An excavating device for municipal pipeline construction

Abstract

This invention relates to the field of municipal pipeline construction and trenchless excavation equipment, specifically an excavation device for municipal pipeline engineering construction; it includes a main shell, a main shaft system with a cutting disc, a negative pressure suction duct, an ultrasonic transducer array, a high-pressure atomizing water spray assembly, and a follow-up guide impeller; the device extracts the current spectrum characteristics of the main drive motor and the back pressure fluctuation slope of the vacuum pump as an index of interface adhesion and dust agglomeration, and outputs a control strategy by combining the load resistance mapping model; its core is to eliminate the dependence on the easily contaminated sensor in front of the cutter disc, and adaptively and collaboratively adjust the ultrasonic array and the high-pressure water pump for vibration and spraying; this invention abandons the traditional method of simply adding water or simply strong suction, and uses high-frequency micro-amplitude vibration to prevent adhesion and dry fog dust suppression to solve the contradiction between adhesion and blockage and dust in enclosed spaces, effectively achieving efficient synergy of dust suppression, slag removal and anti-adhesion.

Description

Technical Field

[0001] This invention relates to the field of municipal pipeline construction and trenchless excavation equipment, specifically to an excavation device for municipal pipeline engineering construction. Background Technology

[0002] In municipal pipeline micro-jacking or trenchless tunneling construction, the front-end cutting device generates a large amount of dust and debris when breaking up soil and mixed strata. Due to the limited and narrow underground working space, if the dust is not discharged in time, it can easily cause the working environment to deteriorate and the operating parts of the equipment to wear out severely. To reduce dust and debris, the existing operation scheme generally adopts a physical structure of water spraying combined with independent negative pressure suction. However, in complex soil layers, simply increasing the water supply can suppress dust, but it can easily cause mud to adhere and accumulate severely on the metal surface of the cutting disc, forming mud that hinders cutting. When relying solely on high vacuum for strong suction, it can easily cause secondary dust, and with the changes in dust concentration and debris size, strong airflow pulsation and oscillation will be generated in the suction duct, inducing front-end flow field deviation and local pressure collapse. This traditional architecture, in which each component operates independently without coordination, creates an inherent contradiction between dust reduction, anti-adhesion, and stable airflow support.

[0003] Therefore, how to resolve the contradiction between water accumulation and dust generation caused by strong suction in a narrow, enclosed space, and achieve efficient dust reduction, smooth slag discharge, and anti-adhesion in a coordinated manner, has become an urgent technical problem to be solved. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides an excavation device for municipal pipeline construction. Specifically, the technical solution of the present invention includes: Main housing, with a main shaft mounted at its front end; The front end of the spindle is fixedly connected to a cutting disc, and the rear end is connected to the output shaft of the main drive motor. The main drive motor is fixed on the inner wall of the main housing. The main housing has a negative pressure suction channel axially opened inside, with its front opening facing the back of the cutting disc and its tail end connected to a vacuum pump through a vacuum pump inlet. An ultrasonic transducer array is fixed to the back of the cutting disc and the periphery of the front opening of the negative pressure suction duct, with its emitting end face facing the cutting surface of the cutting disc. The back of the cutting disc is also fixed with an annular water spray pipe, which has atomizing nozzles evenly distributed towards the cutting surface of the cutting disc and is connected to a high-pressure water pump. A follower-type guide impeller is provided between the main shaft and the negative pressure suction duct. The follower-type guide impeller is loosely fitted on the outer wall of the main shaft. It has anti-flow curved blades evenly distributed along the circumferential direction, and the air inlet side faces the back of the cutting disc, while the air outlet side is connected to the front opening of the negative pressure suction duct.

[0005] According to one embodiment of the present invention, the main housing is a cylindrical steel structure, and the main shaft is mounted on the front end of the main housing via a first main bearing and a second main bearing, both of which are tapered roller bearings.

[0006] According to one embodiment of the present invention, a high-strength flange is machined at the front end of the spindle, and the cutting disc is fixedly connected to the high-strength flange by bolts; the tail end of the spindle is connected to the output shaft of the main drive motor through a plum blossom-shaped flexible coupling, and the main drive motor is fixedly mounted on a motor support on the inner wall of the main housing through a flange.

[0007] According to one embodiment of the present invention, the inner wall of the negative pressure suction duct is coated with a wear-resistant ceramic coating; the annular water spray pipe is connected to the external high-pressure water pump through a rotary joint installed inside the main shaft and a water supply pipeline.

[0008] According to one embodiment of the present invention, the follower-type guide impeller is loosely fitted on the outer wall of the main shaft by a pair of angular contact ball bearings; the number of the reverse guide curved blades is eight.

[0009] According to one embodiment of the present invention, the excavating device further includes a control system, which continuously records the current signal generated by the main drive motor during the rotary cutting process and the back pressure signal generated by the vacuum pump during the suction process; The control system extracts the current spectrum characteristics of the main drive motor and the back pressure fluctuation slope of the vacuum pump, uses the low-frequency harmonic amplitude in the current spectrum as the interface adhesion index, and uses the time-dependent rise rate of the back pressure signal as the dust agglomeration index.

[0010] According to one embodiment of the present invention, the control system inputs the interface adhesion index and the dust agglomeration index into the load resistance mapping model, and calculates the apparent viscosity and spatial resistance distribution of the medium in front of the cutting disc through matrix operations, and maps the medium state to the cutting efficiency attenuation value of the cutting disc.

[0011] According to one embodiment of the present invention, when the interface adhesion index approaches a set warning threshold, the control system automatically increases the working duty cycle of the ultrasonic transducer array, uses high-frequency micro-amplitude vibration to form a micro-bubble cavitation layer on the metal surface of the cutting disc, and at the same time finely adjusts the opening of the bypass valve at the front end of the vacuum pump to reduce the suction vacuum.

[0012] According to one embodiment of the present invention, when the dust agglomeration index is lower than a set safety threshold, the control system increases the water spray pressure of the high-pressure water pump and increases the suction negative pressure of the vacuum pump. At the same time, the ultrasonic transducer array outputs high-frequency mechanical waves to dynamically change the surface tension of the water droplets ejected from the atomizing nozzle, thereby instantly pulverizing the liquid water into dry mist.

[0013] According to one embodiment of the present invention, when the negative pressure suction duct generates airflow pulsation oscillation due to high power output, the drag force of the negative pressure airflow drives the follower-type guide impeller, which is loosely mounted on the main shaft, to rotate at high speed. The reverse guide curved blades of the follower-type guide impeller convert part of the axial airflow into a spiral vortex adhering to the wall. The centrifugal force effect generated by the vortex stabilizes the edge pressure of the negative pressure suction duct and reduces the local pressure collapse caused by airflow pulsation.

