A self-adaptive cable thermal stability test heating device and method

Abstract

The present invention discloses an adaptive cable thermal stability test heating device and method. The adaptive cable thermal stability test heating device includes a winding assembly, a heating assembly, a clamping assembly and a driving assembly. When the wire coil driving motor and the test tube rotating motor are in operation, the graphene-based carbon fiber rope is wound around the outer periphery of the test tube. When the heating tube of the heating assembly is heated, the heat is transferred to the graphene-based carbon fiber rope by thermal radiation, thereby heating the cable sample in the test tube and performing a cable thermal stability test. The graphene-based carbon fiber rope is a highly thermally conductive flexible material. Through the cooperation of the winding assembly and the driving assembly, the graphene-based carbon fiber rope can be adaptively wound around the outer wall of test tubes of different specifications. After the graphene-based carbon fiber rope is tightly wrapped around the outer periphery of the test tube, it receives the heat radiated by the heating tube. The high thermal conductivity of the graphene-based carbon fiber rope ensures that the temperature field is uniform and stable, and no other direct heat conduction media such as silicone oil are required. It is environmentally friendly and easy to clean.

Description

Technical Field

[0001] The invention relates to adaptive cable thermal stability test heating equipment and method, belonging to the technical field of cable thermal stability test. Background Art

[0002] In the prior art, the thermal stability test of cable insulation and sheath is heated by oil bath or metal bath. The high-temperature oil bath currently used in the thermal stability test of cables uses silicone oil as the heat transfer medium, which has a slow heating speed and high power consumption; silicone oil vapor pollutes the environment and easily causes the work surface to become dirty, making cleaning cumbersome; silicone oil needs to be added regularly; silicone oil may smoke or spontaneously combust when the temperature rises, and open flames may also cause fires, so strict fire prevention measures need to be taken, such as using a fume hood and setting a safe temperature. If a metal bath device is used for the thermal stability test of cables, a metal heat conductive block suitable for the size of the test tube needs to be specially customized. The metal heat conductive block is easily oxidized under long-term high-temperature heating; and the metal heat conductive block is too large, with poor thermal conductivity uniformity, and cannot be guaranteed to fit tightly to the wall of the test tube, thus affecting the thermal conductivity effect. Summary of the invention

[0003] The purpose of the present invention is to provide an adaptive cable thermal stability test heating device to solve the technical problems of high power consumption, easy pollution and poor thermal conductivity of metal bath in the prior art. At the same time, the present invention also provides a heating method of the adaptive cable thermal stability test heating device.

[0004] The adaptive cable thermal stability test heating device of the present invention adopts the following technical solution: an adaptive cable thermal stability test heating device, which includes a winding component, a heating component, a clamping component and a driving component, wherein:

[0005] The winding assembly includes a wire storage reel, a wire reel driving motor and a slide guide mechanism. The axis of the wire storage reel is vertically arranged. A graphene-based carbon fiber rope is wound on the wire storage reel. The wire reel driving motor is used to drive the wire storage reel to rotate. The slide guide mechanism includes a vertically arranged screw, a screw motor driving the screw to rotate, a slide and a slide guide. The slide is assembled on the screw by threads. The slide guide is used to guide and limit the up and down movement of the slide. The screw rotates under the drive of the screw motor, and the slide moves up and down along the screw. A wire guide is fixed on the slide.

[0006] The driving assembly includes a test tube rotating motor and an upper plate and a bottom plate spaced apart from each other. A first gear is rotatably mounted on the bottom plate. A turntable is fixed inside the first gear. A support base for conducting heat to the bottom surface of the test tube is fixed at the center of the turntable. The diameter of the support base is equal to the outer diameter of the test tube. A second gear meshing with the first gear is provided outside the bottom plate. The test tube rotating motor is connected to the second gear to drive the second gear to rotate. A third gear is fixedly connected to the bottom surface of the upper plate. A fourth gear meshing with the third gear is provided outside the upper plate. A transmission shaft is fixed between the fourth gear and the second gear. Holes for the test tube to pass through are provided in the centers of the upper plate and the third gear. A connector is connected to the bottom surface of the third gear or the turntable of the first gear.

[0007] The clamping assembly includes a clamping seat fixedly connected to the upper plate and two clamps mounted on the clamping seat, and the inner sides of the two clamps close to each other are provided with grooves for clamping the test tube, and the grooves are located above the hole in the center of the upper plate;

[0008] The heating assembly comprises a heating tube distributed in an annular shape above the chassis, and an insulating cylinder is provided on the outer periphery of the heating tube for enclosing the heating tube;

[0009] One end of the graphene-based carbon fiber rope is connected to the storage wire reel, and the other end passes through the wire passer of the slide, and then passes around the test tube or support base between the upper plate and the bottom plate and is connected to the connector; a vertical channel for the graphene-based carbon fiber rope to pass through is opened on the insulation cylinder.

