Magnetic switch detection device and detection method

Abstract

The present application relates to the technical field of magnetic switch, and particularly relates to a magnetic switch detection device and a detection method. The magnetic switch detection device comprises a base, the base is provided with a containing cavity for fixing the magnetic switch; at least three conductive columns are arranged in the containing cavity, and are respectively arranged in correspondence with and electrically connected with a plurality of terminal posts of the magnetic switch; a driving module comprises a pressure applying mechanism, which is used for making the terminal post of the magnetic switch closely contact with the conductive column through vertical pressure to form a conduction path; an adjustable current source is connected with the conductive column, and is used for inputting a preset current waveform to the magnetic switch. Through the dynamic waveform regulation and control of the adjustable current source and the precise pressure control of the driving module, the taking and placing efficiency of the magnetic switch is significantly improved while avoiding the poor contact and current limitation in the traditional detection, and the extreme working condition simulation and multi-dimensional performance evaluation of the magnetic switch are realized.

Description

Technical Field

[0001] This invention relates to the field of magnetic switch technology, and specifically to a magnetic switch detection device and detection method. Background Technology

[0002] As a core component of the automotive starting system, the reliability of the magnetic switch directly affects the vehicle's normal starting and driving safety. During the ignition process, the magnetic switch controls an electromagnet mechanism to close contacts, transferring a high current from the battery to the starter motor, thereby starting the engine. Defects in the magnetic switch, such as poor contact, welded contacts, or a malfunctioning electromagnet mechanism, will prevent the vehicle from starting and may even cause safety hazards such as short circuits and overheating. Therefore, pre-shipment testing of magnetic switches is an indispensable part of automotive component quality control.

[0003] Currently, the industry's conventional testing methods for magnetic switches mainly focus on verifying their electrical function, that is, testing whether they can conduct electricity normally by simply applying power. However, this type of method has the following significant drawbacks:

[0004] The test conditions are limited: it only verifies the conduction performance under rated current, and cannot simulate extreme working conditions that may occur in actual applications (such as the large current surge during engine cold start, long-term overload operation, etc.).

[0005] Lack of multi-parameter collaborative detection: Existing technologies do not comprehensively evaluate the mechanical properties of magnetic switches (such as the retraction speed and rebound force of the telescopic core) and thermal stability (such as the change of contact resistance of the contacts under high and low temperature environments), making it difficult to detect potential defects in a timely manner.

[0006] Insufficient testing efficiency and accuracy: Traditional manual item-by-item testing relies on operator experience and is prone to errors due to uneven pressure control or poor contact, and cannot achieve automated data recording and analysis.

[0007] In addition, magnetic switches need to withstand the influence of complex environments (such as high temperatures in engine compartments and low temperatures in extremely cold regions) and current fluctuations in actual use. Existing testing equipment generally lacks environmental simulation capabilities, resulting in significant deviations between factory test results and actual operating conditions.

[0008] In summary, developing a magnetic switch testing device and method capable of simulating multiple operating conditions and integrating current-temperature-mechanical performance detection has become an urgent need to improve product reliability and reduce automotive safety hazards. Summary of the Invention

[0009] (i) The technical problem to be solved by the present invention is that the existing magnetic switch detection device lacks dynamic current regulation and contact pressure stabilization mechanism, making it difficult to simulate actual extreme working conditions (such as instantaneous large current impact and continuous overload), resulting in the inability to accurately assess the overload capacity and contact reliability of the product; at the same time, a single current waveform cannot cover the requirements of complex working conditions, and the detection results are seriously out of sync with the actual application scenario, which restricts the efficiency of quality control and product safety.

[0010] (II) Technical Solution

[0011] To solve the above-mentioned technical problems, the present invention provides a magnetic switch detection device, including a base, a drive module and an adjustable current source, wherein a receiving cavity for fixing the magnetic switch is provided; the receiving cavity is provided with at least three conductive posts, which are respectively arranged and electrically connected to multiple terminals of the magnetic switch.

[0012] The drive module includes a pressure application mechanism for applying vertical pressure to make the terminals of the magnetic switch in close contact with the conductive posts to form a conductive path.

[0013] The adjustable current source is connected to the conductive post and is used to input a preset current waveform to the magnetic switch.

[0014] Through the precise alignment design of the three conductive posts and the magnetic switch terminals, and the vertical pressure control of the drive module, uniform pressure distribution on the contact surface is ensured, eliminating the contact problems caused by traditional manual clamping and significantly improving conduction stability and test repeatability. The dynamic waveform control function of the adjustable current source allows for direct input of preset pulse, stepped, or overload currents to the magnetic switch, accurately simulating extreme conditions such as instantaneous high current surges and continuous overloads, verifying its electrical strength and overload resistance in real-world scenarios. Furthermore, the combination of the fixed structure of the base cavity and the rapid conduction path of the conductive posts simplifies the clamping process of the magnetic switch, enabling rapid pick-and-place and stable testing without complex positioning operations. The synergistic effect of these technical solutions overcomes the limitations of traditional testing methods, such as single current conditions, uncontrollable contact pressure, and low testing efficiency, providing a multi-dimensional and accurate evaluation method for the reliability of magnetic switches.