[0014] The present invention has the following beneficial effects: 1. This invention extracts the current spectrum characteristics of the main drive motor and the back pressure fluctuation slope of the vacuum pump through the control system as the interface adhesion index and dust agglomeration index, eliminating the dependence on the easily contaminated sensor in front of the cutter head; combined with the load resistance mapping model, the control system can adaptively and collaboratively adjust the ultrasonic transducer array, high-pressure water pump and bypass valve, and use high-frequency micro-amplitude vibration to prevent adhesion and dry fog dust suppression, effectively solving the contradiction that simply adding water in a closed space can easily cause adhesion and blockage, and simply strong suction can easily cause dust, thus achieving efficient synergy of dust suppression, slag discharge and anti-adhesion. 2. This invention features a hollow, follow-up guide impeller installed between the main shaft and the negative pressure suction duct. When negative pressure suction generates airflow pulsation and oscillation, the drag force of the negative pressure airflow directly drives the impeller to rotate. Through the reverse guide curved blades, part of the axial airflow is converted into a spiral vortex adhering to the wall. This structure can utilize the centrifugal force effect generated by the vortex to stabilize the pressure at the opening edge and reduce the local pressure collapse caused by airflow pulsation without an additional power source. It effectively overcomes the local pressure collapse caused by high-frequency suction and significantly improves the flow field stability of cutting suction operations. Attached Figure Description

[0015] The following drawings, illustrating embodiments of this application, are incorporated herein by reference and are used to understand this application. The drawings illustrate embodiments of this application and their descriptions, serving to explain the principles of this application. In the drawings,

[0016] Figure 1 This is a schematic diagram of the overall structure of the device; Figure 2 This is a schematic diagram of the internal structure of the main casing of the device; Figure 3 This is a schematic diagram of the internal structure of the negative pressure suction duct of the device; Figure 4This is a schematic diagram of the dust collection and ultrasonic structure on the back of the cutting disc of the device; Figure 5 This is a sectional view of the main shaft and support structure at the front end of the device.

[0017] In the diagram: 1. Main housing; 2. Main shaft; 3. Cutting disc; 4. Main drive motor output shaft; 5. Main drive motor; 6. Negative pressure suction duct; 7. Vacuum pump inlet; 8. Ultrasonic transducer array; 9. Annular water spray pipe; 10. Atomizing nozzle; 11. High-pressure water pump; 12. Follow-up guide impeller; 13. Reverse guide curved blade; 14. First main bearing; 15. Second main bearing; 16. High-strength flange; 17. Bolt; 18. Plum blossom-shaped flexible coupling; 19. Flange; 20. Motor support; 21. Wear-resistant ceramic coating; 22. Rotary joint; 23. Water supply pipeline; 24. Angular contact ball bearing; 25. Vacuum pump; 26. Bypass valve. Detailed Implementation

[0018] In the following description, numerous specific details are set forth to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that embodiments of this application may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with embodiments of this application.

