Method for cold-state adjustment of double-gold screw of molded case circuit breaker

Abstract

The application relates to the technical field of low-voltage electrical appliances, and particularly discloses a cold-state adjusting method for double-gold screws of a molded case circuit breaker, which is characterized in that the deformation amount of the double-gold piece is determined according to the loop resistance value, and the adjusting stroke of the double-gold screw is determined in the case of simulating the tripping process by comprehensively considering the deformation amount of the double-gold piece during the adjustment. The method does not need to previously supply power to the molded case circuit breaker, time is saved, the adjusting efficiency is improved, and the influence of various factors on the deformation of the double-gold piece is comprehensively considered, so that the adjusting reliability is relatively high.

Description

Technical Field

[0001] This invention relates to the field of low-voltage electrical technology, and in particular to a cold-state adjustment method for double gold screws in molded case circuit breakers. Background Technology

[0002] In the structure of a molded case circuit breaker (MCCB), the position of the bimetallic screws directly affects its tripping performance. Due to variations in raw materials, processing quality, and assembly processes, under current manufacturing processes, the position of the bimetallic screws must be adjusted after semi-finished assembly of each MCCB under a delay state to ensure the consistency of tripping of the A, B, and C phase operating mechanisms within the same product. Currently, bimetallic screw adjustment methods include manual adjustment, automated pre-adjustment, and automated adaptive adjustment (a bimetallic screw adjustment device and method for molded case circuit breakers, patent number: CN202111662951.1). However, all of these methods have certain drawbacks.

[0003] Manual adjustment: The product is powered on at the time-delay test station. After the set time, the position of the bimetallic screws is manually adjusted with a screwdriver to tighten the screws against the heat-deformed bimetallic material, thus releasing the product. After adjustment, the product is manually removed, and the screw position is checked again. After confirmation, the screws are treated with paint to prevent loosening. The disadvantages of this method are low production efficiency, poor production stability, and the risk of burns from touching the high-temperature electrodes during adjustment. Furthermore, the adjustment process relies heavily on manual experience and techniques, incurring a learning curve, and lacks scalability.

[0004] Automated pre-adjustment: Based on system settings, the adjustment device automatically pre-adjusts the bimetallic screws to the set positions before powering on the product for verification. After verification, the product is automatically unloaded and transferred to the secondary adjustment station. A CCD sensor identifies the screw positions, determines the number of screws that are not properly adjusted and the amount of secondary adjustment needed, and drives the screw adjustment mechanism to readjust the pre-adjusted screws. The screws are automatically locked after adjustment. The disadvantage of this solution is that pre-adjusting screws to the set positions in batches cannot adapt to the differences between different products, requiring secondary screw adjustment and resulting in low adjustment efficiency.

[0005] Automated adaptive adjustment: The product is automatically powered on for 60-70 seconds. Immediately afterward, the product is moved to the adjustment station for CCD identification of the distance between the bimetallic screws and the trip unit. Based on the distance value identified by the CCD, the system uses a pre-defined algorithm to obtain the adjustment distance and drives the screw adjustment assembly to adjust each bimetallic screw in real time. After completion, the product automatically enters the screw tightening station for screw tightening, preventing screw position changes during product movement. However, this solution only adjusts the bimetallic screws based on empirical data and does not actually trip the circuit breaker. Furthermore, it does not consider the different distances between the bimetallic screws and the trip unit at phases A, B, and C of the circuit breaker, nor the influence of resistance in the terminal blocks and other circuits on the deformation of the bimetallic screws, resulting in a low pass rate.

[0006] Therefore, there is an urgent need to propose a cold-state adjustment method for double-metal screws in molded case circuit breakers to solve the above problems. Summary of the Invention

[0007] This invention provides a cold-state adjustment method for bimetallic strips of molded case circuit breakers, which eliminates the need to pre-energize the molded case circuit breaker, saving time and increasing adjustment efficiency. Furthermore, considering the influence of circuit resistance on the deformation of the bimetallic strip, the adjustment reliability is high.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The cold adjustment method for double-metal screws in molded case circuit breakers includes the following steps:

[0010] S100: Obtain the resistance value of the B-phase circuit of the molded case circuit breaker to be adjusted and upload it to the control system.

