Thermal protector and manufacturing equipment and manufacturing method of heating body of thermal protector

Abstract

The invention relates to a thermal protector and manufacturing equipment and a manufacturing method of a heating body of the thermal protector, and belongs to the field of thermal protectors. The heating device comprises a plug pin, a cover plate, a movable contact spring assembly, a bimetallic strip, a first static pin, a second static pin, a heating body, a third static pin assembly and a base, the plug pin is arranged on the cover plate, and the movable contact spring assembly, the bimetallic strip, the first static pin, the second static pin, the heating body and the third static pin assembly are all arranged in a cavity formed by the cover plate and the base. The two ends of the heating body are welded to the first static pin and the second static pin respectively, one end of the movable contact spring assembly is electrically connected with the first static pin, the other end of the movable contact spring assembly is matched with one end of the third static pin assembly, and the other end of the third static pin assembly is electrically connected with the plug pin. The heating element is structurally characterized in that the heating element is arranged in a plane geometrical structure, and the heating element is formed by bending.

Description

Technical Field

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

[0002] Currently, a thermal protector (with a resistance of R2) is connected in series in a refrigeration compressor (with a resistance of R1). The thermal protector is mainly used for over-temperature rise and over-current protection of the refrigeration compressor. The thermal protector in the prior art consists of a pin, a static foot three-component, a moving reed component, and a heating element component to form a protective circuit that is electrically connected normally and disconnected abnormally; the thermal protector is provided with a heating element and a bimetal sheet. When the refrigerator compressor has a locked rotor or unstable voltage, the current increases. When the heat generated by passing through the heating element reaches the action temperature set by the bimetal sheet, the thermal protector can act to disconnect the electrical circuit. When the thermal protector reaches the set recovery temperature, the bimetal sheet can reset and continue to connect the electrical circuit. The related technical parameters of the thermal protector, such as the action current and the action temperature, are mainly applied to disconnect the circuit at a certain temperature under a specific current to play a protective role, that is, over-temperature and over-current protection.

[0003] The resistance value of the heating element is related to the current of the thermal protector. A large resistance value results in a small current, and a small resistance value results in a large current. There are many types and specifications of existing thermal protectors. Usually, the current is 1 - 50A and the disconnection temperature is 100 - 160°C. When the current is 1 - 25A, a spiral heating element is generally used. When the current is 26 - 50A, a planar heating element is generally used. When using a spiral heating element, the resistance value can be made large but it is difficult to make it small. When using a planar heating element, the resistance value can be made small but it is difficult to make it large. Both have their advantages and disadvantages.

[0004] When designing, the resistance value of the heating element determines the product current. The resistance value of the heating element is related to the length, cross-sectional area, and resistivity of the material. Therefore, the required cross-sectional area S can be obtained through the resistance formula That is After conversion, in order to design a geometric heating element that can be accommodated in the heating element loading cavity of the thermal protector base.

[0005] The currently adopted manufacturing methods are winding a wire into a spiral shape and stamping or cutting a plate into a planar shape (such as Figure 3 , Figure 4 ). For the spiral heating element (as shown in Figure 3 ), most of the heat generated when the current passes through is absorbed by the base, prolonging the action protection time. For the planar heating element (as shown in Figure 4Compared with the spiral heating element, less heat generated by the spiral heating element is absorbed by the base, and the action protection time is short. However, since sheet metal stamping or cutting results in a large amount of material waste and high costs, and there are technological differences between sheet metal and wire during raw material processing, the accuracy of controlling the thickness of the sheet metal is far inferior to that of controlling the diameter of the wire. Therefore, after stamping or cutting, the sheet metal heating element has poor resistance value discreteness and consistency due to uneven thickness. Summary of the Invention

[0006] The object of the present invention is to overcome the above-mentioned deficiencies existing in the prior art, and to provide a thermal protector with a reasonable structural design. The heating element in the thermal protector is formed into a planar geometric shape by bending, and its cross-section is circular, which can improve the consistency of the product. The radius r of the heating element can be calculated through a formula, and the purpose is to control the height position of the heating element in the loading cavity, avoiding the risk of short circuit caused by the contact between the heating element and the bimetal sheet due to the too large radius r of the heating element. At the same time, by calculating the size of the heating radius r, the maximum current carrying capacity can be known to meet the usage requirements.

