A method for measuring the bending amount of carcass cords in an all-steel radial tire.

Abstract

This invention discloses a method for measuring the bending amount of tire carcass cords in all-steel radial tires. The method includes cutting the tire into a flat cross-section and establishing a global coordinate reference; removing the inner liner to obtain the complete tire carcass cords, connecting the front and back marking points to form a measurement reference line, and establishing a spatial coordinate system; accurately mapping the three-dimensional cord morphology into a two-dimensional planar imprint, and generating a standardized measurement data source through transfer and fixation; based on the planar imprint, obtaining the bending amount of the tire carcass cords through geometric modeling and trigonometric function calculations, and then calculating the bending degree, converting it into a non-destructive quantitative analysis and engineering parameter output of cord deformation. This invention, through standardized cross-section cutting, symmetrical marking, non-destructive peeling of the inner liner, and carbon powder planar imprinting technology, combined with geometric modeling and trigonometric function calculations, realizes the measurement of the bending amount and bending degree of tire carcass cords, providing quantitative data support.

Description

Technical Field

[0001] This invention relates to the field of tire carcass design technology, and in particular to a method for measuring the bending amount of cords in an all-steel radial tire carcass. Background Technology

[0002] In the early stages of developing all-steel radial tires, a comprehensive evaluation of the product's cross-sectional quality and performance is necessary. The curvature of the tire carcass cords directly affects not only cross-sectional quality (such as the carcass wrap-around height) but also high-speed and durability performance. Therefore, understanding the cord curvature is crucial in the initial stages of product development. However, if the measured cord curvature does not accurately represent the actual curvature, it can mislead the direction of product improvement or even mask product problems, leading to more serious quality issues in the market and damaging brand reputation.

[0003] Currently, there is no complete method in the industry for accurately measuring the amount and degree of bending of the cords in all-steel radial tires. X-ray inspection is commonly used to determine whether the cords are bent. While X-ray inspection technology is relatively mature, its main function is to detect the overall circumference of the product's open cords and the presence of air bubbles. For cord bending, it can only determine whether the cords are bent and the approximate number of bent cords, but cannot accurately calculate the bending value. Furthermore, in actual testing, discrepancies often arise due to equipment imaging issues and the experience of the inspectors. Secondly, the original imprint measurement method commonly used by tire manufacturers does not consider the inherent differences in each cord after transferring the actual curved cross-section to a flat surface. This means that measuring different cords on the cross-section using the original imprint measurement method will yield different results. However, in the early stages of product development, it is necessary to accurately determine the cord bending value and adjust the design based on the bending situation.

[0004] The shortcomings of existing technologies lie in the fact that one of the current methods for determining whether the cords of all-steel radial tires are bent is X-ray inspection. X-ray images are played on a monitor at a certain speed, and inspectors visually assess the bending of the product's cords. If further assessment is needed, the X-ray images must be printed out, the highest and lowest points of the cord bending on the image must be found, a horizontal straight line is drawn through the two points, and the number of cords between the two lines is calculated. The output result is the number of bent cords. However, this method cannot accurately calculate the value of the cord bending or the degree of bending. Furthermore, during the X-ray inspection and assessment process, misjudgments are often made due to equipment imaging problems (such as image distortion and uneven image brightness) and the experience of the assessors, causing difficulties in the product development process.

[0005] Another commonly used method is the original rubbing measurement method. The measurement process is as follows: the inner lining of the cross-section is removed, and a certain width of rubbing paper is cut to rub the direction of the cord in the cross-section. A complete cord is randomly selected on the rubbing, and the intersections of the two ends of the cord with the measurement start and end lines are connected to form a measurement baseline. The maximum vertical distance between the cord and the baseline is the cord bending amount. After measuring the maximum bending amount, the cord bending degree is calculated. This method will result in different measurement results depending on the location of the selected cord; that is, different cords selected on the same cross-section will yield inconsistent measurement results. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology. To achieve the above objective, a method for measuring the bending amount of the carcass cords of an all-steel radial tire is adopted to solve the problems mentioned in the background technology.

[0007] A method for measuring the bending amount of the carcass cords in an all-steel radial tire includes the following steps:

[0008] Step S1: Cut the tire to be tested into a flat cross-section according to the standard thickness, and establish a global coordinate reference by combining symmetry marking technology;

[0009] Step S2: Remove the inner liner layer using non-destructive stripping technology to obtain the complete tire carcass cord, and connect the front and back marking points using physical or optical methods to form a measurement baseline and establish a spatial coordinate system;

[0010] Step S3: Using toner to enhance contrast and the tension-free adhesion technology of adhesive printing paper, the three-dimensional cord morphology is accurately mapped into a two-dimensional planar printing image, and a standardized measurement data source is generated by transfer and fixation.

