An evaluation method and monitoring device for the effectiveness of electrostatic minimal lubrication

Abstract

The present invention relates to an evaluation method and a monitoring device for the effectiveness of electrostatic minimum quantity lubrication. The evaluation method: After collecting the pH value pH, flow rate q, temperature T, concentration value resistivity ρ, TDS value TDS, residual oxygen content RO, turbidity NTU of the cutting fluid, and the electrostatic minimum quantity lubrication voltage V and the cutting fluid aerosol concentration value ω, substitute the parameters into the formula to calculate the cooling and lubrication failure coefficients respectively. When the corresponding coefficient exceeds 1, it is determined that cooling or lubrication fails; otherwise, it does not fail. The monitoring device includes an electrostatic voltage sensor, a cutting fluid aerosol concentration value sensor, and a monitoring sensor box including a pH value sensor, a flow rate sensor, a temperature sensor, a concentration value sensor, a resistivity sensor, a TDS value sensor, a residual oxygen content sensor, and a turbidity sensor. The evaluation method of the present invention can evaluate the effectiveness of electrostatic minimum quantity lubrication and ensure the machining effect; the device of the present invention can ensure the reliability of electrostatic minimum quantity lubrication.

Description

Technical Field

[0001] The invention belongs to the technical field of cutting, and relates to an evaluation method and a monitoring device for the effectiveness of electrostatic micro-lubrication. Background Art

[0002] In the process of metal cutting, various cutting fluids are often used to cool and lubricate the cutting area. The cooling and lubrication of the cutting area by the cutting fluid penetrates and infiltrates the tool-workpiece contact surface, reduces friction, and takes away heat.

[0003] In traditional cutting fluid processing, the cooling and lubrication effect of cutting fluid mainly depends on the composition and state of the cutting fluid. The indicators for cutting fluid status monitoring in the industry often include flow, pH value, concentration, temperature, pressure value, filterability, impurity content, etc. However, under electrostatic micro-lubrication conditions, since the penetration of aerosol cutting fluid into the tool-workpiece contact surface is affected by the aerosol concentration, and the electrostatic charge carried by the cutting fluid affects the wettability of the cutting fluid, the cooling and lubrication effect cannot be judged only by the state of the cutting fluid, but also needs to comprehensively consider the influence of electrostatic voltage and micro-lubrication aerosol concentration. In addition, the amount of cutting fluid used in conventional cutting fluid processing is large, and it can often form fluid accumulation inside the machine tool, so a cutting fluid tank is often set up to recycle the cutting fluid. Monitoring of some indicators of cutting fluid, such as pH value, conductivity, impurity content and concentration, is often completed by installing sensors in the cutting fluid tank. In micro-lubrication cutting, the amount of cutting fluid used is very small, and it is difficult to form fluid accumulation, so the cutting fluid can be regarded as a one-time use. Therefore, it is not suitable to monitor the cutting fluid status in minimal lubrication processing by installing sensors in the cutting fluid tank at the bottom of the machine tool.

[0004] CN215239680U provides an external multifunctional cutting fluid condition monitoring device. Although it also monitors indicators such as pH value, dissolved oxygen, conductivity, resistivity, turbidity and temperature, the monitoring device also only monitors the state of the cutting fluid and the monitoring position is the cutting fluid tank. It is unable to monitor the aerosol concentration and electrostatic voltage in electrostatic micro-lubrication. It is only suitable for traditional casting cutting processing. It is difficult to adapt to the special working form and environment of electrostatic micro-lubrication, and thus cannot effectively evaluate electrostatic micro-lubrication.

[0005] In summary, it is of great significance to study an evaluation method and monitoring device for the effectiveness of electrostatic minimum lubrication in order to solve the problem that the cooling and lubrication effect of electrostatic minimum lubrication is affected by various factors, resulting in the difficulty in evaluating its effectiveness, predicting its failure and determining its causes. Summary of the invention

[0006] The purpose of the present invention is to solve the problems existing in the prior art and to provide an evaluation method and a monitoring device for the effectiveness of electrostatic minimal lubrication.

[0007] To achieve the above object, the scheme adopted by the present invention is as follows:

[0008] An evaluation method for the effectiveness of electrostatic micro-lubrication is provided. The pH value of the cutting fluid, the voltage of the electrostatic micro-lubrication, the concentration value of the cutting fluid mist, the flow rate of the cutting fluid, and the temperature of the cutting fluid are collected and then inserted into a formula to calculate the cooling failure coefficient. The cooling failure coefficient is compared with 1. When the cooling failure coefficient exceeds 1, the cooling fails; otherwise, the cooling does not fail.

[0009] The calculation formula of cooling failure coefficient is as follows:

[0010] ε cool =ε ads +a T ·devi(T)+a coolcoef ·ε ads ·devi(T);

[0011] In the formula, ε cool is the cooling failure coefficient;

[0012] ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of pH, V, ω, and q when calculating the adsorption state coefficient;

[0013] a T is the weight coefficient corresponding to T;

[0014] a coolcoef is the weight coefficient of the synergistic effect of cutting fluid temperature and wetting state;

[0015] All weight coefficients are between 0 and 1 and can be adjusted according to actual monitoring needs. Adjustment according to actual conditions means: when the monitoring results cannot meet the actual production requirements and false alarms or missed alarms often occur in the electrostatic micro-lubrication system under a certain state, the coefficients can be adjusted according to the state indicators and deviation values ​​of the electrostatic micro-lubrication displayed by the monitoring system, so that whether the electrostatic micro-lubrication fails under this state can be accurately judged through the monitoring results. Generally, no adjustment is made and 1 is directly taken;

[0016] All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihc are respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of the normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing, which are obtained from experience, data provided by cutting fluid manufacturers and cutting test results. Specifically, if cutting fluid manufacturers, electrostatic micro-lubrication equipment manufacturers and other manufacturers have given the recommended upper and lower limits of the state indicator, the recommended value can be directly adopted; if a state indicator has no manufacturer and no recommended value, the actual production data on the production line can be used to take the state indicator as the independent variable, and the qualified rate of the cutting workpiece can be statistically analyzed, and the qualified rate curve of the production line products can be fitted, and the upper and lower limits of the normal value can be determined accordingly, that is, the qualified rate can be stabilized. The minimum and maximum values ​​of the status indicators that remain above the production line qualification rate requirements; if determined by experiments, the method is to change a certain indicator while keeping other indicators completely normal, conduct experiments, count the qualification rate of the workpieces in the experiment, and fit the qualification rate curve of the production line products, and determine the upper and lower limits of the normal value, that is, the minimum and maximum values ​​of the status indicators that can keep the qualification rate stably above the production line qualification rate requirements; the lower limit and upper limit of complete failure of each status indicator are the lower limit and upper limit of the status indicator that the cutting processing results cannot meet the process requirements at all due to changes in this single indicator when other indicators are normal, which can be obtained through production experience and cutting experiments.

