Micro-magnetic technology-based hardening nondestructive testing device and method for cutter ring of heading machine

Abstract

The application discloses a micro-magnetic technology-based hard rock tunneling machine roller cutter ring hardness nondestructive detection device and method, and belongs to the technical field of hard rock tunneling machine cutter ring detection. The application discloses a micro-magnetic technology-based hard rock tunneling machine roller cutter ring hardness nondestructive detection device and method, and belongs to the technical field of hard rock tunneling machine cutter ring detection. The application discloses a micro-magnetic technology-based hard rock tunneling machine roller cutter ring hardness nondestructive detection device and method, and belongs to the technical field of hard rock tunneling machine cutter ring detection. The application discloses a micro-magnetic technology-based hard rock tunneling machine roller cutter ring hardness nondestructive detection device and method, and belongs to the technical field of hard rock tunneling machine cutter ring detection. The application discloses a micro-magnetic technology-based hard rock tunneling machine roller cutter ring hardness nondestructive detection device and method, and belongs to the technical field of hard rock tunneling machine cutter ring detection. The application discloses a micro-magnetic technology-based hard rock tunneling machine roller cutter ring hardness nondestructive detection device and method, and belongs to the technical field of hard rock tunneling machine cutter ring detection. The application discloses a micro-magnetic technology-based hard rock tunneling machine roller cutter ring hardness nondestructive detection device and method, and belongs to the technical field of hard rock tunneling machine cutter ring detection. The application discloses a method for detecting the hardness of a roller cutter ring of a hard rock tunneling machine based on micro-magnetic technology.

Description

Technical Field

[0001] This invention relates to the field of tunneling machine cutter ring testing technology, specifically to a non-destructive testing device and method for the hardness of tunneling machine cutter rings based on micro-magnetic technology. Background Technology

[0002] Tunnel boring machines (TBMs) are large, complex, mechatronic, optical, and hydraulic integrated machines that perform excavation, muck removal, and support operations under the protection of a movable steel shield. Full-face hard rock TBMs are widely used in tunnel, subway, underground powerhouse, and water conservancy and hydropower projects due to their high efficiency and safety. Disc cutters, as key and vulnerable components of TBMs, account for approximately one-third of project costs and construction time in terms of maintenance and replacement, according to incomplete statistics. In environments with high ground stress, high quartz content, high compressive strength, high seepage pressure, frequent rock bursts, and complex geological formations, disc cutters experience high rock-breaking impact loads and severe wear. Therefore, higher demands are placed on the comprehensive mechanical properties of the cutter rings. To reduce wear, cutter rings with a hardness of 63-64 HRC have been manufactured; to reduce wear while minimizing cutter ring chipping, gradient hardness cutter rings with a soft core and hard edge, exhibiting a radial hardness gradient distribution, have been developed.

[0003] However, existing hobbing cutter ring hardness testing usually requires destructive testing of the cutter ring, and the testing methods are relatively cumbersome. Measuring the hardness at multiple points is time-consuming and labor-intensive. Furthermore, manual measurement of cutter ring hardness is prone to inaccurate results due to negligence, which affects the test results. Summary of the Invention

[0004] The main objective of this invention is to address the aforementioned technical problems to a certain extent by proposing a non-destructive testing device and method for the hardness of tunneling machine cutter rings based on micro-magnetic technology. This method can effectively avoid the waste of cutter rings caused by destructive testing methods and reduce production costs.

[0005] The above-mentioned problems to be solved by the present invention are achieved through the following technical solutions:

[0006] On one hand, a non-destructive testing device for the hardness of a tunnel boring machine cutter ring based on micro-magnetic technology is proposed, including a frame, a horizontal positioning component, a limiting component, a micro-magnetic sensor, a receiver, and a processor. The frame has a placement groove in which a cutter ring is placed, lying flat within the groove with its lateral surface in contact with the inner wall of the groove. The horizontal positioning component is located on the frame and on one side of the cutter ring, used for detecting the position of the cutter ring after it flips over. The limiting components are located on both sides of the cutter ring on the frame to assist in detecting the position of the cutter ring after it flips over. The micro-magnetic sensor is located in an mounting groove within the placement groove, used to receive micro-magnetic signal characteristics during the magnetization process of the side of the cutter ring in contact with the placement groove. The receiver is connected to the micro-magnetic sensor via a data cable, used to receive the signal transmitted by the micro-magnetic sensor. The processor is connected to the receiver via a data cable, used to receive the signal transmitted by the receiver.

