Control method and control system for a slewing mechanism and a grabber

Abstract

The embodiment of the application provides a control method and system of a slewing mechanism and a grab bucket, a first overflow valve and a second overflow valve are arranged in parallel between a main oil supply valve and the slewing mechanism, the second overflow valve is an electric proportional overflow valve, the control method comprises the following steps: obtaining a pressure signal P2 of a slewing handle; obtaining an amplitude signal d of an arm support; according to the pressure signal P2 of the slewing handle, when the pressure signal P2 is greater than a preset threshold, the second overflow valve is not powered, and the first overflow valve works; when the pressure signal P2 is less than the preset threshold, the second overflow valve is powered on, the opening pressure P of the second overflow valve is in a positive correlation with the amplitude signal d of the arm support, and the opening pressure of the second overflow valve is less than the opening pressure of the first overflow valve, the working state of the overflow valve is dynamically controlled, the braking process is optimized according to the pressure signal of the slewing handle and the amplitude signal of the arm support, and the braking precision and operation efficiency of the slewing mechanism are improved, and the operation safety is enhanced.

Description

Technical Field

[0001] This application relates to the technical field of engineering machinery, and in particular to a control method, control system and material handling machine for a rotary mechanism. Background Technology

[0002] Material handling equipment (such as grab cranes and mining material handling equipment) is widely used in mining, ports, building materials, metallurgy, and other scenarios that require frequent handling of bulk materials. One of its functions is to achieve horizontal rotation of the grab through a slewing mechanism to accurately position, grab, or dump materials.

[0003] In complex operating conditions (such as ore stockpiles, muddy ground, or high-dust environments), the grabber needs to frequently perform rapid start-up and braking operations: during the start-up phase, the grabber must respond to operating commands immediately to ensure operational efficiency; during the braking phase, the rotation speed must be adjusted in real time according to dynamic load changes to ensure accurate and stable positioning after braking. However, the current braking control mechanism of the rotation mechanism lacks adaptability to changes in operating conditions and cannot dynamically adjust the working state of the overflow valve based on the pressure signal of the rotation handle and the boom amplitude parameters, resulting in a significant increase in positional deviation during the braking process. This deviation not only reduces material positioning accuracy and affects continuous operation efficiency but may also cause equipment vibration or structural damage due to unstable braking, posing a potential threat to operational safety. Existing technical solutions are insufficient to meet the real-time control requirements of rotation start-up and braking characteristics in complex environments, thus restricting the overall performance improvement of the grabber. Summary of the Invention

[0004] In view of the above problems, the present application provides a control method, control system and material handling machine for a rotary mechanism, which has the advantages of improving the braking accuracy and operating efficiency of the rotary mechanism and enhancing operational safety.

[0005] In a first aspect, embodiments of this application provide a control method for a slewing mechanism, wherein a first relief valve and a second relief valve are connected in parallel between the main oil supply valve and the slewing mechanism, the second relief valve being an electro-proportional relief valve, and the control method includes the following steps:

[0006] Obtain the pressure signal P2 from the rotary handle;

[0007] Obtain the amplitude signal d of the boom;

[0008] According to the pressure signal P2 of the rotary handle, when the pressure signal P2 is greater than a preset threshold, the second relief valve is de-energized and the first relief valve is activated.

[0009] When the pressure signal P2 is less than a preset threshold, the second relief valve is energized and opens. The opening pressure P of the second relief valve is positively correlated with the amplitude signal d of the boom, and the opening pressure of the second relief valve is less than the opening pressure of the first relief valve.

[0010] In one possible implementation, the following steps are also included:

[0011] Acquire the boom rodless chamber pressure signal P1;

[0012] When the second relief valve is energized and opened, the opening pressure P of the second relief valve is positively correlated with the pressure signal P1 of the boom rodless chamber.

[0013] In one possible implementation, the formula for calculating the opening pressure P of the second relief valve is as follows: P = ( )^0.5,

[0014] Where d is the boom radius, in mm.

[0015] P is the opening pressure of the second relief valve, in MPa.

[0016] P1 is the pressure in the rodless chamber of the boom, in MPa.

[0017] In one possible implementation, the preset threshold is 0.5 MPa.

[0018] Secondly, embodiments of this application also propose a control system for a rotary mechanism, comprising:

[0019] A slewing mechanism, wherein the slewing mechanism is used to perform a slewing action;

[0020] A rotary handle, which is used to output a pressure signal P2 to control the rotation action of the rotary mechanism;

[0021] A boom angle sensor is used to detect the boom amplitude and output the boom amplitude signal d.

[0022] A main oil supply valve is provided, and a rotary oil circuit is provided between the main oil supply valve and the rotary mechanism. The main oil supply valve is used to control the hydraulic oil to enter the rotary oil circuit so as to control the rotary mechanism to perform a rotary action.

[0023] The second relief valve is an electro-proportional relief valve, which is installed in the rotary oil circuit and connected in parallel with the rotary mechanism.

[0024] A first relief valve is disposed in the rotary oil circuit and is connected in parallel with the rotary mechanism;

[0025] The controller is electrically connected to the rotary handle, the second overflow valve and the boom angle sensor. The controller receives the pressure signal P2 and the boom amplitude signal d. The controller is equipped with a preset threshold for comparison with the pressure signal P2.

