Equipment and method for manufacturing a thermal protector and its heating element

Abstract

This invention relates to a thermal protector and its heating element manufacturing equipment and method, belonging to the field of thermal protectors. The invention includes a pin, a cover plate, a moving spring assembly, a bimetallic strip, a first stationary foot, a second stationary foot, a heating element, a third stationary foot assembly, and a base. The pin is disposed on the cover plate. The moving spring assembly, bimetallic strip, first stationary foot, second stationary foot, heating element, and third stationary foot assembly are all disposed within a cavity formed by the cover plate and the base. Both ends of the heating element are welded to the first and second stationary feet, respectively. One end of the moving spring assembly is electrically connected to the first stationary foot, and the other end of the moving spring assembly cooperates with one end of the third stationary foot assembly. The other end of the third stationary foot assembly is electrically connected to the pin. The structural feature is that the heating element has a planar geometric structure and is formed by bending.

Description

Technical Field

[0001] This invention relates to a thermal protector and its heating element manufacturing equipment and manufacturing method, belonging to the field of thermal protectors, and is mainly used for over-temperature rise and over-current protection of refrigeration compressors or other motors. Background Technology

[0002] Current refrigeration compressors (with resistor R1) all have a thermal protector (with resistor R2) connected in series. The thermal protector is mainly used for over-temperature and over-current protection of the refrigeration compressor. Existing thermal protectors consist of a three-component system (pin, stationary pin, moving spring assembly, and heating element assembly) that forms a protective circuit that is electrically connected under normal conditions and disconnected under abnormal conditions. The thermal protector has a heating element and a bimetallic strip. When the refrigerator compressor stalls or the voltage becomes unstable, the current increases. When the heat generated by the heating element reaches the set operating temperature of the bimetallic strip, the thermal protector will trip and disconnect the electrical circuit. When the thermal protector reaches the set reset temperature, the bimetallic strip will reset and reconnect the electrical circuit. The relevant technical parameters of the thermal protector, such as the operating current and operating temperature, are mainly used to disconnect the circuit under specific current and at a certain temperature to provide protection, i.e., over-temperature and over-current protection.

[0003] The resistance of the heating element is related to the current of the thermal protector. A higher resistance results in a lower current, and a lower resistance results in a higher current. There are many types and specifications of thermal protectors available. Typically, the current is 1-50A and the breaking temperature is 100-160℃. When the current is 1-25A, a spiral heating element is generally used, while when the current is 26-50A, a planar heating element is generally used. When using a spiral heating element, the resistance can be increased but it is difficult to decrease. Conversely, when using a planar heating element, the resistance can be decreased but it is difficult to increase. Both have their advantages and disadvantages.

[0004] In the design, the resistance of the heating element determines the product current. The resistance of the heating element is related to the length, cross-sectional area, and resistivity of the material. Therefore, the required resistance value of the heating wire material can be determined using the resistance formula. Right now Only after the required cross-sectional area S is calculated can a geometric heating element be designed to fit the heating element loading cavity of the thermal protector base.

[0005] The current manufacturing method involves winding wire into a spiral shape and stamping or cutting sheet metal into a flat shape (such as...). Figure 3 , Figure 4 ), spiral heating element (such as Figure 3 As shown, most of the heat generated when current passes through is absorbed by the base, extending the protection time, while planar heating elements (such as...) Figure 4(As shown) Compared to spiral heating elements, less heat is absorbed by the base, resulting in a shorter protection time. However, due to the high cost and waste of materials caused by stamping or cutting sheet metal, and the difference in processing between sheet metal and wire during raw material processing, the accuracy of sheet metal thickness control is far inferior to that of wire diameter control. Therefore, the uneven thickness of the sheet metal heating element after stamping or cutting leads to inconsistent and discrete resistance values. Summary of the Invention

[0006] The purpose of this invention is to overcome the aforementioned shortcomings in the prior art and provide a thermal protector with a reasonable structural design. The heating element in this thermal protector is formed into a planar geometric shape by bending, and its cross-section is circular, which can improve product consistency. The radius r of the heating element can be calculated by a formula, which is intended to control the height position of the heating element in the loading cavity and avoid the risk of short circuit caused by the heating element contacting the bimetallic strip due to an excessively large radius r. At the same time, by calculating the size of the heating element's radius r, the maximum current carrying capacity can be known to meet the usage requirements.

[0007] The technical solution adopted by this invention to solve the above problems is as follows: The thermal protector includes a pin, a cover plate, a moving spring assembly, a bimetallic strip, a stationary pin one, a stationary pin two, a heating element, a stationary pin three assembly, and a base. The pin is disposed on the cover plate. The moving spring assembly, bimetallic strip, stationary pin one, stationary pin two, heating element, and stationary pin three assembly are all disposed within the cavity formed by the cover plate and the base. Both ends of the heating element are welded to stationary pin one and stationary pin two, respectively. One end of the moving spring assembly is electrically connected to stationary pin one, and the other end of the moving spring assembly cooperates with one end of stationary pin three assembly. The other end of stationary pin three assembly is electrically connected to the pin. Its structural feature is that the heating element has a planar geometric structure, is formed by bending, and has a circular cross-section with a radius of r.

