Device and method for detecting circumferential rotation bending force of steel cord

Abstract

The invention discloses a device and a method for detecting circumferential rotation bending force of a steel cord. The device comprises a base; the rotary chuck is arranged on the base, can rotate and detachably fixes one end of the steel cord to be tested; the fixed sleeve is arranged on the base and is provided with a hole for accommodating the other end of the tested steel cord; a measuring element of the bending force detection sensor is mounted at the end of the rotary chuck or the end of the fixed sleeve; wherein one end of the tested steel cord is fixed on the rotary chuck, and the other end of the tested steel cord is bent when being arranged in the hole of the fixed sleeve. By measuring the bending force in the rotating process of the steel cord, the microscopic quality of the product can be detected, and the quality stability and consistency of the whole batch of products are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel cord detection, and in particular relates to a device and method for detecting the circumferential rotation bending force of a steel cord. Background Art

[0002] Steel cord, as the structural reinforcement material for rubber tires, has a significant impact on the radial tire's load-bearing capacity, handling, and service life. Before being used in tires, steel cord is extruded or calendered into a cord fabric. A cross-section of the fabric reveals dozens or even hundreds of identical steel cords arranged in a single layer. This requires consistent performance from each individual steel cord to maximize the tire's structural material and deliver superior performance.

[0003] Circumferential rotational bending force refers to the bending force curve generated when a steel cord is bent and rotated 360°. It can be used to detect circumferential quality defects in products, such as uneven circumferential bending force caused by subtle structural defects within the steel cord. These minor structural defects can occur during production due to bearing seizure in the straightener or excessive or insufficient pressure reduction, resulting in subtle structural variations in the steel cord's longitudinal cross-sections. These variations are difficult to detect using conventional diameter and profile projection measurements. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a device and method for detecting the circumferential rotation bending force of a steel cord. By measuring the bending force during the rotation of the steel cord, the microscopic quality of the product can be detected, thereby improving the quality stability and consistency of the entire batch of products.

[0005] To solve the above technical problems, the present invention is implemented by adopting the following solutions: The present invention provides a device for detecting the circumferential rotation bending force of a steel cord, comprising: base; A rotating chuck is provided on the base and is capable of rotating, and is detachably fixed to one end of the steel cord to be measured; A fixed sleeve is arranged on the base and has a hole to accommodate the other end of the steel cord to be measured; Bending force detection sensor, whose measuring element is installed on the rotating chuck end or the fixed sleeve end; Among them, one end of the steel cord to be tested is fixed in the rotating chuck and the other end is placed in the hole of the fixed sleeve, which is in a bent shape.

[0006] Furthermore, it also includes a bending force display, which is electrically connected to the bending force detection sensor.

[0007] Furthermore, the distance C between the rotating chuck and the fixed sleeve is 1.198×E×d / 1200, where E is the elastic modulus of the material and d is the diameter of the outer monofilament of the steel cord being tested.

[0008] Furthermore, the length of the measured steel cord is L=2.19C+28.

[0009] Furthermore, the diameter of the hole and the diameter of the steel cord being measured satisfy 0.5 mm ≤ D1 - D ≤ 5 mm, where D1 is the diameter of the hole and D is the diameter of the steel cord being measured.

[0010] Furthermore, the direction of the circumferential rotational bending force of the steel cord detected by the bending force detection sensor is that the measuring element points to the midpoint between the rotating chuck and the fixed sleeve.

[0011] The present invention also provides a method for detecting the circumferential rotation bending force of a steel cord, which is applied to the aforementioned circumferential rotation bending force detection device of a steel cord, comprising: Cut the steel cord to be tested into a length of L, fix one end of the steel cord to be tested on the rotating chuck and clamp it, rotate the rotating chuck at a set speed, and insert the other end of the steel cord to be tested into the hole of the fixed sleeve; Install the measuring element of the bending force detection sensor on the rotating chuck end or the fixed sleeve end; During the rotation of the rotary chuck, the bending force detection sensor records the continuous bending force value changes and forms a bending force and rotation angle change curve which is displayed on the bending force display; The quality of the tested steel cord is determined based on the bending force and rotation angle change curve.

