A small turning radius open-type TBM tunneling machine and method

Abstract

This invention discloses a small-turn-radius open-type TBM tunneling machine and its method, relating to the field of TBM tunneling machine technology. The tunneling machine includes propulsion cylinders, load detection mechanisms corresponding to each cylinder, independent speed regulation mechanisms for each cylinder, and a control mechanism with a controller. The load detection mechanism acquires the real-time load and stroke of the corresponding cylinder, and the speed regulation mechanism independently adjusts the speed and stroke of the corresponding cylinder. The controller receives load, stroke, and main machine attitude data, combines them with preset tunnel design parameters, calculates the optimal dynamic stroke difference in real time, and then controls each speed regulation mechanism to perform independent closed-loop control on each cylinder, forming a complete closed loop of "perception-decision-execution-feedback". This invention achieves real-time coupling and matching between dynamic changes in surrounding rock load and cylinder stroke difference, ensuring that the main machine's tunneling direction always follows the design axis, and significantly improving tunneling stability and attitude control accuracy under small-turn-radius and variable-slope conditions.

Description

Technical Field

[0001] This invention relates to the field of TBM tunneling machine technology, and particularly to an open-type TBM tunneling machine and method with a small turning radius. Background Technology

[0002] Open-face TBMs (Tunnel Boring Machines) are widely used in tunnel construction projects such as inclined shafts in mines. In the excavation and lining of inclined roadway systems, TBMs often need to complete excavation tasks with small turning radii and dynamic changes in gradient. In such small turning radius construction, the following drawbacks exist during the operation of the TBM: uneven development of surrounding rock fissures and significant differences in water content in the turning section lead to significant differences in the real-time propulsion load borne by the left and right propulsion cylinders; simultaneously, dynamic changes in gradient cause changes in the gravity component of the main unit, further exacerbating the imbalance of load on the left and right sides.

[0003] Currently, most tunneling machines (TBMs) control the left and right cylinders based on a fixed theoretical stroke difference calculated from the designed turning radius. This method cannot dynamically adjust the stroke difference parameters according to changes in surrounding rock conditions and slope, meaning it cannot dynamically adjust the stroke difference parameters based on the actual load on the left and right cylinders. When the surrounding rock strength changes abruptly or the slope changes significantly, the cylinder on the side with the greater load will advance at a slower speed, while the cylinder on the side with the less load will advance relatively excessively. This disrupts the preset balance of the left and right stroke differences, causing the main machine's tunneling direction to deviate from the designed axis. In severe cases, this can cause the TBM to jam, even leading to structural damage, forcing construction to stop, significantly increasing construction costs, and extending the construction period. Therefore, this invention proposes a small-turning-radius open-type TBM tunneling machine and method to meet these requirements. Summary of the Invention

[0004] The purpose of this application is to provide an open-type TBM tunneling machine and method with a small turning radius, which can effectively solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this application provides the following technical solution: In a first aspect, this application proposes a small-turning-radius open-type TBM tunneling machine, including multiple propulsion cylinders disposed on the rear side of the main drive system of the tunneling machine. Each propulsion cylinder includes a cylinder barrel and a piston rod coaxially inserted into the cylinder barrel. The tunneling machine further includes: Multiple load detection mechanisms are provided, and each load detection mechanism is configured to correspond one-to-one with a multiple propulsion cylinder. Each load detection mechanism is used to obtain the real-time axial load borne by the corresponding propulsion cylinder and the real-time stroke of the corresponding piston rod. Multiple single-cylinder independent speed regulating mechanisms are provided, and the multiple single-cylinder independent speed regulating mechanisms are correspondingly set and connected to the multiple propulsion cylinders. Each single-cylinder independent speed regulating mechanism is used to independently adjust the running speed and stroke of the corresponding propulsion cylinder. The control mechanism includes a controller and a laser guidance system data interface module connected to the controller. The controller receives real-time axial load data and real-time stroke data acquired by each load detection mechanism, as well as host attitude data received by the laser guidance system data interface module. Combined with preset tunnel design parameters, the controller calculates the optimal dynamic stroke difference parameter of each propulsion cylinder in real time and controls each single-cylinder independent speed regulation mechanism according to the calculation results to perform independent closed-loop control of the propulsion speed and stroke of each propulsion cylinder.

[0006] Preferably, the load detection mechanism includes: The first pressure sensor is located at the pressure measuring port of the rodless chamber of the cylinder and is used to detect the hydraulic oil pressure in the rodless chamber. The second pressure sensor is located at the pressure measuring port of the rod chamber of the cylinder and is used to detect the hydraulic oil pressure in the rod chamber. A displacement sensor is installed inside the cylinder. The displacement sensor includes a measuring rod and a permanent magnet ring. A mounting hole is coaxially provided on the piston rod. One end of the measuring rod is inserted into the mounting hole. The permanent magnet ring is coaxially sleeved on the measuring rod and coaxially fixed in the mounting hole. The displacement sensor is used to detect the axial position of the permanent magnet ring relative to the measuring rod to obtain the real-time extension length of the piston rod. The self-centering assembly is positioned between the probe and the permanent magnet ring and provides radial support for the probe.

[0007] Preferably, a buffer mechanism is provided between the first pressure sensor and the pressure measuring port of the rodless chamber of the cylinder, and between the second pressure sensor and the pressure measuring port of the rod chamber of the cylinder; the buffer mechanism is used to absorb the vibration load transmitted to the first pressure sensor / second pressure sensor when the cylinder is working.

[0008] Preferably, the buffer mechanism includes a ball joint, a bellows, a sleeve, a telescopic rod, and a return spring; the ball joint is disposed between the flange on the first pressure sensor / second pressure sensor and the flange at the pressure measuring port of the rodless cylinder chamber; the ball joint includes a ball seat and a ball head; the ball seat is coaxially fixed to the flange at the pressure measuring port of the rodless cylinder chamber, and the ball head is coaxially fixed to the flange on the first pressure sensor / second pressure sensor, and the ball head is rotatably connected to the ball seat with respect to the ball center; the ball head has a hollow structure, the bellows is inserted into the ball head, and both ends of the bellows are respectively connected to the flange on the first pressure sensor / second pressure sensor and the flange at the pressure measuring port of the rodless cylinder chamber; the sleeve is coaxially inserted into the bellows, and one end of the sleeve is connected to the input end of the first pressure sensor / second pressure sensor, and the other end of the sleeve is connected to the pressure measuring port of the rodless cylinder chamber; Multiple telescopic rods are provided between the flange on the first pressure sensor / second pressure sensor and the flange at the pressure measuring port of the rodless chamber of the cylinder, and a return spring is sleeved on the telescopic rod; one end of the return spring is connected to the flange on the first pressure sensor, and the other end of the return spring is connected to the flange at the pressure measuring port of the rodless chamber of the cylinder.

