Eddy current probe, sensor and testing method thereof

Abstract

The invention relates to the technical field of eddy current probes, in particular to an eddy current probe, a sensor and a testing method thereof.The eddy current probe comprises a main probe which comprises a main monitoring section and a main connecting section, the main monitoring section is used for penetrating through a shell of a monitored object, a first gap M is formed between the main monitoring section and an inner core of the monitored object, and the main connecting section is fixedly connected with the main monitoring section and extends out of the monitored object; and the auxiliary probe comprises an auxiliary monitoring section which is connected with the main connecting section, and a second gap N is formed between the auxiliary monitoring section and the shell of the monitored object. Wherein the main monitoring section is internally provided with a main induction coil used for monitoring the displacement change value delta M of the first gap M, and the auxiliary monitoring section is internally provided with an auxiliary induction coil used for monitoring the displacement change value delta N of the second gap N. According to the invention, the main probe and the auxiliary probe are matched with each other, so that the influence caused by the change of the measurement value of the main probe during loosening can be eliminated according to the change value measured by the auxiliary probe, and the corrected value can still express the actual operation state of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of eddy current probes, in particular to an eddy current probe, a sensor and a testing method thereof. Background Art

[0002] Eddy current sensors are non-contact measurement sensors based on the principle of electromagnetic induction. When an alternating current passes through the induction coil of the sensor, an alternating magnetic field will be generated around it. When the measured conductor (such as metal) approaches this magnetic field, an induced current, that is, an eddy current, will be generated in the conductor. The eddy current will form a closed current loop inside the conductor and generate a secondary magnetic field opposite to the direction of the original magnetic field. The secondary magnetic field interacts with the original magnetic field, resulting in a change in the impedance of the induction coil. By measuring the change in the impedance of the induction coil, physical quantities (such as displacement, vibration, thickness, etc.) can be converted into electrical signals for output. Usually, the sensor system will convert the impedance change into a voltage or current signal, thereby realizing non-contact measurement of the measured object.

[0003] In the prior art, the probe of the eddy current sensor is generally installed by bonding or screwing. The probe of the eddy current sensor is passed through the outer shell of the monitored object and aligned with the inner core (such as a rotor) of the monitored object, and then the vibration amount of the rotor is monitored. However, both of these installation methods are prone to looseness or even detachment in the complex environment of the power plant. When the probe loosens, the displacement measured by the sensor changes, resulting in an incorrect judgment of the operating state of the system by the system. If the relevant personnel do not discover the looseness of the probe in time at this time, it may lead to unnecessary shutdowns and affect production. Summary of the Invention

[0004] In this part, as well as in the abstract and title of the specification of the present application, some simplifications or omissions may be made to avoid obscuring the purpose of this part, the abstract and the title of the specification, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] To solve the deficiencies of the prior art, an object of the present invention is to provide an eddy current probe.

[0006] To achieve the above object, the present invention adopts the following technical solution: An eddy current probe, comprising,

[0007] A main probe, which includes a main monitoring section for passing through the outer shell of the monitored object and having a first gap M with the inner core of the monitored object, and a main connecting section fixedly connected to the main monitoring section and extending outside the monitored object;

[0008] At least one sub-probe, the sub-probe includes a sub-monitoring section connected to the main connecting section and having a second gap N with the outer shell of the monitored object; and,

[0009] A limiting component, which is connected between the main connection section and the outer shell of the object to be monitored, is used to limit the size of the first gap M;

[0010] Wherein, a main induction coil for monitoring the displacement change value ΔM of the first gap M is arranged in the main monitoring section, and a secondary induction coil for monitoring the displacement change value ΔN of the second gap N is arranged in the secondary monitoring section.

[0011] As a preferred solution of the eddy current probe of the present invention, wherein: the secondary monitoring section and the main connection section are integrally and fixedly connected;

[0012] The relationship between the change value ΔL of the distance L from the inner core of the object to be monitored to the outer shell of the object to be monitored and the change value ΔM of the first gap and the change value ΔN of the second gap is: ΔL = ΔM - ΔN, and both the first gap M and the second gap N are greater than 0.

[0013] As a preferred solution of the eddy current probe of the present invention, wherein: there are i secondary probes, and the change value of the second gap is:

[0014] Wherein, i is an integer not less than 2, and k is a constant taken from [1, i].

[0015] As a preferred solution of the eddy current probe of the present invention, wherein: the limiting component includes a first external thread arranged on the surface of the main connection section, a limiting section arranged on the surface of the main connection section and outside the object to be monitored, and a locking nut threadedly engaged with the surface of the first external thread;

[0016] Wherein, the maximum diameter D of the limiting section 1 is greater than the maximum diameter D of the main monitoring section 2 .