[0011] S200. The molded case circuit breaker is transported to the screw adjustment and testing station for fixing;

[0012] S300. Press the probe mechanisms on both sides of the screw adjustment and testing station onto the terminal block of the molded case circuit breaker to form a current loop. The control system sends a closing action command to the operating mechanism of the molded case circuit breaker to put the molded case circuit breaker in the closed state. At this time, the current loop is connected.

[0013] S400: The CCD vision inspection system is used to acquire the first position of the B-phase bimetallic strip, the initial position of the bimetallic screw head, and the initial position of the trip unit, and uploads them to the control system.

[0014] S500, the control system controls the double gold positioning mechanism to move to the first position of the double gold sheet and clamps and fixes the double gold sheet, and the CCD vision inspection system collects the second position of the double gold sheet at this time and uploads it to the control system.

[0015] S600, The control system controls the screw adjustment mechanism to adjust the double gold screw toward the direction of the trip unit until the current circuit is disconnected, and then stops the adjustment;

[0016] S700, The control system controls the screw adjustment mechanism to adjust the double gold screw away from the trip unit until the adjustment distance is equal to the adjustment stroke A and then stops the adjustment;

[0017] Adjust the A-phase bimetallic screw and the C-phase bimetallic screw using the same method.

[0018] Optionally, the steps for obtaining the adjustment stroke A are as follows:

[0019] A first compensation value A1 is obtained based on the resistance value. The distance between the second position and the first position is defined as the second compensation value A2. The distance between the initial position of the bimetallic screw head and the initial position of the trip unit is defined as the third compensation value A3. A = A1 + A2 + A3. When the second position is closer to the trip unit relative to the first position, the second compensation value A2 is negative. When the second position is farther away from the trip unit relative to the first position, the second compensation value A2 is positive.

[0020] Optionally, the step of adjusting the bimetallic screw of phase B further includes:

[0021] S800, the control system sends a closing action command to the operating mechanism to put the molded case circuit breaker in the closed state, and controls the CCD vision inspection system to collect the position of the double gold screw head and the trip unit again, and uploads the distance between the double gold screw head and the trip unit to the control system at this time.

[0022] S900: The control system compares the distance with a preset value. If the distance falls within the range of the preset value, it indicates that the distance is qualified. If the distance is not within the range of the preset value, steps S600-S900 are repeated until the distance is qualified.

[0023] Optionally, the preset value is 1.2mm-1.4mm.

[0024] Optionally, the bimetallic screws may be adhesive-backed screws.

[0025] Optionally, step S600 specifically includes the following steps:

[0026] S610. The control system controls the screw adjustment mechanism to adjust the double gold screw towards the trip unit until the head of the double gold screw presses against the trip unit.

[0027] S620. Continue to slowly adjust the bimetallic screw. When the current circuit is disconnected, stop adjusting.

[0028] Optionally, the screw adjustment mechanism includes a servo motor and a screwdriver. The output end of the servo motor is driven to the handle of the screwdriver to drive the screwdriver to rotate. The tip of the screwdriver can engage with the bimetallic screw to adjust the position of the head of the bimetallic screw.

[0029] Optionally, the following steps are also included:

[0030] After the double metal screws of phases A, B, and C are adjusted, the defective products are transported to the defective products station, and the qualified products are transported to the next process.

[0031] Optionally, the CCD vision inspection system includes a CCD camera and an image processing system. The output of the CCD camera is connected to the input of the image processing system, and the output of the image processing system is connected to the input of the control system. The image information acquired by the CCD camera is processed into data information by the image processing system and then uploaded to the control system in the form of pulses.

[0032] Optionally, the control system includes a PLC controller.

[0033] The beneficial effects of this invention are as follows:

[0034] This invention provides a cold-state adjustment method for the bimetallic strip of a molded case circuit breaker. This method determines the deformation of the bimetallic strip based on the circuit resistance value and comprehensively considers the deformation during adjustment to determine the adjustment stroke of the bimetallic strip under simulated tripping conditions. This method eliminates the need to pre-energize the molded case circuit breaker, saving time and increasing adjustment efficiency. Furthermore, by comprehensively considering the influence of various factors on the deformation of the bimetallic strip, the adjustment reliability is high. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a molded case circuit breaker provided in an embodiment of the present invention;

[0036] Figure 2 A flowchart illustrating the steps of the cold-state adjustment method for the double gold screws of a molded case circuit breaker provided in an embodiment of the present invention.

