Universal proximity switch three-temperature test system

Abstract

The invention discloses a universal three-temperature test system for a proximity switch. The system comprises a high and low temperature test box, a proximity switch detection device, a servo motion mechanism, an acquisition control system and a man-machine interaction system, the proximity switch detection device is installed in the high-low temperature test box, and the servo motion mechanism penetrates through the back of the test box to be connected with the proximity switch detection device in the test box and is used for controlling the distance between the proximity switch detection device and the induction face of the proximity switch to be detected, and measurement of the induction distance, repeated precision and return difference parameters of the proximity switch is achieved. The acquisition control system communicates with the servo movement mechanism, controls the servo movement mechanism to move according to the measurement stroke of the proximity switch, and simultaneously acquires, controls and monitors the state of the proximity switch in the high-low temperature test box; the man-machine interaction system carries test system software and is used for controlling the temperature change process in the high and low temperature test box according to setting, carrying out data processing on proximity switch information collected in the test process, drawing an electrical characteristic curve of the proximity switch under the three-temperature test condition, making a report and storing the report. According to the invention, automatic testing of electrical performance parameters of the proximity switch at different temperatures can be realized, the problem of difficulty in manual testing of the proximity switch at high temperature and low temperature is solved, and the production and delivery efficiency of the proximity switch is improved.

Description

Technical Field

[0001] This invention relates to the field of automated testing technology, and more specifically to a universal proximity switch three-temperature testing system. Background Technology

[0002] As a core detection component in the field of industrial automation, proximity switches are widely used in machinery manufacturing, automotive industry, logistics and other scenarios. Their operational stability directly affects the accuracy and reliability of equipment operation.

[0003] During the batch production and delivery phase, in accordance with industry standards and customer requirements, the proximity switches need to undergo performance testing under high temperature, normal temperature, and low temperature (three-temperature) environments, including key indicators such as sensing distance, repeatability, hysteresis, no-load current, voltage drop, and load current.

[0004] Currently, the mainstream testing solutions in the industry are mainly manual, which requires manually moving products to different temperature chambers, manually recording test data, and manually judging pass / fail. This process is not only cumbersome and labor-intensive, but also has problems such as low testing efficiency and significant human error.

[0005] Meanwhile, traditional testing methods lack a unified automated testing platform, and different models and specifications of proximity switches require separate testing environments, resulting in poor compatibility.

[0006] In addition, traditional testing methods often store test data in paper or scattered electronic document form, which makes traceability difficult and visualization low, failing to meet the high-efficiency quality control requirements of modern batch production and restricting the improvement of production delivery efficiency and product quality control level. Summary of the Invention

[0007] This invention was made to solve the above-mentioned problems, and its purpose is to provide a universal three-temperature testing system and testing method for proximity switches.

[0008] To achieve the above objectives, the embodiments of the present invention adopt the following technical solution: a universal proximity switch three-temperature testing system, comprising: a high and low temperature test chamber, a proximity switch detection device, a servo motion mechanism, a data acquisition and control system, and a human-machine interaction system;

[0009] The proximity switch detection device is not limited to detecting a single or multiple proximity switches. It is installed inside the high and low temperature test chamber, while the servo motion mechanism is installed outside the chamber. The mechanism passes through the back of the chamber and connects to the proximity switch detection device inside, controlling the distance between the detection device and the sensing surface of the proximity switch under test. This allows for the measurement of the proximity switch sensing distance, repeatability, and hysteresis parameters. The data acquisition and control system communicates with the servo motion mechanism, controlling it to move according to the proximity switch measurement stroke. Simultaneously, it acquires, controls, and monitors the proximity switch status within the high and low temperature test chamber. The human-machine interface system carries test system software and communicates with the data acquisition and control system and the high and low temperature test chamber. It controls the temperature change process within the chamber according to settings, processes the proximity switch information acquired during the test, plots the electrical characteristic curves of the proximity switch under three-temperature test conditions, generates reports, and stores the data.

