FPC flat cable folding and breaking stability detection device and method

Abstract

This invention discloses a device and method for testing the bending and breaking stability of FPC ribbon cables. The device includes a guide support frame on which are mounted a plurality of first flat shape memory alloy tubes, a plurality of flat heat insulation tubes, and a plurality of second flat shape memory alloy tubes, with their ports fixedly connected at intervals. A hot and cold air assembly is fixedly connected to the port of one of the first flat shape memory alloy tubes for switching the supply of hot and cold air. Two detachable resistance testing interfaces are mounted on the top surfaces of two flat heat insulation tubes, and a pressure bar is mounted directly above the second flat shape memory alloy tubes. This invention relates to the field of FPC ribbon cable technology. This invention solves the problems of incomplete detection coverage, low efficiency, unrealistic environmental simulation, and poor driving stability in existing FPC ribbon cable bending and breaking stability testing devices.

Description

Technical Field

[0001] This invention relates to the field of FPC cable technology, and in particular to a device and method for testing the bending and breaking stability of FPC cables. Background Technology

[0002] Flexible printed circuit board (FPC) cables, with their unique advantages such as thinness, flexibility, high wiring density, and strong space adaptability, have become core connection components in various electronic terminal products such as smartphones, laptops, wearable devices, and automotive electronics. During the long-term use of electronic devices, FPC cables frequently withstand bending, vibration, and other mechanical forces. Their bending and continuity stability directly affects the reliability of signal transmission and even determines the overall lifespan of the electronic device. Therefore, conducting bending and continuity stability testing on FPC cables before shipment is a crucial process to ensure product quality.

[0003] Currently, most mainstream FPC cable bending and continuity stability testing devices on the market use traditional mechanical structures such as robotic arm swing and eccentric wheel rotation as their core bending drive methods, and the testing methods generally adopt a local testing mode at a single bending point. Existing technologies of this kind have several insurmountable drawbacks: First, the testing coverage is limited. In practical applications, FPC cables often have multiple bending areas that are prone to fatigue and breakage. Testing a single or a few bending points cannot fully cover these critical vulnerable parts, resulting in severely biased test results that fail to accurately reflect the overall bending and continuity stability of the FPC cable, easily leading to substandard products entering the market. Second, the testing efficiency is low. To achieve bending performance testing of the entire FPC cable area, manual adjustment of bending positions and step-by-step testing are required, which is not only cumbersome and costly but also significantly extends the testing cycle, making it unsuitable for the high-efficiency testing needs of large-scale mass production scenarios for electronic terminal products. Third, the environmental simulation is not realistic enough. Some testing devices cannot accurately simulate the high-temperature working environment of FPC cables inside electronic devices, resulting in deviations between testing conditions and actual application scenarios, further affecting the reliability of test results. Fourth, the mechanical drive stability is poor. Traditional mechanical structures are prone to wear, jamming, and other faults during long-term high-frequency reciprocating motion, which not only increases equipment maintenance costs but may also lead to distorted test data due to unstable bending force and angle.

[0004] To address the shortcomings of existing FPC cable bending and breaking stability testing devices, such as incomplete detection coverage, low efficiency, unrealistic environmental simulation, and poor driving stability, this invention proposes an FPC cable bending and breaking stability testing device based on shape memory alloy phase change driving. Summary of the Invention

[0005] To address the problems of incomplete detection coverage, low efficiency, unrealistic environmental simulation, and poor driving stability in existing FPC cable bending and breaking stability testing devices, the purpose of this invention is to provide an FPC cable bending and breaking stability testing device and method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an FPC cable bending and breaking stability testing device, comprising a guide support frame, on which are installed a plurality of first flat shape memory alloy tubes, a plurality of flat heat insulation tubes and a plurality of second flat shape memory alloy tubes whose ports are fixedly connected at intervals in sequence, and a hot and cold air assembly is fixedly connected at the port of one end of the first flat shape memory alloy tube for switching the supply of hot and cold air.