[0037] In the picture:

[0038] 100, Phase A; 200, Phase B; 210, Trip Unit; 220, Bimetallic Strip; 230, Bimetallic Screw; 300, Phase C. Detailed Implementation

[0039] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0043] To facilitate understanding, a brief introduction to the structure and working principle of molded case circuit breakers is provided, such as... Figure 1As shown, the molded case circuit breaker includes phase A 100, phase B 200, phase C 300, an operating mechanism, and a terminal block. Phase A 100, phase B 200, and phase C 300 have the same structure. Taking phase B 200 as an example, it includes a trip unit 210, a bimetallic strip 220, and a bimetallic screw 230. The bimetallic screw 230 is mounted on the bimetallic strip 220. The working principle of phase B 200 is as follows: when the current in the phase B circuit of the molded case circuit breaker exceeds the rated value, the bimetallic strip 220 deforms due to heat and shifts towards the side closer to the trip unit 210 until the bimetallic screw 230 on the bimetallic strip 220 pushes against the trip unit 210, causing the trip unit 210 to trip and disconnect the current in the phase B circuit, thus achieving overload protection of the circuit breaker.

[0044] This invention provides a cold-state adjustment method for bimetallic strips of molded case circuit breakers, which eliminates the need to pre-energize the molded case circuit breaker, saving time and increasing adjustment efficiency. Furthermore, considering the influence of circuit resistance on the deformation of the bimetallic strip 220, the adjustment reliability is high.

[0045] Specifically, such as Figure 2 As shown, the cold-state adjustment method for the double-metal screws of the molded case circuit breaker includes the following steps:

[0046] S100: Obtain the resistance value of the B-phase circuit of the molded case circuit breaker and upload it to the control system;

[0047] Before adjusting the double gold screws 230 on the molded case circuit breaker, it will be sent to the testing station to test the resistance of each phase circuit of the molded case circuit breaker. This is to prepare for the position adjustment of the double gold screws 230 on the molded case circuit breaker. Then, the test information is stored in the QR code attached to the molded case circuit breaker. When the staff adjusts the double gold screws 230 of the molded case circuit breaker, they only need to scan the QR code to obtain the required resistance value of each phase circuit.

[0048] In this embodiment, since the molded case circuit breaker includes three phases: A phase 100, B phase 200, and C phase 300, and B phase 200 is located in the middle of the molded case circuit breaker, the distance between the double gold screw 230 of B phase 200 and its trip unit 210 fluctuates the least and is the most stable. Therefore, when adjusting the double gold screw 230 of A phase 100 and C phase 300, the trip signal of B phase 200 is used as the origin reference. The double gold screws 230 of A phase 100, B phase 200, and C phase 300 can be adjusted simultaneously at three separate stations, resulting in high adjustment efficiency.

[0049] S200. Transport the molded case circuit breaker to the screw adjustment and testing station for fixing;

[0050] Optionally, molded case circuit breakers can be transported via conveyor belt and moved to the screw adjustment and testing station by a transfer robot. Of course, other methods can also be used to transport the molded case circuit breakers, depending on the actual needs.

[0051] S300: Press the probe mechanisms on both sides of the screw adjustment test station onto the terminal block of the molded case circuit breaker to form a current loop. The control system sends a closing action command to the operating mechanism of the molded case circuit breaker, so that the molded case circuit breaker is in the closed state. At this time, the current loop is connected.

[0052] In this embodiment, by pressing the probe mechanisms on both sides of the screw adjustment detection station onto the terminal block of the molded case circuit breaker, a current loop is formed. This allows the circuit breaker to be in an open or closed state based on the continuity of the current loop. A closed current loop indicates the circuit breaker is in a closed state, while a closed current loop indicates the circuit breaker is in an open state. This enables the adjustment position of the double gold screw 230 to be determined based on the circuit loop disconnection signal when the circuit breaker is subsequently tripped.

