Preparation process of high-flexibility composite drag chain cable

Abstract

The application relates to the technical field of cable preparation, in particular to a preparation process of a high-flexibility composite towline cable, which comprises the following steps: S1: twisting a plurality of metal wires into a cable conductor; S2: adding insulating layer raw materials according to a weight ratio to prepare insulating layer rubber; S3: covering the insulating layer rubber on the surface of the cable conductor by using a core wire insulation extruder, and performing traction take-up treatment on the obtained cable after the covering treatment to obtain a cable product, wherein the traction speed in the traction take-up process is controlled based on the changes of the speed and the temperature in the traction take-up process. The application considers the hysteresis influence of the screw rod speed and the die head temperature of the extruder on the extrusion speed, solves the problem of untimely traction speed response in the traditional method, and improves the insulation and flexibility of the core wire in the composite towline cable.

Description

Technical Field

[0001] The present application relates to the technical field of cable preparation, and in particular to a preparation process of a highly flexible composite drag chain cable. Background Art

[0002] High-flexibility drag chain cable is a special high-flexibility cable that can move back and forth with the drag chain. By placing the high-flexibility cable into the cable drag chain to form a drag chain cable, the wear of the cable during continuous back and forth movement is alleviated. This cable is usually used in automation equipment, robots, machine tools and other occasions that require frequent movement. In order to meet various needs under complex working conditions, such as the simultaneous transmission of power and signals, cables of multiple specifications are usually integrated together to form a high-flexibility composite drag chain cable to enhance the functionality of the high-flexibility drag chain cable.

[0003] In the preparation process of high-flexibility composite drag chain cables, the extrusion step of the cable's insulation layer is a key step to ensure its insulation performance and adapt to the high flexibility requirements of the drag chain cable. In this step, the existing method usually needs to control the pulling speed of the cable core wire to keep it consistent with the extrusion speed of the insulation layer rubber compound to avoid uneven thickness of the cable core wire insulation layer due to speed mismatch. However, this method ignores the hysteresis effect of the extruder's screw speed and the head temperature on its extrusion speed. This hysteresis will cause the pulling speed of the cable core wire to be difficult to respond to the extrusion speed of the insulation layer rubber compound in a timely manner, thereby affecting the uniformity of the thickness of the cable core wire insulation layer, thereby reducing the insulation and flexibility of the core wire in the high-flexibility composite drag chain cable finally prepared. Summary of the Invention

[0004] In order to solve the above technical problems, the present application provides a preparation process of a highly flexible composite drag chain cable to solve the existing problems.

[0005] The preparation process of a highly flexible composite drag chain cable of the present application adopts the following technical solution:

[0006] One embodiment of the present application provides a process for preparing a highly flexible composite drag chain cable, the process comprising the following steps:

[0007] S1: twisting multiple metal wires into cable conductors;

[0008] S2: Add the insulating layer raw materials according to the weight ratio to prepare the insulating layer rubber compound;

[0009] S3: Using a core wire insulation extruder, an insulation layer of rubber is coated on the surface of the cable conductor. The coated cable is pulled and taken up to obtain a cable core. The pulling speed is controlled based on the speed and temperature changes during the pulling and taking-up process. The specific process is as follows:

[0010] Get the extruder's screw speed, die head temperature and extrusion speed in real time;

[0011] Analyze the hysteresis of the corresponding collection moments of each screw speed and each die temperature in the preset period before the current moment relative to the current moment, and determine the speed hysteresis and machine temperature hysteresis at each collection moment; analyze the dispersion of the screw speed and die temperature at each collection moment and its neighborhood in the preset period, and determine the speed dispersion and machine temperature dispersion at each collection moment in the preset period before the current moment, and determine the speed characteristic value and machine temperature characteristic value at the current moment by combining the speed hysteresis and machine temperature hysteresis;

[0012] Analyze the correlation between the screw speed and the die head temperature and the extrusion speed at all acquisition moments within the preset time period, determine the speed correlation and the machine speed correlation at the current moment, and determine the speed response value at the current moment by combining the speed characteristic value and the machine temperature characteristic value;

[0013] Optimizing a proportional coefficient of a PID controller based on the speed response value to control a pulling speed of a pulling machine in a core wire insulation extruder;

[0014] S4: twisting all the manufactured cable cores to obtain a twisted cable;

[0015] S5: Cover the surface of the cable with an inner sheath after cabling;

[0016] S6: Weave a shielding layer on the surface of the cable after covering the inner sheath;

[0017] S7: The braided cable surface is covered with an outer sheath to obtain a highly flexible composite drag chain cable.

[0018] Preferably, the metal wire is a bare copper wire.

[0019] Preferably, during the production process of the insulating layer rubber compound, the insulating rubber compound is distributed by weight as follows: 15-20 parts of EPDM rubber, 15-20 parts of chlorinated polyethylene rubber, 0.2-0.7 parts of vulcanizing agent, 0.1-0.6 parts of antioxidant, 1-2 parts of plasticizer, and 0.4-0.7 parts of activator.