[0007] When hot air is introduced into the hot and cold air assembly, several first flat shape memory alloy tubes, several flat heat insulation tubes, and several second flat shape memory alloy tubes are folded in a wave-like shape; when cold air is introduced into the hot and cold air assembly, several first flat shape memory alloy tubes, several flat heat insulation tubes, and several second flat shape memory alloy tubes return to their initial straight state.

[0008] Two of the flat heat insulation tubes have two detachable resistance test interfaces installed on their top surfaces, and a pressure bar is installed directly above the first flat shape memory alloy tube.

[0009] Preferably, when hot air is introduced into the first flat shape memory alloy tube, it bends and deforms upward due to high-temperature phase change; when cold air is introduced, it returns to its initial flat state due to low-temperature phase change.

[0010] When hot air is introduced into the second flat shape memory alloy tube, it bends and deforms downwards due to a high-temperature phase change; when cold air is introduced, it returns to its initial flat state due to a low-temperature phase change.

[0011] Both the first and second flat shape memory alloy tubes are made of Ti-Ni shape memory alloy material.

[0012] Preferably, the guide support frame includes a base, two support blocks are fixedly installed on the top surfaces of both ends of the base, two guide rods are fixedly connected to the side walls of the two support blocks, several sliders are slidably connected to the outer walls of the two guide rods, a linear motor is fixedly installed on the top surface of the base near one of the support blocks, a first electric push rod is fixedly installed on the top surface of the transmission end of the linear motor, a stop block is fixedly connected to the top of the telescopic end of the first electric push rod, and the side wall of the stop block and the side wall of the slider are in a stop engagement fit.

[0013] Preferably, the hot and cold air assembly includes an air guide chamber. A hot air blower and a cold air blower, which are connected to the top of the air guide chamber, are fixedly installed on the top of the air guide chamber. The air outlet of the air guide chamber is fixedly connected to the port of a first flat shape memory alloy tube at one end. Half of the bottom of the first flat shape memory alloy tube is fixedly installed on a support block, and the air guide chamber is also fixedly installed on the support block. The middle part of the bottom of the remaining several first flat shape memory alloy tubes is fixedly installed on the top surface of several sliders. Control valves are installed at the connection points between the hot air blower and the cold air blower and the air guide chamber.

[0014] Preferably, a second electric push rod is fixedly installed on the side wall of the slider, and the side wall of the second electric push rod near the top of its telescopic end is fixedly connected to the pressure rod.

[0015] Preferably, two mounting blocks are fixedly installed on both sides of the resistance test interface. Two bolts are vertically and downwardly inserted into the two mounting blocks. A clamping plate is threaded through the two bolts. The resistance test interface and the clamping plate are respectively clamped to the top and bottom surfaces of the flat heat insulation tube by tightening the bolts. The two resistance test interfaces are respectively connected to a resistance tester through ribbon cables. The resistance tester is connected to a controller for collecting and analyzing the stability of the resistance.

[0016] A method for using an FPC cable bending and continuity stability testing device includes the following steps:

[0017] Step 1: Lay the FPC cable under test flat on several first flat shape memory alloy tubes, several flat heat insulation tubes and several second flat shape memory alloy tubes that are kept straight, and fix both ends of the FPC cable under test into two resistance test interfaces respectively.

[0018] Step 2: Lower all the pressure bars to press the FPC cable under test.

[0019] Step 3: When hot air is introduced into the hot and cold air assembly, several first flat shape memory alloy tubes, several flat heat insulation tubes, and several second flat shape memory alloy tubes are folded in a wave-like shape; when cold air is introduced into the hot and cold air assembly, several first flat shape memory alloy tubes, several flat heat insulation tubes, and several second flat shape memory alloy tubes return to their initial straight state; through the hot and cold air switching control, the straight state and the wave-like folding state are alternated repeatedly, thereby continuously bending the FPC cable under test. At the same time, when the hot air passes through the first flat shape memory alloy tubes and the second flat shape memory alloy tubes, it also transfers high-temperature heat to the FPC cable under test to simulate bending under high-temperature working conditions.