[0026] When the pressure signal P2 is greater than a preset threshold, the controller de-energizes the second relief valve and the first relief valve operates; when the pressure signal P2 is less than the preset threshold, the second relief valve is energized and opens. The controller controls the opening pressure P of the second relief valve according to the boom amplitude signal d, so that the opening pressure P of the second relief valve is positively correlated with the boom amplitude signal d, and the opening pressure P of the second relief valve is less than the opening pressure of the first relief valve.

[0027] In one possible implementation, a boom rodless chamber pressure detection sensor is further included. The boom rodless chamber pressure detection sensor is electrically connected to the controller. The boom rodless chamber pressure detection sensor is used to detect the boom rodless chamber pressure and output a boom rodless chamber pressure signal P1 to the controller.

[0028] In one possible implementation, the rotary oil circuit between the main oil supply valve and the rotary mechanism includes a left rotary oil circuit and a right rotary oil circuit, and the pressure signal P2 output by the rotary handle includes a left pressure signal and a right pressure signal.

[0029] When the rotary handle outputs a left pressure signal, the main oil supply valve supplies oil to the left rotary oil circuit;

[0030] When the rotary handle outputs a right pressure signal, the main oil supply valve supplies oil to the right rotary oil circuit.

[0031] In one possible implementation, the left-turn oil circuit and the right-turn oil circuit are respectively connected to the second relief valve through connecting pipelines. Each connecting pipeline between the left-turn oil circuit, the right-turn oil circuit and the second relief valve is provided with an oil supply check valve, which prevents the hydraulic oil in the connecting pipeline from flowing towards the left-turn oil circuit and the right-turn oil circuit.

[0032] In one possible implementation, a first overflow valve is provided on both the left-hand rotary oil circuit and the right-hand rotary oil circuit.

[0033] Thirdly, embodiments of this application also propose a material handling machine, including a control system for the aforementioned rotary mechanism.

[0034] This application provides a control method, control system, and material handling machine for a rotary mechanism. By adding a second overflow valve, the braking pressure can be adjusted. The second overflow valve is an electro-proportional overflow valve. The larger the opening pressure P of the second overflow valve, the greater the braking pressure; the smaller the opening pressure P of the second overflow valve, the smaller the braking pressure. This achieves the purpose of slow braking, that is, reducing the braking speed and making the landing point of the rotary mechanism of the material handling machine more accurate after braking. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0036] Figure 1 A schematic diagram of the slewing start-stop system provided in this application;

[0037] Figure 2 A flowchart of the slewing start-stop system provided in this application.

[0038] Reference numerals: 10, slewing handle; 20, left pressure sensor; 30, right pressure sensor; 40, boom angle sensor; 50, controller; 60, main oil supply valve; 70, left slewing oil circuit; 80, right slewing oil circuit; 90, electro-proportional relief valve; 100, starting relief valve; 110, slewing mechanism; 120, oil supply check valve; 130, boom rodless chamber pressure detection sensor; 140, anti-reverse valve; 150, electric pump; 160, replenishment check valve.

[0039] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0040] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0041] Traditional material handling machines suffer from poor positioning accuracy after slewing braking, impacting operational efficiency and precise positioning. Furthermore, under complex operating conditions, it is difficult to dynamically adjust the slewing speed according to load changes, affecting operational efficiency, safety, and equipment lifespan.

[0042] In view of this, this application provides a control method, control system, and material handling machine for a slewing mechanism. A first relief valve and a second relief valve are connected in parallel between the main oil supply valve and the slewing mechanism. The second relief valve is an electro-proportional relief valve 90. The control method includes the following steps: acquiring the pressure signal P2 of the slewing handle; acquiring the amplitude signal d of the boom; according to the pressure signal P2 of the slewing handle, when the pressure signal P2 is greater than a preset threshold, the second relief valve is de-energized, and the first relief valve operates; when the pressure signal P2 is less than the preset threshold, the second relief valve is energized and opens. The opening pressure P of the second relief valve is positively correlated with the amplitude signal d of the boom, and the opening pressure of the second relief valve is less than the opening pressure of the first relief valve. By dynamically controlling the working state of the relief valve, the braking process is optimized according to the pressure signal of the slewing handle and the amplitude signal of the boom, which has the advantages of improving the braking accuracy and operating efficiency of the slewing mechanism and enhancing operational safety.

[0043] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0044] Combination Figures 1 to 2 This application describes a control method for a rotary mechanism according to an embodiment. The method involves a first relief valve and a second relief valve connected in parallel between the main oil supply valve 60 and the rotary mechanism 110. The first relief valve is a start-up relief valve 100, and the second relief valve is an electro-proportional relief valve 90. It should be noted that the rotary mechanism 110 in this application is controlled by a pilot hydraulic system, which includes a rotary oil circuit for driving the rotary mechanism 110 to move, and a pilot control oil circuit for precisely controlling the main oil supply valve 60. The rotary handle 10, as a key component of the pilot control oil circuit, is used to control the opening or closing of the pilot valve, thereby achieving precise control of the oil supply direction and flow rate of the main oil supply valve 60.