[0020] Preferably, the vulcanizing agent, antioxidant, plasticizer and activator used in the raw material of the insulating layer are dicumyl peroxide, 2-mercaptobenzimidazole, paraffin oil and calcium stearate respectively.

[0021] Preferably, the determining of the speed hysteresis and the engine temperature hysteresis at each acquisition moment includes:

[0022] The normalized values ​​of the time intervals between the collection moments corresponding to the screw speeds and the collection moments corresponding to the die temperatures in the preset period before the current moment and the current moment are used as the speed hysteresis of the collection moments corresponding to the screw speeds and the machine temperature hysteresis of the collection moments corresponding to the die temperatures, respectively. All the screw speeds and all the die temperatures are traversed to obtain the speed hysteresis and machine temperature hysteresis at each collection moment.

[0023] Preferably, the speed dispersion and the machine temperature dispersion at each collection moment in a preset period before the current moment include:

[0024] Calculate the absolute value of the difference between the die head temperature and the preset extrusion temperature at each acquisition moment, and record it as the machine temperature difference value at each acquisition moment. The standard deviation of all screw speeds and the standard deviation of all machine temperature difference values ​​at each acquisition moment and its neighborhood within the preset time period before the current moment are respectively used as the speed dispersion and machine temperature dispersion at each acquisition moment within the preset time length before the current moment.

[0025] Preferably, determining the speed characteristic value and the machine temperature characteristic value at the current moment includes:

[0026] Calculate the product of the speed hysteresis and the speed dispersion at each collection moment in a preset period before the current moment, and the product of the engine temperature hysteresis and the engine temperature dispersion, and record them as the first product and the second product at each collection moment respectively;

[0027] The cumulative sum of the first products at all acquisition moments in a preset period before the current moment and the cumulative sum of the second products at all acquisition moments are calculated respectively as the speed characteristic value and the engine temperature characteristic value at the current moment.

[0028] Preferably, determining the speed correlation and the machine speed correlation at the current moment includes:

[0029] The screw speed, die head temperature and extrusion speed at all acquisition moments within a preset time period before the current moment are respectively formed into a screw speed sequence, a die head temperature sequence and an extrusion speed sequence;

[0030] The screw speed sequence and machine temperature sequence are respectively used as subsequences in the grey relational analysis method, and the extrusion speed sequence is used as the parent sequence in the grey relational analysis method. The correlation between the extrusion speed sequence and the screw speed sequence and the machine temperature sequence is obtained, which are recorded as speed correlation and machine speed correlation, respectively.

[0031] Preferably, the method for determining the speed response value at the current moment is:

[0032] The product of the speed correlation and the speed characteristic value, as well as the product of the engine speed correlation and the engine temperature characteristic value at the current moment are calculated respectively, and recorded as the third product and the fourth product respectively. The average of the third product and the fourth product is taken as the speed response value at the current moment.

[0033] Preferably, the optimizing the proportional coefficient of the PID controller based on the speed response value includes:

[0034] The expression of the optimal value K of the proportional coefficient at the current moment is: ;W represents the speed response value at the current moment; k1 and k2 represent the preset upper and lower limits of the proportional coefficient respectively; norm[ ] represents the normalization function.

[0035] This application has at least the following beneficial effects:

[0036] This application quantifies the potential impact of screw speed and die head temperature on extrusion speed stability by analyzing the hysteresis and discreteness of screw speed and die head temperature, and generates speed characteristic values ​​and temperature characteristic values. These characteristic values ​​intuitively reflect the instability of process parameters and their hysteresis effect, provide a basis for timely and accurate adjustment of traction speed, help avoid uneven thickness of insulation layer, and thus improve the stability of extrusion process and product quality; further, this application analyzes the correlation between screw speed and die head temperature and extrusion speed, and combines their respective hysteresis and instability characteristics, namely speed characteristic values ​​and temperature characteristic values, to calculate the speed response value. The speed response value quantifies the actual impact of changes in screw speed and die head temperature on extrusion speed. This makes it possible to more accurately judge the extent to which the pulling speed needs to be adjusted, effectively overcomes the interference of screw speed fluctuations on temperature, improves the targetedness of pulling speed control, and helps to ensure uniform thickness of the insulation layer; further, the present application calculates a comprehensive speed response value by real-time monitoring and analysis of the hysteresis, discreteness and correlation of the screw speed and head temperature of the extruder and the extrusion speed, and dynamically optimizes the proportional coefficient of the PID controller based on this characteristic value, thereby accurately controlling the pulling speed so that it can respond in time to the hysteresis changes in the extrusion speed caused by unstable screw speed and head temperature fluctuations, effectively solving the problem of uneven thickness of the insulation layer caused by the untimely response of the pulling speed in the traditional method, and improving the insulation performance and flexibility of the final cable product. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0038] Figure 1 A flowchart of a process for preparing a highly flexible composite drag chain cable according to one embodiment of the present application;

[0039] Figure 2 A schematic diagram of a speed response value extraction process provided in one embodiment of the present application. DETAILED DESCRIPTION

[0040] To further illustrate the technical means and effectiveness of this application's proposed objectives, the following, combined with the accompanying drawings and preferred embodiments, details the preparation process, specific implementation, structure, features, and effectiveness of a highly flexible composite drag chain cable proposed in this application. In the following description, references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0041] Unless otherwise defined, terms such as "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device comprising a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of additional identical elements in the article or device comprising the element. In addition, the term "and\or" used herein includes any and all combinations of one or more related listed items. All technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The following detailed description of the specific process for the preparation of a highly flexible composite drag chain cable provided by this application is given in conjunction with the accompanying drawings.

