An excavation device and method for simulating typical faults of shield cutters

Abstract

The present invention discloses an excavation device and method for simulating typical faults of shield cutters. The device includes a shield body, a cutter head drive device, a cutter head, a cutter wear fault simulation device, a cutter breakage fault simulation device, and a cutter eccentric wear fault simulation device. The present invention focuses on simulating three typical faults of shield cutters, namely wear, eccentric wear, and breakage. Starting from the manifestation forms of typical faults of shield cutters, a simulation scheme for typical faults of shield cutters is designed. The present invention can be switched arbitrarily between the normal working state and the fault state; the hydraulic cylinder is used to drive the braking device to lock the cutter to simulate the cutter eccentric wear fault. The fault injection form of the present invention is controllable. According to the proportion of the three typical faults of the cutter in different types of cutters, the fault types simulated by the cutters at different positions on the cutter head are determined. The present invention has great application potential in studying the performance differences of the cutter head before and after the occurrence of typical faults of shield cutters.

Description

Technical Field

[0001] The present invention belongs to the field of shield cutterhead test, and particularly relates to a cutting device and method for simulating typical faults of shield cutters. Background Art

[0002] The cutterhead is the main rock-breaking tool of the shield machine. It contacts the rock and applies a thrust far higher than its compressive strength to break the rock. Due to this working characteristic, the cutterhead often fails. The typical faults of the cutterhead include wear, eccentric wear, and fracture. After the cutterhead fails, the rock-breaking performance of the cutterhead decreases, and phenomena such as "unable to cut" and "slow cutting" will occur. Therefore, it is one of the key factors affecting the shield construction period. At present, the key means for scholars to study various characteristics of the shield machine are all achieved by establishing corresponding test benches.

[0003] At present, there is no test bench that can simulate the wear fault, fracture fault, and eccentric wear fault of the shield cutterhead alone or simultaneously. Before and after the cutterhead fails, the performance of the cutterhead varies greatly, which also has a great impact on the construction efficiency of the shield. Therefore, it is particularly important to study the difference in the overall performance of the cutterhead before and after the shield cutterhead fails. Summary of the Invention

[0004] To solve the problems in the prior art, the present invention proposes a cutting device and method for simulating typical faults of shield cutters. The present invention is designed based on the manifestation form of typical faults of shield cutters and uses the scaling principle. The cutting device can simulate the three typical faults of the cutterhead separately or simultaneously, providing a test platform basis for studying the difference in the overall performance of the cutterhead before and after the cutterhead fails.

[0005] The technical solution of the present invention is as follows:

[0006] The present invention first provides a cutting device for simulating typical faults of shield cutters, which includes:

[0007] A shield body, as the main body of the cutting device, includes a housing and a number of brackets located inside the housing;

[0008] A cutterhead, located at one end of the shield body, which can rotate. The cutterhead includes a tool box and a cutterhead seat. A cutterhead for simulating wear and fracture faults is in sliding fit with the tool box, and the cutterhead seat for simulating eccentric wear faults is fixedly connected to the tool box; A cutterhead driving device, located inside the shield body, is connected to the cutterhead and used to drive the cutterhead to rotate;

[0009] The hob wear fault simulation device is located inside the shield body. The hob wear fault simulation device is connected to the hob seat simulating the wear fault through a wear simulator, and drives the hob seat to move relative to the cutter box through a motor to simulate the hob wear fault;

[0010] The hob fracture fault simulation device is located inside the shield body, is connected to the hob seat simulating the fracture fault through a fracture simulator, and drives the hob seat to move relative to the cutter box through a motor to simulate the hob fracture fault;

[0011] The hob uneven wear fault simulation device is located inside the shield body and is used to simulate the hob uneven wear fault.

[0012] As a preferred solution of the present invention, the bracket serves as an installation carrier for the internal components of the shield body; the cutter head drive device, the hob wear fault simulation device, the hob fracture fault simulation device, and the hob uneven wear fault simulation device are all installed on the bracket.

[0013] As a preferred solution of the present invention, according to the number of faults to be simulated, the fault categories, and the fault position distribution, the hobs used to simulate the corresponding faults are selected at the fault positions on the cutter head and the fault types to be simulated are assigned to each hob.