[0019] Example 1: An excavation device for municipal pipeline construction includes: Main housing 1, with a spindle 2 mounted on its front end. The front end of the spindle 2 is fixedly connected to the cutting disc 3, and the tail end is connected to the output shaft 4 of the main drive motor 5. The main drive motor 5 is fixed on the inner wall of the main housing 1. A negative pressure suction channel 6 is provided axially inside the main housing 1. Its front end opening faces the back of the cutting disc 3, and its rear end is connected to a vacuum pump 25 through a vacuum pump inlet 7. An ultrasonic transducer array 8 is fixed around the back of the cutting disc 3 and the front opening of the negative pressure suction duct 6, with its emitting end facing the cutting surface of the cutting disc 3. The back of the cutting disc 3 is also fixed with an annular water spray pipe 9, which has atomizing nozzles 10 evenly distributed towards the cutting surface of the cutting disc 3 and is connected to a high-pressure water pump 11. A follower-type guide impeller 12 is provided between the main shaft 2 and the negative pressure suction duct 6. The follower-type guide impeller 12 is loosely fitted on the outer wall of the main shaft 2. It has anti-flow curved blades 13 evenly distributed along the circumferential direction, and the air inlet side faces the back of the cutting disc 3, while the air outlet side is connected to the front opening of the negative pressure suction duct 6. This excavation device is used as the front-end cutting unit of municipal pipeline micro-jacking or trenchless tunneling equipment. The main housing 1 is used to carry the rotary cutting, suction conveying and dust removal components. The main shaft 2 is set along the axis of the main housing 1 as a power transmission component. The cutting disc 3 is fixedly connected to the front end of the main shaft 2. The output shaft 4 of the main drive motor 5 is connected to the tail end of the main shaft 2 and drives the cutting disc 3 to rotate and cut the soil or mixed strata. The back of the cutting disc 3 is provided with a negative pressure suction channel 6 with an opening at the front end, so that a directional suction area is formed behind the cutting surface. The vacuum pump 25 continuously sucks up the dust, debris and atomized droplets generated during cutting through the negative pressure suction channel 6. An ultrasonic transducer array 8 is fixed around the back of the cutting disc 3 and the front opening of the negative pressure suction duct 6. Its emitting end face is arranged facing the cutting surface of the cutting disc 3, so that high-frequency mechanical vibration can act on the metal surface of the disc and the fluid medium in the cutting zone. The annular water spray pipe 9 is fixed on the back of the cutting disc 3. Multiple atomizing nozzles 10 are evenly distributed around the circumference to spray the cutting surface around the circumference. The high-pressure water pump 11 provides a water supply pressure of 0.8MPa to 8MPa. When dry friction dust increases, it forms a fine mist to capture dust. When adhesion is enhanced, it works with ultrasound to reduce the adhesion between soil and metal. A follower-type guide impeller 12 is set between the main shaft 2 and the negative pressure suction duct 6. The guide impeller is not rigidly connected to the main shaft 2, but is loosely fitted on the outer wall of the main shaft 2. It is driven to rotate by the negative pressure airflow. The reverse guide curved blade 13 directs part of the airflow radially under high-speed suction conditions, forming an annular airflow support area around the front opening of the negative pressure suction duct 6. This combined structure resolves the contradictions of simple water addition leading to adhesion and clumping in enclosed and narrow spaces, and simple strong suction leading to increased dust and airflow pulsation, enabling dust suppression, slag removal, and anti-adhesion to be completed collaboratively by the same front-end mechanism; Those skilled in the art can make corresponding adjustments to the number of nozzles, the power of the vacuum pump 25, and the transducer arrangement density according to the cutter head diameter, pipe diameter, and soil moisture content. As long as the structural relationship of the combined action of cutting, suction, ultrasonic action, and guide impeller is met, the technical solution can be achieved. The main housing 1 is a cylindrical steel structure. The main shaft 2 is installed at the front end of the main housing 1 through the first main bearing 14 and the second main bearing 15. Both the first main bearing 14 and the second main bearing 15 are tapered roller bearings. The first main bearing 14 is located near the cutting disc 3 and is used to bear the main front cutting reaction force. The second main bearing 15 is arranged inside the rear side of the main housing 1 and is used to improve the support span and rotational stability of the spindle 2. The main shell 1 adopts a cylindrical steel structure. The outer diameter can be selected from 900mm to 1600mm according to the diameter of the matching pipe jacking machine. The shell material can be Q355B steel or 42CrMo quenched and tempered steel. The wall thickness can be set from 16mm to 40mm to withstand cutting torque, axial jacking load and local pressure difference caused by negative pressure suction. The front end of the main housing 1 is equipped with a first main bearing and a second main bearing, which are arranged axially along the main shaft 2 with a spacing of 180mm to 420mm. Both the first and second main bearings are tapered roller bearings, which are characterized by being able to withstand radial and axial loads simultaneously. They are suitable for uneven soil pressure, impact force fluctuations, and off-center load conditions of the main shaft 2 when the cutting disc 3 is working. The two tapered roller bearings can be arranged face-to-face or back-to-back, with back-to-back arrangement being preferred to improve overturning stiffness. The bearing preload can be set from 0.02mm to 0.08mm of axial compression to control the axial movement of the spindle 2 during high-speed rotation to not exceed 0.05mm. With the adoption of a cylindrical steel structure and double tapered roller bearing support, the axis of the main shaft 2 and the axis of the negative pressure suction duct 6 are more easily kept coaxial. The vibration peak of the cutting disc 3 during operation can be controlled within the allowable range of the equipment design, which facilitates the stable overlap of the subsequent ultrasonic action area, the annular water spray area and the negative pressure suction area, and improves the actual feasibility of the mechanical structure. A high-strength flange 16 is machined at the front end of the spindle 2, and a cutting disc 3 is fixedly connected to the high-strength flange 16 by bolts 17. The tail end of the main shaft 2 is connected to the output shaft 4 of the main drive motor 5 through a plum blossom-shaped flexible coupling 18. The main drive motor 5 is fixedly installed on the motor support 20 on the inner wall of the main housing 1 through a flange 19. The front end of the spindle 2 is integrally machined with a high-strength flange 16. The outer diameter of the high-strength flange 16 can be 450mm to 650mm, the flange thickness can be 35mm to 70mm, and the flatness of the flange end face is controlled within 0.03mm. It is used to form a high-rigidity connection interface with the cutting disc 3. The high-strength flange 16 is fixedly connected to the cutting disc 3 by bolts 17. The number of bolts 17 can be selected from 10 to 16, and the strength grade can be selected from 10.9 or 12.9. It is preferred to install them evenly to reduce off-center load. Using bolts 17 instead of welding facilitates disassembly and maintenance after the cutter head wears out, and also makes it easier to replace the cutting cutter head 3 with different tool arrangements according to different formations; The tail end of the main shaft 2 is connected to the output shaft 4 of the main drive motor 5 through a plum blossom-shaped flexible coupling 18. The elastic body in the plum blossom-shaped flexible coupling 18 can be made of polyurethane material, and the hardness can be selected from Shore A85 to A98. Its function is to compensate for the radial deviation of 0.1mm to 0.5mm and the angular deviation within 0.5° between the main shaft 2 and the motor output shaft, while reducing the transmission of torque pulsation to the motor side. The main drive motor 5 is fixed to the motor support 20 on the inner wall of the main housing 1 via the flange 19. The motor support 20 and the main housing 1 can be fixed by welding and bolts 17 for auxiliary positioning. A positioning stop can be set between the flange 19 and the support to ensure that the motor output shaft is coaxial with the axis of the main shaft 2. This connection structure creates a stable force transmission path between the front end of the cutter head being loaded, the spindle 2 drive, and the motor drive. This helps the control system to accurately reflect changes in cutting resistance through the motor current signal, reducing false spectral components caused by rigid impacts and installation errors. The inner wall of the negative pressure suction duct 6 is coated with a wear-resistant ceramic coating 21; the annular water spray pipe 9 is connected to the external high-pressure water pump 11 through a rotary joint 22 installed inside the main shaft 2 and a water supply pipe 23. The negative pressure suction duct 6 is the main channel through which the mixture of dust, debris and droplets flows. During long-term operation, it will be subjected to high-speed sand-laden airflow. Therefore, a wear-resistant ceramic coating 21 is applied to the inner wall of the duct. The wear-resistant ceramic coating 21 can be selected from alumina ceramic, silicon carbide ceramic or zirconium oxide toughened ceramic, and the thickness can be 0.5 mm to 3 mm. It is preferred to form a continuous cover layer by plasma spraying or thermal spraying process. The surface roughness of the coating can be controlled between 3.2 μm and 6.3 μm of profile arithmetic mean deviation to take into account both wear resistance and flow resistance. After applying this coating, when pumping sand-containing mixtures continuously for more than 500 hours, the wear of the duct can still be kept within the design allowable range, avoiding flow field turbulence and back pressure fluctuation distortion caused by the aggravation of inner wall wear; The annular water spray pipe 9 is connected to the external high-pressure water pump 11 through the rotary joint 22 and water supply pipe 23 installed inside the main shaft 2. The rotary joint 22 forms a sealed water supply passage between the stationary water supply pipe and the rotating main shaft 2. The rotary joint 22 can be selected as a mechanical seal or a labyrinth seal plus compensation seal structure, and the pressure resistance rating can be set from 10MPa to 25MPa. The water supply pipeline 23 is arranged along the hollow cavity or axial opening channel of the main shaft 2, so that the water supply is not affected by the rotation of the main shaft 2 and the space occupied by the exposed pipeline is reduced; the water output by the high pressure water pump 11 enters the annular spray pipe 9 through the rotary joint 22, and is sprayed onto the cutting surface by the circumferentially distributed atomizing nozzles 10, which can form a continuous and adjustable spray band. This water supply method ensures that the spray direction is stable when the rotary cutter head is working, and the rotation of the main shaft 2 will not be affected by the entanglement or swing of the hose, thus improving the reliability of dust suppression and cake control. The follower-type guide impeller 12 is loosely fitted on the outer wall of the main shaft 2 via a pair of angular contact ball bearings 24; there are eight reverse guide curved blades 13; The follower-type guide impeller 12 is set in the annular space between the main shaft 2 and the negative pressure suction duct 6. Its central hole is loosely fitted on the outer wall of the main shaft 2 through a pair of angular contact ball bearings 24. The loose fitting means that there is no rigid synchronous transmission relationship between the guide impeller and the main shaft 2. The rotation speed of the guide impeller is mainly determined by the drag force of the negative pressure airflow. The rotation of the main shaft 2 is only supported by the bearings and does not directly drive the impeller. The angular contact ball bearing 24 can be from the 7000 series or the 7200 series. When installed in pairs, it can withstand the axial disturbance force and radial unbalanced force generated by the guide impeller when it rotates at high speed. The bearing preload can be set to 200N to 500N to balance low starting resistance and rotational stability. Eight reverse-flow guide curved blades 13 are set and evenly distributed at equal angles along the circumference. Each blade adopts a curved shape with an angle to the main suction flow direction. The blade installation angle can be 25° to 50°, the chord length can be 60mm to 140mm, and the blade height can be 25mm to 80mm. The meaning of reverse flow guidance is that the blade has a predetermined curvature in the radial direction when it is stationary, so that it can stably generate radial flow without complex adjustment mechanism under the action of suction airflow. The use of eight blades can achieve a balance between flow guiding efficiency, processing complexity and rotational inertia. When the vacuum pump 25 increases the negative pressure and causes the airflow velocity in the front area to increase, the speed of the guide impeller increases synchronously. The eight blades form a periodic but spatially uniform airflow support band, which helps to reduce local pressure collapse and flow field deviation near the front opening of the negative pressure suction duct 6.

