Meter weight control device and method for cable crosslinking process

Abstract

The invention discloses a meter weight control device and method for a cable crosslinking procedure, and belongs to the technical field of cable manufacturing, the meter weight control device comprises an extruder and a weighing unit, the extruder adopts a three-layer co-extrusion system and comprises a feeding device, a traction device and an extrusion device, and the meter weight control device further comprises a speed detection unit, a calculation unit and a control unit. The speed detection unit can detect the production line traction speed of the extruder, and the calculation unit can receive a speed signal and calculate a real-time meter weight value and an actual glue thickness value; the control unit controls the working parameters of the extruder according to the comparison between the data calculated by the calculation unit and the set data; the weighing unit, the speed detection unit, the calculation unit and the control unit work cooperatively to control the weight per meter of the extruder. According to the invention, the weighing unit is arranged, and the weight of the extruded material entering the extruder is adjusted through the cooperation of the speed detection unit, the calculation unit and the control unit. The situation that the thickness exceeds the standard can be avoided, and trial production and starting waste products are remarkably reduced.

Description

Technical Field

[0001] This invention relates to a weight-per-meter control device and method for cable cross-linking process, belonging to the field of cable manufacturing technology. Background Technology

[0002] In the cross-linking three-layer co-extrusion process, online quality control is required. A three-layer co-extrusion cross-linking line typically consists of multiple independent feeding devices, several parallel extruders, concentric dies, traction devices, and subsequent cross-linking furnaces. This type of production line needs to stably coat conductors with specified insulation, shielding, and sheathing layers under high-speed, long-batch conditions, with strict requirements on the thickness of each layer, cable outer diameter, and material usage. Due to the physical properties of the cross-linking materials and the interlayer ratio requirements of the three-layer co-extrusion, real-time and accurate measurement and control of material usage and adhesive layer thickness are crucial to ensuring the electrical and mechanical properties of the product while minimizing production costs.

[0003] Existing crosslinking extrusion production control methods mostly rely on online diameter measurement, periodic sampling thickness measurement, or feeding control based on volumetric flow rate to indirectly determine the adhesive thickness. Common practices include measuring the outer diameter using laser or contact diameter measuring devices and inferring the wall thickness through diameter conversion; or setting the speed ratio between the feeding equipment and the extruder empirically and adjusting it manually with frequent sampling. In some applications, devices using weight per meter as a control quantity are also used, but most implementations focus on the quality inspection of single layers or the entire pipe, and are mostly low-sampling-frequency, average-based control methods, lacking a closed-loop distribution strategy for layered material distribution in three-layer structures.

[0004] Therefore, it is necessary to design a meter weight control device and method for the cable cross-linking process to reduce raw material loss and improve the overall quality of the conductor while ensuring quality. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a meter weight control device and method for cable cross-linking process, which solves the problems of excessive raw material loss and poor overall conductor quality.

[0006] The technical problem to be solved by the present invention is achieved by the following technical solution: a meter weight control device for cable cross-linking process, comprising...

[0007] An extruder and a weighing unit, wherein the weighing unit is capable of measuring the weight of the extruded material supplied to the extruder within a sampling time.

[0008] The extruder employs a three-layer co-extrusion system, including a feeding device, a traction device, and an extrusion device.

[0009] Multiple feeding devices are capable of providing extruded material to the traction device, the traction device is capable of feeding the extruded material into the extrusion device, and the extrusion device is capable of extruding the extruded material onto the surface of the conductor.

[0010] Its features are:

[0011] It also includes a speed detection unit, a calculation unit, and a control unit. The speed detection unit can detect the production line traction speed of the extruder. The calculation unit can receive the signal detected by the speed detection unit and calculate the real-time weight per meter and the actual rubber thickness. The control unit compares the data calculated by the calculation unit with the set data and controls the working parameters of the extruder.

[0012] The weighing unit, the speed detection unit, the calculation unit, and the control unit work together to control the weight per meter of the extruder.

[0013] Preferably, the weighing unit includes a weighing hopper, and the bottom of the feeding device is provided with a weighing unit.

