阅读说明：本技术 一种减小铁磁性管棒涡流检测端部效应的装置 (Device for reducing end effect of eddy current testing of ferromagnetic pipe and rod ) 是由 林俊明 沈功田 倪培君 宋凯 卢聪赟 于 2021-03-26 设计创作，主要内容包括：本发明一种减小铁磁性管棒涡流检测端部效应的装置用于长条形金属管棒(1)涡流检测的具有中心通道(3)的磁饱和装置(2),包括磁化线圈(21)、导套(22)和检测探头(23),其特征在于所述导套(22)设置为导磁材料制作的空心柱形结构,磁化线圈(21)设置于导套(22)的外围,所述两个磁化线圈(21)和两个导套(22)形成对称设置的一组,以及设置于一组磁化线圈(21)和导套(22)的中间检测探头(23)。本发明在不改变磁饱和线圈的安匝数的情况下,对被检测金属管棒磁化集中在更靠近检测探头的中间部位,减小无法完全磁化的端部盲区,实现更大范围的检测。(The invention discloses a device for reducing the eddy current detection end effect of a ferromagnetic tube rod, which is used for a magnetic saturation device (2) with a central channel (3) for eddy current detection of a strip-shaped metal tube rod (1), and comprises a magnetizing coil (21), a guide sleeve (22) and a detection probe (23), wherein the guide sleeve (22) is arranged to be a hollow cylindrical structure made of a magnetic conductive material, the magnetizing coil (21) is arranged at the periphery of the guide sleeve (22), the two magnetizing coils (21) and the two guide sleeves (22) form a group which is symmetrically arranged, and the detection probe (23) is arranged between the group of magnetizing coil (21) and the guide sleeve (22). Under the condition of not changing the ampere-turns of the magnetic saturation coil, the invention magnetizes the detected metal tube rod to be concentrated at the middle part closer to the detection probe, reduces the end blind area which can not be magnetized completely, and realizes detection in a wider range.)

1. A device for reducing the eddy current testing end effect of a ferromagnetic tube rod, a magnetic saturation device (2) with a central channel (3) for eddy current testing of a strip-shaped metal tube rod (1), comprises a magnetizing coil (21), a guide sleeve (22) and a testing probe (23), and is characterized in that the guide sleeve (22) is a hollow cylindrical structure made of a magnetic conductive material, the magnetizing coil (21) is arranged at the periphery of the guide sleeve (22), the two magnetizing coils (21) and the two guide sleeves (22) form a group which is symmetrically arranged, and the middle testing probe (23) is arranged between the group of magnetizing coil (21) and the guide sleeve (22),

the outer diameter of the guide sleeve (22) is set to be a cylindrical structure with the same diameter, the hollow inner diameter of the guide sleeve (22) is set to be a structure with a plurality of different diameters, and the thickness of a part, close to the middle detection probe (23), in a group of magnetizing coils (21) and the guide sleeve (22) is larger than two side edges.

2. The device for reducing eddy current testing end effect of ferromagnetic tube and rod as claimed in claim 1, wherein the ratio of the hollow inner diameter of said guide sleeve (22) large direct D1 part length to small diameter D2 part length is between 1: 2 and 2: 1.

3. The apparatus for reducing eddy current testing end effect of ferromagnetic tube and rod as claimed in claim 2, wherein the guide sleeve (22) is made of pure iron with good magnetic permeability, and the ratio of the length of the portion with large inner diameter D1 to the length of the portion with small diameter D2 is set to 1: 1.

4. The apparatus for reducing eddy current testing end effect of ferromagnetic tube and rod as claimed in claim 1, wherein said single guide sleeve (22) is configured as a cylinder (221) with large diameter and large height sleeved with a cylinder (222) with small diameter and small height to form a structure with one end aligned, and when a set of guide sleeves (22) are symmetrically configured, the thickness of the portion near the middle testing probe (23) of two guide sleeves (22) is larger than two sides.