[0020] Example 2: The excavation device also includes a control system, which continuously records the current signal generated by the main drive motor 5 during the rotary cutting process and the back pressure signal generated by the vacuum pump 25 during the suction process. The control system extracts the current spectrum characteristics of the main drive motor 5 and the back pressure fluctuation slope of the vacuum pump 25, uses the low-frequency harmonic amplitude in the current spectrum as the interface adhesion index, and uses the time-dependent rise rate of the back pressure signal as the dust agglomeration index. The excavation device is equipped with a control system, which consists of an industrial controller, an analog signal acquisition module, a signal conditioning module, and an execution drive module. The current signal of the main drive motor 5 can be obtained by a Hall current sensor or the internal sampling module of the motor driver, and the sampling frequency can be set from 1kHz to 20kHz. The back pressure signal of vacuum pump 25 can be obtained by a pressure sensor installed at the tail end of negative pressure suction duct 6 or the inlet end of vacuum pump 25. The pressure measurement range can be from -100kPa to +20kPa, and the sampling frequency can be set from 100Hz to 5kHz. The control system continuously records the above signals and performs DC component removal processing, window function weighting, and spectrum analysis on the current signal, and performs low-pass filtering and time slope calculation on the back pressure signal; the low-frequency harmonic amplitude in the current spectrum characteristics is used to characterize the stick-slip change when the surface of the cutting disc 3 contacts the medium, because the adhesion of mud cake or local agglomeration will cause the load on the cutting disc to increase periodically, which is reflected in the motor current as the increase of low-frequency amplitude. The low-frequency harmonic amplitude is normalized and used as the interface adhesion index. The normalization reference value can be selected from the no-load cutting baseline value and the heavy-load sludge preset value. The back pressure fluctuation slope is used to characterize the change in flow resistance after dust, droplets and fine particles agglomerate in the suction channel. If the back pressure continues to rise over time, it indicates that the agglomerates in the duct are increasing or the dust on the cutting surface is accumulating rapidly. The rise rate over time is normalized and used as the dust agglomeration index. This method does not rely on easily contaminated sensors installed in front of the cutter head, but instead uses measurable signals from the existing power system and suction system to reflect the state of the medium, reducing the risk of control interruption caused by sensor failure in a closed and narrow space. The control system executes the generation process of the two indices in the following order: Step 1: Acquire the raw current signal and raw back pressure signal, and continuously update them in a calculation window of 0.2s to 2s, where adjacent windows can overlap by 20% to 80%. Step 2: First, the current signal is processed to remove the DC component and limit the amplitude to remove glitches. Then, the low-frequency analysis bandwidth is determined according to the actual rotational speed of spindle 2. The low-frequency analysis bandwidth is preferably 1 to 10 times the fundamental frequency of spindle 2. The characteristic amplitude within this bandwidth is extracted. The characteristic amplitude can be the sum of the fundamental frequency component amplitude, the amplitude of the first three harmonics, or the weighted amplitude selected according to the calibration. Step 3: After low-pass filtering the back pressure signal, extract the average back pressure change and time length within the same calculation window to obtain the back pressure climbing trend value within the window. If the back pressure is decreasing or basically stable, the trend value is recorded as zero or processed as the minimum positive value to avoid misjudging the smooth pumping state as enhanced condensation. Step four: Compare the low-frequency characteristic amplitude obtained in step two with the no-load cutting baseline value and the heavy-load sludge preset value to obtain the interfacial adhesion index in the range of 0 to 1; compare the back pressure rise trend value obtained in step three with the unobstructed suction baseline value and the significant blockage preset value to obtain the dust agglomeration index in the range of 0 to 1; specifically, the interfacial adhesion index... The normalization calculation rule is as follows: in, is the dimensionless interfacial adhesion index, with a value range of [0,1]; A is the amplitude of the currently extracted low-frequency feature, in units of A; This is the baseline value for no-load cutting, in meters (A). This is the preset value for heavy-duty sludge formation, in units of A; the subscripts in the formula... Represents adhesion, subscript Represents the baseline state, subscript Represents the preset maximum or limit state; the letters in the formula The formula represents the index; it eliminates the physical unit of the current amplitude by calculating the difference ratio of parameters with the same dimensions, thus achieving index normalization; dust agglomeration index. The calculation rules are as follows: in, It is a dimensionless dust agglomeration index, with a value range of [0,1]. This represents the back pressure climbing trend value extracted within the current window, in Pa / s. The baseline value for unobstructed suction is expressed in Pa / s. The preset value for significant blockage is given, in Pa / s; the subscripts in the formula... Represents consolidation, subscript Represents the baseline state, subscript Represents the preset maximum or limit state; letters The formula ensures that the numerator and denominator have the same dimensions, thus converting the output rate of climb exponent into a standardized scalar. Through this rule, the control system accurately converts the underlying signals of different physical dimensions into standardized dimensionless parameters; the closer the interface adhesion index is to 1, the more obvious the mud cake, clumps or stick-slip effect on the cutter head surface; the closer the dust agglomeration index is to 1, the faster the flow resistance caused by the agglomeration of particles and droplets in the suction channel increases. The above baseline values ​​and preset values ​​can be determined through equipment calibration: record the no-load cutting baseline value and the unobstructed suction baseline value under clean cutter head, stable soil layer and standard suction conditions; record the heavy-load sludge preset value and the significant blockage preset value after artificially increasing the water spray volume, reducing the slag discharge efficiency or introducing high water content clay samples. To ensure consistency across different devices, it is preferable to record at least three consecutive sets of samples for each baseline value and preset value and take the average value; if the real-time value exceeds the preset upper limit, the corresponding index is directly recorded as 1; if the real-time value is lower than the baseline value, the corresponding index is directly recorded as 0. In the subsequent control logic, the interface adhesion index is mainly used as the input to judge the risk of adhesion on the cutter head surface, and the dust agglomeration index is mainly used as the input to judge the agglomeration and blockage trend of the suction channel. The two are passed to the load resistance mapping model to generate the execution control quantity. The control system inputs the interface adhesion index and dust agglomeration index into the load resistance mapping model, and calculates the apparent viscosity and spatial resistance distribution of the medium in front of the cutting disc 3 through matrix operations, mapping the medium state to the cutting efficiency attenuation value of the cutting disc 3. The control system has a pre-set load resistance mapping model, which is used to convert the interface adhesion index and dust agglomeration index into control quantities corresponding to cutting resistance and media flowability. The load resistance mapping model can be implemented using a two-dimensional state matrix model. The input vector is a binary column vector composed of the interface adhesion index and the dust agglomeration index. The state transition matrix is ​​obtained from the calibration data of the equipment in sand, clay, water-bearing gravel layer and mixed backfill layer. The matrix coefficients can be determined by fitting multiple sets of experimental data. After the control system inputs the interface adhesion index and dust agglomeration index within the current sampling window into the model, it outputs the estimated values ​​of apparent viscosity and spatial resistance distribution. Apparent viscosity is used to characterize the flow resistance of mud or water-containing debris in the cutting zone, and the unit can be calculated in Pa·s. Spatial resistance distribution is used to characterize the relative magnitude of the medium resistance borne by different regions in the three circumferences of the cutting disc, and can be discretized into a four-quadrant or eight-sector form. The control system further calculates the cutting efficiency attenuation value based on the apparent viscosity estimate and the spatial resistance distribution estimate. The cutting efficiency attenuation value is used to reflect the degree of decrease in the effective cutting ability of the cutting head 3 under the current medium action relative to the calibration state. The value can be set to a dimensionless parameter from 0 to 1, where 0 indicates no significant loss and 1 indicates reaching the preset upper limit. This model is used to provide a quantitative basis for adjusting the ultrasonic duty cycle, water pump pressure, vacuum pump negative pressure 25, and bypass valve opening 26; those skilled in the art can set and expand the matrix dimensions and the number of calibration samples according to the equipment size, cutter head speed range, and target formation type. The processing flow of the load resistance mapping model can be implemented in the following order; Step 1: The control system reads the interface adhesion index and dust agglomeration index of the current window and calls the corresponding calibration matrix group according to the formation type; the formation type can be preset by the pre-construction survey results or manually switched by the operator on the control interface. Step 2: The control system first performs interval discrimination on the two indices, for example, dividing them into three levels: low, medium, and high, and selects the base matrix accordingly. If the interface adhesion index and the dust agglomeration index belong to different levels, the interpolation results of two adjacent sets of matrices are used to avoid sudden output changes when the operating conditions change. Step 3: After the basic matrix performs operations on the input vector, two intermediate quantities are generated. Specifically, the basic matrix is ​​a pre-calibrated 2-row, 2-column weight coefficient matrix, whose four elements represent the influence weight of the interface adhesion index on flow hysteresis, the influence weight of the dust agglomeration index on flow hysteresis, the influence weight of the interface adhesion index on obstructed unevenness, and the influence weight of the dust agglomeration index on obstructed unevenness, respectively. The operation rule is to multiply the binary