[0015] According to one embodiment of the present invention, the pressure application mechanism includes a lifting cylinder and an upper pressure block connected to the lifting cylinder. The pressing surface of the upper pressure block is provided with a clearance hole, the position of which corresponds to the telescopic part of the magnetic switch, and is used to accommodate the movement of the telescopic part when pressure is applied. Through the rigid drive design of the lifting cylinder and the upper pressure block, a constant and controllable vertical pressure is provided to the magnetic switch, avoiding random errors caused by manual pressure application, and ensuring that the contact pressure between the terminal and the conductive post is always within a safe threshold. Through the precise adaptation of the telescopic part of the magnetic switch by the clearance hole, a non-interference space is reserved for the movement of the telescopic core during the pressure application process, eliminating test errors caused by mechanical collisions, while ensuring the free movement of the telescopic mechanism to simulate the real working state.

[0016] The bottom of the conductive post is provided with an elastic component. The elastic direction of the elastic component is consistent with the vertical pressure direction. It is used to buffer the contact pressure between the conductive post and the magnetic switch terminal. By utilizing its vertical elastic buffering characteristics, the contact pressure is adaptively adjusted to absorb the instantaneous impact energy during the pressure application process, avoid pressure damage to the magnetic switch terminal caused by rigid contact, and compensate for the unevenness of the contact surface caused by machining tolerances or assembly deviations.

[0017] According to one embodiment of the present invention, the base includes a cylindrical structure, the inner cavity of the cylindrical structure forming the receiving cavity, and the shape of its inner wall matching the outer wall of the magnetic switch;

[0018] The cylindrical structure with its contoured inner wall design fits precisely against the outer wall of the magnetic switch, forming a physical limiting and rapid positioning mechanism. This avoids contact deviations caused by displacement during testing and enhances clamping stability.

[0019] The cylindrical structure is a temperature control structure, with an integrated temperature regulation unit inside, used to control the heating or cooling of the test environment temperature of the magnetic switch.

[0020] By actively heating or cooling, the test environment of the magnetic switch is adjusted to a preset high temperature (e.g., 85℃), low temperature (e.g., -40℃), or constant temperature state, accurately simulating real working conditions such as high temperature in the vehicle engine compartment and cold start in extremely cold regions, to verify the contact conductivity, material thermal expansion adaptability, and long-term thermal stability of the magnetic switch under extreme temperatures.

[0021] According to one embodiment of the present invention, the side wall of the cylindrical structure is provided with an observation window, which is located on the operator's side and is used to observe the alignment and contact status of the terminals and conductive posts of the magnetic switch in real time. Through the directional layout and transparent material design of the observation window on the side wall, the operator can directly visually observe the contact interface between the terminals and conductive posts of the magnetic switch, calibrate the alignment deviation in real time and verify the contact tightness, avoiding the problems of poor contact or repeated disassembly and adjustment caused by blind operation in traditional testing.

[0022] According to one embodiment of the present invention, the magnetic switch detection device further includes:

[0023] Central control device;

[0024] The sensor group includes:

[0025] A mechanical sensor is used to detect the retraction force of the telescopic core of a magnetic switch.

[0026] A speed sensor is used to detect the retraction speed of the telescopic core;

[0027] Temperature sensor used to monitor the real-time temperature of the magnetic switch;

[0028] The sensor group is communicatively connected to the central control device, which is also communicatively connected to the adjustable current source and the temperature control structure, and is used to dynamically adjust the current output and temperature parameters based on sensor feedback data.

[0029] Through a real-time data acquisition and feedback mechanism integrating multiple sensors, the mechanical sensor accurately captures changes in the retraction force of the telescopic core, the speed sensor synchronously records the dynamic response of the retraction speed, and the temperature sensor continuously monitors the temperature rise curve of the magnetic switch, forming a multi-dimensional performance data chain. Combined with the closed-loop control logic of the central control device, the sensor data is analyzed in real time, and the output waveform of the adjustable current source is dynamically adjusted (e.g., automatically reducing the current amplitude based on temperature rise) and the temperature setting of the temperature control structure is adjusted (e.g., triggering cooling based on abnormal retraction force), achieving adaptive optimization of test conditions. Furthermore, through correlation modeling of current-temperature-mechanical parameters, the performance degradation law of the magnetic switch under extreme conditions (e.g., retraction delay after contact oxidation due to high temperature) is quantified, providing data support for reliability and lifespan prediction. This technical solution upgrades traditional single electrical testing to multi-physics field collaborative testing involving electro-thermal-mechanical fields, solving the problems of isolated data, lag in adjustment, and insufficient failure mode analysis in traditional methods, significantly improving testing accuracy and the comprehensiveness of product evaluation.

[0030] According to one embodiment of the present invention, the inner sidewall of the clearance hole of the upper pressure block is provided with a mounting groove, and the sensor assembly is disposed in the mounting groove; the extending direction of the mounting groove is consistent with the travel direction of the magnetic switch telescopic member, so that the detection range of the sensor assembly covers the entire travel of the telescopic member.