[0010] The heating tube is a spiral carbon fiber heating tube; the top surface of the support pedestal is a plane, and the material of the support pedestal is graphene-based carbon fiber.

[0011] A temperature sensor is arranged near the center of the heat-insulating cylinder, and the temperature sensor is a high-precision infrared temperature measuring probe; a temperature sensor bracket is arranged outside the heat-insulating cylinder, and an opening is opened on the wall of the heat-insulating cylinder for the temperature sensor bracket to pass through.

[0012] An arc-shaped reflective plate is arranged between the heating tube and the heat-insulating tube, and a side of the reflective plate close to the heating tube is a mirror surface.

[0013] The groove inside the chuck is a V-shaped groove.

[0014] A base enclosing the first gear is fixed to the edge of the upper surface of the chassis, and a notch is provided on the base at the position where the first gear and the second gear are meshed. The insulation tube is fixedly connected to the base up and down, and the base and the insulation tube are both made of ceramic alumina; a boss is fixed to the inner side of the base, and the bottom of the heating tube is fixed on the boss.

[0015] The adaptive cable thermal stability test heating method of the present invention adopts the following technical scheme: a heating method of an adaptive cable thermal stability test heating device, which comprises the following steps:

[0016] S1. Open the clamping assembly, separate the two chucks, insert the test tube between the two chucks, and let the test tube pass through the upper plate and the third gear in sequence until the bottom of the test tube contacts the support base, and adjust the distance between the two chucks so that the chucks are clamped on the upper end of the test tube;

[0017] S2. Start the wire reel drive motor, the lead screw motor and the test tube rotating motor to make the test tube enter the winding state, the wire reel drive motor drives the storage wire reel to rotate so that the storage wire reel unwinds, the test tube rotating motor drives the first gear, the fourth gear and the third gear to rotate synchronously through the second gear, and when the third gear rotates, it drives the upper plate, the clamping assembly and the test tube to rotate at the same time, so that the graphene-based carbon fiber rope is wound on the test tube, the test tube rotating motor is the active motor, the wire reel drive motor is the driven motor, and the tension between the wire reel drive motor and the test tube rotating motor is kept constant, the connector is located on the bottom surface of the third gear, the slide moves downward along the slide guide, guides the graphene-based carbon fiber rope to descend synchronously, and tightly and evenly winds the graphene-based carbon fiber rope on the outer wall of the test tube until the graphene-based carbon fiber rope wraps the support seat; when the connector is located on the turntable of the first gear, the slide moves upward along the slide guide, guides the graphene-based carbon fiber rope to rise synchronously, and tightly and evenly winds the graphene-based carbon fiber rope from the support seat upward on the outer wall of the test tube;

[0018] S3. Start the heating assembly to heat the heating tube, and the heating tube transfers the heat to the graphene-based carbon fiber rope in the form of thermal radiation. The graphene-based carbon fiber rope absorbs the heat and the temperature rises synchronously until the set target temperature is reached. The graphene-based carbon fiber rope transfers the heat to the test tube and the cable sample inside the test tube to perform a cable thermal stability test;

[0019] S4. After the cable thermal stability test is completed, the heating component is turned off, and the winding coil begins to enter the winding state. The rotation directions of the winding coil drive motor, the lead screw motor and the test tube rotating motor are opposite to those in step S2. The test tube rotating motor is a driven motor, and the winding coil drive motor is an active motor. The tension between the winding coil drive motor and the test tube rotating motor is kept constant. At the same time, the slide moves up or down along the slide guide to guide the graphene-based carbon fiber rope to rise or fall synchronously, and the graphene-based carbon fiber rope is pulled back into the winding coil.

[0020] In steps S2 and S4, the FOC driving method is used to ensure that the tension between the wire coil driving motor and the test tube rotating motor is constant.

[0021] In step S2, the height of the graphene-based carbon fiber rope wound on the test tube is 60 mm, and the height of the graphene-based carbon fiber rope wound on the support platform is 10 mm. The diameter of the graphene-based carbon fiber rope is 0.5 mm, and the test tube is a flat-bottomed test tube.

[0022] In step S3, the temperature sensor detects the temperature of the graphene-based carbon fiber rope in real time, and transmits the temperature parameters to the STM32F103RCT6 single-chip microcomputer control core through the CAN bus. The STM32F103RCT6 single-chip microcomputer control core adopts a PID control algorithm to compare the temperature feedback signal with the reference value. According to the comparison result, the conduction angle of the thyristor is adjusted to control the current and output power passing through the carbon fiber heating tube, so that the graphene-based carbon fiber rope reaches the set target temperature.