[0042] The specific solution of the preparation process of a highly flexible composite drag chain cable provided by the present application is described in detail below with reference to the accompanying drawings. Example 1

[0043] Example 1 provides a preparation process for a highly flexible composite drag chain cable. For details, please refer to Figure 1 , the process comprises the following steps:

[0044] S1: Multiple strands of metal wire are twisted together to form a cable conductor.

[0045] A cable conductor is obtained by twisting multiple strands of metal wire together into a metal conductor using a twisting device. The metal wire adopts bare copper wire of Category 6 conductor of GB / T3956-2008 "Conductors of Cables" to increase the flexibility of the conductor. The number of strands of the metal wire is 6, and the number of strands of the metal wire can be set by the implementer. This embodiment does not impose any special restrictions.

[0046] S2: Add the insulating layer raw materials according to the weight ratio to prepare the insulating layer rubber compound.

[0047] The insulating layer raw materials are centrally dehumidified and crushed by a central feeding system, and the insulating layer raw materials are mixed according to a ratio. After uniform mixing, an insulating layer rubber compound is obtained, wherein the insulating layer raw materials and their weight ratio are: 15 parts of ethylene propylene diene monomer rubber, 15 parts of chlorinated polyethylene rubber, 0.2 parts of a vulcanizing agent, 0.1 parts of an antioxidant, 1 parts of a plasticizer, and 0.4 parts of an active agent. In this embodiment, the vulcanizing agent, the antioxidant, the plasticizer, and the active agent are diisopropyl benzene peroxide, 2-mercaptobenzimidazole, paraffin oil, and calcium stearate, respectively.

[0048] S3: Using a core wire insulation extruder to coat the insulating layer rubber on the surface of the cable conductor, the coated cable is subjected to a pulling and winding process to obtain a cable core, wherein the pulling speed during the pulling and winding process is controlled based on the speed and temperature changes during the pulling and winding process.

[0049] The cable conductor obtained in step S1 is subjected to insulation coating treatment by a core wire insulation extruder to obtain a cable core wire. The core wire insulation extruder is mainly composed of a pay-off frame, an extruder, a cooling water tank, a traction machine, and a take-up machine. The insulation layer rubber compound obtained in step S2 is injected into the barrel of the extruder, and the cable conductor is mounted on the pay-off frame and passed through the head of the extruder. The extruder coats the insulation layer rubber compound on the surface of the metal conductor and cools and solidifies it in the cooling water tank to achieve insulation coating treatment of the cable conductor. The cable conductor is then towed by the traction machine and finally wound up by the take-up machine. The traction speed during the traction and take-up process is controlled based on the changes in speed and temperature, specifically:

[0050] S3.1 When the die head temperature of the extruder in the core wire insulation extruder reaches the preset die head temperature, the screw speed, die head temperature and extrusion speed of the extruder are obtained in real time.

[0051] When the extrusion temperature of the extruder in the core wire insulation extruder reaches the preset extruder head temperature, a speed sensor is used to collect the screw speed of the extruder in the core wire insulation extruder in real time. A temperature sensor is used to collect the head temperature of the extruder in real time. A speed sensor is used to collect the extrusion speed of the cable core wire at the extruder head and the pulling speed of the pulling machine in the core wire insulation extruder in real time. In this embodiment, the preset extrusion temperature is set to 180°C, and the sampling frequency of all sensors is set to 20Hz. The preset extrusion temperature and sampling frequency are manually set. In actual application, as other implementations, implementers can also set them according to specific circumstances. This embodiment does not impose any special restrictions. The upper and lower limits of the preset extrusion temperature should be lower than the maximum stable temperature of the insulation layer rubber material and higher than the viscosity flow temperature of the insulation layer rubber material, respectively. It should be noted that all of the above data collection is real-time and synchronous.

[0052] Furthermore, in order to eliminate the influence of dimensions between data, all collected data are normalized according to their classification. In this embodiment, the maximum and minimum normalization method is used to normalize the collected data. In actual application, as other implementation methods, the implementer can also use the z-score normalization method to normalize the data according to specific circumstances. Regarding the selection of normalization method, this embodiment does not impose any special restrictions.

[0053] Among them, the maximum and minimum value normalization method is a well-known technology, and the specific process of using it to normalize the data will not be described in detail.