[0007] The technical solution adopted by the present invention to solve the above problems is: the thermal protector includes pins, a cover plate, a moving reed assembly, a bimetal sheet, a static pin one, a static pin two, a heating element, a static pin three assembly, and a base. The pins are arranged on the cover plate. The moving reed assembly, the bimetal sheet, the static pin one, the static pin two, the heating element, and the static pin three assembly are all arranged in the cavity formed by the cover plate and the base. The two ends of the heating element are respectively welded to the static pin one and the static pin two. One end of the moving reed assembly is electrically connected to the static pin one. The other end of the moving reed assembly cooperates with one end of the static pin three assembly. The other end of the static pin three assembly is electrically connected to the pins. Its structural feature is that: the heating element is arranged in a planar geometric shape structure, the heating element is formed by bending processing, and the cross-section of the heating element is circular with a radius of r. The calculation process of the radius r of the heating element is as follows: (Formula 1) Where △T represents the temperature difference between the action 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 the resistivity and L represents the length of the heating element; Through the above (Formula 1) and (Formula 2), the radius r of the heating element can be calculated.

[0008] Furthermore, when the other end of the moving reed assembly contacts one end of the static pin three assembly, the static pin two, the heating element, the static pin one, the moving reed assembly, the static pin three assembly, and the pins are electrically connected in sequence to form an electrical circuit.

[0009] Furthermore, a loading cavity for placing a heating element is provided on the base, and a limiting platform for limiting the height of the heating element is provided at the bottom of the loading cavity.

[0010] Furthermore, the limiting platform is arranged in the form of two strip-shaped protrusions.

[0011] Furthermore, the heating element is made of alloy resistance wire materials with different wire diameters of nickel-chromium, constantan, and iron-chromium, and is bent into the shape structures of m-shape, u-shape, s-shape, and Ω-shape.

[0012] Furthermore, the heating element, the bimetallic strip, and the moving reed assembly are arranged in sequence from bottom to top.

[0013] Furthermore, another technical object of the present invention is to provide a manufacturing device that processes a heating element by a bending process and can bend the heating element into various planar geometric shape structures.

[0014] The above technical object of the present invention is achieved through the following technical solutions.

[0015] A manufacturing device for manufacturing a heating element, the structural characteristics of which are: the manufacturing device includes a conveying mechanism for conveying a heating wire, a bending mechanism for bending the heating wire into a planar geometric shape 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.

[0016] Furthermore, the conveying mechanism includes a fixed seat, a servo motor 1, a transmission gear set, and a wire aligning wheel set. The servo motor 1, the transmission gear set, and the wire aligning wheel set are all arranged on the fixed seat, and the servo motor 1 is connected to the transmission gear set. The servo motor 1 drives the transmission gear set to push the heating wire, and the wire aligning wheel set adjusts the heating wire to be flat.

[0017] Furthermore, the cutting mechanism includes a fixed frame, a cylinder, and scissors. The cylinder barrel of the cylinder is fixed on the fixed frame, the piston rod of the cylinder is connected to the scissors, and the scissors are pushed by the cylinder.

[0018] Furthermore, the bending mechanism includes a fixed plate, a wire guiding wheel set, a wire positioning seat, a bending needle, a rotating wheel, a servo motor 2, and a bending seat. The wire guiding wheel set, the wire positioning seat, and the bending seat are all arranged on the fixed plate. The wire positioning seat is located between the wire guiding wheel set and the bending seat. The bending needle is arranged on the bending seat. The bending seat is coaxially connected to the rotating wheel, and the rotating wheel is connected to the servo motor 2 through a belt and a pulley.

[0019] Further, the manufacturing equipment is controlled by an electric control system, which includes a first servo driver, a first encoder, a second servo driver, a second encoder, a start button, a first sensor, a second sensor, a home sensor, a third sensor, a fourth sensor, a first solenoid valve, a second solenoid valve, 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 respectively connected to the start button, the first sensor, the second sensor, the home sensor, the third sensor, and the fourth sensor. The output interface is respectively connected to the first servo driver, the second servo driver, the first solenoid valve, and the second solenoid valve. The first servo driver is respectively connected to a first servo motor and a first encoder. The second servo driver is respectively connected to a second servo motor and the second servo motor.

[0020] Further, another technical object of the present invention is to provide a manufacturing method for a heating element.

[0021] The above technical object of the present invention is achieved by the following technical solutions.