[0012] Furthermore, the number of bending force peaks within a rotation angle of 0 to 360 degrees in the bending force and rotation angle variation curve is ≤ 2, and the angle difference between the two bending force peaks is 180 degrees; and the quality of the tested steel cord is determined based on the bending force and rotation angle variation curve, including: When the number of bending force peaks within the 360° rotation angle range exceeds 2, it is determined that the tested steel cord has internal structural defects; When the difference between the bending force peak value measured by the tested steel cord and the bending force peak value tested by the standard sample exceeds 5%, it is determined that the tested steel cord has internal structural defects. Beneficial effects

[0013] The present invention can detect the microscopic quality of products by measuring the bending force during the rotation of the steel cord, thereby improving the quality stability and consistency of the entire batch of products. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 1 is a schematic structural diagram of a device for detecting circumferential rotational bending force of a steel cord provided by an embodiment of the present invention; Figure 2 is a curve diagram of bending force and rotation angle variation in a standard sample test provided by an embodiment of the present invention; Figure 3 This is a curve diagram of bending force and rotation angle variation of a defective sample test provided by an embodiment of the present invention; Figure 4 This is a curve diagram of bending force and rotation angle variation of another defective sample test provided by an embodiment of the present invention; In the figure: 1. Rotating chuck; 2. Fixed sleeve; 3. Steel cord under test; 4. Bending force detection sensor; 5. Signal line; 6. Bending force display; 7. Button; 8. Bending force and rotation angle change curve. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Example 1

[0016] This embodiment provides a device for detecting the circumferential rotation bending force of a steel cord. Figure 1 As shown, it consists of a base, a rotating chuck 1, a fixed sleeve 2, a bending force detection sensor 4 and a bending force display 6; the rotating chuck 1 is arranged on the base and can rotate, and one end of the steel cord 3 to be measured can be detachably fixed, and the fixed sleeve 2 is arranged on the base and has a hole to accommodate the other end of the steel cord 3 to be measured. When one end of the steel cord 3 to be measured is fixed on the rotating chuck 1 and the other end is placed in the hole of the fixed sleeve 2, it is bent; the measuring element of the bending force detection sensor 4 is installed at the end of the rotating chuck 1 or the end of the fixed sleeve 2; the bending force display 6 is electrically connected to the bending force detection sensor 4 through a signal line 5, and the bending force display 6 displays the bending force and rotation angle change curve 8 of the steel cord 3 to be measured tested by the steel cord circumferential rotation bending force detection device, and the bending force display 6 is also provided with a button for control.

[0017] Furthermore, the distance between the rotating chuck 1 and the fixed sleeve 2 is C=1.198×E×d / 1200, and the length of the steel cord 3 under test during measurement is L=2.19C+28, where E is the elastic modulus of the material, and d is the diameter of the outer monofilament of the steel cord 3 under test.

[0018] Furthermore, the diameter of the hole and the diameter of the steel cord 3 to be measured satisfy 0.5 mm ≤ D1 - D ≤ 5 mm, preferably 0.2 mm ≤ D1 - D ≤ 2 mm, where D1 is the diameter of the hole and D is the diameter of the steel cord to be measured.

[0019] Furthermore, the direction of the circumferential rotational bending force of the steel cord detected by the bending force detection sensor 4 is that the measuring element points to the midpoint between the rotating chuck 1 and the fixed sleeve 2 . Example 2

[0020] This embodiment provides a method for detecting the circumferential rotational bending force of a steel cord, which is applied to the circumferential rotational bending force detection device of the steel cord described in Example 1. The specific steps are as follows: The steel cord sample 3 to be tested is cut into pieces of length L, and one end of the sample is fixed to the rotating chuck 1 and clamped with the chuck, which rotates slowly and steadily. The other end is inserted into the hole provided in the fixed sleeve 2. The measuring element of the bending force measurement sensor 4 can be installed at either the end of the rotating chuck 1 or the end of the fixed sleeve 2. During the rotation of the rotating chuck 1, the bending force measuring sensor 4 records the continuous change of the bending force value and forms a bending force and rotation angle change curve. The quality of the steel cord can be judged based on the formed bending force and rotation angle change curve; In this embodiment, the number of bending force peaks in the bending force and rotation angle variation curve within the rotation angle of 0 to 360 degrees is ≤ 2, and the angle difference between the two bending force peaks is 180 degrees (e.g. Figure 2 shown); In the bending force and rotation angle variation curve 8, when the number of bending force peaks within the 360° rotation angle range exceeds 2 (e.g. Figure 3 As shown), it is determined that the tested steel cord sample 3 has internal structural defects; further, when the bending force peak value obtained after the test of a new steel cord test sample differs by more than 5% from the bending force peak value of the standard test sample (as shown), Figure 4 As shown, F0 is the reference value of the bending force of the steel cord test sample after clamping in the equipment, F1 is the peak value of the rotational bending force of the standard sample of the product of this specification, and F2 is the peak value of the rotational bending force of the steel cord sample). It is also determined that the steel cord test sample has internal structural defects. Example 3