5. The device for reducing the eddy current testing end effect of the ferromagnetic tubular rod according to claim 4, wherein the single guide sleeve (22) is formed by overlapping a plurality of hollow sleeve layers with different diameters and different heights in an inner-outer sleeved mode, so as to form a horn-shaped structure with one end aligned and the other end gradually becoming larger and larger in the inner direction, and when a group of guide sleeves (22) are symmetrically arranged, the thickness of a part, which is close to the middle testing probe (23) of the two guide sleeves (22), is larger than that of two side edges.

6. The apparatus for reducing eddy current testing end effect of ferromagnetic pipe rods according to claim 1, wherein the single guide sleeve (22) is configured to be formed by splicing two semi-cylindrical structures, each semi-cylindrical structure is formed by sleeving a semi-cylinder (223) with a large diameter and a large height with a semi-cylinder (224) with a small diameter and a small height to form a structure with one end aligned, and when a set of guide sleeves (22) are symmetrically arranged, the thickness of a portion near the middle testing probe (23) of the two guide sleeves (22) is greater than two sides.

7. The device for reducing the eddy current testing end effect of the ferromagnetic tubular rod according to claim 6, wherein the semi-cylindrical structure is formed by overlapping a plurality of hollow semi-cylindrical sleeve layers with different diameters and different heights in an inner and outer sleeved mode, so as to form a horn-shaped structure with one end aligned and the other end gradually becoming larger and larger in the inner direction, and when a set of guide sleeves (22) are symmetrically arranged, the thickness of a part forming a testing probe (23) near the middle of the two guide sleeves (22) is larger than that of two side edges.

Technical Field

The invention relates to the technical field of nondestructive testing, in particular to an electromagnetic eddy current testing technology of a metal pipe rod, and particularly relates to a device for reducing an eddy current testing end effect of a ferromagnetic pipe rod.

Background

In the magnetic saturation eddy current inspection of steel pipes or bars, as shown in the inspection device diagram of fig. 1, since the steel pipe bar (1) is in a strip shape, the steel pipe bar (1) is generally moved to pass through a channel (3) of a magnetic saturation device (2) for mobile inspection. As shown in the schematic diagram of the internal structure of the detection device in fig. 2, in the detection process, the steel pipe rod (1) needs to be magnetized, generally, a magnetic saturation device as shown in the figure is composed of two symmetrically arranged sets of magnetization coils (21) and a magnetic conductive guide sleeve (22), and the detection probe (23) is arranged between the coils (21) and the guide sleeve (22).

In the detection process, the steel pipe rod (1) is moved to slowly pass through the probe, the magnetic saturation device magnetizes the steel pipe rod, and as can be seen from the figure, the end part of the pipe rod at the beginning has a blind area A which cannot be completely magnetized, so that the end part blind area cannot be accurately detected. In particular, for obtaining sufficient magnetization capability, the ampere-turns and the current intensity of the magnetic saturation device need to be multiplied, which not only causes the instrument to be bulky, but also greatly increases the temperature caused by the heating loss of the magnetizing coil, which affects the current intensity, and the current intensity is difficult to reach the design value required by detection, so that effective detection cannot be realized. Dead end zones have been a relatively difficult problem to solve.

In addition, the number of turns of the magnetizing coil is increased, the instrument is large in size, the length of the guide sleeve is inevitably lengthened, the long strip-shaped steel pipe rod has certain bending rate or defects and the like, the guide sleeve is arranged through the straight long magnetic saturation device, a larger gap is needed to be suitable for the steel pipe rod to pass through, the large magnetic resistance of the gap is inevitably increased, the magnetizing capacity is weakened, and the accurate detection is not facilitated.

Aiming at the problems of the defects, the invention adopts the following technical scheme.

Disclosure of Invention

The invention aims to provide a device for reducing the eddy current testing end effect of a ferromagnetic pipe rod, and the technical scheme is as follows:

a device for reducing the eddy current testing end effect of a ferromagnetic tube rod, a magnetic saturation device (2) with a central channel (3) for eddy current testing of a strip-shaped metal tube rod (1), comprises a magnetizing coil (21), a guide sleeve (22) and a testing probe (23), and is characterized in that the guide sleeve (22) is a hollow cylindrical structure made of a magnetic conductive material, the magnetizing coil (21) is arranged at the periphery of the guide sleeve (22), the two magnetizing coils (21) and the two guide sleeves (22) form a group which is symmetrically arranged, and the middle testing probe (23) is arranged between the group of magnetizing coil (21) and the guide sleeve (22),

the outer diameter of the guide sleeve (22) is set to be a cylindrical structure with the same diameter, the hollow inner diameter of the guide sleeve (22) is set to be a structure with a plurality of different diameters, and the thickness of a part, close to the middle detection probe (23), in a group of magnetizing coils (21) and the guide sleeve (22) is larger than two side edges.

