Steel wire rope plastic coating production method and production line

Abstract

The invention provides a steel wire rope plastic coating production method and production line, and the production method comprises the following steps: starting steel wire rope plastic coating according to a preset steel wire rope diameter, a preset target plastic coating thickness, a set initial extrusion rate, a steel wire rope traction speed and an extrusion temperature; the actual extrusion rate, the actual steel wire rope traction speed and the actual thickness are obtained every t time, and a plurality of actual extrusion rates, actual steel wire rope traction speeds and actual thicknesses in one period are obtained; obtaining an extrusion rate influence coefficient and a traction speed influence coefficient in the current period according to a plurality of actual extrusion rates, actual steel wire rope traction speeds and actual thicknesses in one period; according to the target plastic coating thickness and the extrusion rate influence coefficient and the traction speed influence coefficient in the current period, the initial extrusion rate and the steel wire rope traction speed in the next period are recalculated and set; and the steps are cycled, and the preset target plastic coating thickness and the target plastic coating thickness difference value can be minimized.

Description

Technical Field

[0001] This application relates to the field of steel wire rope production technology, and in particular to a method and production line for producing steel wire rope with plastic coating. Background Technology

[0002] Plastic-coated steel wire rope is a composite material product in which a polymer material (such as PVC, PE, nylon, epoxy resin, etc.) is coated on the surface of the steel wire rope. A protective layer is formed through physical or chemical processes, which combines the high strength of steel wire rope with the corrosion resistance and wear resistance of the coating.

[0003] Extrusion coating is a process in which molten polymer material is uniformly wrapped around a steel wire rope using an extruder. The coating thickness of the steel wire rope is related to factors such as polymer temperature, extrusion speed, and traction speed. Therefore, achieving uniform coating on the surface of the steel wire rope is quite difficult. Currently, the conventional method relies on the experience of the staff to observe the coating situation and make fine adjustments to the parameters to control the coating thickness of the steel wire rope. However, the coating consistency is poor, and the actual coating thickness differs greatly from the target coating thickness, with the difference being unstable.

[0004] In existing technologies, PID extrusion speed and traction speed are commonly used. However, since PID control is only used to stabilize the measured parameters, it cannot solve the problem of a large difference between the actual coating thickness and the target coating thickness.

[0005] In order to solve the above problems, the applicant attempted to use methods such as setting and controlling the extrusion rate or controlling the wire rope traction rate, but due to the many factors affecting the coating thickness, the above methods had little effect. Summary of the Invention

[0006] The inventors of this application have discovered that, during the wire rope winding process, the winding diameter of the wire rope coil gradually increases, resulting in a discrepancy between the actual traction speed and the winding speed of the wire rope. Furthermore, in the coating equipment, the actual extrusion rate of the plastic near the orifice wall differs from that near the center of the orifice. These problems lead to poor consistency in the coating thickness of the wire rope, with a significant and unstable difference between the actual and target coating thickness.

[0007] The technical problem to be solved by this application is to provide a method and production line for producing steel wire rope plastic coating, so as to solve the problem that in the prior art, due to the large number of factors affecting the thickness of steel wire rope plastic coating and the lack of effective means to control the thickness of steel wire rope plastic coating, the consistency of steel wire rope plastic coating thickness is poor, and the difference between the actual plastic coating thickness and the target plastic coating thickness is large and the difference is unstable.

[0008] To address the aforementioned problems, this application provides a method for producing steel wire rope with plastic coating, comprising: Set initial control parameters: based on the preset wire rope diameter Preset target coating thickness Set the initial extrusion rate Initial wire rope traction speed and extrusion temperature The steel wire rope coating process begins; Measure actual control parameters: every t Time to obtain actual extrusion rate Actual wire rope traction speed and actual coating thickness This yields several actual extrusion rates within a single cycle. Several actual wire rope traction speeds and several actual coating thicknesses ; Obtain the influence coefficient: based on several actual extrusion rates within a cycle. Several actual wire rope traction speeds and several actual coating thicknesses The extrusion rate influence coefficient within the current cycle is obtained. traction speed influence coefficient ; Set control parameters based on the influence coefficient: based on the target coating thickness. Influence coefficient of extrusion rate in the current cycle traction speed influence coefficient Recalculate and set the initial extrusion rate for the next cycle. Wire rope traction speed ; By repeating the steps of measuring the actual control parameters, obtaining the influence coefficient, and setting the control parameters based on the influence coefficient, the preset target coating thickness and the difference between the target coating thickness are minimized.