[0009] Preferably, the self-centering assembly includes a guide sleeve, an elastic support ring, and a pair of dustproof rings; the guide sleeve is coaxially sleeved outside the measuring rod and fixed inside the permanent magnet ring, and the elastic support ring is coaxially sleeved between the permanent magnet ring and the guide sleeve; the pair of dustproof rings are sleeved outside the guide sleeve and are used to seal both ends of the annular gap formed between the permanent magnet ring and the guide sleeve to prevent impurities from entering the annular gap.

[0010] Preferably, the guide sleeve is a polytetrafluoroethylene-filled copper powder structure; the guide sleeve is interference-fitted into the central hole of the permanent magnet ring and moves synchronously with the piston rod along with the permanent magnet ring.

[0011] Preferably, the elastic support ring is an open-type wave spring structure; when the piston rod deflects and produces a rigid eccentric displacement, the elastic deformation of the open-type wave spring structure generates an elastic reaction force that pushes the guide sleeve to float radially, so that the guide sleeve remains coaxial with the measuring rod.

[0012] Preferably, the single-cylinder independent speed regulating mechanism includes a hydraulic valve block, a solenoid directional valve, multiple flow valves, multiple relief valves, and multiple bidirectional hydraulic locks; the hydraulic valve block is installed on one side of multiple propulsion cylinders; the solenoid directional valve is located at the front end of the main oil inlet of the hydraulic valve block and is used to control the high-pressure oil flow of the entire single-cylinder independent speed regulating mechanism; each propulsion cylinder corresponds to one flow valve, one relief valve, and one bidirectional hydraulic lock; the flow valve is installed on the hydraulic valve block and is used to change the flow direction of hydraulic oil by controlling the movement direction of its valve core, thereby controlling the extension and retraction of the piston rod on the cylinder; the relief valve is installed in parallel between the oil inlet and return port of the flow valve; the bidirectional hydraulic lock is installed in series on the hydraulic pipeline between the hydraulic valve block and the propulsion cylinder.

[0013] Preferably, the preset tunnel design parameters include at least the turning radius and gradient; the method by which the controller calculates the optimal dynamic travel difference parameter includes: Based on the turning radius, calculate the theoretical basic stroke difference of each propulsion cylinder; based on the slope, calculate the slope gravity feedforward compensation amount of each propulsion cylinder. Based on the real-time axial load data of each propulsion cylinder obtained by each load detection mechanism, the load deviation between the average load of the left cylinder and the average load of the right cylinder is calculated, and the theoretical basic stroke difference is corrected by the load deviation. The slope gravity feedforward compensation is added to the feedforward correction result to obtain the stroke difference after load correction. Based on the host attitude data received by the laser guidance system data interface module, the stroke difference after load correction is fed back and corrected to obtain the optimal dynamic stroke difference of each propulsion cylinder.

[0014] Secondly, this application proposes a method for tunneling with a small turning radius using an open-face TBM, employing the aforementioned open-face TBM tunneling machine; specifically, it includes the following steps: The real-time axial load data and real-time stroke data of each propulsion cylinder are obtained through the load detection mechanism. The host attitude data is acquired in real time through the data interface module of the laser guidance system. Based on the real-time axial load data and real-time stroke data of each propulsion cylinder, as well as the host attitude data, and in conjunction with the preset tunnel design parameters, the optimal dynamic stroke difference of each propulsion cylinder is calculated in real time, and corresponding target stroke and target speed control commands are generated. According to the control command, each of the single-cylinder independent speed regulating mechanisms is controlled to independently adjust the propulsion speed and stroke of each propulsion cylinder in a closed loop, so that the tunneling machine can tunnel along the designed axis.

[0015] In summary, the technical effects and advantages of this invention are as follows: 1. This invention establishes a load detection mechanism and an independent speed control mechanism for each propulsion cylinder, corresponding to each cylinder, and configures a control mechanism connected to the laser guidance system data interface module. Each load detection mechanism acquires the axial load and real-time stroke of its corresponding propulsion cylinder in real time, while the laser guidance system data interface module acquires the host machine's attitude data in real time. The controller integrates the above data with preset tunnel design parameters to calculate the optimal dynamic stroke difference for each propulsion cylinder in real time, and independently controls the independent speed control mechanism of each cylinder to adjust its propulsion speed and stroke in a closed loop, forming a complete closed loop of "perception-decision-execution-feedback". Therefore, this invention achieves real-time coupling and matching between dynamic changes in surrounding rock load and cylinder stroke difference, fundamentally solving the defect in the prior art where the stroke difference parameter could not be dynamically adjusted according to surrounding rock conditions and slope. This ensures that the host machine's tunneling direction always follows the design axis, avoiding problems such as machine jamming, equipment damage, construction interruption, increased costs, and extended construction period caused by yaw.

[0016] 2. This invention, by setting up a dual-chamber pressure detection structure and buffer mechanism, simultaneously detects the hydraulic oil pressure in the rodless and rod-type chambers of the propulsion cylinder. The strong vibrations and impacts generated by the tunneling machine breaking rock are isolated through the synergistic action of the ball joint, return spring, and bellows. This significantly improves the detection accuracy and data stability of axial load, extends the service life of the pressure sensor, and provides a reliable input signal for the accurate calculation of dynamic stroke differences.

[0017] 3. This invention, by incorporating a self-centering component, utilizes the radial elastic deformation of an open-type wave spring to drive the guide sleeve to adaptively float, providing end radial support for the displacement sensor's measuring rod. This ensures that the measuring rod and the guide sleeve remain coaxial, avoiding eccentric friction, significantly extending the displacement sensor's lifespan, and maintaining a consistently high level of displacement detection accuracy.

[0018] 4. This invention, by setting an integrated single-cylinder independent speed control mechanism, integrates the flow valve, relief valve, and two-way hydraulic lock into the same hydraulic valve block, enabling independent speed control, overload protection, and position holding functions for each propulsion cylinder. This reduces the number of external pipeline connections and the risk of leakage, improves the overall reliability of the hydraulic system, and ensures the positional stability of the propulsion cylinder in a stopped state, maintaining the preset dynamic stroke difference. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a three-dimensional structural diagram of the propulsion cylinder of the present invention; Figure 3 This is a partial cross-sectional three-dimensional structural diagram of the buffer mechanism of the present invention; Figure 4 For the present invention Figure 3 Enlarged structural diagram of region A in the middle; Figure 5 This is a partial cross-sectional three-dimensional structural diagram of the propulsion cylinder of the present invention; Figure 6 This is a three-dimensional structural schematic diagram of the displacement sensor of the present invention; Figure 7 This is a partial cross-sectional three-dimensional structural diagram of the permanent magnet ring of the present invention; Figure 8 This is a three-dimensional structural schematic diagram of the elastic support ring of the present invention; Figure 9 This is a three-dimensional structural diagram of the single-cylinder independent speed regulating mechanism of the present invention; Figure 10 This is a flowchart of the method of the present invention.

