Shield tunneling machine cutterhead assembly, shield tunneling machine and cutterhead water jet control method

Abstract

The embodiment of the invention provides a shield tunneling machine cutterhead assembly, a shield tunneling machine and a cutterhead water jet control method, and the shield tunneling machine cutterhead assembly comprises a cutterhead provided with at least two nozzle mounting holes; the water jet nozzle is arranged in the nozzle mounting hole in a penetrating manner; one end of the water jet nozzle is a spraying end which extends out of the outer side surface of the cutter head; the other end of the water jet nozzle is a mounting end which extends out of the inner side surface of the cutter head; a liquid channel is arranged in the water jet nozzle and penetrates through the mounting end of the water jet nozzle to the spraying end; the water jet nozzle can move relative to the cutterhead along the axial direction; and the nozzle driving device is arranged on the inner side surface of the cutter head, is connected with the water jet nozzle and provides axial movement driving force for the water jet nozzle so as to adjust the length of the water jet nozzle extending out of the outer side surface of the cutter head. According to the shield tunneling machine cutterhead assembly, by adjusting the length of the part, extending out of the outer side face of the cutterhead, of the water jet nozzle, the water flow jetting range is adjusted, and the flushing effect is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to underground excavation construction technology, in particular to a shield machine cutterhead assembly, a shield machine and a cutterhead water jet control method. BACKGROUND

[0002] In the process of tunneling in clay strata, clayey sand strata, strongly weathered strata, and fully weathered mudstone strata, the mud-water shield machine generates solid or semi-solid block-shaped objects between the cutterhead and the tunnel face due to unreasonable cutterhead structure, incomplete improvement of muck, large stratum viscosity, and easy clumping of soil, etc., which adhere to the cutterhead and gradually form a mud cake. After the cutterhead forms a mud cake, the cutters are gradually covered with clay, resulting in a decrease in the penetration of the shield cutters and a decrease in the tunneling efficiency. When the cutters are blocked by the mud cake, they cannot rotate, causing uneven wear of the cutters. When the mud cake is severe, the entire cutterhead is covered with mud cake, causing the shield machine to be unable to tunnel.

[0003] To address the problem of cutterhead mud cake, the engineering site can use a chemical method to treat and inject a dispersing agent in front of the excavation face to disperse the mud cake. This method takes a long time, requires a large investment, has little effect, and poses a risk of environmental pollution. A water flow flushing method can also be used, which increases the central flushing flow and performs physical flushing of the front chamber every half hour, which can reduce the accumulation of bottom mud balls, but has little effect on the treatment of cutterhead mud cake.

[0004] Research has found that the range of water flow flushing is limited and can only flush mud cake close to the nozzle. To solve this problem, more nozzles can be installed on the cutterhead, but this brings problems such as complex structure, difficult pipeline layout, and high failure rate. SUMMARY

[0005] To solve one of the above technical defects, a shield machine cutterhead assembly, a shield machine, and a water jet control method are provided in the embodiments of the present application.

[0006] According to a first aspect of the embodiments of the present application, a shield machine cutterhead assembly is provided, comprising: a cutterhead; an excavating cutter is arranged on the outer side of the cutterhead; at least two nozzle mounting holes are arranged on the cutterhead, the nozzle mounting holes being through in the thickness direction of the cutterhead; a water jet nozzle is arranged in the nozzle mounting hole; one end of the water jet nozzle is a jetting end, which extends from the outer side of the cutterhead; the other end of the water jet nozzle is a mounting end, which extends from the inner side of the cutterhead; a liquid channel is arranged in the water jet nozzle, which is through the mounting end to the jetting end of the water jet nozzle; the water jet nozzle can move relative to the cutterhead in the axial direction; The nozzle driving device is arranged on the inner side of the cutter head and connected with the water jet nozzle to provide driving force for axial movement of the water jet nozzle to adjust the length of the water jet nozzle extending out of the outer side of the cutter head.

[0007] According to a second aspect of the embodiments of the present application, a shield tunneling machine is provided, comprising the shield tunneling machine cutter head.

[0008] According to a third aspect of the embodiments of the present application, a water jet control method applied to the shield tunneling machine cutter head assembly is provided, comprising: Step one, obtaining current rotating state parameters of the shield tunneling machine cutter head and tunneling face geological parameters, the current rotating state parameters including cutter head rotating speed and cutter head torque, and the tunneling face geological parameters including soil hardness and water content; Step two, dividing the shield tunneling machine cutter head into a plurality of fan-shaped regions, and calculating a corresponding wear risk level for each of the fan-shaped regions according to the current rotating state parameters and the tunneling face geological parameters; Step three, judging whether there is a high-risk region based on the wear risk level, and if there is a high-risk region, executing step four; if there is no high-risk region, executing step five; Step four, starting a directional water jet mode for the high-risk region, controlling the water jet nozzles to concentrate flushing on the high-risk region, adjusting the water jet pressure to a high pressure state, and monitoring the temperature change of the high-risk region, and when the temperature change reaches a preset threshold, executing step six; Step five, starting an even water jet mode, controlling all water jet nozzles to flush the shield tunneling machine cutter head comprehensively at the same pressure, and executing step six; Step six, monitoring cutting efficiency parameters of the shield tunneling machine cutter head in real time, the cutting efficiency parameters including the ratio of advancing speed to torque, judging whether the cutting efficiency parameters are lower than a preset efficiency threshold, and if lower than the preset efficiency threshold, executing step seven; if not lower than the preset efficiency threshold, returning to step one; Step seven, starting a pulse water jet mode, controlling the water jet nozzles to spray in an intermittent manner, applying high-pressure water flow during spraying and stopping spraying during the intermittent period, and removing adhesions on the cutter head surface through the impact effect of the pulse water jet, and then returning to step one.