[0020] Step four: During the continuous bending of the FPC cable under test, the resistance data is monitored and collected in real time through two resistance test interfaces to test the stability of the resistance.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0022] 1. This invention controls several first flat shape memory alloy tubes, several flat heat insulation tubes, and several second flat shape memory alloy tubes to alternate between straight and wavy folded states, which can drive the FPC cable to achieve multiple synchronous bends. It can simultaneously detect the bending resistance of different areas of the FPC cable, eliminating the need for segment-by-segment testing, greatly improving testing efficiency, and making the test results more comprehensive and representative.

[0023] 2. This invention uses a flat heat insulation tube between the first and second flat shape memory alloy tubes to ensure that the heat from the hot air is fully applied to the shape memory alloy tube to drive deformation, while efficiently transferring it to the bending point of the FPC cable, simulating a real high-temperature bending working environment, thus improving the accuracy and reliability of the test results.

[0024] 3. This invention utilizes the phase change characteristics of Ti-Ni shape memory alloy tubes in conjunction with hot and cold air switching to achieve FPC cable bending, resulting in a simple and compact structure that reduces wear and failure risks of mechanical transmission components. Attached Figure Description

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0026] Figure 1 This is a frontal structural diagram of the present invention;

[0027] Figure 2 This is a frontal view of the structure of the present invention near the end of the hot and cold air assembly;

[0028] Figure 3 This is a schematic diagram of the structure of the present invention viewed from the front near the stop block end;

[0029] Figure 4 This is a schematic diagram of a portion of the present invention, which is folded in a wave-like shape.

[0030] Figure 5 This is a schematic diagram of the present invention, which is folded in a wave-like shape.

[0031] In the diagram: 100, guide support frame; 101, base; 102, support block; 103, guide rod; 104, slider; 105, linear motor; 106, first electric push rod; 107, stop block; 1, first flat shape memory alloy tube; 2, flat heat insulation tube; 3, second flat shape memory alloy tube; 4, hot and cold air assembly; 41, air guide chamber; 42, hot air blower; 43, cold air blower; 5, resistance test interface; 51, mounting block; 52, bolt; 53, clamping plate; 6, pressure rod; 61, second electric push rod. Detailed Implementation

[0032] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0033] Please see Figures 1 to 5 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0034] This invention provides a technical solution: an FPC cable bending and breaking stability testing device, specifically including a guide support frame 100, a first flat shape memory alloy tube 1, a flat heat insulation tube 2, a second flat shape memory alloy tube 3, a hot and cold air assembly 4, a resistance test interface 5, and a pressure rod 6. The components work together to achieve the bending and breaking stability testing of the FPC cable under high temperature environment simulation.

[0035] The guide support frame 100 serves as the load-bearing foundation of the entire device, and its specific structure is as follows: The base 101 is made of metal and has a rectangular structure. The top surface is milled to ensure the flatness of the assembly surface. Two support blocks 102 are symmetrically fixed to the top surface of both ends of the base 101 along its length by bolts. The support blocks 102 are also made of metal, and two coaxial threaded holes are opened on the opposite side walls of the two support blocks 102 for installing the guide rod 103.

[0036] The guide rod 103 is made of stainless steel, and its two ends are fixedly connected to the threaded holes of the two support blocks 102 by threaded engagement, and the two guide rods 103 are parallel to each other. Several sliders 104 are slidably connected to the outer walls of the two guide rods 103. The sliders 104 are made of engineering plastic, and two through holes adapted to the guide rods 103 are opened inside. The inner walls of the through holes are inlaid with a friction-reducing structure to reduce the coefficient of sliding friction and ensure that the sliders 104 slide smoothly along the guide rods 103.