[0011] Step S4: Based on the planar imprint, the bending amount of the tire cord is obtained through geometric modeling and trigonometric function calculation. The bending degree is then calculated and converted into non-destructive quantitative analysis and engineering parameter output of cord deformation.

[0012] As a further aspect of the present invention, the specific steps in step S1 include:

[0013] Step S11: Use precision cutting equipment to cut the tire into sections according to a preset thickness to ensure the cross-section is flat;

[0014] Step S12: Remove cutting burrs by mechanical or manual grinding to make the material boundaries of the tire carcass cords and inner liner clear, for use in confirming the marked measurement points;

[0015] Step S13: Mark the start and end points of the measurement on the front and back bead areas of the cross-section respectively, and use the coordinate positioning tool to confirm that the front and back marking points are symmetrical, so as to establish the baseline.

[0016] As a further aspect of the present invention, the specific steps in step S2 include:

[0017] Step S21: Use a special tool to remove the inner liner layer on the inside of the cross section, leaving only the exposed tire cords;

[0018] Step S22: Connect the front and back marking points into a straight line by physical scribing or laser projection to form the upper and lower mold measurement baseline, which is used to establish a spatial coordinate system.

[0019] As a further aspect of the present invention, the specific steps in step S3 include:

[0020] Step S31: Evenly cover the surface of the tire cord with carbon powder to enhance the contrast of the cord outline by utilizing the adhesion of carbon powder.

[0021] Step S32: Attach the printing paper with an adhesive coating to the inside of the cross-section without tension along the baseline, and use a rolling tool to make the paper surface and the cord in close contact, so as to achieve accurate mapping of the three-dimensional cord to the planar image.

[0022] Step S33: Peel off the rubbing paper and lay it flat on white paper, re-mark the baseline, generate a two-dimensional rubbing map consistent with the actual object, and obtain a planar rubbing map, which is a standardized data source for planar measurement.

[0023] As a further aspect of the present invention, the specific steps in step S4 include:

[0024] Step S41: Select the symmetrical cords at the top and bottom of the rubbing, and connect their intersections with the baseline to form two measurement baselines, which serve as a reference frame for calculating the bending amount.

[0025] Step S42: Locate the midpoint of the maximum bend of the cord and the midpoint of the baseline, measure the vertical distance between them, and obtain the cord bend value β, which is used to quantify the degree of cord center offset.

[0026] Step S43: Construct a right triangle with the cord bending amount β as the right side and the baseline length. Calculate the bending degree α using the arctangent function to accurately characterize the cord deformation angle.

[0027] Compared with the prior art, the present invention has the following technical advantages:

[0028] By adopting the above technical solution, and employing a complete process including standardized cross-sectional cutting, symmetrical marking on both sides, non-destructive peeling of the inner liner to expose the tire carcass cords, toner-enhanced contrast rubbing, and geometric modeling, accurate and non-destructive measurement of tire cord bending deformation is achieved. The method of using the offset of the center of two symmetrical cords to accurately measure the amount and degree of cord bending solves the problems of X-ray detection's inability to calculate the specific bending value and degree of bending, as well as the inaccuracy of the original rubbing measurement method. Attached Figure Description

[0029] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings:

[0030] Figure 1 This is a schematic diagram of the steps of the cord bending measurement method according to an embodiment of this application;

[0031] Figure 2 This is a flowchart of a method for measuring cord bending according to an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the front and back bead structure of an embodiment disclosed in this application;

[0033] Figure 4 This is a schematic diagram of the start and end lines of the upper and lower molds in an embodiment of this application;

[0034] Figure 5 This is a schematic diagram of the upper and lower mold measurement reference lines according to an embodiment of this application;

[0035] Figure 6 This is a schematic diagram showing the position of maximum bending of the cord in an embodiment of this application. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please refer to Figure 1 and Figure 2 In this embodiment of the invention, a method for measuring the bending amount of the carcass cords in an all-steel radial tire includes:

[0038] Step S1: Cut the tire to be tested into a flat cross-section according to the standard thickness, and establish a global coordinate reference using symmetrical marking technology. The specific steps include:

[0039] Step S11: Use precision cutting equipment to cut the tire into sections according to a preset thickness to ensure the cross-section is flat;

[0040] Step S12: Remove cutting burrs by mechanical or manual grinding to make the material boundaries of the tire carcass cords and inner liner clear, for use in confirming the marked measurement points;

[0041] Step S13: Mark the start and end points of the measurement on the front and back bead areas of the cross-section respectively, and use the coordinate positioning tool to confirm that the front and back marking points are symmetrical, so as to establish the baseline.