[0009] The technical solutions provided in the first and second aspects of this application include: excavating cutters on the outer side of the cutterhead; at least two nozzle mounting holes on the cutterhead, which extend along the thickness direction of the cutterhead; water jet nozzles inserted into the nozzle mounting holes; one end of the water jet nozzle is a spraying end, extending from the outer side of the cutterhead; the other end of the water jet nozzle is a mounting end, extending from the inner side of the cutterhead; a liquid channel is provided inside the water jet nozzle, connecting the mounting end to the spraying end; the water jet nozzle can move axially relative to the cutterhead; a nozzle driving device is located on the inner side of the cutterhead and connected to the water jet nozzle, providing axial movement driving force to the water jet nozzle to adjust the length of the water jet nozzle extending from the outer side of the cutterhead. By adjusting the length of the water jet nozzle extending from the outer side of the cutterhead, the water jet range can be adjusted, enabling the washing of mud cake at a greater distance, thereby improving the washing effect, reducing the mud cake adhering to the cutterhead surface, allowing the cutters to perform excavation operations normally, and improving the reliability and tunneling efficiency of the tunnel boring machine.

[0010] The third aspect of this application, through real-time assessment of wear risk in different areas of the cutterhead, automatically selects directional, uniform, or pulsed water jet modes to form a closed-loop control system. This method achieves precise zoned control of the cutterhead water jet, effectively extending the cutterhead's service life; the multi-mode control strategy, especially the pulsed water jet mode, significantly improves the ability to remove adhering substances; closed-loop control based on cutting efficiency parameters enhances the system's adaptability; the application of rotatable nozzles and high-speed solenoid valve arrays enables flexible control of the water jet direction and mode, greatly improving water resource utilization efficiency; simultaneously, the system has low implementation costs, a high degree of automation, reduces the need for manual intervention, and improves construction continuity and efficiency. Attached Figure Description

[0011] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 Schematic diagram of the shield machine cutterhead assembly provided in the embodiments of this application Figure 1 ; Figure 2 Schematic diagram of the shield machine cutterhead assembly provided in the embodiments of this application Figure 2 ; Figure 3 A flowchart of a shield machine cutterhead water jet control method provided in an embodiment of this application.

[0012] Figure label: 1-Cutter head; 2-Water jet nozzle; 21-Nozzle mounting part; 22-Nozzle drive device; 23-Cylinder mounting base; 24-Bolt. Detailed Implementation

[0013] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0014] This embodiment provides a tunnel boring machine cutterhead assembly that can remove mud cake adhering to the outer surface of the cutterhead, and has a good removal effect.

[0015] like Figure 1 As shown, the shield machine cutterhead assembly provided in this embodiment includes: cutterhead 1 and water jet nozzle 2.

[0016] The cutterhead 1 has opposing outer and inner surfaces, with excavation tools mounted on the outer surface. The cutterhead 1 rotates around its own axis, and the excavation tools are used to excavate the ground in front of the tunnel boring machine. The cutterhead 1 has at least two nozzle mounting holes, which extend along the thickness direction of the cutterhead 1.

[0017] A water jet nozzle 2 is inserted into a nozzle mounting hole. One end of the water jet nozzle 2 is the spray end, extending from the outer side of the cutter head 1; the other end is the mounting end, extending from the inner side of the cutter head 1. A liquid channel is provided inside the water jet nozzle 2, running from the mounting end to the spray end. The liquid channel is connected to a water supply pipe at the spray end, and the water supply pipe is connected to a liquid supply source. Liquid supplied by the liquid supply source enters the water jet nozzle 2 through the water supply pipe and is sprayed out from the outer side of the cutter head 1.

[0018] The water jet nozzle 2 can rotate with the cutter head 1 on the one hand, and move relative to the cutter head 1 in the nozzle mounting hole on the other hand along its own axis.

[0019] The nozzle drive device 3 is located on the inner side of the cutter head 1 and is connected to the water jet nozzle 2. It provides the water jet nozzle 2 with an axial moving driving force to adjust the length of the water jet nozzle 2 extending out of the outer side of the cutter head 1.

[0020] When the water jet nozzle 2 extends a longer distance beyond the outer side of the cutter disc 1, its liquid spray range increases, enabling it to flush and clean mud cakes from a greater distance, thereby improving the cleaning effect of mud cakes.

[0021] When there is less mud cake on the outer side of the cutterhead, the water jet nozzle 2 is driven to retract, which can protect the water jet nozzle 2 to a certain extent and prevent the hard structure in the stratum from damaging the water jet nozzle 2 during the excavation process.

[0022] The technical solution provided in this embodiment includes a digging cutter on the outer side of the cutterhead; at least two nozzle mounting holes on the cutterhead, which extend along the thickness direction of the cutterhead; a water jet nozzle is inserted into the nozzle mounting hole; one end of the water jet nozzle is the spray end, which extends from the outer side of the cutterhead; the other end of the water jet nozzle is the mounting end, which extends from the inner side of the cutterhead; a liquid channel is provided inside the water jet nozzle, which connects the mounting end to the spray end; the water jet nozzle can move axially relative to the cutterhead; a nozzle driving device is located on the inner side of the cutterhead and connected to the water jet nozzle, providing axial movement driving force to the water jet nozzle to adjust the length of the water jet nozzle extending from the outer side of the cutterhead. By adjusting the length of the water jet nozzle extending from the outer side of the cutterhead, the water jet range can be adjusted, enabling the washing of mud cake at a greater distance, thereby improving the washing effect, reducing the mud cake adhering to the cutterhead surface, allowing the cutter to perform digging operations normally, and improving the reliability and tunneling efficiency of the tunnel boring machine.