[0037] A linear motor 105 is bolted to the top surface of the base 101 near the left support block 102. A first electric push rod 106 is bolted to the top surface of the transmission end of the linear motor 105. A stop block 107 is welded to the top of the telescopic end of the first electric push rod 106. The right side wall of the stop block 107 is in a stop-fitting engagement with the left side wall of the leftmost slider 104. Driven by the linear motor 105, the stop block 107 presses against the slider 104 to the right, thereby straightening the first flat shape memory alloy tube 1, the flat heat insulation tube 2, and the second flat shape memory alloy tube 3 to facilitate the laying of the FPC cable to be tested.

[0038] The number of first flat shape memory alloy tube 1, flat heat insulation tube 2, and second flat shape memory alloy tube 3 are set to several, and their ports are fixedly connected at intervals to form a continuous load-bearing channel. Among them, the first flat shape memory alloy tube 1 and the second flat shape memory alloy tube 3 are both made of Ti-Ni shape memory alloy material, and their cross-section is flat and elongated oval. The phase change temperature is set according to the detection requirements. At high temperature, it undergoes phase change bending and returns to straight at low temperature.

[0039] The flat heat-insulating tube 2 is made of heat-insulating material with good heat insulation performance to avoid heat absorption, so that the heat can be fully utilized in the phase change heat of the first flat shape memory alloy tube 1 and the second flat shape memory alloy tube 3. The cross-sectional dimensions of the flat heat-insulating tube 2 are matched with those of the shape memory alloy tubes. The joints between the tubes are sealed to ensure the airtightness of hot or cold air within the tubes and prevent leakage.

[0040] Half of the bottom of the first flat shape memory alloy tube 1 on the left is fixedly installed on the top surface of the left support block 102, and the middle part of the bottom of the remaining first flat shape memory alloy tubes 1 is fixedly installed on the top surface of several sliders 104 respectively; the flat heat insulation tube 2 and the second flat shape memory alloy tube 3 are both suspended and positioned only by sealing the two ends with the adjacent tubes, avoiding any interference from any load-bearing structure to their deformation, and ensuring that the subsequent wave-shaped folding deformation can be smoothly achieved.

[0041] The hot and cold air assembly 4 includes an air guide chamber 41, a hot air blower 42, and a cold air blower 43. The air guide chamber 41 has a cavity structure with an internal air guide channel, and the size of the air outlet matches the port size of the first flat shape memory alloy tube 1. The hot air blower 42 and the cold air blower 43 are fixedly mounted on the top of the air guide chamber 41 by bolts. The hot air blower 42 can output hot air within a preset temperature range; the cold air blower 43 can output cold air within a preset temperature range.

[0042] The air outlet of the air guide chamber 41 is fixedly connected to the port of the first flat shape memory alloy tube 1 on the left side by a sealing method. The bottom of the air guide chamber 41 is fixedly installed on the top surface of the left support block 102 by bolts. Control valves are installed at the connection points between the hot air blower 42 and the cold air blower 43 and the air guide chamber 41, respectively. The opening and closing of the control valves are controlled by a controller to realize the switching supply of hot air and cold air.

[0043] Two resistance test interfaces 5 are provided, each detachably mounted on the top surface of one of the two flat heat-insulating tubes 2. Their specific structure is as follows: The resistance test interface 5 is made of conductive material with good conductivity. Its top surface has a slot adapted to the end of the FPC cable. The slot size matches the size of the FPC cable to be tested, and different slot specifications can be replaced according to actual needs. Two mounting blocks 51 are fixedly installed on both sides of the resistance test interface 5 using bolts. The mounting blocks 51 are made of metal and have vertically downward threaded through holes, through which bolts 52 are movably inserted.

[0044] Two bolts 52 have a common threaded connection at their lower ends to a clamping plate 53, which is made of insulating material. During assembly, the resistance test interface 5 is placed on the top surface of the flat heat-insulating tube 2, with the clamping plate 53 positioned on the bottom surface. Tightening the bolts 52 presses the resistance test interface 5 and the clamping plate 53 together against the top and bottom surfaces of the flat heat-insulating tube 2, achieving detachable fixing. The distance between the two resistance test interfaces 5 is determined based on the length of the FPC cable under test. Each of the two resistance test interfaces 5 is connected to a resistance tester via a cable. The resistance tester is connected to a controller, which can collect resistance data in real time and store the data to a compatible host computer. A resistance threshold can also be set, and an alarm signal is issued when the resistance exceeds the threshold.