[0054] It is supplemented that, unless otherwise specified, in this embodiment, all contents involving normalization processing or calculation adopt the maximum and minimum value normalization method.

[0055] S3.2 Analyze the lag of the corresponding collection moments of each screw speed and each head temperature in the preset time period before the current moment relative to the current moment, and determine the speed hysteresis and machine temperature hysteresis at each collection moment; analyze the discrete degree of the screw speed and head temperature at each collection moment in the preset time period and its neighborhood, and determine the speed dispersion and machine temperature dispersion at each collection moment in the preset time period before the current moment, and determine the speed characteristic value and machine temperature characteristic value at the current moment in combination with the speed hysteresis and the machine temperature hysteresis.

[0056] In the process of extruding the insulating layer compound by the core wire insulation extruder, the extruder screw rotation speed will directly affect the conveying speed of the insulating compound in the screw, thereby affecting the basic speed of the extruder. However, the extruder will have unstable screw speed changes due to its internal factors such as the wear or aging of the internal lubrication system and transmission system, as well as external factors such as the change of melt temperature in the extruder and the fluctuation of power supply voltage. As a result, the extrusion speed of the extruder will be unstable due to the instability of the screw speed. However, the change of screw speed will not be immediately reflected in the extrusion speed, and there is a certain hysteresis. This hysteresis is mainly due to the fact that the plasticization and conveying process of the insulating layer compound in the screw takes a certain amount of time.

[0057] At the same time, the head temperature of the extruder will affect the fluidity of the insulating layer rubber in the head, and thus affect the extrusion speed of the extruder. The extruder usually uses a heating and cooling device to maintain the head temperature of the extruder near the preset extrusion temperature. However, the extruder will be affected by the uniformity of the heating or cooling effect of the heating and cooling device and the stability of the head temperature control. It is easy for the head temperature to fluctuate near the preset extrusion head temperature, making the extrusion speed of the extruder unstable. In addition, the change in head temperature will not be immediately reflected in the extrusion speed, and there will be a certain lag. This is because it takes a certain amount of time from the change in head temperature to the change in the fluidity of the rubber, and then to the change in extrusion speed.

[0058] Therefore, in order to make the pulling speed of the cable core respond promptly to the extrusion speed changes caused by the instability of the extruder screw speed and the extrusion speed changes caused by the excessive fluctuation of the extruder head temperature near the preset extrusion temperature, thereby avoiding the uneven thickness of the insulation layer of the cable core obtained by subsequent extrusion due to the slow pulling speed response, the hysteresis of the corresponding collection time of each screw speed and each head temperature in the preset time period before the current moment relative to the current moment is analyzed respectively, and the speed hysteresis and machine temperature hysteresis at each collection moment are determined; the discrete degree of the screw speed and head temperature at each collection moment in the preset time period and its neighborhood is analyzed respectively, and the speed discreteness and machine temperature discreteness at each collection moment in the preset time period before the current moment are determined, and the speed hysteresis and machine temperature hysteresis are combined to determine the speed characteristic value and machine temperature characteristic value at the current moment, specifically:

[0059] First, in this embodiment, the hysteresis of the screw speed and the die temperature corresponding to the collection time relative to the current time in the preset period before the current time is analyzed respectively, and the speed hysteresis and the die temperature hysteresis at each collection time are determined respectively, specifically:

[0060] In this embodiment, the normalized values ​​of the time intervals between the collection moments corresponding to the screw speeds and the collection moments corresponding to the die temperatures within a preset period before the current moment and the current moment are used as the speed hysteresis for the collection moments corresponding to the screw speeds and the machine temperature hysteresis for the collection moments corresponding to the die temperatures, respectively. All the collection moments corresponding to the screw speeds and all the collection moments corresponding to the die temperatures are traversed to obtain the speed hysteresis and machine temperature hysteresis at each collection moment. The speed hysteresis and machine temperature hysteresis are respectively used to evaluate the degree of lag of the collection moments corresponding to the screw speed data and the collection moments corresponding to the die temperature relative to the current moment.

[0061] Furthermore, this embodiment determines the dispersion of the screw speed and the die head temperature at each collection moment in the preset period before the current moment by analyzing the dispersion of the screw speed and the die head temperature at each collection moment and its neighborhood within the preset period, specifically:

[0062] In this embodiment, the absolute value of the difference between the die head temperature and the preset extrusion temperature at each collection moment is calculated and recorded as the machine temperature difference value at each collection moment. The standard deviation of all screw speeds and the standard deviation of all machine temperature difference values ​​at each collection moment and its neighborhood within the preset time period before the current moment are respectively used as the speed dispersion and machine temperature dispersion at each collection moment within the preset time length before the current moment. The speed dispersion and machine temperature dispersion are respectively used to evaluate the instability of the screw speed data and the local instability of the die head temperature.

[0063] It should be noted that the size of the neighborhood is artificially planned. In this embodiment, the neighborhood radius is set to 7. In actual application, the implementer can also set it by himself according to the specific situation. This embodiment does not impose any special restrictions.