[0007] In some embodiments, the limiting component includes a limiting seat and a limiting top rod. The limiting seat is fixed to the frame, and the limiting top rod is movably disposed in a first movable groove provided in the limiting seat. The limiting seat is provided with a clamping mechanism in a direction perpendicular to the limiting top rod. When the limiting top rod abuts against the outer wall of the hobbing cutter ring, the clamping mechanism abuts against the limiting top rod.

[0008] In some embodiments, the clamping mechanism includes a cover plate, a top ball, and a spring. The upper end face of the limiting seat is connected to the first movable groove and has a second movable groove. The cover plate is fixed to the limiting seat and seals the second movable groove. The spring and the top ball are disposed in the second movable groove. One end of the spring is connected to the cover plate, and the other end abuts against the top ball. The outer surface of the limiting rod is provided with a groove so that the top ball extends into the groove under the action of the spring.

[0009] In some embodiments, the two side walls of the groove that contact the top ball are provided with guide slopes.

[0010] In some embodiments, two-thirds of the top ball extends into the groove.

[0011] In some embodiments, the horizontal positioning assembly includes a base, a telescopic rod, a connecting frame, and a level. The base is disposed on the frame, the telescopic rod is disposed on the base, the connecting frame is disposed at the end of the telescopic rod away from the base and extends toward the hobbing cutter ring, and the level is disposed at the end of the connecting frame.

[0012] On the other hand, a non-destructive testing method for the hardness of a tunneling machine cutter ring based on micro-magnetic technology is provided, including the aforementioned testing device, and the specific testing steps are as follows:

[0013] A hardness prediction model for the hob ring is pre-established. The hob ring to be tested is placed on the frame and laid flat in the placement slot of the frame, with half of the lateral surface of the hob ring in contact with the inner wall of the placement slot. The micro-magnetic signal on half of the hob ring in three-dimensional space is acquired by a micro-magnetic sensor, and then the micro-magnetic signal is transmitted to the processor by the receiver to obtain the micro-magnetic signal of half of the hob ring.

[0014] The hob cutter ring is flipped so that the transverse surface of the other half of the hob cutter ring is in contact with the inner wall of the placement groove and the relative position remains unchanged. Then, the micro magnetic signal on the three-dimensional space of the other half of the hob cutter ring is obtained by the micro magnetic sensor, and the micro magnetic signal is transmitted to the processor by the receiver to obtain the micro magnetic signal of the entire cutter ring.

[0015] The processor converts the micro-magnetic signal of the entire hob ring into a three-dimensional hardness field based on a pre-established hob ring hardness prediction model.

[0016] In some embodiments, for the material of the hobbing cutter ring, samples of hobbing cutter ring with different hardness are obtained based on different heat treatment processes. The micro-magnetic signal characteristics of the hobbing cutter ring samples with different hardness are obtained by multiple sets of micro-magnetic sensors. At the same time, the micro-magnetic signal characteristic curve is fitted based on the multiple linear regression method. The correlation coefficient is calculated by the hobbing cutter ring hardness corresponding to multiple sets of micro-magnetic detection signals, thereby establishing a hobbing cutter ring hardness prediction model.

[0017] In some embodiments, the fitting function equation for fitting the characteristic curve of the micromagnetic signal based on the multiple linear regression method is as follows:

[0018] y=a1·Δμ+a2·MFE+a3·HA+a4·BN+R

[0019] Where Δμ is the incremental permeability, MFE is the multi-frequency eddy current, HA is the tangential magnetic field, BN is the Barkhausen noise signal, y is the blade ring hardness, R is the residual error, a1 is the incremental permeability coefficient, a2 is the multi-frequency eddy current coefficient, a3 is the tangential magnetic field coefficient, and a4 is the Barkhausen noise signal coefficient.