[0017] As a preferred solution of the eddy current probe of the present invention, wherein: a secondary connection section is arranged between the secondary monitoring section and the main connection section;

[0018] The secondary monitoring section and the secondary connection section are movably connected, and / or the secondary connection section and the main connection section are movably connected;

[0019] One side of the secondary connection section is provided with an adjusting component for adjusting the size of the second gap N.

[0020] As a preferred solution of the eddy current probe of the present invention, wherein: a calibration probe is fixedly arranged between the secondary monitoring section and the secondary connection section, and / or between the secondary connection section and the main connection section;

[0021] A calibration induction coil is arranged in the calibration probe for monitoring the displacement change value between the secondary monitoring section and the secondary connection section, and / or between the secondary connection section and the main connection section.

[0022] As a preferred solution of the eddy current probe described in the present invention, wherein: the secondary connection section and the main connection section are integrally and fixedly connected;

[0023] The adjusting assembly includes an adjusting bolt rotatably connected to the secondary connection section and a guiding block threadedly connected to the adjusting bolt;

[0024] The secondary monitoring section and the guiding block are integrally and fixedly connected, and the guiding block is slidably connected to the secondary connection section along the axial direction of the adjusting bolt.

[0025] As a preferred solution of the eddy current probe described in the present invention, wherein: the secondary monitoring section and the secondary connection section are integrally and fixedly connected;

[0026] The limiting section includes a first support portion, a threaded portion, a guiding portion, and a second support portion that are sequentially distributed from the main monitoring section towards the locking nut;

[0027] Wherein, the maximum diameter D of the first support portion 3 is greater than the maximum diameter D of the main monitoring section 2 ,

[0028] The surface of the threaded portion has an external thread,

[0029] The secondary connection section moves directionally relative to the guiding portion,

[0030] The second support portion and the threaded portion are integrally and fixedly connected and cooperate with the locking nut;

[0031] The adjusting assembly includes an adjusting block threadedly engaged with the surface of the threaded portion and a synchronous moving member connected between the secondary connection section and the adjusting block;

[0032] The connection point of the synchronous moving member and the secondary connection section moves synchronously along the direction of the threaded sliding of the adjusting block.

[0033] As a preferred solution of the eddy current probe described in the present invention, wherein: the guiding portion is a guiding column coaxial with the threaded sliding direction of the adjusting block,

[0034] The synchronous moving member includes a first connection portion fixed to one side of the adjusting block and a second connection portion fixed to one side of the secondary connection section, and the first connection portion and the second connection portion are rotatably connected;

[0035] The secondary connection section slides in the direction of the guiding column.

[0036] As a preferred solution of the eddy current probe described in the present invention, wherein: the guiding portion is a guiding column coaxial with the threaded sliding direction of the adjusting block,

[0037] On one side of the second support part, at a position deviating from the threaded sliding direction of the adjusting block, there is a rotating shaft rotatably connected to the secondary connecting section.

[0038] At one end of the secondary connecting section away from the secondary monitoring section, a limiting groove is provided, and the limiting groove and the secondary monitoring section are distributed on both sides of the rotating shaft.

[0039] The synchronous moving part includes a first connecting part fixed on one side of the adjusting block, a second connecting part rotatably connected to the first connecting part and slidably connected to the guiding column, and a limiting shaft provided on one side of the second connecting part and slidably connected to the limiting groove.

[0040] Advantageous effects of an eddy current probe of the present invention: By the mutual cooperation between the main probe and the secondary probe provided in the present invention, the influence brought by the change in the measurement value of the main probe during loosening can be eliminated according to the change value measured by the secondary probe, so that the corrected value can still represent the actual operating state of the device, the measurement accuracy can be maintained when the monitoring probe is loose, and the loosening of the probe can be detected in time to facilitate maintenance.

[0041] To solve the deficiencies of the prior art, another object of the present invention is to provide an eddy current sensor.

[0042] To achieve the above object, the present invention adopts the following technical solution: An eddy current sensor includes the eddy current probe described above, and further includes,

[0043] A preamplifier, which is used to provide a high-frequency oscillating current for generating the eddy current effect, and convert the monitored signal change amount into the displacement amount of the monitored object;

[0044] A transmission wire, which includes a main line connected to the preamplifier at one end and branch lines connected to the main induction coil and the secondary induction coil at the other end respectively, and is used to transmit current and feedback the monitored signal; and,

[0045] A processing module, which is arranged in the preamplifier and is used to calculate and process according to the displacement change value ΔN measured by the secondary induction coil and the displacement change value ΔM measured by the main induction coil, and convert it into the actual change value of the distance between the inner core and the outer shell of the monitored object.

[0046] Advantageous effects of an eddy current sensor of the present invention: The same as the advantageous effects of an eddy current probe, which will not be elaborated here.

[0047] To solve the deficiencies of the prior art, the third object of the present invention is to provide a test method for an eddy current sensor.

