A shield cutter wear detection system and method based on electromagnetic mutual inductance

Abstract

The application discloses a shield cutter wear detection system and method based on electromagnetic mutual inductance, and the system comprises an electromagnetic mutual inductance sensing unit, a wireless transmission unit and a computer control processing unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geotechnical engineering, and particularly relates to a shield cutter wear detection system and method based on electromagnetic mutual inductance. BACKGROUND

[0002] The statements herein are provided only to enhance understanding of the present application and are not necessarily intended to constitute the prior art.

[0003] The shield method is widely used in tunnel construction due to its safety and fast tunneling speed. The cutter head is installed at the forefront of the shield machine, and the cutters on the rotating cutter head cut the soil layer of the excavation face. The cutters bear a large cutting load and are constantly worn out. During the shield tunneling process, complex stratum environments are often encountered, and the disc cutters are easily worn or failed. If they are not replaced in time, it will lead to a decrease in shield tunneling efficiency or even damage to the cutter head.

[0004] The current commonly used detection method is manual opening and detection, which has high cost and high risk. There are many cutter wear detection methods in tunnel construction. The gas detection method detects whether the cutter is worn out by discovering the pre-compressed chemical gas in the cutter through a gas detection device. The method is simple but the effect is unstable, especially in earth pressure balance shield and slurry shield. The hydraulic wear detection technology is widely used, but the structure is complex, different height wear detection cutters cannot be installed at many positions, and wear positioning cannot be performed. The metal detection of the electrical wear detection technology has low reliability and is prone to false positives. The tunneling parameter analysis method has the disadvantages of being not intuitive and not accurate. Therefore, as more and more tunnels are built across rivers and seas, shield cutter replacement becomes more difficult, and higher requirements are put forward for cutter working state monitoring, and the existing detection methods all have certain defects. SUMMARY

[0005] In view of the problems in the prior art, the present application provides a shield cutter wear detection system and method based on electromagnetic mutual inductance. By establishing a shield cutter wear detection system based on electromagnetic mutual inductance, a real-time shield cutter state detection scheme is formed to provide effective guidance for shield cutter replacement decision.

[0006] The technical scheme of the present application is as follows:

[0007] In the first aspect of the present application, a shield cutter wear detection system based on electromagnetic mutual inductance is provided, characterized by comprising:

[0008] An electromagnetic mutual inductance sensing unit is used to impart magnetism to the disc cutter ring and acquire a disc cutter ring magnetic field signal.

[0009] A wireless transmission unit is used to transmit the acquired magnetic field signal to a computer control processing unit.

[0010] A computer control processing unit is used to analyze the tool wear of the magnetic field signal and guide the tool replacement timing of the shield machine.

[0011] In some embodiments of the present application, the electromagnetic mutual inductance sensing unit comprises a permanent magnet, a measuring plate and a battery pack arranged in a shell which is mounted on the inner wall of the shield machine cutter box through a fixing plate.

[0012] In some embodiments of the present application, an electromagnetic mutual inductance sensing unit is installed at the place where the cutter ring is prone to wear.

[0013] In some embodiments of the present application, the measuring plate adopts a Hall element.

[0014] In some embodiments of the present application, the wireless transmission unit comprises a wireless transmission internal receiving device arranged in the interior of a nylon block which is fixedly mounted on the inner wall of the shield soil cabin.

[0015] In some embodiments of the present application, the wireless transmission internal receiving device is connected to an external signal acquisition device through a communication line, and the external signal acquisition device is fixedly mounted outside the shield soil cabin.

[0016] In some embodiments of the present application, a hole is opened on the wall of the shield soil cabin for the communication line to pass through, and a sealing valve is arranged at the hole for sealing.

[0017] In some embodiments of the present application, the computer control processing unit comprises a tool wear analysis module and a tool replacement decision module, the tool wear analysis module is used to analyze the tool wear of the magnetic field signal, and the tool replacement decision module is used to guide the tool replacement timing of the shield machine.