[0045] The control method includes the following steps:

[0046] First, acquire the pressure signal P2 from the rotary handle 10. Pressure signal P2 is actually the pressure of the hydraulic oil in the pilot control circuit after the pilot valve is opened by the rotary handle 10. This pressure signal P2 reflects the operator's control intention on the rotary mechanism 110 and can be measured by installing a pressure sensor in the pilot control circuit (e.g., ...). Figure 1 (as shown), or the position signal can be obtained through the potentiometer or encoder of the electric control handle and converted into an analog pressure signal.

[0047] Simultaneously, the amplitude signal d of the boom is acquired. This amplitude signal d represents the extension length or angle of the grabber boom, which can be detected by installing an angle sensor at the boom joint or a displacement sensor on the telescopic cylinder.

[0048] Further, the judgment is made based on the pressure signal P2 obtained from the rotary handle 10. When the pressure signal P2 is greater than a preset threshold, it indicates that the operator is performing rapid rotation or high-intensity operation. At this time, the pilot control oil circuit controls the main oil supply valve 60 to open, and the electric pump 150 supplies oil to the rotation oil circuit through the main oil supply valve 60 to drive the rotary mechanism 110 to move. At the same time, the controller 50 controls the second relief valve to be de-energized, keeping it closed, while the first relief valve is activated. The first relief valve, as the starting relief valve 100, is generally a constant pressure relief valve, and its opening pressure is usually set to a preset fixed high value to provide sufficient system pressure and prevent overload during rapid rotation. For example, when the operator pushes the handle quickly, the system pressure rises, reaching the opening pressure of the first relief valve, and excess oil overflows through the first relief valve to maintain system stability.

[0049] When the pressure signal P2 is less than the preset threshold, it indicates that the operator may be performing fine-tuning or slewing braking. When slewing braking is applied, the main oil supply valve 60 cuts off the oil supply to the slewing circuit. The slewing mechanism 110 continues to rotate under the inertia of the upper structure. At this time, the replenishing oil tank replenishes oil to the low-pressure end of the slewing mechanism 110 through the replenishing check valve 160. The anti-reverse valve 140 maintains the oil pressure balance in the slewing circuit. The controller 50 energizes and opens the second relief valve. The opening pressure P of this second relief valve is controlled to be positively correlated with the boom amplitude signal d. This means that the greater the boom extension, the greater the opening pressure P of the second relief valve. For example, the controller 50 can calculate the corresponding opening pressure P based on a table or a preset function using the boom extension signal d, and output the corresponding electrical signal to the second relief valve. Furthermore, the opening pressure P of the second relief valve is always less than the opening pressure of the first relief valve. This design allows the system pressure to be controlled by the adjustable second relief valve during precise control or braking, thereby achieving gentle braking and a smooth, precise braking effect without the problem of excessively rapid slewing braking.

[0050] In summary, this method achieves adjustable braking pressure by adding a second relief valve. This second relief valve is an electro-proportional relief valve 90. The higher the opening pressure P of the second relief valve, the higher the braking pressure; conversely, the lower the opening pressure P, the lower the braking pressure. This achieves the purpose of gentle braking, i.e., reducing the braking speed, making the landing point of the gripper's slewing mechanism after braking more precise. This effectively solves the problem of poor positioning accuracy after braking caused by excessively rapid slewing braking in traditional grippers. This method can achieve gentle braking of the slewing mechanism 110 according to actual working conditions and operational intentions. Through refined start-stop and braking control, it improves the working efficiency and precise positioning capability of the gripper in complex working environments and helps extend the service life of the equipment.

[0051] This application also discloses that, based on the above control method, it further includes the following steps: acquiring the boom rodless chamber pressure signal P1; when the second relief valve is energized and opened, the opening pressure P of the second relief valve and the boom rodless chamber pressure signal P1 are positively correlated.

[0052] Specifically, acquiring the boom rodless chamber pressure signal P1 involves installing a pressure sensor at the boom cylinder rodless chamber to detect the hydraulic oil pressure within the chamber in real time, and then transmitting this pressure signal P1 to the controller 50. The boom rodless chamber pressure signal P1 directly reflects the actual load borne by the boom and is a key parameter for measuring the actual working load of the boom, providing crucial load information for the control system.

[0053] Furthermore, when the second relief valve is energized and opens, its opening pressure P is positively correlated with the boom rodless chamber pressure signal P1. This means that the controller 50 dynamically adjusts the opening pressure P of the second relief valve based on the real-time detected boom rodless chamber pressure signal P1. This positive correlation can be achieved through a preset mathematical model, lookup table, or empirical curve within the controller 50. For example, when the boom rodless chamber pressure signal P1 is detected to increase, the controller 50 will correspondingly increase the opening pressure P of the second relief valve, thereby increasing the braking pressure; conversely, when P1 decreases, the opening pressure P will also decrease, thereby reducing the braking pressure. This adaptive control strategy ensures that the opening pressure of the second relief valve matches the actual load condition of the boom.