[0048] To achieve the above object, the present invention adopts the following technical solution: A test method for an eddy current sensor, using the eddy current sensor described above, includes the following operating steps:

[0049] After drilling holes in the outer shell of the object to be monitored, the main monitoring section is fixed after being perforated, and the first gap M between the main monitoring section and the inner core of the object to be monitored is adjusted to be within the induction monitoring range;

[0050] Adjust the second gap N between the auxiliary monitoring section and the outer shell of the object to be monitored to be within the induction monitoring range;

[0051] Calculate the actual change value ΔL between the inner core and the outer shell of the object to be monitored according to the measured change value ΔM of the first gap and the change value ΔN of the second gap.

[0052] The beneficial effects of the test method of an eddy current sensor of the present invention: the same as the beneficial effects of an eddy current sensor, which will not be elaborated here. Brief Description of the Drawings

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0054] Figure 1 It is a schematic side view structure diagram when the eddy current probe is installed in Embodiments 1 and 2 of the present invention.

[0055] Figure 2 It is a schematic three-dimensional structure diagram before the detachable limiting section is installed in Embodiment 2 of the present invention.

[0056] Figure 3 It is a schematic three-dimensional structure diagram after the detachable limiting section is installed in Embodiment 2 of the present invention.

[0057] Figure 4 It is a schematic principle structure diagram when there is an angular deviation in Embodiment 1 of the present invention.

[0058] Figure 5 It is a schematic three-dimensional structure diagram of the eddy current probe in Embodiments 2, 4, and 5 of the present invention.

[0059] Figure 6 It is a schematic three-dimensional structure diagram inside the eddy current probe in Embodiments 4 and 5 of the present invention.

[0060] Figure 7 It is a schematic side view structure diagram inside the eddy current probe in Embodiments 4 and 5 of the present invention.

[0061] Figure 8 It is a schematic three-dimensional structure diagram of the eddy current probe in Embodiments 5 and 6 of the present invention.

[0062] Figure 9Schematic side view structure diagram of the eddy current probe in Embodiments 5 and 6 of the present invention.

[0063] Figure 10 Schematic three-dimensional structure diagram of the eddy current probe in Embodiment 3 of the present invention.

[0064] Figure 11 Schematic three-dimensional structure diagram of the eddy current probe in Embodiments 5 and 7 of the present invention.

[0065] Figure 12 Schematic side view structure diagram of the angle adjustment of the eddy current probe in Embodiments 5 and 7 of the present invention.

[0066] Figure 13 Schematic internal three-dimensional structure diagram of the angle adjustment of the eddy current probe in Embodiment 7 of the present invention.

[0067] Figure 14 For the present invention Figure 13 Enlarged schematic diagram of the structure at position A shown.

[0068] Figure 15 Schematic side view sectional structure diagram of the angle adjustment of the eddy current probe in Embodiments 7 and 8 of the present invention.

[0069] Figure 16 Schematic three-dimensional structure diagram of the angle adjustment of the eddy current probe in Embodiment 7 of the present invention.

[0070] Figure 17 Schematic side view structure diagram of the eddy current sensor in Embodiment 8 of the present invention.

[0071] Figure 18 Schematic three-dimensional structure diagram of the eddy current sensor in Embodiment 8 of the present invention. Detailed implementation manners

[0072] To make the objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention in conjunction with the accompanying drawings of the specification.

[0073] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0074] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0075] Example 1

[0076] Reference Figure 1 And Figure 4 This is the first embodiment of the present invention. This embodiment provides an eddy current probe, which can maintain the measurement accuracy when monitoring the looseness of the probe, and can detect the looseness of the probe in time to facilitate maintenance. It includes: a main probe 100, a sub-probe 200 and a limiting component 300. The main probe 100 passes through the outer shell of the monitored object and is close to the inner core of the monitored object. By setting the limiting component 300, the position of the main probe 100 is restricted to prevent the main probe 100 from directly contacting the inner core of the monitored object. The sub-probe 200 is located outside and close to the outer shell of the monitored object.

[0077] Specifically, the main probe 100 includes a main monitoring section 101 for passing through the outer shell of the monitored object and having a first gap M with the inner core of the monitored object, and a main connection section 102 fixedly connected to the main monitoring section 101 and extending outside the monitored object. The main monitoring section 101 and the main connection section 102 are fixedly connected, and can be fixed by welding or integrally formed by a mold to ensure that the displacements of the main monitoring section 101 and the main connection section 102 are synchronized when loose.

[0078] Furthermore, the sub-probe 200 includes a sub-monitoring section 201 connected to the main connection section 102 and having a second gap N with the outer shell of the monitored object. By setting the sub-monitoring section 201 to detect the displacement change between the sub-monitoring section 201 and the outer shell of the monitored object, and since the sub-monitoring section 201 is connected to the main connection section 102, when the main connection section 102 is loose, the measured value of the sub-monitoring section 201 will also change. Furthermore, according to the change value measured by the sub-monitoring section 201, the influence brought by the change of the measured value of the main monitoring section 101 when loose is eliminated, so that the corrected value can still represent the actual operating state of the device.