[0023] The beneficial effects of the present invention are as follows: the present invention is provided with a winding assembly and a driving assembly. When the wire coil driving motor and the test tube rotating motor are in operation, the graphene-based carbon fiber rope is wound around the outer periphery of the test tube. When the heating tube of the heating assembly is heated, the heat is transferred to the graphene-based carbon fiber rope by thermal radiation, thereby heating the cable sample in the test tube, thereby conducting a cable thermal stability test. The graphene-based carbon fiber rope is a highly thermally conductive flexible material. Through the cooperation of the winding assembly and the driving assembly, the graphene-based carbon fiber rope can be adaptively wound around the outer wall of test tubes of different specifications. After the graphene-based carbon fiber rope is tightly wrapped around the outer periphery of the test tube, it receives the heat radiated by the heating tube. The high thermal conductivity of the graphene-based carbon fiber rope ensures that the temperature field is uniform and stable, and the heat insulation tube reduces heat loss and improves heating efficiency. The present invention uses infrared radiation for energy transmission, has a good thermal conductivity effect, does not require other direct heat conduction media such as silicone oil, is environmentally friendly, easy to clean, and has high heating efficiency.

[0024] Preferably, the heating tube adopts a carbon fiber heating tube, which is a black body material, so it has the characteristics of rapid heating, small thermal hysteresis, uniform heating, long heat radiation transmission distance, fast heat exchange speed, etc. During the working process, the luminous flux is much smaller than the electric heating tube of the metal heating body, the electric heat conversion efficiency is as high as about 90%, the heating speed is fast, high efficiency, extremely fast heating, and it is easy to reach the temperature above 300°C required for the cable thermal stability test. Therefore, the power consumption of the equipment of the present invention is much smaller than that of the traditional oil bath equipment and metal bath equipment.

[0025] Preferably, the temperature sensor adopts a high-precision infrared temperature measuring probe with an accuracy of ±0.1°C, which can achieve precise control of the temperature.

[0026] Preferably, a reflective plate with a mirror surface is provided to reflect the heat generated by the heating tube, thereby improving the heating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is an overall schematic diagram of an adaptive cable thermal stability test heating device according to an embodiment of the invention;

[0028] Figure 2 Yes Figure 1 Schematic diagram after the middle heat insulation tube is removed;

[0029] Figure 3 Yes Figure 1 A schematic diagram of the heating component after it is removed;

[0030] Figure 4 yes Figure 1 Plan view of

[0031] Figure 5 yes Figure 2 Schematic diagram of the heating assembly;

[0032] Figure 6 yes Figure 1 A plan view of the middle clamping assembly mounted on the upper plate.

[0033] Among them, 1-winding assembly, 1.1-storage wire reel, 1.2-wire reel driving motor, 1.3-slide guide mechanism, 1.31-screw, 1.32-screw motor, 1.33-slide, 1.34-slide guide, 1.35-wire guide, 1.4-graphene-based carbon fiber rope;

[0034] 2-heating assembly, 2.1-heating tube, 2.2-insulating tube, 2.3-reflecting plate, 2.4-base, 2.5-boss, 2.6-temperature sensor, 2.7-temperature sensor bracket;

[0035] 3-clamping assembly, 3.1-clamping seat, 3.2-chuck, 3.3-groove;

[0036] 4-driving assembly, 4.1-test tube rotating motor, 4.2-upper plate, 4.3-bottom plate, 4.4-first gear, 4.5-second gear, 4.6-third gear, 4.7-fourth gear, 4.8-transmission shaft, 4.9-turntable, 4.10-supporting pedestal, 4.11-connector;

[0037] 5- Test tube. DETAILED DESCRIPTION

[0038] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] like Figures 1 to 5 As shown, an adaptive cable thermal stability test heating device according to an embodiment of the present invention includes a winding component 1, a heating component 2, a clamping component 3 and a driving component 4.

[0040] The winding assembly 1 includes a storage wire reel 1.1, a wire reel driving motor 1.2 and a slide guide mechanism 1.3. The axis of the storage wire reel 1.1 is vertically arranged. A graphene-based carbon fiber rope 1.4 is wound on the storage wire reel 1.1. The wire reel driving motor 1.2 is used to drive the storage wire reel 1.1 to rotate. The slide guide mechanism 1.3 includes a vertically arranged screw rod 1.31, a screw motor 1.32 for driving the screw rod to rotate, a slide 1.33 and a slide guide 1.34. The slide is assembled on the screw rod 1.31 by threads. The slide guide 1.34 is used to guide and limit the up and down movement of the slide 1.33. The screw rod 1.31 rotates under the drive of the screw motor 1.32, and the slide 1.33 moves up and down along the screw rod 1.31. A wire passer 1.35 is fixed on the slide 1.33; the wire passer 1.35 is for the graphene-based carbon fiber rope 1.4 to pass through.

