Comprehensive test and cooperative adjustment method for balance state of bucket-wheel stacker-reclaimer

Abstract

The invention relates to the technical field of large-scale ports and industrial bulk cargo conveying equipment, and particularly discloses a comprehensive test and cooperative adjustment method for the balance state of a bucket-wheel stacker-reclaimer, and the method comprises the steps: carrying out the comprehensive test: carrying out the wheel pressure test, the landing force test and the counterweight check spot check detection of the bucket-wheel stacker-reclaimer, and obtaining the actual measurement data used for evaluating the balance state of the equipment; diagnosis and analysis: calculating the gravity center offset of the whole bucket-wheel stacker-reclaimer based on the actually measured data obtained in the comprehensive test step, evaluating the balance of a pitching system and the actual working pressure of a hydraulic system, and diagnosing leading factors causing equipment imbalance; a cooperative adjustment scheme is generated and executed, specifically, according to the result of the diagnostic analysis step, a cooperative adjustment scheme containing a balance weight adjustment scheme and a hydraulic system back pressure adjustment scheme at the same time is generated, and the scheme is executed; according to the method, the root of equipment unbalance is systematically diagnosed, and safe, efficient and long-service-life operation of equipment is ensured through cooperative adjustment of the balance weight and the hydraulic system.

Description

Technical Field

[0001] This invention relates to the field of large port and industrial bulk material conveying equipment technology, specifically to a comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer. Background Technology

[0002] Bucket wheel stacker-reclaimers are key equipment in raw material yards of industries such as metallurgy, ports, and power. Due to their continuous operation under heavy loads, impacts, and harsh environments, the weight distribution of their upper metal structure (such as the boom and gantry) can change due to structural deformation, wear, maintenance, and modifications, leading to a shift in the overall center of gravity and imbalance in the pitch system. The working principle of a large bucket wheel stacker-reclaimer is to use the rotation of the front bucket wheel to collect the mixed material from the stockpile in the yard. This material is then conveyed via a conveyor belt on the trolley boom to a belt below the central hopper of the trolley. The large bucket wheel stacker-reclaimer then travels on tracks, achieving real-time material collection and mixing in large stockyards. The total length of the boom frame beam is over 60 meters (e.g., Figure 6 As shown in the diagram, the total counterweight of the rear concrete section is approximately 300 tons, and the total weight of the front bucket wheel is approximately 18 tons (with material). According to the lever principle, when the torque balance is disrupted, such as when the rear counterweight is too large, major equipment failures such as the stacker-reclaimer wheels derailing and the frame tilting backward may occur. If the rear counterweight is too small, major equipment failures such as the bucket wheel hitting the ground and malfunctioning, and the frame tilting forward causing deformation, may occur. Therefore, selecting an appropriate counterweight based on actual on-site material handling is crucial. The overall load-bearing capacity of the stacker-reclaimer must also be considered. If the counterweight is too large, there is a risk that the stacker-reclaimer will tear the frame welds and break the boom during operation.

[0003] In existing technologies, the maintenance of stacker-reclaimers often focuses on addressing single problems, such as checking hydraulic pressure alone or simply adding counterweights. However, this piecemeal approach has significant drawbacks: First, it lacks a systematic diagnosis of the equipment's imbalance state, making it impossible to accurately quantify the center of gravity shift, leading to blind adjustment schemes; second, it fails to recognize the strong coupling relationship between the counterweight and the hydraulic system pressure. Simply adding counterweight may exceed the allowable stress of the metal structure, while adjusting only the hydraulic system cannot solve the fundamental torque imbalance problem. In practice, problems such as difficulty in pitching the equipment (especially inability to raise the boom at low positions), long-term overpressure operation of the hydraulic system, and fatigue cracks caused by excessive local stress in the structure often occur, seriously threatening the safety and lifespan of the equipment. Therefore, there is an urgent need in this field for a comprehensive method that can systematically diagnose the balance state of the stacker-reclaimer and perform precise, coordinated, and radical adjustments to solve problems such as deterioration of the metal structure stress, hydraulic system overload, and pitch instability caused by center of gravity shift in long-term operation of the stacker-reclaimer. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer. Strain gauges are placed under the traveling wheels of the bucket wheel stacker-reclaimer. Under safety protection measures, the counterweight at the tail is adjusted. The voltage values ​​of the strain gauges are read using the "lever principle" during the trolley balancing process. Computer software is used to establish a curve relating wheel pressure and strain, thereby scientifically and reliably calculating the balance relationship between the counterweight and the bucket wheel. This achieves systematic management from diagnosis to adjustment, significantly improving the operational safety and lifespan of the equipment.