[0054] Through the above technical solution, the boom rodless chamber pressure signal P1 is introduced into the control of the opening pressure P of the second relief valve, making it positively correlated with P1. This allows the control system of the slewing mechanism 110 to perceive the actual load changes of the boom in real time. When the boom is under heavy load, the boom rodless chamber pressure signal P1 will increase accordingly. Based on this, the controller 50 increases the opening pressure P of the second relief valve, thereby effectively preventing premature hydraulic oil overflow and ensuring that the slewing mechanism 110 can still obtain sufficient braking pressure under heavy load or large boom width conditions, maintaining the stability and control accuracy of the slewing action. At the same time, under light load conditions, the opening pressure P decreases as P1 decreases, avoiding rapid braking caused by excessive braking pressure under light load, and reducing unnecessary energy loss. This adaptive control strategy based on actual load significantly improves the operating performance, control accuracy, and energy efficiency of the slewing mechanism 110 under different working conditions.

[0055] This application also discloses the following formula for calculating the opening pressure P of the second relief valve: P = ( )^0.5, where d is the boom amplitude in mm, P is the opening pressure of the second relief valve in MPa, and P1 is the boom rodless chamber pressure in MPa.

[0056] Specifically, the formula for calculating the opening pressure P of the second relief valve is P = ( The formula ^0.5 provides a precise mathematical model for dynamically calculating the opening pressure of the second relief valve. This formula considers two key parameters: the boom amplitude d and the boom rodless chamber pressure P1, determining the relief valve's opening pressure through a non-linear relationship (square root function). The constant 215 is a coefficient determined through system calibration or experience, used to adjust the dimensions and response characteristics of the calculation results, ensuring that the calculated opening pressure P matches the actual operating characteristics of the hydraulic system. The introduction of this formula allows the controller 50 to accurately output control signals based on real-time changing operating conditions to adjust the opening pressure of the electro-proportional second relief valve.

[0057] Where d represents the boom radius, in mm. The boom radius d refers to the extent of boom extension, usually expressed as the horizontal distance from the center of rotation to the boom tip. This parameter directly reflects the working radius and the inertial moment of the load. The boom radius d is typically obtained by detecting the boom angle using a boom angle sensor 40, and then the controller 50 calculates the corresponding radius value based on the robot's geometry and angular relationship. This radius value is in millimeters (mm) to ensure the accuracy of the calculation.

[0058] P is the opening pressure of the second relief valve, measured in MPa. The opening pressure P is the pressure value at which the second relief valve begins to open and allows hydraulic oil to flow. This pressure value directly determines the resistance encountered by the slewing mechanism 110 during braking or deceleration. By precisely controlling the opening pressure P, the braking effect of the slewing mechanism 110 can be finely adjusted. This pressure value is measured in megapascals (MPa), a commonly used pressure measurement unit in hydraulic systems.

[0059] P1 is the boom rodless chamber pressure, measured in MPa. The boom rodless chamber pressure P1 refers to the hydraulic pressure within the rodless chamber of the boom cylinder. This pressure value effectively reflects the load borne by the boom, i.e., the weight of the material being gripped during operation or the effect of the boom's own gravitational torque. The boom rodless chamber pressure P1 is typically detected in real-time by the boom rodless chamber pressure detection sensor 130, and the signal is transmitted to the controller 50. This pressure value is measured in megapascals (MPa) and provides load information to the controller 50.

[0060] Through the above technical solution, the controller 50 can utilize the boom amplitude signal d and the boom rodless chamber pressure signal P1, and calculate P using the preset formula P=( The opening pressure P of the second relief valve is precisely calculated using a mathematical model. This calculation method, based on a specific mathematical model, overcomes the limitations of relying solely on fuzzy positive correlations for control, allowing the opening pressure of the second relief valve to be dynamically and precisely adjusted according to actual operating conditions (boom radius and load). For example, when the boom radius d is large or the boom rodless chamber pressure P1 is high, the calculated opening pressure P will increase accordingly, thus slowing down the braking process, effectively suppressing the inertial sway of the slewing mechanism 110, and preventing overshoot or instability. Conversely, when the boom radius d is small or the load is light, the opening pressure P will decrease, and the braking process will be faster than under heavy load, thus improving efficiency. This precise pressure control significantly improves the braking smoothness, response speed, and operational safety of the slewing mechanism 110 under different load and radius conditions, effectively reducing equipment wear and improving operating efficiency and comfort.

[0061] In this regard, this application further clarifies that the preset threshold is 0.5 MPa. This preset threshold is a key parameter used by the controller 50 to determine the magnitude of the pressure signal P2 of the slewing handle 10, defining a clear switching point. When the pressure signal P2 of the slewing handle 10 is greater than 0.5 MPa, the controller 50 will de-energize the second relief valve, and the first relief valve will assume the relief function. When the pressure signal P2 of the slewing handle 10 is less than 0.5 MPa, the controller 50 will energize and open the second relief valve, and adjust its opening pressure P according to the boom amplitude signal d (and the boom rodless chamber pressure signal P1). This value of 0.5 MPa is usually determined through extensive experimental testing, system calibration, and analysis of actual working conditions, aiming to ensure that the system can smoothly and accurately switch control modes when the operator performs different degrees of slewing operations, thereby optimizing the performance of the slewing mechanism 110. This value is stored in the internal storage unit of the controller 50 and used as a fixed parameter for comparison and judgment in the control logic.