[0018] In the second aspect of the present application, a shield cutter wear detection method based on electromagnetic mutual inductance is provided, comprising the following steps:

[0019] The monitoring surface of the electromagnetic mutual inductance sensing unit faces the cutter ring, the electromagnetic mutual inductance sensing unit magnetizes the cutter ring and monitors the magnetic field signal of the cutter ring in real time, the wireless transmission unit transmits the acquired magnetic field signal to the computer control processing unit, the computer control processing unit analyzes the tool wear of the magnetic field signal and guides the tool replacement timing of the shield machine.

[0020] In some embodiments of the present application, when the magnetic field signal has a waveform output, the cutter ring is worn.

[0021] The one or more technical solutions of the present application have the following beneficial effects:

[0022] 1、Compared with the traditional method, the tool wear state real-time monitoring is realized by the change of magnetic flux of the magnetic field in the cutter wear process.

[0023] 2、The invention overcomes the problem that signals cannot be transmitted in a closed soil cabin environment, and realizes signal transmission in a closed soil cabin environment of a shield.

[0024] 3、The system has tool state analysis and prediction function, and can provide guidance for shield tool changing decision.

[0025] 4、The invention provides a new detection method for shield tool detection, which has the characteristics of high efficiency and high precision, and is convenient for popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structural diagram of the shield cutter wear detection system based on electromagnetic mutual inductance of the invention;

[0027] Figure 2 is a schematic diagram of the installation structure of the electromagnetic mutual inductance sensing unit of the invention;

[0028] Figure 3 is a schematic diagram of the installation structure of the wireless transmission unit of the invention;

[0029] Figure 4 is a flowchart of the shield cutter wear detection method based on electromagnetic mutual inductance of the invention.

[0030] In the figure: 1, electromagnetic mutual inductance sensing unit; 2, wireless transmission unit; 3, computer control processing unit; 4, cutter ring; 5, measuring plate; 6, permanent magnet; 7, battery pack; 8, shell; 9, cutter box inner wall; 10, fixed plate; 11, shield soil cabin inner wall; 12, nylon block; 13, wireless transmission internal receiving position; 14, fixing device. DETAILED DESCRIPTION

[0031] The invention will be further described below in combination with the drawings and examples.

[0032] Example 1

[0033] In a typical embodiment of the invention, a shield cutter wear detection system based on electromagnetic mutual inductance is provided, as shown in Figure 1 , comprising:

[0034] The electromagnetic mutual inductance sensing unit 1 is used to impart magnetic properties to the cutter ring and obtain the magnetic field signal of the cutter ring.

[0035] The wireless transmission unit 2 is used to transmit the obtained magnetic field signal to the computer control processing unit.

[0036] The computer control processing unit 3 is used for cutter wear analysis of the magnetic field signal and guiding the shield machine cutter replacement time.

[0037] In the embodiment, as shown in the figure, Figure 2 The electromagnetic mutual inductance sensing unit 1 includes a permanent magnet 6, a measuring plate 5 and a battery pack 7 arranged in a shell 8, the shell 8 is installed on the cutter box inner wall 9 of the shield machine through a fixing plate 10, the shell 8 is made of fully enclosed super-strength stainless steel, which protects the electromagnetic mutual inductance sensing unit. The measuring plate 5 of the electromagnetic mutual inductance sensing unit is opposite to the cutter ring, and the permanent magnet 6 is located at the upper part of the measuring plate 5.

[0038] Further, one electromagnetic mutual inductance sensing unit is installed at the key position where the cutter ring is easy to wear.

[0039] In the embodiment, the measuring plate 5 adopts a Hall element, the working principle of which is that a semiconductor sheet (Hall element) is placed in a magnetic field with a magnetic induction intensity B, the magnetic field direction is perpendicular to the sheet, when current I flows through the sheet, an electromotive force eh (called Hall electromotive force) will be generated in the direction perpendicular to the current and the magnetic field. The Hall element is powered by the battery pack 7. The detection principle of the measuring plate 5 in the embodiment is that the cutter ring has a certain magnetic field intensity after being endowed with magnetism, the Hall element is placed in the magnetic field, when the cutter ring itself is worn, the magnetic field intensity changes, thereby the electromotive force of the Hall element changes, thereby the electromotive force change signal is transmitted to the computer through wireless transmission signal, which is not affected by the permanent magnet magnetic field in the working process.

