distribution gradient and a specific plastic deformation rate generated in a plastic deformation process of the elastic arm structure with gradual change thickness, and the specific potential waveform feature is different from a potential response of an equal-thickness cantilever beam structure.
  3. 3. The fisheye terminal crystal slag prevention precision press working control method of claim 1, wherein S2 comprises: S21, electrically isolating a lower die seat of a stamping die from a main body of the stamping machine through an insulating ceramic material, and establishing a die-terminal electric loop; S22, controlling a multiplexing switch to switch the die-terminal electric loop to a differential charge collection channel, taking a non-working area of a stamping die as a reference ground potential, and collecting differential mode charge signals between the gradually-changed thickness elastic arm structures between the fisheye molding insert and the fisheye terminal based on a differential charge amplifier, wherein the differential charge amplifier is arranged on an insulating side wall of the lower die holder and moves synchronously with the die; S23, determining a region where the elastic arm structure with the gradual change thickness generates maximum plastic deformation, using the differential mode charge signal to represent electron escape behavior of the region due to high strain rate, and converting the processed differential mode charge signal into the transient friction voltaic potential after common mode electromagnetic interference generated by operation of a punching machine is filtered.
  4. 4. The fisheye terminal grain slag prevention precision press working control method of claim 1, further comprising the steps of: In the stamping forming stage, a control power supply module is used for superposing a direct-current bias voltage between the stamping die and the fish-eye terminal; The direct-current bias voltage is utilized to induce a dielectric wetting effect, so that the contact angle of the cold lubricating oil on the surface of the fish-eye molding insert is reduced, wherein the contact angle refers to an included angle between a liquid-gas interface tangent of lubricating oil droplets and a solid-liquid interface of the fish-eye molding insert; configuring an input loop of the die-terminal electric loop as an alternating current coupling mode, isolating a direct current component of the direct current bias voltage by using a blocking capacitor, filtering power supply ripple interference, and only extracting an alternating current component of a transient friction voltaic potential superposed on the direct current bias voltage as a basis of the S4 comparison; And maintaining the direct-current bias voltage until lubricating oil overcomes surface tension under the drive of electric field force, and spreading and penetrating the lubricating oil into the root with gradually-changed thickness of the fish-eye terminal and the micro-gap with the rounded inner wall.
  5. 5. The fisheye terminal crystal slag prevention precision press working control method of claim 1, wherein S3 comprises: s31, controlling a multiplexing switch to switch the die-terminal electrical loop to a high-frequency impedance analysis channel, and continuously injecting the high-frequency impedance analysis channel to cover a frequency range Hz to A frequency sweep signal in a preset frequency band of Hz, measuring the current response of the high-frequency impedance analysis channel and calculating a dynamic differential capacitance spectrum; S32, decomposing the acquired dynamic differential capacitance spectrum into a real part capacitance and an imaginary part capacitance, and constructing complex capacitance plane track characteristics reflecting the evolution of the real part capacitance and the imaginary part capacitance along with the change of frequency by taking the real part capacitance as an abscissa and the imaginary part capacitance as an ordinate; s33, extracting the polarization intensity intercept difference of the complex capacitance plane track characteristic on a real axis as the dispersion characteristic, wherein the polarization intensity intercept difference is used for representing the polarization response hysteresis degree of a lubricating oil film under the excitation of a sweep electric field; s34, calculating a dielectric loss peak of which the imaginary part capacitance changes along with frequency, and extracting a frequency domain response bandwidth of the dielectric loss peak, wherein the frequency domain response bandwidth corresponds to half-width of the dielectric loss peak; S35, establishing a mapping model between the frequency domain response bandwidth and the oil film molecule arrangement dispersion based on a Boltzmann distribution function, and normalizing the reciprocal of the frequency domain response bandwidth to obtain the molecule orientation order, wherein the narrower the frequency domain response bandwidth is, the more consistent the arrangement of the oil film molecules in a pressure-keeping state is, and the higher the molecule orientation order is.