[0010] Compared with existing technologies, this invention has the following significant advantages: It significantly improves testing efficiency by automating the entire process, including temperature switching, product positioning, parameter detection, and data recording, without manual intervention. This greatly reduces testing time and manpower per batch, meeting the high-efficiency requirements of batch production delivery. It significantly improves testing accuracy by employing standardized testing procedures and high-precision servo motion mechanisms, avoiding human error and significantly reducing the error rate of test data, ensuring the reliability of product quality assessment. It has broad compatibility by adopting a standardized fixture design that can adapt to different types and specifications of proximity switches, such as inductive, Hall effect, and photoelectric, without requiring separate testing environments and reducing adaptation costs. It enables data traceability and visualization by storing test data in real-time to a database, supporting rapid historical data query and statistical analysis. Combined with a visual interface, it allows for real-time monitoring of testing progress and data changes, facilitating quality traceability and problem troubleshooting. It simplifies the delivery process by reducing manual intervention and labor intensity, while standardizing testing standards to improve the consistency and standardization of product delivery, enhancing the company's market competitiveness.

[0011] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the overall shape provided for an embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of the components provided in an embodiment of the present invention.

[0015] Figure 3 This is a schematic diagram of the proximity switch detection device provided in an embodiment of the present invention.

[0016] Figure 4 This is a diagram showing the outline of the tooling fixture provided in an embodiment of the present invention.

[0017] Figure 5 This is a diagram of the signal adapter board provided in an embodiment of the present invention.

[0018] Figure 6 This is a schematic diagram of the servo motion mechanism provided in an embodiment of the present invention.

[0019] Figure 7 This is a schematic diagram of the detection scheme provided in an embodiment of the present invention.

[0020] Figure 8 This is a block diagram illustrating the principle of the data acquisition and control system provided in an embodiment of the present invention.

[0021] Figure 9 The schematic diagram of the acquisition switching circuit provided in the embodiment of the present invention.

[0022] Figure 10 This is a schematic diagram of the human-computer interaction system provided in an embodiment of the present invention.

[0023] Figure 11 A flowchart provided for embodiments of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0025] Reference Figure 1 and Figure 2 As shown in the example of this invention, a general-purpose proximity switch three-temperature testing system includes: a high and low temperature test chamber (100), a proximity switch detection device (200), a servo motion mechanism (300), a data acquisition and control system (400), and a human-machine interaction system (500). The proximity switch detection device is installed inside the high and low temperature test chamber using structural fasteners, while the servo motion mechanism, data acquisition and control system, and human-machine interaction system are installed outside the high and low temperature test chamber. Depending on the number of proximity switches delivered in a single batch and the internal dimensions of the high and low temperature test chamber, the proximity switch detection device can be designed with multiple layers.

[0026] The human-computer interaction system communicates with the control components of the high and low temperature test chamber through a communication link to achieve real-time temperature control.

[0027] The data acquisition and control system is connected to the servo motion mechanism, proximity switch detection device, and human-machine interface system via wired electrical signals. The servo motion mechanism is connected to the proximity switch detection device inside the high and low temperature test chamber via a nut. The data acquisition and control system receives motion control commands from the human-machine interface system, converts them into servo motor drive signals to drive the servo motion mechanism, which in turn drives the proximity switch detection device to reciprocate within the high and low temperature test chamber, thereby triggering or resetting the proximity switch under test inside the chamber. The data acquisition and control system simultaneously acquires the position information of the servo motion mechanism and the proximity switch status information returned by the proximity switch detection device, and uploads them to the human-machine interface system for data processing, display, monitoring, and storage.

[0028] Reference Figures 3 to 5 As shown in the illustration, this invention provides a general-purpose proximity switch three-temperature testing system. The proximity switch detection device consists of a target sensing device, a fixture, and a signal adapter board. The target sensing device is mounted on a guide rail inside the high and low temperature test chamber. The fixture and signal adapter board are mounted on an outer mounting tray at the same height as the target sensing device. The target sensing device is used to mount the proximity switch sensing target, the fixture is used to mount the corresponding proximity switch product, and the signal adapter board is used to connect the signal line of the proximity switch product on the fixture and to transfer the signal to the external acquisition and control system of the high and low temperature test chamber through the adapter board circuit. This ensures that the acquisition and control of the proximity switch is not affected by the high and low temperature changes inside the test chamber, thereby improving the detection accuracy of the proximity switch testing system.

