Method for determining quality of wire termination using thermal characteristics

Abstract

A crimping apparatus (10) and method that allows for determination of crimp quality. The method includes terminating a wire (26), monitoring a thermal characteristic of the termination with one or more thermal sensors (28), and comparing the monitored thermal characteristic to a stored thermal characteristic to determine if the termination is defective. If the termination is defective, the termination is discarded. The apparatus (10) includes an applicator (12) having an anvil (22) and a crimping tool (20) movable relative to the anvil (22). The anvil (22) and the crimping tool (20) define a crimping zone (18) of the apparatus (10). A thermal sensor is mounted on the crimping apparatus and proximate to the applicator. The thermal sensor (28) monitors a thermal characteristic of a crimp completed by the applicator (12) to determine if the crimp is defective.

Description

Technical Field

[0001] This invention relates to a method and system for monitoring wire termination quality using the thermal characteristics of the termination. Background Technology

[0002] Wire termination employs various methods, such as crimping, brazing, or fusion welding. For example, electrical terminals are typically crimped onto wires using a crimping device to form leads. A crimping device has a crimping tool consisting of a first part mounted on a base to support the electrical terminal, and a second part mounted on a punch that can move back and forth relative to the base to achieve efficient crimping. In operation, the terminal is placed on the first part of the crimping tool, and one end of the wire is inserted into the clamp or sleeve of the terminal. The punch is moved towards the base through a crimping stroke, thereby crimping the terminal onto the wire.

[0003] Therefore, it would be advantageous to provide a wire termination monitoring system and method that can be used to monitor different terminations of wires. In particular, it would be advantageous to provide a wire termination monitoring system and method that not only measures force or size, but also monitors the thermal characteristics of the termination. Summary of the Invention

[0004] One embodiment relates to a crimping apparatus that allows for the determination of crimp quality. The apparatus includes an applicator having an anvil and a crimping tool movable relative to the anvil, the anvil and crimping tool defining a crimping area for the apparatus. A thermal sensor is mounted on the crimping apparatus and close to the applicator. The thermal sensor monitors the thermal characteristics of the crimp performed by the applicator to determine if the crimp is defective.

[0005] One embodiment relates to a method for determining the quality of a wire or terminal termination. The method includes: terminating a wire; monitoring the thermal characteristics of the termination using one or more thermal sensors; and comparing the monitored thermal characteristics with stored thermal characteristics to determine if the termination is defective. If the termination is defective, the termination is discarded. Attached Figure Description

[0006] The invention will now be described by way of example with reference to the accompanying drawings, in which:

[0007] Figure 1 This is a perspective view of an illustrative crimping device that uses a thermal sensor to monitor crimping quality.

[0008] Figure 2 This is a flowchart illustrating an illustrative method for monitoring the quality of wire terminations using thermal properties. Detailed Implementation

[0009] This demonstrates the use of thermal properties and characteristics to monitor the crimping process. Figure 2 and 3) Device for determining the quality of crimping ( Figure 1 The use of crimping machines is illustrative rather than limiting. As described below, in addition to crimping-related applications, there are other uses for monitoring the termination of wires, conductors, or terminals using thermal data and analysis.

[0010] Figure 1 This is a perspective view of a crimping machine 10 with an applicator 12. The crimping machine 10 is illustrated as a terminal crimping machine for crimping terminals to wires; however, other types of machines may also be used, such as insulation displacement connector (IDC) machines, welding machines, etc., which use processes other than crimping to connect connectors to wires. Alternatively, the crimping machine 10 may be another type of crimping machine, such as a leadframe machine.

[0011] Applicator 12 is coupled to crimper 10. Applicator 12 can be removed and replaced with a different applicator, for example, when applicator 12 is worn or damaged, or when an applicator with a different configuration is required. Applicator 12 has a termination area or crimping area 18 and includes a crimper or crimping tool 20 and an anvil 22 as mechanical tools for crimping an electrical connector or terminal 24 to one end of a wire 26 in the crimping area 18. Anvil 22 is a fixed part of applicator 12, and crimping tool 20 represents a movable part.