[0009] Furthermore, in order to facilitate obtaining the extrusion rate influence coefficient And the influence of traction speed And facilitates the calculation of the extrusion rate influence coefficient. And the influence of traction speed Reset the actual coating thickness Actual extrusion rate Influence coefficient of extrusion rate Actual wire rope traction speed traction speed influence coefficient Wire rope diameter The relationship between them: Alternatively, the extrusion rate influence coefficient calculated below can be used. traction speed influence coefficient Substituting into the above formula, it is used to predict the coating thickness. When the error in predicting the coating thickness is large and exceeds the set threshold, it can be inferred that the equipment is faulty and an emergency stop operation can be taken.

[0010] An alternative approach is to use regression analysis to fit the coating thickness using historical data from a given period. With extrusion rate and traction speed Functions between: in, These are the regression coefficients of the extrusion rate influence coefficient; These are the regression coefficients of the traction speed influence coefficient.

[0011] Optionally, the initial extrusion rate for the next cycle is recalculated based on the influence coefficient. Wire rope traction speed : Furthermore, to simplify the influencing factor coefficients, the extrusion rate influence coefficient is... traction speed influence system The overall abstract is the control influence coefficient. The actual coating thickness Actual extrusion rate Actual wire rope traction speed Control influence coefficient Wire rope diameter The relationship between them: Using historical data within a period, regression analysis was employed to fit the coating thickness. With extrusion rate and traction speed Functions between: in, These are the control influence coefficients. The regression coefficients.

[0012] Based on control influence coefficient Recalculate the initial extrusion rate for the next cycle. Wire rope traction speed : Furthermore, when the difference between the actual coating thickness and the target coating thickness is less than a preset minimum threshold, the extrusion rate will not be reset. Wire rope traction speed This means that the difference between the set actual coating thickness and the target coating thickness is very small, indicating that the control parameters are reasonable and no further adjustments are needed to maintain uniform coating.

[0013] Optionally, when the difference between the actual coating thickness and the target coating thickness is less than a preset threshold, the extrusion rate is adjusted. and / or extrusion rate Adaptive PID control is employed.

[0014] For extrusion rate Adaptive PID control is used: in 、 i 、 d These are the proportional, integral, and differential coefficients, respectively. The acquisition time t is used to measure the coating thickness. and setting the coating thickness h The difference, set L p =L i +5 × L d , L=5L d For extrusion rate Adaptive PID control is used: in L p 、L i 、L d These are the proportional, integral, and differential coefficients, respectively. The acquisition time t is used to measure the coating thickness. and setting the coating thickness h The difference, set L p =L i +5 × L d , L=5L d This application also provides a wire rope plastic coating production line, which adopts the wire rope plastic coating production method provided above.

[0015] The technical advantages of this application are as follows: 1. This application is based on several actual extrusion rates within a cycle. Actual wire rope traction speed and actual thickness The extrusion rate influence coefficient within the current cycle is obtained. traction speed influence coefficient According to the target coating thickness Influence coefficient of extrusion rate in the current cycle traction speed influence coefficient Recalculate and set the initial extrusion rate for the next cycle. Wire rope traction speed The process involves iteratively measuring the actual control parameters, obtaining the influence coefficient, and setting the control parameters based on the influence coefficient to minimize the difference between the preset target coating thickness and the target coating thickness. This application uses iterative calculation of the extrusion rate influence coefficient. traction speed influence coefficient And fell to set extrusion rate Wire rope traction speed This method minimizes the difference between the preset target coating thickness and the target coating thickness, resulting in a uniform coating thickness for the final wire rope. It solves the problems in existing technologies where the actual traction speed and winding speed of the wire rope do not match due to the slow increase in the winding diameter of the wire rope coil during winding, and where the actual extrusion rate of the plastic near the hole wall and near the center of the hole differs, leading to poor coating thickness consistency, a large and unstable difference between the actual and target coating thickness.