[0062] By explicitly setting the preset threshold to 0.5 MPa, the control method of this application provides a precise and stable switching point, effectively solving the problem of control instability caused by unclear or improperly set thresholds. This specific numerical setting allows the controller 50 to reliably determine the operator's intention. When the pressure signal P2 of the rotary handle 10 exceeds 0.5 MPa, the system quickly switches to the mode dominated by the first relief valve to cope with larger rotation demands and achieve rapid start-up. When the pressure signal P2 is below 0.5 MPa, it indicates that the rotary handle 10 needs to be braked during the return process. At this time, the second relief valve is activated for fine pressure adjustment and gentle braking, thereby achieving smooth and precise control of the rotary mechanism 110. This explicit threshold setting avoids misjudgments caused by threshold fluctuations or uncertainties in different operating conditions, significantly improving the response consistency and operational smoothness of the rotary mechanism 110. Especially in scenarios requiring precise operation, it can provide more reliable and predictable control performance.

[0063] Secondly, embodiments of this application propose a control system for a slewing mechanism 110. The system includes a slewing mechanism 110 for performing a slewing action; a slewing handle 10 for outputting a pressure signal P2 to control the slewing action of the slewing mechanism 110; a boom angle sensor 40 for detecting the boom amplitude and outputting a boom amplitude signal d; a main oil supply valve 60, with a slewing oil circuit between the main oil supply valve 60 and the slewing mechanism 110, the main oil supply valve 60 controlling the entry of hydraulic oil into the slewing oil circuit to control the slewing mechanism 110 to perform the slewing action; and a second relief valve. The second relief valve is an electro-proportional relief valve 90, which is installed in the rotary oil circuit and connected in parallel with the rotary mechanism 110; the first relief valve is installed in the rotary oil circuit and connected in parallel with the rotary mechanism 110; the controller 50 is electrically connected to the rotary handle 10, the second relief valve and the boom angle sensor 40, and receives the pressure signal P2 and the boom amplitude signal d. The controller 50 is equipped with a preset threshold for comparison with the pressure signal P2.

[0064] During operation, when the pressure signal P2 exceeds a preset threshold, it indicates that the operator is performing a rapid slewing operation. The controller 50 de-energizes the second relief valve, while the first relief valve operates, ensuring sufficient pressure for a rapid response. When the pressure signal P2 is below the preset threshold, it indicates that the operator may be performing fine maneuvers or braking. The controller 50 energizes and opens the second relief valve, dynamically adjusting its opening pressure P based on the boom amplitude signal d. This ensures that the opening pressure P is positively correlated with the boom amplitude signal d, and that P is less than the opening pressure of the first relief valve. This design allows the system to automatically adjust the relief pressure according to the boom extension amplitude during braking, achieving a smooth and precise braking effect.

[0065] The core innovation of this embodiment lies in combining the electro-proportional relief valve 90 with the boom amplitude sensor in a dynamic correlation manner, and intelligently switching the relief valve's operating mode based on the pressure signal from the slewing handle 10 via the controller 50. This achieves precise pressure adjustment based on the boom amplitude during the braking phase, solving the problem of poor position accuracy after slewing braking and improving work efficiency, safety, and equipment lifespan. Specifically, when the boom amplitude is large, the load inertia is greater, requiring higher braking pressure to ensure position accuracy. This system automatically adjusts through a positive correlation, avoiding the shortcomings of traditional fixed-pressure relief valves that cannot adapt to different working conditions. Since the boom amplitude signal d directly reflects changes in load inertia, the controller 50 dynamically sets the opening pressure P of the second relief valve accordingly, thereby forming a gentle braking characteristic that matches the load during braking, significantly improving position control accuracy.

[0066] Through the above technical solution, the control system can optimize the slewing start-braking characteristics in real time according to the actual operation intention and working parameters. While ensuring rapid start-up, it significantly improves the positional accuracy after braking and effectively extends the service life of the equipment. Overall, this design achieves refined management of the slewing start-braking process through the intelligent control mechanism of the electro-proportional overflow valve 90, providing reliable technical support for the operation of the material handling machine under complex working conditions.

[0067] This application further proposes that the control system of the aforementioned slewing mechanism 110 also includes a boom rodless chamber pressure detection sensor 130. This boom rodless chamber pressure detection sensor 130 is electrically connected to the controller 50 and is used to detect the hydraulic pressure in the rodless chamber of the boom hydraulic cylinder in real time, converting it into a boom rodless chamber pressure signal P1 and outputting it to the controller 50. The boom rodless chamber pressure detection sensor 130 can be of various types, such as piezoresistive, piezoelectric, or capacitive. It is typically installed in the oil circuit of the rodless chamber of the boom hydraulic cylinder, operating by converting pressure changes into electrical signals, for example, outputting a voltage or current signal proportional to the pressure value. The controller 50 receives the pressure signal P1 via wires or cables and processes it through sampling, filtering, etc., to obtain real-time load information of the boom.