[0021] In the diagram: 1. Propulsion cylinder; 11. Cylinder barrel; 12. Piston rod; 2. Load detection mechanism; 21. First pressure sensor; 22. Second pressure sensor; 23. Displacement sensor; 231. Measuring rod; 232. Permanent magnet ring; 24. Buffer mechanism; 241. Ball joint; 2411. Ball seat; 2412. Ball head; 242. Bellows; 243. Sleeve; 244. Telescopic rod; 245. Return spring; 25. Self-centering assembly; 251. Guide sleeve; 252. Elastic support ring; 253. Dustproof ring; 3. Single-cylinder independent speed regulation mechanism; 31. Hydraulic valve block; 32. Flow valve; 33. Relief valve; 34. Two-way hydraulic lock; 35. Solenoid directional valve. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: Traditional TBMs calculate the theoretical travel difference based on a fixed turning radius and slope, and then keep it constant. When uneven development of surrounding rock fissures or differences in water content lead to significant differences in the load on the left and right cylinders, or when changes in slope cause changes in the gravity component of the main unit, the cylinder on the side with a larger load will naturally slow down, while the cylinder on the side with a smaller load will advance relatively excessively. The preset travel difference balance is broken, and the main unit deviates from the design axis. To solve this problem, this embodiment proposes an open-type TBM tunneling machine with a small turning radius.

[0024] Please see Figures 1-2 and Figures 5-6 The diagram illustrates a small-turning-radius open-type TBM (Tunnel Boring Machine), comprising multiple propulsion cylinders 1 located behind the main drive system. Each propulsion cylinder 1 includes a cylinder barrel 11 and a piston rod 12 coaxially inserted into the cylinder barrel 11. The tunnel boring machine further includes a control mechanism, multiple load detection mechanisms 2, and a single-cylinder independent speed control mechanism 3. The load detection mechanisms 2 are configured one-to-one with the propulsion cylinders 1, and each load detection mechanism 2 is used to acquire the real-time axial load borne by the corresponding propulsion cylinder 1 and the real-time stroke of the corresponding piston rod 12. The single-cylinder independent speed control mechanisms 3 are configured one-to-one with the propulsion cylinders 1 and control the speed of the propulsion cylinders 1. The system should be connected, and each single-cylinder independent speed regulating mechanism 3 is used to independently adjust the running speed and stroke of the corresponding propulsion cylinder 1; the control mechanism includes a controller and a laser guidance system data interface module connected to the controller; the controller is used to receive real-time axial load data and real-time stroke data obtained by each load detection mechanism 2, as well as host attitude data received by the laser guidance system data interface module, and, in combination with preset tunnel design parameters, calculate the optimal dynamic stroke difference parameter of each propulsion cylinder 1 in real time, and control each single-cylinder independent speed regulating mechanism 3 according to the calculation results to perform independent closed-loop control of the propulsion speed and stroke of each propulsion cylinder 1.

[0025] Furthermore, the load detection mechanism 2 is installed on the corresponding propulsion cylinder 1. The load detection mechanism 2 includes: a first pressure sensor 21, a second pressure sensor 22, a displacement sensor 23, and a self-centering component 25. It is understood that the first pressure sensor 21, the second pressure sensor 22, and the displacement sensor 23 are all existing technologies, and their structures will not be described in detail.

[0026] The first pressure sensor 21 is disposed on the outer wall of the cylinder 11, specifically at the pressure measuring port of the rodless chamber of the cylinder 11, which is located at the upper part of the cylinder 11. The second pressure sensor 22 is disposed on the outer wall of the cylinder 11, specifically at the pressure measuring port of the rod chamber of the cylinder 11, which is located at the lower part of the cylinder 11. The first pressure sensor 21 is provided with a flange, and a matching flange is also provided at the pressure measuring port of the rodless chamber of the cylinder 11. The two are connected through the flange. The second pressure sensor 22 is provided with a flange, and a matching flange is also provided at the pressure measuring port of the rod chamber of the cylinder 11. The two are connected through the flange. The displacement sensor 23 is disposed inside the cylinder 11; the displacement sensor 23 includes a measuring rod 231 and a permanent magnet ring 232; a mounting hole is coaxially provided on the piston rod 12, the head of the displacement sensor 23 is installed inside the cylinder 11, one end of the measuring rod 231 is movably inserted into the mounting hole, the permanent magnet ring 232 is coaxially movably sleeved outside the measuring rod 231, and the permanent magnet ring 232 is coaxially fixed inside the mounting hole; The self-centering assembly 25 is disposed between the probe 231 and the permanent magnet ring 232 to provide radial support for the probe 231.

[0027] It should be noted that when the tunneling machine is working, the first pressure sensor 21 detects the hydraulic oil pressure in the rodless chamber of the cylinder 11 in real time, and the second pressure sensor 22 detects the hydraulic oil pressure in the rod chamber of the cylinder 11 in real time. The actual axial load borne by the propulsion cylinder 1 is calculated by the pressure difference between the two chambers. At the same time, the real-time stroke of a single cylinder is obtained by the displacement sensor 23, which provides basic data for subsequent stroke difference calculation.

[0028] The measuring rod 231 of the displacement sensor 23 is fixed to the cylinder 11. Specifically, the end of the measuring rod 231 that is relatively far away from the piston rod 12 is fixed to the cylinder 11. The permanent magnet ring 232 moves synchronously with the piston rod 12. By detecting the relative position of the permanent magnet ring 232 and the measuring rod 231, the real-time extension length of the piston rod 12 is obtained, which is the real-time stroke data of the current propulsion cylinder 1. This allows the controller to combine the real-time axial load data of each propulsion cylinder 1 to generate corresponding control commands, thereby adjusting the propulsion speed and stroke of each propulsion cylinder 1. When the piston rod 12 undergoes bending deformation, the self-centering component 25 automatically adjusts its own position to keep the measuring rod 231 in the center position, avoiding eccentric friction between the measuring rod 231 and the permanent magnet ring 232.

[0029] Single-chamber detection schemes typically only detect the pressure in the rodless chamber, treating the back pressure in the rod chamber as zero or a fixed constant. This fails to eliminate the interference of the real-time changing return oil back pressure in the rod chamber on the load calculation results. This application uses dual-chamber pressure detection to acquire pressure simultaneously, incorporating the back pressure in the rod chamber as a dynamic variable in real-time calculations. This mathematically and precisely cancels out the reverse force generated by the back pressure, ensuring that the calculation result always equals the actual net thrust. This fundamentally eliminates the impact of rod chamber back pressure fluctuations on load detection accuracy. Therefore, this embodiment achieves accurate calculation of the axial load of the propulsion cylinder 1 through dual-chamber pressure detection, eliminating the influence of rod chamber back pressure on load detection accuracy and significantly reducing load detection errors. The built-in displacement sensor 23 avoids the problems of external sensors being susceptible to rock powder contamination and mechanical impact damage, significantly extending its service life. The self-centering component 25 effectively solves the problem of wear damage to the measuring rod 231 under small-turn off-center load conditions, ensuring that the displacement detection accuracy remains stable at a high level, providing a reliable data foundation for subsequent stroke difference control.