[0016] 2. This application introduces a preset minimum threshold for the difference between the actual coating thickness and the target coating thickness. When the difference between the actual coating thickness and the target coating thickness is less than the preset minimum threshold, the extrusion rate will not be reset. Wire rope traction speed .

[0017] 3. Preferably, when the difference between the actual coating thickness and the target coating thickness is less than a preset threshold, the present application uses a PID algorithm for control, so that when the wire rope traction speed is relatively stable, the extrusion rate can be set quickly to achieve the stability of the coating thickness.

[0018] 4. This application achieves relatively uniform coating thickness by introducing an influence coefficient and combining it with PID control. This application employs a method combining "calculated influence coefficient + PID control" to realize a fusion control strategy of feedforward control (based on calculated influence coefficient) and feedback control (PID). Specifically, in existing technologies, simple PID control requires "correction to begin only after the error occurs," resulting in lag. In contrast, this application provides feedforward output based on the calculated influence coefficient, obtaining control parameters according to the calculated influence coefficient. This significantly shortens the error adjustment response time, reduces overshoot and undershoot when there are sudden changes in traction rate and extrusion rate. When the difference between the actual coating thickness and the target coating thickness is less than a preset minimum threshold, the PID corrects the residual error, eliminating minor deviations and thus achieving accurate thickness control. Attached Figure Description

[0019] Figure 1 A simplified flow chart of the steel wire rope plastic coating production method provided for this application; Detailed Implementation

[0020] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0021] The steel wire rope coating production method of this application aims to solve the problem of poor coating thickness consistency in existing technologies. By dynamically adjusting control parameters, the difference between the preset target coating thickness and the actual coating thickness is minimized. The entire production process mainly includes several key steps: setting initial control parameters, measuring actual control parameters, obtaining influence coefficients, and setting control parameters based on influence coefficients. The operations of measuring, obtaining influence coefficients, and setting control parameters are repeated until the ideal coating effect is achieved.

[0022] like Figure 1 A simplified flow chart illustrating a method for producing a steel wire rope with plastic coating, as provided in this application, is shown. The method includes: S1. Set initial control parameters Before producing the wire rope plastic coating, initial control parameters need to be set based on the preset wire rope diameter and the preset target coating thickness h. Specifically, these initial control parameters include the initial extrusion rate. Initial wire rope traction speed and extrusion temperature The initial parameters can be derived from empirical control parameters obtained from previous coating processes. Initial extrusion rate. This indicates the amount of plastic extruded per unit time, and the unit can be g / s. Since different plastics have relatively consistent densities at different temperatures, the density can be determined based on temperature and extrusion rate. This describes the extruded volume of plastic per unit time. For example, the extrusion density of a certain extruded plastic in its molten state is 1.13 g / cm³. 3 . For example, assuming the preset wire rope diameter is 10mm, the preset target coating thickness is 1.5mm, and the coating material is nylon, based on experience data and previous experiments, the initial extrusion rate is set to 3.06g / s, the wire rope traction speed to 3m / min, and the extrusion temperature to 250℃. After setting these parameters, the extruder is started to begin the wire rope coating production.

[0023] S2, Measure actual control parameters During the wire rope coating process, the actual control parameters are measured at intervals t. The time interval t can be set according to the actual production situation, for example, measuring every 0.5 seconds.