input column vector consisting of the interface adhesion index and the dust agglomeration index with the basic matrix to obtain an output column vector containing two elements. The first element is the first intermediate quantity corresponding to the degree of sluggishness of the medium flow, and the second element is the second intermediate quantity corresponding to the degree of unevenness of the circumferential obstruction between the suction channel and the cutter head. For example, in the clay layer calibration matrix, the weight coefficient of the first row and first column is significantly greater than the weight coefficient of the first row and second column, to highlight the contribution of adhesion dominance to flow hysteresis; specifically, taking a specific water-bearing clay layer calibration condition as an example, the preset two-dimensional state transition matrix is: If the interface adhesion index extracted in the current calculation window Dust aggregation index The resulting binary input column vector is: The matrix operation process of multiplying the input column vector with the state transition matrix is ​​as follows: Obtain the output column vector Among them, the first intermediate value corresponding to the degree of sluggishness in medium flow is 0.56, and the second intermediate value corresponding to the degree of unevenness in the circumferential obstruction between the suction channel and the cutter head is 0.46. The control system multiplies the first intermediate quantity by the reference viscosity coefficient to convert it into an estimated apparent viscosity value. It multiplies the second intermediate quantity by the preset circumferential distribution coefficient of each quadrant or sector to obtain the relative drag coefficient corresponding to each independent quadrant or sector. The set of relative drag coefficients of the above quadrants or sectors forms the estimated spatial drag distribution value. If a four-quadrant method is used, the quadrants can be numbered as top, bottom, left, right or front left, front right, back left, back right, and each quadrant yields a relative drag coefficient. For ease of implementation, the determination of the apparent viscosity estimate does not require direct measurement of the absolute rheological parameters, but rather conversion is performed using the calibration state as a reference. It should be noted that, since no additional local sensors are configured in each quadrant of the cutting disk 3 in this embodiment, the above-mentioned estimated value of spatial resistance distribution is essentially an empirical estimate of the degree of non-uniformity calculated based on the fluctuations of global current signal and air pressure signal. The circumferential distribution coefficient is predetermined by the previous geological exploration or experimental calibration. Its main function is to trigger a conservative early warning of cutting efficiency attenuation in conjunction with the global data of the system, rather than to measure the local actual azimuth resistance with absolute precision. When the interfacial adhesion index increases while the dust agglomeration index is at a low to medium level, the model prioritizes increasing the apparent viscosity estimate to reflect the state of enhanced soil adhesion, reduced fluidity, but no obvious blockage of the culvert. When the dust agglomeration index increases while the interfacial adhesion index changes little, the model prioritizes increasing the resistance coefficient of the central or local sector in the spatial resistance distribution to reflect the agglomeration and accumulation at the front of the suction channel or in the circumferential local area. If both indices increase simultaneously, the estimated apparent viscosity and the estimated spatial resistance distribution will increase in tandem, indicating that both the cutting zone and the suction zone will deteriorate at the same time. After obtaining the estimated values ​​of apparent viscosity and spatial resistance distribution, the control system continues to generate the cutting performance attenuation value. The generation rule is as follows: first, the estimated value of apparent viscosity is compared with the reference viscosity range under calibrated conditions; specifically, it is calculated using a linear normalization formula, i.e.: in, Let be the liquidity loss component, and be a dimensionless parameter; This is the currently calculated estimate of the apparent viscosity, in Pa·s; This is the lower limit of the reference viscosity range under calibration conditions, expressed in Pa·s. The upper limit of the reference viscosity range is given in Pa·s; the loss component is dimensionless by ratioization of the apparent viscosity physical quantity; the letters in the formula... Representing loss, letters Represents viscosity, subscript Representative estimate, subscript Subscript represents the lower limit. Represents the upper limit; Next, the maximum sector drag coefficient in the spatial drag distribution is compared with the circumferential average drag coefficient. Specifically, this is obtained by calculating the relative proportion of the maximum drag deviation, i.e.: in, For non-uniformly hindered components, there is a dimensionless parameter; is the maximum sector drag coefficient in the current spatial drag distribution, and is the dimensionless relative drag coefficient; is the circumferential average drag coefficient for all sectors, and is the dimensionless relative drag coefficient; This is the preset maximum allowable deviation amplification factor, and it is a dimensionless weighting constant. The formula ensures the logical consistency of the calculation results in terms of dimensions by calculating the relative deviation rate; the letters in the formula... Representing resistance, the letter Representative coefficient, subscript Represents average, subscript Represents deviation; to avoid interference from outliers, when or The calculation result is taken as 0 when it is less than 0 and as 1 when it is greater than 1; the two components are combined according to the preset weight to form a cutting performance attenuation value from 0 to 1; the combined cutting performance attenuation value The calculation rules are as follows: in, As a component of liquidity loss, For non-uniformly hindered components, the subscript is... The apparent viscosity and flowability of the corresponding medium are indicated by the subscript. Corresponding spatial distribution and non-uniformity; and The preset weight coefficients sum to 1, and The preset weights assigned to the liquidity loss component, The letters in the formula represent the preset weights assigned to the non-uniformly hindered components. Represents weight; Both the reference viscosity range and the preset weights can be determined experimentally during the calibration phase. For example, after the equipment completes sampling for four states—normal cutting, slight adhesion, significant sludge formation, and partial blockage—four corresponding loss level ranges can be established. To further illustrate the calculation process, the following quantitative calculation example is provided: If the calculated value under the current operating conditions is... , And the calibration weights set for this stratum , The cutting efficiency attenuation value output by the control system ; The cutting efficiency attenuation value is gradually obtained from the interface adhesion index and dust agglomeration index through matrix mapping, intermediate quantity conversion and component synthesis, and is sent to the ultrasonic power adjustment module, the high pressure water pump 11 pressure adjustment module, the vacuum pump 25 negative pressure adjustment module and the bypass valve 26 opening adjustment module as a unified judgment basis for subsequent actions. The load resistance mapping model consists of a state discrimination layer, a medium estimation layer, and a control mapping layer connected in sequence in its logical architecture. The state discrimination layer receives the interface adhesion index and the dust agglomeration index to determine which category the current working condition is closer to: adhesion-dominated, dust-dominated, blockage-dominated, or a combination of deterioration. Based on the aforementioned discrimination results and the corresponding calibration matrix, the medium estimation layer outputs the estimated values ​​of apparent viscosity and spatial resistance distribution; the control mapping layer then converts these two estimates into a unified cutting performance attenuation value, and allocates the corresponding adjustment commands to the ultrasonic, water pump, vacuum pump 25 and bypass valve 26. Therefore, the data flow inside the model is as follows: the original measurable signal first forms two exponents in the corresponding processing process, and the two exponents then enter the state discrimination layer, in which a medium state estimate is generated, and a single cutting performance attenuation value is generated and transmitted to the execution end. In the model, the interface adhesion index characterizes the stickiness and cake development trend on the cutterhead surface and is used to map the apparent viscosity estimate; the dust agglomeration index characterizes the agglomeration, accumulation and back pressure growth trend in the front region and duct and is used to map the spatial resistance distribution estimate. Since both increased apparent viscosity and high local resistance lead to more cutting energy being consumed in destroying the deposits and breaking free from obstructions, the two factors together determine the value of cutting efficiency attenuation. Preferably, during the equipment calibration stage, the control system can record multiple sets of samples under the same cutterhead rotation speed, similar jacking speed and different formation water content conditions, and use the normal cutting state, slight adhesion state, obvious adhesion state, local channel blockage state and compound deterioration state as the reference categories of the matrix group respectively. In real-time operation, the model is not required to be retrained. Instead, the corresponding category matrix is ​​called and the estimation is completed by interpolation of adjacent levels. When the interface adhesion index approaches the set warning threshold, the control system automatically increases the working duty cycle of the ultrasonic transducer array 8 and uses high-frequency micro-amplitude vibration to form a micro-bubble cavitation layer on the metal surface of the cutting disc 3. At the same time, the opening of the bypass valve 26 at the front end of the vacuum pump 25 is finely adjusted to reduce the suction vacuum. The control system compares the interface adhesion index with a preset warning threshold, which can be set to 0.65 to 0.85 of the interface adhesion index under the calibration conditions. When the interface adhesion index reaches this range and continues for a set time, such as 0.5s to 5s, the control system determines that there is a tendency for mud to form on the surface of the cutting disc 3. At this time, the control system increases the working duty cycle of the ultrasonic transducer array 8. The duty cycle can be increased from 10% to 30% under normal working conditions to 40% to 90%, the transduction frequency can be selected from 20kHz to 80kHz, and the vibration displacement amplitude can be from 5μm to 40μm. Since the ultrasonic transducer array 8 is arranged on the back of the cutting disc 3 and around the front opening of the negative pressure suction duct 6, the high-frequency mechanical vibration will be transmitted to the metal substrate of the cutting disc and the adjacent liquid-solid