[0042] In the specific implementation steps, such as Figure 3 As shown in the figure, the diagram is a schematic diagram of the front and back of the tire bead structure. According to the standard requirements, the tire is cut into a cross section of a certain thickness. The front and back of the cross section are polished so that the start and end points of each component material are clearly visible. The start and end points A and B of the upper and lower mold measurement are accurately marked on the front of the cross section in the bead area. The start and end points a and b of the upper and lower mold measurement are marked at the corresponding positions on the back of the cross section in the bead area.

[0043] Step S2: The inner liner layer is removed using a non-destructive stripping technique to obtain the complete tire carcass cords. The front and back marking points are then connected using physical or optical methods to form a measurement baseline, establishing a spatial coordinate system. The specific steps include:

[0044] Step S21: Use a special tool to remove the inner liner layer on the inside of the cross section, leaving only the exposed tire cords;

[0045] Step S22: Connect the front and back marking points into a straight line by physical scribing or laser projection to form the upper and lower mold measurement baseline, which is used to establish a spatial coordinate system.

[0046] In this embodiment, as Figure 4 As shown in the diagram, this is a schematic diagram of the start and end lines of the upper and lower molds. In the diagram, the inner liner layer on the inside of the cross-section is removed, so that the tire cords are completely exposed. Aa and Bb are connected respectively to form the measurement start and end lines on the upper and lower molds.

[0047] Step S3: Utilizing toner to enhance contrast and the tension-free adhesion technology of adhesive printing paper, the three-dimensional cord morphology is accurately mapped into a two-dimensional planar printing image, and a standardized measurement data source is generated through transfer and fixation. The specific steps include:

[0048] Step S31: Evenly cover the surface of the tire cord with carbon powder to enhance the contrast of the cord outline by utilizing the adhesion of carbon powder.

[0049] Step S32: Attach the printing paper with an adhesive coating to the inside of the cross-section without tension along the baseline, and use a rolling tool to make the paper surface and the cord in close contact, so as to achieve accurate mapping of the three-dimensional cord to the planar image.

[0050] Step S33: Peel off the rubbing paper and lay it flat on white paper, re-mark the baseline, generate a two-dimensional rubbing map consistent with the actual object, and obtain a planar rubbing map, which is a standardized data source for planar measurement.

[0051] In this embodiment, a soft brush is used to apply an appropriate amount of toner evenly to the exposed cord of the substrate. A tracing paper with one adhesive side down is then attached to the toner-coated cord along the starting line of the mold on the cross-section. The tracing paper should not be stretched or folded during attachment, and it should completely cover the thickness and width of the cross-section. An auxiliary tool is used to press the tracing paper firmly onto the cord to ensure full contact and clear replication of the direction of each cord on the tracing paper. After completing these steps, the tracing paper is carefully peeled off and transferred, then flattened onto pre-prepared white paper. The positions of the upper and lower molds are marked. The starting and ending lines of the upper and lower molds are then clearly redrawn to obtain a tracing image consistent with the cord direction of the product.

[0052] like Figure 5 As shown, the diagram illustrates the measurement baselines for the upper and lower molds. The bending amount β and bending degree α are measured on the transferred rubbing. Two complete symmetrical cords from the top and bottom of the rubbing are taken, and their intersections with the start and end lines of the upper and lower molds are connected to form two measurement baselines.

[0053] In this step, only the two complete symmetrical cords at the top and bottom of the printing plate are selected as examples for illustration. In actual operation, other sets of symmetrical cords can also be selected for printing. After verification, the measurement results of other sets of symmetrical cords selected for printing are the same according to this technical solution, which also shows that this technical solution is not affected by the selection of cords and can accurately measure the actual bending of the cords on the printing plate.