[0030] See Figures 1-4 A buffer mechanism 24 is provided between the first pressure sensor 21 and the pressure measuring port of the rodless cavity of the cylinder 11, and between the second pressure sensor 22 and the pressure measuring port of the rod cavity of the cylinder 11. The buffer mechanism 24 is used to absorb the vibration load transmitted to the first pressure sensor 21 / second pressure sensor 22 when the cylinder 11 is working. Taking the buffer mechanism 24 on the first pressure sensor 21 as an example, the buffer mechanism 24 includes a ball joint 241, a bellows 242, a sleeve 243, a telescopic rod 244, and a return spring 245. The ball joint 241 is located between the flange on the first pressure sensor 21 and the flange at the pressure measuring port of the rodless cavity of the cylinder 11. The ball joint 241 includes a ball seat 2411 and a ball head 2412. The ball seat 2411 is coaxially fixed on the flange at the pressure measuring port of the rodless cavity of the cylinder 11, and the ball head 2412 is coaxially fixed on the flange on the first pressure sensor 21. 412 is rotatably connected to the ball seat 2411; the ball head 2412 is a hollow structure, and the bellows 242 is inserted through the ball head 2412, with both ends of the bellows 242 connected to the flange on the first pressure sensor 21 and the flange at the pressure measuring port of the rodless cavity of the cylinder 11, respectively; the sleeve 243 is coaxially inserted into the bellows 242, with one end of the sleeve 243 connected to the input end (i.e., pressure measuring interface) of the first pressure sensor 21, and the other end of the sleeve 243 connected to the pressure measuring port of the rodless cavity of the cylinder 11; multiple telescopic rods 244 are provided between the flange on the first pressure sensor 21 and the flange at the pressure measuring port of the rodless cavity of the cylinder 11, and a return spring 245 is sleeved on the telescopic rods 244; one end of the return spring 245 is connected to the flange on the first pressure sensor 21, and the other end of the return spring 245 is connected to the flange at the pressure measuring port of the rodless cavity of the cylinder 11.

[0031] It should be noted that when the strong vibration generated by the tunneling machine cutterhead breaking rock is transmitted to the first pressure sensor 21 through the cylinder 11, the ball joint 241 allows the first pressure sensor 21 to produce a small angular oscillation, offsetting the radial vibration load. The elastic support structure composed of the return spring 245 and the telescopic rod 244 absorbs the axial vibration impact, and the bellows 242, while ensuring the sealed flow of hydraulic oil, allows the first pressure sensor 21 to produce small axial and radial displacements. The sleeve 243 smoothly introduces hydraulic oil into the detection end of the first pressure sensor 21, avoiding pressure fluctuations caused by oil flow from affecting the measurement accuracy.

[0032] It should be noted that the structure and working principle of the buffer mechanism 24 on the second pressure sensor 22 are the same as those of the first pressure sensor 21, so they will not be described again here.

[0033] The buffer mechanism 24, through the coordinated action of the ball joint 241, the return spring 245, and the bellows 242, effectively isolates the strong vibrations and impacts generated during the tunneling machine's operation. This prevents the pressure sensors (including the first pressure sensor 21 and the second pressure sensor 22) from becoming loose due to long-term vibration, thus significantly extending their service life. Simultaneously, the buffer mechanism 24 eliminates pressure signal fluctuations caused by vibration, making the pressure detection data more stable and accurate, further improving the accuracy of load calculation, and providing a more reliable input signal for dynamic stroke difference control.

[0034] See Figures 5-8 The self-centering assembly 25 includes a guide sleeve 251, an elastic support ring 252, and a pair of dustproof rings 253. The guide sleeve 251 is coaxially sleeved outside the measuring rod 231 and fixed inside the permanent magnet ring 232. The elastic support ring 252 is coaxially sleeved outside the guide sleeve 251 and located between the permanent magnet ring 232 and the guide sleeve 251. The pair of dustproof rings 253 are sleeved outside the guide sleeve 251 and are located at both ends of the annular gap formed between the permanent magnet ring 232 and the guide sleeve 251, respectively, to seal the two ends of the annular gap to prevent impurities from entering the annular gap.

[0035] It should be noted that when the piston rod 12 flexes due to off-center load, the permanent magnet ring 232 shifts synchronously with the piston rod 12, compressing the corresponding side of the elastic support ring 252, causing compression deformation of the elastic support ring 252 on that side, while the elastic support ring 252 on the opposite side releases some deformation. The elastic reaction force generated by the deformation of the elastic support ring 252 pushes the guide sleeve 251 to move in the opposite direction of the shift, ensuring that the center of the guide sleeve 251 always coincides with the center of the measuring rod 231. The dustproof ring 253 prevents rock powder and mud from entering the annular gap between the guide sleeve 251 and the permanent magnet ring 232, ensuring that the guide sleeve 251 can move flexibly.

[0036] The self-centering assembly 25 achieves automatic centering of the guide sleeve 251 through the elastic deformation of the elastic support ring 252, requiring no external power or control, and has a simple and reliable structure. A uniform radial clearance is always maintained between the guide sleeve 251 and the measuring rod 231, completely avoiding eccentric friction, significantly reducing the wear of the measuring rod 231, and greatly extending the service life of the displacement sensor 23.

[0037] See Figures 6-7 The guide sleeve 251 is a polytetrafluoroethylene-filled copper powder structure; the guide sleeve 251 is interference-fitted into the center hole of the permanent magnet ring 232 and moves synchronously with the piston rod 12.

[0038] It should be noted that the PTFE-filled copper powder material has an extremely low coefficient of friction and excellent wear resistance. The sliding friction resistance between the guide sleeve 251 and the measuring rod 231 is minimal and will not affect the measurement accuracy of the displacement sensor 23. The interference fit installation method ensures that the connection between the guide sleeve 251 and the permanent magnet ring 232 is firm and reliable, preventing relative displacement and ensuring that the guide sleeve 251 can accurately follow the movement of the permanent magnet ring 232.

[0039] The guide sleeve 251, made of PTFE filled with copper powder, ensures sufficient mechanical strength and has good self-lubricating properties, further reducing the wear of the measuring rod 231 and keeping the measurement accuracy of the displacement sensor 23 stable. The interference fit installation method avoids the risk of the guide sleeve 251 loosening and falling off, improving the reliability of the self-centering assembly 25.