contact layer, forming microbubbles and cavitation disturbances in the local liquid-containing thin layer, weakening the continuous adhesion state between soil particles and the surface of the cutting disc, and reducing sliding friction and adhesion resistance. Synchronous with ultrasonic enhancement, the control system fine-tunes the opening of the bypass valve 26 at the front end of the vacuum pump 25. The bypass valve 26 can be composed of an electric butterfly valve or an electric ball valve. The opening can be increased by 3% to 20% to reduce the instantaneous suction vacuum and prevent high-viscosity mud from being sucked into the duct by excessive negative pressure and causing blockage. The mechanical linkage corresponding to this control method is clear: the interface adhesion index comes from the current signal of the main drive motor 5, and the output action acts on the ultrasonic transducer array 8 and the bypass valve 26. The goal is to reduce the development speed of the mud cake on the cutter head surface and keep the suction channel unobstructed. Approaching the set warning threshold can be achieved using explicit judgment rules, rather than relying solely on operational experience. Preferably, after each calculation window, the control system compares the current interface adhesion index with the warning threshold. When the interface adhesion index reaches more than 90% of the warning threshold and shows an upward trend for two to five consecutive calculation windows, it is determined to be approaching the warning threshold. If the interface adhesion index reaches the specified ratio but drops significantly in the next window, the original operating condition will be maintained without action to avoid false triggering caused by instantaneous impact or collision with hard particles. To prevent control jitter, a release threshold can be set, which can be 0.05 to 0.15 lower than the warning threshold. When the interface adhesion index drops below the release threshold and remains below it for a set time, the ultrasonic duty cycle and the opening of the bypass valve 26 will be gradually restored to normal values. The input, processing and output relationships of the above control process are as follows: The input is the interface adhesion index and its continuous window change trend; the processing end first performs threshold comparison, and then judges the duration and upward trend; the output generates two action commands, one is the duty cycle increase command of ultrasonic transducer array 8, and the other is the bypass valve 26 opening command. Preferably, the control system has a pre-set control command lookup table to achieve precise mapping. The lookup table divides the difference between the interface adhesion index and the warning threshold into multiple discrete intervals, and each interval corresponds to a specific duty cycle increment. For example, when the difference is between 0 and 0.05, the ultrasonic duty cycle increases by 10 percentage points. When the difference is between 0.05 and 0.10, the ultrasonic duty cycle increases by 20 percentage points, thus making the increase in ultrasonic duty cycle positively correlated with the degree to which the interface adhesion index exceeds the warning threshold in a stepwise manner. The bypass valve 26 opening is adjusted in small steps, with each step being 1% to 5%, and an observation time of 0.2s to 2s is reserved between two adjustment steps to read the interface adhesion index changes in subsequent windows; If the interface adhesion index stops rising or begins to fall within a certain number of consecutive windows, the current opening is maintained and no further increase is allowed. In this additional judgment logic, the warning threshold is used to characterize the boundary of the cutterhead transitioning from a normal cutting state to a mud-caking risk state. When the threshold is approached, the control system prioritizes the use of a combination of enhanced ultrasound and moderate desorption to suppress further adhesion. The process of forming a microbubble cavitation layer on the metal surface of the cutting disc 3 is as follows: when there is a liquid film, slurry thin layer or high water content adhering layer formed by spraying on the surface of the disc, the high frequency micro-amplitude vibration of the ultrasonic wave preferentially acts on the liquid phase or liquid-solid mixture interface, causing intermittent microbubble nucleation, oscillation and rupture in the liquid film, and forming a continuously renewed disturbance layer in the near-surface area of ​​the disc, rather than generating cavitation on the dry metal surface alone without liquid phase conditions; Because the liquid film and mud layer on the cutterhead surface are periodically disturbed by ultrasonic vibration, the local shear stress and pore pressure fluctuations inside the adhesion layer increase; and because the front suction vacuum decreases after the bypass valve 26 is appropriately opened, the tendency for high-viscosity mud clumps to be forcibly drawn into the duct is weakened; therefore, the two work together to preferentially weaken the formation and expansion of the initial mud cake, rather than simply relying on increasing suction to directly remove the adhesions under negative pressure. Preferably, when the interface adhesion index just enters the warning range, the control system first increases the ultrasonic duty cycle and then observes the back pressure change after a delay; if the back pressure does not deteriorate synchronously, the bypass valve 26 is only slightly opened; if the interface adhesion index continues to rise and the back pressure fluctuation intensifies, the bypass valve 26 continues to be opened step by step. Ultrasonic vibration directly acts on the liquid film and the adhesion layer to produce viscosity reduction and desorption promotion effects; at the same time, the adjustment of the bypass valve 26 reduces the suction intensity to prevent high-viscosity clumps from being sucked in by excessive negative pressure and causing blockage at the front port. When the dust agglomeration index is lower than the set safety threshold, the control system increases the water spray pressure of the high-pressure water pump 11 and increases the suction negative pressure of the vacuum pump 25. At the same time, the ultrasonic transducer array 8 outputs high-frequency mechanical waves to dynamically change the surface tension of the water droplets sprayed from the atomizing nozzle 10, instantly pulverizing the liquid water into dry mist. The control system compares the dust agglomeration index with a safety threshold, which can be set to 0.25 to 0.45 of the index under stable dust collection conditions. When the dust agglomeration index is lower than this threshold, it indicates that the dust and droplets in the cutting zone are not sufficiently agglomerated, the dry friction component increases, and the risk of dust generation increases. The control system increases the water spray pressure of the high-pressure water pump 11 accordingly, and the water pump outlet pressure can be increased from 1MPa to 3MPa to 4MPa to 10MPa, so that the atomizing nozzle 10 sprays out finer droplets; at the same time, the vacuum pump 25 increases the suction negative pressure, and the negative pressure can be increased from -15kPa to -30kPa to -35kPa to -70kPa, so as to enhance the ability of the dust-laden airflow near the cutting surface to converge towards the negative pressure suction duct 6; Under this operating condition, the ultrasonic transducer array 8 outputs high-frequency mechanical waves. Its frequency and duty cycle can be adjusted according to the spray particle size requirements. The ultrasonic vibration is coupled to the spray liquid film and the nozzle outlet droplets through the back of the cutter head and the structure adjacent to the nozzle, changing the droplet splitting conditions and causing larger droplets to be further broken into smaller dry fog particles. In this embodiment, dry fog refers to the atomized state in which the sprayed particles are suspended in the form of fine droplets and can collide and condense with dust particles with a high probability. The particle size can be controlled between 5μm and 50μm. This particle size range is close to that of fine dust particles. After being pulled by the high-speed flow field formed by the negative pressure suction duct 6, the dry fog and dust collide frequently behind the cutting disc 3 and at the inlet area of ​​the duct front end, forming larger agglomerated particles that can be sucked out by the vacuum pump 25. Since the high-pressure water pump 11, the vacuum pump 25 and the ultrasonic transducer array 8 are coordinated and regulated by the same control system based on the dust agglomeration index, the amount of water added can be controlled while ensuring the dust collection efficiency, reducing the probability of adhesion and agglomeration induced by a large amount of liquid medium entering the cutting surface. The process of dynamically changing the surface tension of water droplets ejected from the atomizing nozzle 10 by ultrasound is as follows: by applying high-frequency disturbance to the liquid film, liquid column and nascent droplets near the nozzle outlet, the breakage boundary conditions, oscillation state and re-split probability of the droplets are changed, making the droplets easier to break and hindering re-aggregation. During this process, the high-pressure water pump 11 increases the pressure difference at the nozzle outlet, enhancing the initial breaking ability of the ejected liquid flow; ultrasonic vibration introduces additional disturbances and liquid film fluctuations, causing the liquid column to further split into small droplets; The increase in negative pressure from the vacuum pump 25 increases the shear velocity of the airflow in the front area, which pulls the small droplets to disperse and make full contact with the dust; the three work together to form a dry fog dust collection zone with finer particle size and more uniform distribution. Preferably, when the dust agglomeration index is lower than the safety threshold, the control system does not directly increase the high-pressure water pump 11 and vacuum pump 25 to the upper limit all at once. Instead, it first increases the water spray pressure by one level increment and simultaneously increases the suction negative pressure, and then observes the change of the dust agglomeration index in the subsequent 1 to 3 calculation windows. If the index remains low, the ultrasonic duty cycle or frequency will be further increased, and the spray will be refined. If the index rises to near the safe threshold, the current parameters will be maintained. The purpose of this setting is to use the dust agglomeration index as input to first drive the continuous control link of pressurized water spray - enhanced suction - promoted secondary crushing, and then decide whether to continue to strengthen it based on the index's rise, thereby avoiding excessive water addition that could lead to mud formation on the cutting surface. This embodiment aims to improve the effective collision probability of droplets and dust and the ability to be sucked out; when the droplet size is too large, the specific surface area of ​​the droplets decreases and they are easy to gather into a liquid film on the surface of the cutter disc. After the droplets are refined by high-pressure atomization and ultrasonic disturbance, the effective dust collection interface corresponding to a unit volume of water increases. As the suction negative pressure increases simultaneously, fine droplets and dust can enter the negative pressure suction duct 6 more quickly after agglomeration, reducing their retention around the cutter head.

