A copper over steel rod coated thickness measurement probe with centering function

Abstract

The application discloses a copper-coated steel rod cladding thickness measuring probe with centering function, which comprises a detection main body and a centering device, the centering device comprises a main shaft, the main shaft comprises an optical axis, left and right ball screw structures are arranged at the two ends of the optical axis respectively, the left ball screw structure comprises a left screw and a left nut arranged on the left screw, the right ball screw structure comprises a right screw and a right nut arranged on the right screw, the left screw and the right screw are connected with the optical axis through a shaft coupling, a sliding block sleeve is installed on the optical axis through a bearing, the detection main body is fixedly arranged on the sliding block sleeve, the centering device further comprises a clamping assembly and an upper guide rail assembly for limiting, and the detection main body can be centered to measure the copper-coated steel rod, and the influence of the factors such as the contact point position of the detection main body, the contact surface and the included angle between the surface of the rod on the detection precision due to the large curvature of the copper-coated steel rod in the prior art is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nondestructive testing, and particularly relates to a copper-coated steel rod cladding thickness measurement probe with centering function. BACKGROUND

[0002] The copper-coated steel rod is a kind of bimetallic composite material, which is a composite conductor formed by processing copper and steel through a certain process. The composite conductor has the characteristics of high strength, high elasticity, high thermal resistance and high magnetic conductivity of steel, and also has the good electrical conductivity and excellent corrosion resistance of copper, and is a high-quality grounding material. However, the copper-coated steel material with unqualified quality has a major safety hazard. If the cladding thickness is too thin, the cladding layer will be damaged or even lost due to bumps during transportation or installation, which will cause the copper-coated layer and the base carbon steel to be directly exposed to corrosive media, thereby inducing galvanic corrosion and causing rust and fracture in a very short time, which greatly reduces the service life of the material. Therefore, copper cladding thickness detection is a necessary link in power system engineering construction.

[0003] For cladding thickness detection, destructive detection methods such as chemical etching drop method or metallographic microscope thickness measurement method are often used. These methods not only damage the workpiece, but also can only individually check the product, which is slow and wasteful. There are also nondestructive testing methods such as infrared thermal imaging method, ultrasonic measurement method and eddy current detection method. However, these methods have many problems such as low measurement accuracy, high cost and low detection efficiency.

[0004] The electromagnetic method for measuring thickness has the advantages of simple operation, high detection accuracy for small thickness cladding and easy automation detection. However, in actual measurement, the contact point position of the probe, the angle between the contact surface and the rod surface and other factors have a great influence on the detection accuracy. The traditional magnetic method thickness gauge probe has the problems of low single-point contact detection accuracy and large influence of operator's skill on measurement accuracy. SUMMARY

[0005] The present application relates to the technical field of nondestructive testing, and particularly relates to a copper-coated steel rod cladding thickness measurement probe with centering function.

[0006] In order to achieve the above object, the technical scheme provided by the present application is as follows: a copper-coated steel rod cladding thickness measurement probe with centering function, comprising a detection main body composed of a thickness measurement sensor and a centering device for fixing the detection main body, the centering device comprises a main shaft, the main shaft comprises an optical axis, left and right ball screw structures are arranged at both ends of the optical axis, the left ball screw structure comprises a left screw and a left nut arranged on the left screw, the right ball screw structure comprises a right screw and a right nut arranged on the right screw, the left screw and the right screw are connected with the optical axis through a shaft coupling, a sliding block sleeve is mounted on the optical axis through a bearing, a detection main body for detecting the cladding thickness of the copper-coated steel rod is fixedly arranged on the sliding block sleeve, the centering device comprises a clamping assembly and an upper guide rail assembly for limiting, the upper guide rail assembly comprises a guide rail shaft, a guide rail support is fixedly arranged at the center position of the guide rail shaft, the guide rail support is fixedly connected with the sliding block sleeve, sliding blocks are arranged at both ends of the guide rail shaft, connecting rods are arranged on the sliding blocks, the connecting rods at both ends are connected with the left nut and the right nut respectively, the clamping assembly comprises clamping legs arranged on the left nut and the right nut, and a bullseye wheel is arranged on the clamping leg.