[0017] The present invention also provides an evaluation method for the effectiveness of electrostatic micro-lubrication, which collects the pH value of the cutting fluid, the electrostatic micro-lubrication voltage, the cutting fluid aerosol concentration value, the cutting fluid flow rate, and the cutting fluid concentration value. Cutting fluid resistivity ρ, cutting fluid TDS value TDS, cutting fluid residual oxygen content RO, cutting fluid turbidity NTU are put into the formula to calculate the lubrication failure coefficient, and the lubrication failure coefficient is compared with 1. When the lubrication failure coefficient exceeds 1, the lubrication fails; otherwise, the lubrication does not fail;

[0018] The calculation formula of lubrication failure coefficient is as follows:

[0019] ε lub =ε wet +ε ads +a RO ·devi(RO)+a NTU ·devi(NTU)+a lubcoef ·ε wet ·ε ads ;

[0020] In the formula, ε lub is the lubrication failure coefficient;

[0021] ε wet is the cutting fluid wetting coefficient, Among them, a pHwet 、a Vwet 、a ωwet , a ρwet 、a TDSwet They correspond to pH, V, ω, ρ, weight coefficient of TDS;

[0022] ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of pH, V, ω, and q when calculating the adsorption state coefficient;

[0023] a RO is the weight coefficient corresponding to RO;

[0024] a NTU is the weight coefficient corresponding to NTU;

[0025] a lubcoef is the weight coefficient of the synergistic effect of the cutting fluid adsorption state and the wetting state;

[0026] All weight coefficients are between 0 and 1 and can be adjusted according to actual monitoring needs. Adjustment according to actual conditions means: when the monitoring results cannot meet the actual production requirements and false alarms or missed alarms often occur in the electrostatic micro-lubrication system under a certain state, the coefficients can be adjusted according to the state indicators and deviation values ​​of the electrostatic micro-lubrication displayed by the monitoring system, so that whether the electrostatic micro-lubrication fails under this state can be accurately judged through the monitoring results. Generally, no adjustment is made and 1 is directly taken;

[0027] All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With Pih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihc are respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of the normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing, which are obtained from experience, data provided by cutting fluid manufacturers and cutting test results. Specifically, if cutting fluid manufacturers, electrostatic micro-lubrication equipment manufacturers and other manufacturers have given the recommended upper and lower limits of the state indicator, the recommended value can be directly adopted; if a state indicator has no manufacturer and no recommended value, the actual production data on the production line can be used to take the state indicator as the independent variable, and the qualified rate of the cutting workpiece can be statistically analyzed, and the qualified rate curve of the production line products can be fitted, and the upper and lower limits of the normal value can be determined accordingly, that is, the qualified rate can be stabilized. The minimum and maximum values ​​of the status indicators that remain above the production line qualification rate requirements; if determined by experiments, the method is to change a certain indicator while keeping other indicators completely normal, conduct experiments, count the qualification rate of the workpieces in the experiment, and fit the qualification rate curve of the production line products, and determine the upper and lower limits of the normal value, that is, the minimum and maximum values ​​of the status indicators that can keep the qualification rate stably above the production line qualification rate requirements; the lower limit and upper limit of complete failure of each status indicator are the lower limit and upper limit of the status indicator that the cutting processing results cannot meet the process requirements at all due to changes in this single indicator when other indicators are normal, which can be obtained through production experience and cutting experiments.

[0028] The present invention also provides a monitoring device for the effectiveness of electrostatic micro-lubrication, wherein the electrostatic micro-lubrication device comprises a liquid storage tank for storing cutting fluid, a high-voltage electrostatic generator, and a flow control monitoring valve installed on a cutting fluid pipeline; the electrostatic micro-lubrication device adopts micro-lubrication technology and electrostatic spray technology, so that the charged cutting fluid is atomized into micron-sized charged droplets under the action of pneumatic force and electrostatic force, and is sprayed to the cutting processing area in the form of aerosol under the action of compressed air, so as to achieve micro-lubrication cooling;

[0029] The monitoring device includes a monitoring sensor box, a cutting fluid pH value sensor, an electrostatic micro-lubrication voltage sensor, a cutting fluid aerosol concentration value sensor, a cutting fluid flow sensor and a cutting fluid temperature sensor;

[0030] The cutting fluid mist concentration sensor is installed in the internal processing area of ​​the machine tool. Specifically, the cutting fluid mist concentration of electrostatic minimal lubrication is monitored by monitoring the mist concentration in the air of the machine tool.

[0031] The cutting fluid flow sensor is installed in the flow control monitoring valve to monitor the cutting fluid flow;

[0032] The electrostatic micro-lubrication voltage sensor is arranged in the high-voltage electrostatic generator, and specifically monitors the voltage of the electrostatic micro-lubrication by monitoring the electrostatic voltage generated by the high-voltage electrostatic generator;

[0033] The cutting fluid pH sensor and cutting fluid temperature sensor are both installed in the monitoring sensor box, where:

[0034] The cutting fluid pH sensor monitors the acid-base state of the cutting fluid by measuring the pH value of the cutting fluid in the fluid storage tank;

[0035] The cutting fluid temperature sensor specifically monitors the cutting fluid temperature state by measuring the cutting fluid temperature in the fluid storage tank;

[0036] The monitoring sensor box is connected to the liquid storage tank. A circulation pump is installed in the monitoring sensor box to control the continuous flow of cutting fluid between the monitoring sensor box and the liquid storage tank. The setting of the circulation pump ensures the accuracy of the monitoring data.

[0037] Specifically, the monitoring sensor box and the liquid storage tank are connected by two pipelines, namely, a liquid outlet pipe and a liquid inlet pipe; the connection method is: the liquid outlet pipe and the liquid inlet pipe are respectively connected to the liquid outlet and the liquid inlet of the monitoring sensor box; a filter is installed at the end of the liquid inlet pipe that is not connected to the monitoring sensor box, the filter is connected to the liquid inlet pipe with a pagoda head, and the pagoda head and the liquid inlet pipe are fixed with a pipe clamp; the filter end of the liquid inlet pipe and the end of the liquid outlet pipe that is not connected to the monitoring sensor box are respectively placed in the liquid storage tank, separated by a certain distance.

[0038] As the preferred technical solution:

[0039] As described above, a monitoring device for the effectiveness of electrostatic micro-lubrication, the monitoring device also includes a cutting fluid status monitoring main screen, a cutting fluid pH value sensor, an electrostatic micro-lubrication voltage sensor, a cutting fluid aerosol concentration value sensor, a cutting fluid flow sensor and a cutting fluid temperature sensor are simultaneously connected to the cutting fluid status monitoring main screen, and the cutting fluid status monitoring main screen is used to resolve the signals of each sensor into specific values ​​of each status indicator.