[0068] By introducing a boom rodless chamber pressure detection sensor 130 and transmitting the detected boom rodless chamber pressure signal P1 to the controller 50, the controller 50 can, when adjusting the opening pressure of the second relief valve, not only consider the boom amplitude signal d but also acquire and utilize the actual load information of the boom in real time. When the load on the boom changes, the boom rodless chamber pressure signal P1 will change accordingly, and the controller 50 can dynamically adjust the opening pressure of the second relief valve based on this real-time load information. For example, when the boom load is large, the controller 50 can correspondingly increase the opening pressure of the second relief valve to provide greater braking or buffering capacity, thereby effectively suppressing the impact and vibration of the slewing mechanism 110 under heavy load conditions and improving the smoothness and safety of the slewing action. Conversely, when the boom load is light, the controller 50 can appropriately reduce the opening pressure to ensure the sensitivity and response speed of the slewing action. This control strategy, based on both boom amplitude and actual load information, significantly enhances the adaptability of the slewing mechanism 110 to different working conditions, making the starting and braking processes of the slewing mechanism 110 smoother and more precise. It effectively avoids shocks and vibrations caused by load changes, and improves the overall control performance and operating efficiency of the equipment.

[0069] This application also discloses that, in the control system of the aforementioned rotary mechanism 110, the rotary oil circuit between the main oil supply valve 60 and the rotary mechanism 110 includes a left rotary oil circuit 70 and a right rotary oil circuit 80. The pressure signal P2 output by the rotary handle 10 includes a left pressure signal and a right pressure signal. When the rotary handle 10 outputs a left pressure signal, the main oil supply valve 60 supplies oil to the left rotary oil circuit 70; when the rotary handle 10 outputs a right pressure signal, the main oil supply valve 60 supplies oil to the right rotary oil circuit 80.

[0070] The left pressure signal and the right pressure signal represent the operator's intention and force in performing left and right rotation operations on the rotary mechanism 110, respectively. These signals are generated by sensors inside the rotary handle 10 when the operator pushes the handle to the left or right. For example, the rotary handle 10 can be designed to have two independent output channels, one channel corresponding to the left rotation operation and outputting the left pressure signal 20, and the other channel corresponding to the right rotation operation and outputting the right pressure signal 30.

[0071] Specifically, the controller 50, as the core of the aforementioned slewing start-stop system, receives the left pressure signal 20 and the right pressure signal 30. It controls the main oil supply valve 60 to supply oil to the left slewing oil circuit 70 or the right slewing oil circuit 80, thereby controlling the left and right rotation of the slewing mechanism 110. A left slewing oil circuit 70 and a right slewing oil circuit 80 are provided between the main oil supply valve 60 and the slewing mechanism 110. The hydraulic oil output from the main oil supply valve 60 is guided to two independent paths, respectively used to drive the slewing mechanism 110 to perform left and right slewing. This allows for independent control of the hydraulic oil supply in different slewing directions, ensuring that the hydraulic oil is accurately and stably delivered to the corresponding actuators when performing left or right slewing movements. For example, a directional control valve can be used to switch the flow direction of the hydraulic oil, directing the oil to the left slewing oil circuit 70 or the right slewing oil circuit 80, or the main oil supply valve 60 itself can integrate directional control functionality, providing two independent outlets.

[0072] Through the above technical solution, the left-turning oil circuit 70 and the right-turning oil circuit 80 set between the main oil supply valve 60 and the slewing mechanism 110 realize independent hydraulic control of the left and right slewing movements of the slewing mechanism 110, thereby enabling more precise distribution and adjustment of hydraulic oil in different directions. With independent left and right pressure signals, the operator's commands can be responded to more accurately, improving the smoothness, response speed, and operational precision of the slewing mechanism 110 during startup and braking. Especially in complex working conditions requiring precise control or rapid switching of slewing direction, it can effectively optimize the overall performance of the slewing mechanism 110.

[0073] This application also discloses that the left-turn oil circuit 70 and the right-turn oil circuit 80 are respectively connected to the second relief valve through connecting pipes. Each connecting pipe between the left-turn oil circuit 70, the right-turn oil circuit 80 and the second relief valve is provided with an oil supply check valve 120, which prevents the hydraulic oil in the connecting pipe from flowing to the left-turn oil circuit 70 and the right-turn oil circuit 80.

[0074] The oil supply check valve 120 is a hydraulic component that allows hydraulic oil to flow in one direction and prevents it from flowing back in the opposite direction. The oil supply check valve 120 is located at the connection point between the left and right rotary oil circuits 80 and the second relief valve. Its function is to ensure that hydraulic oil can only flow from the main oil supply valve 60 through the left rotary oil circuit 70 or the right rotary oil circuit 80 to the rotary mechanism 110, and to relieve pressure through the second relief valve when necessary. It prevents the oil from flowing back from the second relief valve to the oil circuit in the non-working direction, or, when working in one direction, allowing the oil to enter the oil circuit in the other direction through the second relief valve. This helps maintain the pressure stability of the oil circuit and the accuracy of directional control, preventing oil cross-flow or backflow from adversely affecting system performance.

[0075] Through the above technical solution, oil supply check valves 120 are installed on the connecting pipelines between the left-hand slewing oil circuit 70 and the right-hand slewing oil circuit 80 and the second relief valve to prevent hydraulic oil in the connecting pipelines from flowing towards the left-hand slewing oil circuit 70 and the right-hand slewing oil circuit 80, ensuring the single direction of oil flow and the accuracy of control. This allows the second relief valve to more stably and accurately control the braking and buffering process of the slewing mechanism 110 when adjusting the opening pressure, significantly improving the smoothness and response speed of the slewing action, avoiding impacts or vibrations caused by oil circuit interference, thereby improving the control accuracy and operational reliability of the entire slewing mechanism 110.