[0014] As a preferred solution of the present invention, the hob wear fault simulation device includes: a first motor, a first coupling, a first lead screw seat, a first trapezoidal lead screw, a first trapezoidal nut, and a wear simulator;

[0015] The first motor is fixed inside the shield body, and the power output by the first motor is transmitted to the first trapezoidal lead screw through the first coupling to drive it to rotate; both ends of the first trapezoidal lead screw are provided with first lead screw seats; the first trapezoidal nut is installed on the first trapezoidal lead screw; the front end of the first trapezoidal nut is fixed to the wear simulator in a threaded connection manner; the wear simulator is a slewing bearing structure, its outer ring is fixed to the shield body, its inner ring is connected to the hob seats corresponding to all the hobs simulating the wear faults, and can rotate around the center of the cutter head together with the hob seats; the first trapezoidal lead screw has a self-locking function and can lock the wear simulator when the first motor stops rotating, thereby locking the corresponding hob.

[0016] As a preferred solution of the present invention, the hob fracture fault simulation device includes: a second motor, a second coupling, a second lead screw seat, a second trapezoidal lead screw, a second trapezoidal nut, and a fracture simulator;

[0017] The second motor is fixed inside the shield body. The power output by the second motor is transmitted to the second trapezoidal lead screw through the second coupling to drive its rotation. Both ends of the second trapezoidal lead screw are equipped with second lead screw seats. The second trapezoidal nut is installed on the second trapezoidal lead screw. The front end of the second trapezoidal nut is fixedly connected to the fracture simulator by means of thread connection. The fracture simulator is a slewing bearing structure, the outer ring of which is fixed on the shield body, and the inner ring is connected to the cutter head seats corresponding to all the hob cutters simulating fracture faults and can rotate around the cutter head center following the cutter head seats. The second trapezoidal lead screw has a self-locking function and can lock the fracture simulator when the second motor stops rotating, thereby locking the corresponding hob cutters.

[0018] As a preferred embodiment of the present invention, the first motor and the second motor are equipped with a braking function.

[0019] As a preferred embodiment of the present invention, the hob uneven wear fault simulation device includes: a hydraulic cylinder, a transmission rod, a guide sleeve, a slewing support shaft and a brake.

[0020] The hydraulic cylinder is fixed inside the shield body, and the output end of the hydraulic cylinder is connected to the transmission rod. The guide sleeve is fixed inside the shield body. One end of the transmission rod is fitted with the guide sleeve, and the other end is connected to one end of the slewing support shaft. The other end of the slewing support shaft is fixedly installed together with the brake. Under the action of the slewing support shaft, the brake can rotate with the cutter head. When the hob does not simulate the uneven wear fault, the brake is not in contact with the hob. When the hob simulates the uneven wear fault, the brake presses all the hobs simulating the uneven wear fault, and the brake applies a pressure to the hob. When this pressure is higher than the force exerted by the rock on the hob, the reaction torque of the brake on the hob is higher than the rolling torque of the rock on the hob, and the hob cannot rotate self, that is, the uneven wear fault is simulated.

[0021] The present invention also provides a method for simulating typical faults of shield hobs of the excavation device, which includes the following steps:

[0022] 1) According to the number, type and position distribution of the faults to be simulated, select the hobs used to simulate the corresponding faults at the fault positions on the cutter head and assign the fault types to be simulated to each hob. In the initial state, each hob does not simulate a fault, that is, all are in the normal working state.

[0023] 2) When simulating the hob wear fault, drive the first trapezoidal lead screw through the first motor, so that the first trapezoidal nut, the wear simulator and the hobs simulating the wear fault retreat a certain distance compared with the normal working state of the hobs, so as to simulate the situation where the diameter of the cutter ring becomes smaller when the hob has a wear fault. The self-locking mechanism of the first trapezoidal lead screw and the braking function of the first motor can ensure that the hob is fixed at the required position.

