Electromagnetic Relay Low-Temperature Testing Device and Method

Abstract

The present application provides a low-temperature test device and method for an electromagnetic relay. The device includes: a temperature control box, on the surface of the box body of the temperature control box, there are mounting holes, the housing of the electromagnetic relay is located inside the box body, the side wall of the housing is detachably connected to the side of the mounting hole, and the pins of the electromagnetic relay are located outside the box body; a temperature adjustment device is provided inside the box body, and the temperature adjustment device is used to change the gas temperature inside the box body; a heating resistance wire is wound around the middle of the pins and is configured to change the temperature of the contacts connected to the pins. The low-temperature test device and method for an electromagnetic relay provided by the present application have a simple structure, are easy to operate, have strong versatility, reduce the series resistance brought by external leads, reduce measurement errors, facilitate the testing of different pins of the electromagnetic relay, and realize the reproduction and positioning analysis of faults.

Description

Technical Field

[0001] This application relates to the technical field of relay testing, and particularly to a low-temperature testing device and method for electromagnetic relays. Background Art

[0002] An electromagnetic relay is an electronic control device that plays roles such as automatic regulation, safety protection, and circuit conversion in a circuit. In the aerospace field, it is usually required that the electromagnetic relay has good working reliability at low temperatures. However, at low temperatures, water vapor inside the electromagnetic relay will condense and freeze on the contacts, resulting in low-temperature failure of the electromagnetic relay. Therefore, it is crucial to conduct performance tests on the electromagnetic relay at low temperatures.

[0003] The existing low-temperature testing device for electromagnetic relays needs to place the entire electromagnetic relay in a low-temperature chamber for cooling, and connect a long lead wire to the pins of the electromagnetic relay to connect to the detection equipment outside the low-temperature chamber for testing. However, the series resistance of the lead wire is relatively large, which will cause a large error in the measurement results. Summary of the Invention

[0004] In view of this, the purpose of this application is to propose a low-temperature testing device and method for electromagnetic relays to solve the above technical problems.

[0005] In the first aspect of this application, a low-temperature testing device for electromagnetic relays is provided, including: a temperature control box, an installation hole is opened on the surface of the box body of the temperature control box, the housing of the electromagnetic relay is located inside the box body, the side wall of the housing is detachably connected to the side of the installation hole, and the pins of the electromagnetic relay are located outside the box body; a temperature adjustment device is provided inside the box, and the temperature adjustment device is used to change the gas temperature inside the box.

[0006] Further, the installation hole is a rectangular hole, and elastic sealing gaskets are provided on the four sides of the rectangular hole, and the side wall of the housing is clamped on the elastic sealing gaskets.

[0007] Further, a heat insulation sheet is provided between the pins and the housing.

[0008] Further, the low-temperature testing device for electromagnetic relays further includes: a contact resistance tester, electrically connected to the pins, and configured to detect the contact resistance of the contacts connected to the pins, and the contacts are located inside the housing.

[0009] Further, the low-temperature testing device for electromagnetic relays further includes: a heating resistance wire, wound around the middle of the pins, and configured to change the temperature of the contacts connected to the pins.

[0010] Further, the electromagnetic relay low-temperature testing device further includes: an infrared thermal imager configured to detect the temperature of the pin.

[0011] In a second aspect of the present application, there is provided a method for testing an electromagnetic relay at low temperature, using the electromagnetic relay low-temperature testing device as described in the first aspect above. The method includes: installing the electromagnetic relay in the mounting hole; setting the temperature of the temperature control box at a first temperature through the temperature adjustment device; detecting the contact resistance of the contact connected to the pin through the contact resistance tester.

[0012] Further, the method for testing an electromagnetic relay at low temperature further includes: reducing the temperature of the temperature control box from the first temperature to a second temperature through the temperature adjustment device; monitoring the change in the contact resistance of the contact through the contact resistance tester and generating a first contact resistance-temperature change curve.

[0013] Further, the method for testing an electromagnetic relay at low temperature further includes: setting the temperature of the contact connected to the pin at a third temperature through the heating resistance wire; detecting the contact resistance of the contact through the contact resistance tester.