[0040] See Figures 7-8 The elastic support ring 252 is an open wave spring structure. When the piston rod 12 deflects and produces a rigid eccentric displacement, the elastic deformation of the open wave spring structure generates an elastic reaction force to push the guide sleeve 251 to float radially, so that the guide sleeve 251 remains coaxial with the measuring rod 231.

[0041] It should be noted that the wave-shaped structure of the open-type wave spring possesses both axial preload and radial elastic floating capabilities. The open design allows the spring to generate a large amount of radial deformation without causing circumferential stress concentration. When the deflection of the piston rod 12 changes, the open-type wave spring can respond in real time, automatically adjust the deformation, generate a corresponding elastic reaction force, and push the guide sleeve 251 to quickly return to center.

[0042] The open-type wave spring structure of the elastic support ring 252 has a larger radial deformation range, which can completely cover the maximum deflection of the piston rod 12 under small turning conditions, ensuring effective self-centering under any off-center load conditions. The open design effectively releases the circumferential stress generated during spring deformation, avoiding spring fatigue fracture and significantly extending the service life of the elastic support ring 252. At the same time, the axial preload of the wave spring ensures the axial position stability of the guide sleeve 251, preventing axial movement and further improving the accuracy of displacement detection.

[0043] See Figure 1 and Figure 9 A single-cylinder independent speed regulating mechanism 3 is provided on one side of multiple propulsion cylinders 1. The single-cylinder independent speed regulating mechanism 3 is used to control the running speed and stroke of all propulsion cylinders 1, so as to control the dynamic stroke difference of multiple cylinder barrels 11 of multiple propulsion cylinders 1. The single-cylinder independent speed regulating mechanism 3 includes a hydraulic valve block 31, a solenoid directional valve 35, multiple flow valves 32, multiple relief valves 33, and multiple two-way hydraulic locks 34. It is understood that the solenoid directional valve 35, flow valve 32, relief valve 33, and two-way hydraulic locks 34 are all existing technologies and will not be described in detail. The hydraulic valve block 31 is installed on one side of multiple propulsion cylinders 1. The solenoid directional valve 35 is located at the front end of the main oil inlet of the hydraulic valve block 31 and is used to control the entire single-cylinder independent speed regulation. Mechanism 3 controls the on / off of high-pressure oil; multiple flow valves 32 are installed on the hydraulic valve block 31, and each propulsion cylinder 1 corresponds to one flow valve 32; the flow valve 32 is used to change the flow direction of hydraulic oil by controlling the movement direction of its valve core, thereby controlling the extension and retraction of the piston rod 12 on the cylinder 11; multiple relief valves 33 are installed on the hydraulic valve block 31, and each propulsion cylinder 1 corresponds to one relief valve 33, and the relief valves 33 are installed in parallel between the oil inlet and oil return port of the corresponding flow valve 32; multiple bidirectional hydraulic locks 34 are installed on the hydraulic valve block 31, and each propulsion cylinder 1 corresponds to one bidirectional hydraulic lock 34, and the bidirectional hydraulic locks 34 are installed in series on the hydraulic pipeline between the hydraulic valve block 31 and the corresponding propulsion cylinder 1.

[0044] It should be noted that during tunneling, the solenoid directional valve 35 is energized and conducts, allowing high-pressure oil to enter the main inlet channel of the hydraulic valve block 31. Each flow valve 32 adjusts its valve core opening according to the control command issued by the controller, controlling the flow rate and direction of the hydraulic oil entering the corresponding propulsion cylinder 1, thereby precisely controlling the propulsion speed and stroke of the piston rod 12. When the load on a certain propulsion cylinder 1 exceeds a set value, where the set value is the overload protection threshold of the rodless chamber of the propulsion cylinder 1, the maximum set pressure of the corresponding overload protection relief valve 33, and also the upper limit of the range of the first pressure sensor 21, the corresponding relief valve 33 automatically opens to unload, protecting the cylinder and hydraulic system from damage. When the flow valve 32 closes, the bidirectional hydraulic lock 34 immediately locks the hydraulic oil in both chambers of the propulsion cylinder 1, preventing the piston rod 12 from retracting under load and ensuring the stability of the stroke difference.

[0045] The single-cylinder independent speed control mechanism 3 realizes independent speed and stroke control for each propulsion cylinder 1, and can dynamically adjust the propulsion parameters of each cylinder according to real-time load data; specifically, the electronic controller of the flow valve 32 receives the single-cylinder target speed and target stroke instructions output by the PLC controller through the bus.

[0046] Valve core position closed-loop control: The built-in position sensor of the flow valve 32 detects the actual position of the valve core in real time, compares it with the target position, and adjusts the drive current of the valve core through the electronic controller so that the valve core opening accurately corresponds to the target flow rate, ensuring that the cylinder advance speed meets the requirements.

[0047] Pressure-compensated constant flow control: The built-in pressure compensator of flow valve 32 automatically detects the pressure difference between the inlet and outlet of the valve. When the pressure difference changes due to changes in the cylinder load, the pressure compensator automatically adjusts the area of ​​the throttle orifice to maintain a constant pressure difference, so that the flow rate through the valve is only related to the valve core opening and is not affected by load changes.

[0048] Closed-loop control of cylinder stroke: The displacement sensor 23 inside the propulsion cylinder 1 detects the actual extension length of the cylinder piston rod 12 in real time and feeds it back to the PLC controller; the PLC controller compares the actual stroke with the target stroke. When the actual stroke reaches 95% of the target stroke, the opening of the flow valve 32 is gradually reduced to decrease the cylinder propulsion speed; when the actual stroke reaches the target stroke, the flow valve 32 is completely closed and the cylinder stops propulsion.

[0049] Hydraulic lock position holding: After the flow valve 32 is closed, the bidirectional hydraulic lock 34 immediately locks the hydraulic oil in both chambers of the cylinder to prevent the cylinder from retracting on its own under the reaction force of the surrounding rock, thus ensuring the stability of the cylinder position and maintaining the preset stroke difference.

[0050] Overload protection: When the load on the propulsion cylinder 1 exceeds the set maximum safe pressure, the corresponding overload protection relief valve 33 automatically opens to unload and sends an overload signal to the PLC controller. The PLC controller immediately reduces the propulsion speed of the propulsion cylinder 1 and increases the propulsion speed of the adjacent propulsion cylinder 1 to ensure that the overall tunneling efficiency is not affected.

[0051] By dynamically adjusting the propulsion parameters of each cylinder based on real-time load data, the optimal dynamic stroke difference between the left and right cylinders is maintained, effectively solving the coupling mismatch problem between uneven surrounding rock load and cylinder stroke difference. The integrated hydraulic valve block 31 design reduces external pipeline connections, lowers the risk of leakage, and improves system reliability. The relief valve 33 and the two-way hydraulic lock 34 provide multiple safety protections to prevent equipment overload damage and sudden attitude changes, improving construction safety.