[0040] In a monitoring device for the effectiveness of electrostatic minimal lubrication as described above, the cutting fluid status monitoring main screen is also used to calculate the cooling failure coefficient based on the specific values ​​of each status indicator;

[0041] The calculation formula of cooling failure coefficient is as follows:

[0042] ε cool =ε ads +a T ·devi(T)+a coolcoef ·ε ads ·devi(T);

[0043] In the formula, εcool is the cooling failure coefficient;

[0044] ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of the cutting fluid pH value, the electrostatic micro-lubrication voltage, the cutting fluid aerosol concentration, and the cutting fluid flow rate, respectively, when calculating the adsorption state coefficient;

[0045] a T is the weight coefficient corresponding to the cutting fluid temperature T;

[0046] a coolcoef is the weight coefficient of the synergistic effect of cutting fluid temperature and wetting state;

[0047] All weight coefficients are between 0 and 1 and can be adjusted according to actual monitoring needs. Adjustment according to actual conditions means: when the monitoring results cannot meet the actual production requirements and false alarms or missed alarms often occur in the electrostatic micro-lubrication system under a certain state, the coefficients can be adjusted according to the state indicators and deviation values ​​of the electrostatic micro-lubrication displayed by the monitoring system, so that whether the electrostatic micro-lubrication fails under this state can be accurately judged through the monitoring results. Generally, no adjustment is made and 1 is directly taken;

[0048] All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihcare respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of the normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing, which are obtained from experience, data provided by cutting fluid manufacturers and cutting test results. Specifically, if cutting fluid manufacturers, electrostatic micro-lubrication equipment manufacturers and other manufacturers have given the recommended upper and lower limits of the state indicator, the recommended value can be directly adopted; if a state indicator has no manufacturer and no recommended value, the actual production data on the production line can be used to take the state indicator as the independent variable, and the qualified rate of the cutting workpiece can be statistically analyzed, and the qualified rate curve of the production line products can be fitted, and the upper and lower limits of the normal value can be determined accordingly, that is, the qualified rate can be stabilized. The minimum and maximum values ​​of the status indicators that remain above the production line qualification rate requirements; if determined by experiments, the method is to change a certain indicator while keeping other indicators completely normal, conduct experiments, count the qualification rate of the workpieces in the experiment, and fit the qualification rate curve of the production line products, and determine the upper and lower limits of the normal value, that is, the minimum and maximum values ​​of the status indicators that can keep the qualification rate stably above the production line qualification rate requirements; the lower limit and upper limit of complete failure of each status indicator are the lower limit and upper limit of the status indicator that the cutting processing results cannot meet the process requirements at all due to changes in this single indicator when other indicators are normal, which can be obtained through production experience and cutting experiments.

[0049] In the monitoring device for the effectiveness of electrostatic minimal lubrication as described above, the cutting fluid status monitoring main screen is further used to compare the cooling failure coefficient with 1 and to issue an alarm when the cooling failure coefficient exceeds 1.

[0050] In the monitoring device for the effectiveness of electrostatic micro-lubrication as described in any of the above items, the cutting fluid aerosol concentration value sensor is installed at 2 / 3 of the height inside the machine tool.

[0051] In the device for monitoring the effectiveness of electrostatic minimal lubrication as described in any of the above items, the cutting fluid temperature sensor is installed at 1 / 3 of the height inside the monitoring sensor box.

[0052] A monitoring device for the effectiveness of electrostatic micro-lubrication as described in any of the above items, the electrostatic micro-lubrication equipment also includes a liquid storage tank stirring zone, an air pump, a gas-liquid manifold, a charged electrode, an aerosol charging pipeline and an aerosol nozzle; the liquid storage tank is connected to the liquid storage tank stirring zone, the liquid storage tank stirring zone and the air pump are connected to the gas-liquid manifold at the same time, the gas-liquid manifold is connected to the flow control monitoring valve, the high-voltage electrostatic generator is connected to the charged electrode, the charged electrode and the flow control monitoring valve are connected to the aerosol charging pipeline at the same time, the aerosol charging pipeline is connected to the aerosol nozzle, and the aerosol nozzle faces the internal processing area of ​​the machine tool.

[0053] The present invention also provides another device for monitoring the effectiveness of electrostatic micro-lubrication, the electrostatic micro-lubrication device comprising a liquid storage tank for storing cutting fluid, a high-voltage electrostatic generator and a flow control monitoring valve installed on a cutting fluid pipeline;

[0054] The monitoring device includes a monitoring sensor box, a cutting fluid pH value sensor, an electrostatic micro-lubrication voltage sensor, a cutting fluid aerosol concentration value sensor, a cutting fluid flow sensor, a cutting fluid concentration value sensor, a cutting fluid resistivity sensor, a cutting fluid TDS value sensor, a cutting fluid residual oxygen sensor and a cutting fluid turbidity sensor;

[0055] The cutting fluid mist concentration sensor is installed in the internal processing area of ​​the machine tool. Specifically, the cutting fluid mist concentration of electrostatic minimal lubrication is monitored by monitoring the mist concentration in the air of the machine tool.

[0056] The cutting fluid flow sensor is installed in the flow control monitoring valve to monitor the cutting fluid flow;

[0057] The electrostatic micro-lubrication voltage sensor is arranged in the high-voltage electrostatic generator, and specifically monitors the voltage of the electrostatic micro-lubrication by monitoring the electrostatic voltage generated by the high-voltage electrostatic generator;

[0058] The cutting fluid pH sensor, cutting fluid concentration sensor, cutting fluid resistivity sensor, cutting fluid TDS sensor, cutting fluid residual oxygen sensor and cutting fluid turbidity sensor are all arranged in the monitoring sensor box, among which:

[0059] The cutting fluid pH sensor monitors the acid-base state of the cutting fluid by measuring the pH value of the cutting fluid in the cutting fluid box;

[0060] The cutting fluid concentration value sensor monitors the concentration state of the cutting fluid by monitoring the cutting fluid concentration value;

[0061] The cutting fluid resistivity sensor specifically monitors the resistance state of the cutting fluid by monitoring the resistivity value;

[0062] The cutting fluid TDS value sensor monitors the soluble impurities in the cutting fluid by monitoring the TDS value of the cutting fluid;

[0063] The cutting fluid residual oxygen sensor monitors the oxygen content of the cutting fluid by measuring the residual oxygen value of the cutting fluid in the cutting fluid box;

[0064] The cutting fluid turbidity sensor monitors the concentration of suspended matter in the cutting fluid by monitoring the turbidity value of the cutting fluid;

[0065] The monitoring sensor box is connected to the liquid storage tank. A circulation pump is installed in the monitoring sensor box to control the continuous flow of cutting fluid between the monitoring sensor box and the liquid storage tank. The setting of the circulation pump ensures the accuracy of the monitoring data.