[0020] The technical solution provided in this application has the following advantages compared with the prior art:

[0021] This invention utilizes the detection principle of micro-magnetic technology. A micro-magnetic sensor generates an excitation current to magnetize the hobbing ring placed on the frame. The micro-magnetic signal characteristics are transmitted to a processor via a receiver to obtain the micro-magnetic signal of one half of the hobbing ring. The hobbing ring is then flipped to obtain the micro-magnetic signal of the other half. Based on a pre-predictive model, the hardness field of the hobbing ring is obtained from the measured micro-magnetic signal. This detection method effectively avoids destructive hobbing ring hardness detection methods that lead to hobbing ring waste, reducing production costs. The testing method is simple, does not require manual measurement of multiple points on the hobbing ring, reduces workload, and improves the accuracy of hobbing ring hardness results.

[0022] Furthermore, the horizontal positioning component ensures the levelness of the cutter ring during testing, while the limiting component improves the stability of the cutter ring's position on the frame during testing. Simultaneously, the cooperation between the horizontal positioning and limiting components ensures the testing position of the cutter ring after it has been flipped, maintaining the circumferential relative position during testing. This non-destructive testing of the cutter ring allows for repeated heat treatment experiments on the same cutter ring, effectively reducing the manufacturer's production costs. It also enables hardness testing of the cutter rings before they leave the factory, improving the yield rate, reducing the number of abnormal failures, and increasing the construction efficiency of the tunneling machine. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0024] Figure 1 This is a structural diagram of the non-destructive testing device for the hardness of the tunneling machine cutter ring based on micro-magnetic technology according to the present invention;

[0025] Figure 2 This is a structural diagram of the horizontal positioning component of the present invention;

[0026] Figure 3 This is a structural diagram of the limiting component and the clamping mechanism of the present invention;

[0027] Figure 4 This is a comparison between the hardness of the hobbing cutter ring detected by this invention and the predicted model.

[0028] Explanation of icon numbers:

[0029] 100-Rolling cutter ring; 1-Frame; 2-Horizontal positioning assembly; 201-Base; 202-Telescopic rod; 203-Connecting frame; 204-Level indicator; 3-Limiting assembly; 301-Limiting seat; 302-Limiting top rod; 4-Micro magnetic sensor; 5-Receiver; 6-Processor; 7-Tightening mechanism; 701-Cover plate; 702-Top ball; 703-Spring; 8-Groove. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0032] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0033] like Figure 1-3As shown, a non-destructive testing device for the hardness of a tunnel boring machine cutter ring based on micro-magnetic technology is proposed, including a frame 1, a horizontal positioning component 2, a limiting component 3, a micro-magnetic sensor 4, a receiver 5, and a processor 6. The frame 1 has a placement groove, in which a cutter ring 100 is placed, with the cutter ring 100 laid flat in the placement groove and its transverse surface in contact with the inner wall of the placement groove. The horizontal positioning component 2 is located on the frame 1 and on one side of the cutter ring 100, and is used to detect the position of the cutter ring 100 after it flips over. The frame 1 has limiting components 3 on both sides of the cutter ring 100 to assist in detecting the position of the cutter ring 100 after it flips over. The micro-magnetic sensor 4 is located in the mounting groove of the placement groove, and is used to receive the micro-magnetic signal characteristics of the side of the cutter ring 100 that is in contact with the placement groove during the magnetization process. The receiver 5 is connected to the micro-magnetic sensor 4 via a data cable, and is used to receive the signal transmitted by the micro-magnetic sensor 4. The processor 6 is connected to the receiver 5 via a data cable, and is used to receive the signal transmitted by the receiver 5.

[0034] This embodiment ensures the horizontality of the cutter ring 100 during testing by using a horizontal positioning component 2, and improves the stability of the cutter ring 100's position on the frame 1 during testing by a limiting component 3. Simultaneously, the cooperation between the horizontal positioning component 2 and the limiting component 3 ensures the testing position of the cutter ring 100 after it has been flipped, maintaining the circumferential relative position after flipping. This non-destructive testing of the cutter ring allows for repeated heat treatment experiments on the same cutter ring 100, effectively reducing the manufacturer's production costs. It also allows for hardness testing of the cutter rings before they leave the factory, improving the yield rate, reducing the number of abnormal failures, and increasing the construction efficiency of the tunneling machine.

