Device and method for testing stress of tool bit of large-scale submarine trencher

Abstract

The invention relates to a stress testing device and method for a tool bit of a large seabed trencher, and aims to accurately simulate complex stress conditions, including resistances under different working conditions, of the tool bit of the large seabed trencher in actual seabed excavation in an equal proportion of 1: 1. The device comprises a wheel type frame structure, a tool bit installation mechanism and a test system, the wheel type frame structure is made of high-strength alloy steel, the tool bit installation mechanism can adjust the installation height and angle of a tool bit and simulate different excavation working conditions, and the test system is provided with a piezoelectric or strain type force sensor and a data acquisition system. The method is used for monitoring stress and moment data of the tool bit in the excavation process in real time. According to the method, the servo motor drives the frame to rotate, so that the tool bit performs circular trajectory motion, excavation is performed layer by layer, and the stress change rule of different depths is analyzed. Compared with the prior art, the method has the advantages that the defects of a reduced scale model test are overcome, more reliable and accurate data support is provided for tool bit design optimization, and the method has remarkable engineering significance.

Description

Technical Field

[0001] This invention relates to the field of submarine engineering, and in particular to a device and method for testing the force on the cutter head of a large submarine trenching machine. Background Technology

[0002] In subsea engineering construction, trenching is crucial for laying submarine cables, pipelines, and other infrastructure. Subsea trenching machines, as the core equipment for this operation, directly impact the efficiency and quality of the entire project through the interaction between their cutterheads and the seabed soil, as well as the mechanical properties of the cutterheads. Therefore, accurate testing and analysis of the stress on the cutterheads during the physical excavation process are of significant practical importance.

[0003] In actual seabed excavation operations, the cutter head of the trenching machine is responsible for directly contacting the seabed soil and carrying out excavation. The forces experienced by the cutter head during excavation are extremely complex, including conventional pressure, which is the vertical force exerted by the soil on the cutter head surface when the cutter head cuts into the seabed soil; shear force, which is the resistance encountered by the cutter head when cutting the soil in the horizontal direction; and friction between the cutter head and the soil, which hinders the relative movement between the cutter head and the soil. The magnitude and direction of these forces constantly change with various factors such as the excavation depth, soil properties, and the movement state of the cutter head.

[0004] To ensure the cutter head possesses sufficient structural strength to operate normally under long-term complex stress environments and avoid damage or failure, while simultaneously improving its operational efficiency and reducing energy consumption and excavation time, accurate testing of the cutter head's stress conditions under actual working conditions is necessary. However, existing testing methods often rely on scaled-down model tests due to limitations in loading force and propulsion speed, which cannot accurately reflect the complex stress processes of a 1:1 prototype cutter head during actual seabed excavation. This results in significant errors in the test results and fails to provide reliable data for cutter head design and optimization. Therefore, a new testing device is urgently needed to address these issues. Summary of the Invention

[0005] The purpose of this invention is to provide a force testing device and method for the cutter head of a large subsea trenching machine. This force testing device can accurately simulate the complex force conditions of a 1:1 scale large-size cutter head during actual subsea trenching, providing comprehensive and accurate data support for the design and optimization of the cutter head, thereby improving the performance and reliability of the cutter head and reducing the cost and risk of subsea trenching operations.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention provides the following technical solution:

[0007] A test device for the cutting head stress of a large subsea trenching machine includes a wheeled frame structure, a cutting head mounting mechanism, a power system, and a test system. The device is characterized in that the cutting head mounting mechanism connects the wheeled frame structure and the cutting head via detachable bolts, and the cutting head mounting mechanism has a height adjustment function to adjust the installation angle and height of the cutting head to simulate different excavation conditions.

[0008] The power system includes a servo motor, a first pulley, a belt, and a second pulley, used to drive the wheeled frame structure to rotate.