[0031] By ensuring the consistency of the mounting slot and the travel direction of the telescopic component, the detection axis of the sensor assembly is made completely parallel to the movement trajectory of the telescopic core, eliminating measurement errors caused by angular deviations. This also covers the dynamic response of the telescopic component throughout its entire travel, from fully retracted to fully extended. By embedding the sensor assembly within the mounting slot on the sidewall of the clearance hole, the occupation of test space or mechanical interference by external sensors is avoided, maintaining the overall structural strength of the upper pressure block. This solves the problems of measurement deviation, weakened structural strength, and spatial interference caused by traditional external sensors, achieving a dual improvement in high-precision detection and device reliability. It provides a stable hardware foundation for synchronous acquisition of multiple parameters under complex working conditions.

[0032] According to one embodiment of the present invention, the pressing surface of the upper pressing block is provided with a limiting groove, and the contour of the limiting groove matches the upper contour of the housing of the magnetic switch;

[0033] When the upper pressure block is pressed down, the limiting groove and the inner wall of the cylindrical structure together form a circumferential limit on the magnetic switch.

[0034] By precisely matching the limiting groove with the contour of the magnetic switch housing, the magnetic switch is automatically guided to the preset alignment point during the downward pressing of the upper pressure block, eliminating positional deviations during manual clamping and ensuring the initial contact accuracy of the terminals and conductive posts. Furthermore, the synergistic limiting effect of the limiting groove and the inner wall of the cylindrical structure forms a circumferential constraint on the magnetic switch housing while applying vertical pressure, preventing horizontal displacement or rotational shift caused by electromagnetic force or mechanical vibration during testing, and ensuring uniform pressure distribution on the contact surface. Through the composite control mechanism of circumferential limiting and vertical pressure, the design suppresses fretting friction caused by thermal expansion or electromagnetic impact of the magnetic switch under extreme conditions such as high temperature and high current, avoiding oxidation or accelerated wear of the contact surface. This design breaks through the limitations of traditional testing that relies solely on single vertical pressure, achieving multi-dimensional clamping stability control, providing structural protection for high-precision and high-reliability testing, while significantly reducing the misjudgment rate and equipment wear risk caused by displacement deviations.

[0035] According to one embodiment of the present invention, the magnetic switch detection device further includes:

[0036] The cabinet is equipped with a cooling device inside for cooling the temperature control structure and the magnetic switch;

[0037] The outer surface of the cabinet of the central control device is provided with a central control panel for inputting operation commands and displaying parameters.

[0038] Through the coordinated regulation of the high-efficiency cooling device and temperature control structure integrated within the cabinet, the temperature of the magnetic switch and cylindrical structure is rapidly reduced after high-temperature testing, shortening the test cycle interval and improving testing efficiency. At the same time, residual heat is avoided from interfering with subsequent test data. Combined with the external layout and integrated interactive design of the central control panel, operators can directly monitor the current waveform, temperature curve and sensor data in real time through the panel, and dynamically adjust test parameters (such as current step size and temperature control target value), realizing closed-loop control of the entire process of "detection-regulation-analysis".

[0039] An embodiment of the present invention also provides a magnetic switch detection method, which uses the above-described magnetic switch detection device for detection and includes the following steps:

[0040] S1. Vertical pressure is applied to the magnetic switch through the pressure application mechanism of the drive module, so that its terminal block and the conductive post are in close contact to form a conductive path;

[0041] S2. Input an initial current value to the magnetic switch through the adjustable current source. The initial current value is 50%-80% of its rated current, and maintain it for a first preset time to record the initial conduction state.

[0042] S3. Increment the current value step by step with a preset step size, maintain the current value for a second preset duration at each step, and monitor the conduction status and response time of the magnetic switch.

[0043] S4. Determine whether the failure condition is met or the preset limit current threshold is reached:

[0044] If a contact meltdown or conduction interruption is detected, it is determined as a failure and the current current value is recorded as the failure current value.

[0045] If the failure does not occur and the limit threshold is not reached, return to step S3 and continue to increase the current.

[0046] S5. When the current reaches the limit threshold and the magnetic switch does not fail, repeat steps S3 to S4 until all preset current step tests are completed.

[0047] S6. Generate overload capacity evaluation parameters for the magnetic switch based on the failure current value and the limit threshold.

[0048] Furthermore, the above-mentioned magnetic switch detection method can be further extended to the following steps:

[0049] S1. The test environment of the magnetic switch is adjusted to the first target temperature by the temperature control structure and maintained for a preset time to stabilize the temperature;

[0050] S2. Apply vertical pressure to the magnetic switch through the drive module to make its terminals make close contact with the conductive posts to form a conductive path;

[0051] S3. An initial current value is input to the magnetic switch through the adjustable current source. The initial current value is 50%-80% of its rated current, and the following data is collected in real time through the sensor group:

[0052] The retraction speed and retraction force of the telescopic core;

[0053] Real-time temperature of the magnetic switch;

[0054] On status and response time;

[0055] S4. Increment the current value step by step with a preset step size, maintain the current for a second preset duration at each current level, and simultaneously adjust the temperature of the temperature control structure to multiple target temperature gradients at each current level, repeating the data acquisition in step S3.

