A rapid thermocouple compensation wire forming detection industrial control system

Abstract

The application belongs to the technical field of rapid thermocouple manufacturing and electrical detection, and discloses a rapid thermocouple compensation lead forming detection industrial control system, which comprises a workpiece positioning unit, a position detection unit, a forming execution unit, a detection connection unit and a PLC controller. The positioning cavity of the workpiece positioning unit positions the thermocouple head assembly. The PLC controller drives the forming detection plug assembly according to the head position signal, so that the positive forming action area and the negative forming action area press the positive compensation lead and the negative compensation lead into the corresponding positive compensation lead positioning groove and the negative compensation lead positioning groove, respectively, and the positive conductive contact part and the negative conductive contact part establish detection contact. During the work position maintaining period, the external thermocouple polarity detector performs polarity correctness detection and full loop conduction detection, and after the detection result meets the maintaining end condition, the forming detection plug assembly is retracted and reset.

Description

Technical Field

[0001] This invention relates to the fields of rapid thermocouple manufacturing and electrical testing technology, specifically to an industrial control system for rapid thermocouple compensating wire forming and testing. Background Technology

[0002] Fast thermocouples are commonly used in metallurgy, casting, and high-temperature melt temperature measurement. A fast thermocouple head assembly includes a fast thermocouple connector, a positive compensating lead, a negative compensating lead, and a temperature measurement circuit connected to both compensating leads. The fast thermocouple connector internally features a positive compensating lead positioning groove and a negative compensating lead positioning groove. After the positive compensating lead is pre-inserted into the fast thermocouple connector, it must enter the positive compensating lead positioning groove; similarly, after the negative compensating lead is pre-inserted into the fast thermocouple connector, it must enter the negative compensating lead positioning groove, maintaining their predetermined positions to ensure a stable fit between the fast thermocouple connector and the temperature measuring gun connector.

[0003] Current production processes often use handheld forming tools to press the positive and negative terminals of the compensating wires into the positive and negative compensating wire positioning slots, respectively. The insertion direction, pressing depth, and force of the handheld forming tool are controlled by the operator. When there are discrepancies in the position of the compensating wires, the handheld forming tool is prone to causing insufficient pressing on one side, wire misalignment, partial bending, or surface damage. Manual operation also requires transferring the rapid thermocouple head assembly to the testing station after mechanical forming, and then connecting the dedicated testing plug to the rapid thermocouple connector.

[0004] An independent testing station can detect the continuity of a fast thermocouple circuit and determine the polarity of the compensating wire based on the thermocouple type and the operating mode of the testing instrument. When the forming station and the testing station are separated, different positioning references are used for the mechanical forming position and the testing contact position. The position of the fast thermocouple head assembly may change during transfer, handling, and re-insertion. The test results can reflect the electrical state at the time of testing, but the test results cannot directly prove that the positive and negative terminals of the compensating wire have reached the predetermined pressing position at the forming station.

[0005] Wire harness testing equipment includes structures that use cylinders to drive the test head to contact the connector, as well as control methods for continuity testing at the wire harness assembly station. Terminal crimping equipment can also judge the crimping process through pressure curves, crimping height, or displacement. The aforementioned structures respectively address the problems of connector testing, wire harness continuity, or terminal crimping quality judgment. The rapid thermocouple compensating wire forming process still requires a dedicated structure so that the same moving part can both perform the crimping and forming of the positive and negative terminals of the compensating wire, and also perform the polarity detection and connection of the positive and negative terminals of the compensating wire, and ensure that the mechanical forming state and the electrical testing state coexist in the same holding phase. Summary of the Invention

[0006] The purpose of this invention is to provide an industrial control system for rapid thermocouple compensating wire forming and testing, which solves the technical problems of separation between rapid thermocouple compensating wire forming and testing processes, inconsistent positioning benchmarks leading to spatiotemporal separation between mechanical forming state and electrical testing state, and the inability of testing results to directly prove that the compensating wire has reached the predetermined pressing position.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] An industrial control system for the forming and detection of fast thermocouple compensating wires includes a workpiece positioning unit, a positioning detection unit, a forming execution unit, a detection connection unit, and a PLC controller. The workpiece positioning unit includes a workpiece positioning block with a positioning cavity, which is used to position the fast thermocouple head assembly. The fast thermocouple head assembly includes a fast thermocouple connector, a positive compensating wire, and a negative compensating wire. The fast thermocouple connector is provided with a positive compensating wire positioning groove and a negative compensating wire positioning groove. The positive and negative compensating wires are pre-inserted into the fast thermocouple connector.

[0009] The positioning detection unit is used to detect whether the thermocouple head assembly has reached the predetermined position in the positioning cavity and outputs a head positioning signal to the PLC controller; the forming execution unit includes a linear actuator and a forming detection insert assembly driven by the linear actuator. The forming detection insert assembly reciprocates along the motion axis. The forming detection insert assembly has a forming end face, which includes a positive forming action area corresponding to the positive compensation wire positioning groove and a negative forming action area corresponding to the negative compensation wire positioning groove. The end point of the stroke of the forming detection insert assembly moving toward the positioning cavity is the working position;

[0010] The detection connection unit includes a positive conductive contact, a negative conductive contact, an insulating structure, and a polarity detection interface disposed on the molded detection insert assembly. The insulating structure isolates the positive conductive contact and the negative conductive contact. The positive conductive contact is connected to the positive terminal of the polarity detection interface, and the negative conductive contact is connected to the negative terminal of the polarity detection interface. The polarity detection interface also includes a detection completion input terminal, a polarity result input terminal, and a continuity result input terminal connected to the PLC controller.

[0011] After obtaining a valid pair head positioning signal, the PLC controller controls the linear actuator to drive the forming detection insert assembly to perform one continuous working stroke, so that the positive forming action area presses the positive electrode of the compensation wire into the positive compensation wire positioning groove, and the negative forming action area presses the negative electrode of the compensation wire into the negative compensation wire positioning groove, and establishes detection contact between the positive conductive contact part and the positive electrode of the compensation wire, and between the negative conductive contact part and the negative electrode of the compensation wire respectively.

[0012] The PLC controller keeps the molding detection insert assembly in the working position, simultaneously maintaining the compensating wire pressed-in state and the detection contact state. This allows an external thermocouple polarity detector connected to the polarity detection interface to perform polarity correctness detection and full-loop continuity detection. The external thermocouple polarity detector outputs detection completion signal, polarity result signal, and continuity result signal to the PLC controller through the detection completion input terminal, polarity result input terminal, and continuity result input terminal, respectively. After obtaining a valid detection completion signal, the PLC controller records the polarity result signal and continuity result signal. Upon meeting the preset hold end condition, the PLC controller controls the molding detection insert assembly to retract and reset. The preset hold end condition includes at least a continuous and valid detection completion signal for a preset debouncing time. If the preset hold end condition is not met even after reaching the preset maximum hold time, the PLC controller outputs a detection abnormality status and controls the molding detection insert assembly to retract and reset.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] This invention utilizes the same molding and detection insert assembly to complete the pressing and forming of the positive and negative terminals of the compensating wire and the polarity detection connection within the same continuous working stroke. This eliminates the secondary positioning errors caused by the separation of the molding station and the detection station, as well as the risk of position changes during transport. The workpiece positioning block, molding end face, positive conductive contact, and negative conductive contact adopt a common structural positioning reference. When the positive and negative terminals of the compensating wire reach the predetermined pressing position, the detection contact is simultaneously in a maintainable state. The electrical detection result directly corresponds to the mechanical state of the compensating wire during the working position holding period, solving the defect that the detection result cannot directly prove the molding quality due to the spatiotemporal separation of the mechanical molding state and the electrical detection state.

[0015] The independently floating positive and negative conductive contacts are respectively limited by positive and negative elastic elements, which can independently compensate for the surface position differences between the positive and negative terminals of the compensating wire, avoiding insufficient contact or excessive pressing on one side due to height differences in rigid contacts. The axial segmented structure formed by the forming end face protruding from the positive and negative conductive contacts along the working direction ensures that the pressing and forming are completed before the contact detection is completed, ensuring that the electrical connection is established only after the compensating wire reaches the predetermined pressing position, eliminating the risk of misjudgment due to detection before forming.

[0016] When the continuous detection volume fluctuation of the micro-displacement wiping sequence does not converge during the first round of evaluation, the control servo linear actuator performs micron-level reciprocating sliding along the retraction direction with the working position as the reference. The unidirectional amplitude is strictly less than the minimum value of the working retraction amount corresponding to the positive terminal of the compensation wire and the working retraction amount corresponding to the negative terminal of the compensation wire. Without changing the completed mechanical pressing state and without losing the elastic contact pressure, the oxide layer is peeled off by the axial relative sliding friction between the positive conductive contact part and the positive terminal of the compensation wire, and between the negative conductive contact part and the negative terminal of the compensation wire. This reverses the false defective products caused by the electrical detection fluctuation due to the surface oxide film into qualified products, reducing the system's false judgment rate. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart of the main process of the present invention.

[0019] Figure 2 This is a flowchart of the self-test sub-process of the detection link in this invention.

[0020] Figure 3 This is a flowchart of the micro-displacement wiping secondary detection sub-process of the present invention.

[0021] Figure 4 This is a flowchart of the molding force-displacement molding quality determination sub-process of the present invention.

[0022] Figure 5 This is a schematic diagram of the overall structure of the present invention.

[0023] Figure 6 This is a schematic diagram of the internal structure of the present invention.

[0024] Figure label:

[0025] 101 Photoelectric detection sensor, 102 Dust removal assembly, 103 Molding detection insert assembly, 104 Cylinder, 105 Housing. Detailed Implementation

[0026] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0027] The following is in conjunction with the appendix Figures 1-6 The embodiments of the present invention will be described in detail below.

[0028] Example 1: This example discloses an industrial control system for rapid thermocouple compensating wire forming and inspection, including a housing 105, a workpiece positioning unit, a positioning detection unit, a forming execution unit, a detection connection unit, and a PLC controller. The housing 105 forms a mechanical installation space and an electrical installation space. The mechanical installation space houses the workpiece positioning block, the forming and inspection insert assembly 103, the cylinder 104, the connecting frame, and the solenoid valve. The electrical installation space houses the PLC controller, wiring components, and a low-voltage DC power supply. A partition separates the mechanical installation space and the electrical installation space, and the piston rod axis of the cylinder 104 is parallel to the central axis of the positioning cavity.

[0029] The workpiece positioning unit includes a forming insertion hole, a workpiece positioning block, and a detachable locking structure. The workpiece positioning block is installed below the forming insertion hole. The workpiece positioning block has a positioning cavity. The positioning cavity includes an inlet guide surface, a circumferential limiting surface, an axial stop surface, and a clearance groove. The inlet guide surface guides the fast thermocouple head assembly into the positioning cavity. The circumferential limiting surface restricts the rotation angle of the fast thermocouple head assembly. The axial stop surface restricts the insertion depth of the fast thermocouple head assembly. The clearance groove accommodates protruding structures on the outside of the fast thermocouple head assembly that do not participate in positioning.