[0041] The driving assembly 4 comprises a test tube rotating motor 4.1, an upper plate 4.2 and a bottom plate 4.3 spaced apart from each other, a first gear 4.4 being rotatably mounted on the bottom plate 4.3, a turntable 4.9 being fixed inside the first gear 4.4, a support base 4.10 for conducting heat to the bottom surface of the test tube being fixed at the center of the turntable 4.9, the diameter of the support base 4.10 being equal to the outer diameter of the test tube 5, a second gear 4.5 meshing with the first gear 4.4 being provided outside the bottom plate 4.3, the test tube rotating motor 4.1 being connected to the second gear 4.5 for The second gear 4.5 is driven to rotate, and a third gear 4.6 is fixedly connected to the bottom surface of the upper plate 4.2. A fourth gear 4.7 meshing with the third gear 4.6 is provided outside the upper plate 4.2, and a transmission shaft 4.8 is fixed between the fourth gear 4.7 and the second gear 4.5; holes for the test tube to pass through are provided in the centers of the upper plate 4.2 and the third gear 4.6, and a connector 4.11 is connected to the bottom surface of the third gear 4.6; the top surface of the support pedestal 4.10 is a plane, and the material of the support pedestal 4.10 is graphene-based carbon fiber.

[0042] like Figure 6 As shown, the clamping assembly 3 includes a clamping seat 3.1 fixedly connected to the upper plate 4.2 and two chucks 3.2 installed on the clamping seat 3.1. The inner sides of the two chucks 3.2 close to each other are provided with grooves 3.3 for clamping the test tube 5. The grooves 3.3 are located above the hole in the center of the upper plate 4.2. The grooves 3.3 on the inner sides of the chucks 3.2 are V-shaped grooves. The clamping seat 3.1 adopts a screw handwheel structure. Rotating the screw handwheel increases or decreases the distance between the two chucks 3.2, thereby realizing the opening or clamping of the clamping assembly. The screw handwheel structure makes the clamping assembly have a self-retaining characteristic, which can ensure that the test tube is clamped between the two chucks without loosening.

[0043] The heating assembly 2 includes a heating tube 2.1 distributed in an annular shape above the chassis 4.3, and an insulating tube 2.2 is provided on the periphery of the heating tube 2.1 for enclosing the heating tube 2.1; the heating tube 2.1 adopts a spiral carbon fiber heating tube; a temperature sensor 2.6 is provided near the center of the insulating tube 2.2, and the temperature sensor 2.6 is a high-precision infrared temperature measuring probe; a temperature sensor bracket 2.7 is provided outside the insulating tube 2.2, and an opening is provided on the wall of the insulating tube 2.2 for the temperature sensor bracket to pass through. An arc-shaped reflector 2.3 is provided between the heating tube 2.1 and the insulating tube 2.2, and the side of the reflector 2.3 close to the heating tube 2.1 is a mirror surface.

[0044] One end of the graphene-based carbon fiber rope 1.4 is connected to the storage wire reel 1.1, and the other end passes through the wire passer 1.35 of the slide 1.33, and then passes around the test tube between the upper plate 4.2 and the bottom plate 4.3 to connect with the connector 4.11; a vertical channel for the graphene-based carbon fiber rope to pass through is opened on the insulation cylinder 2.2.

[0045] In this embodiment, a base 2.4 enclosing the first gear is fixed to the edge of the upper surface of the chassis 4.3, and a notch is provided on the base at the position where the first gear and the second gear are meshed. The insulation tube 2.2 is fixedly connected to the base 2.4 up and down, and the base 2.4 and the insulation tube 2.2 are both made of ceramic alumina; a boss 2.5 is fixed to the inner side of the base 2.4, and the bottom of the heating tube is fixed on the boss 2.5.

[0046] The heating method using the adaptive cable thermal stability test heating device of the above embodiment comprises the following steps:

[0047] S1. Open the clamping assembly 3, separate the two chucks 3.2, insert the test tube 5 between the two chucks 3.2, and let the test tube 5 pass through the upper plate 4.2 and the third gear 4.6 downwards in sequence until the bottom of the test tube 5 contacts the support base 4.10, adjust the distance between the two chucks 3.2, and clamp the chuck 3.2 on the upper end of the test tube; the test tube used in the test is a cylindrical flat-bottom test tube with A2 grade alkali resistance, HGB3 grade hydrolysis resistance, and acid resistance. The flat-bottom test tube can be stably supported on the support base 4.10, and the contact area with the support base 4.10 is large, and the heat transfer effect is good.

