Device and method for measuring the height of heating wire of thermal protector

Abstract

The present invention relates to a device and method for measuring the height of a heating wire in a thermal protector, primarily for measuring the height of the heating wire relative to a circular platform mounted on a bimetallic strip in thermal protectors for refrigeration compressor motors, such as refrigerators and freezers. The present invention comprises a carriage assembly, a sliding assembly, a laser displacement sensor, and a workbench. Its structural features include: a measuring base assembly, wherein the measuring base assembly and the sliding assembly are both disposed on the workbench, the carriage assembly is disposed on the sliding assembly, the laser displacement sensor is disposed on the carriage assembly, and the laser displacement sensor is positioned above the measuring base assembly; the measuring base assembly comprises a base base, a positioning plate, a positioning cavity, a pad, and a reference pin; the base base is disposed on the workbench, the positioning plate is disposed on the base base, the positioning cavity and the reference pin are both disposed on the positioning plate, and the pad is disposed within the positioning cavity.

Description

Technical Field

[0001] The present invention relates to a device for measuring the height of a heating wire of a thermal protector, mainly for measuring the height of a heating wire relative to a circular platform for mounting a bimetallic strip in a thermal protector for a refrigeration compressor motor such as a refrigerator or freezer. Background Art

[0002] The compressor motors in refrigerators, freezers and other refrigeration appliances are equipped with a thermal protector. When the compressor motor is stalled or the operating current is large, or the surface temperature of the compressor casing rises too high, the thermal protector will automatically operate to disconnect the circuit to protect the compressor motor; as the temperature of the compressor motor and casing drops to the specified value, the thermal protector will automatically reset and reconnect the circuit, and the compressor will start working normally again.

[0003] Most of the refrigerators, freezers and other refrigeration appliances on the market currently use a flat thermal protector. One of the core components of the thermal protector is a heating wire, which is connected in series in the main circuit of the compressor circuit. The heating wire generates heat under the action of the current passing through it, and can radiate and conduct to the bimetallic strip. When the compressor motor is stalled or the current exceeds the design value during operation, the heat generated by the heating wire is radiated and conducted to the bimetallic strip, which is enough to cause the bimetallic strip to suddenly jump and flip.

[0004] The sudden flipping action of the bimetallic strip pushes the moving contact fixed on the moving spring, separating the moving contact and the static contact to achieve the effect of disconnecting the circuit.

[0005] The distance between the heating wire and the bimetallic strip has a great influence on the radiation conduction of heat. This influence is directly reflected in the changes in the cold-state action current (corresponding to the protection of the compressor motor when it is in a stalled state) and the hot-state action current (corresponding to the protection of the compressor motor when it exceeds the specified operating current for a long time). When the change is too large, it may cause the thermal protector to lose its protective effect on the compressor motor and even cause the motor to burn out.

[0006] In the actual production stage, each specification of thermal protector should specify the corresponding heating wire height to ensure the compliance and consistency of the two operating currents in mass production, especially the compliance of the hot operating current, because the compliance of the cold operating current can be determined by a full inspection, while the compliance of the hot operating current can only be determined by spot checking; at the same time, the closer the heating wire is to the bimetallic strip, the greater the risk of electrical short circuit between the two, and technical specifications should also be given.

[0007] like Figure 7As shown, L represents the distance between the heating wire 8 and the bimetallic strip 9. The heating wire 8 will move slightly in the thermal protector base 10 when subjected to external force, and there is a gap between the heating wire 8 and the bottom of the thermal protector base 10. General contact measurements such as dial indicators are not suitable because the mechanical pressure causes the movement of the heating wire 8, resulting in a large error in the measurement result.

[0008] In view of this, a method for detecting the flatness of the heating wire in a micro thermal protector is disclosed in the patent document with application number 201710573488.0. Although the above-mentioned prior art also adopts the non-contact measurement method of the laser test head for measurement, two left and right measuring points, namely the first test point 611 of the heating wire and the second test point 621 of the heating wire, are selected on the upper surface of the heating wire 6, and the heights of the left and right measuring points are measured respectively by moving the laser test head. It is only applicable to the measurement of the heating wire with a cylindrical structure, while the present application is aimed at the measurement of the heating wire with an Ω-shaped structure. At the same time, the present application arranges a gasket 17 above the heating wire to ensure that the laser irradiation point is always a plane to ensure the accuracy of the measurement results and improve the measurement accuracy. Summary of the Invention

[0009] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a device and method for measuring the height of a heating wire of a thermal protector with a reasonable structural design.

[0010] The technical solution adopted by the present invention to solve the above-mentioned problem is as follows: the height measuring device for the heating wire of the thermal protector includes a carriage assembly, a sliding assembly, a laser displacement sensor and a workbench, and its structural characteristics are: it also includes a measuring base assembly, the measuring base assembly and the sliding assembly are both arranged on the workbench, the carriage assembly is arranged on the sliding assembly, the laser displacement sensor is arranged on the carriage assembly, and the laser displacement sensor is located above the measuring base assembly, and the sliding assembly and the laser displacement sensor are both connected to a control system; the measuring base assembly includes a base base plate, a positioning plate, a positioning cavity, a pad and a reference pin, the base base plate is arranged on the workbench, the positioning plate is arranged on the base base plate, the positioning cavity and the reference pin are both arranged on the positioning plate, the pad is arranged in the positioning cavity, the pad is provided with a positioning groove, and the positioning groove is provided with a positioning column;

[0011] The control system includes a programmable controller, a signal amplifier, a human-machine interface, a Y-axis driver, a Y-axis motor, an X-axis driver, an X-axis motor, a Y-axis origin proximity switch, an X-axis origin proximity switch, a start button and a stop button. The programmable controller includes a central processing unit, an analog-to-digital conversion module, a switching signal input interface, a switching signal output interface, and a serial communication interface.

[0012] The data acquisition unit is composed of a laser displacement sensor, a signal amplifier and an analog-to-digital conversion module. The laser displacement sensor is connected to the signal amplifier, the signal amplifier is connected to the analog-to-digital conversion module, and the analog-to-digital conversion module is connected to the central processing unit.

[0013] A switch signal input control unit is composed of a Y-axis origin proximity switch, an X-axis origin proximity switch, a start button, a stop button, and a switch signal input interface. One end of the Y-axis origin proximity switch, the X-axis origin proximity switch, the start button, and the stop button are respectively connected to the X0, X1, X2, and X3 ends of the switch signal input interface. The other ends of the Y-axis origin proximity switch, the X-axis origin proximity switch, the start button, and the stop button are connected and then connected to the V- end of the DC power supply. The COM end of the switch signal input interface is connected to the V+ end of the DC power supply. The switch signal input interface is connected to the central processing unit.

[0014] The position motion control unit is composed of a switch signal output interface, a Y-axis driver, a Y-axis motor, an X-axis driver and an X-axis motor. The central processing unit is connected to the switch signal output interface. The Y0 and Y1 ends of the switch signal output interface are connected to the Y-axis driver, wherein the Y0 end is connected to the negative end of the pulse control PUL of the Y-axis driver, wherein the Y1 end is connected to the negative end of the direction control DIR of the Y-axis driver. The four terminals of the Y-axis driver are connected to the Y-axis motor. The shaft of the Y-axis motor is mechanically connected to the Y-axis linear slide through a coupling. The Y of the switch signal output interface is connected to the Y-axis linear slide. The 2nd and Y3rd terminals are connected to the X-axis driver, wherein the Y2nd terminal is connected to the negative terminal of the pulse control PUL of the X-axis driver, wherein the Y3rd terminal is connected to the negative terminal of the direction control DIR of the X-axis driver, the four terminals of the X-axis driver are connected to the X-axis motor, the shaft of the X-axis motor is mechanically connected to the X-axis linear slide through a coupling, the negative terminal of the switch signal output interface is connected to the DC power supply V-terminal, the positive terminals of the pulse control PUL and direction control DIR of the Y-axis driver are connected to the positive terminals of the pulse control PUL and direction control DIR of the X-axis driver, and then connected to the DC power supply V+terminal.