[0052] In this embodiment, the control mechanism is housed within the electrical control cabinet; the controller is a PLC controller, and the controller is connected to the laser guidance system data interface module via signal control; the laser guidance system data interface module is the data channel connecting the laser guidance system and the controller, responsible for transmitting the host attitude data to the controller in real time for dynamic travel difference calculation and attitude control; it is understood that the electrical control cabinet, controller, and laser guidance system data interface module of the tunneling machine are all existing technologies and will not be described in detail; the laser guidance system data interface module is used to receive host attitude data; the first pressure sensor 21 and the second pressure sensor 22 are both connected to the controller via signal control.

[0053] Furthermore, the preset tunnel design parameters include at least the turning radius and gradient; the method for the controller to calculate the optimal dynamic travel difference parameters includes the following steps: A1. Calculate the theoretical basic stroke difference of each propulsion cylinder based on the turning radius; calculate the slope gravity feedforward compensation amount of each propulsion cylinder based on the slope. A2. Based on the real-time axial load data of each propulsion cylinder obtained by each load detection mechanism 2, calculate the load deviation between the average load of the left cylinder and the average load of the right cylinder, and perform feedforward correction on the theoretical basic stroke difference according to the load deviation, and add the slope gravity feedforward compensation to the feedforward correction result to obtain the stroke difference after load correction. A3. Based on the host attitude data received by the laser guidance system data interface module, the stroke difference after load correction is corrected by feedback to obtain the optimal dynamic stroke difference of each propulsion cylinder.

[0054] First, the controller calculates the theoretical basic travel difference based on the preset turning radius, the TBM's overall lateral width, and the single tunneling step change length. That is, the PLC controller uses a geometric model to calculate the theoretical basic travel difference ΔS0 under no-load deviation conditions by using the pre-stored tunnel turning radius R, TBM's overall lateral width B, and single tunneling step change length L. The calculation formula is as follows: ΔS0 = (B × L) ÷ R; The PLC controller has built-in segmented accumulation logic. When the cycle ends, the theoretical travel difference is accumulated. When the cycle ends, the theoretical travel difference is accumulated again, which serves as the reference value for dynamic correction.

[0055] It should be noted that although the preset slope parameters do not change the geometric travel difference required for turning on the horizontal plane, changes in slope will cause a change in the component of the main engine's gravity along the tunneling direction. This change in force will directly superimpose on the axial load of the left and right hydraulic cylinders, affecting the synchronization of the propulsion speed of the two hydraulic cylinders. To clearly reflect the independent influence of slope in the travel difference calculation, this embodiment calculates the slope gravity feedforward compensation amount ΔS_α based on the preset slope α. This compensation amount is pre-fitted into a function of slope α through engineering calibration experiments, for example, but not limited to, ΔS_α=K_α×sin(α)×ΔS0, where K_α is the slope compensation coefficient adjusted through on-site debugging.

[0056] Among them, the slope α is positive when it is uphill and negative when it is downhill. When α>0 (uphill), ΔS_α is positive. At this time, the gravity component caused by the slope is in the opposite direction of tunneling, and additional propulsion force needs to be compensated. When α<0 (downhill), ΔS_α is negative. The gravity component caused by the slope is in the direction of tunneling, and the propulsion compensation can be appropriately reduced.

[0057] Secondly, the controller receives pressure data from the rodless and rod-side chambers of multiple propulsion cylinders, along with stroke simulation signals, collected by the first pressure sensor 21, the second pressure sensor 22, and the built-in magnetostrictive displacement sensor 23. This data is then filtered and converted by an A / D converter via a multi-channel explosion-proof signal acquisition module. Next, the controller calculates the axial load of a single cylinder in real time according to the formula: F = P1A1 - P2A2. Here, P1 is the real-time hydraulic oil pressure inside the rodless chamber of propulsion cylinder 1, A1 is the effective pressure-bearing area of ​​the rodless chamber of propulsion cylinder 1, P2 is the real-time hydraulic oil pressure inside the rod-side chamber of propulsion cylinder 1, and A2 is the effective pressure-bearing area of ​​the rod-side chamber of propulsion cylinder 1. Finally, the average load F of the multiple cylinders on the left side is obtained. 左 The average load F of the multiple cylinders on the right side 右 Average load of the whole machine F 均 A load correction factor Kf (0.8~1.2, to be adjusted by on-site surrounding rock testing) is introduced.

[0058] In the feedforward correction stage, the theoretical basic stroke difference ΔS0 is first corrected based on the load deviation, and the load deviation correction amount ΔS_load is calculated. The specific calculation formula is as follows: ΔS_load=Kf×[(F 左 -F 右 )÷F 均 ]×ΔS0; When the load on the left side of the surrounding rock is greater than the load on the right side (F) 左 >F 右 When ΔS_load is positive, the target stroke of the left cylinder is increased and the target stroke of the right cylinder is decreased, so that the cylinder on the side with a larger load receives a longer propulsion distance compensation, and the cylinder on the side with a smaller load receives a shorter propulsion distance limitation, ensuring that the propulsion time of the left and right cylinders is basically the same; when the load of the surrounding rock on the right side is greater than the load on the left side (F 右 >F 左 When the load is balanced, ΔS_load is negative, increasing the target stroke of the right cylinder. When the load is balanced, ΔS_load = 0, using only the basic theoretical stroke difference. Then, the slope gravity feedforward compensation ΔS_α and ΔS_load are vector-superimposed to obtain the total feedforward correction ΔS1: ΔS1 = ΔS_load + ΔS_α; that is, the stroke difference ΔS1 after load correction and slope feedforward compensation. When ΔS_α is positive, this compensation further increases the stroke compensation of the heavy-load side cylinder; when ΔS_α is negative, this compensation partially offsets or even reverses the load correction effect, depending on the actual influence of the slope direction on the gravity component.

[0059] Finally, the PLC controller receives the host yaw angle θ synchronously acquired by the laser guidance system data interface module, and uses a position-based PID algorithm to calculate the attitude correction travel difference ΔS2, eliminating the attitude deviation remaining from the feedforward calculation; the calculation formula is as follows: ΔS2=Kp×θ+Ki×∫θdt+Kd×dθ / dt; Wherein, Kp is the proportional coefficient, which is the travel difference theoretically required to completely correct 1 degree yaw within one tunneling cycle, used to offset the current yaw angle in real time; Ki is the integral coefficient, when the main engine has a continuous yaw deviation of 1 degree, the travel difference correction amount output by the integral link increases by Ki millimeters every 1 second, used to eliminate the steady-state axis offset caused by long-term tunneling; Kd is the derivative coefficient, when the main engine yaw angle changes at a rate of 1 degree per second, the derivative link outputs a travel difference correction amount of Kd millimeters, used to suppress overshoot and oscillation caused by sudden changes in yaw angle; it can be understood that Kp, Ki and Kd are all derived from tunnel geometric parameters, single-cycle tunneling logic, and automatic control stability criteria, which are existing technologies and will not be elaborated further; when the main engine yaws to the left by θ, it is positive, and ΔS2 increases the stroke of the right hydraulic cylinder in the positive direction; when the main engine yaws to the right by θ, it is negative, and ΔS2 increases the stroke of the left hydraulic cylinder in the positive direction, realizing closed-loop axis correction.