[0066] Specifically, the monitoring sensor box and the liquid storage tank are connected by two pipelines, namely, a liquid outlet pipe and a liquid inlet pipe; the connection method is: the liquid outlet pipe and the liquid inlet pipe are respectively connected to the liquid outlet and the liquid inlet of the monitoring sensor box; a filter is installed at the end of the liquid inlet pipe that is not connected to the monitoring sensor box, the filter is connected to the liquid inlet pipe with a pagoda head, and the pagoda head and the liquid inlet pipe are fixed with a pipe clamp; the filter end of the liquid inlet pipe and the end of the liquid outlet pipe that is not connected to the monitoring sensor box are respectively placed in the liquid storage tank, separated by a certain distance.

[0067] As the preferred technical solution:

[0068] As described above, a monitoring device for the effectiveness of electrostatic micro-lubrication, the monitoring device also includes a cutting fluid status monitoring main screen, a cutting fluid pH value sensor, an electrostatic micro-lubrication voltage sensor, a cutting fluid aerosol concentration value sensor, a cutting fluid flow sensor, a cutting fluid concentration value sensor, a cutting fluid resistivity sensor, a cutting fluid TDS value sensor, a cutting fluid residual oxygen sensor and a cutting fluid turbidity sensor are simultaneously connected to the cutting fluid status monitoring main screen, and the cutting fluid status monitoring main screen is used to resolve the signals of each sensor into specific values ​​of each status indicator.

[0069] In a monitoring device for the effectiveness of electrostatic micro-lubrication as described above, the cutting fluid status monitoring main screen is also used to calculate the lubrication failure coefficient based on the specific values ​​of each status indicator;

[0070] The calculation formula of lubrication failure coefficient is as follows:

[0071] ε lub =ε wet +ε ads +a RO ·devi(RO)+a NTU ·devi(NTU)+a lubcoef ·ε wet ·ε ads ;

[0072] In the formula, ε lub is the lubrication failure coefficient;

[0073] ε wet is the cutting fluid wetting coefficient, Among them, a pHwet 、a Vwet 、a ωwet , a ρwet 、aTDSwet They correspond to the pH value of the cutting fluid when calculating the wetting state coefficient of the cutting fluid, the electrostatic micro-lubrication voltage V, the cutting fluid mist concentration value ω, and the cutting fluid concentration value Cutting fluid resistivity ρ, cutting fluid TDS value TDS weight coefficient;

[0074] ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of the cutting fluid pH value, the electrostatic micro-lubrication voltage, the cutting fluid aerosol concentration, and the cutting fluid flow rate, respectively, when calculating the adsorption state coefficient;

[0075] a RO is the weight coefficient corresponding to the residual oxygen content RO of the cutting fluid;

[0076] a NTU is the weight coefficient corresponding to the cutting fluid turbidity NTU;

[0077] a lubcoef is the weight coefficient of the synergistic effect of the cutting fluid adsorption state and the wetting state;

[0078] All weight coefficients are between 0 and 1 and can be adjusted according to actual monitoring needs. Adjustment according to actual conditions means: when the monitoring results cannot meet the actual production requirements and false alarms or missed alarms often occur in the electrostatic micro-lubrication system under a certain state, the coefficients can be adjusted according to the state indicators and deviation values ​​of the electrostatic micro-lubrication displayed by the monitoring system, so that whether the electrostatic micro-lubrication fails under this state can be accurately judged through the monitoring results. Generally, no adjustment is made and 1 is directly taken;

[0079] All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihcare respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of the normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing, which are obtained from experience, data provided by cutting fluid manufacturers and cutting test results. Specifically, if cutting fluid manufacturers, electrostatic micro-lubrication equipment manufacturers and other manufacturers have given the recommended upper and lower limits of the state indicator, the recommended value can be directly adopted; if a state indicator has no manufacturer and no recommended value, the actual production data on the production line can be used to take the state indicator as the independent variable, and the qualified rate of the cutting workpiece can be statistically analyzed, and the qualified rate curve of the production line products can be fitted, and the upper and lower limits of the normal value can be determined accordingly, that is, the qualified rate can be stabilized. The minimum and maximum values ​​of the status indicators that remain above the production line qualification rate requirements; if determined by experiments, the method is to change a certain indicator while keeping other indicators completely normal, conduct experiments, count the qualification rate of the workpieces in the experiment, and fit the qualification rate curve of the production line products, and determine the upper and lower limits of the normal value, that is, the minimum and maximum values ​​of the status indicators that can keep the qualification rate stably above the production line qualification rate requirements; the lower limit and upper limit of complete failure of each status indicator are the lower limit and upper limit of the status indicator that the cutting processing results cannot meet the process requirements at all due to changes in this single indicator when other indicators are normal, which can be obtained through production experience and cutting experiments.

[0080] In the monitoring device for the effectiveness of electrostatic minimal lubrication as described above, the cutting fluid status monitoring main screen is further used to compare the lubrication failure coefficient with 1 and to issue an alarm when the lubrication failure coefficient exceeds 1.

[0081] In the monitoring device for the effectiveness of electrostatic micro-lubrication as described in any of the above items, the cutting fluid aerosol concentration value sensor is installed at 2 / 3 of the height inside the machine tool.

[0082] A monitoring device for the effectiveness of electrostatic micro-lubrication as described in any of the above items, the electrostatic micro-lubrication equipment also includes a liquid storage tank stirring zone, an air pump, a gas-liquid manifold, a charged electrode, an aerosol charging pipeline and an aerosol nozzle; the liquid storage tank is connected to the liquid storage tank stirring zone, the liquid storage tank stirring zone and the air pump are connected to the gas-liquid manifold at the same time, the gas-liquid manifold is connected to the flow control monitoring valve, the high-voltage electrostatic generator is connected to the charged electrode, the charged electrode and the flow control monitoring valve are connected to the aerosol charging pipeline at the same time, the aerosol charging pipeline is connected to the aerosol nozzle, and the aerosol nozzle faces the internal processing area of ​​the machine tool.

[0083] Beneficial Effects

[0084] (1) The present invention provides a method for evaluating the effectiveness of electrostatic minimal lubrication, which monitors various states of the cutting fluid by measuring indicators such as pH value, dissolved oxygen value, conductivity, temperature, and concentration. At the same time, in view of the fact that minimal lubrication cutting fluid is used once, the cutting fluid spray concentration in the machine tool is innovatively detected.