[0023] Based on the above technical solution, this embodiment provides an installation method for the water jet nozzle 2: The mounting end of the water jet nozzle 2 extends outward to form a nozzle mounting part 21. A drive mounting space is formed between the nozzle mounting part 21 and the inner side of the cutter head 1. The nozzle drive device 22 is disposed in the drive mounting space. One end of the nozzle drive device 22 is mounted to the inner side of the cutter head 1, and the other end is connected to the nozzle mounting part 21.

[0024] One embodiment is as follows: the nozzle drive device 22 is a hydraulic cylinder, including a cylinder body and a telescopic piston rod. The cylinder body is mounted to the inner side of the cutter head 1, and the piston rod is connected to the nozzle mounting part 21. Figure 1 From this angle, when the piston rod moves to the right, it pushes the water jet nozzle to the right, causing the nozzle to retract; when the piston rod moves to the left, it causes the nozzle to extend out of the cutter head. Figure 2 .

[0025] Based on the above technical solution, a hydraulic cylinder mounting base 23 is also used, which is installed on the inner side of the cutter head 1 by bolts 24. The cylinder body of the hydraulic cylinder is fixed to the hydraulic cylinder mounting base 23. Each water jet nozzle 2 can be equipped with a corresponding first nozzle drive device 22. Each water jet nozzle 2 can be controlled to extend and retract by a controller. For example, the extension and retraction of the corresponding water jet nozzle 2 can be controlled according to the degree of adhesion and amount of mud cake at different positions on the outer side of the cutter head, so as to achieve targeted flushing of mud cake in a certain area, thereby reducing the mud cake adhesion on the cutter head.

[0026] For example, if a large amount of mud cake is detected attached to a certain area of ​​the cutter head and has not been washed away for a long time, several water jet nozzles 2 around that area are controlled to move outward and flush the area together, increasing the impact force and causing the mud cake to fall off.

[0027] The nozzle drive device 22 can be remotely controlled, and control signals can be transmitted via wired or wireless means. The length of the water jet nozzle 2 extending out of the cutter head 1 can also be adjusted according to actual conditions, such as controlling the stroke of the hydraulic cylinder piston rod, so that the water flow can be sprayed onto the mud cake in the target area and the impact force of the water flow can cause the mud cake to fall off.

[0028] Based on the above technical solutions, this embodiment proposes a cutter disc water jet control method based on the cutter disc equipped with water jet nozzles, which can thoroughly flush the cutter disc and has a good flushing effect.

[0029] like Figure 3 As shown, the shield machine cutterhead water jet control method provided in this embodiment includes the following steps: Step 1: Obtain the current rotational state parameters of the tunnel boring machine cutterhead and the geological parameters of the tunneling face. The current rotational state parameters include the cutterhead rotation speed and cutterhead torque, and the geological parameters of the tunneling face include soil hardness and moisture content.

[0030] Step 2: Divide the tunnel boring machine cutterhead into several sector areas, and calculate the corresponding wear risk level for each sector area based on the current rotation parameters and geological parameters of the tunneling face. Step 3: Based on the wear risk level, determine whether there is a high-risk area. If a high-risk area exists, proceed to Step 4; otherwise, proceed to Step 5. Step 4: For high-risk areas, activate the directional water jet mode, control the water jet nozzles to focus on the high-risk areas for concentrated flushing, adjust the water jet pressure to a high-pressure state, and monitor the temperature change in the high-risk areas. When the temperature change reaches the preset threshold, proceed to step 6. Step 5: Activate the uniform water jet mode, control all water jet nozzles to fully flush the shield machine cutterhead with the same pressure, maintain normal cooling and lubrication, and proceed to Step 6; Step 6: Monitor the cutting efficiency parameters of the tunnel boring machine cutterhead in real time. The cutting efficiency parameters include the ratio of propulsion speed to torque. Determine whether the cutting efficiency parameters are lower than the preset efficiency threshold. If they are lower than the preset efficiency threshold, proceed to Step 7; if they are not lower than the preset efficiency threshold, return to Step 1. Step 7: Activate the pulsed water jet mode, control the water jet nozzle to spray intermittently, apply high-pressure water flow during spraying, and stop spraying during the interval. The impact effect generated by the pulsed water jet removes the adhering substances on the cutter head surface, and then return to step 1. The process of obtaining the current rotational parameters of the tunnel boring machine cutterhead and the geological parameters of the tunnel face includes the following steps: Step 11: Obtain the cutterhead rotation speed through the speed sensor installed on the main shaft of the tunnel boring machine, and obtain the cutterhead torque through the torque sensor to form the current rotation state parameters; Specifically, the speed sensor employs a magnetoelectric type. A sensor probe is fixedly installed on the non-rotating part of the tunnel boring machine's main shaft, while several magnetic marker blocks are evenly installed on the rotating part. As the main shaft rotates, the magnetic marker blocks pass sequentially through the sensor probe, generating induced electromotive force pulse signals in the coil within the probe. By counting the number of pulses per unit time and combining this with the total number of magnetic marker blocks, the real-time speed of the cutterhead is calculated. The torque sensor uses a strain gauge type. Several sets of strain gauges are attached to appropriate positions on the main drive shaft, forming a Wheatstone bridge circuit. When the main shaft transmits torque, it generates minute torsional deformation, causing a change in the resistance of the strain gauges. By measuring the change in the bridge output voltage and considering the material's shear modulus and the shaft's geometric parameters, the real-time torque value is calculated. The acquired cutterhead speed and torque data are packaged and timestamped to form a complete data package of current rotational state parameters.