[0021] Example 3: When the negative pressure suction duct 6 generates airflow pulsation and oscillation due to high power output, the drag force of the negative pressure airflow drives the follower-type guide impeller 12, which is loosely fitted on the main shaft 2, to rotate at high speed. The reverse guide curved blades 13 of the follower-type guide impeller 12 convert part of the axial airflow into a spiral vortex attached to the wall. The centrifugal force effect generated by the vortex stabilizes the edge pressure of the negative pressure suction duct 6 and reduces the local pressure collapse caused by airflow pulsation. When the vacuum pump 25 is in a high-power suction state, the airflow pulsation oscillation will occur in the negative pressure suction duct 6 due to fluctuations in dust concentration, changes in debris size and spray volume. At this time, a transient centripetal low-pressure zone is easily formed near the opening at the front end of the duct, making the flow field on the back of the cutting disc 3 and around the spindle 2 unstable. Since the follower-type guide impeller 12 is loosely fitted on the main shaft 2, its rotational speed is not rigidly constrained by the main shaft 2. When the negative pressure airflow velocity increases, the tangential drag force of the airflow on the reverse guide curved blade 13 increases, and the guide impeller accelerates its rotation. The rotational speed can be increased from hundreds of r / min to thousands of r / min. During the rotation of the blades, part of the axial airflow is directed to the radially outward side, thereby forming a continuous annular air curtain around the front opening of the negative pressure suction duct 6. The essence of this annular air curtain is a high-speed airflow band distributed around the main shaft 2. Its local static pressure is higher than that of the low-pressure area in the center of the duct, which can provide radial support for the airflow that collapses inward from the center and reduce the sudden change in pressure gradient in the front opening area. The power of vacuum pump 25 continues to increase, the speed of the guide impeller changes synchronously, and the strength of the annular air curtain automatically matches the suction strength, without the need to set up an independent drive mechanism; the technical significance of this structure is that it transforms the pulsating airflow that may have caused axis deviation and suction inlet fluctuation into a power source for forming a stable peripheral support airflow, thereby reducing the impact of airflow deviation and pressure fluctuation near spindle 2 on cutting accuracy. For equipment of different sizes, the width of the annular air curtain can be adjusted by matching the blade height, impeller diameter and front clearance. It can usually be designed from 10mm to 60mm. As long as the working relationship of negative pressure airflow drag drive, radial flow and annular support is maintained, the technical effect can be achieved. To verify the efficient synergistic effect of this excavation device in preventing adhesion and reducing dust and slag, the applicant designed the following comparative experiment: a traditional constant water spray and constant suction excavation device was used as the control group, and the device of this invention was used as the experimental group; the experimental environment was set as a clay layer with a stable moisture content of 28%, and the continuous excavation test time was... We define dust removal rate With the improvement rate of slag discharge efficiency The formula for calculating the improvement rate of slag discharge efficiency is as follows: In the formula, This represents the average slag discharge per unit time for the experimental group. The average slag discharge per unit time was used as the control group. Experimental results showed that in the control group, adhesion and blockage occurred on the cutterhead metal surface after 3.5 hours of tunneling, while the interface adhesion index of the experimental group... Always maintain under adaptive adjustment Within the safe zone, no blockages occurred throughout the entire process; simultaneously, the dust removal rate measured by the experimental group was [missing information]. Furthermore, the slag removal efficiency has been improved. It reached 42.6%; The above quantitative data fully demonstrates that by combining the ultrasonic transducer array with the follow-up guide impeller, the present invention effectively solves the contradiction between adhesion and blockage and dust in enclosed spaces.

