Defect detection method and equipment for copper rod blank

Abstract

The invention relates to the technical field of copper rod blank detection, in particular to a defect detection method and device for a copper rod blank, and the method comprises the following steps: S10, formulating a quality grade table of the copper rod blank; the copper rod blank is placed on a conveying roller way, and the conveying roller way is started; s20, the speed of a conveying roller way is adjusted, and when the copper rod blank is driven to move to the position in front of a detection area in the conveying direction, an electromagnetic rotation driving device and an electromagnetic induction detection module are started; s30, a second control unit and a second current regulator are used for controlling starting of a second electromagnetic coil, an electromagnetic sensor detects a defect signal, induced voltage is calculated, and defect information of the copper rod blank is collected; s40, calculating an intensity factor X1, a damage degree factor X2 and an influence degree factor X3 according to the defect information; the defect fraction Q of the copper rod blank is calculated according to the formula Q = W1 * X1 + W3 * X2 + W3 * X3; and rating the copper rod blank corresponding to the quality grade table. The method effectively reduces the omission ratio of the defects of the copper rod blank, and accurately recognizes the internal defects.

Description

Technical Field

[0001] The invention relates to the technical field of copper rod blank detection, and in particular to a defect detection method and equipment for copper rod blanks. Background Art

[0002] At present, copper rod billets, as metal materials with excellent conductive properties, are widely used as raw materials in the fields of cables, power facilities, etc.; however, during the production process, copper rod billets are prone to internal cracks, pores, inclusions and surface scratches due to raw material defects, poor processing technology or external environmental factors. These defects will not only affect the yield of subsequent processing, but may also cause the performance of the final product to deteriorate or even fail.

[0003] Existing copper rod blank defect detection methods mainly rely on manual visual inspection or simple mechanical inspection. Especially for short copper rod blanks, manual inspection requires checking each rod one by one, which is cumbersome and difficult to meet the needs of mass production. It is also impossible to evaluate the comprehensive defect impact of each copper rod blank. Traditional mechanical inspection cannot accurately identify tiny internal defects. Some mechanical inspections not only cause damage to the copper rod blank, but are also prone to omissions. It lacks intelligent analysis and automatic processing of defect information and cannot support automated operations of the production line.

[0004] Therefore, there is an urgent need for a method and equipment that can effectively detect defects in short copper rod blanks. Summary of the invention

[0005] The present invention provides a defect detection method and device for a copper rod blank, which can effectively detect defects in the copper rod blank, effectively reduce the defect missed detection rate, and accurately identify tiny defects inside the copper rod blank.

[0006] The present invention provides a defect detection method for a copper rod blank, comprising the following steps:

[0007] S10: Formulate a quality grade table for copper rod blanks; prepare the copper rod blanks to be tested, and start conveying the copper rod blanks;

[0008] S20: adjusting the conveying speed, driving the copper rod blank to move along the conveying direction to the detection area, rotating the copper rod blank at a certain speed and starting to detect defects of the copper rod blank;

[0009] S30: turning on the induction magnetic field, using the induction coil to detect the defect signal of the copper rod blank in real time, calculating the induced voltage and collecting the defect information of the copper rod blank;

[0010] S40: Calculate the density factor X1, the destructive factor X2, and the influence factor X3 according to the defect information; calculate the defect score Q=W1·X1+W3·X2+W3·X3 of the copper rod blank, where W1, W2, and W3 are weight coefficients; and grade the copper rod blank according to the quality grade table.

[0011] Furthermore, in step S30, the specific calculation of the induced voltage is:

[0012] The detection time t starts from 0 when the copper rod billet enters the induction coil;

[0013] Induced voltage V(t) = -N [dΦ(t) / dt];

[0014] Wherein, N is the number of turns of the induction coil; the magnetic flux Φ(t) at time t = B(t)·A, B(t) is the magnetic induction intensity at time t, and A is the cross-sectional area of ​​the induction coil.