[0005] The technical solution adopted by this invention to solve its technical problem is: a comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer, comprising the following steps:

[0006] S1. Comprehensive testing: Perform wheel pressure test, ground force test and counterweight verification spot check on the bucket wheel stacker-reclaimer to obtain measured data for evaluating the balance status of the equipment;

[0007] S2. Diagnostic Analysis: Based on the measured data obtained from the comprehensive testing steps, calculate the overall center of gravity offset of the bucket wheel stacker-reclaimer, evaluate the balance of the pitch system and the actual working pressure of the hydraulic system, and diagnose the main factors causing equipment imbalance.

[0008] S3. Generation and execution of collaborative adjustment scheme: Based on the results of the diagnostic analysis steps, generate a collaborative adjustment scheme that includes both the counterweight adjustment scheme and the hydraulic system back pressure adjustment scheme, and execute the scheme.

[0009] Specifically, the wheel pressure test step in step S1 includes: attaching strain gauges to the track web to form a measuring point; when the stacker-reclaimer wheel rolls over the measuring point, collecting strain data through a dynamic strain testing system; and calculating the actual wheel pressure value of each wheel based on the pre-calibrated wheel pressure-strain relationship curve.

[0010] Specifically, the calculation of the overall center of gravity offset of the bucket wheel stacker-reclaimer in step S2 is as follows: based on the actual wheel pressure value of each wheel, the total weight of the machine and the offset of the center of gravity in the horizontal and vertical directions relative to the design position are calculated using the torque balance principle.

[0011] Specifically, the grounding force test step in step S1 includes: lowering the bucket wheel to its lowest position, lifting the bucket wheel upwards using a crane and a tension sensor, recording the tension value of the sensor when the bucket wheel is about to leave the ground and the pressure value of the pitching cylinder at this time, thereby determining the grounding force.

[0012] Specifically, the counterweight verification and spot check step in step S1 is as follows: use a weighing device to directly measure the actual weight of a single counterweight block and compare it with the weight on the label to calculate the difference between the total on-site counterweight and the theoretically required counterweight.

[0013] Specifically, the diagnostic analysis step in step S2 further includes: comparing the actual working pressure of the rod-side and rodless-side chambers of the hydraulic cylinder detected by the hydraulic system with the theoretically calculated pressure based on the equipment load to determine whether the hydraulic system is in an overload state.

[0014] Specifically, the counterweight adjustment scheme in step S3 is as follows: based on the counterweight difference calculated in the diagnostic analysis step, counterweight blocks of corresponding weight are symmetrically added to the counterweight frame.

[0015] Specifically, the total amount of counterweight added by the counterweight adjustment scheme in the aforementioned coordinated adjustment scheme is determined based on the counterweight difference and in combination with the allowable range of steel structure strength.

[0016] Specifically, the hydraulic system back pressure adjustment scheme in step S3 is as follows: a pressure reducing valve is installed in the rod chamber oil circuit of the pitch cylinder to adjust the system back pressure to below a preset safety threshold.

[0017] Specifically, the pressure reducing valve reduces the back pressure in the rod chamber of the pitch cylinder from a maximum of 12MPa to 4MPa or below, thereby reducing the maximum working pressure in the rodless chamber of the cylinder from above 26MPa to below the rated pressure of 18MPa.