[0012] One or more thermal sensors 28 are mounted to the crimping machine 10. The thermal sensors 28 can be mounted at various locations in or near the crimping area 18. The thermal sensors 28 can be detachably mounted using removable devices, such as, but not limited to, magnets (not shown). Alternatively, the thermal sensors 28 can be held in place using mechanical fasteners, locking devices, adhesives, etc. Although the thermal sensor 28 is shown as a circular component, the thermal sensor 28 can have other shapes.

[0013] In one exemplary embodiment, each thermal sensor 28 is positioned to have a field of view including the crimp region 18. The thermal sensor 28 is positioned to acquire thermal characteristics of the terminal 24 and / or wire 26 in the crimp region 18 in the form of heat dissipation data. In one exemplary embodiment, at least one thermal sensor 28 is positioned in a straight line with the longitudinal axis 42 of the anvil 22 and the sleeve 27 of the terminal 24. This allows the thermal sensor 28 to directly sense and collect thermal data from heat energy emitted directly from the terminal 24 and / or wire 26. In an alternative embodiment, one or more thermal sensors 28 may be positioned not collinear with or eccentric relative to the axis 42. If one or more sensors 28 are positioned not collinear with or eccentric relative to the axis 42, those thermal sensors 28 may collect heat energy transferred through the terminal 24 to the wire 26 or another object, and / or those thermal sensors 28 may collect heat energy reflected from the terminal 24 and / or wire 26.

[0014] For example, an object positioned around terminal 24 and / or wire 26 is configured to intentionally reflect or guide thermal energy from the sensed terminal 24 and / or wire 26. Sensing the object will allow thermal sensor 28 to be non-collinear with or off-center from terminal 24 and to read thermal data reflected from the surrounding object. These surrounding objects can be constructed using materials with known emissivity to enhance reflective imaging of the thermal properties of the terminated terminal 24 and / or wire 26. This will allow for the ability to thermally "sensor" areas that are not easily observed, or the ability to observe a larger surface area of ​​terminal 24 and / or wire 26 using fewer sensors.

[0015] As previously described, the thermal data collected by one or more thermal sensors 28 can be one of three different components of energy or a combination thereof. The first is thermal energy emitted directly from terminal 24 and / or wire 26. The second is thermal energy transferred through an object (heat from other places along the path), such as from terminal 24 to wire 26. The third is thermal energy reflected from terminal 24 and / or wire 26.

[0016] In one exemplary embodiment, thermal data is captured by a plurality of sensors 28 arranged in a matrix (e.g., a charge-coupled device network), which allows thermal data to be captured and arranged in rows and columns—similar to how data pixels describe visual images collected using a conventional visual energy camera. For example, one thermal sensor may be positioned in line with the longitudinal axis of the termination, while other thermal sensors in the matrix may be positioned non-linearly with or off-center from the axis. Due to the number of data points, features are extracted from these data matrices using techniques such as, but not limited to, adaptive convolutional neural networks, to analyze the crimping process before, during, and after crimping formation. These features are evident in specific regions of interest on the terminals 24 and / or wires 26 and form the basis for termination classification.

[0017] The characteristics and features of thermal data collection may include, but are not limited to: i) regional heat; ii) heat transfer time; iii) heat transfer patterns; iv) temperature changes; and v) physical characteristics and changes that can be determined by thermal properties.

[0018] Furthermore, thermal data can be collected at different rates, resulting in time-series images. Using analytical techniques, such as, but not limited to, artificial intelligence, the time-varying data can be analyzed.

[0019] In various illustrative examples, thermal sensor 28 has the ability to collect absolute temperature. Absolute temperature not only enables the analysis of "relative" regions of interest, but also enables the analysis of the potential unique mechanical properties of the termination.

