Shield cutter wear dynamic monitoring system and monitoring method thereof

Abstract

The invention discloses a shield cutter abrasion dynamic monitoring system and a monitoring method thereof. The monitoring system comprises a hob, hob shafts are arranged at the two ends of the hob, and the hob is provided with side pressed faces; the strain gauge is fixed on the side pressed surface of the hobbing cutter in a welding manner and is used for converting the mechanical strain of the hobbing cutter into a resistance change signal; the resistance strain gauge is connected with the strain gauge through a flexible wire, is arranged at a position far away from a welding point of the strain gauge, and is used for receiving and processing a resistance change signal of the strain gauge; and the conductive slip ring coaxially sleeves the peripheral side of the hob shaft through a fixing structure and is used for leading out an output signal of the resistance strain gauge in a rotating state. According to the invention, the strain gauges are mounted in a high-stress area near the cutting edge, so that the tiny strain change of the tool can be sensitively captured, and accurate early warning of early wear such as microcracks and tipping can be realized.

Description

Technical Field

[0001] This invention relates to a dynamic monitoring system and method for wear of tunnel boring machine cutters. Background Technology

[0002] The tunnel boring machine's cutterhead is located within a sealed cutterhead and directly bears high-amplitude, high-impact, and multi-phase complex geological loads. Existing condition monitoring methods mainly include: Hall effect sensors are susceptible to interference from external electromagnetic fields (such as the magnetic field of tunnel boring machine motors and cables), which can cause distortion of measurement signals.

[0003] Acoustic emission sensors: Noise characteristics vary greatly under different geological conditions (such as hard rock and soft soil), requiring frequent adjustment of monitoring thresholds, resulting in poor adaptability.

[0004] Speed ​​sensor: It can only detect abnormalities by fluctuating tool speed (such as jamming or idling). It can only detect abnormalities after wear or failure causes mechanical transmission to be obstructed. It cannot provide early warning of micro-wear.

[0005] Temperature sensor: Temperature changes are delayed (especially when heat conduction inside the tool is slow), and cannot reflect instantaneous load impact or rapid wear in real time.

[0006] The above solutions are all "post-hoc" or "indirect" judgments, and cannot provide quantitative early warnings when the tool has micro-cracks, local chipping, or other early failure stages. They cannot achieve early warning and precise location of tool wear / damage.

[0007] Therefore, a dynamic monitoring system for shield tunneling cutter wear and its monitoring method are proposed. Summary of the Invention

[0008] The purpose of this invention is to provide a dynamic monitoring system and method for shield tunneling cutter wear, in order to overcome the shortcomings of existing technologies in achieving early warning and precise location of cutter wear / damage.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a dynamic monitoring system for shield tunneling cutter wear, comprising: A hob, wherein the hob is provided with hob shafts at both ends and has a side pressure-bearing surface; The strain gauge is fixed to the side pressure surface of the hob by welding and is used to convert the mechanical strain of the hob into a resistance change signal. A resistance strain gauge, connected to the strain gauge via a flexible wire and positioned away from the strain gauge welding point, is used to receive and process the resistance change signal of the strain gauge. A conductive slip ring is coaxially sleeved on the outer periphery of the hob shaft via a fixed structure, and is used to extract the output signal of the resistance strain gauge in the rotating state. A resistance strain gauge is electrically connected to the resistance strain meter via a conductive slip ring. It is used to collect and analyze the resistance change signal to determine the stress state and fatigue degree of the hob, thereby enabling early warning and location of tool wear or damage.

[0010] Preferably, the fixing structure includes a connecting cylinder disposed at the conductive slip ring. Multiple sets of fixing cylinder plates are evenly distributed circumferentially at the end of the connecting cylinder away from the conductive slip ring. Radially protruding positioning blocks are provided on the inner wall side of the multiple sets of fixing cylinder plates so that the fixing cylinder plates are engaged with the hob shaft side by the positioning blocks.