[0014] Preferably, the speed detection unit includes an encoder and a speed measuring wheel. The speed measuring wheel rotates on the surface of the cable, and the encoder can record the rotation of the speed measuring wheel and detect the linear speed signal of the cable.

[0015] Preferably, the sampling and adjustment frequency of the computing unit is 1200 times / minute; the measurement accuracy is ±3‰; and the single control and adjustment accuracy is ±4‰.

[0016] Preferably, the calculation unit converts the weight per meter w into the actual adhesive thickness H based on the following relationship:

[0017] in

[0018]

[0019]

[0020]

[0021] m is the weight measured during the sampling time. Where v is the sampling time and v is the linear velocity. Material density, inner diameter of layer d, outer diameter of layer D, and corresponding cross-sectional area of ​​material A.

[0022] A method for controlling the weight per meter in a cable cross-linking process, wherein the method utilizes a weight control device for the cable cross-linking process.

[0023] S1: The weighing unit and the speed detection unit acquire data at high frequency during the sampling time. The weight m and linear velocity v inside;

[0024] S2: The calculation unit calculates the real-time weight in meters w based on the signal detected by the speed detection unit, obtains the actual weight in meters value, and converts it into the actual glue thickness value H;

[0025] S3: The control unit compares the actual adhesive thickness H with the set target value to confirm the adjustment amount;

[0026] S4: The adjustment amount of the calculation unit is transmitted to the extruder to adjust the parameters of the feeding device, the traction device, and the extrusion device;

[0027] S5: Record and store data, and repeat S1-S5.

[0028] Preferably, the sampling frequency of S1 is 1200 times per minute; the online weighing measurement accuracy of S2 is preferably ±3‰; and the single control and adjustment accuracy of S4 is preferably ±4‰.

[0029] The beneficial effects of this invention are:

[0030] (1) Through this invention, a weighing unit is set up, and the weight of the extruded material entering the extruder is adjusted by the cooperation of the speed detection unit, the calculation unit, and the control unit. The weight per meter and the thickness of the extruded material are controlled in a closed loop by high-frequency detection of the mass and linear speed of the extruded material. The operation of each device of the extruder is adjusted separately, which can quickly detect and avoid the thickness exceeding the standard. During the start-up and trial production process, it can significantly reduce the waste of defective products and raw materials, shorten the debugging time, and improve the consistency and pass rate of products. It can also avoid the occurrence of thickness exceeding the standard and reduce the scrap during trial production and start-up.

[0031] (2) Through this invention, the weighing unit records the weight of the extruded material from the extruder. The extruder is equipped with three layers of feeding equipment. The control unit issues independent commands to the three layers of feeding equipment respectively, which can keep the wall thickness of each layer and the total outer diameter at the same time meeting the set values. It can avoid outer diameter fluctuations, improve the consistency of wall thickness of each layer, avoid the deterioration of electrical performance, prevent local thinning that leads to electric field concentration, and prevent local thickening that leads to increased costs. The geometric and electrical consistency of the conductor product is improved, and the pass rate is increased. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention.

[0033] Figure 2 This is a schematic diagram of the feeding device and weighing unit of the present invention.

[0034] Figure 3 This is a schematic diagram of the speed detection unit of the present invention.

[0035] Figure 4 This is a flow chart of the meter weight controlled extrusion process of the present invention.

[0036] In the diagram: 1-Extruder, 2-Weighing unit, 3-Speed ​​detection unit, 4-Control unit. Detailed Implementation

[0037] To facilitate a clear understanding of the technical means, creative features, objectives, and effects of this invention, the invention will be further described below in conjunction with specific embodiments.

[0038] Example 1

[0039] like Figures 1-4 As shown, a weight-per-meter control device and method for cable cross-linking process includes...

[0040] Extruder 1, weighing unit 2, the weighing unit is capable of measuring the weight of the extruded material supplied to the extruder within the sampling time.