[0053] Optionally, in this embodiment, the control system includes a PLC controller.

[0054] S400: The CCD vision inspection system is used to collect the first position of the B-phase 200 double gold sheet 220, the initial position of the head of the double gold screw 230, and the initial position of the trip unit 210, and upload them to the control system.

[0055] Specifically, the CCD vision inspection system includes a CCD camera and an image processing system. The CCD camera acquires images of the first position of the B-phase 200 double metal plate 220, the initial position of the head of the double metal screw 230, and the initial position of the trip unit 210 by taking pictures. Then, the image processing system processes the image information into data information and uploads it to the control system. The data information can be coordinate information or position difference information from the virtual origin, whichever is selected according to actual needs.

[0056] S500: The control system controls the double gold positioning mechanism to move to the first position of the double gold sheet 220 and clamps and fixes the double gold sheet 220. The CCD vision inspection system collects the second position of the double gold sheet 220 at this time and uploads it to the control system.

[0057] By employing a double-gold positioning mechanism to fix the double-gold plate 200, deformation of the double-gold plate 220 is avoided during subsequent adjustment of the double-gold screw 230, thus preventing any impact on adjustment accuracy. However, during the fixing process, the double-gold plate 220 may undergo slight deformation. To prevent this slight deformation from affecting the adjustment accuracy of the double-gold screw 230, a CCD vision inspection system is used to acquire a second position of the double-gold plate 220 at this moment. This allows for displacement compensation during subsequent adjustment of the double-gold screw 230, thereby improving the adjustment accuracy of the double-gold screw 230.

[0058] S600, the control system controls the screw adjustment mechanism to adjust the bimetallic screw 230 toward the direction of the trip unit 210 until the current circuit is broken;

[0059] In this embodiment, the screw adjustment mechanism includes a servo motor and a screwdriver. After receiving the adjustment command from the control system, the servo motor first positions the bimetallic screw 230, aligning the screwdriver with the bimetallic screw 230. Then, the screwdriver is driven to rotate clockwise, moving the head of the bimetallic screw 230 closer to the trip unit 210 until the head of the bimetallic screw 230 abuts against the trip unit 210 and trips. Tripping is completed based on the disconnection signal of the current loop. When the control system receives the signal of the current loop disconnection, it immediately controls the screw adjustment mechanism to stop adjusting.

[0060] The above steps can simulate the tripping process of a molded case circuit breaker, ensuring normal tripping and improving the reliability of the double gold screw 230 adjustment.

[0061] Specifically, in this embodiment, the detailed steps for adjusting the double metal screw 230 toward the direction closer to the trip unit 210 are as follows:

[0062] S610, The control system controls the screw adjustment mechanism to adjust the double gold screw 230 toward the direction of the trip unit 210 until the head of the double gold screw 230 presses against the trip unit 210.

[0063] S620, continue to slowly adjust the double gold screw 230, and stop adjusting when the current circuit is disconnected.

[0064] S700, the control system adjusts the double gold screw 230 away from the trip unit 210 using the control screw adjustment mechanism until the adjustment distance is equal to the adjustment stroke A, then stops the adjustment; the steps for obtaining the adjustment stroke A are as follows:

[0065] The first compensation value A1 is obtained based on the resistance value. The distance between the second position and the first position is defined as the second compensation value A2. The distance between the initial position of the head of the double gold screw 230 and the initial position of the trip unit 210 is defined as the third compensation value A3. A = A1 + A2 + A3.

[0066] It is worth noting that the correspondence between the resistance value and the first compensation value A1 is obtained through experiments, and the table of resistance value-first compensation value A1 is pre-entered into the control system. After the control system obtains the resistance value, it can directly obtain the first compensation value A1 according to the table of resistance value-first compensation value A1. In this embodiment, the table of resistance value-first compensation value A1 is shown in Table 1. This table of resistance value-first compensation value A1 is the relationship between the resistance of the B-phase circuit and the deformation of the bimetallic strip 220 after a period of energization of a qualified molded case circuit breaker obtained through 2000 experiments.