[0024] When simulating the hob breakage fault, the second motor drives the second trapezoidal lead screw, causing the second trapezoidal nut, the fracture simulator, and the hob simulating the fracture fault to move backward a certain distance compared to the normal working state of the hob, so that the cutting edge of the hob simulating the fracture fault completely retracts into the tool box, that is, the cutting edge of the hob is completely lower than the plane where the cutter head is located, to simulate the situation where the cutter ring of the hob falls off when the hob has a fracture fault; the self-locking mechanism of the second trapezoidal lead screw and the braking function of the second motor can ensure that the hob is fixed at the required position;

[0025] When simulating the hob uneven wear fault, the piston rod of the hydraulic cylinder extends, pushing the transmission rod, so that the brake contacts the hob simulating the uneven wear fault; keeping the resistance moment brought by the force output by the hydraulic cylinder to the hob always higher than the driving moment of the rock and soil to the hob, so that the hob cannot rotate self in the process of cutting the rock and soil, but only revolves around the cutter head, to simulate the situation where the hob cannot rotate self when the hob has an uneven wear fault; ensuring that the output force of the hydraulic cylinder and the braking force of the brake are constant;

[0026] Among them, the hob wear fault, the hob breakage fault, and the hob uneven wear fault can be simulated separately or any number of them can be simulated simultaneously;

[0027] 3) The performance difference of the cutter head before and after the shield hob fault simulation is obtained by the sensors detecting the changes of the corresponding signals on the cutter head respectively.

[0028] Compared with the prior art, the specific beneficial effects of the present invention include:

[0029] According to the manifestation forms of typical faults of shield hobs, the present invention designs simulation schemes for shield hob wear faults, fracture faults, and uneven wear faults to realize the simulation of typical faults of shield hobs. The present invention uses a motor to drive a trapezoidal lead screw to control the movement of the hob seat relative to the tool box of the cutter head to simulate the wear fault and fracture fault of the hob, and uses the self-locking function of the trapezoidal lead screw and the braking function of the motor to lock the hob, greatly improving the reliability and controllability of the wear and fracture fault simulation. The present invention uses a hydraulic cylinder to push the braking device to lock the hob to simulate the uneven wear fault of the hob, and uses the unique force control characteristics of the hydraulic system to control the output force of the hydraulic cylinder, greatly improving the reliability and controllability of the hob uneven wear fault simulation. In addition, the number of hobs simulating the typical faults of shield hobs and the positions of different fault hobs in the present invention are determined according to the proportion of the three typical faults of hobs in different types of hobs, more realistically simulating the faults that occur to shield hobs, and the three typical faults can be simulated simultaneously. To sum up, the present invention has great application potential in studying the performance difference of the cutter head before and after the occurrence of typical faults of shield hobs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the excavation device for simulating typical faults of shield hobs of the present invention.

[0031] Figure 2 Schematic diagram of the shield structure shown in the embodiments of the present invention.

[0032] Figure 3 Schematic diagram of the cutter head drive device structure shown in the embodiments of the present invention.

[0033] Figure 4 Schematic diagram of the cutter head structure shown in the embodiments of the present invention.

[0034] Figure 5 Schematic diagram of the hob wear fault simulation device structure shown in the embodiments of the present invention.

[0035] Figure 6 Schematic diagram of the hob fracture fault simulation device structure shown in the embodiments of the present invention.

[0036] Figure 7 Schematic diagram of the hob uneven wear fault simulation device structure shown in the embodiments of the present invention.

[0037] In the figure, 1 - shield; 2 - cutter head drive device; 3 - cutter head; 4 - hob wear fault simulation device; 5 - hob fracture fault simulation device; 6 - hob uneven wear fault simulation device; 101 - support a; 102 - support b; 103 - support c; 104 - support d; 105 - housing; 201 - leg; 202 - transmission part; 203 - slewing bearing; 204 - bearing; 205 - end cover; 206 - transmission shaft; 301 - cutter box; 302 - hob a; 303 - hob b; 304 - hob c; 305 - hob d; 306 - cutter; 401 - first motor; 402 - first coupling; 403 - first lead screw seat; 404 - first trapezoidal lead screw; 405 - first trapezoidal nut; 406 - wear simulator; 501 - second motor; 502 - second coupling; 503 - second lead screw seat; 504 - second trapezoidal lead screw; 505 - second trapezoidal nut; 506 - fracture simulator; 601 - hydraulic cylinder; 602 - guide sleeve; 603 - transmission rod; 604 - slewing support shaft; 605 - brake. Detailed implementation manners

[0038] The present invention will be further described and explained below in conjunction with the detailed implementation manners. The embodiments are only demonstrations of the present disclosure content and do not delimit the scope of limitation. Without conflict, the technical features of each implementation manner in the present invention can be combined accordingly.