[0030] The fast thermocouple connector assembly includes a fast thermocouple connector, a positive compensating lead, and a negative compensating lead. The fast thermocouple connector internally forms a positive compensating lead positioning groove and a negative compensating lead positioning groove. The positive compensating lead is pre-inserted into the positive channel of the fast thermocouple connector, and the negative compensating lead is pre-inserted into the negative channel of the fast thermocouple connector. In this pre-insertion state, the sections to be formed for the positive and negative compensating leads are located in the opening areas of the positive and negative compensating lead positioning grooves, respectively.

[0031] The dimensions of the positioning cavity are determined based on the outer contour of the fast thermocouple connector. A loading / unloading clearance is maintained between the positioning cavity and the fast thermocouple connector. This clearance must simultaneously meet the requirements of smooth insertion and repeatability of the molding position.

[0032] In this embodiment, the outer diameter of the positioning locating thermocouple connector is 18.00 mm, the diameter of the cylindrical surface corresponding to the positioning cavity is 18.10 mm, and the radial clearance on one side is 0.05 mm. The designed distance from the axial stop surface to the reset position of the forming end face is 12.00 mm. The designed distance is determined by the ferrule depth of the fast thermocouple connector, the positions of the sections to be formed of the positive and negative terminals of the compensating wire, and the safety clearance distance of the forming detection ferrule assembly 103.

[0033] The positioning detection unit employs a photoelectric sensor 101 and a photoelectric switch amplifier. The photoelectric sensor 101 is mounted on the side of the workpiece positioning block. The workpiece positioning block has an optical path hole. The detection beam of the photoelectric sensor 101 passes through the optical path hole and enters the positioning cavity. When the rapid thermocouple head assembly has not reached the axial stop surface, the detection beam remains in a workpiece-free reference state. When the rapid thermocouple head contacts the axial stop surface, the rapid thermocouple head blocks the detection beam, and the photoelectric sensor 101 outputs a valid head positioning signal.

[0034] A photoelectric switch amplifier is used to set the photoelectric detection threshold. The photoelectric detection threshold is calibrated based on the workpiece-free baseline value and the workpiece positioning detection value. During calibration, 20 consecutive sample values ​​are recorded when the positioning cavity is clean and workpiece-free, and another 20 consecutive sample values ​​are recorded when the rapid thermocouple head assembly is in stable contact with the axial stop surface. The photoelectric detection threshold is set between these two sets of sample values, allowing for margins corresponding to changes in ambient light and dust adhesion. The PLC controller also performs debouncing processing on the thermocouple head positioning signal.

[0035] In this embodiment, the coupled head positioning signal is considered valid after being held continuously for 20ms. If the coupled head positioning signal becomes invalid within 20ms, the molding detection cycle is not started. The de-jitter holding time and the number of continuous samples are determined based on the response time of the photoelectric detection sensor 101, the duration of vibration in the production environment, and the scanning cycle of the PLC controller. The calibration is re-performed when the photoelectric detection sensor 101, its installation position, or the scanning cycle changes.

[0036] The molding execution unit comprises a cylinder 104, a connecting frame, a solenoid valve, a working position detection unit, and a reset position detection unit. The cylinder 104 is vertically mounted, and its piston rod is connected to the molding detection insert assembly 103 via the connecting frame. The connecting frame has an axial connection hole and an anti-rotation limiting surface. The axial connection hole determines the axial position of the molding detection insert assembly 103 relative to the piston rod of the cylinder 104. The anti-rotation limiting surface restricts the rotation of the molding detection insert assembly 103 around its axis of motion, ensuring that the positive electrode molding area always corresponds to the positive electrode compensating wire positioning groove, and that the negative electrode molding area always corresponds to the negative electrode compensating wire positioning groove.

[0037] The solenoid valve is a two-position directional valve. When the PLC controller outputs a working signal to the solenoid valve, the solenoid valve extends cylinder 104. When the PLC controller cancels the working signal to the solenoid valve, the solenoid valve retracts cylinder 104. Throttling sections can be installed in the intake and exhaust branches of cylinder 104 to limit the working speed and retraction speed of the molding and inspection insert assembly 103. The opening degree of the throttling section is determined through type change testing and is not the sole limiting condition for the working position.

[0038] The working position detection unit and the reset position detection unit employ magnetic switches. The working position detection unit is installed at the working end of the cylinder body 104, and the reset position detection unit is installed at the reset end of the cylinder body 104. When the piston of cylinder 104 reaches the working end position, the working position detection unit outputs the working position status. When the piston of cylinder 104 reaches the reset end position, the reset position detection unit outputs the reset position status. The working position status and the reset position status cannot be valid simultaneously. If the PLC controller detects that both the working position status and the reset position status are valid simultaneously, it outputs a position detection abnormality status.

[0039] During the current molding inspection cycle, the PLC controller generates a working position arrival record when it detects that the working position status changes from invalid to valid. Similarly, during the retraction phase of the current molding inspection cycle, it generates a reset position arrival record when it detects that the reset position status changes from invalid to valid. At the start of the next molding inspection cycle, the PLC controller clears the working position arrival record, reset position arrival record, abnormal detection status, and the detection completion signal, polarity result signal, and continuity result signal stored in the previous molding inspection cycle.

[0040] The molded test ferrule assembly 103 includes a ferrule body, a molded end face, a positive conductive contact, a negative conductive contact, and an insulation structure. The ferrule body is machined from wear-resistant tool steel. The molded end face is located at the working end of the ferrule body. The molded end face includes a positive molded action area and a negative molded action area. The center of the positive molded action area corresponds to the center of the positive compensating wire positioning groove, and the center of the negative molded action area corresponds to the center of the negative compensating wire positioning groove.

[0041] Both the positive and negative electrode forming zones are equipped with inlet fillets, pressing-in working surfaces, and endpoint limiting surfaces. The inlet fillets of the positive and negative electrode forming zones guide the sections to be formed of the positive and negative compensating wires, respectively, when the forming detection ferrule assembly 103 enters the fast thermocouple connector. The pressing-in working surface of the positive electrode forming zone moves the section to be formed of the positive compensating wire towards the positive compensating wire positioning groove, and the pressing-in working surface of the negative electrode forming zone moves the section to be formed of the negative compensating wire towards the negative compensating wire positioning groove. The endpoint limiting surfaces of the positive and negative electrode forming zones respectively form a mechanical endpoint engagement with the non-wire bearing surface inside the fast thermocouple connector, preventing the forming detection ferrule assembly 103 from further increasing the pressing displacement of the positive and negative compensating wires after reaching the mechanical endpoint.

[0042] The widths of the positive and negative electrode forming zones are determined based on the outer diameters of the positive and negative electrodes of the compensating conductor, as well as the inlet widths of the positive and negative compensating conductor positioning grooves. The widths of the positive and negative electrode forming zones are respectively smaller than the inlet widths of the positive and negative compensating conductor positioning grooves, and greater than 0.8 times the corresponding outer diameter of the compensating conductor.

[0043] In this embodiment, the outer diameters of both the positive and negative terminals of the compensating conductor are 0.80 mm, the inlet widths of both the positive and negative compensating conductor positioning grooves are 1.20 mm, and the widths of both the positive and negative forming areas are 0.90 mm. The inlet fillet radii of both the positive and negative forming areas are 0.20 mm. The pressing surfaces of the positive and negative forming areas form a 3° introductory angle with the axis of motion, allowing the sections to be formed of the positive and negative compensating conductors to gradually enter the positioning grooves. The lower limit of the width of the positive and negative forming areas is determined to cover the corresponding section to be formed, and the upper limit is determined to allow entry into the corresponding positioning groove without contacting its sidewall. The inlet fillet radius and introductory angle are determined based on the outer diameter of the corresponding compensating conductor, the allowable bending radius, and the process requirement of no surface cuts after pressing.

[0044] The positive and negative conductive contacts utilize conductive alloy inserts. The positive conductive contact connects to the positive terminal of the polarity detection interface via an internal positive wire, and the negative conductive contact connects to the negative terminal of the polarity detection interface via an internal negative wire. The insulation structure uses a wear-resistant insulating material and separates the positive and negative conductive contacts from the ferrule body. The internal positive and negative wires extend along independent wire channels within the ferrule body, maintaining structural isolation between the two wire channels.

[0045] In this embodiment, the positive conductive contact and the negative conductive contact are fixedly installed on the insulating structure, and the working ends of the positive conductive contact and the negative conductive contact are respectively oriented toward the predetermined detection positions of the positive and negative terminals of the compensation wire.

[0046] During assembly, the rapid thermocouple head assembly, whose dimensions and electrical condition meet the product process requirements, is placed into the positioning cavity, causing the molding and detection insert assembly 103 to move to the working position. The axial installation positions of the positive and negative conductive contacts are adjusted until an external thermocouple polarity detector establishes a stable detection connection between the positive and negative terminals of the compensating wire. Then, the positive and negative conductive contacts are locked. When the molding and detection insert assembly 103 reaches the working position, the positive and negative molding action areas hold the positive and negative terminals of the compensating wire in the predetermined pressing position, and the positive and negative conductive contacts simultaneously establish detection contact with the positive and negative terminals of the compensating wire.

[0047] The insulation structure design must meet the insulation requirements under the operating voltage of the detector. Even when using low-voltage detection signals for rapid thermocouple and continuity detection, the insulation structure still needs sufficient mechanical strength and resistance to dust contamination. In this embodiment, the minimum solid insulation thickness between the positive and negative conductive contacts is 1.50 mm. When the molded detection insert assembly 103 is clean and dry, the insulation resistance between the positive and negative conductive contacts is not less than 20 MΩ. The insulation resistance threshold is determined by the matching requirements of the input impedance of the external thermocouple detector, the detection signal amplitude, and the allowable misjudgment current.

[0048] The polarity detection interface uses a six-terminal interface. The six-terminal interface includes a positive detection terminal, a negative detection terminal, a detection completion input terminal, a polarity result input terminal, a continuity result input terminal, and a detection fault input terminal. The positive and negative detection terminals are connected to an external thermocouple polarity detector via shielded two-core cables. The detection completion input terminal, polarity result input terminal, continuity result input terminal, and detection fault input terminal are respectively connected to the corresponding input points of the PLC controller. The shielding layer is connected to protective ground at a single point on the control cabinet side to prevent circulating current from forming in the shielding layer. The detection completion input terminal receives the detection completion signal output from the external thermocouple polarity detector. The polarity result input terminal receives the polarity result signal output from the external thermocouple polarity detector, and the value of the polarity result signal is either correct or abnormal. The continuity result input terminal receives the continuity result signal, and the value of the continuity result signal is either on or off. The detection fault input terminal receives the detection fault signal output from the external thermocouple polarity detector. The PLC controller forms a correct polarity state when the polarity result signal is correct, and forms a full-loop conduction qualified state when the conduction result signal is on. It only accepts the detection state defined by the interface protocol of the polarity detection interface.

[0049] The current path for full-loop continuity detection sequentially passes through the positive terminal of the polarity detection interface, the positive conductive contact, the positive terminal of the compensating wire, the temperature measurement circuit of the fast thermocouple head assembly, the negative terminal of the compensating wire, the negative conductive contact, and the negative terminal of the polarity detection interface. When an external thermocouple polarity detector outputs a continuous detection value, a continuous detection value input terminal is added to the polarity detection interface, or the continuous detection value is transmitted to the PLC controller via an industrial communication interface.

