Wire harness processing quality inspection method

Abstract

The present invention provides a method for detecting the processing quality of a wire harness, and relates to the technical field of wire harness quality detection. The method comprises: obtaining a plurality of strip wire harness samples, applying a preset voltage, detecting a first current at both ends of a single conductor, thereby screening a plurality of strip wire harness samples to be tested and dividing them into two test groups. Determine the axial center line of the strip wire harness sample to be tested in the first test group and apply a first stress, detect the second current, and then determine the stress resistance quality score. Determine the folding line of the strip wire harness sample to be tested in the second test group and fold it, detect the third current, and then determine the anti-extrusion quality score, thereby determining the processing quality score of the strip wire harness products of the current production and processing batch. According to the present invention, the processing quality of the wire harness itself can be evaluated from two aspects of the stress resistance and extrusion resistance of the wire harness itself, thereby improving the accuracy and comprehensiveness of the wire harness processing quality detection.

Description

Technical Field

[0001] The present invention relates to the technical field of wire harness quality detection, and in particular to a wire harness processing quality detection method. Background Art

[0002] CN101477166A discloses a harness test control board and harness test control method. It includes: initializing the single chip microcomputer; the single chip microcomputer 1 detects whether there is a key signal; the input key signal is transmitted to the single chip microcomputer 2, and the single chip microcomputer 2 displays the pressed key; judging whether the "*" key is pressed, the key signal stored in the single chip microcomputer is cleared and waits for re-input; the single chip microcomputer 2 judges whether the "#" key is pressed; saving the six-digit number input through the keyboard; executing the test steps of the corresponding code, the single chip microcomputer 1 outputs the test signal, and the single chip microcomputer 2 detects the input signal; comparing with the standard to make a judgment; displaying the test result on the liquid crystal; alarming for failure; transmitting the serial communication program to the host computer. The invention solves the problem of complex harness detection for automobiles with multiple branches, relays, diodes, etc. on the harness, and can detect the three states of 24V, grounding, and suspension, and whether the relay on the harness is working normally, and whether the diode is short-circuited or open-circuited.

[0003] CN116840739A discloses a wiring harness detection method and a wiring harness conduction station, which belong to the field of automotive wiring harness technology. The wiring harness detection method includes: determining the target size of the contact surface between the end of the metal terminal and the sheath; determining the target length of the metal probe according to the target size, and the target length is greater than the target size; installing the metal probe in the test interface; plugging the sheath to be tested into the test interface; inputting a test signal into the test interface, and detecting whether the metal terminal receives the test signal; if the metal terminal receives the test signal, it is determined that the metal terminal is plugged in; if the metal terminal does not receive the test signal, it is determined that the metal terminal is not plugged in. The wiring harness detection method can quickly identify the metal terminal that is not plugged in in the sheath, and solve the problems of the metal terminal in the sheath being backed out and virtual connection.

[0004] In order to ensure the normal operation of the wire harness during application, it is necessary to accurately detect the processing quality of the wire harness to ensure that the wire harness can still work normally after deformation and other treatments. However, according to relevant technologies, only the working condition of the relay in the automotive wire harness, the short circuit and open circuit of the diode, and the retreat and virtual connection of the metal terminal in the sheath can be detected, while there is a lack of effective detection means for the processing quality of the wire harness itself. When the processing quality of the wire harness is poor, it cannot be detected in time, making it difficult to ensure the normal operation of the wire harness during application. Summary of the invention

[0005] The present invention provides a method for detecting the processing quality of a wire harness, which can solve the technical problem that it is difficult to accurately detect the processing quality of the wire harness.

[0006] According to a first aspect of the present invention, there is provided a method for detecting processing quality of a wire harness, comprising:

[0007] Dividing a plurality of ribbon harness samples to be tested into two test groups;

[0008] For a plurality of ribbon harness samples to be tested in the first test group, determining an axial centerline of each ribbon harness sample to be tested, wherein the axial centerline is parallel to a width direction of the ribbon harness sample to be tested;

[0009] Fixing both ends of each strip harness sample to be tested, applying a first stress along the axial centerline of each strip harness sample to be tested, and maintaining the first stress for a preset time period, applying a preset voltage to both ends of a single conductor of each strip harness sample to be tested, and detecting a second current at both ends of the single conductor of each strip harness sample to be tested;

[0010] Determining a stress resistance quality score of the ribbon harness sample to be tested according to the first stress and the second current;

[0011] Dividing the plurality of ribbon harness samples to be tested in the second test group into a plurality of test groups;

[0012] Setting folding lines for the strip harness samples to be tested in each test group, wherein the folding lines are parallel to the width direction of the strip harness samples to be tested, and the number of the folding lines is consistent with the serial number of the test group;

[0013] Folding each strip harness sample to be tested along the folding line, applying a second stress to the folded strip harness sample to be tested, and after maintaining the second stress for a preset time period, applying a preset voltage to both ends of a single wire of each strip harness sample to be tested, and detecting a third current at both ends of a single wire of each strip harness sample to be tested, wherein the application direction of the second stress is perpendicular to the surface of the folded strip harness sample to be tested, and the magnitude of the second stress is proportional to the number of folding lines;

[0014] Determining the anti-extrusion quality score of the ribbon harness sample to be tested according to the third current and the number of fold lines;

[0015] Determine the processing quality score of the ribbon harness product according to the stress resistance quality score and the extrusion resistance quality score.