[0015] Furthermore, in step S30, the defect information specifically includes:

[0016] Assume that n defects are detected in total, and the defects are numbered 1, 2, ... n in the order of detection;

[0017] Calculate the defect depth dn=k1·ΔVn and defect length ln=v·ΔTn of the defect at the nth position;

[0018] Among them, k1 is the depth coefficient; ΔVn is the extreme difference of the induced voltage when the defect is at the nth position; v is the transmission speed of the copper rod blank; ΔTn is the duration of the defect at the nth position.

[0019] Furthermore, in step S30, the defect information also includes the defect quantity Nd:

[0020] statistics

[0021] Among them, Detect is the judgment function; ΔV i is the extreme difference of the induced voltage at the i-th defect; Δt i is the time interval between the i-th defect and the i-1-th defect.

[0022] Furthermore, in step S30, the judgment function Detect is specifically:

[0023] Construction

[0024] Among them, V t is the set voltage change threshold, which is a constant; t min It is the minimum interval time between two sensing signals.

[0025] Furthermore, in step S40, the density factor X1, the destructive factor X2, and the influence factor X3 are specifically calculated as follows:

[0026] Density factor X1 = Nd / L; Destruction factor Influence factor X3 = (l1 + ... ln) / L;

[0027] The specific calculation method of the defect score Q is updated as follows:

[0028]

[0029] Wherein, L is the total length of the copper rod blank; is the diameter of the copper rod blank.

[0030] Furthermore, step S40 also includes storing the defect information, defect score and defect grade of the copper rod blank and generating a test report; and classifying and storing copper rod blanks of different grades.

[0031] The present invention also provides a defect detection device for a copper rod blank, which is used in the above-mentioned defect detection method for a copper rod blank, comprising:

[0032] A transmission rack, mounted on the ground;

[0033] The transmission roller is arranged on the transmission frame and used for conveying the copper rod blank to be tested; a plurality of semi-circular support claws are arranged at intervals on the transmission roller; the support claws are opened upward, and the lowest inner wall viewed from the horizontal direction is flush with the upper end surface of the transmission roller, and are used for supporting the copper rod blank; a detection area is arranged in the middle section of the transmission roller;

[0034] An electromagnetic rotation drive device is provided at each end of the detection area along the conveying direction of the conveying roller, and is connected to the conveying frame; the electromagnetic rotation drive device comprises a first electromagnetic coil, a first current regulator and a first control unit;

[0035] The first electromagnetic coil is in a circular shape, with its opening facing the transport direction of the conveying roller, and the lowest end of the first electromagnetic coil is lower than the conveying roller, and the inner wall diameter of the first electromagnetic coil is larger than the diameter of the copper rod blank;

[0036] The first current regulator is connected to the first electromagnetic coil, and the first control unit is installed on one side of the first electromagnetic coil to control the rotation of the copper rod blank;

[0037] The electromagnetic induction detection module is installed in the detection area, connected to the transmission frame, and located above the transmission roller table, and is used to detect internal and surface defects of the copper rod blank.

[0038] Furthermore, the electromagnetic induction detection module includes a second electromagnetic coil, an electromagnetic sensor, a second current regulator and a second control unit; the second electromagnetic coil is coaxial with the supporting claw and fixedly connected to the transmission frame; the electromagnetic sensor is arranged on one side of the second electromagnetic coil and connected to the transmission frame; the second current regulator is connected to the second electromagnetic coil, and the second control unit is installed on one side of the second electromagnetic coil for controlling the second electromagnetic coil.

[0039] Furthermore, the electromagnetic sensor includes a plurality of independent induction coils which are arranged in a spiral manner at different positions around the axis of the copper rod blank along the transmission direction of the transmission roller, and the spiral direction is opposite to the rotation direction of the copper rod blank.