[0056] S5. The current test phase will terminate when any of the following failure conditions are detected:

[0057] The retraction force weakens beyond a preset threshold.

[0058] The retraction speed exceeds the safe range;

[0059] Temperature exceeds rated limit or conduction is interrupted;

[0060] S6. Switch to the next target temperature gradient and repeat steps S3-S5 until all temperature and current combination tests are completed;

[0061] S7. Based on multi-temperature-current coupling data, analyze the correlation between the mechanical performance, thermal stability and overload capacity of the magnetic switch, and generate a comprehensive evaluation report.

[0062] By employing dynamic waveform control of an adjustable current source, precise pressure control of the drive module, and a multi-sensor collaborative detection mechanism, comprehensive performance evaluation of magnetic switches under extreme current, temperature, and mechanical loads was achieved. The adjustable current source accurately simulates high-current impact and continuous overload conditions to verify electrical strength; the pressure control mechanism ensures uniform pressure on the contact surface, eliminating poor contact; multiple sensors collect force, speed, and temperature data in real time, and combined with the environmental simulation capabilities of the temperature control structure, reveal the failure modes of the magnetic switch under complex operating conditions. Through structural optimization (such as cylindrical contour-following limit and clearance hole design) and intelligent feedback control, detection efficiency, accuracy, and reliability are significantly improved, providing an efficient and multi-dimensional solution for product quality control and lifespan prediction.

[0063] (III) Beneficial effects of the present invention: The present invention, through the dynamic waveform regulation of the adjustable current source and the precise pressure control of the drive module, avoids poor contact and current limitation in traditional detection, and significantly improves the pick-up and put-down efficiency of the magnetic switch, realizing the simulation of extreme working conditions and multi-dimensional performance evaluation of the magnetic switch. Attached Figure Description

[0064] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0065] Figure 1 This is a three-dimensional structural diagram of a magnetic switch detection device provided in one embodiment of the present invention;

[0066] Figure 2 A three-dimensional structural diagram of three independent detection modules on an operating platform provided in an embodiment of the present invention;

[0067] Figure 3 This is a three-dimensional structural diagram of an independent detection module provided in one embodiment of the present invention;

[0068] Figure 4 for Figure 3 A schematic diagram of the three-dimensional structure from a second-person perspective;

[0069] Figure 5 for Figure 3 A top-down view;

[0070] Figure 6 A three-dimensional structural diagram of the guide block and conductive post in an assembly state according to an embodiment of the present invention;

[0071] Figure 7 This is a schematic diagram of a three-dimensional structure of a conductive pillar provided in one embodiment of the present invention;

[0072] Figure 8 This is a schematic diagram of a three-dimensional structure of a magnetic switch provided in an embodiment of the present invention.

[0073] Icons: 1. Base; 11. Cylindrical structure; 111. Observation window; 12. Receiving cavity; 2. Conductive column; 21. Elastic component; 22. Guide block; 3. Magnetic switch; 31. Terminal block; 32. Telescopic iron core; 4. Pressure application mechanism; 41. Lifting cylinder; 42. Upper pressure block; 421. Clearance hole; 422. Mounting slot; 423. Limiting slot; 5. Sensor group; 10. Cabinet; 101. Central control panel; 102. Cooling device; 103. Operating platform. Detailed Implementation

[0074] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Specific implementation examples:

[0076] like Figures 1 to 7 As shown, this embodiment provides a magnetic switch detection device, mainly used for magnetic switches 3 (such as...). Figure 8 The product quality inspection system (shown) adopts a modular design, including a cabinet 10, independent detection modules, an adjustable current source, a central control device, and a cooling device 102. The cabinet 10, serving as the main frame of the device, uses a split design. The main body is welded from cold-rolled steel plates, with an anti-static coating to improve durability. An operating platform 103 is located on the operator's side for easy operation. An independent detection module is fixed in the center of the platform, and a central control panel 101 is embedded in the opposite cabinet. This panel is an industrial-grade touchscreen, integrating parameter settings, data visualization, and alarm functions. Physical buttons (such as an emergency stop button and power switch) are provided below to ensure ease of operation. The cabinet's interior uses a layered layout. The upper layer houses the cooling device 102, which includes a semiconductor cooling module and liquid cooling circulation pipes to quickly reduce the temperature of the detection modules and magnetic switches 3. The lower layer holds the adjustable current source, connected to the conductive posts 2 of the detection modules via shielded cables. The cables are covered with high-temperature resistant sheaths to handle high-current conditions. The cabinet below the control panel 103 integrates a power management unit and a data acquisition module. Strong and weak current cables are arranged through a partitioned cable tray to avoid signal interference.