[0008] The calculation process for the radius r of the heating element is as follows:

[0009] (Formula 1)

[0010] Where △T represents the difference between the operating temperature of the thermal protector and the ambient temperature, KT represents the temperature rise coefficient, U represents the voltage, R1 represents the resistance of the refrigeration compressor, and R2 represents the resistance of the heating element.

[0011] (Formula 2)

[0012] Where ρ represents resistivity and L represents the length of the heating element;

[0013] The radius r of the heat source can be calculated using the above formulas (1) and (2).

[0014] Furthermore, when the other end of the moving spring assembly contacts one end of the stationary foot three-component assembly, the stationary foot two, the heating element, the stationary foot one, the moving spring assembly, the stationary foot three-component assembly, and the pin are sequentially electrically connected to form an electrical circuit.

[0015] Furthermore, the base is provided with a loading cavity for placing the heating element, and the bottom of the loading cavity is provided with a limiting platform for limiting the height of the heating element.

[0016] Furthermore, the limiting platform is provided with two strip-shaped protrusions.

[0017] Furthermore, the heating element is made of alloy resistance wires of different diameters, such as nickel-chromium, constantan, and iron-chromium, and is bent into m-shaped, U-shaped, S-shaped, and Ω-shaped structures.

[0018] Furthermore, the heating element, bimetallic strip, and moving spring assembly are arranged sequentially from bottom to top.

[0019] Furthermore, another technical objective of the present invention is to provide a manufacturing device that uses a bending process to process the heating element and can be bent into various planar geometric shapes.

[0020] The above-mentioned technical objective of the present invention is achieved through the following technical solution.

[0021] A manufacturing apparatus for producing a heating element is characterized in that: the manufacturing apparatus includes a conveying mechanism for conveying a heating wire, a bending mechanism for bending the heating wire into a planar geometric structure, and a cutting mechanism for cutting the bent heating wire to form a heating element. The cutting mechanism is located above the bending mechanism, and both the cutting mechanism and the bending mechanism cooperate with the conveying mechanism.

[0022] Furthermore, the conveying mechanism includes a fixed base, a servo motor, a transmission gear set, and a spool assembly. The servo motor, transmission gear set, and spool assembly are all mounted on the fixed base, and the servo motor is connected to the transmission gear set. The servo motor drives the transmission gear set to push the heating wire, and the spool assembly adjusts the heating wire to a flat position.

[0023] Furthermore, the cutting mechanism includes a fixed frame, a cylinder, and scissors. The cylinder barrel is fixed on the fixed frame, and the piston rod of the cylinder is connected to the scissors, which are pushed by the cylinder.

[0024] Furthermore, the bending mechanism includes a fixed plate, a guide wheel assembly, a line positioning seat, a bending needle, a rotating wheel, a second servo motor, and a bending seat. The guide wheel assembly, the line positioning seat, and the bending seat are all mounted on the fixed plate. The line positioning seat is located between the guide wheel assembly and the bending seat. The bending needle is mounted on the bending seat. The bending seat is coaxially connected to the rotating wheel. The rotating wheel is connected to the second servo motor via a belt and a pulley.

[0025] Furthermore, the manufacturing equipment is controlled by an electronic control system, which includes a servo driver 1, an encoder 1, a servo driver 2, an encoder 3, a start button, a sensor 1, a sensor 2, an origin sensor, a sensor 3, a sensor 4, a solenoid valve 1, a solenoid valve 2, and a programmable controller. The programmable controller includes a central processing unit, an input interface, and an output interface. The input interface and the output interface are both connected to the central processing unit. The input interface is connected to the start button, sensor 1, sensor 2, origin sensor, sensor 3, and sensor 4, respectively. The output interface is connected to servo driver 1, servo driver 2, solenoid valve 1, and solenoid valve 2, respectively. Servo driver 1 is connected to servo motor 1 and encoder 1, respectively, and servo driver 2 is connected to servo motor 2 and servo motor 2, respectively.

[0026] Furthermore, another technical objective of the present invention is to provide a method for manufacturing a heating element.

[0027] The above-mentioned technical objective of the present invention is achieved through the following technical solution.

[0028] A method for manufacturing a heating element manufacturing device, characterized by the following manufacturing method:

[0029] S1. Based on the shape of the heating element, break down the manufacturing steps and set the operating parameters for each manufacturing step;

[0030] S2. Thread the heating wire through the wire assembly, transmission gear assembly, guide wheel assembly, wire positioning seat, and two bending needles;

[0031] S3. Press the start button. The electronic control system will control the production equipment to automatically complete the entire production process according to the program design requirements in the central processing unit and the production steps and operating parameters set in S1.