[0040] The method and device of the present invention can achieve the following technical effects:

[0041] By using two electromagnetic rotary drive devices to drive the rotation of the copper rod blank to be tested, and cooperating with the electromagnetic induction detection module to detect the copper rod blank, it is beneficial to achieve non-destructive and efficient detection of the copper rod blank during the transmission process; the spirally distributed electromagnetic sensors can detect the defects of the copper rod blank more comprehensively and reduce the possibility of missing defects; by calculating the defect depth, length and number of the copper rod blank and grading it according to the quality grade, it is beneficial to improve the reliability of the detection results and improve the detection accuracy of tiny defects inside the copper rod blank. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 A flow chart of the steps of a defect detection method for a copper rod blank in the present invention;

[0044] Figure 2 It is a structural schematic diagram of a defect detection device for copper rod blanks in the present invention;

[0045] Figure numerals: 1. Transmission frame; 2. Transmission roller; 21. Support claw; 22. Detection area; 3. Electromagnetic rotation drive device; 31. First electromagnetic coil; 4. Electromagnetic induction detection module; 41. Second electromagnetic coil; 42. Electromagnetic sensor; 421. Induction coil. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0047] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by “center”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”, “inside” and “outside”, etc., are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] A defect detection method for copper rod blanks, such as Figure 1 As shown, the following steps are included:

[0050] S10: Formulate a quality grade table for copper rod blanks; prepare the copper rod blanks to be tested and place them on the support claws 21 at one end of the starting point of the conveying roller 2, and start conveying the copper rod blanks using the conveying roller 2;

[0051] S20: adjusting the conveying speed by adjusting the speed of the conveying roller 2, and driving the copper rod blank to move along the conveying direction to the area to be tested, i.e., the front of the detection area 22, using the electromagnetic rotation drive device 3 to start rotating the copper rod blank at a certain speed, and using the electromagnetic induction detection module 4 to start detecting defects of the copper rod blank;

[0052] S30: using the second control unit and the second current regulator to control the start of the second electromagnetic coil 41 to control the start of the induction magnetic field, using the electromagnetic sensor 42 to detect the defect signal of the copper rod blank, calculating the induced voltage and collecting the defect information of the copper rod blank;

[0053] S40: Calculate the density factor X1, the destructive factor X2, and the influence factor X3 according to the defect information; calculate the defect score Q=W1·X1+W3·X2+W3·X3 of the copper rod blank, where W1, W2, and W3 are artificially set weight coefficients and are constants; and grade the copper rod blank according to the quality grade table.

[0054] The specific working principle of the present invention is as follows:

[0055] With reference to industry standards or specifications, combined with the different uses of copper rod billets, targeted statistics and analysis of large-scale inspection data are conducted to develop a quality registration form for copper rod billets.

[0056] After the copper rod blank to be tested is prepared, it is placed on the supporting claws 21 of the conveying roller 2 and the copper rod blank begins to be conveyed; the semi-annular supporting claws 21 are opened upward, and the inner diameter of the ring is slightly larger than the outer diameter of the copper rod blank, so that the copper rod blank can move forward along the straight line formed by the spaced supporting claws 21 and will not roll arbitrarily on the conveying roller 2.

[0057] The speed of conveying the copper rod blank is adjusted to drive the copper rod blank to move to the detection area along the transmission direction. Electromagnetic rotation driving devices 3 are set at both ends of the detection area 22. A uniform rotating magnetic field is generated on the surface of the copper rod blank by the first electromagnetic coil 31 in the electromagnetic rotation driving device 3, thereby driving the copper rod blank to rotate at a certain speed after being subjected to force; and after the entire copper rod blank enters the detection area 22, it can rotate as the transmission roller 2 moves forward in the transmission direction, and the defects of the copper rod blank are detected by using the electromagnetic induction detection module 4, so that the entire surface of the copper rod blank can be detected in all directions without dead angles.

[0058] The second electromagnetic coil 41 in the electromagnetic induction detection module 4 is controlled to start the induced magnetic field, and the flow of internal current of the conductor, i.e., the copper rod blank in the present invention, is induced by the changing electromagnetic field, and the induced signals of the copper rod blank are collected in real time in cooperation with the multiple groups of induction coils 421 distributed in a spiral manner; specifically, when a metal object, such as a copper rod blank, is exposed to an alternating magnetic field, an induced current is generated inside it, and the magnitude and shape of these induced currents are directly related to the structural characteristics of the metal object (such as cracks, pores and other defects); by detecting the changes in these induced currents, the defects inside or on the surface of the metal object can be inferred; therefore, in the present invention, the defect signal is obtained by the change of the induced signal, so that the defect information inside and on the surface of the copper rod blank is obtained according to the defect signal, and then the change of the induced voltage is calculated, and the defect depth, position, length and other information are extracted through the formula, and the quality grade of the copper rod blank is evaluated according to the defect score.