[0045] The pressure rod 6 is installed directly above the first flat shape memory alloy tube 1 to press the FPC cable under test. Its specific installation structure is as follows: A second electric push rod 61 is bolted to the side wall of the support block 102 or independently installed mounting bracket corresponding to each first flat shape memory alloy tube 1. The side wall of the second electric push rod 61 near its top telescopic end is fixedly connected to the pressure rod 6 by welding. The pressure rod 6 is made of lightweight metal and its length is the same as that of the first flat shape memory alloy tube 1. The pressure rod 6 can be raised and lowered by the telescopic drive of the second electric push rod 61.

[0046] The core working principle of the FPC cable bending and continuity stability testing device of the present invention is to control the phase change deformation of the shape memory alloy tube by switching between hot and cold air, thereby causing the FPC cable to bend alternately, while simulating a high-temperature working environment. The resistance stability is monitored in real time through a resistance testing interface. The specific working process is as follows:

[0047] S1: All the first flat shape memory alloy tubes 1, flat heat insulation tubes 2 and second flat shape memory alloy tubes 3 are initially in a straight state; control each second electric push rod 61 to drive the pressure rod 6 to rise to the highest position.

[0048] S2: Adjust and straighten the tube body. Based on the length of the FPC cable to be tested, first adjust the spacing between the two resistance test interfaces 5 by disassembling and reinstalling the resistance test interfaces to make them compatible with the length of the FPC cable; then start the linear motor 105 to drive the stop block 107 to move to the right and press against the leftmost slider 104. The slider 104 drives each of the first flat shape memory alloy tubes 1 to move synchronously, so that the first flat shape memory alloy tube 1, the flat heat insulation tube 2, and the second flat shape memory alloy tube 3 connected in sequence are straightened as a whole, providing a flat bearing surface for the FPC cable laying.

[0049] S3: Lay and fix the FPC cable to be tested. Lay the FPC cable to be tested flat on the taut tube bearing surface, so that both ends of the FPC cable are inserted into the slots of the two resistance test interfaces 5 respectively; tighten the bolts 52 on both sides of the resistance test interface 5, which will drive the clamping plate 53 to move upward, cooperate with the resistance test interface 5 to press and fix the end of the FPC cable onto the flat heat insulation tube 2, ensuring good contact between the FPC cable and the resistance test interface 5; finally, activate the second electric push rod 61 to drive the pressure rod 6 to descend until the FPC cable to be tested is pressed down, preventing the FPC cable from shifting during bending.

[0050] S4: Start the monitoring system. Turn on the resistance tester and its controller, set parameters such as the resistance monitoring threshold, ensure that the controller can collect resistance data in real time and store it to the host computer, and confirm that the alarm function is normal.

[0051] S5: Hot air is supplied to drive the tube body to deform and bend. The controller closes the control valve corresponding to the cold air blower 43 and opens the control valve corresponding to the hot air blower 42, starting the hot air blower 42 to output hot air at a preset temperature to the air guide chamber 41. The hot air is introduced through the air guide chamber 41 into the first flat shape memory alloy tube 1 on the left, and then flows sequentially through the remaining first flat shape memory alloy tubes 1, flat heat insulation tubes 2, and second flat shape memory alloy tubes 3. Because the flat heat insulation tube 2 uses heat insulation material to avoid heat absorption, the heat can be fully applied to the first and second flat shape memory alloy tubes, ensuring the phase change effect.