[0079] Among them, the limiting component 300 is connected between the main connection section 102 and the outer shell of the monitored object, and is used to limit the size of the first gap M. In this embodiment, the limiting component 300 is a limiting column integrally and fixedly connected to the main connection section 102, and both the main connection section 102 and the main monitoring section 101 are set to be cylindrical. When installing, a hole is drilled in the outer shell of the monitored object, and the aperture size satisfies the penetration of the main monitoring section 101, and the size of the limiting component 300 and the aperture size should be kept as the same as much as possible without obvious gaps to reduce the influence brought by the deviation in the aperture direction when loose. However, the limiting column of the limiting component 300 is blocked outside the hole, thereby restricting the first gap M between the main monitoring section 101 and the inner core of the monitored object.

[0080] Inside the main monitoring section 101, there is a main induction coil 101a for monitoring the magnitude of the displacement change value ΔM of the first gap M. Inside the secondary monitoring section 201, there is a secondary induction coil 201a for monitoring the magnitude of the displacement change value ΔN of the second gap N. According to the measurement principle of the eddy current probe, there is an optimal range for induction monitoring. Therefore, it is necessary to keep the size of the first gap M within the monitoring range of the main induction coil 101a, and the size of the second gap N within the monitoring range of the secondary induction coil 201a. Among them, since the main monitoring section 101 monitors the inner core with a relatively complex motion state such as a rotor, a main induction coil 101a with a higher standard of measurement accuracy needs to be selected; while the secondary monitoring section 201 monitors the relatively stationary outer shell of the monitored object, and a secondary induction coil 201a with a more economical standard of measurement accuracy can be selected, which can reduce the use cost while ensuring the use effect, and the saved cost can be used to set multiple groups of secondary probes 200 to reduce the influence of data errors that may be brought by a single secondary probe 200.

[0081] Preferably, the secondary monitoring section 201 and the main connection section 102 are integrally and fixedly connected. Similarly, the secondary monitoring section 201 and the main connection section 102 can be fixed by welding or integrally formed by a mold, ensuring that after the main connection section 102 loosens and displaces, the main monitoring section 101 and the secondary monitoring section 201 will move the same displacement amount synchronously. Since the outer shell of the monitored object is relatively stationary, this displacement amount can be converted and known through the measurement change value of the secondary monitoring section 201, and then the monitoring value of the main monitoring section 101 can be corrected. The corrected monitoring value can still accurately represent the motion state of the inner core of the monitored object.

[0082] In this embodiment, the distance between the inner core of the monitored object and the outer shell of the monitored object in the initial state is set as L, and the distance between the inner core of the monitored object and the outer shell of the monitored object after vibration displacement at a certain moment is set as L t ,and this vibration displacement amount is set as ΔL = L t -L. Similarly, the first gap change value ΔM = M t -M, and the second gap change value ΔN = N t -N. Since the outer shell of the monitored object is relatively stationary, when ΔN is not 0, it indicates that a loosening phenomenon has occurred, and ΔN is the loosening displacement value. The magnitude of the first gap change value ΔM is the sum of the loosening displacement value ΔN and the vibration displacement amount ΔL. Therefore, the relationship among the three is obtained as: ΔL = ΔM - ΔN. The first gap M and the second gap N are within the induction measurement range, and this value is greater than 0. Also, the first gap M and the second gap N are within the vibration displacement range to prevent the main monitoring section 101 or the secondary monitoring section 201 from directly contacting the monitored object during vibration and affecting the test results.

[0083]

[0084] Wherein, i is an integer not less than 2, k is a constant taken from [1, i], and multiple secondary probes 200 are distributed in a circular array around the main probe 100. Since the main monitoring section 101 enters the outer shell of the object to be monitored through a perforation, due to processing technology limitations, there will always be a gap between the aperture diameter and the main probe 100 and the limit component 300. As a result, when loose, the main connection section 102 may shift in the angular direction. A loosening displacement value ΔN is measured by each secondary probe 200 in each direction. k , and the average value is calculated to reduce the influence of the angular direction shift during loosening on the monitoring data, making the measured data closer to the actual state. As Figure 4 shown, the dashed box is the position before the shift, and the solid box is the position after the shift. When the loosening angle biases towards one of the secondary probes x200, the loosening displacement value ΔN measured by this secondary probe x200 x is smaller compared to the actual value, while the loosening displacement value ΔN measured by the secondary probe y200 corresponding to this secondary probe x200 y is larger compared to the actual value. Since the offset angle of the loosening itself is small, the value of ΔN x is close to the value of ΔN y . By calculating the average value of ΔN x and ΔN y , the influence caused by the angular offset can be reduced.

[0085] Embodiment 2

[0086] Referring to Figure 1 and Figure 5 , this is the second embodiment of the present invention. Different from the previous embodiment, this embodiment provides a secondary connection section 400 and an adjustment component 500, which can adjust the size of the second gap N while the size of the first gap M is fixed.