[0085] (2) The present invention provides an evaluation method for the effectiveness of electrostatic micro-lubrication. Aiming at the cooling and lubrication mechanism of electrostatic micro-lubrication, a set of failure coefficients and calculation formulas for judging whether electrostatic micro-lubrication has lost its effect are proposed, thereby evaluating the effectiveness of cooling and lubrication to ensure the processing effect.

[0086] (3) The electrostatic micro-lubrication multi-sensor cutting fluid status monitoring device of the present invention monitors various status indicators of electrostatic micro-lubrication during the cutting process and issues an alarm when failure occurs, thereby achieving timely warning of electrostatic micro-lubrication failure and identification of failure causes during the cutting process; effectively ensuring the reliability of electrostatic micro-lubrication, ensuring the quality and consistency of cutting processing, and reducing the labor cost of monitoring and controlling the electrostatic micro-lubrication system and the technical requirements for operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 It is a working schematic diagram of the monitoring device for the effectiveness of the micro-lubrication equipment, machine tool and electrostatic micro-lubrication;

[0088] Figure 2 This is a multi-index monitoring flow chart for cutting fluid status of minimal lubrication equipment;

[0089] Among them, 1-tool, 2-workpiece, 3-machine tool, 4-aerosol nozzle, 5-charged electrode, 6-aerosol charging pipeline, 7-flow control monitoring valve, 8-cutting fluid status monitoring main screen, 9-gas-liquid manifold, 10-high-voltage electrostatic generator, 11-liquid storage tank, 12-monitoring sensor box, 13-liquid storage tank stirring area, 14-air pump, 15-electrostatic micro-lubrication device, 16-cutting fluid aerosol concentration value sensor. DETAILED DESCRIPTION

[0090] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0091] A method for evaluating the effectiveness of electrostatic minimal lubrication, the specific steps are as follows:

[0092] (1) Collect cutting fluid pH value, electrostatic micro-lubrication voltage V, cutting fluid aerosol concentration value ω, cutting fluid flow rate q, cutting fluid temperature T, and cutting fluid concentration value Cutting fluid resistivity ρ, cutting fluid TDS value TDS, cutting fluid residual oxygen content RO, cutting fluid turbidity NTU;

[0093] (2) Substitute the pH value of the cutting fluid, the electrostatic micro-lubrication voltage V, the cutting fluid aerosol concentration ω, the cutting fluid flow rate q, and the cutting fluid temperature T into the formula to calculate the cooling failure coefficient, and compare the cooling failure coefficient with 1. When the cooling failure coefficient exceeds 1, the cooling fails; otherwise, the cooling does not fail;

[0094] The calculation formula of cooling failure coefficient is as follows:

[0095] ε cool =ε ads +a T .devi(T)+a coolcoef ·ε ads ·devi(T);

[0096] In the formula, ε cool is the cooling failure coefficient;

[0097] ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of pH, V, ω, and q when calculating the adsorption state coefficient;

[0098] a T is the weight coefficient corresponding to T;

[0099] a coolcoef is the weight coefficient of the synergistic effect of cutting fluid temperature and wetting state;

[0100] All weight coefficients are between 0 and 1;

[0101] All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ihare the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihc are respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of the normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing, which are obtained from experience, data provided by cutting fluid manufacturers and cutting test results. Specifically, if cutting fluid manufacturers, electrostatic micro-lubrication equipment manufacturers and other manufacturers have given the recommended upper and lower limits of the state indicator, the recommended value can be directly adopted; if a state indicator has no manufacturer and no recommended value, the actual production data on the production line can be used to take the state indicator as the independent variable, and the qualified rate of the cutting workpiece can be statistically analyzed, and the qualified rate curve of the production line products can be fitted, and the upper and lower limits of the normal value can be determined accordingly, that is, the qualified rate can be stabilized. The minimum and maximum values ​​of the state indicators that are maintained above the qualified rate requirements of the production line; if determined by experiments, the method is to change a certain indicator to conduct experiments while keeping other indicators completely normal, statistically calculate the qualified rate of the workpieces in the experiment, and fit the qualified rate curve of the production line products, and determine the upper and lower limits of the normal value, that is, the minimum and maximum values ​​of the state indicators that can keep the qualified rate stably above the qualified rate requirements of the production line; the lower limit and upper limit of complete failure of each state indicator are the lower limit and upper limit of the state indicator that the cutting processing results cannot meet the process requirements completely due to changes in this single indicator when other indicators are normal, which can be obtained through production experience and cutting experiments;

[0102] (3) The pH value of the cutting fluid, the electrostatic micro-lubrication voltage V, the cutting fluid aerosol concentration ω, the cutting fluid flow rate q, and the cutting fluid concentration value The cutting fluid resistivity ρ, cutting fluid TDS value TDS, cutting fluid residual oxygen content RO, and cutting fluid turbidity NTU are substituted into the formula to calculate the lubrication failure coefficient, and the lubrication failure coefficient is compared with 1. When the lubrication failure coefficient exceeds 1, the lubrication fails; otherwise, the lubrication does not fail;

[0103] The calculation formula of lubrication failure coefficient is as follows:

[0104] ε lub =ε wet +ε ads +a RO ·devi(RO)+a NTU ·devi(NTU)+a lubcoef ·ε wet ·ε ads ;

[0105] In the formula, ε lub is the lubrication failure coefficient;

[0106] ε wet is the cutting fluid wetting coefficient, Among them, a pHwet 、a Vwet 、a ωwet , a ρwet 、a TDSwet They correspond to pH, V, ω, ρ, weight coefficient of TDS;

[0107] ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of pH, V, ω, and q when calculating the adsorption state coefficient;

[0108] a RO is the weight coefficient corresponding to RO;

[0109] a NTU is the weight coefficient corresponding to NTU;

[0110] a lubcoef is the weight coefficient of the synergistic effect of the cutting fluid adsorption state and the wetting state;

[0111] All weight coefficients are between 0 and 1;

[0112] All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihcare respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of the normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing, which are obtained from experience, data provided by cutting fluid manufacturers and cutting test results. Specifically, if cutting fluid manufacturers, electrostatic micro-lubrication equipment manufacturers and other manufacturers have given the recommended upper and lower limits of the state indicator, the recommended value can be directly adopted; if a state indicator has no manufacturer and no recommended value, the actual production data on the production line can be used to take the state indicator as the independent variable, and the qualified rate of the cutting workpiece can be statistically analyzed, and the qualified rate curve of the production line products can be fitted, and the upper and lower limits of the normal value can be determined accordingly, that is, the qualified rate can be stabilized. The minimum and maximum values ​​of the status indicators that remain above the production line qualification rate requirements; if determined by experiments, the method is to change a certain indicator while keeping other indicators completely normal, conduct experiments, count the qualification rate of the workpieces in the experiment, and fit the qualification rate curve of the production line products, and determine the upper and lower limits of the normal value, that is, the minimum and maximum values ​​of the status indicators that can keep the qualification rate stably above the production line qualification rate requirements; the lower limit and upper limit of complete failure of each status indicator are the lower limit and upper limit of the status indicator that the cutting processing results cannot meet the process requirements at all due to changes in this single indicator when other indicators are normal, which can be obtained through production experience and cutting experiments.