[0016] According to a second aspect of the present invention, there is provided a wire harness processing quality detection system, comprising:

[0017] A strip harness sample determination module is used to sample multiple strip harness products in a current production and processing batch to obtain multiple strip harness samples;

[0018] A first current determination module, used for applying a preset voltage to both ends of a single wire of each strip harness sample, and detecting a first current at both ends of the single wire of each strip harness sample;

[0019] A strip harness sample determination module to be tested, used for screening a plurality of strip harness samples according to a first current at both ends of a single conductor of each strip harness sample, to obtain a plurality of strip harness samples to be tested;

[0020] A test strip harness sample grouping module, used for dividing a plurality of test strip harness samples into two test groups;

[0021] An axial centerline determination module for the strip wire harness sample to be tested, used for determining the axial centerline of each strip wire harness sample to be tested for the plurality of strip wire harness samples to be tested in the first test group, wherein the axial centerline is parallel to the width direction of the strip wire harness sample to be tested;

[0022] A second current determination module is used to fix the two ends of each strip harness sample to be tested, apply a first stress along the axial center line direction of each strip harness sample to be tested, and after maintaining the first stress for a preset time period, apply a preset voltage to the two ends of a single wire of each strip harness sample to be tested, and detect a second current at the two ends of the single wire of each strip harness sample to be tested;

[0023] A stress resistance quality score determination module, used to determine the stress resistance quality score of the ribbon harness sample to be tested according to the first stress and the second current;

[0024] The strip harness samples to be tested of the second test group are grouped into a module for grouping the strip harness samples to be tested in the second test group, and are used for grouping the strip harness samples to be tested in the second test group into a plurality of test groups;

[0025] A folding line setting module for the strip harness sample to be tested, used for setting a folding line for the strip harness sample to be tested in each test group, wherein the folding line is parallel to the width direction of the strip harness sample to be tested, and the number of the folding lines is consistent with the serial number of the test group;

[0026] a third current determination module, used for folding each strip harness sample to be tested along a folding line, applying a second stress to the folded strip harness sample to be tested, and after maintaining the second stress for a preset time period, applying a preset voltage to both ends of a single wire of each strip harness sample to be tested, and detecting a third current at both ends of a single wire of each strip harness sample to be tested, wherein the application direction of the second stress is perpendicular to the surface of the folded strip harness sample to be tested, and the magnitude of the second stress is proportional to the number of folding lines;

[0027] an anti-extrusion quality score determination module, used to determine the anti-extrusion quality score of the ribbon harness sample to be tested according to the third current and the number of folded lines;

[0028] The processing quality score determination module is used to determine the processing quality score of the ribbon harness product of the current production batch according to the stress resistance quality score, the extrusion resistance quality score, and the ratio between the total number of ribbon harness samples to be tested and the total number of ribbon harness samples.

[0029] Technical effect: According to the present invention, a plurality of strip harness samples to be tested can be screened and determined by applying a preset voltage to obtain a first current and grouped for testing. According to the applied first stress and the measured second current, the stress resistance quality score of the strip harness sample to be tested is determined, and the extrusion resistance quality score of the strip harness sample to be tested is determined according to the number of folding lines and the measured third current, and then the processing quality score of the strip harness product of the current production and processing batch is determined. The processing quality of the harness itself is evaluated from the two aspects of the stress resistance and extrusion resistance of the harness itself, which improves the accuracy and comprehensiveness of the harness processing quality detection. When determining the screening quality score, the maximum deviation degree and the average deviation degree of the resistance value of the strip harness sample can be determined by applying a preset voltage at both ends of the wire of the strip harness sample and measuring the first current at both ends of a single wire, so as to determine the screening quality score of the strip harness sample based on the stability of the resistance of multiple wires and the deviation from the preset resistance value, and then multiple strip harness samples to be tested are screened out, which improves the accuracy and objectivity of screening the strip harness samples to be tested, and provides basic data for determining the processing quality score of the strip harness product of the current production and processing batch. When determining the stress resistance quality score, the stress-current relationship function of the strip harness sample to be tested can be obtained according to the applied first stress and the second current fitting, and the theoretical resistance value of each wire after being subjected to the first stress can be determined based on the stress-current relationship function, so as to determine the stress resistance quality score of the strip harness sample to be tested based on the maximum deviation between the theoretical resistance value and the measured resistance value, and the quality condition of the strip harness sample to be tested under the first stress can be represented by the worst case of the quality of the strip harness sample to be tested after being subjected to the first stress, thereby improving the accuracy and objectivity of the stress resistance quality score. When determining the extrusion resistance quality score, the folding current relationship function can be obtained according to the third current and the number of folded wires, and the theoretical change of the resistance value of each wire after folding can be determined based on the folding current relationship function, so as to determine the extrusion resistance quality score of the strip harness sample to be tested based on the maximum deviation between the measured change of the resistance value after folding and the theoretical change. The quality condition of the strip harness sample to be tested when folded can be represented based on the worst case of the quality of the strip harness sample to be tested after folding, thereby improving the accuracy and objectivity of the extrusion resistance quality score. When determining the processing quality score of the ribbon harness products of the current production and processing batch, the weighted sum of the stress resistance quality score and the extrusion resistance quality score can be used to obtain the comprehensive stress resistance and extrusion resistance of the tested ribbon harness samples, and then the processing quality score of the ribbon harness products of the current production and processing batch can be determined according to the ratio between the total number of tested ribbon harness samples and the total number of ribbon harness samples. This improves the objectivity and comprehensiveness of the harness processing quality detection, and more accurately judges the processing quality of the ribbon harness products of the current production and processing batch. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0032] The processing quality detection method of the wire harness according to the embodiment of the present invention includes:

[0033] Step S101, sampling multiple strip wire harness products in a current production and processing batch to obtain multiple strip wire harness samples;

[0034] Step S102, applying a preset voltage to both ends of a single wire of each strip harness sample, and detecting a first current at both ends of the single wire of each strip harness sample;

[0035] Step S103, screening a plurality of strip wiring harness samples according to the first current at both ends of a single wire of each strip wiring harness sample to obtain a plurality of strip wiring harness samples to be tested;

[0036] Step S104, dividing a plurality of strip harness samples to be tested into two test groups;

[0037] Step S105, for the plurality of strip harness samples to be tested in the first test group, determining the axial centerline of each strip harness sample to be tested, wherein the axial centerline is parallel to the width direction of the strip harness sample to be tested;

[0038] Step S106, fixing both ends of each strip harness sample to be tested, applying a first stress along the axial centerline direction of each strip harness sample to be tested, and maintaining the first stress for a preset time period, applying a preset voltage to both ends of a single conductor of each strip harness sample to be tested, and detecting a second current at both ends of the single conductor of each strip harness sample to be tested;

[0039] Step S107, determining a stress resistance quality score of the ribbon harness sample to be tested according to the first stress and the second current;

[0040] Step S108, dividing the plurality of strip harness samples to be tested in the second test group into a plurality of test groups;