[0077] like Figure 1 and Figure 2As shown, the operating platform 103 is equipped with three sets of independent detection modules. Each set of detection modules can be controlled and operated independently, and each includes a base 1, a drive module, and a corresponding adjustable current source. The base 1 consists of an annular base embedded in the operating platform 103 and a cylindrical structure 11 connected to it. The inner cavity of the cylindrical structure 11 forms a receiving cavity 12, and the shape of its inner wall matches the outer wall of the magnetic switch 3 to be tested (for example, when the outer diameter of the magnetic switch 3 is Φ50mm, the inner diameter of the cylindrical structure 11 is designed to be Φ50.2mm, with a reserved assembly gap of 0.2mm), ensuring that the magnetic switch 3 is automatically aligned after being placed, avoiding manual adjustment deviations. The cylindrical structure 11 is a temperature control structure, with an integrated temperature regulation unit inside its wall, including a flexible heating film embedded in the inner wall (power density 2W / cm², heating range from room temperature to 150℃), a semiconductor cooling chip attached to the outer wall (minimum cooling temperature -40℃), and uniformly distributed PT100 platinum resistance temperature sensors on the inner wall. Closed-loop temperature control is achieved through linkage between the PID controller and the central control device, with an accuracy of ±1℃.

[0078] Furthermore, the cylindrical structure 11 has an observation window 111 on its side wall, located directly opposite the operator. This window can be made of double-layered tempered glass (with argon gas filling for insulation), and the inner side is coated with an anti-fog coating to address condensation issues during high and low temperature testing. The window edge can also have millimeter-level scale markings to quantify the offset distance between the magnetic switch 3 terminal 31 and the conductive post 2, assisting the operator in quickly calibrating or locating faults.

[0079] The cavity 12 contains three conductive posts 2 arranged in a 120° ring, corresponding to the power terminal 31, start terminal 31, and ignition terminal 31 of the magnetic switch 3, respectively. The conductive posts 2 are made of gold-plated copper with high conductivity (surface plating thickness ≥5μm), with a diameter of Φ8mm and a height that can be adaptively adjusted according to the compression of the elastic component 21.

[0080] like Figure 6 and Figure 7 As shown, the bottom of the conductive post 2 is provided with an elastic component 21, including a spring and a guide block 22:

[0081] Spring: A stainless steel helical compression spring is used, with the elastic direction aligned with the vertical pressure direction. The maximum compression stroke is 10mm when compressed, and it is used to buffer the contact pressure and compensate for the assembly tolerance between the magnetic switch 3 and the conductive post 2.

[0082] Guide block 22: Made of POM engineering plastic, it is embedded in the mounting groove 422 of the conductive post 2 and has a vertical guide groove to restrict the conductive post 2 to move only in the vertical direction, so as to prevent poor contact or local overpressure caused by skew.

[0083] The adjustable current source uses a modular programmable DC power supply (such as the Keysight N8900 series) and is connected to conductive post 2 via a high-temperature shielded cable. Its specific functions include:

[0084] Current waveform generation:

[0085] Pulse current: Peak current can reach 200A, simulating the large current surge during vehicle cold start;

[0086] Stepped current: The current is increased step by step from 10A to 200% of the rated current, and each step is maintained for 30 seconds to test the continuous overload capacity.

[0087] Fluctuating current: Random fluctuations of ±15% of the rated current (frequency 0.1-10Hz) are superimposed to simulate unstable voltage scenarios in vehicle-mounted power grids.

[0088] Parameter adjustment:

[0089] Current amplitude (0-100A continuously adjustable), rise / fall time (1ms-10s adjustable), duration (customizable);

[0090] Overcurrent protection threshold (automatic current cut-off), overheat alarm (based on temperature sensor feedback).

[0091] Linkage control:

[0092] It communicates with the central control unit and automatically switches the current mode according to the test stage (such as low temperature precooling, high temperature loading);

[0093] It receives sensor data in real time (such as excessive temperature rise) and dynamically adjusts the output current to avoid damage to the device.

[0094] The drive module includes a pressure application mechanism 4, which is used to make the terminal 31 of the magnetic switch 3 in close contact with the conductive post 2 through vertical pressure to form a conductive path.

[0095] like Figures 3 to 5 As shown, the pressure application mechanism 4 includes a lifting cylinder 41 and an upper pressure block 42 rigidly connected to it. The lifting cylinder 41 is a servo electric cylinder, which is vertically fixed to the operating platform 103 via a guide rail to ensure that the pressure application direction is not deviated. The pressing surface of the upper pressure block 42 is provided with a clearance hole 421, the diameter of which is 1-2mm larger than the outer diameter of the telescopic iron core 32 of the magnetic switch 3 (for example, the hole diameter is 12mm when the iron core is Φ10mm), and the depth penetrates the upper pressure block 42, so as to fully accommodate the movement of the telescopic iron core 32 during pressure application and avoid jamming or wear caused by mechanical interference.

[0096] The limiting groove 423 is opened in the center of the pressing surface of the upper pressing block 42. Its outline matches the upper flange of the magnetic switch 3 housing (such as a square, round or irregular groove). Its width is 0.5-2mm larger than the housing flange to ensure that the magnetic switch 3 is automatically guided to the preset alignment point during pressing.