[0064] Furthermore, this embodiment determines the speed characteristic value and the engine temperature characteristic value at the current moment based on the speed dispersion and the engine temperature dispersion at each collection moment in a preset period before the current moment, in combination with the speed hysteresis and the engine temperature hysteresis, respectively. Specifically,

[0065] In this embodiment, the product of the speed hysteresis and the speed dispersion, as well as the product of the engine temperature hysteresis and the engine temperature dispersion at each collection moment in a preset period before the current moment are calculated and recorded as the first product and the second product at each collection moment respectively;

[0066] Furthermore, the cumulative sum of the first products at all acquisition moments in a preset period before the current moment and the cumulative sum of the second products at all acquisition moments are calculated as the speed characteristic value and the engine temperature characteristic value at the current moment, respectively.

[0067] According to the speed characteristic value at the current moment, it can be understood that the speed characteristic value is used to evaluate the influence of the hysteresis and instability of the screw speed on the change of the extrusion speed. If the speed hysteresis at the current acquisition moment is greater, it means that the hysteresis effect of the screw speed at the current acquisition moment relative to the current moment is significant. Therefore, the larger the corresponding speed characteristic value, the more active the adjustment of the traction speed is required to cope with it. At the same time, if the speed dispersion at the current acquisition moment is greater, it means that the instability of the change of the screw speed in the local range of the current acquisition moment is greater, which directly leads to an increase in the potential for instability of the extrusion speed. Therefore, the final speed characteristic value is also larger, indicating that a stronger traction speed is required to overcome the extrusion speed change caused by the violent fluctuation of the screw speed and the hysteresis effect.

[0068] On the contrary, if the speed hysteresis at the current acquisition moment is smaller, it means that the hysteresis effect of the screw speed at the current acquisition moment relative to the current moment is not significant. Therefore, the corresponding speed characteristic value is smaller, and the traction speed needs to be adjusted relatively less actively to cope with it. At the same time, if the speed dispersion at the current acquisition moment is smaller, it means that the instability of the screw speed change in the local range at the current acquisition moment is smaller, which directly leads to a reduced potential for extrusion speed instability. Therefore, the final speed characteristic value is also smaller, indicating that a weaker traction speed adjustment is required to overcome the extrusion speed change caused by the screw speed fluctuation and hysteresis effect.

[0069] In addition, according to the temperature characteristic value at the current moment, it can be understood that the temperature characteristic value reflects the hysteresis degree of the die head temperature and the degree of fluctuation of the die head temperature around the preset extrusion temperature; if the hysteresis degree of the die head temperature at the current acquisition moment is greater, it means that the fluctuation of the die head temperature occurs at a time point farther away from the current moment, the hysteresis effect is greater, and the corresponding temperature characteristic value is also larger, which means that the traction speed needs to be adjusted more actively to cope with it; at the same time, if the machine temperature dispersion at the current acquisition moment is greater, it means that the amplitude of the die head temperature deviation from the preset extrusion temperature is greater, which directly leads to greater changes in the fluidity of the rubber compound, and thus causes greater potential for instability in the extrusion speed, and this large degree of fluctuation multiplied by its hysteresis degree makes the corresponding temperature characteristic value larger, indicating that a stronger traction speed response is needed to overcome the extrusion speed change caused by the drastic fluctuation of the die head temperature and the subsequent effect.

[0070] Thus, this embodiment has quantified the potential impact of the screw speed and die head temperature on the stability of the extrusion speed by analyzing their hysteresis and discreteness, and generated speed characteristic values ​​and temperature characteristic values. These characteristic values ​​intuitively reflect the instability of the process parameters and their hysteresis effect, providing a basis for timely and accurate adjustment of the traction speed, helping to avoid uneven thickness of the insulation layer, thereby improving the stability of the extrusion process and product quality.

[0071] S3.3 analyzes the correlation between the screw speed and the head temperature and the extrusion speed at all sampling moments in the preset time period before the current moment to determine the speed correlation and the machine speed correlation at the current moment, and combines the speed characteristic value and the machine temperature characteristic value to determine the speed response value at the current moment.

[0072] However, when the screw speed of the extruder changes, the shearing effect of the screw on the melt will change, causing the shear friction heat generated by the shearing effect to change, and then causing the temperature of the melt to change due to the change in the shear friction heat, thereby causing the temperature of the extruder to change, so that the change in extrusion speed caused by the change in the extruder temperature will include a part of the change caused by the screw speed of the extruder.