[0032] S4. Servo motor two performs a home reset action. The input interface receives a signal from the home sensor, indicating that servo motor two is at the zero position; the input interface receives a signal from sensor number two, indicating that the cylinder is at the original position; the input interface receives a signal from sensor number three, indicating that the scissors are at the original position; if all positions are at the original position, proceed to the next action.

[0033] S5. When the output interface is connected to the No. 1 solenoid valve, the air circuit control cylinder drives the scissors to descend to the corresponding position of the heating wire. After the input interface receives the descent signal from the No. 1 sensor, it will proceed with the next action control.

[0034] S6. When the output interface is connected to the second solenoid valve, the air path controls the scissors to perform the closing action, cutting off the excess part of the heating wire. After the input interface receives the scissors closing position signal from the fourth sensor, the output interface disconnects the second solenoid valve, and the air path controls the scissors to perform the opening action. After the input interface receives the opening position signal from the third sensor, the next action control is performed.

[0035] S7. When the output interface disconnects the first solenoid valve, the pneumatic control cylinder drives the scissors to the rising position. After the input interface receives the rising position signal from the second sensor, it will proceed with the next action control.

[0036] S8. Following the manufacturing steps and operating parameters set in S1, the output interface outputs pulse signals and direction signals respectively. After receiving the signals, the servo driver 1, together with the servo motor 1 and the encoder 1, controls the servo motor 1 to operate precisely, driving the transmission gear set to precisely deliver the heating wire according to the set length, speed, and direction.

[0037] S9. According to the production steps and operating parameters set in S1, the output interface outputs pulse signals and direction signals respectively. After receiving the signals, the servo driver 2 cooperates with the servo motor 2 and the encoder 2 to control the servo motor 2 to run precisely in a closed loop. Through the mechanical transmission of belt, pulley, rotating wheel, bending seat and bending needle, the bending action is completed according to the set bending angle and bending direction.

[0038] S10. Repeat steps S8 and S9 according to the decomposed production steps until all production steps are completed.

[0039] S11. After all production steps are completed, the servo motor rotates twice to return to the zero position, and runs S5, S6, and S7 to complete the material cutting action.

[0040] S12, the electronic control system detects the original position and zero point position of all actions, thus ending the production cycle of a product.

[0041] Compared with existing technologies, this invention has the following advantages: This thermal protector uses a bending process to bend the heating wire into various planar shapes such as M-shape, U-shape, S-shape, and Ω-shape, solving the problems of minimizing the resistance of wire heating elements and maximizing the resistance of plate heating elements. This effectively expands the current range and increases the specifications of thermal protector products using both wire and plate heating elements, not only meeting more market demands but also improving the thermal efficiency of the thermal protector, thus better protecting the motor. Simultaneously, it reduces raw material waste, bringing higher profits to enterprises. The heating element made from wire has a uniform thickness and stable, consistent resistance after processing, ensuring stable current and improving the precise protection function of the thermal protector. Attached Figure Description

[0042] Figure 1 This is a three-dimensional structural diagram of the thermal protector according to an embodiment of the present invention.

[0043] Figure 2 This is an exploded structural diagram of the thermal protector according to an embodiment of the present invention.

[0044] Figure 3 This is a schematic diagram of the internal structure of a thermal protector (spiral heating element) in the prior art.

[0045] Figure 4 This is a schematic diagram of the internal structure of a thermal protector (planar heating element) in the prior art.

[0046] Figure 5 This is a schematic diagram of the internal structure of the thermal protector according to an embodiment of the present invention.

[0047] Figure 6 This is a three-dimensional structural diagram of the base according to an embodiment of the present invention.

[0048] Figure 7a This is a three-dimensional structural schematic diagram of the first heating element according to an embodiment of the present invention.

[0049] Figure 7b This is a three-dimensional structural diagram of the second type of heating element according to an embodiment of the present invention.

[0050] Figure 7c This is a three-dimensional structural diagram of the third type of heating element in an embodiment of the present invention.

[0051] Figure 7d This is a three-dimensional structural diagram of the fourth type of heating element according to an embodiment of the present invention.

[0052] Figure 7e This is a three-dimensional structural diagram of the fifth type of heating element in this invention.

[0053] Figure 7f This is a three-dimensional structural diagram of the sixth heating element according to an embodiment of the present invention.

[0054] Figure 7g This is a schematic diagram of the cross-sectional structure of the heating element in an embodiment of the present invention.

[0055] Figure 8 This is a three-dimensional structural diagram of the heating element manufacturing equipment according to an embodiment of the present invention.

[0056] Figure 9 This is a three-dimensional structural diagram of the conveying mechanism according to an embodiment of the present invention.

[0057] Figure 10 This is a three-dimensional structural schematic diagram of the cutting mechanism according to an embodiment of the present invention.

[0058] Figure 11 This is a three-dimensional structural diagram of the bending mechanism according to an embodiment of the present invention.

[0059] Figure 12 This is a schematic diagram of the connection relationship of the electronic control system according to an embodiment of the present invention.