[0009] The testing system includes a force sensor and a data acquisition system. The force sensor is installed in the side friction direction of the cutter head, the digging direction, and at the connection between the cutter head and the wheel frame structure. It is used to measure the resistance of the cutter head in real time during the digging process. The data acquisition system processes and records the sensor signals.

[0010] Furthermore, the wheeled frame structure is made of high-strength alloy steel, and its radius... From the formula Confirmed, among which This refers to the torque of the drive shaft. For the blade tip to bear the force, The length of the cutter head; simultaneously, the radius... pass Confirmed, among which The cutting length of the blade. This is the height of the center of the disk from the soil surface.

[0011] Furthermore, the cutter head mounting mechanism includes a first bolt hole and a second bolt hole. The first bolt is connected to the edge of the wheel frame structure, and the second bolt is detachably fixed to the cutter head. The bolt diameter is determined according to the force on the cutter head to ensure stable installation. The cutter head mounting mechanism is equipped with a torque monitoring device to monitor the force at the contact point between the cutter head and the cutter head mounting mechanism.

[0012] Furthermore, the wheel frame structure is a triangular support structure, including a hollow triangular steel structure and a central hexagonal hollow steel structure disc, to provide sufficient rigidity to resist high-speed rotation and the force on the cutter head.

[0013] Furthermore, the force sensor is a piezoelectric or strain gauge sensor, installed inside the cutter head, for real-time monitoring of the cutting resistance of the cutter head during the excavation process; the data acquisition system adopts wired or wireless output methods. The wired output method is: the data line is led along the radius to the center of the wheel frame structure and outputs the signal to the collector through the brush. The wireless output method is: the data is sent to the data acquisition system in real time through the wireless module.

[0014] Furthermore, the device also includes a wheeled frame structure mounting bracket structure, including a bracket body and a triangular support, for fixing the wheeled frame structure; and an electrical control cabinet, including a motor speed control button, a wheeled frame structure longitudinal movement control button, and a wheeled frame structure lateral movement control button, for controlling the rotation and displacement of the wheeled frame structure.

[0015] On the other hand, the present invention also provides a testing method for a force testing device for a large subsea trenching machine cutter head, used to test the aforementioned force testing device for a large subsea trenching machine cutter head, comprising the following steps:

[0016] S1. Prepare soil of a specified strength in a soil tank;

[0017] S2. Adjust the installation height and angle of the cutter head according to the working conditions;

[0018] S3. The wheeled frame structure is rotated by a servo motor, so that the cutter head moves in a circular trajectory to cut the soil;

[0019] S4. Synchronously collect internal stress data of the cutter head and torque data of the mounting mechanism;

[0020] S5. Excavate layer by layer and analyze the stress variation law of the cutter head at different excavation depths.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. Provides realistic stress simulation: It can accurately simulate the complex stress conditions of a 1:1 scale large-scale seabed trenching machine cutter head in actual seabed excavation, including resistance in different directions and magnitudes. This overcomes the shortcomings of previous scaled-down model tests that could not truly reflect the stress process of the prototype, making the test results more reliable and accurate.

[0023] 2. Optimize cutter head design and performance: Provide a basis for the structural strength design of the cutter head, ensure that the cutter head works normally under long-term complex stress environment, avoid damage or failure, and thus extend the service life of the cutter head; real-time monitoring data from internal stress testing devices and other equipment can be used to evaluate the optimization of the cutter head structure or materials, as well as the rationality of the installation structure and method, thereby optimizing the operating efficiency of the cutter head and reducing energy consumption and excavation time.

[0024] 3. Reduce engineering costs and risks: By accurately testing and analyzing the stress on the cutter head, comprehensive and accurate data support is provided for the design and optimization of the cutter head, thereby improving the performance and reliability of the cutter head and reducing the cost and risks of subsea trenching operations. Attached Figure Description

[0025] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0026] Figure 1 This is a schematic diagram of the overall force testing device of the present invention;

[0027] Figure 2 This is a schematic diagram of the disk structure of the present invention;

[0028] Figure 3 This is a schematic diagram showing the distribution of the cutter head mounting mechanism and torque monitoring device of the present invention;

[0029] Figure 4 This is a schematic diagram showing the distribution of the cutting head and stress testing device of the present invention;

[0030] Figure 5 This is a schematic diagram of the assembly of the cutter head and the cutter head mounting mechanism of the present invention;

[0031] Figure 6 This is a flowchart of the testing method of the present invention.