[0015] The data setting and display unit consists of a human-machine interface (HMI) and a serial communication interface. The serial communication interface is connected to the central processing unit (CPU). The HMI communicates bidirectionally with the CPU via a data cable. The use of a laser displacement sensor for non-contact measurement improves measurement accuracy.

[0016] Furthermore, the sliding assembly includes a Y-axis slide, an X-axis slide, and a connecting arm. The Y-axis slide is disposed on a workbench, the connecting arm is disposed on the Y-axis slide, the X-axis slide is disposed on the connecting arm, and the carriage assembly is disposed on the X-axis slide. Multi-point measurement can be achieved through the movement of the sliding assembly.

[0017] Furthermore, the carriage assembly includes a carriage seat, a dovetail fixed block, a dovetail sliding block, a screw, a screw pressure plate, and a screw handwheel. The carriage seat is mounted on the X-axis slide, the dovetail fixed block is mounted on the carriage seat, the dovetail sliding block is slidably mounted on the dovetail fixed block, the screw pressure plate is mounted on the dovetail sliding block, the screw is rotatably mounted on the screw pressure plate, and the screw is threadably connected to the dovetail fixed block. The screw handwheel is mounted on the screw. The carriage assembly can be used to adjust the initial position of the laser displacement sensor during measurement.

[0018] Furthermore, the base plate and the positioning plate are arranged on a workbench by positioning pins and screws, making installation convenient.

[0019] Furthermore, a thermal protector base assembly is placed in the positioning cavity, and the bottom of the thermal protector base assembly is in contact with the positioning column.

[0020] Furthermore, the bottom of the thermal protector base assembly is provided with a first positioning surface, a second positioning surface, a third positioning surface, and a fourth positioning surface. The number of the positioning posts is four, namely, a first positioning post, a second positioning post, a third positioning post, and a fourth positioning post. The first positioning post, the second positioning post, the third positioning post, and the fourth positioning post are in contact with the first positioning surface, the second positioning surface, the third positioning surface, and the fourth positioning surface, respectively. The positioning posts can be used to position the thermal protector base assembly, facilitating measurement thereof.

[0021] Furthermore, a gasket is placed above the heating wire of the thermal protector base assembly, and the gasket cooperates with the laser displacement sensor. By placing the gasket on the heating wire, the laser irradiation point can always be flat, thereby ensuring the accuracy of the measurement data.

[0022] Furthermore, the gasket is arranged in an Ω-shaped structure. The gasket arranged in the Ω-shape can match the shape of the heating wire to ensure that the laser irradiation point is always irradiated on the gasket.

[0023] Furthermore, another technical purpose of the present invention is to provide a measurement method for a device for measuring the height of a heating wire of a thermal protector.

[0024] The above technical objectives of the present invention are achieved through the following technical solutions.

[0025] A measuring method for a device for measuring the height of a heating wire of a thermal protector is characterized in that: the measuring method is as follows:

[0026] S1. Turn on the power of the control system and move the laser displacement sensor to the reference point a so that the light spot of the laser displacement sensor is irradiated on the near center point of the end face of the reference pin and the center point is visually observed to be within ±1mm;

[0027] S2. The initial position of the laser displacement sensor in the up and down directions is adjusted as follows:

[0028] S21, manually rotate the screw handwheel to drive the laser displacement sensor up and down through the dovetail sliding block;

[0029] S22. The digital display window of the laser displacement sensor should display green when it is within the specified effective detection distance, and red when it is outside the effective detection distance. The digital display should be green. At the same time, the screw should be rotated clockwise for at least 2 turns and counterclockwise for at least 2 turns based on the end detection point of the reference pin. The digital display should be green to ensure that the entire test process is within the effective detection distance of the sensor.

[0030] S3. Place the thermal protector base assembly into the positioning cavity of the positioning plate;

[0031] S4. Place the gasket with the smooth side facing up on the heating wire in the thermal protector base assembly, with the opening of the gasket corresponding to the opening of the heating wire;

[0032] S5. Press the start button. The measuring device automatically moves to each measuring point in the measuring order and obtains the height data of each point. The measurement ends when the measuring point returns to the end face of the reference pin. The measuring order is point a → point b → point c → point 1 → point 2 → point 3 → origin. The position movement of the X and Y axes is completed by the X-axis slide and the Y-axis slide.

[0033] S6. After the measurement is completed, the height measurement data and the test result indication are displayed on the test interface of the human-machine interface of the control system.

[0034] Furthermore, the control method is implemented by the control system as follows:

[0035] S1. After the measuring device is turned on, the laser displacement sensor automatically resets the origin position. If the measuring device does not reset the origin position, you can press the "Origin Reset" button on the parameter setting interface of the human-machine interface to perform the origin reset action. The position motion control unit controls the Y-axis slide and the X-axis slide to move to their respective origin proximity switch sensing positions according to the central processor;

[0036] S2. Set the X-axis and Y-axis position parameters of reference point a in the parameter setting interface of the human-machine interface. The setting data is input into the central processing unit through the serial communication interface and stored in the register. Press the "reference point a" button. The central processing unit calculates and converts the position data into pulse signals and direction signals and outputs them to the position motion control unit. The position motion control unit controls the linkage between the Y-axis slide and the X-axis slide to drive the laser displacement sensor to the reference point a position. If the reference point a position parameters are set correctly, the laser displacement sensor's spot should be near the center point of the reference pin end face. If there is any deviation, it is corrected by changing the X-axis and Y-axis position setting parameters of reference point a until the laser displacement sensor's spot is near the center point of the reference pin end face.

[0037] S3. First, place the thermal protector base assembly to be tested into the positioning cavity of the positioning plate. Then, place the gasket with the smooth side facing up on the heating wire of the thermal protector base assembly, with the opening of the gasket corresponding to the opening of the heating wire.

[0038] S4. Set the X-axis and Y-axis position parameters of test point b, test point c, test point 1, test point 2, and test point 3 in the parameter setting interface of the human-machine interface according to the method in step 2. Press the test point button at the corresponding position. The Y-axis slide and the X-axis slide combination will drive the laser displacement sensor to the corresponding position. Observe whether the light spot of the laser displacement sensor is at the corresponding test position. If a test point is not at the corresponding position, correct it by changing the X-axis and Y-axis position setting parameters of the test point. If all test points are at the corresponding position, the position adjustment is completed.

[0039] S5. Setting comparison parameters related to the test result judgment in the setting interface of the human-machine interface. These setting parameters are saved in the internal register of the central processing unit through the serial communication interface and serve as comparison values for judging whether the test value exceeds the limit or passes.

[0040] S51, there is a height difference setting value of b\c, that is, the height difference between point b and point c on the bimetallic strip mounting platform should be less than the setting value, which serves as a basis for judging whether the thermal protector base is placed flat;

[0041] S52, there are 1\2\3 height difference setting values, that is, the maximum height difference between the heating wire point 1, point 2, and point 3 should be less than the setting value, as a basis for judging whether the heating wire in the thermal protector is assembled flat;

[0042] S53, there is a minimum high point gap setting value, that is, the difference between the highest point value among the heating wire points 1, 2, and 3 and the average height of the bimetallic strip mounting platform should be greater than the set value, which serves as a basis for judging whether the minimum gap between the heating wire and the bimetallic strip in the thermal protector exceeds the minimum limit, thereby avoiding the risk of short circuit between the heating wire and the bimetallic strip;

[0043] S54, there are upper and lower limit settings for the average height gap test value, that is, the difference between the average height of the heating wire at points 1, 2, and 3 and the average height of the bimetallic strip mounting platform should be greater than the set lower limit and less than the set upper limit, as a basis for judging whether the gap between the heating wire and the bimetallic strip is qualified;

[0044] S6. After the start button is pressed, the central processing unit receives a test start signal from terminal X2 via the switch signal input interface, and the test device begins automatic test operation. If the stop button is pressed during the automatic test operation, the central processing unit receives a test stop signal from terminal X3 via the switch signal input interface, and controls the test device to stop the test operation.