[0060] In the diagram: 1. Pin 2. Cover plate 3. Moving spring assembly 4. Bimetallic strip 5. Stationary pin 1 6. Stationary pin 2 7. Heating element 8. Stationary pin 3 assembly 9. Base

[0061] Loading cavity 9-1, limiting stage 9-2,

[0062] A. Conveying mechanism; B. Cutting mechanism; C. Bending mechanism

[0063] Mounting bracket A1, servo motor A2, transmission gear set A3, assembly wheel set A4

[0064] Fixture B1, Cylinder B2, Scissors B3

[0065] Fixed plate C1, guide wheel assembly C2, line positioning seat C3, bending pin C4, rotating wheel C5, servo motor C6, bending seat C7

[0066] Sensor 1 (SQ1), Sensor 2 (SQ2), Origin Sensor (SQ3), Sensor 3 (SQ4), Sensor 4 (SQ5), Start Button (SQ0)

[0067] Solenoid valve No. 1 FB2, Solenoid valve No. 2 FB3,

[0068] Programmable Logic Controller (PLC), Central Processing Unit (CPU), Input Interface IN, Output Interface OUT

[0069] Servo driver SA2, encoder BM1

[0070] Servo driver 2 SC6, encoder 2 BM2. Detailed Implementation

[0071] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0072] Example

[0073] See Figures 1-2 , Figures 5-12 As shown in the accompanying drawings, the structures, proportions, sizes, etc., depicted are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness or purpose of the invention, should still fall within the scope of the disclosed technical content. Furthermore, the use of terms such as "upper," "lower," "left," "right," "middle," and "one" in this specification is merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0074] The thermal protector in this embodiment (such as...) Figures 1-2 , Figures 5-7c As shown), it includes pin 1, cover plate 2, moving spring assembly 3, bimetallic strip 4, stationary foot 1 5, stationary foot 2 6, heating element 7, stationary foot 3 assembly 8 and base 9. Pin 1 is set on cover plate 2. Moving spring assembly 3, bimetallic strip 4, stationary foot 1 5, stationary foot 2 6, heating element 7 and stationary foot 3 assembly 8 are all set in the cavity formed by cover plate 2 and base 9. Heating element 7, bimetallic strip 4 and moving spring assembly 3 are arranged in sequence from bottom to top.

[0075] The two ends of the heating element 7 are welded to stationary foot 5 and stationary foot 6 respectively. One end of the moving spring assembly 3 is electrically connected to stationary foot 5. The other end of the moving spring assembly 3 is engaged with one end of stationary foot assembly 8 (that is, when the other end of the moving spring assembly 3 is in contact with one end of stationary foot assembly 8, stationary foot 6, heating element 7, stationary foot 5, moving spring assembly 3, stationary foot assembly 8, and pin 1 are electrically connected in sequence to form an electrical circuit). The other end of stationary foot assembly 8 is electrically connected to pin 1. The heating element 7 is arranged in various planar geometric shapes. The heating element 7 is formed by bending. "The heating element 7 is arranged in various planar geometric shapes" means that the axes of each section of the heating wire are in the same plane during the bending process to the heating element 7.

[0076] The base 9 is provided with a loading cavity 9-1 for placing the heating element 7. The bottom of the loading cavity 9-1 is provided with a limiting platform 9-2 for limiting the height of the heating element 7. The limiting platform 9-2 is provided with two strip-shaped protrusions. The heating element 7 is made of alloy resistance wire materials of various wire diameters such as nickel-chromium, constantan, and iron-chromium, and is bent into other malleable shapes such as m-shaped, U-shaped, S-shaped, and Ω-shaped. The cross-section of the heating element 7 is circular with a radius of r.

[0077] The calculation process for the radius r of the heating element 7 is as follows:

[0078] (Formula 1)

[0079] Where △T represents the difference between the operating temperature of the thermal protector and the ambient temperature, KT represents the temperature rise coefficient, U represents the voltage, R1 represents the resistance of the refrigeration compressor, and R2 represents the resistance of the heating element 7.

[0080] (Formula 2)

[0081] Where ρ represents resistivity, and L represents the length of heating element 7, which is 10-60 mm.

[0082] The radius r of the heating body 7 can be calculated using the above formulas (1) and (2). In other words, R2 can be obtained using formula 1, and r can be obtained by substituting R2 into formula 2.

[0083] For example, when ΔT=105℃, KT=2.4, U=220V, R1=33Ω, ρ=1.42, L=20mm, substituting these values ​​into (Formula 1) yields R2=0.33Ω, and substituting R2=0.33Ω into (Formula 2) yields r=0.165mm.

[0084] Specifically, the thermal protector is connected to the compressor via the compressor's three-core terminal block. Simply insert pin 1 into the compressor's three-core terminal block; at the same time, the connecting tab of the stationary pin 2 6 is used for power connection; after inserting the starter into the compressor's three-core terminal block and making electrical connection, it can be put into normal use. When the mains voltage is too high or too low or the refrigeration system malfunctions, the bimetallic strip 4 deforms due to heat, pushing the contact of the moving spring assembly 3 away from the contact of the stationary pin assembly 8, and the thermal protector activates, thereby cutting off the above-mentioned protective circuit and protecting the compressor motor.