[0011] Preferably, the inner diameter of the multiple sets of fixed cylinder plates matches the outer diameter of the hob shaft, so that the multiple sets of fixed cylinder plates fit against the outer circumference of the hob shaft.

[0012] Preferably, the conductive slip ring is provided with an outer sleeve on the outer periphery of the connecting cylinder, and a locking cylinder is slidably connected inside the outer sleeve, and the inner diameter of the locking cylinder matches the outer diameter of the fixed cylinder plate.

[0013] Preferably, an annular limiting cavity is formed between the outer sleeve and the connecting cylinder, so that the outer sleeve limits the stroke of the locking cylinder through the limiting cavity.

[0014] Preferably, the outer periphery of the multiple sets of fixed cylinder plates is provided with external threads, and the inner wall of the locking cylinder is provided with internal threads that cooperate with the external threads. The locking cylinder synchronously and radially presses the multiple sets of fixed cylinder plates against the hob shaft side through the helical cooperation of the internal and external threads.

[0015] Preferably, the hob shaft is provided with multiple sets of axial positioning grooves on the outer periphery of the locking cylinder, and the multiple sets of axial positioning grooves are inserted and engaged with the positioning block to prevent the fixed cylinder plate from moving circumferentially and axially relative to the hob shaft.

[0016] Preferably, the resistance strain gauge is bonded to the side pressure surface of the roller with high-temperature resistant epoxy adhesive.

[0017] A monitoring method for a dynamic monitoring system for tunnel boring machine cutter wear includes the following steps: S1. On the side of the hob under pressure, select the area near the cutting edge and where stress is concentrated as the strain measurement point, and use welding to firmly fix the strain gauge to the surface of this area. S2. Connect the resistance strain gauge to the strain gauge via a flexible wire, and apply a 0.1 mm thick layer of high-temperature resistant epoxy adhesive evenly to the side away from the strain gauge welding point to bond the resistance strain gauge. S3. The conductive slip ring is coaxially sleeved on the outer periphery of the hob shaft through the fixing structure, so that the fixing cylinder plate is engaged with the hob shaft side by the positioning block; S4. Remove the locking cylinder from the outer sleeve and use the internal and external threads to radially press the locking cylinder against the fixing plate, thereby achieving synchronous fixing of the conductive slip ring and the hob shaft. S5. Ensure that the rotating part of the conductive slip ring rotates synchronously with the hob shaft, and the stationary part is connected to the data acquisition instrument to form a signal transmission channel; S6. Dynamic monitoring of shield cutter wear.

[0018] S61. When the cutter comes into contact with the soil and rock and bears the normal load during the excavation process, mechanical strain is generated on its surface. The strain gauges attached to the pressure surface of the cutter side undergo synchronous tensile or compressive deformation, which causes the length and cross-sectional area of ​​the internal sensitive grid to change. According to the law of resistance, as shown in formula (1): R = ρ•AL (1) Where R is the strain gauge resistance value, ρ is the resistivity material constant, L is the sensing grid length, and A is the cross-sectional area; When the strain gauge is subjected to force and deforms, L and A undergo slight changes, resulting in a slight change in resistance ΔR. The relationship between them is described by the strain coefficient K, as shown in formula (2): R / ΔR=K•ε (2) Where ε is mechanical strain and K is the strain sensitivity coefficient constant, which is taken as 2.0; S62. The resistance strain acquisition instrument provides a constant excitation voltage to the resistance strain gauge through a conductive slip ring and connects the ΔR to a Wheatstone bridge to output an analog voltage signal proportional to ΔR, as shown in formula (3). ΔU=1 / 4⋅U exc •K•ε (3) Among them, U exc The excitation voltage is ΔU, and the output voltage change is ΔU. S63. The analog voltage signal is transmitted back to the resistance strain acquisition instrument through the same conductive slip ring, and after being amplified, filtered and converted from analog to digital, the digital strain value ε is obtained. S64. Compare the strain value ε with the preset threshold εth. When ε≥εth, immediately issue a wear warning signal and simultaneously record the current cutter head rotation angle and feed position to achieve rapid positioning of the faulty hobbing cutter. S65. If the strain value ε continues to rise above the preset threshold, it is determined to be progressive tool wear; if the strain value ε jumps instantaneously, it is determined to be tool chipping or crack initiation; if the strain value ε fluctuates periodically, it may be local tool damage or uneven wear; based on the strain gauge placement, the wear area is preliminarily determined.