[0020] The display device 32 is communicatively coupled to the thermal sensor 28 and configured to display the thermal characteristics acquired by the thermal sensor 28. The display device 32 can be integrated into the main controller or processor of the crimping machine 10 itself, or it can be a separate controller or processor 34, such as a desktop computer, laptop computer, tablet computer, monitor, projector, etc. Optionally, the display device 32 can be a crimp quality monitor (CQM) device. The controller 34 and / or the display device 32 can be coupled to the thermal sensor 28 via cables, etc. Alternatively, the controller 34 and / or the display device 32 can communicate wirelessly via electromagnetic induction, radio waves, Wi-Fi, etc., to transmit data between the thermal sensor 28 and the controller 34 and / or the display device 32.

[0021] The controller 34 and / or display device may include storage or storage device 36, such as, but not limited to, hard disk drives, RAM, ROM, and / or other internal data storage devices. Storage device 36 may be configured to store data acquired by thermal sensor 28. Such data may be used for subsequent quality reporting objectives.

[0022] In various examples, the crimping machine 10 may include additional sensors 38, such as, but not limited to, force sensors or linear sensors, to provide additional data on the quality of the crimping.

[0023] During the crimping operation, the crimping tool 20 is initially driven toward the fixed anvil 22 and eventually moves away from the anvil 22, as... Figure 2 As shown in 102. 2. Figure 2 A method 100 for determining termination quality is shown. Therefore, the crimping stroke has a downward crimping stroke and an upward crimping stroke. The crimping of terminal 24 to wire 26 occurs during the downward crimping stroke of the crimping stroke. By compressing terminal 24 between crimping tool 20 and anvil 22, crimping tool 20 engages terminal 24 and crimps terminal 24 onto wire 26. When this occurs, heat energy or heat is generated within the crimp and near the crimp point in the terminal and wire.

[0024] As previously described, the thermal sensor 28 (or directly from a thermal sensor 28 positioned in a straight line with axis 42, or indirectly from a thermal sensor positioned not in a straight line with axis 42 or eccentric relative to axis 42) can acquire temperature measurements / data at specified intervals or continuously at the ends of terminals 24 and wires 26 located in the crimping area 18, such as... Figure 2As shown in Figure 104. The collected temperature measurements / data are sent to a display device 32, controller 34, or storage device 36 located on or outside the crimping machine 10. The temperature measurements / data transmitted by the thermal sensor 28 are used by the operator of the crimping machine 10 to determine whether the wire terminations meet the appropriate standards to provide the required electrical and mechanical connections. The term "operator" is used herein to identify the machine or person who operates or controls the crimping machine 10.

[0025] The quality 18 of the crimping can be monitored by directly or indirectly monitoring the temperature of terminal 24. Other characteristics of the crimping can be analyzed by directly or indirectly analyzing the temperature of terminal 24. For example, temperature can be used to calculate the force input to terminal 24, since the magnitude of the force is related to the temperature of terminal 24 after crimping.

[0026] During operation, after detecting the movement of the crimping tool from the closed position to the open position, the sensor 28 is activated and sends data to the controller 34.

[0027] In one exemplary embodiment, such as Figure 2 As shown in Figure 104, during the crimping stroke, the thermal characteristics of the crimp are measured directly or indirectly by one or more thermal sensors 28. The thermal characteristics are measured at predetermined intervals based on time or the position of the crimping tool. For example, a predetermined sampling time can be selected, and the thermal characteristics can be measured at each discrete sampling time. Optionally or additionally, the thermal characteristics can be measured when the crimping tool is at a predetermined crimping height position. The position of the crimping tool can be detected by a distance sensor (not shown), etc.