[0041] Step S109, setting folding lines for the strip harness samples to be tested in each test group, wherein the folding lines are parallel to the width direction of the strip harness samples to be tested, and the number of the folding lines is consistent with the serial number of the test group;

[0042] Step S1010, folding each strip harness sample to be tested along the folding line, applying a second stress to the folded strip harness sample to be tested, and after maintaining the second stress for a preset time period, applying a preset voltage to both ends of a single wire of each strip harness sample to be tested, and detecting a third current at both ends of a single wire of each strip harness sample to be tested, wherein the application direction of the second stress is perpendicular to the surface of the folded strip harness sample to be tested, and the magnitude of the second stress is proportional to the number of folding lines;

[0043] Step S1011, determining the anti-extrusion quality score of the ribbon harness sample to be tested according to the third current and the number of folding lines;

[0044] Step S1012, determining the processing quality score of the ribbon harness product of the current production batch according to the stress resistance quality score, the extrusion resistance quality score, and the ratio between the total number of ribbon harness samples to be tested and the total number of ribbon harness samples.

[0045] According to the processing quality detection method of the wire harness of the present invention, a plurality of strip wire harness samples to be tested can be screened by applying a preset voltage to obtain a first current and grouped for testing. According to the applied first stress and the measured second current, the stress resistance quality score of the strip wire harness sample to be tested is determined, and according to the number of fold lines and the measured third current, the anti-extrusion quality score of the strip wire harness sample to be tested is determined, and then the processing quality score of the strip wire harness products of the current production and processing batch is determined. The processing quality of the wire harness itself is evaluated from the two aspects of the stress resistance and extrusion resistance of the wire harness itself, which improves the accuracy and comprehensiveness of the wire harness processing quality detection.

[0046] According to an embodiment of the present invention, in step S101, a plurality of strip harness products in a current production batch are sampled to obtain a plurality of strip harness samples. For example, there are 20,000 strip harness products in the current production batch, and 200 strip harness products can be randomly sampled as the strip harness samples.

[0047] According to an embodiment of the present invention, in step S102, a preset voltage is applied to both ends of a single conductor of each strip harness sample, and the first current at both ends of the single conductor of each strip harness sample is detected. Since the harness is composed of multiple conductors, a preset voltage can be applied to each conductor of each harness, and then the first current of each single conductor can be measured. Since each single conductor of each strip harness sample has resistance, the first current at both ends of the single conductor of each strip harness sample can be detected after applying the preset voltage. In theory, the material of the conductor used in each strip harness sample is consistent, and the length and cross-sectional area of ​​the conductor are also consistent. Therefore, the first currents of multiple conductors of each strip harness sample are theoretically equal, but due to possible processing quality problems, there are some deviations in the first currents of each conductor of each strip harness sample. Therefore, the strip harness product samples with excessive deviations can be excluded first.

[0048] According to an embodiment of the present invention, in step S103, a plurality of strip harness samples are screened according to the first current at both ends of a single conductor of each strip harness sample to obtain a plurality of strip harness samples to be tested, including: obtaining a screening quality score of the strip harness sample according to formula (1): ,

[0049] (1)

[0050] in, is the preset voltage, is the first current across the i-th wire of the strip harness sample, n is the number of wires in the strip harness sample, is a preset resistance value, max is a maximum value function, min is a minimum value function, i≤n, and i and n are both positive integers; if the screening quality score is less than or equal to the preset score threshold, the strip harness sample is determined as the strip harness sample to be tested.

[0051] According to an embodiment of the present invention, in formula (1), the preset resistance value is included , that is, the theoretical resistance value of the strip harness sample. Based on Ohm's law, the measured resistance value of the i-th conductor of the strip harness sample can be obtained: ,therefore It can represent the maximum value of the measured resistance among the n wires of the strip harness sample. It can represent the minimum value of the resistance measured among the n wires of the ribbon harness sample. It can represent the ratio of the difference between the maximum and minimum values ​​of the measured resistance values ​​of the n wires of the strip wire sample to the preset resistance value, that is, the maximum deviation of the resistance value of the strip wire sample. The maximum deviation of the resistance value of the strip wire sample can be used to represent the stability of the resistance values ​​of multiple wires. The smaller the maximum deviation, the more stable the resistance values ​​of the multiple wires, and the more consistent the resistance values ​​of the multiple wires. Similarly, based on Ohm's law, the average value of the measured resistance values ​​of the wires of the strip wire sample can be obtained. ,therefore It can represent the ratio of the difference between the average value of the measured resistance value of the sample wire of the strip harness and the preset resistance value to the preset resistance value, that is, the average deviation degree of the resistance value of the sample wire harness. The smaller the average deviation degree, the closer the average value of each wire is to the preset resistance value. The closer the maximum deviation degree of the resistance value of the sample wire harness is to 0, and the closer the average deviation degree is to 0, the more consistent the resistance values ​​of multiple wires are, and the closer the resistance values ​​of multiple wires are to the preset resistance value, the higher the quality of the sample wire harness, and the lower the screening quality score of the sample wire harness. On the contrary, the greater the deviation degree of the resistance value of the sample wire harness, or the greater the average deviation degree, the lower the quality of the sample wire harness, and the higher the screening quality score of the sample wire harness.

[0052] According to an embodiment of the present invention, a strip harness sample whose screening quality score is less than or equal to a preset score threshold is determined as the strip harness sample to be tested. For example, a screening quality score threshold of the strip harness sample can be preset. When the screening quality score of the strip harness sample is lower than the preset screening quality score threshold of the strip harness sample, the quality of the strip harness sample is relatively high, and it can be determined as the strip harness sample to be tested, and the next step of quality inspection is carried out. On the contrary, when the screening quality score of the strip harness sample is higher than or equal to the preset screening quality score threshold of the strip harness sample, the quality of the strip harness sample is relatively low, and the strip harness sample to be tested can be screened out as a strip harness sample of unqualified quality.

[0053] In this way, by applying a preset voltage at both ends of the wire of the strip harness sample and measuring the first current at both ends of a single wire, the maximum deviation degree and the average deviation degree of the resistance value of the strip harness sample can be determined, thereby determining the screening quality score of the strip harness sample based on the stability of the resistance of multiple wires and the deviation from the preset resistance value, and then screening multiple strip harness samples to be tested, thereby improving the accuracy and objectivity of screening the strip harness samples to be tested. Basic data is provided for determining the processing quality score of the strip harness products of the current production and processing batch.