[0031] Step 12: Obtain soil hardness through geological exploration and moisture content through humidity detection to form geological parameters of the tunnel face.

[0032] Specifically, the process of obtaining soil hardness includes: installing several soil pressure sensors at different radial positions on the cutterhead. These sensors are piezoresistive pressure sensors. When the cutter cuts the soil, the reaction force generated by the soil on the cutter is transmitted to the pressure-sensitive diaphragm of the pressure sensor through a force transmission mechanism. The deformation of the pressure-sensitive diaphragm causes a change in the resistance of the internal pressure-sensitive resistor. By measuring the resistance change and performing calibration conversion, the pressure value of the soil on the cutterhead is obtained. Simultaneously, the cutterhead feed speed and depth of cut parameters at corresponding moments are recorded. Based on the principles of cutting mechanics, the pressure value, feed speed, and depth of cut parameters are substituted into the soil hardness calculation model to obtain the soil hardness index.

[0033] The process of obtaining moisture content includes: embedding several dielectric soil moisture sensors on the cutterhead panel. Each dielectric soil moisture sensor contains two parallel metal electrode plates. When soil enters the detection area between the electrode plates, the soil acts as a dielectric, changing the capacitance between the electrodes. Since the dielectric constant of water is much greater than that of dry soil, the soil moisture content can be estimated by measuring the change in capacitance. The measured capacitance value is input into a pre-established moisture content calibration curve, and the corresponding moisture content value is obtained by looking up a table. The acquired soil hardness and moisture content data are integrated to form a geological parameter dataset for the tunnel face.

[0034] One method for dividing the tunnel boring machine cutterhead into several sector-shaped areas is as follows: based on the structural characteristics of the cutterhead and the distribution pattern of the cutters, the cutterhead is divided into several sector-shaped areas with equal angles, and a regional identification system is established.

[0035] Specifically, a polar coordinate system is established with the rotation center of the cutter head as the pole, and the entire circumference of the cutter head is divided equally according to a preset angular interval. The determination of the angular interval needs to consider the cutter head diameter, the number of cutters, and the control precision requirements; typically, each sector contains several complete cutters. For each sector, its starting and ending angles are defined, and a unique sector number is assigned. A cutter position database is established, recording the polar coordinate position of each cutter, including radial distance and angular position. By comparing the angular position of the cutters with the angular range of each sector, the sector to which each cutter belongs is determined, generating a mapping table between cutters and sectors. The number of hobs, cutters, and scrapers contained in each sector is counted to ensure that the divided sectors have similar cutter configurations, laying the foundation for subsequent zonal control.

[0036] Furthermore, the method for calculating the wear risk level of each sector area is as follows; Step 21: By calculating the average torque and torque change rate borne by each sector area in real time, extract the fluctuation characteristics of the cutterhead rotation speed and the cutterhead torque in the time series of the tunnel boring machine, so as to analyze the influence of the current rotation state parameters on wear.

[0037] Understandably, in areas with uneven torque distribution, the cutting tool experiences greater alternating stress, thus increasing the risk of wear.

[0038] Step 22: Extend the discrete soil hardness and moisture content measurements to the entire tunnel face using an interpolation algorithm, and calculate the average value of each geological parameter of the tunnel face in each sector area to obtain the mean geological parameter data corresponding to each sector area, so as to analyze the spatial distribution characteristics of the geological parameters of the tunnel face.

[0039] Understandably, in areas where the soil is hard and has low moisture content, the cutting tool wears out faster.

[0040] Step 23: Retrieve wear records from the historical wear database, including the cumulative working time of tools in each area, the number of tools replaced, and the wear amount information from the last inspection.

[0041] Step 24: Input the fluctuation characteristics, average geological parameter data, and various parameters from the wear record as influencing factors into the wear risk assessment model. The wear risk assessment model adopts a weighted comprehensive scoring method, assigning a weight coefficient to each influencing factor to calculate the wear risk index for each sector area. Based on the numerical range of the wear risk index, it is mapped to a predefined risk level category, including several levels such as high risk, medium risk, and low risk.

[0042] Furthermore, based on the wear risk level, determine whether there are high-risk areas. If high-risk areas exist, proceed to step four; if no high-risk areas exist, proceed to step five, which includes the following steps: Step 31: Traverse the wear risk level data of all sector areas, identify and mark high-risk sector areas, and generate a list of high-risk areas.

[0043] Specifically, the wear risk level information for each sector is retrieved from the wear risk assessment database, and a loop-based traversal algorithm is used to check the risk level label of each sector one by one. A rule for determining high-risk levels is established: when the wear risk index of a sector exceeds a preset high-risk threshold, or when the risk level label is "high-risk," the sector's number is added to the high-risk sector list. Simultaneously, the specific location information of each high-risk sector is recorded, including the starting angle, ending angle, and radial range. The total number of high-risk sectors is counted, and the proportion of high-risk sectors to the total area of ​​the cutterhead is calculated. A high-risk sector distribution map is generated, visually displaying the spatial distribution characteristics of high-risk sectors on the cutterhead. The high-risk sector list and distribution map are stored in memory for subsequent control decisions.

[0044] Step 32: Based on the identification results of high-risk areas, execute the preset condition judgment logic and select to enter the corresponding water jet control mode branch.

[0045] Specifically, the high-risk area list is read, and it is determined whether the list is empty. If the high-risk area list is not empty, meaning there is at least one high-risk area, the status flag is set to "directional control mode," and the process is prepared to proceed to step four to execute directional water jet control.