[0035] like Figure 3 As shown, the limiting component 3 includes a limiting seat 301 and a limiting rod 302. The limiting seat 301 is fixed to the frame 1, and the limiting rod 302 is movably disposed in the first movable groove provided in the limiting seat 301. A clamping mechanism 7 is provided inside the limiting seat 301 in the direction perpendicular to the limiting rod 302. When the limiting rod 302 abuts against the outer wall of the hobbing cutter ring 100, the clamping mechanism 7 abuts against the limiting rod 302.

[0036] like Figure 3 As shown, the clamping mechanism 7 includes a cover plate 701, a top ball 702, and a spring 703. The upper end face of the limiting seat 301 is connected to the first movable groove and has a second movable groove. The cover plate 701 is fixed to the limiting seat 301 and seals the second movable groove. The spring 703 and the top ball 702 are located in the second movable groove. One end of the spring 703 is connected to the cover plate 701, and the other end abuts against the top ball 702. The outer surface of the limiting rod 302 is provided with a groove 8 so that the top ball 702 extends into the groove 8 under the action of the spring 703.

[0037] In some embodiments, one end of the spring 703 is welded to the cover plate 701, and the top ball 702 is welded to the other end of the spring 703. After the cover plate 701 is assembled into the limiting seat 301, the spring 703 and the top ball 702 are both placed in the second movable groove, while the limiting rod 302 is inserted into the first movable groove. The top ball 702 abuts against the outer wall of the limiting rod 302 under the action of the spring 703.

[0038] Place the hobbing cutter ring 100 to be tested in the placement slot of the frame 1, then push the position of the limiting rod 302, so that the ends of the limiting rods 302 on both sides are in a tight state against the outer wall of the hobbing cutter ring 100. At this time, the groove 8 of the limiting rod 302 is aligned with the second movable groove, and the top ball 702 will extend into the groove 8 under the action of the spring 703, thereby fixing the position of the limiting rod 302 and ensuring the tightness effect of the limiting rod 302 against the hobbing cutter ring 100.

[0039] like Figure 2 As shown, the horizontal positioning assembly 2 includes a base 201, a telescopic rod 202, a connecting frame 203, and a level 204. The base 201 is located on the frame 1, the telescopic rod 202 is located on the base 201, the connecting frame 203 is located at the end of the telescopic rod 202 away from the base 201 and extends toward the hobbing cutter ring 100, and the level 204 is located at the end of the connecting frame 203.

[0040] In this embodiment, after the limiting top rod 302 abuts against both sides of the hob cutter ring 100, the telescopic rod 202 is retracted, and the connecting frame 203 drives the level 204 to move down, so that the level 204 is in contact with the upper end surface of the hob cutter ring 100 to detect the levelness of the hob cutter ring 100 during the test, and after confirming the levelness, the hardness test is started on half of the hob cutter ring 100.

[0041] After the test is completed, the limiting rod 302 will be pulled to release its clamping force on the hobbing cutter ring 100. In order to facilitate the pulling of the limiting rod 302, the top ball 702 will disengage from the groove 8. Guide slopes are provided on the two side walls of the groove 8 where the top ball 702 contacts the groove 8, and two-thirds of the top ball 702 extends into the groove 8. After the limiting rod 302 is released, the hobbing cutter ring 100 will be flipped to test the other half. After flipping, the limiting rod 302 will clamp the outer wall of the hobbing cutter ring 100 again. Then, the level of the hobbing cutter ring 100 after flipping will be confirmed again by the level instrument 204, and it will be ensured that the level after flipping is the same as before, so as to ensure that the relative position of the hobbing cutter ring 100 for testing remains unchanged after flipping.

[0042] The testing method of the non-destructive testing device for the hardness of the cutter ring of a tunneling machine based on micro-magnetic technology, and its specific testing steps are as follows:

[0043] A hardness prediction model for the hob ring 100 is pre-established. The hob ring 100 to be tested is placed on the frame 1 and laid flat in the placement slot of the frame 1, with half of the transverse surface of the hob ring 100 in contact with the inner wall of the placement slot. The micro-magnetic signal on half of the hob ring 100 in three-dimensional space is acquired by the micro-magnetic sensor 4, and then the micro-magnetic signal is transmitted to the processor 6 by the receiver 5 to obtain the micro-magnetic signal of half of the hob ring 100.