[0024] Each measurement requires obtaining data at intervals of [time period]. t Time to obtain actual extrusion rate Actual wire rope traction speed and actual thickness This yields several actual extrusion rates within a single cycle. Actual wire rope traction speed and actual thickness The above parameters can be achieved using appropriate measuring instruments, such as extrusion rate measuring instruments, traction speed sensors, and coating thickness measuring instruments.

[0025] Within one cycle (e.g., 30 seconds), several sets of data will be obtained for the actual extrusion rate, actual wire rope traction speed, actual extrusion temperature, and actual coating thickness. For example, measuring every 0.5 seconds within 30 seconds will yield 60 sets of data, which will be recorded as follows: (Actual Extrusion Rate) Actual wire rope traction speed Actual coating thickness ... (Actual extrusion rate) Actual wire rope traction speed Actual coating thickness ).

[0026] S3. Obtain the influence coefficient Based on several actual extrusion rates within a cycle Actual wire rope traction speed and actual thickness The extrusion rate influence coefficient within the current cycle is obtained. traction speed influence coefficient .

[0027] The specific calculation method can employ multiple linear regression analysis. Assume the actual coating thickness is the dependent variable. The actual extrusion rate is the independent variable. The actual wire rope traction speed is the independent variable. Establish a multiple linear regression model: in These are the regression coefficients of the extrusion rate influence coefficient; These are the regression coefficients of the traction speed influence coefficient.

[0028] Multiple groups within a period ( , , By substituting the data into the regression model and using statistical software (such as SPSS, R, etc.) for calculation, the extrusion rate influence coefficient within the current cycle can be obtained. traction speed influence coefficient .

[0029] For example, the extrusion rate influence coefficient within the current cycle is calculated. =0.93, traction speed influence coefficient = 1.02.

[0030] In one scenario, the inventors discovered that the coating thickness... h With extrusion rate Proportional to traction speed Inversely proportional. That is, with other parameters remaining constant, an increase in extrusion rate results in more molten polymer material being extruded per unit time, increasing the amount of material covering a unit length of the wire rope, thus leading to a thicker coating. h Increase; conversely, as the traction speed increases, the distance the wire rope travels per unit time becomes longer, and the material extruded in the same amount of time covers a longer wire rope, resulting in a thicker coating. h It will decrease.

[0031] In the production process of steel wire rope plastic coating, the extrusion rate and traction speed need to be dynamically adjusted according to the target coating thickness and the actual measured coating thickness. For example, if the actual coating thickness is less than the target value, the extrusion rate can be appropriately increased or the traction speed can be decreased; conversely, if the actual coating thickness is greater than the target value, the extrusion rate can be decreased or the traction speed can be increased.

[0032] However, since the coating thickness is related to the extrusion rate, traction speed, and extrusion temperature, an extrusion rate influence coefficient is set. α traction speed influence coefficient βThis allows for the quantification of the impact of extrusion rate, traction speed, and extrusion temperature changes on coating thickness. These coefficients can reflect the sensitivity and response characteristics of the production system.

[0033] Set extrusion temperature T and actual temperature It also affects the coating thickness. Extrusion temperature affects the viscosity and flowability of the molten polymer material. If the temperature is too high, the material viscosity decreases and the flowability increases, resulting in uneven coating thickness. If the temperature is too low, the material viscosity increases and the flowability decreases, which will also prevent it from being evenly wrapped on the surface of the steel wire rope. However, since temperature control is usually relatively easy, the inventors found that within a certain temperature range, the influence of temperature on the extrusion thickness is relatively small. Therefore, no temperature influence coefficient is set.

[0034] Based on the inventor's above findings, the actual coating thickness is set. Actual extrusion rate Influence coefficient of extrusion rate Actual wire rope traction speed traction speed influence system Wire rope diameter The relationship between them: (1) in ρ This represents the density of the plastic within the current temperature range.

[0035] In production, the extrusion rate influence coefficient calculated above can be used... traction speed influence coefficient Substituting into the above formula (1), it is used to predict the coating thickness. When the error in predicting the coating thickness is large and exceeds the second preset threshold, it can be inferred that the equipment is faulty and an emergency stop operation can be taken.