Wherein, the ratio of the length of the part D1 with the larger inner aperture diameter and the part D2 with the smaller diameter of the hollow inner aperture of the guide sleeve (22) to the length of the part D2 is between 1: 2 and 2: 1. When the guide sleeve (22) is a structure made of pure iron with good magnetic permeability, the ratio of the length of the part D1 with the large inner aperture diameter to the length of the part D2 with the small diameter is set to be 1: 1.

Furthermore, a single guide sleeve (22) is set into a structure that one end of the large-diameter large-height cylinder (221) is sleeved with the small-diameter small-height cylinder (222) to form an alignment structure, and when a group of guide sleeves (22) are symmetrically arranged, the thickness of a part close to a middle detection probe (23) of the two guide sleeves (22) is larger than two side edges. Wherein, single guide pin bushing (22) cup joint the stack by inside and outside a plurality of different diameters and the cavity jacket layer of co-altitude and form, form one end and align, the other end gradually becomes interior direct horn shape structure bigger and bigger, when a set of guide pin bushing (22) symmetry sets up, the position thickness that forms near two guide pin bushing (22) middle test probe (23) is greater than two sides.

Further, single guide pin bushing (22) set up to form by two semicylinder structures concatenations, every semicylinder structure cup joints for the semicylinder (223) of major diameter major-height and minor diameter minor-height semicylinder (224) and becomes the structure that one end aligns, when a set of guide pin bushing (22) symmetry sets up, the position thickness that forms near two guide pin bushing (22) middle test probe (23) is greater than two sides. Wherein, the semicircle column structure cup joint the stack inside and outside by a plurality of different diameters and not co-altitude cavity semicircle column jacket layer and form, form one end and align, the other end gradually becomes interior direct horn shape structure that becomes bigger and bigger, when a set of guide pin bushing (22) symmetry sets up, the position thickness that forms and is close to two guide pin bushing (22) middle test probe (23) is greater than two sides.

According to the technical scheme, the invention has the following beneficial effects:

firstly, the magnetic conductive guide sleeve in the magnetic saturation device is designed to be thicker at the part close to the middle detection probe and thinner at the two side edges, so that the magnetization of the detected metal pipe rod is concentrated at the middle part close to the detection probe under the condition of not changing the ampere turns of the magnetic saturation coil, the dead zone of the end part which cannot be completely magnetized is reduced, and the detection in a wider range is realized.

The two sides of the guide sleeve are thin, so that the calibers of the two sides of the channel of the magnetic saturation device are larger than the middle part, the small-caliber length of the magnetic saturation device at the detection probe part is shortened, and the channel of the magnetic saturation device can be designed to be more attached to the metal pipe rod, so that the metal pipe rod cannot pass through the detection channel due to the curvature of the metal pipe rod.

The magnetic conductive guide sleeve is designed into a multi-block splicing structure, so that the channels of the magnetic saturation devices with different calibers can be matched and spliced at will to form the channels with different calibers, the detection of metal pipe rods with different structural sizes can be flexibly realized, the magnetic conductive guide sleeve of the magnetic saturation device with different calibers can be selected, and the heating loss of the magnetic saturation device can be reduced by matching the ampere turns of different magnetizing coils.

Drawings

FIG. 1 is a schematic diagram illustrating a preferred embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a prior art structure;

FIG. 3 is a schematic view of the magnetic flux line of the prior art;

FIG. 4 is a schematic sectional view of the structure of the preferred embodiment of the present invention;

FIG. 5 is a schematic view of the magnetic lines of force of the preferred embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of the guide sleeve according to the preferred embodiment of the present invention;

FIG. 7 is a schematic view of a guide sleeve structure according to a preferred embodiment of the present invention;

FIG. 8 is a schematic view of another guide sleeve structure according to the preferred embodiment of the present invention;

FIG. 9 is a schematic view of another guide sleeve structure according to the preferred embodiment of the present invention;

FIG. 10 is a schematic view of another guide sleeve structure according to the preferred embodiment of the present invention;

FIG. 11 is a schematic view of another guide sleeve structure according to the preferred embodiment of the present invention;

fig. 12 is a schematic view of another guide sleeve structure according to the preferred embodiment of the present invention.