[0018] The present invention has the following beneficial effects:

[0019] The comprehensive testing and coordinated adjustment method for the balance state of the bucket wheel stacker-reclaimer designed in this invention is systematic: it integrates the testing and correlation analysis of multiple parameters such as wheel pressure, ground force, counterweight, and hydraulic pressure, forming a complete technical system from data acquisition and state diagnosis to scheme formulation, overcoming the limitations of single-dimensional adjustment.

[0020] The comprehensive testing and coordinated adjustment method for the balance state of the bucket wheel stacker-reclaimer designed in this invention is accurate: the offset of the machine's center of gravity is accurately calculated through wheel pressure testing, and the actual weight difference is identified through counterweight verification, so that the counterweight adjustment is based on evidence and avoids blindness.

[0021] The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer designed in this invention features synergy: it innovatively proposes a coordinated scheme combining "mechanical counterweight adjustment" and "hydraulic back pressure adjustment." Counterweight adjustment corrects torque imbalance at its source, while hydraulic adjustment serves as a key control method, quickly reducing system pressure to a safe range. The two complement each other, resulting in significant effects.

[0022] The comprehensive testing and coordinated adjustment method for the balance state of the bucket wheel stacker-reclaimer designed in this invention has safety and effectiveness: the method can effectively solve prominent problems such as hydraulic system overpressure and pitching motion jamming, restore the equipment to the designed balance state, significantly reduce the risk of fatigue damage to structural components, extend the overall service life of the equipment, and ensure production safety. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the wheel pressure testing system used in an embodiment of the present invention.

[0024] Figure 2 This is a flowchart illustrating the overall process of the method of this invention.

[0025] Figure 3 It is a graph showing the relationship between wheel pressure and strain, with gain 1 / 2 / .

[0026] Figure 4 It is a graph showing the relationship between wheel pressure and strain, with a gain of 1 / 5.

[0027] Figure 5 This is a schematic diagram illustrating the principle of hydraulic system modification (addition of a pressure reducing valve) in an embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram of a stacker-reclaimer assembly.

[0029] In the diagram: 1-Strain gauge; 2-Track; 3-Stacker / reclaimer wheel; P1-Pressure reducing valve. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] like Figures 1-2 As shown, a comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer includes the following steps:

[0032] Comprehensive testing steps: Perform wheel pressure test, ground force test and counterweight verification spot check on the bucket wheel stacker-reclaimer to obtain measured data for evaluating the balance status of the equipment.

[0033] Diagnostic Analysis Steps: Based on the measured data obtained from the comprehensive testing steps, calculate the overall center of gravity offset of the bucket wheel stacker-reclaimer, evaluate the balance of the pitch system and the actual working pressure of the hydraulic system, and diagnose the dominant factors causing equipment imbalance. Coordinated Adjustment Scheme Generation and Execution Steps: Based on the results of the diagnostic analysis steps, generate a coordinated adjustment scheme that includes both a counterweight adjustment scheme and a hydraulic system back pressure adjustment scheme, and execute the scheme. The counterweight adjustment scheme involves symmetrically adding counterweight blocks of corresponding weight to the counterweight frame based on the counterweight difference calculated in the diagnostic analysis steps. The hydraulic system back pressure adjustment scheme involves installing a pressure reducing valve on the rod-side oil circuit of the pitch cylinder to adjust the system back pressure to below a preset safety threshold.

[0034] The wheel pressure test is carried out by attaching and calibrating strain gauge 1 to the track; the diagnostic analysis uses the torque balance principle to calculate the center of gravity offset, with one strain gauge 1 on each side of the track 2 at the same point.