[0007] Preferably, the left ball screw structure and the right ball screw structure are left-right symmetrical about the sliding block sleeve, the vertical axes of the guide rail support, the sliding block sleeve and the detection main body are the same, the thread pitches of the left nut and the right nut are consistent, and the thread rotation directions of the left screw and the right screw are opposite.

[0008] Preferably, a rotating handle is arranged on the left screw.

[0009] Preferably, the detection main body is composed of a first coil and a second coil wound by two enameled wires, the magnetic cores of the first coil and the second coil are all ┏┒-shaped, the magnetic cores are made of iron-based amorphous alloy high magnetic permeability material, and the outside is sealed by using epoxy resin.

[0010] Preferably, the copper-coated steel rod comprises a steel rod inner core and a copper cladding layer, the first coil is arranged on the copper-coated steel rod in the parallel direction of the axis of the copper-coated steel rod, the two prongs of the magnetic core of the first coil respectively contact two points in the axial direction of the copper-coated steel rod, the second coil is fixed on the steel material same as the material of the steel rod inner core of the copper-coated steel rod, and the first coil and the second coil are connected into a differential bridge.

[0011] Preferably, the bullseye wheel comprises freely rotating balls, and the distance from the lower surface of the detection main body to the axis of the balls is 13 mm.

[0012] The present application has the following beneficial effects:

[0013] The application improves the detection sensitivity by detecting the first coil and the second coil and the copper-coated steel rod forming a closed magnetic circuit and the sensor based on the change of magnetic resistance; and limiting the upper rail assembly of the centering device, so that the left nut and the right nut on the left ball screw and the right ball screw drive the two sides of the clamping foot to start equal displacement in opposite directions, so that the detection body is centered to measure the copper-coated steel rod, avoiding the influence of the contact point position of the probe, the contact surface and the angle between the rod surface in the prior art due to the large curvature of the copper-coated steel rod on the detection accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0014] The drawings described herein are used to provide further understanding of the application, and form a part of the application. The illustrative embodiments of the application and their descriptions serve to explain the application, and do not constitute an improper limitation on the application.

[0015] Figure 1 The figure is a schematic diagram of the detection body structure of the application;

[0016] Figure 2 The figure is an assembly front view of the overall structure of the application;

[0017] Figure 3 The figure is an assembly front view of the upper rail assembly of the application;

[0018] Figure 4 The figure is an assembly front view of the main shaft part of the application;

[0019] Figure 5 The figure is an assembly front view of the clamping assembly connected to the detection body of the application;

[0020] Figure 6 The figure is a rail bracket detail view of the upper rail assembly of the application;

[0021] Figure 7 The figure is a detail view of the bull's eye wheel of the clamping assembly of the application;

[0022] Figure 8 The figure is a coupling detail view of the application;

[0023] Figure 9 The figure is a centering principle schematic diagram in the application.

[0024] Drawing legend:

[0025] 1- slider 2- rail bracket 3- rail shaft 4- slider sleeve 5- coupling 6- right nut 7- right screw 8- detection body 9- clamping foot 10- bull's eye wheel 11- rotating handle 12- left screw 13- left nut 14- connecting rod 15- first coil 16- second coil 17- copper coating layer 18- steel rod inner core 19- ball. DETAILED DESCRIPTION

[0026] The specific embodiments of the present application will be described in detail in this part, the preferred embodiments of the present application are shown in the drawings, the role of the drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and visually understand each technical feature and the overall technical solution of the present application, but it cannot be understood as a limitation on the scope of protection of the present application.