[0085] Equipment for manufacturing heating elements (such as) Figures 8-11 As shown, it includes a conveying mechanism A for conveying the heating wire, a bending mechanism C for bending the heating wire into a planar geometric structure, and a cutting mechanism B for cutting the bent heating wire to form a heating element 7. The cutting mechanism B is located above the bending mechanism C, and both the cutting mechanism B and the bending mechanism C cooperate with the conveying mechanism A.

[0086] The conveying mechanism A includes a fixed base A1, a servo motor A2, a transmission gear set A3, and a thread-forming wheel set A4. The servo motor A2, the transmission gear set A3, and the thread-forming wheel set A4 are all mounted on the fixed base A1. The servo motor A2 is connected to the transmission gear set A3. The servo motor A2 drives the transmission gear set A3 to push the heating wire. The thread-forming wheel set A4 adjusts the heating wire to be flat. The thread-forming wheel set A4 consists of multiple rotating wheels arranged in upper and lower rows. The two adjacent rotating wheels are staggered. The upper row of rotating wheels is adjusted to loosen and tighten with the lower row of rotating wheels to press the curved wire (i.e., the heating wire) flat.

[0087] The cutting mechanism B includes a fixed frame B1, a cylinder B2, and scissors B3. The cylinder barrel of cylinder B2 is fixed on the fixed frame B1, and the piston rod of cylinder B2 is connected to scissors B3. Scissors B3 is pushed by cylinder B2. Cylinder B2 cooperates with sensor SQ1, sensor SQ2, and solenoid valve FB2. Scissors B3 cooperates with sensor SQ4, sensor SQ5, and solenoid valve FB3.

[0088] The bending mechanism C includes a fixed plate C1, a guide wheel assembly C2, a line positioning seat C3, a bending needle C4, a rotating wheel C5, a second servo motor C6, and a bending seat C7. The guide wheel assembly C2, the line positioning seat C3, and the bending seat C7 are all mounted on the fixed plate C1. The line positioning seat C3 is located between the guide wheel assembly C2 and the bending seat C7. The bending needle C4 is mounted on the bending seat C7. The bending seat C7 is coaxially connected to the rotating wheel C5. The rotating wheel C5 is connected to the second servo motor C6 via a belt and a pulley. The second servo motor C6 works in conjunction with the origin sensor SQ3.

[0089] The manufacturing equipment consists of an electronic control system (such as...) Figure 12 The system is controlled by a servo driver SA2, encoder BM1, servo driver SC6, encoder BM2, start button SQ0, sensor SQ1, sensor SQ2, origin sensor SQ3, sensor SQ4, sensor SQ5, solenoid valve FB2, solenoid valve FB3, and programmable logic controller (PLC) (model FP2SH). The PLC includes a central processing unit (CPU) (model FP2-C2L), an input interface IN (model FP2-X16D2), and an output interface OUT (model FP2-Y16T). Both the input interface IN and the output interface OUT are connected to the CPU.

[0090] The input interface IN is connected to the start button SQ0, sensor 1 SQ1, sensor 2 SQ2, origin sensor SQ3, sensor 3 SQ4, and sensor 4 SQ5 respectively. The output interface OUT is connected to servo driver 1 SA2, servo driver 2 SC6, solenoid valve 1 FB2, and solenoid valve 2 FB3 respectively. Servo driver 1 SA2 is connected to servo motor 1 A2 and encoder 1 BM1 respectively. Servo driver 2 SC6 is connected to servo motor 2 C6 and servo motor 2 C6 respectively.

[0091] The specific connection methods and functions of the electronic control system are as follows:

[0092] The input interface IN receives various switching signals from external sensors and switches, and transmits them to the central processing unit (CPU).

[0093] The input interface IN is configured with X0, X1, X2, X3, X4, X5, and a common terminal COM.

[0094] Connect the X0 end to one end of the start button SQ0 to start the automatic operation of the production equipment.

[0095] X1 is connected to one end of sensor SQ1, which is the lowering (action) position signal of cylinder B2.

[0096] X2 is connected to one end of sensor SQ2, which is the rising (original) position signal of cylinder B2.

[0097] The X3 terminal is connected to one end of the origin sensor SQ3, which is the zero-point position signal of the servo motor C6.

[0098] The X4 terminal is connected to one end of sensor SQ4 (number 3), which is the position signal of the scissors B3 closing (action).

[0099] The X5 terminal connects to one end of sensor SQ5 (number four), which transmits the original (open) position signal of scissors B3.

[0100] The other ends of the start button SQ0, sensor 1 SQ1, sensor 2 SQ2, origin sensor SQ3, sensor 3 SQ4, and sensor 4 SQ5 are all connected to the negative terminal V- of the DC power supply, and the common terminal COM of the input interface IN is connected to the positive terminal V+ of the DC power supply.