[0050] The PLC controller's input points include: coupler head position signal input, working position status input, reset position status input, detection completion signal input, polarity result signal input, continuity result signal input, detection fault signal input, automatic mode signal input, manual maintenance mode signal input, maintenance enable signal input, and reset operation signal input. The PLC controller's output points include: solenoid valve working signal output, alarm signal output, classification count data output, and production line interlock signal output. The PLC controller is equipped with a classification count module, which generates classification count data, which is received and displayed by the classification count display component. The operation control components include: automatic mode operation, manual maintenance mode operation, maintenance enable switch, maintenance confirmation operation, manual action operation, non-conformance confirmation operation, detection link self-test operation, baseline reconstruction operation, reset operation, and alarm component.

[0051] The PLC controller is configured with standby state, action permission state, working motion state, working position hold state, retraction state, cycle completion state, fault state, and fault latch. The fault latch is enabled when a working action times out, retraction reset fails, position detection fails, or a detection fault occurs, and is cleared after the corresponding fault is cleared and the PLC controller confirms the reset condition. A non-interlocking fault state refers to a situation where the fault latch is invalid, the working position state and the reset position state do not conflict simultaneously, and the detection fault signal is invalid.

[0052] In automatic mode, the PLC controller reads the thermocouple head position signal, reset position status, detection completion signal, and fault latch in standby mode. When the thermocouple head position signal is valid, the reset position status is valid, the detection completion signal is invalid, and the fault latch is invalid, the PLC controller enters the action permission state; when the detection completion signal remains valid, the PLC controller does not start a new molding detection cycle. After the PLC controller confirms that the thermocouple head position signal is continuously valid, it outputs a solenoid valve working signal, and the cylinder 104 pushes the molding detection insert assembly 103 upward. After the molding detection insert assembly 103 enters the quick thermocouple connector, the positive forming action area presses the positive terminal of the compensating wire into the positive compensating wire positioning groove, and the negative forming action area presses the negative terminal of the compensating wire into the negative compensating wire positioning groove. The molding detection insert assembly 103 continues to move to the working position, and the positive conductive contact establishes detection contact with the positive terminal of the compensating wire, and the negative conductive contact establishes detection contact with the negative terminal of the compensating wire. After the working position detection unit outputs the working position status, the PLC controller stops the working action timeout count and starts the hold count.

[0053] The basic control uses a valid detection completion signal as the normal termination condition for holding the working position, and the maximum holding time as a fallback condition for abnormal situations. The maximum holding time is jointly determined by the maximum normal detection time of the external thermocouple polarity detector, the debouncing time of the detection completion signal, and the control margin.

[0054] In this embodiment, the maximum normal detection time of the external thermocouple polarity detector is 180ms, the detection completion signal debouncing time is 20ms, the control margin is 100ms, and the maximum hold time is set to 300ms. When the detection completion signal is continuously valid for 20ms, the PLC controller records the polarity result signal and conduction result signal that remain unchanged within 20ms, forming a stable detection result state and canceling the solenoid valve working signal; if the detection completion signal becomes invalid again within 20ms, or if the polarity result signal or conduction result signal changes within 20ms, the PLC controller restarts the detection completion signal debouncing timer. If a stable detection result state is not formed even after the maximum hold time is reached, the PLC controller records the abnormal detection state and cancels the solenoid valve working signal. The cylinder 104 drives the forming detection insert assembly 103 to retract. After the reset position detection unit outputs the reset position status, the PLC controller stops the reset timeout timer.

[0055] When the current molding inspection cycle ends, the PLC controller increments the molding inspection cycle count; when the inspection completion signal is valid, the PLC controller increments the inspection completion count. When the inspection completion signal is valid, the working position arrival record is valid, the reset position arrival record is valid, the working action timeout status is invalid, the retraction reset abnormal status is invalid, and the polarity result signal value is correct and the conduction result signal value is on, the PLC controller increments the number of qualified products; if any of the aforementioned conditions are not met, the PLC controller increments the number of unqualified products. When the inspection completion signal is invalid, the PLC controller simultaneously records the inspection incomplete status.

[0056] A continuous control process is as follows: At 0ms, the rapid thermocouple head assembly has not yet entered the positioning cavity; the head positioning signal is 0, and the reset position status is 1. At 120ms, the rapid thermocouple head assembly reaches the axial stop surface; the head positioning signal changes from 0 to 1. At 140ms, the head positioning signal remains valid for 20ms, and the PLC controller outputs a solenoid valve working signal. The molding detection insert assembly 103 moves 8.00mm at a set speed of 40mm / s, with a theoretical movement time of 200ms. At 340ms, the working position status changes from 0 to 1, and the working position is recorded. At 520ms, the external thermocouple polarity detector outputs a detection completion signal of 1, a polarity result signal of correct, and a conduction result signal of conduction. From 520ms to 540ms, the detection completion signal remains continuously valid, and the values ​​of the polarity result signal and the continuity result signal remain unchanged. At 540ms, the PLC controller establishes a stable detection result state, records the polarity result signal and the continuity result signal, and cancels the solenoid valve's working signal. The molding detection insert assembly 103 moves 8.00mm at a retraction speed of 50mm / s, with a theoretical retraction time of 160ms. At 700ms, the reset position state changes from 0 to 1, and the reset position arrival record is formed. With the working position arrival record and reset position arrival record valid, the working action timeout state and the retraction reset abnormal state invalid, the polarity result signal value correct, and the continuity result signal value on, the PLC controller increments the molding detection cycle count by 1, the detection completion count by 1, and the number of qualified products by 1, and enters the cycle completion state.

[0057] The timeout period for the working action is determined based on the working stroke and the minimum allowable movement speed. Assuming a working stroke of 8.00 mm, a minimum allowable movement speed of 20 mm / s, and a theoretical maximum movement time of 400 ms, the control margin corresponding to the PLC scan cycle, valve response, and air pressure fluctuation is set to 200 ms, and the working action timeout period is set to 600 ms. If the PLC controller fails to obtain the working position status within 600 ms after outputting the solenoid valve working signal, it will cancel the solenoid valve working signal, output a working action timeout status, and latch the fault. The retraction action timeout period is determined using the same method. Assuming a retraction stroke of 8.00 mm, a minimum allowable retraction speed of 25 mm / s, and a theoretical maximum retraction time of 320 ms, the control margin is set to 180 ms, and the retraction action timeout period is set to 500 ms. If the PLC controller fails to obtain the reset position status within 500 ms after canceling the solenoid valve working signal, it will output a retraction reset abnormal status.

[0058] In some embodiments, the cylinder 104 is replaced by an electric cylinder. The electric cylinder controller outputs the working position status, reset position status, and drive fault status to the PLC controller. The PLC controller outputs the working position command and reset position command to the electric cylinder controller. Replacing the linear actuator does not change the fact that the molding detection insert assembly 103 completes the pressing and molding of the positive and negative terminals of the compensation wire in the same continuous working stroke and establishes the detection contact relationship respectively.

[0059] In some embodiments, the positioning detection unit employs a mechanical trigger detection section. When the rapid thermocouple connector contacts the axial stop surface, it pushes the mechanical trigger detection section, which outputs a thermocouple head positioning signal. The specific form of the positioning detection unit does not alter the positioning function of the positioning cavity for the rapid thermocouple head assembly.

[0060] The molding detection insert assembly 103 changes the mechanical position of the positive and negative terminals of the compensation wire within the same continuous working stroke, and establishes detection contacts on the positive and negative conductive contacts respectively. The working position is maintained to simultaneously maintain the pressed-in state and maintain the detection contact.

[0061] Example 2: Example 2 adds independently floating positive and negative conductive contacts, axial segmented stroke, and matching of forming and inspection tooling specifications to Example 1. Example 2 does not change the core relationship between the workpiece positioning block, forming execution unit, forming and inspection insert assembly 103, and PLC controller.

[0062] The formed end face is fixed to the working end of the insert body. The positive conductive contact is installed in the positive floating hole, and the negative conductive contact is installed in the negative floating hole. The positive and negative floating holes extend along the axis of motion. The positive conductive contact can move axially within the positive floating hole, and the negative conductive contact can move axially within the negative floating hole. The positive conductive contact connects to the positive elastic element, and the negative conductive contact connects to the negative elastic element.

[0063] Both the positive and negative elastic components utilize cylindrical compression springs. They are installed separately and do not share a transverse elastic sheet. Independent installation ensures that the retraction of the positive conductive contact does not alter the contact force of the negative conductive contact, and vice versa. Each of the positive and negative conductive contacts is equipped with an anti-detachment shoulder. These anti-detachment shoulders engage with corresponding limiting steps in the insulation structure, limiting the maximum extension of the positive and negative conductive contacts in the working direction.

[0064] The contact force of the positive electrode conductive contact is determined by the spring stiffness, pre-compression, and working retraction of the positive electrode elastic element. Similarly, the contact force of the negative electrode conductive contact is determined by the spring stiffness, pre-compression, and working retraction of the negative electrode elastic element. The contact force is calculated using the following formula:

[0065] ;

[0066] in, The contact force exerted by the positive or negative conductive contact on the corresponding compensating wire. To correspond to the spring stiffness of the positive or negative elastic element, To correspond to the pre-compression amount of the positive or negative elastic element, Establish the working retraction amount after detection of the corresponding positive or negative conductive contact part; the dimension of contact force is force, the dimension of spring stiffness is the ratio of force to length, and the dimension of pre-compression and working retraction amount is length.

[0067] In this embodiment, the spring stiffness of both the positive and negative elastic elements is 1.20 N / mm, and the pre-compression is 0.30 mm. The working retraction of the positive terminal of the compensating wire is 0.25 mm, and the contact force of the positive conductive contact is 0.66 N; the working retraction of the negative terminal is 0.35 mm, and the contact force of the negative conductive contact is 0.78 N. The contact forces of the positive and negative conductive contacts are formed by the positive and negative elastic elements, respectively, and it is not required that the positive and negative terminals of the compensating wire have exactly the same surface height.

[0068] The maximum permissible retraction of both the positive and negative conductive contacts is 0.80 mm. This maximum permissible retraction is determined by the axial clearance between the anti-detachment shoulder and the limiting step. The maximum permissible retraction is greater than the combined axial tolerance formed by the quick-connect thermocouple connector, the workpiece positioning block, the unformed section of the positive terminal of the compensating wire, and the unformed section of the negative terminal of the compensating wire. This combined axial tolerance is determined by superimposing the limit deviations of each manufacturing dimension. The maximum permissible retraction is also less than the compression amount of the elastic element to prevent the elastic element from entering a solid compression state.

[0069] The forming end face protrudes from the positive and negative conductive contact portions along the working direction. The axial height difference between the foremost tip of the forming end face and the unforced end faces of the positive and negative conductive contact portions is denoted as the segment height. The segment height divides the continuous working stroke into a first stroke segment and a second stroke segment. The first stroke segment begins when the forming end face first contacts the section to be formed of the positive or negative compensating wire, and ends when at least one of the positive and negative conductive contacts begins to establish a detection contact. Before the end of the first stroke segment, the positive and negative compensating wires reach the predetermined pressing positions of the positive and negative compensating wire positioning grooves, respectively. The second stroke segment begins when at least one set of detection contacts begins to establish and ends when the forming detection insert assembly 103 reaches the working position.