Detailed Description

The invention is further described with reference to the following drawings and detailed description.

As shown in figures 1 and 4, a device for reducing the eddy current testing end effect of a ferromagnetic tube bar, a magnetic saturation device 2 with a central channel 3 for eddy current testing of an elongated metal tube bar 1, comprises a magnetizing coil 21, a guide sleeve 22 and a testing probe 23, it is characterized in that the guide sleeve 22 is a hollow cylindrical structure made of magnetic conductive material, the magnetizing coils 21 are arranged at the periphery of the guide sleeve 22, the two magnetizing coils 21 and the two guide sleeves 22 form a group which is symmetrically arranged, and an intermediate detection probe 23 provided to a set of magnetizing coils 21 and a guide bush 22, wherein, the outer diameter of the guide sleeve 22 is set to be a cylindrical structure with the same diameter, the hollow inner diameter of the guide sleeve 22 is set to be a structure with a plurality of different diameters, and the thickness of the part, close to the middle detection probe 23, in the group of the magnetizing coils 21 and the guide sleeve 22 is larger than two side edges. The horn-shaped magnetic conduction sleeve forms a magnetic gathering effect, like the prior art magnetic force trend chart in fig. 3 and the changed magnetic force line trend chart in fig. 5, a group of guide sleeves 22 which are symmetrically arranged form a middle part for concentrating the magnetic force lines near the detection probe 23, the magnetization length of the magnetic saturation device to the detected tube bar is reduced, and the length of an end dead zone in the detection process is reduced.

As shown in FIG. 6, the ratio of the length of the large-diameter D1 part to the length of the small-diameter D2 part of the guide sleeve 22 is 1: 2 to 2: 1. When the guide sleeve 22 is a structure made of pure iron with good magnetic permeability, the ratio of the length of the part D1 with the large inner aperture diameter to the length of the part D2 with the small diameter is set to be 1: 1.

Further, as shown in fig. 7 and 8, the single guide sleeve 22 is configured such that the cylinder 221 with a large diameter and a large height is sleeved with the cylinder 222 with a small diameter and a small height to form a structure with one end aligned, and when a group of guide sleeves 22 are symmetrically arranged, the thickness of the portion near the middle detection probe 23 of the two guide sleeves 22 is larger than the two side edges. Wherein, single guide pin bushing 22 cup joints the stack by inside and outside a plurality of different diameters and the cavity jacket layer of co-altitude and forms, forms one end and aligns, and the horn structure that directly is bigger and bigger in the other end gradual becomes, and when a set of guide pin bushing 22 symmetry set up, the position thickness that forms and is close to two guide pin bushing 22 middle test probe 23 is greater than two sides.

Further, as shown in fig. 9 to 12, the single guide sleeve 22 is configured to be formed by splicing two semi-cylindrical structures, each semi-cylindrical structure is formed by sleeving a semi-cylinder 223 with a large diameter and a large height with a semi-cylinder 224 with a small diameter and a small height to form a structure with one end aligned, and when a group of guide sleeves 22 is symmetrically configured, the thickness of the portion near the middle detection probe 23 of the two guide sleeves 22 is greater than two sides. Wherein, the semicircle column structure cup joint the stack inside and outside by a plurality of different diameters and not co-altitude cavity semicircle column jacket layer and form, form one end and align, the other end gradually becomes interior direct horn structure bigger and bigger, when a set of guide pin bushing 22 symmetry sets up, the position thickness that forms and is close to two guide pin bushing 22 middle test probe 23 is greater than two sides.

The above is one embodiment of the present invention. Furthermore, it is to be understood that all equivalent or simple changes in the structure, features and principles described in the present patent concepts are included in the scope of the present patent.