[0040] In the embodiment, as shown in the figure, Figure 3 The wireless transmission unit 2 includes a wireless transmission internal receiving device 13 arranged in the interior of a nylon block 12 fixedly installed on the shield soil cabin inner wall 11, the wireless transmission internal receiving device 13 is connected with an external signal acquisition device fixedly installed outside the shield soil cabin through a communication line, the internal receiving device receives the measuring signal of the electromagnetic mutual inductance sensing unit and transmits the measuring signal to the external signal acquisition device through the communication line, the shielding effect of the soil cabin signal is solved through the wireless transmission internal receiving device 13 and the external receiving device. Further, a hole is opened on the wall surface of the shield soil cabin for the communication line to pass through, a sealing valve is arranged at the hole for sealing, so as to ensure the sealing property of the soil cabin.

[0041] In the embodiment, the computer control processing unit includes a tool wear analysis module and a tool replacement decision module, the tool wear analysis module is used for tool wear analysis on the magnetic field signal, a matching relationship between the voltage change of the Hall element in the measurement plate after the magnetic field is established and the wear information is matched, a tool wear and voltage change relationship curve is fitted, and the tool wear amount is analyzed according to the relationship curve rule; the tool replacement decision module is used for guiding the tool replacement time of the shield machine, setting a tool wear threshold, and issuing a tool replacement warning after the tool wear reaches the threshold range.

[0042] The working principle of the shield tool wear detection system based on electromagnetic mutual induction provided in the embodiment is as follows:

[0043] The electromagnetic mutual induction sensing unit 1 is mainly used for giving the cutter ring of the roller cutter magnetism and monitoring the magnetic field change of the roller cutter, and includes a permanent magnet 6, a measurement plate 5, and a large-capacity rechargeable battery pack 7, wherein the permanent magnet 6 is used for magnetizing the cutter ring 4 under the action of an external magnetic field, the measurement plate 5 is used for monitoring the magnetic change of the cutter ring, when the cutter ring 4 is defect-free, most of the magnetic force passes through the cutter ring 4, and the magnetic force lines are uniformly distributed inside the cutter ring 4, when there is a defect, the magnetic force lines are bent, and a part of the magnetic force lines leak, the leakage magnetic field signal change is detected by using a Hall element, so that the existence of the defect can be effectively detected, a voltage difference is formed by the Hall element inside the measurement plate 5 after the magnetic field signal changes, and the matching relationship between the tool wear amount and the Hall voltage is obtained by measuring the voltage change. The large-capacity rechargeable battery pack 7 is used for supplying power to the measurement plate 5 to ensure power supply in the running state.

[0044] The wireless transmission unit 2 receives the voltage change signal converted by the measurement plate after the cutter magnetic field change monitored by the electromagnetic mutual induction sensing unit, and transmits the voltage change signal to the computer control processing unit 3 outside the earth chamber, the computer control processing unit 3 analyzes the tool wear amount according to the tool wear and voltage change relationship curve, and overcomes the signal shielding problem in the earth chamber through the earth chamber layout mode of the wireless transmission unit.

[0045] The computer control processing unit 3 and the electromagnetic mutual induction sensing unit 1 of the cutter in the shield earth chamber communicate with each other, include a tool wear analysis module to realize rapid analysis of tool wear, and a tool replacement decision module to guide the tool replacement time of the shield machine.

[0046] The use method of the shield tool wear detection system based on electromagnetic mutual induction provided in the embodiment is as follows:

[0047] A, welding the electromagnetic mutual induction sensing system fixing plate 10 at the position of the shield cutterhead cutter box opposite to the roller cutter ring 4, fixing the electromagnetic mutual induction sensing system 1, the monitoring surface of the electromagnetic mutual induction sensing system 1 is opposite to the roller cutter ring 4, and the sensing system is calibrated on site, and the tool state monitoring is carried out;

[0048] B, the wireless transmission device 13 is arranged at the upper part of the inner wall 11 of the earth chamber of the shield machine. The inner receiving device of the wireless transmission device is arranged in the nylon block 12 and fixed on the inner wall of the earth chamber by a steel plate. The inner receiving device 13 is connected with the external signal collecting end through a communication line passing through the opening position. The external signal collecting end is fixed outside the earth chamber and transmits signals to the computer control processing system 3. The opening position of the earth chamber wall is sealed by a sealing valve.