[0022] A manufacturing method for a manufacturing equipment of a heating element, characterized in that the manufacturing method is as follows: S1. According to the shape of the heating element, decompose the manufacturing steps and set the operating parameters for each manufacturing step. S2. Thread the heating wire through between a wire reel group, a transmission gear group, a wire guiding wheel group, a wire positioning seat, and two bending needles. S3. Press the start button, and the electric control system will control the manufacturing equipment to automatically complete the entire manufacturing process according to the program design requirements in the central processing unit and the manufacturing steps and operating parameters set in S1. S4. The second servo motor performs a home return operation. When the input interface receives the signal from the home sensor, it indicates that the second servo motor is at the zero position. When the input interface receives the signal from the second sensor, it indicates that the cylinder is in the original position. When the input interface receives the signal from the third sensor, it indicates that the scissors are in the original position. If all positions are in the original position, perform the next action. S5. The output interface turns on the first solenoid valve, and the pneumatic circuit controls the cylinder to drive the scissors to descend to the corresponding position of the heating wire. After the input interface receives the signal of the first sensor indicating that the descent is in place, perform the next action control. S6. The output interface turns on the second solenoid valve, and the pneumatic circuit controls the scissors to perform a closing action to cut off the excess part of the heating wire. After the input interface receives the signal of the fourth sensor indicating the closing position of the scissors, then the output interface turns off the second solenoid valve, and the pneumatic circuit controls the scissors to perform an opening action. After the input interface receives the signal of the third sensor indicating the opening in place, perform the next action control. S7, the output interface disconnects the No. 1 solenoid valve, the air circuit controls the cylinder to drive the scissors to the rising position, and the input interface receives the rising position signal from the No. 2 sensor to control the next action; S8. 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 1 cooperates with the servo motor 1 and the encoder 1 to control the servo motor 1 to run accurately in a closed loop, driving the transmission gear set to accurately transport the heating wire according to the set length, speed and direction. 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 close the loop and control the servo motor 2 to run accurately. The bending action is completed according to the set bending angle and bending direction through the mechanical transmission of the belt, pulley, rotating wheel, bending seat and bending needle. S10, repeating S8 and S9 according to the decomposed production steps until all production steps are completed; S11. After all the production steps are completed, the servo motor rotates two times back to the zero position, and runs S5, S6, and S7 to complete the shearing action; S12. The electronic control system detects the original position and zero position of all actions, and the production cycle of a product is completed.

[0023] Compared with the prior art, the present invention has the following advantages: the thermal protector adopts a bending processing method to bend the heating wire into various planar structural shapes such as M-shape, U-shape, S-shape, Ω-shape, etc., thereby solving the problem that the resistance value of the wire heating element can be minimized and the resistance value of the plate heating element can be maximized, which is equivalent to the thermal protector product current range and specifications of wire and plate heating elements being expanded, which not only meets more market demands, but also improves the thermal efficiency response of the thermal protector, thereby better protecting the motor, while reducing the loss of raw materials and bringing higher profit value to the enterprise; the heating element made of wire material has uniform thickness and stable and consistent resistance value after processing, which ensures the stability of the current and improves the precise protection function of the thermal protector. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the three-dimensional structure of the thermal protector according to an embodiment of the present invention.

[0025] Figure 2 It is a schematic diagram of the explosion structure of the thermal protector according to an embodiment of the present invention.

[0026] Figure 3 It is a schematic diagram of the internal structure of a thermal protector (spiral heating element) in the prior art.

[0027] Figure 4It is a schematic diagram of the internal structure of a thermal protector (planar heating element) in the prior art.

[0028] Figure 5 It is a schematic diagram of the internal structure of the thermal protector according to an embodiment of the present invention.

[0029] Figure 6 It is a three-dimensional structure schematic diagram of the base according to an embodiment of the present invention.

[0030] Figure 7a It is a three-dimensional structure schematic diagram of the first heating element according to an embodiment of the present invention.

[0031] Figure 7b It is a three-dimensional structure schematic diagram of the second heating element according to an embodiment of the present invention.

[0032] Figure 7c It is a three-dimensional structure schematic diagram of the third heating element according to an embodiment of the present invention.

[0033] Figure 7d It is a three-dimensional structure schematic diagram of the fourth heating element according to an embodiment of the present invention.

[0034] Figure 7e It is a three-dimensional structure schematic diagram of the fifth heating element according to an embodiment of the present invention.

[0035] Figure 7f It is a three-dimensional structure schematic diagram of the sixth heating element according to an embodiment of the present invention.

[0036] Figure 7g It is a cross-sectional structure schematic diagram of the heating element according to an embodiment of the present invention.

[0037] Figure 8 It is a three-dimensional structure schematic diagram of the manufacturing equipment of the heating element according to an embodiment of the present invention.

[0038] Figure 9 It is a three-dimensional structure schematic diagram of the conveying mechanism according to an embodiment of the present invention.

[0039] Figure 10 It is a three-dimensional structure schematic diagram of the cutting mechanism according to an embodiment of the present invention.

[0040] Figure 11 It is a three-dimensional structure schematic diagram of the bending mechanism according to an embodiment of the present invention.