[0054] According to an embodiment of the present invention, in step S104, the plurality of strip harness samples to be tested are divided into two test groups. For example, the plurality of strip harness samples to be tested are evenly divided into two test groups for testing, or evenly divided, which is not limited by the present invention.

[0055] According to an embodiment of the present invention, in step S105, for a plurality of ribbon harness samples to be tested in the first test group, an axial centerline of each ribbon harness sample to be tested is determined, wherein the axial centerline is parallel to the width direction of the ribbon harness sample to be tested.

[0056] According to an embodiment of the present invention, a plurality of strip harness samples to be tested in one of the two test groups is determined as the first test group. The axial centerline of each strip harness sample to be tested in the first test group is determined, the axial centerline being a line formed by connecting the midpoints of the length direction of each conductor of the harness sample to be tested, and the direction of the axial centerline is perpendicular to the axial direction (length direction) of the strip harness sample and parallel to the width direction of the strip harness sample.

[0057] According to an embodiment of the present invention, in step S106, the two ends of each strip harness sample to be tested are fixed, a first stress is applied along the axial center line of each strip harness sample to be tested, and after maintaining the first stress for a preset time period, a preset voltage is applied to the two ends of a single conductor of each strip harness sample to be tested, and a second current at the two ends of the single conductor of each strip harness sample to be tested is detected.

[0058] According to an embodiment of the present invention, the two ends of each strip harness sample to be tested can be fixed, and a first stress can be applied along the axial centerline direction of each strip harness sample to be tested. The first stress applied to each strip harness sample to be tested is different from each other and can be maintained for a preset time period. For example, the preset time period can be determined as ten minutes, so that the wire of each strip harness sample to be tested is fully subjected to the first stress and deformed. After the deformation occurs, a preset voltage within the carrying capacity of the strip harness sample can be applied to both ends of a single wire of each strip harness sample to be tested, and a second current at both ends of a single wire of each strip harness sample to be tested can be detected.

[0059] According to an embodiment of the present invention, in step S107, determining the stress resistance quality score of the strip wiring harness sample to be tested according to the first stress and the second current includes: obtaining a stress-current relationship function of the jth strip wiring harness sample to be tested according to the first stress of the jth strip wiring harness sample to be tested in the first test group and the second current at both ends of each conductor of the jth strip wiring harness sample to be tested; and determining the stress resistance quality score of the strip wiring harness sample to be tested according to the second current at both ends of each conductor of each strip wiring harness sample to be tested and the stress-current relationship function of each strip wiring harness sample to be tested.

[0060] According to an embodiment of the present invention, after the first stress is applied for a preset time period, the multiple wires of the j-th strip harness sample to be tested will be deformed, and each strip harness sample to be tested is composed of multiple wires, and the direction of applying the first stress is along the axial centerline. Assuming that in the direction of applying the first stress, the serial number of the wire gradually increases, the larger the serial number of the wire, the greater the degree of deformation, the greater the resistance change, and the greater the change of the second current relative to the first current. Since the volume of the wire remains unchanged and the length increases, the cross-sectional area of ​​the wire will decrease, thereby increasing the resistance of the wire. In addition, the deformation of the wire is related to the serial number of the above-mentioned wire and the magnitude of the first stress, and the stress-current relationship function of the j-th strip harness sample to be tested can be fitted.

[0061] According to an embodiment of the present invention, according to the first stress of the jth strip harness sample to be tested in the first test group and the second current at both ends of each wire of the jth strip harness sample to be tested, the stress-current relationship function of the jth strip harness sample to be tested is obtained, including: according to formula (2), obtaining the undetermined coefficient equation of the stress-current relationship function of the jth strip harness sample to be tested,

[0062] (2)

[0063] in, is the preset voltage, is the second current at both ends of the kth conductor of the jth strip harness sample to be tested, is the first stress of the jth ribbon harness sample to be tested, and is the first undetermined coefficient; according to the first stress of the j-th strip wiring harness sample to be tested in the first test group, and the second current at both ends of each wire of the j-th strip wiring harness sample to be tested, the first undetermined coefficient is solved to obtain the stress-current relationship function of the j-th strip wiring harness sample to be tested.

[0064] According to an embodiment of the present invention, in formula (2), based on Ohm's law, the measured resistance value of the kth conductor of the jth strip harness sample to be tested can be obtained: . Since the j-th strip wiring harness sample to be tested is deformed under the action of the first stress, the larger the serial number of the wire, the greater the degree of deformation. Therefore, in the j-th strip wiring harness sample to be tested, the larger the serial number and the first stress, the greater the change in the resistance value of the k-th wire of the j-th strip wiring harness sample to be tested. The deformation of the wire includes two aspects: length change and cross-sectional area change. Since the volume of the wire remains unchanged and the length increases at a certain ratio, the cross-sectional area of ​​the wire will decrease according to the proportion of the increase in length. Therefore, the change in resistance value is related to the square of the deformation, and the deformation is related to the first stress and the serial number k. Therefore, the product of the serial number and the first stress can be used as a quadratic term, and the multiplier of the quadratic term can be set. As the first undetermined coefficient, you can also set the constant term As the first undetermined coefficient, the above undetermined coefficient equation is obtained. Therefore, according to the first stress of the j-th stripline harness sample to be tested in the first test group and the second current at both ends of each wire of the j-th stripline harness sample to be tested, the above undetermined coefficient equation can be substituted to solve the first undetermined coefficient, and then the stress-current relationship function of the j-th stripline harness sample to be tested is obtained.

[0065] According to an embodiment of the present invention, the stress resistance quality score of the strip harness sample to be tested is determined according to the second current at both ends of each wire of each strip harness sample to be tested and the stress-current relationship function of each strip harness sample to be tested, including: determining the stress resistance quality score of the strip harness sample to be tested according to formula (3): ,

[0066] (3)

[0067] in, for The solution value of for The solution value of , n is the number of wires in the ribbon harness sample, k≤n, is the number of ribbon harness samples to be tested in the first test group, j≤ , and k, n, j and All are positive integers.