[0022] This application has been described through the above embodiments; however, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this application to the described embodiments. Those skilled in the art will understand that many more variations and modifications can be made based on the teachings of this application, and all such variations and modifications fall within the scope of protection claimed in this application.

Claims

1. An excavating device for municipal pipeline construction, characterized in that, include: Main housing (1), with a main shaft (2) mounted at the front end of the main housing (1); The front end of the main shaft (2) is fixedly connected to a cutting disc (3), and the rear end is connected to the output shaft (4) of the main drive motor (5). The main drive motor (5) is fixed on the inner wall of the main housing (1). The main housing (1) has a negative pressure suction channel (6) axially opened inside, with its front end opening facing the back of the cutting disc (3), and its tail end connected to a vacuum pump (25) through a vacuum pump inlet (7). An ultrasonic transducer array (8) is fixed around the back of the cutting disc (3) and the front opening of the negative pressure suction duct (6), with its emitting end face facing the cutting surface of the cutting disc (3). The back of the cutting disc (3) is also fixed with an annular water spray pipe (9), which has atomizing nozzles (10) evenly distributed on the cutting surface of the cutting disc (3) and connected to a high-pressure water pump (11). A follower-type guide impeller (12) is provided between the main shaft (2) and the negative pressure suction duct (6). The follower-type guide impeller (12) is loosely fitted on the outer wall of the main shaft (2). It has reverse guide curved blades (13) evenly distributed along the circumferential direction, and the air inlet side faces the back of the cutting disc (3), and the air outlet side is connected to the front opening of the negative pressure suction duct (6). The excavation device also includes a control system, which continuously records the current signal generated by the main drive motor (5) during the rotary cutting process and the back pressure signal generated by the vacuum pump (25) during the suction process; the control system extracts the current spectrum characteristics of the main drive motor (5) and the back pressure fluctuation slope of the vacuum pump (25), uses the low-frequency harmonic amplitude in the current spectrum as the interface adhesion index, and uses the time-dependent rise rate of the back pressure signal as the dust agglomeration index; The control system inputs the interface adhesion index and the dust agglomeration index into the load resistance mapping model, and calculates the apparent viscosity and spatial resistance distribution of the medium in front of the cutting disc (3) through matrix operations, and maps the medium state to the cutting efficiency attenuation value of the cutting disc (3).

2. The excavation device for municipal pipeline construction according to claim 1, characterized in that: The main housing (1) is a cylindrical steel structure. The main shaft (2) is installed at the front end of the main housing (1) through the first main bearing (14) and the second main bearing (15). The first main bearing (14) and the second main bearing (15) are both tapered roller bearings.

3. The excavation device for municipal pipeline construction according to claim 1, characterized in that: The front end of the spindle (2) is machined with a high-strength flange (16), and the high-strength flange (16) is fixedly connected to the cutting disc (3) by bolts (17); the tail end of the spindle (2) is connected to the output shaft (4) of the main drive motor by a plum blossom-shaped elastic coupling (18), and the main drive motor (5) is fixedly installed on the motor support (20) on the inner wall of the main housing (1) by a flange (19).

4. The excavation device for municipal pipeline construction according to claim 1, characterized in that: The inner wall of the negative pressure suction duct (6) is coated with a wear-resistant ceramic coating (21); the annular water spray pipe (9) is connected to the external high-pressure water pump (11) through a rotary joint (22) installed inside the main shaft (2) and a water supply pipe (23).

5. The excavation device for municipal pipeline construction according to claim 1, characterized in that: The follower-type guide impeller (12) is loosely fitted on the outer wall of the main shaft (2) by a pair of angular contact ball bearings (24); the number of the reverse guide curved blades (13) is eight.

6. The excavation device for municipal pipeline construction according to claim 1, characterized in that: When the interface adhesion index approaches the set warning threshold, the control system automatically increases the working duty cycle of the ultrasonic transducer array (8) and uses high-frequency micro-amplitude vibration to form a micro-bubble cavitation layer on the metal surface of the cutting disc (3). At the same time, the opening degree of the bypass valve (26) at the front end of the vacuum pump (25) is finely adjusted to reduce the suction vacuum.

7. The excavation device for municipal pipeline construction according to claim 1, characterized in that: When the dust agglomeration index is lower than the set safety threshold, the control system increases the water spray pressure of the high-pressure water pump (11) and increases the suction negative pressure of the vacuum pump (25). At the same time, the ultrasonic transducer array (8) outputs high-frequency mechanical waves to dynamically change the surface tension of the water droplets sprayed by the atomizing nozzle (10), and instantly pulverizes the liquid water into dry fog.

8. The excavating device for municipal pipeline construction according to claim 1, characterized in that: When the negative pressure suction duct (6) generates airflow pulsation oscillation at high power output, the drag force of the negative pressure airflow drives the follower-type guide impeller (12) on the main shaft (2) to rotate at high speed. The reverse guide curved blades (13) of the follower-type guide impeller (12) convert part of the axial airflow into a spiral vortex attached to the wall. The centrifugal force effect generated by the vortex stabilizes the edge pressure of the negative pressure suction duct (6) and weakens the local pressure collapse caused by airflow pulsation.

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