[0048] S2. Start the wire reel drive motor 1.2, the lead screw motor 1.32 and the test tube rotation motor 4.1, so that the test tube enters the winding state, the wire reel drive motor 1.2 drives the storage wire reel 1.1 to rotate so that the storage wire reel 1.1 unwinds, the test tube rotation motor 4.1 drives the first gear 4.4, the fourth gear 4.7, and the third gear 4.6 to rotate synchronously through the second gear 4.5, and when the third gear 4.6 rotates, it drives the upper plate 4.2, the clamping assembly 3 and the test tube 5 to rotate simultaneously, so that the graphene-based carbon fiber rope 1.4 is wound around the test tube 5, the test tube rotation motor 4.1 is the active motor, the wire reel drive motor 1.2 is the driven motor, and the wire reel drive is maintained through the FOC drive mode The tension between the motor 1.2 and the test tube rotating motor 4.1 is constant, the connector 4.11 is located on the bottom surface of the third gear 4.6, the slide 1.33 moves downward along the slide guide 1.34, guides the graphene-based carbon fiber rope 1.4 to descend synchronously, and tightly and evenly wraps the graphene-based carbon fiber rope 1.4 on the outer wall of the test tube until the graphene-based carbon fiber rope 1.4 wraps around the support base 4.10; the height of the graphene-based carbon fiber rope 1.4 wrapped on the test tube is 60mm, and the height of the graphene-based carbon fiber rope 1.4 wrapped on the support base 4.10 is 10mm, the diameter of the graphene-based carbon fiber rope 1.4 is 0.5mm, and the test tube adopts a flat-bottomed test tube. The graphene-based carbon fiber rope 1.4 is woven from high heat conductivity carbon fiber with large crystal size and high crystal orientation, and the diameter of the graphene-based carbon fiber rope is 0.5mm.

[0049] S3. Start the heating component 2 to make the heating tube 2.1 start heating. The heating tube 2.1 transfers the heat to the graphene-based carbon fiber rope 1.4 in the form of thermal radiation. The graphene-based carbon fiber rope 1.4 absorbs the heat and the temperature rises synchronously until the set target temperature is reached. The graphene-based carbon fiber rope 1.4 transfers the heat to the test tube and the cable sample inside the test tube to conduct a cable thermal stability test. The temperature sensor 2.6 detects the temperature of the graphene-based carbon fiber rope 1.4 in real time and transmits the temperature parameters to the STM32F103RCT6 single-chip microcomputer control core through the CAN bus. The STM32F103RCT6 single-chip microcomputer control core adopts a PID control algorithm to compare the temperature feedback signal with the reference value. According to the comparison result, the conduction angle of the thyristor is adjusted to control the current size and output power passing through the carbon fiber heating tube so that the graphene-based carbon fiber rope reaches the set target temperature.

[0050] S4. After the cable thermal stability test is completed, the heating component 2 is turned off, and the winding coil begins to enter the winding state. The rotation directions of the winding coil drive motor 1.2, the lead screw motor 1.32 and the test tube rotating motor 4.1 are opposite to those in step S2. The test tube rotating motor 4.1 is a driven motor, and the winding coil drive motor 1.2 is an active motor. The tension between the winding coil drive motor 1.2 and the test tube rotating motor 4.1 is kept constant through the FOC drive mode. At the same time, the slide 1.33 moves upward along the slide guide 1.34 to guide the graphene-based carbon fiber rope 1.4 to rise synchronously, and the graphene-based carbon fiber rope 1.4 is pulled back to the winding coil 1.1.

[0051] The core component of the clamping assembly 3 is a chuck with V-shaped groove teeth, which is made of ceramic alumina fiber with low thermal conductivity and has a heat-insulating effect, so that the heat of the test tube wall is not transferred to the clamp. The design of the V-shaped groove teeth allows the test tube to be automatically aligned along the V-shaped groove teeth in the clamp, thereby achieving the effect of centering. The clamping assembly 3 as a whole rotates with the V-shaped groove tooth centering point as the rotation center, and rotates simultaneously under the drive of the upper plate. The first gear 4.4 and the third gear 4.6 have the same specifications (module, number of teeth, pressure angle), and the second gear 4.5 and the fourth gear 4.7 have the same specifications (module, number of teeth, pressure angle), which are driven by the test tube rotating motor 4.1, so that the clamping assembly 3 and the upper plate 4.2 rotate synchronously. The test tube rotating motor 4.1 adopts a brushless DC motor (BLDC motor).

[0052] The support base 4.10 at the center of the turntable 4.9 is cylindrical and supported by a graphene-based carbon fiber material, which has excellent thermal conductivity and is in direct contact with the bottom of the flat-bottomed test tube. The bottom of the support base 4.10 is connected to the turntable 4.9 through a flat cylinder made of ceramic alumina fiber material. The ceramic alumina fiber material has a low thermal conductivity value and can reduce heat loss. The heat of the heating tube can be evenly transferred to the bottom of the test tube through the support base 4.10.