[0067] Furthermore, when the second position is closer to the trip unit 210 relative to the first position, the second compensation value A2 is negative, and when the second position is farther away from the trip unit 210 relative to the first position, the second compensation value A2 is positive.

[0068] To facilitate understanding, the determination of the adjustment stroke A will be illustrated with an example:

[0069] The obtained resistance value ranges from 0.281mΩ to 0.32mΩ. According to Table 1, the first compensation value is +0.1mm. The second position is farther away from the first position from the trip unit 210, and the distance between the second position and the second position is 0.05mm. Therefore, the second compensation value is +0.05mm, and the third compensation value is 1.3mm. Thus, A = 1.3mm + 0.1mm + 0.05mm = 1.4mm. That is, the bimetallic screw 230 is adjusted in the opposite direction so that the distance between the head of the bimetallic screw 230 and the trip unit 210 is 1.4mm, which meets the requirements.

[0070] Table 1

[0071] 0.12-0.16mΩ -0.45mm 0.161-0.20mΩ -0.3mm 0.201-0.24mΩ -0.15mm 0.241mΩ~0.28mΩ No compensation 0.281-0.32mΩ +0.10mm 0.321-0.36mΩ +0.15mm 0.361-0.40mΩ +0.20mm

[0072] Compared with traditional adjustment methods, the above-mentioned adjustment method for the bimetallic screw 230 has several advantages. First, it eliminates the need for manual intervention, resulting in high production stability and efficiency, making it suitable for mass production. Second, it requires only one adjustment to meet the needs, resulting in high adjustment efficiency. Third, it simulates the tripping process and comprehensively considers the influence of circuit resistance on the deformation of the bimetallic sheet 220, thus ensuring high adjustment reliability.

[0073] Preferably, in order to improve the pass rate of molded case circuit breaker products, a confirmation process is added after adjusting the position of the double gold screw 230 to eliminate the possibility that external factors may cause the double gold screw 230 to be improperly adjusted. The specific steps are as follows:

[0074] S800: The control system sends a closing action command to the operating mechanism to put the molded case circuit breaker in the closed state, and controls the CCD vision inspection system to collect the position of the head of the double gold screw 230 and the trip unit 210 again, and uploads the distance between the head of the double gold screw 230 and the trip unit 210 to the control system at this time.

[0075] The main purpose of this step is to reconfirm the distance between the head of the bimetallic screw 230 and the trip unit 210.

[0076] S900: The control system compares the distance with the preset value. If the distance falls within the range of the preset value, it indicates that the distance is qualified. If the distance is not within the range of the preset value, steps S600-S900 are repeated until the distance is qualified.

[0077] In this embodiment, if the product is qualified, the adjustment ends and the next process begins; if it is not qualified, the adjustment continues until it is qualified.

[0078] It is worth noting that the preset value was obtained from a large amount of experimental data, specifically by collecting the distance between the double metal screw 230 and the trip unit 210 in qualified molded case circuit breakers and processing the data to obtain the preset value. In this embodiment, the preset value is 1.2mm-1.4mm.

[0079] Preferably, the double gold screw 230 is a glued screw. After the position is adjusted, the glue on the screw solidifies and fixes its position. Compared with the prior art of fixing the double gold screw 230 with a nut, this avoids the risk of slight displacement of the double gold screw 230 when fixing the nut, and improves the reliability and consistency of adjustment.

[0080] S1000, adjust the A phase 100 double gold screw 230 and the C phase 300 double gold screw 230 using the same method.

[0081] After the double gold screws 230 of S1100, A phase 100, B phase 200 and C phase 300 are adjusted, the defective products are transported to the defective products station, and the qualified products are transported to the next process.