[0041] The extruder 1 includes a three-layer co-extrusion system, including a feeding device, a traction device, and an extrusion device. The feeding device feeds the raw material into the feed port of the extrusion device. The traction device is located after the die head and is used to pull and sizing the extruded wire and feed it into the subsequent equipment. The extrusion device can extrude the extruded material onto the surface of the wire.

[0042] In this embodiment, three feeding devices are provided, and each feeding device is equipped with a weighing unit 2 at its bottom. The weighing unit 2 collects the weight of the extruded material provided by the corresponding feeding device.

[0043] The three feeding devices are connected to the feed inlet of the traction device through feeding pipelines. The traction devices are arranged in parallel on the same production platform. The discharge end of the traction device is connected to the extrusion device through its own flow channel. The three melts are stacked layer by layer in the concentric cavity inside the extrusion device to form a concentric layer structure before being extruded to the surface of the lead wire.

[0044] The extruder 1 is also equipped with a speed detection unit 3, a calculation unit, and a control unit 4. The speed detection unit 3 can detect the production line traction speed of the extruder 1. The calculation unit can receive the detection signal from the speed detection unit 3 and calculate the real-time weight per meter and the actual rubber thickness. The control unit 4 controls the working parameters of the extruder 1 by comparing the data from the calculation unit with the set data.

[0045] Weighing unit 2, speed detection unit 3, calculation unit, and control unit 4 work together to control the weight per meter of extruder 1.

[0046] Reference Figure 1The extruder 1 is located at the front end of the production line. Along the direction of the production line, the following components are arranged in sequence: feeding equipment, extrusion equipment, traction equipment, speed detection unit 3 is installed at the top of the traction equipment to ensure accurate speed measurement, control unit 4 is located in the electrical control cabinet and is equipped with a human-machine interface display, and weighing unit 2 is located at the feeding equipment. The weighing unit 2 can measure the mass m of the extruded material supplied to the extruder 1 within the sampling time.

[0047] The mass signal is sampled by the weighing transmitter and sent to the calculation unit. The calculation unit calculates the weight per meter W and the actual adhesive thickness H based on the mass signal and the real-time linear velocity v.

[0048] The control unit 4 is installed in a dustproof cabinet. A vibration damping mounting base is installed below the weighing unit 2. The speed detection unit 3 is fixed to the flange at the end of the traction roller shaft. The signal line is laid along the extruder 1 to the control unit.

[0049] Reference Figure 2 In this embodiment, the feeding device adopts a feeder, and a weighing unit 2 is provided at the bottom of the feeding device. The feeding device includes a hopper, which is a conical feeding hopper. A variable frequency motor is provided at the top of the hopper, and the variable frequency motor can control the weight of the extruded material entering the hopper.

[0050] The extrusion equipment is a horizontally arranged screw extruder, consisting of a barrel, heating coil, cooling jacket, feed inlet, and gearbox. It has a rectangular barrel and a cylindrical screw cavity. The extrusion equipment employs a three-layer feeding die and a three-layer feeder, concentrically combining three streams of melt within the die. The die is cylindrical and contains a concentric flow channel system. The traction equipment consists of a set of multi-roller traction wheels, driven and controlled by a servo motor, allowing for adjustment of the traction speed and tension.

[0051] Extruder 1 employs a three-layer feeding die and a three-layer feeder, each independently controlling its extrusion rate and temperature to ensure interlayer ratio and concentricity. The extrusion rate is coarsely and finely adjusted via screw speed and feed rate.

[0052] Weighing unit 2 consists of a weighing hopper and a support sensor assembly. The weighing hopper is conical in shape, and the lower end guides the extruded material through the support sensor via a guide structure. The support sensor detects the mass of the extruded material and is located at the bottom of the weighing hopper, with an outer shell. Weighing unit 2 can measure the mass of the extruded material within the sampling time.