[0073] Therefore, in order to reduce the repetitive interference caused by the fluctuation of the screw speed itself when the die temperature changes on the extrusion speed, and thereby improve the accuracy of the evaluation of the hysteresis effect of the screw speed and the die temperature, this embodiment analyzes the correlation between the screw speed and the die temperature and the extrusion speed at all acquisition moments in a preset period before the current moment, so as to determine the speed correlation and the machine speed correlation at the current moment, and combines the speed characteristic value and the machine temperature characteristic value to determine the speed response value at the current moment, specifically:

[0074] In this embodiment, first, the correlation between the screw speed and the die head temperature and the extrusion speed at all acquisition moments in the preset period before the current moment is analyzed respectively to determine the speed correlation and the machine speed correlation at the current moment, which are used to characterize the degree of influence of the screw speed and the die head temperature of the extruder on its extrusion speed in the preset period before the current moment, specifically:

[0075] In this embodiment, the screw speed, die head temperature and extrusion speed at all acquisition moments within a preset time period before the current moment are respectively formed into a screw speed sequence, a die head temperature sequence and an extrusion speed sequence;

[0076] Furthermore, the screw speed sequence and the machine temperature sequence are respectively used as subsequences in the grey relational analysis method, and the extrusion speed sequence is used as the parent sequence in the grey relational analysis method. The correlation between the extrusion speed sequence and the screw speed sequence and the machine temperature sequence is obtained, which are recorded as speed correlation and machine speed correlation, respectively.

[0077] Among them, the grey correlation analysis method is a well-known technology, and the specific process of using it to obtain the correlation between the extrusion speed sequence and the screw speed sequence, and the correlation between the extrusion speed sequence and the machine temperature sequence will not be repeated.

[0078] Furthermore, this embodiment determines the speed response value at the current moment based on the speed correlation and the machine speed correlation at the current moment, in combination with the speed characteristic value and the machine temperature characteristic value, specifically:

[0079] In this embodiment, the product of the speed correlation and the rotational speed characteristic value, and the product of the engine speed correlation and the engine temperature characteristic value at the current moment are calculated respectively, and recorded as the third product and the fourth product respectively. The average of the third product and the fourth product is taken as the speed response value at the current moment.

[0080] Preferably, the speed response value extraction process diagram provided in this embodiment is as follows: Figure 2 shown.

[0081] According to the speed response value at the current moment, it can be understood that if the speed characteristic value at the current moment is larger and the speed correlation is larger, it means that the hysteresis and instability of the screw speed in the preset period before the current moment have a greater impact on the extrusion speed. Therefore, the corresponding speed response value may be larger, and it is necessary to adjust the traction speed in time to cope with the influence of screw speed fluctuations; if the temperature characteristic value at the current moment is larger and the machine speed correlation is larger, it means that the hysteresis and instability of the head temperature in the preset period before the current moment have a greater impact on the extrusion speed. Therefore, the corresponding speed response value may be larger at this time, and it is necessary to adjust the traction speed in time to cope with the influence of screw speed fluctuations.

[0082] At this point, this embodiment calculates the speed response value by analyzing the correlation between the screw speed and the head temperature and the extrusion speed, and combining their respective hysteresis and instability characteristics, that is, the speed characteristic value and the temperature characteristic value. The speed response value quantifies the actual impact of the changes in the screw speed and the head temperature on the extrusion speed, thereby more accurately judging the extent to which the traction speed needs to be adjusted, effectively overcoming the interference of the screw speed fluctuation on the temperature effect, improving the targetedness of the traction speed control, and helping to ensure the uniform thickness of the insulation layer.

[0083] S3.4 optimizes the proportional coefficient of the PID controller based on the speed response value to control the pulling speed of the pulling machine in the core wire insulation extruder.

[0084] In order to reduce the hysteresis effect of the extruder's screw speed and die head temperature on its extrusion speed, this embodiment optimizes the proportional coefficient of the PID controller based on the speed response value to control the traction speed of the traction machine in the core wire insulation extruder, specifically:

[0085] As a specific implementation, in this embodiment, the expression of the optimized value K of the proportional coefficient at the current moment is: ;W represents the speed response value at the current moment; k1 and k2 represent the preset upper and lower limits of the proportional coefficient respectively; norm[ ] represents the normalization function.

[0086] It should be noted that the values ​​of k1 and k2 are manually set. In this embodiment, the values ​​of k1 and k2 are 10 and 0.1 respectively. In actual application, the implementer can also set them according to the specific situation. This embodiment does not impose any special restrictions.

[0087] Based on the current optimized value of the proportional coefficient, it can be understood that a larger speed response value indicates that the combined impact of the extruder's screw speed and die head temperature fluctuations on the extrusion speed is stronger, requiring a stronger control response to stabilize the traction speed of the tractor. Therefore, it is necessary to increase the proportional coefficient to more quickly suppress extrusion speed fluctuations and more actively adjust the traction speed. Furthermore, the current optimized value of the proportional coefficient is used as the proportional coefficient in the PID controller to control the traction speed of the tractor at the current moment.

[0088] S4: Twisting all the manufactured cable cores to obtain a twisted cable.

[0089] This embodiment adopts the above-mentioned steps of making cable cores, and all the cable cores obtained are twisted in a non-backtwisting manner, with the twisting direction being right-handed. In order to ensure that the cable cores are subjected to uniform force during the twisting process, aramid tensile strength is filled between all the cable cores to obtain a twisted cable.