[0070] The segment height is determined based on the required pressing displacement of the positive and negative terminals of the compensating conductor, as well as the required working retraction of the positive and negative conductive contacts. In this embodiment, the axial equivalent displacement required for the forming segments of the positive and negative terminals of the compensating conductor to move from their initial positions to their predetermined positions in the positive and negative compensating conductor positioning grooves is 0.90 mm. To ensure that the detection contact is established only after forming is completed, the segment height is set to 1.00 mm.

[0071] After the forming end face begins to function, the forming detection ferrule assembly 103 moves 0.90 mm, and the positive terminal of the compensation wire reaches the predetermined pressing position of the positive compensation wire positioning groove, while the negative terminal of the compensation wire reaches the predetermined pressing position of the negative compensation wire positioning groove. The forming end face is provided with a retaining surface of equal depth corresponding to the predetermined pressing position. This retaining surface extends along the movement axis and does not further increase the pressing depth of the positive and negative terminals of the compensation wire. When the forming detection ferrule assembly 103 continues to move 0.10 mm, the retaining surface maintains the predetermined pressing positions of the positive and negative terminals of the compensation wire; at least one of the positive conductive contact portion and the positive terminal of the compensation wire, and the negative conductive contact portion and the negative terminal of the compensation wire, begins to establish detection contact. The forming detection ferrule assembly 103 continues to move 0.25 mm to 0.35 mm within the second stroke section, and the positive and negative conductive contacts respectively form a working retraction amount.

[0072] A mechanical endpoint limiting zone is provided on the forming end face. This mechanical endpoint limiting zone mates with the support surface inside the fast thermocouple connector that does not carry the detection current when the forming detection ferrule assembly 103 reaches the working position. During the second stroke section, the equal-depth retaining surface of the forming end face maintains the predetermined pressing positions of the positive and negative terminals of the compensating wire. The positive and negative conductive contacts retract into the positive and negative floating holes, respectively, compressing the positive and negative elastic elements. The mechanical endpoint limiting zone defines the working position of the forming detection ferrule assembly 103, and the positive and negative elastic elements respectively limit the contact force of the positive and negative conductive contacts.

[0073] The workpiece positioning block and the forming detection insert assembly 103 together constitute the forming detection fixture. The workpiece positioning block is equipped with a first specification recognition section, and the forming detection insert assembly 103 is equipped with a second specification recognition section. Both the first and second specification recognition sections use resistance encoding. Each specification recognition section includes an encoded resistor and two contacts. After the workpiece positioning block is installed in place, the first specification recognition section is connected to the first analog input of the PLC controller. After the forming detection insert assembly 103 is installed on the connecting frame, the second specification recognition section is connected to the second analog input of the PLC controller. The PLC controller reads the encoded resistor through a constant current detection branch. The specification code corresponding to the encoded resistor is determined by the resistance range.

[0074] In this embodiment, the first fast thermocouple specification corresponds to 1.00kΩ to 1.10kΩ, the second fast thermocouple specification corresponds to 1.90kΩ to 2.10kΩ, and the third fast thermocouple specification corresponds to 2.90kΩ to 3.10kΩ. A gap of not less than 0.80kΩ is maintained between the intervals to accommodate resistance error, contact resistance, and sampling error.

[0075] The PLC controller establishes a molding inspection tooling pairing table. Each row of the table includes a first specification code, a second specification code, a fast thermocouple specification number, a working stroke, a working speed, holding parameters, and a molding judgment parameter group number. The same first and second specification codes do not necessarily indicate a successful pairing; the pairing result is determined by the molding inspection tooling pairing table. For example, if the first specification code of the workpiece positioning block is 2 and the second specification code of the molding inspection insert assembly 103 is 2, a corresponding pairing exists in the molding inspection tooling pairing table, and the PLC controller loads the second fast thermocouple specification parameter group. If the first specification code of the workpiece positioning block is 2 and the second specification code of the molding inspection insert assembly 103 is 1, a corresponding pairing does not exist in the table, the PLC controller outputs a molding inspection tooling mismatch status and prohibits the output of solenoid valve operating signals to the solenoid valve.

[0076] The molding inspection fixture code reading is performed when the reset position is valid and there is no workpiece in the positioning cavity. The PLC controller continuously reads 10 analog signals and calculates the average value. The average value of the 10 analog signals determines the first specification code and the second specification code. If the average value of the 10 analog signals does not fall within any specification range, the PLC controller outputs a specification identification anomaly status. If the difference between the maximum and minimum values ​​of the 10 analog signals exceeds the allowable fluctuation value, the PLC controller outputs a specification identification anomaly status. In this embodiment, the allowable fluctuation value is set to 0.03kΩ, which is less than the minimum width of each specification range (0.10kΩ) and the minimum interval between adjacent specification ranges (0.80kΩ). The allowable fluctuation value is determined based on the calibration results of the PLC controller's analog input repeatability, coding resistance error, and short-term contact fluctuation. When the specification identification anomaly status is valid, the PLC controller prohibits the output of the solenoid valve working signal to the solenoid valve and rereads the first and second specification codes after the specification identification anomaly status is cleared.

[0077] After successful assembly of the molding inspection tooling, the PLC controller loads the parameter set. In this embodiment, the second fast thermocouple specification parameter set includes a working stroke of 8.00 mm, a working speed of 40 mm / s, a retraction speed of 50 mm / s, a maximum holding time of 300 ms, a working action timeout of 600 ms, and a retraction action timeout of 500 ms. When the third fast thermocouple specification uses different fast thermocouple connectors, the parameter set may include a working stroke of 9.20 mm and different segment heights. The parameter set is only loaded before the start of the molding inspection cycle; switching fast thermocouple specifications is prohibited during the execution of the molding inspection cycle.

[0078] The changeover operation is performed in a controlled sequence. The PLC controller confirms the reset position is valid, and the maintenance personnel enter the maintenance enabled state. The maintenance personnel remove the original workpiece positioning block and the original forming detection insert assembly 103, and install the new workpiece positioning block and the new forming detection insert assembly 103. The PLC controller reads the first specification code and the second specification code and displays the pairing result. After successful pairing of the forming detection insert assembly, a low-speed idle stroke check is performed. When using cylinder 104, a removable inspection limit block is set in the working direction of the forming detection insert assembly 103, with the limit surface of the removable inspection limit block located 0.50mm before the working position. With the positioning cavity free of workpieces, the PLC controller controls the forming detection insert assembly 103 to move at 25% of its normal operating speed to the removable inspection limit block. After the maintenance personnel confirm that there is no mechanical interference between the forming detection insert assembly 103 and the workpiece positioning block, they use the maintenance confirmation operation to cause the PLC controller to control the forming detection insert assembly 103 to retract and reset. When using an electric cylinder, the PLC controller moves the molding inspection insert assembly 103 to an inspection position 0.50mm away from the working position via position commands. After the low-speed idle stroke inspection is passed and the removable inspection limit block is removed, the PLC controller allows trial operation.

[0079] In manual maintenance mode, the positive and negative conductive contacts are still limited by their maximum permissible retraction. Maintenance personnel can use a continuous manual action signal to control the PLC controller to move the molding and detection insert assembly 103 at low speed. The continuous manual action signal uses a continuous pressing method; releasing the manual action button immediately cancels the working direction output. When the working position status is valid, the PLC controller prohibits further increases in the working direction displacement.

[0080] Example 3: This example adds a force detection unit, a displacement detection unit, a detection result stability control, a switching module, a continuity reference branch, and a break reference branch to Example 1. Example 3 is used to determine whether the continuous working stroke conforms to the forming process characteristics of the corresponding fast thermocouple specification, and to verify the basic status of the detection link before the fast thermocouple head assembly is tested.

[0081] The force detection unit can employ an axial load sensor installed between the cylinder 104 and the connecting frame. The axial load sensor directly outputs the axial force acting on the forming detection insert assembly 103. The displacement detection unit can employ a magnetostrictive displacement sensor, a grating displacement sensor, or an electric cylinder encoder.

[0082] In this embodiment, the force detection unit uses an axial load sensor with a range of 0N to 200N, and the displacement detection unit uses a linear displacement sensor with a resolution of 0.01mm. The PLC controller has a built-in high-speed acquisition module that simultaneously acquires force and displacement detection values, with a sampling period of 5ms. The range of the force detection unit is determined according to the expected maximum axial force and overload margin during the molding process, the resolution of the displacement detection unit is determined according to the minimum indentation displacement that needs to be distinguished, and the sampling period is determined according to the maximum operating speed of the molding detection insert assembly 103 and the allowable displacement sampling interval.

[0083] The forming force can also be calculated based on the working chamber pressure of cylinder 104, the effective area of ​​the working chamber, the back pressure of the return chamber, the effective area of ​​the return chamber, and the equivalent frictional force between cylinder 104 and the guide structure. The effective area of ​​the working chamber, the effective area of ​​the return chamber, and the estimated forming force are calculated according to the following formula:

[0084] ;

[0085] ;

[0086] ;

[0087] in, The effective area of ​​the working chamber of cylinder 104. The effective area of ​​the return chamber of cylinder 104. The bore of cylinder 104 is... The piston rod diameter of cylinder 104 is... Pi To estimate the molding force, The working chamber pressure of cylinder 104, The back pressure of the return chamber of cylinder 104, The equivalent frictional force of cylinder 104 and guide structure; the dimensions of the effective area of ​​the working chamber and the effective area of ​​the return chamber are area, the dimensions of the cylinder diameter and piston rod diameter are length, the dimensions of the working chamber pressure and the return chamber back pressure are the ratio of force to area, and the dimensions of the estimated forming force and the equivalent frictional force are force.

[0088] The equivalent friction force is calibrated when there is no workpiece in the positioning cavity and the forming detection insert assembly 103 performs an idle stroke at the same working speed as the forming detection cycle. The PLC controller calculates the stress of the idle stroke based on the working cavity pressure, return cavity back pressure and corresponding effective area during the idle stroke, and determines the average value of the stable motion section as the equivalent friction force.

[0089] In this embodiment, the cylinder diameter of cylinder 104 is 20mm, and the piston rod diameter is 8mm. Based on the aforementioned formula, the effective area of ​​the working chamber is calculated to be 314.16mm², and the effective area of ​​the return chamber is 263.89mm². The working chamber pressure is 0.35MPa, the return chamber back pressure is 0.03MPa, the equivalent frictional force is 8.00N, the force generated by the working chamber pressure is 109.96N, and the reverse force generated by the return chamber back pressure is 7.92N. The estimated forming force is calculated to be 94.04N. This pressure conversion method is applicable to structures without an axial load sensor; when an axial load sensor is installed, the PLC controller directly uses the axial force value calibrated by the axial load sensor.

[0090] The displacement detection value is set to zero at the reset position. Before the molding detection cycle begins, the PLC controller records the current output of the displacement detection unit as the zero-point offset when the reset position is valid. During the working motion of the molding detection insert assembly 103, the PLC controller subtracts the zero-point offset from the displacement detection value to obtain the axial displacement. The force detection value and the axial displacement are arranged into a molding force and axial displacement correspondence sequence according to the same sampling sequence number.

