Method for testing connection reliability of wire harness terminal and shell, controller and medium

Abstract

The invention relates to a method for testing the connection reliability of a wire harness terminal and a shell, a controller and a medium. The method comprises the following steps: respectively establishing an insertion standard curve and a pull-out standard curve in the processes of inserting the wire harness terminal into the shell and pulling the wire harness terminal out of the shell; real-time acting force generated in the process that the wire harness terminal is inserted into the shell is collected and compared with the insertion standard curve, and if the force value of the real-time acting force is correspondingly not larger than the force value on the insertion standard curve and is correspondingly not smaller than the preset force value, the test that the wire harness terminal is inserted into the shell is qualified; the insertion stage comprises a starting section, a friction section, a locking section and a terminal section which are in contact with the wire harness terminal and the shell in sequence; the change information of the acting force in the process of pulling out the wire harness terminal from the shell is collected, the acting force is kept constant or increased within the limited time, the wire harness terminal does not generate displacement, and the test is qualified if the wire harness terminal is not pulled out; meanwhile, the invention discloses a controller and a medium for implementing the method. According to the invention, the product quality is ensured, and automatic detection is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cable harness production, and in particular to a harness terminal and shell connection reliability test method, controller and medium. BACKGROUND

[0002] At present, with the development of industrial automation, various industries need to use electronic cables and harnesses. The cable harness refers to the terminal formed by punching copper material and the cable after pressure connection, and then the plastic pressure insulation body shell is formed outside the harness terminal. In the process of preparing the harness terminal, the terminal of copper or other metal medium is pressure connected on the cable of copper or other metal medium to ensure that the cable harness can be reliably and freely connected and extended with other connectors; after the harness terminal is pressure connected, the harness terminal is inserted into the corresponding shell to form a complete set of cable harness. In this process, it is necessary to detect whether the terminal of the cable harness is inserted in place, whether the terminal is not pulled out, and whether the shell is damaged. At present, only one-way detection is performed between the harness terminal and the shell, and the detection is also performed manually, such as using a certain force to pull the harness terminal out of the shell from the installed cable harness. If it is pulled out, the connection structure is unstable, and if it is not pulled out, it is determined to be qualified. However, such detection can only determine whether the pulling force meets the standard, and the whole process of installing the harness terminal into the shell, whether the installation is in place, and whether the buckle for locking in the shell is intact cannot be determined. The detection result is not accurate, manual detection wastes labor cost, and the detection efficiency is low. SUMMARY

[0003] In view of the existing deficiencies, the present application provides a harness terminal and shell connection reliability test method, controller and medium.

[0004] The technical solution adopted by the present application to solve its technical problems is: a harness terminal and shell connection reliability test method, the steps are as follows: An insertion standard curve of displacement insertion force and a pull-out standard curve of displacement pull-out force in the process of inserting and pulling out the shell by the harness terminal are established respectively; The real-time force in the process of inserting the shell by the harness terminal is collected and compared with the insertion standard curve. If the force value of the real-time force at different insertion stages corresponds to no more than the force value of the corresponding insertion stage on the insertion standard curve, and corresponds to no less than the preset force value of the corresponding insertion stage, the test of the harness terminal inserted into the shell is qualified, wherein the insertion stage includes a starting segment, a friction segment, a locking segment and an end segment in which the harness terminal and the shell are in contact in turn. The force change information of the wire harness terminal during the process of pulling out from the shell is collected with the force value at the pull-out key point of the standard curve as the initial force, the force remains constant or increases within a limited time, and the wire harness terminal does not produce displacement, and the wire harness terminal is not pulled out of the shell, wherein the pull-out key point is the locking section where the wire harness terminal and the shell are in contact.

[0005] Preferably, the preset force value is the difference between the average value of each insertion stage when establishing the insertion standard curve and 3-5 times the standard deviation thereof.

[0006] Preferably, the limited time is 2-5s.

[0007] Preferably, the insertion of the wire harness terminal into the shell is carried out at a constant speed of not less than 25mm / min.

[0008] Preferably, the insertion standard curve is a value of force greater than a preset threshold when the displacement is zero point obtained by continuous sampling within a specified time at a certain sampling frequency.