[0014] Further, the method for testing an electromagnetic relay at low temperature further includes: raising the temperature of the contact from the third temperature to a fourth temperature through the heating resistance wire; monitoring the change in the contact resistance of the contact through the contact resistance tester and generating a second contact resistance-temperature change curve.

[0015] As can be seen from the above, the present application provides an electromagnetic relay low-temperature testing device and method. By detachably connecting the housing of the electromagnetic relay to the side of the mounting hole of the temperature control box, the housing of the electromagnetic relay is located inside the box body, and the pins of the electromagnetic relay are located outside the box body. During measurement, the pins outside the box can be directly measured, eliminating the external connecting wires from inside the box to outside the box, reducing the series resistance, and making the measurement data more accurate; the pins are arranged outside the box body, which is also beneficial for connecting and testing different pins, facilitating the completion of different electromagnetic relay testing work, and avoiding connection operations inside the box, saving time and effort; by adjusting the temperature adjustment device, the temperature of the gas inside the box can be changed, and the gas inside the box contacts the housing of the electromagnetic relay for heat exchange, thereby changing the temperature of the housing, which can simulate the usage environment of the electromagnetic relay and realize the reproduction of low-temperature failure faults of the electromagnetic relay; the electromagnetic relay low-temperature testing device and method have a simple structure, are easy to operate, have strong versatility, reduce the series resistance brought by external connecting wires, reduce measurement errors, are convenient for testing different pins of the electromagnetic relay, and realize the reproduction and positioning analysis of faults. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the present application or related technologies, the following will briefly introduce the drawings required for use in the embodiments or the description of related technologies. Obviously, the drawings in the following description are only embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of a low-temperature test device for an electromagnetic relay according to an embodiment of the present application;

[0018] Figure 2 It is a schematic structural diagram of another low-temperature test device for an electromagnetic relay according to an embodiment of the present application;

[0019] Figure 3 It is a schematic flow diagram of a low-temperature test method for an electromagnetic relay according to an embodiment of the present application;

[0020] Figure 4 It is a schematic flow diagram of another low-temperature test method for an electromagnetic relay according to an embodiment of the present application.

[0021] Reference numerals: 1, temperature control box; 1-1, mounting hole; 1-2, temperature adjustment device; 1-3, elastic sealing gasket; 1-4, heat insulation sheet; 2, electromagnetic relay; 2-1, housing; 2-2, pin; 3, contact resistance tester; 4, heating resistance wire; 5, infrared thermal imager. Detailed implementation manners

[0022] To make the purpose, technical solutions, and advantages of the present application clearer and more understandable, the following will further elaborate on the present application in detail with reference to specific embodiments and the accompanying drawings.

[0023] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the ordinary meaning understood by those of ordinary skill in the field to which the present application belongs. The "first", "second", and similar terms used in the embodiments of the present application do not indicate any order, quantity, or importance, but are only used to distinguish different components. "Including" or "comprising" and similar terms mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. "Connecting" or "being connected" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0024] An electromagnetic relay is an electronic control device. It has a control system and a controlled system and is usually applied to an automatic control circuit. It is an automatic switch that uses a smaller current and a lower voltage to control a larger current and a higher voltage. Therefore, it plays roles such as automatic regulation, safety protection, and circuit conversion in the circuit.

[0025] In the aerospace field, it is usually required that the electromagnetic relay has good working reliability between 85°C above zero and 55°C below zero. However, at low temperatures, water vapor inside the relay will condense and freeze on the contacts, resulting in an increase in the contact resistance of the contacts and the low-temperature failure of the electromagnetic relay. Therefore, it is necessary to test the performance of the electromagnetic relay at low temperatures.

[0026] The existing relay low-temperature test device needs to place the whole relay in a low-temperature chamber for cooling, and connect a long lead to the detection equipment outside the low-temperature chamber for testing on the pins. The contact resistance of the pins of the electromagnetic relay is usually in the milliohm level, and the series resistance of the external lead is relatively large, which will cause a large measurement error for the electromagnetic relay; and for testing different pins of the electromagnetic relay, it is also necessary to adjust and connect inside the low-temperature chamber, which is inconvenient to operate and time-consuming and laborious.