[0029] Reference Figure 3 As shown, the target sensing device also includes: a touch target surface (201), a quick-change sensing target (202), and a first guide rail slider (203). The touch target surface is used to mount the quick-change sensing target of the proximity switch, and the first guide rail slider is used for the smooth movement of the touch target surface inside the high and low temperature test chamber to realize the change of the sensing distance of the proximity switch. The touch target surface is set on the first guide rail slider, which is slidably connected to the guide rail on the inner side of the high and low temperature test chamber. According to the number of proximity switches delivered in a single batch and the internal dimensions of the high and low temperature test chamber, multiple sensing targets can be designed to be installed in one row of the target sensing device, corresponding to multiple measurement stations.

[0030] For different types of proximity switches, the target sensing device is designed with a quick-change structure, which can be used to replace targets of different materials; for example, the sensing target of an inductive proximity switch can be a 45# carbon steel target; for a Hall effect proximity switch, the sensing target can be a samarium cobalt magnet target; and for a photoelectric proximity switch, the sensing target can be an opaque material target.

[0031] For different types of proximity switches, a quick-change inductive target design incorporates a quick-change structure, enabling rapid replacement of targets made of different materials. (Refer to...) Figure 3 The cross-sectional view of the quick-change device shows that the quick-change inductive target uses a rotating indexing pin to fix or detach the target quick-change head from the base, and the quick-change head is limited forward and backward by springs and the indexing pin. For example, the inductive target of an inductive proximity switch can be a 45# carbon steel target; for a Hall effect proximity switch, the inductive target can be a samarium cobalt magnet target; and for a photoelectric proximity switch, the inductive target can be an opaque material target.

[0032] Reference Figure 4 As shown, the fixture includes a fixture body (204) and a second guide rail slider (205). The fixture body is used for the fixed installation of the proximity switch products, and the second guide rail slider is used for the smooth movement of the fixture in the high and low temperature test chamber, compensating for the installation error of the initial position of multiple proximity switch products in the same row, and realizing the determination of the initial position of the proximity switch sensing distance.

[0033] The fixture body (204) is also designed as a quick-release type, with a split upper and lower structure and a spring connection structure in the middle to realize the quick installation and replacement of proximity switch products. For proximity switches of different shapes and sizes, the tooling fixture is designed in a standardized manner. For example, for cylindrical proximity switches, the tooling fixture is designed with upper and lower V-shaped grooves to adapt to cylindrical proximity switches of different diameters. For square or irregularly shaped proximity switches, the tooling fixture is designed with U-shaped grooves to match square or irregularly shaped proximity switches of different shapes and sizes.

[0034] Reference Figure 5 As shown, the signal adapter board (206) is used to transfer the signal and power cables of the proximity switches to the acquisition and control system outside the high and low temperature test chamber. The cable transfer at the input end of the signal adapter board adopts a quick-connect spring terminal (207) to realize the quick transfer of multiple transfer cables. The cable transfer at the output end of the signal adapter board adopts a multi-core connector (208). The number of cores of the connector depends on the number of proximity switches detected in a single (layer) test. Multiple spring segments are reserved for each proximity switch to be compatible with the measurement of two-wire, three-wire (PNP / NPN, normally open / normally closed), four-wire and dual-redundant proximity switches.

[0035] Reference Figure 6As shown in the example of this invention, a general-purpose proximity switch three-temperature testing system includes a servo motion mechanism comprising a servo motor (301), a driver (302), a coupling (303), a lead screw and actuator integrated base (304), and a ball screw pair (305). The servo motion mechanism is installed outside the high and low temperature test chamber, and its motion accuracy is unaffected by temperature changes in the product testing environment inside the chamber. The servo motor is connected and fixed to the high-precision ball screw pair via the motor lead screw and actuator integrated base and coupling. The ball screw pair drive shaft nut is connected to the target sensing device. After the servo motor rotates, it drives the target sensing device to reciprocate on the guide rail.