[0027] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by the above, below, front, back, left, right and the like, is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0028] In the description of the present application, several meanings are one or more, and the meaning of multiple is two or more, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If the first, second is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0029] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be understood broadly, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0030] Reference Figures 1-9In the preferred embodiment of the present application, a copper-coated steel rod cladding thickness measurement probe with centering function comprises a detection main body 8 composed of a thickness measurement sensor and a centering device for fixing the detection main body 8, the centering device can make the detection main body 8 be right above the axis of the copper-coated steel rod to be detected, the centering device comprises a main shaft, the main shaft comprises an optical axis, the left and right ends of the optical axis are respectively provided with a left ball screw structure and a right ball screw structure, the left ball screw structure comprises a left screw 12 and a left nut 13 arranged on the left screw 12, the right ball screw structure comprises a right screw 7 and a right nut 6 arranged on the right screw 7, the parameters of the left screw 12 and the right screw 7 are the same, the left screw 12 and the right screw 7 are connected with the optical axis through a shaft coupling 5, a sliding block sleeve 4 is arranged on the optical axis through a bearing, the bearing can make the sliding block sleeve 4 not rotate when the optical axis rotates, the detection main body 8 for detecting the cladding thickness of the copper-coated steel rod is fixedly arranged on the sliding block sleeve 4, the centering device comprises a clamping assembly and an upper guide rail assembly for limiting, the upper guide rail assembly comprises a guide rail shaft 3, a guide rail support 2 is fixedly arranged on the central position of the guide rail shaft 3, the guide rail support 2 is fixedly connected with the sliding block sleeve 4, the guide rail shaft 3 is provided with a sliding block 1 at the left and right ends, the sliding block 1 is provided with a connecting rod 14, the connecting rods 14 at the left and right ends are respectively connected with the left nut 13 and the right nut 6, the clamping assembly comprises clamping legs 9 arranged on the left nut 13 and the right nut 6, the clamping legs 9 are provided with bull's eye wheels 10, when the ball screw structure rotates, the left nut 13 and the right nut 6 drive the two clamping legs 9 to move linearly in opposite directions, and the copper-coated steel rod to be detected is clamped.

[0031] The first coil 15 and the second coil 16 in the detection main body 8 and the copper-coated steel rod form a closed magnetic circuit, and the sensor based on the change of magnetic resistance improves the detection sensitivity; and the upper guide rail assembly of the centering device is limited, so that the left nut 13 and the right nut 6 on the left ball screw and the right ball screw drive the clamping legs 9 on the two sides to start equal displacement at equidistant positions, so that the detection main body 8 is centered to measure the copper-coated steel rod, and the influence of the factors such as the position of the probe contact point, the contact surface and the angle between the surface of the rod on the detection accuracy due to the large curvature of the copper-coated steel rod in the prior art is avoided.

[0032] As the preferred embodiment of the present application, it can also have the following additional technical features:

[0033] In the embodiment, the left ball screw structure and the right ball screw structure are symmetrical about the sliding block sleeve 4, the vertical axes of the guide rail support 2, the sliding block sleeve 4 and the detection main body 8 are the same, the thread pitches of the left nut 13 and the right nut 6 are consistent, and the threads of the left screw 12 and the right screw 7 are opposite.

[0034] In the embodiment, the left nut 13 is provided with a rotating handle 11, when the rotating handle 11 rotates, the left nut 13 and the right nut 6 will move horizontally in the same straight line displacement.

[0035] In the embodiment, the detection main body 8 is composed of a first coil 15 and a second coil 16 which are both wound by two enameled wires, the magnetic cores of the first coil 15 and the second coil 16 are both in the shape of ┏┒, and the magnetic cores are made of iron-based amorphous alloy high permeability material and sealed by epoxy resin outside.

[0036] In the embodiment, the copper-coated steel rod includes a steel rod inner core 18 and a copper coating layer 17, the first coil 15 is placed on the copper-coated steel rod in the parallel direction of the axis of the copper-coated steel rod, the two contact pins of the magnetic core of the first coil 15 respectively contact two points in the axial direction of the copper-coated steel rod, and the second coil 16 is fixed on the steel material which is the same as the material of the steel rod inner core 18 of the copper-coated steel rod, the first coil 15 and the second coil 16 are connected into a differential bridge, such as Figure 1 .

[0037] In the embodiment, the bull's eye wheel 10 includes a freely rotating ball 19, the bull's eye wheel 10 moves with the left nut 13 and the right nut 6, the freely rotating ball 10 contacts the copper-coated steel rod, which ensures that the detection main body 8 can move smoothly in the clamping rotating state and is not easy to scratch the surface of the copper coating layer 17, the distance from the lower surface of the detection main body 8 to the axis of the ball 10 is 13 mm (greater than the maximum compatible measurement size), so that the diameter range of the copper-coated steel rod which can be compatible with the measurement is φ16-24 mm.