[0053] When the test tube is fixed, the clamping assembly 3 drives the test tube to rotate synchronously, and the slide guide mechanism 1.3 guides the graphene-based carbon fiber rope 1.4 to descend synchronously, so that the graphene-based carbon fiber rope can tightly and evenly wrap the surface of the test tube, that is, for every rotation of the first gear, the slide 1.33 of the slide guide mechanism 1.3 moves in the vertical direction by a distance of the diameter of the graphene-based carbon fiber rope. The speed V of the slide 1.33 in the vertical direction is shown in the following formula:

[0054]

[0055] Where d is the diameter of the graphene-based carbon fiber rope, is the angular velocity of the first gear 4.4, which is determined by the angular velocity of the test tube rotating motor 4.1 and the transmission ratio of the first gear 4.4 and the second gear 4.5, and is in a linear relationship. When the test is completed and the test tube needs to be removed, the equipment uses the STM32F103RCT6 single-chip microcomputer as the control core, and drives the motor driver of the test tube rotating motor 4.1, the motor driver of the wire coil driving motor 1.2, the driver of the screw motor 1.32, the high-precision infrared temperature probe, and the carbon fiber heating tube array temperature control regulator through the CAN bus to transmit and control data signals. Communicate with the human-machine interface touch screen through the USART serial port. The high-precision infrared temperature probe is a precision infrared temperature sensor model GD60914C.

[0056] In order to ensure that the graphene-based carbon fiber rope is always uniform and compact during winding, the graphene-based carbon fiber rope between the storage coil 1.1 and the test tube 5 must always be in a constant tension state. Because the test tubes used in the experiment have different specifications, it is necessary to introduce constant tension control between the coil drive motor 1.2 and the test tube rotation motor 4.1.

[0057] The constant tension control process is as follows: when the graphene-based carbon fiber rope 1.4 needs to be wound around the target test tube wall, this state is defined as the winding state; when the graphene-based carbon fiber rope 1.4 needs to be retracted into the reel 1.1, this state is defined as the retracted state; in the winding state, the test tube rotating motor 4.1 is set as the active motor with a constant speed, and the reel driving motor 1.2 is set as the driven motor; in the retracted state, the reel driving motor 1.2 is set as the active motor with a constant speed, and the test tube rotating motor 4.1 is set as the driven motor. The basic steps are as follows:

[0058] Step 1, set the tension target: set the constant tension target between the two motors according to application requirements;

[0059] Step 2: The tension generated by the motor is determined by the motor winding current. The motor current is detected in real time: the tension is estimated by detecting the motor current.

[0060] Step 3, closed-loop control: Use the PID control closed-loop control algorithm to adjust the q-axis current according to the error between the detected relevant parameters and the set target ( ) reference value;

[0061] Step 4, execute FOC control: execute the FOC control algorithm according to the adjusted q-axis current reference value (Iq_ref) and d-axis current reference value (Id_ref, usually set to 0);

[0062] Step 5, synchronization and coordination: ensure that the q-axis current reference value of the control parameters of the two motors can change synchronously to achieve constant tension control. The specific control method is FOC field-oriented control, which realizes constant tension control between two BLDC (brushless DC motors) under the FOC (field-oriented control) framework. The following formula is used to explain:

[0063] Control parameters. In FOC control, the key control parameters include:

[0064] d-axis current ( ), function: control the magnetic flux of the motor;

[0065] q-axis current ( ), function: control the electromagnetic torque of the motor; in constant tension control, precise control is required To achieve the required torque output;

[0066] Rotor position angle ( ), function: used for Park transformation and inverse Park transformation, converting the current from the stator coordinate system to the rotor coordinate system;

[0067] Voltage vector ( , ), controls the voltage output by the inverter, which in turn affects the current and torque of the motor.

[0068] Parameter detection:

[0069] Current detection: Use current Hall sensor to detect the phase current of the motor ( , , ), the phase current is converted into the d-axis current through Clark transformation and Park transformation ( ) and q-axis current ( );

[0070] Rotor position detection: Use a magnetic encoder to detect the rotor position angle ( ).

[0071] Control strategies and formulas:

[0072] Coordinate transformation:

[0073] Clark transformation: convert three-phase current , , Convert to two-phase current , ;

[0074]

[0075] Park transformation: converting two-phase current , Converted to current in rotating coordinate system , ;

[0076]

[0077] PID control: for d-axis current ( ) and q-axis current ( ) to perform PID control so that the actual current tracks the reference current (Id_ref, Iq_ref). The output of the PID controller is the voltage vector , ;

[0078] Inverse Park transformation: convert the voltage vector , Convert back to the voltage in the two-phase stator coordinate system , ;

[0079]

[0080] SVPWM (Space Vector Pulse Width Modulation): Use the SVPWM algorithm to convert the voltage vector , Converted to inverter switching state, thereby controlling the voltage and current of the motor. The SVPWM algorithm generates a PWM wave to control the inverter by calculating the sector where the voltage vector is located and the corresponding switching time.