[0032] in Figure 1 - Figure 5 The correspondence between the reference numerals and components in the attached drawings is as follows:

[0033] 001. Electrical control cabinet; 101. Motor speed control button; 102. Longitudinal movement control button for wheeled frame structure; 103. Lateral movement control button for wheeled frame structure; 002. Power system; 201. Servo motor; 202. Servo motor pulley; 203. Belt; 204. Wheeled frame structure pulley; 003. Wheeled frame structure mounting bracket structure; 301. Bracket body; 302. Triangular support; 401. Soil trench; 402. Soil of specified strength; 005. Wheeled frame structure. 501. Hollowed-out triangular steel structure; 502. Central hexagonal hollowed-out steel structure disc; 503. Connecting bolts between the wheel frame structure and the cutter head mounting mechanism; 504. Connecting bolts between the cutter head mounting mechanism and the cutter head; 505. Cutter head mounting mechanism; 5051. Bolt holes between the wheel frame structure and the cutter head mounting mechanism; 5052. Bolt holes between the cutter head mounting mechanism and the cutter head; 5053. Internal torque monitoring device of the cutter head mounting mechanism; 506. Cutter head; 5061. Internal stress testing device for the cutter head. Detailed Implementation

[0034] 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.

[0035] This invention provides a device and method for testing the force on the cutter head of a large subsea trenching machine, which will be described in detail below with reference to the accompanying drawings:

[0036] 1. Equipment manufacturing and structural configuration

[0037] 1.1 Wheeled Frame Structure

[0038] The wheel frame structure is simply called a disc. The disc 005 is made of high-strength alloy steel, which has good strength and toughness and can meet the stress requirements during the experiment.

[0039] like Figure 2 As shown, the disc structure adopts a triangular support hollow design 501 combined with a central hexagonal hollow design 502 to reduce weight while ensuring rigidity.

[0040] The radius of the disk is determined by the cutting length. When the required cutting length is... The height of the center of the disc from the ground surface is At that time, the radius of the disk is from Once the equation is determined, the selection of the disk radius must also take into account the torque of the drive shaft. Force on the cutter head and the length of the cutter head Determine the radius of the disk. ;

[0041] It also includes a wheeled frame structure mounting bracket structure 003, which includes a bracket body 301 and a triangular support 302 for fixing the wheeled frame structure.

[0042] 1.2 Cutter Head Mounting Mechanism

[0043] The cutter head mounting mechanism 505 is placed near the edge of the disc 005, aligning it with the edge. The mounting mechanism 505 is then securely connected to the edge of the disc 005 using a first bolt 503. The bolt diameter is determined based on the force applied to the cutter head to ensure its stability during excavation. Next, the cutter head is detachably fixed to the mounting mechanism 505 using a second bolt 504, ensuring a strong and reliable connection and allowing for easy disassembly and replacement of the cutter head. This also supports adjustment of the installation angle and height.

[0044] 1.3 Power System

[0045] The power system 002 includes a servo motor 201, a motor pulley 202, a belt 203, and a disc pulley 204. The servo motor 201 is installed inside the electrical control cabinet 001 and is connected to the disc pulley 204 via the motor pulley 202 and the belt 203, forming a complete power system. This ensures smooth motor operation, appropriate belt tension (without slippage), and provides stable rotational power to the disc 005. The electrical control cabinet 001 has a built-in motor speed control button 101, a disc longitudinal movement control button 102, and a disc lateral movement control button 103, which can synchronously adjust the rotational speed, longitudinal and lateral displacement of the disc 005.