[0038] The detection method of the present application is as follows: the iron core of the detection main body 8 of the detection part is placed on the copper-coated steel rod in alignment, the rotating handle 11 is rotated to make the left screw rod 12, the optical axis and the right screw rod 7 rotate coaxially, the left nut 13 and the right nut 6 on the left screw rod 12 and the right screw rod 7 respectively approach the middle detection main body 8 along the threads of the left screw rod 12 and the right screw rod 7, and the upper guide rail assembly directly above the main shaft can limit the left nut 13 and the right nut 6, preventing the left nut 13 and the right nut 6 from generating circumferential motion. When the clamping assembly clamps the copper-coated steel rod, the copper-coated steel rod can be centered with the detection main body 8 on the sliding block sleeve 4, which reduces the influence of factors such as the position of the contact point of the detection main body 8, the contact surface and the angle between the rod surface on the detection accuracy due to the large curvature of the copper-coated steel rod, and then the bull's eye wheel 10 on the clamping leg 9 can be used to slide and detect the entire exposed part.

[0039] Specifically, as Figure 1As shown: The detection body 8 consists of two coils, a first coil 15 and a second coil 16, wound with enameled wire. The first coil 15 and the second coil 16 have identical structures, and the magnetic core material is a high-permeability amorphous alloy. The first coil 15 is used for measurement, and the second coil 16 is used to provide a comparison reference. The magnetic core contacts of the second coil 16 are in close contact with steel made of the same material as the inner core 18 of the steel rod. The magnetic circuit composition is: magnetic core - inner core 18 of the steel rod - magnetic core. During operation, the two magnetic heads of the magnetic core of the first coil 15 are in close contact with the copper-clad steel rod, and the contact line is parallel to the axis of the copper-clad steel rod. At this time, the magnetic circuit composition is: magnetic core - copper coating 17 - inner core 18 of the steel rod - copper coating 17 - magnetic core.

[0040] Based on the basic knowledge of magnetic circuits, the inductance of the coil is:

[0041]

[0042] Where: N - number of coil turns; R m Total magnetic reluctance of the magnetic circuit

[0043] Total magnetic reluctance of the first coil 15 magnetic circuit:

[0044]

[0045] l1—Total length of magnetic circuit in the core, l2—Length of magnetic circuit in the steel core, S3—Cross-sectional area of ​​magnetic flux in the copper layer, S1—Cross-sectional area of ​​the core, S2—Cross-sectional area of ​​magnetic flux in the steel core, μ1—Permeability of the core material, μ2—Permeability of the steel core material, μ3—Permeability of the copper layer, μ0=4π×10 -7 H / m, l3—Total copper layer thickness (the sum of the thicknesses under the two contacts).

[0046] The total magnetic reluctance of the second coil 16 magnetic circuit:

[0047]

[0048] Since the permeability of the magnetic core and steel rod is much greater than that of copper, the total magnetic reluctance of the first coil is much greater than that of the second coil. When the thickness of the copper rod cladding changes, the inductance of the first coil also changes.

[0049] Second coil inductance:

[0050]

[0051] First coil inductance:

[0052]

[0053] Connecting the first and second coils to form a differential bridge circuit, and ignoring higher-order terms, the output voltage of the bridge is approximately:

[0054]

[0055] The output voltage is a function of the copper cladding thickness.

[0056] Compared with ordinary single-point contact thickness sensors, this method has the following characteristics: the magnetic circuit of the dual-contact contact does not pass through the air, the magnetic resistance in the magnetic circuit is approximately equal to the magnetic resistance of the copper layer, the magnetic resistance of the single-point contact is approximately equal to the sum of the magnetic resistance of the copper layer and the magnetic resistance of the air, and the length of the copper layer magnetic circuit is much shorter than that of the air magnetic circuit. Therefore, the detection sensitivity of the single-point contact method is lower than that of the dual-contact contact probe of this invention.

[0057] In use, the detection body 8 below the spindle rests against the copper-clad steel rod. Rotating the rotating handle 11 on the left lead screw 12 causes the left lead screw 12 and the optical shaft to rotate together, thereby causing the right lead screw 7 to rotate. The left nut 13 moves along with the rotating left lead screw 12, and the right nut 6 moves along with the rotating right lead screw 7, thereby causing the connected clamping foot 9 to move and clamp the bullseye wheel 10. The upper guide rail assembly directly above can constrain the entire clamping assembly to remain on the same plane, preventing axial rotation of the clamping foot 9 and also not affecting the displacement of the left nut 13 and the right nut 6.