[0035] Example 1:

[0036] I. Comprehensive Testing Steps

[0037] 1. Wheel pressure test: such as Figure 1 As shown, multiple sections are selected as measuring points along the web of the stacker-reclaimer's running track 2. A strain gauge 1 is attached to each side of the web at each measuring point and connected in series. A testing system is constructed using a dynamic resistance strain gauge and a data acquisition system. With the equipment unloaded and the boom horizontal, it slowly passes over the measuring point area, and the strain data at each measuring point is recorded. The data is then analyzed based on the "wheel pressure-strain" relationship curve calibrated beforehand using a press (e.g., ...). Figures 3-4 As shown in the figure, the strain value is converted into the pressure value of each stacker-reclaimer wheel 3.

[0038] 2. Ground contact force test: such as Figure 2 As shown, lower the bucket wheel boom to its lowest position. Connect the front end of the bucket wheel boom using a crane, wire rope, and tension sensor. Maintain the pressure of the pitch cylinder and slowly operate the crane to tighten the wire rope. When the tension sensor reading suddenly changes (indicating that the bucket wheel is about to leave the ground), record the tension value F at this moment. This value is the measured grounding force. Simultaneously record the pressure in the rod-side and rodless sides of the pitch cylinder at this moment.

[0039] 3. Counterweight verification and spot check: After the cantilever is reliably supported, use a calibrated crane scale or a crane weighing system to randomly check the actual weight of some counterweight blocks, calculate the average deviation between the actual weight and the weight on the label, and then estimate the difference ΔG between the total on-site counterweight and the theoretically required counterweight.

[0040] 4. Hydraulic system testing: Under both stacking and reclaiming conditions, the boom moves within the full pitch range, and pressure sensors are used to record the dynamic and static pressures of the rod-side and rodless sides of the pitch cylinder.

[0041] II. Diagnostic Analysis Steps

[0042] 1. Center of Gravity Calculation: Based on the wheel pressures obtained from the wheel pressure tests, the total weight W of the machine is summed. Using the track as a reference, the principle of torque balance is applied: Σ(each wheel pressure × distance from that wheel to the reference point) = W × distance from the center of gravity to the reference point. Through calculation, the actual coordinates of the center of gravity in the horizontal direction (along the track) and the vertical direction can be obtained, and compared with the design coordinates to obtain the offset (ΔX, ΔY).

[0043] 2. Balance Assessment: Analyze the ground force test results. The ideal balance is when the ground force F≈0. If F is too large or negative (requiring pressure to press down), it indicates that the balance is severely disrupted. Combined with the cylinder pressure data, determine whether the current operating point of the pitch system is normal.

[0044] 3. Overload Detection: Compare the maximum working pressure detected by the hydraulic system (especially the rodless chamber pressure) with the rated pressure of the cylinder and system. If the measured pressure continuously exceeds the rated value, the system is determined to be in an overload danger state.

[0045] 4. Diagnosis of the dominant factor: Based on the above analysis, if the center of gravity is significantly shifted forward, the ground force is too large and the counterweight is insufficient, and the hydraulic system is over-pressurized, then "insufficient counterweight" is diagnosed as the dominant factor causing imbalance and over-pressurization.

[0046] III. Collaborative Adjustment Plan Generation and Execution Steps Based on the diagnostic results, the following collaborative adjustment plan is generated and executed:

[0047] 1. Counterweight adjustment plan:

[0048] 2. Solution formulation: Based on the diagnosed counterweight difference ΔG, and considering the maximum allowable additional counterweight calculated by the steel structure strength calculation (for example, in this embodiment, based on strength verification, the maximum allowable additional counterweight is 3.5 tons), determine the final counterweight increase G_add (for example, 3.2 tons).

[0049] 3. Implementation: Install the newly added counterweights (G_add) symmetrically and evenly at the designated positions on the counterweight frame.

[0050] 4. Hydraulic system back pressure adjustment scheme:

[0051] 1. Solution formulation: Design to connect a pilot-operated pressure reducing valve in series in the rod chamber oil circuit of the pitch cylinder.