[0019] In the above technical solution, the shield tunneling cutter wear dynamic monitoring system and monitoring method provided by the present invention have the following beneficial effects: This device uses strain gauges installed in high-stress areas near the cutting edge to sensitively capture minute strain changes in the tool, enabling accurate early warning of early wear such as microcracks and chipping. It detects faults earlier than traditional speed and temperature sensors, thus avoiding sudden failures and improving the overall reliability of the equipment.

[0020] Knowing the wear condition of the hob in advance allows for the planning of maintenance or replacement, avoiding unnecessary emergency repairs and reducing the high maintenance costs caused by sudden failures.

[0021] The fixed structure ensures a stable connection between the conductive slip ring and the hob shaft, enhances the connection strength between them, and prevents movement and ensures precise position control, thus guaranteeing the long-term and stable operation of the tool wear dynamic monitoring system.

[0022] Compared with traditional bolt fixing, the design of the fixing structure is more flexible and convenient, enabling the entire system to maintain high stability and convenience in complex shield tunneling environments, thus providing reliable support for the monitoring and analysis of tool wear. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the conductive slip ring side structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the hobbing cutter structure provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the cross-sectional structure of the conductive slip ring provided in an embodiment of the present invention; Figure 5 This is an enlarged schematic diagram of the structure at point A provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of a fixed cylindrical plate structure provided in an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached drawings: 1. Hob; 11. Hob shaft; 111. Axial positioning groove; 12. Side pressure surface; 2. Strain gauge; 3. Resistance strain gauge; 4. Conductive slip ring; 5. Fixing structure; 51. Connecting cylinder; 52. Fixing cylinder plate; 521. Positioning block; 522. External thread; 53. Outer sleeve; 54. Locking cylinder; 541. Internal thread; 57. Limiting clamping cavity. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] Please see Figure 1-6 The present invention provides a technical solution: a shield tunneling cutter wear dynamic monitoring system, a roller cutter 1, wherein the roller cutter 1 is provided with roller cutter shafts 11 at both ends and has a side pressure surface 12; Strain gauge 2, which is fixed to the side pressure surface 12 of the roller 1 by welding, is used to convert the mechanical strain of the roller 1 into a resistance change signal; The resistance strain gauge 3 is connected to the strain gauge 2 via a flexible wire and is positioned away from the welding point of the strain gauge 2. It is used to receive and process the resistance change signal of the strain gauge 2. The conductive slip ring 4 is coaxially sleeved on the outer periphery of the hob shaft 11 via the fixing structure 5, and is used to extract the output signal of the resistance strain gauge 3 in the rotating state. The resistance strain gauge is electrically connected to the resistance strain meter 3 via the conductive slip ring 4. It is used to collect and analyze the resistance change signal to determine the stress state and fatigue degree of the hob 1, and to realize early warning and location of tool wear or damage.

[0028] The fixing structure 5 includes a connecting cylinder 51 disposed at the conductive slip ring 4. Multiple sets of fixing cylinder plates 52 are evenly distributed circumferentially at the end of the connecting cylinder 51 away from the conductive slip ring 4. Radially protruding positioning blocks 521 are provided on the inner wall side of the multiple sets of fixing cylinder plates 52 so that the fixing cylinder plates 52 are engaged with the shaft side of the hob 1 by the positioning blocks 521.

[0029] The inner diameter of the multiple sets of fixed cylindrical plates 52 is matched with the outer diameter of the hob 1 shaft, so that the multiple sets of fixed cylindrical plates 52 are attached to the outer circumference of the hob 1 shaft.