[0068] According to an embodiment of the present invention, the measured resistance value of each wire of each strip harness sample to be tested can be determined according to the second current at both ends of each wire of each strip harness sample to be tested and the preset voltage. Since the stress-current relationship function is obtained by fitting the influence of the deformation of the wire on the resistance change, that is, it is obtained based on a certain physical law, therefore, based on the stress-current relationship function of the jth strip wiring harness sample to be tested and the first stress of each strip wiring harness sample to be tested, the theoretical resistance value of each wire of each strip wiring harness sample to be tested can be determined. If there is a gap between the measured resistance value and the theoretical resistance value, it means that the wire has not deformed according to the theoretical situation, and there may be more or less deformation than the theoretical situation, or even the possibility of breaking. It can represent the maximum relative difference between the measured resistance value of each wire of each tested ribbon harness sample and the theoretical resistance value of each wire of each tested ribbon harness sample, that is, the maximum deviation degree of the resistance value of each wire of each tested ribbon harness sample after being subjected to the first stress, which can be used to represent the worst quality of the tested ribbon harness sample when subjected to the first stress. Then, the average maximum deviation degree of the resistance value of the tested ribbon harness samples in the first test group after being subjected to the first stress can be obtained, so The stress resistance quality score of the tested ribbon harness sample can be represented, that is, based on the worst quality condition of the tested ribbon harness sample after being subjected to the first stress, the quality condition of the tested ribbon harness sample under the condition of being subjected to the first stress is represented. The higher the stress resistance quality score of the tested ribbon harness sample, the stronger the stress resistance ability of the tested ribbon harness sample, and the higher the processing quality of the tested ribbon harness sample; conversely, the lower the stress resistance quality score of the tested ribbon harness sample, the weaker the stress resistance ability of the tested ribbon harness sample, and the lower the processing quality of the tested ribbon harness sample.

[0069] In this way, the stress-current relationship function of the strip wiring harness sample to be tested can be obtained according to the applied first stress and the second current fitting, and the theoretical resistance value of each conductor after being subjected to the first stress can be determined based on the stress-current relationship function, so as to determine the stress resistance quality score of the strip wiring harness sample to be tested based on the maximum deviation between the theoretical resistance value and the measured resistance value. The quality condition of the strip wiring harness sample to be tested under the condition of being subjected to the first stress can be represented by the worst condition of the quality of the strip wiring harness sample to be tested after being subjected to the first stress, thereby improving the accuracy and objectivity of the stress resistance quality score.

[0070] According to an embodiment of the present invention, in step S108, the plurality of strip harness samples to be tested in the second test group are divided into a plurality of test groups. For example, the strip harness samples to be tested in the second test group can be evenly divided into a plurality of test groups or randomly divided into a plurality of test groups. The present invention does not limit the division method of the test groups.

[0071] According to an embodiment of the present invention, in step S109, a folding line is set for the strip harness sample to be tested in each test group, wherein the folding line is parallel to the width direction of the strip harness sample to be tested, and the number of folding lines is consistent with the serial number of the test group. The strip harness samples to be tested in the same test group are set with the same number of folding lines, and the strip harness samples to be tested can be folded according to the folding lines. The folding line is parallel to the width direction of the strip harness sample to be tested and perpendicular to the axis direction. The number of folding lines is consistent with the serial number of the test group, for example, the strip harness sample to be tested in the first test group is set with 1 folding line, and the strip harness sample to be tested in the second test group is set with 2 folding lines, and so on.

[0072] According to an embodiment of the present invention, in step S1010, each strip wiring harness sample to be tested is folded along a folding line, and a second stress is applied to the folded strip wiring harness sample to be tested, and after maintaining the second stress for a preset time period, a preset voltage is applied to both ends of a single conductor of each strip wiring harness sample to be tested, and a third current is detected at both ends of the single conductor of each strip wiring harness sample to be tested, wherein the direction of applying the second stress is perpendicular to the surface of the folded strip wiring harness sample to be tested, and the magnitude of the second stress is proportional to the number of folding lines.

[0073] According to an embodiment of the present invention, each strip harness sample to be tested is folded along a folding line, and a second stress is applied to the folded strip harness sample to be tested, and the direction of application of the second stress is perpendicular to the surface of the folded strip harness sample to be tested, for example, vertically downward. Since the more folds the strip harness sample to be tested has, the more difficult it is for the strip harness sample to be tested to maintain deformation, the magnitude of the second stress is proportional to the number of folding lines, so that the degree of deformation of each strip harness sample to be tested is the same. The second stress is continuously applied for a preset time period. For example, the preset time period can be determined to be ten minutes, so that the strip harness samples to be tested in each test group are fully subjected to the second stress and deformed. A preset voltage within the carrying capacity of the strip harness sample is applied to both ends of a single conductor of each strip harness sample to be tested, and a third current is detected at both ends of a single conductor of each strip harness sample to be tested.

[0074] According to an embodiment of the present invention, in step S1011, the anti-extrusion quality score of the strip harness sample to be tested is determined according to the third current and the number of folding lines, including: determining a folding current relationship function between a change of the third current relative to the first current and the number of folding lines according to the third current at both ends of each conductor of each strip harness sample to be tested in the x-th test group; determining the anti-extrusion quality score of the strip harness sample to be tested according to the folding current relationship function and the change of the third current relative to the first current.

[0075] According to an embodiment of the present invention, after the second stress is applied for a preset time period, each of the strip harness samples to be tested in the x-th test group will be deformed, and each of the strip harness samples to be tested is composed of multiple conductors, so the resistance value of each of the strip harness samples to be tested in the x-th test group will change. Since the more folds there are, the greater the change in the resistance value of each of the strip harness samples to be tested in the x-th test group, the greater the change in the third current of each of the strip harness samples to be tested in the x-th test group relative to the first current, and then based on Ohm's law, the folding current relationship function between the change in the third current relative to the first current and the number of folds can be determined. In theory, the folding current relationship function between the change in the third current relative to the first current and the number of folds is fixed.