[0059] After the inspection is completed, the equipment automatically sorts the copper rod billets according to the defect level and stores them by category. At the same time, it stores the inspection report to provide data support for production process optimization.

[0060] In some embodiments of the present invention, in step S30, the specific calculation of the induced voltage is:

[0061] The detection time t is measured from 0 when the copper rod blank enters the induction coil (421);

[0062] Induced voltage V(t) = -N [dΦ(t) / dt];

[0063] Wherein, N is the number of turns of the electromagnetic sensor 421; the magnetic flux Φ(t) at time t=B(t)·A, B(t) is the magnetic induction intensity at time t, and A is the cross-sectional area of ​​the electromagnetic sensor 421;

[0064] This formula uses the derivative of time t to describe the change of magnetic flux with time, and converts the change of magnetic flux Φ(t) into an induced voltage signal, reflecting the relationship between the disturbance of the magnetic field caused by defects in the copper rod billet and the induced signal, reducing the complex signal processing steps. It is suitable for real-time monitoring of dynamic defect signals of copper rod billets during transmission and rotation, and improves the accuracy and efficiency of detection. The change of magnetic induction intensity B(t) caused by the defect is directly reflected in the change of induced voltage V(t), which can accurately capture the weak magnetic field disturbance caused by the defect, and effectively improve the recognition accuracy of small defects such as small cracks and pores.

[0065] The number of turns N and the cross-sectional area A of the electromagnetic sensor 421 can also be adjusted to meet the detection requirements of copper rod blanks of different specifications; and through the combination of the electromagnetic sensor 421 and the voltage signal, the complex hardware equipment requirements in traditional mechanical or optical detection are avoided, while the detection speed is improved.

[0066] Preferably, in step S30, the defect information specifically includes:

[0067] Assume that n defects are detected in total, and the defects are numbered 1, 2, ... n in the order of detection;

[0068] Calculate the defect depth dn=k1·ΔVn and defect length ln=v·ΔTn of the defect at the nth position;

[0069] Among them, k1 is the depth coefficient; ΔVn is the extreme difference of the induced voltage when the defect is at the nth position; v is the transmission speed of the copper rod blank; ΔTn is the duration of the defect at the nth position.

[0070] The extreme difference of the induced voltage can reflect the depth information of the copper rod blank defect, which directly reflects the impact of the defect on the material integrity. The length of each defect is calculated by the duration ΔT of the defect signal at each location, and the spatial range of the defect can be determined in combination with the defect depth d.

[0071] In some embodiments of the present invention, the calculation of the defect position can be added: defect position x = v·T; wherein v is the transmission speed of the copper rod blank on the transmission roller 2; T is the time point when a defect signal is detected, reflecting the instantaneous position of the defect in the detection area 22; the time when the signal occurs can be mapped to the physical position of the copper rod blank only by the transmission speed v and the time T; with the defect position, the position of each defect can be accurately located, and targeted preparations can be made when repairing the equipment or processing the area where the defect is located; it can also be combined with the defect number Nd to assist in counting and avoid repeated counting of the defect number Nd.

[0072] In step S30, the defect information also includes the defect quantity Nd:

[0073] statistics

[0074] Among them, Detect is the judgment function; ΔV i is the extreme difference of the induced voltage at the i-th defect; Δt i is the time interval between the i-th defect and the i-1-th defect;

[0075] This formula traverses all sensing signals, counts the number of sampling points of all detected defect signals, selects the number of defect signals that meet the conditions, and then adds them up to obtain the number of defects Nd; it effectively avoids the problems of misjudgment and missed detection that occur in traditional statistical methods.

[0076] Preferably, in step S30, the judgment function Detect is specifically:

[0077] Construction

[0078] Among them, V t It is a man-made voltage change threshold, which is a constant; t min It is the minimum interval time between two sensing signals obtained after calculation, preferably calculated based on the transmission speed and detection resolution of the copper rod blank.