[0009] Preferably, the preset threshold is 0.3-0.5N, and the specified time is 10-60ms.

[0010] A controller, comprising: a processor, a memory for storing executable instructions of the processor; wherein the processor is configured to execute the executable instructions to implement the wire harness terminal and shell connection reliability test method of any one of the preceding.

[0011] Preferably, it further comprises a network port, a serial interface, a plurality of IO input and output interfaces, and a detection channel interface for connecting sensors.

[0012] Preferably, it further comprises an alarm mechanism for alarming when the test is unqualified.

[0013] A computer readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the wire harness terminal and shell connection reliability test method of any one of the preceding.

[0014] The present application has the advantages that: the present application collects the force change of the wire harness terminal during the whole process of inserting into the shell in real time, and through the force change in different stages, it can comprehensively detect whether there is a problem with the wire harness terminal and the shell itself, and whether the connection of the wire harness terminal and the shell is in place; the force change within the limited time during the pulling-out process can detect whether the structure between the wire harness terminal and the shell is damaged after the wire harness terminal is inserted into the shell; the reliability of the connection structure of the wire harness terminal and the shell is detected from multiple aspects, the detection result is more accurate, the detection is realized automatically, and the detection efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a principle block diagram of a test method of an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to more clearly illustrate the purpose, technical solutions and advantages of the embodiments of the present application, the present application will be further described below in conjunction with the drawings and embodiments, and a clear and complete description will be made. Obviously, the described embodiments are part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0017] An embodiment of the present application is shown in Figure 1 A harness terminal and shell connection reliability test method is shown in the following steps: The insertion standard curve of displacement insertion force and the pull-out standard curve of displacement pull-out force in the process of inserting and pulling out the harness terminal into and out of the shell are respectively established, that is, the insertion standard curve and the pull-out standard curve are both established with the displacement of the harness terminal as the horizontal coordinate and the insertion force as the vertical coordinate. The insertion force is monitored by setting a force sensor on the clamp clamping the harness terminal, and the displacement is monitored by setting a displacement sensor on the clamp clamping the harness terminal. Then the harness terminal is inserted into the shell at a constant speed. The establishment of the pull-out standard curve is a destructive test, which requires the harness terminal to be completely pulled out of the shell. When establishing the insertion standard curve and the pull-out standard curve, a plurality of products are tested under the same conditions, such as using the same insertion speed, the same sampling frequency, and then the test values of the plurality of products are processed to remove abnormal values and the mean curve method is used to establish. The process of inserting the harness terminal into the shell is to use the clamp clamping the harness terminal (including the force sensor) to clamp the harness terminal, and then insert the cable harness terminal into the corresponding shell jack at a constant speed. The sensor in the clamp senses the insertion force information, and transmits the force information to the processor of the controller through the sensor cable. The processor of the controller processes the received information.