[0053] In this embodiment, the weighing unit 2 is rigidly fixed to the bottom of the feeding device. The weighing unit 2 is connected to the calculation unit via wires, enabling real-time transmission of weight signals. The speed detection unit 3 is mechanically mounted on the top of the traction device to ensure accurate speed measurement, detect the speed of the extruded cable, and output pulse signals to the calculation unit. The calculation results of the weight per meter W and the adhesive thickness H by the calculation unit are fed back to the control unit 4 via PLC. The control unit 4 can adjust the speed of the feeding motor, the speed of the screw, and the traction speed in real time to ensure that the weight per meter remains within the set range.

[0054] Reference Figure 3 The speed detection unit 3 consists of an encoder and a speed measuring wheel. The encoder is a disc-shaped mounting block fixed to the end of the traction shaft and connected to the shaft through a flange. The speed measuring wheel is a disc with a high friction surface. It obtains the rotation speed by contacting the outer surface of the cable. The encoder can record the rotation of the speed measuring wheel and detect the linear speed signal of the cable. The speed detection unit 3 can detect the linear speed of the cable in real time.

[0055] Reference Figure 1 The control unit 4 includes a control cabinet, which houses a PLC and a human-machine interface display. The PLC is electrically connected to the extruder 1, the weighing unit 2, and the speed detection unit 3. The PLC contains a calculation unit that can calculate the real-time weight per meter and the actual rubber thickness of the extruder 1 based on the data transmitted from the weighing unit 2 and the speed detection unit 3.

[0056] The device operates as follows:

[0057] S1. Sampling, weighing unit 2 according to sampling time The mass m of the sampled extruded material is measured; the velocity detection unit 3 synchronously samples the linear velocity v; the signal is transmitted to the calculation unit.

[0058] S2. Calculation: The calculation unit performs the following steps.

[0059] Calculate the weight per meter, w.

[0060]

[0061] Calculate the cross-sectional area A.

[0062]

[0063] Calculate the outer diameter and thickness from the cross-sectional area A, and then obtain the actual adhesive thickness H.

[0064] Outer diameter D

[0065]

[0066] Actual adhesive thickness H

[0067]

[0068] Where m is the weight measured within the sampling time. Where v is the sampling time and v is the linear velocity. Material density, inner diameter of layer d, outer diameter of layer D, and corresponding cross-sectional area of ​​material A.

[0069] S3. Compare the actual adhesive thickness with the set target value to determine the adjustment amount.

[0070] S4. Control the extruder 1 through the control unit 4 and adjust the parameters of the feeding device, traction device, and extrusion device.

[0071] S5. Record and store the data, and repeat S1-S5.

[0072] In this embodiment, the sampling frequency in S1 is 1200 times per minute to achieve real-time calculation and closed-loop control of the weight per meter and the adhesive thickness, ensuring that the outer diameter fluctuation is controlled within approximately 0.1 mm. The online weighing measurement accuracy in S2 is preferably ±3‰; the single control and adjustment accuracy in S4 is preferably ±4‰.

[0073] In S3, the control unit 4 compares the actual glue thickness H with the set target value and determines the deviation. Then, it first issues independent compensation commands to each layer of feeding equipment according to priority, changing the frequency and flow rate of the feeding equipment. If there is still a remaining compensation requirement, the extruder screw speed and traction speed are finely adjusted in sequence according to the preset strategy. The controller uses PID to make the adjustment.

[0074] The control unit can simultaneously transmit control quantities to the three-layer feeders, avoiding imbalance in the interlayer ratio caused by a single adjustment, thereby ensuring that the thickness of a single layer and the overall adhesive simultaneously meet the set values.

[0075] In this embodiment, raw materials can be saved and the scrap rate can be reduced: stable control of the weight per meter can eliminate waste caused by excessive thickness and reduce start-up and commissioning scrap. In an 80 km production batch, the amount of insulation material used before and after the installation of the weight per meter control decreased from 925.6 kg / km to 838.4 kg / km, saving 6976 kg.