[0036] Reference Figure 7 As shown in the example of this invention, a general proximity switch three-temperature testing system is provided, and the measurement methods for its proximity switch sensing distance, repeatability, and hysteresis characteristics are as follows:

[0037] First, determine the initial position: To ensure that the initial positions of proximity switches in the same row are consistent, the initial positions of the proximity switches must be calibrated before proceeding with the automatic detection process. A servo motor drives a high-precision ball screw pair, moving the target sensing device axially to the left until the target in the same row contacts the sensing surface of the proximity switch. After the target is in contact with the sensing surface of the proximity switch, the servo motor continues to run, pushing the proximity switch forward axially by 1-2 mm to compensate for errors caused by inconsistent installation of proximity switches in the same row. The encoder reading at this point is recorded as the initial position of the proximity switch at that station.

[0038] Sensing distance and repeatability: The servo motor drives the target away from the proximity switch from the initial position until all proximity switches in the same row are not triggered. The software records the motor encoder values ​​when the proximity switches at different positions are not triggered during the process. The difference between this reading and the initial position is taken as the sensing distance S1 of the proximity switch. Repeat the above sensing distance measurement steps and record the sensing distances S1 and S2 when the proximity switches are not triggered during the two runs. The absolute difference between the two sensing distances |S1-S2| is the repeatability of the proximity switch.

[0039] Hysteresis: When the target moves from a position away from the proximity switch toward the proximity switch, the motor encoder value is recorded when the proximity switch is triggered again. The difference between this value and the initial position is used as the reset position S3 of the proximity switch. The absolute difference between the reset position and the sensing distance |S1-S3| is the hysteresis of the proximity switch.

[0040] Reference Figure 8As shown in the example of this invention, a general-purpose proximity switch three-temperature testing system is provided. Its acquisition and control system mainly consists of a motion control module (401), a current and voltage acquisition module (402), a limit protection module (403), an acquisition switching circuit (404), and a communication circuit (405). The acquisition and control system is installed outside the high and low temperature test chamber and is interconnected with the output terminal of the proximity switch signal adapter board inside the chamber via a remote interconnection cable. The entire acquisition and control system operates under normal temperature conditions, and the environmental changes of high and low temperatures during the test have no impact on the normal operation of the circuit.

[0041] The CPU of the data acquisition and control system communicates with the human-machine interface system via RS-485 communication. It receives information from the host computer regarding the proximity switch model and limit values ​​for various indicators, switches the corresponding acquisition circuit for the proximity switch model, and uploads the acquired proximity switch no-load current, load current, and on-state voltage drop information to the human-machine interface system. A limit protection module is installed on the power line of each proximity switch. When the acquired values ​​exceed the limits set by the host computer, the CPU triggers a protection action, disconnecting the proximity switch power supply and uploading the fault location and fault information to the host computer.

[0042] The acquisition and switching circuit is connected to the signal conversion board inside the test chamber via a cable, and communicates with the human-machine interaction system via a communication module to obtain the type of the proximity switch under test. Then, the relay in the circuit automatically switches to the voltage drop detection circuit, no-load current detection circuit and load current detection circuit of the corresponding type of proximity switch, so as to realize the one-to-one correspondence between the measurement and the product.

[0043] The limit protection module is connected in series in the power supply circuit of the acquisition and switching circuit. It communicates with the human-machine interaction system through the communication module and receives the protection limit values ​​of various parameters set by the host computer. When the acquired value is greater than the limit value, the protection switch is activated, the power relay is disconnected, the power supply to the proximity switch under test is cut off, and the fault information is uploaded to the human-machine interaction system for display through the communication module.

[0044] The acquisition module is an isolated voltage and current acquisition board. After the acquisition switching circuit is switched, it is used to measure the voltage drop, no-load current and load current of the proximity switch. The isolation design ensures that the product under test is not damaged due to test circuit failure.

[0045] The motion control module includes: a motion control unit, a status acquisition unit, a communication unit, and a drive unit. The motion control unit communicates with the human-computer interaction system through the communication unit to receive test commands issued by the human-computer interaction system and convert them into motion commands to be issued to the drive unit.

[0046] The drive unit is connected to the servo motor, which drives the motor to perform forward and reverse rotation, thereby realizing the reciprocating motion of the target surface sensing device.

[0047] The status acquisition unit is an analog AD acquisition module, used for acquiring the output voltage of the proximity switch;

[0048] Meanwhile, the motion control unit, status acquisition unit, and drive unit are configured to read the motor's operating position and the magnitude of the proximity switch's output voltage in real time, and upload them to the human-machine interaction system through the communication unit.