[0046] Before jumping, preload the parameters required for directional control, including the location coordinates of high-risk areas, the numbers of the rotatable nozzles to be called, and the target water pressure value. If the list of high-risk areas is empty, meaning that the wear risk level of all sector areas is medium or low, set the status flag to "uniform control mode" and prepare to jump to step five to execute uniform water jet control. Before jumping, check the working status of all fixed nozzles to ensure that the uniform jet mode can be started normally. Condition judgment is implemented through the program control structure to ensure that the most suitable control strategy can be automatically selected based on the actual risk assessment results.

[0047] Furthermore, activating the directional water jet mode includes the following steps: Step 41: Based on the location information of the high-risk area, calculate the target angle of each rotatable nozzle and control the rotatable nozzle to rotate and align with the high-risk area.

[0048] Specifically, the orientation alignment process includes the following detailed steps: First, the installation position information of all rotatable nozzles is read, including the radial coordinates and initial angle of each nozzle on the cutterhead. Second, for each high-risk area, its geometric center position is calculated as the target point for the water jet. Then, for each rotatable nozzle, the direction vector from the nozzle position to the target point is calculated to determine the angle by which the nozzle needs to be rotated.

[0049] Angle calculations consider the effective range and spray angle of the nozzles to ensure the water jet completely covers high-risk areas. The calculated target angle is converted into control commands for the servo motors and sent to the angle adjustment mechanisms of each rotatable nozzle via a fieldbus. Upon receiving the commands, the angle adjustment mechanisms drive the servo motors to rotate the nozzles, while simultaneously providing real-time feedback of the current angle via angle encoders. When the deviation between the actual angle and the target angle is less than the allowable error, the nozzle position is locked. For situations with multiple high-risk areas, an optimization algorithm is used to allocate the direction of each rotatable nozzle, ensuring that all high-risk areas receive sufficient water jet coverage.

[0050] Step 42: Adjust the water jet supply pressure to a high-pressure state through the frequency converter and the preset pressure-flow coordination control mechanism to enhance the cooling and flushing intensity of high-risk areas.

[0051] Specifically, firstly, a frequency increase command is sent to the frequency converter to gradually increase the operating frequency of the main water pump motor, causing the pump's output pressure to rise steadily. Then, the pressure sensor readings in the water supply pipeline are monitored; when the pressure approaches the target high-pressure value, the frequency adjustment rate is reduced for fine-tuning.

[0052] If a single main water pump cannot achieve the required high pressure, a standby booster pump is activated to increase the total pressure through parallel operation. During the pressure rise, the flow control valves of each branch are simultaneously adjusted to ensure that the high-pressure water flow is primarily delivered to the rotatable nozzles aimed at high-risk areas. The flow control valves are electrically adjustable, with different opening degrees allocated according to the importance of each rotatable nozzle. For rotatable nozzles in non-critical areas, the water supply flow is appropriately reduced, concentrating more water resources on high-risk areas.

[0053] Furthermore, a pressure-flow coordinated control mechanism is established. When the pressure reaches the set high pressure value, the pressure is maintained stable through a PID control algorithm. The PID control algorithm can calculate the deviation between the pressure setpoint and the actual pressure, the integral value of the deviation, and the rate of change of the deviation in real time. It then weights and sums the deviation, the integral value of the deviation, and the rate of change of the deviation according to preset weighting coefficients to obtain the frequency regulation of the water pump inverter, thereby achieving dynamic control and rapid stabilization of the water supply pressure.

[0054] Through the above steps, the water jet under high pressure has stronger kinetic energy, enabling it to penetrate deep into the tiny gaps on the tool surface and remove the heat and debris generated during cutting.

[0055] Step 43: Deploy an array of infrared temperature sensors to monitor the temperature distribution in high-risk areas in real time to assess the effectiveness of targeted cooling.

[0056] Specifically, the method for monitoring the temperature distribution in high-risk areas is as follows: several infrared temperature sensors are installed on the fixed frame of the cutter head to form a temperature monitoring network covering the entire cutter head.

[0057] The infrared temperature sensor uses a non-contact temperature measurement principle, converting the infrared radiation energy emitted by the target area into a temperature value. The field of view and measurement range of each sensor are calibrated to ensure accurate measurement of the average temperature of the corresponding sector area.

[0058] Before the directional water jet begins, the initial temperature values ​​of each high-risk area are recorded as a baseline. During directional cooling, temperature data is continuously collected at a fixed sampling frequency to generate a temperature-time curve. The difference between the current temperature and the initial temperature is calculated to obtain the temperature drop magnitude. Simultaneously, the temperature drop rate is calculated to evaluate cooling efficiency. A temperature control target is set; when the temperature in the high-risk area drops below a safe threshold and the temperature drop rate flattens, the directional cooling is considered to have achieved the expected effect. Temperature monitoring data is stored in a historical database for optimizing subsequent control parameters. If the temperature drop in some high-risk areas is not significant, the angle of the corresponding nozzle or the water flow rate in that area is adjusted in step 42 until the temperature in all high-risk areas reaches a safe range.

[0059] Furthermore, the uniform water jet mode includes the following steps: Step 51: Activate all the rotatable nozzles at fixed positions on the tunnel boring machine cutterhead, and adjust the opening sequence of each rotatable nozzle to form a uniformly distributed water jet coverage.

[0060] Specifically, forming a uniformly distributed water jet coverage includes the following steps: Step 511: Read the position information and injection parameters of all fixed nozzles from the nozzle configuration database, including the nozzle's radial position, circumferential distribution angle, injection angle, and effective range. Based on the position information and injection parameters, calculate the coverage area of ​​each nozzle, ensuring that the coverage areas of adjacent nozzles have appropriate overlap to avoid injection blind spots.