  6. 6. The fisheye terminal grain slag prevention precision press working control method of claim 1, wherein S3 further comprises: S301, intercepting a data segment of the dynamic differential capacitance spectrum in the die closing downlink stage, and establishing a space charge distribution characteristic curve reflecting a nonlinear relation between the capacitance reciprocal square of a lubricating oil film and a bias voltage; S302, extracting a linear region slope and a voltage axis intercept of the space charge distribution characteristic curve, analyzing charge carrier concentration in a lubricating oil film by utilizing the linear region slope, combining a built-in potential determined by the voltage axis intercept, and inverting and calculating the physical thickness of a charge depletion layer in the lubricating oil film as the width of the effective space charge region by a poisson equation; S303, when the width of the effective space charge region is monitored to exponentially decay to a preset nano threshold value and the dynamic differential capacitance spectrum has negative capacitance characteristics, judging that a lubricating oil film is about to break down due to quantum tunneling, and performing forced triggering before the stamping die is in physical contact with the fisheye terminal to execute S5.
  7. 7. The fisheye terminal crystal slag prevention precision press working control method of claim 1, wherein S4 comprises: s41, in a bottom dead center pressure maintaining window before the end of a single stamping stroke, performing time domain comparison on the transient friction voltammetry potential and the friction voltammetry potential standard response, and extracting deviation between the transient friction voltammetry potential and the friction voltammetry potential standard response to serve as potential variation characteristics; s42, carrying out time sequence correlation on the potential variation characteristic and the dispersion characteristic of the dynamic differential capacitance spectrum acquired in the current bottom dead center pressure maintaining stage, and analyzing whether a causal corresponding relation exists between the potential variation characteristic and the dispersion characteristic; S43, synchronously reading data of an optical fiber probe arranged in a non-contact area of the die, wherein the optical fiber probe is used for collecting photon counts released by a stamping die and a fisheye terminal interface during plastic deformation; S44, confirming and judging the microscopic nucleation stage of the crystal slag only when the potential variation characteristic is detected to be in polarity inversion, the molecular orientation degree of order drops to a preset degree of order threshold, and the friction luminescence photon counting instantaneous value corresponding to the indium oxide energy level transition wavelength is synchronously detected to exceed 3 times of standard deviation of an environmental background photon counting baseline, so as to eliminate potential false positive signals caused by piezoelectric effect.
  8. 8. The fisheye terminal crystal slag prevention precision press working control method of claim 1, wherein S5 comprises: s51, monitoring the residual surface potential of the surface of the stamping die in real time; S52, when the residual surface potential is monitored to exceed a preset saturation threshold, determining that an electrostatic shielding field is formed on the surface of the stamping die, wherein the electrostatic shielding field can prevent the adsorption of subsequent charged oil mist; S53, controlling the polarity of a high-voltage generator of the electrostatic micro-lubrication system to be reversed, spraying lubricating oil mist with charges opposite to the current residual surface potential polarity to neutralize accumulated charges on the surface of the stamping die, eliminating electrostatic shielding fields, and maintaining the continuous targeted adsorption capacity, wherein the high-voltage generator is used for generating a high-voltage electrostatic field at a nozzle, and enabling the flowing lubricating oil mist droplets to carry electrostatic charges with specific polarities through corona discharge or induction electrification effect.
  9. 9. The fisheye terminal grain slag prevention precision press working control method according to claim 1 or 8, wherein S5 comprises: S501, collecting punching frequency data of the stamping die in real time and pneumatic stagnation pressure at the moment of die closing; s502, carrying out weighted evaluation on the stroke frequency and the pneumatic stagnation pressure, and judging that an aerodynamic windbreak which prevents continuous spray adsorption exists in the current working condition when the evaluation result exceeds a preset windbreak critical value; S503, responding to the judging result, and switching the output mode of the electrostatic micro-lubrication system from continuous spraying to a high-pressure pulse spraying mode; S504, controlling the high-voltage generator to apply a pulse electric field between the nozzle and the stamping die, and adjusting the charge frequency of oil mist liquid drops and the frequency of the pulse electric field to keep synchronous resonance; S505, utilizing the peak electric field intensity of the pulse electric field to generate transient electric field force, driving the oil mist particles to obtain kinetic energy exceeding the closing airflow resistance of the die, so that the oil mist particles penetrate through the aerodynamic windbreak in a ballistic track and bombard the surface of the stamping die.