[0046] 1.4 Multidimensional Testing System

[0047] The multi-dimensional testing system includes a stress testing device 5061 and a torque monitoring device 5053. The stress testing device 5061 is arranged inside the cutter head 506 along the side friction direction and the tunneling direction, used to monitor the cutting resistance and structural deformation of the cutter head in real time. Simultaneously, the torque monitoring device 5053 is installed inside the mounting mechanism of the cutter head 505, used to monitor the force, including resistance, on the contact surface between the cutter head and the mounting mechanism in real time. The testing devices are connected to the data acquisition system via wired or wireless means. When using a wired connection, the data lines of the stress testing device 5061 and the torque monitoring device 5053 are led radially to the center of the disk, and a brush outputs the signal to the data acquisition unit. When using a wireless connection, the data acquisition unit is equipped with a wireless module to transmit data to the data acquisition system in real time.

[0048] 2. Implementation steps of the testing method

[0049] 2.1 Soil Preparation

[0050] Soil of a specified strength 402 is prepared in soil trough 401 to ensure that the physical and mechanical properties of the soil match those of the actual seabed soil. Different types of soil materials, such as sand and clay, can be used to simulate different seabed geological conditions, depending on the testing requirements. Simultaneously, the soil is thoroughly compacted and cured to achieve a stable mechanical state.

[0051] 2.2 Adjustment of cutter head mounting height and angle

[0052] Based on actual working conditions, the installation height and angle of the cutter head 506 are precisely adjusted using the adjustable cutter head mounting mechanism 505. By adjusting the bolts and nuts on the mounting mechanism, the relative position of the cutter head 506 and the disc 005 is changed to adapt to excavation requirements at different depths and angles. During the adjustment process, a level and angle measuring tools are used to assist in ensuring the installation accuracy of the cutter head 506.

[0053] 2.3 Disc Rotation and Cutter Head Excavation

[0054] The servo motor 201 is started, driving the disc 005 to rotate at a set speed via the motor pulley 202, belt 203, and disc pulley 204. During the rotation of the disc 005, the cutter head 506 moves in an arc, cutting into the soil 402. Simultaneously, the rotational speed, longitudinal and lateral displacement of the disc are adjusted synchronously via the speed control and movement control buttons within the electrical control cabinet 001 to simulate different working conditions in actual underwater trenching operations.

[0055] 2.4 Data Acquisition and Analysis

[0056] During excavation, the stress testing device 5061 inside the cutter head and the torque monitoring device 5053 in the installation mechanism collect data in real time and transmit the signals to the data acquisition unit via brushes and data cables. After preliminary processing, the data acquisition unit sends the data to the data acquisition system for real-time monitoring and storage via a wireless module. Simultaneously, the analysis software in the data acquisition system performs in-depth analysis of the collected data. The focus is on analyzing the variation of the resistance experienced by the cutter head at different depths, as well as the cutting resistance and structural deformation of the cutter head.

[0057] 2.5 Layer-by-layer excavation and depth analysis

[0058] Excavation is carried out layer by layer according to the predetermined feed rate and excavation depth. After each layer is excavated, the disk rotation is paused, and the test data for that layer is recorded and processed. Then, based on the analysis results, the installation parameters of the cutter head, rotation speed, etc., are adjusted appropriately to optimize the excavation effect. Excavation continues to the next layer until the predetermined total excavation depth is reached. By analyzing the stress variation law at different depths, accurate data support is provided for the optimization of cutter head structural strength, material selection verification, and installation parameter calibration.

[0059] 3. Application of Test Results

[0060] The collected data was used for the optimization design of the cutter head structure. By analyzing the stress distribution and deformation of the cutter head under different stress conditions, weak points in the cutter head structure were identified, and targeted structural improvements and reinforcements were carried out to improve the load-bearing capacity and service life of the cutter head. At the same time, the performance of the cutter head material was verified using test data, and the applicability and reliability of the material under actual working conditions were evaluated, providing a basis for the selection of cutter head materials.