[0076] This application also discloses that the control system of the slewing mechanism 110 further includes pressure sensors, including a left pressure sensor 20 and a right pressure sensor 30, which are electrically connected to the controller 50. The left pressure sensor 20 is used to detect the left pressure signal 20 and transmit it to the controller 50, and the right pressure sensor 30 is used to detect the right pressure signal 30 and transmit it to the controller 50.

[0077] Specifically, the pressure sensors include a left pressure sensor 20 and a right pressure sensor 30. These pressure sensors are used to convert pressure changes in the hydraulic system into electrical signals that can be processed by the controller 50. The left pressure sensor 20 is specifically used to detect the hydraulic pressure associated with left-hand rotation, while the right pressure sensor 30 is used to detect the hydraulic pressure associated with right-hand rotation. They typically employ piezoresistive, piezoelectric, or strain gauge principles and can accurately reflect the intensity of left-hand or right-hand rotation commands applied by the operator through the rotary handle 10 in real time.

[0078] Left pressure sensor 20 and right pressure sensor 30 are electrically connected to controller 50. This electrical connection ensures that the pressure signals detected by the left pressure sensor 20 and right pressure sensor 30 can be reliably and timely transmitted to controller 50. The electrical connection can use analog signal transmission, such as voltage or current signals (e.g., 0-5V or 4-20mA); or it can use digital signal transmission, such as data communication via CAN bus or RS485 interface. After receiving these electrical signals, controller 50 performs necessary signal conditioning and analog-to-digital conversion for subsequent logic judgment and control algorithm execution.

[0079] The left pressure sensor 20 detects the left pressure signal 20 and transmits it to the controller 50. When the operator issues a left turn command through the turn handle 10, the hydraulic pressure in the left turn oil circuit 70 increases accordingly. At this time, the left pressure sensor 20 accurately detects this pressure change and converts it into a corresponding electrical signal, namely the left pressure signal 20, which is then transmitted to the controller 50. The controller 50 uses this left pressure signal 20 to determine the intensity and intent of the left turn operation.

[0080] The right pressure sensor 30 detects the right pressure signal 30 and transmits it to the controller 50. Similarly, when the operator issues a right turn command via the turn handle 10, the hydraulic pressure in the right turn oil circuit 80 increases. The right pressure sensor 30 detects this pressure change and converts it into an electrical signal, namely the right pressure signal 30, which is then transmitted to the controller 50. The controller 50 uses this right pressure signal 30 to determine the intensity and intent of the right turn operation.

[0081] By setting independent left pressure sensor 20 and right pressure sensor 30, controller 50 can accurately acquire the operator's independent command intentions for left and right slewing. This allows the system to perform fine-grained control of the left and right slewing oil circuits 80 separately, avoiding the confusion of left and right slewing commands that may be caused by a single pressure signal. Therefore, the response speed and control accuracy of the slewing mechanism 110 are significantly improved, and the operator can control the slewing action more accurately and smoothly, especially when frequent switching of slewing direction or fine-tuning operations are required. The stability and safety of the system are also enhanced.

[0082] This application also discloses that a first overflow valve is provided on the left-turn oil passage 70 and the right-turn oil passage 80 respectively.

[0083] The first relief valve limits the maximum safe pressure of the rotary oil circuit (its opening pressure is higher than that of the second relief valve). It only works when the pressure signal P2 of the rotary handle 10 is greater than the preset threshold (0.5MPa). This scenario corresponds to "rapid start-up and heavy load rotation" (such as grabbing heavy ore and high-speed positioning of materials). At this time, the oil circuit needs to supply a large flow of oil, and the pressure is prone to rise sharply.

[0084] The first relief valve, through a fixed maximum opening pressure, forcibly releases high-pressure hydraulic oil exceeding the safety threshold in the oil circuit, preventing deformation, leakage, or breakage of components such as the slewing mechanism 110, hydraulic lines, and main oil supply valve 60 due to overpressure. This eliminates the potential for equipment vibration or structural damage caused by unstable braking. The first relief valve has a fast response speed, maintaining a stable pressure output in the high-pressure range of the slewing oil circuit. This ensures that hydraulic oil enters the slewing mechanism 110 with sufficient flow, meeting the power requirements of the grabber during rapid start-up and heavy-load slewing, and avoiding slow start-up and low operating efficiency caused by a delayed response or insufficient flow from the relief valve.

[0085] The design of the first overflow valve and the second overflow valve (electro-proportional overflow valve 90) forms a clear division of operating conditions, realizing "precise adaptation under different operating scenarios. The two work together to cover the entire process of "start-up-run-braking", solving the technical problem that a single overflow mechanism cannot take into account both efficiency and accuracy.

[0086] Thirdly, this application also discloses a material grabber. A material grabber is a type of engineering machinery specifically designed for grabbing, handling, and stacking bulk materials or waste. It typically consists of a chassis, a slewing platform, working devices (including a boom, stick, and grab bucket), a power system, and a control system. The slewing platform carries the working devices and the operator's cab, and achieves horizontal rotation through a slewing mechanism 110, thereby expanding the working range. During operation, the material grabber requires frequent complex actions such as slewing, grabbing, and lifting; therefore, the performance of the slewing mechanism 110 directly affects the overall operating efficiency, stability, and operator fatigue. Integrating an advanced slewing mechanism 110 control system into the material grabber aims to improve its overall operational capabilities.