Description

Control method for precisely stamping fisheye terminal to prevent crystal slag Technical Field The application relates to the field of precision machining, in particular to a fisheye terminal crystal residue prevention precision stamping control method. Background The fish-eye terminal is used as a key precise component in the connector, and the special gradual thickness elastic arm and the inner wall rounding structure of the fish-eye terminal provide higher precision requirements for the stamping forming process. In high speed continuous stamping production, continuous mechanical friction and plastic deformation can occur between the die and the indium-plated layer. Because indium metal is softer in texture and is easy to adhere, if a lubrication state is poor or microscopic defects exist on the surface of a die, metal lattices are easy to break at a contact interface, and tiny metal scraps, namely crystal slag, are induced. The generation of crystal slag not only can scratch the surface of the die, but also can be attached to the conductive contact surface of the terminal, so that the contact resistance of the product is unstable and even electrical failure is caused. Existing stamping die monitoring techniques focus on capturing macroscopic physical quantities, such as monitoring heat accumulation by temperature sensors, analyzing mechanical impact by vibration sensors, or detecting material fracture signals using acoustic emission techniques. However, these physical changes tend to have hysteresis, and are typically not perceived by the system until the slag has formed and accumulated to a degree that results in significant temperature rise or abnormal vibration of the mold. At this point, irreversible physical damage to the mold surface may have occurred, and early identification and intervention by the system during the microscopic nucleation stage of slag formation may be difficult. In addition, the monitoring signal with single dimension is easy to be interfered by the noise of the machine tool environment, and the normal process fluctuation and the early fault symptoms are difficult to be accurately distinguished. In addition, in the aspect of lubrication control, the traditional timing and quantitative oil injection or flooding type lubrication mode is difficult to adapt to the complex geometric shape of the fish-eye terminal. It is difficult for the lubricating oil mist to effectively overcome the penetration resistance to root or tiny rounded corner areas of gradual thickness, so that these areas with high stress concentration are often in a lean oil state and become areas with frequent crystal slag. The existing control means lacks real-time perceptibility of microscopic state of the lubricating oil film, and cannot dynamically adjust the lubricating strategy according to the order degree of oil film molecule arrangement or the electron transfer activity degree of a contact interface. Disclosure of Invention In order to be capable of representing the contact state in real time from the electron and molecule microcosmic level and realizing a control method of self-adaptive targeted lubrication, the application provides a control method for precisely stamping and processing the fisheye terminal crystal slag prevention. The application provides a fisheye terminal crystal residue prevention precision stamping processing control method, which adopts the following technical scheme: a fisheye terminal crystal residue prevention precision stamping processing control method is used for a fisheye terminal processing process, and comprises the following steps: S1, in a test stamping stage, obtaining standard response of a friction voltaic potential of a pre-processed indium-plated layer on a fish-eye terminal and a stamping die interface at the moment of plastic deformation based on a normal stamping working condition, wherein a micro-nano structure is pre-processed on the surface of a fish-eye forming insert of the stamping die, and the micro-nano structure is used for increasing the specific surface area of contact to enhance the friction voltaic effect signal-to-noise ratio of the contact interface and is used for constructing a non-uniformly distributed high-gradient electrostatic field in a friction contact area; S2, in the stamping forming stage, configuring a die-terminal electric loop into a suspension ground potential measuring mode, and collecting transient friction voltaic potential generated by a stamping die and a fisheye terminal in real time; S3, continuously applying sweep frequency signals of a preset frequency range to a die-terminal electric loop in a die closing descending stage and a bottom dead center pressure maintaining stage, so as to acquire a dynamic differential capacitance spectrum of a lubricating oil film to acquire dispersion characteristics and analyze molecular orientation order degree, wherein the die-terminal electric loop is a conductive loop formed by the stamping di