[0091] The forming force-displacement envelope is allowed to be established according to the specifications of the fast thermocouple. The calibration process selects a fast thermocouple head assembly whose dimensions meet the product process requirements, whose compensating wire polarity is confirmed to be correct, and whose entire circuit is conductive. The calibration process is performed under the conditions of the same workpiece positioning block, the same forming detection insert assembly 103, the same movement speed, and the same sampling period.

[0092] In this embodiment, 40 fast thermocouple head assemblies are selected for calibration for each fast thermocouple specification. These 40 fast thermocouple head assemblies ensure that the 5% quantile and 95% quantile positions fall within the low-end and high-end sample regions of the sorted sample sequence, respectively. Each calibrated workpiece forms a forming force-displacement curve. The 40 forming force-displacement curves are linearly interpolated using a uniform displacement grid of 0.20 mm, and a forming force sample set containing 40 forming force values ​​is formed at each displacement point. The uniform displacement grid step size is determined based on the maximum working speed of 40 mm / s and the maximum sampling displacement interval of 0.20 mm corresponding to a sampling period of 5 ms. The entire working segment begins when the forming detection ferrule assembly 103 leaves the reset position and ends when it reaches the working position.

[0093] Valid sampling points are those where the sampling time falls within the entire working section, the force detection value is within the effective range of the force detection unit, the displacement detection value is within the effective range of the displacement detection unit, the force and displacement detection values ​​have the same sampling sequence number, and neither the force nor displacement detection units output a fault status. Sampling points that do not meet any of these conditions are not included in the allowable forming force-displacement envelope determination. The preset minimum number of sampling points is determined based on the length of the entire working section, the maximum working speed, and the sampling cycle; when the working stroke is 8.00 mm, the maximum working speed is 40 mm / s, and the sampling cycle is 5 ms, the preset minimum number of sampling points is set to 30.

[0094] The allowable molding force-displacement envelope is established using the quantile method. At each uniform displacement point, the molding forces corresponding to all calibration curves are sorted from smallest to largest. The position of the 5th quantile is determined by spanning 5% of all adjacent sample intervals starting from the first sorted sample, and the position of the 95th quantile is determined by spanning 95% of all adjacent sample intervals starting from the first sorted sample. When a quantile position falls between two sorted samples, linear interpolation is performed according to the proportion of the quantile position in the corresponding adjacent sample interval. The allowable lower limit of molding force, the allowable upper limit of molding force, and the molding force determination relationship in the molding detection loop are as follows:

[0095] ;

[0096] ;

[0097] ;

[0098] in, axial displacement The corresponding lower limit of allowable molding force, axial displacement The corresponding upper limit of allowable molding force, axial displacement The corresponding 5th percentile value of molding force. axial displacement The corresponding 95th percentile value of molding force, The envelope margin corresponding to the system error and measurement drift of the force detection system. axial displacement The corresponding actual forming force, For the first The axial displacement corresponding to each valid sampling point The sampling sequence number is the valid sampling point number. The dimensions of the lower allowable molding force, upper allowable molding force, 5th percentile of molding force, 95th percentile of molding force, envelope margin, and actual molding force are all force, while the dimension of axial displacement is length. The sampling sequence number is dimensionless. The envelope margin is determined based on the maximum permissible measurement error of the force detection unit, the maximum zero-point drift, and the measurement deviation caused by temperature changes during calibration.

[0099] The PLC controller does not require all sampling points to fall completely within the envelope. Displacement detection noise and minor differences on the workpiece surface may cause the actual forming force of a single sampling point to be lower than the lower limit of the allowable forming force or higher than the upper limit of the allowable forming force. The PLC controller sets a threshold for the number of consecutive out-of-bounds points and a threshold for the cumulative out-of-bounds ratio. In this embodiment, an abnormal forming process status is output when the actual forming force of three consecutive valid sampling points is lower than the lower limit of the allowable forming force or higher than the upper limit of the allowable forming force, or when the proportion of valid sampling points with forces lower than the lower limit of the allowable forming force or higher than the upper limit of the allowable forming force in the entire working range exceeds 5% of the total number of valid sampling points. The threshold for the number of consecutive out-of-bounds points is determined based on the sampling period, the duration of force detection noise, and the shortest duration of mechanical contact abnormality; the threshold for the cumulative out-of-bounds ratio is determined based on the natural out-of-bounds ratio of the qualified calibration curve and the allowable false judgment rate.

[0100] For example, at an axial displacement of 3.00 mm, the allowable molding force range is 42.00 N to 58.00 N, and the actual molding force is 50.00 N, so the current valid sampling point is qualified. At an axial displacement of 4.50 mm, the upper limit of the allowable molding force is 84.00 N, and the actual molding force is 91.00 N, so the current valid sampling point exceeds the limit. When three consecutive valid sampling points corresponding to axial displacements of 4.50 mm, 4.70 mm, and 4.90 mm all exceed the upper limit of the allowable molding force, the PLC controller outputs an abnormal state of the molding process.

[0101] Abnormal states during the molding process are categorized according to the curve regions. If the actual molding force in the initial molding zone is consistently below the lower limit of the allowable molding force, it indicates that the section to be molded on the positive or negative end of the compensating conductor is missing, or has not entered the positive or negative molding action zone. If the actual molding force in the middle molding zone is above the upper limit of the allowable molding force, it indicates the presence of foreign objects in the positioning cavity, positive compensating conductor positioning groove, or negative compensating conductor positioning groove, or that the position of the positive or negative compensating conductor has deviated. If the axial displacement in the final molding zone does not reach the final range and the actual molding force increases prematurely, it indicates that the rapid thermocouple head assembly may not be fully in place. If the actual molding force in the final molding zone is below the lower limit of the allowable molding force, it indicates insufficient pressing or a change in the mechanical limit position.

[0102] When the external thermocouple polarity detector provides the detection completion signal, polarity result signal, and continuity result signal, the PLC controller uses a switching quantity stability determination. After the detection completion signal remains continuously valid and the polarity result signal and continuity result signal maintain the same value for a stable sampling count, the PLC controller establishes a stable detection result state. If the detection completion signal becomes invalid again, or if the value of the polarity result signal or continuity result signal changes, the PLC controller clears the current stable sampling count and restarts the stability determination. In this embodiment, the PLC controller's stable sampling period is 10ms, the stable sampling count is 5, and the detection completion signal, polarity result signal, and continuity result signal need to be continuously maintained for 50ms. The stable sampling period is determined based on the result update cycle of the external thermocouple polarity detector and the sampling period of the PLC controller, and the stable sampling count is determined based on the calibration duration of the detected contact jitter.

[0103] When the external thermocouple polarity detector can output continuous detection values, the PLC controller uses the fluctuation range of the continuous detection values ​​within the stability judgment window to determine stability. The stability condition is:

[0104] ;

[0105] in, To ensure stability within the decision window The continuous detection volume obtained from each sampling. To stabilize the sampling sequence number within the decision window, This is the current sampling sequence number. To determine the number of consecutive samples included in the stable decision window, To allow for fluctuation range, This indicates that the maximum value of the continuous detections within the stability decision window is taken. This indicates the minimum value of the continuous detection quantity within the stability judgment window; the continuous detection quantity and the allowable fluctuation range have the same dimension, and the sampling sequence number and the number of continuous samples are both dimensionless quantities.

[0106] In this embodiment, the continuously detected quantity is the loop resistance output by the external thermocouple polarity detector. The stability judgment window includes 5 consecutive samples, and the allowable fluctuation range is 0.005Ω. The loop resistances for the 5 consecutive samples are 0.184Ω, 0.181Ω, 0.183Ω, 0.182Ω, and 0.181Ω, respectively. The difference between the maximum and minimum values ​​is 0.003Ω, which meets the stability condition. The allowable fluctuation range is determined based on the measurement resolution and repeatability error of the external thermocouple polarity detector, as well as the short-term fluctuation range of the loop resistance of a qualified product when the detection link self-test is valid.

[0107] The maximum holding time is used to limit the molding and testing insert assembly 103 from remaining in the working position for an extended period. In this embodiment, the maximum holding time is 800ms. The PLC controller starts the maximum holding timer after acquiring the working position status. When the detection completion signal is valid and the detection result meets the stability condition within 800ms, the PLC controller ends the holding time and performs retraction. When the detection completion signal is invalid or the detection result does not meet the stability condition within 800ms, the PLC controller records the abnormal detection state and performs retraction to prevent the cylinder 104 from continuously pressing. The maximum holding time is determined based on the longest detection time of the external thermocouple polarity detector under normal detection conditions, the duration of the stability judgment window, and the control margin of the PLC controller.

[0108] A switching module is located between the polarity detection interface and the molded detection insert assembly 103. The switching module includes a detection working position, a continuity self-test position, and a break-circuit self-test position. In the detection working position, the polarity detection interface connects to the positive and negative conductive contacts. In the continuity self-test position, the polarity detection interface connects to the continuity reference branch. In the break-circuit self-test position, the polarity detection interface connects to the break-circuit reference branch.

[0109] The continuity reference branch uses a precision resistor with a known resistance value. This precision resistance value is within the range determined by an external thermocouple polarity detector to indicate continuity, and is distinguishable from a zero-resistance short circuit. In this embodiment, the nominal resistance of the continuity reference branch is 0.200Ω, with an allowable deviation of ±0.002Ω. The disconnection reference branch uses a physical disconnect contact and remains disconnected within the switching module.

[0110] The self-test of the detection link is performed in a fixed sequence. The PLC controller controls the switching module to enter the open-circuit self-test position; the external thermocouple polarity detector should output a valid test completion signal and a continuity result signal indicating an open circuit. The PLC controller then controls the switching module to enter the continuity self-test position; the external thermocouple polarity detector should output a valid test completion signal and a continuity result signal indicating continuity. When the continuity result signal corresponding to the open-circuit reference branch indicates an open circuit and the continuity result signal corresponding to the continuity reference branch indicates continuity, the PLC controller outputs a "detection link self-test qualified" status and controls the switching module to return to the detection working position.

[0111] When the self-test for the open circuit returns a continuity result, there may be an internal short circuit in the polarity detection interface, a short circuit in the shielded wire core, or sticking of the switching module contacts. When the self-test for the continuity returns an open circuit result, there may be a disconnected connection, a loose interface, poor contact in the switching module, or the external thermocouple polarity detector not being operational. The PLC controller will latch the failed self-test status of the detection link and prohibit the forming detection cycle.

[0112] The detection link self-test is executed after the equipment is powered on, after the fast thermocouple specification is switched, after a set number of consecutive product failures, and after maintenance personnel issue a self-test command through the detection link self-test operation device. During the detection link self-test, the forming detection insert assembly 103 remains in the reset position, and the positioning cavity remains free of workpieces. The PLC controller does not initiate the self-test when it detects a valid thermocouple head position signal, to prevent the switching module from changing the detection channel while the fast thermocouple head assembly is connected.