[0027] In the process of implementing the present application, it is found that the low-temperature chamber can be further designed to only control the temperature of the shell of the electromagnetic relay, and expose the pins of the electromagnetic relay outside the low-temperature chamber, eliminating the need for long pin wiring and facilitating the connection operation of different pins, and solving the problem of large measurement errors.

[0028] The following, through specific embodiments and in combination with Figures 1-4 to detail the technical solution of the present application.

[0029] Some embodiments of the present application provide a low-temperature test device for an electromagnetic relay, as Figure 1 shown, including: a temperature control box 1, an installation hole 1-1 is opened on the surface of the box body of the temperature control box 1, the shell 2-1 of the electromagnetic relay 2 is located inside the box body, the side wall of the shell 2-1 is detachably connected to the side of the installation hole 1-1, and the pins 2-2 of the electromagnetic relay 2 are located outside the box body; a temperature adjustment device 1-2 is arranged inside the box, and the temperature adjustment device 1-2 is used to change the gas temperature inside the box.

[0030] The installation hole 1-1 can be obtained by transforming the surface of the existing temperature control box 1. The installation hole 1-1 opened on the surface of the box body matches the shape of the shell 2-1 of the electromagnetic relay 2 without affecting the overall structure and use of the temperature control box 1; after the test of the electromagnetic relay 2 is completed, the electromagnetic relay 2 can be removed and a heat insulation plug can be set to block the installation hole 1-1 for other temperature control tests, reducing the manufacturing cost.

[0031] By detachably connecting the housing 2-1 of the electromagnetic relay 2 to the side of the mounting hole 1-1 of the temperature control box 1, the housing 2-1 of the electromagnetic relay 2 is located inside the box body, while the pins 2-2 of the electromagnetic relay 2 are located outside the box body. When measuring the electromagnetic relay 2, the pins 2-2 outside the box can be directly connected for measurement, eliminating the external connecting wires between the inside and outside of the box body, reducing the series resistance brought by the external connecting wires, reducing the test error, and making the measurement data more accurate.

[0032] The pins 2-2 are arranged outside the box body of the temperature control box 1, which is also beneficial for connecting and testing different pins 2-2, facilitating the completion of the testing work of different electromagnetic relays 2, and avoiding the connection operation of the pins 2-2 inside the box, saving time and effort.

[0033] The temperature adjustment device 1-2 is, for example, a cold air pump or a hot air pump. The cold air pump can be used when conducting a low-temperature test on the electromagnetic relay 2, and there is no specific limitation. By adjusting the temperature adjustment device 1-2, the gas temperature inside the box can be changed. The gas inside the box comes into contact with the housing 2-1 of the electromagnetic relay 2 for heat exchange, thereby changing the temperature of the housing 2-1, simulating the usage environment of the electromagnetic relay 2, so as to realize the reproduction of the process of low-temperature failure of the electromagnetic relay 2. The temperature control range of the temperature adjustment device 1-2 can be from -60°C to +90°C, and there is no specific limitation.

[0034] This low-temperature test device for electromagnetic relays has a simple structure, is easy to operate, has strong versatility, reduces the series resistance brought by external connecting wires, reduces the measurement error, and facilitates the testing of different pins 2-2 of the electromagnetic relay 2.

[0035] In some embodiments, as Figure 1 shown, the mounting hole 1-1 is a rectangular hole, and elastic sealing gaskets 1-3 are provided on the four sides of the rectangular hole. The side wall of the housing 2-1 is clamped on the elastic sealing gaskets 1-3.

[0036] The elastic sealing gasket 1-3 is, for example, a silica gel gasket, and there is no specific limitation. By providing silica gel gaskets on the four sides of the rectangular hole, on the one hand, the housing 2-1 is clamped by the extrusion of the box body and the silica gel gasket, so that the housing 2-1 of the electromagnetic relay 2 is located inside the box body, while the pins 2-2 of the electromagnetic relay 2 are located outside the box body; on the other hand, a sealed environment is formed inside the box body, improving the heat exchange effect between the housing 2-1 and the air inside the box body.