[0045] After the test is started, the measurement and control system automatically performs the following steps:

[0046] S61. Step 1: The central processing unit first outputs a position motion signal to the position motion control unit, controls the linkage between the Y-axis slide and the X-axis slide, and drives the laser displacement sensor to move to the test point b. The laser displacement sensor obtains the height signal of the test point b, which is processed by the data acquisition unit and input into the central processing unit to obtain the height data of point b. Then, the same motion control method is used to move the laser displacement sensor to the test point c to obtain the height data of point c. The central processing unit performs calculations on the height data of the test points b\c to obtain the difference and average value of the height data of b\c. The difference of the height data of b\c is compared with the set b\c height difference setting value. If it is greater than the b\c height difference setting value, the test interface of the human-machine interface indicates "Thermal protection base is not leveled" and the test stops. Otherwise, it indicates that the thermal protection base has been leveled and the next test continues.

[0047] S62, step 2: using the same motion control method to move the laser displacement sensor to test point 1, test point 2, and test point 3 respectively, and inputting the data from the data acquisition unit to the central processing unit to obtain the height data of test point 1, test point 2, and test point 3 respectively, the central processing unit performs calculation processing on the height data of test points 1\2\3, and obtains the maximum difference, the highest point value, and the average value of the height data of test points 1\2\3 respectively. At the same time, the difference between the average value of the height data of test points b\c and the highest point value of the height data of test points 1\2\3 is obtained as the minimum height gap calculation value between the heating wire and the bimetallic strip, and the difference between the average value of the height data of test points b\c and the average value of the height data of test points 1\2\3 is obtained as the average height gap calculation value between the heating wire and the bimetallic strip;

[0048] S63, step 3: compare the maximum difference of the height data of test points 1\2\3 with the height difference setting value of 1\2\3. If it is greater than the height difference setting value of 1\2\3, the test interface of the human-machine interface indicates "heating wire is uneven" and the test stops. Otherwise, the test passes.

[0049] Then compare the calculated minimum height gap between the heating wire and the bimetallic strip with the minimum height gap setting value. If it is less than the minimum height gap setting value, the test interface of the human-machine interface will indicate "heating wire height exceeds safety limit" and the test will stop. Otherwise, the test is passed.

[0050] Then compare the calculated average height gap value of the heating wire and the bimetallic strip with the upper and lower limit settings of the average height gap respectively. If it is less than the lower limit setting value of the average height gap, the test interface of the human-machine interface indicates "heating wire height exceeds the lower limit"; if it is greater than the upper limit setting value of the average height gap, the test interface of the human-machine interface indicates "heating wire height exceeds the upper limit"; if it is greater than the lower limit setting value of the average height gap and less than the upper limit setting value of the average height gap, the test interface of the human-machine interface indicates "passed", and the entire test process is completed;

[0051] During the test, if a certain item is detected to be unqualified and the test is stopped or after the entire test is completed, the sliding component automatically performs a reset procedure and the laser displacement sensor is reset to the origin position.

[0052] Compared with the existing technology, the present invention has the following advantages: the measurement accuracy can be improved by adopting non-contact measurement through the laser displacement sensor, the thermal protector base assembly is placed in the positioning cavity, the four sides of the thermal protector base assembly are positioned by the edge of the positioning cavity, and the upper and lower parts are positioned by four measuring seat positioning columns; the reference pin can ensure a fixed height, which serves as an absolute reference point a for each measurement of the device; during measurement, the gasket is placed on the heating wire so that the laser irradiation point is always a plane; at the beginning of each measurement, the laser irradiation point is first moved to the end face of the measuring reference pin, that is, the reference point a, to obtain the reference height data to ensure the test accuracy; by rotating the screw, the dovetail sliding block can be driven to slide up and down between the dovetail fixed blocks, thereby adjusting the initial position of the laser displacement sensor so that it is in the specified measurement stroke position. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a schematic diagram of the three-dimensional structure of a device for measuring the height of a heating wire of a thermal protector according to an embodiment of the present invention.

[0054] Figure 2 It is a schematic diagram of the three-dimensional structure of the carriage assembly according to an embodiment of the present invention.

[0055] Figure 3 It is a schematic diagram of the three-dimensional structure of the measuring seat assembly according to an embodiment of the present invention.

[0056] Figure 4 It is a schematic diagram of the exploded structure of the measuring seat assembly according to an embodiment of the present invention.

[0057] Figure 5 1 is a schematic top view of the structure of the measuring base assembly according to an embodiment of the present invention.

[0058] Figure 6 Schematic diagram of the measurement of the laser displacement sensor according to the embodiment of the present invention.

[0059] Figure 7 It is a schematic cross-sectional structure diagram of a thermal protector base assembly in the prior art.

[0060] Figure 8 Schematic diagram of the connection relationship of the control system of an embodiment of the present invention.

[0061] Figure 9 1 is a schematic diagram of a setting interface of a human-machine interface in a control system according to an embodiment of the present invention.

[0062] Figure 10 1 is a schematic diagram of a test interface of a human-machine interface in a control system according to an embodiment of the present invention.

[0063] In the figure: measuring seat assembly 1, carriage assembly 2, sliding assembly 3, control system 4, laser displacement sensor 5, workbench 6, thermal protector base assembly 7, heating wire 8, bimetallic strip 9, thermal protector base 10, seat base plate 11, positioning plate 12, positioning cavity 13, cushion block 14, reference pin 15, positioning column 16, gasket 17, positioning pin 18, screw 19, carriage seat 21, dovetail fixing block 22, dovetail sliding block 23, screw 24, screw pressure plate 25, screw handwheel 26, Y-axis slide 31, X-axis slide 32, connecting arm 33, first positioning column 161, second positioning column 162, first Three positioning posts 163, fourth positioning post 164, first positioning surface 71, second positioning surface 72, third positioning surface 73, fourth positioning surface 74, programmable controller PLC, central processing unit CPU, signal amplifier IL-SA, analog-to-digital conversion module AD, Y-axis origin proximity switch SQ1, X-axis origin proximity switch SQ2, start button SB1, stop button SB2, switch signal input interface IN, switch signal output interface OUT, Y-axis driver QDY, Y-axis motor MY, X-axis driver QDX, X-axis motor MX, human-machine interface MT, serial communication interface RS232. DETAILED DESCRIPTION

[0064] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0065] See also Figures 1 to 10 As shown, it should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0066] The height measuring device for the heating wire of the thermal protector in this embodiment includes a measuring base assembly 1, a drag plate assembly 2, a sliding assembly 3, a laser displacement sensor 5 and a workbench 6. The measuring base assembly 1 and the sliding assembly 3 are both arranged on the workbench 6, the drag plate assembly 2 is arranged on the sliding assembly 3, the laser displacement sensor 5 is arranged on the drag plate assembly 2, and the laser displacement sensor 5 is located above the measuring base assembly 1. The sliding assembly 3 and the laser displacement sensor 5 are both connected to the control system 4.

[0067] The measuring seat assembly 1 in this embodiment includes a seat base plate 11, a positioning plate 12, a positioning cavity 13, a cushion block 14 and a reference pin 15. The seat base plate 11 is arranged on the workbench 6, the positioning plate 12 is arranged on the seat base plate 11, the seat base plate 11 and the positioning plate 12 are arranged on the workbench 6 through the positioning pin 18 and the screw 19, the positioning cavity 13 and the reference pin 15 are both arranged on the positioning plate 12, the cushion block 14 is arranged in the positioning cavity 13, a positioning groove is provided on the cushion block 14, and a positioning column 16 is provided in the positioning groove.