[0101] The output interface OUT outputs a switch signal to control the corresponding action.

[0102] The output interface OUT is configured with terminals Y0, Y1, Y2, Y3, Y4, and Y5.

[0103] Y0-Y1: Y0 and Y1 are connected to the PUL and DIR terminals of servo driver SA2, respectively. The positive terminal + of servo driver SA2 is connected to the positive terminal V+ of the DC power supply. The motor line interface UVW and encoder line interface BM of servo driver SA2 are connected to servo motor A2 and encoder BM1, respectively. Closed-loop control is achieved through the operation control of servo motor A2 and the position feedback of encoder BM1 to ensure the precise operation of servo motor A2. Y0 and Y1 output pulse and direction signals, respectively. The PUL terminal of servo driver SA2 receives the pulse signal and controls the rotation angle and speed of servo motor A2. The DIR terminal of servo driver SA2 receives the direction signal and controls the rotation direction of servo motor A2. These rotation states are controlled by the transmission gear set A3 connected to the shaft of servo motor A2 to realize the control of the length, speed and direction of the heating wire push.

[0104] Y2-Y3 terminals: Y2 and Y3 terminals are connected to the PUL and DIR terminals of servo driver SC6, respectively. The positive terminal (+) of servo driver SC6 is connected to the positive terminal (V+) of the DC power supply. The motor line interface (UVW) and encoder line interface (BM) of servo driver SC6 are connected to servo motor C6 and encoder BM2, respectively. Closed-loop control is achieved through the operation control of servo motor C6 and the position feedback of encoder BM2, ensuring the precise operation of servo motor C6. Y2 and Y3 terminals output pulse and direction signals, respectively. The PUL terminal of servo driver SC6... The UL terminal receives pulse signals to control the rotation angle and speed of servo motor C6 off-center. The DIR terminal of servo driver SC6 receives direction signals to control the rotation direction of servo motor C6. These rotation states are mechanically transmitted through pulleys, belts, rotating wheel C5, bending seat C7, and bending needle C4, which are mechanically connected to the shaft of servo motor C6. Finally, the bending needle C4 executes the bending action of the heating wire. The number of pulse signals controls the bending angle, the frequency of the pulse signals controls the bending speed, and the level of the direction signal controls the bending direction.

[0105] Y4 is connected to one end of solenoid valve FB2, controlling the energization and de-energization of solenoid valve FB2.

[0106] The Y5 terminal is connected to one end of the second solenoid valve FB3, controlling the energization and de-energization of the second solenoid valve FB3.

[0107] The other ends of solenoid valves FB2 (number one) and FB3 (number two) are connected to the positive terminal V+ of the DC power supply, and the negative terminal - of the output interface OUT is connected to the negative terminal V- of the DC power supply.

[0108] The central processing unit (CPU) is the core control component of the electronic control system. Its working principle is to receive the input signal from the input interface IN, perform logic control according to the program design requirements, and output the corresponding control signal at the output interface OUT based on the processing result, thereby realizing the automatic control of the heating element 7 manufacturing process.

[0109] Solenoid valve FB2 receives electrical control from Y4 and controls cylinder B2 to perform actions through air circuit switching.

[0110] Solenoid valve FB3 receives electrical control from terminal Y5 and controls scissors B3 to perform actions via air circuit switching.

[0111] Sensor SQ1 is used to detect the descent (action) position of cylinder B2.

[0112] Sensor SQ2 is used to detect the rising (original) position of cylinder B2.

[0113] The origin sensor SQ3 is used for zero-point position detection of servo motor C6.

[0114] Sensor SQ4 is used for detecting the closing (action) position of scissors B3.

[0115] Sensor 4, SQ5, is used for detecting the open (original) position of scissors B3.

[0116] The method for manufacturing the heating element is as follows:

[0117] S1. Based on the shape of the heating element 7, break down the manufacturing steps and set the operating parameters for each manufacturing step. For example, step N1 pushes the heating wire Lmm, step N2 bends it to the left or right at an H angle, and so on.

[0118] S2. Thread the heating wire through the wire assembly A4, the transmission gear assembly A3, the guide wheel assembly C2, the wire positioning seat C3, and the two bending needles C4.

[0119] S3. Press the start button SQ0. The electrical control system will control the production equipment to automatically complete the entire production process according to the program design requirements in the central processing unit (CPU) and the production steps and operating parameters set in S1.

[0120] S4. Servo motor C6 performs a home reset action. The X3 terminal of input interface IN receives a signal from the home sensor SQ3, indicating that servo motor C6 is at the zero position. The X2 terminal of input interface IN receives a signal from sensor SQ2, indicating that cylinder B2 is at its original position. The X4 terminal of input interface IN receives a signal from sensor SQ4, indicating that scissors B3 is at its original position. If all positions are at their original positions, proceed to the next action.