[0037] In some embodiments, as Figure 2 shown, a heat insulation sheet 1-4 is provided between the pins 2-2 and the housing 2-1.

[0038] As Figure 2As shown, the electromagnetic relay 2 is clamped in a rectangular hole, with the side wall and bottom surface of the housing 2-1 inside the box body, while the top surface of the housing 2-1 is still exposed to the outside. By providing a heat insulation sheet 1-4, heat exchange between the outside of the box body and the top surface of the housing 2-1 can be isolated, ensuring the temperature balance of the housing 2-1, making all surfaces of the housing 2-1 inside the box body of the temperature control box 1, and only the pins 2-2 of the electromagnetic relay 2 are exposed; the heat insulation sheet 1-4 can be an asbestos net or a foam board, etc., without specific limitation. The width of the heat insulation sheet 1-4 is equal to the width of the rectangular hole, and the length of the heat insulation sheet 1-4 is greater than or equal to the length of the rectangular hole.

[0039] In some embodiments, as Figure 2 shown, the electromagnetic relay low-temperature testing device further includes: a contact resistance tester 3, electrically connected to the pins 2-2, configured to detect the contact resistance of the contacts connected to the pins 2-2, and the contacts are located inside the housing 2-1.

[0040] The contact resistance tester 3 is designed by combining high-frequency switching power supply technology and digital circuit technology according to the new power execution standard DL / T845.4-2004, and is applicable to the measurement of the contact resistance of switch control equipment. The instrument has accurate measurement and stable performance, meeting the requirements of on-site switch maintenance and contact resistance testing in the power and power supply departments.

[0041] By connecting the two pins 2-2 of the electromagnetic relay 2 with the contact resistance tester 3, the contact resistance between the contacts corresponding to the two pins 2-2 can be measured. For example, if the contacts corresponding to the two pins 2-2 are normally open contacts, the theoretical value of the corresponding contact resistance is infinite. If the contacts corresponding to the two pins 2-2 are normally closed contacts, the theoretical value of the corresponding contact resistance is zero. By measuring the contact resistance, the conduction performance between the contacts can be understood, and then quantitative analysis can be carried out on the abnormal conditions of the contacts.

[0042] In some embodiments, as Figure 2 shown, the electromagnetic relay low-temperature testing device further includes: a heating resistance wire 4, wound around the middle of the pins 2-2, configured to change the temperature of the contacts connected to the pins 2-2.

[0043] The heating resistance wire 4 is, for example, an iron-chromium-aluminum spiral resistance wire, without specific limitation. The heating resistance wire 4 can utilize the heat effect generated by the current passing through the resistor body to electrically heat the pins 2-2, making the heating effect more uniform, having high thermal efficiency, and less environmental pollution. The heating temperature is, for example, from 5°C above zero to 30°C above zero, without specific limitation.

[0044] By heating the pin 2-2 with the heating resistance wire 4, the temperature of the pin 2-2 can be changed, and then the temperature of the contact connected to the pin 2-2 can be changed. When the electromagnetic relay 2 is used in a low-temperature environment, the internal contact is maintained at a certain temperature, for example, 15°C above zero, and the temperature of the contact should be higher than the external environment temperature. By changing the temperature of the contact with the heating resistance wire 4, the actual use situation of the electromagnetic relay 2 can be further simulated, and the failure faults of the electromagnetic relay 2 can be analyzed more accurately. It is also possible to set different contact temperatures for comparison and analyze the variation relationship between the electrical parameters of the contact and the temperature. The electrical parameters can be the contact resistance, contact voltage drop, etc., and are not specifically limited.

[0045] In some embodiments, as Figure 2 shown, the electromagnetic relay low-temperature test device further includes: an infrared thermal imager 5 configured to detect the temperature of the pin 2-2.

[0046] The infrared thermal imager 5 is a device that uses infrared thermal imaging technology to detect the infrared radiation of the target object, processes the signal, and converts the image of the temperature distribution of the target object into a visible image.