[0068] In this embodiment, a thermal protector base assembly 7 is placed in the positioning cavity 13, and the bottom of the thermal protector base assembly 7 contacts the positioning column 16. The bottom of the thermal protector base assembly 7 is provided with a first positioning surface 71, a second positioning surface 72, a third positioning surface 73 and a fourth positioning surface 74. There are four positioning columns 16, and the four positioning columns 16 are respectively a first positioning column 161, a second positioning column 162, a third positioning column 163 and a fourth positioning column 164. The first positioning column 161, the second positioning column 162, the third positioning column 163 and the fourth positioning column 164 are respectively in contact with the first positioning surface 71, the second positioning surface 72, the third positioning surface 73 and the fourth positioning surface 74. A gasket 17 is placed above the heating wire 8 of the thermal protector base assembly 7. The gasket 17 cooperates with the laser displacement sensor 5, and the gasket 17 is arranged in an Ω-shaped structure.

[0069] The carriage assembly 2 in this embodiment includes a carriage seat 21, a dovetail fixing block 22, a dovetail sliding block 23, a screw 24, a screw pressure plate 25 and a screw handwheel 26. The carriage seat 21 is arranged on the X-axis slide 32, the dovetail fixing block 22 is arranged on the carriage seat 21, the dovetail sliding block 23 is slidably arranged on the dovetail fixing block 22, the screw pressure plate 25 is arranged on the dovetail sliding block 23, the screw 24 is rotatably arranged on the screw pressure plate 25, and the screw 24 is connected to the dovetail fixing block 22 by threads, and the screw handwheel 26 is arranged on the screw 24.

[0070] The sliding assembly 3 in this embodiment includes a Y-axis slide 31, an X-axis slide 32 and a connecting arm 33. The Y-axis slide 31 is set on the workbench 6, the connecting arm 33 is set on the Y-axis slide 31, the X-axis slide 32 is set on the connecting arm 33, and the drag plate assembly 2 is set on the X-axis slide 32.

[0071] Specifically, the height measurement works as follows: the laser displacement sensor 5 can detect Figure 5 The absolute height Hx between each point shown and the detection port of the laser displacement sensor 5; point a is the measurement reference point, points b and c are the bimetallic strip installation steps, and their heights should be consistent, otherwise the thermal protector base assembly 7 is not level, and the thermal protector base assembly 7 should be reset; points 1, 2, and 3 of the gasket 17 should theoretically be the same height, but in reality, due to the unevenness of the heating wire 8, they will not be the same height, and the average value is the average height; by calculating the height of each point, the distance between the average height of the heating wire 8 and the bimetallic strip installation step (minus the thickness of the gasket 17) can be obtained.

[0072] The control system 4 in this embodiment includes a programmable controller PLC, a signal amplifier IL-SA, a human-machine interface MT, a Y-axis driver QDY, a Y-axis motor MY, an X-axis driver QDX, an X-axis motor MX, a Y-axis origin proximity switch SQ1, an X-axis origin proximity switch SQ2, a start button SB1 and a stop button SB2. The programmable controller PLC includes a central processing unit CPU, an analog-to-digital conversion module AD, a switch signal input interface IN, a switch signal output interface OUT, and a serial communication interface RS232.

[0073] The central processing unit (CPU) in this embodiment includes components such as a logic operator, registers, and a controller. It performs functions such as data storage, logical operations, and processing result control through software. It receives real-time height data signals from the data acquisition unit, comparative position parameters required for position motion and setup parameters required for test result judgment from the human-machine interface (MT) via the RS232 serial communication interface, and origin position signals and test start / stop signals from the switch signal input control unit. It performs logical operation control and comparison processing on various signals and data according to software design requirements. The processed motion control signals are output to the position motion control unit to implement X-axis and Y-axis linkage. The processed height test data and result judgment indication are output to the human-machine interface (MT) via the RS232 serial communication interface for display.

[0074] In this embodiment, the data acquisition unit is composed of a laser displacement sensor 5, a signal amplifier IL-SA and an analog-to-digital conversion module AD. The laser displacement sensor 5 is connected to the signal amplifier IL-SA, the signal amplifier IL-SA is connected to the analog-to-digital conversion module AD, and the analog-to-digital conversion module AD is connected to the central processing unit CPU.

[0075] Among them, the laser displacement sensor 5 is a sensor that uses laser technology for measurement. Its advantage is that it uses a contactless measurement method. The working principle is that according to the difference in relative displacement between the bimetallic strip installation step test points (points b and c) and the heating wire test points (points 1, 2, and 3) in the thermal protector being measured and the laser displacement sensor 5, the red laser emitted by the laser displacement sensor 5 is reflected at different angles when it is directed at the tested point. The reflected laser at different angles is projected onto the internal photosensitive element through the receiver lens at different light spot positions. This light spot position signal is digitally processed and transmitted to the signal amplifier IL-SA. The signal amplifier IL-SA amplifies and converts the displacement signal input by the laser displacement sensor 5, outputs an analog signal related to the displacement of the tested point, and inputs it into the analog-to-digital conversion module AD. The analog-to-digital conversion module AD converts the input analog signal into a digital signal and transmits it to the central processing unit CPU for logical operation processing.

[0076] In this embodiment, a switch signal input control unit is composed of the Y-axis origin proximity switch SQ1, the X-axis origin proximity switch SQ2, the start button SB1, the stop button SB2 and the switch signal input interface IN. One end of the Y-axis origin proximity switch SQ1, the X-axis origin proximity switch SQ2, the start button SB1 and the stop button SB2 are respectively connected to the X0, X1, X2 and X3 ends of the switch signal input interface IN, and the other ends of the Y-axis origin proximity switch SQ1, the X-axis origin proximity switch SQ2, the start button SB1 and the stop button SB2 are connected to the V- end of the DC power supply, the COM end of the switch signal input interface IN is connected to the V+ end of the DC power supply, and the switch signal input interface IN is connected to the central processing unit CPU.

[0077] The external switch signal is converted and processed through the switch signal input interface IN and then sent to the central processing unit CPU for logic control processing. When the Y-axis origin proximity switch SQ1 senses a signal, the central processing unit CPU receives the X0 end signal of the switch signal input interface IN, indicating that the Y-axis slide 31 has moved to the origin position. When the X-axis origin proximity switch SQ2 senses a signal, the central processing unit CPU receives the X1 end signal of the switch signal input interface IN, indicating that the X-axis slide 32 has moved to the origin position. When the start button SB1 is pressed, the central processing unit CPU receives the X2 end signal of the switch signal input interface IN, and starts the measuring device to automatically run the entire test process according to the software design requirements. When the stop button SB2 is pressed during the test, the central processing unit CPU receives the X3 end signal of the switch signal input interface IN, and controls the measuring device to stop running.

[0078] In this embodiment, the position motion control unit is composed of a switch signal output interface OUT, a Y-axis driver QDY, a Y-axis motor MY, an X-axis driver QDX, and an X-axis motor MX. The central processing unit CPU is connected to the switch signal output interface OUT. The Y0 and Y1 ends of the switch signal output interface OUT are connected to the Y-axis driver QDY, wherein the Y0 end is connected to the negative (-) end of the pulse control PUL of the Y-axis driver QDY, wherein the Y1 end is connected to the negative (-) end of the direction control DIR of the Y-axis driver QDY. The four terminals (A+, A-, B+, B-) of the Y-axis driver QDY are connected to the Y-axis motor MY. The shaft of the Y-axis motor MY is mechanically connected to the Y-axis linear slide through a coupling. The switch signal output interface The Y2 and Y3 terminals of OUT are connected to the X-axis driver QDX, where the Y2 terminal is connected to the negative (-) terminal of the pulse control PUL of the X-axis driver QDX, and the Y3 terminal is connected to the negative (-) terminal of the direction control DIR of the X-axis driver QDX. The four terminals (A+, A-, B+, B-) of the X-axis driver QDX are connected to the X-axis motor MX. The shaft of the X-axis motor MX is mechanically connected to the X-axis linear slide through a coupling. The negative terminal (-) of the switch signal output interface OUT is connected to the V- terminal of the DC power supply. The positive terminal (+) of the pulse control PUL and direction control DIR of the Y-axis driver QDY are connected to the positive terminal (+) of the pulse control PUL and direction control DIR of the X-axis driver QDX and then connected to the V+ terminal of the DC power supply.