[0018] The real-time force during the process of inserting the wire harness terminal into the shell is collected and compared with the insertion standard curve. If the force value of the real-time force at different insertion stages corresponds to no more than the force value of the corresponding insertion stage on the insertion standard curve and corresponds to no less than the preset force value of the corresponding insertion stage, the wire harness terminal insertion into the shell is qualified. The insertion stages include the starting stage, the friction stage, the locking stage and the end stage in which the wire harness terminal and the shell are sequentially contacted. The insertion speed and the sampling frequency used to establish the insertion standard curve are used to collect the data of the real-time force during the process. The starting stage is the stage in which the wire harness terminal is contacted and positioned with the shell and starts to enter the shell. The friction stage is the stage in which the wire harness terminal is frictionally slid with the shell cavity. The locking stage is the stage in which the wire harness terminal is contacted and locked with the buckle or the lock tongue in the shell. The end stage is the stage in which the wire harness terminal reaches the final position after the locking is completed. Meanwhile, the force value of each stage on the insertion standard curve is taken as the upper limit, and the corresponding preset force value of each stage is taken as the lower limit, which means that the preset force value is less than the force value on the insertion standard curve. The force value of the real-time force is compared with the force value on the insertion standard curve. If the force value of the real-time force at the starting stage, the friction stage, the locking stage and the end stage is between the upper limit and the lower limit, it indicates that the wire harness terminal and the shell insertion is qualified. If it exceeds this range, an alarm is given. At this time, if the force value of the real-time force is too large at the starting stage, that is, it exceeds the force value on the insertion standard curve, it can be inferred that the wire harness terminal is deformed during storage and transportation, the size of the wire harness terminal is too large, or there are burrs, flash, or the size of the entrance of the shell is too small, or the wire harness terminal and the shell entrance are misaligned during the insertion of the wire harness terminal into the shell. If the force value of the real-time force is too small, that is, it is less than the preset force value, it can be inferred that the size of the wire harness terminal is too small or the size of the entrance of the shell is too large. When the real-time force exceeds the upper limit and the lower limit, an alarm is given to stop the continuous insertion, so that problems can be found and solved in time to avoid the emergence of unqualified products. If the force value of the real-time force exceeds the force value on the insertion standard curve at the friction stage, it indicates that there is a deviation in the size of the shell cavity or the wire harness terminal, or there are obstacles or structural damages on the surfaces in contact with each other, such as the size of the wire harness terminal being too large or the size of the shell cavity being too small, the obstacles being burrs, metal chips, etc., and the structural damages being the peeling or oxidation of the plating layer of the wire harness terminal. If the force value of the real-time force is less than the preset force value, there is a problem of too large gap between the wire harness terminal and the shell cavity caused by the size of the wire harness terminal being too small or the size of the shell cavity being too large.In the locking section, the force value of the real-time force continues to increase until the maximum value, and after locking, the real-time force decreases; at this time, if the force value of the real-time force does not appear a peak value or is less than the preset force value, there is a case that the wire harness terminal is not completely inserted or the buckle or lock tongue in the shell is broken; if the force value of the real-time force is greater than the force value on the insertion standard curve, there is a case that the buckle or lock tongue in the shell is blocked and cannot be smoothly pushed. In the terminal section, the force value of the real-time force quickly falls from the force value of the locking section and maintains at a lower force value, indicating that the wire harness terminal has reached the set position of the shell; at this time, if the force value of the real-time force does not fall or exceeds the lower limit value, it means that the wire harness terminal is not inserted in place, the locking has occurred, but the wire harness terminal does not reach the specified stop point, or the rear end of the wire harness terminal is squeezed and interfered with the entrance of the shell. By comparing the force value of the real-time force with the insertion standard curve, whether the process of inserting the wire harness terminal into the shell is qualified can be detected in real time.

[0019] The force value of the wire harness terminal at the pull-out key point of the pull-out standard curve is collected as the initial force, and the force changes during the process of pulling out from the shell. The force remains constant or increases within a limited time, and the wire harness terminal does not produce displacement, and the test is qualified when the wire harness terminal is not pulled out of the shell, wherein the pull-out key point is the locking section where the wire harness terminal and the shell are in contact. In this process, the force change within the limited time can detect whether the wire harness terminal can be pulled out of the shell, and whether the structure between the wire harness terminal and the shell is damaged after being inserted into the shell. The limited time is 2-5 seconds. From the material mechanics response, the slight creep or relaxation of the wire harness terminal locking mechanism after being stressed mainly occurs within the first 1-2 seconds. If the terminal can withstand the pull-out force for 2-5 seconds without displacement, it means that the locking mechanism has completed the initial deformation and is in a stable state, preferably 2-3 seconds. If the time is too short, it may not be able to expose the slow slip of the locking mechanism due to the forced size fit; if the time is too long, it may cause unnecessary stress relaxation of the material, and even cause qualified products to be misjudged as unqualified. Moreover, when the pull-out force is applied, it takes a certain time from the loading of the force to the stability. The 2-second holding time is sufficient to ensure that the force value is completely and stably applied to the terminal, excluding false judgments caused by equipment response or contact gap. If the force value remains constant or continues to increase within the limited time without displacement of the wire harness terminal, it means that the cable wire harness terminal cannot be pulled out of the shell, meeting the design requirements of the cable wire harness, and the product is qualified in the pull-out test. On the contrary, if the wire harness terminal produces displacement, it means that the connection between the wire harness terminal and the shell is not firm and loose; if the force value suddenly decreases after increasing within the limited time, it means that the wire harness terminal is pulled out of the shell, or the wire harness terminal and a device in the shell are damaged, and the product is unqualified in the pull-out test.