[0076] According to an embodiment of the present invention, determining a folding current relationship function between a change amount of the third current relative to the first current and the number of folding lines according to a third current at both ends of each wire of each strip harness sample to be tested in an x-th test group includes: determining an undetermined coefficient equation of the folding current relationship function between a change amount of the third current relative to the first current and the number of folding lines according to formula (4),

[0077] (4)

[0078] in, is the third current at both ends of the zth conductor of the yth strip harness sample to be tested in the xth test group, is the first current across the zth conductor of the yth strip harness sample to be tested in the xth test group, is the change of the third current relative to the first current, is the preset voltage, and is the second undetermined coefficient; according to the third current and the first current at both ends of each wire of each strip harness sample to be tested in multiple test groups, and the number of folding lines in multiple test groups, the second undetermined coefficient is solved to obtain the folding current relationship function.

[0079] According to an embodiment of the present invention, based on Ohm's law, the resistance value of the zth wire of the yth tested strip harness sample in the xth test group after folding can be obtained: , and the resistance value of the zth conductor of the yth tested ribbon harness sample in the xth test group before folding Therefore, the change in the resistance value of the zth conductor of the yth strip harness sample to be tested in the xth test group after folding relative to that before folding can be obtained. ,Right now, The change in resistance may be related to the number of folding lines, that is, the more folding lines there are and the more times they are folded, the easier it is for the wire to deform. Therefore, the second unknown coefficient and To express the relationship between the change in resistance value and the number of folding lines, that is, The undetermined coefficient equation of the folding current relationship function between the change amount of the third current relative to the first current and the number of folding lines can be expressed. The second undetermined coefficient can be solved according to the third current and the first current at both ends of each wire of each strip harness sample to be tested in multiple test groups, and the number of folding lines in the multiple test groups, so as to determine the folding current relationship function between the change amount of the third current relative to the first current and the number of folding lines.

[0080] According to an embodiment of the present invention, the anti-extrusion quality score of the strip harness sample to be tested is determined according to the folded current relationship function and the change amount of the third current relative to the first current, including: determining the anti-extrusion quality score of the strip harness sample to be tested according to formula (5): ,

[0081] (5)

[0082] in, for The solution value of for The solution value of , n is the number of wires in the ribbon harness sample, z≤n, is the number of ribbon harness samples to be tested in the xth test group, y≤ , is the number of test groups in the second test group, x≤ , and x, y, z, n, and All are positive integers.

[0083] According to an embodiment of the present invention, based on Ohm's law, the resistance value of the zth wire of the yth tested strip harness sample in the xth test group after folding can be obtained: , and the resistance value of the zth conductor of the yth tested ribbon harness sample in the xth test group before folding , so the measured change in the resistance value of the zth conductor of the yth strip harness sample to be tested in the xth test group after folding relative to before folding can be obtained ,Right now, According to the folding current relationship function between the change of the third current relative to the first current and the number of folding lines, the change of the resistance value of the strip harness sample to be tested after folding can be obtained theoretically: If the measured resistance value is inconsistent with the theoretical resistance value, it means that the wire has not deformed according to the theoretical situation, and there may be more or less deformation than the theoretical situation, or even the possibility of breaking. It can represent the maximum relative difference between the actual measured change in resistance value and the theoretical change after folding the strip harness sample to be tested in the xth test group, that is, the maximum deviation between the actual measured change in resistance value and the theoretical change after folding the strip harness sample to be tested in the xth test group, which can be used to represent the worst quality of the strip harness sample to be tested when folded. Then, the average maximum deviation between the actual measured change in resistance value and the theoretical change after folding the strip harness sample to be tested in each test group in the second test group can be obtained. ,therefore The anti-extrusion quality score of the tested ribbon harness sample can be indicated, that is, based on the worst quality condition of the tested ribbon harness sample after folding, the quality condition of the tested ribbon harness sample when folded is indicated. The higher the anti-extrusion quality score of the tested ribbon harness sample, the stronger the anti-extrusion ability of the tested ribbon harness sample, and the higher the processing quality of the tested ribbon harness sample; conversely, the lower the anti-extrusion quality score of the tested ribbon harness sample, the weaker the anti-extrusion ability of the tested ribbon harness sample, and the lower the processing quality of the tested ribbon harness sample.

[0084] In this way, a folding current relationship function can be obtained by fitting the third current and the number of folded wires, and the theoretical change in the resistance value of each wire after folding can be determined based on the folding current relationship function, so as to determine the anti-extrusion quality score of the tested strip harness sample based on the maximum deviation between the measured change in the resistance value after folding and the theoretical change. The quality condition of the tested strip harness sample when folded can be represented based on the worst quality condition of the tested strip harness sample after folding, thereby improving the accuracy and objectivity of the anti-extrusion quality score.

[0085] According to an embodiment of the present invention, in step S1012, the processing quality score of the ribbon harness product of the current production and processing batch is determined according to the stress resistance quality score, the extrusion resistance quality score, and the ratio between the total number of the ribbon harness samples to be tested and the total number of the ribbon harness samples, including: determining the processing quality score of the ribbon harness product of the current production and processing batch according to formula (6): ,

[0086] (6)

[0087] in, and is the preset weight, To score the stress resistance quality, is the anti-extrusion quality score, and r is the ratio between the total number of ribbon harness samples to be tested and the total number of ribbon harness samples.

[0088] According to an embodiment of the present invention, after a plurality of strip harness samples are screened, the total number of strip harness samples to be tested is recorded, and a ratio r between the total number of strip harness samples to be tested and the total number of strip harness samples is obtained. For example, if the total number of strip harness samples to be tested is 80 and the total number of strip harness samples is 100, then r is 0.8. Formula (6) also includes a preset weight and , so the weighted sum of the stress resistance quality score and the extrusion resistance quality score is obtained , that is, the comprehensive ability of the tested strip harness sample to resist stress and extrusion, so as to determine the quality of the strip harness product in dealing with the two working conditions of lateral stress and extrusion. The weighted summation result can represent the quality of the screened strip harness samples in dealing with the two working conditions of lateral stress and extrusion. In order to represent the quality of multiple strip harness products in the current production and processing batch in dealing with the two working conditions of lateral stress and extrusion, the weighted summation result can be multiplied by the above ratio r, which can represent the processing quality score of the strip harness products in the current production and processing batch. The higher the processing quality score of the strip harness products in the current production and processing batch, the higher the processing quality of the strip harness products in the current production and processing batch. Conversely, the lower the processing quality score of the strip harness products in the current production and processing batch, the lower the processing quality of the strip harness products in the current production and processing batch.