[0113] The molding process pass status and electrical test results are generated separately. The molding process pass status is jointly formed by the following: valid working position arrival record, valid reset position arrival record, invalid working action timeout status, invalid retraction reset abnormal status, and a pass molding force-displacement envelope judgment result. The polarity correct status and the full circuit continuity pass status are generated by an external thermocouple polarity detector. The PLC controller does not use the polarity correct status or the full circuit continuity pass status to replace the molding process pass status, nor does it use the molding process pass status to replace the polarity correct status or the full circuit continuity pass status. The PLC controller will only set the overall product status to pass when the molding process pass status, the test result stable status, the polarity correct status, the full circuit continuity pass status, and the test link self-test pass status are all valid.

[0114] In this embodiment, based on the completion of molding process monitoring, detection result stability control, and detection link self-testing, a workpiece retainer, photoelectric detection baseline judgment, classification counting, and production line interlocking are further set up. The workpiece retainer is used to convert the molding process results and electrical detection results into material handling permission, while the photoelectric detection baseline judgment, classification counting, and production line interlocking are used to handle photoelectric detection contamination, manual maintenance, and continuous abnormal conditions.

[0115] A workpiece retainer is installed on the inlet side of the workpiece positioning block. The workpiece retainer includes a retaining plate, a retaining spring, and a retaining drive. The retaining plate has a restricted position and a released position. When the retaining plate is in the restricted position, it enters the removal path of the rapid thermocouple head assembly, preventing the rapid thermocouple head assembly from being removed in the reverse direction of insertion. When the retaining plate is in the released position, it exits the removal path, allowing the operator to remove the rapid thermocouple head assembly. The retaining drive can be a small electromagnet, a pneumatic micro-actuator, or a motor. The retaining spring returns the retaining plate to the restricted position when de-energized. The PLC controller only controls the retaining drive to release the retaining plate when the overall product status is qualified and the molding detection insert assembly 103 has reached the reset position. When the overall product status is unqualified, the detection incomplete status is valid, the molding process qualified status is invalid, or the reset position status is invalid, the retaining plate maintains the restricted position.

[0116] The limiting position of the workpiece retainer does not provide for the precise positioning of the fast thermocouple head assembly. The precise positioning of the fast thermocouple head assembly is still achieved by the positioning cavity. A 0.30mm to 0.80mm clearance is maintained between the retaining baffle and the fast thermocouple head assembly to ensure that the retaining baffle does not alter the fit between the fast thermocouple connector and the positioning cavity.

[0117] The overall product status is determined according to logical AND relationships. When the molding process is qualified, the test results are stable, the entire circuit is conductive, the polarity is correct, and the test link self-test is qualified, the PLC controller sets the overall product status to qualified; if any of the states is invalid, the PLC controller sets the overall product status to unqualified.

[0118] In Example 1, without setting a molding force-displacement judgment, the qualified state of the molding process is jointly formed by the following: valid working position arrival record, invalid working action timeout state, valid reset position arrival record, and invalid retraction reset abnormal state. In Example 3, with a molding force-displacement judgment, the qualified state of the molding process also needs to meet the allowable molding force-displacement envelope requirement. For example, when the qualified state of the molding process, the stable state of the detection result, the qualified state of the full circuit conduction, the correct polarity state, and the qualified state of the detection link self-test are all valid, the overall product status is qualified, and the PLC controller allows the workpiece holder to enter the release position. When the correct polarity state is invalid, the overall product status is unqualified, and the workpiece holder maintains the restricted position.

[0119] Non-conforming products can be handled using controlled release. After the operator presses the non-conforming confirmation button, the PLC controller verifies that the forming inspection insert assembly 103 has been reset and records the current product as a non-conforming product. The PLC controller then briefly moves the workpiece holder to the release position, allowing the operator to place the non-conforming product into the non-conforming collection container. The non-conforming confirmation operation does not change the number of non-conforming products to the number of conforming products.

[0120] The classification and counting module is equipped with a molding inspection cycle counter, an inspection completion counter, a qualified product counter, a non-qualified product counter, a molding anomaly counter, a polarity anomaly counter, a continuity anomaly counter, and an inspection link anomaly counter. The molding inspection cycle counter increments by 1 after the molding inspection insert assembly 103 completes its working movement and retraction reset. The inspection completion counter increments by 1 after the external thermocouple polarity detector outputs a valid inspection completion signal. The qualified product counter increments by 1 after the current molding inspection cycle ends, the overall product status is qualified, and the workpiece holder enters the release position. The non-qualified product counter increments by 1 after the current molding inspection cycle ends, the overall product status is unqualified, and an unqualified handling instruction is output.

[0121] Count consistency is used to identify process omissions. The number of unprocessed products refers to the number of fast thermocouple head assemblies that have completed the molding inspection cycle but have not yet completed either qualified release or unqualified controlled release. At the end of a normal production batch, each completed molding inspection cycle is checked item by item; excluding unprocessed fast thermocouple head assemblies, each molding inspection cycle corresponds to one qualified product count or one unqualified product count, and the inspection completion count must not exceed the molding inspection cycle count. When the inspection completion counter is less than the molding inspection cycle counter, the difference corresponds to an incomplete inspection or an abnormal inspection loop. The PLC controller displays the count difference on the classification count display component.

[0122] The dust removal assembly 102 is connected to a compressed air source. The dust removal nozzles are directed towards the detection area and positioning cavity of the photoelectric detection sensor 101. The spray direction of the dust removal nozzles avoids the internal wire outlets of the positive and negative conductive contacts to prevent dust from being blown into the molded detection insert assembly 103. The dust removal assembly 102 is equipped with an independent solenoid valve and pressure regulating section.

[0123] The PLC controller performs photoelectric detection baseline judgment only when there is no workpiece in the positioning cavity, the forming detection insert assembly 103 is in the reset position, and the workpiece holder is in the released position. The no-workpiece state is determined by the invalidation of the coupler head position signal and the duration of the no-workpiece confirmation time. In this embodiment, the no-workpiece confirmation time is 200ms.

[0124] The photoelectric sensor 101 provides an analog light intensity value. After the equipment completes cleaning and maintenance, the PLC controller records the cleaning baseline value. Before purging, the PLC controller collects 20 photoelectric detection values ​​and calculates the average value, which is then determined as the baseline value before purging. The relative deviation of the baseline value before or after purging from the cleaning baseline value is calculated using the following formula:

[0125] ;

[0126] in, The relative deviation of the baseline value before or after purging from the cleaning baseline value. The baseline value before or after purging. This is the baseline value for cleaning. This indicates that the absolute value is taken; the relative deviation is a dimensionless quantity, and the baseline value before purging, the baseline value after purging, and the cleaning reference value use the same sampling and counting unit.

[0127] The cleaning baseline range is determined based on a relative deviation threshold. This relative deviation threshold is greater than the deviation caused by normal ambient light variations, sensor temperature drift, and power fluctuations, but less than the deviation before dust affects workpiece identification. In this embodiment, the relative deviation threshold is set to 12%, the cleaning baseline value is 2500 sample counts, and the baseline value before purging is 2075 sample counts. The calculated relative deviation is 17%, and the PLC controller initiates purging.

[0128] A single purging cycle consists of three compressed air pulses, each lasting 80 ms, with a 120 ms interval between adjacent pulses, for a total purging time of 480 ms. After purging, a 300 ms wait is allowed to allow the airflow and dust movement within the positioning cavity to decay. The PLC controller re-acquires 20 photoelectric detection values ​​and calculates the average. With a baseline value of 2420 sample counts after purging, the relative deviation is 3.2%, and the PLC controller determines that the detection area has returned to the clean baseline range. The number of compressed air pulses, duration, interval between adjacent pulses, and waiting time after purging are calibrated based on compressed air pressure, distance from the dust removal nozzle to the detection area, dust adhesion, and the baseline detection value recovery time after purging.

[0129] If the baseline value obtained after the first purging still exceeds the cleaning reference range, the PLC controller performs a second purging. If the baseline value fails to recover after two consecutive purging cycles, the PLC controller outputs an abnormality detection signal and disables automatic mode. Limiting the number of consecutive purging cycles prevents continuous air leakage. After cleaning the positioning cavity and photoelectric detection sensor 101, maintenance personnel update the cleaning reference value via the baseline reconstruction operator when the maintenance enable signal is valid.

[0130] When the photoelectric sensor 101 only provides a switching signal, the PLC controller uses the state transition position or state transition time as the baseline parameter. During equipment maintenance and calibration, a dedicated test strip is used. This test strip is a calibration piece with a fixed light-blocking width and the ability to move along a fixed guide path. When there is no workpiece in the positioning cavity, the dedicated test strip passes through the detection area at a fixed speed, and the PLC controller records the switching position or time of the photoelectric switch signal. If the switching position or time exceeds the cleaning baseline range, the PLC controller initiates a purging process. After purging, the PLC controller reconfirms the switching position or time of the photoelectric switch signal.

[0131] Manual maintenance mode is entered via a key-operated maintenance enable switch. When the maintenance enable signal is valid, the reset position is valid, and there is no interlock fault, the PLC controller begins accepting continuous manual operation signals. After the molding detection insert assembly 103 begins to leave the reset position, the PLC controller does not interrupt the already accepted continuous manual operation signals even when the reset position becomes invalid. When the operator continuously presses the manual operation button to make the continuous manual operation signal valid, the molding detection insert assembly 103 moves in the working direction at the maintenance speed; when the operator releases the manual operation button, the PLC controller cancels the working direction output. The maintenance speed is lower than the automatic mode working speed.

[0132] In this embodiment, the automatic mode operating speed is 40 mm / s, and the maintenance speed is 10 mm / s. After the working position status is valid, the PLC controller prohibits further output of the working direction signal.

[0133] When the phase head position signal is invalid, the manual maintenance mode can perform a low-speed idle stroke check without a workpiece; when the phase head position signal is valid, the PLC controller requires the operator to simultaneously maintain the maintenance confirmation operation piece to avoid accidental triggering of a single operation piece. The maintenance speed is determined based on the control response time after the operation piece is released, the safe stopping distance of the forming detection insert assembly 103, and the requirements for the idle stroke check without a workpiece.

[0134] Production anomaly interlocks include working action timeout status, retraction reset anomaly status, position detection anomaly status, detection link self-test failure status, detection anomaly status, forming detection tooling mismatch status, specification recognition anomaly status, arrival detection anomaly status, and continuous product non-conformity status. The PLC controller assigns a unique fault code to each anomaly. These fault codes are used in the classification counting display component, alarm component, and production line interlock output.

[0135] For continuous product defects, the production line is not directly stopped based on a single defective product. The PLC controller sets a threshold for the number of consecutive product defects. In this embodiment, the PLC controller outputs a continuous product defect status when the overall product status is defective for three consecutive molding and inspection cycles. The continuous product defect count is reset to zero when a single defective product is found. The threshold for the number of consecutive product defects is set based on production cycle time, raw material batch risk, and the capacity to handle defective products.

[0136] Controlled reset includes confirming the reset position status is valid, confirming that there are no workpieces in the positioning cavity or that defective products have been removed under control, confirming that the detection link self-test is valid, confirming that the molding and inspection tooling assembly is successful, and confirming that the photoelectric detection baseline is within the cleanliness reference range. After the PLC controller completes all confirmations, it clears faults that can be automatically recovered. If the working action timeout status or the position detection abnormal status is valid, maintenance personnel need to check the mechanical structure and perform a manual reset.