[0049] Reference Figure 9 As shown in the example of this invention, a general-purpose proximity switch three-temperature testing system is provided. For two-wire, three-wire (NPN / PNP, normally open / normally closed), and four-wire proximity switches, its acquisition switching circuit achieves automatic switching, and the principle is as follows:

[0050] Two-wire system: After K5 and K4 relays are closed, the load is connected between point C of the proximity switch and the programmable power supply -. The load current acquisition circuit can then measure the load current after the proximity switch is loaded. After K5 and K4 relays are closed, the load is connected between point C of the proximity switch and the programmable power supply -. The voltage drop acquisition circuit can then measure the voltage drop between points A and C after the proximity switch is loaded.

[0051] Three-wire PNP: After the K5 relay (limit protection switch) is closed, the static current acquisition circuit can measure the static current after the proximity switch is energized; after the K5 and K2 relays are closed, the load is connected between points B and C of the proximity switch, and the load current acquisition circuit can measure the load current after the proximity switch is loaded; after the K5 and K2 relays are closed, the load is connected between points B and C of the proximity switch, and the voltage drop acquisition circuit can measure the voltage drop between points A and B after the proximity switch is loaded.

[0052] Three-wire NPN: After the K5 relay (limit protection switch) is closed, the static current acquisition circuit can measure the static current after the proximity switch is energized; after the K5 and K2 relays are closed, the load is connected between points A and B of the proximity switch, and the load current acquisition circuit can measure the load current after the proximity switch is loaded; after the K5 and K2 relays are closed, the load is connected between points A and B of the proximity switch, and the voltage drop acquisition circuit can measure the voltage drop between points B and C after the proximity switch is loaded.

[0053] The switching principle between four-wire and three-wire systems is the same, so I won't go into details.

[0054] Reference Figure 10The present invention provides a general proximity switch three-temperature testing system, whose human-machine interface system mainly consists of an industrial control computer (501), a display (502), a mouse and keyboard (503), a barcode scanner (504), and a network switch (505). The industrial control computer is responsible for loading the test program and analyzing, processing, and storing the data; the barcode scanner is used for inputting information about the product under test, and the software, in conjunction with the barcode scanner, can realize the barcode binding of the product and the workstation and perform data acquisition; the display, keyboard, mouse, etc., are used for display and operation interaction with the operator; the network switch is used to provide network communication conversion between other components of the test system and the industrial control computer.

[0055] The industrial control computer is used to carry the test system software and connect to basic peripherals and barcode scanners to realize user management functions, parameter management functions, test monitoring functions and data management functions;

[0056] The basic peripherals also include, but are not limited to, keyboards, mice, monitors, alarm lights, buzzers, etc., which are tools for operators to interact with the test system software;

[0057] The barcode scanner is connected to the industrial control computer via USB or wireless communication for barcode input of the product under test and is bound to the testing station.

[0058] The testing system software includes: user management functions, parameter management functions, test monitoring functions, and data management functions;

[0059] The user management function can add, modify, and delete software users, and can group users and control user permissions;

[0060] The parameter management function stores various technical indicators, data acquisition and judgment indicators, test temperature, and other parameters of the product under test, including input power supply control and output status. Operators can store, add, recall, modify, and delete these parameters. This function also includes fixture positioning functionality.

[0061] The test monitoring function monitors the status of various hardware components such as the product under test and the enclosure in real time during the test. If it finds that the parameters do not match the set parameters, it will alarm, locate the fault, and protect the product. The monitored objects include, but are not limited to, the product's maximum load current, distance, hysteresis, repeatability, static current, and voltage drop. It also has current limiting and overvoltage protection functions for the power supply voltage.

[0062] The data management function records and stores various data during the testing process, barcode values ​​associated with products and workstations, and allows for data playback and report viewing. When saving test data, the operator specifies the storage location and format.