[0039] The device proposed by the present invention for simulating typical failures of shield cutters focuses on simulating three typical failures of shield cutters, namely wear, eccentric wear, and fracture. Starting from the manifestation forms of typical failures of shield cutters, a simulation scheme for typical failures of shield cutters is designed, providing a research basis for studying the performance differences of the overall cutter head before and after the failure of shield cutters.

[0040] The typical failures of shield cutters mainly include wear, fracture, and eccentric wear. The manifestation form of the wear failure of the cutter is that the edge of the cutter becomes wider, the diameter of the cutter ring becomes smaller, and the damage at each part is uniform. The manifestation form of the fracture failure of the cutter is that cracks appear on the cutter. In the initial stage of crack generation, its impact on the normal operation of the cutter is not significant, but over time, phenomena such as cutter ring chipping and cutter ring shedding will occur. The manifestation form of the eccentric wear failure of the cutter is that the cutter cannot rotate self - sufficiently, one side of the cutter wears severely while the other side hardly wears, and the damage at each part is uneven.

[0041] According to the manifestation forms of typical failures of shield cutters, the simulation scheme for the wear failure of shield cutters designed by the present invention is as follows: The cutter holder and the cutter box on the cutter head are set as a relatively movable structure. The motor drives the trapezoidal screw rod to control the cutter holder to move a certain distance relative to the cutter box to simulate the decrease in the diameter of the cutter ring. This distance depends on the wear limit and reduction ratio coefficient of different specifications of the cutters selected. The simulation scheme for the fracture failure of the cutter is: The cutter holder and the cutter box on the cutter head are set as a relatively movable structure. The motor drives the trapezoidal screw rod to control the cutter holder to move a certain distance relative to the cutter box so that the edge of the cutter is completely below the surface of the cutter box to simulate the shedding of the cutter ring and the cutter cannot work. This distance depends on the cutter specifications, reduction ratio coefficient, cutter installation method, etc. The simulation scheme for the eccentric wear failure of the cutter is: The cutter for simulating the eccentric wear failure is installed in the same way as the cutter in normal operation. A braking device is pushed by a hydraulic cylinder to lock the cutter to simulate that the cutter cannot rotate self - sufficiently when the eccentric wear failure occurs. The force output by the hydraulic cylinder depends on the cutter specifications, reduction ratio coefficient, driving torque of the cutter's self - rotation, and the number of cutters for simulating the eccentric wear failure, etc.

[0042] When simultaneously simulating the wear, fracture, and eccentric wear failures of shield cutters on the test bench, the selection of the number of cutters for simulating different failures and the positions of the cutters for different failures in the cutter head depends on the distribution law of the three typical failures of the cutters. A large number of construction cases show that the wear failure of the cutter is the main manifestation form of shield cutter failures. Most of the cutters replaced due to the wear failure of the cutter are the main cutters and side cutters. Most of the cutters replaced due to the eccentric wear failure of the cutter are the center cutters. Most of the cutters replaced due to the fracture failure of the cutter are the side cutters.

[0043] As Figure 1As shown in the figure, the excavation device designed in this embodiment for simulating typical faults of shield cutters is based on the manifestation forms of typical faults of shield cutters and is designed using the scale-down principle. The device mainly consists of a shield body 1, a cutter head drive device 2, a cutter head 3, a cutter wear fault simulation device 4, a cutter breakage fault simulation device 5, and a cutter eccentric wear fault simulation device 6. The cutter head drive device 2 and the cutter head 3 are connected by a support leg 201. The slewing bearing 203 and the support a101 are connected by bolts, and the transmission shaft 206 is respectively connected to the support b102 by bolts through bearings 204 and end covers 205, fixing the cutter head drive device 2 on the shield body 1. The lead screw seat is connected to the support a101 by bolts, fixing the cutter wear fault simulation device 4 on the shield body 1. The lead screw seat 503 is connected to the support a101 by bolts, fixing the cutter breakage fault simulation device 4 on the shield body 1. The hydraulic cylinder 601 is connected to the support d104 by bolts, fixing the cutter eccentric wear fault simulation device 4 on the shield body 1.