[0076] In this embodiment, a weighing unit 2 is set up. Through the cooperation of the speed detection unit 3, the calculation unit, and the control unit 4, the weight of the extruded material entering the extruder 1 is adjusted. Closed-loop control of the weight per meter and rubber thickness is achieved by detecting the mass and linear velocity of the extruded material at high frequency. The operation of each device in the extruder is adjusted accordingly, enabling rapid detection and prevention of thickness exceeding the standard. During startup and trial production, this significantly reduces defective products and raw material waste, shortens debugging time, and improves product consistency and pass rate, thus preventing thickness exceeding the standard and reducing scrap during trial production and startup.

[0077] In this embodiment, the weighing unit 4 records the weight of the extruded material from the extruder 1. The extruder 1 is equipped with a three-layer feeding device. The control unit issues independent commands to the three-layer feeding devices respectively, which can ensure that the wall thickness of each layer and the total outer diameter simultaneously meet the set values. This avoids outer diameter fluctuations, improves the consistency of wall thickness of each layer, avoids deterioration of electrical performance, prevents electric field concentration caused by excessive thinness in some areas, and avoids cost increase caused by excessive thickness in some areas. The geometric and electrical consistency of the finished conductor is improved, thus increasing the yield rate.

[0078] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention, all of which fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A weight-per-meter control device for cable cross-linking process, comprising: An extruder and a weighing unit, wherein the weighing unit is capable of measuring the weight of the extruded material supplied to the extruder within a sampling time. The extruder employs a three-layer co-extrusion system, including a feeding device, a traction device, and an extrusion device. Multiple feeding devices are capable of providing extruded material to the traction device, the traction device is capable of feeding the extruded material into the extrusion device, and the extrusion device is capable of extruding the extruded material onto the surface of the conductor. Its features are: It also includes a speed detection unit, a calculation unit, and a control unit. The speed detection unit can detect the production line traction speed of the extruder, and the calculation unit can receive the signal detected by the speed detection unit and calculate the real-time weight per meter and the actual rubber thickness. The control unit compares the data calculated by the calculation unit with the set data to control the operating parameters of the extruder; The weighing unit, the speed detection unit, the calculation unit, and the control unit work together to control the weight per meter of the extruder.

2. The meter weight control device for cable cross-linking process according to claim 1, characterized in that: The weighing unit includes a weighing hopper, and the bottom of the feeding device is equipped with a weighing unit.

3. The meter weight control device for cable cross-linking process according to claim 1, characterized in that: The speed detection unit includes an encoder and a speed measuring wheel. The speed measuring wheel rotates on the surface of the cable, and the encoder can record the rotation of the speed measuring wheel to detect the linear speed signal of the cable.

4. The meter weight control device for cable cross-linking process according to claim 1, characterized in that: The computing unit samples and adjusts at a frequency of 1200 times / minute; the measurement accuracy is ±3‰; and the single control and adjustment accuracy is ±4‰.

5. A meter weight control device for cable cross-linking process according to claim 1, characterized in that: The calculation unit converts the weight per meter (w) into the actual adhesive thickness (H) based on the following relationship: in m is the weight measured during the sampling time. Where v is the sampling time and v is the linear velocity. Material density, inner diameter of layer d, outer diameter of layer D, and corresponding cross-sectional area of ​​material A.

6. A method for controlling the weight per meter in a cable cross-linking process, wherein the method is implemented using a weight per meter control device for a cable cross-linking process as described in any one of claims 1-5, characterized in that: S1: The weighing unit and the speed detection unit acquire data at high frequency during the sampling time. The weight m and linear velocity v inside; S2: The calculation unit calculates the real-time weight in meters w based on the signal detected by the speed detection unit, obtains the actual weight in meters value, and converts it into the actual glue thickness value H; S3: The control unit compares the actual adhesive thickness H with the set target value to confirm the adjustment amount; S4: The adjustment amount of the calculation unit is transmitted to the extruder to adjust the parameters of the feeding device, the traction device, and the extrusion device; S5: Record and store data, and repeat S1-S5.

7. The method for controlling the weight per meter in a cable cross-linking process according to claim 6, characterized in that: The sampling frequency of S1 is 1200 times per minute; the online weighing measurement accuracy of S2 is preferably ±3‰; and the single control and adjustment accuracy of S4 is preferably ±4‰.

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