[0113] The order of step (2) and step (3) in the above evaluation method is not limited and they can be swapped or performed simultaneously.

[0114] The device used in the above-mentioned method for evaluating the effectiveness of electrostatic micro-lubrication is a monitoring device for the effectiveness of electrostatic micro-lubrication, such as Figures 1-2 As shown, it includes a monitoring sensor box 12, a cutting fluid pH value sensor, an electrostatic micro-lubrication voltage sensor, a cutting fluid aerosol concentration value sensor 16, a cutting fluid flow sensor, a cutting fluid temperature sensor, a cutting fluid concentration value sensor, a cutting fluid resistivity sensor, a cutting fluid TDS value sensor, a cutting fluid residual oxygen sensor, a cutting fluid turbidity sensor and a cutting fluid status monitoring main screen 8;

[0115] The object of the monitoring device is the electrostatic micro-lubrication equipment, which includes a liquid storage tank 11 for storing cutting fluid, a high-voltage electrostatic generator 10, a flow control monitoring valve 7 installed on the cutting fluid pipeline, a liquid storage tank stirring area 13, an air pump 14, a gas-liquid manifold 9, a charging electrode 5, an aerosol charging pipeline 6 and an aerosol nozzle 4;

[0116] The liquid storage tank 11 is connected to the liquid storage tank stirring zone 13, the liquid storage tank stirring zone 13 and the air pump 14 are connected to the gas-liquid manifold 9 at the same time, the gas-liquid manifold 9 is connected to the flow control monitoring valve 7, the high-voltage electrostatic generator 10 is connected to the charged electrode 5, the charged electrode 5 and the flow control monitoring valve 7 are connected to the aerosol charging pipeline 6 at the same time, the aerosol charging pipeline 6 is connected to the aerosol nozzle 4, and the aerosol nozzle 4 faces the internal processing area of ​​the machine tool 3;

[0117] The cutting fluid aerosol concentration value sensor 16 is installed at 2 / 3 of the height inside the machine tool 3; the cutting fluid flow sensor is installed in the flow control monitoring valve 7; the electrostatic micro-lubrication voltage sensor is arranged in the high-voltage electrostatic generator 10; the cutting fluid pH value sensor, the cutting fluid temperature sensor, the cutting fluid concentration value sensor, the cutting fluid resistivity sensor, the cutting fluid TDS value sensor, the cutting fluid residual oxygen sensor and the cutting fluid turbidity sensor are all arranged in the monitoring sensor box 12; the monitoring sensor box 12 is connected to the liquid storage tank 11, and a circulation pump for controlling the continuous flow of the cutting fluid between the monitoring sensor box 12 and the liquid storage tank 11 is installed in the monitoring sensor box 12;

[0118] The cutting fluid pH value sensor, the electrostatic micro-lubrication voltage sensor, the cutting fluid aerosol concentration value sensor 16, the cutting fluid flow sensor, the cutting fluid temperature sensor, the cutting fluid concentration value sensor, the cutting fluid resistivity sensor, the cutting fluid TDS value sensor, the cutting fluid residual oxygen sensor and the cutting fluid turbidity sensor are simultaneously connected to the cutting fluid status monitoring main screen 8;

[0119] The cutting fluid status monitoring main screen 8 is used to resolve each sensor signal into a specific value of each status indicator, calculate the cooling failure coefficient according to the specific values ​​of some status indicators, compare the cooling failure coefficient with 1, and issue an alarm when the cooling failure coefficient exceeds 1, and at the same time calculate the lubrication failure coefficient according to the specific values ​​of some status indicators, compare the lubrication failure coefficient with 1, and issue an alarm when the lubrication failure coefficient exceeds 1;

[0120] The calculation formula of cooling failure coefficient is as follows:

[0121] ε cool =ε ads +a T ·devi(T)+a coolcoef ·ε ads ·devi(T);

[0122] In the formula, ε cool is the cooling failure coefficient;

[0123] ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+aVads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of the cutting fluid pH value, the electrostatic micro-lubrication voltage, the cutting fluid aerosol concentration, and the cutting fluid flow rate, respectively, when calculating the adsorption state coefficient;

[0124] a T is the weight coefficient corresponding to the cutting fluid temperature T;

[0125] a coolcoef is the weight coefficient of the synergistic effect of cutting fluid temperature and wetting state;

[0126] All weight coefficients are between 0 and 1;

[0127] The calculation formula of lubrication failure coefficient is as follows:

[0128] ε lub =ε wet +ε ads +a RO ·devi(RO)+a NTU ·devi(NTU)+a lubcoef ·ε wet ·ε ads ;

[0129] In the formula, ε lub is the lubrication failure coefficient;

[0130] ε wet is the cutting fluid wetting coefficient, Among them, a pHwet 、a Vwet 、a ωwet , a ρwet 、a TDSwet They correspond to the pH value of the cutting fluid when calculating the wetting state coefficient of the cutting fluid, the electrostatic micro-lubrication voltage V, the cutting fluid mist concentration value ω, and the cutting fluid concentration value Cutting fluid resistivity ρ, cutting fluid TDS value TDS weight coefficient;

[0131] ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qadsdevi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of the cutting fluid pH value, the electrostatic micro-lubrication voltage, the cutting fluid aerosol concentration, and the cutting fluid flow rate, respectively, when calculating the adsorption state coefficient;

[0132] a RO is the weight coefficient corresponding to the residual oxygen content RO of the cutting fluid;

[0133] a NTU is the weight coefficient corresponding to the cutting fluid turbidity NTU;

[0134] a lubcoef is the weight coefficient of the synergistic effect of the cutting fluid adsorption state and the wetting state;

[0135] All weight coefficients are between 0 and 1;

[0136] The devi() in the calculation formula of the cooling failure coefficient and the calculation formula of the lubrication failure coefficient is a function for calculating the degree of deviation of each state index from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihcare respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of the normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing, which are obtained from experience, data provided by cutting fluid manufacturers and cutting test results. Specifically, if cutting fluid manufacturers, electrostatic micro-lubrication equipment manufacturers and other manufacturers have given the recommended upper and lower limits of the state indicator, the recommended value can be directly adopted; if a state indicator has no manufacturer and no recommended value, the actual production data on the production line can be used to take the state indicator as the independent variable, and the qualified rate of the cutting workpiece can be statistically analyzed, and the qualified rate curve of the production line products can be fitted, and the upper and lower limits of the normal value can be determined accordingly, that is, the qualified rate can be stabilized. The minimum and maximum values ​​of the status indicators that remain above the production line qualification rate requirements; if determined by experiments, the method is to change a certain indicator while keeping other indicators completely normal, conduct experiments, count the qualification rate of the workpieces in the experiment, and fit the qualification rate curve of the production line products, and determine the upper and lower limits of the normal value, that is, the minimum and maximum values ​​of the status indicators that can keep the qualification rate stably above the production line qualification rate requirements; the lower limit and upper limit of complete failure of each status indicator are the lower limit and upper limit of the status indicator that the cutting processing results cannot meet the process requirements at all due to changes in this single indicator when other indicators are normal, which can be obtained through production experience and cutting experiments.