[0079] During the test run, the data and signals such as the distance, speed, direction, etc. that need to be moved are processed by the logic operation of the software in the central processing unit CPU, and the switch signal output interface OUT is controlled to output the pulse signal and direction signal to the PUL signal input terminal and DIR signal input terminal of the Y-axis driver QDY and the X-axis driver QDX. After the internal signal processing of the Y-axis driver QDY and the X-axis driver QDX, the motor drive signal is output to control the operation of the Y-axis motor MY and the X-axis motor MX, and then the linear slide is driven by the motor to perform linear motion. In this motion control process, the number of pulses of the pulse signal controls the angular displacement of the motor operation and thus controls the linear motion distance of the linear slide. The frequency of the pulse signal controls the operating speed of the motor and thus controls the speed of the linear motion of the linear slide. The direction signal controls the direction of the motor operation and thus controls the direction of the linear slide.

[0080] In this embodiment, the data setting display unit is composed of a human-machine interface MT and a serial communication interface RS232. The serial communication interface RS232 is connected to the central processing unit CPU. The serial communication interface RS232 is connected to the human-machine interface MT via a data line. The human-machine interface MT performs two-way communication with the central processing unit CPU via the serial communication interface RS232.

[0081] Its function is to set the position parameters required for position operation and the comparison parameters required for test result judgment, and to display the height test data and test result indication. The setting parameters required for position operation include the X-axis and Y-axis position parameters of the test reference point a, the bimetallic installation step test points (points b and c), and the heating wire test points (points 1, 2, and 3). The setting parameters required for test result judgment include the maximum limit value of the height difference between points b and c of the bimetallic installation platform (to judge the flatness of the placement of the thermal protector base), the maximum limit value of the height difference between points 1, 2, and 3 of the heating wire (to judge the assembly flatness of the heating wire in the thermal protector), and the minimum limit value of the difference between the highest point of the heating wire at points 1, 2, and 3 and the average height of the bimetallic installation platform (to judge the flatness of the heating wire in the thermal protector). The display data includes the measured height data of points b and c of the bimetallic installation step, the measured height data of points 1, 2 and 3 of the heating wire, the height difference and the height average value calculated data of test points b\c, the maximum height difference and the height average value calculated data of test points 1\2\3, the minimum height gap and the average height gap calculated value of the heating wire and the bimetallic strip, and the test result indication. If any test data exceeds the limit during the test, the test result will indicate the abnormal alarm and the test will be terminated.

[0082] The laser displacement sensor 5 is a KEYENCE non-contact laser measurement sensor, model IL-S065.

[0083] Among them, the model of the signal amplifier IL-SA is IL-1500.

[0084] Among them, the model of the programmable controller PLC is FP-XHC40T.

[0085] Among them, the central processing unit CPU is the central processing device inside the programmable controller PLC.

[0086] Among them, the analog-to-digital conversion module AD is an analog input plug-in on the programmable controller PLC, model AFPX-AD2.

[0087] Among them, the model of the Y-axis origin proximity switch SQ1 is LU672-5NA.

[0088] Among them, the model of the X-axis origin proximity switch SQ2 is LU672-5NA.

[0089] Among them, the model of the start button SB1 is AS2204-10D.

[0090] Among them, the model of the stop button SB2 is AS2204-01D.

[0091] Among them, the switch signal input interface IN is the switch signal input terminal inside the programmable controller PLC.

[0092] Among them, the switch signal output interface OUT is the switch signal output end inside the programmable controller PLC.

[0093] Among them, the model of the Y-axis driver QDY is ASD-545E.

[0094] Among them, the model of Y-axis motor MY is 2304HS42D8.

[0095] Among them, the model of the X-axis driver QDX is ASD-545E.

[0096] Among them, the model of X-axis motor MX is 2304HS42D8.

[0097] Among them, the model of the human-machine interface MT is MT6071iE.

[0098] Among them, the serial communication interface RS232 is the communication interface end inside the programmable controller PLC.

[0099] The measuring method of the device for measuring the height of the heating wire of the thermal protector in this embodiment is as follows:

[0100] S1. Turn on the power of the control system 4 and move the laser displacement sensor 5 to the reference point a so that the light spot of the laser displacement sensor 5 is irradiated on the near center point of the end face of the reference pin 15, and the center point is visually observed to be within ±1 mm.

[0101] S2. The initial position of the laser displacement sensor 5 is adjusted in the up and down directions as follows:

[0102] S21, manually rotating the screw hand wheel 26, can drive the laser displacement sensor 5 to move up and down through the dovetail sliding block 23;

[0103] S22. The digital display window of the laser displacement sensor 5 shows green when the number is within the specified effective detection distance, and red when it is outside the effective detection distance. It is required to display green. At the same time, it is required that based on the end face detection point of the reference pin 15, the screw 24 rotates clockwise for not less than 2 turns and counterclockwise for not less than 2 turns. The digital display should be green to ensure that the entire test process is within the effective detection distance of the sensor.

[0104] S3. Place the thermal protector base assembly 7 into the positioning cavity 13 of the positioning plate 12.

[0105] S4. Place the gasket 17 with its smooth side facing upward on the heating wire 8 in the thermal protector base assembly 7 , with the opening of the gasket 17 corresponding to the opening of the heating wire 8 .

[0106] S5. Press the start button SB1. The measuring device automatically moves to each measuring point in the measuring order and obtains the height data of each point at the same time. The measurement is terminated after the measuring point returns to the end face of the reference pin 15. The measuring order is point a → point b → point c → point 1 → point 2 → point 3 → origin. The position movement of the X and Y axes is completed by the X-axis slide 32 and the Y-axis slide 31.

[0107] S6. After the measurement is completed, the height measurement data and the test result indication are displayed on the test interface of the human-machine interface MT of the control system 4.

[0108] In this embodiment, the control method implemented by the control system 4 is as follows:

[0109] S1. After the measuring device is turned on, the laser displacement sensor 5 automatically resets the origin position. If the measuring device does not reset the origin position, the origin reset action can be performed by pressing the "Origin Reset" button on the parameter setting interface of the human-machine interface MT. The position motion control unit controls the Y-axis slide 31 and the X-axis slide 32 to move to their respective origin proximity switch sensing positions according to the design requirements of the central processing unit CPU reset software.

[0110] S2. Set the X-axis and Y-axis position parameters of the reference point a in the parameter setting interface of the human-machine interface MT, for example, set the X-axis to "10mm" and the Y-axis to "2mm". The setting data is input into the central processing unit CPU through the serial communication interface RS232 and stored in the register. Press the "reference point a" button. The central processing unit CPU processes the position data according to the software design requirements, calculates and converts the position data into pulse signals and direction signals, and outputs them to the position motion control unit. The position motion control unit controls the Y-axis slide 31 and the X-axis slide 32 to move in conjunction, driving the laser displacement sensor 5 to move to the reference point a position. If the reference point a position parameters are set correctly, the light spot of the laser displacement sensor 5 should be near the center point of the end face of the reference pin 15. If there is any deviation, it is corrected by changing the X-axis and Y-axis position setting parameters of the reference point a until the light spot of the laser displacement sensor 5 is near the center point of the end face of the reference pin 15.