[0028] The controller 32 can create a measured temperature profile for crimping based on the measured thermal characteristics. Then, it compares the measured thermal profile with known acceptable temperature profiles or acceptable temperature ranges for successful crimping, such as... Figure 2 As shown in Figure 106. Alternatively, the measured thermal properties can be compared with the known acceptable temperature properties or profiles of the specific material used. Acceptable temperature profiles or acceptable temperature ranges can be preset in controller 32, or can be developed and stored in controller 32 by the user on-site. If the measured temperature profile is within the acceptable temperature range, controller 32 will indicate that the crimping is correct. If the measured temperature profile is not within the acceptable temperature range, controller 32 will indicate that the crimping is unacceptable and reject the crimping, such as... Figure 2 As shown in Figure 108, data related to thermal characteristics, peak temperature, area under the temperature curve, shape of the temperature curve, or any combination thereof can be analyzed to determine if there are defects in the crimping.

[0029] Using thermal data and analysis to monitor wire or conductor terminations has applications beyond crimping. For example, thermal analysis of fusion welding (ultrasonic, resistance, etc.), molding, stamping, thermoplastic welding, and hot-melt (plastic riveting) helps determine if a proper electrical connection has been ensured. In addition to collecting thermal data directly after termination has occurred to determine if proper termination has been compromised, thermal sensors can also be used to collect thermal data during the termination process, allowing the controller to continue the termination process until a good termination / connection is achieved.

[0030] By collecting thermal data during the crimping process, whether through non-contact methods such as thermal sensors, or through direct-contact thermal sensors, or both, the data can be used to provide quality assessments without destructive testing. In fact, thermal data can be used to create non-destructive three-dimensional thermal profiles. The use of thermal data is advantageous in many applications, especially in applications where force variations (between crimping terminals and wires or between crimping terminals without wires) are very small, such as when crimping aluminum wires.

[0031] Although the invention has been described with reference to preferred embodiments, those skilled in the art will understand that various changes can be made without departing from the spirit and scope of the invention as defined by the appended claims, and equivalent technical solutions can replace its technical features. Those skilled in the art will understand that the invention can be used, or practiced, with many modifications to its structure, arrangement, proportions, dimensions, materials, and components, particularly suitable for specific environments and operational requirements, without departing from the principles of the invention. Therefore, the currently disclosed embodiments are considered illustrative in all respects and not restrictive, and the scope of the invention is defined by the appended claims and is not limited to the foregoing description or embodiments.

Claims

1. A wire termination device (10, 210) that allows for determining the quality of wire terminations, the device comprising: Wire termination area (18, 218); A thermal sensor (28, 228) is mounted on a wire termination device (10, 210) and close to a wire termination area (18, 218), the thermal sensor being positioned to acquire thermal characteristics of the terminal (24) and / or wire (26) in the crimp area (18) in the form of heat dissipation data; The thermal sensors (28, 228) monitor thermal data of the termination to determine if the termination is defective.

2. The wire termination device (10, 210) as described in claim 1, wherein, Multiple thermal sensors (28, 228) are mounted on the wire termination device (10, 210) near the wire termination area (18, 218).

3. The wire termination device (10, 210) as described in claim 1, wherein, The thermal sensors (28, 228) are detachably mounted to the wire termination device (10, 210).

4. The wire termination device (10, 210) as described in claim 1, wherein, The thermal sensors (28, 228) are positioned to have a field of view of the wire termination area (18, 218).

5. The wire termination device (10, 210) as described in claim 4, wherein, The thermal sensors (28, 228) are positioned in a straight line with the longitudinal axis (42, 242) of the wires (26, 226) located in the wire termination areas (18, 218).

6. The wire termination device (10, 210) as described in claim 1, wherein, The thermal sensors (28, 228) are positioned off-center from the longitudinal axis (42, 242) of the wires (26, 226) located in the wire termination area (18, 218), wherein the thermal sensors (28, 228) monitor the thermal characteristics of the termination reflected.

7. The wire termination device (10) as described in claim 1, wherein, The wire termination area (18) has an anvil (22) and a crimping tool (20) movable relative to the anvil (22), the anvil (22) and the crimping tool (20) defining the crimping area (18) of the wire termination device (10).

8. The wire termination device (210) as described in claim 1, wherein, The wire termination area (218) is the heating area (218).

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