[0044] The micro-magnetic signals include, but are not limited to, incremental permeability, multi-frequency eddy currents, tangential magnetic fields, and Barkhausen noise signals. The Rockwell hardness of the cutting ring is measured by a Rockwell hardness tester, and a mapping is established with the micro-magnetic signals measured by the micro-magnetic sensor 4 as the independent variable and the cutting ring hardness as the dependent variable.

[0045] The hob cutter ring 100 is flipped so that the transverse surface of the other half of the hob cutter ring 100 is in contact with the inner wall of the placement groove and the relative position remains unchanged. Then, the micro magnetic sensor 4 acquires the micro magnetic signal in the three-dimensional space of the other half of the hob cutter ring 100, and the receiver 5 transmits the micro magnetic signal to the processor 6 to obtain the micro magnetic signal of the entire cutter ring.

[0046] like Figure 4 As shown, the processor 6 converts the micro-magnetic signal of the entire hob ring into a three-dimensional hardness field based on the pre-established hardness prediction model of the hob ring 100.

[0047] For the material of the hobbing cutter ring 100, samples of hobbing cutter ring 100 with different hardness were obtained based on different heat treatment processes. The micro-magnetic signal characteristics of the hobbing cutter ring 100 samples with different hardness were obtained by multiple sets of micro-magnetic sensors 4. At the same time, the micro-magnetic signal characteristic curve was fitted based on the multiple linear regression method. The correlation coefficient was calculated by the hardness of hobbing cutter ring 100 corresponding to multiple sets of micro-magnetic detection signals, thereby establishing a hardness prediction model for hobbing cutter ring 100.

[0048] The fitting function equation for the characteristic curve of the micromagnetic signal based on the multiple linear regression method is as follows:

[0049] y=a1·Δμ+a2·MFE+a3·HA+a4·BN+R

[0050] Where Δμ is the incremental permeability, MFE is the multi-frequency eddy current, HA is the tangential magnetic field, BN is the Barkhausen noise signal, y is the blade ring hardness, R is the residual error, a1 is the incremental permeability coefficient, a2 is the multi-frequency eddy current coefficient, a3 is the tangential magnetic field coefficient, and a4 is the Barkhausen noise signal coefficient.

[0051] This invention utilizes the detection principle of micro-magnetic technology. A micro-magnetic sensor 4 generates an excitation current to magnetize the hobbing cutter ring 100 placed on the frame 1. The micro-magnetic signal characteristics are transmitted to the processor 6 via the receiver 5 to obtain the micro-magnetic signal of one half of the hobbing cutter ring 100. The hobbing cutter ring 100 is then flipped to obtain the micro-magnetic signal of the other half. Based on a pre-predictive model, the hardness field of the hobbing cutter ring 100 is obtained from the measured micro-magnetic signal. This detection method effectively avoids the waste of the hobbing cutter ring 100 caused by destructive hardness detection methods, reduces production costs, and simplifies the testing method. It does not require manual measurement of multiple points on the hobbing cutter ring 100, reducing workload and improving the accuracy of the hardness results.

[0052] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A non-destructive testing device for the hardness of a tunneling machine cutter ring based on micro-magnetic technology, characterized in that, include, The frame is provided with a placement slot, and a hobbing cutter ring is placed in the placement slot. The hobbing cutter ring is laid flat in the placement slot, and its transverse surface is in contact with the inner wall of the placement slot. A horizontal positioning component is provided on the frame and located on one side of the hobbing cutter ring, and is used to detect the position of the hobbing cutter ring after it is flipped. Limiting components are provided on both sides of the hob cutter ring on the frame to assist in detecting the position of the hob cutter ring after it has flipped over. A micro magnetic sensor is disposed in the mounting groove of the placement groove, and is used to receive the micro magnetic signal characteristics of the side of the hobbing cutter ring that is in contact with the placement groove during the magnetization process. A receiver, which is connected to the micro magnetic sensor via a data cable, is used to receive signals transmitted by the micro magnetic sensor; A processor, which is connected to the receiver via a data cable, is used to receive signals transmitted by the receiver.