[0090] S5: Cover the surface of the cable with an inner sheath after cabling.

[0091] In this embodiment, an inner sheath is coated on the surface of the cable obtained after cabling by using an extruder. The raw material of the inner sheath is polyvinyl chloride and is produced by extrusion. The gaps between the outer insulation cores of the cable after cabling are compacted to prevent the inner sheath from being loose.

[0092] S6: A shielding layer is woven on the surface of the cable after it is covered with the inner sheath.

[0093] In this embodiment, a shielding layer is woven on the surface of the cable after being covered with the inner sheath by using a braiding machine, and copper wire is used for the weaving.

[0094] S7: The braided cable surface is covered with an outer sheath to obtain a highly flexible composite drag chain cable.

[0095] In this embodiment, an extruder is used to coat an outer sheath on the surface of the braided cable. The outer sheath is made of butyl nitrile polyvinyl chloride to obtain a highly flexible composite drag chain cable.

[0096] At this point, this embodiment calculates a comprehensive speed response value by real-time monitoring and analyzing the hysteresis, discreteness and correlation of the extruder's screw speed and head temperature with the extrusion speed. Based on this characteristic value, the proportional coefficient of the PID controller is dynamically optimized to accurately control the traction speed so that it can promptly respond to the hysteresis changes in the extrusion speed caused by unstable screw speed and fluctuations in head temperature. This effectively solves the problem of uneven insulation layer thickness caused by untimely traction speed response in traditional methods, and significantly improves the insulation performance and flexibility of the final cable product. Example 2

[0097] Example 2 provides a preparation process for a highly flexible composite drag chain cable. For details, please refer to Figure 1 , the process comprises the following steps:

[0098] S1: Multiple strands of metal wire are twisted together to form a cable conductor.

[0099] S2: Add the insulating layer raw materials according to the weight ratio to prepare the insulating layer rubber compound.

[0100] In this embodiment, the raw materials for the insulating layer and their weight ratio are: 18 parts of EPDM rubber, 18 parts of chlorinated polyethylene rubber, 0.4 parts of vulcanizing agent, 0.3 parts of antioxidant, 1.5 parts of plasticizer, and 0.5 parts of activator. The remaining operations are the same as in Example 1.

[0101] S3: Using a core wire insulation extruder to coat the insulating layer rubber on the surface of the cable conductor, the coated cable is subjected to a pulling and winding process to obtain a cable core, wherein the pulling speed during the pulling and winding process is controlled based on the speed and temperature changes during the pulling and winding process.

[0102] S4: Twisting all the manufactured cable cores to obtain a twisted cable.

[0103] S5: Cover the surface of the cable with an inner sheath after cabling.

[0104] S6: A shielding layer is woven on the surface of the cable after it is covered with the inner sheath.

[0105] S7: The braided cable surface is covered with an outer sheath to obtain a highly flexible composite drag chain cable. Example 3

[0106] Example 3 provides a preparation process for a highly flexible composite drag chain cable. For details, please refer to Figure 1 , the process comprises the following steps:

[0107] S1: Multiple strands of metal wire are twisted together to form a cable conductor.

[0108] S2: Add the insulating layer raw materials according to the weight ratio to prepare the insulating layer rubber compound.

[0109] In this embodiment, the raw materials for the insulating layer and their weight ratio are: 20 parts of EPDM rubber, 20 parts of chlorinated polyethylene rubber, 0.7 parts of vulcanizing agent, 0.6 parts of antioxidant, 2 parts of plasticizer, and 0.7 parts of activator. The remaining operations are the same as in Example 1.

[0110] S3: Using a core wire insulation extruder to coat the insulating layer rubber on the surface of the cable conductor, the coated cable is subjected to a pulling and winding process to obtain a cable core, wherein the pulling speed during the pulling and winding process is controlled based on the speed and temperature changes during the pulling and winding process.

[0111] S4: Twisting all the manufactured cable cores to obtain a twisted cable.

[0112] S5: Cover the surface of the cable with an inner sheath after cabling.

[0113] S6: A shielding layer is woven on the surface of the cable after it is covered with the inner sheath.

[0114] S7: The braided cable surface is covered with an outer sheath to obtain a highly flexible composite drag chain cable.

[0115] It should be noted that the order in which the embodiments of the present application are presented is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. Furthermore, the foregoing descriptions of specific embodiments of this specification are provided. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential sequence shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0116] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0117] The above-described embodiments are only used to illustrate the technical solutions of the present application, and not to limit them. Modifications to the technical solutions described in the aforementioned embodiments, or equivalent replacements of some of the technical features therein, 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 application, and should all be included in the scope of protection of the present application.