[0082] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A cold-state adjustment method for double-metal screws in molded case circuit breakers, characterized in that, Includes the following steps: S100: Obtain the resistance value of the B-phase circuit of the molded case circuit breaker to be adjusted and upload it to the control system. S200. The molded case circuit breaker is transported to the screw adjustment and testing station for fixing; S300. Press the probe mechanisms on both sides of the screw adjustment and testing station onto the terminal block of the molded case circuit breaker to form a current loop. The control system sends a closing action command to the operating mechanism of the molded case circuit breaker to put the molded case circuit breaker in the closed state. At this time, the current loop is connected. S400: The CCD vision inspection system is used to collect the first position of the double metal sheet (220) of phase B (200), the initial position of the head of the double metal screw (230) and the initial position of the trip unit (210), and uploads them to the control system. S500, the control system controls the double gold positioning mechanism to move to the first position of the double gold sheet (220) and clamps and fixes the double gold sheet (220). The CCD vision inspection system collects the second position of the double gold sheet (220) at this time and uploads it to the control system. S600, the control system controls the screw adjustment mechanism to adjust the double gold screw (230) toward the trip unit (210) until the current circuit is disconnected, and then stops the adjustment; S700, The control system controls the screw adjustment mechanism to adjust the double gold screw (230) away from the trip unit (210) until the adjustment distance is equal to the adjustment stroke A and then the adjustment stops; The same method was used to adjust the double gold screws (230) of phase A (100) and phase C (300) (230); The steps for obtaining the adjustment stroke A are as follows: A first compensation value A1 is obtained based on the resistance value. The distance between the second position and the first position is defined as the second compensation value A2. The distance between the initial position of the head of the double gold screw (230) and the initial position of the trip unit (210) is defined as the third compensation value A3. A = A1 + A2 + A3. When the second position is closer to the trip unit (210) relative to the first position, the second compensation value A2 is negative. When the second position is farther away from the trip unit (210) relative to the first position, the second compensation value A2 is positive.

2. The cold adjustment method for double-metal screws in a molded case circuit breaker according to claim 1, characterized in that, The step of adjusting the bimetallic screw (230) of phase B (200) further includes: S800, the control system sends a closing action command to the operating mechanism to put the molded case circuit breaker in the closed state, and controls the CCD vision detection system to collect the position of the head of the double gold screw (230) and the trip unit (210) again, and uploads the distance between the head of the double gold screw (230) and the trip unit (210) to the control system at this time. S900: The control system compares the distance with a preset value. If the distance falls within the range of the preset value, it indicates that the distance is qualified. If the distance is not within the range of the preset value, steps S600-S900 are repeated until the distance is qualified.

3. The cold adjustment method for double-metal screws in a molded case circuit breaker according to claim 2, characterized in that, The preset value is 1.2mm-1.4mm.

4. The cold adjustment method for double-metal screws in a molded case circuit breaker according to claim 1, characterized in that, The bimetallic screw (230) is a glued screw.

5. The cold adjustment method for double-metal screws in a molded case circuit breaker according to claim 1, characterized in that, Step S600 specifically includes the following steps: S610, The control system controls the screw adjustment mechanism to adjust the double gold screw (230) toward the trip unit (210) until the head of the double gold screw (230) presses against the trip unit (210); S620. Continue to slowly adjust the bimetallic screw (230). Stop adjusting when the current circuit is disconnected.

6. The cold-state adjustment method for double-metal screws in a molded case circuit breaker according to claim 1, characterized in that, The screw adjustment mechanism includes a servo motor and a screwdriver. The output end of the servo motor is driven to the handle of the screwdriver to drive the screwdriver to rotate. The screwdriver tip can engage with the bimetallic screw (230) to adjust the position of the head of the bimetallic screw (230).

7. The cold-state adjustment method for double-metal screws in molded case circuit breakers according to any one of claims 1-6, characterized in that, It also includes the following steps: After the double gold screws (230) of phase A (100), phase B (200) and phase C (300) are adjusted, the defective products are transported to the defective products station, and the qualified products are transported to the next process.

8. The cold-state adjustment method for double-metal screws in a molded case circuit breaker according to any one of claims 1-6, characterized in that, The CCD vision inspection system includes a CCD camera and an image processing system. The output of the CCD camera is connected to the input of the image processing system, and the output of the image processing system is connected to the input of the control system. The image information acquired by the CCD camera is processed into data information by the image processing system and then uploaded to the control system in the form of pulses.

9. The cold-state adjustment method for double-metal screws in a molded case circuit breaker according to any one of claims 1-6, characterized in that, The control system includes a PLC controller.

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