[0054] Step S4: Based on the planar imprint, the bending amount of the tire cord is obtained through geometric modeling and trigonometric function calculations. The bending degree is then calculated and converted into non-destructive quantitative analysis and engineering parameter output for cord deformation. The specific steps include:

[0055] Step S41: Select the symmetrical cords at the top and bottom of the rubbing, and connect their intersections with the baseline to form two measurement baselines, which serve as a reference frame for calculating the bending amount.

[0056] Step S42: Locate the midpoint of the maximum bend of the cord and the midpoint of the baseline, measure the vertical distance between them, and obtain the cord bend value β, which is used to quantify the degree of cord center offset.

[0057] Step S43: Construct a right triangle with the cord bending amount β as the right side and the baseline length. Calculate the bending degree α using the arctangent function to accurately characterize the cord deformation angle.

[0058] In this embodiment, as Figure 6The diagram illustrates the location of maximum cord bending. Locate the location of maximum cord bending, and at this location, find the midpoint c of the cord and the midpoint d of the two baselines. The distance between c and d is called the "cord center offset," or the bending amount β. Using β as one right-angled side, draw horizontal lines upwards and downwards to construct right-angled triangles. Calculate the bending degree α of the upper and lower molds using these triangles. 上 and α 下 ;

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents, all of which should be included within the scope of protection of the invention.

Claims

1. A method for measuring the bending amount of the carcass cords in an all-steel radial tire, characterized in that, Includes the following steps: Step S1: Cut the tire to be tested into a flat cross-section according to the standard thickness, and establish a global coordinate reference by combining symmetry marking technology; Step S2: Remove the inner liner layer using non-destructive stripping technology to obtain the complete tire carcass cord, and connect the front and back marking points using physical or optical methods to form a measurement baseline and establish a spatial coordinate system; Step S3: Using toner to enhance contrast and the tension-free adhesion technology of adhesive printing paper, the three-dimensional cord morphology is accurately mapped into a two-dimensional planar printing image, and a standardized measurement data source is generated by transfer and fixation. Step S4: Based on the planar imprint, the bending amount of the tire cord is obtained through geometric modeling and trigonometric function calculation. The bending degree is then calculated and converted into non-destructive quantitative analysis and engineering parameter output for cord deformation. The specific steps include: Step S41: Select the symmetrical cords at the top and bottom of the rubbing, and connect their intersections with the baseline to form two measurement baselines, which serve as a reference frame for calculating the bending amount. Step S42: Locate the midpoint of the maximum bend of the cord and the midpoint of the baseline, measure the vertical distance between them, and obtain the cord bend value β, which is used to quantify the degree of cord center offset. Step S43: Construct a right triangle with the cord bending amount β as the right side and the baseline length. Calculate the bending degree α using the arctangent function to accurately characterize the cord deformation angle.

2. The method for measuring the bending amount of the carcass cords in an all-steel radial tire according to claim 1, characterized in that, The specific steps in step S1 include: Step S11: Use precision cutting equipment to cut the tire into sections according to a preset thickness to ensure the cross-section is flat; Step S12: Remove cutting burrs by mechanical or manual grinding to make the material boundaries of the tire carcass cords and inner liner clear, for use in confirming the marked measurement points; Step S13: Mark the start and end points of the measurement on the front and back bead areas of the cross-section respectively, and use the coordinate positioning tool to confirm that the front and back marking points are symmetrical, so as to establish the baseline.

3. The method for measuring the bending amount of the carcass cords in an all-steel radial tire according to claim 1, characterized in that, The specific steps in step S2 include: Step S21: Use a special tool to remove the inner liner layer on the inside of the cross section, leaving only the exposed tire cords; Step S22: Connect the front and back marking points into a straight line by physical scribing or laser projection to form the upper and lower mold measurement baseline, which is used to establish a spatial coordinate system.

4. The method for measuring the bending amount of the carcass cords in an all-steel radial tire according to claim 1, characterized in that, The specific steps in step S3 include: Step S31: Evenly cover the surface of the tire cord with carbon powder to enhance the contrast of the cord outline by utilizing the adhesion of carbon powder. Step S32: Attach the printing paper with an adhesive coating to the inside of the cross-section without tension along the baseline, and use a rolling tool to make the paper surface and the cord in close contact, so as to achieve accurate mapping of the three-dimensional cord to the planar image. Step S33: Peel off the rubbing paper and lay it flat on white paper, re-mark the baseline, generate a two-dimensional rubbing map consistent with the actual object, and obtain a planar rubbing map, which is a standardized data source for planar measurement.

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