[0097] When the upper pressure block 42 is pressed down, the limiting groove 423 forms a circumferential limit with the inner wall of the cylindrical structure 11, restricting the horizontal displacement and rotational offset of the magnetic switch 3 (gap ≤ 0.1mm), ensuring that the contact surfaces of the terminal 31 and the conductive post 2 are aligned.

[0098] The mounting groove 422 is located on the inner wall of the clearance hole 421. It is a U-shaped groove structure and its extension direction is parallel to the travel direction of the telescopic component of the magnetic switch 3.

[0099] The sensor group consists of 5 pieces, which are fixed in the mounting slot 422 by clips or screws. Their detection ends face the axis of the telescopic iron core 32, and the detection range covers the entire stroke of the iron core from fully retracted (initial position) to fully extended (working position) (e.g., 0-20mm).

[0100] The bottom of the mounting slot 422 has a cable channel through which the sensor signal line is connected to the central control device to avoid external interference.

[0101] Collaborative working mechanism:

[0102] Pressing process: Lifting cylinder 41 drives upper pressure block 42 to press down, limit groove 423 guides magnetic switch 3 to be precisely positioned, and clearance hole 421 provides interference-free movement space for telescopic iron core 32;

[0103] Pressure control: The cylinder has a built-in pressure sensor (range 0-1000N, accuracy ±1%FS) that feeds back the pressure value to the central control device in real time, forming a pressure closed-loop control (e.g., setting the target pressure to 200N±5N).

[0104] Sensor group 5 specifically includes a force sensor, a speed sensor, and a temperature sensor, which are used to detect the retraction force, retraction speed, and real-time temperature of the telescopic core 32 of the magnetic switch 3, respectively. The type, detection principle, and installation location of each sensor are as follows:

[0105] The force sensor can be a piezoelectric force sensor (such as the Kistler 9203) or a strain gauge force sensor (such as the HBM U9C), which is embedded in the mounting groove 422 on the inner side wall of the clearance hole 421 of the upper pressure block 42. The detection end is aligned with the axis of the telescopic iron core 32 to monitor the dynamic force value during the retraction process in real time.

[0106] The speed sensor can be a laser displacement sensor (such as Keyence IL-100) or a magnetic encoder (such as Renishaw RESOLUTE). In this embodiment, a laser sensor is used: by emitting a laser beam and receiving the reflected light, the displacement change is calculated based on the time of flight (ToF) or phase difference, and then the speed is obtained by differentiation; it is arranged in parallel with the mechanical sensor in the mounting slot 422, the detection direction is parallel to the stroke of the telescopic iron core 32, covering the entire stroke from 0 to 20 mm, and the speed resolution is 0.1 mm / s.

[0107] The temperature sensor can be a thermocouple (K type, range -40℃~1250℃) or an infrared temperature sensor (such as OptrisCTlaser); in this embodiment, an infrared sensor is used: it receives the infrared radiation energy from the surface of the magnetic switch 3, converts the temperature using the Stefan-Boltzmann law, and attaches it to the inner wall of the mounting groove 422 near the terminal 31 area, without needing to contact the tested part, ensuring that the test process is non-destructive.

[0108] Sensor group 5 is connected to the central control unit via a shielded cable or a wireless module (such as ZigBee), with a sampling rate of 1kHz, and the data is transmitted to the central control panel 101 for display in real time.

[0109] Based on the aforementioned magnetic switch detection device, this embodiment further provides a magnetic switch 3 detection method. Through temperature regulation, pressure control, multi-stage current loading, and multi-sensor collaborative detection, a multi-faceted performance evaluation of the magnetic switch 3 is achieved. Specifically, the method includes the following steps:

[0110] Step S1: Ambient temperature regulation and stabilization

[0111] Target temperature setting: The test environment is adjusted to the first target temperature (such as -40℃, 25℃ or 85℃) by the temperature control unit (heating film and semiconductor cooling chip) of the cylindrical structure 11.

[0112] Temperature stability control:

[0113] In heating mode, the heating film adjusts the power using a PID control algorithm to ensure that the temperature fluctuation is ≤±1℃;

[0114] In cooling mode, the semiconductor cooling chip and liquid cooling cycle work together, and the ethylene glycol solution flows at a rate of 5L / min to accelerate heat dissipation.

[0115] The temperature sensor (PT100) monitors the ambient temperature in real time and maintains it for at least 5 minutes after reaching the target value to ensure uniform temperature of the magnetic switch 3.

[0116] Step S2: Applying vertical pressure and establishing the conduction path

[0117] Pressure application:

[0118] The servo electric cylinder of the drive module drives the upper pressure block 42 to press down at a constant speed (10mm / s), with a target pressure of 200N±5N;

[0119] The limiting groove 423 cooperates with the inner wall of the cylindrical structure 11 to limit the horizontal displacement of the magnetic switch 3 (gap ≤ 0.1mm).