[0047] The infrared imager does not need to be in direct contact with the pin 2-2. By simply scanning the pin 2-2, the temperature of the pin 2-2 can be obtained, and then the temperature of the contact can be obtained, which is convenient for comparing the contact temperature and electrical parameters. Since the size of the pin 2-2 is small, it is easier to operate and the data is more accurate to measure the temperature of the pin 2-2 with an infrared imager than with a patch thermometer.

[0048] The description of the present application is given for purposes of illustration and description, and is not intended to be exhaustive or to limit the present application to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to better explain the principles of the present application and its practical application, and to enable those of ordinary skill in the art to understand the present application and thus design various embodiments with various modifications suitable for specific purposes.

[0049] Those of ordinary skill in the art should understand that: the discussion of any above embodiment is only exemplary, and is not intended to imply that the scope of the present application (including the claims) is limited to these examples; under the concept of the present application, the technical features between the above embodiments or different embodiments can also be combined, and there are many other variations in different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of brevity.

[0050] Based on the same inventive concept, the present application also provides an electromagnetic relay low-temperature test method, as Figure 3 shown, using as Figure 1 and Figure 2The described electromagnetic relay low-temperature testing device, the method includes the following steps:

[0051] S101. Install the electromagnetic relay 2 in the mounting hole 1-1.

[0052] Position the housing 2-1 of the electromagnetic relay 2 inside the box body to facilitate cooling the housing 2-1; position the pins 2-2 of the electromagnetic relay 2 outside the box body to facilitate measuring the contacts connected to the pins 2-2.

[0053] S102. Set the temperature of the temperature control box 1 to a first temperature through the temperature adjustment device 1-2.

[0054] The first temperature is, for example, -10°C, -20°C or -30°C, and is not specifically limited, and is used to simulate the low-temperature environment during the use of the housing 2-1.

[0055] The temperature inside the temperature control box 1 can be obtained by testing with a patch thermometer.

[0056] S103. Detect the contact resistance of the contacts connected to the pins 2-2 through the contact resistance tester 3.

[0057] The contact resistance measured in step S103 is the contact resistance of the contacts connected to the pins 2-2 of the housing 2-1 at the first temperature. Since the pins 2-2 are arranged outside the temperature control box 1, the external connecting leads from inside the box body to the outside are omitted, making the measured contact resistance more accurate.

[0058] S104. Reduce the temperature of the temperature control box 1 from the first temperature to a second temperature through the temperature adjustment device 1-2.

[0059] The second temperature is, for example, -40°C, -50°C or -60°C, and is not specifically limited, and is used to simulate the process of low-temperature failure of the electromagnetic relay 2 as the external environmental temperature decreases.

[0060] The temperature reduction from the first temperature to the second temperature can be carried out step by step. For example, when reducing from the first temperature of -10°C to the second temperature of -60°C, the temperature reduction operations can be carried out in sequence as -10°C, -20°C, -30°C, -40°C, -50°C and -60°C, which is convenient for data comparison.

[0061] S105. Monitor the change in the contact resistance of the contacts through the contact resistance tester 3 and generate a first contact resistance-temperature change curve.

[0062] The first contact resistance temperature change curve is the curve of the relationship between the contact resistance of the contact connected to pin 2-2 and the temperature of the housing 2-1 during the process of the electromagnetic relay 2 decreasing from the first temperature to the second temperature. The low-temperature failure characteristics of the contact can be analyzed, which is convenient for reproducing the contact failure.

[0063] In some embodiments, when the temperature of the temperature control box 1 decreases to the point where the electromagnetic relay 2 exhibits low-temperature failure, the contact resistance of the normally closed contact will change significantly at this time. For example, the contact resistance increases from 1 milliohm to 500 milliohms. The failure temperature and failure degree of the contact can be obtained from the first contact resistance temperature change curve, which is beneficial for locating and analyzing the contact failure, so as to further improve the electromagnetic relay 2 subsequently.

[0064] The failure degree can be the percentage change in contact resistance, and the failure temperature can be the temperature of the housing 2-1 when the percentage change reaches a preset value. The preset value is, for example, 300%, and is not specifically limited.