[0081] In this embodiment, four groups of carbon fiber heating tubes are evenly distributed along the circumference to form a carbon fiber heating tube array, and the graphene-based carbon fiber rope 1.4 tightly wound on the wall of the target test tube is heated by heat radiation. The mirror surface of the reflector 2.3 behind the carbon fiber heating tube can improve the heating efficiency. The carbon fiber heating tube is connected to the main circuit of the thyristor power regulator. The thyristor power regulator includes a thyristor element, a trigger circuit, a protection circuit and a load (i.e., a carbon fiber heating tube). The temperature of the graphene-based carbon fiber rope 1.4 is collected in real time by a high-precision infrared temperature measuring probe, and the temperature parameter signal is transmitted to the STM32F103RCT6 single-chip microcomputer control core through the CAN bus; the STM32F103RCT6 single-chip microcomputer control core compares the temperature feedback signal with the reference value. If the feedback signal is lower than the reference signal, it means that the current temperature is lower than the target temperature and the heating power needs to be increased; otherwise, the heating power needs to be reduced. According to the comparison result, the conduction angle of the thyristor is adjusted. The thyristor is turned on or off under the action of the trigger signal. By changing the conduction angle, the current and output power passing through the carbon fiber heating tube can be controlled. During the heating process, the temperature feedback signal is continuously monitored, and the conduction angle of the thyristor is adjusted in real time as needed to keep the temperature constant or change according to a predetermined curve.

[0082] The heat insulating tube 2.2 and the base 2.4 on the periphery of the heating component 2 are made of ceramic alumina fiber heat insulating material, which reduces heat loss and plays a role in heat preservation.

[0083] In the above embodiment, the connector is located on the third gear of the upper disk. In other embodiments of the present invention, the connector can also be set on the turntable of the first gear. At this time, in the process of winding the graphene-based carbon fiber rope on the test tube, the graphene-based carbon fiber rope is initially wound around the support base, and the slide moves upward along the slide guide to guide the graphene-based carbon fiber rope to rise synchronously, and the graphene-based carbon fiber rope is tightly and evenly wound on the outer wall of the test tube from the support base upward; when the cable thermal stability test is completed, when the wire reel is reeled in, the slide moves downward along the slide guide to guide the graphene-based carbon fiber rope to descend synchronously, and the graphene-based carbon fiber rope is pulled back into the wire reel.

[0084] The above embodiments are preferred embodiments of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection required by the present invention.

Claims

1. An adaptive cable thermal stability test heating device, characterized in that: It includes a winding assembly, a heating assembly, a clamping assembly and a driving assembly, wherein: The winding assembly includes a wire storage reel, a wire reel driving motor and a slide guide mechanism. The axis of the wire storage reel is vertically arranged. A graphene-based carbon fiber rope is wound on the wire storage reel. The wire reel driving motor is used to drive the wire storage reel to rotate. The slide guide mechanism includes a vertically arranged screw, a screw motor driving the screw to rotate, a slide and a slide guide. The slide is assembled on the screw by threads. The slide guide is used to guide and limit the up and down movement of the slide. The screw rotates under the drive of the screw motor, and the slide moves up and down along the screw. A wire guide is fixed on the slide. The driving assembly includes a test tube rotating motor and an upper plate and a bottom plate spaced apart from each other. A first gear is rotatably mounted on the bottom plate. A turntable is fixed inside the first gear. A support base for conducting heat to the bottom surface of the test tube is fixed at the center of the turntable. The diameter of the support base is equal to the outer diameter of the test tube. A second gear meshing with the first gear is provided outside the bottom plate. The test tube rotating motor is connected to the second gear to drive the second gear to rotate. A third gear is fixedly connected to the bottom surface of the upper plate. A fourth gear meshing with the third gear is provided outside the upper plate. A transmission shaft is fixed between the fourth gear and the second gear. Holes for the test tube to pass through are provided in the centers of the upper plate and the third gear. A connector is connected to the bottom surface of the third gear or the turntable of the first gear. The clamping assembly includes a clamping seat fixedly connected to the upper plate and two clamps mounted on the clamping seat, and the inner sides of the two clamps close to each other are provided with grooves for clamping the test tube, and the grooves are located above the hole in the center of the upper plate; The heating assembly comprises a heating tube distributed in an annular shape above the chassis, and an insulating cylinder is provided on the outer periphery of the heating tube for enclosing the heating tube; One end of the graphene-based carbon fiber rope is connected to the storage wire reel, and the other end passes through the wire passer of the slide, and then passes around the test tube or support base between the upper plate and the bottom plate and is connected to the connector; a vertical channel for the graphene-based carbon fiber rope to pass through is opened on the insulation cylinder.

2. The adaptive cable thermal stability test heating device according to claim 1 is characterized in that: The heating tube is a spiral carbon fiber heating tube; the top surface of the support pedestal is a plane, and the material of the support pedestal is graphene-based carbon fiber.