[0061] Step 512: Group all nozzles radially. Control the on / off state of each fixed nozzle using a solenoid valve, ensuring that fixed nozzles on the same radial direction open simultaneously. Fixed nozzle groups on different radial directions open sequentially, either from the inside out or from the outside in, forming a radial scanning water jet coverage. The opening time interval of each nozzle group is dynamically adjusted according to the cutter head rotation speed. This dynamic adjustment only needs to ensure that all areas receive sufficient water jet flushing within one rotation of the cutter head; the specific method is not limited. The solenoid valve receives switching signals from the central controller.

[0062] Furthermore, after all nozzles are turned on, the actual flow rate of each branch can be monitored by the flow sensor. If an abnormal flow rate is found in a branch, the corresponding fixed nozzle is checked for blockage or the solenoid valve is faulty. Adjustments are made in a timely manner or the nozzle is switched to a backup nozzle.

[0063] Step 52: Adjust the pressure of the water supply system of each fixed nozzle to the preset normal operating range to establish a stable pressure control closed loop and maintain constant cooling and lubrication effects.

[0064] Specifically, the way to maintain constant cooling and lubrication effects is as follows: A frequency reduction command is sent to the frequency converter to gradually decrease the operating frequency of the water pump motor, allowing the system pressure to smoothly decrease from a high-pressure state to the normal operating pressure. The specific value of the normal operating pressure is determined based on factors such as the diameter of the tunnel boring machine cutterhead, the soil type, and the tunneling speed, and is stored in the system parameter table. During the pressure reduction process, the readings of the main pipeline pressure sensor are monitored in real time, and a ramp function is used to control the pressure reduction rate to avoid sudden pressure changes that could impact the system.

[0065] When the pressure approaches the target value, the PID pressure control loop is activated. The input to the PID controller is the deviation between the pressure setpoint and the actual pressure, and the output is the frequency correction value of the frequency converter. By continuously adjusting the water pump speed, the actual pressure is stabilized near the setpoint, with the allowable pressure fluctuation controlled within a certain percentage of the setpoint. Simultaneously, the pressure at each fixed nozzle outlet is monitored to ensure uniform pressure distribution. If localized low pressure is detected, the corresponding pipeline is checked for leaks or improper valve opening. Under normal pressure, the water jet forms a continuous liquid film on the cutter head surface, which not only removes cutting heat but also reduces the friction coefficient between the cutter and the soil, extending the cutter's service life.

[0066] Furthermore, real-time monitoring of the cutting efficiency parameters of the tunnel boring machine cutterhead includes the following steps: Step 61: Synchronously collect the propulsion speed of the propulsion system and the torque data of the main drive system. Obtain the cutting efficiency parameters by calculating the product of the propulsion speed and the cutter head torque.

[0067] Specifically, the cutting efficiency parameters are obtained as follows: A high-precision displacement sensor is installed on the piston rod of the propulsion cylinder. The sensor employs the magnetostrictive principle, determining the piston displacement by measuring the positional change of a magnetic ring on the waveguide wire. Displacement data is continuously recorded at a fixed sampling frequency. The instantaneous propulsion speed is calculated by differentially analyzing the displacement data; that is, the displacement difference between two adjacent sampling points divided by the sampling time interval. A moving average filter is applied to the instantaneous speed sequence to obtain a smooth propulsion speed curve, eliminating the influence of measurement noise. Simultaneously, real-time torque data is acquired from the torque sensor of the main drive system. The sampling frequency of the cutting tool torque is consistent with the displacement data to ensure data time synchronization. The propulsion speed value at each moment is divided by the torque value at the corresponding moment to obtain the instantaneous cutting efficiency parameter. Statistical analysis is performed on the instantaneous cutting efficiency parameter, calculating the average value, standard deviation, and trend within a certain time window. The length of the time window is determined based on the cutterhead rotation cycle, typically selecting several complete rotation cycles to eliminate the influence of periodic fluctuations. The calculated cutting efficiency parameters and their statistical characteristics are stored in a real-time database.

[0068] Step 62: Compare the real-time cutting efficiency parameters with the dynamically adjusted efficiency threshold to determine whether the cleaning program needs to be started.

[0069] Specifically, an efficiency threshold matching the current geological conditions is extracted from a pre-collected parameter database. This efficiency threshold is generally an empirical value derived from statistical analysis of extensive historical data, taking into account factors such as soil type, moisture content, and cutterhead wear. A dynamic adjustment mechanism for the efficiency threshold is then established, adjusting the threshold in real time based on changes in geological parameters during actual tunneling. For example, when entering hard rock formations, the efficiency threshold is appropriately lowered; when the soil moisture content increases, the efficiency threshold is correspondingly increased. The current cutting efficiency parameter is compared with the adjusted efficiency threshold. If the cutting efficiency parameter remains below the efficiency threshold for several consecutive sampling periods, it is determined that the cutterhead cutting capacity has decreased.

[0070] Furthermore, the possible causes of efficiency decline can be analyzed by checking auxiliary indicators such as whether the torque increases abnormally, whether the feed speed decreases significantly, and whether the tool turret vibration intensifies, to infer whether it is due to the accumulation of deposits on the tool surface. If the problem is confirmed to be due to deposits, a cleaning command is generated, and the process proceeds to step seven. If other causes are determined, such as severe tool wear or sudden geological changes, corresponding alarm information is generated to remind the operator to take other measures. The efficiency comparison results and decision-making basis are recorded in the system log for subsequent fault diagnosis and performance optimization.

[0071] Furthermore, the pulsed water jet mode includes the following steps: Step 71: Configure the timing parameters of the pulsed water jet and achieve rapid on / off control of the water flow through a high-speed solenoid valve array.