2. The non-destructive testing device for the hardness of the tunneling machine cutter ring based on micro-magnetic technology according to claim 1, characterized in that, The limiting assembly includes a limiting seat and a limiting top rod. The limiting seat is fixed to the frame, and the limiting top rod is movably disposed in a first movable groove provided in the limiting seat. A tightening mechanism is provided inside the limiting seat in a direction perpendicular to the limiting top rod. When the limiting top rod abuts against the outer wall of the hobbing cutter ring, the tightening mechanism abuts against the limiting top rod.

3. The non-destructive testing device for the hardness of the tunneling machine cutter ring based on micro-magnetic technology according to claim 2, characterized in that, The clamping mechanism includes a cover plate, a top ball, and a spring. The upper end face of the limiting seat is connected to the first movable groove and has a second movable groove. The cover plate is fixed to the limiting seat and seals the second movable groove. The spring and the top ball are located in the second movable groove. One end of the spring is connected to the cover plate, and the other end abuts against the top ball. The outer surface of the limiting rod is provided with a groove so that the top ball extends into the groove under the action of the spring.

4. The non-destructive testing device for the hardness of the tunneling machine cutter ring based on micro-magnetic technology according to claim 3, characterized in that, The two side walls of the groove that contact the top ball are provided with guide slopes.

5. The non-destructive testing device for the hardness of the tunneling machine cutter ring based on micro-magnetic technology according to claim 3, characterized in that, Two-thirds of the top ball extends into the groove.

6. The non-destructive testing device for the hardness of the tunneling machine cutter ring based on micro-magnetic technology according to claim 1, characterized in that, The horizontal positioning assembly includes a base, a telescopic rod, a connecting frame, and a level. The base is located on the frame, the telescopic rod is located on the base, the connecting frame is located at the end of the telescopic rod away from the base and extends towards the hobbing cutter ring, and the level is located at the end of the connecting frame.

7. A non-destructive testing method for the hardness of a tunneling machine cutter ring based on micro-magnetic technology, characterized in that, The detection device according to any one of claims 1-6 includes the following specific detection steps: A hardness prediction model for the hob ring is pre-established. The hob ring to be tested is placed on the frame and laid flat in the placement slot of the frame, with half of the lateral surface of the hob ring in contact with the inner wall of the placement slot. The micro-magnetic signal on half of the hob ring in three-dimensional space is acquired by a micro-magnetic sensor, and then the micro-magnetic signal is transmitted to the processor by the receiver to obtain the micro-magnetic signal of half of the hob ring. The hob cutter ring is flipped so that the transverse surface of the other half of the hob cutter ring is in contact with the inner wall of the placement groove and the relative position remains unchanged. Then, the micro magnetic signal on the three-dimensional space of the other half of the hob cutter ring is obtained by the micro magnetic sensor, and the micro magnetic signal is transmitted to the processor by the receiver to obtain the micro magnetic signal of the entire cutter ring. The processor converts the micro-magnetic signal of the entire hob ring into a three-dimensional hardness field based on a pre-established hob ring hardness prediction model.

8. The method for non-destructive testing of the hardness of the cutter ring of a tunneling machine based on micro-magnetic technology according to claim 7, characterized in that, Based on the material of the hobbing cutter ring and different heat treatment processes, samples of hobbing cutter ring with different hardness were obtained. The micro-magnetic signal characteristics of the hobbing cutter ring samples with different hardness were obtained by multiple sets of micro-magnetic sensors. At the same time, the micro-magnetic signal characteristic curves were fitted by the multiple linear regression method. The correlation coefficient was calculated by the hobbing cutter ring hardness corresponding to multiple sets of micro-magnetic detection signals, thereby establishing a hobbing cutter ring hardness prediction model.

9. The method for non-destructive testing of the hardness of the cutter ring of a tunneling machine based on micro-magnetic technology according to claim 8, characterized in that, The fitting function equation for the characteristic curve of the micromagnetic signal based on the multiple linear regression method is as follows: y=a1·Δμ+a2·MFE+a3·HA+a4·BN+R Where Δμ is the incremental permeability, MFE is the multi-frequency eddy current, HA is the tangential magnetic field, BN is the Barkhausen noise signal, y is the blade ring hardness, R is the residual error, a1 is the incremental permeability coefficient, a2 is the multi-frequency eddy current coefficient, a3 is the tangential magnetic field coefficient, and a4 is the Barkhausen noise signal coefficient.

Images