[0052] 2. Implementation of the plan: such as Figure 5As shown, the existing hydraulic system is modified by installing this pressure-reducing valve. Adjusting the valve's set pressure stably reduces the back pressure in the rod chamber from a maximum of 12 MPa (static or even higher) to a target value of 4 MPa or lower. This measure effectively reduces the maximum working pressure in the rodless chamber from a dangerously high 26 MPa to a safe level below 18 MPa.

[0053] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0054] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A comprehensive test and coordinated adjustment method for the balanced state of a bucket wheel stacker-reclaimer, characterized in that, Includes the following steps: S1. Comprehensive testing: Perform wheel pressure test, ground force test and counterweight verification spot check on the bucket wheel stacker-reclaimer to obtain measured data for evaluating the balance status of the equipment; S2. Diagnostic Analysis: Based on the measured data obtained from the comprehensive testing steps, calculate the overall center of gravity offset of the bucket wheel stacker-reclaimer, evaluate the balance of the pitch system and the actual working pressure of the hydraulic system, and diagnose the main factors causing equipment imbalance. S3. Generation and execution of collaborative adjustment scheme: Based on the results of the diagnostic analysis steps, generate a collaborative adjustment scheme that includes both the counterweight adjustment scheme and the hydraulic system back pressure adjustment scheme, and execute the scheme.

2. The method according to claim 1, characterized in that, The wheel pressure test step in step S1 specifically includes: attaching strain gauges to the track web to form a measuring point; when the stacker-reclaimer wheel rolls over the measuring point, collecting strain data through a dynamic strain testing system; and calculating the actual wheel pressure value of each wheel based on the pre-calibrated wheel pressure-strain relationship curve.

3. The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer according to claim 2, characterized in that, The calculation of the overall center of gravity offset of the bucket wheel stacker-reclaimer in step S2 is as follows: based on the actual wheel pressure value of each wheel, the total weight of the machine and the offset of the center of gravity in the horizontal and vertical directions relative to the design position are calculated using the torque balance principle.

4. The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer according to claim 1, characterized in that, The grounding force test step in step S1 specifically includes: lowering the bucket wheel to its lowest position, lifting the bucket wheel upwards using a crane and a tension sensor, recording the tension value of the sensor and the pressure value of the pitching cylinder when the bucket wheel is about to leave the ground, thereby determining the grounding force.

5. The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer according to claim 1, characterized in that, The counterweight verification and spot check step in step S1 is as follows: use a weighing device to directly measure the actual weight of a single counterweight block and compare it with the weight on the label to calculate the difference between the total on-site counterweight and the theoretical required counterweight.

6. The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer according to claim 1, characterized in that, The diagnostic analysis step in step S2 further includes: comparing the actual working pressure of the rod-side and rodless-side chambers of the hydraulic cylinder detected by the hydraulic system with the theoretically calculated pressure based on the equipment load to determine whether the hydraulic system is in an overload state.

7. The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer according to claim 1, characterized in that, The counterweight adjustment scheme in step S3 is as follows: based on the counterweight difference calculated in the diagnostic analysis step, counterweight blocks of corresponding weight are symmetrically added to the counterweight frame.

8. The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer according to claim 7, characterized in that, The total amount of counterweight added by the counterweight adjustment scheme in the aforementioned coordinated adjustment scheme is determined based on the counterweight difference and in combination with the allowable range of steel structure strength.

9. The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer according to claim 1, characterized in that, The hydraulic system back pressure adjustment scheme in step S3 is as follows: a pressure reducing valve is installed in the rod chamber oil circuit of the pitch cylinder to adjust the system back pressure to below the preset safety threshold.

10. The comprehensive testing and coordinated adjustment method for the balance state of a bucket wheel stacker-reclaimer according to claim 9, characterized in that, The pressure reducing valve reduces the back pressure in the rod chamber of the pitch cylinder from a maximum of 12MPa to 4MPa or below, thereby reducing the maximum working pressure in the rodless chamber of the cylinder from above 26MPa to below the rated pressure of 18MPa.

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