[0072] Embodiment:
[0073] like figure 1 As shown, a tensile test method of a cable insulated dumbbell test piece, including the following steps: Step S100 - Step S500:
[0074] Step S100, the scribe: the upper end of the prepared N test piece, the lower end is made, and the lower end is made, and the distance between the inner side of the upper mark line and the subscript mark is set to a, The length of the upper mark line and the subscript mark is b;
[0075] In step S100, such as figure 2 As shown, first make dumbbell test pieces, dumbbell-shaped cable insulation is pressed out of the abrasive, mainly black and white translucent; need to draw 2 labeled lines on dumbbell test pieces, white test piece with black marker Strike, black test piece with white marker, it is recommended to improve contrast with green marker strokes.
[0076] At the beginning, the inner distance between the two markers is measured, i.e., the distance between the lower side of the upper mark and the upper side of the subscript line, the rated A = 20 mm, b = 4 mm.
[0077] Step S200, heating: placing the N test piece of the scribe in the experimental device, each connected the upper tensile machine at the upper end of the test piece, and the lower end is connected to the automatic clip, and the camera is set to the experimental device for shooting the experimental device. Image of different time point test pieces;
[0078] In this step, the experimental device temperature is 200 degrees Celsius, and the tension of the electric tensioner is determined according to the thickness of the dumbbell test piece, and the tension calculates the thickness (mm) * 0.8N of the test piece;
[0079] The camera camera is separated from 2 glasses inside the experimental device, which is used to isolate 200 degrees Celsius temperature; there is a lighting outside the glass, and the upper and lower rows are set parallel to shoot light. 4 1. 1.3 million low pixels fixed camera continuously.
[0080] In addition, since the clip in the dumbbell test piece and a small distance in the labeling line, it will also be long, and the drawing line of the marking line is also manually controlled, and it may be floated up and down, so the 0.1mm accuracy range of the camera is greater than 35mm. .
[0081] Step S300, the image is acquired: the image is taken once, and the M time to obtain the M group data, as the image data of this time point, remove the automatic clip after obtaining the Mth group data, and retract for a certain time Post-shooting the image of the final state;
[0082] The camera shooting time is a continuous shooting per second. In several images captured, the image data is taken once every 2 minutes, and 5 times, a total of 5 sets of data is obtained. In other tests, you can take the image at a millisecing level. In addition, the heating time was 15 minutes, and the image data was taken in the second minute, the 4th minute, the 6th minute, the first, and the 10th minute respectively took the signal to the automatic clip after taking the image in the 10th minute. The lower end, let the test piece naturally retract for 5 minutes, in the 15th minute, the image of the final state.
[0083] Further, in the present embodiment, N is 4, including N1, N2, N3, N4 a total of 4 test pieces, i.e., 4 test pieces simultaneously test.
[0084] Step S400, calculate the vertical deformation rate according to the M group image data;
[0085] In the present embodiment, the calculation vertical deformation rate includes the following sub-steps:
[0086] H100, the image data taken by the M group is subjected to M1, M2, M3 ... M, a total N * M group in time, and the initial image is recorded as M0, which will be the final state of the retraction.
[0087] like image 3 As shown, the N1-N4 columns represent the data of the four test pieces, and the M0 row represents an image of the initial time, and the M1-M5 line represents photo data taken in 5 time points, and M6 represents the final state data after retreating. Unit is mm.
[0088] H200, a binarization operation of all image data, plotting the detection box around the bid-to-bid marking line, and draws the detection box around the subscript.
[0089] The binarization process of the image in this embodiment is to set the gradation of the point on the N * M image as 255, that is, the entire image exhibits a significant black and white effect, and the color of the marking line is distinguished from the test piece. Come, easy to select the pixel point. Drawing two detection boxes to enclose the tag line to remove the effects of other pixel points, and improve the accuracy of the marking line.
[0090] At high temperatures, the dumbbell test piece is elongated, and the marking line will be slightly deformed, so the position of the tag line is to be redefined.
[0091] H300, acquire all pixel point locations in the upper detection box, take the average of all pixel points, as the current marking line position, recorded as position A;
[0092] H400, acquire all pixel point locations in the lower detection box, take the average of all pixel points, as the current subscript line position, recorded as position B;
[0093] H500, obtains the distance AB1, AB2, AB3 ... ABM between the lower side of each test piece and the upper side of the position B, as the current vertical length of the M group of N test pieces, and acquisition in the final state AB final;
[0094] In this embodiment, if image 3 The data shown in 5 time points is taken in the N test pieces, the data is AB1, AB2, AB3 ... ABM, a total of N * m data.
[0095] H600, according to formula AB i -AB i-1 Calculate the shape variable in unit time, compare N-shaped variables in the same point in time, remove the P test piece corresponding to the large variable variable, of which I = 1, 2, 3 ... M, I ≠ m 终;
[0096] like Figure 5 As shown, the shape variables in unit time are calculated. In the first line, the M2-M1 represented by means of the AB distance at the second time, the difference between the AB distance at the time of the first shot, the first row The second and first difference of the four test pieces, it can be seen from the first line of data in the figure that the difference in N1 is 4.2mm, and the difference in N2 is 4.9mm, and the difference between N3 is 0.2mm. The difference between N4 is 3.7mm, where the difference between N3 differs from N1, N2, N4, indicating that the test piece 3 has an error, and therefore, the third test piece is to be removed, and the N3 is about this column. Data reject. The three columns of N1, N2, N4 are calculated as the calculated data.