[0121] S5. When the output interface OUT is connected to the control signal at the Y4 terminal, the first solenoid valve FB2 is energized, and the air circuit control cylinder B2 drives the scissors B3 to descend to the corresponding position of the heating wire. After receiving the descent signal from the first sensor SQ1 at the X1 terminal of the input interface IN, the next action control is performed.

[0122] S6. When the output interface OUT connects to the control signal at the Y5 terminal, the second solenoid valve FB3 is energized, and the pneumatic control scissors B3 performs a closing action, cutting off the excess portion of the heating wire. After the input interface IN receives the scissor closing position signal from the fourth sensor SQ5 at the X5 terminal, the output interface OUT disconnects the control signal at the Y5 terminal, the second solenoid valve FB3 is de-energized, and the pneumatic control scissors B3 performs an opening action. After the input interface IN receives the opening position signal from the third sensor SQ4, the next action control is performed.

[0123] S7. When the output interface OUT disconnects the control signal at the Y4 terminal, the first solenoid valve FB2 is de-energized, the air circuit control cylinder B2 drives the scissors B3 to the rising position, and the input interface IN receives the rising position signal from the second sensor SQ2 and then proceeds to the next action control.

[0124] S8. Following the manufacturing steps and operating parameters set in S1, execute step N1. The Y0 and Y1 terminals of the output interface OUT output pulse signals and direction signals respectively. After receiving the signals, the PUL and DIR terminals of the servo driver SA2 cooperate with the servo motor A2 and the encoder BM1 to control the servo motor A2 to operate precisely, driving the transmission gear set A3 to accurately deliver the heating wire according to the set length, speed, and direction.

[0125] S9. Following the manufacturing steps and operating parameters set in S1, execute step N2. The Y2 and Y3 terminals of the output interface OUT output pulse signals and direction signals respectively. After receiving the signals, the PUL and DIR terminals of servo driver SC6 cooperate with servo motor C6 and encoder BM2 to control servo motor C6 to operate precisely. Through mechanical transmission via pulley, belt, rotating wheel C5, bending seat C7, and bending needle C4, the bending action is completed according to the set bending angle and bending direction.

[0126] S10. Repeat steps S8 and S9 according to the decomposed production steps until all production steps are completed.

[0127] S11. After all production steps are completed, servo motor C6 returns to the zero position and runs S5, S6, and S7 to complete the material cutting action.

[0128] S12, the electronic control system detects the original position and zero point position of all actions, thus ending the production cycle of a product.

[0129] The aforementioned equipment and method for manufacturing the heating element are not limited to the heating element 7 in the thermal protector of this embodiment, but can also be applied to the manufacturing of the heating wire in a thermal protector with a constant bimetallic strip snap time, as disclosed in application number 202322010874.2. Figures 7d-7f As shown.

[0130] Furthermore, it should be noted that the specific embodiments described in this specification may differ in the shape and name of their components, etc. The above description is merely illustrative of the structure of the present invention. All equivalent or simple variations made based on the structure, features, and principles described in this invention are included within the scope of protection of this invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to substitute them, as long as they do not depart from the structure of the invention or exceed the scope defined by the claims, all of which should fall within the scope of protection of this invention.