[0111] S3. First place the thermal protector base assembly 7 to be tested into the positioning cavity 13 of the positioning plate 12, and then place the gasket 17 with the smooth side facing up on the heating wire 8 of the thermal protector base assembly 7, with the opening of the gasket 17 corresponding to the opening of the heating wire 8.

[0112] S4. Set the X-axis and Y-axis position parameters of test point b, test point c, test point 1, test point 2, and test point 3 in the parameter setting interface of the human-machine interface MT according to the method in step 2. When the test point button at the corresponding position is pressed, the Y-axis slide 31 and the X-axis slide 32 combination will drive the laser displacement sensor 5 to the corresponding position. Observe whether the light spot of the laser displacement sensor 5 is at the corresponding test position. If a test point is not at the corresponding position, correct it by changing the X-axis and Y-axis position setting parameters of the test point. If all test points are at the corresponding position, the position adjustment is completed.

[0113] S5. Set the comparison parameters related to the test result judgment in the setting interface of the human-machine interface MT. These setting parameters are saved in the internal register of the central processing unit CPU through the serial communication interface RS232 and serve as comparison values for judging whether the test value exceeds the limit or is qualified.

[0114] S51. There is a height difference setting value b\c, that is, the height difference between point b and point c on the bimetallic strip mounting platform should be less than the setting value, which serves as a basis for judging whether the thermal protector base 10 is placed flat.

[0115] S52. There are 1\2\3 height difference setting values, that is, the maximum height difference between points 1, 2, and 3 of the heating wire should be less than the setting value, which serves as the basis for judging whether the heating wire in the thermal protector is assembled flat.

[0116] S53. There is a minimum high point gap setting value, that is, the difference between the highest point of the heating wire at points 1, 2, and 3 and the average height of the bimetallic strip mounting platform should be greater than the setting value. This serves as a basis for judging whether the minimum gap between the heating wire and the bimetallic strip in the thermal protector exceeds the minimum limit, thereby avoiding the risk of short circuit between the heating wire and the bimetallic strip.

[0117] S54. There are upper and lower limit settings for the average height gap test value, that is, the difference between the average height of the heating wire at points 1, 2, and 3 and the average height of the bimetallic strip mounting platform should be greater than the set lower limit and less than the set upper limit, which serves as the basis for judging whether the gap between the heating wire and the bimetallic strip is qualified.

[0118] S6. After pressing the start button SB1, the central processing unit CPU receives the test start signal from the X2 end through the switch signal input interface IN, and the test device starts automatic test operation according to the software design requirements. If the stop button SB2 is pressed during the automatic test operation, the central processing unit CPU receives the test stop signal from the X3 end through the switch signal input interface IN, and controls the test device to stop the test operation.

[0119] After the test is started, the measurement and control system automatically performs the following steps:

[0120] S61. The central processing unit CPU first outputs a position motion signal to the position motion control unit, controls the linkage between the Y-axis slide 31 and the X-axis slide 32, and drives the laser displacement sensor 5 to move to the test point b position. The laser displacement sensor 5 obtains the height signal of the test point b, which is processed by the data acquisition unit and input into the central processing unit CPU to obtain the height data of point b. Then, the same motion control method is used to move the laser displacement sensor 5 to the test point c position to obtain the height data of point c. The central processing unit CPU performs calculations on the height data of the test points b\c according to the software design requirements to obtain the difference and average value of the height data of b\c, and compares the difference of the height data of b\c with the set b\c height difference setting value. If it is greater than the b\c height difference setting value, the test interface of the human-machine interface MT indicates "The thermal protection base is not leveled" and the test stops. Otherwise, it indicates that the thermal protection base has been leveled and continues to the next test.

[0121] S62. Use the same motion control method to move the laser displacement sensor 5 to test point 1, test point 2, and test point 3 respectively. After the data acquisition unit inputs the data into the central processing unit CPU, the height data of test point 1, test point 2, and test point 3 are obtained respectively. The central processing unit CPU calculates and processes the height data of test points 1\2\3 according to the software design requirements, and obtains the maximum difference, the highest point value, and the average value of the height data of test points 1\2\3 respectively. At the same time, the difference between the average value of the height data of test point b\c and the highest point value of the height data in test point 1\2\3 is obtained as the minimum height gap calculation value between the heating wire and the bimetallic strip. At the same time, the difference between the average value of the height data of test point b\c and the average value of the height data of test point 1\2\3 is obtained as the average height gap calculation value between the heating wire and the bimetallic strip.

[0122] S63. Compare the maximum difference of the height data of test points 1\2\3 with the height difference setting value of 1\2\3. If it is greater than the height difference setting value of 1\2\3, the test interface of the human-machine interface MT indicates "heating wire is uneven" and the test stops. Otherwise, the test passes.

[0123] Then compare the calculated value of the minimum height gap between the heating wire and the bimetallic strip with the minimum height gap setting value. If it is less than the minimum height gap setting value, the test interface of the human-machine interface MT will indicate "heating wire height exceeds safety limit" and the test will stop. Otherwise, the test is passed.

[0124] Then compare the calculated value of the average height gap between the heating wire and the bimetallic strip with the upper and lower limit settings of the average height gap respectively. If it is less than the lower limit setting value of the average height gap, the MT test interface of the human-machine interface indicates "heating wire height exceeds the lower limit"; if it is greater than the upper limit setting value of the average height gap, the MT test interface of the human-machine interface indicates "heating wire height exceeds the upper limit"; if it is greater than the lower limit setting value of the average height gap and less than the upper limit setting value of the average height gap, the MT test interface of the human-machine interface indicates "qualified", and the entire test process ends here.

[0125] During the test, if a failure is detected and the test is stopped or the entire test is completed, the sliding component 3 automatically performs a reset procedure and the laser displacement sensor 5 is reset to the origin position.

[0126] Here we take the test reference point a as an example and randomly select it as 5.023mm. The test interface is as follows Figure 10 shown.

[0127] Ha: The measured height of the reference point a.

[0128] Hb, Hc: The measured data for the heights of test points b and c of the bimetallic strip installation steps.

[0129] H1, H2, H3: The measured height data of the heating wire test point 1, test point 2, and test point 3.

[0130] b\c Height difference: Hb-Hc=5.873-5.755=0.118mm, smaller than the setting interface Figure 9 The setting value shown is 0.15 mm, which means that the flatness of the thermal protection base is within an acceptable range.

[0131] 1\2\3 Maximum height difference: H1-H3=5.965-5.583=0.382mm, smaller than the setting interface Figure 9 The setting value shown is 0.40mm, which means that the flatness of the heating wire assembly is within an acceptable range.

[0132] Minimum height clearance: the average value of the highest point of the heating wire H3 + the thickness of the gasket - the height of b\c = (5.583 + 1 - 5.814) = 0.769mm, which is greater than the setting interface Figure 9 The setting value shown is 0.65mm, which means that the risk of short circuit between the bimetallic strip and the heating wire is extremely low.

[0133] Average height clearance: 1\2\3 height average + gasket thickness - b\c height average = (5.776+1-5.814) = 0.962 mm, which is larger than the setting interface Figure 9 The lower limit setting value shown is 0.8 mm and is less than the upper limit setting value of 1.2 mm, indicating that the value is within the acceptable range.

[0134] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is merely an example of the structure of the present invention.