[0097] Further, ab i+1 -AB i i -AB i-1 Indicates that the cable insulation is gradually smaller in unit time, of course, this size is only valid for 10 minutes before heating, and is not limited to this formula within 5 minutes starting at the beginning of the 10th minute.
[0098] Take N * M AB i -AB i-1 The variable data is a curve of the basic plotted variable. like Image 6 Indicated Figure 5 Curve of the deformation amount, by Image 6 The difference between the corresponding curve point value in the in N3 is large, and it is more clear that the test piece is a test piece that needs to be removed.
[0099] Then Figure 4 Indicated image 3 Corresponding curve, Figure 4 In the middle, the N3 data corresponding to the M2 time point has a large change, whereby it can be seen that N3 is removed.
[0100] In the present invention, the amount of unqualified product is perbided in the present invention to avoid unqualified product affecting the test.
[0101]H700, the final state image data after the retraction of the N-P after the rejection is removed, according to the formula The N-P extension F1, F2, F3 ... fp corresponding to the final state, wherein P
[0102] like Figure 7 As shown, the N3 is removed, that is, the initial length and final length of the N1, the left N1, N2, N4 leaves N1, N2, N4, and the above formula is calculated, and the elongation at this time is 71.5%, 68.5%, 63%.
[0103] like Figure 8 As shown, the extension curve is drawn based on F1, F2, F3 ... fp.
[0104] Pre-order rules: If the extension f is greater than 175%, the test piece determines that the test piece is unqualified, and more than 175%, that is, 20 mm becomes 55 mm, which is unqualified. The accuracy in this section is ± 0.1mm; if the elongation f More than 150% and less than 175%, then the test piece is determined as a qualified test piece, and if the elongation f is less than 150%, the test piece is determined to be a superior test piece. In this experiment, both Trial of N1, N2, and N4 belong to the qualified level, so three test pieces are determined to qualify.
[0105] More than 175% to 250% of data are still recorded, ie between 55mm and 70 mm, and accuracy can be properly relaxed, more than 250% of data does not make records.
[0106] When testing the same batch of cable insulation, the average elongation f: H800 of the batch can be calculated according to the respective elongation, the f1, f2, f3 ... FP tetles can be obtained, to obtain a vertical extension F . In the present embodiment, the average of 71.5%, 68.5%, 63% is obtained, and the batch elongation mean f = 67.7% can be generally determined that the cable insulation of the batch is qualified.
[0107] Another example, if Figure 9 The data indicated as another batch of test pieces, as can be seen, the elongation of the N5 and N7 test pieces is greater than 175%, which is a unqualified test piece, and the elongation of the N6 test piece is greater than 150% and less than 175%, which is a qualified test. Part.
[0108] Step S500, calculate the lateral deformation rate according to M group image data. Included as follows:
[0109] K100, image binarization: the last shooting image is borid to obtain a binarized image;
[0110] K200, obtain the final length: obtain the leftmost-left-side pixel point position of the upper mark line on the binarized image, the rightmost pixel point position, calculate the leftmost pixel point and the outermost side of the rightmost pixel point The distance D1; obtains the leftmost pixel point position of the subscript line on the binarized image, the rightmost pixel point position, calculates the leftmost pixel point and the outermost side of the rightmost Distance D2;
[0111] K300, calculating lateral deformation rate: according to Calculate the lateral deformation rate E1 of the last mark line of the last image data, according to The lateral deformation rate E2 of the subscript line of the last image data is calculated, and N E1 data and N E2 data are obtained, and the average of E1 and E2 is taken separately.
[0112] With the lateral elongation E, it is possible to know that the ductility of the circumferential direction of the test piece is contracted in the circumference, that is, the lateral direction is contracted. The delay is unqualified. Depending on the cable insulating material, the thickness weight is different, and its lateral deformation rate is different, and therefore, the size of the E is initially learned from the initial experiment based on the self-performance of the test piece during actual test.
[0113] Also included, including the following sub-step: the deformation rate curve of the deformation of the subscript of N test pieces is drawn by n E1 data and N E2 data, and the deformation rate curve of the subscript mark. The form of curves is more convenient to see the lateral deformation.
[0114] In the present invention, in addition to the calculation of the vertical elongation, the calculation of the transverse elongation is also performed, and the lateral elongation can be known that the cable insulating test piece is in production, the vertical extension length of the unit time can be It can be seen that the lateral elongation can be seen that the passive material produced by the batch material is in the lateral extension, if it is tested When the horizontal elongation is large, the unqualified production material can be pushed, or the retrofitable cable can be used in time to prevent unqualified cable insulation from being applied to the cable.
[0115] In another embodiment, a tension test device of a cable insulating dumbbell test piece includes an experimental device, providing n tensiler in the experimental device;
[0116] N cameras are provided outside the experimental device for capturing an image of N test pieces; Figure 10 As shown, two light light light, the light source position, the height, and the irradiation angle must be fine-tuned, and the bracket remains adjustable. The adjustment picture finally causes the imaging picture light to be uniform. Visual According to the markings of the draw, scan the distance between the two markers lines, and process the result to transfer to the PLC via Modbus-TCP.
[0117] It also includes a display screen and a control host for performing a tensile test method, and displays the test in the display screen.