[0041] Figure 12 It is a schematic diagram of the connection relationship of the electric control system according to an embodiment of the present invention.

[0042] In the figure: pin 1, cover plate 2, moving reed assembly 3, bimetal 4, static pin one 5, static pin two 6, heating element 7, static pin three assembly 8, base 9, loading cavity 9-1, limiting platform 9-2, Conveyor mechanism A, cutting mechanism B, bending mechanism C, Fixed seat A1, servo motor 1 A2, transmission gear set A3, whole line wheel set A4, Fixed bracket B1, cylinder B2, scissors B3, Fixed plate C1, wire wheel set C2, wire positioning seat C3, bending needle C4, rotating wheel C5, servo motor 2 C6, bending seat C7, First sensor SQ1, second sensor SQ2, origin sensor SQ3, third sensor SQ4, fourth sensor SQ5, start button SQ0, First solenoid valve FB2, second solenoid valve FB3, Programmable logic controller PLC, central processing unit CPU, input interface IN, output interface OUT, Servo driver 1 SA2, encoder 1 BM1, Servo driver 2 SC6, encoder 2 BM2. Specific implementation mode

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, and the present invention is not limited to the following embodiments.

[0044] Embodiment

[0045] See Figures 1 - 2 、 Figures 5 - 12 As shown, it should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essential significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, if terms such as "upper", "lower", "left", "right", "middle", and "one" are cited in this specification, they are only for the convenience of clear narration and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0046] The thermal protector in this embodiment (such as Figures 1 - 2 、 Figures 5 - 7cAs shown in the figure, it includes a pin 1, a cover plate 2, a moving reed component 3, a bimetal 4, a static pin one 5, a static pin two 6, a heating element 7, a static pin three component 8 and a base 9. The pin 1 is arranged on the cover plate 2. The moving reed component 3, the bimetal 4, the static pin one 5, the static pin two 6, the heating element 7 and the static pin three component 8 are all arranged in the cavity formed by the cover plate 2 and the base 9. The heating element 7, the bimetal 4 and the moving reed component 3 are arranged in sequence from bottom to top.

[0047] Both ends of the heating element 7 are welded to the static pin one 5 and the static pin two 6 respectively. One end of the moving reed component 3 is electrically connected to the static pin one 5, and the other end of the moving reed component 3 cooperates with one end of the static pin three component 8 (that is, when the other end of the moving reed component 3 contacts one end of the static pin three component 8, the static pin two 6, the heating element 7, the static pin one 5, the moving reed component 3, the static pin three component 8 and the pin 1 are electrically connected in sequence and form an electrical circuit). The other end of the static pin three component 8 is electrically connected to the pin 1. The heating element 7 is arranged in a planar geometric shape structure. The heating element 7 is formed by bending. "The heating element 7 is arranged in a planar geometric shape structure" means that the axes of each section of the heating wire are in the same plane during the process of bending the heating wire to the heating element 7.

[0048] 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 arranged in two strip-shaped convex structures. The heating element 7 is processed from various alloy resistance wire materials with different wire diameters such as nickel-chromium, constantan, and iron-chromium, and is bent into other plastic shape structures such as m-shaped, u-shaped, s-shaped, and Ω-shaped. The cross-section of the heating element 7 is circular and its radius is r.

[0049] The calculation process of the radius r of the heating element 7 is as follows: (Formula 1) Where △T represents the temperature difference between the thermal protector action temperature and the ambient temperature, KT represents the heating-up coefficient, U represents the voltage, R1 represents the resistance of the refrigeration compressor, and R2 represents the resistance of the heating element 7; (Formula 2) Where ρ represents the resistivity and L represents the length of the heating element 7, which is 10-60 mm; The radius r of the heating element 7 can be calculated through the above (Formula 1) and (Formula 2). That is, R2 can be obtained through Formula 1, and r can be obtained by substituting R2 into Formula 2.

[0050] For example: when △T = 105 °C, KT = 2.4, U = 220 V, R1 = 33 Ω, ρ = 1.42, and L = 20 mm, substituting these values into (Formula 1) gives R2 = 0.33 Ω. Substituting R2 = 0.33 Ω into (Formula 2) gives r = 0.165 mm.

[0051] Specifically, the thermal protector is connected to the compressor through the three-core terminal of the compressor. Just insert the pin 1 into the three-core terminal of the compressor. At the same time, the connecting piece of the static pin 2-6 is used for power connection. After inserting the starter into the three-core terminal of the compressor and making an electrical connection, it can be put into normal use. When the grid voltage is too high or too low or the refrigeration system fails, the bimetallic strip 4 is heated and deformed, pushing the contact of the moving reed assembly 3 away from the contact of the static pin three assembly 8, and the thermal protector operates, thus cutting off the above protective circuit and playing a role in protecting the compressor motor.