Claims

1. A device for measuring the height of a heating wire of a thermal protector, comprising a carriage assembly, a sliding assembly, a laser displacement sensor, and a workbench, characterized in that: The measuring seat assembly (1) further comprises a measuring seat assembly (1), wherein the measuring seat assembly (1) and the sliding assembly (3) are both arranged on a workbench (6), the drag plate assembly (2) is arranged on the sliding assembly (3), the laser displacement sensor (5) is arranged on the drag plate assembly (2), and the laser displacement sensor (5) is located above the measuring seat assembly (1), and the sliding assembly (3) and the laser displacement sensor (5) are both connected to a control system (4); the measuring seat assembly (1) comprises a seat base plate (11), a positioning plate (12), a positioning cavity (13), a pad (14) and a reference pin (15), the seat base plate (11) is arranged on the workbench (6), the positioning plate ( 12) is arranged on the base plate (11), the positioning cavity (13) and the reference pin (15) are both arranged on the positioning plate (12), the pad (14) is arranged in the positioning cavity (13), the pad (14) is provided with a positioning groove, a positioning column (16) is provided in the positioning groove, a thermal protector base assembly (7) is placed in the positioning cavity (13), the bottom of the thermal protector base assembly (7) is in contact with the positioning column (16), a gasket (17) is placed above the heating wire (8) of the thermal protector base assembly (7), the gasket (17) cooperates with the laser displacement sensor (5), and the gasket (17) is arranged in an Ω-shaped structure; The control system (4) includes a programmable controller (PLC), a signal amplifier (IL-SA), a human-machine interface (MT), a Y-axis driver (QDY), a Y-axis motor (MY), an X-axis driver (QDX), an X-axis motor (MX), a Y-axis origin proximity switch (SQ1), an X-axis origin proximity switch (SQ2), a start button (SB1) and a stop button (SB2); the programmable controller (PLC) includes a central processing unit (CPU), an analog-to-digital conversion module (AD), a switch signal input interface (IN), a switch signal output interface (OUT), and a serial communication interface (RS232). The data acquisition unit is composed of a laser displacement sensor (5), a signal amplifier (IL-SA) and an analog-to-digital conversion module (AD). The switch signal input control unit is composed of the Y-axis origin proximity switch (SQ1), the X-axis origin proximity switch (SQ2), the start button (SB1), the stop button (SB2) and the switch signal input interface (IN). The position motion control unit is composed of a switch signal output interface (OUT), a Y-axis driver (QDY), a Y-axis motor (MY), an X-axis driver (QDX) and an X-axis motor (MX). The data setting display unit is composed of a human-machine interface (MT) and a serial communication interface (RS232).

2. The device for measuring the height of a heating wire of a thermal protector according to claim 1, characterized in that: The sliding assembly (3) comprises a Y-axis slide (31), an X-axis slide (32) and a connecting arm (33), wherein the Y-axis slide (31) is arranged on a workbench (6), the connecting arm (33) is arranged on the Y-axis slide (31), the X-axis slide (32) is arranged on the connecting arm (33), and the carriage assembly (2) is arranged on the X-axis slide (32).

3. The device for measuring the height of a heating wire of a thermal protector according to claim 1, characterized in that: The carriage assembly (2) comprises a carriage seat (21), a dovetail fixing block (22), a dovetail sliding block (23), a screw (24), a screw pressure plate (25) and a screw handwheel (26), wherein the carriage seat (21) is arranged on the X-axis slide (32), the dovetail fixing block (22) is arranged on the carriage seat (21), the dovetail sliding block (23) is slidably arranged on the dovetail fixing block (22), the screw pressure plate (25) is arranged on the dovetail sliding block (23), the screw (24) is rotatably arranged on the screw pressure plate (25), and the screw (24) is connected to the dovetail fixing block (22) by a thread, and the screw handwheel (26) is arranged on the screw (24).

4. The device for measuring the height of a heating wire of a thermal protector according to claim 1, characterized in that: The seat base plate (11) and the positioning plate (12) are arranged on the workbench (6) via positioning pins (18) and screws (19).

5. The device for measuring the height of a heating wire of a thermal protector according to claim 1, characterized in that: The bottom of the thermal protector base assembly (7) is provided with a first positioning surface (71), a second positioning surface (72), a third positioning surface (73) and a fourth positioning surface (74); the number of the positioning columns (16) is four, and the four positioning columns (16) are respectively a first positioning column (161), a second positioning column (162), a third positioning column (163) and a fourth positioning column (164); the first positioning column (161), the second positioning column (162), the third positioning column (163) and the fourth positioning column (164) are in contact with the first positioning surface (71), the second positioning surface (72), the third positioning surface (73) and the fourth positioning surface (74), respectively.

6. The device for measuring the height of a heating wire of a thermal protector according to claim 1, characterized in that: The laser displacement sensor (5) is connected to a signal amplifier (IL-SA), the signal amplifier (IL-SA) is connected to an analog-to-digital conversion module (AD), and the analog-to-digital conversion module (AD) is connected to a central processing unit (CPU). One end of the Y-axis origin proximity switch (SQ1), the X-axis origin proximity switch (SQ2), the start button (SB1), and the stop button (SB2) are respectively connected to the X0, X1, X2, and X3 ends of the switch signal input interface (IN); the other ends of the Y-axis origin proximity switch (SQ1), the X-axis origin proximity switch (SQ2), the start button (SB1), and the stop button (SB2) are connected and then connected to the V-end of the DC power supply; the COM end of the switch signal input interface (IN) is connected to the V+ end of the DC power supply; and the switch signal input interface (IN) is connected to a central processing unit (CPU). The central processing unit (CPU) is connected to the switch signal output interface (OUT), and the Y0 and Y1 ends of the switch signal output interface (OUT) are connected to the Y-axis driver (QDY), wherein the Y0 end is connected to the negative end of the pulse control PUL of the Y-axis driver (QDY), and the Y1 end is connected to the negative end of the direction control DIR of the Y-axis driver (QDY). The four terminals of the Y-axis driver (QDY) are connected to the Y-axis motor (MY), and the shaft of the Y-axis motor (MY) is mechanically connected to the Y-axis linear slide through a coupling. The Y2 and Y3 ends of the switch signal output interface (OUT) are connected to the X-axis driver (QDX). , wherein the Y2 end is connected to the negative end of the pulse control PUL of the X-axis driver (QDX), wherein the Y3 end is connected to the negative end of the direction control DIR of the X-axis driver (QDX), the four terminals of the X-axis driver (QDX) are connected to the X-axis motor (MX), and the shaft of the X-axis motor (MX) is mechanically connected to the X-axis linear slide through a coupling, the negative end of the switch signal output interface (OUT) is connected to the DC power supply V-end, the positive end of the pulse control PUL and direction control DIR of the Y-axis driver (QDY) is connected to the positive end of the pulse control PUL and direction control DIR of the X-axis driver (QDX), and then connected to the DC power supply V+ end, The serial communication interface (RS232) is connected to the central processing unit (CPU), the serial communication interface (RS232) is connected to the human-machine interface (MT) through a data line, and the human-machine interface (MT) performs two-way communication with the central processing unit (CPU) through the serial communication interface (RS232).

7. A method for measuring the height of a heating wire of a thermal protector according to any one of claims 1 to 6, characterized in that: The measuring method is as follows: S1. Turn on the power of the control system (4), move the laser displacement sensor (5) to the reference point a position, so that the light spot of the laser displacement sensor (5) is irradiated on the near center point of the end face of the reference pin (15), and the center point is visually observed to be within ±1 mm; S2. The initial position of the laser displacement sensor (5) in the up and down directions is adjusted as follows: S21, manually rotating the screw hand wheel (26), which can drive the laser displacement sensor (5) to move up and down through the dovetail sliding block (23); S22, the digital display window of the laser displacement sensor (5), when the digital display is green, it means that it is within the specified effective detection distance, and red means that it is outside the effective detection distance. It is required to display green. At the same time, it is required that the screw (24) rotates clockwise for not less than 2 turns and counterclockwise for not less than 2 turns based on the end face detection point of the reference pin (15), and the digital display should be green to ensure that the entire test process is within the effective detection distance of the sensor; S3, placing the thermal protector base assembly (7) into the positioning cavity (13) of the positioning plate (12); S4. Place the gasket (17) with its smooth side facing upward on the heating wire (8) in the thermal protector base assembly (7), with the opening of the gasket (17) corresponding to the opening of the heating wire (8); S5. Press the start button (SB1). The measuring device automatically moves to each measuring point in the measuring order and obtains the height data of each point at the same time. The measurement is terminated after the measuring point returns to the end face of the reference pin (15). The measuring order is point a → point b → point c → point 1 → point 2 → point 3 → origin. The position movement of the X and Y axes is completed by the X-axis slide (32) and the Y-axis slide (31). S6. After the measurement is completed, the height measurement data and the test result indication are displayed on the test interface of the human-machine interface (MT) of the control system (4).