[0137] Now let's explain it with specific cases:

[0138] As shown in Table 1, under the working conditions of a certain automobile engine cylinder head production line, the complete failure lower limit, complete failure upper limit, normal value lower limit, and normal value upper limit of each state indicator;

[0139] Table 1

[0140]

[0141] When the machine tool 3 is processing, the cutting fluid on the electrostatic micro-lubrication device 15 flows out from the liquid storage tank 11 and merges with the gas in the air pump 14 at the gas-liquid manifold 9; then the gas-liquid flow enters the gas mist charging pipeline 6 to charge the gas mist, and the charged gas mist is sprayed out through the gas mist nozzle 4; the charged gas mist is directly sprayed to the contact area between the tool 1 and the workpiece 2; wherein, the processing conditions are: the workpiece 2 is an aluminum alloy cylinder head, the ambient temperature is 13°C, the rotation speed is 3000rpm, the feed rate is 0.08mm / rev, the milling depth is 0.4mm, the electrostatic micro-lubrication cutting fluid flow rate is 120mL / h, the voltage is 10kV, and the total processing time is 8min;

[0142] At the same time, a monitoring device for the effectiveness of electrostatic micro-lubrication of the present invention is used to collect the pH value of the cutting fluid, the electrostatic micro-lubrication voltage V, the cutting fluid aerosol concentration value ω, the cutting fluid flow rate q, the cutting fluid temperature T, and the cutting fluid concentration value. Cutting fluid resistivity ρ, cutting fluid TDS value TDS, cutting fluid residual oxygen RO, cutting fluid turbidity NTU; Specifically, the monitoring process is based on the flow sequence of the cutting fluid in the minimal lubrication equipment, and sensors are installed at different positions to monitor different state indicators of the cutting fluid;

[0143] The monitoring results of the effectiveness of electrostatic minimal lubrication are shown in Table 2:

[0144] Table 2

[0145]

[0146] The monitoring results show that the cooling and lubrication effects of the electrostatic minimal lubrication system remain normal, and the monitoring system has not issued an alarm; the obtained machining surface roughness Ra is 0.19μm, and the milling force and milling temperature meet the process requirements. No phenomena such as increased cutting temperature, burns of workpiece 2, severe wear of tool 1, and increased cutting force and scratches on the surface of workpiece 2 due to cooling failure were found. This proves that during the machining process, the cooling and lubrication effects of the electrostatic minimal lubrication are normal, which is consistent with the results obtained using the monitoring device.

Claims

1. A method for evaluating the effectiveness of electrostatic minimum lubrication, It is characterized in that The pH value of the cutting fluid, the voltage of the electrostatic micro-lubrication, the concentration of the cutting fluid mist, the flow rate of the cutting fluid, and the temperature of the cutting fluid are collected and then put into the formula to calculate the cooling failure coefficient. The cooling failure coefficient is compared with 1. When the cooling failure coefficient exceeds 1, the cooling fails; otherwise, the cooling does not fail. The calculation formula of cooling failure coefficient is as follows: ε cool = ε ads + a T ·devi(T) + a coolcoef ·ε ads ·devi(T); In the formula, ε cool is the cooling failure coefficient; ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of pH, V, ω, and q when calculating the adsorption state coefficient; a T is the weight coefficient corresponding to T; a coolcoef is the weight coefficient of the synergistic effect of cutting fluid temperature and wetting state; All weight coefficients are between 0 and 1; All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihc They are respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing; the lower limit and upper limit of complete failure of each state indicator are the lower limit and upper limit of the state indicator that, when other indicators are normal, the cutting processing results cannot meet the process requirements at all due to changes in this state indicator.

2. A method for evaluating the effectiveness of electrostatic minimum lubrication, It is characterized in that Collect cutting fluid pH value, electrostatic micro-lubrication voltage V, cutting fluid aerosol concentration value ω, cutting fluid flow rate q, cutting fluid concentration value Cutting fluid resistivity ρ, cutting fluid TDS value TDS, cutting fluid residual oxygen content RO, cutting fluid turbidity NTU are put into the formula to calculate the lubrication failure coefficient, and the lubrication failure coefficient is compared with 1. When the lubrication failure coefficient exceeds 1, the lubrication fails; otherwise, the lubrication does not fail; The calculation formula of lubrication failure coefficient is as follows: e lub =e wet +e ads +a RO ·devi(RO)+a NTU ·devi(NTU)+a lubcoef ·e wet ·e ads ; In the formula, ε lub is the lubrication failure coefficient; ε wet is the cutting fluid wetting coefficient, Among them, a pHwet 、a Vwet 、a ωwet , a ρwet 、a TDSwet They correspond to pH, V, ω, ρ, weight coefficient of TDS; ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of pH, V, ω, and q when calculating the adsorption state coefficient; a RO is the weight coefficient corresponding to RO; a NTU is the weight coefficient corresponding to NTU; a lubcoef is the weight coefficient of the synergistic effect of the cutting fluid adsorption state and the wetting state; All weight coefficients are between 0 and 1; All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihc They are respectively the lower limit and upper limit of complete failure of the state indicator; the lower limit and upper limit of normal value of each state indicator are respectively the lower limit and upper limit of the state indicator that can ensure normal cutting processing; the lower limit and upper limit of complete failure of each state indicator are the lower limit and upper limit of the state indicator that, when other indicators are normal, the cutting processing results cannot meet the process requirements at all due to changes in this state indicator.