[0120] Optimization of conduction path:

[0121] The elastic component 21 (spring stiffness 50N / mm) at the bottom of the conductive post 2 is compressed to a contact resistance ≤1mΩ;

[0122] The clearance hole 421 provides interference-free movement space for the telescopic iron core 32, avoiding mechanical jamming.

[0123] Step S3: Initial current loading and data acquisition

[0124] Initial current input:

[0125] The adjustable current source outputs an initial current (e.g., 50% of the rated current), with a steady-state DC waveform that lasts for 30 seconds.

[0126] Sensor data synchronous acquisition:

[0127] Mechanical sensor: Records the initial value of the retraction force of the telescopic iron core 32 (e.g., 200N).

[0128] Speed ​​sensor: Calculates retraction speed (e.g., 10 mm / s) based on laser displacement signal;

[0129] Temperature sensor: monitors temperature changes of magnetic switch 3 (e.g., from 25°C to 30°C);

[0130] On-state: The circuit resistance is detected by a high-precision ammeter and voltmeter (response time ≤ 10ms).

[0131] Step S4: Stepped current increase and temperature gradient switching

[0132] Current increment logic:

[0133] Increase the current in increments of 10A (e.g., 50A → 60A → 70A), maintaining each increment for 30 seconds.

[0134] The adjustable current source supports transient switching (rise time ≤ 1ms) to avoid current fluctuations interfering with testing.

[0135] Temperature gradient adjustment:

[0136] The temperature gradient is switched synchronously during each current loading stage (e.g., from 25℃ to -40℃ or 85℃).

[0137] The temperature control unit completes the temperature transition within 2 minutes. During the high-temperature stage, the heating film operates at full power, while during the low-temperature stage, the cooling element and liquid cooling work together to cool the temperature.

[0138] Step S5: Dynamic Failure Determination and Test Termination

[0139] Failure determination criteria:

[0140] If the retraction force decreases by more than 20% (e.g., from 200N to 160N), it is determined to be spring fatigue or mechanical wear.

[0141] If the retraction speed exceeds ±15% of the rated value (e.g., when the rated speed is 10 mm / s, the speed is >11.5 mm / s or <8.5 mm / s): it is judged as an abnormal electromagnetic response;

[0142] Temperature > 150℃ or conduction interruption (resistance > 10Ω): determined to be contact welding failure or overheating failure.

[0143] Protection mechanism triggered:

[0144] Immediately cut off the current and start the cooling device 102 at full power to cool down (rate 10℃ / min).

[0145] The central control panel 101 triggers an audible and visual alarm and records the current, temperature, and sensor data at the moment of failure.

[0146] Step S6: Full Temperature-Current Combination Errata Test

[0147] Test matrix design:

[0148] Temperature gradient: -40℃, 25℃, 85℃;

[0149] Current steps: 50%, 100%, 150%, 200% of rated current.

[0150] Automated loop logic:

[0151] Switch temperatures in a preset order (e.g., low temperature → room temperature → high temperature), and complete all current step tests at each temperature.

[0152] A single cycle takes approximately 45 minutes and supports multiple batches of continuous testing.

[0153] Step S7: Comprehensive Assessment and Report Generation

[0154] Data preprocessing:

[0155] Outlier removal: A moving average filter (window size 10 sampling points) is used to smooth the data curve;

[0156] Normalization: Force (N), speed (mm / s), and temperature (°C) are normalized to the range of [0,1] to facilitate correlation analysis.

[0157] Mechanical property analysis:

[0158] Force-current relationship modeling: Plot the curves of retraction force versus current at different temperatures, and calculate the slope ΔF / ΔI. If the slope > 0.5N / A, it is determined that the spring stiffness has abnormally decreased;

[0159] Speed ​​consistency statistics: Calculate the standard deviation of speed under the same current level. If the standard deviation is >10% (e.g., fluctuation >1mm / s when rated at 10mm / s), it is determined that the electromagnetic mechanism response is unstable.

[0160] Thermal stability assessment:

[0161] Temperature rise rate calculation: Record the time Δt for the contact temperature to rise from the initial value to the failure threshold, and calculate ΔT / Δt. If the rate is >5℃ / s at high temperature, it indicates insufficient heat dissipation design;

[0162] Thermal hysteresis effect analysis: Compare the difference in recoil force under the same current during heating and cooling processes. If the difference is >15%, it is determined that the thermal expansion coefficients of the materials are mismatched.

[0163] Overload capacity quantification:

[0164] Failure current threshold extraction: Record the failure current value at each temperature (e.g., 180A at -40℃, 150A at 85℃), fit a quadratic polynomial model of "temperature-failure current" to predict the failure risk at untested temperature points.

[0165] Cyclic life test: Repeated overload tests (such as 150% rated current cycling) are performed on unfailed samples, and the number of cycles in which the force decays to 80% of the initial value is recorded to estimate the average life.