Claims

1. A preparation process for a highly flexible composite drag chain cable, characterized in that: The process includes the following steps: S1: twisting multiple metal wires into cable conductors; S2: Add the insulating layer raw materials according to the weight ratio to prepare the insulating layer rubber compound; S3: Using a core wire insulation extruder, an insulation layer of rubber is coated on the surface of the cable conductor. The coated cable is pulled and taken up to obtain a cable core. The pulling speed is controlled based on the speed and temperature changes during the pulling and taking-up process. The specific process is as follows: Get the extruder's screw speed, die head temperature and extrusion speed in real time; Analyze the hysteresis of the corresponding collection moments of each screw speed and each die temperature in the preset period before the current moment relative to the current moment, and determine the speed hysteresis and machine temperature hysteresis at each collection moment; analyze the dispersion of the screw speed and die temperature at each collection moment and its neighborhood in the preset period, and determine the speed dispersion and machine temperature dispersion at each collection moment in the preset period before the current moment, and determine the speed characteristic value and machine temperature characteristic value at the current moment by combining the speed hysteresis and machine temperature hysteresis; Analyze the correlation between the screw speed and the die head temperature and the extrusion speed at all acquisition moments within the preset time period, determine the speed correlation and the machine speed correlation at the current moment, and determine the speed response value at the current moment by combining the speed characteristic value and the machine temperature characteristic value; Optimizing a proportional coefficient of a PID controller based on the speed response value to control a pulling speed of a pulling machine in a core wire insulation extruder; S4: twisting all the manufactured cable cores to obtain a twisted cable; S5: Cover the surface of the cable with an inner sheath after cabling; S6: Weave a shielding layer on the surface of the cable after covering the inner sheath; S7: The braided cable surface is covered with an outer sheath to obtain a highly flexible composite drag chain cable.

2. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: The metal wire is a bare copper wire.

3. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: During the production process of the insulating layer rubber compound, the insulating rubber compound is distributed according to the weight ratio as follows: 15-20 parts of EPDM rubber, 15-20 parts of chlorinated polyethylene rubber, 0.2-0.7 parts of vulcanizing agent, 0.1-0.6 parts of antioxidant, 1-2 parts of plasticizer, and 0.4-0.7 parts of activator.

4. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: The vulcanizing agent, antioxidant, plasticizer and activator used in the insulating layer raw materials are dicumyl peroxide, 2-mercaptobenzimidazole, paraffin oil and calcium stearate respectively.

5. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: Determining the speed hysteresis and the engine temperature hysteresis at each acquisition moment includes: The normalized values ​​of the time intervals between the collection moments corresponding to the screw speeds and the collection moments corresponding to the die temperatures in the preset period before the current moment and the current moment are used as the speed hysteresis of the collection moments corresponding to the screw speeds and the machine temperature hysteresis of the collection moments corresponding to the die temperatures, respectively. All the screw speeds and all the die temperatures are traversed to obtain the speed hysteresis and machine temperature hysteresis at each collection moment.

6. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: The speed dispersion and the machine temperature dispersion at each collection moment in the preset period before the current moment include: Calculate the absolute value of the difference between the die head temperature and the preset extrusion temperature at each acquisition moment, and record it as the machine temperature difference value at each acquisition moment. The standard deviation of all screw speeds and the standard deviation of all machine temperature difference values ​​at each acquisition moment and its neighborhood within the preset time period before the current moment are respectively used as the speed dispersion and machine temperature dispersion at each acquisition moment within the preset time length before the current moment.

7. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: Determining the speed characteristic value and the machine temperature characteristic value at the current moment includes: Calculate the product of the speed hysteresis and the speed dispersion at each collection moment in a preset period before the current moment, and the product of the engine temperature hysteresis and the engine temperature dispersion, and record them as the first product and the second product at each collection moment respectively; The cumulative sum of the first products at all acquisition moments in a preset period before the current moment and the cumulative sum of the second products at all acquisition moments are calculated respectively as the speed characteristic value and the engine temperature characteristic value at the current moment.

8. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: Determining the speed correlation and the machine speed correlation at the current moment includes: The screw speed, die head temperature and extrusion speed at all acquisition moments within a preset time period before the current moment are respectively formed into a screw speed sequence, a die head temperature sequence and an extrusion speed sequence; The screw speed sequence and machine temperature sequence are respectively used as subsequences in the grey relational analysis method, and the extrusion speed sequence is used as the parent sequence in the grey relational analysis method. The correlation between the extrusion speed sequence and the screw speed sequence and the machine temperature sequence is obtained, which are recorded as speed correlation and machine speed correlation, respectively.

9. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: The method for determining the speed response value at the current moment is: The product of the speed correlation and the speed characteristic value, as well as the product of the engine speed correlation and the engine temperature characteristic value at the current moment are calculated respectively, and recorded as the third product and the fourth product respectively. The average of the third product and the fourth product is taken as the speed response value at the current moment.

10. The preparation process of a highly flexible composite drag chain cable according to claim 1, characterized in that: Optimizing the proportional coefficient of the PID controller based on the speed response value includes: The expression of the optimal value K of the proportional coefficient at the current moment is: ;W represents the speed response value at the current moment; k1 and k2 represent the preset upper and lower limits of the proportional coefficient respectively; norm[ ] represents the normalization function.

Images