[0030] The conductive slip ring 4 is provided with an outer sleeve 53 on the outer periphery of the connecting cylinder 51. A locking cylinder 54 is slidably connected inside the outer sleeve 53, and the inner diameter of the locking cylinder 54 matches the outer diameter of the fixed cylinder plate 52.

[0031] An annular limiting cavity 57 is formed between the outer sleeve 53 and the connecting cylinder 51, so that the outer sleeve 53 restricts the stroke of the locking cylinder 54 through the limiting cavity 57.

[0032] The outer periphery of the multiple sets of fixed cylinder plates 52 is provided with external threads 522, and the inner wall of the locking cylinder 54 is provided with internal threads 541 that cooperate with the external threads 522. The locking cylinder 54, through the helical cooperation between the internal threads 541 and the external threads 522, synchronously and radially presses the multiple sets of fixed cylinder plates 52 onto the shaft side of the hob 1.

[0033] The roller cutter 1 shaft is provided with multiple sets of axial positioning grooves 111 on the outer peripheral side of the locking cylinder 54. The multiple sets of axial positioning grooves 111 are inserted and engaged with the positioning block 521 to prevent the fixed cylinder plate 52 from moving circumferentially and axially relative to the roller cutter 1 shaft.

[0034] The resistance strain gauge 3 is bonded to the side pressure surface 12 of the roller cutter 1 with high-temperature resistant epoxy adhesive.

[0035] A monitoring method for a dynamic monitoring system for shield tunneling cutter wear, comprising the following steps: S1. On the side pressure surface 12 of the hob 1, select the area near the cutting edge and where the stress is concentrated as the strain measurement point, and use welding to firmly fix the strain gauge 2 to the surface of this area. S2. Connect the resistance strain gauge 3 to the strain gauge 2 via a flexible wire, and apply a 0.1 mm thick high-temperature resistant epoxy adhesive evenly to the side away from the welding point of the strain gauge 2 to bond the resistance strain gauge 3. S3. The conductive slip ring 4 is coaxially sleeved on the outer periphery of the hob 1 shaft through the fixing structure 5, so that the fixing cylinder plate 52 is engaged with the hob 1 shaft side through the positioning block 521. S4. Remove the locking cylinder 54 from the outer sleeve 53. Through the engagement of the internal and external threads 522, the locking cylinder 54 radially presses against the fixed cylinder plate 52, thereby achieving synchronous fixing of the conductive slip ring 4 and the hob 1 shaft. S5. Ensure that the rotating part of the conductive slip ring 4 rotates synchronously with the shaft of the roller 1, and the stationary part is connected to the data acquisition instrument to form a signal transmission channel; S6. Dynamic monitoring of shield cutter wear.

[0036] S61. When the cutter 1 comes into contact with the soil and rock and bears the normal load during the tunneling process, mechanical strain is generated on its surface. The strain gauge attached to the side pressure surface 12 of the cutter 1 undergoes synchronous tensile or compressive deformation, which causes the length and cross-sectional area of ​​its internal sensitive grid to change. According to the law of resistance, as shown in formula (1): R = ρ•AL (1) Where R is the strain gauge resistance value, ρ is the resistivity material constant, L is the sensing grid length, and A is the cross-sectional area; When the strain gauge is subjected to force and deforms, L and A undergo slight changes, resulting in a slight change in resistance ΔR. The relationship between them is described by the strain coefficient K, as shown in formula (2): R / ΔR=K•ε (2) Where ε is mechanical strain and K is the strain sensitivity coefficient constant, which is taken as 2.0; S62. The resistance strain acquisition instrument provides a constant excitation voltage to the resistance strain gauge 3 through the conductive slip ring 4, and connects the ΔR to the Wheatstone bridge to output an analog voltage signal proportional to ΔR, as shown in formula (3). ΔU=1 / 4⋅U exc •K•ε (3) Among them, U exc The excitation voltage is ΔU, and the output voltage change is ΔU. S63. The analog voltage signal is transmitted back to the resistance strain acquisition instrument through the same conductive slip ring 4, and after being amplified, filtered and converted from analog to digital, the digital strain value ε is obtained. S64. Compare the strain value ε with the preset threshold εth. When ε≥εth, immediately issue a wear warning signal and simultaneously record the current cutter head rotation angle and feed position to achieve rapid positioning of the faulty hobbing cutter 1. S65. If the strain value ε continues to rise above the preset threshold, it is determined to be progressive tool wear; if the strain value ε jumps instantaneously, it is determined to be tool chipping or crack initiation; if the strain value ε fluctuates periodically, it may be local tool damage or uneven wear; based on the strain gauge placement, the wear area is preliminarily determined.