[0060] Calculate the total travel difference based on ΔS0, ΔS1, and ΔS2; the calculation formula is as follows: ΔS = ΔS0 + ΔS1 + ΔS2; Taking an average excavation stroke of 800mm as an example: Target stroke S of the left hydraulic cylinder 左 =Savg + ΔS ÷ 2; Target stroke S of the right cylinder 右 =Savg-ΔS÷2; The synthesized dynamic stroke difference is distributed to each propulsion cylinder 1, generating digital commands for the target stroke and target speed of a single cylinder, which are then sent to each flow valve 32 of the independent speed control mechanism 3 of a single cylinder; The flow valve 32 adjusts the valve core opening according to the control signal, independently controlling the hydraulic flow of the corresponding cylinder, so as to extend the propulsion stroke of the cylinder with a large load and shorten the propulsion stroke of the cylinder with a small load, thereby dynamically maintaining the optimal stroke difference balance.

[0061] It should be noted that the controller receives pressure data transmitted from the first pressure sensor 21 and the second pressure sensor 22, and calculates the actual axial load of each propulsion cylinder 1. Simultaneously, the controller receives the TBM's three-dimensional coordinates, pitch angle, roll angle, and yaw angle, among other host attitude data, via the laser guidance system data interface module. Combining the load data and host attitude data, the controller calculates the optimal dynamic stroke difference under the current operating conditions in real time and outputs control commands to the corresponding flow valve 32 to adjust the propulsion speed and stroke of each propulsion cylinder 1. When a deviation occurs in the host attitude, the controller automatically adjusts the stroke difference of the corresponding cylinder to ensure that the host's tunneling direction always follows the designed axis.

[0062] The control mechanism couples and optimizes real-time surrounding rock load data with host machine attitude data, achieving dynamic adaptive adjustment of the travel difference parameter. Compared with traditional position-based feedback control, the attitude adjustment response speed is significantly improved, and the overshoot is significantly reduced. The controller can predict the impact of load changes on attitude in advance and perform feedforward control, effectively preventing the host machine's tunneling direction from deviating from the design axis, and greatly improving the axis control accuracy for small turning radius construction.

[0063] Example 2: See Figure 10 This embodiment provides a method for tunneling with a small turning radius using an open-face TBM, employing the small turning radius open-face TBM tunneling machine described in Embodiment 1 above; the tunneling method specifically includes the following steps: S1. Cylinder Control: First, set the tunneling parameters according to the geological conditions; during the turning tunneling process, reduce the tunneling slope first, and restore the tunneling slope after the tunneling is completed; and stop the machine to change steps at certain intervals during the tunneling process, and then start the next cycle of tunneling after completion; when the tunneling machine is changing steps, adjust the attitude of the tunneling machine according to the host position data displayed by the measurement and guidance system. S2. Load detection: During the step-changing operation, the axial load borne by each propulsion cylinder 1 and the real-time stroke of each propulsion cylinder 1 are obtained in real time through each load detection mechanism 2. Specifically, the oil pressure is detected by the first pressure sensor 21 and the second pressure sensor 22 on the load detection mechanism 2, and the stroke is detected by the displacement sensor 23, so as to provide data support for dynamic stroke difference coupling calculation.

[0064] S3. Attitude Acquisition: Acquire host attitude data in real time through the laser guidance system data interface module; S4. Dynamic calculation: Based on the real-time axial load data, real-time stroke data and host attitude data of each propulsion cylinder 1, and combined with the preset tunnel design parameters, the optimal dynamic stroke difference of each propulsion cylinder 1 is calculated in real time, and the corresponding target stroke and target speed control commands are generated. S5. Closed-loop control: According to the control command, each single cylinder independent speed regulating mechanism 3 is controlled to independently adjust the propulsion speed and stroke of each propulsion cylinder 1 in a closed loop, so that the tunneling machine can tunnel along the designed axis.

[0065] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A small-turning-radius open-type TBM tunneling machine, comprising a plurality of propulsion cylinders (1) disposed on the rear side of the main drive system of the tunneling machine, wherein each propulsion cylinder (1) comprises a cylinder barrel (11) and a piston rod (12) coaxially inserted into the cylinder barrel (11), characterized in that, The tunneling machine also includes: Multiple load detection mechanisms (2) are provided, and the multiple load detection mechanisms (2) are set one-to-one with the multiple propulsion cylinders (1). Each load detection mechanism (2) is used to obtain the real-time axial load borne by the corresponding propulsion cylinder (1) and the real-time stroke of the corresponding piston rod (12). Multiple single-cylinder independent speed regulating mechanisms (3) are provided and connected to multiple propulsion cylinders (1) in a one-to-one correspondence. Each single-cylinder independent speed regulating mechanism (3) is used to independently adjust the running speed and stroke of the corresponding propulsion cylinder (1). The control mechanism includes a controller and a laser guidance system data interface module connected to the controller. The controller is used to receive real-time axial load data and real-time stroke data obtained by each load detection mechanism (2), as well as host attitude data received by the laser guidance system data interface module. Combined with preset tunnel design parameters, the controller calculates the optimal dynamic stroke difference parameter of each propulsion cylinder (1) in real time, and controls each single-cylinder independent speed regulation mechanism (3) according to the calculation results to perform independent closed-loop control on the propulsion speed and stroke of each propulsion cylinder (1).

2. The open-type TBM tunneling machine with a small turning radius according to claim 1, characterized in that, The load detection mechanism (2) includes: The first pressure sensor (21) is set at the pressure measuring port of the rodless chamber of the cylinder (11) to detect the hydraulic oil pressure in the rodless chamber; The second pressure sensor (22) is located at the pressure measuring port of the rod chamber of the cylinder (11) and is used to detect the hydraulic oil pressure in the rod chamber. A displacement sensor (23) is installed inside the cylinder (11); the displacement sensor (23) includes a measuring rod (231) and a permanent magnet ring (232); a mounting hole is coaxially provided on the piston rod (12), one end of the measuring rod (231) is inserted into the mounting hole, the permanent magnet ring (232) is coaxially sleeved on the measuring rod (231), and the permanent magnet ring (232) is coaxially fixed in the mounting hole; the displacement sensor (23) is used to detect the axial position of the permanent magnet ring (232) relative to the measuring rod (231) to obtain the real-time extension length of the piston rod (12); A self-centering assembly (25) is disposed between the probe (231) and the permanent magnet ring (232) to provide radial support for the probe (231).