[0065] In some embodiments, there are multiple groups of pins 2-2 of the same type in the electromagnetic relay 2. The contact resistance tests can be performed on the pins 2-2 of the same type separately. For example, the pins 2-2 connected to the normally closed contacts are tested separately to obtain their respective first contact resistance temperature change curves, and the differences between different pins 2-2 of the same type are analyzed by comparing the first contact resistance temperature change curves.

[0066] In some embodiments, as Figure 4 shown, the electromagnetic relay low-temperature test method includes the following steps:

[0067] S201. Install the electromagnetic relay 2 in the mounting hole 1-1.

[0068] Position the housing 2-1 of the electromagnetic relay 2 inside the box to facilitate cooling the housing 2-1; position the pins 2-2 of the electromagnetic relay 2 outside the box to facilitate measuring the contacts connected to the pins 2-2.

[0069] S202. Set the temperature of the temperature control box 1 at the first temperature through the temperature adjustment device 1-2.

[0070] The first temperature is, for example, -10°C, -20°C or -30°C, and is not specifically limited, and is used to simulate the low-temperature environment during the use of the housing 2-1.

[0071] S203. Set the temperature of the contact connected to the pin 2-2 at the third temperature through the heating resistance wire 4.

[0072] The third temperature is, for example, 5°C above zero, 10°C above zero, or 15°C above zero, and is not specifically limited, which is used to more realistically simulate the temperature of the contacts when the electromagnetic relay 2 is in use.

[0073] When the electromagnetic relay 2 is used in a low-temperature environment, due to the heat generated by the energization of the internal contacts and other situations, the temperature of the contacts is maintained at a certain temperature, such as 15°C above zero, and the temperature of the contacts is higher than the external environment temperature. By changing the temperature of the contacts through the heating resistance wire 4, the usage situation of the electromagnetic relay 2 can be further simulated, the failure faults of the electromagnetic relay 2 can be analyzed more accurately, and different contact temperatures can also be set for comparison to analyze the variation relationship between the electrical parameters of the contacts and the temperature.

[0074] S204. Detect the contact resistance of the contacts through the contact resistance tester 3.

[0075] The contact resistance measured in step S204 is the contact resistance of the contacts connected to the pin 2-2 at the third temperature of the contacts and the first temperature of the housing 2-1. Since the pin 2-2 is arranged outside the temperature control box 1, the external connecting wire from inside the box to the outside is omitted, making the measured contact resistance more accurate; due to heating the pin 2-2, the measured contact resistance is closer to the contact resistance of the contacts in the real environment.

[0076] S205. Raise the temperature of the contacts from the third temperature to the fourth temperature through the heating resistance wire 4.

[0077] The fourth temperature is, for example, 20°C above zero, 25°C above zero, 30°C above zero, 35°C above zero, or 40°C above zero, and is not specifically limited. By raising the temperature of the contacts, the variation relationship between the electrical performance of the contacts and the contact temperature can be compared.

[0078] The temperature rise from the third temperature to the fourth temperature can be carried out step by step. For example, when raising the temperature from the third temperature of 10°C above zero to the fourth temperature of 30°C above zero, the temperature reduction operation can be carried out in sequence at 10°C above zero, 15°C above zero, 20°C above zero, 25°C above zero, and 30°C above zero, which is convenient for data comparison.

[0079] The temperature of the contacts can be obtained by testing the temperature of the pin 2-2 through the infrared thermal imager 5, and the measured temperature of the pin 2-2 is equal to the temperature of the contacts.

[0080] S206. Monitor the change of the contact resistance of the contacts through the contact resistance tester 3 and generate a second contact resistance-temperature change curve.

[0081] The second contact resistance temperature change curve is a curve showing the relationship between the contact resistance and the contact temperature during the process where the housing 2-1 of the electromagnetic relay 2 is maintained at the first temperature and the contacts of the electromagnetic relay 2 are heated from the third temperature to the fourth temperature, and can be used to analyze the characteristics of the contacts changing with temperature.

[0082] In some embodiments, the contact resistance of the contacts increases as the temperature of the contacts rises. When the temperature of the contacts reaches the melting point of the contact material, the contact resistance decreases due to the melting of the contacts. The characteristics of the contacts changing with temperature can be analyzed from the second contact resistance temperature change curve for subsequent further improvement of the electromagnetic relay 2.