[0036] S4. Set control parameters based on the influence coefficient. Based on the target coating thickness Influence coefficient of extrusion rate in the current cycle traction speed influence coefficient Recalculate the initial extrusion rate for the next cycle. Wire rope traction speed .

[0037] S5, Cyclic Operation After completing steps S2, S3, and S4, the cycle begins again. This involves repeating the steps of measuring the actual control parameters, obtaining the influence coefficients, and setting the control parameters based on the influence coefficients. Through continuous cyclical adjustments, the actual coating thickness gradually approaches the target coating thickness, ultimately minimizing the difference between the preset target coating thickness and the actual coating thickness.

[0038] During the process, continuous monitoring of the coating production is necessary to ensure its stability and safety. Simultaneously, data analysis algorithms and parameter adjustment strategies can be optimized based on actual production results to further improve the precision of coating quality control.

[0039] In some optional embodiments, the extrusion rate is not reset when the difference between the actual coating thickness and the target coating thickness is less than a preset minimum threshold. Wire rope traction speed .

[0040] For example, when thickness deviation When the thickness is less than the threshold (0.01mm is recommended), it means that the difference between the actual coating thickness and the target coating thickness is very small. This indicates that the control parameters are reasonable and no further adjustments are needed to maintain uniform coating.

[0041] Preferably, when the difference between the actual coating thickness and the target coating thickness is less than a preset threshold, adaptive PID control is used for the extrusion rate: in 、 i 、 d These are the proportional, integral, and differential coefficients, respectively. For: t time to determine the coating thickness and setting the coating thickness h The difference; preferably, setting = +4 × d , =4 ， The extrusion rate influence coefficient calculated in the previous cycle 6 to 8 times.

[0042] When the difference between the actual coating thickness and the target coating thickness is less than a preset threshold, the extrusion rate is adjusted. Adaptive PID control is used: in L p 、L i 、L d These are the proportional, integral, and differential coefficients, respectively. The acquisition time t is used to measure the coating thickness. and setting the coating thickness h The difference, set L p =L i +3 × L d , =3L d ，L p The traction speed influence coefficient calculated in the previous cycle 6 to 8 times.

[0043] Using PID control ensures that the actual control parameters remain relatively stable when the coating thickness is relatively stable.

[0044] In the above embodiments, a combined approach of "calculated influence coefficient + PID control" is adopted to achieve a fusion control strategy of feedforward control (based on calculated influence coefficient) and feedback control (PID). Specifically, in the prior art, simple PID control requires "correction to begin only after the error occurs," resulting in a lag. In contrast, the influence coefficient in this application provides a feedforward output, and control parameters are obtained based on the calculated influence coefficient, significantly shortening the error adjustment response time and reducing overshoot and undershoot when there are sudden changes in traction rate and extrusion rate. When the difference between the actual coating thickness and the target coating thickness is less than a preset minimum threshold, the PID corrects the residual error, eliminating minor deviations and thus achieving accurate thickness control.

[0045] In some embodiments, the inventors also considered the extrusion rate influence coefficient during the research and development process. traction speed influence coefficient The overall abstract is the control influence coefficient. The coating thickness Extrusion rate traction speed Control influence coefficient Wire rope diameter The relationship between them: Correspondingly, using historical data within a period, regression analysis was employed to fit the coating thickness. With extrusion rate and traction speed Functions between: in, These are the control influence coefficients. The regression coefficients.

[0046] Based on control influence coefficient Recalculate the initial extrusion rate for the next cycle. Wire rope traction speed : However, in practice, it has been found that, although theoretically... / It can be abstracted as However, because the inventors discovered that the effects of the wire rope traction speed and the extrusion rate are not synchronized—for example, the inventors speculated that the influence of the wire rope traction speed mainly lies in the change of the winding diameter, while the influence of the extrusion rate mainly lies in the inconsistent flow of the molten plastic in different regions within the orifice due to the orifice wall effect—the actual results require separate calculation of the extrusion rate influence coefficient. traction speed influence coefficient The effect is due to the influence coefficient of extrusion rate. and traction speed influence coefficient The overall abstract is the control influence coefficient. The effect.