[0037] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A dynamic monitoring system for shield tunneling cutter wear, characterized in that, include: The hob (1) has hob shafts (11) at both ends and has a side pressure surface (12). Strain gauge (2), the strain gauge (2) is fixed on the side pressure surface (12) of the roller (1) by welding, and is used to convert the mechanical strain of the roller (1) into a resistance change signal; A resistance strain gauge (3) is connected to the strain gauge (2) via a flexible wire and is positioned away from the welding point of the strain gauge (2) to receive and process the resistance change signal of the strain gauge (2); The conductive slip ring (4) is coaxially sleeved on the outer periphery of the hob shaft (11) through the fixing structure (5) and is used to draw out the output signal of the resistance strain gauge (3) in the rotating state. The resistance strain acquisition instrument is electrically connected to the resistance strain gauge (3) through the conductive slip ring (4) and is used to acquire and analyze the resistance change signal to determine the stress state and fatigue degree of the hob (1) and realize early warning and positioning of tool wear or damage.

2. The shield tunneling cutter wear dynamic monitoring system according to claim 1, characterized in that, The fixing structure (5) includes a connecting cylinder (51) disposed at the conductive slip ring (4). Multiple sets of fixing cylinder plates (52) are evenly distributed around the end of the connecting cylinder (51) away from the conductive slip ring (4). Radially protruding positioning blocks (521) are provided on the inner wall side of the multiple sets of fixing cylinder plates (52) so that the fixing cylinder plates (52) are engaged with the shaft side of the hob (1) by the positioning blocks (521).

3. The shield tunneling cutter wear dynamic monitoring system according to claim 2, characterized in that, The inner diameter of the multiple sets of fixed cylinder plates (52) is matched with the outer diameter of the hob (1) shaft so that the multiple sets of fixed cylinder plates (52) fit against the outer circumference of the hob (1) shaft.

4. The shield tunneling cutter wear dynamic monitoring system according to claim 2, characterized in that, The conductive slip ring (4) is provided with an outer sleeve (53) on the outer periphery of the connecting cylinder (51), and a locking cylinder (54) is slidably connected inside the outer sleeve (53), and the inner diameter of the locking cylinder (54) matches the outer diameter of the fixed cylinder plate (52).

5. The shield tunneling cutter wear dynamic monitoring system according to claim 2, characterized in that, An annular limiting cavity (57) is formed between the outer sleeve (53) and the connecting cylinder (51) so that the outer sleeve (53) limits the stroke of the locking cylinder (54) through the limiting cavity (57).

6. The shield tunneling cutter wear dynamic monitoring system according to claim 4, characterized in that, The outer periphery of the multiple sets of fixed cylinder plates (52) is provided with external threads (522), and the inner wall of the locking cylinder (54) is provided with internal threads (541) that cooperate with the external threads (522). The locking cylinder (54) uses the helical cooperation between the internal threads (541) and the external threads (522) to synchronously and radially press the multiple sets of fixed cylinder plates (52) onto the shaft side of the hob (1).