[0087] Specifically, the limit component 300 includes a first external thread 301 provided on the surface of the main connection section 102, a limit section 302 provided on the surface of the main connection section 102 and located outside the object to be monitored, and a locking nut 303 threadedly engaged with the surface of the first external thread 301; wherein, the maximum diameter D of the limit section 302 1 is greater than the maximum diameter D of the main monitoring section 101 2 . In this embodiment, the distance between the main monitoring section 101 and the limit section 302 is adaptively set. The limit section 302 can be set as a detachable sleeve, so as to replace limit sections 302 of different sizes to adaptively adjust the first gap M, making the first gap M between the outer shell of the object to be monitored and the inner core of the object to be monitored meet the induction monitoring range. During installation, a hole is drilled in the outer shell of the object to be monitored with a diameter equal to the maximum diameter D of the main monitoring section 101 2The adapted hole is provided, and after the main monitoring section 101 passes through the hole, the locking nut 303 is threadedly slid on the first external thread 301 until the limiting section 302 is pressed against the outside of the hole of the monitored object housing.

[0088] Further, a secondary connection section 400 is provided between the secondary monitoring section 201 and the main connection section 102. At least one of the connection between the secondary monitoring section 201 and the secondary connection section 400 and the connection between the secondary connection section 400 and the main connection section 102 is set as an adjustable movable connection, and an adjusting component 500 for adjusting the size of the second gap N is provided on one side of the secondary connection section 400. After the first gap M is locked and fixed by the locking nut 303, the size of the second gap N is adjusted by the adjusting component 500 so that the secondary monitoring section 201 and the monitored object housing are also within the induction monitoring range.

[0089] The remaining structure is the same as that of Embodiment 1.

[0090] Embodiment 3

[0091] Refer to Figure 10 , which is the third embodiment of the present invention. Different from the previous embodiment, this embodiment provides a calibration probe 600 to eliminate the influence of the loosening of the secondary probe 200 on the measurement result.

[0092] Specifically, a calibration probe 600 is fixedly provided between the secondary monitoring section 201 and the secondary connection section 400, or / and between the secondary connection section 400 and the main connection section 102. By adding a calibration probe 600 between the movable secondary monitoring section 201 and the secondary connection section 400 and between the secondary connection section 400 and the main connection section 102, the influence of the loosening of the secondary probe 200 on the measurement result is eliminated.

[0093] Further, a calibration induction coil 601 is provided in the calibration probe 600 for monitoring the displacement change value between the secondary monitoring section 201 and the secondary connection section 400, or / and between the secondary connection section 400 and the main connection section 102. The calculation method for eliminating the influence of the loosening or displacement adjustment error of the secondary probe 200 on the measurement result by the calibration probe 600 is the same in principle as the calculation method for eliminating the influence of the loosening of the main probe 100 on the measurement result by the secondary probe 200, so it will not be elaborated here.

[0094] The remaining structure is the same as that of Embodiment 2.

[0095] Embodiment 4

[0096] Refer to Figures 5 - 7, which is the fourth embodiment of the present invention. Different from the previous embodiment, in this embodiment, the secondary connection section 400 and the main connection section 102 are integrally and fixedly connected, while the secondary monitoring section 201 and the secondary connection section 400 are movably connected, enabling individual adjustment of the second gap N of each secondary monitoring section 201, and being applicable to the outer shells of irregular objects to be monitored.

[0097] Specifically, the adjustment assembly 500 includes an adjustment bolt 501 rotatably connected to the secondary connection section 400, and a guide block 502 threadedly connected to the adjustment bolt 501. The secondary monitoring section 201 and the guide block 502 are integrally and fixedly connected, and the guide block 502 is slidably connected to the secondary connection section 400 along the axial direction of the adjustment bolt 501. When it is necessary to individually adjust the second gap N of a certain secondary monitoring section 201, by rotating the adjustment bolt 501 corresponding to the secondary monitoring section 201, the rotation of the adjustment bolt 501 causes the guide block 502 to slide relative to the secondary connection section 400, thereby driving the secondary monitoring section 201 to move to adjust the second gap N.

[0098] The remaining structures are the same as those in Embodiment 3.

[0099] Embodiment 5

[0100] Refer to Figures 5 - 12 , which is the fifth embodiment of the present invention. Different from the previous embodiment, in this embodiment, the secondary monitoring section 201 and the secondary connection section 400 are integrally and fixedly connected, while the secondary connection section 400 and the main connection section 102 are movably connected, enabling overall adjustment of the second gap N of each secondary monitoring section 201, and with a faster adjustment speed.