3. The adaptive cable thermal stability test heating device according to claim 1 is characterized in that: A temperature sensor is arranged near the center of the heat-insulating cylinder, and the temperature sensor is a high-precision infrared temperature measuring probe; a temperature sensor bracket is arranged outside the heat-insulating cylinder, and an opening is opened on the wall of the heat-insulating cylinder for the temperature sensor bracket to pass through.

4. The adaptive cable thermal stability test heating device according to claim 1 is characterized in that: An arc-shaped reflective plate is arranged between the heating tube and the heat-insulating tube, and a side of the reflective plate close to the heating tube is a mirror surface.

5. The adaptive cable thermal stability test heating device according to claim 1 is characterized in that: The groove inside the chuck is a V-shaped groove.

6. The adaptive cable thermal stability test heating device according to claim 1 is characterized in that: A base enclosing the first gear is fixed to the edge of the upper surface of the chassis, and a notch is provided on the base at the position where the first gear and the second gear are meshed. The insulation tube is fixedly connected to the base up and down, and the base and the insulation tube are both made of ceramic alumina; a boss is fixed to the inner side of the base, and the bottom of the heating tube is fixed on the boss.

7. A heating method for an adaptive cable thermal stability test heating device according to any one of claims 1 to 6, characterized in that: It includes the following steps: S1. Open the clamping assembly, separate the two chucks, insert the test tube between the two chucks, and let the test tube pass through the upper plate and the third gear in sequence until the bottom of the test tube contacts the support base, and adjust the distance between the two chucks so that the chucks are clamped on the upper end of the test tube; S2. Start the wire reel drive motor, the lead screw motor and the test tube rotation motor to make the test tube enter the winding state, the wire reel drive motor drives the storage wire reel to rotate so that the storage wire reel unwinds, the test tube rotation motor drives the first gear, the fourth gear and the third gear to rotate synchronously through the second gear, and when the third gear rotates, it drives the upper plate, the clamping assembly and the test tube to rotate at the same time, so that the graphene-based carbon fiber rope is wound on the test tube, the test tube rotation motor is the active motor, and the wire reel drive motor is the driven motor, so as to keep the tension between the wire reel drive motor and the test tube rotation motor constant, the connector is located on the bottom surface of the third gear, the slide moves downward along the slide guide, guides the graphene-based carbon fiber rope to descend synchronously, and the graphene-based carbon fiber rope is tightly and evenly wound on the outer wall of the test tube until the graphene-based carbon fiber rope wraps the support base; When the connector is located on the turntable of the first gear, the slide moves upward along the slide guide, guiding the graphene-based carbon fiber rope to rise synchronously, and the graphene-based carbon fiber rope is tightly and evenly wound on the outer wall of the test tube from the support base upward; S3. Start the heating assembly to heat the heating tube, and the heating tube transfers the heat to the graphene-based carbon fiber rope in the form of thermal radiation. The graphene-based carbon fiber rope absorbs the heat and the temperature rises synchronously until the set target temperature is reached. The graphene-based carbon fiber rope transfers the heat to the test tube and the cable sample inside the test tube to perform a cable thermal stability test; S4. After the cable thermal stability test is completed, the heating component is turned off, and the winding coil begins to enter the winding state. The rotation directions of the winding coil drive motor, the lead screw motor and the test tube rotating motor are opposite to those in step S2. The test tube rotating motor is a driven motor, and the winding coil drive motor is an active motor. The tension between the winding coil drive motor and the test tube rotating motor is kept constant. At the same time, the slide moves up or down along the slide guide to guide the graphene-based carbon fiber rope to rise or fall synchronously, and the graphene-based carbon fiber rope is pulled back into the winding coil.

8. The heating method of the adaptive cable thermal stability test heating device according to claim 7 is characterized in that: In steps S2 and S4, the FOC driving method is used to ensure that the tension between the wire coil driving motor and the test tube rotating motor is constant.

9. The heating method of the adaptive cable thermal stability test heating device according to claim 7, characterized in that: In step S2, the height of the graphene-based carbon fiber rope wound on the test tube is 60 mm, and the height of the graphene-based carbon fiber rope wound on the support platform is 10 mm. The diameter of the graphene-based carbon fiber rope is 0.5 mm, and the test tube is a flat-bottomed test tube.

10. The heating method of the adaptive cable thermal stability test heating device according to claim 7, characterized in that: In step S3, the temperature sensor detects the temperature of the graphene-based carbon fiber rope in real time, and transmits the temperature parameters to the STM32F103RCT6 single-chip microcomputer control core through the CAN bus. The STM32F103RCT6 single-chip microcomputer control core adopts a PID control algorithm to compare the temperature feedback signal with the reference value. According to the comparison result, the conduction angle of the thyristor is adjusted to control the current and output power passing through the carbon fiber heating tube, so that the graphene-based carbon fiber rope reaches the set target temperature.

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