[0083] In some embodiments, there are multiple groups of pins 2-2 of the same type in the electromagnetic relay 2. The contact resistance of the pins 2-2 of the same type can be measured separately. For example, the pins 2-2 connected to the normally closed contacts can be measured separately to obtain their respective second contact resistance temperature change curves, and the differences between different pins 2-2 of the same type can be analyzed by comparing the second contact resistance temperature change curves.

[0084] It should be noted that the method of this embodiment can be applied to a distributed scenario and completed by multiple devices cooperating with each other. In such a distributed scenario, one of the multiple devices can only execute one or more steps of the method of the embodiment of the present application, and these multiple devices will interact with each other to complete the described method.

[0085] It should be noted that some embodiments of the present application have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the above embodiments and still achieve the desired results. Additionally, the processes depicted in the figures do not necessarily require the particular order or sequential order shown to achieve the desired results. In certain implementations, multitasking and parallel processing are also possible or may be advantageous.

[0086] Those of ordinary skill in the art should understand that: the discussion of any above embodiment is exemplary only and is not intended to imply that the scope of the present application (including the claims) is limited to these examples; under the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of brevity.

[0087] In addition, for simplicity of explanation and discussion, and so as not to make the embodiments of the present application difficult to understand, well-known power / ground connections to other components may or may not be shown in the provided drawings. Further, the devices may be shown in block diagram form in order to avoid making the embodiments of the present application difficult to understand, and this also takes into account the fact that details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present application are to be implemented (i.e., these details should be entirely within the understanding of those skilled in the art). In cases where specific details have been set forth to describe exemplary embodiments of the present application, it will be apparent to those skilled in the art that the embodiments of the present application may be practiced without these specific details or with variations of these specific details. Accordingly, these descriptions should be regarded as illustrative rather than restrictive.

[0088] Although the present application has been described in connection with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description. The embodiments of the present application are intended to embrace all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application shall be included within the protection scope of the present application.

Claims

1. An electromagnetic relay low-temperature test device, characterized in that Comprising: A temperature control box, on the surface of the box body of the temperature control box, there are mounting holes, the housing of the electromagnetic relay is located inside the box body, the side wall of the housing is detachably connected to the side of the mounting hole, and the pins of the electromagnetic relay are located outside the box body; inside the box body, there is a temperature adjustment device for changing the gas temperature inside the box body; the mounting hole is a rectangular hole, and elastic gaskets are provided on the four sides of the rectangular hole, and the side wall of the housing is clamped on the elastic gaskets; there is a heat insulation sheet between the pins and the housing; A contact resistance tester, electrically connected to the pins, configured to detect the contact resistance of the contacts connected to the pins, and the contacts are located inside the housing; A heating resistance wire, wound around the middle of the pins, configured to change the temperature of the contacts connected to the pins; An infrared thermal imager, configured to detect the temperature of the pins.

2. A low-temperature test method for an electromagnetic relay, using the low-temperature test device for an electromagnetic relay described in claim 1, characterized in that, The method includes: Installing the electromagnetic relay in the mounting hole; Setting the temperature of the temperature control box at a first temperature through the temperature adjustment device; Detecting the contact resistance of the contacts connected to the pins through the contact resistance tester.

3. The electromagnetic relay low-temperature test method according to claim 2, characterized in that, Further comprising: Lowering the temperature of the temperature control box from the first temperature to a second temperature through the temperature adjustment device; Monitoring the change of the contact resistance of the contacts through the contact resistance tester and generating a first contact resistance-temperature change curve.

4. The electromagnetic relay low-temperature test method according to claim 2, characterized in that, Further comprising: Setting the temperature of the contacts connected to the pins at a third temperature through the heating resistance wire; Detecting the contact resistance of the contacts through the contact resistance tester.

5. The electromagnetic relay low-temperature testing method according to claim 4, characterized in that, Further comprising: Raising the temperature of the contacts from the third temperature to a fourth temperature through the heating resistance wire; Monitoring the change of the contact resistance of the contacts through the contact resistance tester and generating a second contact resistance-temperature change curve.

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