[0044] In this excavation device, the cutter head 3 is the core component of the test bench excavation system, mainly used to support the face and drive the cutters to rotate for cutting rocks. The cutter head drive device is fixedly installed behind the cutter head, mainly used to drive the cutter head to rotate. The cutter wear fault simulation device is fixedly installed inside the shield of the propulsion device and outside the cutter head drive device, connected to the cutter through a wear simulator, and the cutter is driven by a motor to move relative to the cutter box of the cutter head to simulate the cutter wear fault. The cutter breakage fault simulation device is fixedly installed inside the shield of the propulsion device and outside the cutter head drive device, connected to the cutter through a breakage simulator, and the cutter is driven by a motor to move relative to the cutter box of the cutter head to simulate the cutter breakage fault. The cutter eccentric wear fault simulation device is fixed inside the shield of the propulsion device and behind the cutter head, and the brake device is locked by a hydraulic cylinder to simulate the cutter eccentric wear fault.

[0045] As Figure 2 shown, the shield body includes a housing 105 and several supports located inside the housing; Figure 2 There are 4 supports exemplified in the figure, and the support a101, support b102, support c103, and support d104 are fixed on the housing 105 in a welded form. These supports not only support the shield machine housing but also serve as the installation carrier for the internal components of the shield body.

[0046] As Figure 3As shown in the figure, the cutter head drive device mainly includes an output shaft, bearings, end covers, a slewing bearing, a connector, and legs. In this embodiment, the inner ring of the bearing 204 is fitted with the transmission shaft 206, and the outer ring is fitted with the end cover 205. There are at least two sets of the bearing 204, the bearing end cover 205, and the bracket b102, which are located at different positions on the transmission shaft 206 respectively, so as to achieve the purpose of stably supporting the transmission shaft. The transmission shaft 206 is a gear shaft, which forms a gear meshing drive with the internal gear ring of the slewing bearing to drive the slewing bearing to rotate. For the convenience of disassembly, the transmission shaft can also be composed of a gear and a stepped shaft through key fitting. The slewing bearing 203 is connected to the transmission member 202 by bolts. The leg 201 is fixedly connected to the transmission member 202 by welding.

[0047] As Figure 4 shown in the figure, the cutter head is mainly composed of a cutter box, hob cutters, and scraping cutters. In this embodiment, the cutting tool 306 is connected to the cutter box 301 by bolts. The tool holders of the hob cutter a302 and the hob cutter d305 are connected to the cutter box 301 by bolts. The hob cutter a302 simulates a hob cutter in normal operation, and the hob cutter d305 simulates a hob cutter with uneven wear. The tool holder of the hob cutter b303 is slidably fitted with the cutter box 301 and is connected to the inner ring of the wear simulator by threads to fix the hob cutter on the hob cutter wear simulation device. The tool holder of the hob cutter c304 is slidably fitted with the cutter box 301 and is connected to the inner ring of the fracture simulator by threads to fix the hob cutter on the hob cutter fracture simulation device. The number and positions of the hob cutters a, b, c, and d depend on the total number of selected hob cutters, the proportion of each hob cutter failure type, and the proportion of each hob cutter failure type at different positions on the cutter head.

[0048] As Figure 5 shown in the figure, the first motor 401 is fixed on the inner wall of the housing 105 by bolts. The output end of the first motor 401 is fitted with one end of the first coupling 402, and the other end of the first coupling 402 is fitted with the first trapezoidal lead screw 404. The power output by the first motor 401 is transmitted to the first trapezoidal lead screw 404 through the first coupling 402 to drive it to rotate. The two ends of the first trapezoidal lead screw 404 are provided with first lead screw seats 403. The first trapezoidal nut 405 is installed on the first trapezoidal lead screw 404. The front end of the first trapezoidal nut 405 is fixedly connected to the wear simulator 406 by threads. The wear simulator 406 is a slewing bearing structure, the outer ring of which is fixed on the shield 1, and the inner ring is connected to the tool holders corresponding to all the hob cutters simulating wear failures, and the inner ring can rotate together with the cutter head. The trapezoidal lead screw has a self-locking function, which can lock the wear simulator 406 when the first motor 401 stops rotating, so as to lock the hob cutter b303 simulating wear failure and the corresponding tool holder. In order to increase the self-locking effect, the first motor 401 with a braking function can be used.