8. The measuring method for the height measuring device of the heating wire of the thermal protector according to claim 7, characterized in that: The control method is implemented by the control system (4) as follows: S1. After the measuring device is turned on, the laser displacement sensor (5) automatically resets the origin position. If the measuring device does not reset the origin position, the origin reset action can be performed by pressing the "origin reset" button on the parameter setting interface of the human-machine interface (MT). The position motion control unit controls the Y-axis slide (31) and the X-axis slide (32) to move to their respective origin proximity switch sensing positions according to the central processing unit (CPU); S2. Set the X-axis and Y-axis position parameters of the reference point a in the parameter setting interface of the human-machine interface (MT). The setting data is input into the central processing unit (CPU) through the serial communication interface (RS232) and kept in the register. Press the "reference point a" button. The central processing unit (CPU) calculates and converts the position data into a pulse signal and a direction signal and outputs it to the position motion control unit. The position motion control unit controls the Y-axis slide (31) and the X-axis slide (32) to move together, driving the laser displacement sensor (5) to move to the reference point a position. If the reference point a position parameter is set correctly, the light spot of the laser displacement sensor (5) should be near the center point of the end face of the reference pin (15). If there is a deviation, it is corrected by changing the X-axis and Y-axis position setting parameters of the reference point a until the light spot of the laser displacement sensor (5) is near the center point of the end face of the reference pin (15); S3. First, place the thermal protector base assembly (7) to be tested into the positioning cavity (13) of the positioning plate (12), and then place the gasket (17) with the smooth side facing upward on the heating wire (8) of the thermal protector base assembly (7), with the opening of the gasket (17) corresponding to the opening of the heating wire (8); S4. According to the method in step 2, the X-axis and Y-axis position parameters of test point b, test point c, test point 1, test point 2, and test point 3 are set in the parameter setting interface of the human-machine interface (MT). When the test point button at the corresponding position is pressed, the Y-axis slide (31) and the X-axis slide (32) combination will drive the laser displacement sensor (5) to the corresponding position, and observe whether the light spot of the laser displacement sensor (5) is at the corresponding test position. If a test point is not at the corresponding position, it is corrected by changing the X-axis and Y-axis position setting parameters of the test point. If all test points are at the corresponding position, the position adjustment is completed. S5. Set the comparison parameters related to the test result judgment in the setting interface of the human-machine interface (MT). These setting parameters are saved in the internal register of the central processing unit (CPU) through the serial communication interface (RS232) and serve as the comparison values for judging whether the test value exceeds the limit or passes. S51, there is a height difference setting value b\c, that is, the height difference between point b and point c on the bimetallic strip mounting platform should be less than the setting value, as a basis for judging whether the thermal protector base (10) is placed flat; S52, there are 1\2\3 height difference setting values, that is, the maximum height difference between the heating wire point 1, point 2, and point 3 should be less than the setting value, as a basis for judging whether the heating wire in the thermal protector is assembled flat; S53, there is a minimum high point gap setting value, that is, the difference between the highest point value among the heating wire points 1, 2, and 3 and the average height of the bimetallic strip mounting platform should be greater than the set value, which serves as a basis for judging whether the minimum gap between the heating wire and the bimetallic strip in the thermal protector exceeds the minimum limit, thereby avoiding the risk of short circuit between the heating wire and the bimetallic strip; S54, there are upper and lower limit settings for the average height gap test value, that is, the difference between the average height of the heating wire at points 1, 2, and 3 and the average height of the bimetallic strip mounting platform should be greater than the set lower limit and less than the set upper limit, as a basis for judging whether the gap between the heating wire and the bimetallic strip is qualified; S6. After the start button (SB1) is pressed, the central processing unit (CPU) receives the test start signal from the X2 terminal through the switch signal input interface (IN), and the test device begins automatic test operation. If the stop button (SB2) is pressed during the automatic test operation, the central processing unit (CPU) receives the test stop signal from the X3 terminal through the switch signal input interface (IN), and controls the test device to stop the test operation. After the test is started, the measurement and control system automatically performs the following steps: S61, the first step: the central processing unit (CPU) first outputs a position motion signal to the position motion control unit, controls the Y-axis slide (31) and the X-axis slide (32) to be linked, drives the laser displacement sensor (5) to move to the test point b position, the laser displacement sensor (5) obtains the height signal of the test point b, and after being processed by the data acquisition unit, inputs the signal to the central processing unit (CPU) to obtain the height data of point b, and then uses the same motion control method to move the laser displacement sensor (5) to the test point c position, obtains the height data of point c, and the central processing unit (CPU) performs calculation processing on the height data of the test points b\c, obtains the difference and average value of the height data of b\c, compares the difference of the height data of b\c with the set height difference setting value of b\c, if it is greater than the height difference setting value of b\c, the test interface of the human-machine interface (MT) indicates "the thermal protection base is not flat", and the test stops, otherwise, it means that the thermal protection base has been flat, and continues to the next test; S62, the second step: using the same motion control method to make the laser displacement sensor (5) move to the test point 1, test point 2, and test point 3 respectively, and the data acquisition unit inputs the data into the central processing unit (CPU) to obtain the height data of the test point 1, test point 2, and test point 3 respectively, and the central processing unit (CPU) performs calculation processing on the height data of the test point 1\2\3, and obtains the maximum difference, the highest point value, and the average value of the height data of the test point 1\2\3 respectively, and at the same time obtains the difference between the average value of the height data of the test point b\c and the highest point value of the height data of the test point 1\2\3 as the minimum height gap calculation value of the heating wire and the bimetallic strip, and at the same time obtains the difference between the average value of the height data of the test point b\c and the average value of the height data of the test point 1\2\3 as the average height gap calculation value of the heating wire and the bimetallic strip; S63. Step 3: Compare the maximum difference of the height data of test points 1\2\3 with the height difference setting value of 1\2\3. If it is greater than the height difference setting value of 1\2\3, the test interface of the human-machine interface (MT) will indicate "heating wire is uneven" and the test will stop. Otherwise, the test is passed. Then compare the calculated minimum height gap between the heating wire and the bimetallic strip with the minimum height gap setting value. If it is less than the minimum height gap setting value, the test interface of the human-machine interface (MT) will indicate "heating wire height exceeds safety limit" and the test will stop. Otherwise, the test is passed. Then compare the calculated average height gap value of the heating wire and bimetallic strip with the upper and lower limit settings of the average height gap respectively. If it is less than the lower limit setting value of the average height gap, the test interface of the human-machine interface (MT) will indicate "heating wire height exceeds the lower limit". If it is greater than the upper limit setting value of the average height gap, the test interface of the human-machine interface (MT) will indicate "heating wire height exceeds the upper limit". If it is greater than the lower limit setting value of the average height gap and less than the upper limit setting value of the average height gap, the test interface of the human-machine interface (MT) will indicate "passed", and the entire test process is completed. During the test, when a failure is detected and the test is stopped or the entire test is completed, the sliding component (3) automatically performs a reset procedure and the laser displacement sensor (5) is reset to the origin position.

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