[0052] The manufacturing equipment of the heating element (as Figures 8 - 11 shown) includes a conveying mechanism A for conveying the heating wire, a bending mechanism C for bending the heating wire into a planar geometric shape structure, and a cutting mechanism B for cutting the bent heating wire to form the 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.

[0053] The conveying mechanism A includes a fixed seat A1, a servo motor one A2, a transmission gear set A3, and a wire aligning wheel set A4. The servo motor one A2, the transmission gear set A3, and the wire aligning wheel set A4 are all arranged on the fixed seat A1, and the servo motor one A2 is connected to the transmission gear set A3. The servo motor one A2 drives the transmission gear set A3 to push the heating wire, and the wire aligning wheel set A4 adjusts the heating wire to be flat. The wire aligning wheel set A4 is composed of multiple rotating wheels in two rows, upper and lower, and adjacent rotating wheels are arranged offset from each other. The upper row of rotating wheels is adjusted to fit tightly with the lower row of rotating wheels to press the arc-shaped wire (i.e., the heating wire) flat.

[0054] The cutting mechanism B includes a fixed frame B1, a cylinder B2, and scissors B3. The cylinder barrel of the cylinder B2 is fixed to the fixed frame B1, the piston rod of the cylinder B2 is connected to the scissors B3, and the scissors B3 are pushed by the cylinder B2. The cylinder B2 cooperates with a first sensor SQ1, a second sensor SQ2, and a first solenoid valve FB2. The scissors B3 cooperate with a third sensor SQ4, a fourth sensor SQ5, and a second solenoid valve FB3.

[0055] The bending mechanism C includes a fixing plate C1, a wire guiding wheel set C2, a wire positioning seat C3, a bending needle C4, a rotating wheel C5, a servo motor two C6, and a bending seat C7. The wire guiding wheel set C2, the wire positioning seat C3, and the bending seat C7 are all arranged on the fixing plate C1. The wire positioning seat C3 is located between the wire guiding wheel set C2 and the bending seat C7. The bending needle C4 is arranged 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 servo motor two C6 through a belt and a pulley. The servo motor two C6 cooperates with the origin sensor SQ3.

[0056] The manufacturing equipment is controlled by an electric control system (as Figure 12 shown). The electric control system includes a servo driver one SA2, an encoder one BM1, a servo driver two SC6, an encoder two BM2, a start button SQ0, a first sensor SQ1, a second sensor SQ2, an origin sensor SQ3, a third sensor SQ4, a fourth sensor SQ5, a first solenoid valve FB2, a second solenoid valve FB3, and a programmable logic controller PLC (model number FP2SH). The programmable logic controller PLC includes a central processing unit CPU (model number FP2-C2L), an input interface IN (model number FP2-X16D2), and an output interface OUT (model number FP2-Y16T). Both the input interface IN and the output interface OUT are connected to the central processing unit CPU.

[0057] The input interface IN is respectively connected to the start button SQ0, the first sensor SQ1, the second sensor SQ2, the origin sensor SQ3, the third sensor SQ4, and the fourth sensor SQ5. The output interface OUT is respectively connected to the servo driver one SA2, the servo driver two SC6, the first solenoid valve FB2, and the second solenoid valve FB3. The servo driver one SA2 is respectively connected to the servo motor one A2 and the encoder one BM1. The servo driver two SC6 is respectively connected to the servo motor two C6 and the servo motor two C6.

[0058] The specific connection method and functions of the electric control system are as follows: The input interface IN receives various switch quantity signals from peripheral sensors and switches, etc., and transmits them to the central processing unit CPU.

[0059] The input interface IN is provided with an X0 terminal, an X1 terminal, an X2 terminal, an X3 terminal, an X4 terminal, an X5 terminal, and a common terminal COM.

[0060] The X0 terminal is connected to one end of the start button SQ0 to start the automatic operation of the manufacturing equipment.

[0061] The X1 terminal is connected to one end of the first sensor SQ1, which is the descending (action) position signal of the cylinder B2.

[0062] The X2 terminal is connected to one end of the second sensor SQ2, which is the rising (original) position signal of the cylinder B2.

[0063] The X3 terminal is connected to one end of the origin sensor SQ3, which is the zero position signal of the servo motor two C6.

[0064] The X4 terminal is connected to one end of the third sensor SQ4, which is the scissor closing (action) position signal of the scissor B3.