Claims

1. A device for manufacturing a heating element in a thermal protector, the thermal protector comprising pins, a cover plate, a moving spring assembly, a bimetallic strip, a first stationary pin, a second stationary pin, a heating element, a third stationary pin assembly, and a base, characterized in that: The heating element (7) is formed by bending and is bent into a planar geometric shape. The cross-section of the heating element (7) is circular with a radius of r. The base (9) is provided with a loading cavity (9-1) for placing the heating element (7). The bottom of the loading cavity (9-1) is provided with a limiting platform (9-2) for limiting the height of the heating element (7). The limiting platform (9-2) is provided with two strip-shaped protrusions. The radius r of the heating element (7) is calculated as follows: (Formula 1) Where △T represents the difference between the operating temperature of the thermal protector and the ambient temperature, KT represents the temperature rise coefficient, U represents the voltage, R1 represents the resistance of the refrigeration compressor, and R2 represents the resistance of the heating element. (Formula 2) Where ρ represents resistivity and L represents the length of the heating element (7); The radius r of the heated body (7) can be calculated using the above formulas (1) and (2); The manufacturing equipment includes a conveying mechanism (A) for conveying the heating wire, a bending mechanism (C) for bending the heating wire into a planar geometric structure, and a cutting mechanism (B) for cutting the bent heating wire to form a heating element (7). The cutting mechanism (B) is located above the bending mechanism (C), and both the cutting mechanism (B) and the bending mechanism (C) cooperate with the conveying mechanism (A). The conveying mechanism (A) includes a fixed base (A1), a servo motor (A2), a transmission gear set (A3), and a spool set (A4). The servo motor (A2), the transmission gear set (A3), and the spool set (A4) are all mounted on the fixed base (A1). The servo motor (A2) is connected to the transmission gear set (A3). The servo motor (A2) drives the transmission gear set (A3) to push the heating wire, and the spool set (A4) adjusts the heating wire to be flat. The cutting mechanism (B) includes a fixed frame (B1), a cylinder (B2) and scissors (B3). The cylinder barrel of the cylinder (B2) is fixed on the fixed frame (B1), and the piston rod of the cylinder (B2) is connected to the scissors (B3). The scissors (B3) are pushed by the cylinder (B2). The bending mechanism (C) includes a fixed plate (C1), a guide wheel assembly (C2), a line positioning seat (C3), a bending needle (C4), a rotating wheel (C5), a second servo motor (C6), and a bending seat (C7). The guide wheel assembly (C2), the line positioning seat (C3), and the bending seat (C7) are all mounted on the fixed plate (C1). The line positioning seat (C3) is located between the guide wheel assembly (C2) and the bending seat (C7). The bending needle (C4) is mounted on the bending seat (C7). The bending seat (C7) is coaxially connected to the rotating wheel (C5). The rotating wheel (C5) is connected to the second servo motor (C6) via a belt and a pulley. The manufacturing equipment is controlled by an electronic control system, which includes a servo driver (SA2), an encoder (BM1), a servo driver (SC6), an encoder (BM2), a start button (SQ0), a sensor (SQ1), a sensor (SQ2), an origin sensor (SQ3), a sensor (SQ4), a sensor (SQ5), a solenoid valve (FB2), a solenoid valve (FB3), and a programmable logic controller (PLC). The PLC includes a central processing unit (CPU), an input interface (IN), and an output interface (OUT). Both the input interface (IN) and the output interface (OUT) are... Connected to the central processing unit (CPU), the input interface (IN) is connected to the start button (SQ0), sensor 1 (SQ1), sensor 2 (SQ2), origin sensor (SQ3), sensor 3 (SQ4), and sensor 4 (SQ5), respectively. The output interface (OUT) is connected to servo driver 1 (SA2), servo driver 2 (SC6), solenoid valve 1 (FB2), and solenoid valve 2 (FB3), respectively. Servo driver 1 (SA2) is connected to servo motor 1 (A2) and encoder 1 (BM1), respectively. Servo driver 2 (SC6) is connected to servo motor 2 (C6) and servo motor 2 (C6), respectively.

2. The equipment for manufacturing the heating element in the thermal protector according to claim 1, characterized in that: When the other end of the moving spring assembly (3) contacts one end of the stationary foot assembly (8), the stationary foot two (6), the heating element (7), the stationary foot one (5), the moving spring assembly (3), the stationary foot assembly (8), and the pin (1) are connected in sequence to form an electrical circuit.

3. The equipment for manufacturing the heating element in the thermal protector according to claim 1, characterized in that: The pin (1) is set on the cover plate (2). The moving spring assembly (3), bimetallic strip (4), stationary foot one (5), stationary foot two (6), heating element (7), and stationary foot three assembly (8) are all set in the cavity formed by the cover plate (2) and the base (9). The heating element (7), bimetallic strip (4) and moving spring assembly (3) are arranged sequentially from bottom to top. The two ends of the heating element (7) are welded to stationary foot one (5) and stationary foot two (6) respectively. One end of the moving spring assembly (3) is electrically connected to stationary foot one (5). The other end of the moving spring assembly (3) is mutually matched with one end of stationary foot three assembly (8). The other end of stationary foot three assembly (8) is electrically connected to the pin (1).

4. The equipment for manufacturing the heating element in the thermal protector according to claim 1, characterized in that: The heating element (7) is made of alloy resistance wires of different diameters, such as nickel-chromium, constantan, and iron-chromium, and is bent into m-shaped, u-shaped, s-shaped, and Ω-shaped structures.

5. A method for manufacturing a heating element manufacturing device according to claim 1, characterized in that: The production method is as follows: S1. Based on the shape of the heating element (7), decompose the manufacturing steps and set the operating parameters for each manufacturing step; S2. Thread the heating wire into the manufacturing equipment; S3. The electrical control system will control the manufacturing equipment to automatically complete the entire manufacturing process according to the manufacturing steps and operating parameters set in S1. S4, Servo motor two (C6) performs the origin reset action; S5, the cylinder (B2) drives the scissors (B3) to descend to the corresponding position of the heating wire; S6, the scissors (B3) perform a closing action to cut off the excess part of the heating wire, and the scissors (B3) perform an opening action; S7, Cylinder (B2) drives the scissors (B3) to the rising position; S8. Following the manufacturing steps and operating parameters set in S1, servo driver one (SA2) feeds the heating wire according to the set length, speed, and direction. S9. Following the manufacturing steps and operating parameters set in S1, servo driver two (SC6) completes the bending action according to the set bending angle and bending direction. S10. Repeat steps S8 and S9 according to the decomposed production steps until all production steps are completed. S11. After all the production steps are completed, servo motor 2 (C6) returns to the zero position, and runs S5, S6, and S7 to complete the material cutting action; S12, the electronic control system detects the original position and zero point position of all actions, thus ending the production cycle of a product.

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