[0049] As Figure 6As shown in the figure, the second motor 501 is fixed to the housing by means of bolt connection. The output end of the second motor 501 is fitted with one end of the second coupling 502, and the other end of the second coupling 502 is fitted with the second trapezoidal lead screw 504. The power output by the second motor 501 is transmitted to the second trapezoidal lead screw 504 through the second coupling 502 to drive its rotation. Both ends of the second trapezoidal lead screw 504 are provided with second lead screw seats 503. The second trapezoidal nut 505 is installed on the second trapezoidal lead screw 504. The front end of the second trapezoidal nut 505 is fixed to the fracture simulator 506 by means of threaded connection. The fracture simulator 506 is a slewing bearing structure, the outer ring of which is fixed to the shield body 1, and the inner ring is connected to the cutter head seats corresponding to all the cutters simulating fracture faults, and the inner ring can rotate together with the cutter head. The trapezoidal lead screw has a self-locking function and can lock the fracture simulator 506 when the motor 501 stops rotating, thereby locking the cutter c304 simulating the fracture fault and the corresponding cutter head seat. In order to increase the self-locking effect, the second motor 501 with a braking function can be used.

[0050] As Figure 7 shown in the figure, the hydraulic cylinder 601 is fixed to the bracket d by means of bolt connection. The output end of the hydraulic cylinder is connected to the transmission rod 603. The guide sleeve 602 is fixed to the bracket c by means of bolt connection. One end of the transmission rod 603 is fitted with the guide sleeve 602, and the other end is connected to one end of the slewing support shaft 604. The other end of the slewing support shaft 604 is fixedly installed together with the brake 605. Under the action of the slewing support shaft 604, the brake 605 can rotate with the cutter head.

[0051] When the cutter simulating the wear fault is in the normal working state, the first motor 401 drives the first trapezoidal lead screw 404, so that the first trapezoidal nut 405 is located at the forefront of the corresponding first trapezoidal lead screw 404, pushing the wear simulator 406 to fix the cutter simulating the wear fault in the normal working position. The self-locking mechanism of the trapezoidal lead screw and the braking function of the motor can lock the cutter head seat on the tool box.

[0052] When the cutter simulating the fracture fault is in the normal working state, the second motor 501 drives the second trapezoidal lead screw 504, and the second trapezoidal nut 505 is located at the forefront of the corresponding second trapezoidal lead screw 504, pushing the fracture simulator 506 to fix the cutter simulating the fracture fault in the normal working position. The self-locking mechanism of the trapezoidal lead screw and the braking function of the motor can lock the cutter head seat on the tool box.

[0053] When the cutter simulating the eccentric wear fault is in the normal working state, the hydraulic cylinder 601 is in the fully retracted state, driving the transmission rod 603 to move the brake 605 away from the cutter simulating the eccentric wear fault and maintaining a certain distance.

[0054] When simulating the hob wear fault, the first motor 401 drives the first trapezoidal lead screw 404, causing the first trapezoidal nut 405, the first wear simulator 406 and the hob simulating the wear fault to retreat a certain distance, so as to simulate that when the hob has a wear fault, the diameter of the cutter ring becomes smaller. The self-locking mechanism of the trapezoidal lead screw and the braking function of the motor can ensure that the hob is fixed at the required position.

[0055] When simulating the hob breakage fault, the second motor 501 drives the second trapezoidal lead screw 504, causing the second trapezoidal nut 505, the breakage simulator 506 and the hob simulating the breakage fault to retreat a certain distance, so that the cutting edge of the hob simulating the breakage fault completely retreats into the cutter box, that is, it does not participate in the work, to simulate that when the hob has a breakage fault, the cutter ring of the hob falls off. The self-locking mechanism of the trapezoidal lead screw and the braking function of the motor can ensure that the hob is fixed at the required position.

[0056] When simulating the hob uneven wear fault, the piston rod of the hydraulic cylinder 601 extends, pushing the transmission rod 603, so that the brake 605 contacts the hob simulating the uneven wear fault. Keep the resistance moment brought by the force output by the hydraulic cylinder to the hob always higher than the driving moment of the rock and soil to the hob, so that the hob cannot rotate self in the process of cutting the rock and soil, but only revolves around the cutter head, to simulate that when the hob has an uneven wear fault, the hob cannot rotate self. Through the corresponding hydraulic components, the output force of the hydraulic cylinder and the braking force of the braking device can be ensured to be constant.