[0079] The advantage of designing this formula is that if an induction signal continues to exceed the threshold for a period of time, it is considered to be the same defect signal sampling point; when the signal returns to a state below the threshold and exceeds the threshold again, it is considered that a new defect signal sampling point is detected; however, in order to avoid repeated counting, the judgment of time is increased; when the voltage change ΔV of the induction signal exceeds the set threshold V t And the time interval Δt between the two sensing signals i More than t min When , it is counted as an independent defect signal; finally, after traversing all the sensing signals, the sensing signal that meets the conditions is recorded as the defect signal.

[0080] In some embodiments of the present invention, in step S40, the density factor X1, the destructive factor X2, and the influence factor X3 are specifically calculated as follows:

[0081] Density factor X1 = Nd / L; Destruction factor Influence factor X3 = (l1 + ... ln) / L;

[0082] The specific calculation method of the defect score Q is updated as follows:

[0083]

[0084] Wherein, L is the total length of the copper rod blank; is the diameter of the copper rod blank.

[0085] The calculation of the defect score Q links the number of defects Nd, defect depth d, defect length l and the total length L of the copper rod blank. The number of defects Nd represents the overall density of defects. The more defects, the worse the quality. The average value of all defect depths d on the entire copper rod blank reflects the degree of damage to the strength of the copper rod blank by the defects. The greater the depth, the more serious the defect. The average value of all defect lengths l on the entire copper rod blank describes the extension range of the defect. The greater the length, the larger the affected area of ​​the copper rod blank. The impact of all defects on the copper rod blank is comprehensively distributed to the entire copper rod blank, which solves the problem that traditional manual or single indicator evaluation cannot reflect the comprehensive impact of defects and quantifies the overall quality of the copper rod blank.

[0086] Step S40 also includes storing the defect information, defect score and defect grade of the copper rod blank and generating a test report, so as to facilitate historical comparison of the quality of different production batches and provide data support for process optimization; copper rod blanks of different grades are classified and stored, so that they are allocated to different processing flows or sales channels according to their grades, thereby improving product utilization and reducing the impact of defective products on overall production; such full-process detection and storage greatly improves detection efficiency and management capabilities.

[0087] The present invention also provides a defect detection device for copper rod blanks, such as Figure 2 As shown, including:

[0088] The transmission frame 1 is installed on the ground and can be connected with the production and subsequent processing of the copper rod blank to form a smooth and continuous automated production line, reducing the need for personnel; a power source can be set in the gap between the transmission frame 1 to provide power to the transmission roller 2;

[0089] The transmission roller 2 is arranged on the transmission frame 1 and is used to transport the copper rod blank to be tested; a plurality of semi-circular support claws 21 are arranged at intervals on the transmission roller 2; the support claws 21 are opened upward, and the lowest inner wall viewed from the horizontal direction is flush with the upper end surface of the transmission roller 2, and are used to support the copper rod blank, so that when the copper rod blank moves on the transmission roller 2, it will be restricted by the support claws 21 to move to both sides, helping the copper rod blank to rotate along a straight line in the support claws 21, and will not affect the movement of the copper rod blank along the transmission direction of the transmission roller 2; a detection area 22 is arranged in the middle section of the transmission roller 2;

[0090] The electromagnetic rotation drive device 3 is provided at each end of the detection area 22 along the transport direction of the transport roller 2 and is connected to the transport frame 1; the electromagnetic rotation drive device 3 includes a first electromagnetic coil 31, a first current regulator and a first control unit;

[0091] When the copper rod blank is in the magnetic field generated by the electromagnetic rotation drive device, when the magnetic field changes with time, eddy currents will be induced inside the copper rod blank. The eddy currents are generated by Faraday's law of electromagnetic induction, and the direction of the eddy currents is related to the direction of change of the magnetic field. The eddy currents will form a circular closed current inside the copper rod blank. These currents are acted upon by the Lorentz force in the magnetic field, generating a torque, thereby driving the copper rod blank to rotate.