[0101] Specifically, the limiting section 302 includes a first support portion 302a, a threaded portion 302b, a guiding portion 302c, and a second support portion 302d that are sequentially distributed from the main monitoring section 101 towards the locking nut 303. The second support portion 302d and the threaded portion 302b are integrally and fixedly connected and cooperate with the locking nut 303. In this embodiment, the limiting section 302 and the main connection section 102 are integrally and fixedly connected. The first support portion 302a is configured to be abutted against the outer shell of the object to be monitored, and the second support portion 302d is configured to be abutted against the locking nut 303. When the locking nut 303 is tightened, the main probe 100 is installed and fixed through the first support portion 302a and the second support portion 302d.

[0102] Furthermore, the maximum diameter D of the first support portion 302a 3 is greater than the maximum diameter D of the main monitoring section 101 2 , such that the maximum diameter D of the first support portion 302a 3Larger than the installation aperture and can be abutted against the outer shell of the object to be monitored; the surface of the threaded portion 302b has an external thread, and the axial direction of the thread of the threaded portion 302b is adapted to the moving direction of the secondary connection section 400; by providing the guiding portion 302c, the moving trajectory of the secondary connection section 400 is defined.

[0103] The adjusting assembly 500 includes an adjusting block 503 that is in threaded engagement with the surface of the threaded portion 302b, and a synchronous moving member 504 connected between each secondary connection section 400 and the adjusting block 503; the connection point of the synchronous moving member 504 and the secondary connection section 400 moves synchronously along the direction of the threaded sliding of the adjusting block 503. There is at least one position on the secondary connection section 400 connected to the synchronous moving member 504 that can move synchronously with the adjusting block 503, which is convenient for displacement calibration calculation. When overall adjustment is required, it is driven by rotating the adjusting block 503 to slide in a threaded manner, and each secondary connection section 400 is driven to move synchronously through the synchronous moving member 504 connected to the adjusting block 503, thereby achieving overall adjustment.

[0104] The remaining structure is the same as that of Embodiment 4.

[0105] Embodiment 6

[0106] Refer to Figures 8 - 9 , which is the sixth embodiment of the present invention. Different from the previous embodiment, this embodiment provides a specific implementation structure of the guiding portion 302c and the synchronous moving member 504, which is applicable to the case where the outer shell of the object to be monitored is a plane.

[0107] Specifically, the guiding portion 302c is a guiding column coaxial with the threaded sliding direction of the adjusting block 503, and the threaded sliding direction of the adjusting block 503 is perpendicular to the plane where the outer shell of the object to be monitored is located. In this embodiment, the synchronous moving member 504 can be set as a bearing, which includes a first connecting portion 504a fixed on one side of the adjusting block 503 and a second connecting portion 504b fixed on one side of the secondary connection section 400. The first connecting portion 504a and the second connecting portion 504b are rotatably connected. In this way, when the secondary connection section 400 slides relative to the direction of the guiding column, the secondary connection section 400 and the adjusting block 503 on both sides of the synchronous moving member 504 have the same displacement distance in the threaded sliding direction of the adjusting block 503, so that the values of each second gap N are kept the same.

[0108] The remaining structure is the same as that of Embodiment 5.

[0109] Embodiment 7

[0110] Refer to Figures 11 - 16 , which is the seventh embodiment of the present invention. Different from the previous embodiment, this embodiment provides another implementation structure of the guiding portion 302c and the synchronous moving member 504, which is applicable to the case where the outer shell of the object to be monitored is a curved surface, such as the outer shell of a cylinder.

[0111] Specifically, the guiding portion 302c is a guiding column coaxial with the threaded sliding direction of the adjusting block 503. A rotating shaft 302d-1 for rotatably connecting with the secondary connecting section 400 is provided at a position on one side of the second supporting portion 302d that deviates from the threaded sliding direction of the adjusting block 503. The secondary connecting section 400 can rotate relative to the rotating shaft 302d-1 for angle adjustment. In this way, when the adjusting block 503 moves axially by the same distance, the secondary monitoring section 201 can quickly approach the outer shell of the object to be monitored through swinging, with fast adjustment speed and high efficiency.

[0112] A limiting groove 401 is provided at one end of the secondary connecting section 400 away from the secondary monitoring section 201. The limiting groove 401 and the secondary monitoring section 201 are distributed on both sides of the rotating shaft 302d-1; the synchronous moving member 504 includes a first connecting portion 504a fixed on one side of the adjusting block 503, a second connecting portion 504b rotatably connected to the first connecting portion 504a and slidably connected to the guiding column, and a limiting shaft 504c provided on one side of the second connecting portion 504b and slidably connected to the limiting groove 401. The diameter of the limiting shaft 504c is adapted to the width of the limiting groove 401.