[0047] The wire rope coating production method provided in this application, when applied to a wire rope coating production line, effectively solves the problem of poor coating thickness consistency caused by the numerous factors affecting the coating thickness and the lack of effective control methods in existing technologies. In actual production, after multiple cycles of dynamic adjustment, the difference between the actual coating thickness and the target coating thickness can be significantly reduced, and the difference becomes more stable, thereby improving the quality and production efficiency of the wire rope coating products.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing steel wire rope with plastic coating, characterized in that, include: Set initial control parameters: based on the preset wire rope diameter Preset target coating thickness Set the initial extrusion rate Initial wire rope traction speed and extrusion temperature The steel wire rope coating process begins; Measure actual control parameters: every t Time to obtain actual extrusion rate Actual wire rope traction speed and actual coating thickness This yields several actual extrusion rates within a single cycle. Several actual wire rope traction speeds and several actual coating thicknesses ; Obtain the influence coefficient: based on several actual extrusion rates within a cycle. Several actual wire rope traction speeds and several actual coating thicknesses The extrusion rate influence coefficient within the current cycle is obtained. traction speed influence coefficient ; Set control parameters based on the influence coefficient: based on the target coating thickness. Influence coefficient of extrusion rate in the current cycle traction speed influence coefficient Recalculate and set the initial extrusion rate for the next cycle. Wire rope traction speed ; By repeating the steps of measuring the actual control parameters, obtaining the influence coefficient, and setting the control parameters based on the influence coefficient, the preset target coating thickness and the difference between the target coating thickness are minimized.

2. The method for producing steel wire rope with plastic coating according to claim 1, characterized in that: Set the actual coating thickness Actual extrusion rate Influence coefficient of extrusion rate Actual wire rope traction speed traction speed influence coefficient Wire rope diameter The relationship between them: 。 3. The method for producing steel wire rope with plastic coating according to claim 1 or 2, characterized in that: Using historical data within a period, regression analysis was employed to fit the coating thickness. With extrusion rate and traction speed Functions between: ； in, These are the regression coefficients of the extrusion rate influence coefficient; These are the regression coefficients of the traction speed influence coefficient.

4. The method for producing steel wire rope with plastic coating according to claim 3, characterized in that: Based on the influence coefficient, the initial extrusion rate for the next cycle is recalculated. Wire rope traction speed : 。 5. The method for producing steel wire rope with plastic coating according to claim 2, characterized in that: The influence coefficient of extrusion rate traction speed influence coefficient The overall abstract is the control influence coefficient. The actual coating thickness Actual extrusion rate Actual wire rope traction speed Control influence coefficient Wire rope diameter The relationship between them: 。 6. The method for producing steel wire rope with plastic coating according to claim 1 or 5, characterized in that: Using historical data within a period, regression analysis was employed to fit the coating thickness. With extrusion rate and traction speed Functions between: ； in, Control influence coefficients The regression coefficients.

7. The method for producing steel wire rope with plastic coating according to claim 6, characterized in that: Based on control influence coefficient Recalculate the initial extrusion rate for the next cycle. Wire rope traction speed : 。 8. The method for producing steel wire rope with plastic coating according to claim 1, characterized in that: When the difference between the actual coating thickness and the target coating thickness is less than the preset minimum threshold, the extrusion rate will not be reset. Wire rope traction speed .

9. The method for producing steel wire rope with plastic coating according to claim 1, characterized in that: When the difference between the actual coating thickness and the target coating thickness is less than a preset threshold, the extrusion rate is adjusted. and / or extrusion rate Adaptive PID control is employed.

10. A steel wire rope plastic coating production line, characterized in that, The wire rope coating production line adopts the wire rope coating production method according to any one of claims 1 to 9.

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