[0052] S6: The tube body folds in a wave shape, causing the FPC to bend. When hot air flows through the first flat shape memory alloy tube 1, the tube temperature reaches the phase change temperature, undergoing a high-temperature phase change and bending upwards. When hot air flows through the second flat shape memory alloy tube 3, it also reaches the phase change temperature, undergoing a high-temperature phase change and bending downwards. The flat heat insulation tube 2 maintains a stable temperature and does not deform. Ultimately, all tubes together form a wave-shaped fold, and the FPC cable under test, laid flat on the tube body, bends synchronously with the tube deformation. At the same time, the hot air transfers the high temperature to the FPC cable through the shape memory alloy tube, simulating the high-temperature environment at the bending point during actual operation.

[0053] S7: Supplying cold air drives the tube body to return to its straight state. After maintaining the hot air supply for a preset time, the controller switches the hot and cold air supply states, shutting off the hot air blower 42 and its corresponding control valve, and turning on the cold air blower 43 and its corresponding control valve. The cold air blower 43 outputs cold air at a preset temperature, which enters the tube body through the air guide chamber 41 and flows through each shape memory alloy tube. When the cold air acts on the first and second flat shape memory alloy tubes, the tube body temperature drops below the phase change temperature, a low-temperature phase change occurs, and the tube body returns to its initial straight state. The FPC cable unfolds synchronously with the tube body as it returns to its straight state.

[0054] S8: Cyclic bending and real-time resistance monitoring. The controller sets the hot and cold air switching cycle, causing the tube to alternate between a straight state and a folded waveform state, thereby driving the FPC cable under test to repeatedly bend and unfold. During this cycle, the resistance test interface 5 continuously collects the resistance data of the FPC cable and transmits it to the controller in real time. The controller analyzes and processes the resistance data to determine whether the resistance fluctuation is within the set threshold range.

[0055] S9: Abnormal Alarm and Data Recording. If the controller detects that the resistance fluctuation of the FPC cable exceeds the set threshold, it will immediately trigger an alarm signal and record key data such as the current number of bends and resistance value. If no abnormality occurs, the loop will continue until the preset number of bend detections is reached.

[0056] S10: After the test is completed, control the hot and cold air assembly 4 to continuously supply cold air to ensure that the pipe body remains stable and straight; control the second electric push rod 61 to drive the pressure rod 6 to rise and disengage from the FPC cable; remove the tested FPC cable; shut down all equipment, export the resistance data and bending count records stored in the controller, and complete this test.

[0057] Figure 5 The wavy, folded shape shown is for illustrative purposes only. In actual work, the bending angle needs to be greater than [a certain value]. Figure 5 The bend shown is of degree.

[0058] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A device for testing the bending and breaking stability of FPC cables, comprising a guide support frame (100), characterized in that: The guide support frame (100) is equipped with a plurality of first flat shape memory alloy tubes (1), a plurality of flat heat insulation tubes (2) and a plurality of second flat shape memory alloy tubes (3) whose ports are fixedly connected at intervals. A hot and cold air assembly (4) is fixedly connected to the port of one end of the first flat shape memory alloy tube (1) for switching the supply of hot and cold air. When hot air is introduced into the hot and cold air assembly (4), several first flat shape memory alloy tubes (1), several flat heat insulation tubes (2) and several second flat shape memory alloy tubes (3) are folded in a wave shape; when cold air is introduced into the hot and cold air assembly (4), several first flat shape memory alloy tubes (1), several flat heat insulation tubes (2) and several second flat shape memory alloy tubes (3) return to their initial straight state; Two of the flat heat insulation tubes (2) are equipped with two detachable resistance test interfaces (5) on their top surfaces. The FPC cable to be tested is laid flat on the first flat shape memory alloy tube (1), the flat heat insulation tube (2), and the second flat shape memory alloy tube (3) in a straight state. The two ends of the FPC cable to be tested are respectively fixedly inserted into the two resistance test interfaces (5). A pressure bar (6) is installed directly above the first flat shape memory alloy tube (1) to press the FPC cable under test; The guide support frame (100) includes a base (101), two support blocks (102) are fixedly installed on the top surface of both ends of the base (101), two guide rods (103) are fixedly connected to the side walls of the two support blocks (102), and several sliders (104) are slidably connected to the outer walls of the two guide rods (103). A linear motor (105) is also fixedly installed on the top surface of the base (101) near one of the support blocks (102). A first electric push rod (106) is fixedly installed on the top surface of the transmission end of the linear motor (105), and a stop block (107) is fixedly connected to the top of the telescopic end of the first electric push rod (106). The side wall of the stop block (107) and the side wall of the slider (104) are in a stop-fitting relationship. The hot and cold air assembly (4) includes an air guide chamber (41). A hot air blower (42) and a cold air blower (43) communicating with the interior are fixedly installed on the top of the air guide chamber (41). The air outlet of the air guide chamber (41) is fixedly connected to the port of one of the first flat shape memory alloy tubes (1) at one end. Half of the bottom of the first flat shape memory alloy tube (1) is fixedly installed on a support block (102). The air guide chamber (41) is also fixedly installed on the support block (102). The middle part of the bottom of the remaining several first flat shape memory alloy tubes (1) is fixedly installed on the top surface of several sliders (104). The second electric push rod (61) is fixedly installed on the side wall of the slider (104), and the side wall of the second electric push rod (61) near the top of its telescopic end is fixedly connected to the pressure rod (6).