[0089] In this way, the weighted sum of the stress resistance quality score and the extrusion resistance quality score can be used to obtain the comprehensive stress resistance and extrusion resistance of the tested ribbon harness samples, and then the processing quality score of the ribbon harness products in the current production batch can be determined according to the ratio between the total number of tested ribbon harness samples and the total number of ribbon harness samples. This improves the objectivity and comprehensiveness of the wire harness processing quality inspection, and more accurately judges the processing quality of the ribbon harness products in the current production batch.

[0090] According to the processing quality detection method of the wire harness of the embodiment of the present invention, a plurality of strip wire harness samples to be tested can be screened by applying a preset voltage to obtain a first current and grouped for testing. The stress resistance quality score of the strip wire harness sample to be tested is determined based on the applied first stress and the measured second current, and the anti-extrusion quality score of the strip wire harness sample to be tested is determined based on the number of fold lines and the measured third current, and then the processing quality score of the strip wire harness products of the current production and processing batch is determined. The processing quality of the wire harness itself is evaluated from the two aspects of the stress resistance and extrusion resistance of the wire harness itself, which improves the accuracy and comprehensiveness of the wire harness processing quality detection. When determining the screening quality score, the maximum deviation and average deviation of the resistance value of the strip harness sample can be determined by applying a preset voltage at both ends of the wire of the strip harness sample and measuring the first current at both ends of a single wire, so as to determine the screening quality score of the strip harness sample based on the stability of the resistance of multiple wires and the deviation from the preset resistance value, and then screen out multiple strip harness samples to be tested, improve the accuracy and objectivity of screening the strip harness samples to be tested, and provide basic data for determining the processing quality score of the strip harness products of the current production and processing batch. When determining the stress resistance quality score, the stress-current relationship function of the strip harness sample to be tested can be obtained according to the applied first stress and the second current fitting, and the theoretical resistance value of each wire after being subjected to the first stress can be determined based on the stress-current relationship function, so as to determine the stress resistance quality score of the strip harness sample to be tested based on the maximum deviation between the theoretical resistance value and the measured resistance value, and the quality condition of the strip harness sample to be tested under the first stress can be represented by the worst quality condition of the strip harness sample to be tested after being subjected to the first stress, so as to improve the accuracy and objectivity of the stress resistance quality score. When determining the anti-extrusion quality score, the folding current relationship function can be fitted according to the third current and the number of folded wires, and the theoretical change in the resistance value of each wire after folding can be determined based on the folding current relationship function, so as to determine the anti-extrusion quality score of the strip harness sample to be tested based on the maximum deviation between the measured change in the resistance value after folding and the theoretical change. The quality condition of the strip harness sample to be tested when folded can be represented based on the worst case of the quality of the strip harness sample to be tested after folding, thereby improving the accuracy and objectivity of the anti-extrusion quality score. When determining the processing quality score of the strip harness product of the current production and processing batch, the weighted sum of the stress resistance quality score and the anti-extrusion quality score can be obtained to obtain the comprehensive ability of the stress resistance and anti-extrusion of the strip harness sample to be tested, and then the processing quality score of the strip harness product of the current production and processing batch can be determined according to the ratio between the total number of strip harness samples to be tested and the total number of strip harness samples. The objectivity and comprehensiveness of the harness processing quality detection are improved, and the processing quality of the strip harness products of the current production and processing batch is more accurately judged.

[0091] The wire harness processing quality detection system of the embodiment of the present invention comprises:

[0092] A strip harness sample determination module is used to sample multiple strip harness products in a current production and processing batch to obtain multiple strip harness samples;

[0093] A first current determination module, used for applying a preset voltage to both ends of a single wire of each strip harness sample, and detecting a first current at both ends of the single wire of each strip harness sample;

[0094] A strip harness sample determination module to be tested, used for screening a plurality of strip harness samples according to a first current at both ends of a single conductor of each strip harness sample, to obtain a plurality of strip harness samples to be tested;

[0095] A test strip harness sample grouping module, used for dividing a plurality of test strip harness samples into two test groups;

[0096] An axial centerline determination module for the strip wire harness sample to be tested, used for determining the axial centerline of each strip wire harness sample to be tested for the plurality of strip wire harness samples to be tested in the first test group, wherein the axial centerline is parallel to the width direction of the strip wire harness sample to be tested;

[0097] A second current determination module is used to fix the two ends of each strip harness sample to be tested, apply a first stress along the axial center line direction of each strip harness sample to be tested, and after maintaining the first stress for a preset time period, apply a preset voltage to the two ends of a single wire of each strip harness sample to be tested, and detect a second current at the two ends of the single wire of each strip harness sample to be tested;

[0098] A stress resistance quality score determination module, used to determine the stress resistance quality score of the ribbon harness sample to be tested according to the first stress and the second current;

[0099] The strip harness samples to be tested of the second test group are grouped into a module for grouping the strip harness samples to be tested in the second test group, and are used for grouping the strip harness samples to be tested in the second test group into a plurality of test groups;

[0100] A folding line setting module for the strip harness sample to be tested, used for setting a folding line for the strip harness sample to be tested in each test group, wherein the folding line is parallel to the width direction of the strip harness sample to be tested, and the number of the folding lines is consistent with the serial number of the test group;

[0101] a third current determination module, used for folding each strip harness sample to be tested along a folding line, applying a second stress to the folded strip harness sample to be tested, and after maintaining the second stress for a preset time period, applying a preset voltage to both ends of a single wire of each strip harness sample to be tested, and detecting a third current at both ends of a single wire of each strip harness sample to be tested, wherein the application direction of the second stress is perpendicular to the surface of the folded strip harness sample to be tested, and the magnitude of the second stress is proportional to the number of folding lines;

[0102] an anti-extrusion quality score determination module, used to determine the anti-extrusion quality score of the ribbon harness sample to be tested according to the third current and the number of folded lines;

[0103] The processing quality score determination module is used to determine the processing quality score of the ribbon harness product of the current production batch according to the stress resistance quality score, the extrusion resistance quality score, and the ratio between the total number of ribbon harness samples to be tested and the total number of ribbon harness samples.