[0092] The first electromagnetic coil 31 is in a circular shape, with its opening facing the transport direction of the conveying roller 2, and the lowest end of the first electromagnetic coil 31 is lower than the conveying roller 2, and the inner wall diameter of the first electromagnetic coil 31 is larger than the diameter of the copper rod blank;

[0093] The first current regulator is connected to the first electromagnetic coil 31, and the first control unit is installed on one side of the first electromagnetic coil 31 to control the rotation of the copper rod blank;

[0094] The electromagnetic induction detection module 4 is installed in the detection area 22, connected to the transmission frame 1, and located above the transmission roller 2, and is used to detect internal and surface defects of the copper rod blank.

[0095] Preferably, the electromagnetic induction detection module 4 includes a second electromagnetic coil 41, an electromagnetic sensor 42, a second current regulator and a second control unit. The electromagnetic induction module can accurately identify various defects such as internal cracks, pores and surface scratches of the copper rod blank by inducing the change in the magnetic field, realize non-destructive testing, and protect the integrity of the copper rod blank; the second electromagnetic coil 41 is coaxial with the support claw 21 and fixedly connected to the transmission frame 1 to generate a uniform and stable induced magnetic field, covering the entire surface of the copper rod blank, ensuring that the copper rod blank can be fully detected when rotating; the electromagnetic sensor 42 is arranged on one side of the second electromagnetic coil 41, and collects the magnetic field changes caused by internal or surface defects of the copper rod blank in real time, converts the induced signal into an electrical signal, reflects the depth, position and length of the defect, and is connected to the transmission frame 1, avoiding errors caused by equipment movement or vibration, and improving the reliability of the detection result; the second current regulator is connected to the second electromagnetic coil 41, and the second control unit is installed on one side of the second electromagnetic coil 41, which is used to control the second electromagnetic coil 41, and controls the induction intensity of the electromagnetic coil by dynamically adjusting the current size, adapting to copper rod blanks of different specifications, and ensuring the sensitivity and adaptability of the detection.

[0096] Preferably, the electromagnetic sensor 42 includes multiple groups of independent induction coils 421, which are spirally arranged at different positions around the axis of the copper rod blank along the transmission direction of the transmission roller 2, and the spiral direction is opposite to the rotation direction of the copper rod blank, which can form an alternating effect with the dynamic rotational movement of the copper rod blank. The axis of the induction coil 421 is parallel to the axis of the copper rod blank when it is transmitted on the transmission roller 2, which ensures that each induction coil 421 can cover different areas during the rotation of the copper rod blank, forming a comprehensive detection and avoiding repeated detection of the same defect; and the independent multiple groups of induction coils 421 can better adjust the angle and spacing, can flexibly adapt to copper rod blanks of different diameters and specifications, and enhance the adaptability of the equipment.

[0097] The above three coils have different functions and are also interrelated; the first electromagnetic coil 31 is responsible for driving the rotation of the copper rod to be tested, the second electromagnetic coil 41 is responsible for generating the detection magnetic field, and the induction coil 421 is responsible for signal acquisition; the three work together to realize an efficient, accurate and non-destructive defect detection system.

[0098] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A defect detection method for copper rod blanks, characterized in that: The steps include: S10: Formulate a quality grade table for copper rod blanks; prepare the copper rod blanks to be tested, and start conveying the copper rod blanks; S20: adjusting the conveying speed, driving the copper rod blank to move along the conveying direction to the detection area, rotating the copper rod blank at a certain speed and starting to detect defects of the copper rod blank; S30: turning on the induction magnetic field, using the induction coil (421) to detect the defect signal of the copper rod blank in real time, calculating the induced voltage and collecting the defect information of the copper rod blank; S40: Calculate the density factor X1, the destructive factor X2, and the influence factor X3 according to the defect information; calculate the defect score Q=W1·X1+W3·X2+W3·X3 of the copper rod blank, where W1, W2, and W3 are weight coefficients; and grade the copper rod blank according to the quality grade table.

2. The defect detection method for copper rod blank according to claim 1, characterized in that: In step S30, the specific calculation of the induced voltage is: The detection time t is measured from 0 when the copper rod blank enters the induction coil (421); Induced voltage V(t) = -N [dΦ(t) / dt]; Wherein, N is the number of turns of the induction coil (421); the magnetic flux Φ(t) at time t=B(t)·A, B(t) is the magnetic induction intensity at time t, and A is the cross-sectional area of ​​the induction coil (421).