[0113] When adjustment is required, by rotating the adjusting block 503 for threaded sliding, the synchronous moving member 504 drives the limiting shaft 504c to move axially along the adjusting block 503. The movement of the limiting shaft 504c will squeeze the limiting groove 401 of the secondary connecting section 400, thereby driving the secondary connecting section 400 to rotate relative to the rotating shaft 302d-1. After the secondary connecting section 400 rotates, the limiting shaft 504c slides relative to the limiting groove 401, and then the rotation angle of the secondary connecting section 400 is adjusted by the threaded sliding distance of the adjusting block 503, so that each secondary monitoring section 201 can quickly approach the outer shell of the object to be monitored with an arc surface through swinging, making the value of the second gap N within the induction monitoring range.

[0114] The remaining structures are the same as those in Embodiment 5.

[0115] Embodiment 8

[0116] Referring to Figure 15 、 Figure 17 and Figure 18 This is the eighth embodiment of the present invention. Different from the previous embodiment, this embodiment provides an eddy current sensor, which includes the eddy current probe in any of the above embodiments, and further includes a preamplifier 700, a transmission wire 800, and a processing module.

[0117] Specifically, the preamplifier 700 is a prior art device, which is used to provide a high-frequency oscillating current that generates an eddy current effect, and to convert the monitored signal variation into the displacement of the object under monitoring. The transmission wire 800 includes a main line 801 connected to the preamplifier 700 at one end, and branch lines 802 connected to the main induction coil 101a and the secondary induction coil 201a respectively at the other end, and is used to transmit current and feedback the monitored signal. The branch lines 802 for different connected coils are separately arranged, and the overlapping sections of different branch lines 802 are integrated into the same main line 801 to optimize the wire arrangement space.

[0118] Among them, the processing module is arranged in the preamplifier 700 and is a microprocessor, which is used to calculate and process according to the displacement change value ΔN measured by the secondary induction coil 201a and the displacement change value ΔM measured by the main induction coil 101a, and convert them into the actual change value of the distance between the inner core and the outer shell of the object under monitoring according to the foregoing calculation formula.

[0119] Embodiment 9

[0120] The ninth embodiment of the present invention provides a test method for an eddy current sensor, using the eddy current sensor in Embodiment 8.

[0121] Specifically, it includes the following operation steps: First, after drilling a hole in the outer shell of the object under monitoring, the main monitoring section 101 is perforated and fixed, and the first gap M between the main monitoring section 101 and the inner core of the object under monitoring is adjusted to be within the induction monitoring range; then the second gap N between the secondary monitoring section 201 and the outer shell of the object under monitoring is adjusted to be within the induction monitoring range; then the first gap change value ΔM and the second gap change value ΔN are measured respectively; finally, calculations are performed according to the measured first gap change value ΔM and the second gap change value ΔN, and the calculation formula is: ΔL = ΔM - ΔN, and then the actual change value ΔL between the inner core and the outer shell of the object under monitoring is obtained.

[0122] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An eddy current probe, characterized in that: include, A main probe (100) comprising a main monitoring section (101) for passing through the outer shell of the monitored object and having a first gap M between the main monitoring section and the inner core of the monitored object, and a main connecting section (102) fixedly connected to the main monitoring section (101) and extending outside the monitored object; at least one auxiliary probe (200), the auxiliary probe (200) comprising an auxiliary monitoring section (201) connected to the main connecting section (102) and having a second gap N between the auxiliary monitoring section and the housing of the monitored object; and A limit assembly (300), the limit assembly (300) being connected between the main connection section (102) and the housing of the monitored object, and being used to limit the size of the first gap M; The main monitoring section (101) is provided with a main induction coil (101a) for monitoring the displacement change value ΔM of the first gap M, and the secondary monitoring section (201) is provided with a secondary induction coil (201a) for monitoring the displacement change value ΔN of the second gap N.

2. The eddy current probe according to claim 1, characterized in that: The secondary monitoring section (201) and the main connecting section (102) are integrally fixedly connected; The relationship between the change value ΔL of the distance L between the inner core of the monitored object and the outer shell of the monitored object and the first gap change value ΔM and the second gap change value ΔN is: ΔL=ΔM-ΔN, and the first gap M and the second gap N are both greater than zero.

3. The eddy current probe according to claim 2, characterized in that: The auxiliary probes (200) are provided in i numbers, and the second gap variation value is: Where i is an integer not less than 2, and k is a constant in [1,i].

4. The eddy current probe according to any one of claims 1 to 3, characterized in that: The limiting assembly (300) comprises a first external thread (301) provided on the surface of the main connecting section (102), a limiting section (302) provided on the surface of the main connecting section (102) and located outside the monitored object, and a locking nut (303) threadably matched with the surface of the first external thread (301); Wherein, the maximum diameter D1 of the limiting section (302) is greater than the maximum diameter D2 of the main monitoring section (101).

5. The eddy current probe according to claim 1, characterized in that: A secondary connecting section (400) is provided between the secondary monitoring section (201) and the main connecting section (102); The secondary monitoring section (201) and the secondary connecting section (400) are movably connected, or / and the secondary connecting section (400) and the main connecting section (102) are movably connected; An adjustment component (500) for adjusting the size of the second gap N is provided on one side of the secondary connecting section (400).