[0065] The X5 terminal is connected to one end of the fourth sensor SQ5, which is the scissor opening (original) position signal of the scissor B3.

[0066] The other ends of the start button SQ0, the first sensor SQ1, the second sensor SQ2, the origin sensor SQ3, the third sensor SQ4, and the fourth sensor 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.

[0067] The output interface OUT outputs digital quantity signals to control the corresponding execution actions.

[0068] The output interface OUT is provided with terminals Y0, Y1, Y2, Y3, Y4, and Y5.

[0069] Terminal Y0 - Terminal Y1: Terminal Y0 and terminal Y1 are respectively connected to the PUL terminal and DIR terminal of the servo driver one SA2. The positive terminal + of the servo driver one SA2 is connected to the positive terminal V+ of the DC power supply. The motor wire interface UVW and the encoder wire interface BM of the servo driver one SA2 are respectively connected to the servo motor one A2 and the encoder one BM1. Closed-loop control is achieved through the operation control of the servo motor one A2 and the position feedback of the encoder one BM1 to ensure the precise operation of the servo motor one A2; Terminal Y0 and terminal Y1 respectively output pulse and direction signals. The PUL terminal of the servo driver one SA2 receives the pulse signal to control the rotation angle and speed of the servo motor one A2. The DIR terminal of the servo driver one SA2 receives the direction signal to control the rotation direction of the servo motor one A2. These rotation states are used to control the pushing length, speed, and direction of the heating wire through the transmission gear set A3 connected to the shaft of the servo motor one A2.

[0070] Y2 terminal - Y3 terminal: The Y2 terminal and the Y3 terminal are respectively connected to the PUL terminal and the DIR terminal of the second servo driver SC6. The positive terminal + of the second servo driver SC6 is connected to the positive terminal V+ of the DC power supply. The motor wire interface UVW and the encoder wire interface BM of the second servo driver SC6 are respectively connected to the second servo motor C6 and the second encoder BM2. Closed-loop control is achieved through the operation control of the second servo motor C6 and the position feedback of the second encoder BM2 to ensure the precise operation of the second servo motor C6; the Y2 terminal and the Y3 terminal respectively output pulse and direction signals. The PUL terminal of the second servo driver SC6 receives the pulse signal to control the rotation angle and rotation speed of the second servo motor C6 deviating from the zero point. The DIR terminal of the second servo driver SC6 receives the direction signal to control the rotation direction of the second servo motor C6. These rotation states are mechanically transmitted through the pulley, belt, rotating wheel C5, bending seat C7, and bending needle C4 mechanically connected to the shaft of the second servo motor C6. Finally, the bending needle C4 executes the bending action of the heating wire. Among them, 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.

[0071] The Y4 terminal is connected to one end of the first solenoid valve FB2 to control the energization and de-energization of the first solenoid valve FB2.

[0072] The Y5 terminal is connected to one end of the second solenoid valve FB3 to control the energization and de-energization of the second solenoid valve FB3.

[0073] The other ends of the first solenoid valve FB2 and the second solenoid valve FB3 are both connected to the positive terminal V+ of the DC power supply. The negative terminal - of the output interface OUT is connected to the negative terminal V- of the DC power supply.

[0074] The central processing unit CPU is the core control component of the electric control system. Its working principle is to receive the input signals from the input interface IN, perform logical control according to the requirements of the program design, and output corresponding control signals at the output interface OUT according to the processing results to achieve the automatic control of the production process of the heating element 7.

[0075] The first solenoid valve FB2 receives the electrical control from the Y4 terminal and controls the cylinder B2 to execute actions through air circuit switching.

[0076] The second solenoid valve FB3 receives the electrical control from the Y5 terminal and controls the scissors B3 to execute actions through air circuit switching.

[0077] The first sensor SQ1 is used for detecting the descending (action) position of the cylinder B2.

[0078] The second sensor SQ2 is used for detecting the ascending (original) position of the cylinder B2.

[0079] The origin sensor SQ3 is used for detecting the zero position of the second servo motor C6.

[0080] The third sensor SQ4 is used for detecting the closing (action) position of the scissors B3.

[0081] The fourth sensor SQ5 is used for detecting the open (original) position of the scissors B3.

[0082] The manufacturing method of the heating element is as follows: S1. According to the shape of the heating element 7, decompose the manufacturing steps and set the operating parameters for each manufacturing step. For example, in step N1, push the heating wire material by L mm, in step N2, bend it left or right by H degrees, and so on.

[0083] S2. Thread the heating wire material between the wire reel group A4, the transmission gear group A3, the wire guiding wheel group C2, the wire positioning seat C3 and the two bending needles C4.