[0063] Reference Figure 11The present invention provides a general proximity switch three-temperature testing system, and the single test procedure for the proximity switch product is as follows: Test parameters are set, including chamber temperature, working time, and cycle period. After power-on, the system automatically completes the initial position search, and the temperature of the high and low temperature chamber begins to change. After the temperature stabilizes, it is kept at a constant temperature, during which time the product is continuously powered on. After the temperature is kept at a constant temperature, the product under test is powered on to begin the electrical performance test. At this time, the product under test is tested, and after the test time is up, a curve of the index versus temperature is output. The operation steps after the temperature is kept at a constant temperature are repeated until the set number of cycles is reached, at which point the system is powered off.

Claims

1. A universal proximity switch three-temperature testing system, characterized in that, include: High and low temperature test chamber, proximity switch detection device, servo motion mechanism, data acquisition and control system and human-machine interaction system; The proximity switch detection device is installed inside the high and low temperature test chamber, and the servo motion mechanism is installed outside the high and low temperature test chamber. The servo motion mechanism passes through the back of the test chamber and connects to the proximity switch detection device inside the chamber. It is used to control the distance between the proximity switch detection device and the sensing surface of the proximity switch under test, so as to realize the measurement of proximity switch sensing distance, repeatability and hysteresis parameters. The data acquisition and control system communicates with the servo motion mechanism and controls the servo motion mechanism to move according to the proximity switch measurement stroke. At the same time, it collects, controls and monitors the status of the proximity switch inside the high and low temperature test chamber. The human-computer interaction system is equipped with test system software, which communicates with the data acquisition and control system and the high and low temperature test chamber. It is used to control the temperature change process inside the high and low temperature test chamber according to the settings, process the proximity switch information collected during the test, plot the electrical characteristic curve of the proximity switch under three temperature test conditions, generate reports and store them.

2. The universal proximity switch three-temperature testing system according to claim 1, characterized in that, The proximity switch detection device controls: the target surface sensing device, the tooling fixture, and the signal adapter board; The target sensing device is installed on the guide rail inside the high and low temperature test chamber. The tooling fixture and signal adapter are installed on the outer mounting tray at the same height as the target sensing device. The target sensing device is used to install the proximity switch sensing target. The tooling fixture is used to install the corresponding proximity switch product. The signal adapter is used to connect the signal line of the proximity switch product on the tooling fixture and to transfer the signal to the external acquisition and control system of the high and low temperature test through the adapter circuit.

3. The universal proximity switch three-temperature testing system according to claim 1, characterized in that, The target sensing device includes: a touch target, a quick-change sensing target, and a first guide rail slider. The touch target is used to install the quick-change sensing target of the proximity switch. The touch target is set on the first guide rail slider, which is slidably connected to the guide rail on the inner side of the high and low temperature test chamber. This allows the touch target to move smoothly within the high and low temperature test chamber, thereby changing the sensing distance of the proximity switch.

4. The universal proximity switch three-temperature testing system according to claim 3, characterized in that, The quick-change induction target uses a rotating indexing pin to fix or detach the quick-change head from the base, and uses springs and indexing pins to limit the front and rear movement of the quick-change head.

5. The universal proximity switch three-temperature testing system according to claim 1, characterized in that, The cable connection at the input end of the signal adapter board uses a quick-connect spring terminal (207) to enable quick connection of multiple adapter cables. The cable connection at the output end of the signal adapter board uses a multi-core connector (208). The number of cores in the connector depends on the number of proximity switches detected in a single test. Multiple spring segments are reserved for each proximity switch to accommodate measurements of two-wire, three-wire, four-wire, and dual-redundant proximity switches.

6. The universal proximity switch three-temperature testing system according to claim 1, characterized in that, The servo motion mechanism includes: a servo motor, a ball screw pair, an integrated motor and screw base, and a coupling; The servo motor is connected and fixed to a high-precision ball screw pair via an integrated motor screw base and a coupling. The ball screw pair drive shaft nut is connected to the target surface sensing device. After the servo motor rotates, it drives the target surface sensing device to reciprocate on the guide rail.