[0137] The production line interlock output end adopts safety isolation relay contacts. The normal state of the production line interlock output end is to allow feeding. When the PLC controller has a fault requiring line shutdown, it withdraws the feeding permission signal, so that the preceding feeding station or assembly station stops conveying the fast thermocouple head assembly to the current station. After the fault is cleared and controlled reset is completed, the PLC controller restores the feeding permission signal.

[0138] In Embodiment 3, the forming process qualified state, detection result stable state, correct polarity state, full circuit conduction qualified state, detection link self-check qualified state and in-position detection abnormal state are respectively applied to workpiece release, classification counting, dust removal control and production line interlock. The count of qualified products is no longer equivalent to the count of forming detection cycles, and product release no longer only relies on acousto-optic prompts. The technical features recorded in Embodiment 1 to Embodiment 3 can be applied in combination under the condition that the press-fitting forming and polarity detection connection of the positive compensation lead and the negative compensation lead are completed in the same continuous working stroke by the same forming detection ferrule assembly 103.

[0139] When the forming execution unit adopts a pneumatic structure, the working stroke is determined jointly by mechanical limit, position detection and gas circuit parameters. When the forming execution unit adopts an electric structure, the working stroke is determined jointly by position command, driver feedback and mechanical limit. When the polarity detection interface adopts a switching value interface, the PLC controller executes control according to the detection completion signal, polarity result signal, conduction result signal and detection fault signal. When the polarity detection interface adopts an industrial communication interface, the PLC controller reads the detection completion signal, polarity result signal, conduction result signal, detection fault signal and continuous detection quantity.

[0140] The specific dimensions, materials and parameters of the fast thermocouple compensation lead forming detection industrial control system are determined according to the fast thermocouple specification, the outer diameters of the positive compensation lead and the negative compensation lead, the dimensions of the positive compensation lead positioning groove and the negative compensation lead positioning groove, the interface parameters of the polarity detection interface and the production tact time. The parameter determination process shall ensure that the forming end face can complete the predetermined press-in amount, the positive conductive contact part and the negative conductive contact part can form stable and mutually insulated detection contacts, and the PLC controller can obtain clear action states and detection states. The detection threshold, stable sampling quantity, action timeout time, purging sequence and continuous unqualified product quantity threshold are determined according to the corresponding physical dimensions, technical indicators of the sensor or detector, equipment calibration records, and data of workpieces of the same specification confirmed to be qualified through dimension and electrical detection. When the fast thermocouple specification, forming detection tooling combination, sensor, detector or movement speed changes, the corresponding calibration is re-performed.

[0141] Example 4: Based on Example 3, Example 4 adds a servo-driven micro-displacement wiping sequence and a secondary stability determination mechanism to address the micron-level high impedance film formed on the exposed metal surfaces of the positive and negative electrodes of the compensation wires in industrial production environments due to oxidation, dust adhesion, or moisture.

[0142] Before the rapid thermocouple head assembly enters the mass assembly process, the metal wire surfaces of the positive and negative compensating leads are exposed to air. A dense oxide film readily forms on the surface of the nickel-chromium-nickel-silicon or platinum-rhodium alloy wires. This non-conductive film constitutes an extremely high contact resistance barrier layer when the positive and negative conductive contacts are in static pressure contact. Even if the formed detection insert assembly 103 has reached the mechanical working position, and the positive and negative conductive contacts provide contact forces conforming to the design values ​​of Example 2, the external thermocouple polarity detector may still output fluctuating continuous detection values. This random fluctuation manifests as the continuous detection value failing to converge within a stable judgment window. The static holding logic of Examples 1 to 3 directly determines it as unqualified. Rapid thermocouple head assemblies that pass physical forming but fail electrical testing due to the surface oxide film are incorrectly rejected.

[0143] The forming execution unit uses a servo linear actuator instead of cylinder 104. The servo linear actuator has a built-in high-resolution absolute encoder. The PLC controller sends synchronous position commands to the servo linear actuator via the EtherCAT industrial Ethernet bus, and the position closed-loop control cycle is set to 1ms. The rigid lead screw drive structure of the servo linear actuator eliminates position drift caused by air pressure fluctuations.

[0144] The micro-displacement wiping sequence aims to force the positive and negative conductive contacts to undergo shear friction on the surfaces of the positive and negative compensating wires without disrupting the completed mechanical pressing state, using extremely small axial reciprocating displacement. This relative friction process effectively scratches and peels off the oxide layer attached to the surface of the metal wire, exposing the fresh conductive substrate, causing the contact resistance to drop sharply and stabilize.

[0145] The triggering condition depends on the setting of the first-round evaluation time. After the molded inspection insert assembly 103 reaches the working position, the PLC controller starts the first-round evaluation timer. The first-round evaluation time is set to 200ms. Within 200ms, the external thermocouple polarity detector transmits continuous detection quantities (loop resistance values) to the PLC controller at an update cycle of 2ms. The stability judgment window contains 5 consecutive sampled values. When the first-round evaluation time expires, if the difference between the maximum and minimum values ​​of the continuous detection quantities in all the passed stability judgment windows is greater than the allowable fluctuation range (such as 0.005Ω set in Example 3), the PLC controller does not cancel the working position state, suspends the inspection result evaluation process, and calls the micro-displacement wiping function block.

[0146] The micro-displacement wiping motion is subject to extremely strict geometric constraints. The movement of the forming and testing insert assembly 103 must absolutely not alter the physical shape of the compensation wires already pressed into the positive and negative compensation wire positioning slots. The unidirectional wiping amplitude must simultaneously satisfy two physical boundary conditions. Upper boundary: The unidirectional amplitude must be less than the minimum value of the working retraction amount (0.25 mm) corresponding to the positive terminal and the working retraction amount (0.35 mm) corresponding to the negative terminal of the compensation wire described in Example 2, ensuring that at the retraction extreme point, the positive and negative conductive contacts are still compressed by the pre-tightening force of the positive and negative elastic elements and do not detach from the compensation wires. Lower boundary: The unidirectional amplitude must be greater than the sum of the micro-roughness peak spacing of the oxide film and the local elastic deformation of the contact point, ensuring substantial macroscopic slippage rather than pure elastic viscosity.

[0147] The instantaneous position commands generated by the PLC controller follow a specific mathematical model:

[0148] ;

[0149] in, This represents the instantaneous axial coordinate of the servo linear actuator during the wiping sequence. The reference axial coordinate for the working position. For micro-displacement wiping unidirectional amplitude, For the wiping excitation frequency, This is the execution time calculated from the start of the wipe sequence. This indicates taking the absolute value; the dimensions of the coordinates and amplitude are length, the dimension of the frequency is the reciprocal of time, and the dimension of time is time.

[0150] The use of a full-wave rectified sine curve avoids the impact when the velocity crosses zero. The actuator always oscillates behind the working position (retraction side), and movement beyond the working position to a deeper location is strictly prohibited to prevent secondary excessive compression of the positive and negative terminals of the compensation conductor. In this embodiment, the unidirectional amplitude of the micro-displacement wiping is set to 0.15mm. This value is much smaller than the minimum working retraction boundary of 0.25mm. The wiping excitation frequency is set to 10Hz. The high-frequency, low-amplitude motion characteristics induce high shear stress at the contact interface. The duration of the entire wiping sequence is set to 300ms, comprising three complete reciprocating sliding cycles.

[0151] During the wiping sequence, the electrical connection of the detection unit remains conductive. Due to the sliding of the positive and negative conductive contacts on the surface of the compensating wire, the contact resistance exhibits significant and drastic fluctuations. During this 300ms period, the PLC controller actively disables alarm triggers for polarity detection results and continuous detection quantities, while simultaneously activating the high-speed data cache module. The high-speed data cache module records the trajectory of continuous detection quantity changes within this 300ms period. This trajectory data is only used for offline analysis of the contact interface wear condition during subsequent maintenance and is not included in the current pass / fail determination.

[0152] The mechanical state of the friction interface is monitored synchronously by the force detection unit and the displacement detection unit. Micro-displacement wiping alters the force balance of the molding detection insert assembly 103. The introduction of friction causes dynamic alteration of the actual molding force. During the wiping process, the PLC controller calls the allowable molding force-displacement envelope determination subroutine described in Example 3 at 5ms intervals. Instantaneous axial coordinates. The input index is used to extract the corresponding lower and upper limits of the allowable molding force. The actual molding force must be strictly enveloped within this range. If the following error of the servo actuator is too large, or if mechanical jamming occurs at the positive conductive contact causing a surge in local stress, the actual molding force will exceed the upper limit. Once the actual molding force exceeds the limit for two consecutive sampling cycles, the PLC controller immediately triggers a hardware interrupt, urgently stops the servo linear actuator, and outputs an abnormal status of the molding process.

[0153] After the wiping sequence is completed, the servo linear actuator approaches the reference axial coordinate again at a set, extremely low smooth speed of 10 mm / s. Upon reaching the reference axial coordinate, the PLC controller triggers a forced stop command. The positive and negative conductive contacts then rest on the local surface of the compensation wire, which has been rubbed clean to a pure metallic luster.

[0154] The secondary stability assessment process is initiated. The PLC controller clears all historical continuous detection values ​​remaining in the registers from the initial evaluation and wiping sequence phases, and initializes the stability assessment window. After granting the external thermocouple polarity detector a 50ms hardware electrical recovery margin, the PLC controller begins acquiring new continuous detection values. Due to the disruption of the non-conductive thin film, the contact surface changes from point contact to microscopic line / surface contact, resulting in a significant increase in the contact area.

[0155] The system imposes a more stringent convergence time limit on the secondary judgment. The secondary hold time is set to 150ms. Within this 150ms, if the continuous detection quantity output by the external thermocouple polarity detector meets the allowable fluctuation range of the difference between the maximum and minimum values ​​not exceeding 0.005Ω within the preset stable judgment window, the PLC controller determines that the polarity detection interface has established a high-quality ohmic contact. Subsequently, the PLC controller extracts the current polarity result signal and conduction result signal. When the polarity result signal is correct and the conduction result signal is on, the overall product status is marked as qualified. If the continuous detection quantity still fails to converge within the 150ms secondary hold time, or if there is an abnormality in the polarity / conductivity result, it indicates that the fast thermocouple head assembly has a substantial internal open circuit or serious miswiring caused by factors other than the surface oxide layer. The PLC controller outputs a detection abnormality status and initiates retraction.

[0156] Micro-friction cleaning not only reduces false defects caused by surface oxidation, but also enables traceability of material surface quality by monitoring the rate of change in resistance before and after wiping. See Table 1 for details of the production verification record of a certain batch of rapid thermocouple head assemblies.

[0157] Table 1 shows a performance comparison before and after enabling the wiping sequence function:

[0158] Table 1 shows that without the micro-displacement wiping sequence, over 7% of the rapid thermocouple head assemblies were falsely rejected by the system due to fluctuations in continuous inspection volume during the first evaluation period. After enabling this logic, the vast majority of assemblies initially exhibiting fluctuating resistance successfully recovered to normal conduction resistance through a 300ms physical stripping operation. The overall system false rejection rate was reduced to an industrially acceptable, extremely low level. Although the weighted average time per inspection increased slightly, the overall gain in process efficiency and economic benefits was enormous compared to the high material loss from discarding potentially qualified products.