[0166] Failure Mode and Effects Correlation Analysis:

[0167] Multi-parameter cross-validation:

[0168] At high temperatures, "force reduction + excessively rapid temperature rise" occur simultaneously → contact oxidation leads to increased contact resistance;

[0169] At low temperatures, "speed delay + sudden drop in force" → lubrication failure or brittle fracture of materials.

[0170] Root cause verification: Combine microscopic observation (such as SEM analysis) to confirm the failure mode (such as contact welding, crack propagation).

[0171] Report generation and output:

[0172] Key parameter table: failure current threshold, temperature rise rate, and force decay rate;

[0173] Trend curves: Temperature-current-force 3D surface, velocity-time waveform;

[0174] Failure analysis: root cause, impact level (fatal / critical / moderate);

[0175] Improvement suggestions: material optimization (e.g., high-temperature alloy springs), structural improvement (e.g., enhanced heat dissipation design).

[0176] Interactive analysis: The central control panel 101 supports data annotation, curve overlay comparison, and export of PDF / Excel format reports.

[0177] Implementation Examples

[0178] Scenario 1: Low-temperature cold start test (-40℃)

[0179] Test process:

[0180] Temperature setting -40℃, initial current 50A (50% of rated 100A), step-by-step increase to 200A;

[0181] The force sensor detected a sudden drop in the retraction force from 250N to 180N (a decrease of 28%), triggering a failure determination.

[0182] Analysis results:

[0183] Mechanical properties: ΔF / ΔI=0.7N / A (>threshold 0.5N / A), the spring's low-temperature brittleness leads to a decrease in stiffness;

[0184] Recommendation for improvement: Replace the low-temperature toughness spring material (such as silicon-manganese alloy).

[0185] Scenario 2: High-temperature overload durability test (85℃)

[0186] Test process:

[0187] Temperature set at 85℃, continuously apply 150A current (150% of the rated 100A).

[0188] The temperature sensor detected a contact temperature rise to 162℃, and the speed sensor detected a 40% decrease in the retraction speed.

[0189] Analysis results:

[0190] Thermal stability: Temperature rise rate ΔT / Δt = 4℃ / s, contact oxidation leads to increased resistance;

[0191] Failure mode: At high temperatures, the oxide layer on the silver contacts thickens, increasing the retraction resistance;

[0192] Improvement suggestion: Replace the contact plating with an antioxidant material (such as silver tin oxide).

[0193] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for detecting a magnetic switch, characterized in that, The test was performed using a magnetic switch detection device. The magnetic switch detection device includes a base, at least three conductive pillars, a drive module, an adjustable current source, a central control device, and a sensor group. The base includes a cylindrical structure, the inner cavity of which forms a receiving cavity for fixing the magnetic switch. The inner wall shape of the cylindrical structure matches the outer wall shape of the magnetic switch, and the cylindrical structure is a temperature control structure with an integrated temperature adjustment unit inside. The at least three conductive posts are disposed in the receiving cavity, and are respectively disposed and electrically connected to the multiple terminals of the magnetic switch. The bottom of the conductive post is provided with an elastic component, and the elastic direction of the elastic component is consistent with the vertical pressure direction. The drive module includes a pressure application mechanism, which is used to make the terminal of the magnetic switch and the conductive post in close contact through vertical pressure to form a conduction path. The pressure application mechanism includes a lifting cylinder and an upper pressure block connected to the lifting cylinder. The pressing surface of the upper pressure block is provided with a clearance hole corresponding to the telescopic part of the magnetic switch. The adjustable current source is connected to the conductive post and is used to input a preset current waveform to the magnetic switch. The sensor group includes a mechanical sensor for detecting the retraction force of the telescopic core of the magnetic switch, a speed sensor for detecting the retraction speed of the telescopic core, and a temperature sensor for monitoring the real-time temperature of the magnetic switch. The sensor group is communicatively connected to the central control device, which is also communicatively connected to the adjustable current source and the temperature control structure. The magnetic switch detection method includes the following steps: S1. The test environment of the magnetic switch is adjusted to the first target temperature by the temperature control structure and maintained for a preset time to stabilize the temperature; S2. Apply vertical pressure to the magnetic switch through the drive module to make its terminals make close contact with the conductive posts to form a conductive path; S3. An initial current value is input to the magnetic switch through the adjustable current source. The initial current value is 50%-80% of its rated current, and the following data is collected in real time through the sensor group: The retraction speed and retraction force of the telescopic core; Real-time temperature of the magnetic switch; On status and response time; S4. Increment the current value step by step with a preset step size, maintain the current for a second preset duration at each current level, and simultaneously adjust the temperature of the temperature control structure to multiple target temperature gradients at each current level, repeating the data acquisition in step S3. S5. The current test phase will terminate when any of the following failure conditions are detected: The retraction force weakens beyond a preset threshold. The retraction speed exceeds the safe range; Temperature exceeds rated limit or conduction is interrupted; S6. Switch to the next target temperature gradient and repeat steps S3-S5 until all temperature and current combination tests are completed; S7. Based on multi-temperature-current coupling data, analyze the correlation between the mechanical performance, thermal stability and overload capacity of the magnetic switch, and generate a comprehensive evaluation report.

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