7. The universal proximity switch three-temperature testing system according to claim 1, characterized in that, The data acquisition and control system includes: a data acquisition switching circuit, a communication module, a limit protection module, a data acquisition module, and a motion control module; The acquisition and switching circuit is connected to the signal conversion board inside the test chamber via a cable, and communicates with the human-machine interaction system via a communication module to obtain the type of the proximity switch under test. Then, the relay in the circuit automatically switches to the voltage drop detection circuit, no-load current detection circuit and load current detection circuit of the corresponding type of proximity switch, so as to realize the one-to-one correspondence between the measurement and the product. The limit protection module is connected in series in the power supply circuit of the acquisition and switching circuit. It communicates with the human-machine interaction system through the communication module and receives the protection limit values ​​of various parameters set by the host computer. When the acquired value is greater than the limit value, the protection switch is activated, the power relay is disconnected, the power supply to the proximity switch under test is cut off, and the fault information is uploaded to the human-machine interaction system for display through the communication module. The acquisition module is an isolated voltage and current acquisition board. After the acquisition switching circuit is switched, it is used to measure the voltage drop, no-load current and load current of the proximity switch. The isolation design ensures that the product under test is not damaged due to test circuit failure. The motion control module is used to control the servo motion mechanism to move according to the distance measured by the proximity switch.

8. The universal proximity switch three-temperature testing system according to claim 7, characterized in that, The motion control module includes: a motion control unit, a status acquisition unit, a communication unit, and a drive unit. The motion control unit communicates with the human-computer interaction system through the communication unit to receive test commands issued by the human-computer interaction system and convert them into motion commands to be issued to the drive unit. The drive unit is connected to the servo motor, which drives the motor to perform forward and reverse rotation, thereby realizing the reciprocating motion of the target surface sensing device. The status acquisition unit is an analog AD acquisition module, used for acquiring the output voltage of the proximity switch; Meanwhile, the motion control unit, status acquisition unit, and drive unit are configured to read the motor's operating position and the magnitude of the proximity switch's output voltage in real time, and upload them to the human-machine interaction system through the communication unit.

9. The universal proximity switch three-temperature testing system according to claim 1, characterized in that, The human-computer interaction system includes: an industrial control computer, basic peripherals, a barcode scanner, and testing system software; The industrial control computer is used to carry the test system software and connect to basic peripherals and barcode scanners to realize user management functions, parameter management functions, test monitoring functions and data management functions; The barcode scanner is connected to the industrial control computer via USB or wireless communication for barcode input of the product under test and is bound to the testing station; The testing system software includes: user management functions, parameter management functions, test monitoring functions, and data management functions; The user management function enables the addition, modification, and deletion of software users, as well as the grouping of users and control of user permissions; The parameter management function stores various technical indicators, data acquisition and judgment indicators, and test temperature of the input power supply control and output status of the product under test; The test monitoring function monitors the status of the product and housing under test in real time during the test. If it finds that the product does not meet the set indicators, it will alarm, locate the fault, and protect the product. The data management function records and stores various data during the testing process, barcode values ​​associated with products and workstations, and allows for data playback and report viewing. When saving test data, the operator specifies the storage location and format.

10. The universal proximity switch three-temperature testing system according to claim 1, characterized in that, The measurement of proximity switch sensing distance, repeatability, and hysteresis characteristics is achieved through specific methods, including... Determine the initial position: The servo motor drives the high-precision ball screw pair, which moves the target sensing device to the left along the axis until the target in the same row contacts the sensing surface of the proximity switch. After the target is close to the sensing surface of the proximity switch, the servo motor continues to run, pushing the proximity switch forward along the axis by a set distance to compensate for the error caused by the inconsistent installation of proximity switches in the same row. The reading value of the motor encoder at this time is recorded as the initial position of the proximity switch at this station. Sensing distance and repeatability: The servo motor drives the target away from the proximity switch from the initial position until all proximity switches in the same row are not triggered. Record the encoder values ​​of the motor at different positions when the proximity switches are not triggered. The difference between the encoder value and the initial position is taken as the sensing distance S1 of the proximity switch. Repeat the above sensing distance measurement steps and record the sensing distances S1 and S2 when the proximity switches are not triggered in the two runs. The absolute difference between the two sensing distances |S1-S2| is the repeatability of the proximity switch. Hysteresis characteristic parameters: When the target moves from a position away from the proximity switch to the proximity switch, the motor encoder value is recorded when the proximity switch is triggered again. The difference between this value and the initial position is used as the reset position S3 of the proximity switch. The absolute difference between the reset position and the sensing distance |S1-S3| is the hysteresis of the proximity switch.

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