2. The FPC cable bending and breaking stability testing device according to claim 1, characterized in that: When hot air is introduced into the first flat shape memory alloy tube (1), it bends and deforms upward due to high temperature phase change; when cold air is introduced, it returns to its initial flat state due to low temperature phase change. When hot air is introduced into the second flat shape memory alloy tube (3), it bends and deforms downwards due to high temperature phase change; when cold air is introduced, it returns to its initial flat state due to low temperature phase change. Both the first flat shape memory alloy tube (1) and the second flat shape memory alloy tube (3) are made of Ti-Ni shape memory alloy.

3. The FPC cable bending and breaking stability testing device according to claim 1, characterized in that: Control valves are installed at the connection points between the hot air blower (42) and the cold air blower (43) and the air guide chamber (41).

4. The FPC cable bending and breaking stability testing device according to claim 3, characterized in that: Two mounting blocks (51) are fixedly installed on both sides of the resistance test interface (5). Two bolts (52) are vertically and downwardly inserted on the two mounting blocks (51). The two bolts (52) are threaded together to a clamping plate (53). The resistance test interface (5) and the clamping plate (53) are pressed against the top and bottom surfaces of the flat heat insulation tube (2) by the tightening of the bolts (52). The two resistance test interfaces (5) are respectively connected to a resistance tester through a ribbon cable. The resistance tester is connected to a controller for collecting and analyzing the stability of the resistance.

5. A method for using an FPC cable bending and breaking stability testing device, characterized in that, The FPC cable bending and breaking stability testing device according to any one of claims 1-4 includes the following steps: Step 1: Lay the FPC cable to be tested flat on several first flat shape memory alloy tubes (1), several flat heat insulation tubes (2) and several second flat shape memory alloy tubes (3) that are kept straight, and fix both ends of the FPC cable to be tested into two resistance test interfaces (5). Step 2: All pressure bars (6) are lowered to press the FPC cable under test; Step 3: When hot air is introduced into the hot and cold air assembly (4), several first flat shape memory alloy tubes (1), several flat heat insulation tubes (2) and several second flat shape memory alloy tubes (3) are folded in a wave shape; when cold air is introduced into the hot and cold air assembly (4), several first flat shape memory alloy tubes (1), several flat heat insulation tubes (2) and several second flat shape memory alloy tubes (3) return to the initial straight state; through the hot and cold air switching control, the straight state and the wave shape are alternately repeated, thereby continuously bending the FPC cable under test. At the same time, when the hot air passes through the first flat shape memory alloy tubes (1) and the second flat shape memory alloy tubes (3), it also transfers high temperature heat to the FPC cable under test to simulate bending under high temperature working conditions. Step 4: During the continuous bending of the FPC cable under test, the resistance data is monitored and collected in real time through two resistance test interfaces (5) to test the stability of the resistance.

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