[0087] By applying the control system of the aforementioned slewing mechanism 110 to the material grabber, the performance of the material grabber in actual operation can be significantly improved. Specifically, the control system can intelligently adjust the opening pressure P of the second relief valve based on the pressure signal P2 of the slewing handle 10, the amplitude signal d of the boom, and the pressure signal P1 of the boom rodless chamber. When precise operation or low-speed slewing is required, the second relief valve is energized and opens, and the pressure is adjusted according to the boom amplitude, allowing the slewing mechanism 110 to start and brake more smoothly and precisely. This effectively avoids the impact and shaking that may occur when the traditional slewing mechanism 110 starts or stops, thereby improving the accuracy and stability of the material grabber. Especially when grabbing heavy objects or performing high-altitude operations, this precise control can effectively suppress the shaking of the entire machine, reduce operational risks, and reduce material spillage. In addition, by optimizing the response characteristics of the slewing mechanism 110, operators can more easily control the slewing action of the material grabber, reducing the difficulty of operation and improving work efficiency and operating comfort.

[0088] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of this application that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A control method for a rotary mechanism, characterized in that, A first relief valve and a second relief valve are connected in parallel between the main oil supply valve and the rotary mechanism. The second relief valve is an electro-proportional relief valve. The control method includes the following steps: Acquire the boom rodless chamber pressure signal P1; Obtain the pressure signal P2 from the rotary handle; Obtain the amplitude signal d of the boom; According to the pressure signal P2 of the rotary handle, when the pressure signal P2 is greater than a preset threshold, the second relief valve is de-energized and the first relief valve is activated. When the pressure signal P2 is less than a preset threshold, the second relief valve is energized and opened. The opening pressure P of the second relief valve is controlled according to the boom amplitude signal d and the boom rodless chamber pressure signal P1, so that the opening pressure P of the second relief valve is positively correlated with the boom amplitude signal d and the boom rodless chamber pressure signal P1, and the opening pressure of the second relief valve is less than the opening pressure of the first relief valve.

2. The control method according to claim 1, characterized in that, The preset threshold is 0.5 MPa.

3. A control system for a rotary mechanism, characterized in that, include: A slewing mechanism, wherein the slewing mechanism is used to perform a slewing action; A rotary handle, which is used to output a pressure signal P2 to control the rotation action of the rotary mechanism; A boom angle sensor is used to detect the boom amplitude and output the boom amplitude signal d. A main oil supply valve is provided, and a rotary oil circuit is provided between the main oil supply valve and the rotary mechanism. The rotary oil circuit between the main oil supply valve and the rotary mechanism includes a left rotary oil circuit and a right rotary oil circuit. The main oil supply valve is used to control the hydraulic oil to enter the rotary oil circuit in order to control the rotary mechanism to perform a rotary action. A boom rodless chamber pressure detection sensor is used to detect the boom rodless chamber pressure and output a boom rodless chamber pressure signal P1. The second relief valve is an electro-proportional relief valve. The left rotary oil circuit and the right rotary oil circuit are respectively connected to the second relief valve through connecting pipes, so that the second relief valve is set in the rotary oil circuit and the second relief valve is connected in parallel with the rotary mechanism. A first relief valve is disposed in the rotary oil circuit and is connected in parallel with the rotary mechanism; The controller is electrically connected to the slewing handle, the second overflow valve, the boom rodless chamber pressure detection sensor, and the boom angle sensor. The controller receives the pressure signal P2, the boom rodless chamber pressure signal P1, and the boom amplitude signal d. The controller is equipped with a preset threshold for comparison with the pressure signal P2. When the pressure signal P2 is greater than a preset threshold, the controller de-energizes the second relief valve and the first relief valve operates; when the pressure signal P2 is less than the preset threshold, the second relief valve is energized and opens. The controller controls the opening pressure P of the second relief valve according to the boom amplitude signal d and the boom rodless chamber pressure signal P1, so that the opening pressure P of the second relief valve is positively correlated with both the boom amplitude signal d and the boom rodless chamber pressure signal P1, and the opening pressure P of the second relief valve is less than the opening pressure of the first relief valve.

4. The control system for the rotary mechanism according to claim 3, characterized in that, The pressure signal P2 output by the rotary handle includes a left pressure signal and a right pressure signal. When the rotary handle outputs a left pressure signal, the main oil supply valve supplies oil to the left rotary oil circuit; When the rotary handle outputs a right pressure signal, the main oil supply valve supplies oil to the right rotary oil circuit.

5. The control system for the rotary mechanism according to claim 3, characterized in that, Each of the connecting pipelines between the left-turn oil circuit, the right-turn oil circuit, and the second relief valve is equipped with a one-way oil supply valve. The one-way oil supply valve prevents the hydraulic oil on the connecting pipeline from flowing towards the left-turn oil circuit and the right-turn oil circuit.

6. The control system for the rotary mechanism according to claim 3, characterized in that, Each of the left-hand rotary oil circuit and the right-hand rotary oil circuit is provided with a first overflow valve.

7. A material handling machine, characterized in that, The control system includes the rotary mechanism as described in any one of claims 3-6.

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