[0020] Thus, the reliability of the connection between the wire harness terminal and the housing can be comprehensively detected through monitoring the whole process of inserting the wire harness terminal into the housing and the pull-out test, and hidden connection problems between the wire harness terminal and the housing that affect use can be avoided.

[0021] Further improvement, the preset force value is the difference between the average value of each insertion stage when establishing the insertion standard curve and 3 to 5 times of the standard deviation, that is, according to the normal distribution statistical theory and statistical process control theory, the data within the range of μ (average value) ± 3σ (standard deviation) accounts for about 99.73%, which means that in the case of stable process control and only random factors, 99.73% of the product data will fall within the interval of μ ± 3σ, so that the alarm signal has very high reliability, on the contrary, the point outside this interval, the variation caused by random factors is extremely small. In this application, the test values of multiple products when establishing the insertion standard curve are processed to remove abnormal values, and then the average value and the standard deviation are calculated, the calculated average value is used to establish the insertion standard curve and as the basis value of the preset force value, and then the difference between the basis value and 3 to 5 times of the standard deviation is taken as the preset force value, and the preferred 3 times of the standard deviation is used for calculation.

[0022] Further improvement, the wire harness terminal is inserted into the housing at a constant speed of not less than 25 mm / min, keeping the constant insertion speed ensures that the test data can more truly reflect the change of force during the insertion process, and the speed of not less than 25 mm / min can be based on different test requirements, at low speed, it ensures to obtain accurate, repeatable and comparable data, and at high speed, it can realize rapid detection.

[0023] Further improvement, the insertion of the standard curve is the value of the force obtained by continuous sampling at a certain sampling frequency within a specified time greater than the preset threshold, and the displacement zero point is established, which makes the results of each test comparable. When collecting the real-time force of the harness terminal insertion shell, the displacement zero point is also taken as the starting point. Before the harness terminal and the shell start to physically contact, the force sensor cannot detect the force value. When the harness terminal and the shell start to physically contact, the force value starts to rise steadily from zero. When the force value detected by the force sensor continuously and stably exceeds a small preset threshold, it indicates that the harness terminal and the shell start to physically contact. At this time, the current displacement sensor reading is reset to zero. This point is the displacement zero point of the insertion standard curve. Considering whether the harness terminal is a real contact or system noise, through statistical analysis, the background noise of the existing industrial force sensor is in the range of 0.01-0.05N, based on the 3σ principle (covering 99.7% of random noise), the threshold is set to 0.03-0.15N. Considering the device vibration, electromagnetic pulse, and the actual resolution and zero drift of the sensor, it can ensure that the detected is a real contact, and effectively filter most of the noise. At the same time, considering that the system noise is usually transient, its duration usually does not exceed 10ms. After the real mechanical contact occurs, the force signal will continue to exist. The force signal generated by the real contact usually can be stably maintained for tens of milliseconds or more. The confirmation time of 10-60ms matches the inherent response time scale of the mechanical system, and the small elastic oscillation or relaxation of the sensor and the structure in the initial stage of force can be ignored. At the same time, it can quickly respond to real contact events. That is, the preset threshold is 0.3-0.5N. Such a range avoids the problem of affecting the accuracy of all subsequent data by moving the displacement zero point forward and causing any small disturbance before the two contacts to be judged as contact, and avoids the problem of not being able to identify the initial stage of the two contacts. The specified time is 10-60ms, which can avoid the influence of electronic noise or mechanical vibration in the initial stage of force. At the same time, it can quickly respond to the real contact between the two. The sampling frequency is sampled according to different needs, such as sampling 20 times within 20ms. At this time, the sampling frequency is 1000Hz.