[0021] This embodiment uses the steel cord circumferential rotation bending force detection placement described in Example 1 and the steel cord circumferential rotation bending force detection method described in Example 2 to test and evaluate multiple samples: First, the length of the sample to be prepared is determined according to the structure of the sample. For example, for a cord with a 3+8×0.33ST structure, according to L=2.19C+28, C=1.198×E×d / 1200, E=200000 MPa, d=0.33 mm, and C=65.89 mm, the prepared sample length is L=172 mm. The test results are shown in Table 1: Table 1 Statistics of bending force and rotation angle curves of tested samples 3+8×0.33ST Standard Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Peak force CN 120 124 110 128 105 126 114 123 Peak number 2 3 2 2 2 2 2 2 Peak difference compared to standard sample % / 3.3% 8.3% 6.6% 12.5 5.0% 5.0% 2.5% The data in Table 1 show that during the measurement of the circumferential rotational bending force of sample 1, the number of bending force peaks in the bending force and rotation angle variation curve within a 360° rotation cycle exceeded 2, and the product quality of sample 1 did not meet the requirements of the standard sample; the bending force peak values ​​of samples 2, 3, and 4 were compared with the standard, and the deviation exceeded 5%, and all three products met the requirements of the standard sample; the number of peaks in the bending force and rotation angle variation curves of samples 5, 6, and 7 were all 2, and the deviation of the peak values ​​from the bending force peak values ​​of the standard did not exceed 5%. The consistency of the three samples was good, the product structure was tight and defect-free, and they passed the evaluation.

[0022] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A device for detecting the circumferential rotation bending force of a steel cord, characterized in that: include: base; A rotating chuck is provided on the base and is capable of rotating, and is detachably fixed to one end of the steel cord to be measured; A fixed sleeve is arranged on the base and has a hole to accommodate the other end of the steel cord to be measured; Bending force detection sensor, whose measuring element is installed on the rotating chuck end or the fixed sleeve end; Among them, one end of the steel cord to be tested is fixed in the rotating chuck and the other end is placed in the hole of the fixed sleeve, which is in a bent shape.

2. The steel cord circumferential rotation bending force detection device according to claim 1, characterized in that: It also includes a bending force display, which is electrically connected to the bending force detection sensor.

3. The steel cord circumferential rotation bending force detection device according to claim 1, characterized in that: The distance between the rotating chuck and the fixed sleeve is C=1.198×E×d / 1200, where E is the elastic modulus of the material and d is the diameter of the outer monofilament of the steel cord being tested.

4. The device for detecting the circumferential rotation bending force of a steel cord according to claim 3, characterized in that: The length of the steel cord under test is L=2.19C+28.

5. The steel cord circumferential rotation bending force detection device according to claim 1, characterized in that: The diameter of the hole and the diameter of the steel cord being measured satisfy 0.5mm≤D1-D≤5mm, where D1 is the diameter of the hole and D is the diameter of the steel cord being measured.

6. The device for detecting the circumferential rotation bending force of a steel cord according to claim 1, characterized in that: The direction of the circumferential rotational bending force of the steel cord detected by the bending force detection sensor is that the measuring element points to the midpoint between the rotating chuck and the fixed sleeve.

7. A method for detecting the circumferential rotation bending force of a steel cord, applied to the device for detecting the circumferential rotation bending force of a steel cord according to any one of claims 1 to 6, characterized in that: include: Cut the steel cord to be tested into a length of L, fix one end of the steel cord to be tested on the rotating chuck and clamp it, rotate the rotating chuck at a set speed, and insert the other end of the steel cord to be tested into the hole of the fixed sleeve; Install the measuring element of the bending force detection sensor on the rotating chuck end or the fixed sleeve end; During the rotation of the rotary chuck, the bending force detection sensor records the continuous bending force value changes and forms a bending force and rotation angle change curve which is displayed on the bending force display; The quality of the tested steel cord is determined based on the bending force and rotation angle change curve.

8. The method for detecting the circumferential rotation bending force of a steel cord according to claim 7, characterized in that: The number of bending force peaks within the 0-360° rotation angle in the bending force and rotation angle variation curve is ≤ 2, and the angle difference between the two bending force peaks is 180°; the quality of the tested steel cord is determined based on the bending force and rotation angle variation curve, including: When the number of bending force peaks within the 360° rotation angle range exceeds 2, it is determined that the tested steel cord has internal structural defects; When the difference between the bending force peak value measured by the tested steel cord and the bending force peak value tested by the standard sample exceeds 5%, it is determined that the tested steel cord has internal structural defects.

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