3. The open-type TBM tunneling machine with a small turning radius according to claim 2, characterized in that, A buffer mechanism (24) is provided between the first pressure sensor (21) and the pressure measuring port of the rodless chamber of the cylinder (11), and between the second pressure sensor (22) and the pressure measuring port of the rod chamber of the cylinder (11); the buffer mechanism (24) is used to absorb the vibration load transmitted to the first pressure sensor (21) / second pressure sensor (22) when the cylinder (11) is working.

4. The small turning radius open-type TBM tunneling machine according to claim 3, characterized in that, The buffer mechanism (24) includes a ball joint (241), a bellows (242), a sleeve (243), a telescopic rod (244), and a return spring (245); the ball joint (241) is disposed between the flange on the first pressure sensor (21) / second pressure sensor (22) and the flange at the pressure measuring port of the rodless cavity of the cylinder (11); the ball joint (241) includes a ball seat (2411) and a ball head (2412); the ball seat (2411) is coaxially fixed on the flange at the pressure measuring port of the rodless cavity of the cylinder (11), and the ball head (2412) is coaxially fixed on the flange on the first pressure sensor (21) / second pressure sensor (2 ... first pressure sensor (21) / second pressure sensor (22), and the The ball head (2412) is rotatably connected to the ball seat (2411) with the ball center; the ball head (2412) is a hollow structure, the bellows (242) is inserted into the ball head (2412), and the two ends of the bellows (242) are respectively connected to the flange on the first pressure sensor (21) / second pressure sensor (22) and the flange at the pressure measuring port of the rodless cavity of the cylinder (11); the sleeve (243) is coaxially inserted into the bellows (242), and one end of the sleeve (243) is connected to the input end of the first pressure sensor (21) / second pressure sensor (22), and the other end of the sleeve (243) is connected to the pressure measuring port of the rodless cavity of the cylinder (11); Multiple telescopic rods (244) are provided between the flange on the first pressure sensor (21) / second pressure sensor (22) and the flange at the pressure measuring port of the rodless cavity of the cylinder (11), and a return spring (245) is sleeved on the telescopic rod (244); one end of the return spring (245) is connected to the flange on the first pressure sensor (21), and the other end of the return spring (245) is connected to the flange at the pressure measuring port of the rodless cavity of the cylinder (11).

5. A small turning radius open-type TBM tunneling machine according to claim 2, characterized in that, The self-centering assembly (25) includes a guide sleeve (251), an elastic support ring (252), and a pair of dustproof rings (253). The guide sleeve (251) is coaxially sleeved outside the measuring rod (231) and fixed inside the permanent magnet ring (232). The elastic support ring (252) is coaxially sleeved between the permanent magnet ring (232) and the guide sleeve (251). The pair of dustproof rings (253) are sleeved outside the guide sleeve (251) and are used to seal the two ends of the annular gap formed between the permanent magnet ring (232) and the guide sleeve (251) to prevent impurities from entering the annular gap.

6. A small turning radius open-type TBM tunneling machine according to claim 5, characterized in that, The guide sleeve (251) is a polytetrafluoroethylene-filled copper powder structure; the guide sleeve (251) is interference-fitted into the center hole of the permanent magnet ring (232).

7. A small turning radius open-type TBM tunneling machine according to claim 6, characterized in that, The elastic support ring (252) is an open wave spring structure; when the piston rod (12) flexes and generates a rigid eccentric displacement, the elastic deformation of the open wave spring structure generates an elastic reaction force to push the guide sleeve (251) to float radially, so that the guide sleeve (251) remains coaxial with the measuring rod (231).

8. The small turning radius open-type TBM tunneling machine according to claim 1, characterized in that, The single-cylinder independent speed control mechanism (3) includes a hydraulic valve block (31), an electromagnetic directional valve (35), multiple flow valves (32), multiple relief valves (33), and multiple bidirectional hydraulic locks (34); the hydraulic valve block (31) is installed on one side of multiple propulsion cylinders (1); the electromagnetic directional valve (35) is located at the front end of the main oil inlet of the hydraulic valve block (31) and is used to control the high-pressure oil flow of the entire single-cylinder independent speed control mechanism (3); each propulsion cylinder (1) corresponds to one flow valve (32). An overflow valve (33) and a two-way hydraulic lock (34) are provided; the flow valve (32) is mounted on the hydraulic valve block (31) and is used to change the flow direction of hydraulic oil by controlling the movement direction of its valve core, thereby controlling the extension and retraction of the piston rod (12) on the cylinder (11); the overflow valve (33) is installed in parallel between the oil inlet and the oil return port of the flow valve (32); the two-way hydraulic lock (34) is installed in series on the hydraulic pipeline between the hydraulic valve block (31) and the propulsion cylinder (1).

9. A small turning radius open-type TBM tunneling machine according to claim 1, characterized in that, The preset tunnel design parameters include at least the turning radius and the gradient; The method by which the controller calculates the optimal dynamic travel difference parameter includes: Based on the turning radius, calculate the theoretical basic stroke difference of each propulsion cylinder (1); based on the slope, calculate the slope gravity feedforward compensation amount of each propulsion cylinder (1); Based on the real-time axial load data of each propulsion cylinder (1) obtained by each load detection mechanism (2), the load deviation between the average load of the left cylinder and the average load of the right cylinder is calculated, and the theoretical basic stroke difference is corrected by the load deviation. The slope gravity feedforward compensation is added to the feedforward correction result to obtain the stroke difference after load correction. Based on the host attitude data received by the laser guidance system data interface module, the stroke difference after load correction is fed back and corrected to obtain the optimal dynamic stroke difference of each propulsion cylinder (1).

10. A method for tunneling with a small turning radius using an open-face TBM, characterized in that, The method employs an open-type TBM tunneling machine with a small turning radius as described in any one of claims 1-9; the method includes: The real-time axial load data and real-time stroke data of each propulsion cylinder (1) are obtained in real time through each load detection mechanism (2); The host attitude data is acquired in real time through the data interface module of the laser guidance system. Based on the real-time axial load data, real-time stroke data and host attitude data of each propulsion cylinder (1), and combined with the preset tunnel design parameters, the optimal dynamic stroke difference of each propulsion cylinder (1) is calculated in real time, and the corresponding target stroke and target speed control commands are generated. According to the control command, each of the single-cylinder independent speed regulating mechanisms (3) is controlled to independently adjust the propulsion speed and stroke of each propulsion cylinder (1) in a closed loop, so that the tunneling machine can tunnel along the designed axis.

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