3. A monitoring device for the effectiveness of electrostatic micro-lubrication, It is characterized in that The electrostatic micro-lubrication device comprises a liquid storage tank (11) for storing cutting fluid, a high-voltage electrostatic generator (10), a cutting fluid state monitoring main screen (8) and a flow control monitoring valve (7) installed on the cutting fluid pipeline; The monitoring device comprises a monitoring sensor box (12), a cutting fluid pH value sensor, an electrostatic micro-lubrication voltage sensor, a cutting fluid aerosol concentration value sensor, a cutting fluid flow sensor and a cutting fluid temperature sensor; The cutting fluid mist concentration value sensor is installed in the internal processing area of ​​the machine tool (3); The cutting fluid flow sensor is installed in the flow control monitoring valve (7); The electrostatic micro-lubrication voltage sensor is arranged in the high-voltage electrostatic generator (10); The cutting fluid pH value sensor and the cutting fluid temperature sensor are both arranged in the monitoring sensor box (12); The monitoring sensor box (12) is in communication with the liquid storage box (11), and a circulation pump for controlling the continuous flow of cutting fluid between the monitoring sensor box (12) and the liquid storage box (11) is installed in the monitoring sensor box (12); The cutting fluid pH value sensor, the electrostatic micro-lubrication voltage sensor, the cutting fluid aerosol concentration value sensor, the cutting fluid flow sensor and the cutting fluid temperature sensor are simultaneously connected to the cutting fluid state monitoring main screen (8), and the cutting fluid state monitoring main screen (8) is used to resolve the signals of each sensor into specific values ​​of each state indicator; The cutting fluid status monitoring main screen (8) is also used to calculate the cooling failure coefficient according to the specific values ​​of each status indicator; The calculation formula of cooling failure coefficient is as follows: e cool =e ads +a T ·devi(T)+a coolcoef ·e ads ·devi(T); In the formula, ε cool is the cooling failure coefficient; ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of the cutting fluid pH value, the electrostatic micro-lubrication voltage, the cutting fluid aerosol concentration, and the cutting fluid flow rate, respectively, when calculating the adsorption state coefficient; a T is the weight coefficient corresponding to the cutting fluid temperature T; a coolcoef is the weight coefficient of the synergistic effect of cutting fluid temperature and wetting state; All weight coefficients are between 0 and 1; All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihc are the lower limit and upper limit of complete failure of the state indicator respectively; the lower limit and upper limit of normal value of each state indicator are the lower limit and upper limit of the state indicator that can ensure normal cutting processing respectively; the lower limit and upper limit of complete failure of each state indicator are the lower limit and upper limit of the state indicator that when other indicators are normal, due to the change of this state indicator, the cutting processing result cannot meet the process requirements at all; The cutting fluid condition monitoring main screen (8) is also used to compare the cooling failure factor with 1 and issue an alarm when the cooling failure factor exceeds 1.

4. A monitoring device for the effectiveness of electrostatic micro-lubrication, It is characterized in that The electrostatic micro-lubrication device comprises a liquid storage tank (11) for storing cutting fluid, a high-voltage electrostatic generator (10), a cutting fluid state monitoring main screen (8) and a flow control monitoring valve (7) installed on the cutting fluid pipeline; The monitoring device comprises a monitoring sensor box (12), a cutting fluid pH value sensor, an electrostatic micro-lubrication voltage sensor, a cutting fluid aerosol concentration value sensor, a cutting fluid flow sensor, a cutting fluid concentration value sensor, a cutting fluid resistivity sensor, a cutting fluid TDS value sensor, a cutting fluid residual oxygen sensor and a cutting fluid turbidity sensor; The cutting fluid mist concentration value sensor is installed in the internal processing area of ​​the machine tool (3); The cutting fluid flow sensor is installed in the flow control monitoring valve (7); The electrostatic micro-lubrication voltage sensor is arranged in the high-voltage electrostatic generator (10); A cutting fluid pH value sensor, a cutting fluid concentration value sensor, a cutting fluid resistivity sensor, a cutting fluid TDS value sensor, a cutting fluid residual oxygen sensor and a cutting fluid turbidity sensor are all arranged in a monitoring sensor box (12); The monitoring sensor box (12) is connected to the liquid storage box (11), and a circulation pump for controlling the continuous flow of cutting fluid between the monitoring sensor box (12) and the liquid storage box (11) is installed in the monitoring sensor box (12); The cutting fluid pH value sensor, the electrostatic micro-lubrication voltage sensor, the cutting fluid aerosol concentration value sensor, the cutting fluid flow sensor, the cutting fluid concentration value sensor, the cutting fluid resistivity sensor, the cutting fluid TDS value sensor, the cutting fluid residual oxygen sensor and the cutting fluid turbidity sensor are simultaneously connected to the cutting fluid state monitoring main screen (8), and the cutting fluid state monitoring main screen (8) is used to resolve the signals of each sensor into specific values ​​of each state indicator; The cutting fluid status monitoring main screen (8) is also used to calculate the lubrication failure coefficient according to the specific values ​​of each status indicator; The calculation formula of lubrication failure coefficient is as follows: e lub =e wet +e ads +a RO ·devi(RO)+a NTU ·devi(NTU)+a lubcoef ·e wet ·e ads ; In the formula, ε lub is the lubrication failure coefficient; ε wet is the cutting fluid wetting coefficient, Among them, a pHwet 、a Vwet 、a ωwet , a ρwet 、a TDSwet They correspond to the pH value of the cutting fluid when calculating the wetting state coefficient of the cutting fluid, the electrostatic micro-lubrication voltage V, the cutting fluid mist concentration value ω, and the cutting fluid concentration value Cutting fluid resistivity ρ, cutting fluid TDS value TDS weight coefficient; ε ads is the adsorption state coefficient, ε ads =a pHads ·devi(pH)+a Vads ·devi(V)+a ωads ·devi(ω)+a qads devi(q), where a pHads 、a Vads 、a ωads 、a qads They correspond to the weight coefficients of the cutting fluid pH value, the electrostatic micro-lubrication voltage, the cutting fluid aerosol concentration, and the cutting fluid flow rate, respectively, when calculating the adsorption state coefficient; a RO is the weight coefficient corresponding to the residual oxygen content RO of the cutting fluid; a NTU is the weight coefficient corresponding to the cutting fluid turbidity NTU; a lubcoef is the weight coefficient of the synergistic effect of the cutting fluid adsorption state and the infiltration state; All weight coefficients are between 0 and 1; All devi() are functions that calculate the degree of deviation of each state indicator from the normal value. Among them, P i is the value of a specific status indicator, P il With P ih are the lower limit and upper limit of the normal value of the status indicator, respectively, ilc With P ihc are the lower limit and upper limit of complete failure of the state indicator respectively; the lower limit and upper limit of normal value of each state indicator are the lower limit and upper limit of the state indicator that can ensure normal cutting processing respectively; the lower limit and upper limit of complete failure of each state indicator are the lower limit and upper limit of the state indicator that when other indicators are normal, due to the change of this state indicator, the cutting processing result cannot meet the process requirements at all; The cutting fluid condition monitoring main screen (8) is also used to compare the lubrication failure factor with 1 and issue an alarm when the lubrication failure factor exceeds 1.

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