[0072] Specifically, firstly, the basic timing parameters of the pulsed water jet are determined, including the pulse period, jet duration, and interval. The pulse period is determined based on the properties and thickness of the adhered material; thicker adhered layers require longer pulse periods to ensure sufficient penetration time. The ratio of jet duration to interval is the duty cycle, which controls the average flow rate and impact intensity by adjusting the duty cycle. Secondly, the timing parameters are converted into control signals for the solenoid valve. A square wave control signal is generated using pulse width modulation (PWM), where a high level corresponds to the solenoid valve opening and a low level corresponds to its closing. The response time of the high-speed solenoid valve must be at the millisecond level to ensure accurate tracking of changes in the control signal.

[0073] To improve control accuracy, an array-type solenoid valve configuration is adopted, using multiple solenoid valves in parallel to achieve more complex pulse patterns through phase-shift control. For example, the solenoid valve array is divided into several groups, with a phase difference set between each group to form a continuous pulse waveform, enhancing the continuity of the impact effect. A feedback control mechanism is established, using a pressure sensor to monitor the pressure waveform during the pulse. If the actual pressure waveform deviates significantly from the set waveform, the switching sequence of the solenoid valves is automatically adjusted to ensure pulse quality.

[0074] Step 72: During each jet pulse, high-pressure water is rapidly released to increase the water pressure to its peak value, thereby utilizing the mechanical impact and physical effects of the high-pressure pulsed water flow to remove the adhering material.

[0075] Specifically, in the preparation phase before pulse jet injection begins, the main water supply line is connected to the accumulator via a bypass valve, and a water pump continuously operates to build up high pressure in the accumulator. The moment the solenoid valve opens, the high-pressure water in the accumulator is rapidly released, raising the water pressure at the nozzle to peak pressure in a very short time. The magnitude of the peak pressure is determined by the adhesion strength of the adhering material; it needs to be high enough to overcome the adhesion force, but not too high to avoid damaging the tool surface.

[0076] The impact of high-pressure pulsed water jets on the tool surface generates several physical effects: First, there is a direct mechanical impact force, where the kinetic energy of the high-speed water flow is converted into impact force, generating shear stress on the adhered material. Second, there is the water hammer effect, where pressure fluctuations caused by sudden resistance to the high-speed water flow can generate tensile stress within the adhered material. Third, there is the cavitation effect, where tiny bubbles in the water flow rapidly expand and collapse under pressure changes, generating localized high temperatures and pressures that help to break down the structure of the adhered material. During the pulse intervals, stopping the water supply causes a rapid pressure drop, and the loosened adhered material detaches under the pressure release and its own gravity. Through multiple pulse cycles, the adhered material is peeled off layer by layer until the tool surface is restored to a clean state.

[0077] Step 73: Monitor the progress of pulse cleaning and automatically switch back to the preset normal monitoring mode after the predetermined cleaning cycle is completed.

[0078] Specifically, during the pulsed water jet execution, a built-in cycle counter records the number of pulses completed, and the counter value increases after each complete jet-intermittent cycle. Simultaneously, a vibration sensor mounted on the cutter head monitors the vibration characteristics during the cleaning process. Characteristic vibration signals are generated when adhering substances detach, and the cleaning effect can be indirectly assessed by analyzing the spectral changes of these vibration signals.

[0079] The cleaning completion criteria are set as follows: First, a preset number of pulse cycles is reached, which is determined based on historical cleaning experience and the severity of the adhering substances; second, the vibration signal characteristics return to the normal range, indicating that most of the adhering substances have been removed; and third, the cutting efficiency parameters show an upward trend, indicating that the cutter head performance is recovering.

[0080] When any completion criterion is met, the mode switching process begins: First, the pulse frequency is gradually reduced to smoothly transition the water jet from pulse mode to continuous mode; then, the solenoid valve array related to pulse control is shut down, switching back to the normal water supply circuit; finally, all control parameters are reset to their initial state, including clearing the cycle counter, restoring normal water supply pressure, and shutting down the accumulator charging circuit. After completing the mode switch, it automatically jumps back to step one to restart a new round of status monitoring and parameter acquisition, forming a complete closed-loop control cycle. Relevant data from this cleaning process, including comparisons of efficiency parameters before and after cleaning, the number of pulse cycles used, and the cleaning duration, are recorded in the maintenance log to provide data support for optimizing subsequent cleaning strategies.

[0081] Combining the above-mentioned water jet control method, the length of the water jet nozzle extending beyond the cutterhead can be adjusted in high-risk or low-risk areas. By adjusting the length of the water jet nozzle extending beyond the cutterhead, the water jet range can be adjusted to wash away mud cake at a greater distance, thereby improving the washing effect, reducing the mud cake adhering to the cutterhead surface, enabling the cutters to perform excavation operations normally, and improving the reliability and tunneling efficiency of the tunnel boring machine.

[0082] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0083] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0084] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0085] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0086] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A tunnel boring machine cutterhead assembly, characterized in that, include: The cutterhead is equipped with excavating tools on its outer side; the cutterhead is provided with at least two nozzle mounting holes, which are connected along the thickness direction of the cutterhead. A water jet nozzle is inserted into a nozzle mounting hole; one end of the water jet nozzle is the spray end, which extends from the outer side of the cutter head; the other end of the water jet nozzle is the mounting end, which extends from the inner side of the cutter head; a liquid channel is provided inside the water jet nozzle, which runs through the mounting end of the water jet nozzle to the spray end; the water jet nozzle can move axially relative to the cutter head. The nozzle drive device is located on the inner side of the cutter head and is connected to the water jet nozzle. It provides axial driving force to the water jet nozzle to adjust the length of the water jet nozzle extending out of the outer side of the cutter head.