7. The shield tunneling cutter wear dynamic monitoring system according to claim 6, characterized in that, The hob (1) shaft is provided with multiple sets of axial positioning grooves (111) on the outer periphery of the locking cylinder (54). The multiple sets of axial positioning grooves (111) are inserted and engaged with the positioning block (521) to prevent the fixed cylinder plate (52) from moving circumferentially and axially relative to the hob (1) shaft.

8. The shield tunneling cutter wear dynamic monitoring system according to claim 1, characterized in that, The resistance strain gauge (3) is bonded to the side pressure surface (12) of the roller (1) by high temperature resistant epoxy adhesive.

9. A monitoring method for a dynamic monitoring system for shield tunneling cutter wear according to any one of claims 1-8, characterized in that, Includes the following steps: S1. On the side pressure surface (12) of the hob (1), select the area close to the blade and where stress is concentrated as the strain measurement point, and use welding to firmly fix the strain gauge (2) to the surface of the area. S2. Connect the resistance strain gauge (3) to the strain gauge (2) through a flexible wire, and apply a 0.1 mm thick high-temperature resistant epoxy adhesive evenly to the side away from the welding point of the strain gauge (2) to bond the resistance strain gauge (3). S3. The conductive slip ring (4) is coaxially sleeved on the outer circumference of the hob (1) shaft through the fixing structure (5), so that the fixing cylinder plate (52) is engaged with the hob (1) shaft side through the positioning block (521); S4. Move the locking cylinder (54) out from the outer sleeve (53) and use the internal and external threads (522) to make the locking cylinder (54) radially press the fixed cylinder plate (52) to achieve synchronous fixing of the conductive slip ring (4) and the hob (1) shaft. S5. Ensure that the rotating part of the conductive slip ring (4) rotates synchronously with the shaft of the roller (1), and the stationary part is connected to the data acquisition instrument to form a signal transmission channel; S6. Dynamic monitoring of shield cutter wear.

10. The monitoring method of the shield tunneling cutter wear dynamic monitoring system according to claim 9, characterized in that, in, Step S6 specifically includes the following steps: S61. When the cutter (1) comes into contact with the soil and rock and bears the normal load during the excavation process, mechanical strain is generated on its surface. The strain gauge attached to the side pressure surface (12) of the cutter (1) undergoes synchronous tensile or compressive deformation, which causes the length and cross-sectional area of ​​the internal sensitive grid to change. According to the law of resistance, as shown in formula (1): R = ρ·AL (1) Where R is the strain gauge resistance, ρ is the resistivity (material constant), L is the length of the sensing grid, and A is the cross-sectional area; When the strain gauge is subjected to force and deforms, L and A undergo slight changes, resulting in a slight change in resistance ΔR. The relationship between them is described by the strain coefficient K, as shown in formula (2): R / ΔR=K·ε (2) Where ε is mechanical strain and K is strain sensitivity coefficient (constant, taken as 2.0); S62. The resistance strain acquisition instrument provides a constant excitation voltage to the resistance strain gauge (3) through the conductive slip ring (4), and connects the ΔR to the Wheatstone bridge to output an analog voltage signal proportional to ΔR, as shown in formula (3). ΔU=1 / 4⋅U exc ·K·e (3) Among them, U exc The excitation voltage is ΔU, and the output voltage change is ΔU. S63. The analog voltage signal is transmitted back to the resistance strain acquisition instrument through the same conductive slip ring (4), and after being amplified, filtered and converted from analog to digital, the digital strain value ε is obtained. S64. Compare the strain value ε with the preset threshold εth. When ε≥εth, immediately issue a wear warning signal and simultaneously record the current cutter head rotation angle and advance position to achieve rapid positioning of the faulty hobbing cutter (1). S65. If the strain value ε continues to rise above the preset threshold, it is determined to be progressive tool wear; if the strain value ε jumps instantaneously, it is determined to be tool chipping or crack initiation; if the strain value ε fluctuates periodically, it may be local tool damage or uneven wear; based on the strain gauge placement, the wear area is preliminarily determined.

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