[0049] C, the computer control processing system 3 imports the monitoring data into the system, the system automatically analyzes the tool wear information and predicts the tool wear, and guides the tool replacement time of the shield machine.

[0050] Embodiment 2

[0051] In a typical embodiment of the present application, a shield cutter wear detection method based on electromagnetic mutual inductance is provided, as shown in the accompanying drawings, comprising the following steps: Figure 4

[0052] The monitoring surface of the electromagnetic mutual inductance sensing unit is opposite to the cutter ring. After the electromagnetic mutual inductance sensing unit magnetizes the cutter ring, the magnetic field signal of the cutter ring is monitored in real time. The wireless transmission unit transmits the acquired magnetic field signal to the computer control processing unit. The computer control processing unit analyzes the tool wear of the magnetic field signal and guides the tool replacement time of the shield machine.

[0053] Further, when the magnetic field signal has a waveform output, the cutter ring is worn.

[0054] Although the specific embodiments of the present application are described above with reference to the accompanying drawings, the present application is not limited to the above-described embodiments. It should be understood by those skilled in the art that various modifications or changes can be made to the technical solutions of the present application without creative labor, and such modifications or changes are still within the protection scope of the present application.​

Claims

1. A shield cutter wear detection system based on electromagnetic mutual inductance, characterized by, It comprises: An electromagnetic mutual inductance sensing unit for imparting magnetism to the cutter ring and obtaining the cutter ring magnetic field signal; A wireless transmission unit for receiving the voltage change signal converted by the measuring plate after the cutter magnetic field change monitored by the electromagnetic mutual inductance sensing unit and transmitting the obtained magnetic field signal to the computer control processing unit; The computer control processing unit is used for cutter wear analysis of the magnetic field signal and guiding the shield machine cutter replacement timing; The electromagnetic mutual inductance sensing unit comprises a permanent magnet, a measuring plate and a battery pack arranged in a shell, and the shell is installed on the inner wall of the shield machine cutter box through a fixing plate; An electromagnetic mutual inductance sensing unit is installed at the cutter ring where wear is prone to occur; The wireless transmission unit comprises a wireless transmission internal receiving device arranged in the interior of a nylon block fixedly installed on the inner wall of the shield soil cabin; The wireless transmission internal receiving device is connected with an external signal acquisition device through a communication line, and the external signal acquisition device is fixedly installed outside the shield soil cabin; A hole is opened on the wall of the shield soil cabin for the communication line to pass through, and a sealing valve is arranged at the hole for sealing.

2. The electromagnetic mutual inductance based shield cutter wear detection system of claim 1, wherein, The measuring plate adopts a Hall element.

3. The electromagnetic mutual inductance based shield cutter wear detection system of claim 1, wherein, The computer control processing unit comprises a cutter wear analysis module and a cutter replacement decision module, the cutter wear analysis module is used for cutter wear analysis of the magnetic field signal, and the cutter replacement decision module is used for guiding the shield machine cutter replacement timing.

4. A method for detecting wear of a shield cutter based on electromagnetic mutual inductance, which is implemented by using the detection system according to any one of claims 1-3, characterized in that, It comprises the following steps: The monitoring surface of the electromagnetic mutual inductance sensing unit is opposite to the cutter ring, the electromagnetic mutual inductance sensing unit magnetizes the cutter ring and monitors the magnetic field signal of the cutter ring in real time, the wireless transmission unit transmits the obtained magnetic field signal to the computer control processing unit, the computer control processing unit analyzes the cutter wear of the magnetic field signal and guides the shield machine cutter replacement timing.

5. The electromagnetic mutual inductance based shield cutter wear detection method of claim 4, wherein, When the magnetic field signal has waveform output, the cutter ring has wear.

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