3. The defect detection method for copper rod blank according to claim 2, characterized in that: In step S30, the defect information specifically includes: Assume that n defects are detected in total, and the defects are numbered 1, 2, ... n in the order of detection; Calculate the defect depth dn=k1·ΔVn and defect length ln=v·ΔTn of the defect at the nth position; Among them, k1 is the depth coefficient; ΔVn is the extreme difference of the induced voltage when the defect is at the nth position; v is the transmission speed of the copper rod blank; ΔTn is the duration of the defect at the nth position.

4. The defect detection method for copper rod blank according to claim 3, characterized in that: In step S30, the defect information also includes the defect quantity Nd: statistics Among them, Detect is the judgment function; ΔV i is the extreme difference of the induced voltage at the i-th defect; Δt i is the time interval between the i-th defect and the i-1-th defect.

5. The defect detection method for copper rod blank according to claim 4, characterized in that: In step S30, the judgment function Detect is specifically: Construction Among them, V t is the set voltage change threshold, which is a constant; t min It is the minimum interval time between two sensing signals.

6. The defect detection method for copper rod blank according to claim 4, characterized in that: In step S40, the density factor X1, the destructive factor X2, and the influence factor X3 are specifically calculated as follows: Density factor X1 = Nd / L; Destruction factor Influence factor X3 = (l1 + ... ln) / L; The specific calculation method of the defect score Q is updated as follows: Wherein, L is the total length of the copper rod blank; is the diameter of the copper rod blank.

7. The defect detection method for copper rod blank according to claim 1, characterized in that: Step S40 also includes storing the defect information, defect score and defect grade of the copper rod blank and generating a test report; and classifying and storing copper rod blanks of different grades.

8. A defect detection device for copper rod blanks, characterized in that: The defect detection method for a copper rod blank as claimed in any one of claims 1 to 7 comprises: A transmission frame (1) is installed on the ground; A conveying roller (2) is arranged on the conveying frame (1) and is used to convey the copper rod blank to be tested; a plurality of semi-circular supporting claws (21) are arranged at intervals on the conveying roller (2); the supporting claws (21) are opened upward, and the lowest inner wall viewed from the horizontal direction is flush with the upper end surface of the conveying roller (2), and are used to support the copper rod blank; a detection area (22) is arranged in the middle section of the conveying roller (2); An electromagnetic rotary drive device (3) is provided at each end of the detection area (22) along the transport direction of the transport roller (2) and is connected to the transport frame (1); the electromagnetic rotary drive device (3) comprises a first electromagnetic coil (31), a first current regulator and a first control unit; The first electromagnetic coil (31) is in a circular shape, with its opening facing the transport direction of the transport roller (2), and the lowest end of the first electromagnetic coil (31) is lower than the transport roller (2), and the inner wall diameter of the first electromagnetic coil (31) is greater than the diameter of the copper rod blank; The first current regulator is connected to the first electromagnetic coil (31), and the first control unit is installed on one side of the first electromagnetic coil (31) and is used to control the rotation of the copper rod blank; An electromagnetic induction detection module (4) is installed in the detection area (22), connected to the transmission frame (1), and located above the transmission roller (2), and is used to detect internal and surface defects of the copper rod blank.

9. The defect detection device for copper rod blank according to claim 8, characterized in that: The electromagnetic induction detection module (4) comprises a second electromagnetic coil (41), an electromagnetic sensor (42), a second current regulator and a second control unit; the second electromagnetic coil (41) is coaxial with the supporting claw (21) and is fixedly connected to the transmission frame (1); the electromagnetic sensor (42) is arranged on one side of the second electromagnetic coil (41) and is connected to the transmission frame (1); the second current regulator is connected to the second electromagnetic coil (41), and the second control unit is installed on one side of the second electromagnetic coil (41) and is used to control the second electromagnetic coil (41).

10. The defect detection device for copper rod blank according to claim 9, characterized in that: The electromagnetic sensor (42) comprises a plurality of independent induction coils (421) which are arranged in a spiral manner at different positions around the axis of the copper rod blank along the transmission direction of the transmission roller (2), and the spiral direction is opposite to the rotation direction of the copper rod blank.

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