[0058] The centering principle of a centering structure is based on the property of the perpendicular bisector: such as Figure 9 The perpendicular bisector is perpendicular to and bisects the line segment AB. Any point P on the perpendicular bisector is equidistant from the two endpoints A and B of the line segment. In this invention, the bullseye wheel 10 can be considered as the two endpoints A and B of the line segment symmetrical about its midpoint, and the detection body 8 can be considered as the perpendicular bisector P. After moving the clamping assembly, the positions of the bullseye wheel 10 are denoted as A' and B'. The displacements of A and B towards the midpoint N of the line segment, controlled by the rotation of the ball screw structure, are equal in magnitude: AA' and BB'.

[0059] AA' = BB'

[0060] After the bullseye wheel 10 is moved and clamped, positions A' and B' remain symmetrical about the midpoint N. Therefore, the detection body 8 and point P are still located on the perpendicular bisector of the line segment.

[0061] Without causing conflict, those skilled in the art can freely combine and use the above-mentioned additional technical features.

[0062] The above description is only a preferred embodiment of the present invention. Any technical solution that achieves the purpose of the present invention by essentially the same means is within the protection scope of the present invention.

Claims

1. A probe for measuring the coating thickness of a copper-clad steel rod with a centering function, characterized in that: The device includes a detection body (8) composed of a thickness sensor and an alignment device for fixing the detection body (8). The alignment device includes a main shaft, which includes an optical shaft. A left ball screw structure and a right ball screw structure are respectively provided at both ends of the optical shaft. The left ball screw structure includes a left lead screw (12) and a left nut (13) provided on the left lead screw (12). The right ball screw structure includes a right lead screw (7) and a right nut (6) provided on the right lead screw (7). The left lead screw (12) and the right lead screw (7) are both connected to the optical shaft through a coupling (5). A slider sleeve (4) is installed on the optical shaft through a bearing. A detection copper is fixedly provided on the slider sleeve (4). The main body (8) for detecting the coating thickness of the steel bar, the centering device further includes a clamping assembly and an upper guide rail assembly for limiting, the upper guide rail assembly includes a guide rail shaft (3), a guide rail bracket (2) is fixedly provided at the center of the guide rail shaft (3), the guide rail bracket (2) is fixedly connected to the slider sleeve (4), a slider (1) is provided at both ends of the guide rail shaft (3), a connecting rod (14) is provided on the slider (1), the connecting rod (14) at both ends is connected to the left nut (13) and the right nut (6) respectively, the clamping assembly includes clamping feet (9) provided on the left nut (13) and the right nut (6), and a bullseye wheel (10) is provided on the clamping feet (9).

2. The copper-clad steel rod coating thickness measuring probe with centering function according to claim 1, characterized in that: The left and right ball screw structures are symmetrical about the slider sleeve (4). The vertical axes of the guide rail bracket (2), slider sleeve (4) and detection body (8) are the same. The thread pitch of the left nut (13) and the right nut (6) is the same. The thread direction of the left screw (12) and the right screw (7) is opposite.

3. The copper-clad steel rod coating thickness measuring probe with centering function according to claim 2, characterized in that: A rotating handle (11) is provided on the left lead screw (12).

4. The copper-clad steel rod coating thickness measuring probe with centering function according to claim 1, characterized in that: The detection body (8) consists of a first coil (15) and a second coil (16) wound with two enameled wires. The magnetic cores of the first coil (15) and the second coil (16) are of the same shape and are made of iron-based amorphous alloy high magnetic permeability material. The outside is sealed with epoxy resin.

5. A copper-clad steel rod coating thickness measuring probe with centering function according to claim 4, characterized in that: The copper-clad steel rod includes a steel rod core (18) and a copper cladding layer (17). The first coil (15) is placed on the copper-clad steel rod in a direction parallel to the axis of the copper-clad steel rod. The two contacts of the magnetic core of the first coil (15) respectively contact two points in the axial direction of the copper-clad steel rod. The second coil (16) is fixed on a steel material of the same material as the steel rod core (18) of the copper-clad steel rod. The first coil (15) and the second coil (16) are connected to form a differential bridge.

6. The copper-clad steel rod coating thickness measuring probe with centering function according to claim 1, characterized in that: The bullseye wheel (10) includes freely rotating balls (19), and the distance from the lower surface of the detection body (8) to the axis of the balls (19) is 13 mm.

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