[0057] The hob wear fault, the hob breakage fault and the hob uneven wear fault can be simulated simultaneously. Before and after the simulation of the shield hob fault, the performance differences of the cutter head can be compared by detecting the changes of the corresponding signals on the cutter head respectively through three-axis force sensors, acceleration sensors, torque sensors, etc.

[0058] The excavation device designed by the present invention for simulating typical faults of shield hobs can be installed in other reduced-scale test benches for experiments. The present invention brings the following several basic advantages: First, by using the method of driving the trapezoidal lead screw by a motor, the hob seat is controlled to move relative to the cutter box of the cutter head to simulate the hob wear fault and the breakage fault. The self-locking function of the trapezoidal lead screw can make the hob seat stationary relative to the cutter box, enabling it to switch arbitrarily between the normal working state and the fault state; by using the method of driving the braking device by a hydraulic cylinder to lock the hob to simulate the hob uneven wear fault. Second, the three typical faults of the hob are integrally designed on one test bench, and the form of fault injection is controllable, providing a test platform for studying the performance differences of the overall cutter head before and after the hob fault. Third, according to the proportion of the three typical faults of the hob in different types of hobs, the types of faults simulated by the hobs at different positions on the cutter head are determined. To sum up, the present invention has great application potential in studying the performance differences of the cutter head before and after the typical faults of shield hobs occur.

[0059] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present invention. For those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention.

Claims

1. An excavation device for simulating typical faults of shield cutters, characterized in that, it includes: A shield body, which is the main body of the excavation device, including a housing and several brackets located inside the housing; A cutter head, located at one end of the shield body, which can rotate. The cutter head includes a cutter box and a hob seat. Among them, the hob seat is provided with a hob. The hob seat for simulating normal operation is fixedly connected to the cutter box, the hob seat for simulating wear and fracture faults is in sliding fit with the cutter box, and the hob seat and the cutter box for simulating eccentric wear faults are fixedly connected; A cutter head driving device, located inside the shield body, and the cutter head driving device is connected to the cutter head to drive the cutter head to rotate; A hob wear fault simulation device, located inside the shield body. The hob wear fault simulation device is connected to the hob seat simulating wear faults through a wear simulator, and drives the hob seat to move relative to the cutter box through a motor to simulate hob wear faults; A hob fracture fault simulation device, located inside the shield body, is connected to the hob seat simulating fracture faults through a fracture simulator, and drives the hob seat to move relative to the cutter box through a motor to simulate hob fracture faults; A hob eccentric wear fault simulation device, located inside the shield body, is used to simulate hob eccentric wear faults; The hob wear fault simulation device includes: a first motor, a first coupling, a first lead screw seat, a first trapezoidal lead screw, a first trapezoidal nut, and a wear simulator; The first motor is fixed inside the shield body. The power output by the first motor is transmitted to the first trapezoidal lead screw through the first coupling to drive it to rotate. The two ends of the first trapezoidal lead screw are provided with first lead screw seats; the first trapezoidal nut is installed on the first trapezoidal lead screw; the front end of the first trapezoidal nut is fixedly connected to the wear simulator through a threaded connection; the wear simulator is a slewing bearing structure, its outer ring is fixed on the shield body, and its inner ring is connected to the hob seats corresponding to all the hobs simulating wear faults, and can rotate around the cutter head center together with the hob seats; the first trapezoidal lead screw has a self-locking function and can lock the wear simulator when the first motor stops rotating, thereby locking the corresponding hob; The hob fracture fault simulation device includes: a second motor, a second coupling, a second lead screw seat, a second trapezoidal lead screw, a second trapezoidal nut, and a fracture simulator; The second motor is fixed inside the shield body. The power output by the second motor is transmitted to the second trapezoidal lead screw through the second coupling to drive it to rotate. The two ends of the second trapezoidal lead screw are provided with second lead screw seats, the second trapezoidal nut is installed on the second trapezoidal lead screw, and the front end of the second trapezoidal nut is fixedly connected to the fracture simulator through a threaded connection; the fracture simulator is a slewing bearing structure, its outer ring is fixed on the shield body, and its inner ring is connected to the hob seats corresponding to all the hobs simulating fracture faults, and can rotate around the cutter head center together with the hob seats; the second trapezoidal lead screw has a self-locking function and can lock the fracture simulator when the second motor stops rotating, thereby locking the corresponding hob.