2. The tunnel boring machine cutterhead assembly according to claim 1, characterized in that, The mounting end of the water jet nozzle extends outward to form a nozzle mounting part, and a drive mounting space is formed between the nozzle mounting part and the inner side of the cutter head; the nozzle drive device is set in the drive mounting space, one end of the nozzle drive device is mounted to the inner side of the cutter head, and the other end is connected to the nozzle mounting part.

3. The tunnel boring machine cutterhead assembly according to claim 2, characterized in that, The nozzle drive device is a hydraulic cylinder, including a cylinder body and a telescopic piston rod; the cylinder body is mounted on the inner side of the cutter head, and the piston rod is connected to the nozzle mounting part.

4. The tunnel boring machine cutterhead assembly according to claim 3, characterized in that, Also includes: The cylinder mounting base is bolted to the inner side of the cutter head; the cylinder body of the hydraulic cylinder is fixed to the cylinder mounting base.

5. A tunnel boring machine, characterized in that, include: The tunnel boring machine cutterhead assembly as described in any one of claims 1-4.

6. A water jet control method applied to the cutterhead assembly of a tunnel boring machine according to any one of claims 1-4, characterized in that, include: Step 1: Obtain the current rotational state parameters of the tunnel boring machine cutterhead and the geological parameters of the tunneling face. The current rotational state parameters include the cutterhead rotation speed and cutterhead torque, and the geological parameters of the tunneling face include soil hardness and moisture content. Step 2: Divide the tunnel boring machine cutterhead into several sector-shaped areas, and calculate the corresponding wear risk level for each sector-shaped area based on the current rotation state parameters and the geological parameters of the tunneling face; Step 3: Based on the wear risk level, determine whether there is a high-risk area. If there is a high-risk area, proceed to Step 4. If no high-risk area exists, proceed to step five; Step 4: For the high-risk area, activate the directional water jet mode, control the water jet nozzle to focus on the high-risk area for concentrated flushing, adjust the water jet pressure to a high-pressure state, and monitor the temperature change of the high-risk area. When the temperature change reaches a preset threshold, proceed to step 6. Step 5: Activate the uniform water jet mode, control all water jet nozzles to fully flush the shield machine cutterhead with the same pressure, and proceed to Step 6; Step Six: Monitor the cutting efficiency parameters of the tunnel boring machine cutterhead in real time. The cutting efficiency parameters include the ratio of propulsion speed to torque. Determine whether the cutting efficiency parameters are lower than a preset efficiency threshold. If they are lower than the preset efficiency threshold, proceed to Step Seven; if they are not lower than the preset efficiency threshold, return to Step One. Step 7: Activate the pulsed water jet mode, control the water jet nozzle to spray intermittently, apply high-pressure water flow during spraying, and stop spraying during the interval. The impact effect generated by the pulsed water jet removes the adhering substances on the cutter head surface, and then return to step 1.

7. The water jet control method according to claim 6, characterized in that, Obtaining the current rotational parameters of the tunnel boring machine cutterhead and the geological parameters of the tunnel face includes the following steps: Step 11: Obtain the cutterhead rotation speed through the speed sensor installed on the main shaft of the tunnel boring machine, and obtain the cutterhead torque through the torque sensor to form the current rotation state parameters; Step 12: Obtain soil hardness through geological exploration and moisture content through humidity detection to form geological parameters of the tunnel face.

8. The water jet control method according to claim 7, characterized in that, The method for dividing the tunnel boring machine cutterhead into several sector-shaped regions is as follows: Based on the structural characteristics and cutter distribution patterns of the tunnel boring machine (TBM) cutterhead, the TBM cutterhead is divided into several sector-shaped areas with equal angles, and a regional identification system is established.

9. The water jet control method according to claim 8, characterized in that, The method for calculating the wear risk level of each sector area is as follows: Step 21: By calculating the average torque and torque change rate borne by each sector area in real time, extract the fluctuation characteristics of the cutterhead rotation speed and the cutterhead torque in the time series of the tunnel boring machine, so as to analyze the influence of the current rotation state parameters on wear; Step 22: Extend the discrete soil hardness and moisture content measurements to the entire tunnel face using an interpolation algorithm, and calculate the average value of each geological parameter of the tunnel face in each sector area to obtain the mean geological parameter data corresponding to each sector area, so as to analyze the spatial distribution characteristics of the geological parameters of the tunnel face. Step 23: Retrieve wear records from the historical wear database, including the cumulative working time of tools in each area, the number of tools replaced, and the wear amount information from the last inspection; Step 24: Input the fluctuation characteristics, average geological parameter data, and various parameters in the wear record as influencing factors into the wear risk assessment model. The wear risk assessment model adopts a weighted comprehensive scoring method, sets a weight coefficient for each influencing factor, and calculates the wear risk index of each sector area. Based on the numerical range of the wear risk index, it is mapped to a predefined risk level category, including several levels such as high risk, medium risk, and low risk.

10. The water jet control method according to claim 9, characterized in that, Based on the wear risk level, determine whether there is a high-risk area. If there is a high-risk area, proceed to step four. If no high-risk area exists, then step five includes the following steps: Step 31: Traverse all the wear risk level data of the sector areas, identify and mark the high-risk sector areas, and generate a list of high-risk areas; Step 32: Based on the identification results of high-risk areas, execute the preset condition judgment logic, select the corresponding water jet control mode branch, read the high-risk area list, and determine whether the list is empty. If the high-risk area list is not empty, proceed to step four; if the high-risk area list is empty, proceed to step five.

Images