[0061] In addition, the installation parameters of the cutter head, such as installation height and angle, are calibrated based on the test results to ensure that the cutter head can achieve the best excavation effect in actual application, improve the efficiency and quality of submarine trenching operations, and reduce project costs and risks.

[0062] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A test device for the force on the cutter head of a large subsea trenching machine, comprising a wheeled frame structure (005), a cutter head mounting mechanism (505), a power system (002), and a test system (001), characterized in that: The cutter head mounting mechanism (505) connects the wheel frame structure (005) and the cutter head (506) by means of detachable bolts. The cutter head mounting mechanism (505) has a height adjustment function, which is used to adjust the installation angle and height of the cutter head to simulate different excavation conditions. The power system (002) includes a servo motor (201), a first pulley (202), a belt (203), and a second pulley (204) for driving the wheeled frame structure (005) to rotate; The testing system includes a force sensor and a data acquisition system. The force sensor is installed in the side friction direction of the cutter head (506), the digging direction, and at the connection between the cutter head (506) and the wheel frame structure (005) to measure the resistance of the cutter head (506) in real time during the excavation process. The data acquisition system processes and records the sensor signals.

2. The apparatus according to claim 1, characterized in that, The wheeled frame structure (005) is made of high-strength alloy steel, and its radius... From the formula Confirmed, among which This refers to the torque of the drive shaft. For the blade tip to bear the force, The length of the cutter head; simultaneously, the radius... pass Confirmed, among which The cutting length of the blade. This is the height of the center of the disk from the soil surface.

3. The apparatus according to claim 1, characterized in that, The cutter head mounting mechanism (505) includes a first bolt hole (5051) and a second bolt hole (5052). It is connected to the edge of the wheel frame structure (005) by a first bolt (503) and is detachably fixed to the cutter head (506) by a second bolt (504). The bolt diameter is determined according to the force on the cutter head to ensure stable installation. The cutter head mounting mechanism (505) is equipped with a torque monitoring device (5053) to monitor the force on the contact part between the cutter head (506) and the cutter head mounting mechanism (505).

4. The apparatus according to claim 1, characterized in that, The wheel frame structure (005) is a triangular support structure, including a hollow triangular steel structure (501) and a central hexagonal hollow steel structure disc (502) to provide sufficient rigidity to resist high-speed rotation and the force on the cutter head.

5. The apparatus according to claim 1, characterized in that, The force sensor is a piezoelectric or strain gauge sensor, installed inside the cutter head (5061), used to monitor the cutting resistance of the cutter head (506) in real time during the excavation process; the data acquisition system adopts wired or wireless output mode. The wired output mode is: the data line is led along the radius to the center of the wheel frame structure (005) and the signal is output to the collector through the brush. The wireless output mode is: the data is sent to the data acquisition system in real time through the wireless module.

6. The apparatus according to claim 1, characterized in that, The device also includes a wheel frame structure mounting bracket structure (003), including a bracket body (301) and a triangular support (302), for fixing the wheel frame structure (005); and an electrical control cabinet (001), including a motor speed control button (101), a wheel frame structure longitudinal movement control button (102) and a wheel frame structure lateral movement control button (103), for controlling the rotation and displacement of the wheel frame structure.

7. A test method for a force testing device for the cutter head of a large subsea trenching machine, characterized in that, Testing the apparatus as described in claims 1-6 includes the following steps: S1. Prepare soil of specified strength (402) in soil trench (401); S2. Adjust the installation height and angle of the cutter head (506) according to the working conditions; S3. The wheel frame structure (005) is driven to rotate by the servo motor (201), so that the cutter head (506) moves in a circular trajectory to cut the soil; S4. Synchronously collect internal stress data of the cutter head and torque data of the mounting mechanism; S5. Excavate layer by layer and analyze the stress variation law of the cutter head at different excavation depths.

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