[0104] It should be understood by those skilled in the art that the embodiments of the present invention shown in the above description are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the processing quality of a wire harness, characterized in that: include: Sampling multiple ribbon wire harness products in a current production and processing batch to obtain multiple ribbon wire harness samples; Applying a preset voltage to both ends of a single conductor of each strip harness sample, and detecting a first current at both ends of the single conductor of each strip harness sample; Screening a plurality of strip harness samples according to a first current at both ends of a single conductor of each strip harness sample to obtain a plurality of strip harness samples to be tested; Dividing a plurality of ribbon harness samples to be tested into two test groups; For a plurality of ribbon harness samples to be tested in the first test group, determining an axial centerline of each ribbon harness sample to be tested, wherein the axial centerline is parallel to a width direction of the ribbon harness sample to be tested; Fixing both ends of each strip harness sample to be tested, applying a first stress along the axial centerline of each strip harness sample to be tested, and maintaining the first stress for a preset time period, applying a preset voltage to both ends of a single conductor of each strip harness sample to be tested, and detecting a second current at both ends of the single conductor of each strip harness sample to be tested; Determining a stress resistance quality score of the ribbon harness sample to be tested according to the first stress and the second current; Dividing the plurality of ribbon harness samples to be tested in the second test group into a plurality of test groups; Setting folding lines for the strip harness samples to be tested in each test group, wherein the folding lines are parallel to the width direction of the strip harness samples to be tested, and the number of the folding lines is consistent with the serial number of the test group; Folding each strip harness sample to be tested along the folding line, applying a second stress to the folded strip harness sample to be tested, and after maintaining the second stress for a preset time period, applying a preset voltage to both ends of a single wire of each strip harness sample to be tested, and detecting a third current at both ends of a single wire of each strip harness sample to be tested, wherein the application direction of the second stress is perpendicular to the surface of the folded strip harness sample to be tested, and the magnitude of the second stress is proportional to the number of folding lines; Determine the anti-extrusion quality score of the strip harness sample to be tested according to the third current and the number of folded lines; perform weighted summation of the anti-stress quality score and the anti-extrusion quality score to obtain the comprehensive anti-stress and anti-extrusion capabilities of the strip harness sample to be tested; According to the first current at both ends of a single conductor of each strip harness sample, a plurality of strip harness samples are screened to obtain a plurality of strip harness samples to be tested, including: According to the formula ， Obtaining a screening quality score for ribbon harness samples ,in, is the preset voltage, is the first current across the i-th wire of the strip harness sample, n is the number of wires in the strip harness sample, is the preset resistance value, max is the maximum value function, min is the minimum value function, i≤n, and i and n are both positive integers; If the screening quality score is less than or equal to a preset score threshold, the strip harness sample is determined as the strip harness sample to be tested; and according to the first stress and the second current, the stress resistance quality score of the strip harness sample to be tested is determined, including: Obtaining a stress-current relationship function of the jth strip harness sample to be tested according to the first stress of the jth strip harness sample to be tested in the first test group and the second currents at both ends of each wire of the jth strip harness sample to be tested; Determine the stress resistance quality score of the strip harness sample to be tested according to the second current at both ends of each wire of each strip harness sample to be tested and the stress-current relationship function of each strip harness sample to be tested; obtain the stress-current relationship function of the jth strip harness sample to be tested according to the first stress of the jth strip harness sample to be tested in the first test group and the second current at both ends of each wire of the jth strip harness sample to be tested, including: According to the formula ， Obtain the undetermined coefficient equation of the stress-current relationship function of the jth strip harness sample to be tested, where: is the preset voltage, is the second current at both ends of the kth conductor of the jth strip harness sample to be tested, is the first stress of the jth ribbon harness sample to be tested, and is the first undetermined coefficient; According to the first stress of the j-th strip harness sample to be tested in the first test group and the second current at both ends of each wire of the j-th strip harness sample to be tested, the first undetermined coefficient is solved to obtain the stress-current relationship function of the j-th strip harness sample to be tested; according to the second current at both ends of each wire of each strip harness sample to be tested and the stress-current relationship function of each strip harness sample to be tested, the stress resistance quality score of the strip harness sample to be tested is determined, including: According to the formula ， Determine the stress resistance quality score of the ribbon harness sample to be tested ,in, for The solution value of for The solution value of , n is the number of wires in the ribbon harness sample, k≤n, is the number of ribbon harness samples to be tested in the first test group, j≤ , and k, n, j and are all positive integers; and determining the anti-extrusion quality score of the ribbon harness sample to be tested according to the third current and the number of folded lines, including: Determine, according to the third current at both ends of each wire of each strip harness sample to be tested in the xth test group, a folding current relationship function between a change of the third current relative to the first current and the number of folding lines; Determining the anti-extrusion quality score of the strip harness sample to be tested according to the folding current relationship function and the change of the third current relative to the first current; determining the folding current relationship function between the change of the third current relative to the first current and the number of folding lines according to the third current at both ends of each wire of each strip harness sample to be tested in the xth test group, including: According to the formula ， Determine the equation of the unknown coefficients of the folding current relationship function, where, is the third current at both ends of the zth conductor of the yth strip harness sample to be tested in the xth test group, is the first current across the zth conductor of the yth strip harness sample to be tested in the xth test group, is the change of the third current relative to the first current, is the preset voltage, and is the second unknown coefficient; Solving the second unknown coefficient according to the third current and the first current at both ends of each conductor of each strip harness sample to be tested in multiple test groups and the number of folded lines in the multiple test groups to obtain a folded current relationship function; determining the anti-extrusion quality score of the strip harness sample to be tested according to the folded current relationship function and the change of the third current relative to the first current, including: According to the formula ， Determine the compression resistance score of the ribbon harness sample to be tested ,in, for The solution value of for The solution value of , n is the number of wires in the ribbon harness sample, z≤n, is the number of ribbon harness samples to be tested in the xth test group, y≤ , is the number of test groups in the second test group, x≤ , and x, y, z, n, and All are positive integers.

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