6. The eddy current probe according to claim 5, characterized in that: A calibration probe (600) is fixedly arranged between the secondary monitoring section (201) and the secondary connecting section (400), or / and between the secondary connecting section (400) and the main connecting section (102); The calibration probe (600) is provided with a calibration induction coil (601) for monitoring the displacement change value between the secondary monitoring section (201) and the secondary connecting section (400), or / and between the secondary connecting section (400) and the main connecting section (102).

7. The eddy current probe according to claim 5 or 6, characterized in that: The secondary connection section (400) and the main connection section (102) are integrally fixedly connected; The adjustment assembly (500) comprises an adjustment bolt (501) rotatably connected to the secondary connection section (400), and a guide block (502) threadedly connected to the adjustment bolt (501); The auxiliary monitoring section (201) and the guide block (502) are integrally fixedly connected, and the guide block (502) is slidably connected relative to the auxiliary connecting section (400) in the axial direction of the adjusting bolt (501).

8. The eddy current probe according to claim 5 or 6, characterized in that: The secondary monitoring section (201) and the secondary connecting section (400) are integrally fixedly connected; The limiting section (302) comprises a first supporting portion (302a), a threaded portion (302b), a guiding portion (302c) and a second supporting portion (302d) which are sequentially distributed in the direction of the self-monitoring section (101) toward the locking nut (303); The maximum diameter D3 of the first support portion (302a) is greater than the maximum diameter D2 of the main monitoring section (101). The surface of the threaded portion (302b) has external threads, The secondary connecting section (400) moves in a directional manner relative to the guide portion (302c). The second supporting portion (302d) and the threaded portion (302b) are integrally fixedly connected and cooperate with the locking nut (303); The adjustment assembly (500) comprises an adjustment block (503) threadedly matched with the surface of the threaded portion (302b), and a synchronous moving member (504) connected between the secondary connecting section (400) and the adjustment block (503); The connection point between the synchronous moving member (504) and the auxiliary connecting section (400) moves synchronously following the direction of the threaded sliding of the adjusting block (503).

9. The eddy current probe according to claim 8, characterized in that: The guide portion (302c) is a guide column coaxial with the thread sliding direction of the adjustment block (503). The synchronous moving member (504) comprises a first connecting portion (504a) fixed to one side of the adjusting block (503), and a second connecting portion (504b) fixed to one side of the auxiliary connecting section (400), wherein the first connecting portion (504a) and the second connecting portion (504b) are rotationally connected. The secondary connecting section (400) slides relative to the direction of the guide column.

10. The eddy current probe according to claim 8, characterized in that: The guide portion (302c) is a guide column coaxial with the thread sliding direction of the adjustment block (503). A rotating shaft (302d-1) rotatably connected to the secondary connecting section (400) is provided on one side of the second supporting portion (302d) at a position deviating from the thread sliding direction of the adjusting block (503). A limiting groove (401) is provided at one end of the secondary connecting section (400) away from the secondary monitoring section (201), and the limiting groove (401) and the secondary monitoring section (201) are distributed on both sides of the rotating shaft (302d-1); The synchronous moving member (504) comprises a first connecting portion (504a) fixed to one side of the adjusting block (503), a second connecting portion (504b) rotatably connected to the first connecting portion (504a) and slidably connected to the guide column, and a limiting shaft (504c) provided at one side of the second connecting portion (504b) and slidably connected to the limiting groove (401).

11. An eddy current sensor, comprising the eddy current probe, characterized in that: Also includes, A preamplifier (700), the preamplifier (700) is used to provide a high-frequency oscillating current that generates an eddy current effect, and to convert a monitored signal change into a displacement of a monitored object; A transmission wire (800), the transmission wire (800) comprising a trunk line (801) connected to the preamplifier (700) at one end, and a branch line (802) connected to the main induction coil (101a) and the auxiliary induction coil (201a) at the other end, for transmitting current and feeding back monitoring signals; and A processing module is provided in the preamplifier (700) and is used to perform calculation processing based on the displacement change value ΔN measured by the secondary induction coil (201a) and the displacement change value ΔM measured by the primary induction coil (101a), and convert them into an actual change value of the distance between the inner core of the monitored object and the outer shell of the monitored object.

12. A method for testing an eddy current sensor, using the eddy current sensor, characterized in that: The steps include: After punching a hole in the outer shell of the monitored object, the main monitoring section (101) is fixed after being punched, and a first gap M between the main monitoring section (101) and the inner core of the monitored object is adjusted to be within the sensing monitoring range; Adjusting a second gap N between the auxiliary monitoring section (201) and the housing of the monitored object to be within the sensing monitoring range; The actual change value ΔL between the inner core of the monitored object and the outer shell of the monitored object is calculated according to the measured first gap change value ΔM and the second gap change value ΔN.

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