[0159] The micro-displacement wiping process alters the contact state of the physical interface within an extremely small space. The coordinated operation of the forming execution unit, force detection unit, and control algorithm ensures that this additional action is completely isolated below the mechanical damage threshold. The rapid thermocouple compensating wire forming inspection industrial control system eliminates the blind spots of passive static inspection through this servo-driven flexible intervention logic. The classification and counting module establishes a dedicated secondary recovery counter. Each time an event occurs where the wire changes from unqualified to qualified after wiping, this secondary recovery counter increments by 1. This count value is uploaded to the factory manufacturing execution system via the production line interlock output, serving as a core reference indicator for evaluating the quality of the anti-oxidation coating from the upstream compensating wire supplier.

[0160] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0161] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An industrial control system for rapid thermocouple compensating wire forming and inspection, comprising a workpiece positioning unit, a positioning detection unit, a forming execution unit, a detection connection unit, and a PLC controller, characterized in that: The workpiece positioning unit includes a workpiece positioning block with a positioning cavity. The positioning cavity is used to position the fast thermocouple head assembly. The fast thermocouple head assembly includes a fast thermocouple connector, a positive compensating wire, and a negative compensating wire. The fast thermocouple connector is provided with a positive compensating wire positioning groove and a negative compensating wire positioning groove. The positive and negative compensating wires are pre-inserted into the fast thermocouple connector. The positioning detection unit is used to detect whether the thermocouple head assembly has reached the predetermined position in the positioning cavity and outputs a head positioning signal to the PLC controller; the forming execution unit includes a linear actuator and a forming detection insert assembly driven by the linear actuator. The forming detection insert assembly reciprocates along the motion axis. The forming detection insert assembly has a forming end face, which includes a positive forming action area corresponding to the positive compensation wire positioning groove and a negative forming action area corresponding to the negative compensation wire positioning groove. The end point of the stroke of the forming detection insert assembly moving toward the positioning cavity is the working position; The detection connection unit includes a positive conductive contact, a negative conductive contact, an insulating structure, and a polarity detection interface disposed on the molded detection insert assembly. The insulating structure isolates the positive conductive contact and the negative conductive contact. The positive conductive contact is connected to the positive terminal of the polarity detection interface, and the negative conductive contact is connected to the negative terminal of the polarity detection interface. The polarity detection interface also includes a detection completion input terminal, a polarity result input terminal, and a continuity result input terminal connected to the PLC controller. After obtaining a valid pair head positioning signal, the PLC controller controls the linear actuator to drive the forming detection insert assembly to perform one continuous working stroke, so that the positive forming action area presses the positive electrode of the compensation wire into the positive compensation wire positioning groove, and the negative forming action area presses the negative electrode of the compensation wire into the negative compensation wire positioning groove, and establishes detection contact between the positive conductive contact part and the positive electrode of the compensation wire, and between the negative conductive contact part and the negative electrode of the compensation wire respectively. The PLC controller keeps the molding detection insert assembly in the working position, simultaneously maintaining the compensating wire pressed-in state and the detection contact state. This allows an external thermocouple polarity detector connected to the polarity detection interface to perform polarity correctness detection and full-loop continuity detection. The external thermocouple polarity detector outputs detection completion signal, polarity result signal, and continuity result signal to the PLC controller through the detection completion input terminal, polarity result input terminal, and continuity result input terminal, respectively. After obtaining a valid detection completion signal, the PLC controller records the polarity result signal and continuity result signal. Upon meeting the preset hold end condition, the PLC controller controls the molding detection insert assembly to retract and reset. The preset hold end condition includes at least a continuous and valid detection completion signal for a preset debouncing time. If the preset hold end condition is not met even after reaching the preset maximum hold time, the PLC controller outputs a detection abnormality status and controls the molding detection insert assembly to retract and reset.

2. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 1, characterized in that: The molding execution unit is equipped with a working position detection unit for outputting the working position status and a reset position detection unit for outputting the reset position status. In automatic mode, the PLC controller allows the molding detection insert assembly to perform continuous working strokes only when it simultaneously obtains a valid dipstick position signal, a valid reset position status, and a no-interlock fault status. After obtaining a working position status that changes from invalid to valid during the working motion, the PLC controller controls the molding detection insert assembly to maintain the working position. After obtaining a reset position status that changes from invalid to valid during the retraction process, the execution action of the current molding detection cycle ends.

3. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 1, characterized in that: The forming end face is fixedly set relative to the forming detection insert assembly. The positive conductive contact part is floatingly installed along the motion axis and connected to the positive elastic element. The negative conductive contact part is floatingly installed along the motion axis and connected to the negative elastic element. The positive elastic element restricts the contact force of the positive conductive contact part on the positive electrode of the compensating wire, and the negative elastic element restricts the contact force of the negative conductive contact part on the negative electrode of the compensating wire.

4. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 3, characterized in that: The forming end face protrudes from the positive and negative conductive contact portions along the working direction. The axial height difference between the forming end face and the positive and negative conductive contact portions divides the continuous working stroke into a first stroke segment and a second stroke segment. In the first stroke segment, the positive forming action area presses the positive terminal of the compensation wire into the positive compensation wire positioning groove, and the negative forming action area presses the negative terminal of the compensation wire into the negative compensation wire positioning groove. In the second stroke segment, the positive conductive contact portion establishes a detection contact with the positive terminal of the compensation wire, and the negative conductive contact portion establishes a detection contact with the negative terminal of the compensation wire.

5. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 1, characterized in that: The molding execution unit is equipped with a force detection unit and a displacement detection unit. The PLC controller synchronously collects the actual molding force and axial displacement during the continuous working stroke. The entire working section starts from the molding detection insert assembly leaving the reset position and ends when the molding detection insert assembly reaches the working position. The effective sampling point is the sampling point where neither the force detection unit nor the displacement detection unit outputs a fault status, the actual molding force is within the effective range of the force detection unit, the axial displacement is within the effective range of the displacement detection unit, and the actual molding force and axial displacement correspond to the same sampling sequence number. The PLC controller compares the actual forming force of each valid sampling point with the lower limit and upper limit of the allowable forming force of the fast thermocouple specification corresponding to the fast thermocouple head assembly at the same axial displacement. When the total number of valid sampling points is lower than the preset minimum number of sampling points, the PLC controller outputs an abnormal status in the molding process. If, after the total number of valid sampling points reaches the preset minimum number of sampling points, there are three consecutive valid sampling points where the actual molding force is lower than the lower limit of the allowable molding force or higher than the upper limit of the allowable molding force, or if the proportion of valid sampling points with a force lower than the lower limit of the allowable molding force or higher than the upper limit of the allowable molding force in the entire working range exceeds 5% of the total number of valid sampling points, the PLC controller will output an abnormal state of the molding process. If, after the total number of valid sampling points reaches the preset minimum number of sampling points, there are no three consecutive valid sampling points where the actual molding force is lower than the lower limit of the allowable molding force or higher than the upper limit of the allowable molding force, and the proportion of valid sampling points with a force lower than the lower limit of the allowable molding force or higher than the upper limit of the allowable molding force in the entire working range does not exceed 5% of the total number of valid sampling points, the PLC controller will output a qualified state of the molding process.

6. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 1, characterized in that: The polarity detection interface also includes a continuous detection input terminal connected to the PLC controller and used to receive the continuous detection quantity output by an external thermocouple polarity detector; the PLC controller establishes a stable judgment window containing a preset number of continuous sampling values, and the preset hold end condition also includes that the difference between the maximum and minimum values ​​of the continuous detection quantities within the stable judgment window does not exceed the allowable fluctuation range; when the detection completion signal is continuously valid for a preset de-jittering time and the difference between the maximum and minimum values ​​of the continuous detection quantities within the stable judgment window does not exceed the allowable fluctuation range, the PLC controller outputs a stable detection result and controls the molding detection ferrule assembly to retract and reset; when the preset maximum hold time is reached and the stable detection result is still not output, the PLC controller outputs a detection abnormality status and controls the molding detection ferrule assembly to retract and reset.

7. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 1, characterized in that: The detection connection unit also includes a switching module, a conducting reference branch with a known conducting state, and an open reference branch with a known open state. Before the start of the molding detection cycle, the PLC controller controls the switching module to sequentially connect the open reference branch and the conducting reference branch to the polarity detection interface. When the external thermocouple polarity detector outputs an open circuit result signal for the open reference branch and a conducting circuit result signal for the conducting reference branch, it outputs a self-test qualified status for the detection link. The self-test qualified status of the detection link is a necessary condition for allowing the molding detection ferrule assembly to perform continuous working strokes.

8. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 1, characterized in that: The workpiece positioning block is equipped with a first specification recognition part, and the forming detection insert assembly is equipped with a second specification recognition part. The PLC controller reads the first specification code corresponding to the first specification recognition part and the second specification code corresponding to the second specification recognition part. When the first specification code and the second specification code meet the preset pairing relationship, the corresponding working stroke parameters, motion speed parameters, holding parameters and forming judgment parameters are loaded. When the first specification code and the second specification code do not meet the preset pairing relationship, the forming execution unit is prohibited from operating.

9. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 7, characterized in that: The workpiece positioning unit also includes a workpiece holder for restricting the removal of the rapid thermocouple head assembly. The forming execution unit is equipped with a working position detection unit for outputting the working position status and a reset position detection unit for outputting the reset position status. During the current forming and detection cycle, the PLC controller obtains a working position status that changes from invalid to valid within a preset working action timeout period, a reset position status that recovers from invalid to valid within a preset retraction action timeout period during the retraction process, obtains a valid detection completion signal, the polarity result signal is correct, the conduction result signal is on, and the polarity result signal and conduction result signal are continuously maintained for a preset stable time and the detection link self-test is valid. When these conditions are not met, the PLC controller controls the workpiece holder to maintain the restricted material removal state and outputs a non-conforming disposal instruction.

10. The industrial control system for rapid thermocouple compensating wire forming and detection according to claim 6, characterized in that: The linear actuator of the forming execution unit is a servo linear actuator. The continuous detection input terminal of the polarity detection interface is connected to the PLC controller through an industrial communication bus. During the working position holding period, if the difference between the maximum and minimum values ​​of the continuous detection quantities within the preset first round evaluation time within the stable judgment window is continuously greater than the allowable fluctuation range, the PLC controller will not output an abnormal detection status, but will instead control the servo linear actuator to execute a micro-displacement wiping sequence. The micro-displacement wiping sequence starts from the working position and oscillates along the retraction direction. Its unidirectional maximum displacement is strictly less than the working retraction amount corresponding to the positive pole of the compensation wire and the working retraction amount corresponding to the negative pole of the compensation wire, so that the positive pole forming action area and the negative pole forming action area maintain the compensation wire pressed state, and the positive pole conductive contact part and the positive pole of the compensation wire, and the negative pole conductive contact part and the negative pole of the compensation wire maintain contact pressure while undergoing axial relative sliding friction. After the wiping sequence ends, the PLC controller controls the servo linear actuator to accurately return and maintain the working position, clear the historical continuous detection quantities, and re-establish the stable judgment window for full-loop continuity detection.

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