2. The excavation device for simulating typical faults of shield cutters according to claim 1, characterized in that, The bracket serves as the installation carrier for the internal components of the shield body; the cutter head drive device, the hob wear fault simulation device, the hob fracture fault simulation device, and the hob uneven wear fault simulation device are all installed on the bracket.

3. The cutting device for simulating typical faults of shield cutters according to claim 1, characterized in that according to the number of faults to be simulated, the fault categories, and the fault position distribution, the cutters used to simulate the corresponding faults are selected at the fault positions on the cutter head, and the fault types to be simulated are assigned to each cutter.

4. The cutting device for simulating typical faults of shield cutters according to claim 1, characterized in that the first motor and the second motor are equipped with braking functions.

5. The cutting device for simulating typical faults of shield cutters according to any one of claims 1-3, characterized in that the hob uneven wear fault simulation device includes: a hydraulic cylinder, a transmission rod, a guide sleeve, a slewing support shaft, and a brake; The hydraulic cylinder is fixed inside the shield body, and the output end of the hydraulic cylinder is connected to the transmission rod; the guide sleeve is fixed inside the shield body; one end of the transmission rod is fitted with the guide sleeve, and the other end is connected to one end of the slewing support shaft; the other end of the slewing support shaft is fixedly installed with the brake; under the action of the slewing support shaft, the brake can rotate with the cutter head; when the hob does not simulate the uneven wear fault, the brake does not contact the hob; when the hob simulates the uneven wear fault, the brake presses all the hobs simulating the uneven wear fault, and the brake applies a pressure to the hobs. When this pressure is higher than the force exerted by the rock on the hobs, the reaction torque of the brake on the hobs is higher than the rolling torque of the rock on the hobs, and the hobs cannot rotate self - sufficiently, that is, the uneven wear fault is simulated.

6. A method for simulating typical faults of shield cutters based on the cutting device according to claim 5, characterized in that it includes the following steps: 1) According to the number of faults to be simulated, the fault categories, and the fault position distribution, the cutters used to simulate the corresponding faults are selected at the fault positions on the cutter head, and the fault types to be simulated are assigned to each cutter; in the initial state, each cutter does not simulate faults, that is, they are all in the normal working state; 2) When simulating the hob wear fault, the first motor drives the first trapezoidal lead screw, so that the first trapezoidal nut, the wear simulator, and the hobs simulating the wear fault retreat a certain distance compared with the normal working state of the hobs, so as to simulate the situation where the cutter ring diameter becomes smaller when the hob has a wear fault; the self - locking mechanism of the first trapezoidal lead screw and the braking function of the first motor can ensure that the hobs are fixed at the required positions; When simulating the hob fracture fault, the second motor drives the second trapezoidal lead screw, so that the second trapezoidal nut, the fracture simulator, and the hobs simulating the fracture fault retreat a certain distance compared with the normal working state of the hobs, so that the cutting edges of the hobs simulating the fracture fault completely retreat into the cutter box, that is, the cutting edges of the hobs are completely lower than the plane where the cutter head is located, to simulate the situation where the cutter ring of the hob falls off when the hob has a fracture fault; the self - locking mechanism of the second trapezoidal lead screw and the braking function of the second motor can ensure that the hobs are fixed at the required positions; When simulating the hob partial wear fault, the piston rod of the hydraulic cylinder extends to push the transmission rod, causing the brake to contact the hob with the simulated partial wear fault; keep the resistance moment brought by the force output by the hydraulic cylinder to the hob always higher than the driving moment of the rock and soil to the hob, so that the hob cannot rotate self - sufficiently during the process of cutting the rock and soil, but only revolves around the cutterhead, to simulate the situation where the hob cannot rotate self - sufficiently when the hob has a partial wear fault; ensure that the output force of the hydraulic cylinder and the braking force of the brake are constant; Among them, the hob wear fault, the hob fracture fault, and the hob partial wear fault can be simulated separately or any number of them can be simulated simultaneously; 3) Detect the changes of the corresponding signals on the cutterhead through sensors respectively to know the performance differences of the cutterhead before and after the shield hob fault simulation.

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