[0084] S3. Press the start button SQ0, and the electric control system will control the manufacturing equipment to automatically complete the entire manufacturing process according to the requirements of the program design in the central processing unit CPU and the manufacturing steps and operating parameters set in S1.

[0085] S4. The second servo motor C6 performs the origin reset action. When the signal of the origin sensor SQ3 is received at the X3 terminal of the input interface IN, it indicates that the second servo motor C6 is at the zero position; when the signal of the second sensor SQ2 is received at the X2 terminal of the input interface IN, it indicates that the cylinder B2 is in the original position; when the signal of the third sensor SQ4 is received at the X4 terminal of the input interface IN, it indicates that the scissors B3 is in the original position. If all positions are in the original position, perform the next action.

[0086] S5. The output interface OUT turns on the control signal of the Y4 terminal, and the first solenoid valve FB2 is energized. The pneumatic circuit controls the cylinder B2 to drive the scissors B3 to descend to the corresponding position of the heating wire. After the descending in-place signal of the first sensor SQ1 is received at the X1 terminal of the input interface IN, perform the next action control.

[0087] S6. The output interface OUT turns on the control signal of the Y5 terminal, and the second solenoid valve FB3 is energized. The pneumatic circuit controls the scissors B3 to perform the closing action to cut off the excess part of the heating wire. After the scissors closing position signal of the fourth sensor SQ5 is received at the X5 terminal of the input interface IN, then the output interface OUT disconnects the control signal of the Y5 terminal, and the second solenoid valve FB3 is de-energized. The pneumatic circuit controls the scissors B3 to perform the opening action. After the opening in-place signal of the third sensor SQ4 is received at the X4 terminal of the input interface IN, perform the next action control.

[0088] S7. The output interface OUT disconnects the control signal of the Y4 terminal, and the first solenoid valve FB2 is de-energized. The pneumatic circuit controls the cylinder B2 to drive the scissors B3 to the rising position. After the rising in-place signal of the second sensor SQ2 is received at the X2 terminal of the input interface IN, perform the next action control.

[0089] S8. Execute step N1 according to the production steps and operation parameters set in S1. The Y0 and Y1 terminals of the output interface OUT respectively output pulse signals and direction signals. 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 in a closed loop to accurately operate, and drive the transmission gear set A3 to accurately transport the heating wire according to the set length, speed and direction.

[0090] S9. Execute step N2 according to the production steps and operation parameters set in S1. 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 the servo driver SC6 cooperate with the servo motor C6 and the encoder BM2 to close the loop and control the servo motor C6 to operate precisely. The bending action is completed according to the set bending angle and bending direction through the mechanical transmission of the pulley, belt, rotating wheel C5, bending seat C7 and bending needle C4.

[0091] S10. Repeat S8 and S9 according to the decomposed production steps until all production steps are completed.

[0092] S11. After all the production steps are completed, the servo motor C6 returns to the zero position and runs S5, S6, and S7 to complete the shearing action.

[0093] S12. The electronic control system detects the original position and zero position of all actions, and the production cycle of a product is completed.

[0094] The manufacturing equipment and method of the heating element are not limited to the heating element 7 in the thermal protector of the present embodiment, but can also be applied to the manufacturing of a heating wire in a thermal protector with a bimetallic strip with a constant jump time, as disclosed in the application No. 202322010874.2. Figures 7d - 7f shown.

[0095] 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 only an example of the structure of the present invention. All equivalent changes or simple changes made based on the structure, features and principles described in the present invention are included in the protection scope of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A thermal protector, comprising pins, a cover plate, a moving reed assembly, a bimetal sheet, a first static pin, a second static pin, a heating element, a third static pin assembly and a base, characterized in that: The heating element (7) is formed by bending and is arranged in a planar geometric shape structure. 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 arranged in the form of two strip-shaped protrusions; The calculation process of the radius r of the heating element (7) is as follows: (Formula 1) Where △T represents the temperature difference between the operating temperature of the thermal protector and the ambient temperature, KT represents the heating-up 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 the resistivity and L represents the length of the heating element (7); Through the above (Formula 1) and (Formula 2), the radius r of the heating element (7) can be calculated.

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

3. The thermal protector according to claim 1, wherein: The pin (1) is arranged on the cover plate (2). The moving reed assembly (3), the bimetal sheet (4), the static foot one (5), the static foot two (6), the heating element (7), and the static foot three assembly (8) are all arranged in the cavity formed by the cover plate (2) and the base (9). The heating element (7), the bimetal sheet (4), and the moving reed assembly (3) are arranged from bottom to top in sequence. The two ends of the heating element (7) are respectively welded to the static foot one (5) and the static foot two (6). One end of the moving reed assembly (3) is electrically connected to the static foot one (5). The other end of the moving reed assembly (3) cooperates with one end of the static foot three assembly (8). The other end of the static foot three assembly (8) is electrically connected to the pin (1).