[0024] A controller comprises a processor, a memory for storing executable instructions of the processor; wherein the processor is configured to execute the executable instructions to implement the harness terminal and shell connection reliability test method as any one of the preceding. The controller can detect the force between the harness terminal and the shell in real time during the insertion and extraction of the harness terminal and the shell, and then determine whether the harness terminal and the shell are inserted in place, whether the harness terminal and the shell meet the force requirement of not being pulled out, and whether the harness terminal and the shell are damaged or defective; improve production efficiency, ensure the quality of the cable harness, quickly complete the terminal and shell detection of the cable harness, and realize automatic detection. At this time, the controller further comprises a network port, a serial interface, a plurality of IO input and output interfaces, and a detection channel interface for connecting a sensor; the network port is used for display output with an external display screen, and the interface mode is set to realize visual operation and parameter configuration functions, so that the operation is simple and the functions are diversified; the serial interface such as the RS485 communication interface is used to realize communication between devices such as PLC and a clamp for clamping the harness terminal; the IO input and output interface is used for interaction with functional signals such as alarm mechanisms or indicator lights; the detection channel interface is used to connect the sensor, at this time, two independent detection channel interfaces can be set to realize simultaneous detection of two devices or simultaneous detection of two types of cable harnesses, greatly improving production efficiency. The controller further comprises an alarm mechanism for alarming when the test is unqualified, the alarm mechanism adopts an audible and visual alarm mechanism, and can alarm in time when the force exceeds the range, the sensor fails, the displacement is abnormal, and the like during the test; at the same time, the controller stops the insertion or extraction action, at this time, the alarm can also be realized by displaying alarm information on the monitoring interface of the monitoring terminal.

[0025] A computer readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the harness terminal and shell connection reliability test method as any one of the preceding, the computer readable storage medium can include any entity or device, medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory, random access memory, and software distribution medium, etc. that can carry the computer program code, and the computer program code can be in any existing code form.

[0026] Although the present application has been described in detail above with general description and specific embodiments, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, all belong to the scope of protection claimed by the present application.

Claims

1. A method for testing the reliability of the connection between a wire harness terminal and a housing, characterized in that, The steps are as follows: Establish standard curves for insertion force and extraction force during the insertion and extraction of wire harness terminals from the housing, respectively. The real-time force during the insertion of the wire harness terminal into the housing is collected and compared with the insertion standard curve. If the force value of the real-time force in different insertion stages is not greater than the force value of the corresponding insertion stage on the insertion standard curve, and is not less than the preset force value of the corresponding insertion stage, the test of inserting the wire harness terminal into the housing is qualified. The insertion stage includes the starting segment, friction segment, locking segment and ending segment in which the wire harness terminal and the housing contact in sequence. The system collects information on the force changes during the process of pulling the wire harness terminal outward from the housing using the force value at the pull-out key point of the standard curve as the initial force. If the force remains constant or increases within a limited time and the wire harness terminal does not displace, the test is considered successful if the wire harness terminal is not pulled out of the housing. The pull-out key point is the locking section where the wire harness terminal contacts the housing.

2. The method for testing the connection reliability between the wire harness terminal and the housing according to claim 1, characterized in that, The preset strength value is the difference between the average value of each insertion stage and 3 to 5 times the standard deviation when establishing the insertion standard curve.

3. The method for testing the connection reliability between the wire harness terminal and the housing according to claim 1, characterized in that, The specified time is 2-5 seconds.

4. The method for testing the connection reliability between the wire harness terminal and the housing according to claim 1, characterized in that, The wire harness terminals are inserted into the housing at a constant speed of not less than 25 mm / min.

5. The method for testing the connection reliability between the wire harness terminal and the housing according to claim 1, characterized in that, The insertion standard curve is defined as a zero displacement point when the value of the force obtained by continuous sampling at a certain sampling frequency within a specified time exceeds a preset threshold.

6. The method for testing the connection reliability between the wire harness terminal and the housing according to claim 5, characterized in that, The preset threshold is 0.3-0.5N, and the specified time is 10-60ms.

7. A controller, characterized in that, include: A processor and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the executable instructions to implement the connection reliability test method for wire harness terminals and housing as described in any one of claims 1 to 6.

8. The controller according to claim 7, characterized in that, It also includes a network port, a serial interface, multiple I / O input / output interfaces, and a detection channel interface for connecting sensors.

9. The controller according to claim 7, characterized in that, It also includes alarm mechanisms that sound an alarm when a test fails.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the connection reliability test method between the wire harness terminal and the housing as described in any one of claims 1 to 6.

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