4. The thermal protector according to claim 1, wherein: The heating element (7) is made of alloy resistance wire materials with different wire diameters of nickel-chromium, constantan, and iron-chromium, and is bent into the shape structures of m-shaped, u-shaped, s-shaped, and Ω-shaped.

5. A manufacturing device for a heating element according to any one of claims 1-4, characterized in that: 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 shape structure, and a cutting mechanism (B) for cutting the bent heating wire to form the 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).

6. The manufacturing apparatus for the heating element according to claim 5, characterized in that: The conveying mechanism (A) includes a fixed seat (A1), a servo motor one (A2), a transmission gear set (A3), and a wire aligning wheel set (A4). The servo motor one (A2), the transmission gear set (A3), and the wire aligning wheel set (A4) are all arranged on the fixed seat (A1). The servo motor one (A2) is connected to the transmission gear set (A3), and the servo motor one (A2) drives the transmission gear set (A3) to push the heating wire. The wire aligning wheel set (A4) adjusts the heating wire to be flat.

7. The manufacturing apparatus for the heating element according to claim 6, characterized in that: The cutting mechanism (B) includes a fixed frame (B1), a cylinder (B2), and scissors (B3). The cylinder barrel of the cylinder (B2) is fixed to the fixed frame (B1). The piston rod of the cylinder (B2) is connected to the scissors (B3), and the scissors (B3) are pushed by the cylinder (B2).

8. The manufacturing apparatus of a heating element according to claim 7, wherein: The bending mechanism (C) includes a fixed plate (C1), a wire guide wheel set (C2), a wire positioning seat (C3), a bending needle (C4), a rotating wheel (C5), a second servo motor (C6), and a bending seat (C7). The wire guide wheel set (C2), the wire positioning seat (C3), and the bending seat (C7) are all arranged on the fixed plate (C1). The wire positioning seat (C3) is located between the wire guide wheel set (C2) and the bending seat (C7). The bending needle (C4) is arranged on the bending seat (C7). The bending seat (C7) is coaxially connected to the rotating wheel (C5), and the rotating wheel (C5) is connected to the second servo motor (C6) through a belt and a pulley.

9. The manufacturing equipment of the heating element according to claim 8, characterized in that: This manufacturing equipment is controlled by an electric control system. The electric control system includes a first servo driver (SA2), a first encoder (BM1), a second servo driver (SC6), a second encoder (BM2), a start button (SQ0), a first sensor (SQ1), a second sensor (SQ2), a home sensor (SQ3), a third sensor (SQ4), a fourth sensor (SQ5), a first solenoid valve (FB2), a second solenoid valve (FB3), and a programmable logic controller (PLC). The programmable logic controller (PLC) includes a central processing unit (CPU), an input interface (IN), and an output interface (OUT). The input interface (IN) and the output interface (OUT) are both connected to the central processing unit (CPU). The input interface (IN) is respectively connected to the start button (SQ0), the first sensor (SQ1), the second sensor (SQ2), the home sensor (SQ3), the third sensor (SQ4), and the fourth sensor (SQ5). The output interface (OUT) is respectively connected to the first servo driver (SA2), the second servo driver (SC6), the first solenoid valve (FB2), and the second solenoid valve (FB3). The first servo driver (SA2) is respectively connected to the first servo motor (A2) and the first encoder (BM1). The second servo driver (SC6) is respectively connected to the second servo motor (C6) and the second servo motor (C6).

10. A manufacturing method of a manufacturing device for a heating element according to claim 9, characterized in that: The manufacturing method is as follows: S1. Decompose the manufacturing steps according to the shape of the heating element (7) and set the operating parameters for each manufacturing step; S2. Thread the heating wire into the manufacturing equipment; S3. The electric 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. The second servo motor (C6) performs a home return operation; 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. The cylinder (B2) drives the scissors (B3) to rise to the upper position; S8, according to the production steps and operating parameters set in S1, servo driver 1 (SA2) conveys the heating wire according to the set length, speed and direction; S9, according to the production steps and operating parameters set in S1, servo driver 2 (SC6) completes the bending action according to the set bending angle and bending direction; S10, repeating 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 shearing action; S12. The electronic control system detects the original position and zero position of all actions, and the production cycle of a product is completed.

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